Dissociated cell suspensions ofCarcinus maenas Y-organs as a tool to study ecdysteroid production and its regulation

In vitro ecdysteroid production by dissociated Y-organ cells of the shore crabCarcinus maenas was characterized during short-term incubations. Under optimized conditions (M199 adjusted to crab osmolality and with the addition of 10% foetal calf serum), ecdysteroid production by dispersed cells increased linearly during 4-hour incubations, with little intra-assay variation. 25-deoxyecdysone was mainly produced. PurifiedCarcinus molt inhbiting hormone (CamMIH) produced a dose-dependent inhibition of ecdysteroid production by dispersed cells. The cells were about 50 times more sensitive than whole glands to MIH. Other structurally-related peptides were tested.     

智能化温度测控系统的研制方法

本文通过一个微机控制系统的介绍,阐述了智能化温度测控系统的研制方法。该控制系统的主要特点是;硬件方面,输入端采用GBS型信号隔离变送单元,它选用国外先进的变送集成块,运用高速光电隔离,输出端采用具有光电隔离的固态继电器。软件方面,采用了给定值自动设定,教字PID调节算法和PID调节参数的自动寻优,四点中心差分法数字滤波以及控制固态继电器的通断率等措施,成功地解决了温度控制系统响应速度慢的问题。     

PM40电脑温度控制仪软件

本文解剖分析了用于窑炉控温的意大利RM40型电脑温度控制仪(以下简称RM40)的软件.RM40采用Z80CPU,为微机控制方式.程序存贮量为4k,由23个子程序组成.它具有响应快、精度高、掉电记忆、自动报警、稳定性好、调整方便等优点,还可与外设主机联络,是国内外目前控制窑炉温度的理想设备.掌握工作原理及设计思想,有利于维修及逐步实现国产化.     

盐胁迫及其钙调节对竹子根系活力和丙二醛含量的影响

选用了６个竹种进行耐盐性研究。在盐胁迫下，各竹种的根活力有所下降，竹笋和叶片中ＭＤＡ则随之积累。然而多数竹种盐胁迫表现出一定的适应性。随着处理时间延长，根活力得到部分回复，膜脂过氧化程度减轻。盐胁迫下竹种之间根活力和ＭＤＡ、含量变化存在一定的差异。Ｃａ＾２＋对翠竹的氯化钠盐害有明显的缓解作用。Ｃａ＾２＋处理可显著地抑制氯化钠诱导的ＭＤＡ积累，部分恢复盐胁迫下的根系活力。     

Plant thioredoxins: the multiplicity conundrum

Thioredoxins are small proteins distinguished by the presence of a conserved dicysteine active site. In oxidized thioredoxin, the two cysteines form a disulfide bond that is targeted by the enzyme thioredoxin reductase. Together with an electron donor, thioredoxin and thioredoxin reductase form the 'thioredoxin system' that is present in all organisms. Thioredoxins participate in dithiol/disulfide exchange reactions with a large range of cellular substrates. Higher plants possess a very complex thioredoxin profile consisting of at least two different thioredoxin systems that contain distinct, multigenic thioredoxin classes which have different intracellular localizations. In this review we summarise the current state of knowledge regarding the function of plant thioredoxins representing all systems and classes. Received 30 October 2001; received after revision 13 December 2001; accepted 17 December 2001     

Introns in higher plant genes

The intron is an important component of eukaryotic gene. Extensive studies have been conducted to get a better understanding of its structure and function. This paper presents a brief review of the structure and function of introns in higher plant genes. It is shown that higher plant introns possess structural properties shared by all eukaryotic introns, however, they also exhibit a striking degree of diversity. The process of intron splicing in higher plant genes involves interaction between multiple cis-acting elements and trans-acting factors, such as 5′ splicing site, 3′ splicing site and many protein factors. The process of intron splicing is an important level at which gene expression is regulated. Especially alternative splicing of intron can regulate time and space of gene expression. In addition, some introns in higher plant genes also regulate gene expression by affecting the pattern of gene expression, enhancing the level of gene expression and driving the gene expression.     

用Word模版编辑科技论文

编辑是一项十分繁琐、细致的工作,一份期刊中的论文表现形式,更能一目了然地判断刊物编辑工作者编辑质量的优劣.为了确保格式上的一致、规范,减少编辑中出错几率,提供一个统一格式,供作者投稿、修改使用,可以达到事半功倍的效果.同时从长远来说,格式模版的信息可以重复使用,从而可望一劳永逸.     

离子液体的特点及在液-液萃取中的应用研究

介绍了离子液体的定义、组成、产生及特点,阐述了离子液体应用于液-液萃取中所存在的问题.     

浅析煤矿井下低压供电系统

从4个方面阐述了煤矿井下低压供电系统存在的问题,并提出了相应的改进办法。     

我国公安行政调解的规范与完善

与其它非诉纠纷解决机制相比,公安行政调解具有独特的优势。但公安行政调解尚存在违反自愿原则、扩大调解范围、调解与处罚并用等问题,因此,我们应当科学定位并合理规范公安行政调解行为,以化解矛盾与纠纷,推动基层基础建设,增进社会和谐。