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   52760篇
  免费   4017篇
  国内免费   277篇
耳鼻咽喉   638篇
儿科学   1176篇
妇产科学   1046篇
基础医学   7516篇
口腔科学   1081篇
临床医学   5220篇
内科学   11024篇
皮肤病学   1196篇
神经病学   5079篇
特种医学   2277篇
外国民族医学   2篇
外科学   9282篇
综合类   531篇
现状与发展   2篇
一般理论   76篇
预防医学   2918篇
眼科学   1044篇
药学   3224篇
中国医学   119篇
肿瘤学   3603篇
  2023年   462篇
  2022年   845篇
  2021年   1966篇
  2020年   1138篇
  2019年   1516篇
  2018年   1685篇
  2017年   1159篇
  2016年   1373篇
  2015年   1619篇
  2014年   2163篇
  2013年   2510篇
  2012年   4022篇
  2011年   3951篇
  2010年   2191篇
  2009年   1923篇
  2008年   3043篇
  2007年   3081篇
  2006年   2880篇
  2005年   2607篇
  2004年   2439篇
  2003年   2169篇
  2002年   2010篇
  2001年   632篇
  2000年   614篇
  1999年   617篇
  1998年   471篇
  1997年   368篇
  1996年   276篇
  1995年   271篇
  1994年   231篇
  1993年   230篇
  1992年   403篇
  1991年   380篇
  1990年   354篇
  1989年   320篇
  1988年   277篇
  1987年   273篇
  1986年   267篇
  1985年   292篇
  1984年   239篇
  1983年   223篇
  1982年   175篇
  1981年   164篇
  1980年   175篇
  1979年   201篇
  1978年   158篇
  1977年   144篇
  1976年   146篇
  1974年   149篇
  1972年   135篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
93.
Revision endoscopic frontal sinus surgery with surgical navigation.   总被引:9,自引:0,他引:9  
BACKGROUND: Revision surgery of the frontal sinus remains one of the most difficult operations for the endoscopic surgeon. Most agree that knowledge and recognition of its complex anatomy and sparing of frontal recess mucosa are keys to a successful operation. The use of surgical navigation systems may allow for more precise dissections and greater rates of frontal recess patency. METHODS: Retrospective review of all patients undergoing revision endoscopic frontal sinus surgery with surgical navigation was performed with a minimum 24-month follow-up. RESULTS: Sixty-seven patients underwent revision endoscopic frontal sinus surgery with surgical navigation. The average follow-up was 32 months. Fifty-eight (86.6%) had a patent frontal recess and significant subjective improvement in symptoms. No patient underwent external frontal sinus obliteration, and there were no major complications. CONCLUSIONS: Endoscopic techniques with surgical navigation are effective in revision frontal sinus cases. The dissection of remnant agger nasi, obstructing frontal and supraorbital cells are necessary to widen the anterior-posterior as well as the medial-lateral dimensions of the recess. Computer navigational systems appear to serve as a valuable adjunct in preoperative planning and safe intraoperative dissection.  相似文献   
94.
BACKGROUND: The intent of this study was to ascertain the adequacy of delivery of enteral nutrition (EN) to critically ill adult multiple trauma patients and to identify potential detrimental factors that affect EN delivery. METHODS: Retrospective observational study. Trauma intensive care unit (TICU) in a university-affiliated hospital. Adult patients (>/=18 years of age) admitted to the TICU who received enteral feeding. RESULTS: Fifty-six adult patients were enrolled for study. Patients received, on average, 67% +/- 19% of what was prescribed for 5.7 +/- 2.0 days. A total of 222 occurrences for temporary discontinuation of tube feeding were identified. Gastrointestinal intolerance, as defined by a gastric residual volume of >150 mL, abdominal pain, or >3 liquid stools per day, accounted for only 11% of the occurrences for discontinuation of feeding. Surgery (27%) and diagnostic procedures (15%) represented the majority of reasons for inadequate nutrient delivery. Minor factors for EN interruptions were mechanical feeding tube problems (8%), pharmacy delivery delay (4%), and miscellaneous factors (3%). Multiple and unknown reasons contributed to 14% and 18% of the occurrences, respectively. CONCLUSIONS: Surgery and diagnostic procedures accounted for the largest factor in enteral feeding discontinuations in our critically ill trauma patients. Gastrointestinal intolerance contributed a minor role in the temporary discontinuation of enteral feeding.  相似文献   
95.
96.
97.
OBJECTIVE: To compare laser-assisted tympanostomy (LAT) with radiofrequency myringotomy (RFM), as well as the effectiveness of mitomycin C (MC) on the above techniques, in rabbits. STUDY DESIGN: Experimental animal research protocol. SETTING: University of Crete, School of Medicine, Medical Experimental Education and Research Center. METHODS: Bilateral myringotomies were performed under general anesthesia on 40 rabbits. LAT was performed on 20 animals (40 ears) and RFM on the remaining 20 animals (40 ears). MC (0.3 mg/mL) pledgets were applied to the right ears and saline pledgets to the left ears. Animals were monitored weekly using otomicroscopy until myringotomy closure. Kaplan-Meier survival techniques were used to compare myringotomy patency times. INTERVENTIONS: Under general anesthesia, bilateral LAT was performed on 20 rabbits and bilateral RFM on 20 rabbits. MAIN OUTCOME MEASURES: Myringotomy patency time. RESULTS: The mean patency times of the saline-treated ears were: 1.85 weeks (95% confidence interval [CI], 1.556-2.144 wk) for the LAT group and 1.70 weeks (95% CI, 1.494-1.906 wk) for the RFM group. This difference was not significant (p > 0.5). MC application significantly prolonged mean patency time (p < 0.0001) in both LAT and RFM groups. The mean patency times in the MC-treated ears were 5.45 weeks (95% CI, 5.226-5.674 wk) for the LAT group and 5.55 weeks (95% CI, 5.285-5.815 wk) for the RFM group. This difference was not significant (p > 0.5). CONCLUSION: There is no significant difference in myringotomy patency times between LAT and RFM techniques in rabbits, whereas MC significantly prolongs the patency rate of either technique.  相似文献   
98.
99.
Thyroid function tests were performed on 16 clinically euthyroid patients with end-stage renal failure undergoing regular haemodialysis or continuous ambulatory peritoneal dialysis and compared with 8 healthy subjects. The patient groups were carefully matched, especially regarding relative duration of dialysis (mean of 24 months). Total serum thyroxine, total triiodothyronine, free thyroxine, free triiodothyronine and reverse triiodothyronine were significantly lower in both patient groups than control. The thyrothrophin response to the standard thyrotrophin-releasing hormone test was delayed and blunted. Using a novel concentration technique we measured loss of T4 in peritoneal dialysate effluent and found it to be approximately 10% of daily thyroidal T4 release.  相似文献   
100.
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