检索结果-南通市图书馆

Campaign-style U-Pb titanite petrochronology:Along-strike variations in timing of metamorphism in the Himalayan metamorphic core

引用

Geoscience Frontiers 2019年第3期10卷 827-847页

作者： Catherine m.mottram John m.Cottle andrew R.C.Kylander-Clark School of Earth and Environmental Sciences University of Portsmouth Department of Earth Science University of CaliforniaSanta Barbara

Present-day along-strike heterogeneities within the Himalayan orogen are seen at many scales, from variations within the deep architecture of the lithospheric mantle, to differences in geomorphologic surface processes. Here, we present an internally consistent petrochronologic dataset from the Himalayan metamorphic core(HmC), in order to document and investigate the causes of along-strike variations in its Oligocene-miocene tectonic history. Laser ablation split-stream analysis was used to date and characterise the geochemistry of titanite from 47 calc-silicate rocks across >2000 km along the *** combined U-Pb-REE-Zr single mineral dataset circumvents uncertainties associated with interpretations based on data compilations from different studies, mineral systems and laboratories, and allows for direct along-strike comparisons in the timing of metamorphic processes. Titanite dates range from ～30 ma to 12 ma, recording(re-)crystallization between 625 ℃ and 815 ℃. Titanite T-t data overlap with previously published P-T-t paths from interleaved peltic rocks, demonstrating the usefulness of titanite petrochronology for recording the metamorphic history in lithologies not traditionally used for thermobarometry. Overall, the data indicate a broad eastward-younging trend along the *** in the duration and timing of metamorphism within the HmC are best explained by alongstrike variations in the position of ramps on the basal detachment controlling a two-stage process of preferential ductile accretion at depth followed by the formation of later upper-crust brittle *** processes, coupled with variable erosion, resulted in the asymmetric exhumation of a younger,thicker crystalline core in the eastern Himalaya.

关键词： Himalaya Petrochronology Titanite metamorphic petrology

来源：

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

Novel endoscopic management of buried bumper syndrome in percutaneous endoscopic gastrostomy: The Olympus Hook Knife

引用

World Journal of Gastroenterology 2017年第35期23卷 6546-6548页

作者： Laura E Wolpert Dominic m Summers andrew Tsang Department of General Surgery Peterborough City HospitalEdith Cavell Campus

Buried bumper syndrome(BBS) is an uncommon but serious complication of percutaneous endoscopic gastrostomy. It involves the internal fixation device, or "bumper", migrating into the gastric wall and subsequent mucosal overgrowth. We described a case series of four patients with BBS treated with a novel endoscopic technique using a Hook Knife between June 2016 and February 2017. The Hook Knife is a rotating L-shaped cutting wire designed for hooking tissue and pulling it away from the gastric wall towards the lumen. The technique was successful in all four cases with no complications. Each patient was discharged on the day of treatment. The Hook Knife is a manoeuvrable, safe and effective device for endoscopic removal of buried bumpers and could avoid surgery in a high risk group of patients. To our knowledge this technique has not been described previously. We suggest that this technique should be added to the treatment algorithms for managing BBS.

关键词： Buried bumper syndrome Percutaneous endoscopic gastrostomy Hook Knife

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Associations with pancreatic exocrine insufficiency:An United Kingdom single-centre study

引用

World Journal of Clinical Cases 2021年第31期9卷 9469-9480页

作者： Benjamin m Shandro Joshua Chen Jennifer Ritehnia andrew Poullis Department of Gastroenterology St George's University Hospitals NHS Foundation TrustLondon SW170QTUnited Kingdom

BACKGROUND Pancreatic exocrine insufficiency(PEI)is said to be associated with numerous conditions both within and outside the gastrointestinal(GI)*** majority of research has been concerned with conditions that reduce the volume of functioning pancreatic tissue or prevent adequate drainage to the small bowel,such as chronic pancreatitis,cystic fibrosis,pancreatic cancer and pancreatic ***,the evidence base supporting an association with extrapancreatic conditions,such as coeliac disease,diabetes mellitus and congestive cardiac failure,is *** To strengthen the evidence base by studying all previously reported associations with PEI in a large cohort of *** A single-centre retrospective study was *** gastroenterology outpatients tested for PEI with faecal elastase-1(FE1)were identified and information retrieved from the electronic patient *** was defined as FE1me replacement therapy were *** imputation was used to handle missing *** logistic regression was used to study which presenting symptoms predicted *** logistic regression was used to explore the relationship between all previously reported associations and *** Of 1027 patients were included.182 patients(17.7%)were diagnosed with ***[odds ratios(OR):2.51,95%confidence intervals(CI):1.58-3.98]and weight loss(OR:1.49,95%CI:1.08-2.06)were the only presenting symptoms that predicted *** pancreatitis(OR:7.98,95%CI:3.95-16.15),pancreatic cancer(OR:6.58,95%CI:1.67-25.98),upper GI surgery(OR:2.62,95%CI:1.32-5.19),type 2 diabetes(OR:1.84,95%CI:1.18-2.87),proton pump inhibitor therapy(OR:1.87,95%CI:1.25-2.80)and Asian ethnicity(OR:2.11,95%CI:1.30-3.42)were significantly associated with PEI in the multivariable *** of the other historically reported associations with PEI were significant after adjustment for the other variable

关键词： Exocrine pancreatic insufficiency Chronic pancreatitis Pancreatic elastase Steatorrhoea Proton pump inhibitors

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Th17 cells and their associated cytokines in liver diseases

引用

Cellular & molecular Immunology 2010年第4期7卷 250-254页

作者： Fouad Lafdil andrew m miller Sung Hwan Ki Bin Gao Section on Liver Biology Laboratory of Physiologic StudiesNational Institute on Alcohol Abuse and AlcoholismNational Institutes of HealthBethesdaMDUSA INSERm U955Cre´teilFrance Faculte´de me´decine Universite´Paris 12Cre´teilFrance

T helper 17(Th17)cells are a newly identified subset of T helper cells that play important roles in host defense against extracellular bacteria as well as in the pathogenesis of autoimmune *** functions of Th17 cells are mediated via the production of several cytokines including interleukin(IL)-17 and *** studies show that the frequency of IL-171 cells is significantly elevated in a variety of chronic liver diseases including alcoholic liver disease,viral hepatitis and hepatocellular ***-17 receptor is expressed virtually on all types of liver cells,while IL-22 receptor expression is restricted to epithelial cells including hepatocytes in the ***-17 seems to play an important role in inducing liver inflammation via stimulating multiple types of liver nonparenchymal cells to produce proinflammatory cytokines and chemokines,while IL-22 appears to be an important factor in promoting hepatocyte survival and proliferation.

关键词： IL-17 IL-22 hepatitis alcoholic liver disease liver cancer

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Effects of Saccharomyces cerevisiae or boulardii yeasts on acute stress induced intestinal dysmotility

引用

World Journal of Gastroenterology 2016年第48期22卷 10532-10544页

作者： Christine West andrew m Stanisz Annette Wong Wolfgang A Kunze mcmaster Brain-Body Institute St. Joseph’s Healthcare Department of Biology McM aster University Department of Psychiatry and Behavioural Neurosciences Mc Master University

AIm To investigate the capacity of Saccharomyces cerevisiae(S. cerevisiae) and Saccharomyces boulardii(S. boulardii) yeasts to reverse or to treat acute stress-related intestinal *** Adult Swiss Webster mice were stressed for 1 h in a wire-mesh restraint to induce symptoms of intestinal dysmotility and were subsequently killed by cervical dislocation. Jejunal and colon tissue were excised and placed within a tissue perfusion bath in which S. cerevisiae, S. boulardii, or their supernatants were administered into the lumen. Video recordings of contractility and gut diameter changes were converted to spatiotemporal maps and the velocity, frequency, and amplitude of propagating contractile clusters(PCC) were measured. motility pre- and post-treatment was compared between stressed animals and unstressed controls. RESULTS S. boulardii and S. cerevisiae helped to mediate the effects of stress on the small and large intestine. Restraint stress reduced jejunal transit velocity(mm/s)from 2.635 ± 0.316 to 1.644 ± 0.238, P m 0.032 ± 0.008 to 0.016 ± 0.005, P mm/s) from 0.864 ± 0.183 to 1.432 ± 0.329, P minal application of S. boulardii helped to restore jejunal and colonic velocity towards the unstressed controls; 1.833 ± 0.688 to 2.627 ± 0.664, P most apparent in the jejunum. S. cerevisiae increased PCC velocity in the stressed jejunum from 1.763 ± 0.397 to 2.017 ± 0.48, P = 0.0031 and PCC frequency from 0.016 ± 0.009 to 0.027 ± 0.007, P m 1.647 ± 0.187 to 1.038 ± 0.222, P motility to unstressed values in similar capacity. CONCLUSION The

关键词： Intestine Saccharomyces cerevisiae Saccharomyces boulardii Restraint stress motility

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Anal intraepithelial neoplasia: A review of diagnosis and management

引用

World Journal of Gastrointestinal Oncology 2017年第2期9卷 50-61页

作者： Joseph R Roberts Lacey L Siekas andrew m Kaz Department of medicine Division of Gastroenterology University of Washington School of Medicine Gastroenterology Section VA Puget Sound Health Care System

Anal intraepithelial neoplasia(AIN) is a premalignant lesion of the anal mucosa that is a precursor to anal cancer. Although anal cancer is relatively uncommon, rates of this malignancy are steadily rising in the United States, and among certain high risk populations the incidence of anal cancer may exceed that of colon cancer. Risk factors for AIN and anal cancer consist of clinical factors and behaviors that are associated with the acquisition and persistence of human papilloma virus(HPV) infection. The strongest HPV-associated risk factors are HIV infection, receptive anal intercourse, and high risk sexual behavior. A history of HPVmediated genital cancer, which suggests infection with an oncogenic HPV strain, is another risk factor for AIN/anal cancer. Because progression of AIN to anal cancer is known to occur in some individuals over several years, screening for AIN and early anal cancer, as well as treatment of advanced AIN lesions, is reasonable in certain high-risk populations. Although randomized controlled trials evaluating screening and treatment outcomes are lacking, experts support routine screening for AIN in high risk populations. Screening is performed using anal cytological exams, similar to those performed in cervical cancer screening programs, along with direct tissue evaluation and biopsy via high resolution anoscopy. AIN can be treated using topical therapies such as imiquimod, 5-flurouracil, and trichloroacetic acid, as well as ablative therapies such as electrocautery and laser therapy. Reductions in AIN and anal cancer rates have been shown in studies where high-risk populations were vaccinated against the oncogenic strains of HPV. Currently, the CDC recommends both high-risk and average-risk populations be vaccinated against HPV infection using the quadrivalent or nonavalent vaccines. It is important for clinicians to be familiar with AIN and the role of HPV vaccination, particularly in high risk populations.

关键词： Anal cancer Anal intraepithelial neoplasia Anal squamous cell carcinoma Human papillomavirus vaccine Human papillomavirus

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Brain weight predicts yawn duration across domesticated dog breeds

引用

Current Zoology 2020年第4期66卷 401-405页

作者： andrew C.Gallup Lea moscatello Jorg J.m.massen Psychology Program Department of Social and Behavioral SciencesSUNY Polytechnic InstituteUticaNY13502USA Department of Psychology SUNY College at OneontaOneontaNY13820USA Animal Ecology Group Department of BiologyUtrecht UniversityPadualaan 8Utrecht CH3584The Netherlands

Previous research shows that yawning enhances intracranial circulation and regulates brain temperature. Consistent with these functional outcomes, yawn duration correlates positively with interspecies variation in brain weight across mammals, with robust relationships documented at both the taxonomic rank of class and the more restricted scale of family (e.g., Felidae). This study provides the first investigation into whether differences in brain weight within a single species, domesticated dogs Canis lupus familiaris, can predict intraspecific variation in yawn duration. measures of yawn duration were obtained from public videos available online and then paired with previously published brain and body weight data of different dog breeds. The final sample consisted of 272 yawns from 198 dogs across 23 breeds. Consistent with recent studies, we find robust correlations between yawn duration and brain weight across breeds. moreover, these correlations remain significant after controlling for differences in body weight across breeds. These findings replicate and extend upon past work in this area and provide further support that yawns evolved to serve an important and large-scale neurophysiologic function.

关键词： brain cooling brain size cortical arousal neuroanatomy

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Shift current bulk photovoltaic effect in polar materials—hybrid and oxide perovskites and beyond

引用

npj Computational materials 2016年第1期2卷 58-69页

作者： Liang Z Tan Fan Zheng Steve m Young Fenggong Wang Shi Liu andrew m Rappe The makineni Theoretical Laboratories Department of ChemistryUniversity of PennsylvaniaPhiladelphiaPAUSA Center for Computational materials Science United States Naval Research LaboratoryWashingtonDCUSA Geophysical Laboratory Carnegie Institution of ScienceWashingtonDCUSA

The bulk photovoltaic effect(BPVE)refers to the generation of a steady photocurrent and above-bandgap photovoltage in a single-phase homogeneous material lacking inversion *** mechanism of BPVE is decidedly different from the typical p-n junction-based photovoltaic mechanism in heterogeneous ***,there has been renewed interest in ferroelectric materials for solar energy conversion,inspired by the discovery of above-bandgap photovoltages in ferroelectrics,the invention of low bandgap ferroelectric materials and the rapidly improving power conversion efficiency of metal halide ***,as long as the nature of the BPVE and its dependence on composition and structure remain poorly understood,materials engineering and the realisation of its true potential will be *** this review article,we survey the history,development and recent progress in understanding the mechanisms of BPVE,with a focus on the shift current mechanism,an intrinsic BPVE that is universal to all materials lacking inversion *** addition to explaining the theory of shift current,materials design opportunities and challenges will be discussed for future applications of the BPVE.

关键词： mechanism effect ferroelectric

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Elucidating the Degradation Pathways of Human Insulin in the Solid State

引用

Journal of Analysis and Testing 2024年第3期8卷 288-299页

作者： andrew Fagan Lorraine m.Bateman Joseph P.O’Shea Abina m.Crean SSPC the SFI Centre for Pharmaceutical ResearchSchool of PharmacyUniversity College CorkCork T12 YT20Ireland School of Pharmacy University College CorkCork T12 YT20Ireland Analytical and Biological Chemistry Research Facility(ABCRF) University College CorkCork T12 YN60Ireland School of Chemistry University College CorkCork T12 YN60Ireland

While there have been significant advances in the development of peptide oral dosage forms in recent years,highlighted by the clinical and commercial success of approved peptides such as Rybelsus®,there remain several barriers in the way of broad range applicability of this approach to peptide *** such barrier includes the poor physical and chemical stability inherent to their structures,which persists in the solid state although degradation typically occurs at different rates and via different pathways in comparison to the solution *** insulin as a model peptide,this work sought to contribute to the development of analytical techniques for investigating common insulin degradation *** denatured,deamidated and aggregated samples were prepared and used to benchmark circular dichroism spectroscopy,reverse phase HPLC and size exclusion chromatography methods for the investigation of unfolding,chemical modifications and covalent aggregation of the insulin molecule *** state degraded samples were prepared by heating insulin powder at 60°C and 75%relative humidity for 1,3,5 and 7 d,and the degradation profiles of the samples were evaluated and compared with those observed in *** no unfolding was observed to occur,significant deamidation and covalent aggregation were *** disulfide bond cleavage using dithiothreitol allowed for separation of the insulin A-and B-chains,offering a facile yet novel means of assessing the mechanisms of deamidation and covalent aggregation occurring in the solid state.

关键词： Insulin Stability Solid state Deamidation Covalent aggregation Disulfide cleavage Biopharmaceutical analysis

来源：

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

Proton-Resistant Quantum Dots: Stability in Gastrointestinal Fluids and Implications for Oral Delivery of Nanoparticle Agents

引用

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)

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：