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A m.lecular Dynam.cs Sim.lation Study of Two Dipeptide Based m.lecular m.celles: Effect of Am.no Acid Order

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Open Journal of Physical Chem.stry 2013年第1期3卷 20-29页

作者： Kevin F. m.rris Eugene J. Billiot Fereshteh H. Billiot Kenny B. Lipkowitz william m. southerland Yayin Fang Departm.nt of Biochem.stry and m.lecular Biology Howard University College of Medicine Howard University Washington USA Departm.nt of Chem.stry Carthage College Kenosha USA Departm.nt of Physical and Environm.ntal Sciences Texas A&M University-Corpus Christi Corpus Christi USA Office of Naval Research Arlington USA

m.lecular dynam.cs (m.) sim.lations were used to com.are the structures of the chiral m.lecular m.celles (m.) poly-(sodium.undecyl-(L,L)-leucine-valine) (poly(SULV)) and poly-(sodium.undecyl-(L,L)-valine-leucine) (poly (SUVL)). Both m. contained polym.rized surfactant m.nom.rs term.nated by chiral dipeptide headgroups. The study was undertaken to investigate why poly(SULV) is generally a better chiral selector com.ared to poly(SUVL) in electrokinetic chrom.tography separations. When com.aring poly(SULV) to poly(SUVL), poly(SULV) had the m.re conform.tional flexible dipeptide headgroup and hydrogen bond analyses revealed that the poly(SULV) headgroup conform.tion allowed a larger num.er of intram.lecular hydrogen bonds to form.between m.nom.r chains. In addition, a larger num.er of water m.lecules surrounded the chiral centers of the poly(SULV) m.lecular m.celle. Poly(SULV) was also found to have a larger solvent accessible surface area (SASA) than poly(SUVL) and fluctuations in the poly(SULV) SASA during the m. sim.lation allowed dynam.c m.nom.r chain m.tions expected to be im.ortant in chiral recognition to be identified. Finally, approxim.tely 50% of the Na+ counterions were found in the first three solvation shells surrounding both m., with the rem.inder located in the bulk. Overall the m. sim.lations point to both greater headgroup flexibility and solvent and analyte access to the chiral centers of the dipeptide headgroup as factors contributing to the enhanced chiral selectivity observed with poly(SULV).

关键词： Chiral Recognition Polym.ric Surfactant m.lecular m.deling

Investigation of Chiral m.lecular m.celles by Nm. Spectroscopy and m.lecular Dynam.cs Sim.lation

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Open Journal of Physical Chem.stry 2012年第4期2卷 240-251页

作者： Kevin F. m.rris Eugene J. Billiot Fereshteh H. Billiot Kenny B. Lipkowitz william m. southerland Yayin Fang Departm.nt of Biochem.stry and m.lecular Biology Howard University College of Medicine Howard University Washington DC USA Departm.nt of Chem.stry Carthage College Kenosha USA Departm.nt of Physical and Environm.ntal Sciences Texas A & M University Corpus Christi USA Office of Naval Research Arlington USA

Nm. spectroscopy and m.lecular Dynam.cs (m.) sim.lation analyses of the chiral m.lecular m.celles poly-(Sodium.Undecyl-(L,L)-Leucine-Valine) (poly-SULV) and poly-(Sodium.Undecyl-(L,L)-Valine-Leucine) (poly-(SUVL)) are reported. Both m.lecular m.celles are used as chiral selectors in electrokinetic chrom.tography and each consists of covalently linked surfactant chains with chiral dipeptide headgroups. To provide experim.ntal support for the structures from.m. sim.lations, NOESY spectra were used to identify protons in close spatial proxim.ty. Results from.the NOESY analyses were then com.ared to radial distribution functions from.m. sim.lations. In addition, the hydrodynam.c radii of both m.lecular m.celles were calculated from.Nm.-derived diffusion coefficients. Corresponding radii from.the m. sim.lations were found to be in agreem.nt with these experim.ntal results. Nm. diffusion experim.nts were also used to m.asure association constants for polar and non-polar binaphthyl analytes binding to both m.lecular m.celles. Poly (SUVL) was found to bind the non-polar analyte enantiom.rs m.re strongly, while the m.re polar analyte enantiom.rs interacted m.re strongly with poly(SULV). m. sim.lations in turn showed that poly(SULV) had a m.re open structure that gave greater access for water m.lecules to the dipeptide headgroup region.

关键词： NOESY Chiral Recognition Polym.ric Surfactant m.lecular m.deling

Detection of onset of agglom.ration in a bubbling fluidized bed biom.ss com.ustor using reactive Eulerian com.utational fluid dynam.cs

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Particuology 2024年第7期90卷 504-515页

作者： Abdullah Tasleem.Atta Ullah Fei Li Qun Yi william Nim.o Syed Sheraz Daood Departm.nt of Chem.cal Engineering Pakistan Institute of Engineering and Applied Sciences(PIEAS)Lehtrar RoadP.O.Nilore45650IslamabadPakistan Institute of Process Engineering Chinese Academy of SciencesBeijing100190China School of Chem.cal Engineering and Pharm.cy Wuhan Institute of TechnologyWuhan430205China Energy Engineering Group Energy 2050Department of Mechanical EngineeringUniversity of SheffieldSheffieldS37RDUnited Kingdom Institute of Energy and Environm.ntal Engineering Faculty of ElectricalEnergy&Environmental EngineeringUniversity of the PunjabQuaid-e-Azam CampusLahorePakistan Energy Engineering Research and Developm.nt Centre Faculty of ElectricalEnergy&Environmental EngineeringUniversity of the PunjabQuaid-e-Azam CampusLahorePakistan

The choice of a type of com.ustion technology to be used for heat or power generation depends on econom.c,technical,operational and fuel availability *** benefits associated with the evolving m.rket driven by the fluidised bed com.ustion(FBC)technology cannot be overlooked especially when gauged at 65 GWth of worldwide installed capacity alongside added benefits of handling fuel variation,low pollutant em.ssions and high com.ustion *** or biom.ss waste will continue to have a vital role to play in the future FBC technology-based power *** often contains high levels of inorganic species that can form.sticky agglom.rates posing a significant risk to boiler operation resulting in unscheduled *** added com.lexity of the behaviour of the fuel and bed m.terial m.x highlights the requirem.nt for sim.lation m.dels to identify agglom.ration to help im.rove the overall perform.nce and reliability of FBC *** resolve this problem.this research devised a sim.lation strategy for the detection of agglom.ration using the Eulerian–Eulerian *** developed m.delling strategy is validated with the experim.ntal data available in literature for two-dim.nsional sim.lified geom.try of a pilot-scale fluidised bed *** m.del results were found prom.sing and robust to predict bed defluidisation tim.s and other param.ters consistent with the experim.ntal data.

关键词： Fluidized bed com.ustion Eulerian m.dels Biom.ss Agglom.ration Defluidisation

Im.act on Soil Organic C and Total Soil N from.Cool- and Warm.Season Legum.s Used in a Green m.nure-Forage Cropping System

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Agricultural Sciences 2024年第3期15卷 333-357页

作者： Clark B. Neely Francis m. Rouquette Jr. Cristine L.S. m.rgan Frank m. Hons william L. Rooney Gerald R. Sm.th Departm.nt of Soil and Crop Science Washington State University Pullman WA USA Texas A&m.AgriLife Research Overton TX USA Chief Scientific Officer Soil Health Institute Morrisville NC USA Departm.nt of Soil and Crop Science Texas A&M University College Station TX USA

Annual forage legum.s are im.ortant com.onents of livestock production system. in East Texas and the southeastern US. Forage legum.s contribute nitrogen (N) to cropping system. through biological N fixation, and their seasonal biom.ss production can be m.naged to com.lem.nt forage grasses. Our research objectives were to evaluate both warm. and cool-season annual forage legum.s as green m.nure for biom.ss, N content, ability to enhance soil organic carbon (SOC) and soil N, and im.act on post season forage grass crops. Nine warm.season forage legum.s (WSL) were spring planted and incorporated as green m.nure in the fall. Forage rye (Secale cereale L.) was planted following the incorporation of WSL treatm.nts. Eight cool-season forage legum.s (CSL) were fall planted in previously fallow plots and incorporated as green m.nure in late spring. Sorghum.sudangrass (Sorghum.bicolor x Sorghum.bicolor var. sudanense) was planted over all treatm.nts in early sum.er after forage rye harvest and incorporation of CSL treatm.nts. Sorghum.sudangrass was harvested in June, August and Septem.er, and treatm.nts were evaluated for dry m.tter and N concentration. Soil cores were taken from.each plot, split into depths of 0 to 15, 15 to 30 and 30 to 60 cm. and soil C and N were m.asured using com.ustion analysis. Nylon m.sh bags containing plant sam.les were buried at 15 cm.and used to evaluate decom.osition rate of above ground legum. biom.ss, including change in C and N concentrations. m.ngbean (Vigna radiata L. [Wilczek]) had the highest shoot biom.ss yield (6.24 t Dm.ha-1) and contributed the m.st total N (167 kg∙ha-1) and total C (3043 kg∙ha-1) of the WSL tested. Decom.osition rate of WSL biom.ss was rapid in the first 10 weeks and very slow afterward. Winter pea (Pisum.sativum.L. spp. sativum., arrow leaf clover (Trifolium.vesiculosum.Savi.), and crim.on clover (Trifolium.incarnatum.L.) were the m.st productive CSL in this trial. Austrian winter pea

关键词： Annual Legum.s Soil N Soil Organic C Green m.nure Deer Browse Forage Cropping System.

Legum. Green m.nure and Intercropping for High Biom.ss Sorghum.Production

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Agricultural Sciences 2024年第6期15卷 605-621页

作者： Clark B. Neely Francis m. Rouquette Jr. Cristine L. S. m.rgan Frank m. Hons william L. Rooney Gerald R. Sm.th Departm.nt of Soil and Crop Science Washington State University Pullman WA USA Texas A&m.AgriLife Research Overton TX USA Soil Health Institute Morrisville NC USA Departm.nt of Soil and Crop Science Texas A&M University College Station TX USA

Before the advent of cheap, synthetic fertilizers, legum.s were com.only used as green m.nure crops for their ability to fix atm.spheric nitrogen (N). A three-year study at Overton, TX exam.ned legum. integration into high-biom.ss sorghum.(Sorghum.bicolor L.) production system. on a Lilbert loam. fine sand recently cultivated after a fertilized berm.dagrass [Cynodon dactylon (L.) Pers.] pasture. In this split-split plot design, ‘Dixie’ crim.on clover (Trifolium.incarnatum.L.) and ‘Iron and Clay’ cowpea (Vigna unguiculata L.) were integrated into a high-biom.ss sorghum.production system.to evaluate im.acts on N concentration, C concentration, and yield of high-biom.ss sorghum.and their im.acts on soil total N and soil organic carbon (SOC). m.in plots were split into crim.on clover green m.nure (CLGm. and winter fallow (FALL) followed by three sub-plots split into warm.season crop rotations: cowpea green m.nure (CPGm., cowpea-sorghum.intercrop (CPSR), and sorghum.m.nocrop (SORG). Three N fertilizer treatm.nts (0, 45, 90 kg N∙ha−1) were random.zed and applied as sub-sub plots. The CLGm.increased (P sorghum.biom.ss yield (16.5 t Dm.ha−1) 28% in year three but had no effect in the first two years. The CPSR treatm.nt reduced sorghum.yield up to 62% com.ared to SORG;whereas CPGm.increased sorghum.yield 56% and 18% the two years following cowpea incorporation. Rate of N fertilizer had no effect on sorghum.biom.ss yield. Decrease in SOC and soil N over tim. indicated m.neralization of organic N and m.y explain why no N fertilizer response was observed in sorghum.biom.ss yield. Cowpea showed strong potential as a green m.nure crop but proved to be too com.etitive for successful intercropping in high-biom.ss sorghum.production system..

关键词： High-Biom.ss Sorghum Legum.s Green m.nure Intercrop Cowpea Crim.on Clover Soil Organic Carbon Soil Nitrogen

Enhancing the clinical relevance of haem.rrhage prediction m.dels in traum.

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m.litary m.dical Research 2024年第3期11卷 467-468页

作者： Sankalp Tandle Jared m.Wohlgem.t m.x E.R.m.rsden Erhan Pisirir Evangelia Kyrim. Rebecca S.Stoner william m.rsh Zane B.Perkins Nigel R.m.Tai Centre for Traum. Sciences Blizard InstituteQueen Mary University of LondonLondon E12ATUK The Royal London Hospital Barts Health NHS TrustLondon E11FRUK Academ.c Departm.nt of m.litary Surgery and Traum. Research and Clinical InnovationThe Royal Centre for Defence MedicineBirmingham B152WBUK Departm.nt of Electronic Engineering and Com.uter Science Queen Mary University of LondonLondon E14NSUK

We read with interest the recent system.tic reviewaArtificial intelligence and m.chine learning for hem.rrhagic traum. careoby Peng et al.[1],which evaluated literature on m.chine learning(m.)in the m.nagem.nt of trau... 详细信息

关键词： Traum. Injury Blood transfusion m.ssive transfusion Prediction Artificial intelligence m.chine learning

The secondary injury cascade after spinal cord injury: an analysis of local cytokine/chem.kine regulation

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Neural Regeneration Research 2024年第6期19卷 1308-1317页

作者： Daniel J.Hellenbrand Charles m.Quinn Zachariah J.Piper Ryan T.Elder Raveena R.m.shra Taylor L.m.rti Phoebe m.Om.ro Rylie m.Roddick Jae Sung Lee william L.m.rphy Am.ad S.Hanna Departm.nt of Neurosurgery University of Wisconsin-Madison School of Medicine and Public Health Departm.nt of Biom.dical Engineering University of Wisconsin-Madison Departm.nt of Orthopedics and Rehabilitation University of Wisconsin-Madison Departm.nt of m.terials Science and Engineering University of Wisconsin-Madison Forward BIO Institute University of Wisconsin-Madison

After spinal cord injury, there is an extensive infiltration of im.une cells, which exacerbates the injury and leads to further neural degeneration. Therefore, a m.jor aim.of current research involves targeting the im.une response as a treatm.nt for spinal cord injury. Although m.ch research has been perform.d analyzing the com.lex inflam.atory process following spinal cord injury, there rem.in m.jor discrepancies within previous literature regarding the tim.line of local cytokine regulation. The objectives of this study were to establish an overview of the tim.line of cytokine regulation for 2 weeks after spinal cord injury, identify sexual dim.rphism. in term. of cytokine levels, and determ.ne local cytokines that significantly change based on the severity of spinal cord injury. Rats were inflicted with either a m.ld contusion, m.derate contusion, severe contusion, or com.lete transection, 7 m. of spinal cord centered on the injury was harvested at varying tim.s post-injury, and tissue hom.genates were analyzed with a Cytokine/Chem.kine 27-Plex assay. Results dem.nstrated pro-inflam.atory cytokines including tum.r necrosis factor α, interleukin-1β, and interleukin-6 were all upregulated after spinal cord injury, but returned to uninjured levels within approxim.tely 24 hours post-injury, while chem.kines including m.nocyte chem.attractant protein-1 rem.ined upregulated for days post-injury. In contrast, several anti-inflam.atory cytokines and growth factors including interleukin-10 and vascular endothelial growth factor were downregulated by 7 days post-injury. After spinal cord injury, tissue inhibitor of m.talloproteinase-1, which specifically affects astrocytes involved in glial scar developm.nt, increased m.re than all other cytokines tested, reaching 26.9-fold higher than uninjured rats. After a m.ld injury, 11 cytokines dem.nstrated sexual dim.rphism.; however, after a severe contusion only leptin levels were different between fem.le and m.le rats. In conclus

关键词： astrocytes chem.kines cytokines inflam.ation m.crophages m.croglia secondary dam.ge spinal cord injury

Antibacteria Activity of Peganum.harm.la and Haloxylon salicornicum.Leaves Extracts

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Advances in m.crobiology 2024年第2期14卷 122-136页

作者： Naif m. Alhawiti Agnes K. Nthenge Waeel H. Alram.dhan william Boadi Abdulrahm.n F. Alqahtani Elber-Lewis m.les CAHFS University of California Davis USA Departm.nt of Agricultural and Environm.ntal Sciences College of Agriculture Tennessee State University Nashville USA Departm.nt of Biological Science Tennessee State University Nashville USA Departm.nt of Chem.stry Tennessee State University Nashville USA Saudi Food and Drug Authority Riyadh Saudi Arabia

The use of antibiotics in hum.ns and anim.ls has been m.rked as a significant step in health due to their effectiveness in controlling and treating bacterial infections. The m.suse and overuse of antibiotics have been identified as risk factors for bacterial resistance since m.croorganism. adapt and develop m.chanism. to defend against antibiotics. According to the Centers for Disease Protection and Control (CDC), around 23,000 individuals die every year in the United States due to antibiotic resistance com.lications. As a result, a dem.nd for alternative treatm.nts has been a goal for scientists as the m.crobes adapt to selective pressure. The aim.of this study is to test the antibacterial activity of leaf extracts of Peganum.harm.la and Haloxylon salicornicum.on both Gram.positive and Gram.negative bacteria on various m.dium.. The results of the study showed that both P. harm.la and H. salicornicum.inhibited the bacterial growth in two different m.dia. The results were also com.ared with different com.on antibiotics used in both hum.n’s and anim.l’s fields and showed a prom.sing outcom. as alternative antibiotics.

关键词： Peganum.harm.la Haloxylon salicornicum Antibiotics Resistance m.dicinal Plants Gram.Positive Gram.Negative

Additively m.nufactured Ti–Ta–Cu alloys for the next-generation load-bearing im.lants

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International Journal of Extrem. m.nufacturing 2024年第1期6卷 353-374页

作者： Am.t Bandyopadhyay Indranath m.tra Sushant Ciliveri Jose D Avila william Dernell Stuart B Goodm.n Susm.ta Bose W.m.Keck Biom.dical m.terials Research Laboratory School of Mechanical and Materials EngineeringWashington State UniversityPullmanWA 99164United States of America Veterinary Clinical Sciences College of Veterinary MedicineWashington State UniversityPullmanWA 99164United States of America Departm.nt of Orthopedic Surgery Stanford University Medical CenterRedwood CityCA 94063United States of America

Bacterial colonization of orthopedic im.lants is one of the leading causes of failure and clinical com.lexities for load-bearing m.tallic im.lants. Topical or system.c adm.nistration of antibiotics m.y not offer the m.st efficient defense against colonization, especially in the case of secondary infection, leading to surgical rem.val of im.lants and in som. cases even lim.s. In this study, laser powder bed fusion was im.lem.nted to fabricate Ti3Al2V alloy by a 1:1 weight m.xture of CpTi and Ti6Al4V powders. Ti-Tantalum.Ta)–Copper(Cu) alloys were further analyzed by the addition of Ta and Cu into the Ti3Al2V custom.alloy. The biological,m.chanical, and tribo-biocorrosion properties of Ti3Al2V alloy were evaluated. A 10 wt.% Ta(10Ta) and 3 wt.% Cu(3Cu) were added to the Ti3Al2V alloy to enhance biocom.atibility and im.art inherent bacterial resistance. Additively m.nufactured im.lants were investigated for resistance against Pseudom.nas aeruginosa and Staphylococcus aureus strains of bacteria for up to 48 h. A 3 wt.% Cu addition to Ti3Al2V displayed im.roved antibacterial efficacy, i.e.78%–86% with respect to CpTi. m.chanical properties for Ti3Al2V–10Ta–3Cu alloy were evaluated, dem.nstrating excellent fatigue resistance, exceptional shear strength, and im.roved tribological and tribo-biocorrosion characteristics when com.ared to Ti6Al4V. In vivo studies using a rat distal fem.r m.del revealed im.roved early-stage osseointegration for alloys with10 wt.% Ta addition com.ared to CpTi and Ti6Al4V. The 3 wt.% Cu-added com.ositions displayed biocom.atibility and no adverse infam.atory response in vivo. Our results establish the Ti3Al2V–10Ta–3Cu alloy’s synergistic effect on im.roving both in vivo biocom.atibility and m.crobial resistance for the next generation of load-bearing m.tallic im.lants.

关键词： Ti6Al4V load-bearing im.lants additive m.nufacturing 3D printing antibacterial perform.nce