检索结果-南通市图书馆

Differential effects of short term winter thermal stress on diapausing tiger swallowtail butterflies （Papilio spp.）

在线全文

学校读者我要写书评

暂无评论

Insect Science 2012年第3期19卷 277-285页

作者： j. mark Scriber Emily Maher Matthew L. Aardema Department of entomology Michigan State University East Lansing MI McGuire Center for Lepidoptera and Biodiversity Florida Museum of Natural History University of Florida Gainesville FL Department of Ecology and Evolutionary Biology Princeton University Princeton N J USA

It is generally thought that insects inhabiting lower latitudes are more severely impacted by changes in their thermal environment than are high latitude species. This is attributed to the wider range of temperatures to which high-latitude species are exposed. By contrast, low-latitude species have typically evolved in more thermally stable environments with a narrower range of temperature variation. However, deviation from this pattern can occur and here we report that under variable winter conditions a higher latitude species may be more sensitive to thermal variation than its lower latitude sister species. Using split broods, we examined the survival and adult emergence success of diapausing pupae of Papilio canadensis and P. glaucus, as well as a unique, recombinant hybrid population （＂late-flight＂） to short periods of mid-winter cold and heat stress. Our results indicate that the higher latitude, univoltine populations （P. canadensis and late-flights） exhibit lower pupal survival than the lower latitude, facultative diapauser （P. glaucus） for all mid-winter thermal stress treatments, both high and low. Size differences alone do not appear to account for the observed differences in survival or metabolic costs in these three pheno- types, as late-flight individuals are similar in size to R glaucus. We attribute the observed differences in survival and weight loss to potential metabolic differences and variation in the intensity of diapause, in addition to divergent adaptation to winter precipitation levels （e.g. snow cover） and the influences this may have on microhabitat temperature moderation.

关键词： climate change developmental threshold incipient hybrid species metabolic cost Papilionidae post-diapause delays thermal stress

In Vivo and In Vitro Degradation Behavior of Magnesium Alloys as Biomaterials

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 Materials Science & Technology 2012年第3期28卷 261-267页

作者： Dingchuan Xue Yeoheung Yun Zongqing Tan Zhongyun Dong mark j. Schulz Department of Chemical and Materials engineering University of Cincinnati OH 45221 USA Department of Bioengineering North Carolina A ＆ T State University Greensboro NC 27411 USA Department of Internal Medicine University of Cincinnati OH 45221 USA Department of Mechanical engineering University of Cincinnati OH 45221 USA

The corrosion behavior of pure Mg,AZ31,and AZ91D were evaluated in various in vitro and in vivo environments to investigate the potential application of these metals as biodegradable implant *** polarization tests and immersion tests were performed in different simulated body solutions,such as distilled（DI） water,simulated body fluid（SBF） and phosphate buffered solution（PBS）.Mg/Mg alloys were also implanted in different places in a mouse for in vivo weight loss and biocompatibility *** in vivo subcutis bio-corrosion rate was lower than the corrosion rate for all of the in vitro simulated corrosive *** Mg/Mg alloys were biocompatible based on histology results for the liver,heart,kidney,skin and lung of the mouse during the two months *** microscopy and scanning electron microscopy were carried out to investigate the morphology and topography of Mg/Mg alloys after immersion testing and implantation to understand the corrosion mechanisms.

关键词： Mg/Mg alloys In vitro/in vivo testing Bio-degradation rate Biocompatibility

Coal bursts that occur during development: A rock mechanics enigma

在线全文

学校读者我要写书评

暂无评论

International journal of Mining Science and Technology 2018年第1期28卷 35-42页

作者： Christopher mark Safety and Health Administration Pittsburgh 15236USA

Coal bursts are typically associated with highly stressed *** bursts occur during retreat mining(longwall mining or pillar recovery) in highly stressed locations like the tailgate corner of the longwall *** are associated with multiple seam ***, a small but significant percentage of coal bursts have occurred during development or in outby locations unaffected by active *** development bursts have been relatively small, but some have been highly *** theory of coal bursts can be complete if it does not account for this type of *** paper focusses on the development mining coal burst experience in the US, putting it into the context of the entire US coal burst *** first documented development coal burst occurred almost exactly 100 years ago during slope drivage at the Sunnyside Mine in *** subsequently had a long history of bursts, mainly during retreat mining but also during *** Colorado mines have also experienced multiple development ***, but by no means all, of the development bursts in these western US coalfields have been associated with known *** the Central Appalachian coalfields, most development bursts have occurred in multiple seam *** some of these cases, however, there was no retreat mining in either *** paper closes with some lessons from this history, with implications for preventing such events in the future.

关键词： Coal Underground Ground control Bursts Multiple seam

c-MET immunohistochemical expression in sporadic and inflammatory bowel disease associated lesions

在线全文

学校读者我要写书评

暂无评论

World journal of Gastroenterology 2022年第13期28卷 1338-1346页

作者： Grant Halliday Ross j Porter Catherine j Black mark j Arends Shahida Din Department of Pathology Western General HospitalNHS LothianScotland EH42XUUnited Kingdom Centre for Inflammation Research Queen’s Medical Research InstituteUniversity of EdinburghEdinburgh EH164TJUnited Kingdom Edinburgh Inflammatory Bowel Disease Unit Western General HospitalNHS LothianEdinburgh EH42XUUnited Kingdom Cancer Research UK Edinburgh Centre Institute of Cancer&GeneticsWestern General HospitalUniversity of EdinburghEdinburgh EH42XUUnited Kingdom

BACKGROUND Post-colonoscopy colorectal cancer(CRC)rates for patients with inflammatory bowel disease(IBD)are unacceptably *** colonoscopy,an intravenous fluorescent anti-c-MET probe may improve endoscopic detection of ***,c-MET expression in IBD lesions is poorly defined,limiting translational *** To comprehensively define c-MET expression in sporadic and IBD-associated colorectal *** c-MET expression was immunohistochemically assessed in 319 formalin-fixed paraffin-embedded tissue specimens,colonoscopically or surgically retrieved between *** included:30 normal colorectal biopsies,30 hyperplastic polyps(HP),31 sessile serrated lesions(SSL),55 tubular/tubulovillous adenomas with low(TA-LGD,n=32)or high grade dysplasia(TA-HGD,n=23),26 sporadic(s)-CRCs,16 quiescent IBD biopsies,11 active/inflamed IBD biopsies,18 IBDassociated dysplastic lesions(IBD-dys),and 102 *** was scored by two independent observers as:0=absent,1=weak,2=moderate or 3=***-Whitney U and Kruskal-Wallis tests were used to assess *** Positive epithelial cytoplasmic and membranous c-MET expression was observed in all tissues,indicating there is ubiquitous expression in the colorectum.c-MET expression was weak in normal colonic epithelium compared with each of the sporadic colonic lesions,including TA-LGD(Pence between TA-LGD and TA-HGD(P=0.852).Further,there was no difference in c-MET expression between HP and SSL(P=0.065).In IBD,expression was weaker in quiescent colonic mucosa compared with inflamed colonic mucosa(Pence between inflamed colonic mucosa and IBD-dys(P=0.512)or IBD-CRC(P=0.296).However,expression

关键词： Inflammatory bowel diseases Colorectal cancer Surveillance Detection c-MET Immunohistochemistry

Apoptosis block as a barrier to effective therapy in non small cell lung cancer

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World journal of Clinical Oncology 2014年第4期5卷 588-594页

作者： Ian Paul j mark jones Department of Cardiothoracic Surgery Royal Victoria Hospital Belfast BT12 6BA Northern Ireland United Kingdom

Lung cancer, is the most common cause of cancer death in men and second only to breast cancer in women. Currently, the first line therapy of choice is platinumbased combination chemotherapy. A therapeutic plateau has been reached with the prognosis for patients with advanced non-small cell lung cancer(NSCLC) remaining poor. New biomarkers of prognosis as well as new therapies focusing on molecular targets are emerging helping to identify patients who are likely to benefit from therapy. Despite this, drug resistance remains the major cause for treatment failure. In this article we review the role of apoptosis in mediating drug resistance in NSCLC. Better understanding of this fundamental biological process may provide a rationale for overcoming the current therapeutic plateau.

关键词： Apoptosis Lung cancer Adjuvant therapy Mitochondria BAX BAK BCL2

The effect of temperature on the wear behaviour of dental composites

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Biosurface and Biotribology 2022年第4期8卷 329-336页

作者： joseph A.Arsecularatne Serena Tran mark j.Hoffman School of Materials Science and engineering UNSW SydneySydneyNew South WalesAustralia School of Mechanical and Manufacturing engineering UNSW SydneySydneyNew South WalesAustralia School of engineering University of NewcastleCallaghanNew South WalesAustralia

Despite numerous published studies on the wear of dental composites,few have considered the influence of temperature on the two-body wear ***,no previous work has considered the influence of temperature on dominant wear mecha-nisms during the consumption of hot substances,hence the focus of this ***-rocating wear tests were carried out at varying artificial saliva lubricant temperatures(37 and 57℃)and material loss was quantified using *** wear tracks were analysed using FIB/SEM/*** reveal that the wear rate of a dental composite can significantly increase with temperature,with fatigue/delamination and ploughing acting as dominant mechanisms.

关键词： dental composite temperature tribological performance wear mechanism

Senescence-specific Alteration of Hydrogen Peroxide Levels in Arabidopsis thaliana and Oilseed Rape Spring Variety Brassica napus ***

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 2012年第8期54卷 540-554页

作者： Stefan Bieker Lena Riester mark Stahl jürgen Franzaring Ulrike Zentgraf ZMBP (Center for Plant Molecular Biology) University of TübingenAuf der Morgenstelle 2872076 Tübingen Germany Institute for Landscape and Plant Ecology kologiezentrum 2August-von-Hartmann-Str.370599 StuttgartGermany

In order to analyze the signaling function of hydrogen peroxide （H202） production in senescence in more detail, we manipulated intracellular H202 levels in Arabidopsis thaliala （L.） Heynh by using the hydrogen- peroxide-sensitive part of the Escherichia coil transcription regulator OxyR, which was directed to the cytoplasm as well as into the peroxisomes. H202 levels were lowered and senescence was delayed in both transgenic lines, but OxyR was found to be more effective in the cytoplasm. To transfer this knowledge to crop plants, we analyzed oilseed rape plants Brassica napus L. cv. Mozart for H20~ and its scavenging enzymes catalase （CAT） and ascorbate peroxidase （APX） during leaf and plant development. H202 levels were found to increase during bolting and flowering time, but no increase could be observed in the very late stages of senescence. With increasing H202 levels, CAT and APX activities declined, so it is likely that similar mechanisms are used in oilseed rape and Arabidopsis to control H202 levels. Under elevated CO2 conditions, oilseed rape senescence was accelerated and coincided with an earlier increase in H202 levels, indicating that H202 may be one of the signals to inducing senescence in a broader range of Brassicaceae.

关键词： Arabidopsis thaliana Brassica napus E. coil Oxy-RD intracellular hydrogen peroxide senescence phenotype catalase ascorbatePeroxidase elevated CO2.

Modulating p-type doping of two-dimensional material palladium diselenide

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第4期17卷 3232-3244页

作者： jiali Yang Yu Liu en-Yang Wang jinbo Pang Shirong Huang Thomas Gemming jinshun Bi Alicja Bachmatiuk Hao jia Shu-Xian Hu Chongyun jiang Hong Liu Gianaurelio Cuniberti Weijia Zhou mark H Rümmeli Institute for Advanced Interdisciplinary Research(iAIR) University of JinanJinan 250022China Institute for Materials Chemistry Leibniz Institute for Solid State and Materials Research Dresden(IFW Dresden)20 Helmholtz StrasseDresden 01069Germany State Key Lab of Transducer Technology Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China College of energy Soochow Institute for Energy and Materials Innovations Soochow UniversitySuzhou 215006China Key Laboratory of Advanced Carbon Materials and Wearable energy Technologies of jiangsu Province Soochow UniversitySuzhou 215006China School of Integrated Circuits University of Chinese Academy of SciencesBeijing 101408China Institute of Microelectronics of Tianjin Binhai New Area Tianjin 300451China Institute of Microelectronics Chinese Academy of SciencesBeijing 100029China Lukasiewicz Research Network PORT Polish Center for Technology DevelopmentStablowicka 147Wroclaw 54-066Poland School of Mathematics and Physics University of Science and Technology BeijingBeijing 100083China College of electronic information and optical engineering Nankai UniversityTianjin 300350China Centre of Polymer and Carbon Materials Polish Academy of SciencesM.Curie Sklodowskiej 34Zabrze 41-819Poland Center for energy and environmental Technologies VŠB-Technical University of Ostrava17.Listopadu 15Ostrava 70833Czech Republic State Key Laboratory of Crystal Materials Center of Bio&Micro/Nano Functional MaterialsShandong UniversityJinan 250100China Dresden Center for Computational Materials Science Technische Universität DresdenDresden 01062Germany Dresden Center for Intelligent Materials(GCL DCIM) Technische Universität DresdenDresden 01062Germany Institute for Materials Science and Max Bergmann Center of Biomaterials Technische Universität DresdenDresden 01069Germany Center for Advancing Electronics Dresden Technische Universität DresdenDresden 01069Germany

The van der Waals heterostructures have evolved as novel materials for complementing the Si-based semiconductor ***-10 noble metal dichalcogenides(e.g.,PtS_(2),PtSe_(2),PdS_(2),and PdSe_(2))have been listed into two-dimensional(2D)materials toolkit to assemble van der Waals *** them,PdSe_(2) demonstrates advantages of high stability in air,high mobility,and wide tunable ***,the regulation of p-type doping of PdSe_(2) remains unsolved problem prior to fabricating p–n junction as a fundamental platform of semiconductor ***,a quantitative method for the controllable doping of PdSe_(2) is yet to be *** this study,the doping level of PdSe_(2) was correlated with the concentration of Lewis acids,for example,SnCl_(4),used for *** the transfer characteristics,the threshold voltage(the gate voltage corresponding to the minimum drain current)increased after SnCl_(4) soaking ***_(2) transistors were soaked in SnCl_(4) solutions with five different *** threshold voltages from the as-obtained transfer curves were extracted for linear fitting to the threshold voltage versus doping concentration correlation *** study provides in-depth insights into the controllable p-type doping of PdSe_(2).It may also push forward the research of the regulation of conductivity behaviors of 2D materials.

关键词： two-dimensional(2D)materials Lewis acid treatment p-type doping field-effect transistors transfer characteristic

INCIDenCE MATRIX APPROACH FOR CALCULATING READINESS LEVELS

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 Systems Science and Systems engineering 2014年第4期23卷 377-403页

作者： mark A.London Thomas H.Holzer Timothy j.Eveleigh Shahryar Sarkani School of engineering and Applied Science George Washington University

Contemporary system maturity assessment approaches have failed to provide robust quantitative system evaluations resulting in increased program costs and developmental *** assessment metrics,such as Technology Readiness Levels（TRL）,do not sufficiently evaluate increasingly complex *** System Readiness Level（SRL）is a newly developed system development metric that is a mathematical function of TRL and Integration Readiness Level（IRL） values for the components and connections of a particular *** acceptance has been hindered because of concerns over SRL mathematical operations that may lead to inaccurate system readiness *** inaccurate system readiness assessments are called readiness reversals.A new SRL calculation method using incidence matrices is proposed to alleviate these mathematical *** presence of SRL readiness reversal is modeled for four SRL calculation methods across several system *** regression analysis demonstrates that the proposed Incidence Matrix SRL（IMSRL）method has a decreased presence of readiness reversal than other approaches suggested in the *** SRL methods will foster greater SRL adoption by systems engineering professionals and will support system development risk reduction goals.

关键词： Technology Readiness Level(TRL) integration readiness level(IRL) system readiness level(SRL) system readiness graph theory systems engineering