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   46085篇
  免费   3745篇
  国内免费   144篇
耳鼻咽喉   500篇
儿科学   1730篇
妇产科学   1275篇
基础医学   6516篇
口腔科学   625篇
临床医学   5984篇
内科学   9082篇
皮肤病学   796篇
神经病学   4358篇
特种医学   1138篇
外科学   4871篇
综合类   637篇
一般理论   42篇
预防医学   5349篇
眼科学   715篇
药学   2986篇
中国医学   60篇
肿瘤学   3310篇
  2023年   303篇
  2022年   561篇
  2021年   1106篇
  2020年   696篇
  2019年   1143篇
  2018年   1245篇
  2017年   906篇
  2016年   1008篇
  2015年   1068篇
  2014年   1492篇
  2013年   2216篇
  2012年   3270篇
  2011年   3344篇
  2010年   1819篇
  2009年   1535篇
  2008年   2694篇
  2007年   2970篇
  2006年   2834篇
  2005年   2725篇
  2004年   2474篇
  2003年   2342篇
  2002年   2205篇
  2001年   695篇
  2000年   691篇
  1999年   666篇
  1998年   491篇
  1997年   451篇
  1996年   358篇
  1995年   338篇
  1994年   287篇
  1993年   305篇
  1992年   461篇
  1991年   426篇
  1990年   396篇
  1989年   392篇
  1988年   352篇
  1987年   315篇
  1986年   297篇
  1985年   300篇
  1984年   228篇
  1983年   202篇
  1982年   174篇
  1981年   141篇
  1980年   148篇
  1979年   238篇
  1978年   172篇
  1977年   128篇
  1976年   117篇
  1974年   126篇
  1973年   117篇
排序方式: 共有10000条查询结果,搜索用时 7 毫秒
21.
BACKGROUND: There are limited studies of large cohorts of patients with specific polysaccharide antibody deficiency (SPAD) syndrome. OBJECTIVE: To study the clinical and laboratory characteristics of patients with specific polysaccharide antibody deficiency syndrome. METHODS: We retrospectively studied 75 patients with total IgG levels of at least 500 mg/dL and fewer than 9 of 12 responses to vaccination with pneumococcal vaccine polyvalent. Exclusion criteria included an IgG level less than 500 mg/dL, established immunodeficiency syndrome, and secondary immunodeficiency. RESULTS: The most common clinical presentation was frequent infections (n = 69; 92%), including sinusitis (n = 53; 77%), pneumonia (n = 29; 42%), ear infections (n = 18; 26%), and bronchitis (n = 19; 28%). Other presentations were systemic infections (n = 5; 7%), autoimmune or rheumatic diseases (n = 6; 8%), and chronic diarrhea (n = 4; 5%). The median IgG2 level of patients with no response to pneumococcal vaccine polyvalent tended to be lower than that of patients with at least 1 response (150 vs 193 mg/dL, respectively; P = .06). There was no association between total IgG level (categorized as 500-600 or > or = 600 mg/dL) and frequency of infection (P = .43). Patients with fewer responses to pneumococcal vaccine polyvalent and a higher frequency of infections were more likely to receive intravenous immunoglobulin (IVIG) therapy (P = .01 and .003, respectively). Treatment with IVIG significantly reduced the number of infections (P < .001). CONCLUSION: Patients with no response to pneumococcal vaccine polyvalent tended to have lower IgG2 levels; those with fewer responses were more likely to receive IVIG therapy.  相似文献   
22.
23.
There is limited information on the relationship between parental practices that specifically discourage current cigarette smoking and adolescent cessation, and how this relationship varies by age. Among 1629 adolescent smokers, self-reported receipt of parental communication not to smoke was significantly and positively associated with readiness to quit. The strength and significance of this association decreased from early to middle adolescence and was not significant in late adolescence.  相似文献   
24.
25.
26.
27.
Background. Facial acne scarring has been treated with multiple methods with varying degrees of improvement. Although the 1,320 nm neodymium:yttrium-aluminum-garnet (Nd:YAG) laser has been widely used to improve photoaging, studies analyzing its effects on atrophic acne scarring are limited.
Objective. To evaluate the efficacy of a dynamic cryogen-cooled 1,320 nm Nd:YAG laser for the treatment of atrophic facial acne scars in a larger cohort of patients with long-term follow-up.
Methods. Twenty-nine patients (skin phototypes I–IV) with facial acne scarring received a mean of 5.5 (range 2–17) treatments with a 1,320 nm Nd:YAG laser. Objective physician assessment scores of improvement were determined by side-by-side comparison of preoperative and postoperative photographs at a range of 1 to 27 months (mean 10.4 months) postoperatively. Subjective patient self-assessment scores of improvement were also obtained.
Results. Acne scarring was significantly improved by both physician and patient assessment scores. Mean improvement was 2.8 (  p < .05  ) on a 0- to 4-point scale by physician assessment and 5.4 (  p < .05  ) on a 0- to 10-point scale by patient assessment. No significant complications were observed.
Conclusions. Nonablative laser skin resurfacing with a 1,320 nm Nd:YAG laser can effectively improve the appearance of facial acne scars with minimal adverse sequelae.  相似文献   
28.
29.
30.
Results of a study observing autistic children's interactions with nonhandicapped and autistic peers are reported. Six 8- to 12-year-old autistic children played in dyads with younger, normally developing kindergarten children and with nonhandicapped peers matched on chronological age for 10 15-minute sessions spaced over 3 weeks and then with a playmate of the alternate age for another 10 sessions. After intervention, all subjects showed gains in proximity, orientation, and responsiveness when playing with nonhandicapped peers and with autistic classmates. Same-age nonhandicapped playmates initiated more frequently than did younger nonhandicapped playmates and were better able to modify their initiations in ways that increased the likelihood of response from the autistic children.  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