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   57846篇
  免费   5190篇
  国内免费   3346篇
耳鼻咽喉   561篇
儿科学   545篇
妇产科学   684篇
基础医学   7346篇
口腔科学   1103篇
临床医学   7208篇
内科学   8868篇
皮肤病学   803篇
神经病学   3146篇
特种医学   2532篇
外国民族医学   39篇
外科学   6306篇
综合类   8294篇
现状与发展   10篇
一般理论   2篇
预防医学   3616篇
眼科学   1607篇
药学   5813篇
  58篇
中国医学   2928篇
肿瘤学   4913篇
  2024年   164篇
  2023年   830篇
  2022年   2284篇
  2021年   3024篇
  2020年   2046篇
  2019年   1871篇
  2018年   2013篇
  2017年   1750篇
  2016年   1852篇
  2015年   2689篇
  2014年   3368篇
  2013年   3025篇
  2012年   4789篇
  2011年   4875篇
  2010年   3137篇
  2009年   2548篇
  2008年   3333篇
  2007年   3172篇
  2006年   2957篇
  2005年   2671篇
  2004年   1943篇
  2003年   1776篇
  2002年   1569篇
  2001年   1265篇
  2000年   1296篇
  1999年   1221篇
  1998年   694篇
  1997年   733篇
  1996年   571篇
  1995年   481篇
  1994年   392篇
  1993年   264篇
  1992年   348篇
  1991年   257篇
  1990年   223篇
  1989年   189篇
  1988年   154篇
  1987年   139篇
  1986年   107篇
  1985年   91篇
  1984年   52篇
  1983年   50篇
  1982年   22篇
  1981年   24篇
  1980年   13篇
  1979年   23篇
  1978年   11篇
  1973年   11篇
  1971年   9篇
  1969年   10篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
近年来,许多县级医院检验科相继引进了不同档次和类型的血液、尿液、生化等各种自动化检验仪器,从而改变了过去劳动强度大、工作效率低、人为误差相对较大的状况。医学检验工作在医院的地位和作用在不断提高,其在临床诊疗工作中扮演的角色也越来越重要。检验人员素质的高低直接影响着检验质量,而检验质量的高低,是衡量医院技术水平的一个重要标志。因此,提高基层医院检验人员的素质至关重要,其是提高检验质量的关键。  相似文献   
942.
943.
944.
不同的劳动就业制度具有不同的内容规定;计划就业和市场就业是两种不同的就业制度,在我国不同历史时期都实践过这两种就业制度。比较分析两种制度对于推动深化改革具有重要的意义。  相似文献   
945.
microRNAs (miRNAs) are important regulators of tumor development and progression. In this study, we aimed to explore the expression and role of miR-622 in hepatocellular carcinoma (HCC). We found that miR-622 was significantly downregulated in human HCC specimens compared to adjacent noncancerous liver tissues. miR-622 downregulation was significantly associated with aggressive parameters and poor prognosis in HCC. Enforced expression of miR-622 significantly decreased the proliferation and colony formation and induced apoptosis of HCC cells. In vivo studies demonstrated that miR-622 overexpression retarded the growth of HCC xenograft tumors. Bioinformatic analysis and luciferase reporter assays revealed that miR-622 directly targeted the 3′-untranslated region (UTR) of mitogen-activated protein 4 kinase 4 (MAP4K4) mRNA. Ectopic expression of miR-622 led to a significant reduction of MAP4K4 expression in HCC cells and xenograft tumors. Overexpression of MAP4K4 partially restored cell proliferation and colony formation and reversed the induction of apoptosis in miR-622-overexpressing HCC cells. Inhibition of JNK and NF-κB signaling phenocopied the anticancer effects of miR-622 on HCC cells. Taken together, miR-622 acts as a tumor suppressor in HCC and restoration of miR-622 may provide therapeutic benefits in the treatment of HCC.  相似文献   
946.
947.
Numerous medications are used to treat hyperpigmentation. However, several reports have indicated that repeated application of some agents, such as rhododendrol (RD), raspberry ketone (RK) and monobenzone (MB), can be toxic to melanocytes. Although these agents had severe side effects in human trials, no current in vitro methods can predict the safety of such drugs. This study assessed the in vitro effects of five depigmentary compounds including leukoderma‐inducing agents. In particular, we determined the effects of different concentrations and exposure times of different depigmentary agents on cell viability and melanogenesis in the presence and absence of ultraviolet B (UVB) radiation. Concentrations of RD, RK and MB that inhibit melanogenesis are similar to concentrations that are cytotoxic; however, concentrations of rucinol (RC) and AP736 that inhibit melanogenesis are much lower than concentrations that are cytotoxic. Furthermore, the concentrations that cause toxic effects depend on exposure duration, and prolonged exposure to RD, RK and MB had more cytotoxic effects than prolonged exposure to RC and AP736. The cytotoxic effects of RD and RK appear to be mediated by apoptosis due to increased expression of caspase‐3 and caspase‐8; UVB radiation increased the cytotoxicity of these agents and also increased caspase activity. Our results indicate that different leukoderma‐inducing compounds have different effects on the viability of normal epidermal melanocytes and suggest that the in vitro assay used here can be used to predict whether an investigational compound that induces leukoderma may lead to adverse effects in human trials.  相似文献   
948.
Schwann cells are not only myelinating cells, but also function as immune cells and express numerous innate pattern recognition receptors, including the Toll-like receptors. Injury to peripheral nerves activates an inflammatory response in Schwann cells. However, it is unclear whether specific endogenous damage-associated molecular pattern molecules are involved in the inflammatory response following nerve injury. In the present study, we demonstrate that a key damage-associated molecular pattern molecule, high mobility group box 1(HMGB1), is upregulated following rat sciatic nerve axotomy, and we show colocalization of the protein with Schwann cells. HMGB1 alone could not enhance expression of Toll-like receptors or the receptor for advanced glycation end products(RAGE), but was able to facilitate migration of Schwann cells. When Schwann cells were treated with HMGB1 together with lipopolysaccharide, the expression levels of Toll-like receptors and RAGE, as well as inflammatory cytokines were upregulated. Our novel findings demonstrate that the HMGB1 pathway activates the inflammatory response in Schwann cells following peripheral nerve injury.  相似文献   
949.
PurposeTo report the effectiveness and safety of transcatheter arterial sclerosing embolization (TASE) for the treatment of parotid infantile hemangiomas that did not respond appreciably to propranolol.Materials and MethodsA total of 21 infants (12 male and 9 female) with large propranolol-resistant infantile hemangiomas in the parotid region were enrolled in this study. During TASE, the feeding arteries of the lesions were embolized using pingyangmycin-lipiodol emulsion and polyvinyl alcohol particles (300–500 μm) to reduce the blood flow rate. All children were followed up as outpatients at 2 weeks and monthly thereafter. The curative effect was evaluated at the 1- and 3-month follow-up visits.ResultsNine lesions were located on the right side of the parotid gland, whereas 12 were located on the left side. The feeding arteries in all patients originated from branches of the external carotid artery. TASE was technically successful in all patients. The mean (± SD) maximal diameter of the hemangiomas significantly decreased from 6.50 cm ± 2.28 before treatment to 3.56 cm ± 1.84 at 1 month after TASE (P <. 05). Three months after TASE, the mean maximal diameter further significantly decreased to 1.94 cm ± 1.58 (P <. 05). During the follow-up period, 16 cases were rated as excellent and 5 as good; no recurrence or serious complications were noted. Minor side effects, such as slight pain, mild fever, and tissue swelling, were observed.ConclusionsTASE significantly decreased the size of the parotid hemangiomas with minor side effects during a short follow-up period.  相似文献   
950.
目的:分析256排CT低剂量扫描在肺部小结节鉴别诊断中的应用价值。方法:选取我院自2017年2月—2019年2月收治的46例肺部小结节患者,于患者入院时采用常规剂量对患者进行CT扫描检查,并于1周后进行CT低剂量扫描复查。对比患者经过两次扫描后的肺部小结节数量、结节内部的特征以及结节周围的变化。结果:采用常规剂量扫描与低剂量扫描肺部小结节数量相比差异较小(P>0.05);常规剂量扫描与低剂量扫描小结节内部特征比较差异性较小(P>0.05);常规剂量扫描与低剂量扫描诊断结构比较差异较小(P>0.05)。结论:采用256排CT低剂量扫描肺部小结节患者,对常规剂量的进行扫描的价值差异较小,但低剂量CT扫描相对来说辐射更小,值得广泛推广使用。  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