全文获取类型
收费全文 | 5955篇 |
免费 | 333篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 106篇 |
儿科学 | 100篇 |
妇产科学 | 71篇 |
基础医学 | 695篇 |
口腔科学 | 119篇 |
临床医学 | 367篇 |
内科学 | 1622篇 |
皮肤病学 | 117篇 |
神经病学 | 452篇 |
特种医学 | 140篇 |
外科学 | 1236篇 |
综合类 | 17篇 |
预防医学 | 150篇 |
眼科学 | 150篇 |
药学 | 353篇 |
中国医学 | 5篇 |
肿瘤学 | 612篇 |
出版年
2023年 | 40篇 |
2022年 | 63篇 |
2021年 | 146篇 |
2020年 | 93篇 |
2019年 | 107篇 |
2018年 | 158篇 |
2017年 | 111篇 |
2016年 | 119篇 |
2015年 | 146篇 |
2014年 | 165篇 |
2013年 | 203篇 |
2012年 | 332篇 |
2011年 | 341篇 |
2010年 | 191篇 |
2009年 | 175篇 |
2008年 | 275篇 |
2007年 | 288篇 |
2006年 | 289篇 |
2005年 | 331篇 |
2004年 | 283篇 |
2003年 | 273篇 |
2002年 | 261篇 |
2001年 | 151篇 |
2000年 | 176篇 |
1999年 | 139篇 |
1998年 | 84篇 |
1997年 | 55篇 |
1996年 | 59篇 |
1995年 | 43篇 |
1994年 | 46篇 |
1993年 | 39篇 |
1992年 | 114篇 |
1991年 | 102篇 |
1990年 | 102篇 |
1989年 | 88篇 |
1988年 | 92篇 |
1987年 | 82篇 |
1986年 | 61篇 |
1985年 | 72篇 |
1984年 | 37篇 |
1983年 | 33篇 |
1982年 | 24篇 |
1979年 | 25篇 |
1978年 | 26篇 |
1975年 | 22篇 |
1971年 | 21篇 |
1970年 | 22篇 |
1969年 | 24篇 |
1968年 | 18篇 |
1967年 | 23篇 |
排序方式: 共有6312条查询结果,搜索用时 78 毫秒
71.
Hideki Tamura Yasuyuki Ishikawa Noriko Hino Maoko Maeda Shigeru Yoshida Shinsuke Kaku Sadao Shiosaka 《The Journal of physiology》2006,570(3):541-551
Long-term potentiation (LTP) is thought to be particularly important in the acquisition of hippocampus-associated memory, in part because it develops quickly and persists for indefinite periods. Extracellular proteolysis has been hypothesized to contribute to LTP by modifying adhesive relations of synapses and thus the morphology of excitatory synapses. Here we report that neuropsin (NP), an extracellular serine protease, is critically involved in the formation of both the potentiation effect and hippocampus-dependent forms of memory. NP-knockout mice were significantly impaired in the Morris water maze and Y-mazes and failed to exhibit early phase LTP induced by a single tetanus. Potentiation was also impaired or completely blocked by in vivo application of a specific inhibitor or a neutralizing monoclonal antibody for NP. Intriguingly, recombinant (r-) NP alone, without tetanic stimulation, elicited either long-lasting potentiation or depression, depending on the applied dose. The r-NP-elicited potentiation was occluded by prior induction of LTP, while theta-burst-elicited LTP was occluded by application of r-NP alone, suggesting that the two forms of plasticity have a common signalling pathway. r-NP-elicited potentiation and depression increased phosphorylation at different sites on the GluR1 subunit of the AMPA receptor that had previously been associated with LTP or long-term depression. Thus, we conclude that NP is necessary for establishment of LTP and has a significant role in memory acquisition. 相似文献
72.
Masanori Hara Daisuke Mase Susumu Inaba Akira Higuchi Takakuni Tanizawa Noriaki Yamanaka Yuichi Sugisaki Yoshikazu Sado Toshio Okada 《Virchows Archiv : an international journal of pathology》1986,408(4):403-419
Summary The immunofluorescent localization of glomerular basement membrane (GBM) antigens was examined in 52 specimens from normal kidneys and in various renal diseases using antisera to human GBM HGBM), IV type collagen (IV Col) and P3 antigen, a rat nephritogen. Anti-HGBM serum normally stained the GBM and the mesangium in a restrictive pattern, anti-IV Col serum stained the GBM and the mesangium in a wider pattern and anti-P3 serum stained only the GBM. In mesangial proliferative glomerulonephritis, including IgA nephropathy pathy and Henoch-Schönlein nephritis, the widened mesangial areas were stained with anti-HGBM and anti-IV Col sera. In membranous nephropathy, the punched-out lesions of thickened GBM were demonstrated with the three antisera in moderate cases and a double linear distribution with fine granulation with anti-HGBM and anti-IV Col sera were revealed in one severe case. In membranoproliferative glomerulonephritis, the expanded mesangium and thickened capillary walls were stained with anti-HGBM and anti-IV Col sera, while the outer line of glomerular capillary walls was only positive with anti-P3 serum. In crescentic glomerulonephritis, the collapsed glomerular tufts were stained normally with anti-HGBM and anti-P3 sera and weakly with anti-IV Col serum. In diabetic nephropathy, anti-HGBM serum stained the GBM in a double linear distribution without reacting with the expanded mesangium; anti-IV Col serum stained the mesangium and the GBM in a less clear double linear fashion while anti-P3 serum stained the GBM as single line. Thin membrane disease and Alport's syndrome had normal reactivity with all antisera. However, in one case of Alport's syndrome anti-HGBM and anti-P3 sera stained the GBM in a focal and segmental pattern, while normal staining with anti-IV Col serum was found. In lesions with adhesions and crescents the staining was positive for HGBM and IV Col and negative for P3; obsolescent glomeruli were stained with anti-HGBM and anti-P3 sera, and had diminished staining with anti-IV Col serum.The identification of the various structural glomerular antigens is useful in the classification of certain types of glomerular diseases. Further insight into the mechanisms underlying these conditions may be obtained in this way. 相似文献
73.
K Maruoka M Yamanaka M Misago K Nakata J Tsukada K Nagata T Sato N Mori S Oda S Chiba 《Rinsho byori. The Japanese journal of clinical pathology》1990,38(10):1161-1166
The activities of RNase (RNase-U and RNase-C) were determined in the serum and leukocytes of 277 patients with 14 cases of various kinds of eosinophilia (not less than 10(3)/microliters), 28 cases of chronic myelocytic leukemia (CML), using polyuridylic acid and polycytidylic acid as synthetic substrates according to the method of Raddi et al. Serum RNase-U activity, serum RNase-C activity and the activity ratio (U/C x 10(-3)) were 55 +/- 14 U, 1,280 +/- 235 U and 44 +/- 11 (mean +/- SD), 196 +/- 137, 1,992 +/- 1,134 U and 97 +/- 38, and 110 +/- 50 U, 1,854 +/- 625 U and 65 +/- 13 for normal subjects, eosinophilia and CML (untreated), respectively. U/C ratio in eosinophilia and CML (untreated) showed a highly significant positive correlation (p less than 0.001) with peripheral eosinophil count; the activity of serum RNase-U per cells in the supernatant of eosinophil homogenate rose significantly (p less than 0.001) compared with that of lymphocytes or granulocytes. Besides, serum and eosinophil RNase-U had a similar optimal pH. These results suggested that serum RNase-U in eosinophilia originated mostly from eosinophils and its rise was correlated strongly with the increase in eosinophils. 相似文献
74.
K. Miyamoto J. Nagakawa I. Hishinuma K. Hirota M. Yasuda T. Yamanaka K. Katayama I. Yamatsu 《Inflammation research》1992,37(3-4):297-304
E3330 {(2E)-3-[5-(2,3-dimethoxy-6-methyl-1,4-benzoquinoyl)]-2-nonly-2-propenoic acid}, a novel synthesized hepatoprotective compound, has suppressive effects on tumor necrosis factor- (TNF-) generation from monocytes/macrophagesin vitro. E3330 (1–100 M) reduced lipopolysaccharide (LPS, 10 mg/ml or 1g/ml)-induced TNF- generation from rat resident andPropionibacterium acnes (P. acnes)-elicited peritoneal macrophages, rat and human monocytes, rat Kupffer cells, and splenic mononuclear cells in a concentration-dependent manner. E3330 also (1–100 M) suppressed TNF- generation stimulated with egg-albumin immune complex in ratP. acnes-elicited peritoneal macrophages. Northern blot analysis showed that LPS-induced expression of TNF- messenger RNA (mRNA) in human blood monocytes was suppressed by E3330. These findings indicate that E3330 has a suppressive effect on TNF- generation from monocytes/macrophages, regardless of origin or species, and this effect is based in part on the suppression of TNF- mRNA expression. 相似文献
75.
H Yamanaka R Y Kirdani J Saroff G P Murphy A A Sandberg 《The American journal of physiology》1975,229(4):1102-1109
Prostatic weights, 5alpha-reductase, and arginase activities were utilized as indexes for the effects of prolactin in short-term experiments in intact, hypophysectomized or castrated rats. Experiments were performed in which a dose-related response in the above parameters was obtained with testosterone administration in castrated mature and immature rats in order to evaluate the effects of simultaneously administered prolactin. This approach was necessitated by the failure of prolactin alone to affect the parameters listed in intact, castrated or hypophysectomized rats. It was shown that ovine prolactin may have an enhancing effect on the prostatic weight, 5alpha-reductase, and arginase activities, but that this effect is neither consistent nor striking when compared to that of testosterone.. Nevertheless, it is still possible that the long-term effects of prolactin, even if they are only of an enhancing quality, may play an important role in normal prostatic physiology and in abnormal states. 相似文献
76.
Possible role of autoantibodies against nephrin in an experimental model of chronic graft-versus-host disease 总被引:2,自引:0,他引:2
下载免费PDF全文
![点击此处可从《Clinical and experimental immunology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Nagahama K Maru K Kanzaki S Chai HL Nakai T Miura S Yamaguchi A Yamanaka S Nagashima Y Aoki I 《Clinical and experimental immunology》2005,141(2):215-222
Nephrin, a product of the NPHS1 gene, is a component of the slit diaphragms that are found between glomerular foot processes and is a crucial element for glomerular filtration barrier. Recently, nephrin has been focused in a number of studies of proteinuria development including various types of acquired glomerular diseases including minimal change nephrotic syndrome and membranous nephropathy. However, the precise role of nephrin in such acquired glomerular diseases is still unknown. To analyse the role of nephrin further, two kinds of anti-nephrin antibodies were raised in the rabbits and applied to an experimental mouse model of chronic graft-versus-host disease, in which (C57BL/10 x DBA/2) F1 mice developed clinically apparent severe proteinuria with significant glomerular lesions 7 weeks after parental DBA/2 cell transfer. Antibody-sandwich ELISA detected anti-nephrin antibodies during week 2 to week 6, with the peak at week 2 or week 4. Colocalization of nephrin and IgG on week 4, week 6, and week 8 was revealed by confocal microscopic analysis, suggesting that in situ immune complex formation with nephrin in glomerular lesion. Taken together, it seems to be suggested nephrin and its autoantibody have a certain role in the development of glomerular lesion in our model mice. 相似文献
77.
Suzuki K Nakazato H Matsui H Hasumi M Shibata Y Ito K Fukabori Y Kurokawa K Yamanaka H 《Journal of leukocyte biology》2001,69(4):531-537
78.
M Yoshida M Asano Y Morita I Kaetsu K Imai T Mashimo H Yuasa H Yamanaka U Kawaharada K Suzuki 《Biomaterials》1989,10(1):16-22
Cisplatin, cis-dichlorodiamine platinum (II), was incorporated in a needle-type copolymer formulation (0.8 mm diameter, 6 mm long) by radiation-induced polymerization. The copolymer used was copoly(diethylene glycol dimethacrylate/polyethylene glycol #600 dimethacrylate, 80/20 vol%). This copolymer, containing 6 mg of cisplatin, was implanted into the kidney of adult male Wistar rats (420 +/- 20 g). A total of 70 d was required for 100% release of cisplatin in vivo. The kidney tissue surrounding the formulation was strongly necrotized by the action of cisplatin. Two layers of necrosis could be distinguished: necrotic tissue surrounding the formulation and necrobiotic tissue surrounding the necrotic tissue. The amount of necrotic tissue changed markedly over time, but no change was apparent in the amount of necrobiotic tissue. The maximal amounts of necrotized tissue were observed 14 d after implantation: 3100 microns and 600 microns thick for the necrotic and necrobiotic tissues, respectively. 相似文献
79.
80.
Cloning of the fusion gene of rinderpest virus: comparative sequence analysis with other morbilliviruses 总被引:3,自引:0,他引:3
We have cloned the cDNA of the fusion (F) gene of the virulent (Kabete O) strain of rinderpest virus and provided a comparative analysis of its sequence with that of the F genes of measles and distemper viruses. The gene has an open reading frame of 2241 nucleotides with two potential initiation codons in-frame. Use of the first ATG would produce a polypeptide 747 amino acids long with a calculated molecular weight of 81,068. However, we suggest that the second ATG is used to generate the Fo protein, which is 546 amino acids long with a calculated molecular weight of 58,754. During maturation, the cleavage of F0 gives rise to the functional F1 and F2 polypeptides. The F1 polypeptide is 438 amino acids long and has a calculated molecular weight of 46,791, with a single (potential) glycosylation site in its cytoplasmic domain. The F2 polypeptide, probably 89 amino acids long after the signal sequence is cleaved, is estimated to be 9,800 Da and has three potential glycosylation sites. There is a divergence of 18.7% in amino acid sequences between rinderpest and measles virus F0 polypeptides; between distemper and rinderpest viruses the divergence is 31.8%. No significant homology in nucleotide sequences of rinderpest DNA to measles or distemper DNA was found in the 5' and 3' untranslated regions. 相似文献