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   96986篇
  免费   8435篇
  国内免费   3975篇
耳鼻咽喉   965篇
儿科学   2422篇
妇产科学   1153篇
基础医学   10311篇
口腔科学   1426篇
临床医学   11936篇
内科学   16272篇
皮肤病学   1318篇
神经病学   6255篇
特种医学   3474篇
外国民族医学   26篇
外科学   11616篇
综合类   11939篇
现状与发展   6篇
一般理论   88篇
预防医学   7881篇
眼科学   2432篇
药学   9245篇
  52篇
中国医学   4198篇
肿瘤学   6381篇
  2024年   207篇
  2023年   1049篇
  2022年   2540篇
  2021年   4228篇
  2020年   2959篇
  2019年   2914篇
  2018年   3312篇
  2017年   2872篇
  2016年   2808篇
  2015年   3889篇
  2014年   5049篇
  2013年   5251篇
  2012年   8312篇
  2011年   8742篇
  2010年   5754篇
  2009年   4841篇
  2008年   6378篇
  2007年   6089篇
  2006年   5737篇
  2005年   5243篇
  2004年   4343篇
  2003年   3731篇
  2002年   3218篇
  2001年   1295篇
  2000年   1105篇
  1999年   1172篇
  1998年   881篇
  1997年   867篇
  1996年   620篇
  1995年   549篇
  1994年   432篇
  1993年   352篇
  1992年   333篇
  1991年   294篇
  1990年   233篇
  1989年   221篇
  1988年   158篇
  1987年   196篇
  1986年   146篇
  1985年   133篇
  1984年   133篇
  1983年   114篇
  1982年   127篇
  1981年   108篇
  1980年   75篇
  1979年   45篇
  1978年   57篇
  1977年   49篇
  1976年   32篇
  1973年   28篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
41.
42.
工作相关肌肉骨骼疾患(WMSDs)是常见的慢性非传染性疾病。WMSDs已成为影响工人健康、降低工人生命质量和造成经济损失的重要因素,可见于多个行业、工种。本文对WMSDs流行现状及人体工效学负荷相关研究进行综述,以期找到职业人群保护的可行方法。  相似文献   
43.
痘病毒是自然界普遍存在的DNA病毒,能够高效表达外源基因,诱导较强的细胞免疫和体液免疫,受到基因治疗学者的广泛关注。痘病毒发生同源重组的概率较低,所以有效地筛选和纯化痘病毒十分重要。目前常用的筛选重组痘病毒方法有基于CRISPR进行筛选;根据报告基因GFP、LacZ、GPT等进行筛选;利用TK-和Brdu结合荧光进行筛选;利用药物抗性基因与荧光或显色基因融合,即可在药物筛选的同时观察荧光或显色基因表达情况。本文旨在对目前常用的痘病毒的筛选纯化方法进行综述。  相似文献   
44.
Background and Aims: Gastric antral vascular ectasia (GAVE) is commonly found in patients with cirrhosis, but it is also associated with other diseases in the absence of cirrhosis. Whether GAVE confers a different severity of gastrointestinal (GI) bleeding between patients with and without cirrhosis remains unknown. We aim to examine whether there is a difference in clinically significant GI bleeding due to GAVE in patients with or without cirrhosis. Methods: This is a retrospective case-control study of patients who were diagnosed with GAVE between January 2000 and June 2014. Patients were categorized into cirrhosis and noncirrhosis groups, and those with an additional GI bleeding source were excluded. Univariate comparisons and multivariable models were constructed using logistic regression. Results: In total, 110 patients diagnosed with GAVE on esophagogastroduodenoscopy (EGD) were included in our analysis; 84 patients had cirrhosis (76.4%) and 26 (23.6%) did not. Active GI bleeding was more prevalent in patients without cirrhosis (63.4% vs. 32.1%, p=0.003) despite similar indications for EGD, and endoscopic treatment with argon plasma coagulation (APC) was required more often in this group, approaching statistical significance (27% vs. 10.7%, p=0.056). There was no difference in bleeding severity, as evidenced by similar re-bleeding rates, surgery, or death attributed to uncontrolled bleeding. The strongest independent risk factor for GI bleeding was the absence of cirrhosis (odds ratio (OR): 5.151 (95% confidence interval (CI): 1.08-24.48, p=0.039). Conclusions: Patients with GAVE in the absence of cirrhosis are at higher risk for active GI bleeding and require more frequent endoscopic treatment than similar patients with cirrhosis. It may be worthwhile to treat GAVE in this population even in the absence of active bleeding.  相似文献   
45.
46.

Background

Inflammation and infections have been associated with prostate cancer progression. We assessed whether elevated serum cytokines or T. vaginalis seropositivity at the time of diagnosis was associated with higher grade or lethal prostate cancer.

Patients and Methods

Men with localized or metastatic prostate cancer were included in this study. Cytokine serum levels including interleukin (IL)-1α, IL-1β, IL-2, IL-6, IL-8, monocyte chemotactic protein 1 (CCL-2), tumor necrosis factor α, and growth-regulated oncogene α (CXCL-1) using a multiplex enzyme-linked immunosorbent assay and T. vaginalis serology were measured in blood samples at diagnosis.

Results

A total of 324 patients were identified at time of localized disease and 118 at time of metastatic disease. Of the 189 patients with localized disease and clinical follow-up data (median, 73 months), 28 developed lethal disease. There was no association between circulating cytokine levels above median concentrations nor T. vaginalis seropositivity and risk of intermediate- to high-risk or lethal prostate cancer.

Conclusion

Higher levels of serum cytokine levels and T. vaginalis seropositivity at diagnosis are not associated with high-grade or lethal prostate cancer and do not aid risk stratification of localized prostate cancer.  相似文献   
47.

Purpose

The objective of the study was to define factors associated with adolescent and young adult (AYA) experiences with private time and having discussed confidentiality and the impact of these experiences on improving delivery of clinical preventive services.

Methods

In 2016, a nationally representative sample of 1,918 US AYAs (13- to 26-year-olds) was surveyed. Survey questionnaire domains were based on prior research and Fishers' information-motivation-behavior skills conceptual model. Data were weighted to represent US households with AYA and analyzed to identify factors independently associated with ever experiencing private time and discussions of confidentiality with a regular health-care provider (HCP). We examined the association of these experiences on AYA attitudes about health care.

Results

Fifty-five percent of female and 49% of male AYA reported ever having had private time with an HCP and 55% of female and 44% of male AYA had spoken to an HCP about confidentiality. Independent predictors of having experienced private time and confidentiality included older age, race, higher household income, gender of the provider, amount of years with the provider, and involvement in risk behaviors. AYA who had experienced private time and confidentiality discussions had more positive attitudes about their providers, were more willing and comfortable discussing sensitive topics, and thought that these discussions should happen at younger ages.

Conclusions

Although confidentiality and private time are important to AYA, many are not experiencing these components of care. Providing private time and discussions of confidentiality can improve the delivery of health care for young people by enhancing positive youth attitudes about preventive care.  相似文献   
48.
刘培  杨芳  李静 《护理学杂志》2019,34(10):105-109
体外膜肺氧合成为治疗严重心、肺衰竭患者的一种新方法并在重症患者中逐渐应用,而早期活动可促进危重患者康复。本文就近年来关于成人体外膜肺氧合患者早期活动的意义、安全性、开展情况及主要障碍、实施流程、实施策略等进行综述,为促进体外膜肺氧合患者早期活动的开展、改善预后提供参考。  相似文献   
49.
50.
目的观察不同时点电针对直肠癌开腹手术患者围术期应激反应及免疫功能的影响。方法240例择期行直肠癌根治性开腹手术而住院的患者,随机分为A组、B组、C组、D组,每组60例。A组设为空白对照组,B组于手术前1 d、C组于手术前1 d和麻醉诱导前30 min、D组分别于手术前1 d、麻醉诱导前30 min及手术后1 d行电针。分别于手术前1 d电针前(T1)、麻醉诱导前电针前(T2)、术毕(T3)和手术后1 d电针后(T4)4个时间采集患者空腹外周静脉血,用Sysmex血细胞分析仪对白细胞与中性粒细胞进行计数;ELISA检测急性期C反应蛋白(CRP)与热反应蛋白70(HSP70)以及细胞因子白介素6(IL-6)、干扰素(IFN-g)、白介素4(IL-4)水平,并计算IFN-g与IL-4比值;采用流式细胞仪测定CD4、CD8的细胞含量并计算两者比值。结果HSP70与CRP水平、白细胞数与中性粒细胞数、IL-4与IL-6水平变化趋势均一致,4组T1、T2时间比较,差异无统计学意义(P>0.05);A组与B组T3和T4时间比较,差异无统计学意义(P>0.05);C组、D组T3和T4时间显著低于A组与B组(P<0.05);D组T4时间显著低于C组(P<0.05);4组T2时间与T1时间比较差异无统计学意义(P>0.05),T3时间高于T2时间(P<0.05),T4时间低于T3时间(P<0.05)。IFN-g变化不显著(P>0.05),IFN-g/IL-4、CD4/CD8变化趋势与以上相反。结论电针术前使用对直肠癌患者无显著疗效,但能够减轻术后应激反应和免疫抑制,并且随着电针次数的合理增加疗效更加显著。  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