全文获取类型
收费全文 | 4484篇 |
免费 | 387篇 |
国内免费 | 209篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 68篇 |
妇产科学 | 40篇 |
基础医学 | 1182篇 |
口腔科学 | 138篇 |
临床医学 | 266篇 |
内科学 | 680篇 |
皮肤病学 | 62篇 |
神经病学 | 240篇 |
特种医学 | 57篇 |
外国民族医学 | 1篇 |
外科学 | 296篇 |
综合类 | 701篇 |
现状与发展 | 1篇 |
预防医学 | 166篇 |
眼科学 | 67篇 |
药学 | 509篇 |
8篇 | |
中国医学 | 244篇 |
肿瘤学 | 344篇 |
出版年
2025年 | 2篇 |
2024年 | 114篇 |
2023年 | 164篇 |
2022年 | 196篇 |
2021年 | 234篇 |
2020年 | 163篇 |
2019年 | 184篇 |
2018年 | 160篇 |
2017年 | 158篇 |
2016年 | 149篇 |
2015年 | 147篇 |
2014年 | 187篇 |
2013年 | 269篇 |
2012年 | 187篇 |
2011年 | 198篇 |
2010年 | 156篇 |
2009年 | 170篇 |
2008年 | 197篇 |
2007年 | 184篇 |
2006年 | 167篇 |
2005年 | 154篇 |
2004年 | 142篇 |
2003年 | 134篇 |
2002年 | 117篇 |
2001年 | 101篇 |
2000年 | 133篇 |
1999年 | 104篇 |
1998年 | 106篇 |
1997年 | 100篇 |
1996年 | 77篇 |
1995年 | 67篇 |
1994年 | 60篇 |
1993年 | 47篇 |
1992年 | 44篇 |
1991年 | 52篇 |
1990年 | 31篇 |
1989年 | 27篇 |
1988年 | 24篇 |
1987年 | 24篇 |
1986年 | 23篇 |
1985年 | 40篇 |
1984年 | 25篇 |
1983年 | 11篇 |
1982年 | 15篇 |
1981年 | 12篇 |
1980年 | 7篇 |
1979年 | 6篇 |
1978年 | 6篇 |
1977年 | 3篇 |
1976年 | 2篇 |
排序方式: 共有5080条查询结果,搜索用时 15 毫秒
1.
The matricellular protein SPARC induces inflammatory interferon-response in macrophages during aging
《Immunity》2022,55(9):1609-1626.e7
- Download : Download high-res image (179KB)
- Download : Download full-size image
2.
Roberto Codella Lucio Della Guardia Ileana Terruzzi Anna Solini Franco Folli Elena Maria Varoni Antonio Carrassi Livio Luzi 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2021,31(8):2199-2209
While the beneficial impact of physical activity has been ascertained in a variety of pathological scenarios, including diabetes and low-grade systemic inflammation, its potential remains still putative for periodontal health. Periodontal disease has been associated with inflammatory systemic alterations, which share a common denominator with type 2 diabetes mellitus and cardiovascular disease. Physical exercise, along with nutritional counseling, is a cornerstone in the treatment and prevention of type 2 diabetes, also able to reduce the prevalence of periodontal disease and cardiovascular risk. In addition, considering the higher incidence of periodontitis in patients with type 2 diabetes compared to healthy controls, the fascinating research question would be whether physical activity could relieve the inflammatory pressure exerted by the combination of these two diseases. This multi-disciplinary viewpoint discusses available literature in order to argument the hypothesis of a “three–way relationship” linking diabetes, periodontitis, and physical activity. 相似文献
3.
目的在体外破骨细胞分化因子(RANKL)和巨噬细胞集落刺激因子(M-CSF)联合应用的情况下,比较小鼠骨髓细胞和脾细胞形成破骨细胞的能力。方法选用小鼠M-CSF依赖性非附着性骨髓细胞和脾细胞,以不同的细胞密度在含有25ng/mlsM-CSF和30ng/mlsRANKL的(-MEM培养液中培养5、9天后,计数形成的抗酒石酸酸性磷酸酶染色(TRAP)阳性多核细胞的数目和骨吸收面积。结果脾细胞形成的破骨样细胞与骨髓形成的细胞形态与功能均无明显差异,但所需的细胞密度为骨髓细胞的10~20倍。结论在特殊情况下,脾细胞可替代骨髓细胞进行体外破骨细胞实验,但培养条件应适当调整。 相似文献
4.
ObjectivesOsteoclasts can sense the surface topography of materials. However, it is difficult to identify the structural factors that affect osteoclast formation and its function. Furthermore, we hypothesized that the type of osteoclast precursor cells also affects osteoclastogenesis in the materials. In this study, we investigated the effects of defined micro/nanoscale patterns on osteoclastogenesis from bone marrow cells (BMCs).MethodsVarious cyclo-olefin polymer (COP) patterns were prepared using nanoimprinting. The effects of shape, size, and height of the patterns, and the wettability of the patterned surfaces on osteoclastogenesis from BMCs were evaluated in vitro.ResultsOsteoclast formation was promoted on pillars (diameter, 1 μm or 500 nm; height, 500 nm). Notably, osteoclastogenesis from BMCs was better promoted on hydrophobic pillars than on hydrophilic pillars. In contrast, decreased osteoclast formation was observed on the nanopillars (diameter, 100 nm; height, 200 nm).ConclusionsWe demonstrated the promotion of osteoclast formation from BMCs on hydrophobic pillars with diameters of 1 μm and 500 nm. Some cellular behaviors in the patterns were dependent on the type of osteoclast precursor cells. The designed patterns are useful for designing the surface of dental implants or bone replacement materials with a controllable balance between osteoblast and osteoclast activities. 相似文献
5.
Peptostreptococcus micros is a gram‐positive bacterium that has been associated with periodontitis and endodontic infections. In this study, we hypothesized that P. micros binds the immunomodulating component lipopolysaccharide derived from gram‐negative bacteria to increase its capacity to stimulate cytokine production by host cells. The ability of P. micros to bind Actinobacillus actinomycetemcomitans lipopolysaccharide was demonstrated by an enzyme‐linked immunosorbent assay and by immunoelectron microscopy. Pretreatment of P. micros cells with A. actinomycetemcomitans lipopolysaccharide was associated with a 49‐fold increase in tumor necrosis factor alpha production by human monocytic cells U937 differentiated into adherent macrophages, compared to the stimulation with untreated P. micros. This effect was suppressed by incorporating polymyxin B, a lipid A‐binding substance, during treatment of macrophage‐like cells with lipopolysaccharide‐coated P. micros cells. This is the first study reporting a binding interaction between lipopolysaccharide and a gram‐positive bacterium. This interaction represents a new mechanism that could promote the inflammatory response during periodontitis. 相似文献
6.
In situ distribution of CD2+ T-lymphocytes, CD4+ and CD8+ T-cell subsets, CD14+ macrophages, interleukin-2 receptor α-chain (IL-2Rα) and class II major histocompatibility complex antigen (major histocompatibility complex class II, HLA-DR) expressing cells were determined in 14 chronic human periapical granulomas by imrnunohistochemical method using monoclonal antibodies. CD2+ lymphocytes were rather evenly distributed within the classical granulation tissue and comprised 55% of the mononuclear cells. Macrophages were distributed all over the periapical area, but their proportion was much less than that of T lymphocytes. Both small, lymphocyte-like mononuclear cells and larger mononuclear cells resembling macrophages displayed mild to strong circumferential staining with the anti-HLA-DR antibody. The majority of lymphocytes expressed IL-2Rα indicating the activated state of T cells within the lesion. 相似文献
7.
Rezende TM Vieira LQ Cardoso FP Oliveira RR de Oliveira Mendes ST Jorge ML Ribeiro Sobrinho AP 《International endodontic journal》2007,40(8):603-611
AIM: To assess the influence of co-culture with mineral trioxide aggregate (MTA) on phagocytosis and the production of reactive oxygen intermediates (ROI) and nitrogen (NO) species and the arginase activity by M1 and M2 peritoneal macrophages. METHODOLOGY: Cellular viability, adherence and phagocytosis of Saccharomyces boulardii were assayed in the presence of MTA. Macrophages were stimulated with zymosan for ROI assays and with Fusobacterium nucleatum and Peptostreptococcus anaerobius and IFN-gamma for NO production and arginase activity, when in contact with capillaries containing MTA. Data were analysed by T, anova, Kruskall-Wallis and Mann-Whitney tests. RESULTS: M2 macrophages displayed greater cellular viability in polypropylene tubes, greater ability to ingest yeast and smaller production of ROI and higher arginase activity when compared with M1 macrophages. Both macrophages, M1 and M2, presented similar cell adherence and NO production. The addition of bacterial preparations to macrophages interfered with NO and arginase productions. MTA did not interfere with any of the parameters measured. CONCLUSIONS: Phagocytosis and the ability of the two macrophage subtypes to eliminate microbes were not affected by MTA. 相似文献
8.
The exact cell type and site(s) involved in interleukin-1 (lL-1) production during gingival inflammation was determined by combining immunohistochemistry and in situ hybridization. IL-1 messenger RNA (mRNA)-expressing cells in human inflamed gingiva were identified as macrophages. The rate of IL-α mRNA expression in these macrophages was the same as IL-1 β mRNA expression. The rate of IL-1 mRNA expression was higher in connective tissue furthest from the pocket epithelium, although more macrophages were present at the connective tissue subjacent to the pocket epithelium. The IL-1 activity in gingival crevicular fluid (GCF) obtained from inflamed gingiva was higher than that from healthy gingiva and decreased after periodontal therapy. The IL-1 activity in GCF was almost completely abolished by the addition of anti-IL-1α antibody but not by anti-IL-1 β antibody, indicating that IL-1α is the predominant form in GCF. However, the IL-1 activity in GCF was unrelated to the number of IL-1 mRNA-exprerssing macrophages in the same gingival site where the GCF was obtained at the same time. The results suggest that macrophages in the connective tissue subjacent to the oral epithelium contribute to the production of IL-1 but those in connective tissue subjacent to the pocket epithelium play a different role in the generation of gingival inflammation. 相似文献
9.
Bernhard Mihm Markus Bergmann Wolfgang Brück Stefan Probst‐Cousin 《Neuropathology》2014,34(3):236-242
To determine if the pattern of macrophage activation reflects differences in the pathogenesis and clinical presentation of giant cell arteritis and primary angiitis of the central nervous system, specimens of 10 patients with giant cell arteritis and five with primary angiitis of the central nervous system were immunohistochemically studied and the expression of the macrophage activation markers 27E10, MRP14, MRP8 and 25F9 was determined in the vasculitic infiltrates. Thus, a partly different expression pattern of macrophage activation markers in giant cell arteritis and primary angiitis of the central nervous system was observed. The group comparison revealed that giant cell arteritis cases had significantly higher numbers of acute activated MRP14‐positive macrophages, whereas primary angiitis of the central nervous system is characterized by a tendency toward more MRP8‐positive intermediate/late activated macrophages. Furthermore, in giant cell arteritis comparably fewer CD8‐positive lymphocytes were observed. These observations suggest, that despite their histopathological similarities, giant cell arteritis and primary angiitis of the central nervous system appear to represent either distinct entities within the spectrum of granulomatous vasculitides or different stages of similar disease processes. Their discrete clinical presentation is reflected by different activation patterns of macrophages, which may characterize giant cell arteritis as a more acute process and primary angiitis of the central nervous system as a more advanced inflammatory process. 相似文献
10.