检索结果-南通市图书馆

维普期刊数据库

Meta-analysis of ground movements associated with deep excavations using a data mining approach

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2019年第2期11卷 409-416页

作者： Harry Holmes emilio Garcia-Taengua raul Fuentes AECOM Ltd. University of Leeds

This paper presents a rigorous statistical approach to identify the controlling factors in the development of ground movements associated with deep excavations. It also gives the most suitable definition of support stiffness from many suggested definitions in the literature. The study is based on a newly compiled database from 389 case studies of propped and anchored excavations. Data mining techniques(e.g. principal component analysis and multi-linear regression) were used to identify significant relationships between the parameters under study and to quantify the global trends in the database. The study shows that the main factors controlling the ground movements are those related to ground conditions, confirming the conclusions of previous empirical studies. It is also shown that the definition of Addenbrooke et al.(1994) is the most suitable expression of support stiffness, therefore providing conclusive evidence for its future use.

关键词： Geomechanics Slope stability Special soil Unsaturated soil

维普期刊数据库

Action of protoporphyrin-IX (PP-IX) in the lifespan of <i>Drosophila melanogaster</i>deficient in endogenous antioxidants, Sod and Cat

在线全文

学校读者我要写书评

暂无评论

Open Journal of Animal Sciences 2013年第4期3卷 1-7页

作者： emilio Pimentel Luz M. vidal Martha Patricia Cruces Mariusz Krzysztof Janczur Departamento de Biología Instituto Nacional de Investigaciones Nucleares (ININ) Ocoyoacac México Facultad de Ciencias Universidad Autónoma del Estado de México Toluca México

Protoporphyirin-IX (PP-IX) is a precursor of the biosynthesis of the hemo group, most of the cytochromes and the chlorophylls. The PP-IX is used for medical purposes, and recently a report indicated that it exhibits a dual action since it can decrease or increase the genetic damage caused by N-nitroso-N-ethylurea (ENU) in somatic cells of Drosophila. PP-IX is known to be able to act as an anti-or pro-oxidant agent. The aim of the present research was to study the role of PP-IX on the lifespan of Drosophila melanogaster, taking into account the fact that increasing levels of ROS can accelerate the aging process. The Canton-S strain (CS) was used as well as Sod and Cat which are deficient in the endogenous enzymes, superoxide dismutase and catalase, respectively. Groups of females and males were treated separately with 5 mg/ml of PP-IX solution. The comparison of survival curves indicates that this pigment extended the lifespan of CS. In contrast, Sod strain showed that the opposite effect and had no effect in Cat strain. The fact that PP-IX reduces the mean lifespan in Sod deficient strain might suggest a pro-oxidant action of PP-IX, and consequently the cumulating of ROS as a superoxide could have a mutagenic effect as was shown recently. The results presented evidence of the dual effect of PP-IX.

关键词： Protoporphyrin IX (PP-IX) Lifespan Sod Cat Reactive Oxygen Species Longevity Drosophila melanogaster

Sensitivity,specificity and predictive values of anterior chamber tap in cases of bacterial endophthalmitis

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

Eye and Vision 2017年第1期4卷 100-105页

作者： Carl Sjoholm-Gomez de Liano vidal F.Soberon-Ventura Guillermo Salcedo-Villanueva Abril Santos-Palacios Jose Luis Guerrero-Naranjo Jans Fromow-Guerra Gerardo García-Aguirre Virgilio Morales-Canton raul Velez-Montoya Retina Department Asociación para Evitar la Ceguera en MexicoHospital“Dr.Luis Sanchez Bulnes”IAPMexico CityMexico Universidad Popular Autonoma del Estado de Puebla PueblaMexico Ophthalmology Department Macula Retina ConsultantsMexico CityMexico

Background:To assess the sensitivity,specificity,positive predictive value and negative predictive value of anterior chamber tap for the diagnosis of bacterial endophthalmitis on a population with high ***:Retrospective,single centre,case series *** reviewed all medical records with clinical diagnosis of bacterial endophthalmitis in our hospital from January 1st,2000 to December 31st *** each record,we documented general demographic data,best corrected visual acuity and vitreous and aqueous tap microbiological *** cases were further divided according to the endophthalmitis aetiology to perform individual calculations of sensitivity,specificity,positive predictive value,negative predictive value,accuracy and *** used the results of the vitreous tap as the gold standard for diagnosis of bacterial *** excluded those records in which the aqueous and vitreous samples were not taken simultaneously or had an incomplete microbiological *** were assessed with chi squared statistics,with an alpha value of 0.05 for statistical ***:A total of 190 cases fulfilled the inclusion/exclusion *** culture rate from vitreous samples was 64.74%.Positive culture rate from aqueous sample was 32.11%.Bacteria isolated from aqueous samples matched those isolated from vitreous samples 78.68%of the *** overall sensitivity was 38.21%,specificity:75.51%,positive predictive value:79.66%,negative predictive value:32.74%(p=0.08).Subgroup analysis showed that anterior chamber taps in cases of post-surgical endophthalmitis had a moderate to low sensitivity(37.73%),high specificity(93%)and high positive predictive value(95%)(p<0.04).Conclusion:The sensitivity and specificity of anterior chamber tap are low and should not be used for critical therapeutic decisions in patients with suspected bacterial *** cases of post-surgical endophthalmitis,the result of an anterior chamber tap

关键词： Aqueous humour Endophthalmitis Anterior chamber tap Diagnostic test Vitreous tap Aqueous sampling Sensibility Sensitivity

Evaluation of VEGF gene polymorphisms and proliferative diabetic retinopathy in Mexican population

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

International Journal of Ophthalmology(English edition) 2017年第1期10卷 135-139页

作者： Roberto Gonzalez-Salinas Maria C Garcia-Gutierrez Gerardo Garcia-Aguirre Virgilio Morales-Canton raul Velez-Montoya vidal R Soberon-Ventura Victoria Gonzalez Rodrigo Lechuga Pablo Garcia-Solis David G Garcia-Gutierrez Marco Vinicio Garcia-Solis Manuel Saenz de Viteri Juan C Solis-S Biomedical Research Department Autonomous University of QueretaroQueretaro 76170Mexico Retina Department Asociation to Prevent Blindness in MexicoMexico City 04030Mexico Research Department Asociation to Prevent Blindness in MexicoMexico City 04030Mexico Retina Department General Hospital of Queretaro(ISSSTE)Queretaro 76000Mexico Universidad La Salle School of Medicine Mexico City 06140Mexico

AIM： To assess if the included vascular endothelial growth factor （VEGF） polymorphisms rs3025035, rs3025021 and rs2010963 are associated to proliferative retinopathy in a Mexican population with type 2 diabetes mellitus （T2DM）. METHODS： A case-control study was conducted in adult individuals with T2DM associated to proliferative retinopathy or non-proliferative retinopathy from Oct. 2014 to Jun. 2015 from the Retina Department of the Asociation to Prevent Blindness in Mexico. The selected patients were adults with a diagnosis of T2DM ≥5y. All subjects had a comprehensive ocular examination and the classification of the retinopathy severity was made considering the Early Treatment Diabetic Retinopathy Study （ETDRS） standardization protocols. Genomic DNA was extracted from whole fresh blood. All samples were genotyped by qPCR for selected VEGF polymorphisms. Hardy-Weinberg equilibrium was calculated by comparing Chi-square values between the expected and the observed values for genotype ***： In total 142 individuals were enrolled, 71 individuals with T2DM and associated proliferative retinopathy and 71 individuals with non-proliferative retinopathy. One-sided Fisher’s exact test was performed for rs3025021 [OR （95% CI）=0.44（0.08-2.2）; P=0.25] and rs2010963 [OR （95% CI）=0.63（0.25-1.6）; P=0.23]. The minor allelic frequencies obtained were 26% for rs3025021, 10% for rs3025035 and 61% for rs2010963. The pairwise linkage disequilibrium between the three SNP was assessed, and was as follows： rs3025021 vs rs3025035： D’=1.0, r2=0.1043, P≤0.0001; rs3025021 vs rs2010963： D’=0.442, r2=0.0446, P=0.149; rs3025035 vs rs2010963： D’=0.505, r2=0.0214, P=***： This is the first analysis involving VEGF polymorphisms and proliferative diabetic retinopathy in a Mexican population. A major finding of the present study is that none of the polymorphisms studied was significantly associated with proliferative retinopathy. Based on these results, we can infer that differ

关键词： vascular endothelial growth factor polymor-phism proliferative diabetic retinopathy non-proliferative diabetic retinopathy rs3025021 rs3025035 rs2010963

International NeuroAIDS: prospects of HIV-1 associated neurological com-plications

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

Cell Research 2005年第Z1期15卷 962-969页

作者： J Roberto TRUJILLO Gilberto JARAMILLO-RANGEL Marta ORTEGA-MARTINEZ Augusto C PENALVA de OLIVEIRA Jose E vidal Joseph BRYANT Robert C GALLO Institute of Human Virology University of Maryland Biotechnology Institute 725 W Lombard Street Baltimore MD 21201 USA Institute of Infectious Diseases emilio Ribas Sao Paulo 01246 Brazil Clinical Research Unit in Human Retrovirology University of CampinasSao Paulo 01246 Brazil. Institute of Infectious Diseases emilio Ribas Sao Paulo 01246 Brazil

Neurological complications associated with HIV-1/AIDS are being recognized with a high frequency that parallels the increased number of AIDS cases. The early infiltration by HIV-1 into the nervous system can cause primary and/or secondary neurological complications. The most common neurocognitive disorder is AIDS Dementia Complex (ADC). In developing countries of Asia the three most opportunistic infections are tuberculosis (TB), cryptococcosis, and Pneumocystis carinii pneumonia. Therefore, it is expected that secondary neurological complications due to TB and cryptococcosis will be the most common cause of morbility and mortality in HIV-1/AIDS cases in China. Research of NeuroAIDS in China is necessary to understand the impact and the biology of HIV-1 in the nervous system. Future studies would include, the molecular epidemiology and the description of opportunistic infections associated to HIV-1; the neuropathological description of primary and secondary HIV-1 complications in different groups; the HIV-1 neurot- ropism and immune response studies for China’s unique HIV-1 strains and recombinant forms derived from the nervous system, including experimental models such as the use of transgenic rats; and the study of potential resistant virus, primarily when the anti-retroviral therapy (ART) has not full access in the brain.

关键词： NeuroAIDS HIV-1 neurotropism AIDS dementia complex.

RESEARCH PROGRESS ON THE IMPACT OF NITROGEN DEPOSITION ON GLOBAL GRASSLANDS

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Agricultural Science and Engineering 2022年第3期9卷 425-444页

作者： Carly J.STEVENS Sofía BASTO Michael DBELL Tianxiang HAO Kevin KIRKMAN raul OCHOA-HUESO Lancaster Environment Centre Lancaster UniversityLancasterLA14YQUK Unidad de Ecologia y Sistematica Departamento de BiologiaFacultad de CienciasPontificia Universidad JaverianaCarrera 7 No.43-82 Ed.Jesus Emilio Ramirez(53)BogotaColombia National Park Service Air Resources DivisionLakewoodCO 80235USA Synthesis Research Center of Chinese Ecosystem Research Network Key Laboratory of Ecosystem Network Observation and ModelingInstitute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China College of Resources and Environmental Sciences National Academy of Agriculture Green DevelopmentKey Laboratory of Plant-Soil Interactions of Ministry of EducationBeijing Key Laboratory of Farmland Soil Pollution Prevention and RemediationChina Agricultural UniversityBeijing 100193China School of Life Sciences University of KwaZulu-NatalDurban4041South Africa Departamento de Biologia-IVAGRO Universidad de CadizCampus Rio San Pedro11510 Puerto RealSpain Department of Terrestrial Ecology Netherlands Institute of Ecology(NIOO-KNAW)P.O.Box 506700 ABWageningenthe Netherlands

Grasslands are globally-important ecosystems providing critical ecosystem *** species composition and characteristics of grasslands vary considerably across the planet with a wide variety of different grasslands ***,in many regions grasslands have been impacted by atmospheric nitrogen deposition originating from anthropogenic activities with effects on productivity,species composition and diversity widely *** vary across grassland habitats but many show declines in species richness and increases in biomass production related to soil eutrophication and *** a continental level,there is considerable variation in the research effort that has been put into understanding the impacts of nitrogen *** Europe,North America and parts of Asia,although there are unanswered research questions,there is a good understanding of N deposition impacts in most grassland *** is not the case in other regions with large knowledge gaps in some parts of the *** paper reviews the impacts of N deposition on grasslands around the world,highlighting recent advances and areas where research is still needed.

关键词： acidification biomass production critical load eutrophication species composition species richness

维普期刊数据库