全文获取类型
收费全文 | 615篇 |
免费 | 58篇 |
专业分类
673篇 |
出版年
2022年 | 5篇 |
2021年 | 9篇 |
2020年 | 10篇 |
2019年 | 12篇 |
2018年 | 7篇 |
2017年 | 14篇 |
2016年 | 14篇 |
2015年 | 26篇 |
2014年 | 23篇 |
2013年 | 45篇 |
2012年 | 46篇 |
2011年 | 57篇 |
2010年 | 21篇 |
2009年 | 28篇 |
2008年 | 48篇 |
2007年 | 41篇 |
2006年 | 36篇 |
2005年 | 47篇 |
2004年 | 30篇 |
2003年 | 25篇 |
2002年 | 26篇 |
2001年 | 11篇 |
1999年 | 6篇 |
1998年 | 11篇 |
1997年 | 8篇 |
1996年 | 7篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1987年 | 2篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 2篇 |
1968年 | 1篇 |
排序方式: 共有673条查询结果,搜索用时 0 毫秒
1.
2.
Sumitomo Shinichiro Tatemoto Yukihiro Fukui Shin Nakamura Taka-aki Fukushima Shoji Ito Nobuyuki Mori Masahiko 《Virchows Archiv. B, Cell pathology including molecular pathology》1985,49(1):395-399
Virchows Archiv B Cell Pathology - Paget cells from cases of mammary and extramammary Paget’s disease were examined for carcinoembryonic antigen (CEA) and CEA-related antigens by the... 相似文献
3.
Purification and properties of pyridine nucleotide-independent L-lactate dehydrogenase from Polyporus circinatus 总被引:1,自引:1,他引:0
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)
Cell extracts of Polyporus circinatus grown on lactate catalyze the reduction of 2,6-dichlorophenolindophenol by l-lactate without the participation of nicotinamide adenine dinucleotide or nicotinamide adenine dinucleotide phosphate. The enzyme has been purified 78-fold and was homogenous by disc gel electrophoresis. The optimal pH was found to be 6.7. The Michaelis constant for l-lactate was 5.9 x 10(-4) M and the oxalate inhibition constant was 1.5 x 10(-4) M. The nature of the prosthetic group is discussed. 相似文献
4.
5.
Shinichiro Nakamura Wijit Kiatipattanasakul Hiroyuki Nakayama Fumiko Ono Ippei Sakakibara Yasuhiro Yoshikawa Naoaki Goto Kunio Doi 《Journal of medical primatology》1996,25(4):294-300
Abstract: In this study, we immunohistochemically examined the several constituents of senile plaques (SPs) and cerebral amyloid angiopathy (CAA) in aged cynomolgus monkeys. Apolipoprotein E (apoE) deposited in all mature plaques and CAA, and in half of the diffuse plaques. Alpha-1-antichymotripsin (αACT) deposited in half of the mature plaques and in one third of the CAA. Amyloid precursor protein (APP), ubiquitin (Ub), and microtubule-associated protein-2 (MAP-2) accumulated in the swollen neurites of mature plaques. Glial fibrillary acidic protein (GFAP) was detected in the astrocytes and their processes surrounding the mature plaques. Tau was detected in neither the SPs nor CAA. Therefore, mature plaques involved extracellular Aβ, apoE, and αACT, and also astrocytes and swollen neurites. However, diffuse plaques involved only extracellular Aβ and apoE. Since these features, except for tau, were consistent with those in humans, this animal model will be useful for studying the pathogenesis of cerebral amyloid deposition. 相似文献
6.
Nucleotide sequence and characterization of the traABCD region of IncI1 plasmid R64. 总被引:2,自引:2,他引:0
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)
A 3.6-kb BglII-SmaI segment of the transfer region of IncI1 plasmid R64drd-11 was sequenced and characterized. Analysis of the DNA sequence indicated the presence of four genes, traA, traB, traC, and traD, in this region. The expression of the traB, traC, and traD genes was examined by maxicell experiments and that of the traA gene was examined by constructing the traA-lacZ fusion gene. The introduction of frameshift mutations into the four genes indicated that the traB and traC genes are essential for conjugal transfer in liquid medium and on a solid surface. Both were also required for the formation of the thin pilus, which is the receptor for phages I alpha and PR64FS. Upstream of the traA gene, a promoter sequence for sigma 70 of E. coli RNA polymerase was identified by S1 nuclease mapping and primer extension experiments. 相似文献
7.
Extracellular matrix components of the placental extravillous trophoblast: immunocytochemistry and ultrastructural distribution 总被引:7,自引:0,他引:7
B. Huppertz S. Kertschanska H. -G. Frank G. Gaus H. Funayama P. Kaufmann 《Histochemistry and cell biology》1996,106(3):291-301
Invasive extravillous trophoblast cells of the human placenta are embedded in a self-secreted extracellular matrix, the matrix-type
fibrinoid. The ultrastructure and molecular composition of the matrix-type fibrinoid of the term human placenta were studied
by transmission electron microscopy and immunogold labelling. We used antibodies directed against different matrix proteins
such as collagen type IV, laminin, vitronectin, heparan sulfate, various fibronectin isoforms, and against the oncofetal blood
group antigen, ”i”. Immunogold labelling patterns of matrix proteins are the basis for the subdivision of the trophoblast-derived
matrix-type fibrinoid into mosaic-like patches of structurally and immunocytochemically different compartments. Firstly, fine
granular patches with structural similarities to basal lamina material are composed solely of collagen type IV and laminin.
Secondly, an ultrastructurally amorphous glossy substance shows reactivity with antibodies against heparan sulfate and vitronectin.
A third type of patches, fine fibrillar networks embedded in the above-mentioned glossy matrix, are reactive with antibodies
against normal fibronectin isoforms (IST-4, IST-6, IST-9) and oncofetal isoforms (BC-1, FDC-6). The blood group precursor
antigen ”i” was not only expressed on the surfaces of the extravillous trophoblast cells but was associated with the fibronectin-positive
fibrils. In conclusion, within this extracellular matrix, clear compartments of different composition can be distinguished
from each other. Glycosylation with ”i” in this matrix may be involved in immunological masking, thus preventing rejection
of placenta and fetus.
Accepted: 6 May 1996 相似文献
8.
E M Benelli E M Souza S Funayama L U Rigo F O Pedrosa 《Journal of bacteriology》1997,179(14):4623-4626
Two glnB-like genes have been isolated from Herbaspirillum seropedicae by complementation of the Klebsiella pneumoniae glnB502 mutant for growth on nitrate. One of these glnB-like genes has been sequenced and shows strong identity with GlnB proteins derived from other organisms. A Tn5-20 mutation of this glnB was Nif negative. 相似文献
9.
10.