检索结果-南通市图书馆

Thermally stimulated exciton emission in Si nanocrystals

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2017年第1期6卷 228-234页

作者： Elinore mLD de Jong Huub Rutjes Jan Valenta m Tuan Trinh Alexander N Poddubny Irina N Yassievich Antonio Capretti tom Gregorkiewicz Van der Waals-Zeeman Institute University of AmsterdamScience Park 9041098 XHAmsterdamThe Netherlands Department of Chemical Physics and Optics Faculty of Mathematics and PhysicsCharles UniversityKe Karlovu 312116 Prague 2Czech Republic Department of Electrical Engineering and Computer Science University of Michigan2200 Bonisteel BlvdAnn ArborMI 48109USA Ioffe Institute Russian Academy of Sciences26 Polytechnicheskaya194021 St PetersburgRussia

Increasing temperature is known to quench the excitonic emission of bulk silicon,which is due to thermally induced dissociation of ***,we demonstrate that the effect of temperature on the excitonic emission is reversed for quantumconfined silicon *** laser-induced heating of silicon nanocrystals embedded in SiO2,we achieved a more than threefold(4300%)increase in the radiative(photon)emission *** theoretically modeled the observed enhancement in terms of the thermally stimulated effect,taking into account the massive phonon production under intense *** results elucidate one more important advantage of silicon nanostructures,illustrating that their optical properties can be influenced by *** also provide an important insight into the mechanisms of energy conversion and dissipation in ensembles of silicon nanocrystals in solid *** practice,the radiative rate enhancement under strong continuous wave optical pumping is relevant for the possible application of silicon nanocrystals for spectral conversion layers in concentrator photovoltaics.

关键词： micro-photoluminescence nanocrystal optical spectroscopy silicon thermal

High-flow nasal oxygen availability for sedation decreases the use of general anesthesia during endoscopic retrograde cholangiopancreatography and endoscopic ultrasound

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 Gastroenterology 2016年第47期22卷 10398-10405页

作者： Roman Schumann Nikola S Natov Klifford A Rocuts-martinez matthew D finkelman tom V Phan Sanjay R Hegde Robert m Knapp Department of Anesthesiology and Perioperative medicine Tufts Medical CenterBoston MA 02111United States The Gastroenterology/Hepatology Division Tufts Medical CenterBoston MA 02111United States Critical Care medicine Dartmouth-Hitchcock Medical CenterLebanon NH 03756 United States Tufts University School of Dental medicine Boston MA 02111United States Tufts University School of medicine Boston MA 02111United States

AIm To examine whether high-flow nasal oxygen(HfNO) availability influences the use of general anesthesia(GA) in patients undergoing endoscopic retrograde cholangiopancreatography(ERCP) and endoscopic ultrasound(EUS) and associated *** In this retrospective study, patients were stratified into 3 eras between October 1, 2013 and June 30, 2014 based on HfNO availability for deep sedation at the time of their endoscopy. During the first and last 3-mo eras(era 1 and 3), no HfNO was available, whereas it was an option during the second 3-mo era(era 2). The primary outcome was the percent utilization of GA vs deep sedation in each period. Secondary outcomes included oxygen saturation nadir during sedation between periods, as well as procedure duration, and anesthesia-only time between periods and for GA vs sedation cases *** During the study period 238 ERCP or EUS cases were identified for analysis. Statistical testing was employed and a P ficant unless the Bonferroni correction for multiple comparisons was used. General anesthesia use was significantly lower in era 2 compared to era 1 with the same trend between era 2 and 3(P = 0.012 and 0.045 respectively). The oxygen saturation nadir during sedation was significantly higher in era 2 compared to era 3(P me within each era was significantly longer under GA compared to deep sedation(P ≤ 0.007) as was the anesthesia-only time(P ≤ 0.001).CONCLUSION High-flow nasal oxygen availability was associated with decreased GA utilization and improved oxygenation for ERCP and EUS during sedation.

关键词：内视镜的超声内视镜后退 cholangiopancreatography 内视镜检查法镇静麻醉氧化高流动鼻音氧

Increased branching independent of strigolactone in cytokinin oxidase 2-overexpressing tomato is mediated by reduced auxin transport

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

molecular Horticulture 2022年第1期2卷 153-171页

作者： Lilian Ellen Pino Joni E.Lima mateus H.Vicente Ariadne f.L.de Sá francisco Pérez-Alfocea Alfonso Albacete Juliana L.Costa tomášWerner Thomas Schmülling Luciano freschi Antonio figueira Agustin Zsögön Lázaro E.P.Peres Laboratory of Plant Breeding Centro de Energia Nuclear na AgriculturaUniversity of Sao PauloSão PauloBrazil Laboratory of Hormonal Control of Plant Development Department of Biological SciencesEscola Superior de Agricultura‘Luiz de Queiroz’University of Sao PauloPiracicabaBrazil Botany Department ICBFederal University of Minas GeraisBelo HorizonteBrazil Department of Plant Nutrition CEBAS-CSICCampus Univ.EspinardoMurciaSpain Institute of Biology/Applied Genetics Freie Universität BerlinBerlinGermany Institute of Biology University of GrazSchubertstraße 518010 GrazAustria Biosciences Institute University of Sao PauloSão PauloBrazil Plant Sciences Department Federal University of ViçosaViçosaBrazil

tomato production is influenced by shoot branching,which is controlled by different *** we produced tomato plants overexpressing the cytokinin-deactivating gene CYTOKININ OXYDASE 2(CKX2).CKX2-overexpressing(CKX2-OE)plants showed an excessive growth of axillary shoots,the opposite phenotype expected for plants with reduced cytokinin content,as evidenced by LC-mS analysis and ARR5-GUS *** TCP transcription factor SlBRC1b was downregulated in the axillary buds of CKX2-OE and its excessive branching was dependent on a functional version of the GRAS-family gene LAterAL SUPPRESSOR(LS).Grafting experiments indicated that increased branching in CKX2-OE plants is unlikely to be mediated by root-derived *** CKX2-OE plants with transgenic antisense plants for the strigolactone biosynthesis gene CAROTENOID CLEAVAGE DIOXYGENASE(CCD7-AS)produced an additive phenotype,indicating independent effects of cytokinin and strigolactones on increased *** the other hand,CKX2-OE plants showed reduced polar auxin transport and their bud outgrowth was reduced when combined with auxin ***,CKX2-OE basal buds did not respond to auxin applied in the decapitated *** results suggest that tomato shoot branching depends on a fine-tuning of different hormonal balances and that perturbations in the auxin status could compensate for the reduced cytokinin levels in CKX2-OE plants.

关键词： CKX2 Hormones Plant development Solanum

Hydrometallurgical recycling of Ndf eB magnets： Complete leaching, iron removal and electrolysis

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 Rare Earths 2017年第6期35卷 574-584页

作者： mehmet Ali Recai Onal Chenna Rao Borra muxing Guo Bart Blanpain tom Van Gerven Department of.m.terials Engineering University of Leuven Kasteelpark Arenberg 44 3001 Leuven Belgium Process Engineering for Sustainable Sys-terns (ProcESS) Department of Chemical Engineering University of Leuven Celestijnenlaan 200F 3001 Leuven Belgium

NdfeB magnets currently dominate the magnet market. Supply risks of certain rare earth metals（REm）, e.g. Nd and Dy, impose efficient recycling schemes that are applicable to different types and compositions of these magnets with minimum use of chemicals and waste generation. In this study, a hydrometallurgical method was studied that could be adjusted to recover not only REm, but also other valuable metals（***, Ni and Cu） that co-existed in the magnet. The magnet powders were completely dissolved in a dilute sulfuric acid solution giving more than 98% of dissolved iron in the ferrous state. Chemical oxidation of fe-（2＋） into fe-（3＋） by the addition of mnO 2 required only 1 h at ambient temperature. It was then possible to precipitate more than 99% of this ferric iron by adjusting the pH of the solution above 3 with either Ca（OH）2 or mnO additions. However, the addition of Ca（OH）2 resulted in the formation of gypsum and up to ca. 23% REm losses, possibly via co-precipitation into the gypsum. mnO elevated the mn-（2＋） concentration in the solution. However, it was found to be problematic that subsequent direct electrolysis removed mn and Co. Low anodic current efficiencies（ACE） resulted in high energy consumption（EC）, while incomplete mn and Co removals and undesired REm losses were reported. Pre-electrolysis removals of REm and/or Co by oxalate and/or sulfide precipitation were proven to be successful and selective, but this enlarged the flowsheet considerably with only minor improvement of the mn removal, ACE and EC.

关键词： electrolysis magnet recycling precipitate leaching anodic subsequent ferrous dissolved leachate

Compact representations of microstructure images using triplet networks

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 2020年第1期6卷 369-379页

作者： michiel Larmuseau michael Sluydts Koenraad Theuwissen Lode Duprez tom Dhaene Stefaan Cottenier Center for molecular modeling Ghent UniversityTechnologiepark 46B-9052 ZwijnaardeBelgium Department of Electrical Energy MetalsMechanical Constructions and SystemsGhent UniversityTechnologiepark 46B-9052 ZwijnaardeBelgium IDLab Department of Information TechnologyGhent University-IMECTechnologiepark 126B-9052 ZwijnaardeBelgium OCAS NV/Arcelormittal Global R&D Gent Pres.J.F.Kennedylaan 3B-9060 ZelzateBelgium

The microstructure of a material,typically characterized through a set of microscopy images of two-dimensional cross-sections,is a valuable source of information about the material and its *** pixel of the image is a degree of freedom causing the dimensionality of the information space to be extremely *** makes it difficult to recognize and extract all relevant information from the *** experts circumvent this by manually creating a lower-dimensional representation of the ***,the question of how a microstructure image can be best represented remains *** the field of deep learning,we present triplet networks as a method to build highly compact representations of the microstructure,condensing the relevant information into a much smaller number of *** demonstrate that these representations can be created even with a limited amount of example images,and that they are able to distinguish between visually very similar *** discuss the interpretability and generalization of the *** compact microstructure representations,it becomes easier to establish processing–structure–property links that are key to rational materials design.

关键词： networks Compact microstructure

Brain of the blind:transcriptomics of the golden-line cavefish brain

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 2018年第6期64卷 765-773页

作者： fanwei mENG Yahui ZHAO tom TITUS Chunguang ZHANG John H.POSTLETHWAIT State Key Laboratory of membrane Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China Key Laboratory of Zoological Systematics and Evolution Institute of ZoologyChinese Academy of SciencesBeijing 100101China Institute of Neuroscience University of OregonEugeneOR 97403USA

The genus Sinocyclocheilus (golden-line barbel) includes 25species of cave-dwelling blind fish (cavefish)and more than 30 surface-dwelling species with normal *** environments are dark and generally nutrient-poor with few *** of several genera evolved convergent morphological adaptations in visual,pigmentation,brain,olfactory,and digestive systems. We compared brain morphology and gene expression patterns in a cavefish Sinocyclocheilus anophthalmus with those of a closely related surface-dwelling species *** showed that cavefish have a longer olfactory tract and a much smaller optic tectum than surface *** by RNA-seq revealed that many genes upregulated in cavefish are related to lysosomes and the degradation and metabolism of proteins,amino acids,and *** down- regulated in cavefish tended to involve "activation of gene expression in cholesterol biosynthesis" and cholesterol degradation in the *** encoding Srebfs (sterol regulatory element- binding transcription factors)and Srebf targets,including enzymes in cholesterol synthesis,were downregulated in cavefish brains compared with surface fish *** gene encoding Cyp46a1, which eliminates cholesterol from the brain,was also downregulated in cavefish brains,while the total level of cholesterol in the brain remained *** brains misexpressed several genes encoding proteins in the hypothalamus-pituitary axis,including Trh,Sst,Crh,Pomc,and *** results suggest that the rate of lipid biosynthesis and breakdown may both be depressed in golden-line cavefish brains but that the lysosome recycling rate may be increased in cavefish;properties that might be related to differences in nutrient availability in caves.

关键词： cavefish cholesterol cyp46a optic tectum Sinocyclocheilus transcriptomics

Ischemia/reperfusion injury in porcine intestine-Viability assessment

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 Gastroenterology 2018年第18期24卷 2009-2023页

作者： Runar J Strand-Amundsen Henrik m Reims finn P Reinholt tom E Ruud Runkuan Yang Jan O Hogetveit Tor I Tonnessen Department of Clinical and Biomedical Engineering Oslo University HospitalOslo 0424Norway Department of Physics University of OsloOslo 0316Norway Department of Pathology Oslo University HospitalOslo 0424Norway Institute for Surgical Research Oslo University HospitalOslo 0424Norway Department of Surgery Baerum HospitalVestre Viken Hospital TrustDrammen 3004Norway Department of Emergencies and Critical Care Oslo University HospitalOslo 0424Norway Institute of Clinical medicine University of OsloOslo 0424Norway

AIm To investigate viability assessment of segmental small bowel ischemia/reperfusion in a porcine *** In 15 pigs, five or six 30-cm segments of jejunum were simultaneously made ischemic by clamping the mesenteric arteries and veins for 1 to 16 h. Reperfusion was initiated after different intervals of ischemia(1-8 h) and subsequently monitored for 5-15 h. The intestinal segments were regularly photographed and assessed visually and by palpation. Intraluminal lactate and glycerol concentrations were measured by microdialysis, and samples were collected for light microscopy and transmission electron microscopy. The histological changes were described and *** Using light microscopy, the jejunum was considered as viable until 6 h of ischemia, while with transmission electron microscopy the ischemic muscularis propria was considered viable until 5 h of ischemia. However, following ≥ 1 h of reperfusion, only segments that had been ischemic for ≤ 3 h appeared viable, suggesting a possible upper limit for viability in the porcine mesenteric occlusion model. Although intraluminal microdialysis allowed us to closely monitor the onset and duration of ischemia and the onset of reperfusion, we were unable to find sufficient level of association between tissue viability and metabolic markers to conclude that microdialysis is clinically relevant for viability assessment. Evaluation of color and motility appears to be poor indicators of intestinal *** Three hours of total ischemia of the small bowel followed by reperfusion appears to be the upper limit for viability in this porcine mesenteric ischemia model.

关键词： Viability histology reperfusion ischemia microdialysis jejunum porcine model

Comparative morphometric and chemical analyses of phenotypes of two invasive ambrosia beetles （Euwallacea spp.） in the United States

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insect Science 2017年第4期24卷 647-662页

作者： Yigen Chen Paul L. Dallara Lori J. Nelson tom W. Coleman Stacy m. Hishinuma Daniel Carrillo Steven J. Seybold Department of Entomology and Nematology University of California Davis USA USDA forest Service Pacific Southwest Research Station Davis USDA forest Service Forest Health Protection San Bemardino California USA Tropical Research and Education Center University of Florida Homestead Florida USA

The polyphagous shot hole borer （PSHB）, Euwallacea sp., was first detected in 2003 in Los Angeles County, California, USA. Recently, this invasive species has become a major pest of many hardwood trees in urban and wildland forests throughout southern California. PSHB is nearly identical in morphology and life history to the tea shot hole borer （TSHB）, Euwallaceafornicatus, an invasive pest of hardwoods in florida, USA and many other parts of the world. However, molecular studies have suggested that the taxa are different species. We conducted morphometric and chemical analyses of the pheno- types of Euwallacea sp. collected in southern California （Los Angeles County） and E. fornicatus collected in florida （miami-Dade County）. Our analyses indicated that PSHB has 3 larval instars. The third larval instar was separated from the first 2 instars by head capsule width with 0 probability of misclassification. The body length, head width, and pronotal width of PSHB adult males were significantly less than those of females. Head width and pronotal width of female PSHB were significantly less than those of female TSHB. In contrast, body length, and ratio of body length to pronotal width of female PSHB were significantly greater than those of female TSHB. However, females of these 2 species could not be separated completely by these 4 measurements because of the overlapping ranges. Cuticular hydrocarbons detected in both species were exclusively alkanes （i.e., n-alkanes, monomethylalkanes, dimethylalkanes, and trimethylalkanes）. Cuticular hydro- carbon profiles of PSHB males and females were similar, but they both differed from that of TSHB females. Cuticular hydrocarbons of PSHB were predominantly internally branched dimethylalkanes with backbones of 31 and 33 carbons, whereas cuticular hydro- carbons of TSHB females were dominated by internally branched monomethylalkanes and dimethylalkanes with backbones of 28 and 29 carbons. multiple compounds within these classes appear

关键词： cuticular hydrocarbons Euwallaceafornicatus larval instars polyphagousshot hole borer Scolytidae tea shot hole borer

Prevalence and Risk factors Associated with <i>Campylobacter</i>Infection in Diarrheal Patients in Busia County, Kenya

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 microbiology 2021年第11期11卷 657-680页

作者： tom T. Ouko Andrew K. Nyerere John m. Njeru Eric m. fèvre Samuel Kariuki Centre for microbiology Research Kenya Medical Research Institute Nairobi Kenya Department of medical microbiology Jomo Kenyatta University of Agriculture and Technology Nairobi Kenya Institute of Infection Veterinary and Ecological Sciences University of Liverpool Liverpool United Kingdom International Livestock Research Institute Nairobi Kenya

Introduction: Campylobacter are zoonotic bacteria that cause gastroenteritis worldwide with the species, Campylobacter jejuni and Campylobacter coli commonly associated with human diarrhea. Transmission is mainly through direct contact with farm animals, consumption of chicken and contaminated water. There is paucity of data on the epidemiology of Campylobacter in developing countries despite its global widespread and expansion of poultry farming;hence there is the need to explore and build on the available data. This study aimed at determining prevalence and homestead risk practices associated with Campylobacter infection in diarrheal patients in Busia County. methods: A cross-sectional study was conducted from february, 2017 to April, 2019. Stool samples were collected from patients of all ages attending Busia County referral Hospital and structured questionnaires on homestead associated risk practices administered. Isolation and identification of Campylobacter species was performed using standard culture method on modified Charcoal Cefoperazone Deoxycholate medium and confirmed by mPCR. factors associated with Campylobacter infection were evaluated using logistic regression analysis. Results: A total of 132 (11.6%) Campylobacter comprising 89.2% C. jejuni and 10.8% C. coli were isolated from 1200 diarrhoegenic patients sampled. Isolation rate was higher in children aged mpared to 2 - 5 years (10.2%) and >5 years (9.4%). multilevel logistic models showed that homestead poultry farming was a significant risk associated with Campylobacter infection in 5 years (OR 10.05;95% CI: 2.60 - 24.29, P mestead risk practices linked to children f pond water (OR 7.43, 95% CI: 1.70 - 16.33, P <

关键词： Risk factors Prevalence Diarrhea Campylobacter