Preparation and properties of keratin-poly(vinyl alcohol) blend fiber

Unit 1 Production of DrugsDepending on their production or origin pharmaceutical agents can be split into three groups:I .Totally synthetic materials (synthetics)，Ⅱ.Natural products，andⅢ.Products from partial syntheses (semi-synthetic products).The emphasis of the present book is on the most important compounds of groups I and Ⅲ一thus Drug synthesis. This does not mean，however，that natural products or other agents are less important. They can serve as valuable lead structures，and they are frequently needed as starting materials or as intermediates for important synthetic products.Table 1 gives an overview of the different methods for obtaining pharmaceutical agents.Table 1 Possibilities for the preparation of drugsMethods Examples1. Total synthesis -over 75 % of all pharmaceutical agents (synthetics)2. Isolation from natural sources (natural products):2.1 Plants -alkaloids;enzymes;heart glycosides;polysaccharides;tocopherol;steroid precursors (diosgenin, sitosterin);citral (intermediate product forvitamins A, E，and K)2.2 Animal organs一enzymes;peptide hormones;cholic acid from gall; insulin) from thepancreas;sera and vaccines2. 3 Other sources一cholesterol from wool oils;L-amino acids from keratin and gelatinehydrolysates3. Fermentation一antibiotics;L-amino acids;dextran; targeted modifications on steroids，e.g. 11-hydroxylation; also insulin, interferon, antibodies, peptidehormones，enzymes，vaccines4. Partial synthetic modification of natural products (semisynthetic agents):一alkaloid compounds;semisynthetic /3-lactam antibiotics;steroids;human insulinSeveral therapeutically significant natural products which were originally obtained from natural sources are today more effectively -i. e. more economically -prepared.. by total synthesis. Such examples include L-amino acids，Chloramphenicol，Caffeine, Dopamine，Epinephrine，Levodopa, peptide hormones，Prostaglandins，D-Penicillamine，Vincamine，and practically all vitamins.Over the last few years fermentation - i. e. microbiological processes has become extremely important. Through modern technology and results from genetic selection leading to the creation of high performance mutants of microorganisms，fermentation has already become the method of choice for a wide range of substances. Both Eukaryonts (yeasts and moulds)and Prokaryonts(single bacterial cells，and actinomycetes)are used microorganisms. The following product types can be obtained:1. cell material (single cell protein)，2. enzymes，3. primary degradation products (primary metabolites)，4. secondary degradation products (secondary metabolites).Disregarding the production of dextran from the mucous membranes of certain microorganisms，e. g. Leuconostoc mesenteroides，classes 2 and 3 are the relevant ones for the preparation of drugs. Dextran itself，with a molecular weight of 50,000 ~ 100,000，is used as a blood plasma substitute. Among the primary metabolites the L-amino acids from mutants of Corynebacterium glutamicum and Brevibacterium flavum are especially interesting. From these organisms some 350，000 tones of monosodium L-glutamate (food additive)and some 70，000 tones of L-lysine(supplement for vegetable proteins)are produced. Further important primary metabolites are the purina nucleotides，organic acids，lactic acid，citric acid，and vitamins，for example vitamin B,2 from Propionibacterium shermanii.Among the secondary metabolites the antibiotics must be mentioned first. The following five groups represent a yearly worldwide value of US-$17 billion:penicillins ( Penicillium chrysogenum )，cephalosporins ( Cephalosporium acremonium )，tetracyclines ( Streptomyces aureofaciens )，erythromycins ( Streptomyces erythreus )，aminoglycosides (e. g. streptomycin from Streptomyces griseus).About 5000 antibiotics have already been isolated from microorganisms，but of these only somewhat fewer than 100 are in therapeutic use. It must be remembered，however，that many derivatives have been modified by partial synthesis for therapeutic use;some 50，000 agents have been semisynthetically obtained from户lactams alone in the last decade. Fermentations are carried out in stainless steel fermentors with volumes up to 400 m3. To avoid contamination of the microorganisms with phages etc. the whole process has to be performed under sterile conditions. Since the more important fermentations occur exclusively under aerobic conditions a good supply of oxygen or air(sterile)is needed. Carbon dioxide sources include carbohydrates，e. g. molasses，saccharides，and glucose. Additionally the microorganisms must be supplied in the growth medium with nitrogen-containing compounds such as ammonium sulfate，ammonia，or urea，as well as with inorganic phosphates. Furthermore，constant optimal pH and temperature are required. In the case of penicillin G，the fermentation is finished after 200 hours，and the cell mass is separated by filtration. The desired active agents are isolated from the filtrate by absorption or extraction processes. The cell mass，if not the desired product，can be further used as an animal feedstuff owing to its high protein content.By modern recombinant techniques microorganisms have been obtained which also allow production of peptides which were not encoded in the original genes. Modified E. coli bacteria make it thus possible to produce A- and B- chains of human insulin or proinsulin analogs. The disulfide bridges are formed selectively after isolation，and the final purification is effected by chromatographic procedures. In this way human insulin is obtained totally independently from any pancreatic material taken from animals.Other important peptides，hormones，and enzymes，such as human growth hormone (HGH)，neuroactive peptides，somatostatin，interferons，tissue plasminogen activator (TPA)，lymphokines，calcium regulators like calmodulin，protein vaccines，as well as monoclonal antibodies used as diagnostics，are synthesized in this way.The enzymes or enzymatic systems which are present in a single microorganism can be used for directed stereospecific and regiospecific chemical reactions. This principle is especially useful in steroid chemistry. Here we may refer only to the microbiological 11-a- hydro xylation of progesterone to 11-a-hydroxyprogesterone，a key product used in the synthesis of cortisone. Isolated enzymes are important today not only because of the technical importance of the enzymatic saccharification of starch，and the isomerization of glucose to fructose，They are also significant in the countless test procedures used in diagnosing illness，and in enzymatic analysis which is used in the monitoring of therapy.A number of enzymes are themselves used as active ingredients. Thus preparations containing proteases (e. g. chymotrypsin，pepsin，and trypsin)，amylases and lipases，mostly in combination with synthetic antacids，promote digestion. Streptokinase and urokinase are important in thrombolytics，and asparaginase is used as a cytostatic agent in the treatment of leukemia.Finally mention must be made of the important use of enzymes as `biocatalyst s’in chemical reactions where their stereospecificity and selectivity can be used. Known examples are the enzymatic cleavage of racemates of N-acetyl-D，L-amino acids to give L-amino acids，the production of 8-aminopenicillanic acid from benzylpenicillin by means of penicillinamidase and the aspartase-catalysed stereospecific addition of ammonia to fumaric acid in order to produce L-aspartic acid.In these applications the enzymes can be used in immobilized forms-somehow bound to carriers - and so used as heterogeneous catalysts. This is advantageous because they can then easily be separated from the reaction medium and recycled for further use.Another important process depending on the specific action of proteases is applied for the production of semisynthetic human insulin. This starts with pig insulin in which the alanine in the 30-position of the B-chain is replaced by a threonine tert-butyl ester by the selective action of trypsin. The insulin ester is separated，hydrolyzed to human insulin and finally purified by chromatographic procedures.Sources for enzymes include not only microorganisms but also vegetable and animal materials.In Table 1 it was already shown that over 75%of all pharmaceutical agents are obtained by total synthesis. Thereforeknowledge of the synthetic routes is useful. Understanding also makes it possible to recognize contamination .of the agents by intermediates and by- products. For the reason of effective quality control the registration authorities in many countries demand as essentials for registration a thorough documentation on the production process. Knowledge of drug syntheses provides the R&D chemist with valuable stimulation as well.There are neither preferred structural classes for all pharmaceutically active compounds nor preferred reaction types. This implies that practically the whole field of organic and in part also organometallic chemistry is covered. Nevertheless，a larger number of starting materials and intermediates are more frequently used，and so it is useful to know the possibilities for their preparation from primary chemicals. For this reason it is appropriate somewhere in this book to illustrate a tree of especially important intermediates. These latter intermediates are the key compounds used in synthetic processes leading to an enormous number of agents. For the most part chemicals are involved which are produced in large amounts. In a similar way this is also true for the intermediates based on the industrial aromatic compounds toluene，phenol and chlorobenzene. Further key compounds may be shown in a table which can be useful in tracing cross-relationships in syntheses.fIn addition to the actual starting materials and intermediates solvents are required both as a reaction medium and ,for purification via recrystallization. Frequently used solvents are methanol，ethanol，isopropanol，butanol，acetone，ethyl acetate，benzene，toluene and xylene. To a lesser extent diethyl ether，tetrahydrofuran，glycol ethers，dimethylformamide (DMF) and dimethyl sulphoxide (DMSO) are used in special reactions.Reagents used in larger amounts are not only acids (hydrochloric acid，sulfuric acid，nitric acid，acetic acid) but also inorganic and organic bases (sodium hydroxide，potassium hydroxide，potassium carbonate，sodium bicarbonate，ammonia，triethylamine，pyridine). Further auxiliary chemicals include active charcoal and catalysts. All of these supplementary chemicals (like the intermediates) can be a source of impurities in the final product.In 1969 the WHO published a treatise on `Safeguarding Quality in Drugs'.Appendix 2 is concerned with the `Proper Practice for Reparation and Safeguarding Quality in Drugs' (WHO Technical Report No. 418，1969，Appendix 2;No. 567，1975，Appendix 1A). This has in the meantime become known as `Good Manufacturing Practices' or GMP rules，and these should now be obeyed in drug production. They form the basis for mutual recognition of quality certificates relating to the production of pharmaceuticals and for inspections of the production. facilities.For a long time the US drug authority，the Food and Drug Administration (FDA)，has issued regulations for the preparation of drugs analogous to the WHO rules，and it applies these strictly. Exports of drugs to the USA，like those of finished products，require regular inspection of the production facilities by the FDA. 5It may merely be noted here that such careful control applies not only to the products，but also to the raw materials (control of starting Materials)，and also to the intermediates. Clearly. the technical and hygienic equipment of the production and the storage areas have to fulfill set conditions.Since only a few compounds，such as acetylsalicylic acid，paracetamol and vitamins，are prepared in large amounts，most of the actual production takes place in multi-purpose (multi-product) facilities. .Special care has to be taken to avoid cross-contamination by other products what can be effected by good cleansing of used apparatus. A careful description and definition of all stored intermediates and products is needed.Selected -from H. J. Roth and A. Kleemann, Pharmaceutical Chemistry, Vol. 1，Drug Synthesis,Ellis Horwood Limited，England, 1988.Unit 5 Drug Development (I)1. IntroductionDrug Development is a very complex process requiring a great deal ofcoordination and communication between a wide range of different functionalgroups. It is expensive，particularly in the later phases of clinical development，where studies involve hundreds of patients. It is currently estimated that thedevelopment of a new drug costs about$230 million(1987 dollars)and takessomewhere between 7 and 10 years from initiation of preclinical development tofirst marketing (excluding regulatory delays). Drug development is a high-riskbusiness;although the rate is increasing，only about ONE out of every TEN newchemical entities studied in human beings for the first time will ever become a product. As a drug candidate progresses through development the risks of failure decrease as ‘hurdles’are overco me along the way. Typical reasons for failure include unacceptable toxicity，lack of efficacy，or inability to provide advantages over competitive products(Fig. 1).Attrition Rate of New Chemical Entities(NCE's) entering development. On averageonly about I in 400^1000 compoundssynthesized enters development.Reasons for termination of development of NCE's(excluding anti-infectives)1:Lack of efficacy2: Pharmacokinetics3: Animal toxicity4: Miscellaneous5: Adverse effects in man6: Commercial reasonsFig. 1 Attrition rates and reasons for terminations2. Planning for developmentAssessment of whether a drug candidate is likely to provide competitive advantages highlights the need first to have in place a set of product `goals' or target product profile. Particular attention should be paid to the differentiation from competitors. This is becoming 55 more and more critical with the increasing emphasis on limited formularies，healthcare costs，and pharmacoeconomics (discussed later in the chapter).A target profile will define the indication(s) that a drug candidate will be developed for，along with goals such as once a day dosing，faster onset of action，better side effect profile than a major competitor. The target profile can be refined and revised as a drug candidate moves through development and new data on the drug candidate or competitors become available. The logical next steps are to define the development strategy，for example，which indications to develop first，which countries to aim to market the drug in and then to define the core clinical studies necessary to achieve regulatory approval and commercial success.This chapter will describe the main activities required for successful development of a new drug. All these activities，many of which are interdependent，need to be carefully planned and co-ordinate. Speed to market with collection of high quality data is critical for success. The path of activities which determine the time it will take to get to registration is called，in project management terms，the critical path. It is vital to plan and prepare before studies begin and to monitor and manage problems so as to ensure that the critical path remains on schedule. With increased economic pressures and competitive intensity it is important for companies to explore ways to shorten this critical path. Running activities in parallel，or overlapping studies which would usually run sequentially，often involves an increase in risk but the dividends in time-saving can make such strategies worthwhile.The critical path for development of a new drug generally runs through the initial synthesis of compound，subacute toxicology studies，and then the clinical program. A chart showing the critical path activities for a typical drug candidate is shown in Fig. 2.Chemistry chemical Synthesis Route selection Pilot plant,scale up and stability testing Manufacturing plant productionToxicology Acute&subacute toxicology Long term and repro-toxicologyClinical Phase I Phase ll Phase lll Analysis data and report Phase lV ReviewRegulatory Submission and updating of clinical trial application prepare submit AuthorityMAA/NDA Regulatory ApprovalPost marketing SurverillancePharmaceuticsDevelopment and stability testing Prepare labellingDrug metabolismand pharmacokinetics Animal ADME* Healthy humans Human patientsActivities likely to be on the critical path are shown in bold* Absorption , Distribution , Metabolism , ExcretionFig. 2 The major processes in new drug developmentThe following sections highlight the objectives and activities of drug development work.Activities within each technical discipline are described broadly in chronological order.At any one time，work in all these disciplines may be proceeding in parallel. The timing and outcome of much of the work has direct impact on work in other disciplines. The major phases of drug development are Preclinical ( studies required before the compound can be dosed in humans)，Phase I (clinical studies usually in healthy human volunteers ) Phase Ⅱ( initial efficacy and safety and dose finding studies in patients)，and Phase Ⅲ(studies in several hundred patients). There then follows assembly of a marketing application dossier for subsequent review by country regulatory authorities.3. Chemical developmentRapid development of a drug candidate is dependent on the availability of sufficient quantity of the compound. The purity of compound needs to reach certain standards in order for it to be used in safety (toxicology)，pharmaceutical，and clinical studies. Initially，chemists will work on a small to medium scale to investigate production of the compound by several different methods so as to identify the optimum route for synthesizing the compound. ‘Optimum’here may mean a combination of several factors，for example，most efficient，cheapest safe，or that producing minimal waste. Analysis of the final product as well as intermediates and impurities plays a key role in identifying the best method of synthesis. Development and validation of analytical methods are necessary to support process development and guarantee the purity of the drug substance.In some cases levels of impurities may be unacceptably high and either improved purification procedures will need to be developed or the synthetic process may require significant alterations. The main aim is to ensure that the composition of compound is understood and that ultimately the material that is prepared is as pure as possible.As a drug candidate progresses through development，larger and larger amounts of compound are required. The amount of material required for different tests will often depend on the actual potency and dosage form of the compound.A pilot plant can be regarded as a mini-manufacturing set-up. Before transferring to a pilot plant，extensive evaluation and testing of the chemical synthesis is undertaken to ensure that any changes and hazards are minimized. Procedures are optimized，particular attention being paid to developing environmentally acceptable ways of disposing of waste products. Commercial production of bulk drug substance for production of a drug，once approved and marketed，will likely take place on a larger scale or at a registered manufacturing plant.4. Formulation developmentThe dosage form of a drug is the form by which it is administered to the patient. There are a vast array of possible dosage forms ranging from transdermal patches to inhalers to intranasal medicines. The more common dosage forms include oral tablets or capsules，oral liquids，topical ointments or creams，and injectables. The dosage form or forms chosen for a particular drug candidate will be defined in the target profile.Sometimes a more simple dosage form，for example an oral solution，is chosen for early 57 clinical studies in human beings. This may save time and upfront costs at an early，high-risk stage of the drug development process. Later clinical studies would use the expected marketed dosage form.Whatever the dosage form，the combination of drug and other materials which constitute it must fulfil certain criteria. One of the most important is that of adequate stability. That means a predetermined potency level must remain after，for example，two or three years. The stability data generated on a dosage form will determine its shelf-life and recommended storage conditions. Early in development the shelf-life may be limited to several months. This will not be a problem provided it is sufficient to cover use of the drug over the duration of the clinical study or studies.5. PharmacologyBefore a drug candidate is given to man，its pharmacological effects on major systems are often investigated in a number of species. The body systems studied include cardiovascular，respiratory，and nervous systems;the effects on gross behavior can also be studied.Experiments are sometimes conducted to see whether the drug candidate interferes with the actions of other medicines which，because of their specific effects or because of their common use，are likely to be taken concurrently with the drug candidate. Any synergism or antagonism of drug effects should be investigated，and any necessary warning issuedto clinical investigators.(It may be judged necessary to investigate such effects further in clinical studies，and any potential or proven drug interactions are likely to be noted in the product labeling for the drug.)It may also be appropriate to identify a substance for possible use in the management of overdosage，particularly if the therapeutic margin of the drug candidate is small.6. Safety evaluationThe objective of animal toxicology testing，carried out prior to the administration of a drug to man，is to reject compounds of unacceptable toxicity and to identify potential target organs and timings for adverse effects of the drug. This means that in early human studies these organs and tissues can be monitored with particular attention. It is important to establish whether toxic effects are reversible or irreversible，whether they can be prevented and，if possible，the mechanism of the toxicological effects. It is also important to interrelate drug response to blood levels in humans and blood levels in various animal species.The toxicological studies required for the evaluation of a drug candidate in man will be relevant to its proposed clinical use in terms of route of administration and duration of treatment of the clinical studies. The size and frequency of the doses and the duration of the toxicology studies are major determinants of permissible tests in man. Countries，including UK，USA，Australia，and Nordic countries，have regulatory guidelines which relate the duration of treatment allowed in man to the length of toxicity studies required in two species. Points from the guidelines are referenced in the subsequent sections.58 Initially，the pharmacological effects of increasing doses of the test substances are established in acute toxicity studies in small numbers of animals，generally using two routes of administration (one being that used in man). Results provide a guide to the maximum tolerated doses in subsequent chronic. toxicity tests，aid selection of dose levels，and identify target organs.The main aim of the subsequent sub-acute toxicity tests is to determine whether or not the drug candidate is adequately tolerated after administration to animals for a prolonged period as a guide to possible adverse reactions in man. Two to four week (daily dosing) studies are required，using the same route of administration as in man，in two species (one non-rodent)prior to administration of the compound to man. Three dose levels are usually necessary:the low daily dose should be a low multiple of the expected therapeutic dose，and the highest dose should demonstrate some toxicity.A general guide for the evaluation of new chemical entities would be that toxicology studies of a minimum duration of14 days are required to support single-dose exposure of a new drug candidate in normal volunteers in Phase 1. Toxicology studies of 30 days duration are required to support clinical studies of 7 to 10 days duration. Clinical studies of greater than 7 to 10 days up to 30 days duration require the support of at least 90 days toxicology studies. These requirements illustrate the need to plan ahead in drug development. The duration and approximate timings for future clinical trials need to be considered well in advance in order to schedule and conduct the appropriate toxicology studies to support the clinical program and avoid any delays.Two types of safety test are used to detect the ability of the drug candidate to produce tumours in man. The first are short-term in vitro genotoxicity tests，for example bacterial tests. The second are long-term animal carcinogenicity studies which are conducted in mice and rats;their length of often 2 years covers a large part of the lifespan of the animal. Mice and rats are used because of their relatively short life span，small size，and ready availability. Also，knowledge，which has accumulated concerning spontaneous diseases and tumours②in particular strains of these species，helps greatly in the interpretation of‘results.Long-term toxicology and carcinogenicity studies are conducted in order to obtain approval to test and finally to market a product for chronic administration to man. These studies may need to start during the late preclinical/ early clinical phase in order to `support' the subsequent clinical program. Long-term toxicity studies will normally include toxicity studies of six and twelve months duration in two species (one non-rodent).Any toxicity previously detected may be investigated more closely，for example extra enzymes looked at in blood samples.Reproductive toxicology is that part of toxicology dealing with the effect of compounds on reproduction-fertility，foetal abnormalities，post-natal development. Prior to clinical studies in women of child-bearing age，regulatory authorities require teratology data from two species (normally rat and rabbit)as well as clinical data from male volunteers. No reproductive data are required prior to clinical studies in male subjects. The effects of 59 compounds on reproduction differ with the period of the reproductive cycle in which exposure takes place and studies are designed to look at thesephases. Teratology`'' studies are designed to detect foetal abnormalities，fertility studies to investigate the compounds' effect on reproductive performance，And peri- and post-natal studies to study the development of pups.Unit 6 Isolation of Caffeine from TeaIn this experiment，Caffeine will be isolated from tea leaves. The major problem of the isolation is that caffeine does not occur alone in tea leaves，but is accompanied by other natural substances from which it must be separated. The major component of tea leaves is cellulose，which is the major structural material of all plant cells. Cellulose is a polymer of glucose. Since cellulose is virtually insoluble in water，it presents no problems in the isolation procedure. Caffeine，on the other hand，is water soluble and is one of the major substances extracted into the solution called "tea.”Caffeine comprises as much as 5 percent by weight of the leaf material in tea plants. Tannins also dissolve in the hot water used to extract tea leaves. The term tannin does not refer to a single homogeneous compound，or even to substances which have similar chemical structure. It refers to a class of compounds which have certain properties in common. Tannins are phenolic compounds having molecular weights between 500 and 3000. They a re widely used to "tan”leather. They precipitate alkaloids'z and proteins from aqueous solutions. Tannins are usually divided into two classes: those which can be hydrolyzed and those which cannot. Tannins of the first type which are found in tea generally yield glucose and gallic acid when they are hydrolyzed. These tannins are esters of gallic acid and glucose. They represent structures in which some of the hydroxyl groups in glucose have been esterified by digalloyl groups. The non-hydrolyzable tannins found in tea are condensation polymers of catechin. These polymers are not uniform in structure，but catechin molecules are usually linked together at ring positions 4 and 8.When tannins are extracted into hot water，the hydrolyzable ones are partially hydrolyzed，meaning that free gallic acid is also found in tea. The tannins，by virtue of their phenolic groups，and gallic acid by virtue of its carboxyl groups，are both acidic. If calcium carbonate，a base，is added to tea water，the calcium salts of these acids are formed. Caffeine can be extracted from the basic tea solution with chloroform，but the calcium salts of gallic acid and the tannins are not chloroform soluble and remain behind in the aqueous solution.The brown color of a tea solution is due to flavonoid pigments and chlorophylls，as well as their respective oxidation products. Although chlorophylls are somewhat chloroform soluble，most of the other substances in tea are not. Thus，the chloroform extraction of the basic tea solution removes nearly pure caffeine. The chloroform is easily removed by distillation(by 61'C)to leave the crude caffeine. The caffeine may be purified by recrystallization or by sublimation.68Catechin Gallic AcidIn a second part of this experiment，Caffeine will be converted to a derivative. A derivative of a compound is a second compound，of known melting point，formed from the original compound by a simple chemical reaction. In trying to make a positive identification of an organic compound，it is often customary to convert it into a derivative. If the first compound，Caffeine in this case，and its derivative both have melting points which match those reported in the chemical literature (e.g.，a handbook)，it is assumed that there is no coincidence and that the identity of the first compound，Caffeine，has been definitely established.Caffeine is a base and will react with an acid to give a salt. Using salicylic acid，a derivative salt of Caffeine，Caffeine salicylate，will be made in order to establish the identity of the Caffeine isolated from tea leaves.Special Instructions Be careful when handling chloroform. It is a toxic solvent，and you should not breathe it excessively or spill it on yourself. When discarding spent tea leaves，do not put them in the sink because they will clog the drain. Dispose of them in a waste container.Procedure Place 25g of dry tea leaves，25g of calcium carbonate powder，and 250ml of water in a 500ml three neck round bottom flask equipped with a condenser for reflux. Stopper the unused openings in the flask and heat the mixture under reflux for about 20 minutes. Use a Bunsen burner to heat. While the solution is still hot，filter it by gravity through a fluted filter using a fast filter paper such as E&D No. 617 or S&S No. 595. You may need to change the filter paper if it clogs.Cool the filtrate (filtered liquid)to room temperature and，using a separatory funnel，extract it twice with 25ml portions of chloroform. Combine the two portions of chloroform in a 100ml round bottom flask，Assemble an apparatus for simple distillation and remove the chloroform by distillation. Use a steam bath to heat. The residue in the distillation flask contains the caffeine and is purified as described below (crystallization). Save the chloroform that was distilled. You。

尼龙的主要成分尼龙，作为一种重要的合成纤维材料，具有广泛的应用领域和出色的性能特点。

它的主要成分是聚酰胺（Polyamide），经由特定的聚合反应所形成。

在本文中，我将深入探讨尼龙的主要成分，包括聚酰胺的结构、特性以及其在尼龙中的应用。

1. 聚酰胺（Polyamide）的结构和特性：聚酰胺是由含有酰基和胺基的官能团组成的聚合物。

其结构中的酰基和胺基通过酰胺键（Amide bond）相连形成聚酰胺链。

聚酰胺的重复单元中含有酸基和胺基，可以通过不同的酸基和胺基组合形成不同类型的聚酰胺。

聚酰胺具有以下主要特性：- 强度高：聚酰胺拥有出色的强度和韧性，使其在纺织、工程塑料等领域得到广泛应用。

- 耐磨性好：聚酰胺具有较好的耐磨性能，使其在制造耐磨部件、纺织品等方面表现出色。

- 耐化学性强：聚酰胺对一些常见的化学品和溶剂有较好的抗腐蚀能力，使其在化工和医疗领域得到广泛应用。

- 热稳定性好：聚酰胺能够在高温环境下保持较好的稳定性，使其在高温工艺和高温环境中发挥重要作用。

2. 聚酰胺在尼龙中的应用：尼龙是聚酰胺类合成纤维的一种，通过合成聚酰胺链来制备。

尼龙具有许多优秀的性能和应用特点，拥有广泛的应用领域。

2.1 尼龙的纺织应用：尼龙纤维由聚酰胺链组成，具有出色的强度、耐磨性和耐腐蚀性，因此在纺织行业中得到广泛应用。

尼龙纤维可制成各种类型的面料，包括尼龙绸、尼龙绒等，用于制作服装、袜子、家居纺织品等。

尼龙纤维的特性使得纺织品具有良好的强度和柔软性，同时具备吸湿性和透湿性，使其舒适适应各种气候条件。

2.2 尼龙的工程塑料应用：尼龙作为一种工程塑料，被广泛应用于制造各种零件和组件。

其高强度、耐磨性和耐化学性使得尼龙在汽车、航空航天、机械制造等领域中得到广泛应用。

尼龙可以用于制造汽车发动机零部件、制动系统组件、齿轮、轴承等。

在航空航天领域，尼龙被用于制造飞机构件、航天器零件等。

尼龙的轻质和高强度使其成为替代金属材料的理想选择。

开启片剂完整性的窗户日本东芝公司，剑桥大学摘要：由日本东芝公司和剑桥大学合作成立的公司向《医药技术》解释了FDA支持的技术如何在不损坏片剂的情况下测定其完整性。

太赫脉冲成像的一个应用是检查肠溶制剂的完整性，以确保它们在到达肠溶之前不会溶解。

关键词：片剂完整性，太赫脉冲成像。

能够检测片剂的结构完整性和化学成分而无需将它们打碎的一种技术，已经通过了概念验证阶段，正在进行法规申请。

由英国私募Teraview公司研发并且以太赫光（介于无线电波和光波之间）为基础。

该成像技术为配方研发和质量控制中的湿溶出试验提供了一个更好的选择。

该技术还可以缩短新产品的研发时间，并且根据厂商的情况，随时间推移甚至可能发展成为一个用于制药生产线的实时片剂检测系统。

TPI技术通过发射太赫射线绘制出片剂和涂层厚度的三维差异图谱，在有结构或化学变化时太赫射线被反射回。

反射脉冲的时间延迟累加成该片剂的三维图像。

该系统使用太赫发射极，采用一个机器臂捡起片剂并且使其通过太赫光束，用一个扫描仪收集反射光并且建成三维图像(见图)。

技术研发太赫技术发源于二十世纪九十年代中期13本东芝公司位于英国的东芝欧洲研究中心，该中心与剑桥大学的物理学系有着密切的联系。

日本东芝公司当时正在研究新一代的半导体，研究的副产品是发现了这些半导体实际上是太赫光非常好的发射源和检测器。

二十世纪九十年代后期，日本东芝公司授权研究小组寻求该技术可能的应用，包括成像和化学传感光谱学，并与葛兰素史克和辉瑞以及其它公司建立了关系，以探讨其在制药业的应用。

虽然早期的结果表明该技术有前景，但日本东芝公司却不愿深入研究下去，原因是此应用与日本东芝公司在消费电子行业的任何业务兴趣都没有交叉。

这一决定的结果是研究中心的首席执行官DonArnone和剑桥桥大学物理学系的教授Michael Pepper先生于2001年成立了Teraview公司一作为研究中心的子公司。

TPI imaga 2000是第一个商品化太赫成像系统，该系统经优化用于成品片剂及其核心完整性和性能的无破坏检测。

P O S I T I O N P A P E RInternational Consensus on drug allergyP.Demoly1,N.F.Adkinson2,K.Brockow3,M.Castells4,A.M.Chiriac1,P.A.Greenberger5,D.A.Khan6, ng7,H.-S.Park8,W.Pichler9,M.Sanchez-Borges10,T.Shiohara11&B.Y.-H.Thong121D e partement de Pneumologie et Addictologie,H^o pital Arnaud de Villeneuve,University Hospital of Montpellier,France and SorbonneUniversit e s,Paris,France;2Division of Allergy and Clinical Immunology,The Johns Hopkins Asthma and Allergy Center,The Hopkins Bayview Medical Campus,Baltimore,MD,USA;3Department of Dermatology and Allergology Biederstein,Technische Universit€a t M€u nchen,Munich, Germany;4Division of Rheumatology,Allergy and Immunology,Department of Medicine,Brigham and Women’s Hospital,Boston,MA;5Division of Allergy-Immunology,Northwestern University Feinberg School of Medicine,Chicago,IL;6Division of Allergy&Immunology,University of Texas Southwestern Medical Center,Dallas,TX;7Department of Allergy/Immunology,Respiratory Institute,Cleveland Clinic Foundation, Cleveland,OH,USA;8Department of Allergy and Clinical Immunology,Ajou University School of Medicine,Suwon,Korea;9Division of Allergology,Department of Rheumatology and Allergology/Clinical Immunology,Inselspital,University of Bern,Bern,Switzerland;10Allergy and Clinical Immunology Department,Centro Medico Docente La Trinidad,Caracas,Venezuela;11Department of Dermatology,Kyorin University School of Medicine,Tokyo,Japan;12Department of Rheumatology,Allergy and Immunology,Tan Tock Seng Hospital,SingaporeTo cite this article:Demoly P,Adkinson NF,Brockow K,Castells M,Chiriac AM,Greenberger PA,Khan DA,Lang DM,Park H-S,Pichler W,Sanchez-Borges M, Shiohara T,Thong BY-H.International Consensus on drug allergy.Allergy2014;69:420–437.Keywordsdrug allergy work-up;drug hypersensitivity reaction;recommendation.CorrespondencePascal Demoly,D e partement de Pneumologie et Addictologie,H^o pital Arnaud de Villeneuve, University Hospital of Montpellier,France and Sorbonne Universit e s,UPMC Paris06,UMR-S1136,IPLESP,Equipe EPAR,75013, Paris,France.Tel.:0033467336107Fax:0033467042708E-mail:pascal.demoly@inserm.frDraft reviewed by:Apter AJ(USA);Asero R (Italy);Barbaud A(France);Bavbek S(Turkey); Bircher AJ(Switzerland);Bonadonna P(Italy); Bousquet PJ(France);Caubet JC(Switzerland); Celik G(Turkey);Cernadas JR(Portugal); Commins SP(USA);Descamps V(France);Drouet M(France);Ebo DG(Belgium);Garvey LH (Denmark);Gomes E(Portugal);Grendelmeier P (Switzerland);Terreehorst I(the Netherlands); Jensen-Jarolim E(Austria);Kanny G(France); Kano Y(Japan);Kidon MI(Israel);Laroche D (France);Macy E(USA);Mertes PM(France); Mirakian R(UK);Musette P(France);Naisbitt DJ (UK);Nasser SM(UK);Nicolas JF(France); Nizankowska-Mogilnicka E(Poland);Pagani M (Italy);Park BK(UK);Ponvert C(France);Romano A(Italy);Roujeau JC(France);Sanz ML(Spain); Schiavino D(Italy);Tanno LK(Brazil);Torres MJ (Spain);Valeyrie-Allanore L(France);Ventura M (Italy);Volcheck GW(USA);Volkenstein P (France);Vultaggio A(Italy);Wallace DV(USA). Accepted for publication18November2013DOI:10.1111/all.12350Edited by:Hans-Uwe Simon AbstractWhen drug reactions resembling allergy occur,they are called drug hypersensitiv-ity reactions(DHRs)before showing the evidence of either drug-specific antibod-ies or T cells.DHRs may be allergic or nonallergic in nature,with drug allergies being immunologically mediated DHRs.These reactions are typically unpredict-able.They can be life-threatening,may require or prolong hospitalization,and may necessitate changes in subsequent therapy.Both underdiagnosis(due to under-reporting)and overdiagnosis(due to an overuse of the term‘allergy’)are common.A definitive diagnosis of such reactions is required in order to institute adequate treatment options and proper preventive measures.Misclassification based solely on the DHR history without further testing may affect treatment options,result in adverse consequences,and lead to the use of more-expensive or less-effective drugs,in contrast to patients who had undergone a complete drug allergy workup.Several guidelines and/or consensus documents on general or spe-cific drug class-induced DHRs are available to support the medical decision pro-cess.The use of standardized systematic approaches for the diagnosis and management of DHRs carries the potential to improve outcomes and should thus be disseminated and implemented.Consequently,the International Collaboration in Asthma,Allergy and Immunology(iCAALL),formed by the European Acade-my of Allergy and Clinical Immunology(EAACI),the American Academy of Allergy,Asthma and Immunology(AAAAI),the American College of Allergy, Asthma and Immunology(ACAAI),and the World Allergy Organization (WAO),has decided to issue an International CONsensus(ICON)on drug allergy.The purpose of this document is to highlight the key messages that are common to many of the existing guidelines,while critically reviewing and commenting on any differences and deficiencies of evidence,thus providing a comprehensive reference document for the diagnosis and management of DHRs.Drugs can induce several different types of immunological reactions that,together with nonallergic drug hypersensitivity reactions(DHRs),comprise15%of all adverse drug reac-tions(1).Nonallergic DHRs resemble allergy,but without any proven immunological mechanism.Drug hypersensitivity reactions are of significant concern for clinicians and patients and are also a significant cause of the postmarketing withdrawal of drugs(2).Even though urti-carial and maculopapular eruptions are the most frequent manifestations,there are many other clinical presentations (1).DHRs affect more than7%of the general population and therefore represent an important public health problem (3).Both underdiagnosis(due to under-reporting(3,4))and overdiagnosis(due to an overuse of the term‘allergy’,for example,in the presence of symptoms due to co-existing fac-tors such as infections(3,5))are potential problems.Misclas-sification based on the DHR history alone may limit therapeutic options and can lead to the use of more-expen-sive and potentially less-effective drugs(6).Moreover,one drug allergy may lead to the misconception that the patient is allergic to all drugs.Few guidelines and/or consensus documents are available to support medical decision making on all aspects of DHR.These documents vary in scope and methodology:They are national (6–10),regional,or international(11–22);concern one specific drug class(7,8,14–16,18,20,21,23);focus specifically on evaluation tools/management(11–13,17,19,23);or are more general(6,8,24,25).Although there is no doubt that the use of common systematic approaches for the diagnosis and man-agement of DHRs can considerably improve outcomes,world-wide dissemination and implementation remain major challenges.For these reasons,the International Collaboration in Asthma,Allergy and Immunology(iCAALL)(26),recently formed by the European Academy of Allergy and Clinical Immunology(EAACI),the American Academy of Allergy, Asthma and Immunology(AAAAI),the American College of Allergy,Asthma and Immunology(ACAAI),and the World Allergy Organization(WAO),has decided to proceed with the compilation of an International CONsensus(ICON)on drug allergy.The purpose of this document is to highlight the key messages that are common to the existing guidelines,while crit-ically reviewing and commenting on any differences,thus pro-viding a comprehensive reference to be disseminated more widely.As for the ICON on pediatric asthma(27),unmet needs,research,and guideline update recommendations are generated.MethodologyA working committee was formed and approved by the cur-rent board of iCAALL and the participating organizations. The criteria used for the formation of the committee were as follows:regional representation,relevance to thefield,and previous participation in drug allergy guidelines.The mem-bers of the committee proposed relevant documents for appraisal.These included(i)the AAAAI/ACAAI/Joint Council of Allergy,Asthma and Immunology drug allergy updated practice parameters(6,7),(ii)the WAO drug allergy initiatives(24,25),(iii)the British Society of Allergy and Clinical Immunology(BSACI)guidelines(8,9),and(iv)the many task force reports and consensus documents of the EAACI Drug Allergy Interest Group(DAIG)as well as its core group,the European Network of Drug Allergy(ENDA) (11–21,23).Each member was responsible for the prepara-tion of text and relevant tables comparing the included docu-ments in a specific domain.A draft was subsequently compiled and circulated(in September2012)among the authors for comments and corrections.The revised document was then sent(in April2013)to an independent reviewing committee,selected on the basis of their publications over the past5years in top peer-reviewed journals asfirst/last authors.Their comments were taken into account in thefinal draft,which was then approved by the governing boards of the participating organizations.Recommendations were extrapolated from the reference documents and presented using levels of Evidence A–D(28)(Table1).Definition and classifications of drug hypersensitivity reactionsDefinitionDrug hypersensitivity reactions(DHRs)are the adverse effects of pharmaceutical formulations(including active drugs and excipients)that clinically resemble allergy(29) (Box1).DHRs belong to type B adverse drug reactions, which are defined by the World Health Organization as the dose-independent,unpredictable,noxious,and unintended response to a drug taken at a dose normally used in humans(30,31).A-type reactions,including overdoses and pharmacological reactions,are dose dependent and predict-able.However,some dose dependence has been shown repeatedly in DHRs(e.g.,for nonsteroidal anti-inflamma-tory drugs(NSAIDs),antiepileptic drugs)and some areAbbreviationsAAAAI,American Academy of Allergy,Asthma and Immunology;ACAAI,American College of Allergy,Asthma and Immunology;AGEP,acute generalized exanthematous pustulosis;AIDS,acquired immunodeficiency syndrome;BSACI,British Society of Allergy and Clinical Immunology; CD,cluster of differentiation;DAIG,Drug Allergy Interest Group;DHR(s),drug hypersensitivity reaction(s);DPT(s),drug provocation test(s); EAACI,European Academy of Allergy and Clinical Immunology;EBV,Epstein–Barr virus;Fc e RI,high-affinity IgE receptor;FDE,fixed drug eruption;HHV,human herpes virus;HIV,human immunodeficiency virus;HLA,human leukocyte antigen;HSS/DRESS/DiHS,hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms/drug-induced hypersensitivity syndrome;iCAALL,International Collaboration in Asthma,Allergy and Immunology;ICON,International CONsensus;IgE,immunoglobulin E;MCH,major histocompatibility complex;MDH, multiple drug hypersensitivity;NMBA,neuromuscular-blocking agents;NPV,negative predictive value;NSAID(s),nonsteroidal anti-inflammatory drug(s);RCM,radiocontrast media;SDRIFE,symmetrical drug-related intertriginous andflexural exanthema;SJS,Stevens–Johnson syndrome;TEN,toxic epidermal necrolysis;TNF-a,tumor necrosis factor alpha;WAO,World Allergy Organization.Demoly et al.ICON on drug allergypredictable due to the disease state(e.g.,human immunode-ficiency virus(HIV)infection/acquired immunodeficiency syndrome(AIDS),Epstein–Barr virus(EBV)infection)or a similar previous reaction to the same drug or drug class.Only when a definite immunological mechanism(either drug-specific antibody or T cell)is demonstrated,these reac-tions should be classified as drug allergy.For general communication,when an allergic drug reaction is suspected,Table1Recommendations for DHR diagnosis and managementNo.Statement Levels ofevidenceGrade ofrecommendation ReferencesR1Lifelong avoidance of the drug and cross-reactive drugsis recommended when drug-induced anaphylaxis has occurred4D(6,102) R2The specific allergy work-up should be carried out4–6weeksafter complete resolution of all clinical symptoms and signs of asuspected DHR4D(12,13)R3Sensitivity and predictive values of skin tests vary among drug classes:from‘good’for immediate DHRs to b-lactam antibiotics,musclerelaxants,platin salts and heparins,to moderate to low for mostother drugs2++B(22)R4Skin testing is helpful for diagnosis of immediate DHRsto iodinated RCM2+C(16,22)R5A DPT is the gold standard for the identification of the drugeliciting a DHR2+C(6,8,13)R6For DPT,the oral route is preferred whenever possible3D(6,8,13) R7Contraindications must be observed before performing DPT,and immediate treatment available allowing complete andrapid recovery4D(6,8,13)R8Patients who suffered severe immediate reactions to b-lactamsand who displayed negative results at thefirst evaluation,which included a DPT,can be considered for retesting2–4weeksafter initial evaluation2ÀD(6,18)R9For currently available biological methods to diagnose drug allergy,a negative test does not exclude the imputability of thedrug,whilst a positive result shows sensitivity to the drugbut does not reliably confirm causality 2+forß-lactams2Àto3forothersC(6,8)R10HLA-B*5701screening reduces the risk of DHR to abacavir and is mandatory before starting treatment 1++A(47)Not rated inpreviousconsensuses(6–23)R11An indicative,regularly updated list of drugs to avoid and thelist of possible alternatives should be given to patientswith a DHR4D(8)R12The search for safe alternatives may require DPTs in a hospitalsetting when the alternatives belong to the same drug class2+C(6,8,13)R13Specific questioning for a history of drug allergy by every clinicianprior to issuing a prescription is essential from both a medicaland a medico-legal view-point4D(6,8,20)R14Preventive measures by pre-medication(e.g.slow injection andpre-treatment with glucocorticosteroids and H1-antihistamines)are useful mainly for non-allergic DHRs,but corticosteroids andH1-antihistamines may not reliably prevent IgE-dependentanaphylaxis2+C(6,8,102)R15In the absence of generally accepted protocols for drug desensitizationin cases of immediate DHRs,reference to successfully appliedexisting protocols is recommended2+C(6,19)R16Desensitization to aspirin as a therapeutic intervention may beconsidered in selected asthmatic patients with aspirin exacerbatedrespiratory disease or nasal polyps2ÀD(6,19)DHR(s),drug hypersensitivity reaction(s);RCM,radiocontrast media;DPT(s),drug provocation test(s);HLA,human leukocyte antigen.ICON on drug allergy Demoly et al.DHR is the preferred term,because true drug allergy and nonallergic DHR (29)may be difficult to differentiate based on the clinical presentation alone,especially in cases of acute severe DHR.ClassificationsThe classification of DHRs is challenging because,for many drugs and clinical presentations,the underlying mechanism is poorly understood (Box 2).A generally accepted classifica-tion should facilitate the comparison of studies and help to enhance and validate diagnostic techniques.Clinically,DHRs are commonly classified as immediate or nonimmediate/delayed depending on their onset during treatment (18).Immediate DHRs are possibly induced by an IgE-mediated mechanism and occur within 1–6h after the last drug administration (32)(Fig.1).Typically,they occur within the first hour following the first administration of a new course of treatment.They usually manifest as isolated symptoms such as urticaria,angioedema,conjunctivitis,rhinitis,bronchospasm,gastrointestinal symptoms (nausea,vomiting,diarrhea,abdominal pain),or as anaphylaxis oranaphylactic shock.In certain guidelines,when DHR symp-toms are systemic,non-IgE-dependent,and mimicking ana-phylaxis,they are designated as ‘anaphylactoid’reactions (6).This is no longer the case in EAACI and WAO (29)guidelines,where the term ‘nonallergic DHRs’is preferred.Nonimmediate DHRs may occur any time as from 1h after the initial drug administration.They commonly occur after many days of treatment and are often associated with a delayed T-cell-dependent type of allergic mechanism.Macu-lopapular exanthemas and delayed urticaria are the most common clinical presentations of nonimmediate DHRs.Although artificial,this classification is very important in clinical practice for workup planning.In any case,a precise description of the morphology and chronology of the reac-tion is mandatory.But there are still limitations,because other factors such as the route of administration,the role of drug metabolites,and the presence of co-factors or co-prescribed drugs may accelerate or slow down the onset or progression of a reaction (32)(Fig.1).Mechanistically,drugs are capable of inducing all of the types of immunological reactions described by Gell and Coo-mbs (33),but the most common are IgE-and T-cell-mediated reactions (Table 2).Certain drugs,such as antiepileptic drugs and allopurinol,cause mainly T-cell-mediated reactions,while others,such as neuromuscular-blocking agents (NMBA),provoke mainly IgE-mediated reactions.Some of the others (e.g .,b -lactams)may lead to both types of reaction.Pathogenesis and pathophysiologyImmune/allergic and nonimmune/nonallergic DHRsDrug allergies are adverse reactions whereby antibodies and/or activated T cells are directed against the drugs oragainstDemoly et al.ICON on drug allergyone of its metabolites.Numerous reactions with symptoms suggestive of allergy are often erroneously considered to be real drug allergies.The suggested pathomechanisms of these reactions include the following:(i)nonspecific mast cell or basophil histamine release(e.g.,opiates,radiocontrast media, and vancomycin),(ii)bradykinin accumulation(angiotensin-converting enzyme inhibitors),(iii)complement activation (e.g.,protamine),(iv)possibly an alteration in arachidonate metabolism(e.g.,aspirin and nonsteroidal anti-inflammatory drugs),and(v)the pharmacological action of certain sub-stances inducing bronchospasm(e.g.,b-blockers,sulfur diox-ide[S02]released by pharmaceutical formulations containing sulfites).Immediate allergic DHRsImmediate allergic DHRs develop as a result of IgE produc-tion by antigen-specific B lymphocytes after sensitization. IgE antibodies bind to the high-affinity Fc RI receptors on the surface of mast cells and basophils,creating a multiva-lent binding site for the drug antigen(34).Following subsequent drug exposure,the antigen–presumably a hapten–protein complex–cross-links bound IgE,stimulating the release of preformed mediators(e.g.,histamine,tryptase, some cytokines such as TNF-a)and the production of new mediators(e.g.,leukotrienes,prostaglandins,kinins,other cytokines).The preformed mediators stimulate a response within minutes,whereas the cytokine inflammatory compo-nent develops after several hours,the time required for pro-tein synthesis and the recruitment of immune cells.b-Lactam-mediated anaphylaxis is the best defined immediate allergic DHR(18).Nonimmediate/delayed allergic DHRsMost nonimmediate/delayed allergic DHRs are mediated through the actions of T lymphocytes(34).The skin is the most commonly targeted organ by drug-responsive T cells, but any organ can be involved.Diclofenac,for example,as well as several other carboxylic acid nonsteroidal anti-inflam-matory drugs,can cause immune-mediated liver injury,which may be explained by hepatic metabolism and selective modifi-cation of hepatic proteins(35).It is important to note that the same drug might produce different clinical symptoms and signs in different individuals,despite the drug being adminis-tered at the same dose via the same route.We are lacking data regarding specific drug processing,but,based on peptide immune recognition,the following scenario is possible.To stimulate naive T cells,dendritic cellsfirst process the drug antigen.The antigen is then internalized and transported to the regional lymph nodes.To develop an effective immune response,the innate immune system needs to be activated, providing important maturation signals,often referred to as ‘danger signals’(36)which include direct drug or disease-related stress.On arrival at the lymph nodes,the antigen is presented to naive T cells.Alternatively,some drug antigens might directly stimulate pathogen-specific T cells,thus avoid-ing the requirement for dendritic cell priming of T cells.How-ever,for some authors,this hypothesis is difficult to reconcile with the time between initial drug exposure and the develop-ment of clinical signs(34).Antigen-specific T cells migrate to target organs and,once re-exposed to the antigen,they are activated to secrete cytokines that regulate the response and cytotoxins(e.g.,perforin,granzymes,and granulysins)that produce tissue damage.Table2Classification of drug allergies(adapted from(33))Type Type of immuneresponse Pathophysiology Clinical symptoms Typical chronology of the reactionI IgE Mast cell and basophildegranulation Anaphylactic shockAngioedemaUrticariaBronchospasmWithin1to6h after the last intake of the drugII IgG and complement IgG andcomplement-dependentcytotoxicityCytopenia5–15days after the start of the eliciting drugIII IgM or IgG andcomplement or FcR Deposition of immunecomplexesSerum sicknessUrticariaVasculitis7–8days for serum sickness/urticaria7–21days after the start of the eliciting drugfor vasculitisIVa Th1(IFN-c)Monocytic inflammation Eczema1–21days after the start of the eliciting drugIVb Th2(IL-4and IL-5)Eosinophilic inflammation Maculopapularexanthema,DRESS 1to several days after the start of the eliciting drug for MPE2–6weeks after the start of the eliciting drug for DRESSIVc Cytotoxic T cells(perforin,granzyme B,FasL)Keratinocyte deathmediated by CD4orCD8Maculopapular exanthema,SJS/TEN,pustularexanthema1–2days after the start of the eliciting drug forfixed drug eruption4–28days after the start of the eliciting drugfor SJS/TENIVd T cells(IL-8/CXCL8)Neutrophilic inflammation Acute generalizedexanthematouspustulosis Typically1–2days after the start of the eliciting drug(but could be longer)ICON on drug allergy Demoly et al.Chemical basis of drug allergiesAccording to the hapten hypothesis,in order to stimulate a reaction,a drug should act as a hapten and bind irreversibly to proteins(34),generating antigens.This theory is relevant for chemical compounds,but not for proteic or carbohydrate compounds of drugs such as insulin,enzymes,monoclonal antibodies,and recombinant proteins.This is also especially relevant for oral drugs that preferentially bind to proteins such as albumin in gastric stomachfluid(37).However,in most cases,the gastric peptic function digests and inactivates the hapten–protein complex.Several drug modifications of the same protein are possible,generating a multivalent anti-gen for eliciting IgE-mediated immediate DHRs.For the elic-itation of delayed-type T-cell-mediated reactions,the role of the carrier protein and/or the hapten has not always been fully defined.Furthermore,it is not known as to whether there is a threshold level of modification that needs to be sur-mounted to stimulate a T-cell response.The majority of drugs,however,are not directly protein reactive(33),and in such cases,hapten formation is thought to occur as a conse-quence of metabolic activation(e.g.,sulfonamides)(the pro-hapten hypothesis).By generating a reactive metabolite,it is also feasible that activation of the innate immune system occurs,which is a prerequisite for a classical immune response.An alternative hypothesis(the pharmacological interaction with immune receptor(p-i)concept)has evolved from analy-sis of the response of T-cell clones to drug stimulation,sug-gesting that drugs,although smaller than traditional antigens,might also interact directly with immunological receptors through a reversible interaction with the immune receptors(33).According to this hypothesis,a drug can directly bind and activate T cells(providing MHC binding as well)or bind to HLA molecules,which then activate T cells indirectly,by altering the MHC–peptide groove.This latter concept was recently further extended by showing that some drugs,when they bind to HLA molecules,promote an exchange of embedded peptides(38).However,the functional consequence of this peptide exchange is still unclear.Abaca-vir binds at the F pocket antigen-binding site of HLA-B*5701,selecting an array of novel self-peptides that induce the activation of CD8-positive T cells,inducing a severe DHR similar to graft-vs-host disease without eosinophilia (38).This recently uncovered mechanism of DHRs may be applicable to other small molecules with HLA allotype preferences.Pharmaco-and immunogenetic basis of drug allergiesDrug hypersensitivity reactions involve both immune-and nonimmune-mediated mechanisms,with strong genetic interplay in some severe nonimmediate/delayed allergic DHRs.Indeed,a strong association between carbamaze-pine-induced Stevens–Johnson syndrome/toxic epidermal necrolysis(SJS/TEN)has been described for HLA-B*1502 in a Han Chinese population(39)and subsequently in Indian(40)and Thai(41),but not in European and Japa-nese patients(42–45).The association seems to be pheno-type specific(SJS,but not hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms/drug-induced hypersensitivity syndrome(HSS/DRESS/DiHS)) (46).In contrast,HLA-A*3101has been shown to be asso-ciated,in northern Europeans,with a spectrum of carba-mazepine-induced reactions including maculopapular exanthemas,DRESS/DIHS,and SJS/TEN(42).For the drug abacavir,an association between HLA-B*5701expres-sion and severe DHRs in Caucasians has been shown(47). The incidence of this allele in abacavir-hypersensitive patients is high(94.4%)(48)in the Australian cohort,but lower(22.2%)in other studies(49),although still signifi-cantly higher than in the average population prevalence. Other genetic variants have been associated with DHRs (50)(Table3).In immediate DHRs,some cytokine gene polymorphisms have been weakly associated with b-lactam-induced anaphylaxis(51,52).Role of viruses in the pathogenesis of DHRsViral infections can lead to skin eruptions and mimic DHRs if a drug(mostly an antibiotic)is taken at the same time (53).Although they are the leading cause of skin eruptions, viral infections can also interact with drugs,leading to mild eruptions in the case of the‘ampicillin rash’linked to the EBV infection(54)and severe reaction during DRESS(55). Thefirst virus shown to be re-activated in DRESS patients was the human herpesvirus(HHV)-6(56),but all herpesvi-ruses can be involved(55).Strikingly,it was shown that HHV-6replication can be induced in vitro by amoxicillin (57).Clinical presentationsAcute and delayed manifestations of DHRsImmediate DHRs usually present in the form of isolated urti-caria,angioedema,rhinitis,conjunctivitis,bronchospasm, gastrointestinal symptoms(nausea,vomiting,diarrhea),or anaphylaxis,which can lead to cardiovascular collapse(ana-phylactic shock)(58).Nonimmediate DHRs often affect the skin with variable cutaneous symptoms(59–61)such as late-occurring or delayed urticaria,maculopapular eruptions,fixed drug eruptions(FDE),vasculitis,blistering diseases (such as TEN,SJS,and generalized bullousfixed drug erup-tions),HSS,acute generalized exanthematous pustulosis (AGEP),and symmetrical drug-related intertriginous and flexural exanthemas(SDRIFE).Internal organs can be affected either alone or with cutaneous symptoms(HSS/ DRESS/DiHS,vasculitis,SJS/TEN)and include hepatitis, renal failure,pneumonitis,anemia,neutropenia,and throm-bocytopenia.Danger/severity signs of DHRsThe approach to the patient with a presumed DHR in the acute phase involves the following steps:(i)a complete his-tory of the drugs taken(types,doses,duration),(ii)a detailed description of the symptoms and signs(types, onset,localization,and evolution),with(iii)a complete examination of the skin and the mucous membranes (including the mouth,eyes,and genitals),and(iv)theDemoly et al.ICON on drug allergy。

一、专业单词absorptiometric analysis 吸光分析acetic acid 醋酸acetic acid glacial 冰醋酸acetic aldehyde 乙醛acetic anhydride 醋酐acetone 丙酮acetylene 乙炔acetylsalicylic acid 乙酰水杨酸acid of lemon 柠檬酸acridine 吖啶adamantane 金刚烷addition polymer 加聚物addition reaction 加成反应barite 重晶石barium 钡benzene hexachloride 六六六bromoform 溴仿burnt lime 生石灰butyraldehyde 丁醛calcium chloride 氯化钙calcium chloride tube 氯化钙管calcium chromate 铬酸钙calcium cyanamide 氰氨化钙calcium cyanide 氰化钙calcium fluoride 氟化钙calcium hydride 氢化钙calcium hydrosulfide 氢硫化钙dimerization 二聚酌dimethyl ether 二甲醚dimethyl phthalate 酞酸二甲酯dimethyl sebacate 癸二酸二甲酯dimethyl sulfate 硫酸二甲酯dimethyl sulfoxide 二甲亚砜dimethyl terephthalate 对酞酸二甲酯dimethylacetal 二甲基缩醛dimethylacetamide 二甲基乙酰胺dimethylamine 二甲胺dimethylaniline 二甲基苯胺dimethylarsine 二甲胂dimethylbenzene 二甲苯electron configuration 电子构型electron density 电子密度electron diffraction 电子衍射electron donor 电子供体electron emission 电子发射electron exchange 电子交换electron exchange resin 电子交换尸electron gas 电子气electron lattice interaction 电子点阵相互酌electron microscope 电子显微镜electron orbit 电子轨道free convection 自然对流free electron model 自由电子模型free energy 自由能free energy at constant pressure 定压自由能free energy of activation 活化自由能free expansion 自由膨胀free heat convection 自然对粱热free moisture 游离水分free path 自由程free radical 自由基free radical initiation 游离基开始反应free radical reaction 游离基反应gelometry 凝胶强度测定法gelose 琼脂gelsemine 钩吻碱甲gelseminic acid 钩吻酸gene 基因gene cloning 基因无性繁殖general chemistry 普通化学general formula 通式general theory of relativity 广义相对论generalized momentum 广义动量generating function 母函数generator gas 发生炉煤气geneva nomenclature 日内瓦命名法genom 基因组hydraulic modulus 水硬系数hydraulic press 水压机hydraulic radius 水力半径hydraulic separation 水力离析hydraulic test 水力试验hydraulicity 水凝性hydrazine 肼hydrazine sulfate 硫酸肼hydrazinium 肼hydrazo compound 肼基化合物hydrazobenzene 肼撑苯hydrazoic acid 叠氮酸hydrazone 腙isoamyl acetate 醋酸异戊酯isoamyl alcohol 异戊醇isoamyl benzoate 苯甲酸异戊酯isoamyl bromide 异戊基溴isoamyl butyrate 丁异戊酯isoamyl chloride 异戊基氯isoamyl ether 异戊醚isoamyl nitrite 亚硝酸异戊酯isoamyl propionate 丙酸异戊酸jet fuel 喷气发动机燃料jet pump 喷射泵jewel 宝石jig sieve 振动筛joule 焦耳joule effect 焦耳效应joule thomson effect 焦耳汤姆森效应joule's law 焦耳定律juglone 胡桃酮julian tube 凯撒管junker's calorimeter 容克量热计jute 黄麻karyoplasm 核质kata thermometer 卡他温度计kauri butanol value 贝壳杉脂丁醇值kauri gum 栲里松脂kauri resin 栲里松脂keene's cement 金纳水泥keesom relationship 基朔关系kelp 海草灰kelvin's temperature 开氏温度keratin 角蛋白keratin plastics 角质塑料kermes 胭脂虫粉kermesite 红锑矿kerogen 油母质lime sulfur mixture 石硫合剂lime water 石灰水limestone 石灰石liming 用石灰处理limit dextrin 有限糊精limit of error 误差极限limit of identification 证实限度limit of inflammability 可燃限度limiting concentration 极限浓度limiting current 极限电流limiting current density 极限电淋度limiting value 极限值limonene 二戊烯mannitol 甘露糖醇mannitol hexanitrate 六硝酸甘露醇mannonic acid 甘露糖酸mannose 甘露糖manocryometer 融解压力计manometer 压力计manostat 恒压器manufacture 制造manufacture of common salt 食盐制造法manufactured gas 人造煤气manufacturing cost 造价manufacturing in series 成批生产manufacturing method 制造法manufacturing process 制造法nodal plane 节平面nodal point 节点nomenclature 命名法nominal horsepower 标称马力nomogram 列线图解nomograph 列线图解nomography 列线图解法non adiabatic 非绝热的non adiabatic rectification 非绝热精馏non diffusible ion 固定离子non inflammable 耐火的non newtonian flow 非牛顿怜non return valve 逆止阀octyne 辛炔ocular 目镜ocular dichroscope 接眼二色镜ocular examination 目视检查法ocular micrometer 目镜测微计odd even nucleus 奇偶核odor 气味odorant 着嗅剂odorimeter 气味计odorimetry 气味测定法odoriphore 生臭团oenometer 酒度计permselectivity 选择渗透性permutation 置换permutite 人造沸石perovskite 钙钛矿peroxidase 过氧物酶peroxide 过氧化peroxide effect 过氧化物效应peroxide index 过氧化值peroxide number 过氧化值peroxo acid 过氧基酸peroxy acid 过酸peroxydisulfuric acid 过硫酸perpetual motion 永久运动perphenazine 佩吩嗪quantity of heat 热量quantity of state 状态量quantity production 大量生产quantization 量子化quantometer 光量计quantum 量子quantum chemistry 量子化学quantum condition 量子条件quantum efficiency 量子效率quantum hypothesis 量子假说quantum jump 量子跃迁quantum leakage 量子漏泄quantum liquid 量子液体quantum mechanics 量子力学quantum number 量子数rubber insulation 橡胶绝缘rubber isomer 橡胶异构体rubber latex 胶乳rubber like elasticity 似橡胶弹性rubber lining 橡皮衬里rubber resin 橡胶尸rubber solvent 橡胶溶剂rubber sponge 海绵橡胶rubber stopper 橡皮塞rubber substitute 油膏rubber thread 橡胶线rubber tube 橡皮管rubbing 磨损safety engineering 安全工程safety explosive 安全炸药safety factor 安全率safety film 安全软片safety fuel 安全燃料safety glass 安全玻璃safety lamp 安全灯safety match 安全火柴safety technique 安全工程safety valve 安全阀safflower oil 红花油saffron 擦粉safranal 藏花醛safranine 藏红safrole 黄樟素theory of valence 原子价理论thermal absorption 热吸收thermal activation 热活化thermal analysis 热分析thermal black 热炭黑thermal conductivity 导热系数thermal cracking 热分解thermal decomposition 热分解thermal diffusion 热扩散thermal diffusivity 热扩散系数thermal dissociation 热力离解thermal efficiency 热效率thermal equilibrium 热平衡thermal equivalent 热当量unsaturated hydrocarbon 不饱烃unsaturated solution 不饱和溶液unsaturation 不饱和unshared electron pair 未共享电子对unstable compound 不稳定化合物unstable equilibrium 不稳定平衡unsteady state 非稳定态untreated oil 未处理油料unusual valency 异常原子价unvulcanized rubber 未硫化橡胶vacuum evaporation 真空蒸发vacuum evaporation coating 真空镀膜vacuum evaporator 真空蒸发器vacuum filter 真空过滤器vacuum filtration 真空过滤vacuum flask 真空瓶vacuum forming 真空成型vacuum gage 真空计vacuum plating 真空镀膜water meter 水量计water of crystallization 结晶水water of hydration 水合水water paint 水性漆water permeability 渗水性water pipe 水管water purification 水的净化water purifier 净水器water purifying plant 净水设备water repellent 防水剂water resistance 抗水性water seal 水封xanthopterin 黄蝶呤xanthotoxin 黄原毒xanthurenic acid 黄尿酸xanthydrol 口山吨氢醇xenocryst 捕获晶xenon 氙xenon lamp 氙灯xerogel 干凝胶xylan 木聚糖xylene 二甲苯xylenol 二甲苯酚xylenol blue 二甲酚蓝xylenol orange 二甲酚橙xylenol resin 二甲苯酚尸yttrium bromide 溴化钇yttrium carbonate 碳酸钇yttrium chloride 氯化钇yttrium fluoride 氟化钇yttrium hydroxide 氢氧化钇yttrium iodide 碘化钇yttrium nitrate 硝酸钇yttrium oxide 氧化钇yttrium phosphate 磷酸钇yttrium sulfate 硫酸钇yttrium sulfide 硫化钇zeotrope 非共沸混合物zero adjustment 零点蝶zero group 零族zero method 零位法zero order reaction 零级反应zero point energy 零点能zero position 零位zero potential 零电势zerogel 零凝胶zeta potential 界面动电势ziegler catalyst 齐格勒催化剂zinc 锌二、专业文献(1) Nano-materials in the production of chemicalNano-materials in the structure, photoelectric and chemical nature of the attractive features, from physicists, materials scientists and chemists great interest. The early 1980s the concept of a nano-materials, the world of great concern to such material. It is the unique physical and chemical properties, so that people may be aware of it to the development of physics, chemistry, materials, biology, medicine and other disciplines bring new opportunities for research. Nano-materials application prospects are bright. In recent years, in the field of chemical production has also been a certain amount of applications, and demonstrated its unique charm.1. In the application of catalystsIn many chemical catalyst in the field of play a decisive role, it can be controlled response time and improve the efficiency of reaction and reaction speed. Most of the traditional catalyst not only by low efficiency, and its preparation is to use their experience, not only caused the tremendous waste of raw materials production, to improve economic efficiency, but also caused pollution to the environment. Nanoparticles surface active sites, as the catalyst for it to provide the necessary conditions. Nanoparticles in a catalyst, can greatly improve the efficiency of reaction, the reaction speed control, and even the original can not be the reaction can be carried out. Nanoparticles catalyst for the reaction than the normal speed of the catalyst 10 to 15 times.Nanoparticles Application more as a catalyst for the semiconductor photocatalyst, especially in the areas of organic matter. Dispersed in the solution of each of a semiconductor particles, similar to a short-circuit as a micro-battery, with energy than the bandgap semiconductor-rays scattered in the semiconductor, semiconductor nanoparticles absorbed light from electronic - hole right. In the electric field, electronics and hole separation, were moved to the surface of particles different locations, and similar components in the solution by oxidation and reduction reactions.Photocatalytic reaction to the reaction of many types, such as alcohol and hydrocarbon oxidation, and oxidation-reduction of inorganic ions, organic catalytic hydrogenation and dehydrogenation of amino acid synthesis, nitrogen fixation reaction, water purification treatment, water-gas shift, and so on, some of which are difficult to heterogeneous catalysis realize. Heterogeneous Photocatalysis semiconductor catalystcan effectively degrade organic pollutants in water. Nano TiO2, for example, both high photocatalytic activity, but also Acid and Basic Resistance, light stable, non-toxic and inexpensive easy to get, was the catalyst light-load the best choice. The article has reported that the silica gel used for the substrate, the system had a higher catalytic activity TiO/SiO2-Supported Catalysts. Ni Cu or Zn compound of a nano-particles, some of organic compounds on the hydrogenation reaction is an excellent catalyst, can be a substitute for expensive platinum catalyst or button. Nano-platinum and ethylene oxide catalysts enable the reaction temperature from room temperature to 600 ℃. Nanoparticles used as catalyst improve the efficiency of reaction, the reaction path optimization, the reaction rate increased research in the fields of science and the future can not be ignored by an important research topic is likely to Catalysis in Industrial Application bring about revolutionary changes.2. In the application of paintNano-materials because of its special nature and structure of the surface with general access to the material excellent performance demonstrated strong vitality. Surface coating technology is the focus of attention of the world today. Nano-materials for the surface coating provided a good opportunity to make the function of the material has great potential. With traditional coating technology, add nanomaterials, nano-composite coating will be to achieve a leap in functionality means that the traditional function of coating modified. Coating their use can be divided into functional coatings and coating. That the structure is coated substrate coating raise some of nature and modification; functional coating to the substrate is not available in performance, access to traditional coating did not function. A superhard coatings, wear-resistant coatings, anti-oxidation, heat-resistant, fire-retardant coating, corrosion-resistant, decorative coatings, and other functional coatings are absorbing light, reflected light, light choice of the optical absorption coatings, conductive, insulation, electrical characteristics of semiconductor coating, oxygen-min, humidity, and gas-sensing properties of the coating, such as sensitive. In the paint by adding nano-materials can further enhance its defense capabilities and achieving anti-ultraviolet radiation, atmospheric against resistance and anti-degradation, discoloration, in the application of sanitary products can play a role in cleaning sterilization. Signs in the use of Nano-coating, can use its optical properties, to store solar energy, energy conservation purposes. In building materials such as glass, paint adding suitable nano-materials, and they can reduce the transmission of light and heat transfer effects, a thermal insulation, fire-retardant, and other effects.Japan's Matsushita has developed a good electrostatic shielding the nanocomposite coating, the application of iron oxide nanoparticles have, titanium dioxide and zinc oxide, etc.. Such a semiconductor properties of nano-oxide particles at room temperature than conventional oxides have high electrical conductivity properties, which can play a role in electrostatic shielding, and oxide nanoparticles of different colors, such can also compound control electrostatic shielding paint color, carbon black overcome electrostatic shielding paint only the monotony of a single color. Nano-materials not only with the size and color change also has the effect of discoloration angle. In the automobile industry in the decorative spraying will be added Nano TiO2 in the automotive, metal flashlight Topcoat sedan, the coating can produce rich and mysterious colors, so that an old traditional automotive topcoat Huanxinya. Nano-SiO2 is a resistance to ultraviolet radiation materials. In the paint by adding nano-SiO2 can paint anti-aging properties, finish and strength increased manifold. Nano coating have a good prospect, coating technology will bring a new technological revolution, it will promote the research and development of composite materials and applications.3. Other in the use of chemicalFine Chemicals is a huge industry, the number of many products, a wide range of uses, and affect every aspect of human life. Nanomaterials superiority will certainly bring the Gospel to the chemical, and display of its unique plot. In the rubber, plastics, paints and other chemical fields, nano-materials can play an important role. If included in the rubber nano-SiO2 can be enhanced rubber anti-UV radiation and infrared reflectivity. Nano-Al2O3 and SiO2, by adding to the general rubber, rubber can improve the wear resistance and dielectric properties, but also flexibility is better than for white carbon black rubber filler. Plastic add some nano-materials, can improve the strength and toughness of plastic, and compact and waterproof and has correspondingly increased. Nano-SiO2 has been abroad, as additives into sealants and adhesives, sealing and adhesion to have greatly improved. In addition, nano-materials in the fiber modification, plexiglass manufacturers also have good applications. After adding in the plexiglass surface modification with SiO2, plexiglass resistance to ultraviolet radiation can achieve the purpose of anti-aging; A12O3 to join, not only do not affect the transparency of the glass, but it will also enhance the high-temperature impact toughness of the glass. Certain size anatase TiO2 have excellent UV shielding performance, but also delicate texture, non-toxic odorless, add in cosmetics, cosmetics performance can be improved. Ultrafine TiO2 can be extended to the application of coatings, plastics, man-made fibres industries. Recently developed for food packaging TiO2 and luxury cars pearlescent finish withthe Titanium Dioxide. Nano TiO2 to strong sunlight absorption in the UV, generate strong photochemical activity can be consumed by the industrial degradation of organic pollutants in the wastewater, with the exception of high-net, no secondary pollution, the advantages of broad applicability, Environmental water treatment has good prospects. In the field of environmental science, in addition to use of nanomaterials as a catalyst to deal with emissions from industrial production processes in the waste, there will be unique nano-membrane function. This membrane can detect chemical and biological agents from the pollution caused, and is able to filter these agents, thereby eliminating pollution.4. In the application of Chinese medicine21st century health sciences, will be expected to speed access to the development, the people's growing demand for high drug. Control drug release, reduce side effects and improve efficacy, the development of targeted drug therapy, has been mentioned research agenda. Nanoparticles drugs in the human body will make the transmission more convenient. With several layers of nano-particles coated smart drugs enter the body, may take the initiative to search and attack cancer cells or repairing damage; use of a new type of nano-technology diagnostic apparatus, a small amount of blood can be detected only through which the protein and DNA diagnosis of various diseases, the Massachusetts Institute of Technology has produced a nano-magnetic material to the target as a drug carrier directional drugs, called "directional missile." This technology is in the magnetic nanoparticles coated surface protein carrying drugs, injected into the blood vessels of the human body through magnetic navigation transported to lesions, and then the release of drugs. Nanoparticles small size, can flow freely in the bloodstream, it can be used to examine and treat the physical location of lesions. Nanoparticles on the clinical and radiological treatment is the application of a great deal of research work. According to "People's Daily" reported that China will be used in nano-technology medical field success. Nanjing Xike groups use nano-silver technology to the development and production of medical dressings - long-term broad-spectrum antimicrobial cotton. Antibacterial cotton production this principle through nano-technology will be made of silver nano-size in the small ultra-fine particles, and then make it attached to the cotton fabric. Silver is the prevention of ulcers and accelerate wound healing role, through nano-technology deal with the silver surface increases rapidly, changes in the structure of the surface, disinfection raise about 200 times the common clinical surgical infection have better inhibition of bacteria .And satisfied that the tablets as particulate delivery systems, the basicnature of the material is non-toxic, stable, and there are good biological and drug and not a chemical reaction. Nano system is mainly used for toxicity, short biological half-life, susceptible to biological degradation of the drug administration.Nano-biology used to study the nano-scale biological processes, in accordance with principles of molecular biology applications engineering. Rail in the ultrafine particles of metal surface covered a thickness of 5 to 20 nm polymer, can be fixed in particular a large number of proteins and thus control biochemical reactions. This biochemical technology, enzyme engineering in the great usefulness. Nano-technology and the integration of biology, molecular biology research devices using nano-sensors, can be obtained within the cell biological information to understand the body state and deepen people's physiological and pathological explanation.5. ConclusionNano-science is a keeper of basic science and applied science in integrated set of emerging science, including nano-electronics, nano-materials science, biology and nanotechnology. The 21st century will be the era of nano-technology is, to that end, the State Science Commission, the Chinese Academy of Sciences will be nano-technology as "the 21st century's most important and most leading edge of science." Nano-materials applications relate to various areas in mechanical, electronic, optical, magnetic, chemical and biological fields have broad application prospects. The birth of nano-science and technology, human society will have a far-reaching impact, and is likely to fundamentally solve the many problems facing humanity, particularly energy, human health and environmental protection, and other major issues. Beginning of the 21st century is the main task of all kinds of novel nano-materials basis of the physical and chemical characteristics, design of new materials and devices. Through nano-materials science and technology on the traditional products modified to increase its high-tech content and the development of a new type of nano-structured products, there have been encouraging signs, with the formation of 21 new economic growth points basis. Nano materials will become a field of materials science show the grade star in the new materials, energy, information and other fields, play a pivotal role. With its preparation and modification technology and the continuing development of nano-materials in the chemical and pharmaceutical production, and other areas will be increasingly wider range of applications.纳米材料在化工生产中的应用纳米材料在结构、光电和化学性质等方面的诱人特征，引起物理学家、材料学家和化学家的浓厚兴趣。

Advances in Environmental Protection 环境保护前沿, 2023, 13(3), 670-678 Published Online June 2023 in Hans. https:///journal/aep https:///10.12677/aep.2023.133083可降解塑料及其微生物降解研究进展吴佳云*，李茹欣*，陈恩祈，卢得雨，谢桂英，杜星辰，钟宇晴，邓博晖，成彩霞， 廖三阳子，黄金岚，黄玉杰#，曾 斌#深圳技术大学药学院，广东 深圳收稿日期：2023年5月19日；录用日期：2023年6月19日；发布日期：2023年6月28日摘要为了缓解塑料制品广泛使用造成的环境污染，人们逐渐使用可降解塑料代替传统塑料。

根据后期处理方式的差异，可降解塑料主要可分为四大类：光降解塑料、生物降解塑料、化学降解塑料、光/氧–生物复合降解塑料。

其中，生物降解塑料的应用最为广泛。

根据化学结构和性能上的不同，目前常用的可降解塑料主要可分为聚α-羟基酸类、二元酸二元醇共聚酯类、聚羟基烷酸酯类及淀粉基类。

本文我们综述了近年来国内外研究者针对以上四类生物降解塑料的降解条件及机理等相关研究进展，并整理了可降解生物塑料的主要微生物研究及种类等信息，有助于对可降解塑料的深入认识、新型可降解塑料的研制及优质降解方法的开发。

关键词塑料，可降解塑料，生物降解塑料，微生物降解Research Progress on Biodegradable Plastics and Their Microbial DegradationJiayun Wu *, Ruxin Li *, Enqi Chen, Deyu Lu, Guiying Xie, Xingchen Du, Yuqing Zhong, Bohui Deng, Caixia Cheng, Sanyangzi Liao, Jinlan Huang, Yujie Huang #, Bin Zeng #Pharmaceutical College of Shenzhen University of Technology, Shenzhen GuangdongReceived: May 19th , 2023; accepted: Jun. 19th , 2023; published: Jun. 28th , 2023AbstractIn order to alleviate the environmental pollution caused by the widespread use of plastic prod-*共同第一作者。

As a high school student with a keen interest in wildlife, Ive always been fascinated by the enigmatic creature known as the pangolin. This essay is an attempt to share my knowledge and experiences about these unique animals, which are often referred to as the scaly anteaters.Pangolins are mammals that are native to Asia and Africa. They are the only known mammals to have evolved scales made of keratin, the same material found in human hair and nails. These scales serve as a defense mechanism, allowing them to curl into a ball when threatened, protecting their soft underbellies from predators.My fascination with pangolins began when I was introduced to them in a wildlife documentary. The documentary highlighted the plight of these animals, which are often targeted for their scales and meat, leading to a significant decline in their population. This sparked my curiosity, and I began to research more about these elusive creatures.One of the most intriguing aspects of pangolins is their feeding habits. As nocturnal animals, they spend most of their time foraging for ants and termites, using their long, sticky tongues to extract these insects from their nests. Their strong, curved claws are also adapted for digging into the ground or tree bark to access insect colonies.During a school trip to a wildlife sanctuary, I had the opportunity to observe a pangolin up close. The sanctuary had rescued a pangolin that had been injured by a poachers trap. Seeing this gentle creature in person was a humbling experience. Its scales were rough to the touch, but its eyesheld a softness that conveyed a sense of vulnerability.Pangolins are also known for their solitary nature. They are not social animals and prefer to live alone, only coming together during mating season. This solitary lifestyle makes them even more challenging to study, as they are rarely seen in the wild.However, the pangolins existence is under severe threat due to poaching and habitat loss. Their scales are believed to have medicinal properties in some cultures, and their meat is considered a delicacy in certain regions. This has led to an increase in illegal hunting, pushing some species of pangolins to the brink of extinction.In recent years, there has been a growing awareness about the plight of pangolins, with many conservation efforts being initiated to protect them. These efforts include antipoaching patrols, habitat preservation, and public education campaigns to raise awareness about the importance of pangolins in the ecosystem.As a student, I feel it is crucial to contribute to these conservation efforts. I have participated in awareness campaigns at my school, sharing information about pangolins and the threats they face. I have also volunteered at local wildlife sanctuaries, helping to care for rescued pangolins and other endangered species.In conclusion, pangolins are extraordinary creatures that deserve our attention and protection. Their unique adaptations, solitary lifestyle, andthe challenges they face due to human activities make them a compelling subject for study and conservation. As a society, we must take action to ensure the survival of these remarkable animals, not just for their sake, but for the health of our planets ecosystems as a whole.。

穿山甲英文作文初一English: Pangolin is a unique and intriguing animal that is also known as the "scaly anteater". Pangolins are covered in tough, overlapping scales made of keratin, the same material found in human nails and hair. They are found in tropical regions of Africa and Asia, and are known for their distinctive walking style, using their hind legs and their tails for support. Pangolins are insectivorous, feeding on ants and termites using their long, sticky tongues. Unfortunately, pangolins are highly endangered due to illegal poaching for their scales, which are believed to have medicinal properties in some cultures. Conservation efforts are being made to protect and raise awareness about the plight of these unique creatures.中文翻译: 穿山甲是一种独特而引人入胜的动物，也被称为“鳞翅目”。

穿山甲的身上覆盖着坚硬、重叠的鳞片，由角蛋白构成，这与人类指甲和头发中所含的物质相同。