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   60914篇
  免费   6016篇
  国内免费   4502篇
耳鼻咽喉   428篇
儿科学   793篇
妇产科学   439篇
基础医学   5978篇
口腔科学   987篇
临床医学   7630篇
内科学   7987篇
皮肤病学   553篇
神经病学   2752篇
特种医学   2733篇
外国民族医学   21篇
外科学   7828篇
综合类   12451篇
现状与发展   12篇
一般理论   3篇
预防医学   4485篇
眼科学   1193篇
药学   6498篇
  62篇
中国医学   3939篇
肿瘤学   4660篇
  2024年   149篇
  2023年   758篇
  2022年   1666篇
  2021年   2729篇
  2020年   2102篇
  2019年   1748篇
  2018年   1812篇
  2017年   1886篇
  2016年   1750篇
  2015年   2757篇
  2014年   3454篇
  2013年   3426篇
  2012年   4844篇
  2011年   5553篇
  2010年   4085篇
  2009年   3363篇
  2008年   3901篇
  2007年   3749篇
  2006年   3511篇
  2005年   3204篇
  2004年   2417篇
  2003年   2266篇
  2002年   1843篇
  2001年   1505篇
  2000年   1344篇
  1999年   1100篇
  1998年   582篇
  1997年   685篇
  1996年   484篇
  1995年   419篇
  1994年   339篇
  1993年   240篇
  1992年   263篇
  1991年   251篇
  1990年   209篇
  1989年   185篇
  1988年   152篇
  1987年   145篇
  1986年   126篇
  1985年   81篇
  1984年   50篇
  1983年   30篇
  1982年   19篇
  1981年   19篇
  1980年   26篇
  1979年   46篇
  1978年   22篇
  1976年   12篇
  1975年   17篇
  1974年   20篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
目的:观察PCR仪与测序仪在丙型肝炎病毒(HCV)基因型检测中的应用。方法:选择2018年1月~2018年12月收治的134例HCV感染患者为研究对象,给予患者PCR仪检测、测序仪检测。结果:测序仪检测134例均可分型,PCR仪检测130例患者可分型,4例未能分型。PCR检测结果:134例HCV感染患者中,1b型59例,2a型47例,3a型6例,3b型15例,6a型3例,4例为分出型别。基因测序结果:134例均可分型:1型59例,2a型40例,2i型7例,3a型6例,3b型15例,6a型3例,6n型4例。PCR仪检测法检测符合率97.0%。结论:PCR仪测序仪检测用于丙型肝炎病毒基因型检测,操作便捷,但其只能检测探针覆盖的型别,个别罕见型别不能分型。  相似文献   
13.
14.
探讨将临床路径引入临床医学实践教学中,形成临床医学教学路径,在临床医学专业人才培养数量激增的压力下保证教学质量的同质化。将PDCA循环引入临床医学实践教学,在提高临床医学教学路径质量的同时提高临床医学专业学生的临床医学技能,以促进医学类高职院校临床医学专业人才培养体系的不断完善,提升医学类高职院校临床医学专业应用型人才的质量。  相似文献   
15.

Aim

Leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) is an immune inhibitory receptor which is expressed within most types of hematopoietic cells and negatively regulates immune responses. Recently, we found LAIR-1 expression to be present within tumors of nonhematopoietic lineages. However, the roles of LAIR-1 in hepatocellular carcinoma (HCC) have yet to be examined. The purpose of this study was to investigate the expression of LAIR-1 in HCC tissue and assess its clinical significance at this site.

Materials and methods

Expression levels of LAIR-1 within HCC samples collected from 90 patients and compared with that of slides of normal liver tissue collected from 9 non-HCC patients were measured by immunohistochemistry using tissue microarrays. A semiquantitative score was assigned, as was based on staining intensity and percent of positive cells and a Spearman Rank correlation test was used to assess any potential significant correlations between LAIR-1 expression and clinicopathological factors. Overall survival analysis was performed using the Kaplan-Meier and Log Rank statistical test.

Results

LAIR-1 expression was detected in cancer tissue and adjacent tumor tissue, but not in normal liver tissue. The percent of LAIR-1-positive expression in cancer tissue of HCC samples was 97.78% (88/90) while that in adjacent tumor tissue was 96.67% (87/90). Significantly greater expression levels of LAIR-1 were obtained from cancer tissue (Mean?±?SD?=?5.722?±?2.145) than that in adjacent tumor tissue (4.141?±?1.486). In addition, LAIR-1 expression was found to be significantly correlated with pathological grade of HCC, T stage, and age. Expression levels of LAIR-1 were related with worse overall survival rates of HCC patients, especially in HCC patients with hepatic cirrhosis.

Conclusion

Results of this study show that LAIR-1 is expressed in HCC tissues and that high levels of LAIR-1 expression are associated with the poor cancer differentiation. In addition, overexpression of LAIR-1 was significantly associated with worse overall survival in the patients with HCC. These data suggest that LAIR-1 may be an independent predictor for clinical outcomes in patients with HCC.  相似文献   
16.
目的探讨高血压合并脑卒中患者的血浆同型半胱氨酸(Hcy)水平与其他危险因素对于脑卒中复发的影响。 方法分析徐州市中心医院心内科和徐州医科大学附属医院神经外科自2012年5月至2013年12月收治的1623例高血压脑卒中患者的基线资料,中位随访4.9年,根据随访事件中是否发生脑卒中分为复发组(312例)与未复发组(1311例)。Kaplan-Meier生存分析比较不同危险因素脑卒中复发率的差异,单因素与多因素Cox回归模型分析影响脑卒中复发的独立危险因素,以及危险因素之间的交互作用。 结果复发组年龄、空腹血糖、Lg Hcy的水平,以及糖尿病、房颤的患病率均高于未复发组(P<0.05)。Kaplan-Meier生存分析显示,糖尿病、房颤、年龄≥60岁、空腹血糖≥7.0 mmol/L、Hcy≥15 μmol/L的脑卒中复发率明显升高(Log-rank检验,P<0.05)。多因素Cox回归模型分析显示,高龄、Lg Hcy水平升高,以及房颤、糖尿病是脑卒中复发的独立危险因素。Lg Hcy分别与糖尿病、空腹血糖、年龄存在交互作用。 结论血浆Hcy水平升高既是高血压合并脑卒中患者卒中复发的独立危险因素,又通过与糖尿病、高龄、空腹血糖水平升高的交互作用显著增加脑卒中复发风险。  相似文献   
17.
近年来,医疗器械口咽通气道产品的注册数量日益增加,针对该产品的相关咨询也逐渐增多。但该产品暂无相关的注册技术审查指导原则,以致该产品的注册申报资料经常出现一些共性问题。现根据医疗器械口咽通气道产品相关法规和标准,对日常工作中遇到的常见问题进行归纳,分析该产品注册申报中的技术审评要求及共性问题,并给出对策或建议。  相似文献   
18.
Ferroptosis is an iron-dependent novel cell death pathway. Deferoxamine, a ferroptosis inhibitor, has been reported to promote spinal cord injury repair. It has yet to be clarified whether ferroptosis inhibition represents the mechanism of action of Deferoxamine on spinal cord injury recovery. A rat model of Deferoxamine at thoracic 10 segment was established using a modified Allen's method. Ninety 8-week-old female Wistar rats were used. Rats in the Deferoxamine group were intraperitoneally injected with 100 mg/kg Deferoxamine 30 minutes before injury. Simultaneously, the Sham and Deferoxamine groups served as controls. Drug administration was conducted for 7 consecutive days. The results were as follows:(1) Electron microscopy revealed shrunken mitochondria in the spinal cord injury group.(2) The Basso, Beattie and Bresnahan locomotor rating score showed that recovery of the hindlimb was remarkably better in the Deferoxamine group than in the spinal cord injury group.(3) The iron concentration was lower in the Deferoxamine group than in the spinal cord injury group after injury.(4) Western blot assay revealed that, compared with the spinal cord injury group, GPX4, xCT, and glutathione expression was markedly increased in the Deferoxamine group.(5) Real-time polymerase chain reaction revealed that, compared with the Deferoxamine group, mRNA levels of ferroptosis-related genes Acyl-CoA synthetase family member 2(ACSF2) and iron-responsive element-binding protein 2(IREB2) were up-regulated in the Deferoxamine group.(6) Deferoxamine increased survival of neurons and inhibited gliosis. These findings confirm that Deferoxamine can repair spinal cord injury by inhibiting ferroptosis. Targeting ferroptosis is therefore a promising therapeutic approach for spinal cord injury.  相似文献   
19.
HIV-1 infection usually leads to systemic chronic inflammation that is associated with gut microbial translocation. The recently defined group 3 innate lymphoid cells (ILC3s) are critical for maintenance of intestinal barrier function; however, it is not clear whether and how HIV-1 infection influences the function of these cells. In this issue of the JCI, Zhang and colleagues present compelling evidence that the survival and function of ILC3s are dramatically impaired by HIV-1 infection. The authors provide evidence that HIV-1 infection induces persistent activation of plasmacytoid dendritic cells (pDCs) and production of type I IFNs, which together increase expression of death receptor CD95 on ILC3s and thereby promote subsequent ILC3 apoptosis. Together, these results identify a mechanism that explains the impaired intestinal barrier function that results from chronic HIV-1 infection and shed light on the role of pDCs in HIV-1 immunopathogenesis and therapy.  相似文献   
20.
目的探讨附着龈重建应用于口腔种植修复中的临床效果。方法将本院于2016年10月-2018年10月期间收治的行口腔种植修复治疗的附着龈缺失患者82例作为研究资料,依据治疗方案分组,对照组为传统修复治疗方案,观察组采用附着龈重建治疗修复方案,各41例,评价两组术后不同阶段附着龈宽度、龈缘外形及附着点重建改善效果,并评价患者评价治疗满意度。结果术后3个月观察组患者附着龈宽度改善Ⅲ级率56.10%明显高于对照组0.00%,龈缘外形与附着点重建Ⅲ级率60.98%明显高于对照组0.00%(P <0.05);术后6个月观察组患者附着龈宽度改善Ⅲ级率75.61%明显高于对照组0.00%,龈缘外形与附着点重建Ⅲ级率73.17%明显高于对照组0.00%(P <0.05);观察组治疗满意度97.56%与对照组70.73%比较明显更高(P <0.05)。结论针对行口腔种植修复治疗的附着龈缺失患者采用附着龈重建治疗修复方案利于快速恢复附着龈增加宽度,改善龈缘外形及附着点重建效果,获得患者的高度满意度,治疗价值较高。  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