全文获取类型
收费全文 | 14226篇 |
免费 | 743篇 |
国内免费 | 8篇 |
专业分类
14977篇 |
出版年
2022年 | 68篇 |
2021年 | 119篇 |
2020年 | 59篇 |
2019年 | 90篇 |
2018年 | 148篇 |
2017年 | 150篇 |
2016年 | 251篇 |
2015年 | 388篇 |
2014年 | 443篇 |
2013年 | 1161篇 |
2012年 | 785篇 |
2011年 | 850篇 |
2010年 | 491篇 |
2009年 | 471篇 |
2008年 | 799篇 |
2007年 | 885篇 |
2006年 | 867篇 |
2005年 | 916篇 |
2004年 | 986篇 |
2003年 | 923篇 |
2002年 | 872篇 |
2001年 | 161篇 |
2000年 | 109篇 |
1999年 | 156篇 |
1998年 | 228篇 |
1997年 | 209篇 |
1996年 | 174篇 |
1995年 | 150篇 |
1994年 | 116篇 |
1993年 | 154篇 |
1992年 | 128篇 |
1991年 | 102篇 |
1990年 | 95篇 |
1989年 | 99篇 |
1988年 | 96篇 |
1987年 | 70篇 |
1986年 | 81篇 |
1985年 | 97篇 |
1984年 | 108篇 |
1983年 | 87篇 |
1982年 | 115篇 |
1981年 | 100篇 |
1980年 | 86篇 |
1979年 | 50篇 |
1978年 | 57篇 |
1977年 | 45篇 |
1976年 | 52篇 |
1975年 | 35篇 |
1974年 | 57篇 |
1973年 | 43篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
132.
Hiroshi Kadokura Michiko Saito Akio Tsuru Akira Hosoda Takao Iwawaki Kenji Inaba Kenji Kohno 《Biochemical and biophysical research communications》2013
ERdj5 (also known as JPDI) is a member of PDI family conserved in higher eukaryotes. This protein possesses an N-terminal J domain and C-terminal four thioredoxin domains each having a redox active site motif. Despite the insights obtained at the cellular level on ERdj5, the role of this protein in vivo is still unclear. Here, we present a simple method to purify and identify the disulfide-linked complexes of this protein efficiently from a mouse tissue. By combining acid quenching and thiol-alkylation, we identified a number of potential redox partners of ERdj5 from the mouse epididymis. Further, we show that ERdj5 indeed interacted with two of the identified proteins via formation of intermolecular disulfide bond. Thus, this approach enabled us to detect and identify redox partners of a PDI family member from an animal tissue. 相似文献
133.
Toshio Yoshida Shigeru Muraki Hiroshi Kawamura Akira Komatsu 《Bioscience, biotechnology, and biochemistry》2013,77(3):343-352
The main component of Japanese Ho-leaf oil has been shown to be (?)-linalool (80~90%), and the following twenty minor constituents newly have been identified; methyl vinyl ketone, methyl isobutyl ketone, mesityl oxide, β-pinene, myrcene, (+)-limonene, cis- and trans-ocimene, n-hexanol, cis-3-hexenol, cis- and trans-linalool oxide, (?)-1-terpinen-4-ol, (+)-cis and (+)-trans-2,6,6-trimethyl-2-vinyl-5-hydroxytetrahydropyran, citronellol, nerol, (+)-β-selinene, (+)-tagetonol and (?)-trans-hotrienol. (+)-Tagetonol and (?)-trans-hotrienol have been demonstrated to be (+)-3,7-dimethyl-3-hydroxy-1-octen-5-one (III) and (3R)-(?)-trans-3,7-dimethyl-3-hydroxy-1,5,7-octatriene (IX), respectively. 相似文献
134.
135.
Two distinct forms of β-glucosidase, A and B, were found to occur in the cells of Pseudomonas fluorescens var. cellulosa : A was membrane-bound, while B cytosolic. They differed also from each other in some properties, such as molecular size, kinetic parameters, and susceptibility to various compounds. β-Glucosidase B was partially purified and studied especially of its substrate specificity. The results indicated that it may be an atypical β-glucosidase which possesses a certain character of exo-cellulase. 相似文献
136.
137.
Hiroshi Shiragami Yasuhiro Tanaka Yumiko Uchida Hisao Iwagami Kunisuke Izawa Toshihide Yukawa 《Nucleosides, nucleotides & nucleic acids》2013,32(2-4):391-400
Abstract Regioselective 2′-O-deacetylation of 9-(2,5-di-O-acetyl-3-bromo-3-deoxy-β-D-xylofuranosyl)adenine (1) is achieved by treatment of 1 with β-cyclodextrin (β-CyD) / aq. NaHCO3 or N2H4·H2O / EtOH. The 9-(5-O-Acetyl-3-bromo-3-deoxy-β-D-xylo-furanosyl)adenine (2) obtained is a common intermediate for the synthesis of 2′,3′-dideoxy-adenosine (ddA) (7) and 9-(2-fluoro-2,3-dideoxy-β-D-threo-pentofuranosyl)-adenine (F-ddA) (9). 相似文献
138.
Tissue-specific expression of betaKlotho and fibroblast growth factor (FGF) receptor isoforms determines metabolic activity of FGF19 and FGF21 总被引:3,自引:0,他引:3
Kurosu H Choi M Ogawa Y Dickson AS Goetz R Eliseenkova AV Mohammadi M Rosenblatt KP Kliewer SA Kuro-o M 《The Journal of biological chemistry》2007,282(37):26687-26695
139.
The seed coat surface morphology of Celtidaceae and Ulmaceae (Urticales) indicates a significant evolutionary diversity.Celtis, Chaetachme andPteroceltis (Celtidaceae) have a unique sculpturing with many crateriform holes; such holes occasionally sparsely occur in seeds ofAphananthe, Gironniera (Celtidaceae) andPlanera (Ulmaceae), but not in those of the nine remaining genera of the two families. The perforated seed coat further occurs in
at least some genera of all other urticalean families. A pattern of its occurrence in families and genera suggest that the
perforation represents a common archaic feature of all Urticales, rather than a feature derived many times independently within
the order. The seed coat of Celtidaceae and Ulmaceae seems to have lately lost the holes probably by a neotenic evolution:
one or more times within Celtidaceae, and one time in an ancestral line leading to all Ulmaceae. The derived reticulate seed
coat surface sculpturing, which is shared byGironniera (Celtidaceae) and some Ulmaceae, is probably the result of parallel evolution. On the basis of evidence from seed coat morphology
and other sources, close relationships ofLozanella, Parasponia andTrema within Celtidaceae, as well as variously distinct positions ofAmpelocera, Aphananthe andGironniera, are also discussed. 相似文献
140.