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   1194篇
  免费   81篇
  国内免费   13篇
耳鼻咽喉   16篇
儿科学   63篇
妇产科学   24篇
基础医学   126篇
口腔科学   19篇
临床医学   79篇
内科学   272篇
皮肤病学   24篇
神经病学   35篇
特种医学   48篇
外科学   89篇
综合类   71篇
预防医学   199篇
眼科学   56篇
药学   90篇
中国医学   1篇
肿瘤学   76篇
  2024年   5篇
  2023年   7篇
  2022年   21篇
  2021年   29篇
  2020年   12篇
  2019年   14篇
  2018年   29篇
  2017年   18篇
  2016年   23篇
  2015年   40篇
  2014年   31篇
  2013年   58篇
  2012年   66篇
  2011年   61篇
  2010年   32篇
  2009年   45篇
  2008年   47篇
  2007年   58篇
  2006年   40篇
  2005年   58篇
  2004年   67篇
  2003年   53篇
  2002年   29篇
  2001年   38篇
  2000年   33篇
  1999年   22篇
  1998年   21篇
  1997年   25篇
  1996年   20篇
  1995年   12篇
  1994年   14篇
  1993年   11篇
  1992年   19篇
  1991年   16篇
  1990年   16篇
  1989年   15篇
  1988年   20篇
  1987年   16篇
  1986年   17篇
  1985年   13篇
  1984年   13篇
  1983年   19篇
  1982年   14篇
  1981年   10篇
  1980年   5篇
  1977年   5篇
  1976年   4篇
  1968年   7篇
  1958年   11篇
  1957年   4篇
排序方式: 共有1288条查询结果,搜索用时 15 毫秒
21.
OBJECTIVE: To determine the optimal numbers and sites of biopsies required for diagnosis of Helicobacter pylori by using the CLOtest and comparing the results with those of a routine histological assessment in a district general hospital (DGH) setting. METHODS: A prospective study comparing the sensitivity of the CLOtest containing one antral (CLO 1), two antral (CLO 2) and two antral and one body biopsy (CLO 3), and with histological examination for H. pylori. Consecutive patients undergoing upper gastrointestinal endoscopy (UGIE) at Stepping Hill Hospital, Stockport, UK, who had evidence of gastritis, gastric ulcer, duodenitis or duodenal ulcer were included in the study. RESULTS: Ninety-six patients were biopsied. Forty were positive on at least one of the CLOtests; of these, nine were negative on histological assessment. Of these nine, two were positive on all CLOtests and seven were positive only on CLO 3. One was positive on histology but negative on all CLOtests. This study showed that CLO 3 was more sensitive than CLO 1 (P = 0.004), CLO 2 (P = 0.016) and histology (P = 0.022). There was no significant difference between CLO 1 and CLO 2 (P = 0.500), CLO 1 and histology (P = 1.000), CLO 2 and histology (P = 1.00). CONCLUSION: We feel that in a busy clinical setting, taking two antral and one body biopsy in a single CLOtest is superior to routine histological assessment for the detection of H. pylori, with resulting cost saving.  相似文献   
22.
The appearance of resistance to a number of hepatotoxins in primary cultures of hepatocytes prepared at various time intervals up to 2 weeks after partial hepatectomy is the major focus in this study. Resistance to the cytocidal effect of aflatoxin B1, 2-acetylaminofluorene, N-hydroxy-2-acetylaminofluorene, methotrexate, or methyl methanesulfonate shows a progressive increase until 48 hr and then returns to the resting level of susceptibility by 2 weeks. The genesis of mutagens from 2-acetylaminofluorene and aflatoxin B1 by S-9 liver fractions shows a decrease from and return to control values after partial hepatectomy that parallels the resistance. The levels of total cellular cytochromes P-450 also decrease following partial hepatectomy and remain from 28 to 36% less than those of controls for at least 1 week. The glutathione and total soluble sulfhydryl ("glutathione") content increase following partial hepatectomy, and the pattern is consistent with a partial role for glutathione in the resistance phenomenon as it relates to 2-acetylaminofluorene. The possible relationship between resistance to the cytocidal effects in vitro and the resistance to inhibition of cell proliferation in vivo during liver carcinogenesis is discussed.  相似文献   
23.
PAM (pressure-activated microsyringe) is a new microfabrication technique that allows the fabrication of two- and three-dimensional scaffolds with a well-defined geometry using polymers soluble in volatile solvents. In this study, polymeric scaffolds were realized with four different polymers--PCL, PLLA, PLGA, and a blend of PCL and PLLA--and with three different geometries-square grids, hexagonal grids, and octagonal grids. The scaffolds were characterized in terms of porosity, hydrophilicity, cell adhesion, and their mechanical properties. An analysis of the measured data shows that the physical and mechanical properties of the scaffold depend on its geometry and line width, both of which are easily modulated using PAM.  相似文献   
24.
OBJECTIVES: To evaluate the medium-term outcome of cricothyroid approximation and subluxation (CTAS) with postoperative speech therapy for pitch elevation in male-to-female transsexuals. STUDY DESIGN: Retrospective study of male-to-female transsexuals who underwent pitch-raising surgery between November 1996 and August 2001. METHODS: Twenty-one male-to-female transsexuals opted for surgical feminization of their voices after inadequate improvements with speech therapy alone. Electrolaryngographic measurements were obtained by a single speech therapist of modal fundamental frequencies and the percentage of irregularities before, at 2 weeks, and 6 months after surgery. All 21 patients underwent CTAS, and 20 underwent simultaneous cosmetic thyroid chondroplasty by a single surgeon. RESULTS: Electrolaryngographic results 2 weeks after surgery showed an average postoperative gain in modal frequency of free speech of 71.05 Hz (95% confidence interval [CI]: 42.9-99.2, P < .001). There was a concomitant average rise in irregularities of 9.9% (95% CI 0.7-18.5, P = .03). At median follow-up of 6 months after six sessions of speech therapy (n = 15), there was a decrease in irregularities to preoperative levels. The overall gain at 6 months in modal frequency of free speech was 56.9 Hz (95% CI 38.3-75.4, P < .001). Smoking and age did not predict a worse outcome. CONCLUSIONS: Cricothyroid approximation effectively raises pitch in male-to-female transsexuals. There is a concomitant rise in voice irregularities that is effectively addressed by speech therapy.  相似文献   
25.
26.
27.
OBJECTIVE: To determine the feasibility of continuous glucose monitoring in the very low birthweight baby requiring intensive care, as these infants are known to be at high risk of abnormalities of glucose control. METHOD: Sixteen babies were studied from within 24 hours of delivery and for up to seven days. RESULTS: The subcutaneous glucose sensors were well tolerated and readings were comparable to those on near patient whole blood monitoring devices. CONCLUSION: Continuous glucose monitoring is practical in neonates, giving detailed information about glucose control.  相似文献   
28.
A 16-year-old girl accompanied by her mother was noted to have several thin, well healed brown lines on the distal third of her left flexural forearm (Figure). She admits to having recently made these marks by skin cutting. She feels depressed and at times feels life "is not worth living." She denies alcohol or substance abuse or true suicidal ideation, plan, or intent. Her mother describes her as previously well adjusted and a good student who has become erratic and moody in the past 6 months, with worsening school performance. Her father had a history of depression and alcoholism and died 3 years ago. She is undergoing psychotherapy and pharmacotherapy with sertraline with good results. She has not cut her skin in 3 months. Her mood and behavior have improved.  相似文献   
29.
30.
OBJECTIVE: To examine the prevalence of mental and physical distress indicators among women of reproductive age and the association of these indicators with cigarette smoking and alcohol use, by pregnancy status. METHODS: The Behavioral Risk Factor Surveillance System data for several years were aggregated across states and weighted for this analysis. Seven measures of self-reported mental and physical distress and general health were examined along with demographic variables. RESULTS: Overall, 6.7% (95% confidence interval [CI] 6.5-6.9) of women reported frequent physical distress, 12.3% (95% CI 12.0-12.6) reported frequent mental distress, 9.9% (95% CI 9.4-10.4) reported frequent depression, 18.4% (95% CI 17.8-19.1) reported feeling anxious, and 34.3% (95% CI 33.5-35.1) reported that they frequently did not get enough rest. At the time of the survey 4.6% of the women were pregnant. Pregnant women were less likely than nonpregnant women to report frequent mental distress. Although there was attenuation of cigarette smoking and alcohol use during pregnancy, those with mental and physical distress were more likely to consume cigarettes and alcohol than were those without such experiences. CONCLUSION: High proportions of reproductive-age women report frequent mental and physical distress. Women experiencing mental and physical distress were more likely to report consuming cigarettes and alcohol than women without such experiences.  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