Structural study of circulating thymic factor: a peptide isolated from pig serum. I. Isolation and purification.

A circulating thymic factor (FTS) has been characterized by a bioassay based on its ability to render theta-negative rosette-forming cells theta-positive and azathioprine-sensitive. FTS was sequentially purified and finally isolated from 1000 liters of pig serum by ultrafiltration, gel filtration, and ion exchange chromatography. Its amino acid composition and apparent molecular weight estimated by Sephadex G-25 chromatography, indicate that FTS is a nonapeptide of composition lysine, aspartic acid (or asparagine), serine 2, glutamic acid (or glutamine) 2, glycine 2, and alanine.     

Pindolol acts as beta-adrenoceptor agonist in orthostatic hypotension: therapeutic implications.

Three bedridden patients with severe orthostatic hypotension due to chronic autonomic failure were treated with pindolol (15 mg/day), a beta-adrenoceptor antagonist with partial agonist activity. While taking this drug the patients were free of orthostatic symptoms: they could walk, and standing blood pressure was maintained above 90/50 mm Hg. Supine heart rate rose during treatment by 12-21 beats/minute, and stroke volume and cardiac output by 12-24 ml and 1.5-3.1 l/min respectively. Supine blood pressure rose by 21-68 mm Hg systolic and 14-49 mm Hg diastolic. Pindolol 15 mg/day was therapeutically effective in these three patients with severe orthostatic hypotension due to chronic autonomic failure. Further studies in a larger series of patients are needed to confirm this result.     

Release of heat pretreatment-induced dormancy in lettuce seeds by ethylene or cytokinin in relation to the production of ethylene and the synthesis of 1-aminocyclopropane-1-carboxylic acid during germination

The germination of lettuce (Lactuca sativa L.) seeds was greatly reduced when the seeds were heated at 97°C for 30 h prior to imbibition. This dormancy was effectively released when ethylene (1–100 ppm) or benzyladenine (BA) (0.005–0.05 mM) was applied during the imbibition period. Ethylene was not required during the early part of imbibition, but was essential during the period immediately prior to radicle protrusion. Treatment with 1-aminocyclopropane-1-carboxylic acid (ACC) (0.1–10 mM) stimulated germination, but was not as effective as ethylene or cytokinin treatment. During the germination of nondormant lettuce seeds, ethylene production increased rapidly and reached a peak at 24 h, which coincided with the emergence of the radicle, and then declined; the level of ACC increased as ethylene production rate increased, but remained at a high level after radicle protrusion. In heat-pretreated dormant lettuce seeds, the increases in percent germination, ethylene production, and ACC levels were all delayed and lower than those of nondormant seeds, and these increases were accelerated by treatment with ethylene or cytokinin.     

黑河上游灌丛建群种中国沙棘自由授粉子代父本分析和花粉流

利用SSR分子标记对中国沙棘（Hippophae rhamnoides ssp. sinensis Rousi）自由授粉的种子进行父本分析,研究其子代的父本来源和花粉散布模式。结果显示：在80%的置信水平上,193个子代中有104个个体可以确定花粉来源;在20个确定的父本中,16个为中国沙棘,4个为肋果沙棘（H.neurocarpa S.W.Liu et T.N.He）。传粉格局分析结果显示,中国沙棘有效花粉散布范围为3~71 m,平均距离为20.4 m,2株母本分别有87.23%和78.95%的有效花粉来自距其30 m的范围之内,研究结果表明中国沙棘自然种群以近距离传粉为主。此外,在黑河上游沙棘杂交带中,中国沙棘子代中的肋果沙棘花粉平均贡献率达到14.84%,表明中国沙棘与肋果沙棘存在较高的种间当代花粉流。     

湖北新资源植物—神农香菊的地理分布、生态习性与蕴藏量的调查研究

神农香菊(Dendranthema indicum (L.) Des Monl. var. aromaticum Q. H. Liu et S. F. Zhang, var. nov.)是我所多年来通过调查,在鄂西神农架首先发现的一种新的资源植物。这种植物与野菊[D. indicum (L.) Des Monl.]很近似,其主要区别在于神农香菊的花、叶具有浓郁的特殊香气。经化学初步分析和药理试验结果表明,本植物含α—侧柏酮、β—侧柏酮、龙脑等萜类化合物成分,并无剧毒性及致癌因素反应。可广泛应用于化工、饮料和医药等方面的原料,是一种很有经济价值的香料和药用的植物资源。本文着重阐述和讨论了本植物的地理分布,习性生境、自然繁殖概况及蕴藏量。并提出进一步开发利用神农架山区植物资源,合理利用和发展神农香菊生产等方面的途径和科学依据。     

准噶尔盆地荒漠灌丛对融雪水空间分布的反馈初探

温带荒漠的积雪沿灌丛始融,并以灌丛为中心形成融雪漏斗,导致融雪水向灌丛基部汇集。观测资料表明:通过灌丛对融雪水分布的反馈,使灌丛周围的沙层含水量明显增加,为裸沙区的152.1-228.9％,从而提高融雪水的利用率并改善灌丛自身的供水条件,对荒漠植被的分布格局亦起一定影响。