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171.
A. Studer 《Cellular and molecular life sciences : CMLS》1948,4(6):232-233
Summary The hyperplasia and hyperaemia of the thyreoidea of rats caused by thiouracil treatment can be largely avoided by simultaneous doses of vitamin-A methylether. 相似文献
172.
E. Häfliger 《Cellular and molecular life sciences : CMLS》1948,4(6):223-225
Summary The action of DDT on honey-bees depends to a high extent on the temperature (see graph). At 36°C (breeding temperature) DDT has a far weaker insecticidal action than at 20°C (laboratory temperature). This shows that the insecticidal properties of DDT diminish with the raise of temperature.This resistance to DDT at higher temperature is most propitious for bee-keeping and also explains the fact why in agricultural practice there has been no corroborated case of poisoning of bees, though in laboratory tests DDT avered itself to be toxic to bees. 相似文献
173.
A. Valle 《Cellular and molecular life sciences : CMLS》1948,4(10):388-389
Riassunto Nella specieLycides idas L. si osservano variazioni numeriche dei cromosomi anche nelle spermatogonie di uno stesso individuo. Questo fatto è posto in relazione con la presenza nelle femmine dei caratteri secondari dei due sessi, come risultato dell'unione tra gameti con assetti sbilanciati. 相似文献
174.
R. Cavelti 《Cellular and molecular life sciences : CMLS》1948,4(12):489-490
Summary (1) No double refractile Iipoid droplets can be obtained by alcohol ether extraction from urine or from urinary protein as it is possible from blood serum.(2) The conclusion is drawn that the double refractile lipoids droplets in urinary sediment do not pass through the glomeruli and therefore are not reabsorbed by the tubuli, but that they come from the own lipoproteins of the epithelial cells of renal tubuli and pass into urine by dissolution and desquamation of these cells. 相似文献
175.
Summary Five species ofChiroptera were studied and the following numbers were found:Rhinolophus hipposideros Bechst.N=27;Barbastella barbastellus Schr.N=16;Plecotus auritus L.N=16;Myotis myotis Bork.N=21;Miniopterus schreibersii Kuhl,N=23. Centric fusions occur in the chromosomal evolution ofChiroptera. Sex-chromosomes ofX-Y type. 相似文献
176.
1 Results In addition to single wall and multiwall carbon nanotubes[1], several structures,which are more or less related to fullerenes,including carbon nanohorns[2a], carbon nanospheres[2b] and onion like carbon structures[2c] have been reported.A new simple straight forward method to access some of these structures is the solid-state pyrolysis of different organometallic complexes in a sealed vessel,which led so far to carbon nanotubes[3a,b], carbon nanocables[3c] and onions[3d]. 相似文献
177.
1 Results Strongly disordered metals with the high chemical and catalytic activity are often called as skeletal metals.Usually for their preparation the metallides of d-metal (which afterwards will be left in the “skeleton“) and chemically active component(s) are firstly synthesized.Then the last one(s) is (are) removed by the leaching with aqueous solutions of alkalis or carbonates.However,this method sometime fails,first of all,for the reactions,which should be realized in non-aqueous conditions.In th... 相似文献
178.
1 Results Classic oxidants require rigorous control of the experimental conditions added with the problem of lack of selectivity. Catalysis by transition metals with environmentally safe oxidants provides synthetic routes to minimize pollution by giving environmental benign by-products. Fe (Ⅵ) is a powerful and a selective oxidant with Fe(Ⅲ) as a by-product, while hydrogen peroxide is clean with water as the only by-product. Separation of sodium or potassium ferrates requires tedious processes. Associat... 相似文献
179.
1 Results The photosynthetic bacterial reaction center (RC) is a membrane protein complex.The RC is composed of three protein subunits and redox components such as bacteriochlorophylls, bacteriopheophytins,and quinones.The RC performs the photochemical electron transfer from the bacteriochlorophyll dimer through a series of electron donor and acceptor molecules to a secondary quinone,QB.QB accepts electrons from a primary quinone,QA,in two sequential electron transfer reactions.The second electron trans... 相似文献
180.
Yu.Shchipunov 《复旦学报(自然科学版)》2007,(5)
1 Results The entrapment of biopolymers into silica by the sol-gel technique meets with incompatibility of inorganic and bioorganic components. The aim was to develop a compatible procedure biomimicking the biomineralization processes in the living nature. A suggested solution in Ref.[1-2] for the biopolymer entrapment into silica matrix is based on a novel silica precursor. The developed approach is distinguished from the common technique for fabrication of hybrid biopolymer-silica nanocomposite materi... 相似文献