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   879篇
  免费   51篇
  国内免费   98篇
耳鼻咽喉   5篇
儿科学   46篇
妇产科学   5篇
基础医学   86篇
口腔科学   26篇
临床医学   145篇
内科学   245篇
皮肤病学   11篇
神经病学   68篇
特种医学   119篇
外科学   51篇
综合类   41篇
预防医学   46篇
眼科学   7篇
药学   92篇
肿瘤学   35篇
  2023年   3篇
  2021年   8篇
  2020年   3篇
  2019年   6篇
  2018年   6篇
  2017年   8篇
  2016年   10篇
  2015年   11篇
  2014年   18篇
  2013年   28篇
  2012年   29篇
  2011年   33篇
  2010年   42篇
  2009年   35篇
  2008年   24篇
  2007年   67篇
  2006年   29篇
  2005年   43篇
  2004年   13篇
  2003年   16篇
  2002年   19篇
  2001年   26篇
  2000年   23篇
  1999年   22篇
  1998年   45篇
  1997年   39篇
  1996年   31篇
  1995年   36篇
  1994年   29篇
  1993年   38篇
  1992年   19篇
  1991年   17篇
  1990年   27篇
  1989年   34篇
  1988年   32篇
  1987年   19篇
  1986年   21篇
  1985年   17篇
  1984年   10篇
  1983年   10篇
  1982年   8篇
  1981年   5篇
  1980年   10篇
  1979年   6篇
  1978年   6篇
  1977年   9篇
  1976年   9篇
  1973年   3篇
  1972年   4篇
  1967年   4篇
排序方式: 共有1028条查询结果,搜索用时 15 毫秒
61.
INTRODUCTION: Susceptibility to motion sickness (MS) is known to be affected by gender and ethnic origin, but whether gender and ethnicity are interacting is unknown. METHODS: We investigated MS development in healthy Caucasian subjects (n = 227), and in subjects of Chinese origin (n = 82). All subjects were exposed to nausea-inducing body rotations in a rotation chair, and rotated around the yaw axis for 5 x 1 min, while they were instructed to move their heads. Prior to rotation, subjects had to fill out a motion-sickness susceptibility questionnaire (MSSQ). Total rotation tolerance time (RT) was noted. Symptom ratings (SR) were performed at the beginning, and immediately after the end of each rotation, and 15 and 30 min later. RESULTS: The average RT was significantly higher in Caucasian (163 +/- 6 s) than in Chinese subjects (111 +/- 7 s) (F = 24.84, p < 0.0001). The adult MSSQ score was significantly lower in Caucasians (17.8 +/- 1.1) than in Chinese volunteers (24.2 +/- 2.1) (F = 6.05, p = 0.014). Maximal SR post rotation was similar in Chinese and Caucasian subjects. RT was highly predictable from the MSSQ scores, but separate for both genders. CONCLUSION: Susceptibility to MS is affected by both ethnic origin and by gender in a rather complex fashion. The most reliable prediction of RT can be based on the individual's history as assessed by the MSSQ.  相似文献   
62.
63.
BACKGROUND: Because apomorphine is a dopamine agonist that acts on areas of the central nervous system believed to mediate penile erection, its use in erectile dysfunction (ED) has been investigated. However, it also produces nausea by dopamine-receptor stimulation of the chemotrigger zone in the brain. Therefore, a low plasma concentration, achieved rapidly, would be selective for the desired erectile response but would be below the dopamine threshold for nausea. OBJECTIVE: We evaluated the efficacy and tolerability of a dose-optimized regimen of a sublingual formulation of apomorphine (apomorphine SL) in the treatment of ED. METHODS: This was a multicenter, open-label, uncontrolled, Phase III dose-optimization study of apomorphine SL in heterosexual men with ED. The 2-week screening period, during which baseline severity of ED was determined using the International Index of Erectile Function, was followed by a 3-week dose-optimization period beginning at a dose of 2 mg. Patients were to make at least 2 attempts at intercourse per week throughout the study, placing 1 apomorphine tablet under the tongue beforehand. At the end of the first week, the dose could be increased to 3 mg at the discretion of the investigator; at the end of the second week, the dose could be increased to a maximum of 4 mg or decreased as needed. In the following 4-week treatment period, patients took their individual optimal doses. The primary efficacy variable was the percentage of attempts resulting in erections firm enough for intercourse, as assessed by investigators' review of data from patients' diaries. Secondary variables included the percentage of attempts resulting in successful intercourse, time to erection, and duration of erection. Information about adverse events, including their severity and relation to treatment, was determined on the basis of direct questioning, spontaneous reports, and review of patient diaries. RESULTS: The study enrolled 849 heterosexual men whose ages ranged from 31 to 78 years (mean, 58.1 years). They had a mean 5.7-year history of ED of varbus causes. ED was mild in 11.5% of the men, moderate in 23.8 c, and severe in 48.1%. When results of the last 8 attempts were pooled, representing the period during which patients were taking their optimal doses of apomorphine SL, the mean percentage of attempts resulting in erections firm enough for intercourse was 39.4%, compared with 13.1% at baseline; attempts resulting in intercourse increased from a mean of 12.7% at baseline to 38.3% with treatment. The average median time to erection was 23 minutes, and the average median duration of erection was 13 minutes. Nausea, the most common treatment-related adverse event (11.7%). was dose related and diminished with continued dosing. One patient had a single syncopal episode that was judged to be related to apomorphine SL. CONCLUSIONS: In the present study, a dose-optimization regimen of apomorphine SL-with dosing initiated at 2 mg and adjusted up to a maximum of 4 mg as needed-was effective and well tolerated in the treatment of ED, regardless of its cause or severity.  相似文献   
64.
According to cognitive models of anxiety, anxiety patients exhibit an attentional bias towards threat, manifested as greater distractibility by threat stimuli and enhanced detection of them. Both phenomena were studied in two experiments, using a modified visual search task, in which participants were asked to find single target words (GAD-related, speech-related, neutral, or positive) hidden in matrices made up of distractor words (also GAD-related, speech-related, neutral, or positive). Generalized anxiety disorder (GAD) patients, social phobia (SP) patients afraid of giving speeches, and healthy controls participated in the visual search task. GAD patients were slowed by GAD-related distractor words but did not show statistically reliable evidence of enhanced detection of GAD-related target words. SP patients showed neither distraction nor enhancement effects. These results extend previous findings of attentional biases observed with other experimental paradigms.  相似文献   
65.
Background: An outbreak of food poisoning in a military establishment mess was investigated and remedial measures suggested.  相似文献   
66.
高效液相色谱法测定寒痹停片中士的宁含量   总被引:6,自引:0,他引:6  
目的:建立用HPLC测定寒痹停片中士的含量的方法。方法:氰基柱;流动相-甲醇-水-三乙胺-乙酸(9800:155:15:30);紫外检测波长254nm。结果:在4~20ug/ml范围内,标准曲线回归方程为:Y=-2803+8967x(r=0.9997),RSD=1.65%?加样回收率的平均值为99.82%。结论:实验表明,这是一个适用于生产控制和产品质量检验的简单、快速、准确的方法。  相似文献   
67.
68.
69.
70.
Primary synovial chondromatosis is a rare and usually monarticular metaplasia of the synovia. It may recur, but the tendency to malignant transformation is very low. The radiological and histopathological differentiation from low grade chondrosarcoma can be difficult. We present a case report of a 32-year-old male with synovial chondromatosis in the tarsometatarsal joint area, which is an uncommon localization.  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