878 resultados para ALLYL ISO-THIOCYANATE


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The International Organization for Standardization (ISO) method 5136 is widely used in industry and academia to determine the sound power radiated into a duct by fans and other flow devices. The method involves placing the device at the center of a long cylindrical duct with anechoic terminations at each end to eliminate reflections. A single off-axis microphone is used on the inlet and outlet sides that can theoretically capture the plane-wave mode amplitudes but this does not provide enough information to fully account for higher-order modes. In this study, the "two-port" source model is formulated to include higher-order modes and applied for the first three modes. This requires six independent surface pressure measurements on each side or "port." The resulting experimental set-up is much shorter than the ISO rig and does not require anechoic terminations. An array of six external loudspeaker sources is used to characterize the passive part of the two-port model and the set-up provides a framework to account for transmission of higher-order modes through a fan. The relative importance of the higher-order modes has been considered and their effect on inaccuracies when using the ISO method to find source sound power has been analyzed.

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Teleost vitellogenins (VTGs) are large multidomain apolipoproteins, traditionally considered to be estrogen-responsive precursors of the major egg yolk proteins, expressed and synthesized mainly in hepatic tissue. The inducibility of VTGs has made them one of the most frequently used in vivo and in vitro biomarkers of exposure to estrogen-active substances. A significant level of zebrafish vtgAo1, a major estrogen responsive form, has been unexpectedly found in heart tissue in our present studies. Our studies on zebrafish cardiomyopathy, caused by adrenergic agonist treatment, suggest a similar protective function of the cardiac expressed vtgAo1. We hypothesize that its function is to unload surplus intracellular lipids in cardiomyocytes for "reverse triglyceride transportation" similar to that found in lipid transport proteins in mammals. Our results also demonstrated that zebrafish vtgAo1 mRNA expression in heart can be suppressed by both (x-adrenergic agonist, phenylephrine (PE) and beta-adrenergic agonist, isoproterenol (ISO). Furthermore, the strong stimulation of zebrafish vtgAo1 expression in plasma induced by the beta-adrenergic antagonist, MOXIsylyl, was detected by Enzyme-Linked ImmunoSorbent Assay (ELISA). Such stimulation cannot be suppressed by taMOXIfen, an antagonist to estrogen receptors. Thus, Our present data indicate that the production of teleost VTG in vivo can be regulated not only by estrogenic agents, but by adrenergic signals as well. (c) 2009 Elsevier Inc. All rights reserved.

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Teleost vitellogenins (VTGs) are large multidomain apolipoproteins and traditionally considered as the estrogen responsive precursors of the major egg yolk proteins. We identified five clones encoding VTGs, about 16% of the random EST clones from our constructed cDNA library from Chinese rare minnow liver tissue treated with 17 beta-estradiol (E2). Full-length vtgAo1 has been obtained based on the sequence information of four partial cDNA inserts by RACE. The inducibility of the vtgAo1 expression in liver by E2 was confirmed by RT-PCR. The presence of vtgAo1 transcripts have been observed primarily in liver. However. a significant level of the vtgAo1 was found in an unexpected location, heart, particularly in atrial cells by RT-PCR and whole mount in situ hybridization analyses. The vtgAo1 mRNA expression in heart and liver tissue could be suppressed by both alpha-adrenergic agonist, phenylephrine (PE) and beta-adrenergic agonist, isoproterenol (ISO). The expression of VTG in the heart observed in the present studies suggested it may provide protection from surplus intracellular lipids in fish cardiomyocytes as triglyceride transport proteins do in mammals. The results also indicated that the production of teleost vtg in vivo can be regulated by riot only estrogenic agents, but adrenergic signals as well. (c) 2008 Elsevier B.V. All rights reserved.

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This work was aimed at the study of some physical properties of two current light-cured dental resin composites, Rok (hybrid) and Ice (nanohydrid). As filler they both contain strontium aluminosilicate particles, however, with different size distribution, 40 nm-2.5 mum for Rok and 10 nm-1 mum for Ice. The resin matrix of Rok consists of UDMA, that of Ice of UDMA, Bis-EMA and TEGDMA. Degree of conversion was determined by FT-IR analysis. The flexural strength and modulus were measured using a three-point bending set-up according to the ISO-4049 specification. Sorption, solubility and volumetric change were measured after storage of composites in water or ethanol/water (75 vol%) for 1 day, 7 or 30 days. Thermogravimetric analysis was performed in air and nitrogen atmosphere from 30 to 700 degrees C. Surface roughness and morphology of the composites was studied by atomic force microscopy (AFM). The degree of conversion was found to be 56.9% for Rok and 61.0% for Ice. The flexural strength of Rok does not significantly differ from that of Ice, while the flexural modulus of Rok is higher than that of Ice. The flexural strengths of Rok and Ice did not show any significant change after immersion in water or ethanol solution for 30 days. The flexural modulus of Rok and Ice did not show any significant change either after immersion in water for 30 days, while it decreased significantly, even after 1 day immersion, in ethanol solution. Ice sorbed a higher amount of water and ethanol solution than Rok and showed a higher volume increase. Thermogravimetric analysis showed that Rok contains about 80 wt% inorganic filler and Ice about 75 wt%.

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Based on the results of the temperature-dependent photoluminescence (PL) measurements, the broad PL emission in the phase-separated GaNP alloys with P compositions of 0.03, 0.07, and 0.15 has investigated. The broad PL peaks at 2.18, 2.12 and 1.83 eV are assigned to be an emission from the optical transitions from several trap levels, possibly the iso-electronic trap levels related to nitrogen. With the increasing P composition (from 0.03 to 0.15), these iso-electronic trap levels are shown to become resonant with the conduction band of the alloy and thus optically inactive, leading to the apparent red shift (80-160meV) of the PL peak energy and the trend of the red shift is strengthened. No PL emission peak is observed from the GaN-rich GaNP region, suggesting that the photogenerated carriers in the GaN-rich GaNP region may recombine with each other via non-radiation transitions.

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内部质量审核是实施ISO9000认证的质量保证体系的重要组成部分。文章阐述了吸取CMM模型思想在过程控制与改进方面的优势,建立企业的过程数据库,拓宽内部质量审核工作的时间与空间,寻求工作方式方法的改进与优化。

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针对软件质量评价研究中的度量问题建立了基于ISO/IEC 9126标准的软件质量指标体系模型,结合质量评价方法研究中的常见问题,运用指标体系模型和模糊数学方法对软件质量评价标准进行模糊化处理,以度量数据为基础,根据软件质量子特性和指标之间的关系,采用模糊综合评价方法评价子特性质量和特性质量,通过建立软件质量评价模型,有效地解决了软件质量的多指标评价问题,可用于指导用户进行软件过程改进.

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基于ISO/ IEC 10646和UNICODE国际标准,用传统的字体技术(如TrueType)来实现少数民族文字处理所面临的一个"瓶颈"问题是:"变形显现字符"不存在确定的码位.这也是多年来民文系统重复开发、互不兼容的根本原因.本文基于ICU的文字处理体系结构,阐述了完全支持Unicode标准的少数民族文字(本文主要指蒙古文字、维文、藏文等)的实现方法.文中首先介绍了少数民族文字的特点,分析其与拉丁文字、汉字在计算机输入、输出过程中的不同之处,并指出少数民族文字处理的难点.其次介绍了一种能满足少数民族文字处理需求的字体技术--OpenType.最后,阐述了文字处理引擎的工作原理,以及ICU中如何实现对少数民族文字的支持.

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编码字符集标准是计算机处理文字信息的基础,本文提出了编码字符集三元组抽象,对现有编码字符集标准进行了简单回顾和总结,深入剖析了影响巨大的ISO 2022标准及其派生标准,对ISO 2022编码机制应用于多语言环境的局限性进行了探讨,阐明了使用通用编码字符集UCS的必要性,并对其进行了分析.探讨了现有编码分类方法存在的问题,引入了一种对编码字符集以及实现方法进行分类的新方法,使用该方法对现有标准进行了归类;最后对汉字字符集相关的国家标准进行了分析评介.

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多年来蒙古文处理系统重复开发、互不兼容的根本原因就是没有统一的标准:编码标准不统一、字库标准不统一、输入法不统一。随着国际化、多语言化的发展,开发基于ISO/IEC10646和UNICODE国际编码标准、OpenType智能字体技术的不同语言文字处理系统已经成为趋势。本文阐述了一个蒙古文显示系统,它完全支持Unicode标准并使用了OpenType技术自动进行字形选型,其实现是基于QT库的,但核心实现很容易移植到Pango,ICU等其他复杂文本布局(CTL)处理项目中。

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国内藏文软件开发普遍使用的是基于垂直预组合字符的实现方案,但是缺乏统一的编码标准.藏文编码字符集扩充集的推出,对于国内藏文软件的标准化、国际化具有重要意义.本文通过分析ISO/IEC 10646藏文编码字符集基本集、藏文编码字符集扩充集国家标准,区分它们描述字丁的差异,分析由编码方案所导致的实现上的关键问题.最后,针对藏文扩充集B的特殊性,提出并实现了基于Linux国际化架构下支持藏文扩充集标准的解决方案.

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随着我国计算机应用水平的提高 ,Internet的迅速普及 ,GB2 31 2 - 80中的 6 76 3个汉字已不能满足应用的需要。ISO 1 0 6 46标准的制定 ,使得为开发支持大汉字字符集的中文平台提供了宽阔的代码空间。我们的工作目标就是探讨在现有的的开放系统上 ,提供支持ISO 1 0 6 46标准CJK大字符集、支持多种内码、兼容现有中文平台、与原英文系统及版本无关、符合国际、国家标准、具有一定跨平台功能、实用高效的中文平台解决方案及实现技术。本文详细阐述了该中文平台的设计目标、模块结构、以及各个子系统的实现方法

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目前流行的各种大型数据库系统都缺乏对民族语言如藏、蒙、维文的支持。如何实现民文信息在数据库中存储、查询和检索等处理及支持各种基于民文的数据库应用,是一个重要问题。本文提出了一个数据库管理系统多民族语言支持框架,支持多民族语言、数据库客户端工具和应用编程接口;并在此框架下提出了一种符合ISO/IEC 14651语义的藏文排序方法,从而实现了PostgreSQL数据库对藏文信息处理的全面支持。并在Linux平台的PostgreSQL数据库系统上加以实现。

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Here we reported the fatty-acids and their δ 13C values in seep carbonates collected from Green Canyon lease block 185 (GC 185; Sample GC-F) at upper continental slope (water depth: ∼540 m), and Alaminos Canyon lease block 645 (GC 645; Sample AC-E) at lower continental slope (water depth: ∼2200 m) of the Gulf of Mexico. More than thirty kinds of fatty acids were detected in both samples. These fatty acids are maximized at C16. There is a clear even-over-odd carbon number predominance in carbon number range. The fatty acids are mainly composed of n-fatty acids, iso-/anteiso-fatty acids and terminally branched odd-numbered fatty acids (iso/anteiso). The low δ 13C values (−39.99‰ to.32.36‰) of n-C12:0, n-C13:0, i-C14:0and n-C14:0 suggest that they may relate to the chemosynthetic communities at seep sites. The unsaturated fatty acids n-C18:2 and C18:1Δ9 have the same δ 13C values, they may originate from theBeggiatoa/Thioploca. Unlike other fatty acids, the terminally branched fatty acids (iso/anteiso) show lowerδ 13C values (as low as −63.95‰) suggesting a possible relationship to sulfate reducing bacteria, which is common during anaerobic oxidation of methane at seep sites.

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随着人类基因组计划的完成,蛋白质组学研究已成为生命科学乃至自然科学中最活跃的学科领域之一。蛋白质组学将对我们理解后基因组学时代的基因功能有极大的帮助。差异表达蛋白质组学通过对不同样品蛋白质表达水平的比较,已经被广泛地应用在疾病的研究领域。P糖蛋白已经被证实参与介导了在急性粒白血病中发生的多药耐药,然而越来越多的研究结果表明,在急性粒白血病中多药耐药的机制是多因素的。为了寻找白血病肿瘤细胞中与耐药相关的靶蛋白,我们采用蛋白质组学研究技术,对多药耐药细胞系K562/A02的蛋白质表达谱进行了分析。 本研究采用蛋白质组学研究技术,对多药耐药细胞系K562/A02和药物敏感细胞系K562/S的总蛋白质进行双向凝胶电泳(2 DE)的差异分析,结果发现在K562/A02细胞中有41个蛋白质点差异显著,并用基质辅助激光解离飞行时间质谱(MALDI-MS)成功鉴定了大多数的蛋自点。在被鉴定出的差异蛋白质中,有一些是首次发现与耐药相关,包括chloride intracellular charmel,chaperonin,proteindisulfide-isomerase ER6o precursor and constitutive heat shock protein 70等。所得结果不但能够使我们更加深入的理解肿瘤耐药的病理机制,更重要的是通过找到肿瘤细胞发生耐药的标志性蛋白,可以为开发肿瘤耐药预测方法和寻找抗耐药肿瘤靶标新药的线索,同时也为计算机虚拟筛选设计抗耐药肿瘤新药奠定基础。除了详细的研究了K562/A02细胞系差异蛋白质组,我们还采用蛋白质组学的方法,以乳鼠心肌细胞为实验模型,研究在ARs激动的不同清况下心肌细胞蛋白质表达谱的变化。心肌肥厚是心脏工作超负荷的一种代偿反应。目前,越来越多的证据表明ARs在心肌肥厚的发生中起着非常重要的作用,但人们对其机制了解尚不全面。通过检测心肌肥厚时全蛋白表达的变化,将有助于我们全面、深入了解ARs在心肌肥厚中的作用机制。通过严格的2D胶图象分析,蛋白取点后胶内水解,高灵敏度的质谱鉴定及数据库检索,我们成功地进行了乳鼠心肌细胞肥厚为模型的蛋白质组学的研究。本实验通过比较研究不同肾上腺素受体激动剂norePinephrine伽E),phenylephxine(PE)and isoprenaline(ISO)诱导组与未诱导对照组的蛋白质组学变化,分析确定蛋白丰度差异在2倍以上的蛋白质点,并通过MALDI-MS进行蛋白鉴定。20个具有显著差异的蛋白质被鉴定,包括caspase-11,vimeniin,4-hydroxyphenylpyruvic acid dioxygenase,Modl protein,Txndcs protein等,其中一些蛋白在此之前并没发现与心肌肥厚相关,对它们在心肌肥厚中的意义和机制我们将做进一步的探讨。本研究结果将为我们更好理解肾上腺素受体之间以及肾上腺素受体与心肌肥厚之间的关系提供有益的线索,并将为最终发现可应用于临床的新的诊断和治疗心血管疾病的标志性蛋白打下基础。