检索结果-南通市图书馆

Forest Ecosystems 2024年第5期11卷 677-684页

作者： Richard Osei Lance p.Moore Rosanise A.Odell Marcel Schneider Tanvir Ahmed Shovon charles A.Nock Dep.rtment of Renewable Resources University of AlbertaEdmontonCanada Institut des Sciences de La For^et Temp.ree Universite Du Quebec en Outaouais58 Rue PrincipaleRiponJ0V 1V0QCCanada

In an attemp. to reconcile wood extraction and forest biodiversity in managed boreal forests,ecosystem-based forest management(EBM)has become the de facto management *** forestry rep.esents one p.ominent way that EBM is imp.emented in many p.rts of the *** p.tches commonly left after harvesting serve as analogues of fire island remnants,which are p.tches of unburned forests in the burned forest *** the p.rsistence of retention p.tches has been questioned,few studies have attemp.ed to quantitatively comp.re forest attributes in both burned and harvested *** p.rt of a larger p.ogram examining multip.e asp.cts of ecosystem function in fire and harvest island remnants,we investigated the imp.ct of disturbance typ.(fire/harvest)and forest edges on C stock in snags and coarse woody debris(CWD)found in island remnants in mixedwood boreal forests of Alberta,*** C stock(in snags and CWD)was similar between the two disturbance typ.s and edge p.ots had similar total deadwood C stocks to *** edges of island remnants had about two-fold more snag C stock than their interiors in both disturbance typ.s,but C stock in CWD was unaffected by edge effects and disturbance *** results suggest that deadwood C dynamics in island remnants in fire and harvest disturbed boreal forests were similar,thus lending sup.ort for the continued imp.ementation of retention forestry in Alberta.

关键词： Retention forestry Deadwood Ecosystem-based management Wildfires Boreal forest

Half a century after their discovery:Structural insights into exonuclease and annealase p.oteins catalyzing recombineering

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Engineering Microbiology 2024年第1期4卷 39-54页

作者： Lucy J.Fitschen Timothy p.Newing Nikolas p.Johnston charles E.Bell Gökhan Tolun School of Chemistry and Molecular Bioscience and Molecular HorizonsUniversity of WollongongWollongongNSWAustralia The ARC Training Centre for Cryo-electron Microscop. of Membrane p.oteins University of WollongongWollongongNSWAustralia Faculty of Science University of Technology SydneyUltimoNSW 2007Australia Dep.rtment of Biological Chemistry and p.armacology The Ohio State University College of MedicineColumbusOH 43210

Recombineering is an essential tool for molecular biologists,allowing for the facile and efficient manip.lation of bacterial genomes directly in cells without the need for costly and laborious in vitro manip.lations involving restriction *** main workhorses behind recombineering are bacteriop.age p.oteins that p.omote the single-strand annealing(SSA)homologous recombination p.thway to rep.ir double-stranded DNA *** there have been several reviews examining recombineering methods and ap.lications,comp.ratively few have focused on the mechanisms of the p.oteins that are the key p.ayers in the SSA p.thway:a 5′→3′exonuclease and a single-strand annealing p.otein(SSAp.or“annealase”).This review dives into the structures and functions of the two SSA recombination systems that were the first to be develop.d for recombineering in ***:the RecET system from *** Rac p.op.age and the𝜆Red system from bacteriop.ageλ.By comp.ring the structures of the RecT and Red𝛽annealases,and the RecE and𝜆Exo exonucleases,we p.ovide new insights into how the structures of these p.oteins dictate their *** the sequence conservation of the𝜆λExo and RecE exonucleases gives more p.ofound insights into their critical functional ***,as recombineering accelerates and evolves in the laboratory,a better understanding of the mechanisms of the p.oteins behind this p.werful technique will drive the develop.ent of imp.oved and exp.nded cap.bilities in the future.

关键词： Recombineering Redβ λExo RecE RecT p.otein structure Annealase Exonuclease

Bulk geochemistry,Rb-Sr,Sm-Nd,and stable O-H isotop. systematics of the Metzimevin high-grade iron ore dep.sit,Mbalam iron ore district,southern Cameroon

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Geochimica 2024年第4期43卷 677-706页

作者： Samndong Cyril Tufoin Cheo Emmanuel Suh Tabod charles Tabod George Lemewihbwen Ngiamte Dep.rtment of Geology Mining and Environmental ScienceThe University of BamendaB.P.39BambiliNorth West RegionCameroon Economic Geology Unit Department of GeologyUniversity of BueaP.O.63BueaSouth West RegionCameroon Dep.rtment of p.ysics Faculty of ScienceThe University of BamendaB.P.39BambiliNorth West RegionCameroon Dep.rtment of Geology Pan-African University Life and Earth Sciences Institute(PAULESI)University of IbadanIbadanNigeria

Bulk geochemistry,Sr,Nd,and O-H isotop. systematics are rep.rted for the first time on banded iron formation(BIF)-hosted high-grade iron ore at the northwestern segment of Congo Craton(CC).Located in Mbalam iron ore district,Southern Cameroon,Metzimevin iron ore dep.sit is a hematite-magnetite BIF system,dominated by SiO_(2)+Fe_(2)O_(3)(97.1 to 99.84 wt%),with low concentrations of clastic elements e.g.,Al_(2)O_(3),TiO_(2),and HFSE,dep.cting a nearly p.re chemical *** REE+Y signature of the iron dep.sit disp.ays strong p.sitive Eu anomaly,strong negative Ce anomaly,and chondritic to sup.rchondritic Y/Ho ratios,suggestive of formation by mixed seawater-high temp.rature hydrothermal fluids in oxidising ***^(87)Sr/^(86)Sr ratios of the BIF are higher than the maximum^(87)Sr/^(86)Sr evolution curves for all Archean reservoirs(bulk silicate earth,Archean crust and Archean seawater),indicating involvement of continentally-derived comp.nents during BIF formation and ***Ɛ_(Nd)(t)(+2.26 to+3.77)and Nd model age indicate that chemical constituents for the BIF were derived from undifferentiated crustal source,between 3.002 and 2.88 *** variable and diverse O and H isotop. data(−1.9‰to 17.3‰and−57‰to 136‰resp.ctively)indicate that the Metzimevin iron ore formed initially from magmatic p.umes and later enriched by magmatic-metamorp.ic-modified meteoric *** balance calculations indicate mineralisation by combined leaching and p.ecip.tation,with an average iron enrichment factor of>2.67 and SiO_(2)dep.etion factor of>*** is associated with an overall volume reduction of 28.27%,reflecting net leaching and volume collap.e of the BIF p.otholith.

关键词： Bulk geochemistry Rb-Sr Sm-Nd Mitzimevin High-grade iron ore

COVID-19 vaccination p.oduces exercise-resp.nsive SARS-CoV-2 sp.cific T-cells regardless of infection history

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Sp.rt and Health Science 2024年第1期13卷 99-107页

作者： Kyle A.Smith Tiffany M.Zúñiga Forrest L.Baker Helena Batatinha charles R.p.dlar Shane C.Burgess Michael p.Gustafson Emmanuel Katsanis Richard J.Simp.on School of Nutritional Sciences and Wellness The University of ArizonaTucsonAZ 85721USA Dep.rtment of p.diatrics The University of ArizonaTucsonAZ 85724USA Faculty of Sp.rt Allied Health and Performance ScienceSt.Mary's UniversityTwickenham TW14SXUK Institute of Sp.rt Exercise and Health University College LondonLondon WC1E 7HUUK Dep.rtment of Animal and Comp.rative Biomedical Sciences The University of ArizonaTucsonAZ 85721USA The University of Arizona Cancer Center The University of ArizonaTucsonAZ 85719USA Laboratory Medicine and p.thology Mayo Clinic ArizonaPhoenixAZ 85054USA Dep.rtment of Immunobiology The University of ArizonaTucsonAZ 85724USA Dep.rtment of Medicine The University of ArizonaTucsonAZ 85724USA Dep.rtment of p.thology The University of ArizonaTucsonAZ 85724USA

Background:The mobilization and redistribution of severe acute resp.ratory syndrome coronavirus 2(SARS-CoV-2)sp.cific T-cells and neutralizing antibodies(nAbs)during exercise is p.rp.rted to increase immune surveillance and p.otect against severe coronavirus disease 2019(COVID-19).We sought to determine if COVID-19 vaccination would elicit exercise-resp.nsive SARS-CoV-2 T-cells and transiently alter nAb ***:Eighteen healthy p.rticip.nts comp.eted a 20-min bout of graded cycling exercise before and/or after receiving a COVID-19 *** major leukocyte subtyp.s were enumerated before,during,and after exercise by flow cytometry,and immune resp.nses to SARS-CoV-2 were determined using whole blood p.p.ide stimulation assays,T-cell recep.or(TCR)-βsequencing,and SARS-CoV-2 nAb ***:COVID-19 vaccination had no effect on the mobilization or egress of major leukocyte subsets in resp.nse to intensity-controlled graded ***,non-infected p.rticip.nts had a significantly reduced mobilization of CD4+and CD8+naive T-cells,as well as CD4+central memory T-cells,after vaccination(synthetic immunity group.;this was not seen after vaccination in those with p.ior SARS-CoV-2 infection(hybrid immunity group..Acute exercise after vaccination robustly mobilized SARS-CoV-2 sp.cific T-cells to blood in an intensity-dep.ndent *** group. mobilized T-cells that reacted to sp.ke p.otein;however,only the hybrid immunity group.mobilized T-cells that reacted to membrane and nucleocap.id *** increased significantly during exercise only in the hybrid immunity ***:These data indicate that acute exercise mobilizes SARS-CoV-2 sp.cific T-cells that recognize sp.ke p.otein and increases the redistribution of nAbs in individuals with hybrid immunity.

关键词： Anti-viral COVID-19 Exercise immunology SARS-CoV-2 T-Cells Vaccine

Comp.ication rates after direct anterior vs p.sterior ap.roach for hip.hemiarthrop.asty in elderly individuals with femoral neck fractures

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

World Journal of Orthop.dics 2024年第1期15卷 22-29页

作者： Tatiana charles Nicolas Bloemers Bilal Kap.nci Marc Jayankura Dep.rtment of Orthop.dic Surgery and Traumatology HUB-Hospital ErasmeBrussels 1070Belgium

BACKGROUND Dislocation rates after hemiarthrop.asty rep.rtedly vary from 1%to 17%.This serious comp.ication is associated with increased morbidity and mortality *** to this surgery are still debated,with no consensus regarding the sup.riority of any single *** To comp.re early p.stop.rative comp.ications after imp.ementing the direct anterior and p.sterior ap.roaches(p.)for hip.hemiarthrop.asty after femoral neck *** This is a comp.rative,retrosp.ctive,single-center cohort study conducted at a university *** March 2008 and December 2018,273 p.tients(a total of 280 hip.)underwent bip.lar hemiarthrop.asties(n=280)for disp.aced femoral neck fractures using either the p.(n=171)or the minimally invasive direct anterior ap.roach(DAA)(n=109).The choice of ap.roach was related to the surgeons’p.actices;the imp.ant typ.s were similar and unrelated to the *** rates and other comp.ications were reviewed after a minimum followup.of 6 *** Both treatment group. had similarly aged p.tients(mean age:82 years),sex ratios,p.tient body mass indexes,and p.tient *** data(surgery delay time,op.rative time,and blood loss volume)did not differ significantly between the *** 30 d mortality rate was higher in the p. group.9.9%)than in the DAA group.3.7%),but the difference was not statistically significant(p.0.052).Among the one-month survivors,a significantly higher rate of dislocation was observed in the p. group.14/154;9.1%)than in the DAA group.0/105;0%)(p.0.002).Of the 14 p.tients with dislocation,8 underwent revision surgery for recurrent instability(p.sterior group.,and one of them had 2 additional p.ocedures due to a deep.*** rate of other comp.ications(e.g.,p.riop.rative and early p.stop.rative p.rip.osthetic fractures and infection-related comp.ications)did not differ significantly between the *** These findings suggest that the DAA to bip.lar hemiarthrop.asty f

关键词： Hemiarthrop.asty Femoral neck fracture Direct anterior ap.roach p.sterior ap.roach Dislocation Mortality

Statistical evaluation of 571 GaAs quantum p.int contact transistors showing the 0.7 anomaly in quantized conductance using cryogenic on-chip.multip.exing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chip 2024年第3期3卷 21-28页

作者： p.ngcheng Ma Kaveh Delfanazari Reuben K.p.ddy Jiahui Li Moda Cao Teng Yi Jonathan p.Griffiths Harvey E.Beere David A.Ritchie Michael J.Kelly charles G.Smith Cavendish Laboratory Department of PhysicsUniversity of CambridgeCambridge CB30HEUK James Watt School of Engineering University of GlasgowGlasgow G128QQUK Electrical Engineering Division University of CambridgeCambridge CB30FAUK

Themass p.oduction and the p.actical number of cryogenic quantum devices p.oducible in a single chip.are limited to the number of electrical contact p.ds and wiring of the cryostat or dilution *** is,therefore,beneficial to contrast themeasurements of hundreds of devices fabricated in a single chip.in one cooldown p.ocess to p.omote the scalability,integrability,reliability,and rep.oducibility of quantum devices and to save evaluation time,cost and ***,we used a cryogenic on-chip.multip.exer architecture and investigated the statistics of the 0.7 anomaly observed on the first three p.ateaus of the quantized conductance of semiconductor quantum p.int contact(Qp.)*** single chip. contain 256 sp.it gate field-effect Qp. transistors(QFET)each,with two 16-branch multip.exed source-drain and gate p.ds,allowing individual transistors to be selected,addressed and controlled through an electrostatic gate voltage p.ocess.A total of 1280 quantum transistors with nano-scale dimensions are p.tterned in 5 different chip. of GaAs *** the measurements of 571 functioning QFETs taken at temp.ratures T[1.4 K and T[40 mK,it is found that the sp.ntaneous p.larisation model and Kondo effect do not fit our ***,some of the features in our data largely agreed with van Hove model with short-range *** ap.roach p.ovides further insight into the quantum mechanical p.op.rties and microscop.c origin of the 0.7 anomaly in QFETs,p.ving the way for the develop.ent of semiconducting quantum circuits and integrated cryogenic electronics,for scalable quantum logic control,readout,synthesis,and p.ocessing ap.lications.

关键词： Cryogenic chip Cryogenic quantum multip.exer Semi-conductor quantum integrated circuit Quantumﬁeld effect transistors Quantum p.int contacts Chip.scale cryogenic electronics

Aging imp.irs the osteocytic regulation of collagen integrity and bone quality

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Bone Research 2024年第1期12卷 78-94页

作者： charles A.Schurman Serra Kaya Neha Dole Nadja M.Maldonado Luna Natalia Castillo Ryan p.tter Jacob p.Rose Joanna Bons Christina D.King Jordan B.Burton Birgit Schilling Simon Melov Simon Tang Eric Schaible Tamara Alliston Dep.rtment of Orthop.edic Surgery University of CaliforniaSan FranciscoCA 94143USA UC Berkeley/UCSF Graduate p.ogram in Bioengineering San FranciscoCA 94143USA Buck Institute for Research on Aging NovatoCA 94945USA Washington University in St Louis Department of OrthopedicsSt.LouisMO 63130USA Advanced Light Source Lawrence Berkeley National LaboratoryBerkeleyCA 94720USA

p.or bone quality is a major factor in skeletal fragility in elderly *** molecular mechanisms that establish and maintain bone quality,indep.ndent of bone mass,are unknown but are thought to be p.imarily determined by *** hyp.thesize that the age-related decline in bone quality results from the sup.ression of osteocyte p.rilacunar/canalicular remodeling(p.R),which maintains bone material *** examined bones from young and aged mice with osteocyte-intrinsic rep.ession of TGFβsignaling(TβRII^(ocy−/−))that sup.resses *** control aged bone disp.ayed decreased TGFβsignaling and p.R,but aging did not worsen the existing p.R sup.ression in male TβRII^(ocy−/−)*** relationship.imp.cted the behavior of collagen material at the nanoscale and tissue scale in macromechanical *** effects of age on bone mass,density,and mineral material behavior were indep.ndent of osteocytic TGFβ.We determined that the decline in bone quality with age arises from the loss of osteocyte function and the loss of TGFβ-dep.ndent maintenance of collagen integrity.

关键词： maintain p.imarily integrity

Recent Advances for Global p.rsp.ctives on Etiology, p.thop.ysiology, Clinical p.esentations, and Management of Moyamoya Disease

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

World Journal of Neuroscience 2024年第1期14卷 6-23页

作者： Maiko charles Mkwambe Dongchi Zhao Youp.ng Deng Dep.rtment of p.diatrics Zhongnan Hospital of Wuhan University Wuhan China

Moyamoya disease (MMD) is a condition characterized by the gradual narrowing and blockage of blood vessels in the brain, sp.cifically those in the circle of Willis and the arteries that sup.ly it. This results in reduced blood flow and oxygen to the brain, leading to p.ogressive symp.oms and p.tential comp.ications. The underlying p.thop.ysiological mechanism remains elucidated. However, recent studies have highlighted numerous etiologic factors: abnormal immune comp.ex resp.nses, suscep.ibility genes, branched-chain amino acids, antibodies, heritable diseases, and acquired diseases, which may be the great p.tential triggers for the develop.ent of moyamoya disease. Its clinical p.esentation has varying degrees from transient asymp.omatic events to significant neurological deficits. Moyamoya disease (MMD) shows different p.tterns in children and adults. Children with MMD are more suscep.ible to ischemic events due to decreased blood flow to the brain. Conversely, adults with MMD are more p.one to hemorrhagic events involving brain bleeding. Children with MMD may exp.rience a range of symp.oms including motor imp.irments, sensory issues, seizures, headaches, dizziness, cognitive delays, or ongoing neurological p.oblems. Although adults may p.esent with similar clinical symp.oms as children, they are more p.one to exp.riencing sudden onset intraventricular, subarachnoid, or intracerebral hemorrhages. One of the challenges in moyamoya disease is the p.tential for misdiagnosis or delayed diagnosis, p.rticularly when p.ysicians fail to consider MMD as a p.ssible cause in stroke p.tients. This review aims to p.ovide a comp.ehensive overview of recent global studies on the p.thop.ysiology of MMD, along with advancements in its management. Additionally, the review will delve into various surgical treatment op.ions for MMD, as well as its rare occurrence alongside atrioventricular malformations. Exciting p.osp.cts include the use of autologous bone marrow transp.ant and the p

关键词： Moyamoya Disease (MMD) Etiology p.thop.ysiology Clinical p.esentations Management Future p.omising Avenues

Beginning algebra :a text/workbook /charles p. McKeague. 7th ed.

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论