Simplification and analysis of models of calcium dynamics based on IP3-sensitive calcium channel kinetics.

We study the models for calcium (Ca) dynamics developed in earlier studies, in each of which the key component is the kinetics of intracellular inositol-1,4,5-trisphosphate-sensitive Ca channels. After rapidly equilibrating steps are eliminated, the channel kinetics in these models are represented by a single differential equation that is linear in the state of the channel. In the reduced kinetic model, the graph of the steady-state fraction of conducting channels as a function of log10(Ca) is a bell-shaped curve. Dynamically, a step increase in inositol-1,4,5-trisphosphate induces an incremental increase in the fraction of conducting channels, whereas a step increase in Ca can either potentiate or inhibit channel activation, depending on the Ca level before and after the increase. The relationships among these models are discussed, and experimental tests to distinguish between them are given. Under certain conditions the models for intracellular calcium dynamics are reduced to the singular perturbed form epsilon dx/d tau = f(x, y, p), dy/d tau = g(x, y, p). Phase-plane analysis is applied to a generic form of these simplified models to show how different types of Ca response, such as excitability, oscillations, and a sustained elevation of Ca, can arise. The generic model can also be used to study frequency encoding of hormonal stimuli, to determine the conditions for stable traveling Ca waves, and to understand the effect of channel properties on the wave speed.     

Overall Informativity,OI, in DNA Polymorphisms Revealed by inter-AluPCR: Detection of Genomic Rearrangements

We studied two systems of multilocus markers revealed by PCR using primers directing amplification betweenAlurepeats in a tail-to-tail orientation. Genomic polymorphisms were detected as the presence or absence of the electrophoretic bands representing DNA fragments of a given length. A total of 104 such fragments segregating as Mendelian markers in a panel of eight CEPH families were analyzed by two-point linkage analysis. Fifty-one of these fragments were localized with respect to CEPH markers; they represented 33 loci, 7 of which were multiallelic. Locus-specific oligonucleotides were developed and used as hybridization probes to identify the mapped loci within a complex pattern of inter-AluPCR products. A great proportion of inter-AluPCR polymorphisms represented length variants within amplified DNA segments, while others were presumably due to mutations within the priming sites. To describe the expected number of informative loci per typing experiment we introduced a parameter called overall informativity (OI), which provides a single measure of the multiplex ratio and the informativity of markers contributing to a multilocus system (OIof a single locus is equivalent to its heterozygosity and cannot exceed 0.5 for a biallelic codominant marker). HighOIvalues (5.8 and 11.5) of the two presented systems of inter-AluPCR markers of random chromosomal distribution render them suitable for mapping genomic rearrangements such as genomic deletions in tumoral tissues. This was illustrated by the detection of loss of heterozygosity in the 9q22–qter region in sporadic colon cancer.     

水杉人工林树冠结构及生物生产力的研究

研究了水杉人工林的树冠结构和林分生物生产力。结果表明,不同密度及林龄的林分树冠结构存在较大差异,随着树冠部位上升和林分密度增大,分枝角度逐渐减小;径阶大小与枝叶率成反比,与树冠重量成正比,径阶增大,树冠最大叶量层的集团上移,有效光合面积相对减少,树冠结构的变化直接影响到林分的生物量生产、分配分配和经济生物量,林分干、枝、叶的干物质累积趋势可用Ｒｉｃｈａｒｄ方程描述;林龄增大,分配到主干的生物量比例     

江苏野菜资源的利用与开发

江苏野菜资源丰富,共计１９２种,隶属４４科１０８属,其中蕨类植物７科１５属５１种,种子植物３７科９３属１４１种。江苏野菜利用历史悠久,近年已发展成为规模种植,产生良好的经济效益和社会效益。     

东方法老蛛雌蛛的描述（蜘蛛目：跳蛛科）

报道采自甘肃文县的东方法老蛛雌蛛,为该种雌蛛的首次记述。     

复合氨基酸治疗眼角膜溃疡的研究

复合氨基酸在临床上的应用越来越被人们重视,我们利用水解猪血粉的方法得到含１７种氨基酸的复合液,配制成滴眼剂用于多种原因引起的眼角膜溃疡疾病的治疗研究取得了较好的效果。     

以淀粉珠为载体的亲和层析法分离纯化高温α淀粉酶

 以淀粉珠为载体的亲和层析法分离纯化高温α淀粉酶张学忠,宋伦,王群,吴晓霞,唐锌进（吉林大学酶工程国家重点实验室,长春１３００２３;南京师范大学生物系,南京２１００２４）金凤燮等人从酒曲中筛选出高产热稳定α淀粉酶的菌株,命名为Ｂａｃｉｌｌｕｓｓｐ－ＪＦ...     

Bi（Ⅲ）与金属硫蛋白作用性质研究

 Ｂｉ（Ⅲ）与金属硫蛋白作用性质研究张保林,黄辉,朱凌燕,岳晟,唐雯霞（南京大学配位化学研究所,配位化学国家重点实验室,南京２１００９３）如何降低顺铂或其它抗癌铂的毒性,一直是癌症化疗中的重要课题之一,最近研究发现预先给大鼠或肺癌病人服用铋盐,可以极大...     

湿地松粉蚧夏季数量凋落的原因分析

利用生命表技术及其相应的控制指数分析方法,对新侵入害虫湿地松粉蚧Ｏｒａｏｅｌｌａａ－ｃｕｔａ（Ｌｏｂｄｅｌｌ）夏季数量凋落的某些因子进行了量化分析。结果表明：在广东南部的新侵入区,夏季高温引起的松梢迅速老化,上代为害以后引起的营养质量的变化、拥挤以及煤污病的严重发生等,均对湿地松粉蚧夏季种群数量的凋落有着明显的影响,其总的排除作用控制指数ＥＩＰＣ为４６．８９,如果排除这几个因子的作用,下代种群的数量将为当代的４６．８９倍。     

How effective is nicotine replacement therapy in helping people to stop smoking?

OBJECTIVE--To assess the efficacy of nicotine replacement therapy in helping people to stop smoking. DESIGN--Analysis of the results of 28 randomised trials of nicotine 2 mg chewing gum, six trials of nicotine 4 mg chewing gum, and six trials of nicotine transdermal patch. SUBJECTS AND SETTING--Subjects were self referred (responding to advertisements or attending anti-smoking clinics) in 20 trials and invited (general practice or hospital patients) in 20. Therapists in self referred trials were generally experienced in helping people stop smoking but not in invited trials. MAIN OUTCOME MEASURE--Efficacy was defined as difference in percentages of treated and control subjects who had stopped smoking at one year. RESULTS--Efficacy was highly significant (P < 0.001) for both gum and patch. Nicotine 2 mg chewing gum had an overall efficacy of 6% (95% confidence interval 4% to 8%), greater in self referred subjects than in invited subjects (11% v 3%). Efficacy depended on the extent of dependence on nicotine as assessed by a simple questionnaire; it was 16% (7% to 25%) in "high dependence" smokers, but in "low dependence" smokers there was no significant effect. The 4 mg gum was effective in about one third of "high dependence" smokers. The efficacy of the nicotine patch (9% (6% to 13%) overall) was less strongly related to nicotine dependence, perhaps because the patch cannot deliver a bolus of nicotine to satisfy craving. CONCLUSIONS--Both gum and patch are effective aids to help nicotine dependent smokers who seek help in stopping. Among the most highly nicotine dependent smokers (those craving a cigarette on waking) the 4 mg gum is the most effective form of replacement therapy; it could enable one third to stop. In less highly dependent smokers the different preparations are comparable in their efficacy but the patch offers greater convenience and minimal need for instruction in its use. Overall, nicotine replacement therapy could enable about 15% of smokers who seek help in stopping smoking to give up the habit.