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   324136篇
  免费   29170篇
  国内免费   22904篇
耳鼻咽喉   2982篇
儿科学   3427篇
妇产科学   4928篇
基础医学   39908篇
口腔科学   5494篇
临床医学   45287篇
内科学   49744篇
皮肤病学   3083篇
神经病学   18365篇
特种医学   12023篇
外国民族医学   213篇
外科学   33219篇
综合类   49845篇
现状与发展   76篇
一般理论   20篇
预防医学   19616篇
眼科学   9566篇
药学   32814篇
  334篇
中国医学   17396篇
肿瘤学   27870篇
  2024年   997篇
  2023年   5014篇
  2022年   13047篇
  2021年   16314篇
  2020年   12034篇
  2019年   10827篇
  2018年   11410篇
  2017年   9917篇
  2016年   9356篇
  2015年   14350篇
  2014年   17800篇
  2013年   15349篇
  2012年   22799篇
  2011年   25807篇
  2010年   15906篇
  2009年   12255篇
  2008年   17014篇
  2007年   17037篇
  2006年   17052篇
  2005年   16784篇
  2004年   10663篇
  2003年   9763篇
  2002年   8443篇
  2001年   7468篇
  2000年   8283篇
  1999年   9024篇
  1998年   5490篇
  1997年   5515篇
  1996年   4346篇
  1995年   3936篇
  1994年   3217篇
  1993年   2103篇
  1992年   2830篇
  1991年   2421篇
  1990年   2122篇
  1989年   1871篇
  1988年   1572篇
  1987年   1358篇
  1986年   1110篇
  1985年   913篇
  1984年   529篇
  1983年   374篇
  1982年   242篇
  1981年   238篇
  1980年   191篇
  1979年   221篇
  1978年   84篇
  1977年   94篇
  1974年   102篇
  1973年   84篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
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   
92.
93.
94.
In order to solve the problem of long-term (>9 months) efficacy in the treatment of Alzheimer''s disease (AD) by conventional therapy (CT), a staged and multiply-targeted sequential therapy based on the evolvement of patterns (STEP) was developed. Its main innovations include: (1) the time order of evolution of patterns defined by Chinese medicine (CM) in AD was found, that is, "the orderly pattern evolution starting from Shen (Kidney) deficiency, progressing to phlegm, stasis and fire, and worsening to severe toxin as well as functional collapse"; (2) the cascade hypothesis of Shen deficiency in AD and its sequential therapy based on Shen-reinforcing was proposed, that is, "reinforcing Shen in the early stage and throughout the whole process, resolving phlegm, activating blood and purging fire in the middle stage, detoxifying and replenishing vitality to stop the collapse in the advanced stage", and through meta-analysis, clinical drug use was optimized, thus the leap from "inferential selection" to "evidence-based selection" was realized; (3) the STEP regimen combined with CT maintained cognitive and behavioral stability in AD patients for at least 12 months, with cognitive enhancement and behavioral synergy after 9 months, and cognitive benefit was superior to CT at 9, 12, 15, 18, 21, and 24 months, respectively. The 2-year cognitive improvement rate was increased by 25.64% (P=0.020) and the cognitive deterioration rate was decreased by 48.71% (P=0.000). Among them, the cognitive and functional benefits of Shen-reinforcing therapy for very early AD (350 cases) for 1 year were better than the placebo (P<0.001), and the dementia conversion rate was reduced by 8.85% (P=0.002). The behavioral symptomatic relief of patients with vascular dementia received fire-purging therapy (540 cases) was superior to those received CT (P=0.016). These data suggested that the STEP regimen has synergistic effects on CTs at least in terms of cognitive benefit, and the earlier the use, the greater the benefit will have. Therefore, the STEP regimen should be considered as one of the clinical options, particularly for the dearth of effective pharmaceutical or immunological interventions that are currently available for AD.  相似文献   
95.
The purpose of this meta-analysis is to compare the relative merits among laparoscopic-assisted operations and laparotomy operations for patients with Hirschsprung disease.PubMed, Web of Science, and Wanfang databases were searched for the related articles. We analyzed dichotomous variables by estimating odds ratios (ORs) with their 95% confidence intervals (CIs) and continuous variables using the weighted mean difference (WMD) with the 95% CI. The random-effects model (REM) was used to combine the results. The outcome measures included operating time (OT), estimated blood loss (EBL), length of hospital stay (LOHS), mean first bowel movement (MFBM), and number of complications.Sixteen articles were included in the meta-analysis. These studies involved a total of 774 patients, 396 of whom underwent laparoscopic-assisted operations and 378 of whom underwent laparotomy operations. The EBL (WMD = −1.48, 95% CI = −1.82, −1.13), LOHS (WMD = −0.67, 95% CI = −0.86, −0.49), MFBM (WMD = −0.83, 95% CI = −1.05, −0.61), and number of complications (OR = 0.60, 95% CI = 0.40, 0.89) were significantly lower in laparoscopic-assisted operations than in laparotomy operations. The OT (WMD = 0.12, 95% CI = −0.05, 0.28) showed no significant differences between laparoscopic-assisted operations and laparotomy operations.Compared with laparotomy operations, laparoscopic-assisted operations are generally safer and more reliable for patients with Hirschsprung disease.  相似文献   
96.
97.
侯银萌  李硕  王泠 《护理学杂志》2020,35(19):105-109
对潮湿相关性皮炎的概念、危险因素、国内外发生率进行简要介绍。从皮肤长期接触水分导致浸渍,化学、物理、生物等因素在疾病发展过程中产生的作用进行综述,以增强对潮湿相关性皮炎病理机制的认识;从发病机制视角综述目前局部护理新进展,包括避免与水分长期接触、清洁、保湿、皮肤保护、使用温和的产品5个方面,旨在为相关研究及临床实践提供参考。  相似文献   
98.
99.
100.
ObjectivesTo investigate the effect of corneal stromal pocket irrigation after small-incision lenticule extraction (SMILE) on visual acuity, intraocular pressure (IOP), corneal parameters and complications after surgery.MethodsA total of 242 eyes of 121 patients undergoing SMILE were enrolled in this prospective controlled study, and it was designed for one eye to randomly undergo SMILE with balanced salt solution irrigation of the corneal stromal pocket, while the other eye was not. The uncorrected distance visual acuity (UDVA) and slit lamp examination were recorded at 1 hour, 1 day, 1 week, and 1 month. Postoperative corneal density, corneal biomechanical, corneal endothelial cell number, and anterior OCT images were compared at 1 day, 1 week, and 1 month.ResultsCompared with the nonirrigation group, the irrigation group showed significantly higher UDVA at 1 day postoperatively (P < 0.05), but there was no significant difference during the rest of the postoperative period (1 hour, 1 week, and 1 month). In addition, no significant differences were found in IOP, corneal density, corneal biomechanics, corneal endothelial cells, and corneal morphology. No visual decline or severe postoperative complications were found in the patients in this study.ConclusionsInterlamellar irrigation did not affect IOP, corneal parameters, morphology, complications, or UDVA at 1 hour, 1 week, and 1 month after the operation, but it may promote UDVA 1 day after the operation.Subject terms: Refractive errors, Outcomes research, Surgery  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