全文获取类型
收费全文 | 1279篇 |
免费 | 100篇 |
出版年
2023年 | 7篇 |
2022年 | 18篇 |
2021年 | 31篇 |
2020年 | 15篇 |
2019年 | 17篇 |
2018年 | 21篇 |
2017年 | 19篇 |
2016年 | 35篇 |
2015年 | 55篇 |
2014年 | 60篇 |
2013年 | 92篇 |
2012年 | 102篇 |
2011年 | 108篇 |
2010年 | 74篇 |
2009年 | 62篇 |
2008年 | 100篇 |
2007年 | 103篇 |
2006年 | 81篇 |
2005年 | 80篇 |
2004年 | 73篇 |
2003年 | 79篇 |
2002年 | 57篇 |
2001年 | 12篇 |
2000年 | 7篇 |
1999年 | 13篇 |
1998年 | 13篇 |
1997年 | 9篇 |
1996年 | 2篇 |
1995年 | 7篇 |
1994年 | 7篇 |
1993年 | 6篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1974年 | 2篇 |
排序方式: 共有1379条查询结果,搜索用时 93 毫秒
991.
Ye Z Guo L Barakat KJ Pollard PG Palucki BL Sebhat IK Bakshi RK Tang R Kalyani RN Vongs A Chen AS Chen HY Rosenblum CI MacNeil T Weinberg DH Peng Q Tamvakopoulos C Miller RR Stearns RA Cashen DE Martin WJ Metzger JM Strack AM MacIntyre DE Van der Ploeg LH Patchett AA Wyvratt MJ Nargund RP 《Bioorganic & medicinal chemistry letters》2005,15(15):3501-3505
A novel isoquinuclidine containing selective melanocortin subtype-4 receptor small molecule agonist, 3 (RY764), is reported. Its in vivo characterization revealed mechanism-based food intake reduction and erectile activity augmentation in rodents. 相似文献
992.
Ujjainwalla F Warner D Snedden C Grisson RD Walsh TF Wyvratt MJ Kalyani RN Macneil T Tang R Weinberg DH Van der Ploeg L Goulet MT 《Bioorganic & medicinal chemistry letters》2005,15(18):4023-4028
Optimization of the biological activity of a new class of non-peptidyl, pyridazinone derived human melanocortin subtype-4 receptor agonists is disclosed. 相似文献
993.
Heightman TD Gaster LM Pardoe SL Pilleux JP Hadley MS Middlemiss DN Price GW Roberts C Scott CM Watson JM Gordon LJ Holland VA Powles J Riley GJ Stean TO Trail BK Upton N Austin NE Ayrton AD Coleman T Cutler L 《Bioorganic & medicinal chemistry letters》2005,15(19):4370-4374
The novel 8-piperazinyl-2,3-dihydropyrroloisoquinoline template was synthesized in nine steps. The template was N-substituted to give a series of compounds showing binding to human cloned 5-HT1A, 5-HT1B and 5-HT1D receptors with pKi's greater than 9 and selectivities up to 1000-fold against other serotonin, dopamine and adrenergic receptors. Several compounds were shown to possess weak partial agonist activity in cloned receptors, which translated to antagonism in in vitro studies. 相似文献
994.
Structural conservation of mouse and rat zona pellucida glycoproteins. Probing the native rat zona pellucida proteome by mass spectrometry 总被引:4,自引:0,他引:4
The mammalian zona pellucida is an egg extracellular matrix to which sperm bind. Mouse zonae are composed of three glycoproteins (ZP1, ZP2, and ZP3), while rat zonae contain four (ZP1, ZP2, ZP3, and ZP4/ZPB). Mouse sperm bind to zonae comprised solely of mouse ZP2 and ZP3. In this report, we show that rat sperm also bind to these zonae, indicating that ZP2 and ZP3 contain a "minimum structure(s)" to which rodent sperm can bind, and ZP1 and ZP4/ZPB are dispensable in these two rodents. These data are consistent with our mass spectrometric analysis of the native rat zona pellucida proteome (defined as the fraction of the total rat proteome to which the zonae glycoproteins contribute) demonstrating that the rat zonae glycoproteins share a high degree of conservation of structural features with respect to their mouse counterparts. The primary sequences of the rat zonae proteins have been deduced from cDNA. Each zona protein undergoes extensive co- and post-translational modification prior to its secretion and incorporation into an extracellular zona matrix. Each has a predicted N-terminal signal peptide that is cleaved off once protein translation begins and an anchoring C-terminal transmembrane domain from which the mature protein is released. Mass spectrometric analysis with a limited amount of native material allowed determination of the mature N-termini of rat ZP1 and ZP3, both of which are characterized by cyclization of glutamine to pyroglutamate; the N-terminus of ZP2 was identified by Edman degradation. The mature C-termini of ZP1 and ZP3 end two amino acids upstream of a conserved dibasic residue that is part of, but distinct from, the consensus furin cleavage sequence, while the C-terminus of ZP2 was not determined. Each zona protein contains a "zona domain" with eight conserved cysteine residues that is thought to play a role in the polymerization of the zona proteins into matrix filaments. Partial disulfide bond assignment indicates that the intramolecular disulfide patterns in rat ZP1, ZP2, and ZP3 are identical to those of their corresponding mouse counterparts. Last, nearly all potential N-glycosylation sites are occupied in the rat zonae glycoproteins (three of three for ZP1, six or seven of seven for ZP2, and four or five of six for ZP3). In comparison, potential O-glycosylation sites are numerous (59-83 Ser/Thr residues), but only two regions were observed to carry O-glycans in rat ZP3. 相似文献
995.
Schwarzenbacher R Jaroszewski L von Delft F Abdubek P Ambing E Biorac T Brinen LS Canaves JM Cambell J Chiu HJ Dai X Deacon AM DiDonato M Elsliger MA Eshagi S Floyd R Godzik A Grittini C Grzechnik SK Hampton E Karlak C Klock HE Koesema E Kovarik JS Kreusch A Kuhn P Lesley SA Levin I McMullan D McPhillips TM Miller MD Morse A Moy K Ouyang J Page R Quijano K Robb A Spraggon G Stevens RC van den Bedem H Velasquez J Vincent J Wang X West B Wolf G Xu Q Hodgson KO Wooley J Wilson IA 《Proteins》2004,55(2):474-478
996.
Levin I Schwarzenbacher R Page R Abdubek P Ambing E Biorac T Brinen LS Campbell J Canaves JM Chiu HJ Dai X Deacon AM DiDonato M Elsliger MA Floyd R Godzik A Grittini C Grzechnik SK Hampton E Jaroszewski L Karlak C Klock HE Koesema E Kovarik JS Kreusch A Kuhn P Lesley SA McMullan D McPhillips TM Miller MD Morse A Moy K Ouyang J Quijano K Reyes R Rezezadeh F Robb A Sims E Spraggon G Stevens RC van den Bedem H Velasquez J Vincent J von Delft F Wang X West B Wolf G Xu Q Hodgson KO Wooley J Wilson IA 《Proteins》2004,56(2):404-408
997.
Xu Q Schwarzenbacher R Page R Sims E Abdubek P Ambing E Biorac T Brinen LS Cambell J Canaves JM Chiu HJ Dai X Deacon AM DiDonato M Elsliger MA Floyd R Godzik A Grittini C Grzechnik SK Hampton E Jaroszewski L Karlak C Klock HE Koesema E Kovarik JS Kreusch A Kuhn P Lesley SA Levin I McMullan D McPhillips TM Miller MD Morse A Moy K Ouyang J Quijano K Reyes R Rezezadeh F Robb A Spraggon G Stevens RC van den Bedem H Velasquez J Vincent J von Delft F Wang X West B Wolf G Hodgson KO Wooley J Wilson IA 《Proteins》2004,56(3):619-624
998.
Santelli E Schwarzenbacher R McMullan D Biorac T Brinen LS Canaves JM Cambell J Dai X Deacon AM Elsliger MA Eshagi S Floyd R Godzik A Grittini C Grzechnik SK Jaroszewski L Karlak C Klock HE Koesema E Kovarik JS Kreusch A Kuhn P Lesley SA McPhillips TM Miller MD Morse A Moy K Ouyang J Page R Quijano K Rezezadeh F Robb A Sims E Spraggon G Stevens RC van den Bedem H Velasquez J Vincent J von Delft F Wang X West B Wolf G Xu Q Hodgson KO Wooley J Wilson IA 《Proteins》2004,56(1):167-170
999.
Miller MD Schwarzenbacher R von Delft F Abdubek P Ambing E Biorac T Brinen LS Canaves JM Cambell J Chiu HJ Dai X Deacon AM DiDonato M Elsliger MA Eshagi S Floyd R Godzik A Grittini C Grzechnik SK Hampton E Jaroszewski L Karlak C Klock HE Koesema E Kovarik JS Kreusch A Kuhn P Lesley SA Levin I McMullan D McPhillips TM Morse A Moy K Ouyang J Page R Quijano K Robb A Spraggon G Stevens RC van den Bedem H Velasquez J Vincent J Wang X West B Wolf G Xu Q Hodgson KO Wooley J Wilson IA 《Proteins》2004,57(1):213-217
1000.
It has been argued from first principles that plants mate assortatively by flowering time. However, there have been very few studies of phenological assortative mating, perhaps because current methods to infer paternal phenotype are difficult to apply to natural populations. Two methods are presented to estimate the phenotypic correlation between mates-the quantitative genetic metric for assortative mating-for phenological traits. The first method uses individual flowering schedules to estimate mating probabilities for every potential pairing in a sample. These probabilities are then incorporated into a weighted phenotypic correlation between all potential mates and thus yield a prospective estimate based on mating opportunities. The correlation between mates can also be estimated retrospectively by comparing the regression of offspring phenotype over one parent, which is inflated by assortative mating, to the regression over mid-parent, which is not. In a demonstration experiment with Brassica rapa, the prospective correlation between flowering times (days from germination to anthesis) of pollen recipients and their potential donors was 0.58. The retrospective estimate of this correlation strongly agreed with the prospective estimate. The prospective method is easily employed in field studies that explore the effect of phenological assortative mating on selection response and population differentiation. 相似文献