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   19867篇
  免费   1455篇
  国内免费   86篇
耳鼻咽喉   231篇
儿科学   561篇
妇产科学   319篇
基础医学   2429篇
口腔科学   470篇
临床医学   2313篇
内科学   4333篇
皮肤病学   315篇
神经病学   1605篇
特种医学   865篇
外科学   3020篇
综合类   297篇
一般理论   5篇
预防医学   1371篇
眼科学   426篇
药学   1321篇
中国医学   31篇
肿瘤学   1496篇
  2023年   112篇
  2022年   104篇
  2021年   506篇
  2020年   281篇
  2019年   441篇
  2018年   541篇
  2017年   349篇
  2016年   447篇
  2015年   525篇
  2014年   669篇
  2013年   878篇
  2012年   1415篇
  2011年   1384篇
  2010年   812篇
  2009年   668篇
  2008年   1218篇
  2007年   1256篇
  2006年   1194篇
  2005年   1095篇
  2004年   926篇
  2003年   903篇
  2002年   761篇
  2001年   445篇
  2000年   398篇
  1999年   389篇
  1998年   193篇
  1997年   171篇
  1996年   145篇
  1995年   123篇
  1994年   112篇
  1993年   93篇
  1992年   219篇
  1991年   191篇
  1990年   200篇
  1989年   198篇
  1988年   175篇
  1987年   163篇
  1986年   143篇
  1985年   161篇
  1984年   129篇
  1983年   103篇
  1982年   84篇
  1981年   73篇
  1980年   79篇
  1979年   112篇
  1978年   80篇
  1977年   56篇
  1975年   60篇
  1974年   65篇
  1971年   57篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
22.
BACKGROUND: The impact of infection with Burkholderia gladioli in cystic fibrosis, other chronic airway diseases and immunosuppressed patients is unknown. METHODS: A six-year retrospective review of all patients with B. gladioli infection was performed in a tertiary referral center with cystic fibrosis and lung transplantation programs. In addition, a targeted survey of all 251 lung transplant recipients was performed. Available B. gladioli isolates were analyzed via pulsed field gel electrophoresis. RESULTS: Thirty-five patients were culture positive for B. gladioli, including 33 CF patients. No bacteremia was identified. Isolates were available in 18 patients and all were genetically distinct. Two-thirds of these isolates were susceptible to usual anti-pseudomonal antibiotics. After acquisition, only 40% of CF patients were chronically infected (> or =2 positive cultures separated by at least 6 months). Chronic infection was associated with resistance to > or =2 antibiotic groups on initial culture and failure of eradication after antibiotic therapy. The impact of acquisition of B. gladioli infection in chronic infection was variable. Three CF patients with chronic infection underwent lung transplantation. One post-transplant patient developed a B. gladioli mediastinal abscess, which was treated successfully. CONCLUSIONS: The majority of patients' culture positive for B. gladioli at our center have CF. B. gladioli infection is often transient and is compatible with satisfactory post-lung transplantation outcomes.  相似文献   
23.
Transabdominal sacrocolpopexy has been shown, in multiple long-term studies of its success and durability, to be the definitive treatment option for post-hysterectomy vaginal vault prolapse. It is, however, associated with greater morbidity than vaginal repair. We describe a minimally invasive technique for vaginal vault prolapse repair and present our experience with a minimum of one-year follow-up. The surgical technique involves five laparoscopic ports—three for the da Vinci robot and two for the assistant. After appropriate dissection a polypropylene mesh is attached to the sacral promontory and to the vaginal apex by use of Gore-Tex sutures. The mesh material is then covered by the peritoneum. Patient analysis focused on complications, urinary continence, patient satisfaction, and morbidity, with a minimum of 12 months follow-up. Forty-two patients with post-hysterectomy vaginal vault prolapse underwent robot-assisted laparoscopic sacrocolpopexy at our institute and 35 have a minimum of 12 months follow-up, with a mean follow-up of 36 months (range 12–48) in the group. Mean age was 67 (47–83) years and mean operating time was 3.1 (2.15–4.75) h for the entire cohort. All but one patient were discharged home on postoperative day one; one patient left on postoperative day two. One developed recurrent grade three rectocele, one had recurrent vault prolapse, and two suffered from vaginal extrusion of mesh. All patients were satisfied with their outcome. The robot-assisted laparoscopic sacrocolpopexy is a minimally invasive technique for vaginal vault prolapse repair, combining the advantages of open sacrocolpopexy with the reduced morbidity of laparoscopy. We observed reduced hospital stay, low occurrence of complications, and high patient satisfaction, with a minimum of 1-year follow-up. Most importantly, the long-term results of the robotic repair are similar to those of open repair, but with significantly less morbidity.  相似文献   
24.
PURPOSE: Morphine is an effective analgesic, but adverse effects limit its clinical use in higher doses. The non-opioid antitussive, dextromethorphan (DM), can potentiate the analgesic effect of morphine and decrease the dose of morphine in acute postoperative pain, but the underlying mechanism remains unclear. We previously observed that DM increases the serum concentration of morphine in rats. Therefore, we investigated the effects of drugs administered at the spinal level to exclude possible pharmacokinetic interactions. As DM has widespread binding sites in the central nervous system [such as N-methyl-D-aspartate (NMDA) receptors, sigma receptors and alpha(3)ss(4) nicotinic receptors], we investigated whether the potentiation of morphine antinociception by DM at the spinal level is related to NMDA receptors. METHODS: We used MK-801 as a tool to block the NMDA channel first, and then studied the interaction between intrathecal (i.t.) morphine and DM. The tail-flick test was used to examine the antinociceptive effects of different combinations of morphine and other drugs in rats. RESULTS: DM (2-20 microg) or MK-801 (5-15 microg) showed no significant antinociceptive effect by themselves. The antinociceptive effect of morphine (0.5 microg, i.t.) was significantly enhanced by DM and reached the maximal potentiation (43.7%-50.4%) at doses of 2 to 10 microg. Pretreatment with MK-801 (5 or 10 microg, i.t.) significantly potentiated morphine antinociception by 49.9% or 38.7%, respectively. When rats were pretreated with MK-801, DM could not further enhance morphine antinociception (45.7% vs 50.5% and 43.3%). CONCLUSION: Our results suggest that spinal NMDA receptors play an important role in the effect of DM to potentiate morphine antinociception.  相似文献   
25.
We report the two-dimensional and Doppler color flow mapping echocardiographic findings in a neonate with left circumflex coronary arteriovenous fistula to a left superior vena cava. Doppler color flow mapping, in concert with detailed imaging, was essential to identify this rare fistula and to prepare for therapeutic intervention at initial cardiac catheterization.  相似文献   
26.
Critical to the proper management of pyoderma gangrenosum are correct diagnosis, identification and treatment of any underlying disorder, and the proper choice of topical and systemic therapy. Many agents are available for the treatment of pyoderma gangrenosum. We review the current therapeutic options, their efficacy and side effects, and we offer some guidelines for their proper selection.  相似文献   
27.
A high incidence of bladder cancer has been documented in an area of chronic arsenic (As) exposure. This study investigates the characteristics of As-associated (n = 49) and other (n = 64) bladder cancers. A higher histological grading was observed for the As-exposed tumours (P = 0.04), but no other difference in pathobiological features or prognosis was found between the two groups.  相似文献   
28.
A cohort study of tobacco use,diet, occupation,and lung cancer mortality   总被引:1,自引:0,他引:1  
In 1966, a cohort of White males aged 35 or over, who were policy-holders with the Lutheran Brotherhood Insurance Society (United States), completed a mail questionnaire on tobacco use, diet, and demographic characteristics. During the 20 years of follow-up, 219 lung cancer deaths occurred. Besides the strong relationship with cigarette smoking, we observed an effect on lung cancer risk among current users of cigars or pipes who were nonsmokers of cigarettes (relative risk [RR]=3.5, 95 percent confidence interval[CI]=1.0–12.6) or who were past/occasional users of cigarettes (RR=2.7, CI=1.4–5.3). In addition, elevated risks (from 1.5 to 2.6) of lung cancer were found among craftsmen and laborers, with the highest risks among subjects who worked in the mining or manufacturing industry. No association between current (as of 1966) use of beer or hard liquor and lung cancer was observed, although past users were at elevated risk. An inverse association between lung cancer and intake of fruits was observed, and risks of lung cancer were lower among persons in the highest dietary intake quintiles of vitamins A and C. Except for oranges, however, none of the inverse associations with fruits or dietary nutrients had statistically significant trends. The findings from this cohort study add to the evidence of an adverse effect of cigar/pipe smoking and possibly protective effect of dietary factors on lung cancer risk.  相似文献   
29.
SEVERAL SCIENTIFIC AND GENERAL MEDICAL JOURNALS publish full-length articles on their Web sites and abridged versions in their print journals. We surveyed a stratified random sample of BMJ readers and authors to elicit their preferred format for the abridged print version. Each participant received a research paper abridged in 3 different formats: conventional abridged version, journalistic version and enhanced-abstract version. Overall, 45% (95% confidence interval [CI] 42%–48%) of the respondents said they liked the conventional version most, 31% (95% CI 28%–34%) preferred the journalistic version and 25% (95% CI 22%–27%) preferred the enhanced-abstract version. Twenty-eight percent (95% CI 25%–32%) indicated that use of the journalistic format for abridged articles would very likely stop them from submitting papers to BMJ, and 13% (95% CI 11%–16%) said the use of the enhanced-abstract version would stop them from submitting to BMJ. Publishers of general medical journals who publish shortened articles should consider that authors and readers prefer a more conventional style of abridged papers.  相似文献   
30.
Anterior Cruciate Ligament Reconstruction: State of the Art   总被引:2,自引:0,他引:2  
Abstract The rupture of the Anterior cruciate ligament (ACL) belongs to the most common ligament injuries of the human knee joint. ACL rupture results in an increased anterior translation and internal rotation of the tibia. Untreated knee instability causes a disintegration of the roll and sliding movement and a high incidence of secondary meniscus and chondral damages with consecutive or advanced arthritic changes. For deciding on a conservative or operative therapy, it is necessary to develop a high-risk profile. Elderly, inactive patients without instability symptoms can be treated conservatively; younger, active people and complex ligament injuries should receive an ACL replacement. The goal is to eliminate instability by maintaining the physiological kinematics of the knee. Anterior cruciate ligament may be reconstructed arthroscopically assisted by autologous tendons. Predominantly, hamstring- and bone-patellar-tendon grafts are used. No significant differences in knee laxity, clinically and functionally, were observed between both grafts. Various reconstruction techniques, single- or double-bundle techniques, were described. Successful replacement depends on a correct tunnel placement and reconstruction of the physiological band tension, a sufficient mechanical stability of fixation, an impingement-free range of motion and an adequate rehabilitation. A high degree of patient satisfaction in clinical and functional outcome could be evaluated.  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