Mechanical responses of the isolated cervix of the day-22 pregnant rat to field stimulation.

Field stimulation of isolated, spirally-cut cervix from day-22 pregnant rats produced contractions which could be inhibited by tetrodotoxin or hyoscine and potentiated by propranolol. The rat cervix would appear to receive both cholinergic and noradrenergic innervations whose transmitters activate muscarinic cholinoceptors and beta-adrenoceptors respectively.     

PPD-induced blastogenesis is auto-regulated by suppressor cells generated in vitro.

Suppressor cell induction can be demonstrated during antigen specific blastogenesis by using the same methods which have shown induction of suppressor cells by Con A. Since suppressor cells are rapidly generated during antigen specific blastogenesis, they must regulate the final level of blastogenesis induced during the seven day in vitro incubation.     

Monolayer cultures of perikarya isolated from postnatal rat cerebellum

Summary Viable cerebellar perikarya of mixed cell type obtained from 7–9-day-old rats were maintained in monolayer culture for up to 12 days. During this time extensive neurite formation and outgrowth occurred. The large majority of the cells developing in culture were tentatively identified as granule neurons. This identification was based on the large number isolated from the starting tissue, and the cells general morphological features in culture such as perikaryal and nuclear size, the bipolar nature of neurite extension, and their migratory behaviour.D.N. Currie was supported by a grant from Hoechst Pharmaceuticals, Ld, U.K.J.C. was supported by an S.R.C. Grant to S.P.R. RoseThe authors would like to thank Kathleen Tear for excellent technical assistance and members of the Brain Research Group for helpful discussions.     

Lysergic acid diethylamide affects blood flow to specific areas of the conscious rat brain

Zusammenfassung Die i.v. Verabreichung von LSD an Ratten steigert den Blutkreislauf im Hirnstamm sowie im frontalen und parietalen Cortex selektiv. Es wurden durch 6-Nor-LSD, 2-Methyl-LSD und ^{8, 9}-LSD weder wahrnehmbare Verhaltensänderungen noch Änderungen des regionalen Blutkreislaufs verursacht.     

Ecdysone 20-hydroxylase from the midgut of the tobacco hornworm (Manduca sexta L.)

Summary An ecdysone 20-hydroxylase enzyme system that converts -ecdysone to 20-hydroxyecdysone was prepared from the midgut of the tobacco hornworm prepupa. This partially purified enzyme is NADPH dependent and is localized in the mitochondrial fraction of the midgut tissue.     

攀枝花地区水土流失动态变化研究

选择攀枝花市部分地区的Landsat-5 TM(1988年)和Landsat-7 ETM (1999年)遥感数据,通过遥感图像信息挖掘,提取植被覆盖度、沟谷分布、土地利用现状及土壤成土母质等信息,结合地形数据等水土流失因子;利用地理信息系统强大的空间分析功能,获取水土流失信息进行统计分析,对研究区水土流失的强度等级以及动态变化进行分析评价.研究表明,水土流失变化主要发生于植被覆盖不良的荒地和坡耕地上,其中坡耕地水土流失变得最严重,大部分为强度及强度以上级别水土流失区.从地貌上看,水土流失变化主要发生在低山、丘陵地区,这些地区人类活动频繁,植被破坏严重,大量开垦耕地,有利于水土流失发生.从岩类上看,半胶结砂岩、粘土岩岩组和紫红色泥岩、砂岩、页岩岩组分布区,由于多开垦为耕地,抗蚀能力弱,且多未实施保水保土措施,因此是水土流失严重的地区.     

反相HPLC色谱法测定盐芥和菠菜中的甜菜碱含量

本实验利用反相HPLC色谱法测定了盐芥和菠菜中的甜菜碱含量，实验分别以菠菜和盐芥的叶组织为材料，用去离子水提取甜菜碱．提取液经浓缩后依次通过阳离子交换树脂柱和阴离子交换树脂柱进行纯化，用NH4OH洗脱阳离子交换树脂柱，洗脱液收集浓缩干后用磷酸盐流动相溶解．样品用C18反相色谱柱进行分离，流动相为50nmol／L的KH2PO4溶液(pH4．56)，色谱条件为0．7ml/min。192nm波长测定；此色谱条件能使甜菜碱与其它组分很好的分离，甜菜碱加样回收率达到90％-98％．经测定。盐芥叶片中的甜菜碱含量为1．367mg/g，菠菜叶片中的甜菜碱含量为1．656mg/g．     

交错波纹板原表面换热器通道内对流换热的数值研究

对具有正弦波形通道交叉排列的原表面换热器多通道单元内三维稳态层流流动与换热特性进行了分析，利用数值模拟方法探讨了上下波纹板交错角θ、波纹相对节距P／H(波长／波高)及雷诺数RP对流动与换热性能的影响．结果表明：在入口段流动与换热性能的变化较大，此变化在沿主流方向第4个单元后基本消失；在水力直径基本相同的前提下，阻力系数厂及平均努谢尔特数Nu随θ的增大而增大；f及Nu在P／H为1．5～3．1的范围内随P／H的增大而增大，在RP大于900及P／H为3．1～4．0时随P／H的增大却开始减小；壁面局部Nu的最大值发生在主流尾部以及与流体出口邻近的2个入口处附近，最小值在上下波纹板的接触点上产生。     

特低渗储层应力敏感性及对油井产量的影响

对长6某特低渗储层进行了系统的应力敏感性实验研究.研究表明:该特低渗储层岩石的应力敏感程度在26%~80%的范围,岩石的渗透率越低,应力敏感性越强;原始条件下地下渗透率明显小于地面渗透率,它们之间有较好的线性关系;储层岩石应力敏感伤害后,储层岩石的渗透率不能立即恢复,最终渗透率恢复率在68.6%~100.0%,岩石渗透率越高,渗透率恢复值越大;当岩石的渗透率小于0.5×10-3μm2时,储层岩石的应力敏感性明显增强.模型预测表明,当地层压力降低5MPa时,该储层岩石的应力敏感性对油井产量的影响在8.6%~35.7%,渗透率越低下降幅度越大.