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   1603547篇
  免费   134067篇
  国内免费   2584篇
耳鼻咽喉   21702篇
儿科学   53147篇
妇产科学   46349篇
基础医学   228364篇
口腔科学   47295篇
临床医学   141511篇
内科学   315508篇
皮肤病学   34131篇
神经病学   130595篇
特种医学   64822篇
外国民族医学   474篇
外科学   244353篇
综合类   39831篇
现状与发展   3篇
一般理论   560篇
预防医学   123119篇
眼科学   36472篇
药学   121505篇
  2篇
中国医学   2974篇
肿瘤学   87481篇
  2018年   14845篇
  2016年   12961篇
  2015年   15116篇
  2014年   20744篇
  2013年   31519篇
  2012年   42784篇
  2011年   44965篇
  2010年   26476篇
  2009年   25431篇
  2008年   43200篇
  2007年   45439篇
  2006年   46261篇
  2005年   44897篇
  2004年   44275篇
  2003年   42378篇
  2002年   41436篇
  2001年   75804篇
  2000年   78468篇
  1999年   66522篇
  1998年   17815篇
  1997年   16397篇
  1996年   16360篇
  1995年   16070篇
  1994年   15115篇
  1993年   14260篇
  1992年   55533篇
  1991年   53877篇
  1990年   52671篇
  1989年   50948篇
  1988年   47328篇
  1987年   46675篇
  1986年   44388篇
  1985年   42925篇
  1984年   32118篇
  1983年   27630篇
  1982年   16188篇
  1981年   14483篇
  1980年   13613篇
  1979年   30530篇
  1978年   21121篇
  1977年   17810篇
  1976年   16728篇
  1975年   17623篇
  1974年   21536篇
  1973年   20724篇
  1972年   18895篇
  1971年   17808篇
  1970年   16319篇
  1969年   15298篇
  1968年   13970篇
排序方式: 共有10000条查询结果,搜索用时 343 毫秒
981.
This study reports the purification and characterization of a high molecular weight human breast cancer-associated antigen identified by a previously described (1,2) murine monoclonal antibody, BCD-B4. Immunohistochemical analysis indicated that BCD-B4 recognizes an antigen expressed in an altered form on the human breast carcinoma cell line, BT-20, compared to the non-malignant human mammary epithelial cell line, HBL-100. Chemical treatments and enzymatic digestions suggested that the recognized moiety was a protein. The antigenic determinant was resistant to neuraminidase and periodate treatments but was sensitive to trypsin and proteinase K. The antigen was purified by affinity chromatography and its molecular weight, determined by SDS-PAGE analysis under non-reducing conditions, was proven to be 250 Kd. Under reducing conditions, the molecule dissociated into two polypeptides of 125 and 45 Kd, respectively. Both subunits could be isolated from normal HBL-100 and neoplastic BT-20 cellular protein extracts by affinity chromatography. The higher molecular weight subunit showed; however, qualitative and quantitative differences between the two cell lines: it was expressed in greater quantity on BT-20 cells and its molecular weight was 15 Kd higher. Both subunits could also be identified by immunoblots of BT-20 cells.  相似文献   
982.
983.
984.
985.
986.
Cough and paradoxical vocal fold motion   总被引:8,自引:0,他引:8  
OBJECTIVES: The differential diagnosis and treatment of patients with chronic cough, paradoxical vocal fold motion, and disordered breathing can be a challenge to most practicing otolaryngologists. Tracheobronchial (ie, asthma, bronchitis, and tracheal stenosis), laryngeal (ie, vocal fold paralysis and neoplasms), and rhinologic (ie, allergies and rhinosinusitis) etiologies are commonly diagnosed and treated effectively. However, occasionally one is faced with patients who are refractory to medical treatment and have no obvious rhinologic, laryngeal or pulmonary cause. STUDY DESIGN AND SETTING: We conducted a review of the literature. METHODS: We present a thorough review of the current medical literature exploring the complex neurologic mechanisms involved in the production of cough and the relationship between gastroesophageal reflux disease, vagal neurapathy, and paradoxical vocal fold motion. RESULTS: The diagnosis and successful treatment of chronic cough can be complex. It requires a thorough understanding of the neurologic mechanisms behind cough excitation and suppression. Successful treatment strategies include aggressive management of the patient's reactive airway disease, gastroesophageal reflux disease, and, in select cases, paradoxical vocal fold motion. This may involve a well-coordinated effort among pulmonologists, otolaryngologists, gastroenterologists, and speech pathologists. CONCLUSION: Gastroesophageal reflux disease, vagal neuropathy, and paradoxical vocal fold motion are additional causes of chronic cough and disordered breathing that need to be considered, in the absence of obvious laryngotracheal and/or rhinologic pathology. A high index of suspicion is essential in making the diagnosis and formulating an effective multidisciplinary treatment plan for these patients.  相似文献   
987.
988.
989.
Tc-99m HMPAO was used to evaluate cerebral perfusion in a patient with tuberous sclerosis. The SPECT images demonstrated reduced HMPAO uptake in regions corresponding with MRI-confirmed locations of cortical tubers. These results indicate that the lesions are characterized by vascular perfusion deficits and support the hypothesis that cortical tubers result from developmental abnormalities of the embryonic central nervous system.  相似文献   
990.
Fifty to 100 children receive transplanted kidneys, hearts, livers, or bone marrow in Florida each year and many more bone allografts or other tissues (skin, cornea). Children are in the minority of the total solid organ transplantation but those with successful transplants are strong proponents of the procedure. Many (liver or heart failure) would have died without transplantation; others (kidney failure) would have lived but been tied to dialysis for life. The success rate varies with the organ or tissue transplanted. Some children return to a completely normal life without the need for immunosuppressive medications. Others require them continually. Cyclosporine, azathioprine and prednisone are the most frequently used. Rejection continues to be the leading cause of graft loss. Major impediments to solid organ transplantation are the paucity of acceptable organs and the high cost associated with maintenance of transplant patients.  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