全文获取类型
收费全文 | 8025篇 |
免费 | 324篇 |
国内免费 | 59篇 |
专业分类
耳鼻咽喉 | 72篇 |
儿科学 | 96篇 |
妇产科学 | 202篇 |
基础医学 | 1052篇 |
口腔科学 | 207篇 |
临床医学 | 500篇 |
内科学 | 2021篇 |
皮肤病学 | 157篇 |
神经病学 | 520篇 |
特种医学 | 399篇 |
外科学 | 1141篇 |
综合类 | 19篇 |
一般理论 | 1篇 |
预防医学 | 368篇 |
眼科学 | 117篇 |
药学 | 469篇 |
中国医学 | 18篇 |
肿瘤学 | 1049篇 |
出版年
2023年 | 35篇 |
2022年 | 87篇 |
2021年 | 157篇 |
2020年 | 81篇 |
2019年 | 124篇 |
2018年 | 149篇 |
2017年 | 116篇 |
2016年 | 122篇 |
2015年 | 131篇 |
2014年 | 188篇 |
2013年 | 218篇 |
2012年 | 350篇 |
2011年 | 391篇 |
2010年 | 239篇 |
2009年 | 201篇 |
2008年 | 370篇 |
2007年 | 425篇 |
2006年 | 406篇 |
2005年 | 423篇 |
2004年 | 421篇 |
2003年 | 440篇 |
2002年 | 417篇 |
2001年 | 278篇 |
2000年 | 253篇 |
1999年 | 244篇 |
1998年 | 123篇 |
1997年 | 86篇 |
1996年 | 77篇 |
1995年 | 53篇 |
1994年 | 53篇 |
1993年 | 50篇 |
1992年 | 166篇 |
1991年 | 134篇 |
1990年 | 145篇 |
1989年 | 146篇 |
1988年 | 111篇 |
1987年 | 117篇 |
1986年 | 113篇 |
1985年 | 94篇 |
1984年 | 67篇 |
1983年 | 51篇 |
1982年 | 30篇 |
1981年 | 29篇 |
1979年 | 73篇 |
1978年 | 43篇 |
1977年 | 37篇 |
1973年 | 29篇 |
1970年 | 31篇 |
1969年 | 36篇 |
1967年 | 31篇 |
排序方式: 共有8408条查询结果,搜索用时 31 毫秒
71.
Okano H Shiraki K Inoue H Kawakita T Deguchi M Sugimoto K Sakai T Murata K Nakano T Enjoji M 《International journal of molecular medicine》2003,12(6):867-870
PPARgamma is known to induce apoptosis in malignant tumor cells, but the mechanism of this induction is not well understood. We investigated induction of apoptosis with 15-Deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2), a PPARgamma ligand, in cholangio cell carcinoma (CCC) cells (RBE, ETK-1 or HuCCT-1). Apoptosis was induced in RBE and ETK-1 cells with 15d-PGJ2, but not in HuCCT-1 cells, although PPARgamma was expressed in all CCC cells. Apoptosis-related proteins were also expressed, including FLIP, bclx, Apaf-1 and XIAP, but expression levels differed among the three cell lines. RBE cells treated with 15d-PGJ2 showed caspase activation, and it appeared that PPARgamma-induced apoptosis was dependent on caspase activation. However, neither ETK-1 nor HuCCT-1 cells showed significant activation of caspase-8 or -3 with 15d-PGJ2 treatment, raising the possibility of a caspase-independent apoptosis induction pathway. XIAP was down-regulated by 15d-PGJ2 in all three CCC cell lines. Therefore, 15d-PGJ2 induces apoptosis in CCC cells via caspase-dependent or independent pathways. 15d-PGJ2 may also induce down-regulation of XIAP and may promote caspase cascade activation through TNF-family receptor signaling pathways. 相似文献
72.
Kabashima K Murata T Tanaka H Matsuoka T Sakata D Yoshida N Katagiri K Kinashi T Tanaka T Miyasaka M Nagai H Ushikubi F Narumiya S 《Nature immunology》2003,4(7):694-701
Physical interaction of T cells and dendritic cells (DCs) is essential for T cell proliferation and differentiation, but it has been unclear how this interaction is regulated physiologically. Here we show that DCs produce thromboxane A2 (TXA2), whereas naive T cells express the thromboxane receptor (TP). In vitro, a TP agonist enhances random cell movement (chemokinesis) of naive but not memory T cells, impairs DC-T cell adhesion, and inhibits DC-dependent proliferation of T cells. In vivo, immune responses to foreign antigens are enhanced in TP-deficient mice, which also develop marked lymphadenopathy with age. Similar immune responses were seen in wild-type mice treated with a TP antagonist during the sensitization period. Thus, TXA2-TP signaling modulates acquired immunity by negatively regulating DC-T cell interactions. 相似文献
73.
Yoko Mamada Takahiro Murata Ayumi Taniguchi Yuki Hasegawa Tetsuomi Suzuki Kyoko Kohda Kiyoto Nasuno Toshiaki Watanabe Seiji Yamaguchi Akira Ishiguro 《Arerugī》2008,57(5):552-557
We reported a 4-month-old girl with biotin deficiency caused by amino acid formula. Two weeks after birth, she was diagnosed as having a milk protein allergy. After switching to amino acid formula from usual formula, her symptoms and laboratory findings became normal. About three weeks after the beginning of amino acid formula, she developed intractable skin erosions around the eyes, mouth, neck, and anogenital area. By measuring concentrations of some trace elements, she was diagnosed as having a biotin deficit, because of the organic aciduria and undetectable serum biotin concentration. Her serum biotinidase level was normal. Upon administration of oral biotin supplementation, all her symptoms and laboratory findings were dramatically improved. Since amino acid formula contains very few biotin, we should pay attention to biotin deficiency when infants receiving amino acid formula. 相似文献
74.
S. Sharmin M. Shiota E. Murata P. Cui H. Kitamura M. Yano H. Kido 《Inflammation research》2002,51(4):195-200
OBJECTIVE AND DESIGN: Investigation of the role of a novel inflammatory mediator 31-amino acid endothelin-1 [ET-1 (1-31)], a major ET derivative in granulocytes, in eosinophil recruitment after its subcutaneous administration to mice. METHODS: Various ET-1 derivatives (100 pmol), with or without ET receptor antagonists (200 pmol), were administered subcutaneously to mice, and then the eosinophil migration into and chemokine levels in the injected loci were analyzed. RESULTS: ET-1 (1-31) and a 21-amino acid endothelin-1 (ET-1), but not big ET-1, induced eosinophil migration into the injected loci with a peak after administration for 12 h, and increased the levels of eotaxin and interleukin-5 with peaks at 6 and 24 h, respectively. These effects of ET-1(1-31) and ET-1 were significantly inhibited by an ETA receptor antagonist, BQ-123, but not by an ETB receptor antagonist, BQ-788. CONCLUSION: Novel bioactive ET-1 (1-31) induces local eosinophil migration, and increases in eotaxin and interleukin-5 through an ETA or ETA-like receptor. 相似文献
75.
Toshiharu Yasaka Go Kato Hidemasa Furue Md Harunor Rashid Motoki Sonohata Akihiro Tamae Yuzo Murata Sadahiko Masuko Megumu Yoshimura 《The Journal of physiology》2007,581(2):603-618
The substantia gelatinosa (SG) of the spinal dorsal horn shows significant morphological heterogeneity and receives primary afferent input predominantly from Aδ- and C-fibres. Despite numerous anatomical and physiological studies, correlation between morphology and functional connectivity, particularly in terms of inhibitory inputs, remains elusive. To compare excitatory and inhibitory synaptic inputs on individual SG neurones with morphology, we performed whole-cell recordings with Neurobiotin-filled-pipettes in horizontal slices from adult rat spinal cord with attached dorsal roots. Based on dendritic arborization patterns, four major cell types were confirmed: islet, central, radial and vertical cells. Dorsal root stimulation revealed that each class was associated with characteristic synaptic inputs. Islet and central cells had monosynaptic excitatory inputs exclusively from C-afferents. Islet cells received primary-afferent-evoked inhibitory inputs only from Aδ-fibres, while those of central cells were mediated by both Aδ- and C-fibres. In contrast, radial and vertical cells had monosynaptic excitatory inputs from both Aδ- and C-fibres and inhibitory inputs mediated by both fibre types. We further characterized the neurochemical nature of these inhibitory synaptic inputs. The majority of islet, central and vertical cells exhibited GABAergic inhibitory inputs, while almost all radial cells also possessed glycinergic inputs. The present study demonstrates that SG neurones have distinct patterns of excitatory and inhibitory inputs that are related to their morphology. The neurotransmitters responsible for inhibitory inputs to individual SG neurones are also characteristic for different morphological classes. These results make it possible to identify primary afferent circuits associated with particular types of SG neurone. 相似文献
76.
To investigate the significance of nitric oxide (NO)-mediated neuron death in aging and Alzheimer's disease (AD), the 3-nitrotyrosine concentration in the cerebrospinal fluid (CSF) was investigated in neurologically normal controls and patients with AD. The 3-nitrotyrosine concentration and the 3-nitrotyrosine/tyrosine ratio significantly increased with advancing age, whereas the tyrosine concentration was unaltered. In patients with AD, the 3-nitrotyrosine concentration and the 3-nitrotyrosine/tyrosine ratio increased significantly (>six-fold) compared with controls of similar age, and increased significantly with decreasing cognitive functions, whereas the tyrosine concentration did not change. These findings suggest that an activation of tyrosine nitration, increase in nitrated tyrosine-containing proteins, and/or its degradation may be involved in brain aging and play an important role in the pathogenesis of AD. 相似文献
77.
T Murata T Yoshida H Takanari N Toyoda T Sakakura P I Liu 《Archives of pathology & laboratory medicine》1989,113(7):729-734
A variation of Perlman's syndrome of the pancortical type is reported in a male neonate whose parents were cousins. The patient was the product of a 35-week pregnancy, the Apgar score was 3, and the patient died of respiratory failure one hour and 12 minutes after delivery. Autopsy revealed bilateral diffuse nephroblastomatosis, pancortical type, associated with malformations (usually facial), congenital anomalies of the heart, hepatosplenomegaly, pancreatic islet cell hyperplasia, bilateral cryptorchidism, and hyperflexibility of the left knee joint. Renal immunohistochemical investigations revealed positive bindings with peanut and soybean agglutinins and epithelial membrane antigen along the luminal surface of the epithelium in the moderately differentiated tubules, but not in blastoma or primitive epithelium. 相似文献
78.
Ryoichi Sakamoto Tetsuya Nitta Yoshiaki Kamikawa Kazumasa Sugihara Kazuhisa Hasui Shinichiro Tsuyama Fusayoshi Murata 《Medical Electron Microscopy》2004,37(1):52-61
The aim of this study was to investigate cell kinetics and ultrastructural changes during carcinogenesis using a hamster 9,10-dimethyl-1,2-benzanthracene (DMBA)-induced tongue cancer model. Five squamous cell carcinomas, five dysplastic epithelia, seven hyperplastic epithelia, and four normal epithelia were obtained from 21 hamster tongues by applying 1.0% acetone solution of DMBA on the left lingual mucosa after scratching with a root canal broach. Ultrastructural examination revealed that the number of microvilli increased, whereas that of desmosomes decreased during carcinogenesis. Cell proliferation was analyzed by means of 5-bromodeoxyuridine (BrdU) immunohistochemistry and in situ hybridization (ISH) for histone H3 mRNA. The BrdU and histone H3 mRNA labeling indices (LIs) were lowest for normal epithelium, higher for hyperplastic and dysplastic epithelia, and highest for squamous cell carcinoma. Cytoplasmic histone H3 mRNA and nuclear BrdU were localized in virtually identical areas of serial sections. The correlation coefficient for the relationship between these two LIs was 0.97 (P 0.001). These results suggest that the assessment of cell proliferation using H3 mRNA ISH will be a useful technique for investigating biological behavior during carcinogenesis. 相似文献
79.
Enhancement of chronic viral hepatitic changes by alcohol intake in patients with persistent HBs-antigenemia 总被引:1,自引:0,他引:1
T Murata H Takanari S Watanabe T Tanaka S Suzuki 《American journal of clinical pathology》1990,94(3):270-273
The clinical and histologic changes in 116 Japanese patients with persistent HBs-antigenemia and chronic liver diseases were analyzed after the patients were divided into three groups depending on the history of alcohol consumption. Group 1 consisted of 45 nondrinkers, Group 2 of 51 social drinkers, and Group 3 of 20 habitual drinkers with a daily intake of more than 60 g of ethanol for at least ten years. The frequency of chronic active hepatitis (CAH) in Group 3 was higher than in Groups 1 and 2 (P less than 0.05). The histologic comparison of patients with CAH between the three groups revealed that only the inflammatory changes at/near portal tracts, such as piecemeal necrosis and inflammatory cell infiltration in Group 3, were more prominent than those in Groups 1 and 2. The alcohol-related changes except for fatty change were not found in any specimens. These findings suggest that alcohol intake, particularly of more than 60 g of ethanol a day, may enhance the viral inflammatory changes of the liver in patients with persistent HBs-antigenemia. 相似文献
80.
Protease inhibitors (gebexate mesylate and ulinastatin) stimulate intracellular chemiluminescence in human neutrophils. 总被引:2,自引:0,他引:2
J Nishijima N Hiraoka A Murata Y Oka K Kitagawa N Tanaka H Toda T Mori 《Journal of leukocyte biology》1992,52(3):262-268
The effect of protease inhibitors on the intracellular production of free radicals was investigated by measuring chemiluminescence (CL) elicited from phagocytosed luminol-bound microspheres (Lumispheres) in human neutrophils stimulated with formylmethionyl-leucyl-phenylalanine (fMLP), interleukin-8 (IL-8), phorbol 12-myristate 13-acetate, or diacylglycerol. Both gabexate mesylate (Foy) and ulinastatin (Miraclid), urinary trypsin inhibitor, increased intracellular CL in a dose dependent manner. Compared to control buffer without protease inhibitor, gabexate mesylate (322 micrograms/ml) caused about a 10-fold increase in intracellular CL in stimulated neutrophils, and ulinastatin (3100 U/ml) a twofold increase in neutrophils stimulated with fMLP or IL-8. When the protease inhibitors were added to the cell suspension after the phagocytosis of lumispheres, CL responses rapidly increased again to the level which was observed when both protease inhibitors and neutrophil stimulants were incubated simultaneously. In contrast, extracellular release of oxygen metabolites from stimulated neutrophils, assayed by a conventional measurement of luminol-dependent CL, was reduced by the protease inhibitors in a dose dependent fashion. When luminol-unbound microspheres were incubated with neutrophils stimulated by fMLP in luminol solution, extracellular CL was almost completely inhibited by gabexate mesylate. These results indicate that the protease inhibitors enhance the generation of intracellular CL and suppress the extracellular release of free radicals. 相似文献