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State of the art of friction modelling at interfaces subjected to elastohydrodynamic lubrication(EHL)

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Friction 2021年第2期9卷 207-227页

作者： Zhuming BI donald W.MUELLER Chris W.j.ZHANG Civil and Mechanical Engineering Purdue University Fort WayneIN 46805USA Department of Mechanical Engineering University of SaskatchewanSaskatoon SK S7N 5A9Canada

Elastohydrodynamic lubrication(EHL)is a type of fluid-film lubrication where hydrodynamic behaviors at contact surfaces are affected by both elastic deformation of surfaces and lubricant *** of contact interfaces under EHL is challenging due to high nonlinearity,complexity,and the multi-disciplinary *** paper aims to understand the state of the art of computational modelling of EHL by(1)examining the literature on modeling of contact surfaces under boundary and mixed lubricated conditions,(2)emphasizing the methods on the friction prediction occurring to contact surfaces,and(3)exploring the feasibility of using commercially available software tools(especially,Simulia/Abaqus)to predict the friction and wear at contact surfaces of objects with relative reciprocating motions.

关键词： elastohydrodynamic lubrication(EHL) lubricant rheology finite element analysis(FEA) friction prediction Simulia/Abaqus surface roughness coefficient of friction(CoF)

Adult neural stem cell plasticity

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Neural Regeneration Research 2019年第2期14卷 256-257页

作者： Elizabeth j.Sandquist donald S.Sakaguchi Department of Zoology Weber State University Department of Genetics Development and Cell Biology Iowa State University Neuroscience Program Iowa State University Nanovaccine Institute Iowa State University

Stem cells derived from adult tissues have long been consideredmultipotent, able to differentiate into a limited number of cell typesfound in their tissue of origin. Embryonic stem cells, in contrast,are pluripotent, which may differentiate into almost all cell *** the ability to create induced pluripotent stem cells from somaticcells now available, the properties of multipotent stem cellsare being re-evaluated. If adult cells may be reverted to pluripotentstem cells, can multipotent stem cells also be manipulated towardspluripotency? Advancements in biotechnology now allow for bettermethods to investigate stem cell plasticity, such as the relativeinfluence of external versus intrinsic factors on cell fate. Recentstudies indicate that adult neural stem cells (NSCs) demonstrategreater plasticity under certain conditions, resulting in the derivationof a variety of cell types including muscle, hematopoietic, andepithelial cells. This suggests that NSCs may provide a potentialsource of rare cell types for clinical application as an alternative toembryonic stem cells. Producing rare cell types from NSCs ratherthan embryonic stem cells avoids the ethical issues surrounding theuse of this cell type. Further, NSCs may be an advantageous sourcecompared to induced pluripotent stem cells, which are difficult tocreate, expensive, and time-consuming to

关键词： cells stem cell NSCs types

Fundamentals,preparation,and mechanism understanding of Li/Na/Mg-Sn alloy anodes for liquid and solid-state lithium batteries and beyond

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Nano Research 2023年第6期16卷 8191-8218页

作者： Amardeep Amardeep donald jFreschi jiajun Wang jian Liu School of Engineering Faculty of Applied Sciencethe University of British ColumbiaKelownaBC V1V 1V7Canada Fenix Advanced Materials Trail BCV1R 2T3Canada MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage School of Chemistry and Chemical EngineeringHarbin Institute of TechnologyHarbin 150001China

Lithium metal is one of the most promising anodes to develop high energy density and safe energy storage devices due to its highest theoretical capacity(3860 mAh·g^(−1))and lowest electrochemical potential,demonstrating great potential to fulfill unprecedented demand from electronic gadgets,electric vehicles,and grid *** these good merits,lithium metal suffers from low Coulombic efficiency and dendritic growth,leading to internal short-circuiting of the cell and raising safety concerns about employing lithium metal as an ***,lithium-tin(Li-Sn)alloys,among other lithium alloys,have emerged as a potential alternative to lithium metal to efficiently suppress the lithium dendrite formation and reduce interfacial resistance for safer and longer-lasting lithium ***,this work first reviews the fundamentals of Li-Sn alloys,and critically analyzes the failure mechanisms of pristine Li-metal anode and how Li-Sn alloys could overcome those *** subsequent section examines various strategies to synthesize Li-Sn bulk and protection film alloys,followed by an evaluation of symmetric cell ***,the comparative electrochemical performance of full cells against different cathodes and solid electrolytes provides an overview of the present ***,advanced characterization techniques were discussed to visualize lithium dendrites directly and quantify the mechanical performance of Li-Sn *** but not the least,the state-of-the-art progress of applying M-Sn(M=Na and Mg)beyond lithium batteries was *** closing,this work identifies the critical challenges and provides future perspectives on Li-Sn alloy for lithium batteries and beyond.

关键词： Li-Sn alloys fundamental studies dendrite-free anodes liquid/solid-state batteries Li-Sn alloys synthesis approachescum-electrochemical performance lithium batteries and beyond

Kyanite far from equilibrium dissolution rate at 0–22℃ and pH of 3.5–7.5

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Acta Geochimica 2019年第4期38卷 472-480页

作者： Yilun Zhang donald j.Rimstidt Yi Huang Chen Zhu Department of Earth and Atmospheric Sciences Indiana UniversityBloomingtonIN 47405USA Department of Geological Sciences Virginia TechBlacksburgVA 24061USA Department of Geochemistry Chengdu University of TechnologyChengdu 610059People's Republic of China School of Public and Environmental Affairs Indiana UniversityBloomingtonIN 47405USA

Kyanite is an important and slow-dissolving mineral. Earlier work has measured its dissolution rate at high temperature and acidic pH, but experimental measurements at low temperature and near neutral p H were lacking. The rate equation by Palandri and Kharaka(A compilation of rate parameters of water–mineral interaction kinetics for application to geochemical modeling. US Geological Survey, Open File Report 2004-1068, 2004) indicates that the rate of kyanite dissolution at room temperature and near neutral pH is on the order of 10^-17 mol m^-2 s^-1, orders of magnitudes slower than most common silicate minerals such as albite and quartz. This study used an externallystirred mixed-flow reactor, which allows high solid:solution ratios, to measure the dissolution rate of kyanite at 0–22 ℃ and pH of 3.5–7.5. The measured dissolution rate of kyanite is 4.6–7.6 9 10-13 mol m^-2 s^-1 at 22℃, and the apparent activation energy is 73.5 kj mol^-1. This dissolution rate is close to the rate of quartz dissolution and four orders of magnitude faster than the prediction by rate equation of Palandri and Kharaka(2004).Based on our new experimental data, we recommend the following rate equation for modeling the dissolution of kyanite at ambient temperatures.r=ke(-Ea)/R(1/T-1/(298.15))where k = 5.08 9 10-13 mol m^-2 s^-1, and Ea= 73.5 kj mol^-1. Review of literature data(Carroll in The dissolution behavior of corundum, kaolinite, and andalusite: a surface complex reaction model for the dissolution of aluminosilicate minerals in diagenetic and weathering environs. Dissertation, Northwestern University, 1989) led to a recommended rate equation for andalusite as for T = 25℃ and pH = 2–10:r=k1aH+^n1+k2+k3aH^+^n3where k1= 4.04 9 10^-10 mol m^-2 s^-1, k2= 7.95×10^-10 mol m^-2 s^-1, k3= 1.01×10^-17 mol m^-2 s^-1, n1= 1.2 and n3=-0.6.

关键词： Kinetics Kyanite Reaction rates Mixed-flow reactor

Investigating ischemia and reperfusion-induced organ damage in severe cardiac arrest:A comprehensive proteomics perspective

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journal of Pharmaceutical Analysis 2024年第3期14卷 427-430页

作者： ju Yeon Lee Muhammad Shoaib jin-Woong Choi Rishabh C.Choudhary Tai Yin Nara Yoon Kei Hayashida Seunguk j.Baek Santiago j.Miyara Lance B.Becker junhwan Kim Research Center of Bioconvergence Analysis Korea Basic Science InstituteCheongjuSouth Korea Bio-Analytical Science University of Science and TechnologyCheongjuSouth Korea Laboratory for Critical Care Physiology Feinstein Institutes for Medical ResearchManhassetNY11030USA donald and Barbara Zucker School of Medicine at Hofstra/Northwell School of Medicine HempsteadNY11549USA Mathematics and Computer Science Adelphi UniversityGarden CityNY11530USA Department of Emergency Medicine North Shore University HospitalManhassetNY11030USA

Cardiac arrest(CA)is a life-threatening condition with complex pathophysiology and limited treatment *** gain deeper insights into the pathological state of vital organs,we employed a proteomics analysis in rodents to assess proteome alterations in the brain,heart,kidney,and liver using a rat model of *** brain displayed severe protein alterations in essential cellular pathways,including three major energy-generating pathways after CA,which worsened after resuscitation,resulting in the most significant overall protein changes among the ***,the liver,experiencing the most substantial protein alterations post-CA,demonstrated significant recovery,presenting the least protein changes post-resuscitation.

关键词： alterations organs damage

Comparison of esophageal capsule endoscopy and esophagogastroduodenoscopy for diagnosis of esophageal varices

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World journal of Gastroenterology 2008年第28期14卷 4480-4485页

作者： Catherine T Frenette john G Kuldau donald j Hillebrand jill Lane Paul j Pockros Division of Gastroenterology and Hepatology Scripps ClinicLa JollaCaliforniaSan Francisco 94115United States

AIM： To investigate the utility of esophageal capsule endoscopy in the diagnosis and grading of esophageal varices. METHODS： Cirrhotic patients who were undergoing esophagogastroduodenoscopy （EGD） for variceal screening or surveillance underwent capsule endoscopy. Two separate blinded investigators read each capsule endoscopy for the following results： variceal grade, need for treatment with variceal banding or prophylaxis with beta-blocker therapy, degree of portal hypertensive gastropathy, and gastric varices. RESULTS： Fifty patients underwent both capsule and EGD. Forty-eight patients had both procedures on the same day, and 2 patients had capsule endoscopy within 72 h of EGD. The accuracy of capsule endoscopy to decide on the need for prophylaxis was 74%, with sensitivity of 63% and specificity of 82%. Interrater agreement was moderate （kappa = 0.56）. Agreement between EGD and capsule endoscopy on grade of varices was 0.53 （moderate）. Inter-rater reliability was good （kappa = 0.77）. In diagnosis of portal hypertensive gastropathy, accuracy was 57%, with sensitivity of 96% and specificity of 17%. Two patients had gastric varices seen on EGD, one of which was seen on capsule endoscopy. There were no complications from capsule endoscopy.CONCLUSION： We conclude that capsule endoscopy has a limited role in deciding which patients would benefit from EGD with banding or beta-blocker therapy. More data is needed to assess accuracy for staging esophageal varices, PHG, and the detection of gastric varices.

关键词： Esophageal varices Capsule endoscopy Portal hypertension

Characterization of Binding Sites of Eukaryotic Transcription Factors

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Genomics, Proteomics & Bioinformatics 2006年第2期4卷 67-79页

作者： jiang Qian jimmy Lin donald j. Zack The Wilmer Institute Department of Molecular Biology and Genetics Department of Neuroscience McKusick-Nathans Institute of Genetic Medicine Johns Hopkins University School of Medicine Baltimore MD 21287 USA.

To explore the nature of eukaryotic transcription factor （TF） binding sites and determine how they differ from surrounding DNA sequences, we examined four features associated with DNA binding sites： G＋C content, pattern complexity, palindromic structure, and Markov sequence ordering. Our analysis of the regulatory motifs obtained from the TRANSFAC databases using yeast intergenic sequences as background, revealed that these four features show variable enrichment in motif sequences. For example, motif sequences were more likely to have palindromic structure than were background sequences. In addition, these features were tightly localized to the regulatory motifs, indicating that they are a property of the motif sequences themselves and are not shared by the general promoter ＂environment＂ in which the regulatory motifs reside. By breaking down the motif sequences according to the TF classes to which they bind, more specific associations were identified. Finally, we found that some correlations, such as G＋C content enrichment, were species-specific, while others, such as complexity enrichment, were universal across the species examined. The quantitative analysis provided here should increase our understanding of protein-DNA interactions and also help facilitate the discovery of regulatory motifs through bioinformatics.

关键词： transcription factor promoter gene regulation bioinformatics

How do small birds evolve in response to climate change?Data from the long-term record at La Brea tar pits

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Integrative Zoology 2020年第4期15卷 249-261页

作者： Katherine L.LONG donald R.PROTHERO Valerie j.P.SYVERSON Department of Geological Sciences Cal Poly PomonaPomonaCaliforniaUSA Natural History Museum of Los Angeles County Los AngelesCaliforniaUSA Department of Geosciences University of Wisconsin MadisonMadisonWisconsinUSA

Biology textbooks describe the small changes in the beaks of the Galápagos finches as exemplars of how birds evolve in response to environmental ***,recent studies of the abundant fossil birds at Rancho La Brea find no evidence of evolutionary responses to the dramatic climate changes of the glacial–interglacial cycle over the past 35000 years:none of the large birds exhibit any change in body size or limb proportions,even during the last glacial maximum approximately 18000–20000 years ago,when the southern California chaparral was replaced by snowy coniferous ***,these are all large birds with large ranges and broad habitat preferences,capable of living in many different *** the smaller birds at La Brea,which have smaller home ranges and narrower habitats,might respond to climate more like Galápagos *** only 3 common small birds at La Brea are the western meadowlark,the yellow-billed magpie and the *** this study,we demonstrate that these birds also show complete stasis over the last glacial–interglacial cycle,with no statistically significant changes between dated *** research suggests that the small-scale changes over short timescales seen in the Galápagos finches are merely fluctuations around a stable morphology,and rarely lead to long-term accumulation of changes or ***,the prevalence of stasis supports the view that long-term directional changes in morphology are quite *** directional changes in morphology occur frequently over short(<1 ka)timescales,in the long term such changes only rarely remain stable for long enough to appear in the fossil record.

关键词： birds evolution macroevolution microevolution Pleistocene

Fluidization and bubbling behavior of potash particles in a deep fluidized bed

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Particuology 2023年第9期80卷 103-114页

作者： Mojtaba Nabipoor Hassankiadeh jingsi Yang Mark Berrey Dave jordison Lifeng Zhang donald Bergstrom Raymond j.Spiteri Department of Chemical and Biological Engineering University of SaskatchewanSKS7N 5A9SaskatoonCanada The Mosaic Company Belle PlaineSKCanada Department of Mechanical Engineering University of SaskatchewanSaskatoonCanada Department of Computer Science University of SaskatchewanSaskatoonSKCanada

Most existing models for predicting bubble size and bubble frequency have been developed for freely bubbling fluidized *** prediction of bubbling behavior in deep fluidized beds,however,has been a challenge due to the higher degree of bubble coalescence and break up,high probability of the slugging regime,partial fluidization,and chaotic behavior in the bubbling *** this work,the bubbling and fluidization behavior of potash particles was investigated in a deep fluidized bed employing a twin-plane electrical capacitance tomography(ECT)*** volume fraction,average bubble velocity,average bubble diameter,and bubble frequency in both bubbling and slugging regimes were measured at two different bed height ratios(H/D=3.5 and H/D=3.78).This work is the first to illustrate a sequential view of bubbles at different superficial gas velocities in a fluidized *** results show that both the bubble diameter and rising velocity increased with increasing the superficial gas velocity for the two bed heights,with larger values observed in the deeper bed compared to the shallower *** values for bubble diameter,bubble rise velocity and bubble frequency from different models are compared with the experimental data obtained from the ECT system in this *** agreement has been achieved between the values predicted by the previous models and the experimental data for the bubble diameter and bubble rise velocity with an average absolute deviation of 16%and 15%for the bed height of 49 cm and 13%and 8%for the bed height of 53 cm,respectively.

关键词： Deep fluidized bed Potash particle Electrical capacitance tomography Image reconstruction Bubbling and slugging regime