全文获取类型
收费全文 | 10177篇 |
免费 | 654篇 |
国内免费 | 492篇 |
出版年
2023年 | 162篇 |
2022年 | 150篇 |
2021年 | 244篇 |
2020年 | 279篇 |
2019年 | 300篇 |
2018年 | 347篇 |
2017年 | 219篇 |
2016年 | 252篇 |
2015年 | 341篇 |
2014年 | 495篇 |
2013年 | 632篇 |
2012年 | 372篇 |
2011年 | 568篇 |
2010年 | 482篇 |
2009年 | 602篇 |
2008年 | 559篇 |
2007年 | 591篇 |
2006年 | 535篇 |
2005年 | 511篇 |
2004年 | 434篇 |
2003年 | 318篇 |
2002年 | 323篇 |
2001年 | 238篇 |
2000年 | 212篇 |
1999年 | 198篇 |
1998年 | 161篇 |
1997年 | 149篇 |
1996年 | 134篇 |
1995年 | 130篇 |
1994年 | 143篇 |
1993年 | 122篇 |
1992年 | 106篇 |
1991年 | 85篇 |
1990年 | 83篇 |
1989年 | 90篇 |
1988年 | 63篇 |
1987年 | 60篇 |
1986年 | 53篇 |
1985年 | 56篇 |
1984年 | 106篇 |
1983年 | 79篇 |
1982年 | 75篇 |
1981年 | 59篇 |
1980年 | 53篇 |
1979年 | 38篇 |
1978年 | 24篇 |
1977年 | 28篇 |
1976年 | 14篇 |
1975年 | 13篇 |
1973年 | 12篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Leehyeon Kim Jiwon Heo Do Hoon Kwon Jin Seok Shin Se Hwan Jang ZeeYong Park Hyun Kyu Song 《Protein science : a publication of the Protein Society》2021,30(3):700
The N‐degron pathway determines the half‐life of proteins in both prokaryotes and eukaryotes by precisely recognizing the N‐terminal residue (N‐degron) of substrates. ClpS proteins from bacteria bind to substrates containing hydrophobic N‐degrons (Leu, Phe, Tyr, and Trp) and deliver them to the caseinolytic protease system ClpAP. This mechanism is preserved in organelles such as mitochondria and chloroplasts. Bacterial ClpS adaptors bind preferentially to Leu and Phe N‐degrons; however, ClpS1 from Arabidopsis thaliana (AtClpS1) shows a difference in that it binds strongly to Phe and Trp N‐degrons and only weakly to Leu. This difference in behavior cannot be explained without structural information due to the high sequence homology between bacterial and plant ClpS proteins. Here, we report the structure of AtClpS1 at 2.0 Å resolution in the presence of a bound N‐degron. The key determinants for α‐amino group recognition are conserved among all ClpS proteins, but the α3‐helix of eukaryotic AtClpS1 is significantly shortened, and consequently, a loop forming a pocket for the N‐degron is moved slightly outward to enlarge the pocket. In addition, amino acid replacement from Val to Ala causes a reduction in hydrophobic interactions with Leu N‐degron. A combination of the fine‐tuned hydrophobic residues in the pocket and the basic gatekeeper at the entrance of the pocket controls the N‐degron selectivity of the plant ClpS protein. 相似文献
102.
Dávid Kurszán Jász Ágnes Lilla Szilágyi Eszter Tuboly Bálint Baráth Anett Roxána Márton Petra Varga Gabriella Varga Dániel Érces Árpád Mohácsi Anna Szabó Renáta Bozó Kamilla Gömöri Anikó Görbe Mihály Boros Petra Hartmann 《Journal of cellular and molecular medicine》2021,25(11):5113-5123
Albeit previous experiments suggest potential anti-inflammatory effect of exogenous methane (CH4) in various organs, the mechanism of its bioactivity is not entirely understood. We aimed to investigate the potential mitochondrial effects and the underlying mechanisms of CH4 in rat cardiomyocytes and mitochondria under simulated ischaemia/reperfusion (sI/R) conditions. Three-day-old cultured cardiomyocytes were treated with 2.2% CH4-artificial air mixture during 2-hour-long reoxygenation following 4-hour-long anoxia (sI/R and sI/R + CH4, n = 6-6), with normoxic groups serving as controls (SH and SH + CH4; n = 6-6). Mitochondrial functions were investigated with high-resolution respirometry, and mitochondrial membrane injury was detected by cytochrome c release and apoptotic characteristics by using TUNEL staining. CH4 admixture had no effect on complex II (CII)-linked respiration under normoxia but significantly decreased the complex I (CI)-linked oxygen consumption. Nevertheless, addition of CH4 in the sI/R + CH4 group significantly reduced the respiratory activity of CII in contrast to CI and the CH4 treatment diminished mitochondrial H2O2 production. Substrate-induced changes to membrane potential were partially preserved by CH4, and additionally, cytochrome c release and apoptosis of cardiomyocytes were reduced in the CH4-treated group. In conclusion, the addition of CH4 decreases mitochondrial ROS generation via blockade of electron transport at CI and reduces anoxia-reoxygenation-induced mitochondrial dysfunction and cardiomyocyte injury in vitro. 相似文献
103.
Ross A. Robinson Samuel C. Griffiths Lieke L. van de Haar Tomas Malinauskas Eljo Y. van Battum Pavol Zelina Rebekka A. Schwab Dimple Karia Lina Malinauskaite Sara Brignani Marleen H. van den Munkhof Özge Düdükcü Anna A. De Ruiter Dianne M.A. Van den Heuvel Benjamin Bishop Jonathan Elegheert A. Radu Aricescu R. Jeroen Pasterkamp Christian Siebold 《Cell》2021,184(8):2103-2120.e31
104.
105.
《Molecular cell》2021,81(16):3386-3399.e10
106.
107.
108.
109.
《FEBS letters》1989,250(2):166-170
The characterization, in human pancreatic juice, of a binary complex associating procarboxypeptidase A with a 32 kDa inactive glycoprotein (G32) is reported in this paper. Free G32 was isolated after dissociation of the binary complex. N-terminal sequence analysis revealed a complete homology between this protein and human protease E (HPE 1), except for the two strongly hydrophobic N-terminal residues (Val-Val) which are missing in G32. This protein might be a truncated protease E highly analogous to the subunit III of the ruminant procarboxypeptidase A-S6 ternary complex. The analogy with bovine subunit III is further supported by interspecies reassociation experiments showing that bovine procarboxypeptidase A can specifically bind human G32. 相似文献
110.
《FEBS letters》1989,250(2):183-186
A model of the cooperative changes in optical properties of light-harvesting bacteriochlorophyll molecules of complex B890 in response to the absorption of light quanta is proposed. According to the model, each antenna chromophore may persist in either of two optically non-excited states, R and T. The occurrence of at least one excitation per complex causes all optically non-excited chromophores of the complex to be converted from state R to state T. The theory is shown to be in good agreement with experimental ‘light curves’ (ΔAvs intensity of picosecond excitation pulse) for the ‘minor’ and ‘major’ signals of light-harvesting bacteriochlorophylls of complex B890 from Chromatium minutissimum. 相似文献