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   82173篇
  免费   7105篇
  国内免费   5353篇
耳鼻咽喉   652篇
儿科学   982篇
妇产科学   812篇
基础医学   7612篇
口腔科学   1524篇
临床医学   11460篇
内科学   9962篇
皮肤病学   974篇
神经病学   2964篇
特种医学   2576篇
外国民族医学   32篇
外科学   6950篇
综合类   18221篇
现状与发展   24篇
一般理论   1篇
预防医学   7112篇
眼科学   1707篇
药学   9501篇
  108篇
中国医学   5859篇
肿瘤学   5598篇
  2024年   272篇
  2023年   963篇
  2022年   2509篇
  2021年   3128篇
  2020年   2598篇
  2019年   2081篇
  2018年   2132篇
  2017年   2341篇
  2016年   2037篇
  2015年   3446篇
  2014年   4398篇
  2013年   4397篇
  2012年   6755篇
  2011年   7241篇
  2010年   5654篇
  2009年   5062篇
  2008年   5525篇
  2007年   5502篇
  2006年   5271篇
  2005年   4666篇
  2004年   3349篇
  2003年   2994篇
  2002年   2472篇
  2001年   1926篇
  2000年   1649篇
  1999年   1349篇
  1998年   819篇
  1997年   810篇
  1996年   556篇
  1995年   498篇
  1994年   517篇
  1993年   284篇
  1992年   257篇
  1991年   230篇
  1990年   218篇
  1989年   145篇
  1988年   138篇
  1987年   129篇
  1986年   94篇
  1985年   80篇
  1984年   27篇
  1983年   17篇
  1982年   22篇
  1981年   18篇
  1980年   6篇
  1979年   18篇
  1978年   4篇
  1976年   4篇
  1974年   8篇
  1970年   3篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Tang  Xin  Chen  Lixin  Chen  Wenwen  Li  Peiyun  Zhang  Ling  Fu  Ping 《International urology and nephrology》2021,53(9):1911-1921
Purpose

Intradialytic hypotension (IDH) is a serious complication in dialysis patients. Diuretics might reduce the incidence of IDH by decreasing ultrafiltration. However, the effect of diuretics on IDH in maintenance dialysis patients is still unclear.

Methods

We searched Medline, Embase, the Cochrane Library, China National Knowledge Infrastructure and clinical trials registries from 1945 to May 2019. Randomized controlled trials (RCTs) or observational studies about IDH in maintenance dialysis with diuretics were included.

Results

Seven studies including 28,226 patients were included, of which 4 were RCTs involving mineralocorticoid receptor antagonists (MRAs) and 3 were observational studies involving loop diuretics. There was a trend that a lower incidence rate of IDH in maintenance dialysis patients who used loop diuretics than control, although the result was not statistically significant (OR 0.65, 95% CI 0.34–1.22, P?=?0.18). Similarly, lower incidence rate of all-cause mortality (OR 0.92, 95% CI 0.87–0.99; P?=?0.02) and cardiovascular (CV) mortality (OR 0.86, 95% CI 0.75–0.99, P?=?0.03) in dialysis patients who used loop diuretics than control. On the contrary, there were no significant difference in the incidence of IDH (OR 1.35, 95% CI 0.78–2.34, P?=?0.29) and all-cause mortality (OR 0.73, 95% CI 0.26–2.01; P?=?0.54) and CV mortality (OR 0.57, 95% CI 0.14–2.25; P?=?0.42) in maintenance dialysis patients who used MRAs compared with control.

Conclusion

Loop diuretics, but not MRAs, might have a potential benefit to reduce the incidence rate of IDH, all-cause mortality and CV mortality. More high-quality studies are needed to strengthen the arguments.

  相似文献   
82.
Wang  Ben  Deng  Yu-xuan  Yan  Sha  Xie  Hong-fu  Li  Ji  Jian  Dan 《Lasers in medical science》2021,36(3):649-655
Lasers in Medical Science - Acne scarring is one of the most common facial skin disorders. The appropriate treatments for acne scars in patients with rosacea have not been studied. This study was...  相似文献   
83.
We aimed to compare intracavernosal injection (ICI), tail vein injection (IV), and periprostatic injection (PPI) of adipose-derived stem cells (ADSCs) for their ability to improve erectile function in cavernous nerve injury-induced erectile dysfunction (CNIED) rats and to explore the possible mechanism. Eighty-four male SD rats were divided into the sham group (n = 6), BCNI group (bilateral CN crush injury, n = 6), PBS-ICI group (n = 6), PBS-IV group (n = 6), PBS-PPI group (n = 6), ADSC-ICI group (n = 18), ADSC-IV group (n = 18) and ADSC-PPI group (n = 18). ADSCs were labelled with 5-ethynyl-2′-deoxyuridine (EdU), and six rats each in the ADSC-ICI group, ADSC-IV group, and ADSC-PPI group were sacrificed 2, 7, and 28 days after injection. EdU-labelled ADSCs were tracked by immunofluorescence staining. The intracavernosal pressure (ICP)/mean arterial pressure (MAP) ratio, neuronal nitric oxide synthase (nNOS)-positive nerve fibres in the dorsal penile nerve and the smooth muscle/collagen ratio in the cavernosum between groups were also evaluated. ADSCs can significantly improve erectile function through ICI or IV. The two are similar in efficacy and superior to PPI. The mechanism may be that after CN injury, ADSCs are recruited to around the MPG and secrete a variety of neurotrophic factors that promote the repair of the CN, thereby improving erectile function.  相似文献   
84.
85.
86.
87.
本文介绍我们近年研制成功的一种全新的微型化的心电监视仪。该仪器集主机,显示器,电极导联于一体,适合医务人员随身携带,用于需要快速、简易、准确地获取人体心电图形与心率数据的场合。  相似文献   
88.
Surface modification of titanium implant is processed by microarc oxidation and hydrothermal treatment. A porous surface with a biologically active bone-like apatite layer was formed. The apatite layer consists of very fine crystals and high crystallinity and is integrated with the titanium alloy substrate with a graded structure without a distinct interface. Such a bioactive layer is expected not only to enhance the bony ingrowth into the porous structure, but also to improve the interlocking between implant and bone.  相似文献   
89.
Morphological typing of argyrophilic nucleolar organizer regions (AgNOR) in 300 caws of malignant tumors and 140 cams of benign lesions was analyzed and five morphological types of ApNOR were described in detail. In malignant tumors, the diffuse type (78%) was the most frequently seen, and in benign lesions, the nucleolar type (92.85%); the difference was thus highly significant (P < 0.001). The intranucleolar and aggregate types were not observed in benign lesions. There was no obvious difference in the proportion of the mixed type in benign and malignant lesions (P > 0.05). The relationship between grade of malignancy and morphological typing of AgNOR and its clinical significance are discussed.  相似文献   
90.
超抗原是指一些细菌或病毒编码的蛋白分子,只需极低浓度即可激活大量的淋巴细胞克隆.作为一种强大的T细胞激活剂,超抗原成为肿瘤免疫治疗研究的热点之一.本文对其特性及目前的研究进展作一综述.  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