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51.
正出版:高等教育出版社出版时间:2018年7月ISBN:978-7-04-049873-8定价:180元内容简介本书原版是国际上最具声誉的微生物学教科书之一,2017年最新版次为第10版。本书秉承《Prescott微生物学》一直以来博大精深、新颖、系统的特点,几乎涵盖了微生物学领域的所有概念,具有一定的深度和广度。全书共9篇43章,既包含学习微生物学的目的、微生物学的化学原理、研究微生物的技术方法、微生物的特 相似文献
52.
Murine leukemia virus envelope protein in transgenic-mouse serum blocks infection in vitro. 下载免费PDF全文
Transgenic mice bearing a murine retroviral envelope transgene (Fv4) have Fv4 gp70env (SU) in their serum in amounts sufficient to block infection by ecotropic virus in vitro. Fv4 Env in serum is derived largely but not exclusively from hematopoietic cells. Tail cells from Fv4 mice and cell lines transduced with the Fv4 env transgene synthesize both components of the envelope protein (gp70 SU and p15E TM) but secrete the gp70 moiety, in the absence of retroviral particles. Blocking of the ecotropic viral receptor by secreted gp70 SU may contribute to resistance to retroviral infection in these mice. 相似文献
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54.
Evolution of eutherian cytochrome c oxidase subunit II: heterogeneous rates of protein evolution and altered interaction with cytochrome c 总被引:3,自引:1,他引:2
Cytochrome c oxidase subunit II (COII), encoded by the mitochondrial
genome, exhibits one of the most heterogeneous rates of amino acid
replacement among placental mammals. Moreover, it has been demonstrated
that cytochrome c oxidase has undergone a structural change in higher
primates which has altered its physical interaction with cytochrome c. We
collected a large data set of COII sequences from several orders of mammals
with emphasis on primates, rodents, and artiodactyls. Using phylogenetic
hypotheses based on data independent of the COII gene, we demonstrated that
an increased number of amino acid replacements are concentrated among
higher primates. Incorporating approximate divergence dates derived from
the fossil record, we find that most of the change occurred independently
along the New World monkey lineage and in a rapid burst before apes and Old
World monkeys diverged. There is some evidence that Old World monkeys have
undergone a faster rate of nonsynonymous substitution than have apes. Rates
of substitution at four-fold degenerate sites in primates are relatively
homogeneous, indicating that the rate heterogeneity is restricted to
nondegenerate sites. Excluding the rate acceleration mentioned above,
primates, rodents, and artiodactyls have remarkably similar nonsynonymous
replacement rates. A different pattern is observed for transversions at
four-fold degenerate sites, for which rodents exhibit a higher rate of
replacement than do primates and artiodactyls. Finally, we hypothesize
specific amino acid replacements which may account for much of the
structural difference in cytochrome c oxidase between higher primates and
other mammals.
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55.
56.
Effects of EDTA treatment upon the protein subunit composition and mechanical properties of mammalian single skeletal muscle fibers 总被引:9,自引:0,他引:9 下载免费PDF全文
Considerable interest has been focused on the role of myosin light chain LC(2) in the contraction of vertebrate striated muscle. A study was undertaken to further our investigations (Moss, R.L., G.G. Giulian, and M.L. Greaser, 1981, J. Biol. Chem., 257:8588-8591) of the effects of LC(2) removal upon contraction in skinned fibers from rabbit psoas muscles. Isometric tension and maximum velocity of shortening, V(max), were measured in fiber segments prior to LC(2) removal. The segments were then bathed at 30 degrees C for up to 240 min in a buffer solution containing 20 mM EDTA in order to extract up to 60 percent of the LC(2). Troponin C (TnC) was also partially removed by this procedure. Mechanical measurements were done following the EDTA extraction and the readditions of first TnC and then LC(2) to the segments. The protein subunit compositions of the same fiber segments were determined following each of these procedures by SDS PAGE of small pieces of the fiber. V(max) was found to decrease as the LC(2) content of the fiber segments was reduced by increasing the duration of extraction. EDTA treatment also resulted in substantial reductions in tension due mainly to the loss of TnC, though smaller reductions due to the extraction of LC(2) were also observed. Reversal of the order of recombination of LC(2) and TnC indicated that the reduction in V(max) following EDTA treatment was a specific effect of LC(2) removal. These results strongly suggest that LC(2) may have roles in determining the kinetics and extent of interaction between myosin and actin. 相似文献
57.
Production of acquired immunodeficiency syndrome-associated retrovirus in human and nonhuman cells transfected with an infectious molecular clone. 总被引:284,自引:193,他引:91 下载免费PDF全文
A Adachi H E Gendelman S Koenig T Folks R Willey A Rabson M A Martin 《Journal of virology》1986,59(2):284-291
We constructed an infectious molecular clone of acquired immunodeficiency syndrome-associated retrovirus. Upon transfection, this clone directed the production of infectious virus particles in a wide variety of cells in addition to human T4 cells. The progeny, infectious virions, were synthesized in mouse, mink, monkey, and several human non-T cell lines, indicating the absence of any intracellular obstacle to viral RNA or protein production or assembly. During the course of these studies, a human colon carcinoma cell line, exquisitely sensitive to DNA transfection, was identified. 相似文献
58.
59.
Bombesin and the C-terminal tetradecapeptide of gastrin-releasing peptide are growth factors for normal human bronchial epithelial cells 总被引:25,自引:0,他引:25
Bombesin and the C-terminal portion of gastrin-releasing peptide (GRP14-27) each increase clonal growth rate and colony-forming efficiency of normal human bronchial epithelial cells. These effects occur in the presence or absence of an optimal concentration (5 ng/ml) of epidermal growth factor (EGF). In contrast to EGF bombesin and GRP14-27 do not stimulate cell migration. Thus, bombesin and the C-terminal fragment of gastrin-releasing peptide represent a new class of peptides mitogenic for normal human epithelial cells. 相似文献
60.
Paired sequence difference in ribosomal RNAs: evolutionary and phylogenetic implications 总被引:12,自引:1,他引:11
Ribosomal RNAs have secondary structures that are maintained by internal
Watson-Crick pairing. Through analysis of chordate, arthropod, and plant 5S
ribosomal RNA sequences, we show that Darwinian selection operates on these
nucleotide sequences to maintain functionally important secondary
structure. Insect phylogenies based on nucleotide positions involved in
pairing and the production of secondary structure are incongruent with
those constructed on the basis of positions that are not. Furthermore,
phylogeny reconstruction using these nonpairing bases is concordant with
other, morphological data.
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