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291.
Bryophytes have been screened for lectins. From the liverwortMarchantia polymorpha (Marchiantiales) a lectin could be purified to homogeneity using a combination of ultrafiltration, size exclusion chromatography and ion exchange chromatography. SDS polyacrylamide gel electrophoresis, size exclusion chromatography and electrospray mass spectroscopy showed that the lectin is a monomeric protein with a Mr of 16,134.64 ± 2.93.Marchantia polymorpha lectin agglutinates erythrocytes of different mammalia and exhibits carbohydrate specifity against complex carbohydrate structures. This is the first report of a lectin isolated from liverworts.This article forms Publication No. 71 of the Arbeitskreis Biologie und Chemie der Moose. 相似文献
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Reverse engineering of regulatory networks in human B cells 总被引:1,自引:0,他引:1
Basso K Margolin AA Stolovitzky G Klein U Dalla-Favera R Califano A 《Nature genetics》2005,37(4):382-390
Cellular phenotypes are determined by the differential activity of networks linking coregulated genes. Available methods for the reverse engineering of such networks from genome-wide expression profiles have been successful only in the analysis of lower eukaryotes with simple genomes. Using a new method called ARACNe (algorithm for the reconstruction of accurate cellular networks), we report the reconstruction of regulatory networks from expression profiles of human B cells. The results are suggestive a hierarchical, scale-free network, where a few highly interconnected genes (hubs) account for most of the interactions. Validation of the network against available data led to the identification of MYC as a major hub, which controls a network comprising known target genes as well as new ones, which were biochemically validated. The newly identified MYC targets include some major hubs. This approach can be generally useful for the analysis of normal and pathologic networks in mammalian cells. 相似文献
294.
Stephens P Edkins S Davies H Greenman C Cox C Hunter C Bignell G Teague J Smith R Stevens C O'Meara S Parker A Tarpey P Avis T Barthorpe A Brackenbury L Buck G Butler A Clements J Cole J Dicks E Edwards K Forbes S Gorton M Gray K Halliday K Harrison R Hills K Hinton J Jones D Kosmidou V Laman R Lugg R Menzies A Perry J Petty R Raine K Shepherd R Small A Solomon H Stephens Y Tofts C Varian J Webb A West S Widaa S Yates A Brasseur F Cooper CS Flanagan AM Green A Knowles M Leung SY Looijenga LH 《Nature genetics》2005,37(6):590-592
We examined the coding sequence of 518 protein kinases, approximately 1.3 Mb of DNA per sample, in 25 breast cancers. In many tumors, we detected no somatic mutations. But a few had numerous somatic mutations with distinctive patterns indicative of either a mutator phenotype or a past exposure. 相似文献
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Kong A Gudbjartsson DF Sainz J Jonsdottir GM Gudjonsson SA Richardsson B Sigurdardottir S Barnard J Hallbeck B Masson G Shlien A Palsson ST Frigge ML Thorgeirsson TE Gulcher JR Stefansson K 《Nature genetics》2002,31(3):241-247
Determination of recombination rates across the human genome has been constrained by the limited resolution and accuracy of existing genetic maps and the draft genome sequence. We have genotyped 5,136 microsatellite markers for 146 families, with a total of 1,257 meiotic events, to build a high-resolution genetic map meant to: (i) improve the genetic order of polymorphic markers; (ii) improve the precision of estimates of genetic distances; (iii) correct portions of the sequence assembly and SNP map of the human genome; and (iv) build a map of recombination rates. Recombination rates are significantly correlated with both cytogenetic structures (staining intensity of G bands) and sequence (GC content, CpG motifs and poly(A)/poly(T) stretches). Maternal and paternal chromosomes show many differences in locations of recombination maxima. We detected systematic differences in recombination rates between mothers and between gametes from the same mother, suggesting that there is some underlying component determined by both genetic and environmental factors that affects maternal recombination rates. 相似文献
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Gilman AG Simon MI Bourne HR Harris BA Long R Ross EM Stull JT Taussig R Bourne HR Arkin AP Cobb MH Cyster JG Devreotes PN Ferrell JE Fruman D Gold M Weiss A Stull JT Berridge MJ Cantley LC Catterall WA Coughlin SR Olson EN Smith TF Brugge JS Botstein D Dixon JE Hunter T Lefkowitz RJ Pawson AJ Sternberg PW Varmus H Subramaniam S Sinkovits RS Li J Mock D Ning Y Saunders B Sternweis PC Hilgemann D Scheuermann RH DeCamp D Hsueh R Lin KM Ni Y Seaman WE Simpson PC O'Connell TD Roach T Simon MI 《Nature》2002,420(6916):703-706
The Alliance for Cellular Signaling is a large-scale collaboration designed to answer global questions about signalling networks. Pathways will be studied intensively in two cells--B lymphocytes (the cells of the immune system) and cardiac myocytes--to facilitate quantitative modelling. One goal is to catalyse complementary research in individual laboratories; to facilitate this, all alliance data are freely available for use by the entire research community. 相似文献
300.
Functional profiling of the Saccharomyces cerevisiae genome 总被引:1,自引:0,他引:1
Giaever G Chu AM Ni L Connelly C Riles L Véronneau S Dow S Lucau-Danila A Anderson K André B Arkin AP Astromoff A El-Bakkoury M Bangham R Benito R Brachat S Campanaro S Curtiss M Davis K Deutschbauer A Entian KD Flaherty P Foury F Garfinkel DJ Gerstein M Gotte D Güldener U Hegemann JH Hempel S Herman Z Jaramillo DF Kelly DE Kelly SL Kötter P LaBonte D Lamb DC Lan N Liang H Liao H Liu L Luo C Lussier M Mao R Menard P Ooi SL Revuelta JL Roberts CJ Rose M Ross-Macdonald P Scherens B Schimmack G 《Nature》2002,418(6896):387-391
Determining the effect of gene deletion is a fundamental approach to understanding gene function. Conventional genetic screens exhibit biases, and genes contributing to a phenotype are often missed. We systematically constructed a nearly complete collection of gene-deletion mutants (96% of annotated open reading frames, or ORFs) of the yeast Saccharomyces cerevisiae. DNA sequences dubbed 'molecular bar codes' uniquely identify each strain, enabling their growth to be analysed in parallel and the fitness contribution of each gene to be quantitatively assessed by hybridization to high-density oligonucleotide arrays. We show that previously known and new genes are necessary for optimal growth under six well-studied conditions: high salt, sorbitol, galactose, pH 8, minimal medium and nystatin treatment. Less than 7% of genes that exhibit a significant increase in messenger RNA expression are also required for optimal growth in four of the tested conditions. Our results validate the yeast gene-deletion collection as a valuable resource for functional genomics. 相似文献