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GRADE指南：Ⅳ.证据质量分级--研究的局限性(偏倚风险)

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中国循证医学杂志 2011年第4期11卷 456-463页

作者： Gordon H.Guyatt Andrew D.Oxman Gunn Vist Regina Kunz Jan Brozek Pablo Alonso-Coello Victor Montori Elie A.Akl Ben Djulbegovic Yngve Falck-Ytter Susan L.Norris john w.williams jr. David Atkins Joerg Meerpohl Holger J.Schünemann GRADE工作组李幼平杨晓妍李鸿浩李玲

在GRADE方法中,若多数相关证据来自高偏倚风险的研究,则起初被定为高质量证据的随机试验和低质量证据的观察性研究均有可能被降低质量等级。随机试验已确定的局限性包括:未进行分配隐藏、未实施盲法、未报告失访情况及未恰当考虑意向性... 详细信息

在GRADE方法中,若多数相关证据来自高偏倚风险的研究,则起初被定为高质量证据的随机试验和低质量证据的观察性研究均有可能被降低质量等级。随机试验已确定的局限性包括:未进行分配隐藏、未实施盲法、未报告失访情况及未恰当考虑意向性治疗原则。最近提出的局限性包括:因明显获益而早期终止试验和基于结果选择性报告结局。观察性研究的主要局限性包括使用不合适的对照及未能充分调整预后的不平衡。偏倚风险可因不同结果而异(如全死因死亡率的失访远少于生命质量的失访),许多系统评价都容易忽略这一点。在决定是否因偏倚风险而降低质量等级时,不管是随机试验还是观察性研究,作者不应采用对各个研究取平均值的方法。相反,对任何单个结果,当同时存在高、低偏倚风险的研究时,则应考虑只纳入较低偏倚风险的研究。

关键词： GRADE 证据质量偏倚风险估计值的可信度盲法分配隐藏

GRADE指南：Ⅴ.证据质量评价--发表偏倚

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中国循证医学杂志 2011年第12期11卷 1430-1434页

作者： Gordon H.Guyatt Andrew D.Oxman Victor Montori Gunn Vist Regina Kunz Jan Brozek Pablo Alonso-Coello Ben Djulbegovic David Atkins Yngve Falck-Ytter john w.williams jr. Joerg Meerpohl Susan L.Norris Elie A.Akl Holger J.Schünemann 代表GRADE工作组李幼平王莉钟大可蒋兰慧机构不详

GRADE方法中,随机试验起评即为高质量证据,观察性研究起评即为低质量证据;但若证据本身存在高发表偏倚风险,则两者证据质量级别都应降低。即使最佳证据汇总表纳入的各项研究仅有低发表偏倚风险,发表偏倚仍会极大高估效应值。当可得证据... 详细信息

GRADE方法中,随机试验起评即为高质量证据,观察性研究起评即为低质量证据;但若证据本身存在高发表偏倚风险,则两者证据质量级别都应降低。即使最佳证据汇总表纳入的各项研究仅有低发表偏倚风险,发表偏倚仍会极大高估效应值。当可得证据来自小样本研究、且多数由厂商资助时,作者应怀疑存在发表偏倚。若干基于检验数据类型的方法可用于评价发表偏倚,其中最常用的为漏斗图,但这些方法都有较大局限。发表偏倚可能较常见,必须特别关注早期结果、对样本量与事件数都很小的早期试验结果尤需小心。

关键词： GRADE 证据质量发表偏倚漏斗图利益冲突制药业

Development of a 3D model for particle-wall collision and induced rotation and its influence on particle trajectories

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Particuology 2024年第11期94卷 211-228页

作者： Cairen Miranda john Palmore jr. Department of Mechanical Engineering Virginia TechBlacksburg24060VAUSA Department of Mechanical Engineering University of WashingtonSeattle98195WAUSA

The present research focuses on improving the prediction of rotating particle *** particle-surface collision models do not accurately predict the particle rebound when taking rotation into *** data,such as the studies by Gorham and Kharaz(2000),Buck,Tang,Heinrich,Deen and Kuipers(2017),and Dong and Moys(2006)show that the Tsuji,Oshima and Morikawa(1985)model is inaccurate due to the incorrect tangential coefficient of restitution ***,Kuipers,Mohd Salleh,Stein,and Seville(2001)introduced a similar model to the work by Tsuji et al.(1985)which includes a tangential coefficient of restitution but is only in two dimensions and does not consider out of plane *** work re-derives the particle collision model from the impulse equations for binary collisions in 3D while considering rotating *** derived equations in this work compares well to experimental particle-surface impact *** implications of this model are seen by investigating erosion due to particle collision in a simple pipe *** is shown that Tsuji et al.(1985)over predicts the *** small differences in particle trajectories between the present model and the Tsuji et al.(1985)model will grow in complex flows with multiple close range particle impacts leading to inaccurate erosion predictions which will negatively impact the design of turbomachinery and pneumatic pipes.

关键词： Particle collisions CFD Rotation Three dimensional

Organizational Behavior Don Hellriegel, john w. Slocum, jr.

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Emerging complexity and new roles for the RIG-I-like receptors in innate antiviral immunity

2007年

作者： Don Hellriegel john w. Slocum jr.

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Virologica Sinica 2015年第3期30卷 163-173页

作者： john S.Errett Michael Gale jr. Center for Innate Immunity and Immune Disease Department of Immunology School of Medicine University of Washington

Innate immunity is critical for the control of virus infection and operates to restrict viral susceptibility and direct antiviral immunity for protection from acute or chronic viral-associated diseases including cancer. RIG-I like receptors(RLRs) are cytosolic RNA helicases that function as pathogen recognition receptors to detect RNA pathogen associated molecular patterns(PAMPs) of virus infection. The RLRs include RIG-I, MDA5, and LGP2. They function to recognize and bind to PAMP motifs within viral RNA in a process that directs the RLR to trigger downstream signaling cascades that induce innate immunity that controls viral replication and spread. Products of RLR signaling also serve to modulate the adaptive immune response to infection. Recent studies have additionally connected RLRs to signaling cascades that impart inflammatory and apoptotic responses to virus infection. Viral evasion of RLR signaling supports viral outgrowth and pathogenesis, including the onset of viral-associated cancer.

关键词： RIG-I MDA5 pattern recognition receptor pathogen associated molecular pattern innate immunity virus infection

Alternative expressions for stand diameter in complex forests

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Forest Ecosystems 2023年第3期10卷 328-336页

作者： Mark J.Ducey john A.Kershaw jr. Department of Natural Resources and the Environment University of New HampshireDurhamNHUSA Faculty of Forestry and Environmental Management University of New BrunswickFrederictonNBCanada

Quadratic mean diameter is the most frequently reported descriptor of the diameter distribution of *** such,it is often used as an indicator of forest stand structure,developmental stage,and ecological and economic ***,quadratic mean diameter can be heavily influenced by the presence or absence of large numbers of small stems in lower canopy strata,and it is also sensitive to left-truncation of the diameter distribution,making its interpretation across inventories with different protocols ***,we examine three alternative expressions of stand diameter:the arithmetic and quadratic mean diameter of the thickest 100 trees per hectare,and the basal area-weighted mean *** data from the United States Forest Inventory and Analysis program for New York and New England,these alternative expressions showed closer correlation with multiple stand structural variables than did quadratic mean diameter,including merchantable cubic and board foot volume per hectare,aboveground live tree carbon per hectare,and total number of live and dead standing trees greater than 40 cm diameter at breast height per hectare(previously proposed as an index of old-growth structure).Arithmetic and quadratic mean diameter of the thickest 100 trees per hectare showed nearly identical performance,and the strongest correlations across the *** develop closed-form expressions for these variables when the diameter distribution is a weibull,and illustrate their behavior relative to quadratic mean diameter for that *** the reasons for prevalence of quadratic mean diameter as an indicator remain valid,we suggest that these alternative measures should be more widely reported and analyzed to give a more informative depiction of stand structure and development in complex forests.

关键词： Forest structure Diameter at breast height weibull distribution

Nanoembryonic thermoelastic equilibrium and enhanced properties of defected pretransitional materials

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npj Computational Materials 2018年第1期4卷 178-184页

作者： Ye-Chuan Xu wei-Feng Rao john w.Morris jr. Armen G.Khachaturyan Department of Materials Physics and IEMMNanjing University of Information Science and TechnologyNanjing 210044China Department of Materials Science and Engineering University of CaliforniaBerkeleyCA 94720USA Department of Materials Science and Engineering Rutgers UniversityPiscatawayNJ 08854USA

Behaviors of displacive phase-transforming materials above the temperature of transformation,where abnormal thermal,elastic,magnetic properties are often observed,are mostly explained by intrinsic peculiarities in electronic/atomic ***,we show these properties may also be attributed to extrinsic effects caused by a thermoelastic equilibrium in highly defected pretransitional *** demonstrate that the stress concentration near stress-generating defects such as dislocations and coherent precipitates could result in the stress-induced transformation within nanoscale regions,producing equilibrium embryos of the product *** nanoembryos in thermoelastic equilibrium could anhysteretically change their equilibrium size in response to changes in applied stress or magnetic fields leading to superelasticity or *** response to cooling may explain the observed diffuse phase transformation,changes in the coefficient of thermal expansion and effective elastic modulus,which,in turn,may explain the invar and elinvar behaviors.

关键词： transformation equilibrium transitional

Selling : building partnerships Barton A. weitz, Stephen B. Castleberry, john F. Tanner, jr. 5th ed.

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Investigation of normal,lateral,and oblique impact of microscale projectiles into unidirectional glass/epoxy composites

丛书名： The Irwin/McGraw-Hill series in marketing

2004年

作者： Barton A. weitz Stephen B. Castleberry john F. Tanner jr.

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Defence Technology（防务技术） 2022年第11期18卷 1960-1978页

作者： Christopher S.Meyer Isabel G.Catugas john w.Gillespie jr. Bazle Z.Gama Haque University of Delaware Center for Composite Materials(UD-CCM) 101 Academy StreetNewarkDE19716USA

Spacesuits and spacecraft must endure high velocity impacts from micrometeoroids. This work considers the impact of 100 μm diameter projectiles into composite targets at velocities from 0.5 km/s to 2 km/*** work begins by presenting an energy-based theoretical model relating depth of penetration(Do P)and impact force to impact velocity, characteristic time, and threshold velocity and force. Next, this work compares numerical simulations of normal impact on composites to the theoretical model. Numerical simulations are conducted with LS-DYNA and the well-known composite model, MAT-162. The numerical models consider unidirectional S2-glass fiber reinforced SC-15 epoxy composite laminates. The numerical model shows good correlation with the theoretical model. The numerical model also investigates lateral impact, parallel to the fiber direction, and oblique impact at angles from 30°to 82.5°.This work decomposes oblique impact into normal and lateral components, and compares them with normal and lateral impact results. The results show good correlation of the normal component of oblique results with the theoretical model. This numerical and theoretical study focuses on Do P, velocity, and penetration resistance force as functions of time. The theoretical model and numerical simulations are used to determine new Do P parameters: characteristic time of depth of penetration and threshold impact velocity. These models are a first step in developing the capability to predict Do P for oblique,microscale, high-speed impact on composite materials.

关键词： Microscale Hypervelocity impact Composites Erosion Penetration