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Bioactive Materials 2023年第6期24卷 438-449页

作者： nathan Lagneau Pierre Tournier Boris Halgand François Loll Yves Maugars Jérôme Guicheux Catherine Le Visage Vianney Delplace Nantes Université OnirisCHU NantesINSERMRegenerative Medicine and SkeletonRMeSUMR 1229F-44000France

The cellular microenvironment plays a major role in the biological functions of ***,biomaterials,especially hydrogels,which can be design to mimic the cellular microenvironment,are being increasingly used for cell encapsulation,delivery,and 3D culture,with the hope of controlling cell ***,much remains to be understood about the effects of cell-material interactions,and advanced synthetic strategies need to be developed to independently control the mechanical and biochemical properties of *** address this challenge,we designed a new hyaluronic acid(HA)-based hydrogel platform using a click and bioorthogonal strain-promoted azide-alkyne cycloaddition(SPAAC)*** approach facilitates the synthesis of hydrogels that are easy to synthesize and sterilize,have minimal swelling,are stable long term,and are *** provides bioorthogonal HA gels over an uncommonly large range of stiffness(0.5-45 kPa),all forming within 1-15 *** importantly,our approach offers a versatile one-pot procedure to independently tune the hydrogel composition(e.g.,polymer and adhesive peptides).Using this platform,we investigate the independent effects of polymer type,stiffness,and adhesion on the secretory properties of human adipose-derived stromal cells(hASCs)and demonstrate that HA can enhance the secretion of immunomodulatory factors by hASCs.

关键词： Hydrogels Click and bioorthogonal chemistry Hyaluronic acid Mesenchymal stromal cells Cell-material interactions Secretome

Adult bobcat(Lynx rufus)habitat selection in a longleaf pine savanna

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ecological Processes 2018年第1期7卷 206-217页

作者： Andrew R.Little L.Mike Conner Michael J.Chamberlain nathan P.Nibbelink Robert J.Warren Warnell School of Forestry and Natural Resources University of Georgia180 E.Green StAthensGA 30602USA Joseph W.Jones ecological Research Center at Ichauway NewtonGeorgia 39870USA

Background:Pine savannas are primarily managed with frequent prescribed fire(≤3 years)to promote diversity of flora and fauna,and to maintain open,park-like conditions needed by species such as the endangered red-cockaded woodpecker(Picoides borealis).However,a knowledge gap exists in our understanding of bobcat(Lynx rufus)habitat selection in longleaf pine savannas and research is warranted to direct our future management ***:We examined bobcat habitat selection in a pine savanna managed with frequent fires at two spatial scales(i.e.,study area boundary[hereafter,landscape scale])and annual area of use[95%kernel density;local scale],and assessed effects of prescribed fire on bobcat habitat ***,we monitored 45 bobcats(16 males and 29 females)during 2001–***:We found differential habitat selection by *** the landscape scale,female bobcats were closer to mixed pine-hardwoods,young pine,and secondary roads,but farther from mature pine and hardwoods stands relative to *** found no difference in selection of agriculture,shrub-scrub,and primary roads between *** the annual area of use scale,female bobcats were closer to secondary roads,but farther from agriculture and shrub-scrub relative to *** found no difference in selection of mature pine,mixed pine-hardwoods,hardwoods,young pine,and primary roads between *** primarily selected for stands burned≤1.1 years ***:Our results show that bobcats exploit a broad range of habitat types in pine landscapes managed with frequent fire and commonly use recently burned stands(≤1.1 year post-fire),suggesting prey in many areas of this system are at risk of bobcat ***,we suggest land managers consider scale of selection by bobcats when developing habitat management strategies.

关键词： Georgia Habitat selection Lynx rufus Pinus palustris Prescribed fire

Development of a sample preparation approach to measure the size of nanoparticle aggregates by electron microscopy

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Particuology 2019年第4期17卷 49-57页

作者： Agnieszka Dudkiewicz Angela Lehner Qasim Chaudhry Kristian Molhave Guenter Allmaier Karen Tiede Alistair B.A. Boxall Peter Hofmann John lewis The Food and environment Research Agency Sand Hutton York Y041 1LZ UK Department of environment The University of York Heslington York YO10 5DD UK National Centre for Food Manufacturing The University of Lincoln Holbeach PE12 7AG UK Research Group Bio- and Polymer Analysis Institute of Chemical Technologies and Analytics TU Wien (Vienna University of Technology) Getreidemarkt 9 A-1060 Vienna Austria University of Chester Parkgate Road Chester CH1 4BJ UK Department of Micro and Nanotechnology Technical University of Denmark DTU Bldg 345b Lyngby 2800 Denmark Research Centre for Global Food Security and ecosystems University of Hohenheim Wollgrasweg 43 70155 Stuttgart Germany Department of Geoinformatics - Z.GIS University of Salzburg Schillerstr. 30 A-5020 Salzburg Austria

electron microscopy (eM) is widely used for nanoparticle (NP) sizing. Following an initial assessment of two sample preparation protocols described in the current literature as"unperturbed", we found that neither could accurately measure the size of NPs featuring a broad size distribution, e.g., aggregates. Because many real-world NP samples consist of aggregates, this finding was of considerable concern. The data showed that the protocols introduced errors into the measurement by either inducing agglomeration artefacts or providing a skewed size distribution towards small particles (skewing artefact). The focus of this work was to develop and apply a mathematical refinement to correct the skewing artefact. This refinement provided a much improved agreement between eM and a reference methodology, when applied to the measurement of synthetic amorphous silica NPs. Further investigation, highlighted the influence of NP chemistry on the refinement. This study emphasised the urgent need for greater and more detailed consideration regarding the sample preparation of NP aggregates to routinely achieve accurate measurements by eM. This study also provided a novel refinement solution applicable to the size characterisation of silica and c让rate-coated gold NPs featuring broad size distributions. With further research, this approach could be extended to other NP types.

关键词： Nanoparticles Aggregates Measurement electron microscopy Sample preparation Artefacts

Selective Deactivation of Gibberellins below the Shoot Apex is Critical to Flowering but Not to Stem elongation of Lolium

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Molecular Plant 2008年第2期1卷 295-307页

作者： Rod W. King lewis N. Mander Torben Asp Colleen R MacMillan Cheryl A. Blundell Lloyd T. evans CSIRO Plant Industry Canberra ACT 2600 Australia Research School of Chemistry Australian National University Canberra ACT 0200 Australia Department of Genetics and-Biotechnology University of Aarhus 4200 Slagelse Denmark Present Address: eNSIS PO Box E 4008 Kingston ACT 2604 Australia

Gibberellins （GAs） cause dramatic increases in plant height and a genetic block in the synthesis of GA1 explains the dwarfing of Mendel＇s pea. For flowering, it is GAs which is important in the long-day （LD） responsive grass, Loliurn. As we show here, GA1 and GA4 are restricted in their effectiveness for flowering because they are deactivated by C-2 hydroxylation below the shoot apex. In contrast, GAs is effective because of its structural protection at C-2. excised vegetative shoot tips rapidly degrade [14C]GA1, [14C]GA4, and [14C]GA20 （〉80% in 6 h）, but not [14C]GAs. CoincidentaUy, genes encoding two 2β-oxidases and a putative 16-17-epoxidase were most expressed just below the shoot apex （〈3 mm）. Further down the immature stem （〉4 mm）, expression of these GA deactivation genes is reduced, so allowing GA1 and GA4 to promote sub-apical stem elongation. Subsequently, GA degradation declines in florally induced shoot tips and these GAs can become active for floral development. Structural changes which stabilize GA4 confirm the link between florigenicity and restricted GA 2β-hydroxylation （e.g. 2α-hydroxylation and C-2 di-methylation）. Additionally, a 2-oxidase inhibitor （Trinexapac ethyl） enhanced the activity of applied GA4, as did limiting C-16,17 epoxidation in 16,17-dihydro GAs or after C-13 hydroxylation. Overall, deactivation of GA1 and GA4 just below the shoot apex effectively restricts their florigenicity in Loliurn and, conversely, with GAs, C-2 and C-13 protection against deactivation allows its high florigenicity. Speculatively, such differences in GA access to the shoot apex of grasses may be important for separating floral induction from inflorescence emergence and thus could influence their survival under conditions of herbivore predation.

关键词： flowering shoot apices Shoots Gallium Lolium plant height Deactivation G(A1) ganglioside Apex APeX1 protein, human Gibberellins stem elongation

Current review of excimer laser Trabeculostomy

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eye and Vision 2020年第1期7卷 232-240页

作者： Georges M.Durr Marc Töteberg-Harms Richard lewis Antonio Fea Paola Marolo Iqbal Ike K.Ahmed Department of Ophthalmology Universitéde MontréalMontrealQuebecCanada Department of Ophthalmology Centre Hospitalier Universitaire de Montréal(CHUM)1051 Rue SanguinetMontreal H2X 3E4QuebecCanada Department of Ophthalmology University Hospital ZurichZurichSwitzerland Sacramento eye Consultants SacramentoCaliforniaUSA Struttura Complessa Oculistica Cittàdella Salute e della Scienza di TorinoDipartimento di Scienze ChirurgicheUniversitàdegli Studi di TorinoTorinoItaly Department of Ophthalmology&Vision Sciences University of TorontoTorontoOntarioCanada

Background:excimer laser trabeculostomy(eLT)is a microinvasive glaucoma surgery(MIGS)that creates multiple laser channels through the trabecular meshwork using a cold laser system,which minimizes tissue fibrosis and aids in bypassing the main area of resistance to aqueous *** purpose of this review is to evaluate the current body of evidence surrounding eLT in terms of efficacy and review the safety profile of the *** text:Studies screened had to show clear inclusion and exclusion criteria as well as well-defined outcome ***,MeDLINe,eMBASe and the Cochrane Controlled Trial Database were *** Reporting Items of Systematic Reviews(PRISMA)guidelines were used to assess for study quality and for any ***-four articles were initially identified with 18 meeting preliminary screening ***,8 studies met inclusion criteria and 2 additional non-referenced publications were also included:1 randomized control trial,4 prospective case series and 5 retrospective *** studies showed moderate intraocular pressure(IOP)lowering of between 20%and 40%from baseline without medication washout and mostly a decrease in glaucoma medications with few ***:Current literature shows a significant IOP-lowering effect of eLT with a favorable safety-profile in standalone cases or combined with cataract *** to these studies are the lack of controls and washout ***,eLT is an attractive MIGS option that does not require any residual device remaining in the angle.

关键词： excimer laser trabeculostomy Trabeculotomy eLT Intraocular pressure Glaucoma MIGS Cataract

eastern wild turkey nest site selection in two frequently burned pine savannas

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ecological Processes 2016年第1期5卷 38-47页

作者： Andrew R.Little nathan P.Nibbelink Michael J.Chamberlain LMike Conner Robert J.Warren Warnell School of Forestry and Natural Resources University of Georgia180 E.Green St.AthensGA 30602USA Joseph W.Jones ecological Research Center at Ichauway NewtonGeorgia 39870USA

Introduction:Reproductive success is a critical factor affecting avian demographics and can be influenced by many factors including nesting chronology,predation risk,and fine-scale nest site ***:We modeled the relative influences of habitat-related covariates at six spatial scales(nest site:15-,40-,80-,120-,160-,and 200-m radii)on eastern wild turkey(Meleagris gallopavo silvestris)nest site selection in two pine savannas managed by frequent prescribed fire(≤3 years)in southwestern Georgia during ***:Nest site(15-m scale)habitat metrics(mean visual obstruction[cm]and canopy closure[%])had the greatest influence on nest site selection relative to covariates measured at larger spatial *** odds ratios suggested that nests were 26.8% more likely to occur for every 10 cm increase in mean vegetation height with a range of 7.5 to 150.0 cm and 18.5% less likely to occur for every 10% increase in canopy closure with a range from 0.0 to 97.8%.Total ground cover,canopy closure,edge density,and percent land cover type(e.g.,mature pine,mixed pine/hardwood,shrub/scrub)had minimal influence on nest site ***:Management of pine savannas for turkey nest sites should focus on creating early-successional vegetation to conceal nests from potential ***,we suggest that future studies consider evaluating the influence of spatial scale on turkey nest site selection.

关键词： Georgia Land cover Meleagris gallopavo silvestris Multi-scale Nest site selection Pinus palustris Radio-telemetry

Bench-top aqueous two-phase extraction of isolated individual single-walled carbon nanotubes

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Nano Research 2015年第5期8卷 1755-1769页

作者： Navaneetha K. Subbaiyan A. Nicholas G. Parra-Vasquezt Sofie Cambre Miguel A. Santiago Cordoba Sibel ebru Yalcin Christopher e. Hamilton nathan H. Mack Jeffrey L. Blackburn Stephen K. Doorn Juan G. Duque Chemistry Division Physical Chemistry and Applied Spectroscopy Group (C-PCS) Center for Integrated Nanotechnologies (CINT) and Materials Science & Technology Division (MST-7) Los Alamos National Laboratory Los Alamos New Mexico 87544 USA experimental Condensed Matter Physics Laboratory University of Antwerp Antwerp B-2610 Belgium National Renewable energy Laboratory Golden Colorado 80401 USA

Isolation and purification of single-walled carbon nanotubes （SWCNTs） are prerequisites for their implementation in various applications. In this work, we present a fast （-5 min）, low-cost, and easily scalable bench-top approach to the extraction of high-quality isolated SWCNTs from bundles and impurities in an aqueous dispersion. The extraction procedure, based on aqueous two-phase （ATP） separation, is widely applicable to any SWCNT source （tested on samples up to 1.7 nm in diameter） and independent of defect density, purity, diameter, and length. The extracted dispersions demonstrate that the removal of large aggregates, small bundles, and impurities is comparable to that by density gradient ultracentrifugation, but without the need for high-end instrumentation. Raman and fluorescence-excitation spectroscopy, single-nanotube fluorescence imaging, atomic force and transmission electron microscopy, and thermogravimetric analysis all confirm the high purity of the isolated SWCNTs. By predispersing the SWCNTs without sonication （only gentle stirring）, full-length, pristine SWCNTs can be isolated （tested up to 20 μm）. Hence, this simple ATP method will find immediate application in the generation of SWCNT materials for all levels of nanotube research and applications, from fundamental studies to high-performance devices.

关键词： carbon nanotubes aqueous two-phase (ATP)separation aggregate removal isolation sorting

effect of Activated Milt Residence Time on Landlocked Fall Chinook Salmon egg Survival

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Open Journal of Applied Sciences 2020年第4期10卷 135-141页

作者： Jessica Shannon nathan Huysman Jill M. Voorhees eric Krebs Michael e. Barnes Department of Game Fish and Parks McNenny State Fish Hatchery Spearfish South Dakota USA

During artificial spawning of salmonids, activated sperm is allowed to remain in contact with eggs for variable durations. This study examined multiple residence times (20, 40, 60, 90, or 120 seconds) for activated sperm on landlocked fall Chinook salmon (Oncorhynchus tshawytscha) eggs during spawning. There was no significant difference in egg survival to the eyed-stage of development or to hatch among any of the treatments, with a mean (Se) percent survival to the eyed stage of 63.9 (5.8). These results indicate that only relatively short residence times of activated milt on eggs during landlocked fall Chinook salmon spawning are needed to ensure egg survival, resulting in potentially substantial reductions in production-level spawning times and associated labor costs.

关键词： Chinook Salmon Oncorhynchus tshawytscha Milt eggs Spawning Sperm

The AFB1 auxin receptor controls the cytoplasmic auxin response pathway in Arabidopsis thaliana

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Molecular Plant 2023年第7期16卷 1120-1130页

作者： Shiv Mani Dubey Soeun Han nathan Stutzman Michael J.Prigge eva Medvecka Matthieu Pierre Platre Wolfgang Busch Matyas Fendrych Mark estelle Department of experimental Plant Biology Faculty of SciencesCharles UniversityPragueCzech Republic Section of Cell and Developmental Biology University of California San DiegoLa JollaCAUSA Plant Molecular and Cellular Biology Laboratory and Integrative Biology Laboratory Salk Institute for Biological StudiesLa JollaCAUSA Department of Biology Chungbuk National UniversityCheongjuKorea

The phytohormone auxin triggers root growth inhibition within seconds via a *** members of the TIR1/AFB auxin receptor family,AFB1 has a primary role in this rapidresponse. However, the unique features that confer this specific function have not been *** we show that the N-terminal region of AFB1, including the F-box domain and residues thatcontribute to auxin binding,is essential and sufficient for its specific role in the rapid response. Substitutionof the N-terminal region of AFB1 with that of TIR1 disrupts its distinct cytoplasm-enriched localizationand activity in rapid root growth inhibition by auxin. Importantly, the N-terminal region of AFB1 isindispensable for auxin-triggered calcium influx, which is a prerequisite for rapid root growth ***, AFB1 negatively regulates lateral root formation and transcription of auxin-induced genes,suggesting that it plays an inhibitory role in canonical auxin signaling. These results suggest that AFB1may buffer the transcriptional auxin response, whereas it regulates rapid changes in cell growth thatcontributeto rootgravitropism.

关键词： gravitropism calcium auxin signaling Arabidopsis lateral root

evaluation of Four Geomembrane-Mounted PV Systems for Land Reclamation in Southern Arizona

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Journal of energy and Power engineering 2013年第5期7卷 834-840页

作者： Adria e. Brooks nathan Allen Vincent P. Lonij Alexander D. Cronin Department of Physics University of Arizona Tucson AZ 85721 USA Biosphere 2 College of Science University of Arizona Tucson AZ 85739 USA

Four different PV （photovoltaic） systems deployed around Tucson Arizona on geomembranes are used to test the feasibility of converting mine tailings and landfills into solar energy generating sites. Differences between these deployed systems include： two types of geomembrane materials, two different module anatomies and two different locations. Module mounting techniques unique to mine tailing sites are described. Several system failures observed during the first two years of operation are explained here in detail. Validated predictions for the operating temperature of these systems and their associated electrical performance are presented. It was determined that PV modules mounted on light-colored thermoplastic with shielded wiring operate at lower temperatures, are structurally stable, and experience fewer wiring failures.

关键词： Photovoltaic systems system performance current-voltage characteristics surface-mount technology land reclamation mining applications polyethylene geomembrane.