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651.
652.
The ability of isolated pea-shoot mitochondria conditioned to incorporate ammonia into glutamate to reassimilate endogenously produced ammonia from glycine transformation was investigated. In the presence of 1 mM to 20 mM glycine less than 15% of the ammonia liberated was found to be incorporated into glutamate. Thus, a prominent role of mitochondrial glutamate dehydrogenase in the reassimilation of intramitochondrially produced ammonia can be excluded.Abbreviation GDH
Glutamate dehydrogenase (L-glutamate: NAD+ oxidoreductase (deaminating), EC 1.4.1.2) 相似文献
653.
Guido Bonthond Till Bayer Stacy A. Krueger-Hadfield Nadja Strck Gaoge Wang Masahiro Nakaoka Sven Künzel Florian Weinberger 《The ISME journal》2021,15(6):1668
Invasive species are co-introduced with microbiota from their native range and also interact with microbiota found in the novel environment to which they are introduced. Host flexibility toward microbiota, or host promiscuity, is an important trait underlying terrestrial plant invasions. To test whether host promiscuity may be important in macroalgal invasions, we experimentally simulated an invasion in a common garden setting, using the widespread invasive macroalga Agarophyton vermiculophyllum as a model invasive seaweed holobiont. After disturbing the microbiota of individuals from native and non-native populations with antibiotics, we monitored the microbial succession trajectories in the presence of a new source of microbes. Microbial communities were strongly impacted by the treatment and changed compositionally and in terms of diversity but recovered functionally by the end of the experiment in most respects. Beta-diversity in disturbed holobionts strongly decreased, indicating that different populations configure more similar –or more common– microbial communities when exposed to the same conditions. This decline in beta-diversity occurred not only more rapidly, but was also more pronounced in non-native populations, while individuals from native populations retained communities more similar to those observed in the field. This study demonstrates that microbial communities of non-native A. vermiculophyllum are more flexibly adjusted to the environment and suggests that an intraspecific increase in host promiscuity has promoted the invasion process of A. vermiculophyllum. This phenomenon may be important among invasive macroalgal holobionts in general.Subject terms: Symbiosis, Molecular ecology, Microbial ecology 相似文献
654.
Abstract Non-acid and acid glycolipids were isolated from the small intestine of a newborn calf and tested for the ability to bind Escherichia coli carrying K99 fimbriae. The bacteria did not bind to any of the non-acid glycolipids, whereas in the acid glycolipid fraction several gangliosides were detected which bind to K99 fimbriae. Gangliosides capable of binding K99 fimbriated E. coli were characterized as NeuGc-GM3, NeuGc-GM2, NeuGc-GD1a NeuAc-SPG and NeuAc-SPG. No binding was detected to NeuAc-GM3 and NeuGc-GM1. 相似文献
655.
Host-Virus Interaction in Ribonucleic Acid Bacteriophage-Infected Escherichia coli: I. Location of “Late” MS2-Specific Ribonucleic Acid Synthesis 总被引:3,自引:3,他引:0 下载免费PDF全文
When actinomycin-treated, MS2-infected Escherichia coli are labeled during a brief period later than 16 min after infection, the newly synthesized MS2 ribonucleic acid (RNA) appears first in the 30,000 x g sediment, probably bound to fragments of bacterial membranes, since the radioactivity can be released from the sediment with deoxycholate or urea. With longer labeling times, radioactivity also appears in the 30,000 x g supernatant fluid. While on the membrane, the RNA is organized into particles with sedimentation coefficients of 40, 32, and 27S in the presence of low Mg(2+). In the presence of high Mg(+), MS2-specific RNA is found in polyribosomes. These data are interpreted to mean that MS2-specific RNA is synthesized and organized into larger structures on membrane. More than 8 min of labeling is required before radioactivity is found in the 81S virion which appears in the supernatant fluid. 相似文献
656.
Cynthia L. Mundy Nadja Patenge Adam G. W. Matthews Marjorie A. Oettinger 《Molecular and cellular biology》2002,22(1):69-77
Assembly of antigen receptor genes by V(D)J recombination requires the site-specific recognition of two distinct DNA elements differing in the length of the spacer DNA that separates two conserved recognition motifs. Under appropriate conditions, V(D)J cleavage by the purified RAG1/RAG2 recombinase is similarly restricted. Double-strand breakage occurs only when these proteins are bound to a pair of complementary signals in a synaptic complex. We examine here the binding of the RAG proteins to signal sequences and find that the full complement of proteins required for synapsis of two signals and coupled cleavage can assemble on a single signal. This complex, composed of a dimer of RAG2 and at least a trimer of RAG1, remains inactive for double-strand break formation until a second complementary signal is provided. Thus, binding of the second signal activates the complex, possibly by inducing a conformational change. If synaptic complexes are formed similarly in vivo, one signal of a recombining pair may be the preferred site for RAG1/RAG2 assembly. 相似文献