检索结果-南通市图书馆

Nano Research 2009年第6期2卷 500-508页

作者： Aaron m.mohs Hongwei Duan Brad A.Kairdolf andrew m.Smith Shuming Nie Departments of Biomedical Engineering and Chemistry Emory University and Georgia Institute of Technology101 Woodruff Circle NESuite 2001AtlantaGeorgia 30322USA

Semiconductor quantum dots(QDs)have shown great promise as fluorescent probes for molecular,cellular and in vivo ***,the fluorescence of traditional polymer-encapsulated QDs is often quenched by proton-induced etching in acidic *** is a major problem for applications of QDs in the gastrointestinal tract because the gastric(stomach)environment is strongly acidic(pH 12).Here we report the use of proton-resistant surface coatings to stabilize QD fl uorescence under acidic *** both hyperbranched polyethylenimine(PEI)and its polyethylene glycol derivative(PEG-grafted PEI),we show that the fl uorescence of coreshell CdSe/CdS/ZnS QDs is effectively protected from quenching in simulated gastric *** comparison,amphiphilic lipid or polymer coatings provide no protection under similarly acidic *** proton-resistant QDs are found to cause moderate membrane damage to cultured epithelial cells,but PEGylation(PEG grafting)can be used to reduce cellular toxicity and to improve nanoparticle stability.

关键词： Nanoparticle quantum dot oral delivery gastrointestinal polyethylenimine(PEI) polyethylene glycol(PEG)

The development of a high-performance Ni-superalloy additively manufactured heat pipe

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in manufacturing 2022年第4期10卷 610-624页

作者： Sheng Li Khamis Essa James Carr States Chiwanga andrew Norton moataz m.Attallah School of Electromechanical Engineering Guangdong University of TechnologyGuangzhou 510006People’s Republic of China School of Engineering University of BirminghamEdgbastonBirmingham B152TTUK Henry moseley X-ray Imaging Facility Henry Royce Institute for Advanced MaterialsDepartment of MaterialsUniversity of ManchesterManchester M139PLUK European Thermodynamics Ltd 8 Priory Business ParkWistow RoadKibworthLeicestershire LE80RXUK Rolls-Royce plc P.O.Box 31Derby DE248BJUK School of metallurgy and materials University of BirminghamEdgbastonBirmingham B152TTUK

Additively manufacturing(Am)has been used to manufacture fine structures with structured/engineered porosity in heat management *** this study,laser powder bed fusion(LPBF)was used to manufacture a high-performance Ni-superalloy heat pipe,through tailoring LPBF process parameters to fabricate thin wall and *** using novel laser scanning strategies,wick structure heat pipes with maximised surface-area-to-volume ratio,fine features size around 100µm,and controlled porosity were successfully *** and X-ray microtomography(micro-CT)were used to investigate the 3D structure of the void space within the *** test results showed that most of the heat pipes made by LPBF had better performance than the conventionally manufactured *** study also investigated the influences of the process parameters on the porosity volume fraction and the feature *** results showed that LPBF process could fabricate thin structure due to the change of melt pool contact *** relationship between process parameters and bead size reported in this study could help design and manufacture heat pipe with complex fine structure.

关键词： Laser powder bed fusion(LPBF) Heat pipe melt pool microtomography(micro-CT)

Adjustment of Forest Ecosystem Root Respiration as Temperature Warms

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2008年第11期50卷 1467-1483页

作者： andrew J.Burton Jerry m.melillo Serita D.Frey Ecosystem Science Center Michigan Technological University School of Forest Resources and Environmental Science Michigan Technological University The Ecosystems Center Marine Biological Laboratory Department of Natural Resources University of New Hampshire

Adjustment of ecosystem root respiration to warmer climatic conditions can alter the autotrophic portion of soil respiration and influence the amount of carbon available for biomass production. We examined 44 published values of annual forest root respiration and found an increase in ecosystem root respiration with increasing mean annual temperature （mAT）, but the rate of this cross-ecosystem increase （Q10 = 1.6） is less than published values for short-term responses of root respiration to temperature within ecosystems （Q10 = 2-3）. When specific root respiration rates and root biomass values were examined, there was a clear trend for decreasing root metabolic capacity （respiration rate at a standard temperature） with increasing mAT. There also were tradeoffs between root metabolic capacity and root system biomass, such that there were no instances of high growing season respiration rates and high root biomass occurring together. We also examined specific root respiration rates at three soil warming experiments at Harvard Forest, USA, and found decreases in metabolic capacity for roots from the heated plots. This decline could be due to either physiological acclimation or to the effects of co-occurring drier soils on the measurement date. Regardless of the cause, these findings clearly suggest that modeling efforts that allow root respiration to increase exponentially with temperature, with Q10 values of 2 or more, may over-predict root contributions to ecosystem CO2 efflux for future climates and underestimate the amount of C available for other uses, including net primary productivity.

关键词： acclimation climatic warming root biomass root respiration soil warming.

Coprophilous contributions to the phylogeny of Lasiosphaeriaceae and allied taxa within Sordariales(Ascomycota,Fungi)

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

Fungal Diversity 2015年第1期70卷 101-113页

作者： Åsa Kruys Sabine m.Huhndorf andrew N.miller Systematic Biology Department of Organismal BiologyEvolutionary Biology CentreUppsala UniversityNorbyvägen 18DSE-75236 UppsalaSweden Botany Department Field MuseumChicagoIL 60605USA Illinois Natural History Survey University of IllinoisChampaignIL 61820US

The phylogenetic relationships of Lasiosphaeriaceae are complicated in that the family is paraphyletic and includes Sordariaceae and Chaetomiaceae,as well as several polyphyletic *** study focuses on the phylogenetic relationships of the coprophilous genera,Anopodium,Apodospora,Arnium,Fimetariella and *** are traditionally circumscribed based on ascospore characters,which have proven homoplasious in other genera within the *** results based on LSU nrDNA andß–tubulin sequences distinguish four lineages of Lasiosphaeriaceae *** joins the clade of mor-phologically similar,yellow-pigmented species of Cercophora and *** is monophyletic and joins a larger group of taxa with unclear affinities to each other,while Arnium is polyphyletic being scattered throughout three of the four major clades of *** is represented by a single collection and joins the clade containing Cercophora scortea and Podospora *** shows affinities to the Lasiosphaeris *** on a combination of morphological and molecular data,Echria *** recognized at the genus level for the former Arnium section and two new combinations are proposed:*** and ***.

关键词： Ascomal wall Ascomycete β-tubulin LSU nrDNA Systematics,Taxonom

metabolic reprogramming in tumors:Contributions of the tumor microenvironment

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Genes & Diseases 2020年第2期7卷 185-198页

作者： andrew N.Lane Richard m.Higashi Teresa W-m.Fan Center for Environmental and Systems Biochemistry Markey Cancer CenterDepartment of Toxicology and Cancer BiologyUniversity of KentuckyUSA

The genetic alterations associated with cell transformation are in large measure expressed in the metabolic phenotype as cancer cells proliferate and change their local environment,and prepare for ***,the fundamental biochemistry of cancer cells is generally the same as in the untransformed cells,but the cancer cells produce a local environment,the TmE,that is hostile to the stromal cells,and compete for *** order to proliferate,cells need sufficient nutrients,either those that cannot be made by the cells themselves,or must be made from simpler ***,in solid tumors,the nutrient supply is often limiting given the potential for rapid proliferation,and the poor quality of the ***,cancer cells may employ a variety of strategies to obtain nutrients for survival,growth and *** much has been learned using established cell lines in standard culture conditions,it is becoming clear from in vivo metabolic studies that this can also be misleading,and which nutrients are used for energy production versus building blocks for synthesis of macromolecules can vary greatly from tumor to tumor,and even within the same *** we review the operation of metabolic networks,and how recent understanding of nutrient supply in the TmE and utilization are being revealed using stable isotope tracers in vivo as well as in vitro.

关键词： Cancer metabolism Nutrient supply Stable isotope resolved metabolomics Tumor microenvironment metabolic flux

Transcriptional regulation of secretory capacity by bZip transcription factors

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers in Biology 2015年第1期10卷 28-51页

作者： Rebecca m. FOX Deborah J. andrew The Department of Cell Biology The Johns Hopkins University School of Medicine Baltimore MD 21205 USA

Cells of specialized secretory organs expand their secretory pathways to accommodate the increased protein load necessary for their function. The endoplasmic reticulum （ER）, the Golgi apparatus and the secretory vesicles, expand not only the membrane components but also the protein machinery required for increased protein production and transport. Increased protein load causes an ER stress response akin to the Unfolded Protein Response （UPR）. Recent work has implicated several bZip transcription factors in the regulation of protein components of the early secretory pathway necessary to alleviate this stress. Here, we highlight eight bZip transcription factors in regulating secretory pathway component genes. These include components of the three canonical branches of the UPR-ATF4, XBP1, and ATF6, as well as the five members of the Creb3 family of transcription factors. We review findings from both invertebrate and vertebrate model systems suggesting that all of these proteins increase secretory capacity in response to increased protein load. Finally, we propose that the Creb3 family of factors may have a dual role in secretory cell differentiation by also regulating the pathways necessary for cell cycle exit during terminal differentiation.

关键词： bZip transcription factors endoplasmic reticulum Golgi secretion secretory capacity secretory vesicles

Transdermal delivery of 4-aminopyridine accelerates motor functional recovery and improves nerve morphology following sciatic nerve crush injury in mice

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2020年第1期15卷 136-144页

作者： andrew RClark Chia George Hsu m A Hassan Talukder mark Noble John CElfar Center for Orthopaedic Research and Translational Science Penn State Hershey College of MedicineMilton S.Hershey Medical CenterHersheyPAUSA Department of Orthopaedics The University of Rochester Medical CenterRochesterNYUSA Department of medicine Aab Cardiovascular Research InstituteUniversity of Rochester School of Medicine and DentistryRochesterNYUSA Department of Biomedical Genetics The University of Rochester Medical CenterRochesterNYUSA

Oral 4-aminopyridine(4-AP)is clinically used for symptomatic relief in multiple sclerosis and we recently demonstrated that systemic 4-AP had previously unknown clinically-relevant effects after traumatic peripheral nerve injury including the promotion of re-myelination,improvement of nerve conductivity,and acceleration of functional *** hypothesized that,instead of oral or injection administration,transdermal 4-AP(TD-4-AP)could also improve functional recovery after traumatic peripheral nerve *** with surgical traumatic peripheral nerve injury received TD-4AP or vehicle alone and were examined for skin permeability,pharmacokinetics,functional,electrophysiological,and nerve morphological properties.4-AP showed linear pharmacokinetics and the maximum plasma 4-AP concentrations were proportional to TD-4-AP *** a single dose of TD-4-AP administration demonstrated rapid transient improvement in motor function,chronic TD-4-AP treatment significantly improved motor function and nerve conduction and these effects were associated with fewer degenerating axons and thicker myelin sheaths than those from vehicle *** findings provide direct evidence for the potential transdermal applicability of 4-AP and demonstrate that 4-AP delivered through the skin can enhance in-vivo functional recovery and nerve conduction while decreasing axonal *** animal experiments were approved by the University Committee on Animal Research(UCAR)at the University of Rochester(UCAR-2009-019)on march 31,2017.

关键词： 4-aminopyridine electron microscopy functional recovery nerve conduction velocity peripheral nerve injury pharmacokinetics transdermal administration

A deep convolutional neural network for real-time full profile analysis of big powder diffraction data

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

npj Computational materials 2021年第1期7卷 671-679页

作者： Hongyang Dong Keith T.Butler Dorota matras Stephen W.T.Price Yaroslav Odarchenko Rahul Khatry andrew Thompson Vesna middelkoop Simon D.m.Jacques andrew m.Beale Antonis Vamvakeros Department of Chemistry University College London20 Gordon StreetLondon WC1H 0AJUnited Kingdom ScimL Scientific Computer DivisionSTFCRutherford Appleton LaboratoryHarwell OX110QXUnited Kingdom Finden Limited Merchant House5 East St Helens StreetAbingdon OX145EGUnited Kingdom National Physical Laboratory Hampton RoadTeddington TW110LWUnited Kingdom Flemish Institute for Technological Research VITO NVBoeretang 200Mol 2400Belgium Research Complex at Harwell Rutherford Appleton LaboratoryHarwell Science and Innovation CampusDidcotOX110FA OxfordshireUnited Kingdom Present address:Diamond Light Source Harwell Science and Innovation CampusDidcotOxfordshire OX110DEUnited Kingdom Present address:The Faraday Institution Quad OneHarwell Science and Innovation CampusOX110RA OxfordshireUnited Kingdom

We present Parameter Quantification Network(PQ-Net),a regression deep convolutional neural network providing quantitative analysis of powder X-ray diffraction patterns from multi-phase *** network is tested against simulated and experimental datasets of increasing complexity with the last one being an X-ray diffraction computed tomography dataset of a multi-phase Ni-Pd/CeO_(2)-ZrO_(2)/Al_(2)O_(3) catalytic material system consisting of ca.20,000 diffraction *** is shown that the network predicts accurate scale factor,lattice parameter and crystallite size maps for all phases,which are comparable to those obtained through full profile analysis using the Rietveld method,also providing a reliable uncertainty measure on the *** main advantage of PQNet is its ability to yield these results orders of magnitude faster showing its potential as a tool for real-time diffraction data analysis during in situ/operando experiments.

关键词： network powder analysis

Genetic mapping and survey of powdery mildew resistance in the wild Central Asian ancestor of cultivated grapevines in Central Asia

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Horticulture Research 2020年第1期7卷 1444-1458页

作者： Summaira Riaz Cristina m.menéndez Alan Tenscher Daniel Pap m.andrew Walker Department of Viticulture and Enology University of CaliforniaDavisCA 95616USA Instituto de Ciencias de la Vid y del Vino(ICVV) Universidad de La Rioja-CSICGobierno de La RiojaCarretera de Burgos Km6Finca La GrajeraLogroñoLa Rioja 26007Spain

Cultivated grapevines(Vitis vinifera)lack resistance to powdery mildew(Pm)with few *** to this pathogen within *** has been reported in earlier studies and identified as the Ren1 locus in two Central Asian table grape *** Pm-resistant cultivated varieties and accessions of the wild ancestor *** *** were soon identified raising questions regarding the origin of the *** this study,F1 breeding populations were developed with a Pm susceptible *** *** breeding line and a Pm-resistant *** *** was carried out with five Ren1 locus linked SSR markers.A Pm resistance locus explaining up to 96%of the phenotypic variation was identified in the same genomic position,where the Ren1 locus was previously *** SSR marker alleles linked with the resistance locus were *** report results of Pm resistance in multiple accessions of *** collected as seed lots or cuttings from five countries in the Caucasus and Central Asia.A total of 20 females from 11 seed lots and 19 males from nine seed lots collected from Georgia,Armenia,and Azerbaijan were resistant to *** male and one female plant collected as cuttings from Afghanistan and Iran were also resistant to *** analysis of markers linked with the Ren1 locus in conjunction with disease evaluation data found a high diversity of allelic haplotypes,which are only possible via recombination events occurring over a long time *** analysis of two alleles of the SSR marker that cosegregates with the resistance found SNPs that were present in the wild progenitor and in cultivated *** levels of Pm resistance among the tested accessions were also *** lines of evidence suggest that the powdery mildew fungus may have been present in Asia for a longer time than currently thought,giving the wild progenitor *** *** time to coevolve with and develo

关键词： breeding resistance Central

multimodal alarm behavior in urban and rural gray squirrels studied by means of observation and a mechanical robot

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Current Zoology 2010年第3期56卷 313-326页

作者： Sarah R.PARTAN andrew G FULmER maya A.m.GOUNARD Jake E.REDmOND Hampshire College School of Cognitive Science

Urbanization of animal habitats has the potential to affect the natural communication systems of any species able to survive in the changed environment. Urban animals such as squirrels use multiple signal channels to communicate, but it is un- known how ttrbanization has affected these behaviors. multimodal commtmication, involving more than one sensory modality, can be studied by use of biomimetic mechanical animal models that are designed to simulate the multimodal signals and be pre- sented to animal subjects in the field. In this way the responses to the various signal components can be compared and contrasted to determine whether the multimodal signal is made up of redundant or nonredundant components. In this study, we presented wild gray squirrels in relatively urban and relatively rural habitats in Western massachusetts with a biomimetic squirrel model that produced tail flags and alarm barks in a variety of combinations. We found that the squirrels responded to each unimodal component on its own, the bark and tail flag, but they responded most to the complete multimodal signal, containing both the acoustic and the moving visual components, providing evidence that in this context the signal components are redundant and that their combination elicits multimodal enhancement. We expanded on the results of Partan et al. （2009） by providing data on sig- naling behavior in the presence and absence of conspecifics, suggesting that alarm signaling is more likely if conspecifics are present. We found that the squirrels were more active in the urban habitats and that they responded more to tail flagging in the urban habitats as compared to the rural ones, suggesting the interesting possibility of a multimodal shift from reliance on audio to visual signals in noisier more crowded urban habitats [Current Zoology 56 （3）： 313-326, 2010].

关键词： Alarm behavior Communication Gray squirrel Sciurus carolinensis multisensory signaling Redundancy Urbanization Ethorobotics