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   3450827篇
  免费   277022篇
  国内免费   6099篇
耳鼻咽喉   50018篇
儿科学   110689篇
妇产科学   95250篇
基础医学   487418篇
口腔科学   102366篇
临床医学   313872篇
内科学   666819篇
皮肤病学   72873篇
神经病学   289030篇
特种医学   137672篇
外国民族医学   1247篇
外科学   519123篇
综合类   83321篇
现状与发展   4篇
一般理论   1459篇
预防医学   276967篇
眼科学   81796篇
药学   258223篇
  6篇
中国医学   6379篇
肿瘤学   179416篇
  2018年   35540篇
  2016年   30989篇
  2015年   34804篇
  2014年   48742篇
  2013年   75327篇
  2012年   100931篇
  2011年   107084篇
  2010年   63044篇
  2009年   59365篇
  2008年   102151篇
  2007年   108151篇
  2006年   109161篇
  2005年   106235篇
  2004年   102932篇
  2003年   99255篇
  2002年   97897篇
  2001年   155871篇
  2000年   162014篇
  1999年   136690篇
  1998年   39905篇
  1997年   36083篇
  1996年   35471篇
  1995年   34373篇
  1994年   32350篇
  1993年   30250篇
  1992年   110080篇
  1991年   106400篇
  1990年   103266篇
  1989年   99793篇
  1988年   92733篇
  1987年   91541篇
  1986年   86887篇
  1985年   83469篇
  1984年   63422篇
  1983年   54397篇
  1982年   33028篇
  1981年   29502篇
  1980年   27837篇
  1979年   60147篇
  1978年   42374篇
  1977年   35822篇
  1976年   33556篇
  1975年   35532篇
  1974年   43748篇
  1973年   41741篇
  1972年   38867篇
  1971年   36203篇
  1970年   33806篇
  1969年   31577篇
  1968年   28813篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
941.
Abstract Chorea is a rare complication of polycythaemia vera. Polycythaemic chorea occurs predominantly in females and usually in generalised form. We present a 66-year-old woman with acute onset hemichorea-ballism with no vascular pathology in the basal ganglia region. A clear relationship was observed between the onset of chorea and worsening of haematological parameters in the patient. After repeated phlebotomies the patient's clinical status was improved. Polycythaemic chorea must be considered, especially in the elderly, as early diagnosis leads to effective treatment and prevention of complications.  相似文献   
942.
943.
OBJECTIVE: There are only a few studies correlating diverse radiological and EEG features of subacute sclerosing panencephalitis (SSPE). The objective of the study was to (a) describe EEG profile and (b) correlate it with the clinical and imaging data of patients with confirmed SSPE. METHODS: This study was conducted at a University teaching hospital in south India and involved 58 patients (M:F=37:21, age: 12.3, SD 4.8 years) of SSPE. Diagnosis of SSPE was based on the characteristic clinical manifestations, and raised IgG (1:625) anti-measles antibody in cerebrospinal fluid (CSF) by ELISA in all the patients. Scalp EEGs were recorded on 16 channel machines using standard parameters and procedures. The EEG, clinical and imaging data were reviewed. RESULTS: EEGs were frequently abnormal: typical (37) and atypical (21). Diffuse slowing of background activity (BGA) was noted in 46 records being asymmetrical in six. Periodic complexes were periodic (32), quasi-periodic (21) or a-periodic (4). Periodic complexes (PC) (amplitude: 370.7, SD 171.2 microV; duration - 1.7, SD 2.0 s; inter-complex interval: 8.4, SD 9.2s) were symmetrical in 39 and asymmetrical in 19. CT (32) and MRI (23) scans were normal in 16 patients while others had white matter (15), cerebral edema (8), cerebral atrophy (8), basal ganglia (2), and thalamic (2) changes. There was an independent association of frontally dominant slowing of BGA (p=0.04) and typical PCs (p=0.03) with the diffuse cerebral edema on imaging. White matter changes correlated with slowing of BGA (p=0.04), but not with typical PC (p=0.16). CONCLUSIONS: This study provides valuable insight into the structural and clinical correlates of EEG changes in SSPE. SIGNIFICANCE: Irrespective of the incidence of occurrence of SSPE in a community, a clinician should be aware of the wide spectra of EEG findings. This study also discusses the possible underlying structural and clinical correlates.  相似文献   
944.
SETTING: Tuberculosis (TB) cases reported from nine districts of Madrid, where the percentage of immigrant population varied from 1.9% in 1996 to 12.2% in 2003. OBJECTIVE: To describe the trends in TB incidence from 1994 to 2003. DESIGN: Observational study. RESULTS: Between 1994-1995 and 2002-2003, the TB rate decreased from 48.5 (95% CI 45.8-51.1) to 23.3 per 100000 population (95% CI 21.5-25.1) (P < 0.001). The percentage of TB cases co-infected with HIV decreased from 55.9% in 1994 to 14.3% in 2003 (P < 0.001), whereas TB cases in foreigners increased from 2.6% in 1994 to 33.7% in 2003 (P < 0.001). CONCLUSION: Although the TB rates showed a marked decrease in the study period, the increasing impact of immigration contributed to slowing down the trend.  相似文献   
945.
946.
A 72-year-old man presented with a short duration of symptoms relating to a right fronto-parietal glioblastoma and a family history of children with brain tumours. Analysis of the patient's family tree revealed that out of seven children, he had a living son with anaplastic astrocytoma, a daughter who had died with a glioblastoma, and a son who had died with a histologically undiagnosed intrinsic brain tumour. One niece was also thought to have died from a brain tumour. All of the other affected family members had onset in their third or fourth decades. Tissue was only available from two of the affected individuals, precluding familial genetic analysis at this stage. There is no clinical evidence to support a diagnosis of a multiple cancer or neurocutaneous syndrome in this family. In view of what is known about the genetics of familial glioma, it is interesting to note the clinical evidence of both 'primary' glioblastoma and anaplastic astrocytoma in the same kindred.  相似文献   
947.
948.
Larson  A.  M.  Poison  J.  Fontana  R.  J.  宋平 《世界核心医学期刊文摘》2006,2(8):43-44
严重的对乙酰氨基酚肝毒性常常会引起急性肝衰竭(ALF),作者在美国的22所三级护理中心调查了由对乙酰氨基酚引起的肝衰竭的发生率、危险因素和预后,用超过6年的时间收集到662例完全符合ALF(包括肝源性凝血症和肝性脑病)标准的患者资料,详细分析后发现:其中有275例(45%)是由对乙酰氨基酚引起的。调查发现,对乙酰氨基酚相关性ALF的年度百分比由1998年的28%上升至2003年的51%。对乙酰氨基酚的中位摄入量为24g(相当于48个高含量的片剂)。在上述275例中,误服过量者有131例(48%),有意服用者(即有自杀倾向者)有122例(44%),还有22例(8%)为不明意图。在误服组中38%同时服用了两种或多种对乙酰氨基酚制剂,63%患者服用了含有镇静剂的复合制剂。据报道,81%患者因为急性或慢性疼痛误服了对乙酰氨基酚和(或)其他镇痛剂。总体上,有178例研究对象(65%)存活,74例(27%)未经肝移植而死亡,23例(8%)进行了肝移植,其中71%的患者仅存活了3周。未接受移植的存活率和肝移植存活率在误服组和有意服用组差别不明显。  相似文献   
949.
OBJECTIVE: Video-assisted thoracic surgery (VATS) is usually performed with general anesthesia and double-lumen endotracheal intubation, but minor procedures have been carried out with patients spontaneously breathing and with epidural or regional analgesia. We have broadened our indications for VATS utilizing purely local anesthesia and sedation. METHODS: The medical records of all patients undergoing VATS under local anesthesia and sedation at Geisinger Wyoming Valley Medical Center between 7/1/02 and 6/1/06 were reviewed. All procedures were performed in the operating room with patients in full lateral position; no patient had endotracheal intubation or epidural or nerve block analgesia. RESULTS: One hundred and fifteen patients, ranging in age from 21 to 88 years and in size from 40 to 172 kg, underwent 126 video-assisted thoracic operations: pleural biopsy/effusion drainage with or without talc 81, drainage of empyema 21, lung biopsy 18, evacuate hemothorax 3, pericardial window 2, biopsy chest wall mass 1. No patient required intubation or conversion to thoracotomy. Three patients who underwent lung biopsy died of their underlying disease (cytomegalovirus and pneumocystis, primary amyloidosis, metastatic cancer to contra-lateral lung) on postoperative days 18, 14, and 4, respectively. One patient developed transient renal insufficiency attributed to ketorolac. CONCLUSION: VATS utilizing local anesthesia and sedation is well tolerated, safe, and valuable for an increasing number of indications.  相似文献   
950.
Systems of care (SOCs) have been developed throughout the country to meet the needs of children with severe emotional disturbances (SED) and their families. In these SOCs, multiple agencies and disciplines are expected to work together with informal community supports to address families' needs (Stroul & Friedman, 1986a). A review of the literature on the impact of SOCs suggests: (a) communities' service delivery systems change; and (b) children experience modest improvements in symptomatology and functioning. At the same time, little is known about (a) which components of the SOC approach, at what levels, are necessary to impact child and family outcomes; (b) the degree to which SOCs affect other family members, beyond the target child; and (c) the impact of community contexts and supports in SOCs. Future research should improve measurement of key SOC constructs, examine the relation between specific levels of implementation and outcomes for the entire family, and investigate the impact of broader community systems and supports on families within SOCs. © 2004 Wiley Periodicals, Inc. J Comm Psychol 32: 655–674, 2004.  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