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An Efficient Distributed Verification Protocol for Data Storage Security in Cloud ComputingAbstract— Data storage is an important application of cloud computing, where clients can remotely store their data into the cloud. By uploading their data into the cloud, clients can be relieved from the burden of local data storage and maintenance. This new paradigm of data storage service also introduces new security challenges. One of these risks that can attack the cloud computing is the integrity of the data stored in the cloud. In order to overcome the threat of integrity of data, the client must be able to use the assistance of a Third Party A uditor (TPA), in such a way that the TPA verifies the integrity of data stored in cloud with the client’s public key on the behalf of the client. The existing schemes with single verifier (TPA) may not scale well for this purpose. In this paper, we propose A n Efficient Distributed Verification Protocol (EDVP) to verify the integrity of data in a distributed manner with support of multiple verifiers (Multiple TPA s) instead of single Verifier (TPA). Through the extensive security, performance and experimental results, we show that our scheme is more efficient than single verifier based scheme. Keywords: cloud storage, Integrity, Client, TPA, SUBTPAs, Verification, cloud computing.I.I NTRODUCTIONCloud computing is a large-scale distributed computing paradigm in which a pool of computing resources is available to Clients via the Internet. The Cloud Computing resources are accessible as public utility services, such as processing power, storage, software, and network bandwidth etc. Cloud storage is a new business solution for remote backup outsourcing, as it offers an abstraction of infinite storage space for clients to host data backups in a pay-as-you-go manner [1]. It helps enterprises and government agencies significantly reduce their financial overhead of data management, since they can now archive their data backups remotely to third-party cloud storage providersrather than maintaining local computers on their own. For example, Amazon S3 is a well known storage service.The increasing of data storage in the cloud has brought a lot of attention and concern over security issues of this data. One of important issue is with cloud data storage is that of data integrity verification at untrusted cloud servers. For example, the storage service provider, which experiences Byzantine failures occasionally, may decide to hide the data loss incidents from the clients for the benefit of their own. What is more serious is that for saving money and storage space the service provider might neglect to keep or deliberately delete rarely accessed data files which belong to thin clients. Consider the large size of the outsourced data and the client’s constrained resource capability, the main problem can be generalized as how can the client find an efficient way to perform periodical integrity verifications without local copy of data files.To verify the integrity of data in cloud without having local copy of data files, recently several integrity verification protocols have been developed under different systems [2-13].A ll these protocols have verified the integrity of data with single verifier (TPA). However, in single auditor verification systems, they use only one Third Party A uditor (TPA) to verify the Integrity of data based Challenge-Response Protocol. In that verification process, the TPA stores the metadata corresponding to the file blocks and creates a challenge and sends to the CSP. The CSP generates the Integrity proof for corresponding challenge, and send back to the TPA. Then, TPA verifies the response with the previously stored metadata and gives the final audit result to the client. However, in this single A uditor system, if TPA system will crash due to heavy workload then whole verification process will be aborted. In addition, during the verification process, the network traffic will be very high near the TPA organization and may create network congestion. Thus, the performance will be degrading in single auditor verification schemes. Therefore, we need an efficient distributed verification protocol to verify the integrity of data in cloud.In this paper, we propose an Efficient Distributed Verification Protocol (EDVP) to verify the integrity of data in a distributed manner with support of multiple verifiers (Multiple TPAs) instead of single Verifier (TPA), which were discussed in existing prior works[2-13]. In our protocol, many number of SUBTPA s concurrently works under the single TPA and workload also must be uniformly distribute among the SUBTPA s, so that each SUBTPA will verify over the whole part, Suppose if TPA fails, one of the SUBTPA will act as TPA. Our protocol would detect the data corruptions in the cloud efficiently when compared to single verifier based protocols.Our protocol design is based on RSA-based Dynamic Public Audit Service for Integrity Verification of data in cloud proposed by Syam et al.[11] in a distributed manner. Here, the n verifiers challenge the n servers uniformly and if m server’s response is correct out of n servers then, we can say that Integrity of data is ensured. To verify the Integrity of the data, our verification process uses multiple TPA s, among theSyam Kumar.P1Dept.of Computer ScinceIFHE(Deemed University)Hyderabad, Indiashyam.553@1,Subramanian. R2, Thamizh Selvam.D3Dept.of Computer Science School of Engineering and Technology,Pondicherry University, Puducherry, India, rsmanian.csc@.in2,dthamizhselvam@32013 Second International Conference on Advanced Computing, Networking and Securitymultiple TPAs, one TPA will act as main TPA and remaining are SUBTPA s. The main TPA uses all SUBTPA s to detect data corruptions efficiently, if main TPA fails, then one of the SUBTPA will act as main TPA. The SUBTPA s do not communicate with each other and they would like to verify the Integrity of the stored data in cloud, and consistency of the provider’s responses. The propose system guarantee the atomic operations to all TPA s; this means that TPA which observe each SUBTPA operations are consistent, in the sense that their own operations plus those operations whose effects they see have occurred atomically in same sequence.In Centrally Controlled and Distributed Data paradigm, where all SUBTPA s are controlled by the TPA and SUBTPA’s communicate to any Cloud Data Storage Server, we consider a synchronous distributed system with multiple TPA s and Servers. Every SUBTPA is connected to Server through a synchronous reliable channel that delivers a challenge to the server. The SUBTPA and the server together are called parties P. A protocol specifies the behaviours of all parties. An execution of P is a sequence of alternating states and state transitions, called events, which occur according to the specification of the system components. A ll SUBTPA s follow the protocol; in particular, they do not crash. Every SUBTPA has some small local trusted memory, which serves to store distribution keys and authentication values. The server might be faulty or malicious and deviate arbitrarily from the protocol; such behaviour is also called Byzantine failure.The Synchronous system comes down to assuming the following two properties:1. Synchronous computation. There is a known upper bound on processing delays. That is, the time taken by any process to execute a step is always less than this bound. Remember that a step gathers the delivery of a message (possibly nil) sent by some other process, a local computation (possibly involving interaction among several layers of the same process), and the sending of a message to some other process.2. Synchronous communication. There is a known upper bound on challenge/response transmission delays. That is, the time period between the instant at which a challenge is sent and the time at which the response is delivered by the destination process is less than this bound.II.RELATED WORKBowers et al. [2] introduced a High Availability Integrity Layer (HAIL) protocol to solve the Availability and Integrity problems in cloud computing using error correcting codes and Universal Hash Functions (UHFs). This scheme achieves the A vailability and Integrity of data. However, this scheme supports private verifiability.To support public verifiability of data integrity, Barsoum et al. [3] proposed a Dynamic Multiple Data Copies over the Cloud Servers, which is based on multiple replicas. This scheme achieves the Availability and Integrity of data stored in cloud. Public verification enables a third party auditor (TPA) to verify the integrity of data in cloud with the data owner's public key on the behalf of the data owner,. Wang et al. [4] designed an Enabling Public Auditability and Data Dynamics for data storage security in cloud computing using Merkle Hash Tree (MHT). It achieves the guarantee of the data Integrity with efficient data dynamic operations and public verifiability. Similarly,Wang et al. [5] proposed a flexible distributed verification protocol to ensure the dependability, reliability and correctness of outsourced data in the cloud by utilizing homomorpic token and distributed erasure coded data. This scheme allow users to audit the outsourced data with less communication and computation cost. Simultaneously, it detects the malfunctioning servers. In their subsequent work, Wang et al. [6] developed a privacy-preserving data storage security in cloud computing. Their construction utilizes and uniquely combines the public key based homomorpic authenticator with random masking while achieving the Integrity and privacy from the auditor. Similarly, Hao et al. [7] proposed a privacy-preserving remote data Integrity checking protocol with data dynamics and public verifiability. This protocol achives the deterministic guaranty of Integrity and does not leak any information to third party auditors. Zhuo et al. [8] designed a dynamic audit service to verify the Integrity of outsourced data at untrusted cloud servers. Their audit system can support public verifiability and timely abnormal detection with help of fragment structure, random sampling and index hash table. Yang et al. [9] proposed a provable data possession of resource-constrained mobile devices in cloud computing. In their framework, the mobile terminal devices only need to generate some secret keys and random numbers with the help of trusted platform model (TPM) chips, and the needed computing workload and storage space is fit for the mobile devices by using bilinear signature and Merkle hash tree (MHT), this scheme aggregates the verification tokens of the data file into one small signature to reduce the communication and storage burden.Although, all these schemes achieved the Integrity of remote data assurance under different systems, they do not provide a strong integrity assurance to the clients because their verification process using pseudorandom sequence. If we use pseudorandom sequence to verify the remote data Integrity, sometimes they may not detect the data modifications on data blocks. Since pseudorandom sequence is not uniform (uncorrelated numbers), it does not cover the entire file while generating Integrity proof for a challenge. Therefore, probabilistic Integrity checking methods using pseudorandom sequence may not provide strong Integrity assurance to user’s data stored in remotely.To provide better Integrity assurance, Syam et al. [10] proposed a homomorpic distributed verification protocol using Sobol sequence instead of pseudorandom sequence [2-9]. Their protocol ensures the A vailability, Integrity of data and also detects the data corruption efficiently. In their subsequent work, Syam et al. [11] described a RSA-based Dynamic Public Audit protocol for integrity verification of data stored in cloud. This scheme gives probabilistic proofs based on random challenges and like [10] it also detects the data modification on file. Similarly, Syam et al. [12] developed an Efficient and Secure protocol for both Confidentiality andIntegrity of data with public verifiability and dynamic operations. Their construction uses Elliptic Curve Cryptography instead of RSA because ECC offers same security as RSA with small key size. Later, Syam et al.[13] proposed a publicly verifiable Dynamic secret sharing protocol for A vailability, Integrity, Confidentiality of data with public verifiability.Although all these schemes achieved the integrity of remote data under different systems with Single TPA, but in single auditor verification protocols, they use only one Third Party A uditor (TPA) to verify the Integrity of data based Challenge-Response Protocol. However, in this single Auditor system, if TPA system will crash due to heavy workload then whole verification process will be aborted.III.PROBLEM STATEMENTA.Problem DefinitionIn cloud data storage, the client stores the data in cloud via cloud service provider. Once data moves to cloud he has no control over it i.e. no security for outsourced data stored in cloud, even if Cloud Service Provider (CSP) provides some standard security mechanism to protect the data from attackers but still there is a possibility threats from attackers to cloud data storage, since it is under the control of third party provider, such as data leakage, data corruption and data loss. Thus, how can user efficiently and frequently verify that whether cloud server storing data correctly or not? A nd will not be tampered with it. We note that the client can verify the integrity of data stored in cloud without having a local copy of data and any knowledge of the entire data. In case clients do not have the time to verify the security of data stored in cloud, they can assign this task to trusted Third Party Auditor (TPA). The TPA verifies the integrity of data on behalf of clients using their public key.B.System ArchitectureThe network representation architecture for cloud data storage, which consists four parts: those are Client, Cloud Service Provider (CSP), Third Party A uditors (TPA s) and SUBTPAS as depicted in Fig 1:Fig 1: Cloud Data Storage Architecture Client: - Clients are those who have data to be stored, and accessing the data with help of Cloud Service Provider (CSP). They are typically desktop computers, laptops, mobile phones, tablet computers, etc.Cloud Service Provider (CSP):- Cloud Service Providers (CSPs) are those who have major resources and expertise in building, managing distributed cloud storage servers and provide applications, infrastructure, hardware, enabling technology to customers via internet as a service.Third Party Auditor (TPA):- Third Party Auditor (TPA) who has expertise and capabilities that users may not have and he verify the security of cloud data storage on behalf of users. SUBTPAS: the SUBTPA s verifies the integrity of data concurrently under the control of TPAThroughout this paper, terms verifier or TPA and server or CSP are used interchangeablyC.Security ThreatsThe cloud data storage mainly facing data corruption challenge:Data Corruption: cloud service provider or malicious cloud user or other unauthorized users are self interested to alter the user data or deleting.There are two types of attackers are disturbing the data storage in cloud:1) Internal Attackers: malicious cloud user, malicious third party user (either cloud provider or customer organizations) are self interested to altering the user’s personal data or deleting the user data stored in cloud. Moreover they decide to hide the data loss by server hacks or Byzantine Failure to maintain its reputation2) External Attackers: we assume that an external attacker can compromise all storage servers, so that he can intentionally modify or delete the user’s data as long as they are internally consistent.D.GoalsIn order to address the data integrity stored in cloud computing, we propose an Efficient Distribution Verification Protocol for ensuring data storage integrity to achieve the following goals:Integrity: the data stored safely in cloud and maintain all the time in cloud without any alteration.Low-Overhead: the proposed scheme verifies the security of data stored in cloud with less overhead.E.Preliminaries and Notations•f key(.)- Sobol Random Function (SRF) indexed on some key, which is defined asf : {0,1}* ×key-GF (2w).•ʌkey– Sobol Random Permutation (SRP) indexed under key, which is defined asʌ : {0,1}log2(l) × key –{0,1}log2(l) .IV. EFFICENT DISTRIBUTION VERIFICATIONPROTOCOL:EDVP The EDVP protocol is designed based on RSA -based Dynamic Public A udit Protocol (RSA -DPA P), which is proposed by Syam et al.[11]. In EDVP, we are mainly concentrating on verification phase of RSA -DPA P. The EDVP contains three phases: 1) Key Distribution, 2) Verification Process 3) Validating Integrity. The process of EDVP is: first, the TPA generates the keys and distribute to SUBTPA s. Then the SUBTPA s verify the integrity of data and gives result to main TPA. Finally, the main TPA validates the integrity by observing the report from SUBTPAs.A. Key DistributionIn key distribution, the TPA generates the random keyand distributes it to his SUBTPAs as follows:The TPA first generates the Random key by using SobolRandom Function [15] then Compute)(1i f K k =Where1 i n and the key is indexed on some (usually secret) key: f :{0,1}*× keyĺZ p Then, employ (m, n ) secret sharing scheme [14] andpartition the random key K into n pieces. To divide K into npieces, the client select a polynomial a(x) with degree m-1andcomputes the n pieces: 1221....−++++=m j i i a i a i a K K (2)¦−=+=11m j j j i i a K K (3)A fter that TPA chooses nSUBTPA s and distributes n pieces to them. The procedure of key distribution is given in algorithm 1.Algorithm 1: Key Distribution1.1. Generates a random key K using Sobol Sequence. )(1i f K k =2. Then, the TPA partition the K into n pieces using (m,n) secret sharing scheme3. TPA select the Number of SUBTPAs: n, and threshold value m;4. for i ĸ1 to n do5. TPA sends k i to the all SUBTPA i s6. end for7. endB. Verification ProcessIn verification process, all SUBTPAs verify the Integrity of data and give results to the TPA, if m SUBTPAs responses meet the threshold value then TPA says that Integrity of data is valid. At a high level, the protocol operates like this: A TPA assigns a local timestamp to every SUBTPA of its operations. Then, every SUBTPA maintains a timestamp vector T in itstrusted memory. A t SUBTPA i , entry T[j] is equal to thetimestamp of the most recently executed operation by SUBTPA j in some view of SUBTPA i .To verify the Integrity of data, each SUBTPA creates a challenge and sends to the CSP as follows: first SUBTPA generates set of Random indices c of set [1, n] using Sobol Random Permutation (SRP) with random key)(c j j K π= (4) Where 1 c l and ʌkey (.) is a Sobol Random Permutation (SRP), which is indexed under key: ʌ : {0,1}log2(l ) ×key–{0,1} log2(l ).Next, each SUBTPA also chooses a fresh random key r j, wherer j = )(2l f k (5)Then, creates a challenge chal ={j, r j } is pairs of random indices and random values. Each SUBTPA sends a challenge to the CSP and waits for the response. The CSP computes a response to the corresponding SUBTPA challenges and send responses back to SUBTPAs.When the SUBTPA receives the response message, first he checks the timestamp, it make sure that V T (using vectorcomparison) and that V [i] = T[i]. If not, the TPA aborts theoperation and halts; this means that server has violated the consistency of the service. Otherwise, the SUBTP COMMITS the operation and check if stored metadata and response (integrity proof) is correct or not? If it is correct,then stores TRUE in its table and sends true message to TPA, otherwise store FALSE and send a false signal to the TPA for corrupted file blocks. The detailed procedure of verification processes is given in algorithm 2. Algorithm 2: Verification Process 1. Procedure: Verification Process 2. Timestamp T3. Each SUBTPA i computes4. Compute )(c j SRPk π=5. the Generate the sobol random key r j6. Send (Chal=(j, r j ) as a challenge to the CSP;7. the server computes the Proof PR i send back to theSUBTPAs;8. PR i ĸReceive(V);9. If (V T V [i] = T[i]) 10. return COMMIT then11. if PR i equals to Stored Metadata then 12. return TRUE;13. Send Signal, (Packet j , TRUE i ) to theTPA14. else15. return FALSE;16. Send Signal, (Packet i , FALSE i ) to the TPA; 17. end if 18. else19. ABORT and halt the process 20. e nd if 21. e nd(1)C.Validating IntegrityTo validate the Integrity of the data, the TPA will receive the report from any subset m out of n SUBTPAs and validates the Integrity. If the m SUBTPA s give the TRUE signal to TPA, then the TPA decides that data is not corrupted otherwise he decides that data has been corrupted. In the final step, the TPA will give an A udit result to the Client. In algorithm 3, we given the process of validating the Integrity, in which, we generalize the Integrity of the verification protocol in a distributed manner. Therefore, we can use distribution verification on scheme [11].Algorithm 3: Validating Integrity1.Procedure: validation(i)2.TPA receives the response from the m SUBTPAs3.for iĸ1 to m do4.If(response==TRUE)5. Integrity of data is valid6. else if(response==FALSE)7. Integrity is not valid8.end if9.end for10.endV.A NALYSIS OF EDVPIn this section, we analyse the security, and performance of EDVP.A.Security AnalysisIn security analysis, we analyze the Integrity of the data in terms of probability detection.Probability Detection:It is very natural that verification activities would increase the communication and computational overheads of the system. To enhance the performance, we used Secret sharing technique [14] to distribute the Key k that provides minimum communication and tractable computational complexity. Thus, it reduces the communication overhead between TPA and SUBTPAs. For a new verification, the TPA can change the Key K for any SUBTPA and send only the different part of the multiset elements to the SUBTPA. In addition, we used probabilistic verification scheme based on Sobol Sequences that provides uniformity not only for whole sequences but also for each subsequences, so each SUBTPA will independently verify over the entire file blocks. Thus, there is a high probability to detect fault location very quickly. Therefore, a Sobol sequence provides strong Integrity proof for the remotely stored data.The probability detections of data corruptions of this protocol same as previous protocols [9-12].In EDVP, we use Sobol random sequence generator to generate the file block number, because sequence are uniformly distributed over [0, 1] and cover the whole region. To make integers, we multiply constant powers of two with the generated sequences. Here, we consider one concrete example, taking 32 numbers from the Sobol sequences.B. B. Performance Analysis and Experimental ResultsIn this section, we evaluate the performance of theverification time for validating Integrity and compare theexperimental results with previous single verifier basedprotocol [11] as shown in Tables 1-3. In Table 4 and 5, wehave shown that the Computation cost of the Verifier and CSPrespectively.Table 1: Veri ication times (Sec) with 5 veri iers whendifferent percentages of 100000 blocks are corruptedCorruption data in percentageSingle Verifierbased Protocols[11]EDVP[5 verifiers]1% 25.99 12.145% 53.23 26.55 10% 70.12 38.6315% 96.99 51.2220% 118.83 86.4430% 135.63 102.8940% 173.45 130.8550% 216.11 153.81 Table 2: Verif ication times (Sec) with 10 Verif ierswhen di f f erent percentages o f 100000 blocks are corruptedCorruption data in percentage Single Verifier basedProtocols[11]EDVP[10verifiers]1% 25.9908.14 5% 53.2318.55 10% 70.12 29.63 15% 96.99 42.22 20% 118.83 56.44 30% 135.63 65.89 40% 173.45 80.85 50% 216.11 98.81T able 3: Verification times (Sec) with 20 verifiers when different percentages of 100000 blocks are corruptedCorruption data in percentage Single VerifierbasedProtocols[11]EDVP[20verifiers]1% 25.9904.145% 53.2314.5510% 70.12 21.6315% 96.99 32.2220% 118.83 46.4430% 135.63 55.8940% 173.45 68.8550% 216.11 85.81From Tables 1-3, we can observe that verification time is lessfor detecting data corruptions in cloud when compared to single verifier based protocol [11]Table 4:Verifier computation Time (ms) for the differentfile sizesFile Size Single Verifier basedProtocol[11]EDVP1MB 148.26 80.07 2MB 274.05 192.65 4MB 526.25 447.23 6MB 784.43 653.44 8MB 1083.9 820.87 10MB 2048.26 1620.06Table 5:CSP computation Time (ms) for the different filesizesFile Size Single Verifier basedProtocols[11]EDVP1MB 488.16 356.272MB 501.23 392.554MB 542.11 421.116MB 572.17 448.678MB 594. 15 465.1710MB 640.66 496. 02 From the table 4 & 5, we can observe that computation cost of verifier and CSP is less compared existing scheme[11]VI.C ONCLUSIONIn this paper, we presented an EDVP scheme to verify the Integrity of data stored in the cloud in a distributed manner with support of multiple verifiers (Multiple TPAs) instead of single Verifier (TPA). This protocol use many number of SUBTPA s concurrently works under the single TPA and workload also must be uniformly distribute among SUBTPAs, so that each SUBTPA will verify the integrity of data over the whole part. Through the security and performance analysis, we have proved that an EDVP verification protocol would detect the data corruptions in the cloud efficiently when compared to single verifier verification based scheme.R EFERENCES[1]R. Buyya, C. S. Yeo, S. Venugopal, J. Broberg, and I.Brandic.“Cloud Computing and Emerging IT Platforms: Vision, Hype, and Reality for Delivering Computing as the 5thUtility,” Future Generation Computer Systems, vol. 25, no. 6,June 2009, pp 599–616, Elsevier Science, A msterdam, TheNetherlands.[2]Bowers K. D., Juels A., and Oprea A., (2008) “HAIL: A High-vailability and Integrity Layer for Cloud Storage,”Cryptology ePrint Archive, Report 2008/489.[3]Barsoum, A. F., and Hasan, M. 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2008 Nov;135(21):3611-22. Epub 2008 Oct 2.LinksZhang J, Lin Y, Zhang Y, Lan Y, Lin C, Moon AM, Schwartz RJ, Martin JF, Wang F.Center for Cancer and Stem Cell Biology, Institute of Biosciences and Technology, Texas A&M Health Science Center, 2121 W. Holcombe Boulevard, Houston, TX 77030, USA.The cardiac outflow tract (OFT) is a developmentally complex structure derived from multiple lineages and is often defective in human congenital anomalies. Although emerging evidence shows that fibroblast growth factor (FGF) is essential for OFT development, the downstream pathways mediating FGF signaling in cardiac progenitors remain poorly understood. Here, we report that FRS2alpha (FRS2), an adaptor protein that links FGF receptor kinases to multiple signaling pathways, mediates crucial aspects of FGF-dependent OFT development in mouse. Ablation of Frs2alpha in mesodermal OFT progenitor cells that originate in the second heart field (SHF) affects their expansion into the OFT myocardium, resulting in OFT misalignment and hypoplasia. Moreover, Frs2alpha mutants have defective endothelial-to-mesenchymal transition and neural crest cell recruitment into the OFT cushions, resulting in OFT septation defects. These results provide new insight into the signaling molecules downstream of FGF receptor tyrosine kinases in cardiac progenitors.PMID: 18832393 [PubMed - in process]2008 Jul 28;182(2):315-25.LinksNiessen K, Fu Y, Chang L, Hoodless PA, McFadden D, Karsan A. Department of Medical Biophysics, British Columbia Cancer Agency, Vancouver V5Z 1L3, Canada.Snail family proteins are key regulators of epithelial-mesenchymal transition, but their role in endothelial-to-mesenchymal transition (EMT) is less well studied. We show that Slug, a Snail family member, is expressedby a subset of endothelial cells as well as mesenchymal cells of the atrioventricular canal and outflow tract during cardiac cushion morphogenesis. Slug deficiency results in impaired cellularization of the cardiac cushion at embryonic day (E)-9.5 but is compensated by increased Snail expression at E10.5, which restores cardiac cushion EMT. We further demonstrate that Slug, but not Snail, is directly up-regulated by Notch in endothelial cells and that Slug expression is required for Notch-mediated repression of the vascular endothelial cadherin promoter and for promoting migration of transformed endothelial cells. In contrast, transforming growth factor beta (TGF-beta) induces Snail but not Slug. Interestingly, activation of Notch in the context of TGF-beta stimulation results in synergisticup-regulation of Snail in endothelial cells. Collectively, our data suggest that combined expression of Slug and Snail is required for EMT in cardiac cushion morphogenesis.PMID: 18663143 [PubMed - indexed for MEDLINE]Potenta S, Zeisberg E, Kalluri R.[1] 1Division of Matrix Biology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA [2] 2Department of Cell Biology, Harvard Medical School, Boston, MA, USA.Recent evidence has demonstrated that endothelial-to-mesenchymal transition (EndMT) may have a significant role in a number of diseases. Although EndMT has been previously studied as a critical process in heart development, it is now clear that EndMT can also occur postnatally in various pathologic settings, including cancer and cardiac fibrosis. During EndMT, resident endothelial cells delaminate from an organised cell layer and acquire a mesenchymal phenotype characterised by loss of cell-cell junctions, loss of endothelial markers, gain of mesenchymal markers, and acquisition of invasive and migratory properties.Endothelial-to-mesenchymal transition -derived cells are believed to function as fibroblasts in damaged tissue, and may therefore have an important role in tissue remodelling and fibrosis. In tumours, EndMT is an important source of cancer-associated fibroblasts (CAFs), which are known to facilitate tumour progression in several ways. These new findings suggest that targeting EndMT may be a novel therapeutic strategy, which is broadly applicable not only to cancer but also to various other disease states.British Journal of Cancer advance online publication, 16 September 2008;doi:10.1038/sj.bjc.6604662 .PMID: 18797460 [PubMed - as supplied by publisher]2008 Jul;24(4):462-8.LinksRieder F, Fiocchi C.Department of Internal Medicine I, University of Regensburg, Regensburg, Germany.PURPOSE OF REVIEW: Intestinal fibrosis is a potentially serious complication of inflammatory bowel disease and its pathophysiology is still unclear. This review will discuss recent developments relating to sources of fibroblasts in intestinal inflammation, mediators that modulate fibroblast activation and function, as well as new clinical, laboratory, endoscopic and radiological studies aimed at improving diagnosis and management of intestinal fibrosis in inflammatory bowel disease. RECENT FINDINGS: The fibroblast remains the central cell responsible for intestinal fibrosis in inflammatory bowel disease and transforming growth factor-beta1 is still the most potent pro-fibrogenic cytokine. Novel mediators, however, are being identified that modulate fibroblast function, such as interleukin-13, interleukin-21, galectin-3, osteopontin, Wnt and toll-like receptor ligands, and anti-tumor necrosis factor-alpha agents. New fibroblast sources are being identified, such as fibrocytes, and new mechanisms of fibroblast generation, like epithelial- and endothelial-to-mesenchymal transition. Animal models of intestinal fibrosis are still few, but new ways to induce gut fibrosis are being explored. Serological markers indicating a clinically complicated course that includes intestinal fibrosis are promising and are being tested in adult and pediatric populations, particularly in Crohn's disease. Video capsule endoscopy, the Given Patency capsule, double balloon enteroscopy, and computed tomographic enteroscopy are some of the new modalities being developed to assess the risk and improve the diagnosis of intestinal fibrosis. Novel therapeutic approaches include endoscopic balloon dilatation with conventional and double balloon enteroscopy, and local injection of glucocorticoids and tumor necrosis factor-alpha blockers, showing partial but encouraging success. SUMMARY: More studies are needed to improve knowledge of the pathophysiology of intestinal fibrosis if better preventive, diagnostic and therapeutic measures are to be expected in the near future.PMID: 18622160 [PubMed - indexed for MEDLINE]Nat Med. 2007 Aug;13(8):952-61. Epub 2007 Jul 29.LinksZeisberg EM, Tarnavski O, Zeisberg M, Dorfman AL, McMullen JR, Gustafsson E, Chandraker A, Yuan X, Pu WT, Roberts AB, Neilson EG, Sayegh MH, Izumo S, Kalluri R.Division of Matrix Biology, Department of Medicine, Beth Israel Deaconess Medical Center & Harvard Medical School, Boston, Massachusetts 02215, USA.Cardiac fibrosis, associated with a decreased extent of microvasculature and with disruption of normal myocardial structures, results from excessive deposition of extracellular matrix, which is mediated by the recruitment of fibroblasts. The source of these fibroblasts is unclear and specificanti-fibrotic therapies are not currently available. Here we show that cardiac fibrosis is associated with the emergence of fibroblasts originating from endothelial cells, suggesting an endothelial-mesenchymal transition (EndMT) similar to events that occur during formation of the atrioventricular cushion in the embryonic heart. Transforming growth factor-beta1 (TGF-beta1) induced endothelial cells to undergo EndMT, whereas bone morphogenic protein 7 (BMP-7) preserved the endothelial phenotype. The systemic administration of recombinant human BMP-7 (rhBMP-7) significantly inhibited EndMT and the progression of cardiac fibrosis in mouse models of pressure overload and chronic allograft rejection. Our findings show that EndMT contributes to the progression of cardiac fibrosis and that rhBMP-7 can be used to inhibit EndMT and to intervene in the progression of chronic heart disease associated with fibrosis.PMID: 17660828 [PubMed - indexed for MEDLINE]2006 Jul;74(6):277-92.LinksArciniegas E, Neves YC, Carrillo LM.Servicio Autónomo Instituto de Biomedicina, Facultad de Medicina,Universidad Central de Venezuela, Apartado de correos 4043, Carmelitas,Caracas 1010, Venezuela. earciniegasbeta@Endothelial-to-mesenchymal transition (EndoMT) is a process throughwhich certain subsets of endothelial cells lose endothelial characteristicsand transform into mesenchymal or smooth muscle-like cells. Emergingevidence suggests that this process plays an important role during vasculardevelopment and in many vascular pathologies. As inepithelial-mesenchymal transition, EndoMT seems to progress through aseries of important steps whose interdependence and order are not clear, andthat some of them are regulated by soluble growth factors. Insulin-likegrowth factor II (IGFII), apart from being considered important in cancer,angiogenesis, and atherosclerotic lesions, is also considered as essential toembryonic development. Here, we report that addition of IGFII promotedthe EndoMT process in the presence of very low amounts of chicken serumto arrested primary embryonic aortic chicken endothelial cells attached tofibronectin (FN), gelatin, or native type I collagen. This was demonstratedby cell spreading, loss of cell-cell contacts, detachment, migration, andtransformation. These cellular events also occurred when IGFII was addedto medium containing vitronectin (VN). Additionally, we demonstrated thatthese proteins were present in the spontaneous intimal thickenings that areobserved at day 11-13 of chicken embryo development. We also show thatalterations in the distribution of VE-cadherin and beta-catenin occur afterIGFII and serum or VN stimulation, and propose that the via VN IGFIIeffects may be facilitated by interaction of the mannose-6-phosphate/IGFIIreceptor (M6P/IGFIIR) with the urokinase-type plasminogen activatorreceptor (uPAR) and its ligand (uPA). Collectively, these findings providethe first evidence for a potential role of the IGFII-VN complex during theEndoMT process. From our observations and previous studies, we postulatea working hypothesis supporting a fundamental role for these moleculesduring EndoMT.PMID: 16831197 [PubMed - indexed for MEDLINE]Rac regulates integrin-mediated endothelial cell adhesion and migration on laminin-8Hironobu Fujiwara a, b, Jianguo Gu a and Kiyotoshi Sekiguchi a, b, ,a Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japanb Sekiguchi Biomatrix Signaling Project, ERATO, Japanese Science and Technology Corporation, Aichi Medical University, Nagakute-cho, Aichi480-1195, JapanReceived 6 February 2003;revised 1 July 2003.Available online 3 October 2003.AbstractBlood vessel formation requires endothelial cell interactions with the extracellular matrix through cell surface receptors, and signaling events that control endothelial cell adhesion, migration, and lumen formation. Laminin-8 (α4β1γ1) is present in all basement membranes of blood vessels in fetal and adult tissues, but despite its importance in vessel formation, its role in endothelial cell adhesion and migration remains undefined. We examined adhesion and migration of HMEC-1 human microvascular endothelial cells on laminin-8 with an emphasis on the integrin-mediated signaling events, as compared with those on laminin-10/11 and fibronectin. We found that laminin-8 was less potent in HMEC-1 cell adhesion than laminin-1, laminin-10/11, and fibronectin, and mediated cell adhesion through α6β1 integrin. Despite its weak cell-adhesive activity, laminin-8 was as potent as laminin-10/11 in promoting cell migration. Cells adhering to laminin-8 displayed streaks of thin actin filaments and formed lamellipodia at the leading edge of the cells, as observed with cells adhering to laminin-10/11, while cells on fibronectinshowed thick actin stress fibers and large focal adhesions. Pull-down assays of GTP-loaded Rho, Rac, and Cdc42 demonstrated that Rac, but not Rho or Cdc42, was preferentially activated on laminin-8 and laminin-10/11, when compared with fibronectin. Furthermore, a dominant-negative mutant of Rac suppressed cell spreading, lamellipodial formation, and migration on laminin-8, but not on fibronectin. These results, taken together, indicate that Rac is activated during endothelial cell adhesion to laminin-8, and is pivotal for α6β1 integrin-mediated cell spreading and migration on laminin-8.Author Keywords: Basement membrane; Laminin; Endothelial cell; Integrin; RacAbbreviations: FBS, fetal bovine serum; HUVECs, human umbilical vein endothelial cells; mAb, monoclonal antibody; PBS, phosphate-buffered saline; GST-RBD, a fusion protein of glutathione S-transferase to the Rho-binding domain of rhotekin; GST-CRIB, a fusion protein of glutathione S-transferase to the Cdc42/Rac-interactive-binding domain of PAK1; BSA, bovine serum albuminArticle Outline• Introduction• Materials and methods• Cell culture• Reagents and antibodies• Cell-adhesive proteins• Purification of laminin-8• SDS-PAGE and immunoblotting• Expression vectors• Cell spreading assay• Cell migration assay and microinjection• Immunofluorescence staining• Detection of GTP-loaded Rho, Rac, and Cdc42• Results• HMEC-1 cell adhesion to laminin-8• Laminin-8 stimulates HMEC-1 migration through α6β1 inTransdifferentiation of pulmonary arteriolar endothelial cells into smooth muscle-like cells regulated by myocardin involved in hypoxia-induced pulmonary vascular remodelling.P Zhu, L Huang, X Ge, F Yan, R Wu, and Q AoInt J Exp Pathol, December 1, 2006; 87(6): 463-74.AbstractF ull text via InfotrieveAlert me when citedF ind more like thisDepartment of Pathology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan City, China.Myocardin gene has been identified as a master regulator of smooth muscle cell differentiation. Smooth muscle cells play a critical role in the pathogenesis of hypoxia-induced pulmonary hypertension (PH) and pulmonary vascular remodelling (PVR). The purpose of this study was to investigate the change of myocardin gene expression in the pulmonary vessels of hypoxia-induced PH affected by Sildenafil treatment and the involvement of endothelial cells transdifferentiation into smooth muscle cells in the process of hypoxia-induced PH and PVR. Myocardin and relative markers were investigated in animal models and cultured endothelial cells. Mean pulmonary artery pressure (mPAP) was measured. Immunohistochemistry and immunofluorescence were used to show the expression of smooth muscle alpha-actin (SMA), in situ hybridization (ISH) and reverse transcription polymerase chain reaction (RT-PCR) were performed respectively to detect the myocardin and SMA expression at mRNA levels. Small interfering RNA (siRNA) induced suppression of myocardin in cultured cells. We confirmed that hypoxia induced the PH and PVR in rats. Sildenafil could attenuate thehypoxia-induced PH. We found that myocardin mRNA expression is upregulated significantly in the hypoxic pulmonary vessels and cultured cells but downregulated in PH with Sildenafil treatment. The porcine pulmonary artery endothelial cells (PAECs) transdifferentiate into smooth muscle-like cells in hypoxic culture while the transdifferentiation did not occur when SiRNA of myocardin was applied. Our results suggest that myocardin gene, as a marker of smooth muscle cell differentiation, was expressed in the pulmonary vessels in hypoxia-induced PH rats, which could be downregulated by Sildenafil treatment, as well as in hypoxic cultured endothelial cells. Hypoxia induced the transdifferentiation of endothelial cells of vessels into smooth muscle-like cells which was regulated by myocardin.Erratum in Int J Exp Pathol. 2007 Apr;88(2):127-8Publication Types。

CCF推荐的国际学术会议和期刊目录修订版发布CCF(China Computer Federation中国计算机学会)于2010年8月发布了第一版推荐的国际学术会议和期刊目录，一年来，经过业内专家的反馈和修订，于日前推出了修订版，现将修订版予以发布。

本次修订对上一版内容进行了充实，一些会议和期刊的分类排行进行了调整，目录包括：计算机科学理论、计算机体系结构与高性能计算、计算机图形学与多媒体、计算机网络、交叉学科、人工智能与模式识别、软件工程/系统软件/程序设计语言、数据库/数据挖掘/内容检索、网络与信息安全、综合刊物等方向的国际学术会议及期刊目录，供国内高校和科研单位作为学术评价的参考依据。

目录中，刊物和会议分为A、B、C三档。

A类表示国际上极少数的顶级刊物和会议，鼓励我国学者去突破；B类是指国际上著名和非常重要的会议、刊物，代表该领域的较高水平，鼓励国内同行投稿；C类指国际上重要、为国际学术界所认可的会议和刊物。

这些分类目录每年将学术界的反馈和意见，进行修订，并逐步增加研究方向。

中国计算机学会推荐国际学术刊物（网络/信息安全）一、 A类序号刊物简称刊物全称出版社网址1. TIFS IEEE Transactions on Information Forensics andSecurity IEEE /organizations/society/sp/tifs.html2. TDSC IEEE Transactions on Dependable and Secure ComputingIEEE /tdsc/3. TISSEC ACM Transactions on Information and SystemSecurity ACM /二、 B类序号刊物简称刊物全称出版社网址1. Journal of Cryptology Springer /jofc/jofc.html2. Journal of Computer SecurityIOS Press /jcs/3. IEEE Security & Privacy IEEE/security/4. Computers &Security Elsevier http://www.elsevier.nl/inca/publications/store/4/0/5/8/7/7/5. JISecJournal of Internet Security NahumGoldmann. /JiSec/index.asp6. Designs, Codes andCryptography Springer /east/home/math/numbers?SGWID=5 -10048-70-35730330-07. IET Information Security IET /IET-IFS8. EURASIP Journal on InformationSecurity Hindawi /journals/is三、C类序号刊物简称刊物全称出版社网址1. CISDA Computational Intelligence for Security and DefenseApplications IEEE /2. CLSR Computer Law and SecurityReports Elsevier /science/journal/026736493. Information Management & Computer Security MCB UniversityPress /info/journals/imcs/imcs.jsp4. Information Security TechnicalReport Elsevier /locate/istr中国计算机学会推荐国际学术会议（网络/信息安全方向）一、A类序号会议简称会议全称出版社网址1. S&PIEEE Symposium on Security and Privacy IEEE /TC/SP-Index.html2. CCSACM Conference on Computer and Communications Security ACM /sigs/sigsac/ccs/3. CRYPTO International Cryptology Conference Springer-Verlag /conferences/二、B类序号会议简称会议全称出版社网址1. SecurityUSENIX Security Symposium USENIX /events/2. NDSSISOC Network and Distributed System Security Symposium Internet Society /isoc/conferences/ndss/3. EurocryptAnnual International Conference on the Theory and Applications of Cryptographic Techniques Springer /conferences/eurocrypt2009/4. IH Workshop on Information Hiding Springer-Verlag /~rja14/ihws.html5. ESORICSEuropean Symposium on Research in Computer Security Springer-Verlag as.fr/%7Eesorics/6. RAIDInternational Symposium on Recent Advances in Intrusion Detection Springer-Verlag /7. ACSACAnnual Computer Security Applications ConferenceIEEE /8. DSNThe International Conference on Dependable Systems and Networks IEEE/IFIP /9. CSFWIEEE Computer Security Foundations Workshop /CSFWweb/10. TCC Theory of Cryptography Conference Springer-Verlag /~tcc08/11. ASIACRYPT Annual International Conference on the Theory and Application of Cryptology and Information Security Springer-Verlag /conferences/ 12. PKC International Workshop on Practice and Theory in Public Key Cryptography Springer-Verlag /workshops/pkc2008/三、 C类序号会议简称会议全称出版社网址1. SecureCommInternational Conference on Security and Privacy in Communication Networks ACM /2. ASIACCSACM Symposium on Information, Computer and Communications Security ACM .tw/asiaccs/3. ACNSApplied Cryptography and Network Security Springer-Verlag /acns_home/4. NSPWNew Security Paradigms Workshop ACM /current/5. FC Financial Cryptography Springer-Verlag http://fc08.ifca.ai/6. SACACM Symposium on Applied Computing ACM /conferences/sac/ 7. ICICS International Conference on Information and Communications Security Springer /ICICS06/8. ISC Information Security Conference Springer /9. ICISCInternational Conference on Information Security and Cryptology Springer /10. FSE Fast Software Encryption Springer http://fse2008.epfl.ch/11. WiSe ACM Workshop on Wireless Security ACM /~adrian/wise2004/12. SASN ACM Workshop on Security of Ad-Hoc and Sensor Networks ACM /~szhu/SASN2006/13. WORM ACM Workshop on Rapid Malcode ACM /~farnam/worm2006.html14. DRM ACM Workshop on Digital Rights Management ACM /~drm2007/15. SEC IFIP International Information Security Conference Springer http://sec2008.dti.unimi.it/16. IWIAIEEE International Information Assurance Workshop IEEE /17. IAWIEEE SMC Information Assurance Workshop IEEE /workshop18. SACMATACM Symposium on Access Control Models and Technologies ACM /19. CHESWorkshop on Cryptographic Hardware and Embedded Systems Springer /20. CT-RSA RSA Conference, Cryptographers' Track Springer /21. DIMVA SIG SIDAR Conference on Detection of Intrusions and Malware and Vulnerability Assessment IEEE /dimva200622. SRUTI Steps to Reducing Unwanted Traffic on the Internet USENIX /events/23. HotSecUSENIX Workshop on Hot Topics in Security USENIX /events/ 24. HotBots USENIX Workshop on Hot Topics in Understanding Botnets USENIX /event/hotbots07/tech/25. ACM MM&SEC ACM Multimedia and Security Workshop ACM。

标题：有机化学常用期刊网址yonghaiqi(金币+0,VIP+0):与其他版块的帖子重复！1． ScienceDirect (SD)网址：/(1) Catalysis Communications （催化通讯）(2) Journal of Molecular Catalysis A: Chemical （分子催化A：化学）(3) Tetrahedron (T) （四面体）(4) Tetrahedron: Asymmetry (TA) （四面体：不对称）(5) Tetrahedron Letters (TL) （四面体快报）(6) Applied Catalysis A: General （应用催化A）2． EBSCOhost数据库网址：/(1) Synthetic Communcations （合成通讯）(2) Letters in Organic Chemistry (LOC)(3) Current Organic Synthesis(4) Current Organic Chemistry3. Springer数据库网址：http:// /(1) Molecules （分子）(2) Monatshefte für Chemie / Chemical Monthly （化学月报）(3) Science in China Series B: Chemistry （中国科学B）(4) Catalysis Letts （催化快报）4. ACS Publications (美国化学会)网址：/(1) Journal of the American Chemical Society (JACS) （美国化学会志）(2) Organic Letters (OL) （有机快报）(3) The Journal of Organic Chemistry (JOC) （美国有机化学）(4) Journal of Medicinal Chemistry (JMC) （美国药物化学）(5) Chemical Reiew （化学评论）5. Royal Society of Chemistry (RSC) (英国皇家化学会)网址：/Publishing/Journals/Index.asp(1) Green Chemistry （绿色化学）(2) Chemical Communications (CC) （化学通讯）(3) Chemical Society Reviews （化学会评论）(4) Journal of the Chemical Society （化学会志）Journal of the Chemical Society, Perkin Transactions 1 (1972-2002) Journal of the Chemical Society, Perkin Transactions 2 (1972-2002) Journal of the Chemical Society B: Physical Organic (1966-1971)Journal of the Chemical Society C: Organic (1966-1971)(5) Organic & Biomolecular Chemistry (OBC) （有机生物化学）/publishing/jo ... p?type=CurrentIssue6. Wiley网址：/(1) Advanced Synthesis & Catalysis (ASC) （先进合成催化）(2) Angewandte Chemie International Edition （德国应用化学）(3) Chemistry - A European Journal （欧洲化学）(4) Chinese Journal of Chemistry （中国化学）(5) European Journal of Organic Chemistry （欧洲有机化学）(6) Helvetica Chimica Acta （瑞士化学）(7) Heteroatom Chemistry （杂原子化学）7. Ingent网址：/(1) Journal of Chemical Research (JCR) （化学研究杂志）(2) Canadian Journal of Chemistry （加拿大化学）(3) Current Organic Chemistry(4) Mini-Reviews in Organic Chemistry(5) Phosphorus, Sulfur, and Silicon and the Related Elements （磷、硫、硅和相关元素）(6) Letters in Organic Chemistry8. Taylor & Francis数据库网址：http://www.journalsonline.tandf. ... sp?referrer=default(1) Synthetic Communications(2) Journal of Sulfur Chemistry（硫化学杂志）(3) Phosphorus, Sulfur, and Silicon and the Related Elements9. Thieme数据库网址：/(1) Synlett （合成快报）(2) Synthesis （合成）10. 日本化学会网址：(1) Chem. Lett. (CL) （化学快报）http://www.jstage.jst.go.jp/browse/cl/_vols(2) Bull. Chem. Soc. Jpn. http://www.csj.jp/journals/bcsj/index.html11. 澳大利亚化学会（Australian Journal of Chemistry）http://www.publish.csiro.au/nid/52.htm12．巴西化学会.br/13．Molecules/molecules/14．韩国化学会http://journal.kcsnet.or.kr/15．印度化学会http://www.niscair.res.in/Scienc ... hin.htm&d=test816．国际有机制备和程序（Organic Preparations and Procedures International，OPPI）/17．有机化学/index.htm有机合成：Organic Syntheses(有机合成手册), John Wiley & Sons (免费)/Named Organic Reactions Collection from the University ofOxford (有机合成中的命名反应库) (免费)/thirdyearcomputing/NamedOrganicReac...有机化学资源导航Organic Chemistry Resources Worldwide/有机合成文献综述数据库Synthesis Reviews (免费)/srev/srev.htmCAMEO (预测有机化学反应产物的软件)/products/cameo/index.shtmlCarbohydrate Letters (免费,摘要)/Carbohydrate_Letters/Carbohydrate Research (免费,摘要)/locate/carresCurrent Organic Chemistry (免费,摘要)/coc/index.htmlElectronic Encyclopedia of Reagents for Organic Synthesis (有机合成试剂百科全书e-EROS) /eros/European Journal of Organic Chemistry (免费,摘要)/jpages/1434-193X/Methods in Organic Synthesis (MOS,有机合成方法)/is/database/mosabou.htmOrganic Letters (免费,目录)/journals/orlef7/index.htmlOrganometallics (免费,目录)/journals/orgnd7/index.htmlRussian Journal of Bioorganic Chemistry (Bioorganicheskaya Khimiya) (免费,摘要)http://www.wkap.nl/journalhome.htm/1068-1620Russian Journal of Organic Chemistry (Zhurnal Organicheskoi Khimii) (免费,摘要)http://www.maik.rssi.ru/journals/orgchem.htmScience of Synthesis: Houben-Weyl Methods of Molecular Transformation/Solid-Phase Synthesis database (固相有机合成)/chem_db/sps.htmlSynthetic Communications (免费,摘要)/servlet/product/productid/SCCSyntheticPages (合成化学数据库) (免费)/The Complex Carbohydrate Research Center (复杂碳水化合物研究中心)/合成材料老化与应用(免费,目录)/default.html金属卡宾络合物催化的烯烃复分解反应(免费)/html/books/O61BG/b1/2002/2.6%20.htm上海化学试剂研究所/英国化学数据服务中心CDS (Chemical Database Service)/cds/cds.html英国皇家化学会碳水化合物研究组织(Carbohydrate Group of the Royal Society of Chemistry)/lap/rsccom/dab/perk002.htm有机反应催化学会(ORCS, Organic Reaction Catalysis Society)/有机合成练习(免费)/中国科学院成都有机化学研究所：催化与环境工程研究发展中心/MainIndex.htm金属有机及元素有机化学：CASREACT - Chemical Reactions Database(CAS的化学反应数据库)/CASFILES/casreact.html日本丰桥大学Jinno实验室的研究数据库(液相色谱、多环芳烃/药物/杀虫剂的紫外谱、物性) (免费)http://chrom.tutms.tut.ac.jp/JINNO/ENGLISH/RESEARCH/research...A New Framework for Porous Chemistry (金属有机骨架) (免费)/alchem/articles/1056983432324.htmlActa Crystallographica Section B (免费,摘要)/b/journalhomepage.htmlActa Crystallographica Section E (免费,摘要)/e/journalhomepage.htmlBibliographic Notebooks for Organometallic Chemistryhttp://www.ensc-lille.fr/recherche/cbco/bnoc.htmlBiological Trace Element Research (生物痕量元素研究杂志) (免费,摘要)/JournalDetail.pasp?issn=0163-4984...Journal of Organometallic Chemistry (免费,摘要)/locate/jnlabr/jomOrganic Letters (免费,目录)/journals/orlef7/index.htmlOrganometallics (免费,目录)/journals/orgnd7/index.htmlSyntheticPages (合成化学数据库) (免费)/金属卡宾络合物催化的烯烃复分解反应(免费)/html/books/O61BG/b1/2002/2.6%20.htm金属有机参考读物：The Organometallic HyperTextBook by Rob Toreki/organomet/index.html金属有机化学国家重点实验室，中国科学院上海有机所/元素有机化学国家重点实验室（南开大学）/在线网络课程：有机金属反应和均相催化机理(Dermot O'Hare 主讲)/icl/dermot/organomet/药物化学：Fisher Scientific/PubMed: MEDLINE和PREMEDLINE (免费)/PubMed/生物医药:BioMedNet: The World Wide Club for the Biological and Medical Community /AIDSDRUGS (艾滋病药物) (免费)/pubs/factsheets/aidsinfs.htmlautodock (分子对接软件) (免费)/pub/olson-web/doc/autodock/DIRLINE (卫生与生物医药信息源库) (免费)/HISTLINE (医药史库) (免费)/TOXNET (化合物毒性相关数据库系列) (免费)/日本药典，第14版(免费)http://jpdb.nihs.go.jp/jp14e/index.html小分子生物活性数据库ChemBank (免费)/Ashley Abstracts Database (药物研发、市场文献摘要) (免费)/databases/ashley/search.aspBIOSIS/BIOSIS/ONLINE/DBSS/biosisss.html从检索药物交易信息库PharmaDeals (部分免费)/从ChemWeb检索有机药物用途及别名库Negwer: organic-chemical drugs and their synonyms (部分免费)/negwer/negwersearch.html美国常用药品索引库RxList (免费)/美国国家医学图书馆NLM的免费在线数据库(免费)/hotartcl/chemtech/99/tour/internet.html制药公司目录(Pharmaceutical Companies on Virtual Library: Pharmacy Page)/company.html37℃医学网/AAPS PharmSci (免费,全文)/Abcam Ltd.有关抗体、试剂的销售，抗体的搜索)/Acta Pharmaceutica (免费,摘要)http://public.srce.hr/acphee/Advanced Drug Delivery Reviews (免费,摘要)http://www.elsevier.nl/locate/drugdelivAmerican Journal of Drug and Alcohol Abuse (免费,摘要)/servlet/product/productid/ADAAmerican Journal of Pharmaceutical Education (AJPE) (免费,全文)/Amgen Inc. 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《丝胶靶向Akt1调控糖酵解及氧化应激保护STZ致损伤INS-1细胞》篇一一、引言糖尿病是一种全球性的慢性疾病，其发病机制复杂，与糖酵解异常和氧化应激密切相关。

INS-1细胞作为研究糖尿病的重要细胞模型，常被用于模拟胰岛β细胞的功能。

近年来，丝胶作为一种天然的生物活性物质，其抗氧化、抗炎等特性备受关注。

本研究旨在探讨丝胶靶向Akt1调控糖酵解及氧化应激保护STZ致损伤INS-1细胞的机制，为糖尿病的治疗提供新的思路。

二、材料与方法1. 材料INS-1细胞、链脲佐菌素（STZ）、丝胶、相关试剂与仪器等。

2. 方法（1）INS-1细胞培养与处理：培养INS-1细胞，用不同浓度的STZ处理细胞以建立损伤模型。

（2）丝胶处理：将丝胶加入损伤模型中，观察其对细胞的保护作用。

（3）Western blot、RT-PCR等技术检测：检测Akt1、糖酵解相关蛋白、氧化应激相关指标等表达水平。

（4）数据分析：采用GraphPad Prism软件进行数据分析，P<0.05表示差异有统计学意义。

1. 丝胶对STZ致损伤INS-1细胞的保护作用STZ处理后，INS-1细胞出现明显的损伤，表现为细胞活力降低、凋亡增加。

丝胶处理后，细胞活力得到显著恢复，凋亡率降低，表明丝胶对STZ致损伤的INS-1细胞具有保护作用。

2. 丝胶靶向Akt1调控糖酵解丝胶处理后，Akt1的磷酸化水平升高，糖酵解相关蛋白的表达也得到上调。

这表明丝胶可能通过靶向Akt1调控糖酵解过程。

3. 丝胶抑制氧化应激STZ处理导致INS-1细胞内活性氧（ROS）水平升高，而丝胶处理后ROS水平得到显著降低。

此外，丝胶还能上调抗氧化酶的表达，进一步证实了其抑制氧化应激的作用。

4. 丝胶对INS-1细胞功能的影响丝胶处理后，INS-1细胞的胰岛素分泌功能得到恢复，表明丝胶可能对糖尿病的治疗具有潜在的应用价值。

四、讨论本研究表明，丝胶对STZ致损伤的INS-1细胞具有保护作用，其机制可能与丝胶靶向Akt1调控糖酵解及抑制氧化应激有关。

Application of Transfer Technology to Manufacturing of Transmissive OLED and Reflective LC Hybrid (TR-Hybrid) Display Takayuki Ohide*, Seiji Yasumoto*, Masataka Nakada*, Hiroki Adachi*, Satoru Idojiri*, Kenichi Okazaki*, Yoshiharu Hirakata**, Johan Bergquist**, and Shunpei Yamazaki***Advanced Film Device Inc., Tochigi, Japan**Semiconductor Energy Laboratory Co., Ltd., Kanagawa, JapanAbstractOur previously established transfer technology using an inorganic separation layer was applied to enable a novel through electrode structure including a conductive material exposed after separation. Using this structure, we succeeded in fabricating a transmissive OLED and reflective LC hybrid display.Author KeywordsTR-Hybrid display; through electrode structure; reflective LCD; OLED display; inorganic separation layer; transfer technology.1. IntroductionRecently, small- to medium-sized mobile devices such as smartphones and tablet PCs have become increasingly popular. Such mobile devices require some of the same properties as general displays, including high image quality and moving image function, and low power consumption. With a focus on reducing power consumption, we fabricated a display that includes two types of display devices between two glass substrates. This display exhibits sufficient display quality in both the reflective and transmissive modes. However, the general structure of the display requires four glass substrates to bond an organic light-emitting diode (OLED) panel to a reflective liquid-crystal display (LCD) panel, making the product heavy. Moreover, since the light-emitting portion of the structure is far from the opening, the light-extraction efficiency cannot be improved.We fabricated a semiconductor device on our novel through electrode structure in which a pixel, terminal, and common contact are exposed after separation through the inorganic-separation-layer process. The combination of the through electrode structure and OLED and reflective LCD processes enabled the fabrication of a display that includes a reflective LCD and an OLED between two glass substrates. In this structure, the distance between a light-emitting portion and the opening is several micrometers or smaller, leading to an improvement in light-extraction efficiency or a reduction in power consumption.This study applies a transfer technology [1–8] to establish a through electrode technique in which a conductive material serving as an electrode is exposed after separation. The through electrode technique is used to expose a pixel electrode, an extraction terminal, and a common contact of a device fabricated over a separation layer on a substrate after separation.2. Structure of TR-Hybrid DisplayFigure 1 is a schematic of a transmissive OLED and reflective LC hybrid (TR-Hybrid) display that includes two types of display devices between two glass substrates. In the pixel, a reflective LCD and a bottom-emission OLED are individually fabricated. To increase the visibility of the display with low power consumption, display is performed by the reflective LCD under outside light [9,10] and by the OLED in dark environments. The transfer technology and through electrode technique are employed for these two different display devices. The through electrode structure, which involves an electrode being exposed after separation, enables the OLED and LCD in the TR-Hybrid display to be driven by one circuit.Figure 1. Schematic of TR-Hybrid display.3. Application of Transfer Technology to ThroughElectrode StructureFigure 2 shows general flexibilization processes. We fabricated flexible displays using an inorganic-separation-layer process using a separation layer containing an inorganic material [6–8]. In the fabrication of a flexible display, the inorganic separation layer lies over a glass substrate, and a passivation layer lies on the flat surface of the separation layer. The passivation layer protects an element layer, which includes field-effect transistors (FETs) and wiring, and an organic electroluminescent layer over the element layer from moisture and oxygen. In the TR-Hybrid display, the passivation layer also protects FETs and an OLED from damage during the LCD process. Owing to the inorganic separation layer, the passivation and element layers can be formed in a general manufacturing process using a glass substrate, and high workability can be obtained. Furthermore, the process temperature can be as high as that for the general manufacturing process in which a glass substrate is used, which provides favorable FET characteristics and a high-quality passivation layer.74-1 / T. Ohide1002 • SID 2016 DIGEST ISSN 0097-966X/16/4702-1002-$1.00 © 2016 SIDFigure 2. Flexibilization processes.Our transfer technology uses a highly reliable passivation layer. By combining the through electrode structure and the inorganic-separation-layer process having these advantages, we developed FET boards for TR-Hybrid displays.Figure 3 provides an overview of the manufacturing process for a TR-Hybrid display employing the through electrode structure. As illustrated in Fig. 3(a), an inorganic separation layer and a passivation layer containing through electrodes are formed on a glass substrate. Subsequently, an FET element is formed through a general FET process. Then, a bottom-emission OLED that emits light through the FET is formed on the board (Fig. 3(b)). Figure 3(c) shows a structure in which the OLED panel is provided on the FET board including the through electrodes; a glass substrate lies beneath the OLED, and the highly reliable passivation layer lies above the OLED. Separation at the passivation–separation layer interface is performed by applying the transfer technology (Fig. 3(d)). Consequently, the glass substrate is separated, and the conductive materials that pass through the passivation layer are exposed. This enables the extraction of FET signals. Using the exposed electrode, extraction terminal, and common contact, the reflective LCD can be fabricated (Fig. 3(e)). Thus, a TR-Hybrid display with the OLED below the FET element and the LCD over the FET element is completed (Fig. 3(f)). As we can see from the structure, the display includes just two glass substrates for supporting the two types of display devices: the reflective LCD and the OLED.The separation force was evaluated using a compact table-top tester (EZ-Test, Shimadzu Corporation). Each sample for evaluation was fabricated as follows: a separation layer and a passivation layer were formed over a glass substrate, the substrate was then cut to dimensions of 25 mm 126 mm, and a film was bonded to the substrate. The perpendicular force required to separate the film was measured for each sample. Figure 4 shows the results for (a) the conventional structure and (b) the through electrode structure. The separation force required for the through electrode structure was similar to that for the conventional structure. This indicates that the through electrode structure can be formed through the conventional separation process.Figure 3. Schematics of manufacturing process ofTR-Hybrid display.Figure 4. Separation force results.74-1 / T. OhideSID 2016 DIGEST • 1003To manufacture the TR-Hybrid display, glass separation was performed after the formation of the OLED panel. Thus, the FET characteristics were evaluated before and after the separation (Figs. 5(a) and 5(b), respectively). No significant differences were observed in the FET characteristics, indicating that the separation did not affect the FET element. This suggests that favorable FET characteristics are retained after the separation process.(a) (b)Figure 5. FET (L/W= 3/3 μm) characteristics (a) before separation and (b) after separation.4. Fabrication of TR-Hybrid Display usingThrough Electrode StructureWe produced a prototype 4.38-inch TR-Hybrid display including a reflective LCD and an OLED using an FET board with the through electrode structure. Table 1 lists the display specifications. The pixel density was 292 ppi. Figure 6 shows photographs of the display. The display can be used in a reflective LCD mode in bright environments (outdoors) and in an OLED display mode in dark environments (indoors). The display can also be used in a hybrid mode, a combination of the two modes. We promote the development of large-sized panels and aim to achieve large and high-definition panels with low power consumption.Table 1. Display specifications.SpecificationScreen Diagonal 4.38 inchEffective Pixels 768 ⨯ RGB ⨯ 1024Pixel Pitch 29 μm ⨯ 87 μmPanel Size 76 mm ⨯ 140.1 mmPixel Density 292 ppiOLED Bottom-emissionOLED LCD ReflectiveLCD (a)(b)Figure 6. Photographs of prototype TR-Hybrid display(a) under outside light and (b) in dark environment.5. ConclusionBy applying a transfer technology using an inorganic separationlayer, we established a novel through electrode technique in whichan electrode is exposed after separation. The technique led to thesuccessful fabrication of a TR-Hybrid display in which an OLEDand a reflective LCD can be driven by one circuit. We expect thatthe application of the display technology will lead to thedevelopment of large-sized panels with high visibility underoutside light and low power consumption.6. References[1]R. Kataishi et al., SID Digest 45, 187 (2014).[2]Y. Jimbo et al., SID Digest 45, 322 (2014).[3]R. Komatsu et al., SID Digest 45, 326 (2014).[4] D. Nakamura et al., SID Digest 46, 1031 (2015).[5] A. Chida et al., SID Digest 44, 196 (2013).[6]S. Idojiri et al., SID Digest 46, 8 (2015).[7]K. Hatano et al., SID Digest 42, 498 (2011).[8]T. Aoyama et al., AM-FPD’13, 223 (2013).[9]S. Fukai et al., SID Digest 45, 1496 (2014).[10]D. Kubota et al., SID Digest 46, 1084 (2015).74-1 / T. Ohide1004 • SID 2016 DIGEST。

Conversion of cellobiose into sorbitol in neutral water medium over carbon nanotube-supported ruthenium catalystsWeiping Deng,Mi Liu,Xuesong Tan,Qinghong Zhang *,Ye Wang *State Key Laboratory of Physical Chemistry of Solid Surfaces,National Engineering Laboratory for Green Chemical Productions of Alcohols,Ethers and Esters,Department of Chemistry,College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,PR Chinaa r t i c l e i n f o Article history:Received 30August 2009Revised 6January 2010Accepted 26January 2010Available online 24February 2010Keywords:Biomass conversion Cellobiose SorbitolRuthenium catalyst Carbon nanotubes Hydrogenation Hydrolysisa b s t r a c tCarbon nanotube (CNT)-supported ruthenium catalysts were studied for the hydrogenation of cellobiose in neutral water medium.The acidity of catalysts and the size of Ru particles played key roles in the con-version of cellobiose to sorbitol.A higher concentration of nitric acid used for CNT pretreatment provided a better sorbitol yield,suggesting an important role of catalyst acidity.The catalysts with larger mean sizes of Ru particles and abundant acidic sites exhibited better sorbitol yields,while those with smaller Ru particles and less acidic sites favored the formation of 3-b -D -glucopyranosyl-D -glucitol.We elucidated that cellobiose was first converted to 3-b -D -glucopyranosyl-D -glucitol via the hydrogenolysis,and then sorbitol was formed through the cleavage of b -1,4-glycosidic bond in 3-b -D -glucopyranosyl-D -glucitol over the catalysts.The catalyst with smaller Ru particles favored the first step but was disadvantageous to the second step due to the less acidity.Smaller Ru particles also accelerated the degradation of sorbitol.Ó2010Elsevier Inc.All rights reserved.1.IntroductionThe production of fuels and chemicals from renewable biomass resources has attracted much attention in recent years [1–4].As the most abundant source of biomass and because of the non-edible feature,lignocellulosic biomass may become an important feedstock to replace or partially replace the fossil feedstock for the sustainable production of fuels and chemicals [5–8].However,the effective utilization of lignocellulosic biomass,which contains cellulose as a main component,is still a challenge because of the robust crystalline structure of cellulose [9,10].So far,processes for hydrolysis of cellulose to glucose in the presence of strong mineral acids (e.g.,H 2SO 4)and for high-temperature pyrolysis or gasification of cellulose to bio-oils or synthesis gas have been developed,but these processes suffer from problems of high-en-ergy input and low selectivity [5–8].It would be highly desirable to develop a catalytic route for the conversion of cellulose selec-tively into a platform or building block molecule such as sorbitol,ethylene glycol or 5-hydroxymethylfurfural (HMF)[11],which may be facilely transformed into fuels or chemicals.A few studies have succeeded in converting cellulose into such a platform molecule under mild conditions [12–16].The hydrogena-tion of cellulose in water medium was found to be catalyzed by aPt/Al 2O 3catalyst,providing a yield of 31%to hexitols (sorbitol and mannitol,25%and 6%,respectively)at 463K [12].Liu and coworkers [13]developed a two-step transformation of cellulose to polyols catalyzed by reversibly formed acids and activated car-bon-supported Ru nanoclusters in hot water,and they obtained a yield of polyols of $40%(sorbitol,$30%)at 518K.Ni-promoted tungsten carbide was demonstrated to catalyze the conversion of cellulose into ethylene glycol with a yield as high as 61%at 518K [14].Zhang and coworkers recently developed an effective route for the rapid conversion of cellulose to sugars and further to HMF (HMF yield,$55%)catalyzed by CuCl 2/CrCl 2catalysts in 1-ethyl-3-methyl-imidazolium chloride solvent at 353–393K [15].Very recently,we found that a multi-walled carbon nanotube (CNT)-supported Ru catalyst could catalyze the conversion of cellu-lose to hexitols with a yield of 40%(sorbitol,36%)in the presence of H 2in water medium at 458K [16].However,basic understanding of catalyst requirements for the conversion of cellulose is very lim-ited.Undoubtedly,more extensive studies are needed to gain in-sights into the requirements for the rational design of more efficient catalysts for selective transformations of cellulose.However,because cellulose is a very complex macromolecule and is insoluble in most solvents,it is not easy to perform funda-mental research directly with cellulose.In this context,the funda-mental studies with a model molecule would be helpful in the present stage.Cellobiose,which is a D -glucose dimer connected by a b -1,4-glycosidic bond (see Fig.1for structural formula),represents the simplest model of cellulose.The studies on catalytic0021-9517/$-see front matter Ó2010Elsevier Inc.All rights reserved.doi:10.1016/j.jcat.2010.01.024*Corresponding authors.Fax:+865922183047.E-mail addresses:zhangqh@ (Q.Zhang),wangye@ (Y.Wang).Journal of Catalysis 271(2010)22–32Contents lists available at ScienceDirectJournal of Catalysisjournal homepage:www.else v i e r.c o m /l o c a t e /j c atconversion of cellobiose may also be useful for transformations of the decrystallized or the soluble oligosaccharides released in hydrothermal or acidic treatments of cellulose,which contain b -1,4-glycosidic bonds.However,there only exist scattered studies on catalytic conversion of cellobiose.Kou and coworkers [17]dis-closed that Ru nanoclusters dispersed in water were efficient for the hydrogenation of cellobiose to sorbitol in an acidic aqueous medium (pH =2.0),whereas under neutral or basic conditions (pH =7.0or 10.0),the selectivity of sorbitol was significantly low-er.Thus,the protons in the liquid phase might participate in the hydrolysis of cellobiose.Bootsma and Shanks [18]reported that a kind of solid acid catalysts,i.e.,organic–inorganic hybrid mesopor-ous materials containing acidic functional groups,could catalyze the hydrolysis of cellobiose into glucose.Supported Ru catalysts are known as efficient catalysts for the hydrogenation of glucose to sorbitol [19,20].The Ru/CNT catalyst was once reported to be more active for the hydrogenation of glu-cose than the Ru/Al 2O 3and Ru/SiO 2[21].As mentioned earlier,in our preceding work,we found that the Ru/CNT catalyst could effi-ciently catalyze the conversion of cellulose to sorbitol in the pres-ence of H 2in water medium [16].However,there is still little knowledge about the effect of the Ru/CNT catalyst on the conver-sion of cellulose to sorbitol.Very recently,we chose cellobiose as a model molecule of cellulose and performed detailed studies on catalytic conversion of cellobiose.The present article reports the effects of key factors of Ru/CNT catalysts on the catalytic hydroge-nation of cellobiose to sorbitol.We will also discuss the possible reaction mechanism for this catalytic reaction.2.Experimental 2.1.Catalyst preparationThe CNTs with outer diameters of 20–80nm and inner diame-ters of 3–5nm were prepared by a method reported previously [22].The prepared CNTs were typically pretreated in concentrated HNO 3(68wt.%)at 383K under refluxing conditions to remove the remaining Ni catalyst used for CNT preparation,the amorphous carbon,and to create function groups (e.g.,hydroxyl and carboxylic groups)for anchoring metal precursors [23].To investigate the role of CNT functionalization,CNTs were also pretreated by HNO 3with different concentrations (5–68wt.%)or by concentrated HCl (37wt.%).No Ni was detected after these pretreatments.Stan-dardly,CNT-supported Ru catalysts were prepared by an impreg-nation method.The CNTs after pretreatment were added into a RuCl 3aqueous solution and then were dispersed ultrasonically for 0.5h.After being further stirred for 5h,the suspension was evaporated at 343K to remove water.The dried sample was cal-cined at 623K in air,followed by H 2reduction at 623K for 0.5h to obtain the Ru/CNT catalyst.The loading of Ru was 1.0wt.%un-less otherwise stated.We have attempted to prepare Ru/CNT catalysts with different sizes of Ru particles by the impregnation followed by differentpost-treatments.For this purpose,the dried sample was either di-rectly reduced by H 2at 623and 773K or was first calcined at 623K in air and then reduced by H 2at different temperatures (623–773K).An ethylene glycol reduction method [24]was also applied to the preparation of the Ru/CNT catalysts with different sizes of Ru particles.In this method,RuCl 3was first dissolved in ethylene gly-col,and then,the CNTs after pretreatment were added into the RuCl 3solution.After being treated ultrasonically for 0.5h,the mix-ture was refluxed at 453or 483K for 1h.The solid product was then recovered by filtration followed by drying.2.2.Catalyst characterizationTransmission electron microscopy (TEM)measurements were performed on a FEI Tecnai 30electron microscope (Phillips Analyt-ical)operated at an acceleration voltage of 300kV.The mean sizes of Ru particles in Ru/CNT samples were estimated from TEM micrographs by counting ca.150–200particles.X-ray photoelec-tron spectra (XPS)were recorded with a Quantum 2000Scanning ESCA Microprob instrument (Physical Electronics)using Al K a radi-ation.The binding energy was calibrated using C 1s photoelectron peak at 284.6eV as a reference.Ru dispersions were measured by H 2A O 2titration using an ASAP2010C Micromeritics apparatus with the procedures reported in literature [25].NH 3-temperature-programmed desorption (NH 3-TPD)was per-formed on a Micromeritics AutoChem 2920II instrument.Typi-cally,the sample loaded in a quartz reactor was first pretreated with high-purity He at 623K for 1h.After the sample was cooled to 393K,NH 3adsorption was performed by switching the He flow to a NH 3A He (10vol.%NH 3)gas mixture and then keeping at 393K for 1h.Then,the gas phase or the weakly adsorbed NH 3was purged by high-purity He at the same temperature.NH 3-TPD was performed in the He flow by raising the temperature to 973K at a rate of 10K min À1,and the desorbed NH 3molecules were detected by ThermoStar GSD 301T2mass spectrometer with the signal of m /e =16.Titration method was also used to evaluate the acidity of Ru/CNT catalysts.In a typical experiment,0.15g Ru/CNT catalysts was added into a 25cm 30.01mol dm À3NaOH aqueous solution and stirred overnight.The mixture was titrated with a 0.01mol dm À3HCl solution to determine the excess NaOH in the solu-tion to quantify the concentration of the acidic sites on Ru/CNT cat-alysts.For comparison,the acidity of CNT samples without Ru was also evaluated by the titration method.2.3.Catalytic reactionThe conversion of cellobiose was performed with a batch-type high-pressure autoclave reactor.Typically,the catalyst (0.050g)and cellobiose (0.50mmol)were added into a Teflon-lined stain-less steel reactor pre-charged with H 2O (20cm 3),and then the reaction was carried out at 458K under 5MPa H 2for 3h.After the reaction,the solid catalyst was separated by centrifugation,and the liquid products were analyzed by a HPLC (Shimazu LC-20A)equipped with a RI detector and a Transgenomic™CARBON-Sep CHO-620column (10l m, 6.5Â300mm).The eluent was water with a flow rate of 0.5cm 3min À1.The column was thermo-stated at 338K by a column heater.Sampling loop has a volume of 20l L.The pH value of the reaction solution was $7after the con-version of cellobiose.Chemicals including sorbitol,mannitol,erythritol [C 4H 6(OH)4],HMF purchased from Alfa Aesar,and glu-cose,glycerol,ethylene glycol purchased from Sinopharm Chemi-cal Reagent Co.Ltd.were used for calibrations without further treatment.3-b -D -Glucopyranosyl-D -glucitol synthesized in our lab-oratory,which was characterized by mass spectroscopy,was also used for thecalibration.Fig.1.Structure formulas of cellobiose and some typical products.W.Deng et al./Journal of Catalysis 271(2010)22–32233.Results and discussion3.1.Role of CNT functionalization in catalytic conversion of cellobiose over Ru/CNT catalystsBecause the protons in liquid phase were indispensable for sor-bitol formation in the conversion of cellobiose catalyzed by water-dispersed Ru nanoclusters[17],the hydrolysis and hydrogenation were proposed to be two requisite steps for the conversion of cel-lobiose to sorbitol.To realize the conversion of cellobiose to sorbi-tol in neutral water medium,we selected Ru supported on acid-functionalized CNTs as the catalyst for this reaction.We prepared Ru/CNT catalysts,in which the CNT was pretreated by the concen-trated HCl solution(37wt.%)or the HNO3solutions with concen-trations in the range of5–68wt.%to generate acidic functional groups[26].Characterizations with XPS and TEM were performed for this series of catalysts to gain information about the state of Ru species. We did notfind significant differences in the chemical state and the mean size of Ru particles in these catalysts.XPS studies re-vealed that the binding energy of Ru3d5/2over each catalyst was around280.3eV,suggesting that the Ru species loaded on the CNTs pretreated differently were all in metallic(Ru0)state [27,28].Fig.2shows the TEM micrographs of the Ru/CNT catalysts with CNTs pretreated by HNO3with different concentrations.The size distributions for Ru particles in these catalysts,derived from the TEM micrographs by counting$150–200particles,are also shown in Fig.2.With changing the concentration of HNO3used for CNT pretreatment from5to68wt.%,the mean sizes of Ru par-ticles in these catalysts were almost the same(8.6–8.9nm).NH3-TPD results in Fig.3show that almost no desorption of NH3 occurs over the CNT pretreated by HCl.On the other hand,desorp-tion of NH3was observed from the CNTs pretreated by HNO3,and the peak intensity increased with increasing the concentration of HNO3.Desorption of NH3was also observed from the Ru/CNT cat-alysts prepared using CNTs pretreated by HNO3with different con-centrations(Fig.3B).This indicates that the acidic sites generated on CNT surfaces could be sustained on the prepared Ru/CNT cata-lysts.Similar phenomenon was observed in our recent studies on the same catalysts for Fischer–Tropsch synthesis[29].We performed the hydrogenation of cellobiose over the acid-functionalized Ru/CNT catalysts.As shown in Fig.4,the Ru/CNT could catalyze the formation of sorbitol from cellobiose at 458K,and the catalytic performance depended on the acid used for CNT pretreatment.Sorbitol yield was only26%when the CNT pretreated by HCl(37wt.%)was used as the support of Ru catalyst.Sorbitol yield rose from56%to87%when the concentra-tion of HNO3for CNT pretreatment increased from5wt.%to 68wt.%.Therefore,the acidity generated on CNTs during the pre-treatment by concentrated HNO3plays an important role in the conversion of cellobiose to sorbitol.This result is in essence the same with that obtained in our previous studies for the conver-sion of cellulose to sorbitol[16].The following studies have been focused on the catalysts using the CNT pretreated by68wt.% HNO3as the support.To gain further information on the conversion of cellobiose to sorbitol,we have investigated the temperature dependence of product distributions for cellobiose conversion over the Ru/CNT catalyst with the CNT pretreated by68wt.%HNO3.Fig.5shows that3-b-D-glucopyranosyl-D-glucitol is formed as the main product at lower temperatures,and it is transformed to sorbitol with increasing the reaction temperature up to458K.A further higher temperature favored the formation of degradation products includ-ing C6H10(OH)4,C4H6(OH)4,C3H5(OH)3,C2H4(OH)2,and CH4.From these results,we suggest that3-b-D-glucopyranosyl-D-glucitol may be an important intermediate for sorbitol formation from cel-lobiose over the Ru/CNT catalyst.3.2.Ru/CNT catalysts with different sizes of Ru particles and their catalytic behaviors3.2.1.Preparation of Ru/CNT catalysts with different sizes of Ru particlesBesides the acidity of the catalyst,Ru nanoparticles are believed to play important roles in the formation of sorbitol from cellobiose. Because the size of metal nanoparticles is one of the most impor-tant factors dominating the performances of nanoparticles-based catalysis[30],we have prepared a series of Ru/CNT sampleswith Fig.2.TEM micrographs and Ru particle size distributions of the Ru/CNT catalysts with CNTs pretreated by HNO3with different concentrations.Concentration of HNO3used for CNT pretreatment:(A)5wt.%,(B)19wt.%,(C)37wt.%,(D)52wt.%, and(E)68wt.%.24W.Deng et al./Journal of Catalysis271(2010)22–32different mean sizes of Ru particles to clarify the size effect in the Ru/CNT-catalyzed conversion of cellobiose.With TEM observa-tions,we clarified that the direct H 2reduction at 773K without calcination resulted in smaller Ru nanoparticles finely dispersed on the CNT surfaces (Fig.6A,Ru/CNT-H773).The mean size of Ru (D )in this sample estimated from TEM images by counting ca.150–200particles was 2.4nm.The size of Ru particles increased significantly if the calcination at 623K was adopted before H 2reduction.Moreover,a change of the temperature for H 2reduction could change the mean size of Ru particles.The catalysts with mean sizes of Ru particles at 8.7and 12nm were obtained by usingreduction temperatures of 623K (Fig.6B,Ru/CNT-C623-H623)and 773K (Fig.6C,Ru/CNT-C623-H773),respectively.On the other hand,Ru/CNT catalysts with mean sizes of Ru particles at 5.1and 6.8nm could be obtained by using the method of ethylene glycol reductions at 483K (Fig.6D,Ru/CNT-EG483)and 453K (Fig.6E,Ru/CNT-EG453),respectively.In short,we have succeeded in pre-paring the Ru/CNT catalysts with mean sizes of Ru particles varying from 2.4to 12nm.3.2.2.Acidity of the prepared Ru/CNT catalysts with different sizes of Ru particlesFrom the results described previously,we know that the forma-tion of sorbitol is affected by the catalyst acidity,which arises from the CNT pretreatment by concentrated HNO 3.Therefore,we have evaluated the acidity of the prepared Ru/CNT catalysts with differ-ent mean sizes of Ru particles by both the NH 3-TPD and the titra-tion methods.Fig.7shows the NH 3-TPD profiles of these catalysts.Only a low-er-temperature NH 3desorption peak ($480K)was observed for the Ru/CNT catalyst with a mean size of Ru particles at 2.4nm,and the intensity of this peak was lower than that for other cata-lysts.Moreover,for the catalysts with mean sizes of Ru particles P 5.1nm,in addition to the lower-temperature peak,another NH 3desorption peak at higher temperatures (>700K)could be ob-served,indicating the presence of acid sites with stronger acidity,and the peak associated with the stronger acid sites further shifts to higher temperatures over the samples with Ru particles at 8.7nm or 12nm.From these NH 3-TPD results,it becomes clear that there exist differences in the acidity among the Ru/CNT cata-lysts with different mean sizes of Ru particles.When compared to the Ru/CNT catalysts with larger Ru particles,the Ru/CNT catalyst with a mean size of Ru particles at 2.4nm (Ru/CNT-H773)pos-sesses much lower acidity.This observation has further been con-firmed by the result obtained from the titration method.As shown in Table 1,the amount of acidic sites for the Ru/CNT-H773(2.4nm)catalyst was significantly lower than those for the other Ru/CNT catalysts.The amounts of acidic sites over the CNTs alone,which underwent post-treatments with the same procedures as those for the preparation of the Ru/CNT catalysts with different Ru sizes,were also measured by the titration method.When compared to the CNTs after different post-treatments,unexpectedly,the Ru/CNT catalysts showed larger amounts of acidicsites.Fig.3.NH 3-TPD profiles of the CNTs pretreated by concentrated HCl or by HNO 3with different concentrations (A)and the Ru/CNT catalysts prepared using CNTs pretreated by HNO 3with different concentrations(B).Fig.4.Sorbitol yield in the conversion of cellobiose over the Ru/CNT catalysts prepared using CNTs pretreated by concentrated HCl or by HNO 3with different concentrations.Reaction conditions:cellobiose,0.50mmol;catalyst,0.050g;H 2O,20cm 3;H 2,5MPa;temperature,458K;time,3h.Fig.5.Dependence of catalytic performances with reaction temperature for the conversion of cellobiose over the Ru/CNT catalyst with a mean size of Ru particles at 8.7nm.Reaction conditions:cellobiose,0.50mmol;catalyst,0.050g;H 2O,20cm 3;H 2,5MPa;time,3h.W.Deng et al./Journal of Catalysis 271(2010)22–3225Although the reason for the differences in the acidity among the Ru/CNT catalysts with different Ru sizes and the CNTs is still un-clear at this moment,the acidity of our catalysts is believed to stem from the oxygen-containing functional groups on CNT surfaces generated during the HNO 3pretreatment or the post-treatments.Several groups [31–33]reported that the analysis of O1s XPS spec-tra could give useful information on the functional groups on CNT surfaces.For example,it was proposed that the O1s peak with binding energies at 531.1,532.3,533.3,and 534.2eV could be attributed to the carbonyl groups,the carbonyl oxygen atoms in es-ters and anhydrides or the oxygen atoms in hydroxyls or ethers,the ether oxygen atoms in esters and anhydrides,and the oxygen atoms in carboxylic groups,respectively [32–34].Thus,we have performed XPS studies for our catalysts with different mean sizes of Ru particles,and the results are shown in Fig.8.The broad fea-ture of O1s peak in Fig.8implies that several types of oxygen-con-taining functional groups co-exist on our catalysts.The results derived from the deconvolution of O1s peaks are summarized inTable 2.The percentage of the composition at a binding energy of 534.2eV,which could be ascribed to the acidic carboxylic group on the CNT surface,increased from 8.8%to 16%,17%,22%,and 18%when the mean size of Ru particles rose from 2.4to 5.1,6.8,8.7,and 12nm,respectively.These results further suggest that the cat-alyst with a mean size of Ru particles at 2.4nm possesses less acid sites.However,from Table 2,the differences in the fraction of the acidic carboxylic groups among the catalysts with other mean sizes of Ru particles are not very significant.Moreover,it is still difficult to explain the differences in the peak positions of the higher-tem-perature peak observed in NH 3-TPD profiles among the catalysts with different mean sizes of Ru particles (Fig.7).3.2.3.Catalytic conversions of cellobiose to sorbitol over Ru/CNT catalystsFig.9shows the catalytic performances of the Ru/CNT catalysts with different mean sizes of Ru for the conversion of cellobiose at 458K for 3h.The catalyst with a smaller mean size of Ru (2.4nm)showed a lower sorbitol yield.The sorbitol yield increased with increasing the mean size of Ru particles up to 8.7nm,and a further increase in the mean size of Ru particles to 12nm only slightly changed sorbitol yield.3-b -D -Glucopyranosyl-D -glucitol,mannitol,and degradation products (including C 6H 10(OH)4,C 4H 6(OH)4,Fig.6.TEM micrographs and Ru particle size distributions of the Ru/CNT catalysts prepared by the impregnation (A–C)and the ethylene glycol reduction (D and E)methods.(A)Direct reduction by H 2at 773K after impregnation (without calcination);(B)and (C)with calcination at 623K after impregnation,followed by H 2reductions at 623and 773K,respectively;(D)and (E)reductions by ethylene glycol at 483and 453K,respectively.Fig.7.NH 3-TPD profiles of the Ru/CNT catalysts with different mean sizes of Ru particles.(A)Ru/CNT-H773(Ru,2.4nm);(B)Ru/CNT-EG483(Ru,5.1nm);(C)Ru/CNT-EG453(Ru,6.8nm);(D)Ru/CNT-C623-H623(Ru,8.7nm);(E)Ru/CNT-C623-H773(Ru,12nm).Table 1Amount of acidic sites over the CNTs after different post-treatments and the Ru/CNT samples with different mean sizes of Ru particles.aSample bMean size of Ru (nm)Amount of acidic sites (mmol g À1)CNT-H773–0.12CNT-EG483–0.20CNT-EG453–0.22CNT-C623-H623–0.25CNT-C623-H773–0.17Ru/CNT-H773 2.40.37Ru/CNT-EG483 5.10.50Ru/CNT-EG4536.80.55Ru/CNT-C623-H6238.70.56Ru/CNT-C623-H773120.51a Measured by the titration method.bThe numbers after H,C,and EG denote temperatures for H 2reduction,calci-nation and ethylene glycol reduction,respectively (also see the main text).26W.Deng et al./Journal of Catalysis 271(2010)22–32C 3H 5(OH)3,and C 2H 4(OH)2)were formed with higher yields over the catalysts with smaller Ru particles (<8.7nm).These observa-tions suggest that the mean size of Ru nanoparticles is one of the important factors,which influence the conversion of cellobiose into sorbitol.However,the acidity of these catalysts is different as shown in Table 1,Figs.7and 8,while the result in Fig.4has indi-cated the important role of acidity in the formation of sorbitol.The contribution of acidity in these catalysts will be discussed in Sec-tion 3.3.3.We have performed the recycling uses of the Ru/CNT-C628-H628(Ru,8.7nm)catalyst,which can provide the highest sorbitol yield.No decreases in sorbitol yield were observed in the repeated uses,and a sorbitol yield of 88%was obtained after four recycling tests.Thus,our Ru/CNT catalyst could be used repeatedly.3.3.Possible reaction mechanism for the conversion of cellobiose over Ru/CNT catalysts3.3.1.Reaction pathwaysTo understand the possible reaction pathways for the conver-sion of cellobiose over the Ru/CNT catalysts,we performed kinetic studies.Fig.10shows the time courses for cellobiose conversions over the Ru/CNT catalysts with mean sizes of Ru particles at 2.4,5.1,8.7,and 12nm.Over all of these catalysts,it is found that 3-b -D -glucopyranosyl-D -glucitol is formed as the main product at the initial reaction stage.The yield of 3-b -D -glucopyranosyl-D -gluc-itol could reach 93%over the catalyst with a mean size of Ru par-ticles at 2.4nm after 20min of reaction (Fig.10A).With prolonging the reaction time,the yield of sorbitol,the target product,in-creased significantly along with a decrease in that of 3-b -D -gluco-pyranosyl-D -glucitol,indicating that sorbitol was formed from the consecutive conversion of 3-b -D -glucopyranosyl-D -glucitol.For the Ru/CNT catalysts with mean Ru sizes of 8.7(Fig.10C)and 12nm (Fig.10D),the yield of sorbitol could reach 80–90%,while the highest sorbitol yields were lower than $40%and $60%over the catalysts with mean Ru sizes of 2.4nm (Fig.10A)and 5.1nm (Fig.10B),respectively.The lower yield of sorbitol over the Ru/CNT catalysts with smaller Ru particles was likely due to the rapid conversion of sorbitol consecutively to mannitol and other degra-dation products over these catalysts.Glucose was formed with very lower yields (<5%)over all of the catalysts in Fig.10,except for that over the Ru/CNT-C623-H773catalyst with a larger mean size of Ru (12nm),where a relatively higher yield of glucose ($20%)could be achieved at the initial reaction stage (Fig.10D).These observations strongly suggest that the main reaction intheFig.8.O1s XPS spectra of the Ru/CNT catalysts with different mean sizes of Ru particles.The dotted lines are deconvolution results.(A)Ru/CNT-H773(Ru,2.4nm);(B)Ru/CNT-EG483(Ru,5.1nm);(C)Ru/CNT-EG453(Ru,6.8nm);(D)Ru/CNT-C623-H623(Ru,8.7nm);and (E)Ru/CNT-C623-H773(Ru,12nm).Table 2Deconvolution results of XPS O1s peaks for the Ru/CNT catalysts with different mean sizes of Ru particles.CatalystMean sizes of Ru (nm)Fraction of each O1s component (%)531.1eV a532.3eV b 533.3eV c 534.2eV d Ru/CNT-H773 2.44035168.8Ru/CNT-EG483 5.111433016Ru/CNT-EG4536.820372617Ru/CNT-C623-H6238.719273222Ru/CNT-C623-H7731212462418a The C @O groups at 531.1eV.b The carbonyl oxygen atoms in esters,amides,anhydrides or oxygen atoms in hydroxyls or ethers at 532.3eV.c The ether oxygen atoms in esters and anhydrides at 533.3eV.dThe oxygen atoms in carboxyl groups at 534.2eV.Fig.9.Product yields in the conversion of cellobiose over the Ru/CNT catalysts with different mean sizes of Ru particles.Reaction conditions:cellobiose,0.50mmol;catalyst,0.050g;H 2O,20cm 3;H 2,5MPa;temperature,458K;time,3h.W.Deng et al./Journal of Catalysis 271(2010)22–3227。

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Not for use in diagnostic or therapeutic procedures.Windows and Excel are a registered trademarks of Microsoft Corporation.BD, BD Logo and all other trademarks are property of Becton, Dickinson and Company. © 2009 BDBD Biosciences 2350 Qume Drive San Jose, CA 95131**************。

我的科研感悟先介绍一下我的学术背景，我本科学的是化学工程专业，硕士和博士学的是控制理论与控制工程专业，本硕在一所211工程学校就读，博士毕业于中科院某研究所。

博士在读期间，在本学科国际杂志上发表了两篇SCI文章，获一项发明专利，另有其它科研成果若干。

下面我就结合我的专业背景谈一谈我的科研之路。

希望能对从事科研的人起到一个抛砖引玉的作用。

也希望从事科研的人努力工作，多多创新，为祖国的发展贡献自己的一份力量。

文章中所列均代表本人观点，如觉不适，敬请忽略。

1. 科研好点子从哪里来？1.1选题要做一流的学术，选题非常关键。

一个好的课题，会使你在很短的时间内就能取得一些进展；一个前沿的课题，会使你站在巨人的肩膀上。

为什么国内的一些学者，也做了很多工作，但是却发不出高档次的SCI论文，你可以说他们不屑得发，但其中很大一个原因是他们的选题”Out of date”，很难在国际期刊上激起读者的兴趣，甚至他们做的东东早已经有人做过了，即便其中有一些新东西，也很难让国际审稿人认同，因为审稿人一看到论文题目就会在他们的心里留下“这个问题，我们在七八十年代已经做过了”的印象，最后难逃拒稿的命运。

那么怎么样选题呢？一个简单的办法是阅读国际顶级杂志最新发表的文章，看看他们都在搞什么？再结合自己的专业背景，或进行学科交叉，或查找缺陷、不足，或进行方法移植，这样选择的课题实际上已经和国外同行站在同一跑道上了。

但由于别人已经有了一定的基础了，且稿件有一定的滞后性，他的加速度会比我们大，所以我们在具体搞研究时一定要另辟蹊径。

等到我们自己开辟的路在国际上已经得到别人的认可并且成体系时，我们就可以沿着这条路继续前进了。

总之，我的选题原则是“基于国际前沿，另辟蹊径”。

1.2方法论科学研究是需要方法的，而且是有方法的。

我们在做化学实验时，需要先构思实验方案；在控制被控对象时，需要先设计控制算法。

这些“构思”、“设计”等过程就是一个点子产生的过程。

一种n,s,b掺杂的中草药药渣碳点,荧光探针及应用全文共四篇示例，供读者参考第一篇示例：2.方法本研究选取了一种中草药药渣为原料，经过碳化和掺杂等一系列处理步骤，制备出了一种n，s，b掺杂的中草药药渣碳点。

通过透射电镜（TEM）、扫描电子显微镜（SEM）、X射线光电子能谱（XPS）等手段对制备的碳点进行了表征，并分析了其形貌、结构和成分。

3.结果通过表征分析，我们得到了一种n，s，b掺杂的中草药药渣碳点，具有较好的结晶性和荧光性能。

该碳点的荧光发射波长范围在400-700nm之间，具有较高的发光强度和稳定性。

该碳点还表现出了较好的生物相容性和细胞内穿透性，在细胞成像和生物传感方面具有很大的潜力。

第二篇示例：中药药渣是指中药煎煮后剩余的药渣，通常被视为废弃物。

科学家们发现，这些药渣中含有丰富的有机物质，可以被提取并加工成碳点。

碳点是一种直径在1-10nm之间的碳基纳米材料，具有优异的荧光性能和生物相容性，被广泛应用于荧光成像、生物传感等领域。

将中药药渣转化为碳点可以实现资源的再利用，并为中药药渣赋予新的价值。

在碳点的制备过程中，通常会采用掺杂的方法来改变其性能。

掺杂是指在碳点晶格中引入其他元素，以改变其光电性能。

本文介绍的中药药渣碳点是n,s,b三元掺杂的碳点，其中n代表氮元素，s代表硫元素，b代表硼元素。

这种三元掺杂能够调控碳点的能带结构和表面性质，提高其荧光性能和生物活性，具有更广泛的应用前景。

n,s,b掺杂的中草药药渣碳点具有一系列优异的性能。

由于氮、硫、硼元素的影响，碳点表面带有丰富的官能团，使其具有较好的水溶性和生物相容性，可以用于细胞成像、靶向药物输送等生物医学应用。

三元掺杂可以调控碳点的能带结构，增强其荧光性能，使其在荧光探针领域具有更广泛的应用潜力。

n,s,b掺杂的碳点还具有较高的载荷能力和可控释放性，可用于药物传输、生物标记等领域。

除了在生物医学领域，n,s,b掺杂的中药药渣碳点还具有潜在的环境应用价值。