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   3025篇
  免费   373篇
  国内免费   24篇
耳鼻咽喉   30篇
儿科学   110篇
妇产科学   41篇
基础医学   275篇
口腔科学   144篇
临床医学   403篇
内科学   627篇
皮肤病学   47篇
神经病学   205篇
特种医学   373篇
外科学   245篇
综合类   47篇
一般理论   1篇
预防医学   509篇
眼科学   17篇
药学   161篇
肿瘤学   187篇
  2023年   49篇
  2022年   18篇
  2021年   26篇
  2020年   49篇
  2019年   33篇
  2018年   64篇
  2017年   50篇
  2016年   61篇
  2015年   70篇
  2014年   121篇
  2013年   163篇
  2012年   122篇
  2011年   148篇
  2010年   113篇
  2009年   109篇
  2008年   106篇
  2007年   119篇
  2006年   112篇
  2005年   85篇
  2004年   94篇
  2003年   58篇
  2002年   48篇
  2001年   79篇
  2000年   66篇
  1999年   69篇
  1998年   78篇
  1997年   104篇
  1996年   92篇
  1995年   69篇
  1994年   74篇
  1993年   63篇
  1992年   62篇
  1991年   48篇
  1990年   66篇
  1989年   77篇
  1988年   73篇
  1987年   66篇
  1986年   66篇
  1985年   70篇
  1984年   34篇
  1983年   31篇
  1982年   34篇
  1981年   46篇
  1980年   26篇
  1979年   28篇
  1977年   22篇
  1976年   28篇
  1975年   18篇
  1974年   18篇
  1972年   15篇
排序方式: 共有3422条查询结果,搜索用时 15 毫秒
11.
12.
13.
The purpose of this study was to determine whether disruption of early social attachment alters the activity of brain biogenic amine systems in rhesus monkeys (Macaca mulatta). Male rhesus monkey infants were deprived of maternal interaction, peer interaction, or both, during the first 22 months of life. Cerebrospinal fluid (CSF) was collected under rigorously controlled conditions approximately every month and assayed for levels of norepinephrine (NE), its major metabolite, and the metabolites of dopamine and serotonin. Mother-Deprived infants had lower levels of CSF NE than Mother-Reared infants. Mother-Deprived infants also failed to develop the same pattern of intercorrelations between compounds and month-to-month stability in levels of neurotransmitter and metabolites in CSF as the Mother-Reared infants. Finally, there were changes in CSF NE levels associated with social separation and social group formation. The brain NE system appears to be sensitive to changes in the social environment. Its level of activity, as reflected in levels of NE in CSF, appears to depend on both the prevailing social environment and the prior rearing environment.  相似文献   
14.
There is little information describing the effects of activated charcoal preadministration on drug absorption. This study was undertaken to determine the effect of activated charcoal preadministration at two different times on aspirin absorption. Fifteen volunteer subjects completed three study phases: 1) 975 mg aspirin alone, 2) 975 mg aspirin 30 min after 10 g activated charcoal, and 3) 975 mg aspirin 60 min after 10 g activated charcoal. Urine was collected for 48 h after the initiation of each study phase, and total aspirin recovery determined by HPLC. The aspirin recovery was 88.8% +/- 4.5% for the control phase, and 84.8% +/- 9.4% (Phase 1) and 85.8% +/- 12.6% (Phase 2) for the activated charcoal treatments (p > 0.05). These results suggest that activated charcoal administered 30 and 60 min prior to drug ingestion has little effect on drug absorption. Further studies of the effect of charcoal preadministration on the absorption of other drugs may provide useful information regarding factors important in determining activated charcoal efficacy.  相似文献   
15.
16.
Confidentiality is a promise rooted in tradition, law andmedical ethics. Emergency physicians treat a variety of patients to whom confidentiality is of vital importance: employees, celebrities, victims of violence or disaster, minors, students, criminals, drug abusers, and patients with STDs. EDs should develop methods of ensuring confidentiality for all patients.34Although confidentiality is an important principle thatshould be respected and guarded, it is not absolute. Various laws mandate disclosure of certain patient information; in addition, an overriding moral duty may occasionally require, a breach of confidentiality. As Beauchamp and Childress noted, “the therapeutic role may sometimes have to yield to ones role as citizen and as protector of the interests of others”.19 In general, however, circumstances requiring a breach of confidentiality are rare.  相似文献   
17.
18.
C K Ohrt  W P McKinney 《JAMA》1992,267(10):1377-1380
OBJECTIVE--To determine the optimal method to increase influenza immunization rates of medical house staff and students. DESIGN--Prospective randomized trial and cross-sectional survey. STUDY GROUP--Four hundred forty-two internal medicine, obstetrics-gynecology, and general surgery residents and junior medical students. MEASUREMENTS--The four interventions employed were (1) an educational memorandum outlining vaccine indications sent to all study group members, (2) a personal letter mailed to a random sample of half of the remaining unimmunized persons, (3) a telephone call to half of the unimmunized letter recipients, and (4) vaccine offered directly to the remaining unimmunized persons in clinics and conferences. In addition, a questionnaire was administered to all persons requesting or offered vaccine. MAIN RESULTS--During the 3 weeks after the memorandum, 87 (20%) of 442 persons were immunized. Five weeks after the letter, 61 (34%) of persons receiving a letter and 30 (17%) of the no-letter controls (P = .0005) had been immunized. After the telephone call, there was a statistically insignificant trend toward increased compliance. In clinics and conferences, 90% of persons reached were immunized and 10% refused, largely extinguishing the effect of prior interventions. At completion of the study, 275 (62%) of 442 participants were immunized, 29 (7%) refused, and 138 (31%) were not reached. Questionnaire results revealed that only 32% had ever been previously immunized against influenza, yet 70% stated that they had worked despite having influenzalike symptoms. CONCLUSION--A high rate of immunization of house staff and medical students can be achieved most effectively by offering vaccine in clinics and conferences. Continued education about influenza immunization is necessary for physicians and medical students.  相似文献   
19.
20.
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