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Stimulated Neutrino Conversion in the CERN Beam

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Self-induced conversion in dense neutrino gases Pendulum in flavour space

Self-induced conversion in dense neutrino gases Pendulum in flavour space
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Department of Physics and Astronomy, University of Aarhus, Ny Munkegade, DK-8000 Aarhus C, Denmark Max-Planck-Institut f¨ ur Physik (Werner-Heisenberg-Institut), F¨ ohringer Ring 6, 80805 M¨ unchen, Germany 3 APC ∗ (AstroParticules et Cosmologie), 11, place Marcelin Berthelot, F-75005 Paris, France 4 Institut d’Astrophysique de Paris, 98bis Boulevard Arago, 75014 Paris, France (Dated: 30 August 2006, Revised version of 17 October 2006) Neutrino-neutrino interactions can lead to collective flavour conversion effects in supernovae and in the early universe. We demonstrate that the case of “bipolar” oscillations, where a dense gas of neutrinos and antineutrinos in equal numbers completely converts from one flavour to another even if the mixing angle is small, is equivalent to a pendulum in flavour space. Bipolar flavour conversion corresponds to the swinging of the pendulum, which begins in an unstable upright position (the initial flavour), and passes through momentarily the vertically downward position (the other flavour) in the course of its motion. The time scale to complete one cycle of oscillation depends logarithmically on the vacuum mixing angle. Likewise, the presence of an ordinary medium can be shown analytically to ntribute to a logarithmic increase in the bipolar conversion period. We further find that a more complex (and realistic) system of unequal numbers of neutrinos and antineutrinos is analogous to a spinning top subject to a torque. This analogy easily explains how such a system can oscillate in both the bipolar and the synchronised mode, depending on the neutrino density and the size of the neutrino-antineutrino asymmetry. Our simple model applies strictly only to isotropic neutrino gasses. In more general cases, and especially for neutrinos streaming from a supernova core, different modes couple to each other with unequal strength, an effect that can lead to kinematical decoherence in flavour space rather than collective oscillations. The exact circumstances under which collective oscillations occur in non-isotropic media remain to be understood.

经皮穿刺激光、臭氧联合应用治疗神经根型颈椎病

经皮穿刺激光、臭氧联合应用治疗神经根型颈椎病

经皮穿刺激光、臭氧联合应用治疗神经根型颈椎病发表时间：2012-12-04T10:37:35.233Z 来源：《中外健康文摘》2012年第30期供稿作者：沈世红1 路江鸿2 刘永才1 陈刚1 张芬芬1 邓[导读] 一是气管、食管、血管的推移训练，二是穿刺技术必须熟练掌握，三是光纤尖端只能超出穿刺针导管3-5mm。

沈世红1 路江鸿2 刘永才1 陈刚1 张芬芬1（1解放军第五三四医院河南洛阳 471003；2陕西省黄龙县人民医院外科陕西黄龙 715700）【中图分类号】R681.5+4【文献标识码】A【文章编号】1672-5085（2012）30-0254-01【摘要】目的探讨经皮穿刺激光、臭氧联合应用治疗神经根型颈椎病的临床治疗效果。

方法 120例神经根型颈椎病，颈椎间盘突出186个节段。

采用波长980mm半导体激光光纤，功率为6W，每个椎间盘使用激光600焦耳，拔出光纤后从穿刺针缓慢注入57μg/L臭氧每个病变间隙5ml。

结果优良率为93.4%。

结论经皮穿刺激光、臭氧联合应用治疗神经根型颈椎病安全、创伤小、恢复快。

【关键词】经皮穿刺激光臭氧神经根型颈椎病我院自2007年4月至2012年1月采用经皮穿刺激光、臭氧联合应用治疗神经根型颈椎病患者120例，取得了满意疗效，现报道如下： 1 临床资料1.1一般资料本组120例患者中男性49例，女性71例，年龄35～69岁，平均57.1岁；病程半年～20年不等。

所有病例均经牵引、理疗、按摩、中药熏蒸等治疗，效果欠佳或无效，且反复发作。

症状及体征：所有患者均有一侧或双侧上肢疼痛、麻木、乏力，伴有轻重不等的肩背疼、沉重、酸胀感，偶伴有头晕头痛；65例伴有上肢肌力减退，74例伴有皮肤感觉减退，Hoffman’s症阳性，CT或MRI提示：所有患者均有不同程度的颈椎间盘向后突出，压迫神经根或硬膜囊。

1.2设备与器械使用北京海特光电有限公司生产的HT—M15型半导体激光治疗仪。

细胞器之间相互作用在非酒精性脂肪性肝病发生发展中的作用

细胞器之间相互作用在非酒精性脂肪性肝病发生发展中的作用

2 ＤＯＩ：１０．３９６９／ｊ．ｉｓｓｎ．１００１－５２５６．２０２３．０１．０２８细胞器之间相互作用在非酒精性脂肪性肝病发生发展中的作用刘天会首都医科大学附属北京友谊医院肝病中心，北京１０００５０通信作者：刘天会，ｌｉｕ＿ｔｉａｎｈｕｉ＠１６３．ｃｏｍ（ＯＲＣＩＤ：００００－０００１－６７８９－３０１６）摘要：细胞器除了具有各自特定的功能外，还可与其他细胞器相互作用完成重要的生理功能。

细胞器之间相互作用的异常与疾病的发生发展密切相关。

近年来，细胞器之间相互作用在非酒精性脂肪性肝病（ＮＡＦＬＤ）发生发展中的作用受到关注，特别是线粒体、脂滴与其他细胞器之间的相互作用。

关键词：非酒精性脂肪性肝病；细胞器；线粒体；脂肪滴基金项目：国家自然科学基金面上项目（８２０７０６１８）ＲｏｌｅｏｆｏｒｇａｎｅｌｌｅｉｎｔｅｒａｃｔｉｏｎｉｎｔｈｅｄｅｖｅｌｏｐｍｅｎｔａｎｄｐｒｏｇｒｅｓｓｉｏｎｏｆｎｏｎａｌｃｏｈｏｌｉｃｆａｔｔｙｌｉｖｅｒｄｉｓｅａｓｅＬＩＵＴｉａｎｈｕｉ．（ＬｉｖｅｒＲｅｓｅａｒｃｈＣｅｎｔｅｒ，ＢｅｉｊｉｎｇＦｒｉｅｎｄｓｈｉｐＨｏｓｐｉｔａｌ，ＣａｐｉｔａｌＭｅｄｉｃａｌＵｎｉｖｅｒｓｉｔｙ，Ｂｅｉｊｉｎｇ１０００５０，Ｃｈｉｎａ）Ｃｏｒｒｅｓｐｏｎｄｉｎｇａｕｔｈｏｒ：ＬＩＵＴｉａｎｈｕｉ，ｌｉｕ＿ｔｉａｎｈｕｉ＠１６３．ｃｏｍ（ＯＲＣＩＤ：００００－０００１－６７８９－３０１６）Ａｂｓｔｒａｃｔ：Ｉｎａｄｄｉｔｉｏｎｔｏｉｔｓｏｗｎｓｐｅｃｉｆｉｃｆｕｎｃｔｉｏｎｓ，ａｎｏｒｇａｎｅｌｌｅｃａｎａｌｓｏｉｎｔｅｒａｃｔｗｉｔｈｏｔｈｅｒｏｒｇａｎｅｌｌｅｓｔｏｃｏｍｐｌｅｔｅｉｍｐｏｒｔａｎｔｐｈｙｓｉｏｌｏｇｉｃａｌｆｕｎｃｔｉｏｎｓ．Ｔｈｅｄｉｓｏｒｄｅｒｓｏｆｏｒｇａｎｅｌｌｅｉｎｔｅｒａｃｔｉｏｎｓａｒｅｃｌｏｓｅｌｙａｓｓｏｃｉａｔｅｄｔｈｅｄｅｖｅｌｏｐｍｅｎｔａｎｄｐｒｏｇｒｅｓｓｉｏｎｏｆｖａｒｉｏｕｓｄｉｓｅａｓｅｓ．Ｉｎｒｅｃｅｎｔｙｅａｒｓ，ｔｈｅｒｏｌｅｏｆｏｒｇａｎｅｌｌｅｉｎｔｅｒａｃｔｉｏｎｓｈａｓａｔｔｒａｃｔｅｄｍｏｒｅａｔｔｅｎｔｉｏｎｉｎｔｈｅｐｒｏｇｒｅｓｓｉｏｎｏｆｎｏｎａｌｃｏｈｏｌｉｃｆａｔｔｙｌｉｖｅｒｄｉｓｅａｓｅ，ｅｓｐｅｃｉａｌｌｙｔｈｅｉｎｔｅｒａｃｔｉｏｎｓｂｅｔｗｅｅｎｍｉｔｏｃｈｏｎｄｒｉａ，ｌｉｐｉｄｄｒｏｐｌｅｔｓ，ａｎｄｏｔｈｅｒｏｒｇａｎｅｌｌｅｓ．Ｋｅｙｗｏｒｄｓ：Ｎｏｎ－ａｌｃｏｈｏｌｉｃＦａｔｔｙＬｉｖｅｒＤｉｓｅａｓｅ；Ｏｒｇａｎｅｌｌｅｓ；Ｍｉｔｏｃｈｏｎｄｒｉａ；ＬｉｐｉｄＤｒｏｐｌｅｔｓＲｅｓｅａｒｃｈｆｕｎｄｉｎｇ：ＮａｔｉｏｎａｌＮａｔｕｒａｌＳｃｉｅｎｃｅＦｏｕｎｄａｔｉｏｎｏｆＣｈｉｎａ（８２０７０６１８） 细胞器可以通过膜接触位点与其他细胞器相互作用，完成物质与信息的交换，形成互作网络［１］。

CP and T Violation in Neutrino Oscillations and Invariance of Jarlskog's Determinant to Mat

CP and T Violation in Neutrino Oscillations and Invariance of Jarlskog's Determinant to Mat
RAL-TR/1999-086 hep-ph/9912435 20 December 1999
CP and T Violation in Neutrino Oscillations and Invariance of Jarlskog’s Determinant to r Effects
arXiv:hep-ph/9912435v1 21 Dec 1999
2
trix, Mν is in general, an arbitrary 3x3 matrix. The Hermitian square of the neutrino † mass matrix, Mν Mν , may be diagonalised to find its eigenvalues, and its eigenvectors form the columns of the lepton mixing matrix, U. It is well-known that under these circumstances, neutrinos propagating in vacuum undergo flavour oscillations, and furthermore, in general, these result in CP - and T -violating asymmetries. The CP - and T -violating asymmetries in the transition probabilities are given (for arbitrary mixing matrix) by the universal function P (να → νβ ) − P (ν α → νβ ) = P (να → νβ ) − P (νβ → να ) = 16J sin (∆12 L/2) sin (∆23 L/2) sin (∆31 L/2)

高分子化学实验教学中的创新探索

高分子化学实验教学中的创新探索

高分子化学实验教学中的创新探索作者：***来源：《赤峰学院学报·自然科学版》2023年第11期摘要：以偶氮二異丁腈（AIBN）为引发剂，正己烷和丁酮为混合溶剂，在可见光辐照下，进行苯乙烯（St）和马来酸酐（MA）的沉淀聚合教学实验探索。

分别研究了溶剂的配比、引发剂的用量、单体浓度、反应时间、单体配比对聚合反应的影响。

当正己烷和丁酮的质量比为1：1，St和MA的摩尔比为1：1，单体质量浓度为17.5%，引发剂用量为2%，反应时间为120min时，单体的转化率为88.3%。

与目前教材中普遍使用以甲苯为溶剂的“苯乙烯与马来酸酐的交替共聚合”教学实验相比，该实验具有绿色低毒、节能环保、简单新颖、重复性好等优点。

关键词：可见光；沉淀聚合；聚苯乙烯马来酸酐；实验教学；创新中图分类号：G642.423 文献标识码：A 文章编号：1673-260X（2023）11-0092-04在我国大力推动经济转型升级的趋势下，创新成为经济发展的主要动力[1]。

因此，培养创新型人才，既是高等教育的核心任务，也是社会发展的客观需要。

实践教学是人才培养中不可或缺的重要环节，是培养创新型人才的关键步骤[2]。

实验结果可以修正理论，激发学生的学习兴趣，培育创新能力和探索精神[3]。

因此，实验创新在培养创新型人才方面具有举足轻重的作用。

创新不能脱离基本的概念，必须和基础、经典的实验方法结合起来，否则“夹生”的理解反而会妨碍学生的进一步创新。

“高分子化学实验”是材料化学专业的一门重要的专业基础课，是进行高分子化学实验操作训练的一门课程。

通过实验训练，学生能够加深对高分子化学的基本原理和概念的理解，掌握高分子化学实验的基本方法，训练科学研究方法和创新思维。

聚苯乙烯马来酸酐（SMA）是一种性能优良、用途广泛的聚合物[4-6]；通过沉淀聚合制备SMA具有后处理工艺简单方便、溶剂可直接反复利用等优点[7]。

“苯乙烯与马来酸酐的交替共聚合”是高分子化学实验中的经典教学实验，但是按照教材的方案进行实验几乎得不到任何产物[8，9]，我院高分子化学实验课程指导老师在预实验中也多次失败。

Supersymmetric Neutrino Masses and Mixing with R-parity Violation

Supersymmetric Neutrino Masses and Mixing with R-parity Violation

[9] [5, 10] [7]
(1) (2) (3)
With ordinary three neutrinos, any two of the mass-squared differences in the above equations can be obtained: that is, those corresponding to (i) solar and atmospheric (S+A), (ii) solar and LSND (S+L), or (iii) atmospheric and LSND (A+L) neutrino data. For (S+A), the LSND result has to be disregarded. In the case of (S+L) or (A+L), the presence of a sterile neutrino is necessary for the explanation of the atmospheric or solar neutrino experiment, respectively. One of the desirable features of the supersymmetric extension of the standard model would be the generation of small neutrino masses within its context, as the supersymmetric standard model with the minimal particle content (MSSM) allows for the lepton (L) and baryon number (B) violating operators. In order to ensure the longevity of a proton, one usually assumes the conservation of R-parity, forbidding both (renormalizable) B and L violating operators. As a consequence, the lightest supersymmetric particle (LSP) is stable and thus cold dark matter of the universe may consist of neutral LSP’s. However, there is no obvious theoretical reason why R-parity needs to be conserved, or why both B and L conservation have to be imposed. L-violation would be present in the MSSM and it may be the origin of nonzero neutrino masses and mixing that explain current experimental data, while proton stability is ensured by B conservation alone. The L-violating operators in the MSSM are µi Li H2 ,

Field Stimulation

Peripheral Nerve Stimulation and Peripheral Nerve Field StimulationOverview:The use of electrical stimulation in the treatment of pain is not a new concept, as it in fact has origins in the time of the Roman Empire when the electric eel known as the torpedo fish was used to treat pain. In the more modern era, this application has evolved into the increasingly common use of Spinal Cord Stimulation for treatment of refractory pain conditions. Likewise, there have been increasing reports of utilization of stimulation peripherally in the form of Peripheral Nerve Stimulation (PNS) and Peripheral Nerve Field Stimulation (PNFS).Interestingly, Slavin has noted that, although implanted spinal cord stimulator devices have more “approved” indications, the first articles reporting implanted devices for Peripheral Nerve Stimulation predated those of spinal cord stimulation. [21]First, it is helpful to discuss the similarities and differences between Peripheral Nerve Stimulation and Peripheral Nerve Field Stimulation. The former generally implies implantation of a stimulating electrode either directly on a particular nerve via surgical visualization (a summary of one group‟s approach to this is detailed well in Mobbs et al, 2007) or perhaps more commonly percutaneous placement of a stimulating electrode in close proximity to a particular peripheral nerve. [15]In the latter, stimulating electrodes are percutaneously placed in the painful areas themselves without respect to a particular named nerve‟s loca tion. In both, the underlying concept remains the same: using electrical stimulation peripherally (as opposed to centrally in the case of dorsal column stimulation) to provide paresthesias in painful areas leading to pain relief. The exact mechanism(s) by which these approaches render pain relief is incompletely understood. A widely held hypothesis is that pain relief may be (at least in part) explained by the “gate-control” theory originally described by Melzack and Wall in their landmark paper published in 1965. The gate of pain transmission is opened by activation of nociceptive specific neurons, while stimulation of large myelinated fibers closes the gate. Putative inhibitory neurotransmitters thought to be released during large myelinated nerve fiber stimulation include gamma-aminobutyric acid (GABA) and adenosine. [11] [12][9] With regards to indications, it is generally accepted that Peripheral Nerve Stimulation and Peripheral Nerve Field Stimulation are modalities reserved for neuropathic pain that is refractory to conventional treatment methods. Neuropathic pain in this context would include a wide variety of pathologic conditions and the literature (as discussed later in this text) reports the use of Peripheral Nerve Stimulation and Peripheral Nerve Field Stimulation in conditions including chronic headache, post-herpetic neuralgia, abdominal pain, complex regional pain syndromes (CRPS) and post-thoracotomy pain among many others. The pain must be chronic and neuropathic in nature, with an intensity that negatively impacts the patient‟s quality of life and/or ability to function.Most would likely agree that candidates for peripheral nerve/field stimulation should meet the same psychological criteria as those deemed suitable for spinal cord stimulation. Many implanters (andinsurance carriers) actually insist upon formal psychology evaluation before deciding to proceed with trial and implantation of a peripheral stimulation device. Beyond these points, the actual selection criteria vary to a degree amongst practitioners, but converge on the fact that the painful condition must be consistently well localized. In some instances (such as supraorbital or greater occipital neuralgia), authors report using significant (albeit transient) response to peripheral blockade of the nerves in question as a screening criteria in order to consider trial of peripheral stimulation. [1]Others contend that response to nerve blocks are not predictive of success [19], and in some conditions (particularly those involving Peripheral Field Stimulation), a dedicated nerve-block may not even be an option as the painful area is not necessarily overlying a particular named nerve that is amenable to blockade. [21] The current literature no longer requires relief from peripheral blocks as a screening test for considering a trial of peripheral stimulation.It should be noted that none of the most commonly implanted stimulator devices currently have FDA approval for use in Peripheral Nerve Stimulation and Peripheral Field Stimulation, and as such use in this context is “off label.”AnatomyAs the conditions treated with Peripheral Nerve Stimulation and Peripheral Nerve Field Stimulation vary widely, the relevant anatomy for these procedures is a broad concept. As previously noted, this modality has been used for a myriad of conditions, and (considering the indications) could conceivably be applied almost anywhere on the body with chronic, neuropathic pain.Procedure:An advantage of using Peripheral Nerve Stimulation and Peripheral Nerve Field Stimulation as a modality for treating pain includes the fact the devices are nearly always trialed before a permanent implantation allowing for a “try before you buy” clinical situation. As the most frequently utilized method of lead placement at present is percutaneous, this will be the focus of this section. (As noted previously, Mobbs et al, 2007 contains an explanation of their surgical technique with a direct visualization method should further information on this technique be desired.)[15] Additionally, not unlike spinal cord stimulator placement, rarely is more than IV sedation or Monitored Anesthesia Care (MAC) needed, thus sparing the patient a general anesthetic in most cases.The initial portion of the trial procedure and the permanent implantation are largely identical with regard to lead placement. In the case of Peripheral Nerve Stimulation, the appropriate anatomic location of the nerve to be stimulated is identified and prepped in a sterile fashion. Similarly in the case of Peripheral Nerve Field Stimulation, the area of the patient‟s maximal pain is identified and marked preoperatively, then prepped in a sterile fashion. Following administration of appropriate sedation, local anesthesia is injected overlying the skin entry point. An introducer needle, such as a 14g Tuohy, is then placed subcutaneously to the target area (either the location of a particular nerve or the area of maximal pain). An electrode is then threaded into place through the Tuohy needle. Many practitione rs will then obtain a fluoroscopic radiograph to verify and record lead placement. TheTuohy is subsequently removed and the lead is secured to the skin. Again not unlike the case in spinal cord stimulation, the lead is connected to an external pulse generator for the trial period. There is variability in the literature regarding the duration of the trial period as time frames of 2-14 days are commonly reported. There is general agreement that should there be >50% improvement in the patient‟s symptoms, the trial is interpreted as positive, and the patient is scheduled for permanent implantation. The permanent implantation procedure involves lead placement as previously described with suitable anchoring of the leads to an appropriate area (such as ligamentous tissue) and tunneling to a dissected pocket (in a preoperatively designated location chosen in concert with patient preference) where the leads are connected to an implanted pulse generator (IPG). Once verified to be connected appropriately and functional, the IPG is placed into the pocket, secured, and the incisions are closed. Both the trial and the permanent implantation procedures can be performed in the ambulatory setting, with no inpatient hospitalization required in most cases.Benefits:The lack of Class I and/or II evidence for Peripheral Nerve Stimulation and Peripheral Nerve Field Stimulation is mentioned frequently in discussions of this modality of therapy and editorials on the subject. Though a randomized controlled trial would certainly be a welcomed piece of supporting evidence for this therapy, it may not be practical to pursue. Mobbs et al, point out that “a study that included randomizing patients to a …best medical therapy‟ versus a peripheral nerve stimulator would be ideal, although not feasible as these patients are referred because they have failed the …best medical therapy… option.” [15]Although there is lack of large randomized controlled trials studying PNS and PNFS, the available data overall suggest that this is a safe and effective modality for the treatment of otherwise refractory pain of a variety of etiologies. In their recent review of the available evidence published on the subject of peripheral neuromodulation, Bittar and Teddy state: “The published studies suggest tha t a significant proportion (60-70%) of patients with certain intractable pain syndromes will benefit from peripheral nerve stimulation...the risk of serious adverse events is relatively low.” [3] With regards to intractable headache, there have been several studies that looked at the use of Peripheral Nerve Stimulation and Peripheral Nerve Field Stimulation in addressing various types of headache. Overall, this data has been positive. For instance, in transformed migraine and occipital neuralgia, a number o f studies of occipital nerve stimulation (as summarized by Bittar and Teddy) have shown decreased frequency and/or intensity of headache symptoms with occipital stimulation. [3] [19] [17][22] Additionally there is promising data on use of supraorbital stimulation. [1]Post Herpetic Neuralgia can be an extremely painful condition refractory to medications and many percutaneous interventions. Case reports addressing the use of Peripheral Nerve Field Stimulation for PHN have been encouraging; though represent a limited number of patients. [7][10][18][23]Abdominal Pain can present a challenge to the Pain Medicine Physician on account of multiple etiologies and limited diagnostic studies for determining the source of pain. A 2006 case report by Paicius et al reports the use of Peripheral Nerve Field Stimulation in three patients with refractory abdominal pain of different etiologies, all of which derived “significant relief from pain, enabling patients to decrease or discontinue their opioid medications and to enjoy significant improvement in their quality of life.” [16] This series suggests that abdominal wall pain that is neuropathic may respond well to peripheral neuromodulatory techniques.With respect to Complex Regional Pain Syndrome (formerly called Reflex Sympathetic Dystrophy), Hassenbusch et al published a study in 1996 documenting long-term results of PNS in a subset of CRPS patients. In their work >60% of patients experienced fair to good relief of symptoms as far out as 4 years, which was consistent with the 60% rate of >50% pain reduction reported by Mobbs et al in patients with isolated nerve injuries and neuropathic pain. [8][15]Risks:The overall risk of serious complications with Peripheral Nerve Stimulation and Peripheral Nerve Field Stimulation appears to be very low. Peripheral neuromodulatory techniques avoid the spinal canal, and as a consequence, the risk of bleeding and/or infection into the epidural space resulting in possibly catastrophic neurologic deficit or need for emergent spine surgery are essentially nil. Bleeding and infection associated with the implantation are still a possibility with the infection rate estimated to be between 3-5% [6].Other possible complications include hardware complications such as skin erosion of components, lead migration, component breakage or disconnection, and superficial foreign body reaction to components.Additionally, persistent hardware pain can occur (estimated at a rate of 5%) [6], and can be significant enough as to result in explantation of the device (author‟s experience).Contraindications differ between implanters for Peripheral Nerve Stimulation and Peripheral Nerve Field Stimulation but include active infection, anticoagulation or coagulopathy, and untreated psychological conditions. Whether or not to include unresolved litigation concerning the underlying pain condition as a relative contraindication remains a controversial topic.References:1.Amin S et al. Peripheral nerve stimulator for the treatment of supraorbitalneuralgia: a retrospective case series. Cephalalgia 2008; 28:355-9.2.Bhatnagar S et al. Peripheral nerve field stimulation for intractablepost-thoracotomy scar pain not relieved by conventional treatment. Pain Practice 2010.3.Bittar RG and Teddy PJ. Peripheral neuromodulation for pain. Journal ofClinical Neuroscience 2009; 16:1259-61.4.Broggi G et al. Neuromodulation for refractory headaches. Journal of theNeurological Sciences 2010; 31(supp 1): S87-92.5.Coffey RJ and Lozano AM. Neurostimulation for chronic noncancer pain: anevaluation of the clinical evidence and recommendations for future trial designs.Journal of Neurosurgery 2006; 105:175-89.6.De Leon-Casasola, OA. Spinal cord and peripheral nerve stimulationtechniques for neuropathic pain. Journal of Pain and Symptom Management 2009;38(supp 2): S28-38.7.Dunteman E. Peripheral nerve stimulation for unremitting ophthalmicpostherpetic neuralgia. Neuromodulation. 2002; 5:32-78.Hassenbusch SJ et al. Long-term results of peripheral nerve stimulation forreflex sympathetic dystrophy. Journal of Neurosurgery 1996; 84:415-23.9.Linderoth B et al. Dorsal column stimulation induces release of serotonin andsubstance P in the cat dorsal horn. Neurosurgery 1992; 31:289-9710.Kouroukli I et al. Peripheral Subcutaneous Stimulation for the treatment ofIntractable Postherpetic Neuralgia: Two case reports and literature review. Pain Practice 2009; 9:225-229.11.Melzack R and Wall PD. Pain mechanisms: a new theory. Science 1965; 150:971–97912.Meyerson BA; Linderoth B. Mode of action of spinal cord stimulation inneuropathic pain. Journal of Pain and Symptom Management 2006; 31(4 Suppl): S6-12.13.Meyerson et al. Spinal cord stimulation in animal models of mononeuropathy:Effects on the withdrawal response and the flexor reflex. Pain 1999; 79:229-4314.Mirone G, Natale M and Rotondo M. Peripheral median nerve stimulation forthe treatment of iatrogenic complex regional pain syndrome (CRPS) type II after carpal tunnel surgery. Journal of Clinical Neuroscience 2009; 16:825-7.15.Mobbs RJ, Nair S and Blum P. Peripheral nerve stimulation for the treatmentof chronic pain. Journal of Clinical Neuroscience 2007; 14:216-21.16.Paicius R, Bernstein CA and Lempert-Cohen C. Peripheral Nerve FieldStimulation in Chronic Abdominal Pain. Pain Physician 2006; 9:261-6.17.Popeney CA, Alo KM. Peripheral neurostimulation for the treatment ofchronic disabling transformed migraine. Headache 2003; 43:369-7518.Rodrigo-Royo MD, Azcona JM, Quero J, Lorente MC, Acin P, Azcona J.Peripheral neurostimulation in the management of cervicogenic headache: four case reports. Neuromodulation. 2005; 8:241–24819.Schwedt et al. Occipital nerve stimulation for chronic headache- long termsafety and efficacy. Cephalalgia 2007; 27:153-720.Schwedt TJ et al. Response to occipital nerve block is not useful in predictingefficacy of occipital nerve stimulation. Cephalalgia 2007; 27:271-421.Slavin KV. Peripheral Nerve Stimulation for Neuropathic Pain.Neurotherapeutics 2008; 5:100-106.22.Trentman TL et al. Greater occipital nerve stimulation via the Bionmicrostimulator: implantation technique and stimulation parameters. Pain Physician 2009; 12:621-8.23.Yakovlev AE, Peterson AT. Peripheral nerve stimulation in treatment ofintractable postherpetic neuralgia. Neuromodulation 2007; 10:373–375The content on this website is for educational purposes only, and is in no way intended to replace your physician's advice. Please always consult your doctor before taking any advice learned here or on any other website.。

Gravitationally Induced Neutrino-Oscillation Phases


Gen. Rel. and Grav. 28 (1996)1161-1170, GRF First Prize Essay for 1996
For decades the solar neutrino anomaly [10] has indicated that the neutrino flavor eigenstates may be a linear superposition of mass eigenstates [11]. This view has been further strengthened by the data on atmospheric neutrinos [12], and most recently by the observation of excess ν e observed at the Liquid Scintillator Neutrino Detector (LSND) Neutrino Oscillation Experiment (NOE) at LAMPF [13]. The excess events observed at LSND NOE have been tentatively interpreted as ν µ → ν e oscillations [13]. At the present time, (a) the question of neutrino masses [14], (b) the relation of the neutrinos to the spacetime symmetries as manifested in Dirac [15], or Majorana [16–18], or other fundamental constructs appropriate to the neutral particles [19], (c) the question of CP violation in the leptonic sector [21], and (d) other related issues that extend the physics beyond the standard model [22], are being probed with intense theoretical and experimental vigor. Gravitation plays no direct role on neutrino oscillations in the existing literature. 3 In this essay we shall introduce the notion of gravitationally induced quantum mechanical neutrino–oscillation phases and discuss the possibility of their observation for type-II supernova. A bit of history is necessary at this point. In one of the classic experiments of physics, Colella, Overhauser, and Werner (COW) established that quantum mechanics and gravitation, despite the well–known conceptual problems, behave in a manner expected for any other interaction [26]. Given the fact that the experiment involved thermal neutrons (non-relativistic quantum realm) and the Earth’s gravitational field (weak gravity), this may not be too unexpected. Nevertheless, theoretical investigation of this elegant experiment provides a deep understanding of gravitation in the context of quantum mechanics [27]. From a formal point of view the COW experiment studies the effect of gravitation on the quantum mechanical evolution of a single–mass eigenstate. For neutrinos, when we extend the COW–like considerations to the linear superposition of mass eigenstates, a new gravitationally induced quantum mechanical effect emerges. Despite the similarities between the COW effect and the new effect introduced here, there are important conceptual differences between the two effects. These differences shall also be enumerated at the appropriate place in this essay. In a certain sense (to become precise below), the two effects shall be seen to be complementary. Let us assume that in the “creation region,” Rc , located at rc ,

On the physics of massive neutrinos


The eigenvalues of γ5 (chirality) agree with those of helicity in the massless case. Here the Dirac equation decouples into two seperate equations for ψL,R 2
respectively. An alternative 2-component description was developed by Majorana [6] to describe a particle identical to its antiparticle. If neutrinos acquire a mass, in general both helicity states for neutrinos and antineutrinos can exist, making a 4-component description necessary. Here a 4-component Dirac-spinor can be treated as a sum of two 2-component Weyl-spinors or as composed out of two degenerated Majorana neutrinos. However it is still an open question whether neutrinos are Dirac or Majorana particles. The Majorana condition, for a particle to be its own antiparticle, can be written as
2.1 Weyl-, Majorana- and Dirac-neutrinos The neutrino states observed in weak interactions are neutrinos with helicity -1 and antineutrinos with helicity +1. For massless neutrinos and the absence of right-handed currents there is no chance to distinguish between Dirac- and Majorana neutrinos . Because V-A theory is maximal parity violating the other two states (neutrinos with helicity +1 and antineutrinos with helicity -1), if they exist, are unobservable. If neutrinos are massless a 2-component spinor (Weyl-spinor) is sufficient for description, first discussed for the general case of massless spin 1/2 particles by Weyl [5], which are the helicity -1(+1) projections for particles (antiparticles) out of a 4-component spinor Ψ. They are given by 1 ΨL,R = (1 ± γ5 )Ψ 2 (1)

英国手术预防使用抗菌药物指南


CONTENTS
Contents
1 Introduction...................................................................................................................... 1 1.1 1.2 1.3 1.4 2 2.1 2.2 2.3 The need for a guideline.................................................................................................... 1 Remit of the guideline........................................................................................................ 1 Definitions......................................................................................................................... 3 Statement of intent............................................................................................................. 3 Key ............................................ 4 Benefits and risks of antibiotic prophylaxis......................................................................... 4 Administration of prophylactic antibiotics.......................................................................... 4 Implementing the guideline. ............................................................................................... 5
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Abstract
We discuss the possibility of searching for anomalous magnetic transitions of neutrinos in the CERN beam induced by the absorption or emission of low-energy photons in a high-quality resonant cavity such as the LEP radiofrequency cavities. With the attainable sensitivities of the present CERN neutrino detectors, this experiment would impose strong limits on this transition and on the radiative decay lifetime of neutrinos with masses in the range of interest to the resolution of the dark matter solar and atmospheric neutrino puzzles. CERN-TH/95-262 October 1995
−2 −3 with a mass difference ∆m2 eV2 . µi ≈ 10 –10
Massive neutrinos also play an important role in cosmology as the substance of hot dark matter. Currently, the cosmological best-fit scenario includes a mixture of cold plus hot dark matter [3]. This translates into an upper limit on neutrino masses [4]:
CERN-TH/95-2பைடு நூலகம்2
Stimulated Neutrino Conversion in the CERN Beam
M. C. Gonzalez-Garcia
Theory Division, CERN, CH-1211 Geneva 23, Switzerland.
arXiv:hep-ph/9510316v1 17 Oct 1995
< 10 eV. mνi ∼
where |a| = |µ| (2 Im(µ)) and |b| = |d| (2 Re(d)) for Dirac (Majorana) neutrinos. The supernova SN1987 limits on this decay mode [7] only apply to neutrinos with nondegenerate masses. For mass-degenerate neutrinos there exist limits on this decay mode from a laboratory search for gamma-rays from decaying ν ¯e ’s produced at a nuclear reactor [8,9]. In this letter we study the possibility of imposing stringent limits on this transition using the CERN neutrino beam. The CERN neutrino beam produces predominantly νµ ’s with 2
The existing indications for non-zero neutrino masses include the deficit of solar electron neutrinos [1], the deficit in the atmospheric muon neutrino flux [2] and the indications favouring a hot component in the dark matter of the Universe [3,4]. All solar neutrino experiments [1] find fewer νe ’s than predicted theoretically. If the current solar models are correct, the explanation for this deficit relies on the oscillation of νe to another neutrino
−5 species with a mass difference ∆m2 eV2 . Some atmospheric neutrino experiments [2] ei ≈ 10
also observe a deficit in the ratio of experimental-to-expected ratio of muon-like to electronlike events. An explanation for this anomaly relies on νµ oscillations into another flavour
i
Putting all this information in a common framework and restricting ourselves to the three known neutrinos, we arrive at the scenario with three almost mass-degenerate neutrinos with the mass differences quoted above [5]. Such spectrum could arise, for instance, from the imposition of a cyclic permutation symmetry among the generations as pointed out by Harrison, Perkins and Scott [6]. Neutrinos with masses in this range could decay radiatively provided that they posses an anomalous transition magnetic moment of the form 1 ′ Ltrans = ν ¯ σαβ (µ + dγ5)νF αβ + h.c. , 2 which would give a lifetime for the ν → ν ′ γ decay τ −1 = (|a|2 + |b|2 ) (∆m2 )3 . 8πm3 (2) (1)
momentum k , k ′ , the wave function is given by ν (′) (x) ≈

(′)
For highly relativistic neutrinos moving along the z direction with helicity s, s′ = ±1 and
F. Vannucci
LPNHE, Universit´ e Paris VII, F-75251 Paris CEDEX 05, France.
J. Castromonte
Departamento de F´ ısica y Matem´ aticas, Universidad Peruana Cayetano Heredia, Lima, Per´ u.

exp(−ik · x) φs(′) √ ¯ 2V s(′) φ (′)
s
(4)
¯ is the volume in which the neutrino field is with φ1 = 1 and φ−1 = 0 . Here, V 0 1 quantized. We are going to consider the first transverse magnetic mode of the resonant cavity. The electric field is then aligned with the incident neutrino beam. This configuration will give the largest conversion rate since it corresponds to photons polarized in the same direction as the neutrino beam. The electromagnetic fields inside the cavity are given by: Ez = E0 J0 (x01 r/R) exp(−iαwt) Bφ = ∓iE0 J1 (x01 r/R) exp(−iαwt) where r is the distance to the cavity axis in the transverse plane and Bφ is the azimuthal component of the magnetic field. All other components are zero. Ji are the Bessel functions 3 (5)
fractions of 6% ν ¯µ ’s, 0.7% νe ’s and 0.2% ν ¯e ’s. The mean energy of the beam is 27 GeV. At present two experiments, NOMAD [10] and CHORUS, [11] search for the appearance of ντ in the CERN beam due to neutrino oscillations. They expect a sample of about 1 million νµ charged current (CC) events and the experiments can reach sensitivities of few ×10−4 in the νµ → ντ channel. The proposal is to use a resonant high-quality cavity intercepting the beam line to stimulate the neutrino conversion by absorption or emission of resonant photons inside the cavity, much as the experiment proposed by Matsuki and Yamamoto in Ref. [12] for solar or reactor neutrinos. The large number of photons in the cavity enhances the conversion and improves substantially the accessible range of lifetimes. In a realistic vein, we will use as resonant cavity one of the LEP radio-frequency cavities. These are cylindrical cavities with a diameter of 60 cm and a length of 20 cm along the beam direction. The transition amplitude for the conversion is given by Tf i = d4 xLtrans (x) . (3)