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| 1 | 2019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 |
| 2 | BCLC策略:预后预测和治疗推荐2022版更新显示文摘2018版BCLC预后和治疗推荐策略发布后,肝细胞癌(简称HCC)的研究又取得了重大进展。本次更新基于肝癌各领域的研究进展结果。重点关注影响策略的重要研究进展。虽然近年的研究结果成绩斐然,但将其引入为临床医生和研究者提供行动依据的循证模型指南来说证据效力依然不够确切。本文对该问题进行分析,阐述了为HCC患者制定个体化治疗临床决策所需的批判性思维和专业知识。 | Reig M Forner A Rimola J Ferrer-Fabrega J Burrel M Garcia-Criado A Kelley RK Galle PR Mazzaferro V Salem R Sangro B Singal AG Vogel A Fuster J Ayuso C Bruix J 刘永凡(摘译) 崔笑(摘译) 耿小平(审校) | 2022 | 肝胆外科杂志2022,30,5: | 80 |
| 3 | 前庭性偏头痛:诊断标准——Barany学会及国际头痛学会共识文件显示文摘本文提供了前庭性偏头痛的诊断标准,由Barany学会前庭疾患分类委员会及国际头痛学会(IHS)偏头痛分类分委员会共同制定。分类包括前庭性偏头痛及很可能的前庭性偏头痛。与IHS的常规程序相同,前庭性偏头痛作为一种新分类,将首先出现在第3版国际头痛分类(ICHD-3)的附录中。若积累了进一步的证据,很可能的前庭性偏头痛也许会纳入更晚的ICHD版本中。前庭性偏头痛的诊断建立在反复发作的前庭症状、具有偏头痛病史、前庭症状与偏头痛症状间存在时间上的相关性,并排除其他可导致前庭症状的病因。符合前庭性偏头痛诊断的症状包括不同类型的眩晕及头部活动诱发的头晕伴恶心。症状的严重程度必须为中重度。急性发作的持续时间限于5 min^72 h的时间窗内。 | 华驾略 李焰生 Lempert T Olesen J Furman J Waterston J Seemungal B Carey J Bisdorff A Versino M Evers S Newman-Toker D | 2013 | 神经病学与神经康复学杂志2013,10,3: | 60 |
| 4 | MicroRNA-34a inhibits glioblastoma growth by targeting multiple oncogenes显示文摘 | Li Y Guessous F Zhang Y Dipierro C Kefas B Johnson E Marcinkiewicz L Jiang J Yang Y Schmittgen TD Lopes B Schiff D Purow B Abounader R | 2009 | 中国神经肿瘤杂志2009,7,4: | 56 |
| 5 | 美国国立老化研究所与阿尔茨海默病协会诊断指南写作组:阿尔茨海默病痴呆诊断标准的推荐显示文摘由美国国立老化研究所(NIA)和阿尔茨海默病(AD)协会组织了一个工作组,负责修订1984年版AD痴呆的诊断标准。旨在确保修订后的标准具有足够的灵活性,既可供缺乏神经心理学测验、先进的影像技术和脑脊液检查措施的普通医务人员使用,也可供具备上述措施的科研、临床试验的专业研究者使用。新的标准广泛适用于各种原因的痴呆以及专门针对AD痴呆的标准,保留了1984年版标准中的“很可能的AD痴呆”的总体框架。在过去27年的经验基础上,工作组对临床诊断标准做了一些修改,保留了“可能的AD痴呆”的术语,但对其进行了更有针对性的重新定义。在科研用的“很可能的和可能的AD痴呆”的诊断标准中纳入了生物标志物证据。AD痴呆的核心临床标准仍将是临床实践中诊断的基础,但用生物标志物证据来提高AD痴呆诊断的病理生理学特异性也被人们寄予厚望。要实现AD痴呆的生物标志物诊断,还有许多工作摆在面前。 | McKhann GM Knopman DS Chertkow H Hyman BT Jack CR Jr Kawas CH Klunk WE Koroshetz WJ Manly J J Mayeux R Mohs RC Morris JC Rossor MN Scheltens P Carrillo MC Thies B Weintraub S Phelps CH 贾建平(译) 陆璐(译) 张逸驰(译) 黄丽(译) 韩阅(译) | 2012 | 中华神经科杂志2012,45,5: | 52 |
| 6 | Antiviral innate immunity pathways显示文摘最近的研究揭开了激活主人的二个发信号小径对病毒的感染的天生的免疫。小径之一利用像使用费的受体(TLR ) 的成员检测通过 endocytosis 进入内涵体的病毒的家庭。TLR 小径通过最终导致抄写因素 NF-kappaB, IRF3 和 IRF7 的激活的几发信号的蛋白质导致干扰素生产。另外的抗病毒的小径为细胞内部的病毒的双 stranded RNA 把 RNA helicase RIG-I 用作受体。RIG-I 通过最近识别的适配器蛋白质 MAVS 激活 NF-kappaB 和 IRF,包含居住在 mitochondrial 膜的蛋白质的一个卡片领域。MAVS 为抗病毒的天生的免疫是必要的,但是它也用作丙肝病毒(HCV ) 的一个目标,它采用病毒的朊酶劈开 MAVS 离开线粒体,从而允许 HCV 逃离主人免疫系统。 | Rashu B Seth Lijun Sun Zhijian J Chen | 2006 | Cell Research2006,16,2: | 45 |
| 7 | Oxidative stress and male reproductive health显示文摘有缺点的精子功能的主要原因之一是氧化应力,它不仅破坏精子 DNA 的正直而且在精子血浆膜由于蛋白质和类脂化合物的并行的损坏限制这些房间的使肥沃的潜力。如此的氧化压力的起源看起来包含精子线粒体,它有一个趋势作为一篇序言产生 superoxide 阴离子的高水平到进入内在的 apoptotic 串联。不幸地,这些房间有很小的能力因为他们仅仅在基础切除修理(BER ) 拥有第一酶,对如此的攻击作出回应小径, 8-oxoguanine glycosylase 1 (OGG1 ) 。后者成功地创造一个 abasic 地点,而是精子因为他们缺乏下游的蛋白质,不能进一步处理氧化损害(APE1, XRCC1 ) 需要完成修理过程。在第一个有丝分裂的部门的 S 阶段的开始以前继续 BER 小径是卵母细胞的责任。如果一个错误被卵母细胞在开发的这个阶段犯,一个变化将被创造那将在身体在每个房间被代表。如此的机制可以在在作为年龄的后果在他们的细菌线承受了氧化应力的男性的后代观察的童年癌症和另外的疾病解释增加,环境或生活方式因素。在男不孕病人的精子的氧化 DNA 损坏的高流行可以为在 vitro 构思的孩子的健康有含意并且在细菌线为对免费激进的产生的起源的当前的研究担任一位司机。 | Robert J Aitken Tegan B Smith Matthew S Jobling Mark A Baker Geoffry N De Iuliis | 2014 | Asian Journal of Andrology2014,16,1: | 48 |
| 8 | AGNP精神科治疗药物监测共识指南:2011显示文摘治疗药物监测(Therapeutic drug monitoring,TDM),如通过定量测定血清或血浆药物浓度指导用药剂量优化,已经成为对患者进行精神药物治疗的很有价值的工具。在患者用药依从性难以判断、药物耐受性不佳、治疗剂量下无效以及可能存在药代动力学药物-药物相互作用等情况下,测定药物浓度是很有用的。在精神科,有可能明显获益于TDM的主要患者群体包括儿童、孕妇、老年患者、智力障碍患者、涉及司法的患者、已知或怀疑携带药代动力学相关基因变异的患者,以及合并躯体疾病影响药代动力学的患者。然而,只有将TDM充分整合到临床治疗过程中去,才能发挥其优化药物治疗的潜在优势。为了促进TDM的合理应用,神经精神药理学与药物精神病学协会(Arbeitsgemeinschaft für Neuropsychopharmakologie und Pharmakopsychiatrie,AGNP)的TDM专家组在2004年发表了精神药物治疗药物监测指南。之后,随着知识不断更新,又有许多可能需要进行TDM的新药上市。因此,本次更新将神经精神药物的种类扩展到了128种,并将其TDM必要性划分为从'强烈推荐'到'可能有用'的四个等级。经过大量细致且全面的文献检索与分门别类的汇总整理,将基于循证医学理念的'治疗参考浓度范围'和'剂量相关参考浓度范围'呈现给大家。本共识指南引入了'实验室警戒浓度'的新概念,即实验室需要马上告知治疗医生的药物浓度上限。本共识指南还给出了诸如药物作为细胞色素P450酶的底物和抑制剂的性质,代谢物与母药浓度比值的常见范围,以及与结果解释相关的内容,还提供了何时将TDM与遗传药理学检测相结合的建议。遵循本指南,有助于改善许多患者精神药物治疗的效果,特别是那些存在药代动力学异常的患者。TDM是一门交叉学科,有时针对看起来不一致的数据,需要多学科坦诚地讨论,只有这样,患者才能从这种合作中获益。 | Hiemke C Baumann P Bergemann N Conca A Dietmaier O Egberts K Fric M Gerlach M Greiner C Gründer G Haen E Havemann-Reinecke U Jaquenoud Sirot E Kirchherr H Laux G Lutz UC Messer T Müller MJ Pfuhlmann B Rambeck B Riederer P Schoppek B Stingl J Uhr M Ulrich S Waschgler R Zernig G 李文标(译) 果伟(译) 阮灿军(译) 贺静(译) 汤宜朗(审校) 王传跃(审校) | 2016 | 实用药物与临床2016,19,10: | 37 |
| 9 | Abnormal activation of the synuclein-gamma gene in hepatocellular carcinomas by epigenetic alteration.显示文摘 | Zhao W Liu H Liu W Wu Y Chen W Jiang B Zhou Y Xue R Luo C Wang L Jiang JD Liu J | 2006 | 中国生物学文摘2006,20,4: | 31 |
| 10 | Impact of postoperative omega-3 fatty acid-supplemented parenteral nutrition on clinical outcomes and immunomodulations in colorectal cancer patients显示文摘AIM: To investigate the effect of omega-3 fatty acid parenteral supplementation postoperatively on clinical outcomes and immunomodulation in colorectal cancer patients. METHODS: Forty-two patients undergoing radical colorectal cancer resection with an indication for total parenteral nutrition postoperatively were enrolled in this prospective, double-blind, randomized, controlled study. Patients received total parenteral nutrition supplemented with either soybean oil (LCT; Intralipid, Fresenius-Kabi, SO group, n = 21) or a combination of omega-3 fish oil and soybean oil (LCT:fish oil = 5:1, fish oil; Omegaven, Fresenius-Kabi, FO group, n = 21), up to a total of 1.2 g lipid/kg per day for 7 d postoperatively. A same volume calorie and nitrogen was administrated. Routine blood test, biochemistry, systemic levels of IL-6 and TNF-α, percentage of CD3+, CD4+, and CD8+ lymphocytes were evaluated preoperatively and on postoperative d 1 and 8. Patient outcome was evaluated considering mortality during the hospital stay, length of postoperative hospital stay, and occurrence of infectious complications. RESULTS: Both lipid regimens were well tolerated. No differences between the two groups were noticed in demographics, baseline blood test, biochemistry, serum levels of IL-6 and TNF-α, percentage of CD4+, CD8+ lymphocytes, and ratios of CD4+/CD8+. Compared with those on postoperative d 1, serum IL-6 levels onpostoperative d 8 were significantly depressed in the FO group than in the reference group (-44.43 ± 30.53 vs -8.39 ± 69.08, P = 0.039). Simultaneously, the ratios of CD4+/CD8+ were significantly increased in the FO group (0.92 ± 0.62 vs 0.25 ± 1.22, P = 0.035). In addition, depression of serum TNF-α levels (-0.82 ± 2.71 vs 0.27 ± 1.67, P = 0.125) and elevation of CD3+ and CD4+ lymphocyte percentage (12.85 ± 11.61 vs 3.84 ± 19.62, P = 0.081, 17.80 ± 10.86 vs 9.66 ± 17.55, P = 0.084, respectively) were higher in the FO group than in the reference group. Patients in the FO group trended to need a shorter postoperative hospital stay (17.45 ± 4.80 d vs 19.62 ± 5.59 d, P = 0.19). No statistically significant difference was found when stratified to mortality and occurrence of infectious complications. CONCLUSION: Postoperative supplementation of omega-3 fatty acids may have a favorable effect on the outcomes in colorectal cancer patients undergoing radical resection by lowering the magnitude of inflammatory responses and modulating the immune response. | Bin Liang, Shan Wang, Ying-Jiang Ye, Xiao-Dong Yang, You-Li Wang, Jun Qu, Qi-Wei Xie, Mu-Jun Yin, Division of Surgical Oncology and Division of Gastroenterological Surgery, Peking University People’s Hospital, Beijing 100044, China Author contributions: Liang B and Wang S contributed equally to this work Liang B and Wang S designed the research Liang B, Ye YJ, Yang XD, Wang YL, Qu J, Xie QW, Yin MJ performed the research and collected the data Wang S and Ye YJ supervised the research Liang B and Ye YJ analyzed the data Liang B wrote the paper and revised the manuscript. | 2008 | World Journal of Gastroenterology2008,14,15: | 31 |
| 11 | Current state of laparoscopic parastomal hernia repair:A meta-analysis显示文摘AIM:To evaluate the efficacy and safety of the laparoscopic approaches for parastomal hernia repair reported in the literature.METHODS:A systematic review of PubMed and MEDLINE databases was conducted using various combination of the following keywords:stoma repair,laparoscopic,parastomal,and hernia.Case reports,studies with less than 5 patients,and articles not written in English were excluded.Eligible studies were further scrutinized with the 2011 levels of evidence from the Oxford Centre for Evidence-Based Medicine.Two authors reviewed and analyzed each study.If there was any discrepancy between scores,the study in question was referred to another author.A meta-analysis was performed using both random and fixed-effect models.Publication bias was evaluated using Begg's funnel plot and Egger's regression test.The primary outcome analyzed was recurrence of parastomal hernia.Secondary outcomes were mesh infection,surgical site infection,obstruction requiring reoperation,death,and other complications.Studies were grouped by operative technique where indicated.Except for recurrence,most postoperative morbidities were reported for the overall cohort and not by approach so they were analyzed across approach.RESULTS:Fifteen articles with a total of 469 patients were deemed eligible for review.Most postoperative morbidities were reported for the overall cohort,and not by approach.The overall postoperative morbidity rate was 1.8%(95%CI:0.8-3.2),and there was no difference between techniques.The most common postoperative complication was surgical site infection,which was seen in 3.8%(95%CI:2.3-5.7).Infected mesh was observed in 1.7%(95%CI:0.7-3.1),and obstruction requiring reoperation also occurred in 1.7%(95%CI:0.7-3.0).Other complications such as ileus,pneumonia,or urinary tract infection were noted in16.6%(95%CI:11.9-22.1).Eighty-one recurrences were reported overall for a recurrence rate of 17.4%(95%CI:9.5-26.9).The recurrence rate was 10.2%(95%CI:3.9-19.0) for the modified laparoscopic Sugarbaker approach,whereas the recurrence rate was27.9%(95%CI:12.3-46.9) for the keyhole approach.There were no intraoperative mortalities reported and six mortalities during the postoperative course.CONCLUSION:Laparoscopic intraperitoneal mesh repair is safe and effective for treating parastomal hernia.A modified Sugarbaker approach appears to provide the best outcomes. | Francis J DeAsis Brittany Lapin Matthew E Gitelis Michael B Ujiki | 2015 | World Journal of Gastroenterology2015,21,28: | 34 |
| 12 | 囊性肾瘤、肾脏混合性上皮和间质肿瘤34例临床病理分析显示文摘 | Turbiner J Amin M B Humphrey P A 刘飞飞(摘译) 张仁亚(审校) | 2007 | 临床与实验病理学杂志2007,23,3: | 29 |
| 13 | Arginase-1:一种新的肝细胞和肝细胞肿瘤的标记物显示文摘 | Yang B C Gong C Song J 黄文斌(摘译) | 2010 | 临床与实验病理学杂志2010,26,5: | 27 |
| 14 | Structure and function of aggrecan显示文摘Aggrecan is the major proteoglycan in the articular cartilage. This molecule is important in the proper functioning of articular cartilage because it provides a hydrated gel structure (via its interaction with hyaluronan and link protein) that endows the cartilage with load-bearing properties. It is also crucial in chondroskeletal morphogenesis during development. Aggrecan is a multimodular molecule expressed by chondrocytes. Its core protein is composed of three globular domains (G1, G2, and G3) and a large extended region (CS) between G2 and G3 for glycosaminoglycan chain attachment. G1 comprises the amino terminus of the core protein. This domain has the same structural motif as link protein. Functionally, the G1 domain interacts with hyaluronan acid and link protein, forming stable ternary complexes in the extracellular matrix. G2 is homologous to the tandem repeats of G1 and of link protein and is involved in product processing. G3 makes up the carboxyl terminus of the core protein. It enhances glycosaminoglycan modification and product secretion. Aggrecan plays an important role in mediating chondrocyte-chondrocyte and chondrocyte-matrix interactions through its ability to bind hyaluronan. | CHRIS KIANI, LIWEN CHEN, YAO JIONG WU, ALBERT J YEE, BURTON B YANG, Sunnybrook and Women’s College Health Sciences Centre and Department of Laboratory Medicine and Patobiology, 2 Department of Surgeny, Faculty of Medicine, University of Toronto, Canada | 2002 | Cell Research2002,12,1: | 27 |
| 15 | Outcome of patients with acute, necrotizing pancreatitis requiring drainage-does drainage size matter?显示文摘AIM:To assess the outcome of patients with acute necrotizing pancreatitis treated by percutaneous drainage with special focus on the influence of drainage size and number. METHODS:We performed a retrospective analysis of 80 patients with acute pancreatitis requiring percutaneous drainage therapy for infected necroses. Endpoints were mortality and length of hospital stay. The influence of drainage characteristics such as the median drainage size, the largest drainage size per patient and the total drainage plane per patient on patient outcome was evaluated. RESULTS:Total hospital survival was 66%. Thirty-four patients out of all 80 patients (43%) survived acute necrotizing pancreatitis with percutaneous drainage therapy only. Eighteen patients out of all 80 patients needed additional percutaneous necrosectomy (23%). Ten out of these patients required surgical necrosectomy in addition, 6 patients received open necrosectomy without prior percutaneous necrosectomy. Elective surgery was performed in 3 patients receiving cholecystectomy and one patient receiving resection of the parathyroid gland. The number of drainages ranged from one to fourteen per patient. The drainage diameter ranged from 8 French catheters to 24 French catheters. The median drainage size as well as the largest drainage size used per patient and the total drainage area used per patient did not show statistically significant influence on mortality. CONCLUSION:Percutaneous drainage therapy is an effective tool for treatment of necrotizing pancreatitis.Large bore drainages did not prove to be more effective in controlling the septic focus. | T Bruennler J Langgartner S Lang CE Wrede F Klebl S Zierhut S Siebig F Mandraka F Rockmann B Salzberger S Feuerbach J Schoelmerich OW Hamer | 2008 | World Journal of Gastroenterology2008,14,5: | 23 |
| 16 | 美国国立老化研究所与阿尔茨海默病协会诊断指南写作组:阿尔茨海默病临床前阶段的定义显示文摘阿尔茨海默病(AD)的病理生理过程在痴呆诊断的多年前就开始了。这一长期的AD“临床前”阶段是治疗干预的关键机会,但需进一步阐明AD的病理级联过程和临床症状出现之间的联系。美国国立老化研究所和AD协会召集了一个国际工作组对AD生物标志物、流行病学和神经心理学的证据进行综述并提出建议,以确定能够预测由“正常”认知到轻度认知功能障碍(MCI)及AD痴呆的最佳预测指标。根据目前已有的主要科学证据,我们提出了一个概念性的框架和用于操作的研究标准,以通过纵向临床研究来验证和改进这些模型。这些建议仅用于研究目的,目前不涉及临床应用。我们希望这些建议能提供一个共识,以推进临床前AD的研究,最终推动更早期治疗干预的进展,使得一些疾病减缓药物的疗效发挥最大。 | Sperling RA Aisen PS Beckett LA Bennett DA Craft S Fagan AM Iwatsubo T Jack CR Jr Kaye J Montine TJ Park DC Reiman EM Rowe CC Siemers E Stern Y Yaffe K Carrillo MC Thies B Morrison-Bogorad M Wagster MV Phelps CH 贾建平(译) 郭起浩(译) 黄丽(译) 陆璐(译) 张逸驰(译) 邢怡(译) | 2012 | 中华神经科杂志2012,45,5: | 22 |
| 17 | 模拟城市蔓延对自然资本存量和生态服务功能流的影响:美国华盛顿州普吉特海湾的案例研究显示文摘城市增长是全球和区域环境变化的主要驱动力,也是生态系统服务供应及以此为基础的社会的变革模式。发展中国家的巨型城市不断涌现,而发达国家的城市土地使用也在不断蔓延。大量研究表明,土地转换是过去的几十年中区域尺度生态系统服务变化的重要原因之一,并且也将是未来生态系统服务损失的主要原因。 | ZANKA B BAGSTADB K J VOIGTC B | 2016 | 城市规划学刊2016,,3: | 22 |
| 18 | The ReaxFF reactive force-field: development, applications and future directions显示文摘The reactive force-field(ReaxFF)interatomic potential is a powerful computational tool for exploring,developing and optimizing material properties.Methods based on the principles of quantum mechanics(QM),while offering valuable theoretical guidance at the electronic level,are often too computationally intense for simulations that consider the full dynamic evolution of a system.Alternatively,empirical interatomic potentials that are based on classical principles require significantly fewer computational resources,which enables simulations to better describe dynamic processes over longer timeframes and on larger scales.Such methods,however,typically require a predefined connectivity between atoms,precluding simulations that involve reactive events.The ReaxFF method was developed to help bridge this gap.Approaching the gap from the classical side,ReaxFF casts the empirical interatomic potential within a bond-order formalism,thus implicitly describing chemical bonding without expensive QM calculations.This article provides an overview of the development,application,and future directions of the ReaxFF method. | Thomas P Senftle Sungwook Hong Md Mahbubul Islam Sudhir B Kylasa Yuanxia Zheng Yun Kyung Shin Chad Junkermeier Roman Engel-Herbert Michael J Janik Hasan Metin Aktulga Toon Verstraelen Ananth Grama Adri CT van Duin | 2016 | npj Computational Materials2016,,1: | 22 |
| 19 | 运输应激猪骨骼肌中热应激蛋白HSP_(70)和HSP_(90)家族的表达显示文摘利用Westernblot技术 ,检测长途运输试验猪骨骼肌 (背最长肌和臀大肌 )中分属于HSP70 家族和HSP90 家族的 4种应激蛋白 (HSP70 ,HSP72 ,HSP86和HSP90 )的表达。所有运输应激猪和对照猪肌肉组织中均检测到了上述 4种HSP。对照猪组织中HSP的表达说明HSP除了在受应激的细胞内行使生理功能外 ,还具有独立于应激刺激应答以外的其它作用。6h的长途运输后 ,HSP的表达量明显不同 ,HSP70 和HSP72 在肌肉组织中的表达虽然有一定的增加 ,但统计学分析差异不显著 (P >0 0 5 ) ;而HSP86和HSP90 在骨骼肌中的表达明显下降 ,尤以HSP90 下降最为显著 (P <0 0 1)。提示HSP90 家族成员与肉品品质相关 。 | 鲍恩东 K R Sultan B Nowak J Hartung | 2001 | 南京农业大学学报2001,24,1: | 21 |
| 20 | 龙门山断裂带沉积岩和天然断层泥的摩擦滑动性质与启示显示文摘对采自四川龙门山断裂带(LFZ)地震发生区段的样品进行摩擦滑动实验研究,得到一系列实验结果。实验样品包括用富含黏土的完整泥岩和砂岩制备的模拟断层泥、由富含方解石的灰岩制备的模拟断层泥和一种天然断层泥。其中,天然断层泥是通过人工探槽方法采自于穿过泥岩和砂岩层的地表破裂中。富含黏土矿物的样品主要由伊利石和石英组成。在实验中,将1 mm厚的断层泥夹于具有倾斜锯切面的围岩之间,在三轴实验系统中对其进行剪切变形实验,实验条件与龙门山断裂带2 km深处的条件相一致。实验温度范围为25℃~150℃,同时为了研究摩擦强度的速度依赖性,对剪切位移的速度实施1.22~0.122μm/s的阶跃式变化。分析结果表明,天然断层泥比原岩的泥岩和砂岩更富含伊利石,而且强度比原岩弱得多。天然断层泥的稳态摩擦系数约为0.4,而原岩则约为0.6。另外,灰岩断层泥的摩擦系数为0.6~0.7。除了灰岩,所有样品均表现为稳定、速度强化的滑动行为。灰岩在25℃~50℃表现为速度强化,但是在100℃~150℃时表现为准静态的振荡,在150℃时显示速度弱化行为。运用此次实验结果讨论沉积岩在类似于汶川地震这样的地震事件中所起的作用,指出该区域富含黏土的沉积层可能对从深部扩展而来的破裂扩展有阻尼作用,而灰岩则有可能会加速破裂的传播,同时产生明显的应力降。 | 何昌荣 VERBERNE B A SPIERS C J | 2011 | 岩石力学与工程学报2011,30,1: | 20 |