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   135907篇
  免费   30415篇
  国内免费   1259篇
耳鼻咽喉   2687篇
儿科学   3243篇
妇产科学   2901篇
基础医学   7295篇
口腔科学   5992篇
临床医学   28210篇
内科学   33904篇
皮肤病学   3843篇
神经病学   14788篇
特种医学   4984篇
外科学   25224篇
综合类   290篇
现状与发展   40篇
预防医学   14323篇
眼科学   2675篇
药学   3847篇
中国医学   142篇
肿瘤学   13193篇
  2024年   756篇
  2023年   5193篇
  2022年   1447篇
  2021年   3339篇
  2020年   5649篇
  2019年   2466篇
  2018年   7440篇
  2017年   7765篇
  2016年   8443篇
  2015年   8599篇
  2014年   11174篇
  2013年   12996篇
  2012年   5240篇
  2011年   5096篇
  2010年   7656篇
  2009年   9774篇
  2008年   4909篇
  2007年   3972篇
  2006年   5109篇
  2005年   3763篇
  2004年   3215篇
  2003年   2828篇
  2002年   2765篇
  2001年   3482篇
  2000年   2751篇
  1999年   3240篇
  1998年   2617篇
  1997年   2363篇
  1996年   2355篇
  1995年   2048篇
  1994年   1444篇
  1993年   1242篇
  1992年   1749篇
  1991年   1581篇
  1990年   1328篇
  1989年   1427篇
  1988年   1280篇
  1987年   1079篇
  1986年   1101篇
  1985年   978篇
  1984年   689篇
  1983年   688篇
  1982年   426篇
  1981年   394篇
  1980年   264篇
  1979年   377篇
  1978年   373篇
  1977年   331篇
  1975年   273篇
  1974年   266篇
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
81.
82.
83.
84.
85.
86.
Two patients with mesenteric panniculitis are presented. In the first patient, a provisional diagnosis of ileus was made, based on the clinical features and imaging data. Laparotomic findings showed that the ileum was bound tightly by a fibrous strip and dilated, with thickened and swollen mesentery. Incision of the fibrous strip was performed, and the clinical symptoms were improved. The second patient was strongly suspected to have mesenteric panniculitis, from characteristic features on abdominal computed tomography and barium enema. Conservative therapy was effective in this case. We emphasize the variety of clinical courses in mesenteric panniculitis, requiring selection of the most suitable treatment.  相似文献   
87.
The purpose of this study was to investigate radiographic measurements in a cohort of patients with juvenile hallux valgus (with a hallux valgus angle > 15 degrees ) using standardized weightbearing x-rays compared with an age-matched control group. First metatarsal protrusion distance, metatarsus primus adductus angle, metatarsus adductus, first metatarsal cuneiform angle, calcaneal inclination angle, and talocalcaneal angles were assessed with discriminant functional analysis. A total of 37 sets of data were analyzed from patients with a mean age of 13.45 +/- 1.75 years. The study identified 2 significant components of juvenile hallux valgus: a positive first metatarsal protrusion distance (P <.001) and metatarsal primus adductus angle (P = .002). Discriminant functional analysis was then used to determine the best predictors of juvenile hallux valgus. This analysis allowed only 1 variable, metatarsal protrusion distance, as a predictor of whether juvenile hallux valgus was present (P < .001), with 94.3% accuracy. This study showed that a positive metatarsal protrusion distance is a significant component of juvenile hallux valgus.  相似文献   
88.
CONTEXT: Although the nonmedical use of stimulant drugs such as cocaine and methamphetamine is increasingly common in many rural areas of the United States, little is known about the health beliefs of people who use these drugs. PURPOSE: This research describes illicit stimulant drug users' views on health and health-related concepts that may affect their utilization of health care services. METHODS: A respondent-driven sampling plan was used to recruit 249 not-in-treatment, nonmedical stimulant drug users who were residing in 3 rural counties in west central Ohio. A structured questionnaire administered by trained interviewers was used to collect information on a range of topics, including current drug use, self-reported health status, perceived need for substance abuse treatment, and beliefs about health and health services. FINDINGS: Participants reported using a wide variety of drugs nonmedically, some by injection. Alcohol and marijuana were the most commonly used drugs in the 30 days prior to the interview. Powder cocaine was used by 72.3% of the sample, crack by 68.3%, and methamphetamine by 29.7%. Fair or poor health status was reported by 41.3% of the participants. Only 20.9% of the sample felt they needed drug abuse treatment. Less than one third of the sample reported that they would feel comfortable talking to a physician about their drug use, and 65.1% said they preferred taking care of their problems without getting professional help. CONCLUSIONS: Stimulant drug users in rural Ohio are involved with a range of substances and hold health beliefs that may impede health services utilization.  相似文献   
89.
90.
BACKGROUND AND PURPOSE: Dot-like low intensity spots (dot-like hemosiderin spots: dotHSs) on gradient echo T2*-weighted MRI have been histologically diagnosed to represent old cerebral microbleeds associated with microangiopathies. They have also been correlated to the fragility of small vessels and the tendency to bleed. Therefore, a substantial number of dotHSs might be associated with a large-sized, deep intracerebral hematoma (ICH). On the other hand, dotHSs may reflect old microbleeds that did not enlarge to symptomatic size. METHODS: To investigate how dotHSs are related to the size (maximal diameter) of primary deep ICH, we analyzed the diameter and the number of dotHSs in 151 patients with deep ICH not associated with subarachnoid hemorrhage or intraventricular hemorrhage (75 males and 76 females, age ranged from 37 to 90 [65.7 +/- 11.3 years old] who were consecutively admitted to Hakodate Municipal Hospital. The hazard ratio (HR) for a maximal diameter of deep ICH < or =2 cm was estimated, using the number of dotHSs and risk factors for stroke. RESULTS: The number of dotHSs associated with the diameter < or =2 cm was 9.2 +/- 11.5, significantly larger than that with the diameter > or =2 cm (4.7 +/- 7.0, P= .012). Multivariate analysis revealed that a maximal diameter of deep ICH of < or =2 cm was found in patients with dotHS (HR, 3.7; 95% confidence interval [CI], 1.4-10.1; P= .009). CONCLUSION: Though small sample size limited the power of our analyses, these findings suggest that the number of dotHSs may be associated with a small diameter of deep ICH.  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