检索结果-南通市图书馆

se-Bearing Colloidal Particles Produced by sulfate-Reducing Bacteria and sulfide-Oxidizing Bacteria: TEM study

Advances in Microbiology 2013年第2期3卷 205-211页

作者： Huifang Xu Larry L. barton NAsA Astrobiology Institute Department of Geoscience University of Wisconsin-Madison Madison USA

As determined by transmission electron microscopy (TEM), the reduction of selenate and selenite by Desulfovibrio desulfuricans, a sulfate-reducing bacterium, produces spherical (se, s) sub-micro particles outside the cell. The particles are crystalline or amorphous, depending on medium composition. Amorphous-like se-rich spherical particles may also occur inside the bacterial cells. The bacteria are more active in the reduction of selenite than selenate. The Desulfovibrio desulfuricans bacterium is able to extract s in the (s, se) solid solution particles and transform s-rich particles into se-rich and se crystals. Photoautotrophs, such as Chromatium spp., are able to oxidize sulfide (s2-). When the bacteria grow in sulfide- and selenide-bearing environments, they produce amorphous-like (s, se) globules inside the cells. TEM results show that compositional zonation in the (s, se) globules occur in Chromatium spp. collected from a top sediment layer of a se-contaminated pond. s2-?may be from the products of sulfate-reducing bacteria. Both the sulfate-reducing bacteria and photosynthetic Chromatium metabolize s preferentially over se. It is proposed that the s-rich zones are formed during photosynthesis (day) period, and the se-rich zones are formed during respiration active (night) period. The results indicate that both Desulfovibrio desulfuricans and Chromatium spp. are able to immobilize the oxidized selenium (selenate and/or selenite) in the forms of elemental selenium and (se, s) solid solutions. The bacteria reduce s in the (se, s) particles and further enrich se in the crystalline particles. The reduced s combines with Fe2+ to form amorphous Fes.

关键词： selenium sulfate-Reducing Bacteria sulfide-Oxidizing Bacteria Transmission Electron Microscopy

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

局部自反原理的推广

引用

科学通报 1993年第10期38卷 876-877页

作者： T.barton 俞鑫泰 Memphis state Univ.UsA 华东师范大学数学系上海200062

大家知道,局部自反原理是Banach空间理论中最基本的定理之一。本文得到了局部自反原理的“最完备”的形式。我们证明定理1 设E是X^(**)的一个有限维子空间,F是X~*的一个自反子空间,对于任给ε>0,则存在一个线性算子s:E→X使得‖s‖‖s^(... 详细信息

大家知道,局部自反原理是Banach空间理论中最基本的定理之一。本文得到了局部自反原理的“最完备”的形式。我们证明定理1 设E是X^(**)的一个有限维子空间,F是X~*的一个自反子空间,对于任给ε>0,则存在一个线性算子s:E→X使得‖s‖‖s^(-1)‖sx=x,其中x∈E∩X,且f(sx^(**)=x^(**)(f),对一切x^(**)∈X,f∈F.

关键词：局部自反原理巴拿赫空间

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

Monitoring adenoviral based gene delivery in rat glioma by molecular imaging

引用

World Journal of Clinical Oncology 2013年第4期4卷 91-101页

作者： Nadimpalli Ravi s Varma Kenneth N barton Branislava Janic Adarsh shankar AsM Iskander Meser M Ali Ali s Arbab Cellular and Molecular Imaging Laboratory Department of RadiologyHenry Ford HospitalDetroitMI 48202United States Department of Radiation Oncology Henry Ford HospitalDetroitMI 48202United States

AIM:To determine whether endothelial progenitor cells(EPCs)can be used as delivery vehicle for adenoviral vectors and imaging probes for gene therapy in ***:To use cord blood derived EPCs as delivery vehicle for adenoviral vectors and imaging probes for glioma gene therapy,a rat model of human glioma was made by implanting U251 cells *** were transfected with an adenovirus(AD5/carrying hNIs gene)and labeled with iron oxide and inoculated them directly into the tumor 14 d following implantation of U251 *** resonance imaging(MRI)was used to in vivo track the migration of EPCs in the *** expression of gene products was determined by in vivo Tc-99m single photon emission computed tomography(sPECT).The findings were validated with immunohistochemistry(IHC).REsULTs:EPCs were successfully transfected with the adenoviral vectors carrying hNIs which was proved by significantly(Psfected *** of EPCs following transfection and iron labeling was not *** vivo imaging showed the presence of iron positive cells and the expression of transgene(hNIs)product on MRI and sPECT,respectively,all over the tumors following administration of transfected and iron labeled EPCs in the *** confirmed the distribution of EPC around the tumor away from the injection site and also showed transgene expression in the *** results indicated the EPCs’ability to deliver adenoviral vectors into the glioma upon intratumor ***:EPCs can be used as vehicle to deliver adenoviral vector to glioma and also act as imaging probe at the same time.

关键词： Cord blood endothelial progenitor cells Adenovirus Human sodium iodide symporter single photon emission computed tomography Magnetic resonance imaging

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

selling : building partnerships / 6th ed.

引用

2007年

作者： barton A. Weitz stephen B. Castleberry John F. Tanner Jr.

来源：畅想之星图书光盘版（南... 评论

在线全文

畅想之星图书光盘版（南通市图书馆镜像）

学校读者我要写书评

暂无评论

Archaeological records of Dadiwan in the past 60 ka and the origin of millet agriculture

引用

Chinese science Bulletin 2010年第16期55卷 1636-1642页

作者： ZHANG DongJu CHEN FaHu BETTINGER R L barton L JI DuXue MORGAN C WANG Hui CHENG XiaoZhong DONG GuangHui GUILDERsON T P ZHAO Hui Key Laboratory of West China's Environmental system (MOE) Lanzhou University Lanzhou 730000 China Department of Anthropology University of California Davis CA 95616 USA Department of sociology Social Work and Anthropology Utah State University Logan UT 84322 USA Gansu Province Institute of Cultural Relics and Archaeology Lanzhou 730000 China Preservation Institute ofDadiwan Qin'an 741600 China Center for Accelerator Mass spectrometry Lawrence Liverrnore National Laboratory Livermore CA 94550 USA Key Laboratory of Desert and Desertification Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

This paper reports the recent excavation of Unit Dadiwan06 at the Dadiwan site in Qin’an County, Gansu.A 65 ka chronological framework is established for Dadiwan06 on the basis of absolute dating (AMs 14C and OsL), stratigraphy, climate change events and *** distributions reveal patterns of human behavioral variation and adaptation over the past 60 ka, from primitive hunting and gathering to advanced hunting and gathering, to primitive Neolithic agriculture, and finally to advanced Neolithic agriculture.

关键词：原始农业考古学大地新石器时代起源小米年代框架气候变化

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

Thermoelastic stress Analysis of Aged sandwich structures

Thermoelastic Stress Analysis of Aged Sandwich Structures

引用

第十三届国际复合材料会议

作者： J.s.Earl J.M.Dulieu-barton R.A.shenoi school of Engineering sciences University of Southampton Highfield Southampton SO 17 1BJ school of Engineering sciences University of Southampton Highfield Southampton SO 17 1BJ school of Engineering sciences University of Southampton Highfield Southampton SO 17 1BJ

＜正＞The aim of this paper is to use the thermoelastic stress analysis （TsA） technique to determine the load transfer mechanisms in sandwich construction tee joints, which have been environmentally aged, and to assess how their performance has changed with respect to the unaged case. An extensive literature review has shown that although a wealth of information exists on the long-term performance of FRP materials exposed to hygrothermal environments, the behaviour of aged composite sandwich structures has not been addressed. The purpose of this work is to begin to fill this void.

关键词： TsA deltatherm sandwich structures hygrothermal exposure ageing

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

The Effect of Direct Gas Fluorination on Medical Grade Poly(methyl methacrylate)

引用

Open Journal of Organic Polymer Materials 2014年第4期4卷 74-83页

作者： Baljit K. Ghatora stephen J. barton Peter J. s. Foot Philip Miller Tate Materials Research Centre Kingston University Penrhyn Road Kingston upon Thames Surrey UK

Medical-grade poly(methyl methacrylate) (PMMA) is extensively employed in the fabrication of a variety of medical implants, including intraocular lenses (IOLs). However, a postoperative complication that leads to the failure of the implanted intraocular lenses has been recently identified. This process, termed calcification, occurs when calcium-containing deposits accumulate on the surface of the IOL. In this study direct gas fluorination was used to modify the surface of PMMA in an attempt to increase the service lifetime of the material in optical applications. PMMA discs exposed to a 20% fluorine/nitrogen gas mixture for 24 h were compared with untreated PMMA discs serving as control samples. Over time, both surface-fluorinated and untreated PMMA samples immersed in a simulated aqueous humour solution (sAHs) (pH 7.4, 35°C) were used to carry out in vitro studies. Attenuated total refractive Infrared spectroscopy (ATR-IR) scanning electron microscopy (sEM), coupled with Energy dispersive X-ray analysis (EDX), showed that calcium-containing surface deposits were less abundant on surface-fluorinated PMMA compared with the control samples, indicating that the fluorinated surface was acting as a barrier to the deposits. Gravimetric analysis data showed that the decreased rate of diffusion compared with that of a control sample was due to the fluorinated surface.

关键词： Poly(methyl methacrylate) (PMMA) surface Fluorination In Vitro studies simulated Aqueous Humour solution (sAHs) Medical Polymers

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

surface Perfluoroalkyl Chains segregation: A Tool for Reducing Calcium Deposits in Medical Grade Poly(Methyl Methacrylate)

引用

Journal of Biomaterials and Nanobiotechnology 2017年第2期8卷 176-187页

作者： Baljit K. Ghatora Peter J. s. Foot stephen J. barton Ravtej s. Thatti Antonio Papagni Luca Vaghi Materials Research Centre SEC Faculty Kingston University Surrey UK Department of Materials science University of Milano-Bicocca Milano Italy

Intraocular lenses can be manufactured from a wide variety of polymers, but due to the lost cost associated with the use of Poly (methyl methacrylate) (PMMA), it is still the preferred material used in the developing countries. However, a major drawback to its use is the build-up of calcium containing deposits that are formed on the intraocular lens over a period of time. In an attempt to hinder this deposition, surface modification of medical grade PMMA has been carried out using perfluoroalkyl chain (1,2,4-trifluoro-3-(C10F21CH2O)-7-(N,N)-dimethylaminoacridine) segregation. The segregation was explored using a 1% 1,2,4-trifluoro-3-(C10F21CH2O)-7-(N,N)-dimethyla-minoacridine in two methods: film casting and spin-coating, a thin film onto preformed PMMA discs. Both methods were compared against control PMMA to determine which method provided the best hindrance against calcium containing deposits when immersed in a simulated aqueous humour solution. Characterisation of the surface using scanning electron microscopy coupled with energy;dispersive x-ray analysis indicated that the surface segregation of perfluoroalkyl chains had hindered calcification in both methods. This pleminary research shows promising results of employing perfluoroalkyl chains in the surface segregation of biomaterials that can be employed in intraocular lenses.

关键词： Poly(Methyl Methacrylate) (PMMA) Perfluoroalkyl segregation Medical Polymers Wettability Calcium Deposits

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

Comparison of pediatric ventriculoperitoneal shunt infections arising in antibiotic-impregnated and standard catheters:a multicenter observational study

引用

World Journal of Pediatric surgery 2023年第3期6卷 196-199页

作者： Joan Robinson Archana Balamohan Michelle barton Marie-Astrid Lefebvre Ahmed Almadani Dolores Freire Alastair McAlpine Jocelyn srigley Patrick Passarelli John Bradley Dele Davies Gwenn skar Isabelle Viel-Theriault sarah Khan Rupeena Purewal Nicole Lesaux Jennifer Bowes Michael Hawkes 无 Department of Pediatrics University of AlbertaEdmontonAlbertaCanada University of Arkansas for Medical sciences Little RockArkansasUSA Arkansas Children's Hospital Little RockArkansasUSA Western University LondonOntarioCanada McGill University Faculty of Medicine MontrealQuebecCanada Umm Al-Qura University MakkahSaudi Arabia University of Alberta EdmontonAlbertaCanada The University of British Columbia VancouverBritish ColumbiaCanada Pediatrics Rady Children's Hospital San DiegoSan DiegoCaliforniaUSA Arnot Ogden Medical Center ElmiraNew YorkUSA Rady Children's Hospital san Diego San DiegoCaliforniaUSA Pediatrics University of Nebraska Medical CenterOmahaNebraskaUSA University of Nebraska Medical Center OmahaNebraskaUSA Laval University QuebecQuebecCanada McMaster University HamiltonOntarioCanada University of saskatchewan SaskatoonSaskatchewanCanada CHEO OttawaOntarioCanada for the Pediatric Investigators Collaborative Network on Infections in Canada(PICNIC)

Antibiotic-impregnated ventricular shunt catheters(AIVsCs)with 0.15%clindamycin and 0.054%rifampin are commonly used to prevent ventriculo-peritoneal(VP)shunt *** approved by the United states Food and Drug Administration in 2003(https://***/file/general/***),they have antimicrobial activity documented for minimum 31 days(https://***/cdrh_docs/pdf11/***).These antibiotics were chosen as they cover the majority of staphylococcus aureus and may provide some activity against coagulase negative staphylococci.1 These normal skin flora account for the majority of VP shunt *** the largest randomized controlled trial(RCT)to date,AIVsCs significantly reduced the risk of infection compared with standard shunts(cause-specific hazard ratio(HR)0.38).2 This effect was mainly due to a reduction in staphylococcal infections;the number of gram-negative infections was similar in both *** studies3–5 and a meta-analysis6 in children support the findings of this *** objective of this study was to examine the spectrum of pathogens,time to infection,and outcomes with AIVsCs vs standard shunts.

关键词： shunt infections peritoneal

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

Microvascular response to transfusion in elective spine surgery

引用

世界骨科杂志：英文版 2017年第1期8卷 49-56页

作者： J Matthias Walz Ottokar stundner Federico P Girardi Bruce A barton Aimee R Koll-Desrosiers stephen O Heard stavros G Memtsoudis Department of Anesthesi-ology and Perioperative Medicine UMass Memorial Healthcare Department of Anesthesiology Hospital for Special SurgeryWeill Cornell Medical Center Department of Anesthesiology PerioperativeMedicine and Intensive Care MedicineParacelsus Medical University Department of Orthopedic surgery Hospital for Special SurgeryWeill Cornell Medical Center Department of Quantitative Health sciences University of Massachusetts Medical School

AIM To investigate the microvascular(skeletal muscle tissue oxygenation; smO_2) response to transfusion in patients undergoing elective complex spine *** After IRB approval and written informed consent, 20 patients aged 18 to 85 years of age undergoing > 3level anterior and posterior spine fusion surgery were enrolled in the study. Patients were followed throughout the operative procedure, and for 12 h postoperatively. In addition to standard American society of Anesthesiologists monitors, invasive measurements including central venous pressure, continual analysis of stroke volume(sV), cardiac output(CO), cardiac index(CI), and stroke volume variability(sVV) was performed. To measure skeletal muscle oxygen saturation(smO_2) during the study period, a non-invasive adhesive skin sensor based on Near Infrared spectroscopy was placed over the deltoid muscle for continuous recording of optical spectra. All administration of fluids and blood products followed standard procedures at the Hospital for special surgery, without deviation from usual standards of care at the discretion of the Attending Anesthesiologist based on individual patient comorbidities, hemodynamic status, and laboratory data. Time stamps were collected for administration of colloids and blood products, to allow for analysis of smO_2 immediately before, during, and after administration of these fluids, and to allow for analysis of hemodynamic data around the same time points. Hemodynamic and oxygenation variables were collected continuously throughout the surgery, including heart rate, blood pressure, mean arterial pressure, sV, CO, CI, sVV, and smO_2. Bivariate analyses were conducted to examine the potential associations between the outcome of interest, smO_2, and each hemodynamic parameter measured using Pearson's correlation coeffi-cient, both for the overall cohort and within-patients individually. The association between receipt of packed red blood cells and smO_2 was performed by runni

关键词： Transfusion Complex spine surgery Near infrared spectroscopy Microvascular blood flow Hemodynamic monitoring

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：