检索结果-南通市图书馆

Blood pressure gradients in cerebral arteries:a clue to pathogenesis of cerebral small vessel disease

Stroke & Vascular Neurology 2017年第3期2卷 108-117页

作者： Pablo J Blanco Lucas O müller J david Spence National Laboratory for Scientific Computing PetrópolisBrazil National Institute of Science and Technology in medicine Assisted by Scientific Computing INCT-MACCPetrópolisBrazil Stroke Prevention&Atherosclerosis Research Centre Robarts Research InstituteWestern UniversityLondon

rationale The role of hypertension in cerebral small vessel disease is poorly *** the base of the brain(the‘vascular centrencephalon’),short straight arteries transmit blood pressure directly to small resistance vessels;the cerebral convexity is supplied by long arteries with many branches,resulting in a drop in blood *** small vessel disease(lipohyalinosis)causes the classically described lacunar infarctions at the base of the brain;however,periventricular white matter intensities(WmIs)seen on mRI and WmI in subcortical areas over the convexity,which are often also called‘lacunes’,probably have different *** We studied pressure gradients from proximal to distal regions of the cerebral vasculature by mathematical *** and results Blood flow/pressure equations were solved in an Anatomically Detailed Arterial Network(ADAN)model,considering a normotensive and a hypertensive *** parameters were suitably modified to account for structural changes in arterial vessels in the hypertensive *** predict a marked drop in blood pressure from large and medium-sized cerebral vessels to cerebral peripheral *** blood pressure in the brachial artery is 192/113 mm Hg,the pressure in the small arterioles of the posterior parietal artery bed would be only 117/68 mm *** the normotensive case,with blood pressure in the brachial artery of 117/75 mm Hg,the pressure in small parietal arterioles would be only 59/38 mm *** These findings have important implications for understanding small vessel *** marked pressure gradient across cerebral arteries should be taken into account when evaluating the pathogenesis of small WmIs on *** small vessel disease,affecting the arterioles at the base of the brain should be distinguished from small vessel disease in subcortical regions of the convexity and venous disease in the periventricular white matter.

关键词： cerebral Blood pathogenesis

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

Profitability analysis of a femtosecond laser system for cataract surgery using a fuzzy logic approach

引用

International Journal of Ophthalmology(English edition) 2016年第7期9卷 1046-1050页

作者： Jose Antonio Trigueros david P Pinero mahmoud m Ismail Department of Financial Economic and Accounting Miguel Hernandez University Elche 03202 Alicante Spain Department of Optics Pharmacology and AnatomyUniversity of Alicante Crta San Vicente del RaspeigAlicante 03690 Spain Al-Azhar University Cairo 11651 Egypt

AIm：To define the financial and management conditions required to introduce a femtosecond laser system for cataract surgery in a clinic using a fuzzy logic ***：In the simulation performed in the current study,the costs associated to the acquisition and use of a commercially available femtosecond laser platform for cataract surgery（VICTUS,TECHNOLAS Perfect Vision GmbH,Bausch ＆ Lomb,munich,Germany） during a period of 5y were considered.A sensitivity analysis was performed considering such costs and the countable amortization of the system during this 5y ***,a fuzzy logic analysis was used to obtain an estimation of the money income associated to each femtosecond laser-assisted cataract surgery（G）. RESULTS：According to the sensitivity analysis,the femtosecond laser system under evaluation can be profitable if 1400 cataract surgeries are performed per year and if each surgery can be invoiced more than $*** contrast,the fuzzy logic analysis confirmed that the patient had to pay more per surgery,between $661.8 and $667.4 per surgery,without considering the cost of the intraocular lens（IOL）.CONCLUSION：A profitability of femtosecond laser systems for cataract surgery can be obtained after a detailed financial analysis,especially in those centers with large volumes of *** cost of the surgery for patients should be adapted to the real flow of patients with the ability of paying a reasonable range of cost.

关键词： cataract surgery femtosecond laser fuzzy logic femto-cataract victus profitability analysis

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

Effect of genotype on duodenal expression of nutrient transporter genes in dairy cows

引用

Journal of Animal Science and Biotechnology 2014年第2期5卷 145-153页

作者： Sinéad m Waters Kate Keogh Frank Buckley david A Kenny Teagasc Animal and Bioscience Research Department Animal and Grassland Research and Innovation CentreGrangeDunsanyCo.MeathIreland Teagasc Animal and Bioscience Research Department Animal and Grassland Research and Innovation Centre MooreparkFermoyCo CorkIreland

Background： Studies have shown clear differences between dairy breeds in their feed intake and production efficiencies. The duodenum is critical in the coordination of digestion and absorption of nutrients. This study examined gene transcript abundance of important classes of nutrient transporters in the duodenum of non lactating dairy cows of different feed efficiency potential, namely Holstein-Friesian （HF）, Jersey （JE） and their F1 hybrid. Duodenal epithelial tissue was collected at slaughter and stored at -80℃. Total RNA was extracted from tissue and reverse transcribed to generate cDNA. Gene expression of the following transporters, namely nucleoside amino acid; sugar; mineral; and lipid transporters was measured using quantitative real-time RT-PCR. Data were statistically analysed using mixed models ANOVA in SAS. Orthogonal contrasts were used to test for potential heterotic effects and spearman correlation coefficients calculated to determine potential associations amongst gen, expression values and production efficiency variables. Results： While there were no direct effects of genotype on expression values for any of the genes examined, there was evidence for a heterotic effect （P 〈 0.05） on ABCGS, in the form of increased expression in the F1 genotype compared to either of the two parent breeds. Additionally, a tendency for increased expression of the amino acid transporters, SLC3A1 （P= 0.072）, SLC3A2 （P= 0.081） and SLC6A 14 （P= 0.072） was also evident in the F1 genotype. A negative （P 〈 0.05） association was identified between the expression of the glucose transporter gene SLCSA1 and total lactational milk solids yield, corrected for body weight. Positive correlations （P 〈 0.05） were also observed between the expression values of genes involved in common transporter roles. Conclusion： This study suggests that differences in the expression of sterol and amino acid transporters in the duodenum could contribute towards the documented differences in feed effic

关键词： Bovine Duodenum Gene expression Nutrient transporters

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

Topography and human disturbances are major controlling factors in treeline pattern at Barun and manang area in the Nepal Himalaya

引用

Journal of mountain Science 2017年第1期14卷 119-127页

作者： Parveen K.CHHETRI Krishna B.SHRESTHA david m.CAIRNS Department of Geography Texas A&M University College Station TX 77840 USA UiB Global Jekteviksbakken 31 PO Box 7800 5020 Bergen Norway

The alpine treeline ecotone is an important component of mountain ecosystems of the Nepal Himalaya; it plays a vital role in the livelihood of indigenous people,and provides ecosystem services. However,the region faces a problem of paucity of data on treeline characteristics at the regional and landscape scales. Therefore,we used Remote Sensing(RS),and Geographic Information Science(GIS) approaches to investigate cross-scale interactions in the treeline ecotone. Additionally,European Space Agency land cover map,International Center for Integrated mountain Development(ICImOD) land cover map,ecological map of Nepal,and United States Geological Survey Shuttle Radar Topography mission-Digital Elevation model were used to analyze treeline pattern at the regional scale. Digital Globe high-resolution satellite imagery of Barun(eastern Nepal) and manang(central Nepal) were used to study treeline patterns at the landscape scale. Treeline elevation ranges from 3300-4300 m above sea level. Abies spectabilis,Betula utilis,and Pinus wallichiana are the main treeline-forming species in the Nepal Himalaya. There is an east to west treeline elevationgradient at the regional scale. No slope exposure is observed at the regional scale; however,at the landscape scale,slope exposure is present only in a disturbed area(manang). Topography and human disturbance are the main treeline controlling factor in Barun and manang respectively.

关键词： Alpine Treeline mountain ecosystem Himalaya Remote Sensing(RS) Geographic Information Science(GIS)

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

Early Cenozoic rapid flight enigma of the Indian subcontinent resolved:Roles of topographic top loading and subcrustal erosion

引用

Geoscience Frontiers 2017年第1期8卷 15-23页

作者： muthuvairavasamy Ramkumar david menier manoj mathew m.Santosh Numair A.Siddiqui Department of Geology Periyar UniversitySalem 636011India South East Asia Carbonate Research Laboratory(SEACaRL) Universiti Teknologi Petronas31750 TronohMalaysia GmGL UmR CNRS 6538 Universite de Bretagne Sud56017 Vannes CedexFrance Department of Earth Sciences University of AdelaideSA 5005Australia School of Earth Sciences and Resources China University of Ceosciences Beijing29 Xueyuan RoadBeijing 100083China Department of Geosciences Universiti Teknologi Petronas31750 TronohMalaysia

Intrinsic magmatic processes are considered as critical operators of plate movements. Here we demonstrate the role of extrinsic processes consequent to intrinsic processes as a catalyst for anomalous rapid plate movement. The rapid and accelerated flight of the Indian subcontinent since Deccan volca- nism until its collision with Eurasia remains as one of the geological conundrums. Data on seismic to- mography, peninsular geomorphology and inferences on continuum of subcrustal structures are utilized to address this enigma. We propose geomorphic isostasy as the mechanism that has driven this fastest drift ever recorded in geological history. It was initiated by sudden instability after the Deccan volcanism and resultant extensive accumulation of lava pile over continental lithosphere of northern India, northern-eastern tilt due to crustal thickness heterogeneity and subcrustal thermal stratification. The drift was sustained by Carlsberg and Central Indian ridge-push until collision and sediment top loading at northeast thenceforth. These inferences and geomorphic isostasy as a catalytic mechanism necessitate variability of drift rates as integral inputs for any continental scale modeling.

关键词： Geomorphic isostasy mantle plume Continental drift Plate reorganization India

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

Quantitative analysis of ruminal methanogenic microbial populations in beef cattle divergent in phenotypic residual feed intake(RFI)offered contrasting diets

引用

Journal of Animal Science and Biotechnology 2014年第4期5卷 439-447页

作者： Ciara A Carberry david A Kenny Alan K Kelly Sinead m Waters Animal and Bioscience Research Department Animal and Grassland Research and Innovation CentreTeagascGrangeDunsanyCo.MeathIreland UCD School of Agriculture Food Science and Veterinary MedicineCollege of Life SciencesUniversity College DublinBelfieldDublin 4Ireland

Background：methane（CH_4） emissions in cattle are an undesirable end product of rumen methanogenic fermentative activity as they are associated not only with negative environmental impacts but also with reduced host feed *** aim of this study was to quantify total and specific rumen microbial methanogenic populations in beef cattle divergently selected for residual feed intake（RFI） while offered（i） a low energy high forage（HF） diet followed by（ii） a high energy low forage（LF） *** fluid was collected from 14 high（H）and 14 low（L） RFI animals across both dietary *** real time PCR（qRT-PCR） analysis was conducted to quantify the abundance of total and specific rumen methanogenic *** correlation analysis was used to investigate the association between the relative abundance of methanogens and animal performance,rumen fermentation variables and diet ***：Abundance of methanogens,did not differ between RFI ***,relative abundance of total and specific methanogen species was affected（P〈 0.05） by diet type,with greater abundance observed while animals were offered the LF compared to the HF ***：These findings suggest that differences in abundance of specific rumen methanogen species may not contribute to variation in CH_4 emissions between efficient and inefficient animals,however dietary manipulation can influence the abundance of total and specific methanogen species.

关键词： Bovine qRT-PCR Residual feed intake Rumen methaongens

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

Release models for leaks from high-pressure hydrogen storage systems

引用

Chinese Science Bulletin 2014年第19期59卷 2302-2308页

作者： Xue-Fang Li david m. Christopher Jing-Liang Bi Key Laboratory for Thermal Science and Power Engineering of ministry of Education Tsinghua University

Simulations and analyses of experimental data from leaks from high-pressure hydrogen storage systems will require knowledge of the stagnation state time histories and stream properties exiting the *** analytical ideal-gas model based on the ideal gas state equation and a computer program making use of the NIST standard reference database(REFPROP)were developed to model the entire process of leaks from high-pressurized hydrogen gas *** results obtained by the two methods agree with each other *** the gas behavior departs from the ideal gas properties at high pressures,the actual stagnation pressure and temperature decay more rapidly than with the ideal-gas assumption.

关键词：存储系统高压氢理想气体状态方程泄漏释放模式理想气体模型计算机程序时间历程

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

History and evaluation of national-scale geochemical data sets for the United States

引用

Geoscience Frontiers 2013年第2期4卷 167-183页

作者： david B.Smith Steven m.Smith John D.Horton U.S.Geological Survey.Denver Federal Center MS 973.DenverCO 80225USA

Six national-scale,or near national-scale,geochemical data sets for soils or stream sediments exist for the United *** earliest of these,here termed the ＇Shacklette＇ data set,was generated by a U.S. Geological Survey（USGS） project conducted from 1961 to *** project used soil collected from a depth of about 20 cm as the sampling medium at 1323 sites throughout the conterminous *** National Uranium Resource Evaluation Hydrogeochemical and Stream Sediment Reconnaissance（NUREHSSR） Program of the *** of Energy was conducted from 1975 to 1984 and collected either stream sediments,lake sediments,or soils at more than 378,000 sites in both the conterminous *** *** sampled area represented about 65%of the *** Natural Resources Conservation Service（NRCS）,from 1978 to 1982,collected samples from multiple soil horizons at sites within the major crop-growing regions of the conterminous *** data set contains analyses of more than 3000 *** National Geochemical Survey,a USGS project conducted from 1997 to 2009,used a subset of the NURE-HSSR archival samples as its starting point and then collected primarily stream sediments, with occasional soils,in the parts of the *** covered by the NURE-HSSR *** data set contains chemical analyses for more than 70,000 *** USGS,in collaboration with the mexican Geological Survey and the Geological Survey of Canada,initiated soil sampling for the North American Soil Geochemical Landscapes Project in *** of three horizons or depths at more than 4800 sites in the *** completed in 2010,and chemical analyses are currently *** NRCS initiated a project in the 1990s to analyze the various soil horizons from selected pedons throughout the *** data set currently contains data from more than 1400 *** paper（1） discusses each data set in terms of its purpose,sample collection protocols,and analytical methods;and（2） evaluates each data set in terms

关键词： Geochemical mapping National-scale geochemical data Geochemical baselines United States

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

Tailoring the degradation rate of magnesium through biomedical nano-porous titanate coatings

引用

Journal of magnesium and Alloys 2021年第1期9卷 336-350页

作者： matthew D.Wadge Jamie mcGuire Benjamin V.T.Hanby Reda m.Felfel Ifty Ahmed david m.Grant Advanced materials Research Group Faculty of EngineeringUniversity of NottinghamNG72RD United Kingdom Physics Department Faculty of ScienceMansoura UniversityMansoura 35516Egyp

A novel approach was developed to reduce the corrosion rate of magnesium(mg)metal,utilising titanate *** sputtering was used to deposit ca.500 nm titanium(Ti)coatings onto pure mg discs,followed by hydrothermal conversion and ion exchange reactions to produce sodium and calcium titanate *** confirmed the characteristic nanoporous structure of sodium and calcium titanate,with thicknesses ranging from ca.0.8 to 1.4μ*** analysis confirmed the presence of Ti^(4+)-O,Na-O,and Ca-O bonding,whilst Raman spectroscopy demonstrated characteristic vibrational modes(such as TiO 6 octahedral vibrations)of the sodium and calcium titanate perovskite ***,corrosion studies through potentiodynamic polarisation measurements demonstrated the NB/NH CaTC samples to be superior in reducing mg degradation,compared to other samples tested,through an increase in E_(corr)from-1.49 to-1.33 V,and the reduction in corrosion current density,i corr,from 0.31 to 0.06 mA/cm^(2)for mg and NB/NH CaTC samples,*** was a clear trend noted for the NB/NH samples,which showed an increase in E corr to more positive values in the following order:mg

关键词： magnesium degradation Titanate Biodegradable Ion exchange Electrochemical corrosion magnetron sputtering

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

The Shishugou Fauna of the middle-Late Jurassic Transition Period in the Junggar Basin of Western China

引用

Acta Geologica Sinica(English Edition) 2022年第4期96卷 1115-1135页

作者： XU Xing James m.CLARK david A.EBERTH Philip J.CURRIE Centre for Vertebrate Evolutionary Biology Yunnan UniversityKunming 650500China Key Laboratory of Vertebrate Evolution and Human Origins Institute of Vertebrate Paleontology and PaleoanthropologyChinese Academy of SciencesBeijing 100044China Department of Biological Sciences George Washington UniversityWashington DC20052USA Royal Tyrrell museum of Palaeontology Box 7500DrumhellerAlberta T0J 0Y0Canada Department of Biological Sciences University of Alberta 116 Street and 85 AvenueEdmontonAB T6G 2R3Canada

The middle-Late Jurassic transition period is a critical period for the evolution of terrestrial vertebrates,but the global fossil record from this time is relatively *** Shishugou Fauna of this period has recently produced significant fossil remains of dinosaurs and other vertebrate groups,some representing the earliest known members of several dinosaurian groups and other vertebrate groups and some representing the best-known specimens of their *** discoveries are significant for our understanding of the origin and evolution of several vertebrate *** dating indicates that the fauna is aged approximately 159-164 *** with other similarly-aged terrestrial faunas such as Shaximiao and Yanliao show both taxonomic similarities and differences between these faunas and indicate that the Junggar deposits might have preserved the most complete vertebrate fossil record for a middle-Late Jurassic Laurasian terrestrial fauna.

关键词： middle-Late Jurassic Shishugou Fauna Shishugou Formation terrestrial ecosystem Shaximiao Yanliao Junggar Basin

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

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：