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1氯吡格雷的使用与药物洗脱支架植入后远期临床结果显示文摘背景:近来的冠状动脉内药物洗脱支架研究提示,现行的抗血小板治疗方案可能并不足以预防后期支架内血栓形成。目的:于接受药物洗脱支架(drug-eluting stents,DESs)和裸金属支架(bare-metal stents,BMSs)治疗的冠状动脉病患者中评估氯吡格雷使用与患者远期结果的关系。设计、地点及患者:于连续患者中进行观察性研究。患者于2000年1月1日至2005年7月31日在杜克心脏治疗中心(一家位于北卡罗来纳州达累姆市的三级治疗中心)接受冠状动脉内支架治疗。于6、12、24个月时进行随访,直至2006年9月7日。研究人群包括4666例最初接受BMS(n=3165)或DES(n=1501)经皮冠状动脉介入治疗的患者。对随访6和12个月没有事件(没有死亡、心肌梗死或血管重建手术)的患者进行界标分析(landmark analysis)。在这些时间点上根据支架类型以及自我报告之氯吡格雷的使用情况将患者分为4组:DES使用氯吡格雷组、DES不用氯吡格雷组、BMS使用氯吡格雷组以及BMS不用氯吡格雷组。主要观测指标:随访24个月时死亡、非致命性心肌梗死以及死亡或心肌梗死之复合终点。结果:在6个月时没有事件发生的DES组患者(637例使用、579例未使用氯吡格雷)中,氯吡格雷的使用是随访24个月校正死亡率较低(使用2.0%比未使用5.3%;差异,-3.3%;95%CI,-6.3%至-0.3%;P=0.03)以及死亡或心肌梗死发生率较低(3.1%比7.2%;差异,-4.1%;95%CI,-7.6%至-0.6%;P=0.02)的显著预测指标。然而,在BMS组患者中(417例使用、1976例未用氯吡格雷),死亡(3.7%比4.5%;差异,-0.7%;95%CI,-2.9%至1.4%;P=0.50)以及死亡或心肌梗死发生率(5.5%比6.0%;差异,-0.5%;95%CI,-3.2%至2.2%;P:0.70)没有差异。在12个月随访没有事件发生的DES组患者(252例使用、276例未用氯吡格雷)中,氯吡格雷的使用依然可以预测24个月死亡(0%比3.5%;差异,-3.5%;95%CI,-5.9%至-1.1%;P=0.004)以及死亡或心肌梗死发生率(0%比4.5%;差异,-4.5%;95%CI,-7.1%至-1.9%;P〈0.001)较低。然而,在BMS组患者中(346例使用、1644例未用氯吡格雷),在死亡(3.3%比2.7%;差异,0.6%;95%CI,1.5%至2.8%;P=0.57)以及死亡或心肌梗死(4.7%比3.6%;差异,1.0%;95%CI,-1.6%至3.6%;P=0.44)发生方面,依然没有差异。结论:在接受DES治疗的患者中,延长氯吡格雷的使用可以使死亡以及死亡或心肌梗死的发生率下降。然而,使用氯吡格雷的适宜期限只能通过大型临床随机试验确定。Eric L Eisenstein, DBA Kevin J. Anstrom, PhD David F. Kong, MD Linda K. Shaw, MS Robert H. Tuttle, MSPH Daniel B. Mark, MD, MPH Judith M. Kramer, MD, MS Robert A. Harrington, MD David B. Matchar, MD David E. Kandzari, MD 1 Eric D. Peterson, MD, MPH Kevin A. Schulman, MD Robert M. Califf, MD 李呈亿(译) David E. Kandzari, MD 2007美国医学会杂志(中文版)2007,26,3:60
2Analysis of Autopilot Disengagements Occurring During Autonomous Vehicle Testing显示文摘In present-day highly-automated vehicles, there are occasions when the driving system disengages and the human driver is required to take-over. This is of great importance to a vehicle's safety and ride comfort. In the U.S state of California, the Autonomous Vehicle Testing Regulations require every manufacturer testing autonomous vehicles on public roads to submit an annual report summarizing the disengagements of the technology experienced during testing. On 1 January 2016,seven manufacturers submitted their first disengagement reports:Bosch, Delphi, Google, Nissan, Mercedes-Benz, Volkswagen, and Tesla Motors. This work analyses the data from these disengagement reports with the aim of gaining abetter understanding of the situations in which a driver is required to takeover, as this is potentially useful in improving the Society of Automotive Engineers(SAE) Level 2 and Level 3 automation technologies.Disengagement events from testing are classified into different groups based on attributes and the causes of disengagement are investigated and compared in detail. The mechanisms and time taken for take-over transition occurred in disengagements are studied. Finally, recommendations for OEMs, manufacturers, and government organizations are also discussed.Chen Lv Dongpu Cao Yifan Zhao Daniel J. Auger Mark Sullman Huaji Wang Laura Millen Dutka Lee Skrypchuk Alexandros Mouzakitis 2018IEEE/CAA Journal of Automatica Sinica2018,5,1:15
3远程皮肤病学的现状和展望显示文摘远程医学泛指应用远程通讯技术交换医学信息,以达到诊断、咨询、治疗和教学目的。远程放射学、远程病理学和远程皮肤病学是目前应用较为广泛的远程医学领域。文中对远程皮肤病学的发展简史、现状和可能的发展趋势进行综述。崔勇 W.P. Daniel Sue Mark D.P. Davis Mark R. Pittelkow 张学军 2011中国皮肤性病学杂志2011,25,11:12
4人HCN4通道的滞后现象:影响窦房结起搏的潜在决定因素(英文)显示文摘超极化活化环核苷酸门控(hyperpolarization-activated cyclic-nucleotide-gated,HCN)通道参与调制心脏跳动的节律和速率。与HCN1和HCN2有所不同,慢通道HCN4可能不存在电压依赖的滞后现象。本研究采用单细胞膜片钳方法,在稳定转染hHCN4的HEK293细胞上进行电生理记录,观察hHCN4通道是否存在滞后现象,以及cAMP对其的调制作用;同时采用实时定量RT-PCR方法检测窦房结和心房组织中HCNs的表达。电压钳实验结果显示hHCN4电流(Ih)激活随着保持电位超极化的变化而向去极化方向移动。三角电位变化钳(triangular ramp)和动作电位钳的结果也显示了hHCN4的滞后现象。cAMP增加Ih电流幅度,且使电流激活向去极化方向移动,从而改变内源性hHCN4滞后行为。RT-PCR结果显示,人窦房结组织主要表达HCN4,占75%,HCN1占21%,HCN2占3%,HCN3占0.7%。以上结果提示,人窦房结组织主要表达HCN4亚型,hHCN4的Ih存在电压依赖性的滞后现象,且受cAMP调制。由此推断,hHCN4通道的滞后现象可能在窦房结起搏活动中起到了关键作用。萧永福 Natalie Chandler Halina Dobrzynski Eric S.Richardson Erica M.TenBroek Joshua J.Wilhelm Vinod Sharma Anthony Varghese Mark R.Boyett Paul A.Iaizzo Daniel C.Sigg 2010生理学报2010,62,1:10
5Current Status and Future Challenges of Weather Radar Polarimetry: Bridging the Gap between Radar Meteorology/Hydrology/Engineering and Numerical Weather Prediction显示文摘After decades of research and development, the WSR-88 D(NEXRAD) network in the United States was upgraded with dual-polarization capability, providing polarimetric radar data(PRD) that have the potential to improve weather observations,quantification, forecasting, and warnings. The weather radar networks in China and other countries are also being upgraded with dual-polarization capability. Now, with radar polarimetry technology having matured, and PRD available both nationally and globally, it is important to understand the current status and future challenges and opportunities. The potential impact of PRD has been limited by their oftentimes subjective and empirical use. More importantly, the community has not begun to regularly derive from PRD the state parameters, such as water mixing ratios and number concentrations, used in numerical weather prediction(NWP) models.In this review, we summarize the current status of weather radar polarimetry, discuss the issues and limitations of PRD usage, and explore potential approaches to more efficiently use PRD for quantitative precipitation estimation and forecasting based on statistical retrieval with physical constraints where prior information is used and observation error is included. This approach aligns the observation-based retrievals favored by the radar meteorology community with the model-based analysis of the NWP community. We also examine the challenges and opportunities of polarimetric phased array radar research and development for future weather observation.Guifu ZHANG Vivek N.MAHALE Bryan J.PUTNAM Youcun QI Qing CAO ANDrew D.BYRD Petar BUKOVCIC Dusan S.ZRNIC Jidong GAO Ming XUE Youngsun JUNG Heather D.REEVES Pamela L.HEINSELMAN AlexANDer RYZHKOV Robert D.PALMER Pengfei ZHANG Mark WEBER Greg M.MCFARQUHAR Berrien MOORE III Yan ZHANG Jian ZHANG J.VIVEKANANDAN Yasser AL-RASHID Richard L.ICE Daniel S.BERKOWITZ Chong-chi TONG Caleb FULTON Richard J.DOVIAK 2019Advances in Atmospheric Sciences2019,36,6:9
6皮肤病摄影的回顾和展望显示文摘医学知识最早由文字或绘画记载,皮肤病学亦是如此,已知最早被绘画记载的皮肤病是梅毒。很多著名皮肤病学家如Ferdinand Hebra(1816--1880年,Vienna皮肤病学校创立者)、Moritz Kaposi(1837—1902年,最早研究红斑狼疮、扁平苔藓等疾病,崔勇 W.P. Daniel Su Mark D.P. Davis Mark R. Pittelkow 张学军 2011中华皮肤科杂志2011,44,10:8
7Evolution and future of urban ecological science:ecology in,of,and for the city显示文摘The contrast between ecology in cities and ecology of cities has emphasized the increasing scope of urban ecosystem research.Ecology in focuses on terrestrial and aquatic patches within cities,suburbs,and exurbs as analogs of non-urban habitats.Urban fabric outside analog patches is considered to be inhospi-table matrix.Ecology of the city differs from ecology in by treating entire urban mosaics as social-ecolog-ical systems.Ecology of urban ecosystems incorporates biological,social,and built components.Originally posed as a metaphor to visualize disciplinary evolution,this paper suggests that the contrast has conceptual,empirical,and methodological contents.That is,the contrast constitutes a disciplinary or“local”paradigm shift.The paradigm change between ecology in and ecology of represents increased complexity,moving from focus on biotic communities to holistic social-ecological systems.A third paradigm,ecology for the city,has emerged due to concern for urban sustainability.While ecology for includes the knowledge generated by both ecology in and ecology of,it considers researchers as a part of the system,and acknowledges that they may help envision and advance the social goals of urban sustainability.Using urban heterogeneity as a key urban feature,the three paradigms are shown to contrast in five important ways:disciplinary focus,the relevant theory of spatial heterogeneity,the technology for representing spatial structure,the resulting classification of urban mosaics,and the nature of application to sustainability.Ecology for the city encourages ecologists to engage with other specialists and urban dwellers to shape a more sustainable urban future.Steward T.A.Pickett Mary L.Cadenasso Daniel L.Childers Mark J.McDonnell Weiqi Zhou 2016Ecosystem Health and Sustainability2016,2,7:7
8Complications associated with prone positioning in elective spinal surgery显示文摘Complications associated with prone surgical positioning during elective spine surgery have the potential to cause serious patient morbidity.Although many ofthese complications remain uncommon,the range of possible morbidities is wide and includes multiple organ systems.Perioperative visual loss(POVL)is a well described,but uncommon complication that may occur due to ischemia to the optic nerve,retina,or cerebral cortex.Closed-angle glaucoma and amaurosis have been reported as additional etiologies for vision loss following spinal surgery.Peripheral nerve injuries,such as those caused by prolonged traction to the brachial plexus,are more commonly encountered postoperative events.Myocutaneous complications including pressure ulcers and compartment syndrome may also occur after prone positioning,albeit rarely.Other uncommon positioning complications such as tongue swelling resulting in airway compromise,femoral artery ischemia,and avascular necrosis of the femoral head have also been reported.Many of these are well-understood and largely avoidable through thoughtful attention to detail.Other complications,such as POVL,remain incompletely understood and thus more difficult to predict or prevent.Here,the current literature on the complications of prone positioning for spine surgery is reviewed to increase awareness of the spectrum of potential complications and to inform spine surgeons of strategies to minimize the risk of prone patient morbidity.J Mason De Passe Mark A Palumbo Maahir Haque Craig P Eberson Alan H Daniels 2015World Journal of Orthopedics2015,6,3:7
9Anti-tumour necrosis factor agent and liver injury:literature review,recommendations for management显示文摘Abnormalities in liver function tests,including transient and self-limiting hypertransaminasemia,cholestatic disease and hepatitis,can develop during treatment with anti-tumour-necrosis-factor(TNF)therapy.The optimal management of liver injury related to antiTNF therapy is still a matter of debate.Although some authors recommend discontinuing treatment in case of both a rise of alanine aminotransferase more than5 times the upper limit of normal,or the occurrence of jaundice,there are no standard guidelines for the management of anti-TNF-related liver injury.Bibliographical searches were performed in Pub Med,using the following key words:inflammatory bowel disease(IBD);TNF inhibitors;hypertransaminasemia;drugrelated liver injury;infliximab.According to published data,elevation of transaminases in patients with IBD treated with anti-TNF is a common finding,but resolution appears to be the usual outcome.Anti-TNF agents seem to be safe with a low risk of causing severe drugrelated liver injury.According to our centre experience,we found that hypertransaminasemia was a common,mainly self-limiting finding in our IBD cohort and was not correlated to infliximab treatment on both univariate and multivariate analyses.An algorithm for the management of liver impairment occurring during antiTNF treatment is also proposed and this highlights the need of a multidisciplinary approach and suggests liver biopsy as a key-point in the management decision in case of severe rise of transaminases.However,hepatic injury is generally self-limiting and drug withdrawal seems to be an exception.Roberta Elisa Rossi Ioanna Parisi Edward John Despott Andrew Kenneth Burroughs James O'Beirne Dario Conte Mark Ian Hamilton Charles Daniel Murray 2014World Journal of Gastroenterology2014,20,46:7
10Ground response to high horizontal stresses during longwall retreat and its implications for longwall headgate support显示文摘Roof falls in longwall headgate can occur when weak roof and high horizontal stress are present. To prevent roof falls in the headgate under high horizontal stress, it is important to understand the ground response to high horizontal stress in the longwall headgate and the requirements for supplemental roof support. In this study, a longwall headgate under high horizontal stress was instrumented to monitor stress change in the pillars, deformations in the roof, and load in the cable bolts. The conditions in the headgate were monitored for about six months as the longwall face passed by the instrumented site.The roof behavior in the headgate near the face was carefully observed during longwall retreat.Numerical modeling was performed to correlate the modeling results with underground observation and instrumentation data and to quantify the effect of high horizontal stress on roof stability in the longwall headgate. This paper discusses roof support requirements in the longwall headgate under high horizontal stress in regard to the pattern of supplemental cable bolts and the critical locations where additional supplemental support is necessary.Peter Zhang Dave Gearhart Mark Van Dyke Daniel Su Essie Esterhuizen Berk Tulu 2019International Journal of Mining Science and Technology2019,29,1:6
11Direct laser writing of volumetric gradient index lenses and waveguides显示文摘Direct laser writing(DLW)has been shown to render 3D polymeric optical components,including lenses,beam expanders,and mirrors,with submicrometer precision.However,these printed structures are limited to the refractive index and dispersive properties of the photopolymer.Here,we present the subsurface controllable refractive index via beam exposure(SCRIBE)method,a lithographic approach that enables the tuning of the refractive index over a range of greater than 0.3 by performing DLW inside photoresist-filled nanoporous silicon and silica scaffolds.Adjusting the laser exposure during printing enables 3D submicron control of the polymer infilling and thus the refractive index and chromatic dispersion.Combining SCRIBE’s unprecedented index range and 3D writing accuracy has realized the world’s smallest(15μm diameter)spherical Luneburg lens operating at visible wavelengths.SCRIBE’s ability to tune the chromatic dispersion alongside the refractive index was leveraged to render achromatic doublets in a single printing step,eliminating the need for multiple photoresins and writing sequences.SCRIBE also has the potential to form multicomponent optics by cascading optical elements within a scaffold.As a demonstration,stacked focusing structures that generate photonic nanojets were fabricated inside porous silicon.Finally,an all-pass ring resonator was coupled to a subsurface 3D waveguide.The measured quality factor of 4600 at 1550 nm suggests the possibility of compact photonic systems with optical interconnects that traverse multiple planes.SCRIBE is uniquely suited for constructing such photonic integrated circuits due to its ability to integrate multiple optical components,including lenses and waveguides,without additional printed supports.Christian R.Ocier Corey A.Richards Daniel A.Bacon-Brown Qing Ding Raman Kumar Tanner J.Garcia Jorik van de Groep Jung-Hwan Song Austin J.Cyphersmith Andrew Rhode Andrea N.Perry Alexander J.Littlefield Jinlong Zhu Dajie Xie Haibo Gao Jonah F.Messinger Mark L.Brongersma Kimani C.Toussaint Jr Lynford L.Goddard Paul V.Braun 2020Light(Science & Applications)2020,9,1:6
12Ulcerative colitis显示文摘Ingrid Ordás Lars Eckmann Mark Talamini Daniel C Baumgart William J Sandborn 2012The Lancet2012,,9853:5
13Expression of the oxygen-sensitive transcription factor subunit HIF-1α in patients suffering from secondary Raynaud syndrome显示文摘Anti-ischemic therapy remains a challenge due to the complexity of hypoxia response pathways. Hypoxia-inducible factor (HIF)-1 is a heterodimer tran scription factor con sisti ng of 2 sub units, HIF-1α and HIF-1β. Hypoxia-depe ndent activatio n of HIF-1α regulates cellular 02 homeostasis. Raynaud syndrome (RS), as a comorbidity of the autoimmune disease systemic sclerosis (SS), is characterized by vasospasms that limit blood flow to the limbs, resulting in hypoxia. A single-center randomized study was con ducted to compare prostagla ndin E1 (PgEI) therapy with a treatme nt combi ning PgE1 and an en dotheli n-1 blocker, bosentan. A total of 30 patients suffering from SS with RS were enrolled. We examined the regulation of HIF-1α, its target heme oxygenase-1 (HMOX-1), and the serum levels of the HIF-1α protein in a subset of patients as well as in ten healthy individuals. The expression of HIF-1α and HMOX-1 in monocytes was measured using absolute plasmid-based quantitative real-time PCR, whereas serum HIF-1α levels were measured with ELISA. Samples were taken at the time of randomization and after 24 weeks. We found that HIF-1α and HMOX-1 mRNA expression in monocytes and serum HIF-1α protein levels were significantly higher in the SS/RS patients compared to the healthy control group. Single-drug therapy significantly increased HIF-1α and HMOX-1 mRNA expression in monocytes and serum HIF-1α protein levels in the SS/RS patients compared to those at the time of randomization, whereas combining PgE1 with an en dotheli n-1 blocker preve nted the further in creases in HIF-1α and HMOX-1 expressi on. We propose HIF-1α and HMOX-1 as novel markers for anti-ischemic therapy in RS.Lukas Andreas Heger Mark Kerber Marcus Hortmann Samuel Robinson Maximilian Mauler Daniela Stallmann Daniel Duerschmied Christoph Bode Christoph Hehrlein Ingo Ahrens 2019Acta Pharmacologica Sinica2019,40,4:5
14Relationship between HER-2 overexpression and brain metastasis in esophageal cancer patients显示文摘AIM:To study if HER-2 overexpression by locally advanced esophageal cancers increase the chance of brain metastasis following esophagectomy.METHODS:We retrospectively reviewed the medical records of esophageal cancer patients who underwent esophagectomy at University of Iowa Hospitals and Clinics between 2000 and 2010.Data analyzed consisted of demographic and clinical variables.The brain metastasis tissue was assayed for HER-2 overexpression utilizing the FDA approved DAKO Hercept Test.RESULTS:One hundred and forty two patients were reviewed.Median age was 64 years(36-86 years).Eighty eight patients(62%) received neoadjuvant chemoradiotherapy.Pathological complete and partial responses were achieved in 17(19%) and 71(81%) patients.Cancer relapsed in 43/142(30%) patients.The brain was the first site of relapse in 9/43 patients(21%,95% CI:10%-36%).HER-2 immunohistochemistry testing of the brain metastasis tissue showed that 5/9(56%) cases overexpressed HER-2(3+ staining).CONCLUSION:HER-2 overexpression might be associated with increased risk of brain metastasis in esophageal cancer patients following esophagectomy.Further studies will be required to validate this observation.Taher Abu Hejleh Barry R DeYoung Eric Engelman Jeremy M Deutsch Bridget Zimmerman Thorvardur R Halfdanarson Daniel J Berg Kalpaj R Parekh William R Lynch Mark D Iannettoni Sudershan Bhatia Gerald Clamon 2012World Journal of Gastrointestinal Oncology2012,4,5:5
15Four-sample lactose hydrogen breath test for diagnosis of lactose malabsorption in irritable bowel syndrome patients with diarrhea显示文摘AIM: To validate 4-sample lactose hydrogen breath testing(4SLHBT) compared to standard 13-sample LHBT in the clinical setting.METHODS: Irritable bowel syndrome patients with diarrhea(IBS-D) and healthy volunteers(HVs) were enrolled and received a 10 g, 20 g, or 40 g doselactose hydrogen breath test(LHBT) in a randomized, double-blinded, controlled trial. The lactase gene promoter region was sequenced. Breath samples and symptoms were acquired at baseline and every 15 min for 3 h(13 measurements). The detection rates of lactose malabsorption(LM) and lactose intolerance(LI) for a 4SLHBT that acquired four measurements at 0, 90, 120, and 180 min from the same data set were compared with the results of standard LHBT.RESULTS: Sixty IBS-D patients and 60 HVs were studied. The genotype in all participants was C/C-13910. LM and LI detection rates increased with lactose dose from 10 g, 20 g to 40 g in both groups(P < 0.001). 4SLHBT showed excellent diagnostic concordance with standard LHBT(97%-100%, Kappa 0.815-0.942) with high sensitivity(90%-100%) and specificity(100%) at all three lactose doses in both groups.CONCLUSION: Reducing the number of measurements from 13 to 4 samples did not significantly impact on the accuracy of LHBT in health and IBS-D. 4SLHBT is a valid test for assessment of LM and LI in clinical practice.Jian-Feng Yang Mark Fox Hua Chu Xia Zheng Yan-Qin Long Daniel Pohl Michael Fried Ning Dai 2015World Journal of Gastroenterology2015,21,24:4
16Ulcerative colitis显示文摘Ingrid Ordás Lars Eckmann Mark Talamini Daniel C Baumgart William J Sandborn 20122012 (9853)2012,,9853:3
17Characteristics of Clostridium difficile infection in patients hospitalized with myelodysplastic syndrome or acute myelogenous leukemia显示文摘AIM To evaluate factors associated with Clostridium difficile infection (CDI) and outcomes of CDI in the myelodysplastic syndrome(MDS) and acute myeloid leukemia (AML) population.METHODS After IRB approval,all MDS/AML patients hospitalized at the University of Maryland Greenebaum Comprehensive Cancer Center between August 2011 and December 2013 were identified.Medical charts were reviewed for demographics,clinical information,development of CDI,complications of CDI,and mortality.Patients with CDI,defined as having a positive stool PCR done for clinical suspicion of CDI,were compared to those without CDI in order to identify predictors of disease.A t-test was used for comparison of continuous variables and chisquare or Fisher's exact tests were used for categorical variables,as appropriate.RESULTS Two hundred and twenty-three patients (60.1% male,mean age 61.3 years,13% MDS,87% AML) had 594 unique hospitalizations during the study period.Thirtyfour patients (15.2%) were diagnosed with CDI.Factors significantly associated with CDI included lower albumin at time of hospitalization (P < 0.0001),prior diagnosis of CDI (P < 0.0001),receipt of cytarabine-based chemotherapy (P = 0.015),total days of neutropenia (P = 0.014),and total days of hospitalization (P = 0.005).Gender (P = 0.10),age (P = 0.77),proton-pump inhibitor use (P = 0.73),receipt of antibiotics (P = 0.66),and receipt of DNA hypomethylating agent-based chemotherapy (P = 0.92) were not significantly associated with CDI.CONCLUSION CDI is common in the MDS/AML population.Factors significantly associated with CDI in this population include low albumin,prior CDI,use of cytarabine-based chemotherapy,and prolonged neutropenia.In this study,we have identified a subset of patients in which prophylaxis studies could be targeted.Kamini Shah Bryan F Curtin Christopher Chu Daniel Hwang Mark H Flasar Erik von Rosenvinge 2017World Journal of Clinical Oncology2017,8,5:3
18Transitional geology and its effects on development and longwall mining in Pittsburgh Seam显示文摘This paper presents the geologic and ground control challenges that were encountered by Consol Energy's coal mining operations in southwestern Pennsylvania,USA. Geologic encounters,such as sandstoneto-limestone geology transition,massive sandstone channels,shale channels,pyritic rich green claystone,laminated roof,and soft floor,have significantly impacted the development and longwall mining in Consol's Pittsburgh Seam coal mines. Experience from different mines shows that,in the sandstone-to-limestone geology transition zone,1.83 m high-tension,fully-grouted primary bolts employed along with 4.88 m center cable bolts at every other strap greatly improved beam building and ensured proper anchorage into the competent roof. Hydraulic fracturing of the massive sandstone was often necessary to enhance caving of the massive sandstone behind the shields to relieve pressure at the face. The presence of soft floor coupled with presence of thick floor coal and deep cover,induced excessive headgate convergence during retreat of the first right hand longwall panel. In all,it is important to explore the roof and in-seam geology in detail to delineate normal and anomalous geologic conditions prior to and during development. With diligent geologic reconnaissance,geotechnical monitoring,and assessment,site-specific geotechnical solutions have been provided to mine operations to improve safety and productivity.Lu Jun Van Dyke Mark Su Daniel W.H. Hasenfus Greg 2016International Journal of Mining Science and Technology2016,26,1:3
19A multi‐institutional phase 2 study of neoadjuvant gemcitabine and oxaliplatin with radiation therapy in patients with pancreatic cancer显示文摘Edward J. Kim Edgar Ben‐Josef Joseph M. Herman Tanios Bekaii‐Saab Laura A. Dawson Kent A. Griffith Isaac R. Francis Joel K. Greenson Diane M. Simeone Theodore S. Lawrence Daniel Laheru Christopher L. Wolfgang Terence Williams Mark Bloomston Malcolm J. Moo 2013Cancer2013,,15:3
20农作物病虫害在全球变暖中向极地扩散显示文摘农作物病虫害的发生和传播威胁着全球食品安全。病虫害主要通过人类交通运输途径传播,而由于气候变化导致病虫害能够在非适生区定殖的情况也日益受到关注。然而,气候变化、农作物和病虫害三者之间的互作关系十分复杂,关于全球变暖导致病虫害分布纬度改变的研究还远远不足。本文论证了自1960年以来,数百种病虫害平均每年以2.7±0.8 km的速度向极地扩散,但不同生物类群之间的扩散趋势显著不同。尽管存在观测的偏差,如高纬度的发达国家往往比低纬度的发展中国家更早发现新的病虫害,容易得出病虫害向赤道方向扩散的表面结论,然而,我们研究得出的多种生物类群向高纬度地区扩散的趋势支持了全球变暖导致病虫害扩散的假说。Daniel P.Bebber Mark A.T.Ramotowski Sarah J.Gurr 曾娟 王晓亮 李天娇 曹烨 2017中国植保导刊2017,37,3:3
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