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111.
M Leppert V E Anderson T Quattlebaum D Stauffer P O'Connell Y Nakamura J M Lalouel R White 《Nature》1989,337(6208):647-648
Recurrent seizures, commonly known as epilepsies, occur in 1.7% of the general population by age 40. The factors that initiate or underlie seizures are not well understood, but trauma, infectious disease and genetics have been implicated. An understanding of the molecular basis of seizures would shed light on the basic mechanisms of neuronal homeostasis and allow new therapeutic strategies to be explored. Here, we report the mapping of an epilepsy gene to a specific chromosomal region, on the basis of cosegregation of two closely-linked DNA markers with a form of epilepsy known as benign familial neonatal convulsions (BFNC2, 12120 in ref. 3). The linked markers confirm the genetic basis and autosomal dominant inheritance of this trait, and localize the gene causing BFNC in this family to the long arm of chromosome 20. This regional placement is the first step towards the isolation of a gene involved in neuronal activity in the human brain. 相似文献
112.
Pleistocene dates from three cave sites indicate the human capacity to colonise across two oceanic straits to the east of a former Tasmania-Australia-New Guinea continent by 33 kyr BP. The sites demonstrate exploitation of costal marine and lowland tropical forest resources. They extend Pleistocene occupation into island Melanesia and demonstrate that the large islands of northern Melanesia have an antiquity of human occupation of the same order as the adjacent Greater Australian continent. 相似文献
113.
R H White 《Experientia》1990,46(3):274-276
2-Acetylthiazole-4-carboxylic acid was shown to be widely distributed in all organisms tested, which included members of the eukaryotes, archaebacteria, and eubacteria. This thiazole, which was identified and quantitated as the methyl ester methoxyamine derivative, was found in these organisms at levels of from 27 to 1100 nmol/g dry weight (d.wt) of tissue. On the basis of its widespread occurrence, the levels at which it occurs in these organisms, and its chemical structure, which contains a reactive carbonyl group, it is proposed that this compound is a previously undescribed coenzyme. 相似文献
114.
Short term visual memory and the Pulfrich phenomenon 总被引:3,自引:0,他引:3
115.
U. Hollstein R. A. Burton J. A. White 《Cellular and molecular life sciences : CMLS》1966,22(4):210-211
Zusammenfassung Im Kern markierte14C-Anthranilsäure und Derivate wurden an Mikroorganismen, die Phenazin- und Phenoxazon-Farbstoffe produzieren, verfüttert. Der erfolgte Einbau beweist die oxydative Kupplung von Anilinen und phenolischen Anilinen in vivo.
This work was supported by Grant GB-2290 of the National Science Foundation. 相似文献
This work was supported by Grant GB-2290 of the National Science Foundation. 相似文献
116.
J. F. White J. B. Jones R. D. Lange J. E. Fuhr 《Cellular and molecular life sciences : CMLS》1978,34(10):1367-1368
Summary Serum samples collected through the cycle of a cyclic hematopoietic (CH) dog under reduced atmospheric conditions, were assayed for their ability to affect hemoglobin synthesis by normal canine bone marrow. Varying levels of hemoglobin synthesis in the presence of different serum samples suggest an agent cycles in the serum of CH dogs which influences hemoglobin synthesis. 相似文献
117.
Vision substitution by tactile image projection 总被引:4,自引:0,他引:4
118.
Konso-Gardula is a palaeoanthropological area discovered by the 1991 Palaeoanthropological Inventory of Ethiopia in the southern Main Ethiopian Rift. The Konso-Gardula sediments span the period about 1.3-1.9 million years ago. They contain rich Acheulean archaeological occurrences. Vertebrate fossils include early Homo. 相似文献
119.
Mismatch-specific post-meiotic segregation frequency in yeast suggests a heteroduplex recombination intermediate 总被引:4,自引:0,他引:4
Post-meiotic segregation of alleles, which is seen, for example, in the 5:3 distribution of alleles in the products of a single meiosis in fungi, has been thought to be due to the non-repair of heteroduplex regions formed during genetic recombination. In current models of genetic recombination, heteroduplex DNA is formed either as the primary intermediate generated by two interacting non-sister chromatids or as a short region flanking a double-stranded gap. The frequency of post-meiotic segregation differs for different alleles, and this is presumed to reflect the varying efficiencies with which different types of mismatches in the heteroduplex are repaired. To gain some insight into this process, we have now determined the nucleotide sequences of various yeast alleles with different post-meiotic segregation frequencies and compared the mismatches predicted to occur in heteroduplexes of these alleles with wild-type DNA with those repaired with varying efficiency in bacterial systems. A striking correlation is observed, with the mismatches predicted for high post-meiotic segregation frequency alleles being similar to mismatches repaired with low efficiency in bacteria. These results support the view that postmeiotic segregation frequency reflects heteroduplex repair efficiency and the contention that meiotic gene conversion is the result of the successful repair of heteroduplex mismatches. 相似文献
120.
Although single heterozygous markers in yeast usually segregate during meiosis in a 2:2 ratio, abberant 3:1 segregations occur quite frequently as a result of gene-conversion events. A second type of aberrant segregation, post-meiotic segregation, results from the segregation of two genotypes from a single haploid spore; in yeast such events are detected as sectored spore colonies and usually occur rarely. Post-meiotic segregation is thought to result from the replication of heteroduplex DNA formed during meiotic recombination. We report here that if the heteroduplex includes a palindromic insertion sequence, a high frequency of post-meiotic segregation results. This suggests that palindromic insertions are poorly repaired, which may be the result of hairpin-loop formation that affects the efficiency of repair of heteroduplex DNA. 相似文献