检索结果-南通市图书馆

Reverse mode switching of the random laser emission in dye doped liquid crystals under homogeneous and inhomogeneous electric fields

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Photonics Research 2016年第1期4卷 7-12页

作者： M.Shasti P.Coutino S.Mukherjee A.Varanytsia T.smith A.P.Luchette L.Sukhomlinova T.Kosa A.Munoz b.Taheri Alpha Micron Inc. Liquid Crystal Institute Kent State University

We report the observation of electric field induced random lasing in a dye doped liquid crystal system. This was achieved by using a liquid crystal host with negative dielectric anisotropy doped with laser dye PM 597 in a 75 μm cell with a homeotropic alignment layer. In the absence of an applied field, only amplified spontaneous emission was observed since the liquid crystal orientation was uniform. However, application of a field resulted in a fieldinduced planar-like configuration with local nonuniformity in liquid crystal orientation. This led to random lasing in the energized state(voltage greater than a transition threshold). The onset of lasing occurs by application of either a spatially homogenous or a spatially inhomogeneous electric field across the liquid crystal. The characteristics of the emission spectra as a function of different(i) dye concentration and(ii) applied voltage were investigated using nanosecond pulsed laser excitation at 532 nm. The effects of using an inhomogeneous field were compared to the use of a homogenous field and reported. It is shown that the spatial configuration can be used to alter the emission spectra of the system. The work is used to suggest a new configuration, referred to here as"reverse mode," for liquid crystal-based random lasers. This new configuration may provide additional avenues for their use in commercial devices.

关键词： mode Reverse mode switching of the random laser emission in dye doped liquid crystals under homogeneous and inhomogeneous electric fields

Anti-onchocerca Metabolites from Cyperus articulatus:Isolation,In Vitro Activity and In Silico‘Drug-Likeness’

在线全文

学校读者我要写书评

暂无评论

Natural Products and bioprospecting 2014年第4期4卷 243-249页

作者： Jonathan Alunge Metuge smith b.babiaka James A.Mbah Fidele Ntie-Kang Godfred A.Ayimele Fidelis Cho-Ngwa ANDI Centre of Excellence Department of Biochemistry and Molecular BiologyFaculty of ScienceUniversity of BueaP.O.Box 63BueaCameroon Department of Chemistry Faculty of ScienceUniversity of BueaP.O.Box 63BueaCameroon Chemical and bioactivity Information Centre Chemistry DepartmentFaculty of ScienceUniversity of BueaP.O.Box 63BueaCameroon

The aims of this investigation were to isolate active ingredients from the roots/rhizomes of Cyperus articulatus used as herbal medicine in Cameroon for the treatment of human onchocerciasis and to assess the efficacy of the metabolites on the Onchocerca *** antifilarial activity was evaluated in vitro on microfilariae(Mfs)and adult worms of the bovine derived Onchocerca ochengi,a close relative of Onchocerca *** was assessed in vitro on monkey kidney epithelial *** structures of the active compounds were determined using spectroscopic methods and their drug-likeness evaluated using Lipinski *** secondary metabolites,AMJ1[containing mustakone(1)as the major component]and linoleic acid or(9Z,12Z)-octadeca-9,12-dienoic acid(2)were *** compounds were found to kill both the microfilariae and adult worms of *** in a dose dependent *** IC50s for AMJ1 were 15.7 lg/mL for Mfs,17.4 lg/mL for adult males and 21.9 lg/mL for adult female worms while for linoleic acid the values were,15.7 lg/mL for Mfs,31.0 lg/mL for adult males and 44.2 lg/mL for adult *** present report provides the first ever evidence of the anti-Onchocerca efficacy of AMJ1 and linoleic ***,these secondary metabolites may provide a lead for design and development of new antifilarial agents.

关键词： Cyperus articulates Linoleic acid Microfilariae Mustakone Onchocerca ochengi Onchocerca volvulus

Exploring ancestral phenotypes and evolutionary development of the mammalian middle ear based on Early Cretaceous Jehol mammals

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

National Science Review 2021年第5期8卷 57-66页

作者： Fangyuan Mao Cunyu Liu Morgan Hill Chase Andrew K.smith Jin Meng Key Laboratory of Evolutionary Systematics of Vertebrates Institute of Vertebrate Paleontology and PaleoanthropologyChinese Academy of Sciences CAS Center for Excellence in Life and Paleoenvironment Division of Paleontology American Museum of Natural History beipiao Pterosaur Museum of China 5. Microscopy and Imaging Facility American Museum of Natural History Earth and Environmental Sciences Graduate CenterCity University of New York

We report a new Cretaceous multituberculate mammal with 3 D auditory bones preserved. Along with other fossil and extant mammals, the unequivocal auditory bones display features potentially representing ancestral phenotypes of the mammalian middle ear. These phenotypes show that the ectotympanic and the malleus-incus complex changed notably during their retreating from the dentary at various evolutionary stages and suggest convergent evolution of some features to extant mammals. In contrast, the incudomalleolar joint was conservative in having a braced hinge configuration, which narrows the morphological gap between the quadroarticular jaw joint of non-mammalian cynodonts and the incudomalleolar articulations of extant mammals. The saddle-shaped and abutting malleus-incus complexes in therians and monotremes, respectively, could have evolved from the braced hinge joint *** evolutionary changes recorded in the Mesozoic mammals are largely consistent with the middle ear morphogenesis during the ontogeny of extant mammals, supporting the relation between evolution and development.

关键词： Cretaceous Jehol biota malleus-incus ectotympanic mammal evolution

A machine learning framework for damage mechanism identification from acoustic emissions in unidirectional SiC/SiC composites

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

npj Computational Materials 2021年第1期7卷 1326-1335页

作者： C.Muir b.Swaminathan K.Fields A.S.Almansour K.Sevener C.smith M.Presby J.D.Kiser T.M.Pollock S.Daly Materials University of California-Santa BarbaraSanta BarbaraCAUSA Mechanical Engineering University of California-Santa BarbaraSanta BarbaraCAUSA NASA Glenn Research Center ClevelandOHUSA Materials Science and Engineering University of Michigan-Ann ArborAnn ArborMIUSA

In this work,we demonstrate that damage mechanism identification from acoustic emission(AE)signals generated in minicomposites with elastically similar constituents is *** waveforms were generated by SiC/SiC ceramic matrix minicomposites(CMCs)loaded under uniaxial tension and recorded by four sensors(two models with each model placed at two ends).Signals were encoded with a modified partial power scheme and subsequently partitioned through spectral *** cracking and fiber failure were identified based on the frequency information contained in the AE event they produced,despite the similar constituent elastic properties of the matrix and ***,the resultant identification of AE events closely followed CMC damage chronology,wherein early matrix cracking is later followed by fiber breaks,even though the approach is fully domain-knowledge ***,the partitions were highly precise across both the model and location of the sensors,and the partitioning was *** presented approach is promising for CMCs and other composite systems with elastically similar constituents.

关键词： composites damage mechanism

Systematic mechanism-orientated approach to chronic pancreatitis pain

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 2015年第1期21卷 47-59页

作者： Stefan AW bouwense Marjan de Vries Luuk TW Schreuder Soren S Olesen Jens b Frokjær Asbjorn M Drewes Harry van Goor Oliver HG Wilder-smith Pain and Nociception Neuroscience Research Group Department of SurgeryRadboud University Medical Center6500HB GelderlandThe Netherlands Department of Gastroenterology and Hepatology and Clinical Medicine Aalborg University Hospital9100 AalborgDenmark Center for Sensory-Motor Interaction Department of Health Science and TechnologyAalborg University9100 AalborgDenmark Department of Anaesthesiology Pain and Palliative MedicineRadboud University Medical Center6500HB GelderlandThe Netherlands

Pain in chronic pancreatitis(CP) shows similarities with other visceral pain syndromes(i.e.,inflammatory bowel disease and esophagitis),which should thus be managed in a similar *** causes of CP pain include increased intrapancreatic pressure,pancreatic inflammation and pancreatic/extrapancreatic ***,CP pain continues to be a major clinical *** is recognized that ongoing pain may induce altered central pain processing,e.g.,central sensitization or pro-nociceptive pain *** this is present conventional pain treatment targeting the nociceptive focus,e.g.,opioid analgesia or surgical/endoscopic intervention,often fails even if technically *** central nervous system pain processing is altered,specific treatment targeting these changes should be instituted(e.g.,gabapentinoids,ketamine or tricyclic antidepressants).Suitable tools are now available to make altered central processing visible,including quantitative sensory testing,electroencephalograpy and(functional) magnetic resonance *** techniques are potentially clinically useful diagnostic tools to analyze central pain processing and thus define optimum management approaches for pain in CP and other visceral pain *** present review proposes a systematic mechanism-orientated approach to pain management in CP based on a holistic view of the mechanisms *** research should address the circumstances under which central nervous system pain processing changes in CP,and how this is influenced by ongoing nociceptive input and *** we hope to predict which patients are at risk for developing chronic pain or not responding to therapy,leading to improved treatment of chronic pain in CP and other visceral pain disorders.

关键词： Chronic pancreatitis Pain Pain treatment Central sensitization Quantitative sensory testing Electroencephalograpy Magnetic resonance imaging

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

biomedical and Environmental Sciences 2021年第9期34卷 734-738页

作者： James b.Hittner Folorunso O.Fasina Almira L.Hoogesteijn Renata Piccinini Dawid Maciorowski Prakasha Kempaiah Stephen D.smith Ariel L.Rivas Department of Psychology College of CharlestonCharlestonSouth CarolinaUnited States of America29424 Food and Agriculture Organization Dar es SalamTanzania&Department of Veterinary Tropical DiseasesUniversity of PretoriaSouth Africa0010 Human Ecology Centro de Investigación y de Estudios Avanzados(CINVESTAV)MéridaMéxico97133 Department of Veterinary Medicine University of MilanMilanItaly20122 Loyola University Medical Center ChicagoIllinoisUnited States of America60153 Institute for Resource Information Science College of AgricultureCornell UniversityIthacaUnited States of America14853 Center for Global Health Department of Internal MedicineMedical SchoolUniversity of New MexicoAlbuquerqueNew MexicoUnited States of America87131

The COVID-19 pandemic has wreaked havoc around the globe and caused significant disruptions across multiple domains[1].Moreover,different countries have been differentially impacted by COVID-19—a phenomenon that is d... 详细信息

关键词： Strongly COV Death

High-Level Accumulation of Exogenous Small RNAs Not Affecting Endogenous Small RNA biogenesis and Function in Plants

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2014年第5期13卷 1017-1023页

作者： SHEN Wan-xia Neil A smith ZHOU Chang-yong WANG Ming-bo College of Plant Protection Southwest University CSIRO Plant Industry National Citrus Engineering Research Center Citrus Research Institute Chinese Academy of Agricultural Sciences

RNA silencing is a fundamental plant defence and gene control mechanism in plants that are directed by 20-24 nucleotide （nt） small interfering RNA （siRNA） and microRNA （miRNA）. Infection of plants with viral pathogens or transformation of plants with RNA interference （RNAi） constructs is usually associated with high levels of exogenous siRNAs, but it is unclear if these siRNAs interfere with endogenous small RNA pathways and hence affect plant development. Here we provide evidence that viral satellite RNA （satRNA） infection does not affect siRNA and miRNA biogenesis or plant growth despite the extremely high level of satRNA-derived siRNAs. We generated transgenic Nicotiana benthamiana plants that no longer develop the specific yellowing symptoms generally associated with infection by Cucumber mosaic virus （CMV） Y-satellite RNA （Y-Sat）. We then used these plants to show that CMV Y-Sat infection did not cause any visible phenotypic changes in comparison to uninfected plants, despite the presence of high-level Y-Sat siRNAs. Furthermore, we showed that the accumulation of hairpin RNA （hpRNA）-derived siRNAs or miRNAs, and the level of siRNA-directed transgene silencing, are not significantly affected by CMV Y-Sat infection. Taken together, our results suggest that the high levels of exogenous siRNAs associated with viral infection or RNAi-inducing transgenes do not saturate the endogenous RNA silencing machineries and have no significant impact on normal plant development.

关键词： Nicotiana benthamiana transformation satellite RNA RNA silencing small RNA

在线全文

学校读者我要写书评

暂无评论

从心脏移植术看经验对成本费用的影响作用

国外医学（卫生经济分册） 1991年第2期8卷 43-46页

作者： smith D b 刘江红

以心脏移植术来评价经验的积累对结果的影响作用.以前从外科手术的研究发现,在经验和质量(即死亡率和并发症)之间有明显的一致关系,但关于经验和成本费用关系的研究甚少.传统的手术研究或经营管理模式用于设计经验对累计平均资源消耗的... 详细信息

以心脏移植术来评价经验的积累对结果的影响作用.以前从外科手术的研究发现,在经验和质量(即死亡率和并发症)之间有明显的一致关系,但关于经验和成本费用关系的研究甚少.传统的手术研究或经营管理模式用于设计经验对累计平均资源消耗的四个测定值(死亡率、住院时间、财会单位和费用)的影响,现将此模式进行修饰,用于心脏移植术经验的研究。所得数据与此模式吻合。该经验曲线最陡处是死亡率、最平坦处是费用。本文以此讨论了在研究机构和卫生服务设施的计划和管理的总体考虑方面可能得到的启示。

关键词：心脏移植术经验费用手术成本

Fibrin sealant for esophageal anastomosis:A phase II study

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2020年第6期12卷 651-662页

作者： Yao-bin Lin Jian-Hua Fu Yan Huang Yi-Huai Hu Kong-Jia Luo Ke-Xi Wang amosÉla bella Dong-Rong Situ Ji-Yang Chen Ting Lin Xavier b D’Journo Nuria M Novoa Alessandro brunelli Hiran C Fernando Robert J Cerfolio Mahmoud Ismail Hong Yang 无 Department of Thoracic Surgery State Key Laboratory of Oncology in South ChinaCollaborative Innovation Center for Cancer MedicineGuangdong Esophageal Cancer InstituteSun Yat-sen University Cancer CenterGuangzhou 510060Guangdong ProvinceChina Department of Thoracic Surgery Avicenne HospitalBobigny 93000France Department of Surgery and Specialties Faculty of Medicine and Biomedical SciencesUniversity of YaoundéIYaoundéCameroon Department of Surgery Royal Darwin HospitalNorthern Territory 0811Australia Department of Thoracic Surgery and Diseases of Esophagus Aix-Marseille UniversityHôpital NordMarseille 13915France Thoracic Surgery Service University Hospital of SalamancaSalamanca 37007Spain Department of Thoracic Surgery St James's University HospitalLeeds LS97TFUnited Kingdom Section of Thoracic Surgery Inova Fairfax Medical CenterInova Schar Cancer InstituteFalls ChurchVA 22042United States Department of Cardiothoracic Surgery New York University Langone HealthNew YorkNY 10016United States Department of Thoracic Surgery Academic Hospital of the Charité–UniversitätsmedizinHumboldt University BerlinBerlin 10117Germany the AME Thoracic Surgery Collaborative Group

bACKGROUND Esophagectomy is a pivotal curative modality for localized esophageal or esophagogastric junction cancer(EC or EJC).Postoperative anastomotic leakage(AL)remains *** use of fibrin sealant(FS)may improve the strength of esophageal anastomosis and reduce the incidence of *** To assess the efficacy and safety of applying FS to prevent AL in patients with EC or *** In this single-arm,phase II trial(*** identifier:NCT03529266),we recruited patients aged 18-80 years with resectable EC or EJC clinically staged as *** open or minimally invasive McKeown esophagectomy was performed with a circular stapled *** performing the anastomosis,2.5 mL of porcine FS was applied *** primary endpoint was the proportion of patients with AL within 3 *** From June 4,2018,to December 29,2018,57 patients were *** the data cutoff date(June 30,2019),three(5.3%)of the 57 patients had developed AL,including two(3.5%)with esophagogastric AL and one(1.8%)with gastric *** incidence of anastomotic stricture and other major postoperative complications was 1.8%and 17.5%,*** median time needed to resume oral feeding after operation was 8 d(Interquartile range:7.0-9.0 d).No adverse events related to FS were *** deaths occurred within 90 d after *** Perioperative sealing with porcine FS appears safe and may prevent AL after esophagectomy in patients with resectable EC or *** phase III studies are warranted.

关键词： Esophageal cancer McKeown esophagectomy Fibrin sealant Anastomotic leakage Postoperative complications Prevention