维普中文期刊产品整合服务
599篇 您的检索式:作者名="David Z"
    题名 作者 年代 出处 被引量
1The role of gut microbiota(commensal bacteria)and the mucosal barrier in the pathogenesis of inflammatory and autoimmune diseases and cancer:contribution of germ-free and gnotobiotic animal models of human diseases显示文摘Metagenomic approaches are currently being used to decipher the genome of the microbiota(microbiome),and,in parallel,functional studies are being performed to analyze the effects of the microbiota on the host.Gnotobiological methods are an indispensable tool for studying the consequences of bacterial colonization.Animals used as models of human diseases can be maintained in sterile conditions(isolators used for germ-free rearing)and specifically colonized with defined microbes(including non-cultivable commensal bacteria).The effects of the germ-free state or the effects of colonization on disease initiation and maintenance can be observed in these models.Using this approach we demonstrated direct involvement of components of the microbiota in chronic intestinal inflammation and development of colonic neoplasia(i.e.,using models of human inflammatory bowel disease and colorectal carcinoma).In contrast,a protective effect of microbiota colonization was demonstrated for the development of autoimmune diabetes in non-obese diabetic(NOD)mice.Interestingly,the development of atherosclerosis in germ-free apolipoprotein E(ApoE)-deficient mice fed by a standard low-cholesterol diet is accelerated compared with conventionally reared animals.Mucosal induction of tolerance to allergen Bet v1 was not influenced by the presence or absence of microbiota.Identification of components of the microbiota and elucidation of the molecular mechanisms of their action in inducing pathological changes or exerting beneficial,disease-protective activities could aid in our ability to influence the composition of the microbiota and to find bacterial strains and components(e.g.,probiotics and prebiotics)whose administration may aid in disease prevention and treatment.Helena Tlaskalova-Hogenova Renata Stepankova Hana Kozakova Tomas Hudcovic Luca Vannucci Ludmila Tuckova Pavel Rossmann TomasHrncır Miloslav Kverka Zuzana Zakostelska Klara Klimesova Jaroslava Pribylova Jirina Bartova Daniel Sanchez Petra Fundova Dana Borovska Dagmar Sru˚tkova Zdenek Zıdek Martin Schwarzer Pavel Drastich David P Funda 2011Cellular & Molecular Immunology2011,8,2:47
2Chinese Stroke Center Alliance:a national effort to improve healthcare quality for acute stroke and transient ischaemic attack:rationale,design and preliminary findings显示文摘Background In June 2015,the Chinese Stroke Association(CSA)initiated the Chinese Stroke Center Alliance(CSCA)to establish the national hospital-based stroke care quality assessment and improvement platform.This article outlines its objectives,operational structure,patient population,quality improvement(QI)intervention tools,data elements,data collection methodology and current patient and hospital data.Methods The CSCA is a national,hospital-based,multicentre,voluntary,multifaceted intervention and continuous QI initiative.This multifaceted intervention includes stroke centre development,written care protocols,workshops and a monitoring/feedback system of evidencebased performance measures.The data coordinating centre of the CSCA resides at the China National Clinical Research Center for Neurological Diseases,Beijing Tiantan Hospital.results As of July 2017,1576 hospitals in China have contributed detailed clinical information to serve as a benchmark for the stroke care quality of 433264 patients with acute stroke/transient ischaemic attacks(TIA),including 352572(81.38%)acute ischaemic stroke,30362(7.01%)TIA,42080(9.71%)spontaneous intracranial haemorrhage,5505(1.27%)subarachnoid haemorrhage and 2745(0.63%)not specified stroke.Conclusion The CSCA programme is designed to establish a continuous national stroke registry and help healthcare providers develop stroke centres and treat patients in a consistent manner in accordance with accepted national guidelines and,ultimately,improve patient outcomes.It supports the CSA mission to reduce stroke burden in China.Yongjun Wang Zixiao Li Yilong Wang Xingquan Zhao Liping Liu Xin Yang Caiyun Wang Hongqiu Gu Fuying Zhang Chunjuan Wang Ying Xian David Z Wang Qiang Dong Anding Xu Jizong Zhao Chinese Stroke Center Alliance investigators 2018Stroke & Vascular Neurology2018,3,4:38
3MicroRNAs, development of Barrett’s esophagus, and progression to esophageal adenocarcinoma显示文摘Barrett's esophagus is a premalignant condition caused by gastroesophageal reflux. Once developed, it can progress through varying grades of dysplasia to esoph-ageal adenocarcinoma. Whilst it is well accepted that Barrett's esophagus is caused by gastroesophageal reflux, the molecular mechanisms of its pathogenesis and progression to cancer remain unclear. MicroRNAs (miRNAs) are short segments of RNA that have been shown to control the expression of many human genes. They have been implicated in most cellular processes, and the role of miRNAs in disease development is be-coming increasingly evident. Understanding altered miRNA expression is likely to help unravel the molecular mechanisms that underpin the development of Barrett's esophagus and its progression to cancer.Cameron M Smith David I Watson Michael Z Michael Damian J Hussey 2010World Journal of Gastroenterology2010,16,5:23
4香港大学学术库——机构知识库的应用扩展显示文摘香港大学学术库是香港大学的机构知识库,是响应大学知识交流政策而建立的知识管理系统。凭借丰富的数据来源以及合理的设计机制,学术库已成为颇具影响力的香港大学人才和科研成果的展示平台,成为校内外学术交流的中心,为学术评估和声誉管理提供了基础。Liu Eliot Z H Palmer David T 2015大学图书馆学报2015,33,4:14
5miR-200 family expression is downregulated upon neoplastic progression of Barrett's esophagus显示文摘AIM: To investigate miR-200 family expression in Barrett's epithelium, gastric and duodenal epithelia, and esophageal adenocarcinoma. METHODS: Real-time reverse transcriptase-polymerase chain reaction was used to measure miR-200, ZEB1 and ZEB2 expression. Ingenuity Pathway Analysis of miR-200 targets was used to predict biological outcomes. RESULTS: Barrett's epithelium expressed lower levels of miR-141 and miR-200c than did gastric and duodenal epithelia (P < 0.001). In silico analysis indicated roles for the miR-200 family in molecular pathways that distinguish Barrett's epithelium from gastric and duodenalepithelia, and which control apoptosis and proliferation. All miR-200 members were downregulated in adenocarcinoma (P < 0.02), and miR-200c expression was also downregulated in non-invasive epithelium adjacent to adenocarcinoma (P < 0.02). The expression of all miR-200 members was lower in Barrett's epithelium derived high-grade dysplastic cell lines than in a cell line derived from benign Barrett's epithelium. We observed signif icant inverse correlations between miR-200 family expression and ZEB1 and ZEB2 expression in Barrett's epithelium and esophageal adenocarcinoma (P < 0.05). CONCLUSION: miR-200 expression might contribute to the anti-apoptotic and proliferative phenotype of Barrett's epithelium and regulate key neoplastic processes in this epithelium.Cameron M Smith David I Watson Mary P Leong George C Mayne Michael Z Michael Bas PL Wijnhoven Damian J Hussey 2011World Journal of Gastroenterology2011,17,8:13
6Validation of Fujinon intelligent chromoendoscopy with high definition endoscopes in colonoscopy显示文摘AIM:To validate high definition endoscopes with Fujinon intelligent chromoendoscopy(FICE) in colonoscopy.METHODS:The image quality of normal white light endoscopy(WLE),that of the 10 available FICE filters and that of a gold standard(0.2% indigo carmine dye) were compared.RESULTS:FICE-filter 4 [red,green,and blue(RGB) wavelengths of 520,500,and 405 nm,respectively] provided the best images for evaluating the vascular pattern compared to white light.The mucosal surface was best assessed using filter 4.However,the views obtained were not rated significantly better than those observed with white light.The 'gold standard',indigo carmine(IC) dye,was found to be superior to both white light and filter 4.Filter 6(RGB wavelengths of 580,520,and 460 nm,respectively) allowed for exploration of the IC-stained mucosa.When assessing mucosal polyps,both FICE with magnification,and magnification following dye spraying were superior to the same techniques without magnification and to white light imaging.In the presence of suboptimal bowel preparation,observation with the FICE mode was possible,and endoscopists considered it to be superior to observation with white light.CONCLUSION:FICE-filter 4 with magnification improves the image quality of the colonic vascular patterns obtained with WLE.Adolfo Parra-Blanco Alejandro Jiménez Bjrn Rembacken Nicolás González David Nicolás-Pérez Antonio Z Gimeno-García Marta Carrillo-Palau Takahisa Matsuda Enrique Quintero 2009World Journal of Gastroenterology2009,15,42:12
7Association of elevated hs-CRP and multiple infarctions with outcomes of minor stroke or TIA: subgroup analysis of CHANCE randomised clinical trial显示文摘Background and purpose The relationship of high-sensitive C-reactive protein(hs-CRP)levels and infarction numbers with the prognosis of stroke is uncertain.This study evaluated the association of different hs-CRP levels and infarction numbers with the prognosis of acute minor ischaemic stroke or transient ischaemic attack(TIA).Methods A subset of 807 patients with both hs-CRP measurement and baseline MRI was included from the Clopidogrel in High-risk Patients with Acute Non-disabling Cerebrovascular Events trial.The primary efficacy outcome was the occurrence of an ischaemic stroke at the 1-year follow-up.Infarction numbers were classified as multiple acute infarctions(MAIs),single acute infarction and no acute infarction(NAI).The association between different hs-CRP levels with different infarction numbers and the risk of any outcome was analysed using multivariable Cox regression models.Results Among the 807 patients,84(10.4%)patients had a recurrent ischaemic stroke within 1 year.After adjustment for conventional confounding factors,patients with both elevated hs-CRP levels and MAIs were associated with approximately 4.7-fold of risk of ischaemic stroke within 1 year(16.7% vs 3.5%,HR 4.68,95% CI 1.54 to 14.23,p=0.007),compared with those with non-elevated hs-CRP levels and NAI.Similar results were observed for the composite events.Conclusions Combined elevated hs-CRP levels and MAIs may increase 1-year stroke risk stratification efficiency in patients with minor ischaemic stroke or TIA compared with using those markers alone,which indicated that the combination of inflammatory and imaging markers might improve the effectiveness of risk stratification concerning minor ischaemic stroke or TIA.Guangyao Wang Jing Jing Jiejie Li Yuesong Pan Hongyi Yan Xia Meng Xingquan Zhao Liping Liu Hao Li David Z Wang Yongjun Wang Yilong Wang 2021Stroke & Vascular Neurology2021,6,1:11
8Endoscopic submucosal dissection training with pig models in a Western country显示文摘AIM:To test a strategy for endoscopic submucosal dissection(ESD) training in animal models designed to overcome the initial learning curve.METHODS:ESD was attempted in ex vivo and in vivo pig models.Thirty ESD procedures were attempted in the esophagus(n=9) or the stomach(n=21).The ex vivo model was used until initial competence was achieved.In the in vivo model,several ESD procedures were performed in up to 3 sessions.The following variables were analyzed:specimen size,complete and en bloc resection rate,time for circumferential incision,time for submucosal dissection,total ESD duration,and complications.RESULTS:Complete resection was achieved in 28 cases(en bloc 27);2 could not be completed(one perforation,one technical diff iculty).The mean ± SD time for circumferential incision was 36.2±16.8 min(range:8-87 min),and the mean±SD time for submucosal dissection was 45.1±35.7 min(range:9-196 min).The mean±SD size of the resected specimens was 45.2±17.8 mm.The mean±SD total resection time was signif icantly increased for the gastric cases performed in the f irst half of the study(n=13) than in the second half(n=8)(98.9±62.4 min vs 61.7±17.6 min,P=0.04),although the specimen size did not differ.CONCLUSION:Training in animal models could help endoscopists overcome the learning curve before starting ESD in humans.Adolfo Parra-Blanco María Rosa Arnau David Nicolás-Pérez Antonio Z Gimeno-García Nicolás González Juan A Díaz-Acosta Alejandro Jiménez Enrique Quintero 2010World Journal of Gastroenterology2010,16,23:9
9MicroRNA signatures in chemotherapy resistant esophageal cancer cell lines显示文摘AIM:To investigate expression of microRNA(miRNA)and potential targets in chemotherapy resistant esoph-ageal cancer cell lines.METHODS:An in-vitro model of acquired chemotherapy resistance in esophageal adeno-(EAC)and squamous cell carcinoma(ESCC)cells was used,and microRNA expression profiles for cisplatin or 5-fluorouracil(5-FU)resistant variants vs chemotherapy sensitive controls were compared using microarray and quantitative real-time polymerase chain reaction(PCR).The expression of chemotherapy-relevant genes potentially targeted by the dysregulated microRNAs in the chemotherapy resistant variants was also evaluated.RESULTS:Chemotherapy resistant sublines were found to have specific miRNA signatures,and these miRNA signatures were different for the cisplatin vs 5-FU resistant cells from the same tumor cell line,and also for EAC vs ESCC cells with resistance to the same specific chemotherapy agent.Amongst others,miR-27b-3p,miR-193b-3p,miR-192-5p,miR-378 a-3p,miR-125a-5p and miR-18a-3p were dysregulated,consistent with negative posttranscriptional control of KRAS,TYMS,ABCC3,CBL-B and ERBB2 expression via these miRNAs.CONCLUSION:The current study supports the hypothesis that microRNA expression has an impact on chemotherapy resistance in esophageal cancer.Richard Hummel Corina Sie David I Watson Tingting Wang Alfiya Ansar Michael Z Michael Mark Van der Hoek Joerg Haier Damian J Hussey 2014World Journal of Gastroenterology2014,20,40:8
10Comparison of two remote sensing models for estimating evapotranspiration: algorithm evaluation and application in seasonally arid ecosystems in South Africa显示文摘Remote sensing tools are becoming increasingly important for providing spatial information on water use by different ecosystems. Despite significant advances in remote sensing based evapotranspiration(ET) models in recent years, important information gaps still exist on the accuracy of the models particularly in arid and semi-arid environments. In this study, we evaluated the Penman-Monteith based MOD16 and the modified Priestley-Taylor(PT-JPL) models at the daily time step against three measured ET datasets. We used data from two summer and one winter rainfall sites in South Africa. One site was dominated by native broad leaf and the other by fine leafed deciduous savanna tree species and C4 grasses. The third site was in the winter rainfall Cape region and had shrubby fynbos vegetation. Actual ET was measured using open-path eddy covariance systems at the summer rainfall sites while a surface energy balance system utilizing the large aperture boundary layer scintillometer was used in the Cape. Model performance varied between sites and between years with the worst estimates(R2<0.50 and RMSE>0.80 mm/d) observed during years with prolonged mid-summer dry spells in the summer rainfall areas. Sensitivity tests on MOD16 showed that the leaf area index, surface conductance and radiation budget parameters had the largest effect on simulated ET. MOD16 ET predictions were improved by:(1) reformulating the emissivity expressions in the net radiation equation;(2) incorporating representative surface conductance values;and(3) including a soil moisture stress function in the transpiration sub-model. Implementing these changes increased the accuracy of MOD16 daily ET predictions at all sites. However, similar adjustments to the PT-JPL model yielded minimal improvements. We conclude that the MOD16 ET model has the potential to accurately predict water use in arid environments provided soil water stress and accurate biome-specific parameters are incorporated.Sebinasi DZIKITI Nebo Z JOVANOVIC Richard DH BUGAN Abel RAMOELO Nobuhle P MAJOZI Alecia NICKLESS Moses A CHO David C LE MAITRE Zanele NTSHIDI Harrison H PIENAAR 2019Journal of Arid Land2019,11,4:4
11Is tenecteplase ready to replace alteplase to treat acute ischaemic stroke? The knowns and unknowns显示文摘Tenecteplase(TNKase,TNK-tPA or TNK)is a thrombolytic agent derived from the tissue plasminogen activator(tPA).It is a 527-amino acid glycoprotein developed by replacing three amino acids at the T,N and K positions of the glycoprotein structure of tPA under genetic recombinant technology.After replacing threonine 103 with asparagine,asparagine 117 with glutamine and a tetra-alanine at amino acids 296–299,TNK is about eightfold more potent in dissolving clot,80-fold higher resistance to plasminogen activator inhibitor-1 and 14-fold enhanced relative fibrin specificity,and with a longer half-life(20 min).1 Hence,TNK is administered as a single intravenous bolus.Yi Dong Yi Sui Xin Cheng David Z Wang 2022Stroke & Vascular Neurology2022,7,1:3
12Factor analysis identifies subgroups of constipation显示文摘AIM:To determine whether distinct symptom groupings exist in a constipated population and whether such grouping might correlate with quantifiable pathophysiological measures of colonic dysfunction.METHODS:One hundred and ninety-one patients presenting to a Gastroenterology clinic with constipation and 32 constipated patients responding to a newspaper advertisement completed a 53-item,wide-ranging selfreport questionnaire.One hundred of these patients had colonic transit measured scintigraphically.Factor analysis determined whether constipation-related symptoms grouped into distinct aspects of symptomatology.Cluster analysis was used to determine whether indi-vidual patients naturally group into distinct subtypes.RESULTS:Cluster analysis yielded a 4 cluster solution with the presence or absence of pain and laxative unresponsiveness providing the main descriptors.Amongst all clusters there was a considerable proportion of patients with demonstrable delayed colon transit,irritable bowel syndrome positive criteria and regular stool frequency.The majority of patients with these characteristics also reported regular laxative use.CONCLUSION:Factor analysis identified four constipation subgroups,based on severity and laxative unresponsiveness,in a constipated population.However,clear stratification into clinically identifiable groups remains imprecise.Philip G Dinning Mike Jones Linda Hunt Sergio E Fuentealba Jamshid Kalanter Denis W King David Z Lubowski Nicholas J Talley Ian J Cook 2011World Journal of Gastroenterology2011,17,11:3
13SARS-COV-2 infection(coronavirus disease 2019)for the gastrointestinal consultant显示文摘The current pandemic due to the severe acute respiratory syndrome coronavirus 2 has caused an extreme burden for health care systems globally,and the number of cases is expected to continue to increase,at least in the immediate future.The virus is estimated to have infected more than 1.5 million individuals.The available reports suggest that gastrointestinal(GI)involvement in coronavirus disease 2019(COVID-19)is common and in some cases the GI symptoms may precede the respiratory symptoms.In addition to direct effects of severe acute respiratory syndrome coronavirus 2,the infected patients remain at risk for the complications commonly managed by gastroenterology and hepatology consultants.The most commonly reported GI manifestation of COVID-19 is diarrhea,which is reported in a third to up to more than half of the patients.Mild to moderate elevation of the liver enzymes are also common,although no case of acute liver failure has been reported so far.Many of the medications used for treatment of COVID-19 can also be associated with GI symptoms or liver injury and can be included in the differential diagnosis in these patients.Although the diagnosis of the infection is currently based on RNA analysis in respiratory samples,the available literature on fecal shedding of this virus suggests that fecal RNA testing might prove to be a useful diagnostic test.It is reasonable to delay all non-urgent endoscopic procedures during the peak of the pandemic and use additional protective equipment such as N95 respirators during endoscopy while most patients can be considered high risk for having been exposed to the virus.Kaveh Hajifathalian Srihari Mahadev Robert E Schwartz Shawn Shah Kartik Sampath Felice Schnoll-Sussman Robert S Brown Jr David Carr-Locke David E Cohen Reem Z Sharaiha 2020World Journal of Gastroenterology2020,26,14:2
14New synthesis method of a Si nanocomposite anode for Li - ion batteries 显示文摘Laurence L O Monique T David Z 2008Chem Mater2008,20,4:1
15Wheeling Rates of Reactive Power Flow under Marginal Cost Pricing显示文摘LI Y Z DAVID A K 1994IEEE Transactions on Power Systems1994,9,3:1
16Influence of design parameters on cogging torque in permanent magnet machines 显示文摘Z Q Zhu David Howe 2000IEEE Trans on Energy Converision2000,15,4:1
17Comparison of sulfadimethoxine residue analyses in salmon muscle using HPLC and charm Ⅱ test 显示文摘David DK Ming Z Erin BF 1995Jounal of Food Protection1995,58,6:1
18Depression among older adults in the United States and England 显示文摘Kara Z David JL Iain AL 2010Am J Geriatr Psychiatry2010,18,11:1
19Eutrophication: Nitrate flux in the Mississippi River显示文摘Mcisaa C G David M B Gertner G Z et ai 2001Nature2001,414,:1
20A Completed modeling of local binary pattern operator for texture classification显示文摘Guo Z H Zhang L Zhang David 2010IEEE Trans?actions on Image Processing2010,19,6:1
返回顶部 每页显示:
共30页 首页 上一页 第1页 下一页 末页 /30 跳转

网站首页 | 关于我们 | 联系我们 | 产品服务 | 客服中心 | 广告服务 | 版权声明 | 网站联盟 | 友情链接 | 售卡网点

版权所有© 渝B2-20050021-1 渝公网安备 50019002500403号 违法和不良信息举报中心

互联网出版许可证 新出网证(渝)字10号 全国400电话 - 免长途话费