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991.
Linoleic acid and linolenic acid elongation products in muscle tissue of Syncerus caffer and other ruminant species 下载免费PDF全文
The metabolic elongation products of both linoleic acid and linolenic acid were found in muscle tissues of Syncerus caffer and other ruminants. The acids with four double bonds were predominantly in the linoleic acid series, whereas the higher degrees of unsaturation, mainly five double bonds, were in the linolenic acid series. The total linoleic acid and linolenic acid groups were present in the relative proportions of about 4:1, in contrast with the fish oils, where the acids are mainly in the linolenic acid series. The consistent occurrence of members of both groups of acids in the animals studied here suggests to us that both may be important for structural purposes. 相似文献
992.
993.
994.
Kerryanne Crawford Juan José Bonfiglio Andreja Mikoč Ivan Matic 《Critical reviews in biochemistry and molecular biology》2018,53(1):64-82
Proper and timely regulation of cellular processes is fundamental to the overall health and viability of organisms across all kingdoms of life. Thus, organisms have evolved multiple highly dynamic and complex biochemical signaling cascades in order to adapt and survive diverse challenges. One such method of conferring rapid adaptation is the addition or removal of reversible modifications of different chemical groups onto macromolecules which in turn induce the appropriate downstream outcome. ADP-ribosylation, the addition of ADP-ribose (ADPr) groups, represents one of these highly conserved signaling chemicals. Herein we outline the writers, erasers and readers of ADP-ribosylation and dip into the multitude of cellular processes they have been implicated in. We also review what we currently know on how specificity of activity is ensured for this important modification. 相似文献
995.
Bronwyn A. Crawford Winthrop J. Harewood David J. Handelsman 《Journal of medical primatology》1997,26(3):153-163
Abstract: The semi-longitudinal collection of growth measurements in male and female hamadryas baboons has enabled documentation of the timing of puberty and the development of sexually dimorphic growth patterns in body weight, crown-rump length (CRL), limb lengths, and muscle mass. In addition, another sexually dimorphic characteristic appears to be the presence of a pubertal growth spurt in body weight, and possibly CRL, in male but not female baboons. Serum testosterone levels rose during male development; however, there was a progressive decrease in dehydroepiandrosterone sulfate levels indicating the absence of adrenarche. Insulin-like growth factor-I (IGF-I) and its major binding protein, IGFBP-3, both rose during pubertal development; however, a simultaneous rise in the IGF-I:IGFBP-3 molar ratio suggests other factors may enhance the bioactivity of IGF-I during puberty. A distinct rise in serum osteocalcin levels was also associated with puberty in male baboons. These growth and hormonal changes during puberty in the hamadryas baboon indicate that this species provides a close primate model for human puberty. 相似文献
996.
We have isolated a haploid cell line of N. plumbaginifolia, hNP 588, that is constitutive and not inducible for nitrate reductase. Nitrate reductase mutants were isolated from hNP 588 protoplasts upon UV irradiation. Two of these nitrate reductase-deficient cell lines, nia 3 and nia 25, neither of which contained any detectable nitrate reductase activity, were selected for complementation studies. A cloned Arabidopsis thaliana nitrate reductase gene Nia 2 was introduced into each of the two mutants resulting in 56 independent kanamycin-resistant cell lines. Thirty of the 56 kanamycin-resistant cell lines were able to grow on nitrate as the sole nitrogen source. Eight of these were further analyzed for nitrate reductase enzyme activity and nitrate reductase mRNA production. All eight lines had detectable nitrate reductase activity ranging from 7% to 150% of wild-type hNP 588 callus. The enzyme activity levels were not influenced by the nitrogen source in the medium. The eight lines examined expressed a constitutive, non-inducible 3.2 kb mRNA species that was not present in untransformed controls. 相似文献
997.
Liu Junli Crawford John W. Viola Roberto Goodman Bernard 《Plant molecular biology》1997,33(4):573-581
The application of mathematical theories to understanding the behaviour of complex biochemical systems is reviewed. Key aspects of behaviour are identified as the flux through particular pathways in a steady state, the nature and stability of dynamical states, and the thermodynamic properties of systems. The first of these is dealt primarily in theories of metabolic control, and metabolic control analysis (MCA) is an important example. The valid application of this theory is limited to steady-state systems, and the cases where the essential features of control can be derived from calibration experiments which perturb the state of the system by a sufficiently small amount from its operating point. In practice, time-dependent systems exist, it is not always possible to know a priori whether applied perturbations are sufficiently small, and important features of control may lie farther from the operating point than the application of the theory permits. The nature and stability of dynamical and thermodynamical states is beyond the scope of MCA. To understand the significance of these limitations fully, and to address the dynamical and thermodynamical properties, more complete theories are required. Non-linear systems theory offers the possibility of studying important questions regarding control of steady and dynamical states. It can also link to thermodynamic properties of the system including the energetic efficiency of particular pathways. However, its application requires a more detailed characterisation of the system under study. This extra detail may be an essential feature of the study of non-equilibrium states in general, and non-ideal pathways in particular. Progress requires considerably more widespread integration of theoretical and experimental approaches than currently exists. 相似文献
998.
999.
Michael J. Crawford Christian Lanctôt Jacques J. Tremblay Nancy Jenkins Debra Gilbert Neal Copeland Barbara Beatty Jacques Drouin 《Mammalian genome》1997,8(11):841-845
Ptx1 belongs to an expanding family of bicoid-related vertebrate homeobox genes. These genes, like their Drosophila homolog, seem to play a role in the development of anterior structures and, in particular, the brain and facies. We report
the chromosomal localization of mouse Ptx1, and the cloning, sequencing, and chromosomal localization of the human homolog PTX1. The putative encoded proteins share 100% homology in the homeodomain and are 88% and 97% conserved in the N- and C-termini
respectively. Intron/exon boundaries are also conserved. Murine Ptx1 was localized, by interspecific backcrossing, to Chr 13 within 2.6 cM of Caml. The gene resides centrally on Chromosome (Chr) 13 in a region syntenic with human Chr 5q. Subsequent analysis by fluorescent
in situ hybridization places the human gene, PTX1, on 5q31, a region associated with Treacher Collins Franceschetti Syndrome. Taken together with the craniofacial expression
pattern of Ptx1 during early development, the localization of the gene in this chromosomal area is consistent with an involvement in Treacher
Collins Franceschetti Syndrome.
Received: 3 May 1997 / Accepted: 1 July 1997 相似文献
1000.
Identification and genetic mapping of random amplified polymorphic DNA (RAPD) markers to the sheep genome 总被引:2,自引:0,他引:2
The random amplified polymorphic DNA (RAPD) assay utilizes the polymerase chain reaction (PCR) and short primers of arbitrary
nucleotide sequence to amplify DNA. In this study, the RAPD assay was used to identify and map polymorphic markers in the
AgResearch International Mapping Flock (IMF) sheep pedigrees. Sires and dams of eight of the full-sib IMF pedigrees were screened
with 131 different 10-mer oligonucleotide primers. An average of 85 RAPD polymorphisms was identified between each parental
pair, and 53 markers were contributed to the AgResearch IMF collaboration. Forty-five of the RAPD markers were mapped in the
AgResearch IMF genetic linkage map, and at least one marker was located on 17 of the 26 autosomes and both sex chromosomes.
Three lines of evidence were used to check for the homology of scored polymorphisms in different pedigrees, pedigree evaluation,
segregation analysis, and Southern blot analysis. These results demonstrate that the RAPD assay is a powerful approach for
identifying polymorphisms that can be used as markers for constructing a sheep genetic linkage map.
Received: 5 October 1995 / Accepted: 16 April 1996 相似文献