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51.
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DISTRIBUTION AND TURNOVER OF PHOSPHATE COMPOUNDS IN GROWING CHLORELLA CELLS   总被引:1,自引:0,他引:1  
  1. Using the Chlorella cells which had been uniformly labeled with32P, the distribution of phosphorus in various fractions ofcell material was investigated. Uniformly 32P-labeled Chlorellawas further grown in a P-free medium or in a standard "cold"medium, and the change of distribution of 32P (as well as theuptake of exogenous P) in various cell fractions was followed.
  2. Analysis of the 32P-labeled algal cells showed that the highestin P-content was the fraction of RNA followed by those of polyphosphates,lipid, nucleotidic labile phosphate compounds, DNA and protein(in decreasing order). ATP and ADP were found to be only minorfractions of the total labile phosphates.
  3. On incubating the3P-labeled alga in a P-free medium, the P.contentsin the fractionsof DNA, protein, lipid and ATP increased, thosein polyphosphatesand ADP decreased, and that in RNA remainedalmost unchanged.When the 32P-labeled alga was further grownin the normal "cold"medium, DNA and protein increased withthe expenditure of endogenous32P, but with practically no incorporationof external P. Inthe meantime the P in polyphosphates decreasedconsiderably,and the RNA fraction incorporated a large amountof externalP but only a little of endogenous32P.
  4. It was inferred that,under the experimental conditions of thepresent study, thephosphorus used in the syntheses of DNA andprotein was primarilytaken from polyphosphates, while thatused in the synthesesof RNA, phospholipid and polyphosphateswas, for the most part,taken from the extracellular P-source.
1A part of this paper was read at the Vth International Congressof Biochemistry, Moscow, August 10–16, 1961. (Received June 4, 1961; )  相似文献   
54.
  1. Chlorella ellipsoidea was grown synchronously using variouspossible techniques and the mode of nuclear division in eachcase was followed by staining the nuclei according to FEULGEN.
  2. A satisfactory synchrony in respect to nuclear and cellulardivision was obtained by starting the culture from a homogeneouspopulation of young and small cells and by discontinuing theillumination at the stage which was called the L3-stage. Thestarting young cells were invariably mononuclear and the L3-cellswere either dinuclear or tetranuclear. When the L3 were incubatedin the dark, they ripened further, and after passing througha tetranuclear stage (referred to as the L4) divided into fourmononuclear daughter cells which have been called the Dn-cells.The most clear-cut and repetitive synchronous culture was obtainedwhen the culture (in the light) was started from the Dn-cellsand the illumination was discontinued at the L3-stage untilthe fully ripened cells divided into four each of Dn-cells.
  3. An apparently "synchronous" culture was also obtained by themethod of programmed light-and-dark regimen, in which a randomculture is subjected to a regular alternation of light and darkperiods of adequate durations. In this case, however, the cellsat different stages of culture showed irregular nuclear patterns,and the average "division number" of mother cells was not constant,being subject to change between 4.0 and 4.9.
(Received May 25, 1961; )  相似文献   
55.
We investigated the embryology of the ‘lower’ monimioids, i.e. Monimioideae (Monimia, Palmeria and Peumus) and Hortonioideae (Hortonia), which are poorly described embryologically. Our results show that, contrary to what has been reported in the literature, ‘lower’ monimioids show very little variation in their embryological characters. Comparisons with Mollinedioideae (a large derived subfamily in Monimiaceae) and other families in Laurales show that the ‘lower’ monimioids are relatively consistent in sharing predominantly isobilateral tetrads of microspores and megaspores, a non‐specialized chalaza, and a mesotestal–endotestal seed coat (with tracheoidal cells of the meso‐ and endotesta). It is likely that, while the shared successive cytokinesis during meiosis of microspore mother cells supports the Monimiaceae–Hernandiaceae–Lauraceae clade obtained by molecular evidence, no synapomorphies exist to support a sister‐group relationship of Monimiaceae with Hernandiaceae or Lauraceae. Instead, the lack of hypostase in ovules and/or young seeds, the lack of endosperm in mature seeds and the amoeboid tapetum in the anther are likely synapomorphies of Hernandiaceae and Lauraceae. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 228–241.  相似文献   
56.
Luciobliviidae, a new family in the superfamily Gammaroidea (Amphipoda: Crustacea), is described on the basis of species in the genus Lucioblivio gen. nov. from subterranean waters of Japan. Mesogammaridae Bousfield, 1977 is rediagnosed; Octopupilla gen. nov. from subterranean waters of Japan is described and Eoniphargus (Uéno, 1955) from subterranean waters of Japan and Korea is included. The members of Lucioblivio , Octopupilla and Eoniphargus share several characters, including reduced eyes, a setose body, reduced coxae, feeble appendages and pedunculate coxal gills. To elucidate the phylogeny of the three genera among others, a sequence analysis of the 28S rRNA gene was conducted for 14 species in six families, including the three genera, from the superfamilies, Gammaroidea, Crangonyctoidea and Hadzioidea. The tree from a neighbour-joining analysis and the strict consensus tree from a maximum-parsimony analysis indicate monophyly of Mesogammaridae. Luciobliviidae is embedded within a clade of taxa belonging to the superfamily Gammaroidea. These results and the occurrence of gammarid-type calceoli in species of the new family indicate that Luciobliviidae should be placed within the superfamily Gammaroidea. © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society , 2007, 149 , 643–670.  相似文献   
57.
Lauraceae are relatively well-known embryologically and embryological data are available for 23 of about 50 genera. In this paper we present the embryology of Eusideroxylon , an unstudied and key genus within Cryptocaryeae, which are positioned basally in the evolution of Lauraceae, and discuss the evolution of embryological characters in the family. Based on comparisons of over 50 characters, it was found that Eusideroxylon is consistent with Aspidostemon , the core Cryptocaryeae ( Beilschmiedia , Cryptocarya , Endiandra and Potameia ), Caryodaphnopsis and Cassytha in having a glandular anther tapetum. The core Cryptocaryeae further agrees with both Caryodaphnopsis and Cassytha in having an embryo sac protruding from the nucellus. In light of the phylogenetic trees available, both the glandular tapetum and the embryo sac protruding from the nucellus have evolved as homoplasies in Lauraceae, once each in a clade of Cryptocaryeae, and the Caryodaphnopsis and Cassytha clade, respectively. Such character-state distributions suggest that it is better to place both Caryodapnopsis and Cassytha in the same clade as the core Cryptocaryeae. Embryologically, Eusideroxylon appears to have an intermediate state between Hypodaphnis , a genus positioned basal-most in the family, and the core Cryptocaryeae. Supplementary data on the anther and seed of Hypodaphnis are also provided.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 187–201.  相似文献   
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Crude extracts of Bombyx mori brains can provoke adult development when injected into brain-removed dormant pupae of Bombyx mori and Samia Cynthia ricini. From this fact the prothoracicotropic hormone (PTTH) of Bombyx has long been thought to be species-nonspecifically active on Samia. Chemical fractionation of Bombyx brain or head extracts by fractional precipitation with acetone, Sephadex G-50 gel-filtration, and DEAE-Sepharose CL-6B chromatography, however, separated the fractions which activated Bombyx brainless pupae from those which activated Samia. Those results reveal the existence of two species-specific PTTHs.  相似文献   
60.
Twenty monoclonal antibodies were produced against trophozoites of Entamoeba histolytica strains HK-9 and HM-1: IMSS. When reactivity to various enteric protozoa was examined by an indirect fluorescence antibody test, 15 of the monoclonal antibodies were strongly reactive with E. histolytica trophozoites. Species-specific antigens recognized by these monoclonal antibodies were located on the plasma membrane, nucleus, cytoplasm, and cytoskeletal structures of the trophozoites. Two of the remaining five monoclonals reacted strongly with trophozoites of the E. histolytica -like Laredo strain. The determinant antigen was located in the cytoplasm. The three remaining monoclonal antibodies were found to recognize cross-reactive antigens between E. histolytica and E. histolytica -like Laredo, E. hartmanni, E. coli, Dientamoeba fragilis, Giardia lamblia , and Trichomonas hominis. These three antibodies were also reactive with T. vaginalis  相似文献   
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