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   2132027篇
  免费   165814篇
  国内免费   7340篇
耳鼻咽喉   28207篇
儿科学   63762篇
妇产科学   56636篇
基础医学   295762篇
口腔科学   61395篇
临床医学   191670篇
内科学   429216篇
皮肤病学   48259篇
神经病学   171718篇
特种医学   85943篇
外国民族医学   347篇
外科学   338630篇
综合类   46862篇
现状与发展   3篇
一般理论   654篇
预防医学   161010篇
眼科学   46355篇
药学   156457篇
  8篇
中国医学   4091篇
肿瘤学   118196篇
  2018年   21011篇
  2016年   19369篇
  2015年   21751篇
  2014年   30130篇
  2013年   44956篇
  2012年   57094篇
  2011年   60796篇
  2010年   37218篇
  2009年   36076篇
  2008年   57629篇
  2007年   61120篇
  2006年   62700篇
  2005年   60587篇
  2004年   58045篇
  2003年   56369篇
  2002年   54327篇
  2001年   109906篇
  2000年   113451篇
  1999年   94785篇
  1998年   26031篇
  1997年   22967篇
  1996年   23884篇
  1995年   23443篇
  1994年   21841篇
  1993年   20340篇
  1992年   76112篇
  1991年   73569篇
  1990年   71022篇
  1989年   68348篇
  1988年   63019篇
  1987年   61643篇
  1986年   57979篇
  1985年   55897篇
  1984年   41437篇
  1983年   35066篇
  1982年   20459篇
  1981年   18128篇
  1980年   17015篇
  1979年   37096篇
  1978年   26125篇
  1977年   22180篇
  1976年   19989篇
  1975年   21221篇
  1974年   25254篇
  1973年   24033篇
  1972年   22498篇
  1971年   20950篇
  1970年   19424篇
  1969年   18202篇
  1968年   16781篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Background: The aim of this study was to determine whether pre-existing diabetes mellitus increases the risk of rejection, infection and/or death in cystic fibrosis patients undergoing bilateral sequential single-lung transplantation.
Methods: A retrospective audit of 25 consecutive patients with cystic fibrosis who underwent bilateral sequential single-lung transplantation between 1 January 2003 and 31 December 2005 at a tertiary referral hospital was carried out.
Results: Although 32% patients had diabetes diagnosed before lung transplantation, 92% had random blood glucose levels ≥11.1 mmol/L requiring insulin during admission. Patients with pre-existing diabetes had increased infection-related (3.9 vs 1.2, P = 0.01) and putative rejection-related (1.4 vs 0.5, P = 0.04) hospital admissions post-transplantation compared with those without diabetes pre-transplant. During the period of observation, four of eight patients with a prior diagnosis of diabetes died compared with none of 17 patients without prior diabetes ( P = 0.0055).
Conclusion: Almost all cystic fibrosis patients develop hyperglycaemia after lung transplantation, but patients with prior diabetes have more complication-related admissions to hospital and a higher mortality rate.  相似文献   
992.
Aims: To explore the quality of life in patients treated medically during the acute phase of pancreatitis as well as at 2 and 12 months after discharge from the hospital. Patients: 40 patients were studied. The etiology of the pancreatitis was biliary causes in 31 patients and non-biliary causes in 9; mild disease was present in 29 patients and severe disease in 11. 30 patients completed the two surveys at 2 and 12 months after hospital discharge. Methods: The SF-12 and EORTC QLQ-C30 questionnaires were used for the purpose of the study. Results: The two physical and mental component summaries of SF-12, all the domains of EORTC QLQ-C30 (except for physical functioning and cognitive functioning) and some symptom scales of EORTC QLQ-C30 (fatigue, nausea/ vomiting, pain, and constipation) were significantly impaired during the acute phase of pancreatitis. There was a significant improvement in the SF-12 physical component summary, and global health, role functioning, social functioning, nausea/vomiting, pain, dyspnea, and financial difficulties (EORTC QLQ-C30) at 2 months after discharge as compared to the basal evaluation. Similar results were found after 12 months except for the mental component score at 12-month evaluation, which was significantly impaired in acute pancreatitis patients in comparison to the norms. The physical functioning of the EORTC QLQ-C30 at basal evaluation was significantly impaired in patients with severe pancreatitis in comparison to patients with mild pancreatitis. Conclusions: Two different patterns can be recognized in the quality of life of patients with acute pancreatitis: physical impairment is immediately present followed by mental impairment which appears progressively in the follow-up period.  相似文献   
993.
994.

Introduction  

Although ependymoma is the third most common pediatric brain tumor, we know little about the genetic/epigenetic basis of its initiation, maintenance, or progression. This is due in part to the heterogeneity of the disease, as well as the small sample size of the cohorts analyzed in most studies.  相似文献   
995.
996.
Designed to help persons with schizophrenia to persist and perform better at job placements, the Indianapolis Vocational Intervention Program (IVIP) is a program of cognitive-behavioral group and individual interventions. While its feasibility has been previously demonstrated, it is unknown whether IVIP assists persons to achieve greater levels of participation in vocational rehabilitation and higher levels of job performance. In this study, 100 participants with schizophrenia or schizoaffective disorder were offered a six month job placement and randomized to receive IVIP (n = 50) or support services (n = 50) matched for treatment intensity. Number of hours worked was recorded weekly and job performance was assessed biweekly using the Work Behavior Inventory with raters blind to condition. t-tests revealed that participants in the IVIP group worked a significantly greater number of weeks than those in the support condition. Also, repeated measures ANOVA revealed the IVIP group worked more hours across that 26 week period as well. And with regards to work performance, repeated measures of the 56 participants who worked for at least two-thirds of the intervention revealed that participants in the IVIP group had generally better work performance than those in the support condition. Results suggest a connection between cognitive-behavioral interventions and higher levels of work performance in people with schizophrenia.  相似文献   
997.
998.
999.
Identification of an individual plays a vital part of any medicolegal investigation. Fingerprint is considered to be the most accurate and reliable indicator in identification.The present study was conducted on 500 South Indian subjects to determine the individuality and the predominant fingerprint pattern among South Indian population. Two-hundred and fifty males and 250 females of South Indian origin were included for this study and rolled prints were taken from all the 10 digits and the same were stored on a proforma.The most frequent fingerprint pattern was ulnar loop in the total population, as well as in the sex wise distribution.  相似文献   
1000.
Background: In elderly patients, opioids may cause prominent postoperative sedation and respiratory depression. We evaluated the influence of age on the effects of opioids and plasma concentrations of fentanyl and oxycodone in cardiac surgery patients.
Methods: Thirty (≥75 years, gender M9/F21) and 20 (≤60 years, gender M20/F0) patients scheduled to undergo cardiac surgery. A standard anesthesia with fentanyl as an opioid was used. Fentanyl plasma concentrations were measured at the end of surgery and 2 h later. After tracheal extubation, when the pain intensity was at least moderate, blood samples for fentanyl and oxycodone plasma concentration measurements were taken. Thereafter, oxycodone hydrochloride 0.05 mg/kg i.v. was administered. After 15 and 45 min, pain intensity, sedation and oxycodone plasma concentration were determined. This test protocol was repeated twice.
Results: The elderly had a higher plasma concentration of fentanyl at the end of surgery than younger patients (5.7±2.2 vs. 3.8±1.2 ng/ml, P =0.001). The plasma concentrations of oxycodone were comparable between the groups. The interval between the second and the third oxycodone dose was longer in the elderly patients ( P =0.036). Pain intensity on the verbal rating scale was lower at the 45-min assessment point after all three oxycodone test doses ( P =0.008) and sedation scores were significantly higher after the third dose in the elderly patients ( P =0.035).
Conclusions: In elderly patients, the plasma concentration of fentanyl was higher but plasma levels of oxycodone were at a similar level compared with middle-aged patients. However, the elderly patients had less pain and were more sedated after doses of oxycodone.  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