Studies on the behaviour of circular dichroism of different haemoglobins in the 260 nm region

Zusammenfassung CD-Messungen mit hoher Auflösung an Hämoglobinen verschiedener Spezies ergaben eine Aufspaltung der breiten Absorptionsbande bei 260 nm in 4 einzelne Maxima. Diese stimmen mit der Bandenlage des Phenylalanins im Absorptionsspektrum vom Hämoglobin gut Überein und werden daher diesem Chromophor zugeordnet.     

Effects of polysorbates and Cremophor EL on vascular responses in rat aorta

The effects of Tween 20, Tween 80, and Cremophor EL, surface active agents which are used for dispersion of water-insoluble substances, on vascular responsiveness were investigated using rat aortic rings. In high concentrations all these agents produced persistent contractions in aortic rings independent of the presence of endothelium. These contractions were not influenced by inhibitors of known endogenous contractile mediators. Incubation with these agents caused a concentration-dependent inhibition of the endothelium-dependent relaxant responses to acetylcholine in intact precontracted aortic rings. Endothelium-independent relaxations produced by sodium nitroprusside were not inhibited, but rather potentiated in the presence of Tween 80 (10^–1 ml/l). On the other hand, Tween 80 inhibited the contractile effects of 5-hydroxytryptamine, phenylephrine, and bradykinin significantly. The data suggests that these substances affect both endothelial cells and vascular smooth muscle.     

(S)-(+)-4,4,4-Trifluoro-3-(indole-3-)butyric acid,a novel fluorinated plant growth regulator

Racemic 4,4,4-trifluoro-3-(indole-3-)butyric acid (TFIBA) has been synthesized and shown to inhibitAvena coleoptile elongation. (S)-(+)-TFIBA (fig. 1), which was prepared by an enzymatic method and markedly promotes root growth of Chinese cabbage, lettuce and rice plants, is a novel fluorinated plant growth regulator. Activity of the (S)-(+)-enantiomer of TFIBA was 10-fold greater than that of the (R)-(–)-enantiomer in the first two plant species and 5-fold greater in rice.     

Mate choice and male competition inOrchesella cincta (Collembola)

Summary Both male and femaleOrchesella cincta (Collembola) were able to discriminate between spermatophores of different origin. Females chose spermatophores deposited by closely related males while males preferentially destroyed spermatophores of other males.     

图书馆的人力资源建设

分析了人才资源与图书馆生存和发展的关系，指出：应从发现人才、重用人才和培养人才3个方面建立人才培养机制；同时强调只有加强领导班子建设才能充分发挥人才的作用。     

浅析城市水资源管理及利用

针对城市水环境污染严重、城市水利设施不完善、水资源管理缺乏经济学观念的状况，提出一系列强化城市水资源管理及利用的措施。     

Preliminary observations of a bacteriophage infectingXenorhabdus luminescens (Enterobacteriaceae)

A bacteriophage infective toXenorhabdus luminescens, a bacterial symbiont of heterorhabditid nematodes, was recovered from insects that supported poor nematode development. Plaque tests showed the phage particles to be infective only to primary and not secondary colonies ofX. luminescens. The phage was not infective toX. nenatophilus primaries or secondaries. The bacteriophage particles ranged 80–90 nm in length, with the head ranging from 40 to 50 nm in diameter. Restriction analysis was performed on isolated bacteriophage DNA. This first report of a bacteriophage fromXenorhabdus species has pratical implications since it could be detrimental to cultures ofHeterorhabditis nematodes that are being produced throughout the world for the biological control of insects.     

Serum thymic factor as a radioprotective agent promoting survival after X-irradiation

Summary Serum thymic factor (FTS, zinc-free thymulin) protected mice from death after whole-body X-irradiation. It was significantly radioprotective even when administered after irradiation, but it was more effective when administered both before and after irradiation. The protective effect appears to be due to the enhancement of hematologic recovery in the animals.