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排序方式: 共有110条查询结果,搜索用时 265 毫秒
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Genetics of gene expression surveyed in maize,mouse and man 总被引:111,自引:0,他引:111
Schadt EE Monks SA Drake TA Lusis AJ Che N Colinayo V Ruff TG Milligan SB Lamb JR Cavet G Linsley PS Mao M Stoughton RB Friend SH 《Nature》2003,422(6929):297-302
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It is unclear when, where and how novel pathogens such as human immunodeficiency virus (HIV), monkeypox and severe acute respiratory syndrome (SARS) will cross the barriers that separate their natural reservoirs from human populations and ignite the epidemic spread of novel infectious diseases. New pathogens are believed to emerge from animal reservoirs when ecological changes increase the pathogen's opportunities to enter the human population and to generate subsequent human-to-human transmission. Effective human-to-human transmission requires that the pathogen's basic reproductive number, R(0), should exceed one, where R(0) is the average number of secondary infections arising from one infected individual in a completely susceptible population. However, an increase in R(0), even when insufficient to generate an epidemic, nonetheless increases the number of subsequently infected individuals. Here we show that, as a consequence of this, the probability of pathogen evolution to R(0) > 1 and subsequent disease emergence can increase markedly. 相似文献
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Heilig R Eckenberg R Petit JL Fonknechten N Da Silva C Cattolico L Levy M Barbe V de Berardinis V Ureta-Vidal A Pelletier E Vico V Anthouard V Rowen L Madan A Qin S Sun H Du H Pepin K Artiguenave F Robert C Cruaud C Brüls T Jaillon O Friedlander L Samson G Brottier P Cure S Ségurens B Anière F Samain S Crespeau H Abbasi N Aiach N Boscus D Dickhoff R Dors M Dubois I Friedman C Gouyvenoux M James R Madan A Mairey-Estrada B Mangenot S Martins N Ménard M Oztas S Ratcliffe A Shaffer T Trask B 《Nature》2003,421(6923):601-607
Chromosome 14 is one of five acrocentric chromosomes in the human genome. These chromosomes are characterized by a heterochromatic short arm that contains essentially ribosomal RNA genes, and a euchromatic long arm in which most, if not all, of the protein-coding genes are located. The finished sequence of human chromosome 14 comprises 87,410,661 base pairs, representing 100% of its euchromatic portion, in a single continuous segment covering the entire long arm with no gaps. Two loci of crucial importance for the immune system, as well as more than 60 disease genes, have been localized so far on chromosome 14. We identified 1,050 genes and gene fragments, and 393 pseudogenes. On the basis of comparisons with other vertebrate genomes, we estimate that more than 96% of the chromosome 14 genes have been annotated. From an analysis of the CpG island occurrences, we estimate that 70% of these annotated genes are complete at their 5' end. 相似文献
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Minyi HUANG Peter E. CAINES Roland P. MALHAME 《系统科学与复杂性》2007,20(2):162-172
We study large population stochastic dynamic games where the so-called Nash certainty equivalence based control laws are implemented by the individual players. We first show a martingale property for the limiting control problem of a single agent and then perform averaging across the population; this procedure leads to a constant value for the martingale which shows an invariance property of the population behavior induced by the Nash strategies. 相似文献
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Meijers R Puettmann-Holgado R Skiniotis G Liu JH Walz T Wang JH Schmucker D 《Nature》2007,449(7161):487-491
The Dscam gene gives rise to thousands of diverse cell surface receptors thought to provide homophilic and heterophilic recognition specificity for neuronal wiring and immune responses. Mutually exclusive splicing allows for the generation of sequence variability in three immunoglobulin ecto-domains, D2, D3 and D7. We report X-ray structures of the amino-terminal four immunoglobulin domains (D1-D4) of two distinct Dscam isoforms. The structures reveal a horseshoe configuration, with variable residues of D2 and D3 constituting two independent surface epitopes on either side of the receptor. Both isoforms engage in homo-dimerization coupling variable domain D2 with D2, and D3 with D3. These interactions involve symmetric, antiparallel pairing of identical peptide segments from epitope I that are unique to each isoform. Structure-guided mutagenesis and swapping of peptide segments confirm that epitope I, but not epitope II, confers homophilic binding specificity of full-length Dscam receptors. Phylogenetic analysis shows strong selection of matching peptide sequences only for epitope I. We propose that peptide complementarity of variable residues in epitope I of Dscam is essential for homophilic binding specificity. 相似文献