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关键词： YCR041W   Chromosome engineering   Sir4   Zds1   Yeast artificial chromosome   PCR-mediated chromosome splitting   Mini-chromosome   Chromosome segregation  

摘要： Chromosome engineering enables large-scale genome manipulation and can be used as a novel technology for breeding of yeasts. PCR-mediated chromosome splitting (PCS) offers a powerful tool for chromosome engineering by enabling a yeast chromosome to be split at any desired site. By applying PCS, a huge variety of chromosome combinations can be created and the best strain under specific conditions can be selected a technology that we have called genome reorganization. Once the optimal strain is obtained, chromosome constitutions need to be maintained stably;however, mini-chromosomes of less than 50 kb are at relatively high frequency lost during cultivation. To overcome this problem, in this study we screened for multicopy suppressors of the high loss of mini-chromosomes by using a multicopy genomic library of Saccharomyces cerevisiae. We identified a novel gene, YCR041W, that stabilizes mini-chromosomes. The translational product of YCR041W was suggested to play an important role in increasing stability for mini-chromosome maintenance, probably by decreasing the rate of loss during mitotic cell division. The stabilization of mini-chromosomes conferred by YCR041W overexpression was completely dependent on the silencing protein Sir4, suggesting that a process related to telomere function might be involved in mini-chromosome stabilization. Overexpression of YCR041W stabilized not only a yeast artificial chromosome vector, but also a mini-chromosome derived from a natural chromosome. Taking these results together, we propose that YCR041W overexpression can be used as a novel chromosome engineering tool for controlling mini-chromosome maintenance and loss. (C) 2014, The Society for Biotechnology, Japan. All rights reserved.

关键词： 探究   生物分离工程   实验教学   运用  

摘要： 根据学院应用型和工程化的办学理念,结合多年生物分离工程课程教学经验,我们对探究式教学在这门课中的运用进行了探讨和实践。重视和鼓励学生的质疑、建立探究式的课堂氛围以及构建开放式的实验室等一系列改革举措可以充分调动学生学习这门课的主动性和创新性,同时也培养了他们从事研究探索活动的思维品质。

关键词： 分离工程   多层次   课程体系  

摘要： 介绍了在化工专业开展分离工程多层次课程体系建设的探索与实践。针对化工专业从专科到本科(一本,二本和英才班)等不同层次的分离工程课程教学,阐述了构建适应不同层次培养需要的课程体系的必要性及可行性,提出了按照各类基础研究型人才、应用技术型人才和一般技术人才的培养定位,设计难易有别、基础与应用并重、统一性与灵活性兼备的分离工程课程体系结构,并根据课程体系设计要求改革教学内容和教学方法。

关键词： 膜分离   技术   环境   工程  

摘要： 随着近些年新科学技术的发展,我国在膜分离技术方面已经有着很大的突破和进展。我国的膜分离技术在很多领域都有所应用,其中环境工程当中应用较为广泛,膜分离技术具有低能高效、工艺精简、生产过程无污染、无化学变化等特点,这些都是膜分离技术的最大特点。本文笔者对膜分离技术进行简单的技术概述,并对环境工程中膜分离技术的应用进行具体的阐述和分析。

关键词： 教考分离   有机化学   开放式试题库  

摘要： 考试是教学过程中的一个重要环节,教学质量是高等教育的生命线。考试文化是校园文化的重要组成部分,良好考风对学校校风、教风、学风建设及教学质量提高都具有积极的推动作用。本文分析了目前高校理论课考试的几种形式与存在的一些问题,阐述了实施质量工程背景下基于教考分离的基础有机化学开放式试题库建设的思路与应用方法,提出了开放式试题库建设中需要处理好的几个问题。笔者认为高校理论课考试中实行教考分离势在必行,开放式试题库对教师提高教学质量,引导学生自主学习、主动学习,发挥学生的主动性和能动性,培养学生综合能力等诸多方面有积极意义。

关键词： LIQUEFIED natural gas  

摘要： The article reports on the Ichthys Liquefied Natural gas (LNG) project which is a joint venture (JV) between several firms including INPEX Corp., Tokyo Gas Co. Ltd., Osaka Gas Co. Ltd., and Chubu Electric Power Co. Inc. Topics discussed include electrical equipment in hazardous areas (EEHA), diesel processing by OSE separators, and floating production, storage and offloading (FPSO).

关键词： 石脑油正异构分离   炼化一体化   催化重整   蒸汽裂解   方案优化  

摘要： 炼化一体化工程一般将直馏石脑油作为蒸汽裂解装置和催化重整装置的原料,虽然催化重整和蒸汽裂解装置的原料都是石脑油,但两个装置对于原料组成的要求却差别很大,石脑油正异构分离装置可同时优化催化重整和蒸汽裂解装置的原料,使石脑油的利用效率达到最优。该技术可以分别为两个装置提供适宜的原料,将石脑油分离为富含正构烷烃的抽出液和富含非正构烷烃的抽余液,抽出液是优质的蒸汽裂解原料,而抽余液的芳烃潜含量较高,是优质的催化重整原料。本文探讨了通过该装置提高全厂经济效益的可行性,石脑油正异构分离装置分离出的抽出液中,正构烷烃含量为93.0%;抽余液中分离出的轻石脑油中,异构烷烃、环烷烃和芳烃的含量高达84.9%,C6~C10组分的芳烃潜含量为49.0%。与基础方案相比,抽出液做蒸汽裂解原料可以提高乙烯收率47.16%,轻石脑油的RON值提高12个单位,达到80左右,C6~C10组分进催化重整装置可以提高对二甲苯收率14.09%。

关键词： 快速检测   纤维素   生物医学工程材料   医用纱布   成分   化学合成纤维   铜氨溶液   掺假  

摘要： 目的：建立用铜氨溶液溶解法快速检测医用脱脂棉纱布和脱脂棉粘胶混纺纱布中化学合成纤维掺假。方法：将样品剪成小块并拆成独立的纱线,采用氢氧化铜-氨水（0.25 g∶25 m L）的铜氨溶液,在透明PET瓶中采用人工或机械方式对瓶体不断振荡（振荡的频率均为200次·min-1）常温溶解棉与粘胶纤维,保留化学合成纤维,并对残留纤维进一步鉴别。结果：采用该方法可以在10 min内对待测纱布的掺杂化学合成纤维情况进行判断,加标回收试验中测得回收率为98.1%-99.7%,RSD为0.82%-1.8%。检测了50批纱布,发现有15批含有不溶性纤维,其化学合成纤维含量在5%-12%之间。结论：本方法经方法学验证可用于此类产品掺假的现场和实验室快速检测。

关键词： Medium Fe-Mn alloy   Embrittlement   Grain boundary segregation   3-D atom probe tomography   Austenite reversion  

摘要： We study grain boundary embrittlement in a quenched and tempered Fe Mn high-purity model martensite alloy using Charpy impact tests and grain boundary characterization by atom probe tomography. We observe that solute Mn directly embrittles martensite grain boundaries while reversion of martensite to austenite at high-angle grain boundaries cleans the interfaces from solute Mn by partitioning the Mn into the newly formed austenite, hence restoring impact toughness. Microalloying with B improves the impact toughness in the quenched state and delays temper embrittlement at 450 degrees C. Tempering at 600 degrees C for 1 min significantly improves the impact toughness and further tempering at lower temperature does not cause the embrittlement to return. At higher temperatures, regular austenite nucleation and growth takes place, whereas at lower temperature, Mn directly promotes its growth. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.