全文获取类型
收费全文 | 5911篇 |
免费 | 247篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 54篇 |
儿科学 | 71篇 |
妇产科学 | 61篇 |
基础医学 | 712篇 |
口腔科学 | 71篇 |
临床医学 | 364篇 |
内科学 | 1357篇 |
皮肤病学 | 50篇 |
神经病学 | 505篇 |
特种医学 | 203篇 |
外科学 | 1087篇 |
综合类 | 25篇 |
预防医学 | 154篇 |
眼科学 | 285篇 |
药学 | 478篇 |
中国医学 | 20篇 |
肿瘤学 | 686篇 |
出版年
2023年 | 32篇 |
2022年 | 58篇 |
2021年 | 124篇 |
2020年 | 68篇 |
2019年 | 83篇 |
2018年 | 93篇 |
2017年 | 89篇 |
2016年 | 91篇 |
2015年 | 125篇 |
2014年 | 143篇 |
2013年 | 206篇 |
2012年 | 327篇 |
2011年 | 373篇 |
2010年 | 212篇 |
2009年 | 168篇 |
2008年 | 348篇 |
2007年 | 313篇 |
2006年 | 362篇 |
2005年 | 380篇 |
2004年 | 368篇 |
2003年 | 359篇 |
2002年 | 349篇 |
2001年 | 118篇 |
2000年 | 101篇 |
1999年 | 119篇 |
1998年 | 82篇 |
1997年 | 73篇 |
1996年 | 69篇 |
1995年 | 68篇 |
1994年 | 70篇 |
1993年 | 48篇 |
1992年 | 75篇 |
1991年 | 57篇 |
1990年 | 55篇 |
1989年 | 49篇 |
1988年 | 58篇 |
1987年 | 54篇 |
1986年 | 40篇 |
1985年 | 38篇 |
1984年 | 31篇 |
1983年 | 24篇 |
1981年 | 24篇 |
1980年 | 20篇 |
1979年 | 29篇 |
1978年 | 17篇 |
1977年 | 22篇 |
1974年 | 21篇 |
1973年 | 16篇 |
1970年 | 16篇 |
1969年 | 20篇 |
排序方式: 共有6183条查询结果,搜索用时 0 毫秒
41.
Yoshizawa K Oishi Y Nambu H Yamamoto D Yang J Senzaki H Miki H Tsubura A 《Toxicologic pathology》2000,28(4):555-564
Cataract was induced by a single intraperitoneal injection of 100 mg/kg N-methyl-N-nitrosourea (MNU) to 0-, 5-, 10-, 15-, or 20-day-old male and female Sprague-Dawley rats. In day 0, 5, 10, and 15 MNU-treated rats, mature cataracts were constantly seen 7, 14, 14, and 30 days after dosing, respectively. In the day 20 MNU-treated rats, only subcapsular cataract was seen 30 days after dosing. Therefore, the rats exposed to MNU at an earlier age caused cataract more rapidly and severely. In the day 0 MNU-treated rats, 7-methyldeoxyguanosine DNA adduct was detected in the lens epithelial nuclei 12 hours after MNU dosing, followed by apoptosis, which was confirmed by morphology, by TUNEL signals, and by DNA ladder and peaked 3 days after MNU dosing. In the apoptosis cascade, upregulation of Bax, downregulation of Bcl-2, and increased CPP32 protease (caspase-3) activity were seen 12 hours after MNU dosing. Therefore, the pathogenesis of MNU-induced cataract was associated with DNA adduct formation in the lens epithelial cell nuclei leading to apoptosis by upregulation of Bax protein, downmodulation of Bcl-2 protein, and activation of caspase-3. 相似文献
42.
T Urasawa K Taniguchi N Kobayashi F Wakasugi I Oishi Y Minekawa M Oseto M U Ahmed S Urasawa 《Journal of clinical microbiology》1990,28(12):2837-2841
In our previous study (S. Urasawa, T. Urasawa, K. Taniguchi, F. Wakasugi, N. Kobayashi, S. Chiba, N. Sakurada, S. Morita, O. Morita, M. Tokieda, T. Kawamoto, K. Minekawa, and M. Oseto, J. Infect. Dis. 160:44-51, 1989) of antigenic characterization of about 300 human rotavirus (HRV) isolates collected at different localities in Japan, we found 4 HRV isolates having unique antigenic and genetic constructions. The four strains possessed both subgroup I and subgroup II antigens, serotype 3 antigen, and a long RNA electropherotype. The reactivity pattern of these four HRV isolates with three monoclonal antibodies (MAbs) directed to an outer capsid protein, VP4, and with one MAb directed to an inner capsid protein, VP2, was clearly different from those of usual subgroup II HRVs having serotype 1, serotype 3, or serotype 4 specificity and a long RNA pattern, whereas their reactivity pattern was similar to that of strain K8 (subgroup II, serotype 1), which possessed unique VP4 and VP2 proteins. RNA-RNA cross-hybridization analysis indicated that while the four isolates were genetically distinct from the two genetic groups of HRV reported previously, i.e., the Wa family (strains KU, S3, and YO) and the DS-1 family (strain S2), they were closely related to strain K8, a strain having unique antigenic and genetic properties (K. Taniguchi, K. Nishikawa, T. Urasawa, S. Urasawa, K. Midthun, A. Z. Kapikian, and M. Gorziglia, J. Virol. 63:4101-4106, 1989). 相似文献
43.
Mitsuyo Nishimura Tetsuro Kodama Hiroyuki Nishiyama Yutaka Nishiwaki Tomoyuki Yokose Yukio Shimosato 《Pathology international》1997,47(4):260-263
A 57-year-old woman presented with a 10×10 cm anterior mediations mass. The tumor had Invaded the pericardium, both lungs and the left brachiocephallc vein, and was treated by partial resection and postoperative radiation therapy. Pathological examination of the tumor revealed squamous cell carcinoma with a spindle cell sarcomatous component. Immunohistochemically, keratin and epithelial membrane antlgen were posltive In both the spindle cell sarcomatous areas and the squamous cell carcinomatous area and thus, a diagnosis of thymic carcinoma of sarcomatoid type was made. The patient died of recurrent disease 1 year after surgery. This case is the seventh reported In the English literature Because of the poor outcome, adjuvant therapy is recommended. 相似文献
44.
Jun Nakura Lin Ye Koichi Kihara Hidehisa Yamagata Kouzin Kamino Yusuke Nakamura Tetsuro Miki Toshio Ogihara 《Journal of human genetics》1995,40(3):281-282
Two polymorphic dinucleotide (CA) repeat clones were isolated from cosmids, cCI8-1121 and cCI8-1199, mapped to chromosome 8p11.2-p12. 相似文献
45.
Mianserin (5-20 mg/kg), like chlordiazepoxide (2.5-10 mg/kg), inhibits the shock-induced suppression of drinking (SSD) in rats. However, in contrast to chlordiazepoxide, the effect of mianserin is not blocked by the benzodiazepine antagonist, Ro 15-1788 (10 mg/kg). Although mianserin does not inhibit [3H]diazepam binding in vitro it has now been found to enhance [3H]flunitrazepam binding to mouse whole brain in vivo at 10-100 mg/kg p.o. These results suggest that mianserin does influence central benzodiazepine receptors, but the mechanism by which it does so differs from that of chlordiazepoxide. 相似文献
46.
Assignment of a polymorphic locus of OS-4(D18S5) DNA segment to human chromosome region 18q21.3→qter
47.
Saburo Kawaguchi Tetsuro Yamamoto Noboru Mizuno Nobuharu Iwahori 《Neuroscience letters》1975,1(6):301-304
Destruction of the inferior olivary nucleus was performed in newborn kittens in order to study the role of climbing fibers in the postnatal development of the cerebellum. In the three kittens which survived for 40–45 days after the unilateral destruction at 2 days old, histological examination demonstrated the lack of dendritic arborization in many Purkinje cells in the cerebellar cortex contralateral to the lesion. The olivectomized kittens showed cerebellar symptoms which became conspicous when the kittens started to walk. The results reveal an important role of climbing fibers in the development of Purkinje cell dendrites. 相似文献
48.
49.
Fukao T Yamada T Tanabe M Terauchi Y Ota T Takayama T Asano T Takeuchi T Kadowaki T Hata Ji J Koyasu S 《Nature immunology》2002,3(3):295-304
Mice that lack the p85alpha regulatory subunit of phosphatidylinositol-3 kinase (PI3K) are deficient in gastrointestinal and peritoneal mast cells but have dermal mast cells. Accordingly, these mice show impaired bacterial clearance in response to acute septic peritonitis and are highly susceptible to infection by the intestinal nematode Strongyloides venezuelensis. Systemic anaphylactic shock responses, however, are intact. We found that although reconstitution of PI3Kminus sign/minus sign mice with bone marrow--derived mast cells (BMMCs) restored anti-bacterial immunity, only T helper type 2 (TH2)-conditioned BMMCs, not "standard" BMMCs, were able to restore anti-nematode immunity. This finding highlights the importance of the TH2 response in the control of nematode infection. Thus, PI3K likely plays an essential role in host immune responses by regulating both the development and induction of mast cells. 相似文献
50.
We develop a compact scanning head for use in laser confocal fluorescence microscopy for in situ fluorescence imaging of organs. The head, cylindrical in shape, has 3.5 mm diameter and 30 mm length, and is thus small enough to operate in a living rat heart. The lateral and axial resolutions, defined as full widths at half maximum (FWHM) of a point spread function (PSF), measures 1.0 and 5.0 microm, respectively, for 488-nm excitation and 1.0 and 5.4 microm, respectively, for 543-nm excitation. The chromatic aberration between 488- and 543-nm laser beams is well suppressed. We perform Ca2+ imaging in cardiomyocytes through the right ventricular chamber of a perfused rat heart in line-scan mode with 2.9-ms time resolution. We also carried out two-color imaging of a fixed mouse heart and liver with subcellular resolution. The compact head of the microscope equipped with a line-scan imaging mode and two-color imaging mode is useful for in situ imaging in living organs with subcellular resolution and can advantageously be applied to in vivo research. 相似文献