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   1570篇
  免费   108篇
  国内免费   1篇
耳鼻咽喉   1篇
儿科学   25篇
妇产科学   22篇
基础医学   233篇
口腔科学   15篇
临床医学   139篇
内科学   285篇
皮肤病学   24篇
神经病学   81篇
特种医学   60篇
外科学   245篇
综合类   23篇
一般理论   1篇
预防医学   232篇
眼科学   156篇
药学   90篇
中国医学   1篇
肿瘤学   46篇
  2022年   8篇
  2021年   18篇
  2019年   19篇
  2018年   26篇
  2017年   23篇
  2016年   20篇
  2015年   31篇
  2014年   45篇
  2013年   70篇
  2012年   104篇
  2011年   94篇
  2010年   40篇
  2009年   40篇
  2008年   99篇
  2007年   88篇
  2006年   100篇
  2005年   102篇
  2004年   74篇
  2003年   91篇
  2002年   74篇
  2001年   25篇
  2000年   15篇
  1999年   23篇
  1998年   12篇
  1997年   9篇
  1995年   10篇
  1994年   11篇
  1992年   19篇
  1991年   12篇
  1990年   19篇
  1988年   9篇
  1987年   15篇
  1984年   12篇
  1983年   9篇
  1982年   8篇
  1981年   8篇
  1980年   10篇
  1979年   16篇
  1978年   10篇
  1977年   13篇
  1975年   10篇
  1974年   11篇
  1973年   8篇
  1948年   11篇
  1947年   13篇
  1946年   16篇
  1945年   14篇
  1944年   10篇
  1943年   7篇
  1925年   7篇
排序方式: 共有1679条查询结果,搜索用时 0 毫秒
81.
82.
West Nile virus-associated flaccid paralysis   总被引:1,自引:0,他引:1  
The causes and frequency of acute paralysis and respiratory failure with West Nile virus (WNV) infection are incompletely understood. During the summer and fall of 2003, we conducted a prospective, population-based study among residents of a 3-county area in Colorado, United States, with developing WNV-associated paralysis. Thirty-two patients with developing paralysis and acute WNV infection were identified. Causes included a poliomyelitislike syndrome in 27 (84%) patients and a Guillain-Barré-like syndrome in 4 (13%); 1 had brachial plexus involvement alone. The incidence of poliomyelitislike syndrome was 3.7/100,000. Twelve patients (38%), including 1 with Guillain-Barré-like syndrome, had acute respiratory failure that required endotracheal intubation. At 4 months, 3 patients with respiratory failure died, 2 remained intubated, 25 showed various degrees of improvement, and 2 were lost to followup. A poliomyelitislike syndrome likely involving spinal anterior horn cells is the most common mechanism of WNV-associated paralysis and is associated with significant short- and long-term illness and death.  相似文献   
83.
BACKGROUND: Increased dietary calcium is associated with changes in body composition. One proposed mechanism is that dietary calcium increases fat oxidation, potentially via regulation of serum parathyroid hormone (PTH) concentrations. OBJECTIVES: The objectives of the study were to determine whether acute or chronic increased dairy calcium intakes alter postprandial whole-body fat oxidation and whether the increased intake is related to changes in PTH concentrations. DESIGN: Normal-weight women aged 18-30 y were randomly assigned to a low (<800 mg/d, control; n = 10) or high (1000-1400 mg/d; n = 9) dietary calcium intake group for 1 y. Whole-body fat oxidation was assessed by measuring respiratory gas exchange after each subject consumed 2 isocaloric liquid meals containing 100 or 500 mg Ca at baseline and 1 y. Fasting serum PTH was measured at baseline and 1 y. RESULTS: The mean 1-y change in fat oxidation was higher in the high-calcium group than in the low-calcium control group after a low-calcium meal (0.10 +/- 0.05 compared with 0.005 +/- 0.04 g/min; P < 0.001) and a high-calcium meal (0.06 +/- 0.05 compared with 0.03 +/- 0.04 g/min; P < 0.05). The 1-y change in serum log PTH was negatively associated with the 1-y change in postprandial fat oxidation after a high-calcium meal (partial r = -0.46, P < 0.04) when controlled for the1-y change in total body fat mass. CONCLUSIONS: The results suggest that a chronic diet high in dairy calcium increases whole-body fat oxidation from a meal, and increases in fasting serum PTH relate to decreases in postprandial whole-body fat oxidation.  相似文献   
84.
85.
86.
87.
We describe a rare case of unilateral leiomyoma of the nipple in a man presenting with pruritus of the nipple for 3 months. A conservative surgical excision is performed for diagnosis. Histologic examination and immunostaining confirmed the diagnosis of leiomyoma. The leiomyoma is completely excised, and the patient denies pruritus after surgery. Conservative surgical excision of a persistently hard and pruritic nipple can be effectively used as both diagnostic measure and treatment modality.  相似文献   
88.
89.
90.
BACKGROUND: The incidence of ulnar collateral ligament injury has increased in baseball, especially at the high school level. HYPOTHESIS: Ulnar collateral ligament injury in high school baseball players is associated with overuse, high-velocity throwing, early throwing of breaking pitches, and improper warm-ups. STUDY DESIGN: Retrospective cohort study. METHODS: Follow-up physical examination and questionnaire data were collected at an average of 35 months after ulnar collateral ligament reconstruction from 27 former high school baseball players. Six potential risk factors were evaluated: year-round throwing, seasonal overuse, event overuse, throwing velocity more than 80 mph, throwing breaking pitches before age 14, and inadequate warm-ups. RESULTS: Overall, 74% returned to baseball at the same or higher level. Patients averaged 3 potential risk factors, and 85% demonstrated at least one overuse category. Of the pitchers, the average self-reported fastball velocity was 83 mph, and 67% threw breaking pitches before age 14. CONCLUSIONS: The success rate of ulnar collateral ligament reconstruction in high school baseball players is nearly equal to that in more mature groups of throwers. Overuse of the throwing arm and throwing breaking pitches at an early age may be related to their injuries. Special attention should be paid to elite-level teenage pitchers who throw with high velocity.  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