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91.
C. Val Grant 《西北部美国博物学家》2011,46(3)
Distribution and abundance of 215 amphibians, reptiles, birds, and mammals were monitored for 10 years on Utah's Oil Shale Tracts using line transects, mist netting, and live trapping. Wildlife monitoring was conducted in four major vegetation types and during all seasons to establish a quantitative baseline for use in impact identification during oil shale mining. Habitat preferences were established for many species in cold desert vegetation of two types of desert shrub, and juniper and riparian woodlands. Seasonal, annual, and habitat distribution of each class demonstrated a variety of adaptive responses to environmental variables. The most important environmental variables, that is, those factors resulting in a predictable change in wildlife populations, were, in descending order: weather, food resource, shelter, and competition. 相似文献
92.
MDC1 is a mediator of the mammalian DNA damage checkpoint 总被引:43,自引:0,他引:43
To counteract the continuous exposure of cells to agents that damage DNA, cells have evolved complex regulatory networks called checkpoints to sense DNA damage and coordinate DNA replication, cell-cycle arrest and DNA repair. It has recently been shown that the histone H2A variant H2AX specifically controls the recruitment of DNA repair proteins to the sites of DNA damage. Here we identify a novel BRCA1 carboxy-terminal (BRCT) and forkhead-associated (FHA) domain-containing protein, MDC1 (mediator of DNA damage checkpoint protein 1), which works with H2AX to promote recruitment of repair proteins to the sites of DNA breaks and which, in addition, controls damage-induced cell-cycle arrest checkpoints. MDC1 forms foci that co-localize extensively with gamma-H2AX foci within minutes after exposure to ionizing radiation. H2AX is required for MDC1 foci formation, and MDC1 forms complexes with phosphorylated H2AX. Furthermore, this interaction is phosphorylation dependent as peptides containing the phosphorylated site on H2AX bind MDC1 in a phosphorylation-dependent manner. We have shown by using small interfering RNA (siRNA) that cells lacking MDC1 are sensitive to ionizing radiation, and that MDC1 controls the formation of damage-induced 53BP1, BRCA1 and MRN foci, in part by promoting efficient H2AX phosphorylation. In addition, cells lacking MDC1 also fail to activate the intra-S phase and G2/M phase cell-cycle checkpoints properly after exposure to ionizing radiation, which was associated with an inability to regulate Chk1 properly. These results highlight a crucial role for MDC1 in mediating transduction of the DNA damage signal. 相似文献
93.
Growth hormone releasing factor of microbial origin 总被引:2,自引:0,他引:2
94.
Plasminogen activator, secreted by metastatic tumor cells, was strongly inhibited in buffer or tissue culture medium containing physiological concentrations of NaCl. Intact cells, however, expressed strong activity under similar conditions. Thus, if plasminogen activator is involved in invasion and metastasis, the cellular activity, acting as an ectoenzyme, may be more important than secreted enzyme under physiological conditions. 相似文献
95.
M. S. Likar Dorothy S. King E. A. Belle L. S. Grant 《Cellular and molecular life sciences : CMLS》1965,21(12):733-733
Zusammenfassung Aus Seren von Dengue-Fieberkranken (Epidemie 1963) wurden zwei «Dengue-like» Viren isoliert. Die Isolierung der Stämme gelang in Bristol-HeLa-Zellen, die mit dem LKB 6300 A Ultrafilter dargestellt wurden. Die Identifizierung der Viren erfolgte mit der Reaktion der Komplementbindung. 相似文献
96.
Davierwala AP Haynes J Li Z Brost RL Robinson MD Yu L Mnaimneh S Ding H Zhu H Chen Y Cheng X Brown GW Boone C Andrews BJ Hughes TR 《Nature genetics》2005,37(10):1147-1152
The nature of synthetic genetic interactions involving essential genes (those required for viability) has not been previously examined in a broad and unbiased manner. We crossed yeast strains carrying promoter-replacement alleles for more than half of all essential yeast genes to a panel of 30 different mutants with defects in diverse cellular processes. The resulting genetic network is biased toward interactions between functionally related genes, enabling identification of a previously uncharacterized essential gene (PGA1) required for specific functions of the endoplasmic reticulum. But there are also many interactions between genes with dissimilar functions, suggesting that individual essential genes are required for buffering many cellular processes. The most notable feature of the essential synthetic genetic network is that it has an interaction density five times that of nonessential synthetic genetic networks, indicating that most yeast genetic interactions involve at least one essential gene. 相似文献
97.
The gene encoding 5-lipoxygenase activating protein confers risk of myocardial infarction and stroke 总被引:29,自引:0,他引:29
Helgadottir A Manolescu A Thorleifsson G Gretarsdottir S Jonsdottir H Thorsteinsdottir U Samani NJ Gudmundsson G Grant SF Thorgeirsson G Sveinbjornsdottir S Valdimarsson EM Matthiasson SE Johannsson H Gudmundsdottir O Gurney ME Sainz J Thorhallsdottir M Andresdottir M Frigge ML Topol EJ Kong A Gudnason V Hakonarson H Gulcher JR Stefansson K 《Nature genetics》2004,36(3):233-239
We mapped a gene predisposing to myocardial infarction to a locus on chromosome 13q12-13. A four-marker single-nucleotide polymorphism (SNP) haplotype in this locus spanning the gene ALOX5AP encoding 5-lipoxygenase activating protein (FLAP) is associated with a two times greater risk of myocardial infarction in Iceland. This haplotype also confers almost two times greater risk of stroke. Another ALOX5AP haplotype is associated with myocardial infarction in individuals from the UK. Stimulated neutrophils from individuals with myocardial infarction produce more leukotriene B4, a key product in the 5-lipoxygenase pathway, than do neutrophils from controls, and this difference is largely attributed to cells from males who carry the at-risk haplotype. We conclude that variants of ALOX5AP are involved in the pathogenesis of both myocardial infarction and stroke by increasing leukotriene production and inflammation in the arterial wall. 相似文献
98.
99.
100.
K Grant P Gogan J P Guéritaud G Horcholle-Bossavit S Tyc-Dumont 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1979,289(16):1303-1306
The oculomotor effects of vibrissae stimulation have been studied in the "encéphale isolé" non-anaesthetized Cat. Intracellular recording of lateral rectus motoneurones showed an excitatory projection via the ipsilateral infraorbital nerve to these motoneurones. The afferent fibers are type A alpha, recuited with a low threshold (0.2-0.5 mA) and convey information about vibrissae displacement. 相似文献