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   1842880篇
  免费   126135篇
  国内免费   3708篇
耳鼻咽喉   26716篇
儿科学   54861篇
妇产科学   49899篇
基础医学   261547篇
口腔科学   53688篇
临床医学   155712篇
内科学   363332篇
皮肤病学   39618篇
神经病学   146615篇
特种医学   74966篇
外国民族医学   432篇
外科学   295405篇
综合类   35622篇
现状与发展   1篇
一般理论   503篇
预防医学   125574篇
眼科学   43037篇
药学   136920篇
  3篇
中国医学   3976篇
肿瘤学   104296篇
  2018年   18911篇
  2017年   14941篇
  2016年   16798篇
  2015年   19112篇
  2014年   25653篇
  2013年   38496篇
  2012年   52809篇
  2011年   54983篇
  2010年   32932篇
  2009年   31009篇
  2008年   53542篇
  2007年   56645篇
  2006年   57518篇
  2005年   56555篇
  2004年   54296篇
  2003年   52655篇
  2002年   51727篇
  2001年   92051篇
  2000年   95068篇
  1999年   80220篇
  1998年   20520篇
  1997年   18390篇
  1996年   18087篇
  1995年   16788篇
  1994年   15846篇
  1993年   14722篇
  1992年   60736篇
  1991年   58235篇
  1990年   56640篇
  1989年   54890篇
  1988年   50296篇
  1987年   49425篇
  1986年   46560篇
  1985年   44485篇
  1984年   32439篇
  1983年   27536篇
  1982年   15484篇
  1979年   29690篇
  1978年   20418篇
  1977年   17403篇
  1976年   15705篇
  1975年   17536篇
  1974年   21000篇
  1973年   19855篇
  1972年   18958篇
  1971年   17719篇
  1970年   17009篇
  1969年   15921篇
  1968年   14823篇
  1967年   13621篇
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
991.
992.
Although general suggestions have been made regarding a radiology residency curriculum, no specific list of entities has been offered. Over the past ten years, we have developed a resident-run morning conference in musculoskeletal radiology that is supervised by faculty and covers a specific curriculum. We offer our curriculum as an example that may assist other departments in developing their own curricula.  相似文献   
993.
The relationship between cystic fibrosis, nasal polyposis and chronic sinusitis is clearly defined. Mucoceles of the paranasal sinuses, however, are a well-described complication of chronic sinusitis in adults; but they rarely occur in the pediatric age group. We report a three-year-old who presented with epiphora and fullness at the right medial canthus. Computed tomography confirmed a right ethmoid mucocele which was surgically drained, with resolution of symptoms. Approximately 12 other cases of mucoceles have been reported in the pediatric age group. Although many of these patients had recognized cystic fibrosis, some were previously undiagnosed. Only after presentation with a mucocele, did sweat testing reveal their underlying pathology. No pediatric patients in the literature were found with mucoceles and normal sweat tests. Paranasal sinus mucoceles may be diagnostic of cystic fibrosis and may be the presenting sign in some patients.  相似文献   
994.
995.
This report examines long-term and short-term benefits of achieving abstinence from opioids in a sample of opioid addicts who were reevaluated 2.5 years following seeking treatment. Extensive assessment of drug use history and drug-associated problems had been obtained when the subjects applied for treatment. At follow-up evaluations, detailed information was obtained on intervening course of drug use, treatment, legal problems, psychological problems, social functioning, occupational functioning, and medical status. The results were as follows: (1) Achieving abstinence from illicit opioids was associated with concurrent improvement in other aspects of functioning including reduction of criminal activity, improved medical status, improved social functioning, and reduced abuse of other psychoactive substances. However, many of these improvements were reversed immediately if relapse to opioid use occurred. (2) Achieving abstinence was associated with being in drug treatment, especially treatment in a methadone maintenance program. (3) Achievement of abstinence was not successfully predicted by client characteristics measured at entrance into treatment. (4) Long-range benefits of abstinence were detectable in social functioning even for those who had relapsed at the time of follow-up reevaluation.  相似文献   
996.
997.
We sought to determine if chronic endurance training would increase mitochondrial respiration or protein content in rat diaphragm muscle. To this end, 20 male Wistar rats were randomly assigned to control (C) or an 8-week endurance training (T) group, n = 10 per group. At the end of T, VO2 max was 13% greater in T (83.3 vs 73.8 ml X kg-1 X min-1) and peak max power output was 32% greater (2.63 vs 1.98 kg X m X min-1). Mitochondrial specific activities of pyruvate-malate and cytochrome oxidase (expressed per mg mitochondrial protein) in both plantaris and diaphragm were similar in C and T rats, as were ADP/O and respiratory control ratios. When expressed per gram wet weight, whole muscle homogenate oxygen uptake (pyruvate + malate) and cytochrome oxidase activity increased 36 and 23%, respectively (P less than 0.05) in plantaris from T rats but did not change in diaphragm. Control oxidative capacity and mitochondrial protein content in the diaphragm were ca. 2-fold those in control plantaris. Plantaris mitochondrial protein content increased ca. 50% with T while the diaphragm was unaffected. We conclude that: plantaris muscle oxidative capacity adapts to training by increasing mitochondrial protein content, since there was no evidence for functional improvement of existing mitochondria, and in the face of a substantial training effect in whole animal and plantaris, the T stimulus was not sufficient to induce mitochondrial protein changes in the diaphragm. This finding is the result of either a 'pre-adaptation' secondary to the diaphragm's high chronic activity, or a sub-threshold increase in diaphragm recruitment during the exercise conditions studied.  相似文献   
998.
A rare case of craniopharyngioma extending to the cranial base and nasopharynx is reported and eight other cases in the literature are reviewed. The embryology and the clinical features of these tumors are discussed. Tomograms of the skull and computed tomography are the most useful radiological tools of investigation. A nasoseptal or transpalatal approach to surgery, which has been performed in reported cases of cystic nasopharyngeal craniopharyngiomas, was not performed on our patient because of the hard consistency and the diffusely infiltrating aspect of the tumor.  相似文献   
999.
1000.
We carried out a nonrandomized, unblinded study to compare the efficacy of rifampin alone with that of rifampin in combination with trimethoprim in the eradication of the Haemophilus influenzae type b (HIB) carrier state among contacts of patients with invasive HIB infection. The study population comprised 17 index patients admitted to hospital with severe HIB infections and 233 contacts, 43 of whom had nasopharyngeal colonization with HIB of the same biotype as that of the index patient. Rifampin in a daily dose of 20 mg/kg (maximum 600 mg) for 4 days eradicated the carrier state in 86% of cases, as did the combination of rifampin at the same dosage and trimethoprim in a daily dose of 5 mg/kg (maximum 160 mg) for 4 days.  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