体外酸处理对提高测定酯酶A_4的活性期有效

许多昆虫在它们生活周期的某一个特定期都会停止发育,进入滞育。而滞育则并非会立刻停止去适应环境的有利变化。相反,一般是经过很长一段冷冻后,才停止滞育的。家蚕滞育卵的冷藏,对打破滞育,是个有效处理。可是,低温下打破滞育的机制,迄今还未弄清。

抗球虫药在鸡胚球虫感染中活性峰期测定方法的研究

用鸡胚感染柔嫩艾美耳球虫子孢子作为抗球虫药活性峰期测定的模型。每一鸡胚在接种５０００个子孢子后，分别于感染的当天、第２天、第３天和第４天注入测试药物，以不同注药时间对鸡胚卵囊所产生的抑制率的差异，判定药物的活性峰期。结果表明，氯甲吡啶酚和丁氧喹啉的活性峰期是球虫生活史的第１天，卵囊抑制率分别为１００％和９８％；莫能菌素、盐霉素、球Ｒ和加福的作用峰期是第２天，卵囊抑制率均为１００％；氨丙啉的峰期是第３天，卵囊抑制率为１００％；尼卡巴嗪的峰期是第４天，卵囊抑制率为１００％；速丹则在球虫生活史的整个无性阶段均呈现活性作用。加福＋氨丙体＋乙氧乙胺苯甲酯、球Ｒ＋氨丙啉＋乙氧乙胺苯甲酯、加福＋速丹、加福＋尼卡巴嗪及加福＋乙氧乙胺苯甲酯等合剂亦在球虫生活史的整个无性阶段发挥高峰作用，其印囊的抑制率均为１００％；尼卡巴嗪＋氨丙啉合剂则在球虫生活史的第２～４天发挥最大作用，卵囊抑制率为１００％。作者认为，本方法具有操作简单，结果可信及成本低廉的特点，可作为抗球虫药的筛选方法。

抗球虫药在鸡胚球虫感染中活性峰期测定方法的初探

引言据现有抗鸡球虫药研究的资料阐述,各种抗球虫药,均有在球虫生活史的特定时期发挥最大作用的活性峰期.因此,在研究开发新药时,用简便、经济的实验方法测定其活性峰期,具有重要的实用意义.国外一般应用体外细胞培养的方法测定抗球虫药的活性峰期,用鸡胚培养的方法测定抗球虫药的药效。而对于鸡胚感染球虫技术能否用于测定抗球虫药的活性峰期,尚不清楚.为此,本文选用鸡胚感染球虫子孢子作为实验模型,探讨了其用于测定抗球虫药活性峰期的可能性。

环境温湿度条件对聚硫密封胶性能的影响

摘要：着重探讨了典型的环境温湿度条件对聚硫密封胶之活性期、不粘期、标准硫化期和粘接强度等影响。研究结果表明：随着温度或湿度的升高，聚硫密封胶的活性期、不粘期和标准硫化期均呈缩短趋势，而粘接强度呈先升后降态势；当施工环境温度为18-32℃、相对湿度为30％．75％时，聚硫密封胶的综合性能相对较好，其活性期为0．7～4．2h、不粘期为5～15h、标准硫化期为15～80h和剥离强度为5．2～7．0kN／m。

常温固化型实木复合地板用API胶黏剂的研究

针对水性高分子-异氰酸酯(简称API)胶黏剂在实木复合地板应用过程中结膜速度快、活性期短等缺点,采用API冷压桦木胶合板检测湿胶合强度的方法,设计正交实验,优化API主剂构成及其与固化剂的配比。结果表明:主剂与固化剂最佳配比为100:15;最终经此调制的API胶压制三层实木复合地板,制品的胶接性能完全能够达到GB/T17657-1999中的性能要求。

以多硫化物齐聚物为基础的密封胶

讨论了多硫化物齐聚物及其与液体聚硫胶并用得到的密封胶的性能及并用比例对性能的影响。

聚二甲基硅氧烷填充胶料固化过程中的流变学

文中研究了α,ω-二乙烯基聚二甲基硅橡胶(ДВК-5)在填料含量不同的条件下,甲基氢化硅氧烷用不同催化剂硫化的反应动力学。获得了液体硅橡胶的极限凝胶时间及活性期与填料、温度及抑制剂浓度之间的相关性,它可在不同胶料配方及硫化条件下,优化胶料的硫化过程。

ZSM-5沸石晶粒结焦失活过程的Monte-Carlo模拟研究

建立了ZSM-5分子筛催化剂晶粒的三维Monte-Carlo模拟体系,模拟了在该体系上对苯/乙烯烷基化制乙苯反应的结焦失活过程。模拟实验结果和催速失活实验结果吻合; 模拟失活历程经历高水平活性稳定期、活性衰退期和低水平活性稳定期三个阶段。并用Monte-Carlo方法研究了酸性位比例、晶粒大小和苯烯比对活性稳定性的影响。

不同给药方案对鸡现场球虫免疫的影响

20日龄海赛克斯雏鸡连续50余天经垫料自然免疫接种一定量的球虫卵囊，同时采用不同的给药方案，饲喂含抗球虫药的饲料，72日龄时用大剂量卵囊（8×10^4）攻击。根据试验鸡的增重、盲肠病变评分和盲肠卵囊数等指标，评定不同给药方案对鸡球虫免疫的影响，结果表明：单独使用作用于球虫生活史早期的聚醚类离子载体抗生素，会严重抑制鸡对球虫的免疫力，聚醚类离子载体抗生素与作用于球虫生活史后期的化学合成药联合用药或低剂量配合用药，则对免疫无影响。

金属用底胶表面处理的工艺研究

以730胶粘剂为底胶对金属被粘表面进行处理。试验了底胶和处理工艺对金属与丁腈橡胶粘接强度的影响,对产品进行了老化试验和实际应用。结果表明,该工艺金属被粘面的活性期长达21d,且可大幅度提高粘接强度。

Characterization of Endopeptidases in Wheat Leaves During Dark-induced Senescence

The characterization of senescence-associated endopeptidase (EP) isoenzymes in wheat (Triticum aestivum L. cv. Yangmai 158) leaves during dark-induced senescence was performed. It was found that there was much higher endoproteolytic activity in dark-induced wheat leaves than in control. Six endopeptidase isoenzymes (EP1-EP6) were identified by natural gradient-polyacrylamide gel electrophoresis (PAGE) co-polymerized gelatin in the gel, five of which (EP1, EP2, EP4, EP5 and EP6) were only detected in senescing leaves. Treatment with 6-benzyl aminopurine (6-BA) delayed the expression of these EP isoenzymes and abscisic acid (ABA) accelerated it. The activity of EP3 could be detected at a wider range of pH and temperature levels while EP4, EP5 and EP 6 could be only detected at pH 4-5 and 30 -45 degreesC, EP1 and EP2 at pH 3-5 and 30-45 degreesC. All of the EP isoenzymes showed high thermal stability, especially EP3, EP5 and EP6 which still had activitiy even by incubation at 55 degreesC for 1 h. By using different class-specific inhibitors, EP1 and EP2 were characterized as metal-dependent cysteine-proteases, EP4 as a serine-protease.

Effects of Drought Stress on Activity of POD and CAT in Wheat during Generation Period

[Objective] This study aimed to investigate the changes in activity of POD and CAT in wheat during generation period under drought stress. [Method] Four wheat cultivars, including Yunong 51, Zhoumai 22, Jimai 19 and Huaimai 22, were selected as experimental materials and cultured under drought stress simulated by different concentrations of PEG6000, to determine the activity of POD and CAT. [Result] POD and CAT activity in wheat during generation period increased gradual y under stress of 5% and 15% PEG6000 from 0 to 120 h; POD and CAT activity in wheat under stress of 15% PEG6000 increased more compared with that under stress of 5% PEG6000; POD and CAT activity in wheat under stress of 25% and 35% PEG6000 increased first and then decreased. Stress duration significantly af-fected the activity of POD and CAT in wheat during generation period. [Conclusion] This study provided theoretical references for breeding drought-tolerant wheat.

Effects of Water Deficit and Increased Nitrogen Application in the Late Growth Stage on Physiological Characters of Anti-aging of Leaves in Different Hybrid Rice Varieties

[Objective] This study aimed to explore the effects of water and fertilizer regulation on the function of leaves in the filling stage. [Method] Six hybrid rice vari- eties including prematurely aged types and non-prematurely aged ones were selected as experimental materials. Limiting water treatment （with soil water potential of about -25 kpa） and increasing nitrogen treatment （additional 10% of granular nitrogen fertiliz- er in addition to limiting water treatment） were applied after heading to analyse the rates of aging and physiological responses of anti-aging in different hybrid rice vari- eties under water deficit and increased nitrogen conditions taking regular water and fertilizer as control. [Result] The results showed that water deficit accelerated the leaf senescence, and prematurely aged types-＇Zhongyou838＇, ＇Tianyou998＇ and ＇Long- ping601 ＇-were more markedly affected by water deficit, of which the rates of chloro- phyll degradation were 6%-8% higher compared to that in another three hybrids. In- creasing nitrogen treatment raised chlorophyll content and slowed down its degrada- tion. Water deficit caused the increase of abscisic acid （ABA） content to obviously varying degrees in leaves of six hybried rice varieties. Responses of ABA content in six hybried rice varieties to increased nitrogen fertilizer were not consistent. Except in ＇Zhongyou838＇, ABA content in the other five hybrids had varying degrees of in- crease. The responses of the activity of antioxidant enzymes in different hybried rice varieties were inconsistent. In response to increased nitrogen fertilizer in combination with water deficit, the activity of each antioxidant enzyme changed differently. Water deficit enhanced the accumulation of malondialdehyde （MDA） in leaves of each hybrid rice. The correlation analysis showed that chlorophyll content was extremely signifi- cantly positively correlated to the resistance of each antioxidant enzyme; SOD activity in leaves also positively related to ABA content. [Conclusion] The rate of leaf aging, physiological activity of anti-aging, and response to water deficit varied in different hy- bried rice varieties. The activity of antioxidant enzymes were not all induced to improve by ABA. SOD activity can be an indicator of resistance to stress. Increasing nitrogen ap- plication significantly postponed leave senescence in the late growth stage of rice.

无醛木材制品胶粘剂

武汉现代工业技术研究院开发成功的无醛木材制品胶粘剂，产品经检测，各项性能指标均达到或优于标准，解决了人造板中长期存在有毒游离甲醛的问题。该剂是系高级乳胶和优质改性剂精制而成的，它以较好的耐水性、初粘性、剪切强度、固化速度快和活性期长等优点，可适用于多层胶合板、细木工板、刨花板、中密度板等其他木制品，该产品的开发成功不仅具有较大的经济效益和社会价值，而且对推动全民绿色消费具有积极的意义。

Impact of Transgenic Bt+CpTI Cotton on Soil Enzyme Activities and Soil Microorganisms

Due to its strong and effective insecticidal properties, transgenic Bt＋CpTI cotton has witnessed an expanding planting area in recent years, and the impact of its cultivation on soil ecosystem becomes an important part of environmental risk assessment. Using transgenic Bt＋CpTI cotton sGK321 and its parental homologous conventional cotton Shiyuan 321 as the study objects, a comparative analysis was conducted on the changes in enzyme activities （urease, alkaline phosphatase, and catalase） of the rhizosphere soil and changes in the number of culturable microor-ganisms （bacteria, fungi, and actinomycetes） at different growth stages （seedling stage, budding stage, flower and bol stage, and bol opening stage） of sGK321 and Shiyuan 321 under the condition of 13 years field plantings. The results showed that, the populations of bacteria, fungi, and actinomycete and the soil enzyme activi-ties of urease, alkaline phosphatase and catalase had a similar variation trend along with the cotton growing process for transgenic cotton and conventional cotton. Some occasional and inconsistent effects on soil enzyme activities and soil fungi composi-tion in the rhizosphere soil of transgenic Bt＋CpTI cotton were found at the seedling stage, budding stage, flower and bol stage as compared with that of conventional cotton. The amount of bacteria and actinomycetes were not significantly different during a certain stage; however, the activities of urease, catalase, alkaline phos-phatase, also with the number of fungi were significantly different, e.g. the urease activities at seedling stage, the alkaline phosphatase at seedling and budding stages, and the soil culturable fungi at flower and bol stage were less than that of conven-tional cotton, while the soil alkaline phosphatase activities at flower and bol stage were higher. Cluster analysis showed that soil enzyme activities and microbial popu-lation changed mainly along the growth processes, suffering little from the planting of transgenic Bt＋CpTI cotton.

Relationship between Living Rate of Bud and Emergence Rate of Ratoon Rice and Characteristics of the First Cropping Mid-season Hybrid Rice

[Objective] The aim was to study the relationship of plant characters with bud living rate and mother stem emergence rate of ratoon rice before harvest. [Method] Eighteen mid-season hybrid rice cultivators approved recently were taken as materials and relationship of plant characters including bud living rate and moth- er stem emergence rate of ratoon rice before harvest was explored, based on relat- ed data. [Result] The shorter rice with lower harvesting index is the main character of high emergence rate for first cropping rice; decline of plant height and increase of ear-bearing percentage would improve emergence of regenerative seedlings. [Conclusion] The research provided scientific reference for breeding of rice cultivars with high regenerative capacity.

The cell cycle related apoptotic susceptibility to arsenic trioxide is associated with the level of reactive oxygen species

Double staining flow cytometry was performed using 7-amino actinomycin D and 6-carboxy-2',7'-dichlorodihydrofluorescein diacetate,to detect the level fluctuation of reactive oxygen species (ROS) during the cell cycle of normal NB4 cells. Our results showed that NB4 cells possessed higher level of ROS in G2/M phase than in G1 and S phases. Double staining flow cytometry,with TdT mediated dUTP nick end labeling (Tunel) and propidium iodide (PI),indicated that As2O3 (2 μM) could induce apoptosis in NB4 cells prevailingly from G2/M phase,and this efficacy was enhanced upon co-administration of 2,3-dimethoxy-1,4-naphthoquinone (DMNQ) (2.5 μM) which could produce the endogenous ROS. These results suggested that different ROS level in different cell cycle phases of NB4 cells might determin the selective induction of G2/M apoptosis and the cells' susceptibility to apoptosis by As2O3.

The Flavivirus Protease As a Target for Drug Discovery

Many flaviviruses are significant human pathogens causing considerable disease burdens,including encephalitis and hemorrhagic fever,in the regions in which they are endemic.A paucity of treatments for flaviviral infections has driven interest in drug development targeting proteins essential to flavivirus replication,such as the viral protease.During viral replication,the flavivirus genome is translated as a single polyprotein precursor,which must be cleaved into individual proteins by a complex of the viral protease,NS3,and its cofactor,NS2B.Because this cleavage is an obligate step of the viral life-cycle,the flavivirus protease is an attractive target for antiviral drug development.In this review,we will survey recent drug development studies targeting the NS3 active site,as well as studies targeting an NS2B/NS3interaction site determined from flavivirus protease crystal structures.

Study on the Activity of Herbal Extract to Kill Root-knot Nematode of Cucumber Seedlings Stage

Present mature plants hydroponic technology was used,combined with some excellent characteristics,such as growth conditions was easy to control and process of root growth was easy to continuously observe,the nematicidal activity of 5 kinds of Chinese herbs extracts and the compound solution of Avermectin,with strong contact toxicity effect indoor,was systematically studied and investigated the affection on the root-knot nematode parasitized on the cucumber seeding stage. It is found that under the premise of no influence on root growth of cucumber,extracts from Picrorhiza scrophulariiflora and Punica granatum showed strong prevention and nematicidal activity,and had the similar efficacy of Avermectin; while the extracts from Cibotium barometz,Aucklandia lappa Decne and Fructus cnidii showed low nematicidal activity and various degrees inhibition effect on plant growth.

An electron microscopic-cytochemical localization of plasma membrane Ca^(2+)-ATPase activity in poplar apical bud cells during the induction of dormancy by short-day photoperiods

Plasma membrane （PM） Ca2+-ATPase activity in poplar apical bud meristematic cells during short-day （SD）-induced dormancy development was examined by a cerium precipitation EM-cytochemical method. Ca2+-ATPase activity, indicated by the status of cerium phosphate precipitated grains, was localized mainly on the interior face （cytoplasmic side） of the PM when plants were grown under long days and reached a deep dormancy. A few reaction products were also observed on the nuclear envelope.When plant buds were developing dormancy after 28 to 42 d of SD exposure, almost no reaction products were present on the interior face of the PM. In contrast, a large number of cerium phosphate precipitated grains were distributed on the exterior face of the PM. After 70 d of SD exposure, when buds had developed a deep dormancy, the reaction products of Ca2+-ATPase activity again appeared on the interior face of the PM. The results seemed suggesting that two kinds of Ca2+-ATPases may be present on the PM during the SD-induced dormancy in poplar.One is the Ca2+-punlping ATPase, which is located on the interior face of the PM, for maintaining and restoring the Ca2+homeostasis. The other might be an ecto-Ca2+-ATPase, which is located on the exterior face of the PM, for the exocytosis of cell wall materials as suggested by the fact of the cell wall thickening during the dormancy developlnent in poplar.