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1.
南瓜雌蕊与自花及远缘花粉的相互作用   总被引:2,自引:0,他引:2  
南瓜柱头表面经去垢剂、蛋白酶及Con A处理后花粉不能萌发或花粉管生长受阻,Con A能专一地与柱头表面结合。柱头块加入培养液可促进花粉萌发。不同的远缘花粉授粉后在雌蕊不同部位受阻。在成熟南瓜雌蕊提取液中检测到血凝活性,凝集素可能参与雌蕊对远缘花粉的抑制。  相似文献   
2.
球体蛛在我国首次被发现,本文记述了产于我国海南的纳尔蛛属一新种,定名为华纳尔蛛Wendilgarda sinensis sp. nov.,模式标本保存在河北教育学院生物系。  相似文献   
3.
本文记述我国皿蛛科一新纪录属:前延首蛛届Archaraeoncus Tanasevitch 1987,并对天山前延首蛛A.tianshanicus(Hu et Wu,1989)n.comb.重新作了描述,本种的雌蛛系首次发现。本文还对Araeoncus tianschanica Hu et Wu 1989原学名命名的原始拚缀作了改正。文中测量数据均以mm为单位。  相似文献   
4.
本文记述采自新疆的皿蛛科蜘蛛一新届——颚齿蛛属Maxillodens gen.nov.及其一新种——鞭状颚齿蛛M.flageuatus sp.nov。  相似文献   
5.
The effects of an extract from the green alga Ulva lactuca and the Essentiale® commercial preparation, which was used as a reference, on the weight indexes of the viscera and the biochemical markers of the liver have been studied in a model of acute stress in rats. Acute stress was simulated by suspending animals in the upright position by their neck dorsal skin fold for 24 hours. Administration of the U. lactuca extract to rats exposed to the extreme stress resulted in a pronounced preventive action, which was manifested in the support of the weight index of their viscera, lipids metabolism, the antioxidant defense system of liver, and a reduction of lipid peroxidation. The extract from U. lactuca was no less effective in protecting the metabolic reactions of the liver under acute stress than the Essentiale® commercial preparation. The pronounced protective properties of the U. lactuca extract are explained by the combined effects of phospholipids of marine origin, n-3 PUFAs, and antioxidant polyphenols that comprise it.  相似文献   
6.
The results of radiative and of chemical monitoring show definite contamination of this zone by 90Sr and toxic metals. The essential local contaminations of geosystems (up to 2.3 x 10(4) Bk/kg of soil) require in environmental condition assessment at biocenosis level. Biotesting found the increase of metallothioneines levels in kidney (up to 15.63 microg/g of tissue) and liver (up to 19.22 microg/g of tissue) of rodents inhabited in the region of RWS placing as compared with the control group (3.51 and 4.44 microg/g of tissue accordingly). Besides, the decrease of total quantity of leucocytes (by 14.5% as compared with the control group) and absolute quantity all forms of them in animal blood were noted. It was assumed the increase of protein--MT is the result of complex influence by ionizing radiation and toxic metals.  相似文献   
7.
The concentrations of metabolites altered immediately after culture inoculation into fresh medium and depended on the their dilution (in small dilutions metabolites were released into the medium, and, on the contrary, in great dilutions they were adsorbed). Acetate was the main exometabolite. The growth of culture started only when the acetate concentration reached the threshold value. At the stage of growth deceleration an intensive release of acetate and other exometabolites occurred. The process had the explosive character of chemical chain reaction. It could be initiated by high local concentrations of metabolites around bacteria, most sensitive to changes in growth conditions. At a high concentration of such cells the signal could be transmitted from one bacteria to another, otherwise the reaction chain was quickly broken and no mass release of metabolites occurred. At the stationary phase succinate, valine and lactate were consumed by bacteria with lactate concentration dropping practically to 0. At the same time acetate and citrate concentrations oscillated about some constant value. The release of growth inhibitors, formiate and alanine, continued to the end of cultivation, which was, seemingly, one of the factors of growth cessation. The specific features of the dymamics of metabolites were indicative of the fact that they had their individual regulatory functions. The problem of the self-synchronization of the bacterial culture is discussed.  相似文献   
8.
Fossil mandibles of the Bornean shrew Crocidura foetida recovered from excavations at the west mouth of Niah cave, Sarawak, Malaysia, show that the late Pleistocene population at this lowland location was comparable in size with the large subspecies Crocidura foetida doriae , presently occurring at inland, upland locations. Two Holocene specimens fall in the size range of the smaller lowland subspecies C. f. foetida . Comparable post-Pleistocene size-reduction is known among other mammals of Borneo, but this is the first instance of dated examples. The evolutionary trend conforms with Bergmann's 'rule' but, other than climate change, no selective agent is apparent.  © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 94 , 413–419.  相似文献   
9.
Fucoidan--nontoxic sulfated polysaccharide was isolated from brown algae Fucus evanescens in Okhotskoe Sea. Chemical analysis of the compound was performed, it was shown that fucoidan is freely soluble in water and acid solutions. Immunotropic and anticoagulating properties of the compound were evaluated in comparison with heparin. It was demonstrated that fucoidan in wide range of doses stimulated phagocytic and bactericidic activity at leucocytes of mice peritoneal exudate. Heparin on the contrary demonstrated depressive effect on these functions at high dose. It was shown that fucoidan has dose-dependent anticoagulating activity in vitro and in vivo comparable with heparin activity. The results of investigation demonstrated possibility of fucoidan application as immunomodulating and anticoagulating agent of plant origin.  相似文献   
10.
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