全文获取类型
收费全文 | 9439篇 |
免费 | 416篇 |
国内免费 | 39篇 |
专业分类
耳鼻咽喉 | 46篇 |
儿科学 | 202篇 |
妇产科学 | 263篇 |
基础医学 | 1158篇 |
口腔科学 | 113篇 |
临床医学 | 598篇 |
内科学 | 2546篇 |
皮肤病学 | 216篇 |
神经病学 | 702篇 |
特种医学 | 283篇 |
外科学 | 1607篇 |
综合类 | 30篇 |
一般理论 | 2篇 |
预防医学 | 165篇 |
眼科学 | 145篇 |
药学 | 491篇 |
中国医学 | 21篇 |
肿瘤学 | 1306篇 |
出版年
2023年 | 61篇 |
2022年 | 97篇 |
2021年 | 191篇 |
2020年 | 112篇 |
2019年 | 148篇 |
2018年 | 167篇 |
2017年 | 151篇 |
2016年 | 187篇 |
2015年 | 176篇 |
2014年 | 236篇 |
2013年 | 318篇 |
2012年 | 500篇 |
2011年 | 623篇 |
2010年 | 310篇 |
2009年 | 266篇 |
2008年 | 548篇 |
2007年 | 588篇 |
2006年 | 515篇 |
2005年 | 555篇 |
2004年 | 567篇 |
2003年 | 502篇 |
2002年 | 473篇 |
2001年 | 194篇 |
2000年 | 222篇 |
1999年 | 188篇 |
1998年 | 135篇 |
1997年 | 104篇 |
1996年 | 114篇 |
1995年 | 94篇 |
1994年 | 101篇 |
1993年 | 71篇 |
1992年 | 132篇 |
1991年 | 140篇 |
1990年 | 129篇 |
1989年 | 119篇 |
1988年 | 120篇 |
1987年 | 102篇 |
1986年 | 82篇 |
1985年 | 66篇 |
1984年 | 58篇 |
1983年 | 56篇 |
1982年 | 28篇 |
1981年 | 29篇 |
1980年 | 34篇 |
1979年 | 50篇 |
1978年 | 30篇 |
1977年 | 42篇 |
1974年 | 18篇 |
1973年 | 23篇 |
1969年 | 18篇 |
排序方式: 共有9894条查询结果,搜索用时 857 毫秒
61.
Akitaka Nonomura Yuji Mizukami Fujitsugu Matsubara Naoko Kono Yasuni Nakanuma 《Pathology international》1989,39(5):328-335
A case of pancreatic tumor with features of both duct and islet cell components was found incidentally at autopsy in a 76 year old male who had died of intrahepatic cholan-giocarcinoma. The tumor, measuring about l.0cm in diameter, was located in the pancreatic tail. The tumor was composed of two distinct cell populations, islet cells and duct cells. Immunocytochemically, nearly all of the former cells were positive for insulin but negative for cytokeratin, carcinoembryonic antigen (CEA) and mucin, while the latter were positive for cytokeratin, CEA and mucin but negative for insulin. Additionally, a majority of the tumor cells that had formed islet-like structures were positive for neuron specific enolase (NSE), whereas NSE-positive cells were found only rarely in duct components. Electron microscopy confirmed the presence of two cell populations. Simultaneous occurrence of duct and islet cell components in a single pancreatic tumor indicates an intimate histogenetic relationship between pancreatic endocrine and duct cells. Acta Pathol Jpn 39: 328 335, 1989. 相似文献
62.
A promoter variant of the ATP-binding cassette transporter A1 gene alters the HDL cholesterol level in the general Japanese population 总被引:3,自引:0,他引:3
Shioji K Nishioka J Naraba H Kokubo Y Mannami T Inamoto N Kamide K Takiuchi S Yoshii M Miwa Y Kawano Y Miyata T Miyazaki S Goto Y Nonogi H Tago N Iwai N 《Journal of human genetics》2004,49(3):141-147
To investigate the effects of polymorphisms in the ATP-binding cassette transporter A1 (ABCA1) gene on the high-density lipoprotein cholesterol (HDL-C) level and the incidence of myocardial infarction (MI), we performed association studies. Sequence analysis identified 14 polymorphisms in the promoter region of ABCA1. After considering linkage disequilibrium, three polymorphisms in the promoter region and 11 polymorphisms from the JSNP database were determined in 1,880 subjects recruited from the Suita Study, representing the general population in Japan. We evaluated the association between the ABCA1 genotype and HDL-C level adjusted not only for standard factors, but also for genetic factors including ApoA1 and ApoE genotypes. Of the 14 polymorphisms tested, the G(–273)C (P=0.0074), C(–297)T (P=0.0195), and IMS-JST071749
(P=0.0093) polymorphisms were significantly associated with the HDL-C level in the Suita population. We could reconfirm that the G(–273)C genotype was influential in another set of subjects (P=0.0310, n=743). However, the distribution of the ABCA1 G(–273)C
genotype in subjects with MI (n=598) was not different from that in the control population (n=801). These results indicate that ABCA1 G(–273)C
has a significant effect on the HDL-C level in the general Japanese population, but not on the incidence of MI. 相似文献
63.
Koichiro Yuji Shigesaburo Miyakoshi Daisuke Kato Yuji Miura Tomohiro Myojo Naoko Murashige Yukiko Kishi Kazuhiro Kobayashi Eiji Kusumi Hiroto Narimatsu Tamae Hamaki Tomoko Matsumura Masahiro Kami Takahiro Fukuda Shigeru Masuo Kazuhiro Masuoka Atsushi Wake Junichi Ueyama Akiko Yoneyama Ko Miyamoto Haruhisa Nagoshi Michio Matsuzaki Shinichi Morinaga Yoshitomo Muto Yoichi Takeue Shuichi Taniguchi 《Biology of blood and marrow transplantation》2005,11(4):314-318
We report the results of reduced-intensity unrelated cord blood transplantation (RI-UCBT) in patients with advanced malignant lymphoma. Twenty patients (median age, 46.5 years; range, 27-66 years) underwent RI-UCBT with a preparative regimen consisting of fludarabine 125 mg/m2 , melphalan 80 mg/m 2 , and 4 Gy of total body irradiation. The median infused total cell dose was 2.75 x 10(7)/kg (range, 2.3-3.4 x 10(7)/kg). Graft-versus-host disease (GVHD) prophylaxis was composed of cyclosporine or tacrolimus alone. Fifteen patients achieved primary neutrophil engraftment after a median of 20 days. Eight patients developed grade II to IV acute GVHD, and 2 developed chronic GVHD. Of the 16 patients with evaluable disease, 10 achieved a complete response. Primary disease recurred in 1 patient, and transplant-related mortality within 100 days occurred in 8 of 20 patients. The estimated 1-year probability of progression-free survival was 50%. These data suggest that RI-UCBT is a feasible option for patients with refractory lymphoma who lack an HLA-matched donor. 相似文献
64.
Hisamatsu K Kusano KF Morita H Takenaka S Nagase S Nakamura K Emori T Matsubara H Ohe T 《Acta medica Okayama》2004,58(1):29-35
We attempted to determine the usefulness of body surface mapping (BSM) for differentiating patients with Brugada syndrome (BS) from patients with asymptomatic Brugada syndrome (ABS). Electrocardiograms (ECG) and BSM were recorded in 7 patients with BS and 35 patients with ABS. Following the administration of Ic antiarrhythmic drugs, BSM was recorded in 5 patients with BS and 16 patients with ABS. The maximum amplitudes at J0, J20, J40 and J60 were compared between the 2 groups, as were 3-dimensional maps. The maximum amplitudes at J0, J20 and J60 under control conditions were larger in patients with BS than in patients with ABS (P < 0.05). A three-dimensional map of the ST segments under control conditions in patients with BS showed a higher peak of ST elevation in the median precordium compared to that for patients with ABS. Increases in ST elevation at J20, J40 and J60 following drug administration were greater in patients with BS than in patients with ABS (P < 0.05). Evaluation of the change in amplitude of the ST segment at E5 caused by Ic drug administration was also useful for differentiating between the 2 groups. In conclusion, BSM was useful for differentiating patients with BS from those with ABS. 相似文献
65.
J Okumura M Nagahara Y Mizukami T Hashimoto F Matsubara S Migita 《Rinsho byori. The Japanese journal of clinical pathology》1991,39(3):263-268
We found M-proteins with two peaks by agarose electrophoresis in the serum of a myeloma patient. The M-proteins were identified as both IgG 1-kappa type, and classified as IgG-F (fast mobility) and IgG-S (slow mobility). 1) The possibility that the two M-proteins were derived from the post translational differences of sugar moieties of the same IgG molecule was unlikely, because no migration changes were observed in IgG-F and IgG-S after the treatment with 4 different sugar enzymes. 2) Fab fractions of IgG-F and IgG-S were analyzed. After papain or pepsin digestion, western blotting with anti-Fab antiserum revealed that the Fab fraction of IgG-F and IgG-S had identical mobility by agarose electrophoresis. However the Fc fractions of IgG-F and IgG-S analyzed by the same procedures with anti-Fe antiserum, were different. 3) Anti-idiotype antiserum prepared in rabbits against IgG-S, or -F, and absorbed by normal IgG and normal human serum showed a fused precipitin line with IgG-F and IgG-S. These findings suggest that two M-proteins with both IgG 1 and kappa type, have the same VH and VL regions but have different constant regions of heavy chain. Since one copy of IgG 1 constant gene is found in each human haploid gene. It is speculated that the switching of the rearranged VDJ gene to constant region gene occurred not only between cis chromosome but also between trans chromosome. 相似文献
66.
Tadashi Terada Yasuni Nakanuma Takeo Matsubara Tetsuo Suematsu 《Pathology international》1988,38(10):1345-1351
The pathology of a rare case of primary diffuse angiosarcoma of the pericardium is reported. Grossly, the heart was entirely encased by the pericardial tumor, and the myocardium was only superficially invaded by the tumor. The tumor tissue extended directly to the mediastinum, where the great vessels were embedded in the tumor. A few minute distant metastases were found only in the bilateral lungs and pulmonary hilar lymph nodes. Microscopically, the tumor tissue was composed of malignant cells forming vascular channels admixed with solid areas. Histo- and immunohistochemically, no mesothelial characteristics were evident. Factor VHI-related antigen and Ulex'europaeus I lectin were positive, implying that the tumor was of vascular origin. Grossly, and in part microscopically, this case resembled malignant diffuse mesothelioma, indicating that pericardial angiosarcoma may sometimes mimick malignant mesothelioma. ACTA PATHOL JPN 38: 1345-1351, 1988. 相似文献
67.
We describe seven cases of invasive fibrous tumors of the trachea and major bronchi with distinctive histologies and patterns of growth. The tumors are composed of proliferating fibroblasts and have moderate nuclear pleomorphism and low mitotic activity. The tumors bear some resemblance to inflammatory pseudotumor of the lung, fibrous histiocytoma, and fibromatosis, but differ from each of these entities. The tumors are neoplastic and invade down to or between plates of cartilage. Because of their proximal location, these tumors are usually amenable to sleeve resection. Recurrence is possible. Metastasis has not occurred. Distinction from more malignant mesenchymal tumors of the trachea and bronchus will prevent unnecessarily radical surgery. 相似文献
68.
Capillary endothelial proliferation is often a prominent feature of malignant gliomas. The understanding of structural and functional characteristics of the vascular microenvironment in gliomas is essential for the design of future therapeutic strategies against this tumor. Electron microscopic analysis of the capillary endothelial proliferation in malignant gliomas indicated that the complex vascular structures within the tumor were composed essentially of immature capillaries. Immature capillaries had a narrow slitlike lumen composed of endothelial cells with their high nuclear:cytoplasmic ratio and the relative paucity of organelles. They resembled capillary buds seen in normal repair tissue. Immature microvessels caused by angiogenesis were found more frequently in marginal zone of the tumors with increased microvessels. The tubular body was an organelle observed in vascular endothelial cells and was used frequently as a marker of the endothelial cell. Tubular bodies were evaluated by quantitative measurement of the mean percent (%) ratio of the number of endothelial cells with tubular bodies to all endothelial cells in microvessels of tumors. In glioblastomas it yielded a value of 32.4% in the margin, about two times as high as that in the center of the tumors. However, it was lower in all locations of astrocytomas. Tubular bodies in endothelial cells could be increased in proportion to neovascularization, and they might serve as a marker for increasing microvessels in astrocytic tumors. Tumor angiogenesis may be regulated by growth factors with angiogenic activities that are secreted by tumor cells. Vascular endothelial growth factor (VEGF) may play a critical role in the regulation of vascular endothelial proliferation. We found that 86% of 29 glioblastomas and 79% of 14 anaplastic astrocytomas demonstrated immunoreactivity for VEGF in their tumor cells. There tended to be a correlation between VEGF and vascularity. A correlation existed between the grade of immunoreactivity for VEGF and the grade of p53 protein expression in the malignant gliomas. However, the MIB-1 indices did not increase in correlation with increase in the extent of immunoreactivity for VEGF. 相似文献
69.
Developmental switch from GABA to glycine release in single central synaptic terminals 总被引:8,自引:0,他引:8
Nabekura J Katsurabayashi S Kakazu Y Shibata S Matsubara A Jinno S Mizoguchi Y Sasaki A Ishibashi H 《Nature neuroscience》2004,7(1):17-23
Early in postnatal development, inhibitory inputs to rat lateral superior olive (LSO) neurons change from releasing predominantly GABA to releasing predominantly glycine into the synapse. Here we show that spontaneous miniature inhibitory postsynaptic currents (mIPSCs) also change from GABAergic to glycinergic over the first two postnatal weeks. Many 'mixed' mIPSCs, resulting from co-release of glycine and GABA from the same vesicles, are seen during this transition. Immunohistochemistry showed that a large number of terminals contained both GABA and glycine at postnatal day 8 (P8). By P14, both the content of GABA in these mixed terminals and the contribution of GABA to the mixed mIPSCs had decreased. The content of glycine in terminals increased over the same period. Our results indicate that switching from GABAergic to glycinergic inputs to the LSO may occur at the level of a single presynaptic terminal. This demonstrates a new form of developmental plasticity at the level of a single central synapse. 相似文献
70.