Progress in modeling of protein structures and interactions

The prediction of the structures and interactions of biological macromolecules at the atomic level and the design of new structures and interactions are critical tests of our understanding of the interatomic interactions that underlie molecular biology. Equally important, the capability to accurately predict and design macromolecular structures and interactions would streamline the interpretation of genome sequence information and allow the creation of macromolecules with new and useful functions. This review summarizes recent progress in modeling that suggests that we are entering an era in which high-resolution prediction and design will make increasingly important contributions to biology and medicine.     

单缸柴油机交流电起动装置的设计

研究开发了适用于单缸柴油机的交流电起动装置.阐述了该装置的设计思路及功率计算方法,提供了该机型在低温下的起动阻力矩实验数据.     

北京地区舞毒蛾寄生性天敌昆虫及其转主寄主的研究

我国舞毒蛾天敌昆虫已有较系统的报道,但对其天敌昆虫的转主寄主研究和报道较少.该文针对北京地区舞毒蛾的17种寄生性天敌,在查阅文献、野外调查和室内饲养的基础上,对这些寄生性天敌昆虫的生物学和它们在北京地区危害林木的转主寄主作一报道.卵期主要寄生性天敌大蛾卵跳小蜂,室内饲养可繁殖4～5代,羽化的成蜂可继续在舞毒蛾卵块中寄生.舞毒蛾平腹小蜂转主寄主有油松毛虫、斑衣蜡蝉、绿尾大蚕蛾.幼虫期主要寄生性天敌毒蛾绒茧蜂一年发生4代,转主寄主有黄褐天幕毛虫、油松毛虫、杨毒蛾.黑腿绒茧蜂转主寄主为柳毒蛾.黑足凹眼姬蜂转主寄主为油松毛虫、古毒蛾、角斑古毒蛾.幼虫及蛹期主要寄生性天敌为毛虫追寄蝇和日本追寄蝇,其中,毛虫追寄蝇转主寄主有杨扇舟蛾(寄生率高达36%～50%)、柳毒蛾、黄褐天幕毛虫、腰带燕尾舟蛾;日本追寄蝇一年可发生3～4代,转主寄主有柳毒蛾、杨扇舟蛾、油松毛虫、腰带燕尾舟蛾.蛹期主要寄生性天敌舞毒蛾黑瘤姬蜂的转主寄主有:油松毛虫、黄褐天幕毛虫、杨扇舟蛾、臭椿皮蛾、樗蚕、丝棉木金星尺蛾、侧柏毒蛾等.脊腿囊爪姬蜂转主寄主有:油松毛虫、杨毒蛾、黄褐天幕毛虫.广大腿小蜂由于其寄主广泛,也可成为螟蛉绒茧蜂、松毛虫黑胸姬蜂、螟蛉悬茧姬蜂的重寄生昆虫.     

北京地区舞毒蛾寄生性天敌昆虫及其转主寄主的研究

我国舞毒蛾天敌昆虫已有较系统的报道 ,但对其天敌昆虫的转主寄主研究和报道较少 .该文针对北京地区舞毒蛾的 17种寄生性天敌 ,在查阅文献、野外调查和室内饲养的基础上 ,对这些寄生性天敌昆虫的生物学和它们在北京地区危害林木的转主寄主作一报道 .卵期主要寄生性天敌大蛾卵跳小蜂 ,室内饲养可繁殖 4～ 5代 ,羽化的成蜂可继续在舞毒蛾卵块中寄生 .舞毒蛾平腹小蜂转主寄主有油松毛虫、斑衣蜡蝉、绿尾大蚕蛾 .幼虫期主要寄生性天敌毒蛾绒茧蜂一年发生 4代 ,转主寄主有黄褐天幕毛虫、油松毛虫、杨毒蛾 .黑腿绒茧蜂转主寄主为柳毒蛾 .黑足凹眼姬蜂转主寄主为油松毛虫、古毒蛾、角斑古毒蛾 .幼虫及蛹期主要寄生性天敌为毛虫追寄蝇和日本追寄蝇 ,其中 ,毛虫追寄蝇转主寄主有杨扇舟蛾 (寄生率高达 36 %～ 5 0 % )、柳毒蛾、黄褐天幕毛虫、腰带燕尾舟蛾 ;日本追寄蝇一年可发生 3～ 4代 ,转主寄主有柳毒蛾、杨扇舟蛾、油松毛虫、腰带燕尾舟蛾 .蛹期主要寄生性天敌舞毒蛾黑瘤姬蜂的转主寄主有 :油松毛虫、黄褐天幕毛虫、杨扇舟蛾、臭椿皮蛾、樗蚕、丝棉木金星尺蛾、侧柏毒蛾等 .脊腿囊爪姬蜂转主寄主有 :油松毛虫、杨毒蛾、黄褐天幕毛虫 .广大腿小蜂由于其寄主广泛 ,也可成为螟蛉绒茧蜂、松毛虫黑胸姬蜂、螟蛉悬?     

建水县柑桔大小年结果的原因及防治对策

<正>柑桔大小年结果就是大年开花多,坐果多,消耗的养分多,抑制了枝叶生长;小年就是第2年结果母枝减少,产量低;但枝叶生长旺盛,当年抽生较多的结果母枝,下一年就会变成大年,如此大小年交替循环。柑桔大小年结果现象是建水县柑桔生产中普遍存在的问题,对柑桔生产影响较大,是制约建水县柑桔生产稳步发展的重要因素。     

Acetylcholine and cholinacetylase content of synaptic vesicles

Acetylcholine, cholinacetylase, and acetylcholinesterase were determined in three subfractions that resulted from the osmotic shock of the "mitochondrial" fraction of the rat brain. Acetylcholine and cholinacetylase were found concentrated in the subfraction that contained mainly synaptic vesicles and some membranes, whereas the larger proportion of the acetylcholinesterase was observed in the subfraction that contained torn nerve endings. These results support the idea that synaptic vesicles are the morphological units of acetylcholine within the synapse.     

The structural organization of the readily releasable pool of synaptic vesicles

The defining morphological feature of chemical synapses is the vesicle cluster in the presynaptic nerve terminal. It has generally been assumed that vesicles closest to release sites are recruited first during nerve activity. We tested this by selectively labeling the "readily releasable" pool, those vesicles released first during physiological stimulation. The readily releasable vesicles were not clustered close to the presynaptic membrane but instead were dispersed almost randomly throughout the vesicle cluster. Thus, vesicles are not recruited according to proximity to release sites but are mobilized differently, perhaps by being peeled from the surface of the cluster.     

陇县不同烟草品种对赤星病的抗性以及品种筛选

[目的]筛选出对烟草赤星病抗性较好的烟草品种,从而提高烟叶的产量和品质,满足卷烟工业的需求.[方法]选取6个烤烟品种（豫烟10号、2819、中烟203、南江3号、云烟105、K326）进行了抗性研究.[结果]不同烟草品种对赤星病的抗性存在很大差异,豫烟10号和中烟203为中感品种;2819、南江3号和云烟105为中抗品种;K326为高抗品种.[结论]可以考虑小面积试种K326和2819,进而综合考虑筛选出符合当地的品种.     

皖南双季稻区烟稻轮作生态环境的配套技术研究

本文通过对K326、RGH51两个烤烟品种不同移栽期、不同施氮水平及配比试验研究,结果表明:皖南双季稻区烟稻轮作生态环境[1]中等肥力田块,烤烟生产以3月25—4月8日期间移栽到大田,施化学纯氮97.5-105kg/hm2,N:P2O5:K2O=1:1-1.5:3等为宜,既可保证上部叶充分成熟采烤,获得优质适产,又能适时腾茬栽插晚稻,科学地解决烟稻争茬矛盾,能充分地利用皖南烟区温光资源,获得烟稻轮作双丰收。     

芦竹内生真菌F0238对烟草赤星病的防治作用

从黄海岸芦竹(Arundo donax)中分离得到一株木霉属的内生真菌F0238，在皿内及盆栽苗上对该菌防治烟草赤星病(Alternarina alternate)的作用进行了试验研究。皿内的对峙培养结果表明，F0238对烟草赤星病菌有较强的营养竞争作用；盆栽试验表明，F0238在10^10个／ml孢子浓度下对烟草赤星病的预防能力达90％以上，10^8-10^9个／ml孢子浓度下对烟草赤星病的治疗效果达50％以上，表明该菌具有潜在的防治烟草赤星病的能力。     

蛋白质与核酸的高级结构预测

对基于分子力学和基于知识的蛋白质高级结构预测方法进行了较详细的评述。介绍了Nussinov碱基最大配对法、Zuker极小自由能法及螺旋区组合类算法等RNA高级结构预测的原理，并对其预测效果进行了评估。此外，还简要论述了基于EST的网络电子克隆技术，并对基于网络的蛋白质与核酸高级结构分析作了概要的介绍。     

Cp-S316菌株发酵培养基的优化及其对烟草赤星病菌的抑制作用

通过单次单因子试验和正交试验,对Cp-S316菌株抗真菌活性物质的发酵培养基进行了优化,获得适合菌株生长和抗真菌活性物质产生的最佳培养基配方为：土豆100g、乳糖40g、蛋白胨15g、硝酸钠0．5g、硫酸镁2g、水1L。经摇瓶发酵试验,发酵液效价比基础培养基配方提高了325．24％。Cp-S316菌株产生的抗真菌活性物质粗提物对烟草赤星病菌菌丝具有强烈的抑制作用,采用抑制菌丝生长速率法测定了其对烟草赤星病菌的抑制中浓度为EC50=0．248mg·mL^-1;显微镜下观察发现,活性物质能够引起菌丝原生质凝集。     

棉豆间作种植模式优势与配套栽培技术

分析了江汉平原推广棉花与大豆间作种植模式的优势、经济效益 ,介绍了棉豆间作的配套高产栽培技术     

The preparation and structures of hydrogen ordered phases of ice

Two hydrogen ordered phases of ice were prepared by cooling the hydrogen disordered ices V and XII under pressure. Previous attempts to unlock the geometrical frustration in hydrogen-bonded structures have focused on doping with potassium hydroxide and have had success in partially increasing the hydrogen ordering in hexagonal ice I (ice Ih). By doping ices V and XII with hydrochloric acid, we have prepared ice XIII and ice XIV, and we analyzed their structures by powder neutron diffraction. The use of hydrogen chloride to release geometrical frustration opens up the possibility of completing the phase diagram of ice.     

Reversible conversion of monomeric human prion protein between native and fibrilogenic conformations

Prion propagation involves the conversion of cellular prion protein (PrPC) into a disease-specific isomer, PrPSc, shifting from a predominantly alpha-helical to beta-sheet structure. Here, conditions were established in which recombinant human PrP could switch between the native alpha conformation, characteristic of PrPC, and a compact, highly soluble, monomeric form rich in beta structure. The soluble beta form (beta-PrP) exhibited partial resistance to proteinase K digestion, characteristic of PrPSc, and was a direct precursor of fibrillar structures closely similar to those isolated from diseased brains. The conversion of PrPC to beta-PrP in suitable cellular compartments, and its subsequent stabilization by intermolecular association, provide a molecular mechanism for prion propagation.     

烟草赤星病发生为害调查及药剂防治试验

在贵州省兴义市白碗窑镇,采用五点取样法对烤烟品种云烟87号的烟草赤星病发生为害情况进行了调查及药剂防治试验,结果表明:烟草赤星病于7月中下旬至8月初发生为害,多雨天气下扩展蔓延较快,成熟采收期的平均发病率达30.81%,平均病情指数为10.43;采用40%菌核净400⁸00倍液喷雾防治均有明显效果,防效为53.12%800倍液喷雾防治均有明显效果,防效为53.12%⁶4.60%,以600倍液喷雾处理的烟叶烘烤后质量等级最高,中上等烟比例较对照提高14个百分点,折合综合经济效益较对照提高6783.35元/hm2,增收效果明显,但不同施药浓度对烟叶产量的影响不明显。     

烟草赤星病发生为害调查及药剂防治试验

在贵州省兴义市白碗窑镇,采用五点取样法对烤烟品种云烟87号的烟草赤星病发生为害情况进行了调查及药剂防治试验,结果表明:烟草赤星病于7月中下旬至8月初发生为害,多雨天气下扩展蔓延较快,成熟采收期的平均发病率达30.81%,平均病情指数为10.43;采用40%菌核净400~800倍液喷雾防治均有明显效果,防效为53.12%~64.60%,以600倍液喷雾处理的烟叶烘烤后质量等级最高,中上等烟比例较对照提高14个百分点,折合综合经济效益较对照提高6783.35元/hm2,增收效果明显,但不同施药浓度对烟叶产量的影响不明显。     

The developing synapse: construction and modulation of synaptic structures and circuits

Synapse formation and stabilization in the vertebrate central nervous system is a dynamic process, requiring bi-directional communication between pre- and postsynaptic partners. Numerous mechanisms coordinate where and when synapses are made in the developing brain. This review discusses cellular and activity-dependent mechanisms that control the development of synaptic connectivity.