全文获取类型
收费全文 | 1895篇 |
免费 | 82篇 |
国内免费 | 123篇 |
专业分类
2100篇 |
出版年
2024年 | 3篇 |
2023年 | 20篇 |
2022年 | 23篇 |
2021年 | 51篇 |
2020年 | 31篇 |
2019年 | 39篇 |
2018年 | 35篇 |
2017年 | 36篇 |
2016年 | 43篇 |
2015年 | 57篇 |
2014年 | 66篇 |
2013年 | 84篇 |
2012年 | 47篇 |
2011年 | 79篇 |
2010年 | 63篇 |
2009年 | 90篇 |
2008年 | 101篇 |
2007年 | 93篇 |
2006年 | 96篇 |
2005年 | 104篇 |
2004年 | 81篇 |
2003年 | 85篇 |
2002年 | 51篇 |
2001年 | 68篇 |
2000年 | 66篇 |
1999年 | 57篇 |
1998年 | 60篇 |
1997年 | 51篇 |
1996年 | 57篇 |
1995年 | 49篇 |
1994年 | 49篇 |
1993年 | 51篇 |
1992年 | 30篇 |
1991年 | 26篇 |
1990年 | 15篇 |
1989年 | 14篇 |
1988年 | 6篇 |
1987年 | 18篇 |
1986年 | 13篇 |
1985年 | 21篇 |
1984年 | 16篇 |
1983年 | 12篇 |
1982年 | 14篇 |
1981年 | 9篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1978年 | 5篇 |
1977年 | 2篇 |
1976年 | 4篇 |
排序方式: 共有2100条查询结果,搜索用时 15 毫秒
91.
Jochen Baßler Yasar Luqman Ahmed Martina Kallas Markus Kornprobst Fabiola R. Calviño Marén Gnädig Matthias Thoms Gunter Stier Sherif Ismail Satyavati Kharde Nestor Castillo Sabine Griesel Sonja Bastuck Bettina Bradatsch Emma Thomson Dirk Flemming Irmgard Sinning Ed Hurt 《Protein science : a publication of the Protein Society》2017,26(2):327-342
Ribosome biogenesis in eukaryotic cells is a highly dynamic and complex process innately linked to cell proliferation. The assembly of ribosomes is driven by a myriad of biogenesis factors that shape pre‐ribosomal particles by processing and folding the ribosomal RNA and incorporating ribosomal proteins. Biochemical approaches allowed the isolation and characterization of pre‐ribosomal particles from Saccharomyces cerevisiae, which lead to a spatiotemporal map of biogenesis intermediates along the path from the nucleolus to the cytoplasm. Here, we cloned almost the entire set (~180) of ribosome biogenesis factors from the thermophilic fungus Chaetomium thermophilum in order to perform an in‐depth analysis of their protein–protein interaction network as well as exploring the suitability of these thermostable proteins for structural studies. First, we performed a systematic screen, testing about 80 factors for crystallization and structure determination. Next, we performed a yeast 2‐hybrid analysis and tested about 32,000 binary combinations, which identified more than 1000 protein–protein contacts between the thermophilic ribosome assembly factors. To exemplary verify several of these interactions, we performed biochemical reconstitution with the focus on the interaction network between 90S pre‐ribosome factors forming the ctUTP‐A and ctUTP‐B modules, and the Brix‐domain containing assembly factors of the pre‐60S subunit. Our work provides a rich resource for biochemical reconstitution and structural analyses of the conserved ribosome assembly machinery from a eukaryotic thermophile. 相似文献
92.
Hori K Kobayashi T Shimizu A Sato K Takeda K Kawasaki S 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2003,107(5):806-813
Using a High Efficiency Genome Scanning (HEGS) system and recombinant inbred (RI) lines derived from the cross of Russia 6
and H.E.S. 4, a high-density genetic map was constructed in barley. The resulting 1,595.7-cM map encompassed 1,172 loci distributed
on the seven linkage groups comprising 1,134 AFLP, 34 SSR, three STS and vrs1 (kernel row type) loci. Including PCR reactions, gel electrophoresis and data processing, 6 months of work by a single person
was sufficient for the whole mapping procedure under a reasonable cost. To make an appraisal of the resolution of genetic
analysis for the 95 RI lines based on the constructed linkage map, we measured three agronomic traits: plant height, spike
exsertion length and 1,000-kernel weight, and the analyzed quantitative trait loci (QTLs) associated with these traits. The
results were compared on the number of detected QTLs and their effects between a high-density map and a skeleton map constructed
by selected AFLP and anchor markers. The composite interval mapping on the high-density map detected more QTLs than the other
analyses. Closely linked markers with QTLs on the high-density map could be powerful tools for marker-assisted selection in
barley breeding programs and further genetic analyses including an advanced backcross analysis or a map-based cloning of QTL.
Electronic Supplementary Material Supplementary material is available in the online version of this article at
Communicated by J.S. Heslop-Harrison 相似文献
93.
Last glacial maximum biomes reconstructed from pollen and plant macrofossil data from northern Eurasia 总被引:15,自引:0,他引:15
P. E. Tarasov V. S. Volkova T. Webb III J. Guiot A. A. Andreev L. G. Bezusko T. V. Bezusko G. V. Bykova N. I. Dorofeyuk E. V. Kvavadze I. M. Osipova N. K. Panova D. V. Sevastyanov 《Journal of Biogeography》2000,27(3):609-620
Pollen and plant macrofossil data from northern Eurasia were used to reconstruct the vegetation of the last glacial maximum (LGM: 18,000 ± 2000 14C yr bp ) using an objective quantitative method for interpreting pollen data in terms of the biomes they represent ( Prentice et al., 1996 ). The results confirm previous qualitative vegetation reconstructions at the LGM but provide a more comprehensive analysis of the data. Tundra dominated a large area of northern Eurasia (north of 57°N) to the west, south and east of the Scandinavian ice sheet at the LGM. Steppe‐like vegetation was reconstructed in the latitudinal band from western Ukraine, where temperate deciduous forests grow today, to western Siberia, where taiga and cold deciduous forests grow today. The reconstruction shows that steppe graded into tundra in Siberia, which is not the case today. Taiga grew on the northern coast of the Sea of Azov, about 1500 km south of its present limit in European Russia. In contrast, taiga was reconstructed only slightly south of its southern limit today in south‐western Siberia. Broadleaved trees were confined to small refuges, e.g. on the eastern coast of the Black Sea, where cool mixed forest was reconstructed from the LGM data. Cool conifer forests in western Georgia were reconstructed as growing more than 1000 m lower than they grow today. The few scattered sites with LGM data from the Tien‐Shan Mountains and from northern Mongolia yielded biome reconstructions of steppe and taiga, which are the biomes growing there today. 相似文献
94.
Shi XW Fitzsimmons CJ Genêt C Prather R Whitworth K Green JA Tuggle CK 《Animal genetics》2001,32(4):205-209
A comparative study of human chromosome 17 (HSA17) and pig chromosome 12 (SSC12) was conducted using both somatic cell hybrid panel (SCHP) and radiation hybrid (RH) panel analysis. Sequences from an expressed sequence tag (EST) project in pig reproduction were examined and six genes and ESTs originally believed to map to HSA17 were selected for this study. The genes/ESTs were TATA box binding protein-associated factor (TAF2N/RBP56), alpha-2-plasmin inhibitor (SERPINF2/PLI), H3 histone family 3B (H3F3B), aminopeptidase puromycin sensitive (NPEPPS), an expressed sequence tag (ESTMI015) and P311 protein (P311). The SCHP analysis mapped five genes/ESTs (TAF2N, H3F3B, SERPINF2, NPEPPS and ESTMI015) to SSC12q11-q15 and SSC12p11-p15 with 100% concordance, and assigned P311 to SSC2 (1/2q24)-q29 with 100% concordance. Radiation hybrid analysis of all six genes confirmed the SCHP mapping results, with average retention frequency of 25%. Recent human sequence data demonstrated that P311 is actually located on HSA5q. As HSA5q and SSC2q show conserved syntenic regions predicted from bi-directional painting, our P311 mapping data is consistent with these results. An expanded comparative SSC12 RH map integrating the five new type I markers and 23 previously mapped loci was established using a LOD score threshold of 4.8. The gene order of the five genes/ESTs on the SSC12 framework RH map (H3F3B-ESTMI015-NPEPPS-TAF2N-SERPINF2) is identical to the HSA17 GB4 map but with inversion of the map as conventionally drawn. 相似文献
95.
Kurar E Barendse W Bottema CD Davis S Föster M Kalm E Kappes SM Kister A Lewin HA Klungland H Medjugorac I Olsaker I Pitchford WS Schmutz SM Taylor J Thomsen H Kirkpatrick BW 《Animal genetics》2002,33(6):460-463
This study describes development of a consensus genetic linkage map of bovine chromosome 24 (BTA24). Eight participating laboratories contributed data for 58 unique markers including a total of 25 409 meioses. Eighteen markers, which were typed in more than one reference population, were used as potential anchors to generate a consensus framework map. The framework map contained 16 loci ordered with odds greater than 1000:1 and spanned 79.3 cM. Remaining markers were included in a comprehensive map relative to these anchors. The resulting BTA24 comprehensive map was 98.3 cM in length. Average marker intervals were 6.1 and 2.5 cM for framework and comprehensive maps, respectively. Marker order was generally consistent with previously reported BTA24 linkage maps. Only one discrepancy was found when comparing the comprehensive map with the published USDA-MARC linkage map. Integration of genetic information from different maps provides a high-resolution BTA24 linkage map. 相似文献
96.
中国白菜RAPD分子遗传图谱的构建 总被引:19,自引:0,他引:19
A molecular genetic map of Brassica campestris L. (syn. B. rapa) was constructed based on the segregation of 99 RAPDs (random amplified polymorphic DNAs) markers from eighty-four 10-base random primers using DNA samples extracted from F2 population of turnip (B. campestris L. ssp. rapifera Metzg) × Chinese cabbage (B. campestris L. ssp. pekinensis Lour. Olsson). This genetic map covered 1 632.4 cM (centiMorgan) genome (Kosambi Function) with 16.5 cM mean intervals between flanking markers and defined thirteen linkage groups, in which the longest linkage group is 267.5 cM with 20.6 cM mean interval and the shortest linkage group is 62.2 cM with 15.6 cM mean interval. The size and distribution of linkage groups in this map is similar to other RFLP maps and karyotype data in B. campestris. 相似文献
97.
The flavoprotein tryptophan 2-monooxygenase catalyzes the oxidative decarboxylation of tryptophan to indoleacetamide. His338, Cys339, and Cys511 of the Pseudomonas savastanoi enzyme were previously identified as possible active-site residues by modification with 2-oxo-3-pentynoate ([G. Gadda, L.J. Dangott, W.H. Johnson Jr., C.P. Whitman, P.F. Fitzpatrick, Biochemistry 38 (1999) 5822-5828]). The H338N, C339A, and C511S enzymes have been characterized to determine the roles of these residues in catalysis. The steady-state kinetic parameters with both tryptophan and methionine decrease only slightly in the case of the H338N and C339A enzymes; the decrease in activity is greater for the C511S enzyme. Only in the case of the C511S enzyme do deuterium kinetic isotope effects on kinetic parameters indicate a significant change in catalytic rates. The structural bases for the effects of the mutations can be interpreted by identification of L-amino acid oxidase and tryptophan monooxygenase as homologous proteins. 相似文献
98.
99.
100.
David A. Patton Linda H. Franzmann David W. Meinke 《Molecular & general genetics : MGG》1991,227(3):337-347
Summary We have previously isolated and characterized over 90 recessive mutants of Arabidopsis thaliana defective in embryo development. These emb mutants have been shown to differ in lethal phase, extent of abnormal development, and response in culture. We demonstrate in this report the value and efficiency of mapping emb genes relative to visible and molecular markers. Sixteen genes essential for embryo development were mapped relative to visible markers by analyzing progeny of selfed F1 plants. Embryonic lethals are now the most common type of visible marker included on the linkage map of Arabidopsis. Backcrosses were used in several cases to orient genes relative to adjacent markers. Three genes were located to chromosome arms with telotrisomics by screening for a reduction in the percentage of aborted seeds produced by F1 plants. A restriction fragment length polymorphism (RFLP) mapping strategy that utilizes pooled EMB/EMB F2 plants was devised to increase the efficiency of mapping embryonic lethals relative to molecular markers. This strategy was tested by demonstrating that the biol locus of Arabidopsis is within 0.5 cM of an existing RFLP marker. Mapping embryonic lethals with both visible and molecular markers may therefore help to identify large numbers of genes with essential functions in Arabidopsis. 相似文献