全文获取类型
收费全文 | 8735篇 |
免费 | 762篇 |
国内免费 | 310篇 |
出版年
2024年 | 14篇 |
2023年 | 115篇 |
2022年 | 235篇 |
2021年 | 421篇 |
2020年 | 211篇 |
2019年 | 321篇 |
2018年 | 321篇 |
2017年 | 260篇 |
2016年 | 350篇 |
2015年 | 470篇 |
2014年 | 490篇 |
2013年 | 614篇 |
2012年 | 737篇 |
2011年 | 660篇 |
2010年 | 417篇 |
2009年 | 324篇 |
2008年 | 452篇 |
2007年 | 444篇 |
2006年 | 378篇 |
2005年 | 351篇 |
2004年 | 277篇 |
2003年 | 247篇 |
2002年 | 274篇 |
2001年 | 174篇 |
2000年 | 223篇 |
1999年 | 156篇 |
1998年 | 60篇 |
1997年 | 43篇 |
1996年 | 43篇 |
1995年 | 53篇 |
1994年 | 42篇 |
1993年 | 34篇 |
1992年 | 73篇 |
1991年 | 63篇 |
1990年 | 64篇 |
1989年 | 63篇 |
1988年 | 46篇 |
1987年 | 37篇 |
1986年 | 44篇 |
1985年 | 45篇 |
1984年 | 26篇 |
1983年 | 21篇 |
1982年 | 12篇 |
1981年 | 17篇 |
1980年 | 9篇 |
1979年 | 18篇 |
1978年 | 12篇 |
1977年 | 12篇 |
1976年 | 7篇 |
1972年 | 6篇 |
排序方式: 共有9807条查询结果,搜索用时 31 毫秒
121.
S Shefer L B Nguyen G Salen G C Ness I R Chowdhary S Lerner A K Batta G S Tint 《Journal of lipid research》1992,33(8):1193-1200
122.
Purification and characterization of cytosolic 6-phosphogluconate dehydrogenase isozymes from maize 总被引:1,自引:1,他引:0
下载免费PDF全文
![点击此处可从《Plant physiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Cytosolic isozymes of 6-phosphogluconate dehydrogenase were purified from roots of maize (Zea mays L.). The final preparation contained two 55-kD proteins. Affinity-purified dehydrogenases from a maize line that is null for both cytosolic 6-phosphogluconate dehydrogenase isozymes (Pgd1-null, Pgd2-null) lacked the 55-kD proteins. The substrate kinetics of the purified enzyme were determined. 相似文献
123.
Summary We report here an improved method for nuclei counting utilizing Triton-X 100 to reduce the size of cell debris, thereby allowing the use of a particle sizer/counter. Furthermore, nuclei are completely released within 30 seconds, as compared to 1 hour using hypotonic solution. The method is accurate above 0.3 × 106 cells/mL. 相似文献
124.
The substrate specificity of purified PKC-alpha, -beta and -gamma has been investigated. A series of synthetic peptides based upon the sequence surrounding serine-7 in glycogen synthase were generated and used to determine the basic residue requirements of these PKC isotypes. While PKC-alpha and -beta are indistinguishable in their phosphorylation of these peptides, PKC-gamma shows a distinct specificity profile for these synthetic substrates. 相似文献
125.
Interaction between corticosteroid binding globulin and activated leukocytes in vitro 总被引:1,自引:0,他引:1
G L Hammond C L Smith C M Underhill V T Nguyen 《Biochemical and biophysical research communications》1990,172(1):172-177
The interaction between human corticosteroid binding globulin and activated leukocytes is restricted to the granulocyte population, and is characterized by specific proteolytic cleavage of corticosteroid binding globulin which markedly reduces its steroid binding activity. A direct interaction between corticosteroid binding globulin and the activated cells appears to enhance this event, and does not involve cellular internalization of corticosteroid binding globulin or its proteolytic degradation products, which resemble those obtained after incubation of corticosteroid binding globulin with neutrophil elastase. These data suggest that corticosteroid binding globulin interacts with elastase on the surface of activated neutrophils, and may promote glucocorticoid delivery to these cells during inflammation. 相似文献
126.
Transabdominal fine needle aspiration biopsy of a solitary space-occupying lesion in the liver produced smears containing irregular bundles of smooth muscle cells with granular or fibrillary cytoplasm and slightly pleomorphic nuclei. In a few bundles, aggregates of mature fat cells were present, which is characteristic for an angiomyolipoma. Histologic examination of the resected mass showed it to be a solitary angiomyolipoma of the liver. The diagnosis was further confirmed by immunohistochemical and electron microscopic studies. 相似文献
127.
Twenty independent man-mouse (Cl1D,LA/TK-, HPRT-) and man-hamster (CH,HPRT-) hybrids using female human cells with balanced reciprocal translocation XX,t(X;5)(q21;q11) were analyzed for human genes localized on chromosome 5 (HEXB), on chromosome X (PGK, GALA, HPRT, G6PD) and for the different chromosomes in relation with the balanced reciprocal translocation (chr.5, chr.5q-, chr.Xq+, chr.X). The different results obtained indicate that the genes for human markers HEXB, PGK are on Xq+, and that the genes for human markers GALA, G6PD are on 5q-. These data implicate finally the following localizations: HEXB on 5q11 leads to 5qter; PGK on Xq21 leads to Xpter; GALA, HPRT, G6PD on Xq21 leads to Xqter. 相似文献
128.
Comparative ultrastructure of Mycobacterium leprae and Mycobacterium lepraemurium cell envelopes.
下载免费PDF全文
![点击此处可从《Journal of bacteriology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
H T Nguyen D D Trach N V Man T H Ngoan I Dunia M A Ludosky-Diawara E L Benedetti 《Journal of bacteriology》1979,138(2):552-558
The structural properties of the cell envelopes of Mycobacterium leprae and Mycobacterium lepraemurium were investigated by freeze-fracture, freeze-etching, and negative-staining techniques. Freeze-fracture split the cell wall and exposed the internal features of the peptidoglycolipid mycosidic filamentous network. The cell membrane was also split into two asymmetric faces. The external fracture face was characterized by linear arrays of intramembranous particles, whereas the protoplasmic fracture face showed randomly distributed clusters of particulate entities. Comparative analysis of the ultrastructural features observed in M. leprae and M. lepraemurium indicated that the organization of the cell envelope in these two species differed particularly with respect to the amount and complexity of the superficial peptidoglycolipid and mycosidic integument, which is poorly developed in the mycobacterium responsible for human disease. 相似文献
129.
130.
Size of the pool of alveolar neutrophils in normal rabbit lungs 总被引:3,自引:0,他引:3
Cohen A. B.; Batra G.; Petersen R.; Podany J.; Nguyen D. 《Journal of applied physiology》1979,47(2):440-444