洈水水库鳡鱼(Elopichthys bambusa)生长规律的研究

本文对洈水水库鳡鱼的生长及其利用进行了分析研究,结果表明:1.该种鱼生长快,高速生长时间长,可连续5年每年生长6kg以上;2.雌、雄鱼体长与体重生长分别适合Von.Bertalanffy的生长公式:L=L_∞(1-e-k(t-t·))和W=W_∞(1-e-k(t-t·))~3;3.雌鱼体重生长速度快于雄鱼,体长生长无明显差别;4.建议大中型水体中的鳡鱼与其它鱼类群落体重之比控制在3—5％为宜。     

Regulation of bacterial physiological processes by three types of protein phosphorylating systems

A single type of protein-phosphorylating system, the ATP-dependent protein kinases, is employed in the regulation of a variety of cellular physiological processes in eukaryotes. By contrast, recent work with bacteria has revealed that three types of protein-phosphorylating systems are involved in regulation: (1) the classical protein kinases, (2) the newly discovered sensor-kinase/response-regulator systems, and (3) the multifaceted phosphoenolpyruvate-dependent phosphotransferase system. Physiological and mechanistic aspects of these three evolutionarily distinct systems are discussed.     

维西香茶菜的二萜成分

维西香茶菜Rabdosia weisiensis C. Y. Wu产云南西北部海拔2600米沟谷中,其化学成分的研究未见报道。从该植物叶的乙醚提取物中,分得两个二萜成分,一为已知成分trichorabdal A(2),一为新成分,命名为维西香茶菜甲素weisiensin A(1)。 维西香茶菜甲素weisiensin A(1),C_(26)H_(36)O_9,mp 298—300℃,其~(13)C NMR谱显示存在三个CH_3,三个CH_2,八个CH,三个四取代碳,三个Ac,二个烯碳和一个羰基     

Prostaglandin I2 and the constricted maternal ovine placenta: effects of local infusion and placental age

We have tested the hypotheses that systemic responses to the infusion of prostaglandin I2 may have masked the ability of this substance to dilate the maternal placenta and that the inability of prostaglandin I2 to dilate the maternal near-term placenta may be a function of placental age. Regional blood flows were measured with radioactive microspheres. In 8 near-term sheep the control flows were measured and angiotensin II (AII) infusion was begun at 5 micrograms/min and continued for the duration of the experiments. At t = 15 min, regional blood flows were again measured. Prostaglandin I2 was then infused via a retrograde uterine arterial catheter at 10 micrograms/min. At t = 30 min, the flows were again measured. At this time the infusion of prostaglandin I2 was stopped and at t = 45 min the blood flows were measured for the last time. AII increased the resistance of all tissues examined. The blood pressure increased with AII and did not change thereafter. The non-placental uterine tissue served by the retrograde catheter dilated with prostaglandin I2. The placental tissue had an initial resistance of 59 +/- 6 mmHg.ml-1.min.g which increased to 98 +/- 22 mmHg.ml-1.min.g with the infusion of AII (P less than 0.05). This resistance remained constant at 82 +/- 19 mmHg.ml-1.min.g with the administration of prostaglandin I2 and did not change after prostaglandin I2 was removed. The local application of prostaglandin I2 in the presence of AII induced vasoconstriction caused vasodilatation in the nonplacental vessels but could not change the AII induced constriction in the placental vasculature.(ABSTRACT TRUNCATED AT 250 WORDS)     

紫茎泽兰的化学成分初报

紫茎泽兰(Eupalorium adenophorum Spreng)原产中美墨西哥,现在滇南一带广泛分布,对林、牧业生产造成严重危害。其化学成分研究未见报道。 从紫茎泽兰的叶和花序中,分到九个单体,经详细的光谱解析和与标准品对照,其中五个成分的化学结构分别为:正三十二烷n-dotriacontane(1),β-谷甾醇β-sitosterol(2),豆甾醇stigmasterol(3),蒲公英醇棕榈酸酯taraxasteryl palmitate(4),蒲公英醇乙酸酯taraxastcryl acetate(5)。     

不同品种、不同花期的依兰花精油成分研究

为探讨依兰花精油的香气质量,我们对云南省西双版纳产依兰花精油以及引种栽培于西双版纳的泰国种、老挝种的依兰花精油的化学成分在Finnigan-4510 GC/MS/DS上用毛细管柱进行了定性和定量分析,鉴定了44个化学成分。分析结果表明,依兰油的香气与品种及精油中的酯类、醇类和酚醚的含量有关。倍半萜烯类和倍半萜醇类的含量越高,其香气质量越差。就西双版纳产依兰油的香气而言,依兰花由青转黄时得到的精油远较绿花和花蕾油为好。     

盐肤木上四种倍蚜主要生物学特性和预测的研究

本文报道1983—1986年作者在四川省绵竹、成都、夹江、涪陵和南川等县(市)境内,海拔500～1500米范围内,对寄生在盐肤木上的角倍蚜,倍蛋蚜,倍花蚜和红倍花蚜等四种主要倍蚜春迁蚜羽化迁飞期、干母营瘿期、倍子生长进程和瘿内倍蚜的生殖数量与世代数以及干母营瘿的寄主物候等的观察测定结果,并建立预测方程,为引移挂放和适宜采倍期的确定提供科学依据。