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   5161篇
  免费   622篇
  国内免费   10篇
耳鼻咽喉   23篇
儿科学   371篇
妇产科学   151篇
基础医学   889篇
口腔科学   95篇
临床医学   499篇
内科学   1123篇
皮肤病学   58篇
神经病学   324篇
特种医学   218篇
外科学   517篇
综合类   189篇
一般理论   2篇
预防医学   549篇
眼科学   87篇
药学   413篇
中国医学   17篇
肿瘤学   268篇
  2021年   60篇
  2020年   51篇
  2019年   76篇
  2018年   107篇
  2017年   64篇
  2016年   52篇
  2015年   88篇
  2014年   106篇
  2013年   154篇
  2012年   245篇
  2011年   250篇
  2010年   127篇
  2009年   103篇
  2008年   218篇
  2007年   216篇
  2006年   212篇
  2005年   225篇
  2004年   232篇
  2003年   200篇
  2002年   195篇
  2001年   179篇
  2000年   169篇
  1999年   165篇
  1998年   106篇
  1997年   70篇
  1996年   88篇
  1995年   56篇
  1994年   68篇
  1993年   53篇
  1992年   139篇
  1991年   124篇
  1990年   117篇
  1989年   127篇
  1988年   130篇
  1987年   104篇
  1986年   103篇
  1985年   84篇
  1984年   60篇
  1983年   47篇
  1982年   40篇
  1980年   40篇
  1979年   52篇
  1978年   47篇
  1976年   40篇
  1974年   37篇
  1973年   41篇
  1972年   38篇
  1971年   46篇
  1969年   35篇
  1967年   40篇
排序方式: 共有5793条查询结果,搜索用时 31 毫秒
1.
2.
Summary Adrenaline, when administered in dental local anaesthetic solutions, significantly reduces the plasma potassium concentration in young healthy adults. This effect occurs within 10 min of extravascular injections into the maxillary buccal sulcus and may influence the choice of local anaesthetic solution for patients receiving kaliuretic diuretics.  相似文献   
3.
A lawsuit directed by parents at a day care program following an outbreak of infectious disease would most likely be based on the legal theory of negligence--the failure to exercise due care as required by circumstances. In the determination of liability for infectious diseases in child day care, the element of causation is most critical. Did the day care facility's actions or failure to act cause the harm? Another important question is whether an infectious disease can be occupational and under what circumstances. Although worker's compensation laws initially had no provisions for occupational disease, now all states recognize responsibility for them. Awareness of potential problems with legal liability and establishment of procedures to minimize risk are important for day care providers, public health officials, clinicians, and parents.  相似文献   
4.
In a study of rock music preferences, listening/watching behavior, and views on destructive rock lyrics, 894 adolescents in grades 9 through 12 in rural, urban, suburban public, and metropolitan parochial schools were administered a questionnaire. Demographic information on parents was also collected. It was found that 17.5% of the students were fans of rock music with lyrics that promote homicide, suicide, or satanic practices (HSSR). Loglinear and multiple regression analyses were used to analyze the data. Parents' marital status, student sex, race, and school environment (urban, rural, suburban, etc.) were found to be significant predictors of HSSR status. As compared with non-HSSR fans, the HSSR fans were more likely to have parents who were “Never married” or “Remarried” and less likely to have parents in the “married” category. The HSSR fans were more likely to be male, white, and enrolled in urban schools but not parochial schools than expected; HSSR status also significantly predicted other music-related attitudes and behaviors. The HSSR fans reported liking both the sound and the lyrics of rock music more often than did non-HSSR fans, as did females and urban students. The HSSR fans more often felt that children under 10 years of age should be allowed to listen to HSSR lyrics, and they more frequently expressed the conviction that HSSR music does not affect adolescents' homicidal or self-destructive behavior. The HSSR fans and females reported more nearly complete knowledge of lyrics than did non-HSSR fans and males. The HSSR fans reported that they watch more MTV than did any other group except rural students.  相似文献   
5.
6.
7.
With their unique perspectives in the identification, design, promotion, and evaluation of cancer patient education programs and services, the National Cancer Institute and the American Cancer Society have the abilities to meet a wide variety of cancer patient education needs. With federal support and connections to national organizations and the comprehensive and clinical cancer center networks, the National Cancer Institute has access to nationwide experts in medical care and the resources to develop, design, and promote quality, state-of-the-art education programs. The American Cancer Society, with its strong volunteer community base, can pull together local expertise and collaborate with local organizations to meet the special needs of local population groups. In addition, the American Cancer Society volunteer committees have the flexibility to individualize programming and resources to answer specific patient/family education problems. As the number of people affected by cancer continues to raise, and as organizations realize the need to maximize their resources with collaborative efforts, the National Cancer Institute and the American Cancer Society are challenged to focus their energies on the patient education initiatives that build upon and combine their unique strengths.  相似文献   
8.
This study was undertaken to determine whether the dose-dependent effect of glucagon on gluconeogenesis parallels its effect on hepatic glycogenolysis in conscious overnight-fasted dogs. Endogenous insulin and glucagon secretion were inhibited by somatostatin (0.8 micrograms X kg-1 X min-1), and intraportal replacement infusions of insulin (213 +/- 28 microU X kg-1 X min-1) and glucagon (0.65 ng X kg-1 X min-1) were given to maintain basal hormone concentrations for 2 h (12 +/- 2 microU/ml and 108 +/- 23 pg/ml, respectively). The glucagon infusion was then increased 2-, 4-, 8-, or 12-fold for 3 h, whereas the rate of insulin infusion was left unchanged. Glucose production (GP) was determined with 3-[3H]glucose, and gluconeogenesis (GNG) was assessed with tracer (U-[14C]alanine conversion to [14C]glucose) and arteriovenous difference (hepatic fractional extraction of alanine, FEA) techniques. Increases in plasma glucagon of 53 +/- 8, 199 +/- 48, 402 +/- 28, and 697 +/- 149 pg/ml resulted in initial (15-30 min) increases in GP of 1.1 +/- 0.4 (N = 4), 4.9 +/- 0.5 (N = 4), 6.5 +/- 0.6 (N = 6), and 7.7 +/- 1.4 (N = 4) mg X kg-1 X min-1, respectively; increases in GNG (approximately 3 h) of 48 +/- 19, 151 +/- 50, 161 +/- 25, and 157 +/- 7%, respectively; and increases in FEA (3 h) of 0.14 +/- 0.07, 0.37 +/- 0.05, 0.42 +/- 0.04, and 0.40 +/- 0.17, respectively. In conclusion, GNG and glycogenolysis were similarly sensitive to stimulation by glucagon in vivo, and the dose-response curves were markedly parallel.  相似文献   
9.
10.
Mean pulmonary excretion rate of carbon monoxide in 13 premature babies on ventilators was significantly higher (p less than 0.001) than that of 19 healthy infants born at full term. This correlated with carboxyhaemoglobin concentrations in blood, indicating that the premature infants on ventilators produced abnormally large amounts of bilirubin.  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