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   3800篇
  免费   377篇
  国内免费   9篇
耳鼻咽喉   27篇
儿科学   107篇
妇产科学   45篇
基础医学   594篇
口腔科学   196篇
临床医学   410篇
内科学   689篇
皮肤病学   31篇
神经病学   305篇
特种医学   167篇
外科学   652篇
综合类   75篇
预防医学   327篇
眼科学   82篇
药学   182篇
  1篇
中国医学   1篇
肿瘤学   295篇
  2021年   27篇
  2020年   27篇
  2019年   54篇
  2018年   63篇
  2017年   49篇
  2016年   58篇
  2015年   66篇
  2014年   90篇
  2013年   132篇
  2012年   185篇
  2011年   170篇
  2010年   100篇
  2009年   98篇
  2008年   164篇
  2007年   157篇
  2006年   137篇
  2005年   161篇
  2004年   150篇
  2003年   125篇
  2002年   134篇
  2001年   151篇
  2000年   141篇
  1999年   142篇
  1998年   85篇
  1997年   58篇
  1996年   71篇
  1995年   52篇
  1994年   54篇
  1993年   42篇
  1992年   74篇
  1991年   81篇
  1990年   79篇
  1989年   65篇
  1988年   80篇
  1987年   67篇
  1986年   75篇
  1985年   77篇
  1984年   54篇
  1983年   44篇
  1982年   28篇
  1981年   34篇
  1980年   26篇
  1979年   57篇
  1978年   37篇
  1977年   36篇
  1976年   36篇
  1975年   25篇
  1974年   29篇
  1973年   31篇
  1971年   28篇
排序方式: 共有4186条查询结果,搜索用时 31 毫秒
1.
2.
3.
Chorioretinal folds have been reported as a result of many intraocular and extraocular inflammatory processes or tumors. Visual loss is usually secondary to a combination of the underlying process and chorioretinal folds involving the macula. We report a patient who developed decreased vision, metamorphopsia, chorioretinal folds, and a lamellar macular hole secondary to global compression by a bone fragment. The chorioretinal folds regressed and his vision stabilized following surgical decompression. Chorioretinal folds and lamellar macular hold formation are previously unrecognized complications of reconstructive craniofacial surgery.  相似文献   
4.
Five cases of unilateral vocal cord paralysis/paresis were diagnosed following extracorporeal membrane oxygenation for newborn respiratory failure. All were right sided and transient in nature. None of the five patients had other findings commonly associated with vocal cord palsy. The extracorporeal membrane oxygenation procedure requires surgical dissection in the carotid sheath on the right side of the neck, an area immediately adjacent to both the vagus and recurrent laryngeal nerve. It is speculated that vocal cord paralysis in these infants was acquired as a result of the extracorporeal membrane oxygenation cannulation. Although the vocal cord paralysis resolved in all cases, two patients had difficult courses after extracorporeal membrane oxygenation. Therefore, laryngoscopic examination should be considered for patients after extracorporeal membrane oxygenation.  相似文献   
5.
The aim of this investigation was to establish the relationship between short-term perceived comfort and pressure distribution on the dorsal and plantar surfaces of the foot, while walking in a range of commercially available casual footwear. The study was carried out in the biomechanics laboratory of Manchester Metropolitan University using 15 male subjects without foot pathology. Perceived upper and plantar comfort were measured using a specially designed questionnaire, while dorsal and plantar pressure distributions were measured using a rectangular sensor pad recording at 30 Hz and a Mikro-EMED insole recording at 100 Hz respectively. Analysis of variance tests were used to determine differences in perceived comfort and pressure distribution between three pairs of shoes. The findings of this study suggest that an increase in total plantar force and force-time integral may relate to a decrease in perceived plantar comfort. For the three shoes examined in this study, overall peak plantar pressure, the pressure-time integral, and total plantar area did not appear to be linked to perceived plantar comfort. Findings for the shoe upper indicate that decreased dorsal forces and pressures may be related to decreased upper comfort. These findings suggest that the measurement of pressure distribution at the foot-shoe interface could be a useful tool in identifying the causes of discomfort in footwear.  相似文献   
6.
7.
8.
Study Objective . To investigate the effect of simultaneously administered didanosine (ddI) on the absorption of a single dose of itraconazole. Design . Randomized, crossover, unblinded single-dose pharmacokinetic study in healthy volunteers. Comparisons of itraconazole alone and itraconazole with simultaneous ddI were performed on days 1 and 15. Setting . A university medical center. Patients . Seven healthy men and women. Six subjects (86%) completed the study; one was removed due to the development of a rash. Interventions . Volunteers received a single 200-mg oral dose of itraconazole or itraconazole with concomitant oral ddI 300 mg (two 150-mg tablets) dispersed in 240 ml water. Each regimen was separated by a 2-week washout period. Serum samples were obtained frequently for 12 hours after the dose. Measurements and Main Results . Concentrations of itraconazole were determined using a microbiologic assay. Individual concentrations in serum versus time data were evaluated by linear regression analysis. Peak serum concentration and time to peak were determined by visual inspection of each individual's serum concentration-time curve. A mean ± SD peak serum itraconazole concentration of 0.90 ± 0.30 μg/ml was observed at 3.0 ± 0.7 hours when itraconazole was administered alone, compared with undetectable levels in all patients during therapy with ddI. Conclusions . Simultaneous oral administration of ddI significantly decreases absorption of itraconazole. These drugs should not be administered concurrently.  相似文献   
9.
10.
Extracorporeal membrane oxygenation for pediatric cardiopulmonary failure   总被引:1,自引:0,他引:1  
Extracorporeal membrane oxygenation is now standard treatment of severe respiratory failure in newborn infants in our center (200 cases) and worldwide (over 2500 cases), but there are few reports of such trials in older children. We reviewed our experience with extracorporeal membrane oxygenation in 33 children aged 1 week to 18 years between 1971 and 1989. The modality was used when all other treatment failed. Extracorporeal membrane oxygenation provided excellent cardiopulmonary support for 1 to 25 days (average 7 1/2 days). The survival rate was 25% for cardiac support patients and 47% for respiratory failure patients (36% overall survival). Mechanical complications included membrane lung failure, tubing rupture, and pump failure, all managed without mortality. Physiologic complications included bleeding, pneumothorax, cardiac arrest, renal failure, hepatic failure, and brain injury. The major cause of death was irreversible injury to lung, heart, or brain. Extracorporeal life support is a reasonable approach for children with serious but reversible cardiopulmonary failure.  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