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排序方式: 共有418条查询结果,搜索用时 218 毫秒
71.
Boris Yu. Zaslavsky Nicolai N. Ossipov Sergei V. Rogozhin Yurii L. Sebyakin Ludmila V. Volkova Rimma P. Evstigneeva 《生物化学与生物物理学报:生物膜》1979,556(2):314-321
The hemolytic action of a homologous series of β-d-glucopyranosyl-1-alkylphosphates on human erythrocytes has been examined. The agent's affinity for the red cell membrane and the mean number of the agent's molecules which, upon interaction with an erythrocyte, make it undergo hemolysis have been measured. The contribution of the head group and that of a CH2 group of the surfactants to the free energy of the agents' binding to the cell membrane have been estimated. The effect of the surfactants on the red cell volume and the lytic concentrations of the agents have been measured. The contribution of a CH2 group to the free energy of the interaction of the amphiphiles embedded in the membrane bilayer with their environment has been evaluated and is proposed to be used as a measure of the membrane matrix stability. 相似文献
72.
D. S. Pavlov A. E. Veselov V. V. Kostin D. A. Efremov M. A. Ruchiev S. B. Tuniev 《Journal of Ichthyology》2018,58(1):93-103
Conditions of reproduction and distribution of the Black Sea trout Salmo trutta labrax in the basin of the Mzymta River after Olympic objects′ construction are considered. In the main river channel of the Mzymta, the structure of spawning and nursery grounds are destroyed along 57 km from the river mouth. The total area of these grounds in the Mzymta basin is 572800 m2, and 49% of this area is situated above the dam of the Krasnopolyanskaya Power Plant and is inaccessible for spawners of the migratory form of the Black Sea trout listed in the Red Data Book of the Russian Federation. Consequently, natural reproduction of the migratory form discontinued. The resident form of trout still exists in the upper parts of the Mzymta and in 19 of its tributaries not affected by construction. On the 2.4-km-long stretch of the riverbed situated below the inflow of the Pslukh tributary, the substrate is in the process of natural restoration due to the descent of mudslides followed by washing of the substrate by the flow. The river is partially inhabited by trout individuals from habitats not affected by construction. 相似文献
73.
New genetic evidence of affinities and discontinuities between bronze age Siberian populations
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74.
Ziegfrid G. Gritchenko Lyudmila M. Ivanova Yurii A. Panteleev Natalya A. Tishkova Tarja K. Ikäheimonen Erkki Ilus Ritva Saxen 《Hydrobiologia》1996,322(1-3):125-128
In August 1992 a joint Russian-Finnish expedition was arranged to the NW part of Lake Ladoga to study radioactive contamination in the region. Special attention was paid to the area surrounding the Heinämaa Islands, where the wreck of the former mine carrier ship Kit had been lying about 30 years before it was moved to Novaya Zemlya in 1991. During this period the wreck had been used as a store for radioactive waste containing principally 90Sr, 137Cs and 239,24OPu. Lake water, bottom sediment and some biological samples were collected for strontium, plutonium and gammaspectrometric analyses. In all the samples the radioactivity concentrations were very low, indicating radioactive contamination of about the same level as caused by global fallout in the 1960's and the Chernobyl fallout in the area. Only in two water samples taken close to the former site of the wreck slightly elevated 239,240Pu concentrations were detected. The great water volume of Lake Ladoga and effective water exchange at the wreck site may explain the very low levels of radioactive wastes detected in the aquatic environment. 相似文献
75.
B. Markovska G.D. Efremov S. Vuk-Pavlović B. Benko S. Maričić 《Archives of biochemistry and biophysics》1975,171(1):337-342
Solvent-proton longitudinal magnetic relaxation rates as dependent on temperature were measured for human (H)/canine (C) valency hybrids of the type {αH(III)βC(II)}2 and {αC(II)βH(III)}2. The two metheme irons in the human methemoglobin chains induce quite different proton magnetic relaxation (pmr) rates reflecting a tighter β-heme-pocket compared to the α subunit. Both heme-pockets appear to be loosened in the presence of inositol hexaphosphate (IHP) although this allosteric effector binds only to the β chains, the binding assumed to be the same for canine as for human hemoglobin. The subunit nonequivalence is retained also in the T-quaternary state induced by IHP. In the species hybrids the pmr rates due to the metheme iron are sensitive to the valency (ligand) state, which was either CO or H2O in the partner half of the hybrid. All results show very clearly the interrelationship of the tertiary (protomer) structure with the quaternary (oligomer) structure in hemoglobin. 相似文献
76.
77.
78.
Biljana Cepreganova Jerry B. Wilson Brooke B. Webber Biljana Kjovkareska Georgi D. Efremov Titus H. J. Huisman 《Biochemical genetics》1992,30(7-8):385-399
We have analyzed the hemoglobins of five individual trout from the Ohrid Lake (Salmo L. typicus) by electrophoretic methods, by reversed-phase high-performance liquid chromatography, and by limited structural analyses. The two major classes of hemoglobin are type I (35% of total) and type IV (65%). Type IV is the major oxygen-transporting hemoglobin; it consists of three types of chain (in about equal quantities) and three types of chain (one major and two minor types). Several structural differences have been observed between these three (IV) chains and between the three (IV) chains, suggesting a complex genetic system governing the synthesis of these proteins. Moreover, a few amino acid substitutions occur at positions involved in contacts between chains, which suggests that differences in oxygen affinity may exist between these various type IV hemoglobins. Type I hemoglobin is less complex because it contains one type of chain and two chains; the latter two differ in numerous positions, suggesting duplications of the (I)-globin gene. The and chains of type I hemoglobin differ considerably from the and chains of type IV hemoglobin, indicating the existence of (I)- and (I)-globin genes separate from the (IV)- and (IV)- globin genes.This study was supported in part by the Yugoslav-American Joint Funds, pp 812 (to G.D.E.), and by United States Public Health Service Research Grant HLB-05168 (to T.H.J.H.). 相似文献
79.
The detection of beta-globin gene mutations in beta-thalassemia using oligonucleotide probes and amplified DNA 总被引:2,自引:0,他引:2
J C Diaz-Chico K G Yang K Y Yang D G Efremov T A Stoming T H Huisman 《Biochimica et biophysica acta》1988,949(1):43-48
DNA amplification combined with the use of synthetic oligonucleotide probes has become an important tool in the identification of base substitutions. We report the use of this DNA amplification technique for the detection of mutations in beta-thalassemia. A series of oligonucleotide primers are synthesized which span the beta-globin gene; one primer is complementary to the coding strand and the other to the non-coding strand. The primers are chosen so that there is little homology with other DNA segments, especially the delta gene. Each set of primers spans an area of the gene between 100 and 300 bp, while the suspected mutation point is located between these two primers. With the use of such a primer set, the beta-globin gene region is amplified by denaturation, annealing and DNA synthesis. The amplification cycle is repeated 25-30 times, using the Klenow fragment of DNA polymerase I. The resulting amplified DNA is hybridized with normal and synthetic deoxynucleotide probes using a standard dot-blot method. We have designed a set of primers and experimental conditions which should prove useful to diagnostic centers for detection of numerous beta-thalassemia mutations. 相似文献
80.
G I Nepomniashchikh V N Efremov V P Tumanov L M Nepomniashchikh 《Biulleten' eksperimental'no? biologii i meditsiny》1986,101(1):105-109
Cells obtained by bronchoalveolar lavage from patients with chronic nonspecific pulmonary inflammatory diseases were studied using light and electron microscopy and radioautography. Five morphological forms of alveolar macrophages, distinct in their structure and 3H-uridine content were described. A higher level of RNA synthesis has been revealed in alveolar macrophage forms 2 and 3 than in forms 1, 4 and 5; with it being lower in polymorphonuclear leukocytes and lymphocytes. It was shown that changes in the number of lavage cells and the structure-to-function characteristics in each cellular population depended on the phase of the inflammatory process. It was postulated that structural and metabolic heterogeneity of alveolar macrophages reflected the successive stages of cellular development from cell-precursors (through activation of protein synthesis) to cells with complete lysosomal cycle and the following phagocytosis. 相似文献