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131.
Dr. Gottfried Bringmann 《Planta》1952,40(5):398-406
Zusammenfassung In den Zellzentren von Schizophyten können außer Desoxyribonukleinsäure — die den kernäquivalenten Charakter der Organelle begründet — Ribonukleinsäure, Phosphate und Lipoide nachgewiesen werden. Das Vorhandensein dieser Stoffgruppen macht Beziehungen der Zellzentren zu den Mitochondrien höher organisierter Zellen wahrscheinlich. Desoxyribonukleinsäurekomplexe der Kernäquivalente und Phosphatkörper der Mitochondrienäquivalente haben — obwohl Komponenteneines Organells — eine gesonderte ontogenetische Entwicklung.Der gemeinsame Ursprung der phylogenetischen Entwicklung von Zellkern und Mitochondrien bzw. von diesen ableitbaren Zellorganellen (Plastiden) wird als möglich angesehen. Die Rolle dieser Organelle als Organisationszentren erscheint durch die aufgezeigten Zusammenhänge unter neuen Gesichtspunkten.Mit 2 Textabbildungen. 相似文献
132.
133.
Arthur L. Kellermann 《The Western journal of medicine》1995,162(5):473-474
134.
Due to post-translational modifications such as phosphorylation, proteins exist as distinct charge variants. Two-dimensional (2D) gel electrophoresis followed by immunoblotting enables the detection of these isoforms. For their accurate relative quantitation in different samples, a loading control is necessary to compensate for technical errors such as imprecise sample loading or transfer. The study reveals that the combinatory approach of SYPRO Ruby and chemiluminescence-based 2D Western blot analysis exhibits high linearity and excellent reproducibility and is applicable for limited sample amounts. 相似文献
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136.
Strategies for the development of diagnostic products for acquired immune deficiency syndrome (AIDS) are inextricably linked to the status of our knowledge of the human immunodeficiency virus (HIV) and the events associated with the pathogenesis of AIDS. This review traces product development strategies from 1984 to the present day. Product development activities in the HIV-1 antibody screening test market were a response to the need to remove contaminated units from the blood supply. With the successes in screening blood and blood products, there has been a shift towards product development for personal health care and applicant suitability. Identification of markers for disease progression and the need to monitor therapeutic efficacy is now leading to tests for patient disease staging, monitoring and prognosis. 相似文献
137.
The Peyer's patch microenvironment suppresses T cell responses to chemokines and other stimuli. 总被引:1,自引:0,他引:1
Immunosurveillance of mucosal sites presents immune cells with challenges not encountered in the periphery. T cells in the gut must distinguish enteric pathogens from innocuous non-self Ag derived from food or commensal bacteria. The mechanisms that regulate T cells in the gut remain incompletely understood. We assessed the effect of the Peyer's patch microenvironment on T cell responses to chemokines. Chemokines are believed to play an important role during T cell priming by facilitating T cell migration into and within lymphoid tissues as well as T cell encounter and interaction with APCs. We found a profound suppression of chemokine-stimulated T cell chemotaxis and actin polymerization in Peyer's patch relative to lymph node. Chemokine hyporesponsiveness is imposed upon T cells within hours of their entry into Peyer's patches and is reversed following their removal. Suppression was not restricted to chemokine stimulation, as T cell responses to Con A and PMA were also suppressed. The global nature of this defect is further underscored by an impairment in calcium mobilization. Evidence indicates that a soluble factor contributes to this hyporesponsiveness, and comparison of Peyer's patches and lymph nodes revealed striking differences in their chemokine and cytokine constitution, indicating a marked Th2 bias in the Peyer's patches. The role of the Th2 microenvironment in mediating suppression is suggested by the ability of Nippostrongylus brasiliensis to elicit hyporesponsiveness in lymph node T cells. The suppressive milieu encountered by T cells in Peyer's patches may be critical for discouraging undesired immune responses and promoting tolerance. 相似文献
138.
Genome‐wide SNP analysis unveils genetic structure and phylogeographic history of snow sheep (Ovis nivicola) populations inhabiting the Verkhoyansk Mountains and Momsky Ridge (northeastern Siberia)
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Arsen V. Dotsev Tatiana E. Deniskova Innokentiy M. Okhlopkov Gabor Mészáros Johann Sölkner Henry Reyer Klaus Wimmers Gottfried Brem Natalia A. Zinovieva 《Ecology and evolution》2018,8(16):8000-8010
Insights into the genetic characteristics of a species provide important information for wildlife conservation programs. Here, we used the OvineSNP50 BeadChip developed for domestic sheep to examine population structure and evaluate genetic diversity of snow sheep (Ovis nivicola) inhabiting Verkhoyansk Range and Momsky Ridge. A total of 1,121 polymorphic SNPs were used to test 80 specimens representing five populations, including four populations of the Verkhoyansk Mountain chain: Kharaulakh Ridge–Tiksi Bay (TIK, n = 22), Orulgan Ridge (ORU, n = 22), the central part of Verkhoyansk Range (VER, n = 15), Suntar‐Khayata Ridge (SKH, n = 13), and Momsky Ridge (MOM, n = 8). We showed that the studied populations were genetically structured according to a geographic pattern. Pairwise FST values ranged from 0.044 to 0.205. Admixture analysis identified K = 2 as the most likely number of ancestral populations. A Neighbor‐Net tree showed that TIK was an isolated group related to the main network through ORU. TreeMix analysis revealed that TIK and MOM originated from two different ancestral populations and detected gene flow from MOM to ORU. This was supported by the f3 statistic, which showed that ORU is an admixed population with TIK and MOM/SKH heritage. Genetic diversity in the studied groups was increasing southward. Minimum values of observed (Ho) and expected (He) heterozygosity and allelic richness (Ar) were observed in the most northern population—TIK, and maximum values were observed in the most southern population—SKH. Thus, our results revealed clear genetic structure in the studied populations of snow sheep and showed that TIK has a different origin from MOM, SKH, and VER even though they are conventionally considered a single subspecies known as Yakut snow sheep (Ovis nivicola lydekkeri). Most likely, TIK was an isolated group during the Late Pleistocene glaciations of Verkhoyansk Range. 相似文献
139.
Accumulation of the chalcone isosalipurposide in primary leaves of barley flavonoid mutants indicates a defective chalcone isomerase 总被引:3,自引:0,他引:3
Sebastian Reuber Barbro Jende-Strid Victor Wray Gottfried Weissenböck 《Physiologia plantarum》1997,101(4):827-832
Mutants defective in flavonoid biosynthesis have become increasingly useful in elucidating the potential functions of these compounds in plants. To define the role of flavonoids as UV-B protectants in barley, we have screened part of the collection of proanthocyanidin-free barley mutants at the Carlsberg Research Laboratory, Copenhagen, Denmark. The four mutants ant 30–245, ant 30–272, ant 30–287 and ant 30–310 showed drastically reduced flavonoid levels in the primary leaf as compared to their corresponding parent varieties, and in addition accumulated a new mutant-specific phenolic compound which was identified as the chalcone glucoside isosalipurposide. Results from diallelic crosses indicate that all four mutants belong to the same new complementation group, which is designated as the Ant 30 locus. This gene has not earlier been described in barley. The data presented suggest a defective chalcone isomerase gene for the observed flavonoid pattern in leaves of ant 30 mutants. 相似文献
140.
Corinna Weinz Gottfried Blaschke Hans-Martin Schiebel 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1997,690(1-2):233-242
Due to our interest in drugs with a glutarimide structure, we reinvestigated the stereoselectivity of the in vitro biotransformation of the chiral hypnotic-sedative drug glutethimide. Glutethimide enantiomers were separated on a preparative scale by HPLC on cellulose tris(4-methylbenzoate) as chiral stationary phase. The enantiometric purity was higher than 99%. A reversed-phase HPLC method was developed to determine the metabolites of glutethimide. After incubations with rat liver microsomes both enantiomers formed 5-hydroxyglutethimide as the main metabolite, as well as additional metabolites, of which some were formed stereoselectivity. Mass spectrometry of the unknown metabolites indicated a hydroxylation in the ethyl side chain for two of the metabolites. A third metabolite was tentatively identified as desethylgutethimide. 相似文献