首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   11198篇
  免费   814篇
  国内免费   41篇
耳鼻咽喉   77篇
儿科学   304篇
妇产科学   243篇
基础医学   1923篇
口腔科学   95篇
临床医学   1027篇
内科学   2482篇
皮肤病学   187篇
神经病学   1276篇
特种医学   292篇
外科学   1122篇
综合类   49篇
一般理论   1篇
预防医学   856篇
眼科学   210篇
药学   747篇
中国医学   20篇
肿瘤学   1142篇
  2023年   92篇
  2022年   61篇
  2021年   323篇
  2020年   214篇
  2019年   309篇
  2018年   403篇
  2017年   246篇
  2016年   245篇
  2015年   312篇
  2014年   449篇
  2013年   574篇
  2012年   977篇
  2011年   968篇
  2010年   516篇
  2009年   545篇
  2008年   834篇
  2007年   855篇
  2006年   752篇
  2005年   753篇
  2004年   668篇
  2003年   652篇
  2002年   624篇
  2001年   61篇
  2000年   54篇
  1999年   63篇
  1998年   95篇
  1997年   94篇
  1996年   50篇
  1995年   51篇
  1994年   44篇
  1993年   38篇
  1992年   20篇
  1991年   14篇
  1990年   11篇
  1989年   8篇
  1988年   9篇
  1987年   7篇
  1986年   9篇
  1984年   4篇
  1983年   3篇
  1982年   5篇
  1981年   3篇
  1979年   3篇
  1978年   3篇
  1973年   2篇
  1968年   3篇
  1966年   2篇
  1964年   3篇
  1947年   2篇
  1942年   2篇
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
1.
2.
3.
4.
In a previous article we reported that mutations favoring cancer at adulthood seemed to improve fertility and limit miscarriages. Because spontaneous abortion may result from anomalies in embryo, we questioned if an increased frequency of congenital malformation could be evidenced among cancer-prone families. Oncogenetics database (≈193 000 members) of the comprehensive cancer center Jean Perrin was crossed with regional registry of congenital malformations (≈10 000). Among children born between 1986 and 2011, 176 children with malformation matched in both databases. In breast/ovaries cancer-prone families, the risk for malformations was multiplied by 2.4 [1.2-4.5] in case of a BRCA1 mutation. Frequencies of malformation in BRCA2 and MMR mutated families were similar to families without a cancer syndrome. In comparison to malformations concerning a unique anatomical system, multimalformations were significantly more frequent in case of BRCA or MMR mutations: compared to families without cancer syndrome, the risk of multimalformations was multiplied by 4.1 [0.8-21.7] for cancer-prone families but with no known deleterious mutation, by 6.9 [1.2-38.6] in families with a known mutation but an unknown parental mutational status and by 10.4 [2.3-46.0] when one parent carried the familial mutation. No association with the type of anatomical system was found, nor with multiple births. These results suggest that BRCA and MMR genes play an important role in human embryogenesis and that if their function is lowered because of heterozygote mutations, congenital malformations are either more likely (BRCA1 mutations) and/or more susceptible to concern several anatomical systems.  相似文献   
5.
Evidence continues to grow on potential environmental health hazards associated with engineered nanomaterials (ENMs). While the geno- and cytotoxic effects of ENMs have been investigated, their potential to target the epigenome remains largely unknown. The aim of this study is two-fold: 1) determining whether or not industry relevant ENMs can affect the epigenome in vivo and 2) validating a recently developed in vitro epigenetic screening platform for inhaled ENMs. Laser printer-emitted engineered nanoparticles (PEPs) released from nano-enabled toners during consumer use and copper oxide (CuO) were chosen since these particles induced significant epigenetic changes in a recent in vitro companion study. In this study, the epigenetic alterations in lung tissue, alveolar macrophages and peripheral blood from intratracheally instilled mice were evaluated. The methylation of global DNA and transposable elements (TEs), the expression of the DNA methylation machinery and TEs, in addition to general toxicological effects in the lung were assessed. CuO exhibited higher cell-damaging potential to the lung, while PEPs showed a greater ability to target the epigenome. Alterations in the methylation status of global DNA and TEs, and expression of TEs and DNA machinery in mouse lung were observed after exposure to CuO and PEPs. Additionally, epigenetic changes were detected in the peripheral blood after PEPs exposure. Altogether, CuO and PEPs can induce epigenetic alterations in a mouse experimental model, which in turn confirms that the recently developed in vitro epigenetic platform using macrophage and epithelial cell lines can be successfully utilized in the epigenetic screening of ENMs.  相似文献   
6.
7.
There is increasing public interest in natural or herbal-based healthcare products. This trend is not only visible in supermarkets and dental practices, but also in the scientific world. An improving number of clinical trials are being conducted to validate the claims made about these products in regards to periodontal health. Among single component preparations, Aloe vera and green tea are the most studied natural ingredients. Concerning polyherbal mixtures, triphala has garnered great interest. The effects of these natural products on periodontal health is encouraging, with almost all studies showing an inhibitory effect on plaque accumulation and an improvement in gingival health. However, more studies are needed to be able to design clinical guidelines to guide the use of these natural products in periodontal practice. For most of these products, few studies are available and, moreover, the available studies are limited in duration, the number of participants, and the specific composition of the natural product is often not described in detail.  相似文献   
8.
9.
10.
Ovarian carcinoma is one of the most lethal malignancies, but only very few prognostic biomarkers are known. The degradome, comprising proteases, protease non-proteolytic homologues and inhibitors, have been involved in the prognosis of many cancer types, including ovarian carcinoma. The prognostic significance of the whole degradome family has not been specifically studied in high-grade serous ovarian cancer. A targeted DNA microarray known as the CLIP-CHIP microarray was used to identify potential prognostic factors in ten high-grade serous ovarian cancer women who had early recurrence (<1.6 years) or late/no recurrence after first line surgery and chemotherapy. In women with early recurrence, we identified seven upregulated genes (TMPRSS4, MASP1/3, SPC18, PSMB1, IGFBP2, CFI – encoding Complement Factor I – and MMP9) and one down-regulated gene (ADAM-10). Using immunohistochemistry, we evaluated the prognostic effect of these 8 candidate genes in an independent cohort of 112 high-grade serous ovarian cancer women. Outcomes were progression, defined according to CA-125 criteria, and death. Multivariate Cox proportional hazard regression models were done to estimate the associations between each protein and each outcome. High ADAM-10 expression (intensity of 2–3) was associated with a lower risk of progression (adjusted hazard ratio (HR): 0.51; 95% confidence interval (CI): 0.29-0.87). High complement factor I expression (intensity 2–3) was associated with a higher risk of progression (adjusted HR: 2.30, 95% CI: 1.17–4.53) and death (adjusted HR: 3.42; 95% CI: 1.72–6.79). Overall, we identified the prognostic value of two proteases, ADAM-10 and complement factor I, for high-grade serous ovarian cancer which could have clinical significance.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号