全文获取类型
收费全文 | 9140篇 |
免费 | 445篇 |
国内免费 | 87篇 |
专业分类
耳鼻咽喉 | 119篇 |
儿科学 | 154篇 |
妇产科学 | 72篇 |
基础医学 | 1016篇 |
口腔科学 | 124篇 |
临床医学 | 471篇 |
内科学 | 2726篇 |
皮肤病学 | 144篇 |
神经病学 | 666篇 |
特种医学 | 371篇 |
外科学 | 1647篇 |
综合类 | 42篇 |
预防医学 | 219篇 |
眼科学 | 159篇 |
药学 | 548篇 |
中国医学 | 11篇 |
肿瘤学 | 1183篇 |
出版年
2024年 | 14篇 |
2023年 | 69篇 |
2022年 | 123篇 |
2021年 | 257篇 |
2020年 | 132篇 |
2019年 | 177篇 |
2018年 | 216篇 |
2017年 | 185篇 |
2016年 | 234篇 |
2015年 | 252篇 |
2014年 | 315篇 |
2013年 | 363篇 |
2012年 | 598篇 |
2011年 | 632篇 |
2010年 | 338篇 |
2009年 | 355篇 |
2008年 | 620篇 |
2007年 | 665篇 |
2006年 | 639篇 |
2005年 | 644篇 |
2004年 | 611篇 |
2003年 | 580篇 |
2002年 | 566篇 |
2001年 | 91篇 |
2000年 | 75篇 |
1999年 | 88篇 |
1998年 | 133篇 |
1997年 | 96篇 |
1996年 | 80篇 |
1995年 | 83篇 |
1994年 | 67篇 |
1993年 | 45篇 |
1992年 | 50篇 |
1991年 | 40篇 |
1990年 | 33篇 |
1989年 | 25篇 |
1988年 | 25篇 |
1987年 | 23篇 |
1986年 | 11篇 |
1985年 | 11篇 |
1984年 | 13篇 |
1983年 | 15篇 |
1982年 | 17篇 |
1981年 | 9篇 |
1980年 | 7篇 |
1979年 | 8篇 |
1978年 | 5篇 |
1975年 | 4篇 |
1973年 | 4篇 |
1966年 | 4篇 |
排序方式: 共有9672条查询结果,搜索用时 15 毫秒
71.
72.
Interaction of cholecystokinin (CCK) with vasoactive intestinal peptide (VIP) in body shaking response to ice-water immersion was observed in pentobarbital-anesthetized rats. Although CCK itself had no influence on the response, VIP suppressed it and this effect of VIP was antagonized by simultaneous administration of sulfated octapeptide of CCK, but not by non-sulfated CCK. 相似文献
73.
T cell immunity and primary biliary cirrhosis 总被引:4,自引:0,他引:4
T lymphocytes play a pivotal role in the autoimmune response in primary biliary cirrhosis (PBC). Recent studies have shown that there is overlapping in the PDC-E2-specific T and B cell epitopes. In addition, helper T and cytotoxic T cell epitopes all contain a shared peptide sequence. In addition, recognition of exogenous antigens including bacterial antigens by autoantigen-specific T cell and the mechanism of molecular mimicry provide a clue to clarifying the pathogenesis of PBC. Furthermore, the findings that autoantigen-immune complexes cross present and also that the presentation of autoantigen is of a higher relative efficiency, define a unique role of autoantibodies in the pathogenesis of the autoimmune disease. The mechanism of immune-mediated bile duct damage in PBC, including the possible role of T cell-mediated cytotoxicity and molecular mimicry is discussed. 相似文献
74.
Atsuko Masunaga Isamu Sugawara Hisayoshi Nakamura Tsuyoshi Yoshitake Shinji Itoyama 《Pathology international》1997,47(12):842-847
Subsets of thymic epithellal cells were examined Immuno-histochemically to determine whether or not their pheno-types change during thymic growth and at early involution in terms of cytokeratin (CK) expression. Five monoclonal antibodies specific for CK4, CK8, CK13, CK18 and CK19 were used and applied for 16 neonatal, three Infantile and one adult thymus speeimen, which had been obtained at autopsy, that were normal macroscopically and microscopicaily. CK4, CK8, CK13, CK18 and CK19 were expressed simultaneously in the cortex, medulla and subcapsular area with the exception of CK4, which showed expression on the adult thymus. Light and electron microscopy showed that CK8 and CK19 expression was overlapped. Thus, It was thought that CK8 and CK19 formed complexes in the cytoplasm of thymic epithelial cells. The Immunoreactivity to CK4, CK13 and CK18 were attenuated or disappeared In the subcapsular area during the early involution stage. Interestingly, two patterns of CK18 expression were observed in the neonatal and Infantile thymus tissues, which Indicated that the thymic microenvironment was changeable even under normal conditions. 相似文献
75.
Yuichi Takeoka Shao-Yuan Chen Richard L. Boyd Koichi Tsuneyama Nobuhisa Taguchi Shinji Morita Hisashi Yago Seishi Suehiro Aftab A. Ansari Leonard D. Shultz M. Eric Gershwin 《Clinical & developmental immunology》1997,5(2):79-89
It is widely accepted that the thymic microenvironment regulates normal thymopoiesis
through a highly coordinated and complex series of cellular and cytokine interactions. A direct
corollary of this is that abnormalities within the microenvironment could be of etiologic
significance in T-cell-based diseases. Our laboratory has developed a large panel of
monoclonal antibodies (mAbs) that react specifically with epithelial or nonepithelial
markers in the thymus. We have taken advantage of these reagents to characterize the
thymic microenvironment of several genetic strains of mice, including BALB/cJ,
C57BL/6J, NZB/BlnJ, SM/J, NOD/Ltz, NOD/Ltz-scid/sz, C57BL/6J-Hcph
me/Hcph me, and
ALY/NscJcl-aly/aly mice, and littermate control animals. We report herein that control
mice, including strains of several backgrounds, have a very consistent phenotypic profile
with this panel of monoclonal antibodies, including reactivity with thymic epithelial cells
in the cortex, the medulla and the corticomedullary junction, and the extracellular matrix.
In contrast, the disease-prone strains studied have unique, abnormal staining of thymic cortex
and medulla at both the structural and cellular levels. These phenotypic data suggest
that abnormalities in interactions between developing thymocytes and stromal cells characterize
disease-prone mice. 相似文献
76.
The bisphosphonate pamidronate on the surface of titanium stimulates bone formation around tibial implants in rats 总被引:9,自引:0,他引:9
Kajiwara H Yamaza T Yoshinari M Goto T Iyama S Atsuta I Kido MA Tanaka T 《Biomaterials》2005,26(6):581-587
Many materials with differing surfaces have been developed for clinical implant therapy in dentistry and orthopedics. We analyzed the quantity of new bone formed in vivo around calcium-immobilized titanium implants with surfaces modified using pamidronate (PAM), a nitrogen-containing bisphosphonate (N-BP), implants of pure titanium, and titanium implants immobilized with calcium ions. New bone formation was visualized using fluorescent labeling (calcein blue and alizarin complexone) with intravenous injection at 1 and 3 weeks after implantation. After 4 weeks, undecalcified sections were prepared, and new bone formation around the implants was examined by morphometry using confocal laser scanning microscopy images. After 1 week, more new bone formed around the PAM-immobilized implant than around the calcium-immobilized and pure titanium implants. This was also seen with the new bone formation after 3 weeks. After 4 weeks, significantly more new bones were formed around the BP-immobilized implant than around the calcium ion-implanted and pure titanium implants. The new N-BP-modified titanium surface stimulates new bone formation around the implant, which might contribute to the success of implant therapy. 相似文献
77.
Interferon-{beta} inhibits bleomycin-induced lung fibrosis by decreasing transforming growth factor-{beta} and thrombospondin 总被引:2,自引:0,他引:2
Azuma A Li YJ Abe S Usuki J Matsuda K Henmi S Miyauchi Y Ueda K Izawa A Sone S Hashimoto S Kudoh S 《American journal of respiratory cell and molecular biology》2005,32(2):93-98
Pulmonary fibrosis is the result of abnormal processes of repair that occur after lung injury. Transforming growth factor (TGF)-beta is a key molecule in the progression of pulmonary fibrosis. Although clinical use of interferon (IFN)-beta did not improve survival in patients with idiopathic pulmonary fibrosis, because some preclinical studies have suggested that IFN-beta is a potent inhibitor of fibrogenesis, beneficial effects of IFN-beta have been expected. We therefore attempted to determine effects of IFN-beta and investigated the mechanism of action of IFN-beta in bleomycin-induced pulmonary fibrosis. Bleomycin at Day 0 and IFN-beta for 4 wk were administered intravenously to ICR mice. At 28 d after bleomycin injection, histologic and chemical analysis was performed for evaluation of effects of IFN-beta. Tissue distribution and amounts of TGF-beta1 and thrombospondin (TSP)-1/2 were analyzed. IFN-beta attenuated prolylhydroxylase activity, resulting in inhibition of pulmonary fibrosis. Bleomycin-induced increase in TGF-beta1 in epithelial cells and extracellular matrix was attenuated by IFN-beta. TSP-1/2 was limited in platelets of control mice, but was present in foamy cells in fibrotic regions induced by bleomycin. These findings suggest that the antifibrotic effect of IFN-beta is inhibition of TGF-beta and its activation via decrease in TSP-1/2 in lung tissue and change in location of TSP-1/2 from platelets to foamy cells. 相似文献
78.
Fukumoto S Tamaki Y Shirafuji H Harakawa S Suzuki H Xuan X 《Clinical and diagnostic laboratory immunology》2005,12(4):557-559
This is a report of a vaccine trial directed against Babesia gibsoni infection in dogs with the use of the recombinant antigen P50. Dogs immunized with P50 showed partial protection manifested as a significantly low level of parasitemia. The results indicated that P50 is a primary vaccine candidate molecule against canine B. gibsoni infection. 相似文献
79.
Kusumi T Nishikawa S Tanaka M Ogawa T Jin H Sato F Toh S Hasegawa T Kijima H 《Pathology international》2005,55(12):802-806
Low-grade fibromyxoid sarcoma (LGFMS) is a rare tumor. Reported herein is a case of LGFMS arising in the big toe. The patient was a 58-year-old man who underwent excision of the tumor. The tumor was well-demarcated. Histologically, there were proliferating spindle-shaped tumor cells arranged in a whorled growth pattern, and the stroma showed hyalinized collagen bundles and a myxoid matrix. Nuclear mitotic figures were conspicuous in part. A large rosette-like structure with hyalinized stroma was found, which is characteristic of LGFMS. The differential diagnosis included tumor occurrence in adults; tending to arise in distal extremities; and having bland fibromyxoid histological features, such as fibroma of tendon sheath, low-grade myxofibrosarcoma and acral myxoinflammatory fibroblastic sarcoma. It was not possible to detect the FUS/CREB3L2 and FUS/CREB3L1 fusion genes from the formalin-fixed and paraffin-embedded tissue, although the histological features of the present case were typical of LGFMS. LGFMS may become more common with time, and unique cases may accumulate. 相似文献
80.
Role of macrophage migration inhibitory factor in otitis media with effusion in adults 总被引:4,自引:0,他引:4
Kariya S Okano M Aoji K Kosaka M Chikumoto E Hattori H Yuen K Nishioka S Nishioka K Nishizaki K 《Clinical and diagnostic laboratory immunology》2003,10(3):417-422
Otitis media with effusion (OME) is one of the most common ear diseases. Bacterial endotoxins and several inflammatory cytokines appear to be involved in the pathogenesis of OME in children; however, little is known of the immunological aspects of the onset of OME in adults. We sought to determine the presence of macrophage migration inhibitory factor (MIF) as well as interleukin 1beta (IL-1beta), tumor necrosis factor alpha (TNF-alpha), RANTES (regulated upon activation, normal T-cell expressed and presumably secreted), and endotoxin in middle ear effusions (MEEs) from adult patients with OME. In addition, the levels of MIF in MEEs from adults and children were compared. MEE was obtained from 95 adults and 11 children. The levels of MIF, IL-1beta, TNF-alpha, and RANTES were determined by enzyme-linked immunosorbent assay, and the concentrations of endotoxin and total protein were determined by the Endospec assay and bicinchoninic acid assay, respectively. MIF was detected in 97.9% of the MEEs from adults, while endotoxin, IL-1beta, TNF-alpha, and RANTES were detected in 96.8, 12.6, 5.3, and 43.9%, respectively. In addition, the level of MIF was significantly higher than those of endotoxin, IL-1beta, and TNF-alpha. A positive correlation between the levels of MIF and endotoxin was observed. MIF and endotoxin were detected in 81.8 and 72.7%, respectively, of the MEEs from the children. The level of MIF was significantly higher in the children, and conversely that of endotoxin was significantly higher in the adults. These results suggest that the interaction between MIF and endotoxin may promote fluid collection in the middle ear, particularly in adults. 相似文献