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1Caspase-3 activation as a bifurcation point between plasticity and cell death显示文摘Death-mediating proteases such as caspases and caspase-3 in particular,have been implicated in neurodegenerative processes,aging and Alzheimer's disease.However,emerging evidence suggests that in addition to their classical role in cell death,caspases play a key role in modulating synaptic function.It is remarkable that active caspases-3,which can trigger widespread damage and degeneration,aggregates in structures as delicate as synapses and persists in neurons without causing acute cell death.Here,we evaluate this dichotomy,and discuss the hypothesis that caspase-3 may be a bifurcation point in cellular signaling,able to orient the neuronal response to stress down either pathological/apoptotic pathways or towards physiological cellular remodeling.We propose that temporal,spatial and other regulators of caspase activity are key determinants of the ultimate effect of caspase-3 activation in neurons.This concept has implications for differential roles of caspase-3 activation across the lifespan.Specifically,we propose that limited caspase-3 activation is critical for synaptic function in the healthy adult brain while chronic activation is involved in degenerative processes in the aging brain.Shikha Snigdha Erica D Smith G Aleph Prieto Carl W Cotman 2012Neuroscience Bulletin2012,28,1:91
22019新型冠状病毒基因组特征和流行病学:病毒起源和受体结合的意义显示文摘研究者对来自9例新型冠状病毒肺炎住院患者的支气管肺泡灌洗液样本和培养的分离株进行了下一代测序。从这些个体中获得了严重急性呼吸综合征-冠状病毒2(severe acute respiratory syndrome-coronavirus 2,SARS-CoV-2)的完整和部分基因组序列。利用Sanger测序连接病毒重叠群以获得全长基因组,cDNA末端快速扩增确定终端区。对这些SARSCoV-2基因组和其他冠状病毒基因组进行了系统进化分析,以确定该病毒的进化史并有助于推断其可能的起源。刘青(译) 刘莉(审校) Lu R Zhao X Li J Niu P Yang B Wu H Wang W Song H Huang B Zhu N Bi Y Ma X Zhan F Wang L Hu T Zhou H Hu Z Zhou W Zhao L Chen J Meng Y Wang J Lin Y Yuan J Xie Z Ma J Liu WJ Wang D Xu W Holmes EC Gao GF Wu G Chen W Shi W Tan W 2020中华高血压杂志2020,28,3:516
3初级保健中原发性醛固酮增多症的患病率和临床表现显示文摘原发性醛固酮增多症(primaryaldosteronism,PA)是一种异质性疾病,以高血压和相对自主于肾素血管紧张素系统产生过量醛固酮为特征。与心血管病风险相似的原发性高血压患者相比,PA患者发生心脑血管并发症的风险以及代谢综合征患病率增加,提示正确诊断PA的重要性。Monticone S Burrello J Tizzani D Bertello C Viola A Buffolo F Gabetti L Mengozzi G Williams TA Rabbia F Veglio F Mulatero P 练桂丽 叶鹏 2017中华高血压杂志2017,25,5:58
45自由度大工作空间/支链行程比混联机械手的概念设计与尺度综合显示文摘研究一类新型5自由度可重构混联机械手的创新设计和尺度综合问题,该机械手模块由一2自由度球面并联机构和一条通过滑移副与之串接的两转动一移动串联运动链组成。该混联机械手由于将定点转动与相对滑移运动解耦,因此具有工作空间/支链行程比大的特点,适合高速轻载作业,可作为即插即用模块用于搭建不同类型的加工制造装备。在建立2自由度球面并联机构的速度映射模型的基础上,分析该机构的奇异性和各向同性问题,并以速度雅可比矩阵最小奇异值的全域均值为操作性能指标,研究2自由度球面并联机构的尺度综合问题。通过单调性分析揭示出尺度参数对该指标的影响规律,进而将尺度综合问题简化为求解杆长等式约束问题。最后给出一组算例,使该尺度综合方法的有效性得到验证。刘海涛 黄田 CHETWYND D G 李曚 2007机械工程学报2007,43,6:42
5长期保护性耕种方式对农田表层土壤性质的影响显示文摘研究了不同耕种方式对澳大利亚同一地区3种土壤表层(0-5cm)理化性质的作用,以揭示保护性耕作对土壤质量恢复的影响。结果表明:免耕穴播/保留残茬(DD/SR)、多年生人工草地(PP)和自然草地(NP)表层土壤的〉2mm水稳性团聚体含量、全氮、有机碳含量、田间持水量均显著高于其相应对照传统耕作/秸秆焚烧(CC/SB)、人工草地/作物轮作(PPC)和耕作(CT)的;土壤全氮含量、田间持水量分别与有机碳含量之间有极显著的正相关关系(r=0.994**,r=0.996**,n=6),而受土壤质地等因素的影响较小;在同一类型的土壤上,土壤有机碳含量与水稳定性团聚体含量之间存在显著的相关性;在不同试验区,耕作措施对表层土壤容重和孑L隙分布的影响存在较大差异;秸秆焚烧和施用石膏对表层土壤的pH及交换性阳离子含量有较大的影响。研究表明长期保护性耕作、草田轮作或多年生草地有利于提高表层土壤有机碳含量和结构稳定性,从而改善土壤的供肥供水能力。张国盛 K Y Chan G D Li D P Heenan 2008生态学报2008,28,6:45
6Fecal microbiota transplantation as novel therapy in gastroenterology:A systematic review显示文摘AIM:To study the clinical efficacy and safety of Fecal microbiota transplantation(FMT).We systematically reviewed FMT used as clinical therapy.METHODS:We searched MEDLINE,EMBASE,the Cochrane Library and Conference proceedings from inception to July,2013.Treatment effect of FMT was calculated as the percentage of patients who achieved clinical improvement per patient category,on an intention-to-treat basis.RESULTS:We included 45 studies;34 on Clostridium difficile-infection(CDI),7 on inflammatory bowel disease,1 on metabolic syndrome,1 on constipation,1 on pouchitis and 1 on irritable bowel syndrome(IBS).In CDI 90% resolution of diarrhea in 33 case series(n = 867) was reported,and 94% resolution of diarrhea after repeated FMT in a randomized controlled trial(RCT)(n = 16).In ulcerative colitis(UC) remission rates of 0% to 68% were found(n = 106).In Crohn's disease(CD)(n = 6),no benefit was observed.In IBS,70% improvement of symptoms was found(n = 13).100% Reversal of symptoms was observed in constipation(n = 3).In pouchitis,none of the patients(n = 8) achieved remission.One RCT showed significant improvement of insulin sensitivity in metabolic syndrome(n = 10).Serious adverse events were rare.CONCLUSION:FMT is highly effective in CDI,and holds promise in UC.As for CD,chronic constipation,pouchitis and IBS data are too limited to draw conclusions.FMT increases insulin sensitivity in metabolic syndrome.Noortje G Rossen John K Mac Donald Elisabeth M de Vries Geert R D'Haens Willem M de Vos Erwin G Zoetendal Cyriel Y Ponsioen 2015World Journal of Gastroenterology2015,21,17:41
7Analysis of the phosphatidylinosit ol 3'-kinase signaling pathway in glioblastoma patients in vivo显示文摘Deregulated signaling through the p hosphatidylinositol 3-kinase(PI3K)pathway is common in many types of can cer,including glioblastoma.Dissecting the molecular events associated with activation of this pathway in glioblastoma p atients in vivo presents an important challenge that has implic ations for the development and clini cal testing of PI3K pathway inhibito rs.Using an immunohistochemical analysis appl ied to a tissue microarray,we performed hierarchical clustering and mul tidimensional scaling,as well as univariate and multivariate analyses,to dissect the PI3K pathway in v ivo.We demonstrate that loss of the t umor suppressor protein PTEN,which antagonizes PI3K pathwa y activation,is highly correlated w ith activation of the main PI3K effec tor Akt in vivo.We also show that Akt activation is signific antly correlated with phosphorylation of mammalian target of rapamycin(mTOR),the family of forkhead transcription factors(FOXO1,FOXO3a,and FOXO4),and S6,which are thought to promote its effects.Expression of the mutan t epidermal growth factor receptor vIII is also tightly correlated with phosphorylation of these effectors,d emonstrating an additional route to PI3K pathway activation in glioblastomas in vivo.These results provide the first dissection of the PI3K path way in glioblastoma in vivo and suggest an approach to stratifying patients for targeted kinase inhi bitorChoe G Horvath S Cloughesy TF Crosby K Seligson D Palotie A Inge L Smith BL Sawyers CL Mischel PS 2003癌症2003,22,7:41
8Clinical implication of VEGF serum levels in cirrhotic patients with or without portal hypertension显示文摘INTRODUCTIONAngiogenesisorformationofnewbloodvesels,isatightlyregulatedprocesinwhichbloodveselssupplygrowingtisuewithnutrient...Nimer Assy 1,4 , M Paizi 3,4 , D Gaitini 2, Y Baruch 1,4 and G Spira 3,4,5 1999World Journal of Gastroenterology1999,5,4:35
9有机阴离子柱撑水滑石的插层组装及超分子结构显示文摘以水滑石Mg4Al2(OH)12CO3.4H2O为前体,采用离子交换法进行插层组装制备了丁二酸、己二酸、十二烷基磺酸、对羟基苯甲酸、苯甲酸和对苯二甲酸柱撑水滑石,并用XRD, FTIR和DTA测试技术对样品进行了表征. 结果表明,通过控制离子交换条件,6种有机酸根离子可以插入水滑石的层间完全取代CO32离子,并形成具有超分子结构的稳定有机阴离子柱撑水滑石.李殿卿 冯桃 Evans D G 段雪 2002过程工程学报2002,2,4:35
10考虑土体非饱和特性的无限长斜坡降雨入渗解析解显示文摘由降雨诱发的残积土滑坡在亚热带和热带地区非常普遍,产生此类滑坡的主要原因是雨水入渗使斜坡内非饱和土体的负孔隙水压力降低导致了土体抗剪强度的减小。基于二维非饱和渗流控制方程,采用指数函数描述非饱和土体的土水特征曲线及其渗透系数随含水率(或负孔隙水压力)的变化,建立了降雨入渗条件下无限长斜坡内水分运移模型,在合理简化的基础上给出了模型的解析解。通过与成熟的有限元数值模拟软件计算结果的比较与分析,证明该解析解稳定可靠。由该解析解获得的负孔隙水压力剖面可用于评估降雨入渗对非饱和土斜坡稳定性的影响。詹良通 贾官伟 陈云敏 FREDLUND D G 2010岩土工程学报2010,32,8:33
11欧洲早产儿呼吸窘迫综合征防治共识指南(2013版)显示文摘本次指南更新包括了自2010年以来Cochrane系统评价和医学文献中的最新证据,并采纳了一种新的证据评估分级系统(GRADE)。以往关于早期肺表面活性物质和持续气道正压通气治疗的推荐目前拥有了更坚定的循证依据。对产房复苏、稳定生命体征等内容进行了较大扩充。生命体征稳定后的氧疗目前仍存在一定的争议,但是在获得更多的证据之前,血氧饱和度的目标范围不应低于90%,支持治疗对于超早早产儿仍然极为重要。指南对其他注意事项进行了缩减。Sweet D Carnielli V Greisen G Hallman M Ozek E Plavka R Saugstad OD Simeoni U Speer CP Halliday HL 王敏婕 袁琳 陈超 2014中华儿科杂志2014,52,10:34
12最新AD研究用诊断标准:IWG-2标准显示文摘在过去的8年中,国际工作组织(IWG)和美国国立老化研究院-阿尔茨海默协会(NIA-AA)建立了阿尔茨海默病(AD)诊断标准,它能更好地定义AD的临床表型,整合了生物标记物于诊断流程中,并覆盖了疾病的全程。本意见书充分地权衡了IWG标准的优缺点,建议改进诊断框架。依据这些改进,AD的诊断变得简单,只要有恰当的AD临床表型(典型或不典型)和与AD的病理相一致的病理生理学生物标志物出现。我们认为疾病的下游的定位性生物标志,如容积性磁共振成像(MRI)和氟脱氧葡萄糖-正电子发射型计算机断层成像(FDG-PET)等,适合更好地测量和监测疾病过程。本文还详述了非典型性AD、混合性AD和AD临床前期的特异诊断标准。陈刚 曹雯炜 俞羚 糜建华 Dubois B Feldman HH Jacova C Hampel H Molinuevo JL Blennow K DeK osky ST Gauthier S Selkoe D Bateman R Cappa S Crutch S Engelborghs S Frisoni GB Fox NC Galasko D Habert MO Jicha GA Nordberg A Pasquier F Rabinovici G Robert P Rowe C Salloway S Sarazin M Epelbaum S de Souza LC Vellas B Visser PJ Schneider L Stern Y Scheltens P Cummings JL 2014神经病学与神经康复学杂志2014,11,3:31
13阿尔泰—阿尔金地学断面地壳结构显示文摘根据阿尔泰—阿尔金地学断面的地震纵、横波资料 ,建立了地壳速度及泊松比结构 .测区的地壳具有明显的三分结构特征 ,其纵波速度自上而下依次为 6 .0~ 6 .3km s、6 .3~ 6 .6km s及 6 .9~ 7.0km s ;阿尔泰南缘的地壳最厚 ,为 5 6km ,准噶尔盆地的地壳最薄 ,为 4 6km ,大部分地区的地壳厚度为 5 0km左右 .准噶尔盆地与天山之间上地幔顶部的纵波速度为 7.7~ 7.8km s ;阿尔泰南缘及塔里木盆地上地幔顶部的纵波速度较高 ,为 7.9~ 8.0km s.测线南部 ,包括东天山及塔里木东缘 ,自地表至 30km深处的地壳纵波速度低 ,泊松比为 0 .2 5 ,表明上地壳主要为石英及花岗质成分 ;而测线北部 (包括阿尔泰及准噶尔盆地 )的中、上地壳则呈现较高的泊松比 (0 .2 6~ 0 .2 7) ,可能为基性地壳的体现 .厚 15~ 30km的下地壳纵波速度 (6 .9~ 7.0km s)较高 ,泊松比为 0 .2 6~ 0 .2 8,可能以镁铁质的麻粒岩成分为主 .位于天山及其南侧地壳中部的低速层 (VP=5 .9km s,σ=0 .2 5 )则可能为晚古生代的构造热事件中的花岗质侵入岩 .王有学 韩果花 姜枚 袁学诚 Walter D Mooney Robert G Coleman 2004地球物理学报2004,47,2:32
14Tectonic evolution of the Dabieshan orogen: In the view from polyphase deformation of the Beihuaiyang metamorphic zone显示文摘The Beihuaiyang metamorphic zone was formed by the Early Mesozoic collision of the North and South China Blocks. It consisted of the Foziling and Luzhenguan complexes and was thought to have never afforded a deep subduction. A similar feature of the deformation in the Dabieshan UHP metamorphic rocks implies that these different tectonic units share the same geodynamic background. The early stage of deformation can be preserved on account of their relatively shallower subduction than that for UHP rocks. On the basis of an analysis of the geo- logical structure and geochronological results, five deformational stages have been recognized: a D1-Early compressional deformation which represents the continental subduction; a D2-Early exhumation deformation producing a syn-convergence exhumation; a D3-Main deformation, represented by an exhumation deformation with Late Triassic age; a D4-Doming and its margin extensional gravity collapse deformation and finally a D5-regional extensional deformation of Cretaceous that was mostly introduced by the migmatization and plutonism.LIN Wei1, 2, Faure Michel3, WANG Qingchen1 & Arnaud Nicolas4 1. LTE, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China 2. Department of Earth and Planetary Sciences, Graduate School of Science, Nagoya University, Japan 3. ISTO, UMR CNRS 6113, Batiment Géosciences, Orléans Université d’Orléans, 45067 Orléans Cedex 2, France 4. UMR 6524 'Magmas et Volcans', 5 Rue Kessler, 63000 Clermont-Ferrand, France 2005Science China Earth Sciences2005,48,7:25
15Pancreatic stellate cell: Pandora's box for pancreatic disease biology显示文摘Pancreatic stellate cells(PSCs) were identified in the early 1980 s, but received much attention after 1998 when the methods to isolate and culture them from murine and human sources were developed. PSCs contribute to a small proportion of all pancreatic cells under physiological condition, but are essential for maintaining the normal pancreatic architecture. Quiescent PSCs are characterized by the presence of vitamin A laden lipid droplets. Upon PSC activation, these perinuclear lipid droplets disappear from the cytosol, attain a myofibroblast like phenotype and expresses the activation marker, alpha smooth muscle actin. PSCs maintain their activated phenotype via an autocrine loop involving different cytokines and contribute to progressive fibrosis in chronic pancreatitis(CP) and pancreatic ductal adenocarcinoma(PDAC). Several pathways(e.g., JAK-STAT, Smad, Wnt signaling, Hedgehog etc.), transcription factors and mi RNAs have been implicated in the inflammatory and profibrogenic function of PSCs. The role of PSCs goes much beyond fibrosis/desmoplasia in PDAC. It is now shown that PSCs are involved in significant crosstalk between the pancreatic cancer cells and the cancer stroma. These interactions result in tumour progression, metastasis, tumour hypoxia, immune evasion and drug resistance. This is the rationale for therapeutic preclinical and clinical trials that have targeted PSCs and the cancer stroma.Ratnakar R Bynigeri Aparna Jakkampudi Ramaiah Jangala Chivukula Subramanyam Mitnala Sasikala G Venkat Rao D Nageshwar Reddy Rupjyoti Talukdar 2017World Journal of Gastroenterology2017,23,3:25
16Tricept机械手静刚度解析建模方法显示文摘以Tricept机械手的3自由度球坐标型并联机构为例,提出含恰约束支链的球坐标型并联构型装备静刚度解析建模方法。该方法首先借助子结构综合思想将末端执行器位姿变形分解为无约束主动支链的拉压变形、恰约束支链的弯曲变形及其扭转变形3个部分,然后利用虚功原理和结构矩阵法建立各子结构系统的静柔度模型,最后借助线性叠加原理组集整机末端静柔度模型。在建模过程中,侧重研究恰约束支链弯曲剐度以及铰链刚度的建模方法。在此基础上,考察了Tricept机械手中3自由度并联机构静刚度在工作空间中的变化规律,并借助全局性能指标评价了主要构件柔度对整机柔度的贡献。王友渔 黄田 CHETWYND D G HU S J 2008机械工程学报2008,44,8:24
17Depression in patients with irritable bowel syndrome in Jos,Nigeria显示文摘AIM: To study the brain-gut interaction and the effect of behavioral or psychiatric conditions on irritable bowel syndrome (IBS) in an African population. METHODS: IBS was diagnosed using the Rome Ⅱ diagnostic criteria. The entry of each patient was confirmed following detailed explanations of the questions. Four hundred and eighteen patients were studied. Subjects satisfying the Rome Ⅱ criteria for IBS were physically examined and stool microscopy was done to identify the presence of “alarm factors”. Depression was diagnosed using the symptom-check list adapted from the Research Diagnostic Criteria (DSM-Ⅳ) of the American Psychiatric Association. RESULTS: Seventy-five (56.8%) of the 132 IBS patients were depressed whereas only 54 (20.1%) of the 268 non-IBS patients were depressed. There was a significant relationship between IBS and depression (χ2 = 54.29, Odds ratio = 5.21, 56.8 ± 8.4 vs 20.1 ± 5.2, P = 0.001). Even though constipation predominant IBS patients were more likely to be depressed, no significant relationship was found between the subtype of IBS and depression (χ2 = 0.02, OR = 0.95, P = 0.68). CONCLUSION: IBS is significantly associated with major depression but not gender and bowel subtypes of the patients. Patients with IBS need to be evaluated for depression due to the highly significant relationship between the two conditions.Nimzing G Ladep Taiwo J Obindo Moses D Audu Edith N Okeke Abraham O Malu 2006World Journal of Gastroenterology2006,12,48:22
18Mixolab参数与粉质、拉伸参数及面包烘烤品质的关系显示文摘根据仪器测定的面粉品质特性预测面包烘烤品质是进行小麦品质改良的重要方法。法国肖邦公司(Chopin Technologies,France)最新推出的Mixolab分析仪可以同时测定面粉加水后恒温揉混及面团升温后蛋白质弱化和淀粉糊化特性,明确其与现有相似仪器如粉质仪和拉伸仪等的关系对小麦品质测试具有重要意义。利用Mixolab分析仪、粉质仪、拉伸仪测定了41份高代育种品系的有关参数和面包烘烤品质,并分析了Mixolab与粉质仪和拉伸仪相关参数的关系及预测面包品质的可靠性。结果表明,可以用Mixolab的形成时间、稳定时间、面团受热后蛋白质弱化值(C2值)和到达淀粉糊化反弹值的时间(C4时间)来预测粉质仪和拉伸仪的品质参数,可解释其变异的74%~90%;可以直接用C2值预测面包体积、外观、结构和总分,决定系数分别为52%、73%、70%和68%;预测面包质地和弹性的参数不仅包含Mixolab稳定时间和C2值,还有表示淀粉糊化特性的C3时间、C4和C5值及C5温度。用Mixolab分析仪既可以了解蛋白质特性和面包烘烤品质的关系,又明确了淀粉品质对面包品质的显著影响,在品质测试中有其独特之处。Mixolab、粉质仪和拉伸仪各参数对预测小麦面包体积、内部质地结构等烘烤品质性状的贡献不同。张艳 王彦飞 陈新民 王德森 Humieres G D 冯建军 何中虎 2009作物学报2009,35,9:22
19钢的回火时间-温度-硬度动力学关系显示文摘研究了 5 5NiCrMoV7钢在 10 0°C~ 70 0°C、90s~ 6 6 5h之间回火的组织和力学性能变化。以钢的淬、回火和退火硬度作为基本参数 ,定义了回火度的概念 ,提出了具有Johnson Mehl Avrami关系式形式的、适用于无二次硬化钢的回火 (时效 )动力学规律。由该规律出发可以推出Hollomon Jaffe回火参数与时间、温度和硬度的关系式。张占平 齐育红 DELAGNES D BERNHART G 2004材料热处理学报2004,25,1:21
20Non-invasive means of measuring hepatic fat content显示文摘Hepatic steatosis affects 20% to 30% of the general adult population in the western world. Currently, the technique of choice for determining hepatic fat deposition and the stage of fibrosis is liver biopsy. However, it is an invasive procedure and its use is limited, particularly in children. It may also be subject to sampling error. Non-invasive techniques such as ultrasound, computerised tomography (CT), magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (1H MRS) can detect hepatic steatosis, but currently cannot distinguish between simple steatosis and steatohepatitis, or stage the degree of fibrosis accurately. Ultrasound is widely used to detect hepatic steatosis, but its sensitivity is reduced in the morbidly obese and also in those with small amounts of fatty infiltration. It has been used to grade hepatic fat content, but this is subjective. CT can detect hepatic steatosis, but exposes subjects to ionising radiation, thus limiting its use in longitudinal studies and in children. Recently, magnetic resonance (MR) techniques using chemical shift imaging have provided a quantitative assessment of the degree of hepatic fatty infiltration, which correlates well with liver biopsy results in the same patients. Similarly, in vivo 1H MRS is a fast, safe, non-invasive method forthe quantification of intrahepatocellular lipid (IHCL) levels. Both techniques will be useful tools in future longitudinal clinical studies, either in examining the natural history of conditions causing hepatic steatosis (e.g. non-alcoholic fatty liver disease), or in testing new treatments for these conditions.Sanjeev R Mehta E Louise Thomas Jimmy D Bell Desmond G Johnston Simon D Taylor-Robinson 2008World Journal of Gastroenterology2008,14,22:21
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