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Effects of prior freezing or drying on the swelling behaviour of the bovine cornea

1979年

作者： Johnson keith.

来源：畅想之星图书光盘版（南... 评论

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chinese Medical Journal 2009年第2期122卷 212-218页

作者： HUANG Yi-fei keith M. Meek WANG Li-qiang WANG Da-jiang Department of Ophthalmology Chinese PLA General Hospital Beijing 100853 China Department of Optometry and Vision Sciences University of Cardiff Cardiff CF1 3AT United Kingdom

Background Frozen or dried corneal grafts are commonly used for stromal transplantation such as lamellar keratoplasty （full or partial thickness）, keratophakia, epikeratophakia. Structural properties are important for the final optical results of these surgeries but the effects of freezing/thawing and drying/rehydration on the properties of the stroma are known little compared with the corneal endothelium, mainly because of lack of non-invasive technique to evaluate the stromal structure. This study aimed to investigate the swelling and structural properties of the bovine corneal stroma following freezing or drying by X-ray diffraction which was a non-invasive technique and could give ultra-structural information in hydrated tissues. Methods Bovine corneas were either frozen at -40~c or dried to constant weight in a dessicator over silica gel. Swelling was carried out by placing the corneas into dialysis tubing and equilibrating them against various concentrations of polyethylene glycol （PEG） to obtain a range of tissue hydrations. This method minimises the loss of soluble tissue components during the swelling process. Synchrotron X-ray diffraction was used to measure the average intermolecular spacing, the interfibrillar spacing and the fibril diameter as a function of hydration. changes in light scattering were detected using a microdensitometer. Results Freezing and thawing of the cornea caused an increase in light scattering by 63.9% at tissue hydration （H）=3.4, and by 50.0% at H=4.9. Repeated freezing and thawing causes further increased by 38.9% at the second time and another 36.0% at the third time （P 〈0.05）. There was a tendency for both the frozen and the dried comeas to lose some swelling ability, achieving hydrations respectively of 10% and 18% below those of fresh corneas at 0 PEG. There were no changes in the fibril diameters, interfibrillar or intermolecular spacings as measured by X-ray diffraction in the equilibrated fresh, pre-frozen and pre-dried c

关键词： cornea freezing stroma swelling X-ray diffraction

Robust reduction of graphene fluoride using an electrostatically biased scanning probe

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Nano Research 2013年第11期6卷 767-774页

作者： Woo-Kyung Lee Stanislav Tsoi keith E. Whitener Rory Stine Jeremy T. Robinson Jonathon S. Tobin Asanka Weerasinghe Paul E. Sheehan Sergei F. Lyuksyutov Division of chemistry US Naval Research Laboratory Washington DC20375 USA NOVA Research Alexandria Virginia 22308 USA Division of Electronic Science and Technology US Naval Research Laboratory Washington DC 20375 USA The University of Akron Department of Physics Akron OH 44325 USA

We report a novel and easily accessible method to chemically reduce graphene fluoride （GF） sheets with nanoscopic precision using high electrostatic fields generated between an atomic force microscope （AFM） tip and the GF substrate. Reduction of fluorine by the electric field produces graphene nanoribbons （GNR） with a width of 105-1,800 nm with sheet resistivity drastically decreased from 〉1 TΩ.sq.^-1 （GF） down to 46 kΩ.sq.^-1 （GNR）. Fluorine reduction also changes the topography, friction, and work function of the GF. Kelvin probe force microscopy measurements indicate that the work function of GF is 180-280 meV greater than that of graphene. The reduction process was optimized by varying the AFM probe velocity between 1.2 μm.s^-1 and 12 μm.s^-1 and the bias voltage applied to the sample between -8 and -12 V. The electrostatic field required to remove fluorine from carbon is -1.6 ***-1. Reduction of the fluorine may be due to the softening of the c-F bond in this intense field or to the accumulation and hydrolysis of adventitious water into a meniscus.

关键词： graphene fluoride graphene electrostatic lithography Kelvin force probemicroscopy atomic force microscopy-based electrostaticnanolithography(AFMEN)

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周恩来的外交

1992年

作者： Ronald c.·柯让

来源：南通市图书馆图书评论

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饲料加工技术:目前的问题和挑战

国外畜牧学（饲料） 1998年第2期 29-33页

作者：高占峰 keith c.Behnke

在动物生产中饲料占据了主要的成本。因此人们在不断地努力以优化饲料加工技术来降低成本,从而提高动物的生产效益。饲料加工技术的改进是无止境的,但任何一项改进都必须以动物的生产性能的改善与否来衡量。在某些情况下,饲料加工技术... 详细信息

在动物生产中饲料占据了主要的成本。因此人们在不断地努力以优化饲料加工技术来降低成本,从而提高动物的生产效益。饲料加工技术的改进是无止境的,但任何一项改进都必须以动物的生产性能的改善与否来衡量。在某些情况下,饲料加工技术和改进不是依据动物的生产性能而是由于其他方面如行业规则或人类健康等方面的原因。其中之一就是湿-热加工的使用,如制粒、膨化、烤制等以减少饲料中微生物的数量。业已证明这些加工工艺可使微生物达到或接近完全杀灭,而几乎不影响人体健康。

关键词：粉碎混合营养均匀性制粒饲料加工

Self-Diffusion of Fluids confined in Ordered and Disordered Microporous carbons

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GRADE在系统评价中应用的必要性及注意事项

第十届全国计算(机)化学学术会议

作者： Joshua D.Moore Jeremy c.Palmer Thomas J.Roussel keith E.Gubbins Institute for computational Science & Engineering and Department of chemical and Biomolecular Engineering North Carolina State UniversityRaleighNC 27695 U.S.A Institut de ciencia de Materials Consejo Superior de Investigaciones CientificasCampus de la UAB 08193 BellaterraBarcelonaSpain

Microporous carbons have found numerous applications in the areas of chemistry, chemical engineering and materials science due to their potential for use in separation and storage of *** activated carbons are an example of a disordered microporous *** have found widespread use in industry due to their low production cost and high adsorption *** co.’s bituminous coal-based carbon(BPL) is among the most widely studied and has been used extensively in environmental applications as an adsorbent for the removal of toxic and odorous industrial *** the Hybrid Reverse Monte carlo method,Palmer et *** recently developed a morphologically realistic model of BPL,that successfully predicts the adsorptive properties of the real material. A second class of materials which has had recent interest are carbon templates of silica materials such as McM-41,SBA-15 or various *** type of material is inherently highly ordered.A carbon replica of the zeolite Faujasite(c-FAU) has shown potential application in the areas of hydrogen storage and in the development of hydrogen fuel cells. Using a mimetic Grand canonical Monte carlo templating process,Roussel et *** modeled c-FAU and compared its structural and adsorptive properties with experiment. Using microcanonical molecular dynamics simulations,we compare the self-diffusion of fluids confined in the model BPL and c-FAU and show that the microporous features of the materials lead to multi-modal diffusion *** also compare to the diffusion of fluids in a carbon nanotube(cNT) bundle,which has distinct bimodal diffusion,with Fickian diffusion occurring inside the cNTs and single-file diffusion occurring in *** show that the diffusion of fluids in the ordered(c-FAU) and disordered(BPL) microprous carbons possess both slower(quasi-single-file) and faster(Fickian) diffusion modes.

关键词： bituminous coal-based carbon BPL bimodal diffusion carbon replica Faujasite carbon nanotube bundle single-file diffusion Fickian diffusion

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中国循证医学杂志 2013年第12期13卷 1401-1404页

作者：陈耀龙姚亮 Susan norris 杜亮陈昊曾宪涛毛智杨克虎兰州大学循证医学中心/GRADE中国中心兰州大学基础医学院兰州730000 世界卫生组织指南评审委员会秘书处日内瓦四川大学华西医院中国循证医学中心成都610041 南京中医药大学第二临床医学院南京210000 湖北医药学院附属太和医院口腔科/循证医学中心湖北十堰441000 解放军总医院北京100853

本文通过具体实例分析了为何需要在系统评价中应用GRADE分级的原因,以及在使用过程中可能存在的误区与注意事项,主要包括:如何区分指南和系统评价中GRADE的不同应用,如何确定总的证据质量分级,是否应对单个研究进行分级,RcT和观察性研... 详细信息

本文通过具体实例分析了为何需要在系统评价中应用GRADE分级的原因,以及在使用过程中可能存在的误区与注意事项,主要包括:如何区分指南和系统评价中GRADE的不同应用,如何确定总的证据质量分级,是否应对单个研究进行分级,RcT和观察性研究分级的差异,分级条目权重的考虑,升降级级数的考虑和可能影响GRADE分级结果的因素,以期为正确理解和应用GRADE分级提供一定参考。

关键词： GRADE 证据分级系统评价

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前列腺癌近距离放疗41例疗效回顾

中华男科学杂志 2004年第5期10卷 371-373页

作者：白强王益鑫 keith W Kaye 上海第二医科大学附属仁济医院泌尿外科上海200001 西澳大利亚州医学院泌尿外科研究中心

目的 :观察早期局限性前列腺癌12 5I近距离放疗的临床效果。　方法 :对 4 1例确诊的局限性前列腺癌患者进行前列腺内12 5I植入。采用两步法 ,即治疗前进行前列腺体积研究 ,确定前列腺各部位放射量 ,处方剂量 16 0Gy;治疗中直肠超声波探... 详细信息

目的 :观察早期局限性前列腺癌12 5I近距离放疗的临床效果。　方法 :对 4 1例确诊的局限性前列腺癌患者进行前列腺内12 5I植入。采用两步法 ,即治疗前进行前列腺体积研究 ,确定前列腺各部位放射量 ,处方剂量 16 0Gy;治疗中直肠超声波探头和c臂X线协助定位 ,专职护士长期随访。　结果 :获得长期随访 (3～ 4年 ) 33例(80 % ) ,其中 2例 (6 % )前列腺特异抗原 (PSA)升高者经穿刺确诊肿瘤局部复发 ,无死亡病例。早期并发症主要为尿路刺激症状 ,6个月内症状严重 ,1年以后症状消失。　结论 :前列腺近距离放疗生存率高 ,有短期尿路刺激症状 ,长期并发症少。

关键词：前列腺癌 ^125I 生存率并发症

Acid-Functionalized Nanoparticles for Pretreatment of Wheat Straw

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Journal of Biomaterials and Nanobiotechnology 2012年第3期3卷 342-352页

作者： Leidy Pena Myles Ikenberry keith L.Hohn Donghai Wang Department of Biological and Agricultural Engineering Kansas State UniversityManhattanUSA Department of chemical Engi-neering Kansas State UniversityManhattanUSA

Perfluoroalkylsufonic (PFS) and alkylsufonic (AS) acid-functionalized magnetic nanoparticles were synthesized and characterized, then evaluated for their ability to hydrolyze hemicelluloses. The magnetic core was made of cobalt spinel ferrite and was coated with silica to protect it from oxidation. The silanol groups allowed surface chemical modification of the nanoparticles with the PFS and AS acid functionalities. Thermogravimetric analysis gave a total organic load of 12.6% and 32.5% (w/w) for AS and PFS nanoparticles, respectively. The surface sulfur content was calculated from XPS analysis as 1.37% and 1.93% for PFS and AS nanoparticles, respectively. Wheat straw samples were treated with the acid-functionalized nanoparticles at two different conditions: 80℃ for 24 h and 160℃ for 2 h. These experiments aimed to hydrolyze wheat straw hemicelluloses to soluble oligosaccharides. PFS nanoparticles solubilized significantly higher amounts of hemicelluloses (24.0% ± 1.1%) than their alkyl-sulfonic counterparts (9.1% ± 1.7%) at 80℃, whereas the hydrothermolysis control solubilized 7.7% ± 0.8% of the original hemicelluloses in the sample. At 160℃, PFS and AS nanoparticles gave significantly higher amounts of oligosaccharides (46.3% ± 0.4% and 45 ± 1.2%, respectively) than the control (35.0% ± 1.8%). The hemicelluloses conversion at 160?c reached 66.3% ± 0.9% using PFS nanoparticles and 61.0% ± 1.2% using AS nanoparticles compared with the control experiment, which solubilized 50.9% ± 1.7% of hemicelluloses in the biomass.

关键词： Acid-Functionalized Magnetic Nanoparticles Biomass Hemicelluloses Hydrolysis

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六西格玛在卡特彼勒的成功

首席财务官 2011年第5期9卷 72-75页

作者： keith T.Jones clement c.chen 伊利诺伊州立大学密西根大学福林特分校

在自上而下的推动之下，卡特彼勒取得了六西格玛的成功，而且即使在管理层更替之后，这种成功还在继续。

关键词：六西格玛成功卡特管理层