全文获取类型
收费全文 | 5280篇 |
免费 | 235篇 |
国内免费 | 30篇 |
专业分类
耳鼻咽喉 | 17篇 |
儿科学 | 80篇 |
妇产科学 | 26篇 |
基础医学 | 643篇 |
口腔科学 | 86篇 |
临床医学 | 335篇 |
内科学 | 1314篇 |
皮肤病学 | 51篇 |
神经病学 | 376篇 |
特种医学 | 181篇 |
外科学 | 1089篇 |
综合类 | 19篇 |
预防医学 | 233篇 |
眼科学 | 48篇 |
药学 | 429篇 |
中国医学 | 7篇 |
肿瘤学 | 611篇 |
出版年
2023年 | 30篇 |
2022年 | 46篇 |
2021年 | 73篇 |
2020年 | 53篇 |
2019年 | 91篇 |
2018年 | 82篇 |
2017年 | 59篇 |
2016年 | 72篇 |
2015年 | 80篇 |
2014年 | 104篇 |
2013年 | 100篇 |
2012年 | 187篇 |
2011年 | 223篇 |
2010年 | 139篇 |
2009年 | 141篇 |
2008年 | 252篇 |
2007年 | 270篇 |
2006年 | 233篇 |
2005年 | 251篇 |
2004年 | 217篇 |
2003年 | 243篇 |
2002年 | 211篇 |
2001年 | 197篇 |
2000年 | 159篇 |
1999年 | 154篇 |
1998年 | 45篇 |
1997年 | 41篇 |
1996年 | 30篇 |
1995年 | 39篇 |
1994年 | 50篇 |
1993年 | 53篇 |
1992年 | 124篇 |
1991年 | 103篇 |
1990年 | 134篇 |
1989年 | 140篇 |
1988年 | 125篇 |
1987年 | 89篇 |
1986年 | 99篇 |
1985年 | 87篇 |
1984年 | 71篇 |
1983年 | 64篇 |
1981年 | 31篇 |
1979年 | 51篇 |
1978年 | 50篇 |
1977年 | 31篇 |
1975年 | 30篇 |
1973年 | 48篇 |
1972年 | 50篇 |
1971年 | 40篇 |
1970年 | 36篇 |
排序方式: 共有5545条查询结果,搜索用时 46 毫秒
61.
A "floral" variant of nodal marginal zone lymphoma 总被引:1,自引:0,他引:1
Karube K Ohshima K Tsuchiya T Yamaguchi T Kawano R Suzumiya J Harada M Kikuchi M 《Human pathology》2005,36(2):202-206
We describe 6 cases of a specific variant of nodal marginal zone lymphoma with "floral" lymph follicles in patients ranging in age from 18 to 66 years. All 6 patients had lymphadenopathy, either local (n = 5) or systemic (n = 1), and good performance status (0), and none had fever, weight loss, or night sweating. They all underwent excisional biopsy. Histologically, all lesions had a distinctive morphology, with proliferation of medium-sized atypical lymphoid cells in the marginal zone, hyperplastic lymph follicles with enlarged germinal centers, and a thickened mantle zone. In places, folliculolysis was observed. On immunohistochemical staining, the atypical lymphoid cells showed a B-cell phenotype (CD20 +), IgM positivity in 2 of 5 cases, and negativity for CD5, CD10, CD23, CD43, bcl-6, and IgD. Polymerase chain reaction examination for immunoglobulin heavy chain in 5 cases showed monoclonality in all. Five patients did not receive adjuvant chemotherapy and had no recurrences. The patient with systemic lymphadenopathy received chemotherapy and had a complete response without relapse. This variant should be differentiated from the usual nodal marginal zone lymphoma because of its specific clinical and pathological features. 相似文献
62.
Polyelectrolyte complexes (PEC) were prepared from chitosan as the polycation and several synthesized functional anion polysaccharides, and their effects on cell attachment, morphology, proliferation and differentiation were estimated using normal human osteoblasts (NHOst). After a 1-week incubation, PEC made from polysaccharides having carboxyl groups as polyanions showed low viability of NHOst on it although the NHOst on it showed an enhancement in their differentiation level. On the other hand, NHOst on PEC made from sulfated or phosphated polysaccharides showed similar attachment and morphology to those on the collagen-coated dish. When the number of NHOst was estimated after 1 week, the number on the PEC was ranged from 70% to 130% of those on the collagen-coated dish, indicating few effects of these PEC on cell proliferation. In addition, NHOst on PEC films made from sulfated polysaccharides differentiated to a level very similar to that observed on the collagen-coated dish, indicating that these PEC films maintain the normal potential of NHOst to both proliferate and differentiate. Measurement of gap junctional intercellular communication of NHOst on PEC revealed that PEC did not inhibit communication, suggesting that PEC films have few effects on cell homeostasis. Thus, PEC made from the sulfated polysaccharide may be a useful material as a new scaffold for bone regeneration. 相似文献
63.
Yamamoto N Yang M Jiang P Xu M Tsuchiya H Tomita K Moossa AR Hoffman RM 《Clinical & experimental metastasis》2003,20(7):633-638
We have established stable, bright green fluorescent protein (GFP)- or red fluorescent protein (RFP)-expressing HT-1080 human
fibrosarcoma clones. These cell lines showed similar cell proliferation rates and high-frequency experimental lung metastasis.
The HT-1080-GFP and -RFP clones enable simultaneous real-time dual-color imaging in the live animal. HT-1080 cells were transduced
with retroviral vectors containing GFP or RFP and the neomycin resistance gene. Stable transformants were selected stepwise
with G418 up to 800 μl/ml. Subsequently, high GFP- or RFP-expressing clones, HT-1080-GFP or HT-1080-RFP, respectively, were
selected. 3×106 cells from each clone were mixed and injected into the tail vein of SCID mice. The cells seeded the lung at high frequency
with subsequent formation of pure green and pure red colonies as well as mixed yellow colonies with different patterns visualized
directly on excised lungs. The lung metastases were also visualized by external fluorescence imaging in live animals through
skin-flap windows over the chest wall. Lung metastases were observed on the lung surface of all mice. SCID mice well tolerated
multiple surgical procedures for direct-view imaging via skin-flap windows. Real-time metastatic growth of the two different
colored clones in the same lung was externally imaged with resolution and quantification of green, red, or yellow colonies
in live animals. The color coding enabled determination of whether the colonies grew clonally or were seeded as a mixture
with one cell type eventually dominating, or whether the colonies grew as a mixture. The simultaneous real-time dual-color
imaging of metastatic colonies described in this report gives rise to the possibility of color-coded imaging of clones of
cancer cells carrying various forms of gene of interest.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
64.
Nakagawa Y Murai T Hasegawa C Hirata M Tsuchiya T Yagami T Haishima Y 《Journal of biomedical materials research. Part B, Applied biomaterials》2003,66(1):347-355
Contamination by endotoxin of nine kinds of wound dressings made of natural biomaterials (calcium alginate, collagen, chitin, and poly-L-leucine) was examined with the use of water extracts. By applying the Limulus amoebocyte lysate (LAL) test, high concentrations of endotoxin were detected in extracts from three kinds of products made of calcium alginate. These extracts evoked fever in rabbits and induced the release of a proinflammatory (pyrogenic) cytokine, interleukin-6 (IL-6), from human monocytic cells (MM6-CA8). The effects disappeared when the extracts were treated with endotoxin-removing gel column chromatography or with an endotoxin antagonist, B464, confirming that the contaminating pyrogen was endotoxin. A noteworthy finding was that one of the endotoxin-containing extracts showed very weak IL-6-inducibility in human monocytic cells in contrast to its high pyrogenicity to rabbits. The discrepancy could be explained based on differences between humans and rabbits in sensitivity to the endotoxin, because the extract showed higher proinflammatory-cytokine (TNF-alpha)-inducibility in rabbit whole-blood cells (WBCs) than human WBCs. The results suggest that the LAL test is a useful method of detecting endotoxin contamination in wound dressings and the MM6-CA8 assay is a good supplement to the LAL test for evaluating pyrogenicity in humans accurately. 相似文献
65.
Ito Y Kawamura I Kohda C Tsuchiya K Nomura T Mitsuyama M 《International immunology》2005,17(12):1597-1606
Seeligeriolysin O (LSO), a member of cholesterol-dependent cytolysins of Listeria seeligeri, exhibits cytokine-inducing activity. In this study, we examined the profile of cytokines expressed in macrophages of mice after stimulation with full-length form of recombinant LSO (rLSO530), C-terminal-truncated protein (rLSO483) and two authentic cytokine-inducing Toll-like receptor (TLR) ligands from bacteria, peptidoglycan (PGN) and LPS. Both rLSO530 and rLSO483 were able to induce IL-12 p40 and IL-12 p70 more strongly in macrophages than PGN or LPS. In contrast, IFN-beta and nitric oxide were induced by LPS but not by rLSO530, rLSO483 or PGN. In the presence of exogenously added IFN-beta, IL-12 p40 and IL-12 p70 production was inhibited after LSO stimulation, but IL-12 p70 production was enhanced after PGN stimulation. Although LSO signaling appeared to be associated with both TLR2 and TLR4, the profile of cytokine production by LSO stimulation was distinct from those by stimulation with PGN or LPS. Thus, it was shown that LSO is a unique bacterial ligand that induces macrophage cytokine production in a manner different from PGN or LPS. 相似文献
66.
Nakaoka R Tsuchiya T Sakaguchi K Nakamura A 《Journal of biomedical materials research》2001,57(2):279-284
Gap junctional intercellular communication is a function that plays an important role in maintaining cell and tissue homeostasis and in regulating cell growth, development, and differentiation. Change in this function when contacting fibroblasts with various polymer microspheres was estimated using the metabolic cooperation assay system. When the cells were in contact with the microspheres after their adhesion onto a substrate, the function did not alter. However, when they were in contact with precoated microspheres on test dishes, the function was inhibited as the quantity of microspheres increased. Moreover, the inhibition level increased as the diameters of polyethylene and polystyrene microspheres decreased. However, no inhibition was observed if precoated microspheres were composed from poly(L-lactic acid). These findings suggest that the size and the material of microspheres, and how cells recognize the microspheres, are factors affecting cell function of gap junctional intercellular communication. Therefore, estimating this function may provide valuable information about the biocompatibility of many kinds of materials even in the form of particles. 相似文献
67.
Itoh Y Igarashi T Tatsuma N Imai T Yoshida J Tsuchiya M Murakami M Fukunaga Y 《Autoimmunity》2000,32(3):193-197
We have previously reported that approximately 50% of children with chronic nonspecific complaints were positive for antinuclear antibodies (ANA), and that a novel autoantibody to a 62 kD protein (anti-Sa) was found in 40% of these ANA-positive patients. Therefore, we proposed a distinct disease entity termed autoimmune fatigue syndrome (AIFS). We hypothesized that if autoimmune mechanisms did play an important role in the pathogenesis of AIFS, it is possible that it is immunogenetically regulated as observed in other autoimmune disorders. In order to examine the immunogenetic background of AIFS patients, HLA-A, -B, -C, and -DR loci were analyzed serologically in 61 AIFS patients. AIFS was found to be positively associated with the class I antigen HLA-B61 and with the class II antigen HLA-DR9, with odds ratios of 2.77 (p = 0.015, Pcorr = 0.48) and 2.60 (p= 0.012, Pcorr = 0.17), respectively. A negative association was also found between AIFS and HLA-DR2 with odds ratio of 0.25 (p = 0.029, Pcorr = 0.041). When comparing anti-Sa positive AIFS patients with healthy controls, the odds ratios associated with HLA-B61, DR9, and DR2 were 3.42 (p = 0.021, Pcorr = 0.22), 3.96 (p = 0.0011, Pcorr = 0.015), and 0.16 (p = 0.0022, Porr = 0.031), respectively. Thus, the HLA associations observed in this study suggested that immunogenetic background might play a role in AIFS. 相似文献
68.
A new monoclonal antibody, PM-2K, specifically recognizes tissue macrophages but not blood monocytes 总被引:2,自引:0,他引:2
A new monoclonal antibody, PM-2K, was raised against 24-h cultured human peritoneal macrophages. Immunohistochemically, PM-2K recognized most tissue macrophages in lymphoreticular organs such as the thymus, spleen, lymph node, and tonsil. Kupffer cells of the liver, alveolar macrophages, and macrophages in the interstitial tissue of the kidney, pancreas, and many other organs were also positively labelled. On the other hand, PM-2K failed to recognize blood monocytes, freshly isolated peritoneal macrophages, microglial cells, osteoclasts, and dendritic cells such as Langerhans cells, interdigitating cells, and follicular dendritic cells. In various pathological conditions, PM-2K labelled a wide variety of proliferating macrophages. Reaction products of PM-2K were observed by immunoelectron microscopy on the cytoplasmic membrane of cultured peritoneal macrophages. The molecular weight of the antigen recognized by PM-2K was determined to be 150 kD by Western blotting. As no cells other than macrophages were reactive with PM-2K, this antibody is considered to be very useful not only in the investigation of macrophage differentiation and maturation, but also in the diagnosis of various proliferative disorders of macrophages. 相似文献
69.
Effect of heat treatment of poly(L-lactide) on the response of osteoblast-like MC3T3-E1 cells 总被引:2,自引:0,他引:2
Poly(L-lactide) (PLLA) products are molded by heat extrusion. These treatments may change chemical properties and biological response of the PLLA to cells. In this study, the effect of heat treatment of PLLA on osteoblast proliferation and differentiation was examined in vitro. Osteoblast-like MC3T3-E1 cells were cultured for 2 weeks on the PLLA subjected to various heating temperature and time combinations. The protein, DNA, and hydroxyproline (HYP) contents and alkaline phosphatase (ALP) activity of cells cultured on the untreated (non-heated) PLLA with a weight average molecular weight (Mw) of 1,000,000 (high Mw PLLA) were not significantly different from those of cells cultured on glass. The activation of osteoblast differentiation by the high Mw PLLA was weak. In contrast, increases in ALP activity and HYP content were found for cells cultured on the PLLA heated at a high temperature of 200 or 250 degrees C. Heat treatment of high Mw PLLA increased differentiation of MC3T3-E1 cells cultured upon it. Significant degradation of PLLA (decrease in molecular weight and increase in molecular weight distribution) were observed following heat treatment. The Mw of PLLA decreased from 1,000,000 to below 20,000, and 14.4 microg of L-lactic acid was released from 10 mg of PLLA by heating at 250 degrees C. Therefore, the effect of low Mw chemicals, which were expected to be the degradation products of high Mw PLLA after heat treatment, on MC3T3-E1 cell activities was examined. Increases in the protein, DNA and HYP amounts and ALP activity for cells cultured with L-lactide or L-lactic acid were observed at 100 microg/ml, but not at 10 microg/ml. When the cells were cultured on the low Mw PLLA (Mw 20,000), their biological parameters also increased. Twelve micrograms of L-lactic acid released from 10 mg of the low Mw PLLA during 2 weeks incubation. The concentration of L-lactic acid in the incubation solution of low Mw PLLA or heat-treated PLLA was too small to cause cell activation. These results suggested that increases in osteoblast differentiation on the heat-treated PLLA was not to due to soluble degradation chemicals, such as L-lactic acid, rather than the remaining low Mw PLLA. 相似文献
70.
Shin'ichi Tsuchiya 《Pathology international》1981,31(1):45-54
Intracytoplasmic lumina (ICLs) of breast carcinoma cells are dominantly noted as rather specific structures in various organella of carcinoma cells. The present study deals with the characteristic patterns of ICLs in the ultrastructural and cytological features of breast carcinomas. Ultrastructural analysis of benign and malignant breast lesions for ICLs revealed a high occurrence of such lumina in the carcinomas. Especially the lumina were frequently noted in cells of scirrhous carcinomas (scirrhous carcinoma: 42 ICLs, medullary tubular carcinoma: 24, papillotubular carcinoma: 17 per each 300 carcinoma cells, mastopathy: 7 ICLs, flbroadenoma: 3, normal mammary gland: 1 or 2 per each epithelial cell). In 55.6% of the cytological cases of scirrhous carcinoma, the tumor cells showed ICLs, whereas such lumina were found at a rate of only 3.4% in benign lesions. These results demonstrate that the detection of ICLs by cytological examination can be useful in the establishment of a diagnosis of scirrhous carcinoma, and in the decision on a breast origin for metastatic tumors. 相似文献