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1.
Class II HLA molecules are the most useful markers for susceptibility to different autoimmune diseases, including insulin-dependent diabetes mellitus (IDDM) and rheumatoid arthritis (RA). Polymerase chain reaction and hybridization with a set of allele-specific oligonucleotide have been used for analysis of allelic sequence variation. The analysis of frequencies of HLA-DQA1 alleles among 10 patients of the russian population revealed a uneven distribution. We have developed a method for preparing non-radioactive oligonucleotide probes with terminal deoxynucleotidyl transferase and Bio-11-dUTP. Comparison of biotinylated and 32P-labeled hybridization probes gave the same sensitivity for HLA-DQA1 typing of amplified DNA. Amplification of the HLA-DQA1 gene has been successful on 10 pg of total DNA. This amount of DNA is close to the amount of DNA in a single cell. Alternatively, HLA-DQA1 typing could be based on the analysis of buccal cells of saliva that would avoid the problem of individuals who object to giving blood samples. 相似文献
2.
The optical properties of the complexes of the pH-dependent dye bromophenol blue (BPB) with human serum albumin were investigated by the spectrophotometric method. The solvatochromic longwave displacement of bound BPB-2 absorption and BPB-1/BPB-2 redistribution were shown to form the optical signal of complexes. Because of the distortion of the bound BPB-2 signal its quantity was determined as delta A630 = A630 - A660 and the use of lambda max as structural parameter was limited to low pH less than or equal to 3. The conclusion was made that BPB is inapplicable as a structural probe on account of low structural dependence of delta A630 and pH-limitation of lambda max used. The maximal absorption delta Amax = Amax - A660 and its structural independence were obtained in the region of 70-100% occupation of the dye-binding centers of the protein. It is the optimal conditions for the quantitative determination of protein. After maximal dye binding (15-16 molecules of BPB per 1 molecule of albumin) the aggregation and precipitation of the complexes occurred. 相似文献
3.
Nielsen J; Peixoto AA; Piccin A; Costa R; Kyriacou CP; Chalmers D 《Molecular biology and evolution》1994,11(6):839-853
The region of the clock gene period (per) that encodes a repetitive tract
of threonine-glycine (Thr-Gly) pairs has been compared between Dipteran
species both within and outside the Drosophilidae. All the non-
Drosophilidae sequences in this region are short and present a remarkably
stable picture compared to the Drosophilidae, in which the region is much
larger and extremely variable, both in size and composition. The
accelerated evolution in the repetitive region of the Drosophilidae appears
to be mainly due to an expansion of two ancestral repeats, one encoding a
Thr-Gly dipeptide and the other a pentapeptide rich in serine, glycine, and
asparagine or threonine. In some drosophilids the expansion involves a
duplication of the pentapeptide sequence, but in Drosophila pseudoobscura
both the dipeptide and the pentapeptide repeats are present in larger
numbers. In the nondrosophilids, however, the pentapeptide sequence is
represented by one copy and the dipeptide by two copies. These observations
fulfill some of the predictions of recent theoretical models that have
simulated the evolution of repetitive sequences.
相似文献
4.
Iu A Barshte?n A F Frolov Iu V Persidski? S V Gavrilov 《Mikrobiologicheekij zhurnal》1989,51(4):44-50
The dynamic light-optic and electron microscopic examination of the organs of experimental animals with the influenza infection have revealed the most pronounced pathology in vessels of the lung and brain microcirculation. The early developing perivascular edema around capillaries which is induced by an increase in the transcellular transport without a disturbance of the dense contact integrity is observed in the brain tissue. Variations in the lung microvessels manifested in a rise of the pinocytosis activity of endothelial cells, in a change of the luminal surface profile and damage of the supermembrane layer. A reversible aggregation of plate and erythrocytes was observed in the lung and brain microvessel lumen at early periods. The revealed changes, including the main of them--microvessel permeability disturbance, are associated with the dynamics of the concentration of the influenza virus and its complexes with antibodies in the organs under study. 相似文献
5.
Evolutionary origin of human and primate malarias: evidence from the circumsporozoite protein gene 总被引:8,自引:1,他引:7
We have analyzed the conserved regions of the gene coding for the
circumsporozoite protein (CSP) in 12 species of Plasmodium, the malaria
parasite. The closest evolutionary relative of P. falciparum, the agent of
malignant human malaria, is P. reichenowi, a chimpanzee parasite. This is
consistent with the hypothesis that P. falciparum is an ancient human
parasite, associated with humans since the divergence of the hominids from
their closest hominoid relatives. Three other human Plasmodium species are
each genetically indistinguishable from species parasitic to nonhuman
primates; that is, for the DNA sequences included in our analysis, the
differences between species are not greater than the differences between
strains of the human species. The human P. malariae is indistinguishable
from P. brasilianum, and P. vivax is indistinguishable from P. simium; P.
brasilianum and P. simium are parasitic to New World monkeys. The human P.
vivax-like is indistinguishable from P. simiovale, a parasite of Old World
macaques. We conjecture that P. malariae, P. vivax, and P. vivax-like are
evolutionarily recent human parasites, the first two at least acquired only
within the last several thousand years, and perhaps within the last few
hundred years, after the expansion of human populations in South America
following the European colonizations. We estimate the rate of evolution of
the conserved regions of the CSP gene as 2.46 x 10(-9) per site per year.
The divergence between the P. falciparum and P. reichenowi lineages is
accordingly dated 8.9 Myr ago. The divergence between the three lineages
leading to the human parasites is very ancient, about 100 Myr old between
P. malariae and P. vivax (and P. vivax-like) and about 165 Myr old between
P. falciparum and the other two.
相似文献
6.
Photosynthetic enhancement studies performed at 619 nm (excitation of Systems I and II) and at 446 nm (mainly excitation of System I) revealed an 18% photosynthetic enhancement simultaneously with a 31% reduction in glycolate excretion. This observation supports the hypothesis that some glycolate may be consumed in an oxidation process associated with System I when System II is poorly excited and the supply of electrons from the water splitting process of photosynthesis is low. 相似文献
7.
During fetal life, formation and arrangement of the microcirculatory bed in the serous membrane of the sigmoid colon correspond to the growth and functioning of the latter at different stages of ontogenesis. Two periods in the development of the microcirculatory bed of the serous membrane of the sigmoid colon are revealed: the first period coincides with the first half of the fetal development when capillary growth is considerable, i.e. with the growth of metabolic part in the microcirculatory bed; the second period coincides with the second half of the fetal development when intensified growth of the sigmoid portion of the large intenstine and its transport sections in the microcirculatory bed (arterioles, precapillaries, postcapillaries, venules) are observed. 相似文献
8.
9.
V A Gabassov E G Popov I Iu Gavrilov E Ia Pozin R A Markosian 《Biulleten' eksperimental'no? biologii i meditsiny》1989,108(10):437-440
A new approach to the investigation of the kinetics of platelet aggregation is described. The method is based on the analysis of light transmission fluctuations produced on the changes in the number of platelets in optical channel. The relative dispersion of the fluctuations of transmitted light intensity was used as a parameter to estimate the degree of platelet aggregation. Application of this method for the analysis of platelet aggregation permits to get new information about this process. 相似文献
10.