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   1827篇
  免费   113篇
  国内免费   3篇
耳鼻咽喉   19篇
儿科学   41篇
妇产科学   46篇
基础医学   218篇
口腔科学   33篇
临床医学   205篇
内科学   354篇
皮肤病学   108篇
神经病学   137篇
特种医学   41篇
外科学   274篇
综合类   20篇
一般理论   1篇
预防医学   176篇
眼科学   8篇
药学   101篇
中国医学   1篇
肿瘤学   160篇
  2023年   19篇
  2022年   45篇
  2021年   103篇
  2020年   43篇
  2019年   73篇
  2018年   75篇
  2017年   55篇
  2016年   60篇
  2015年   56篇
  2014年   74篇
  2013年   102篇
  2012年   128篇
  2011年   152篇
  2010年   66篇
  2009年   50篇
  2008年   109篇
  2007年   102篇
  2006年   107篇
  2005年   88篇
  2004年   88篇
  2003年   92篇
  2002年   61篇
  2001年   14篇
  2000年   10篇
  1999年   14篇
  1998年   4篇
  1997年   5篇
  1996年   6篇
  1995年   5篇
  1994年   4篇
  1992年   6篇
  1991年   10篇
  1990年   6篇
  1989年   7篇
  1988年   9篇
  1987年   15篇
  1986年   8篇
  1985年   5篇
  1984年   8篇
  1983年   6篇
  1982年   5篇
  1981年   7篇
  1980年   6篇
  1979年   3篇
  1974年   3篇
  1972年   2篇
  1965年   2篇
  1947年   3篇
  1927年   3篇
  1924年   2篇
排序方式: 共有1943条查询结果,搜索用时 31 毫秒
11.
To assess the effectiveness of maternal self-administration of nevirapine for prevention of mother-to-child transmission (MTCT) of HIV, we conducted a program to provide maternal and newborn doses of nevirapine to pregnant women in rural Uganda. Women provided blood for HIV testing and were offered voluntary counseling and testing (VCT) during annual community HIV surveys. HIV-positive women who accepted VCT were offered nevirapine tablets and syrup. Blood samples were collected postpartum from women and their babies. Infants were tested for HIV by polymerase chain reaction (PCR), and a subsample of maternal and infant blood was assayed for nevirapine. Among the 981 women tested for HIV, 900 (91.7%) accepted VCT, of whom 105 (11.7%) were HIV-positive. Ninety-three women accepted nevirapine, of whom 81 (87.1%) were followed postpartum; 75 (92.6%) reported receipt of the drug, and 69 reported taking the tablets (85.2%). There were 81 liveborn babies (3 sets of twins), and 67 (84.8%) received the syrup. In a subsample of 25 mothers reporting receipt of the drug, nevirapine was detected in 22 (88.0%) and 24 (96.0%) babies tested. PCR of 67 infant blood samples identified 5 HIV-positive (MTCT rate = 7.5%, 95% confidence interval [CI]: 0.3%-16.6%). Mothers can administer nevirapine to themselves and their newborns and can achieve low rates of perinatal HIV infection.  相似文献   
12.
13.
The Journal of Behavioral Health Services & Research - Characterizing community mental health (CMH) treatment duration and discharge is an important step toward understanding how to better meet...  相似文献   
14.
15.
PurposeMetastatic recurrence occurs in over 25% of upper tract urothelial carcinoma patients treated with radical nephroureterectomy. While metastatic recurrence suggests poor prognosis, the impact of the specific site of recurrence on prognosis is not well documented.Materials and methodsWe retrospectively analyzed 188 patients who underwent radical nephroureterectomy for high-grade, node-negative upper tract urothelial carcinoma at our institution from 2003 to 2018 without receiving neoadjuvant or adjuvant chemotherapy. Competing-risks survival analysis was performed to evaluate the cumulative incidence and predictors of metastatic recurrence. The Kaplan-Meier method and log-rank test were used to estimate and compare recurrence site-specific survival probabilities following metastatic recurrence. Cox regression analyses were performed to assess site-specific prognoses.ResultsOf the 188 patients, 47 (25%) developed metastatic recurrence over a median follow-up of 30 months (interquartile range: 10.5–58.5 months). The 1- and 2-year cumulative incidences of metastatic recurrence were 13.6% and 23.6%, respectively. On multivariable analysis, lymphovascular invasion was significantly predictive of metastatic recurrence (subhazard ratio: 2.6, P = 0.01). Of the 47 patients who developed recurrence, 38 (80.9%) died over a median follow-up of 10 months (interquartile range: 5–20 months). Metastatic recurrence was most common in the lungs (n= 13, 28%) and at multiple sites (n= 14, 30%). Median time to recurrence was shorter for recurrences at multiple sites (6.5 months) and those in the liver (13 months) and bone (18 months) compared to other sites. Patients who recurred in the liver (hazard ratio: 6.3, P = 0.007), bone (hazard ratio: 4.9, P = 0.02), and multiple sites (hazard ratio: 4.6, P = 0.01) had significantly worse prognosis compared to those who recurred in lymph nodes. Statistical significance persisted after adjusting for treatment with salvage therapy.ConclusionsA significant proportion of high-grade upper tract urothelial carcinoma patients recur systemically after radical nephroureterectomy. Lymphovascular invasion is a predictor of metastatic recurrence and may inform decisions regarding perioperative chemotherapy. Hepatic and osseous recurrences have relatively quicker onset and less favorable prognosis compared to other sites. These findings may benefit future efforts to develop recurrence site-specific treatment plans and highlight the necessity of subsequent endeavors to explore the genetic associations of recurrence in upper tract urothelial carcinoma.  相似文献   
16.
BackgroundBariatric surgery is well established in adults as the most effective tool for sustained weight loss and reduction of obesity-related co-morbidities, and is an emerging option for adolescents in whom conservative approaches have failed. Narratives are vital in understanding the motivating reasons and psychosocial profiles of adolescents considering bariatric surgery during a developmental period of evolving self-concept, body image sensitivity, peer pressure, and increased opportunity for risky behaviors.ObjectivesTo explore preoperative adolescent patient perspectives on their decision to pursue bariatric surgery, anticipated physical and psychosocial effects, and preparation process.SettingsThe Hospital for Sick Children (SickKids) in Toronto, Ontario, Canada.MethodsWe conducted 14 semi-structured interviews with adolescents (16–18 yr old) 2–4 months before bariatric surgery. A theoretical thematic analysis was conducted with 3 independent reviewers (interrater reliability, Cronbach’s α= .81) and conflicts were resolved through discussion.ResultsPatients’ perspectives are captured in 4 themes: motivation for surgery, effects on health and habits, psychosocial changes, and support systems during preparation. Participants perceived surgery as a tool but not a solution for weight loss. Most were motivated for health and daily functional improvement rather than aesthetic reasons, and some anticipated improved social interactions while maintaining their self-identity. Participants were selective in sharing news of their surgery, and received varying levels of support from families, friends, and healthcare teams.ConclusionAdolescents seem generally prepared for and informed about surgery, with expectations for weight loss and psychosocial improvements, although uncertainty and contradictory thoughts were prevalent. Insights provided by these adolescent patients will help optimize bariatric surgery assessments and support from clinical teams and inform preoperative education for future patients and families.  相似文献   
17.
The present study evaluates how liability influences mental health clinicians’ assessment of suicide risk. In this online vignette-based experiment, clinicians (N = 268) were either primed with a legal standard prior to a case vignette or presented the case vignette alone. Clinicians then rated the patient’s likelihood of suicide and need for hospitalization. Results indicated that trainees provided significantly lower ratings of suicide risk following presentation of the legal standard, but this was not associated with hospitalization endorsement. Results have training and legal implications for improving the accuracy of suicide risk assessment in both trainees and licensed professionals.  相似文献   
18.
19.
Patients born with congenital right ventricular outflow tract lesions are faced with invasive procedures to establish hemodynamic and physiological stability. Commonly, multiple subsequent surgical procedures are required due to deterioration of a previous repair. These procedures carry additive risks of mortality and morbidity. Less aggressive procedures with accompanying lower risk is ideal. Success in percutaneously placing a transcatheter valve has previously been reported; however, continued safety and efficacy of any technique needs continual assessment. We developed a model for preclinical evaluation of a percutaneous placement of a pulmonic transcatheter valve in adult sheep, including preoperative, surgical, and postoperative techniques for long-term evaluation. Adult sheep were assessed and determined to be acceptable for study enrollment. Perioperative antibiotics and analgesics were given prior to a left thoracotomy. A Medtronic, Hancock 1 valve conduit was inserted for reconstruction of the right ventricular outflow tract. The Hancock 1 valve conduit alone represented the control group and the test animals comprised the addition of a Melody? transcatheter pulmonary valve (TPV), within the Hancock 1 valve conduit. Fifteen adult sheep survived the surgical implant procedure with no perioperative mortality. There were four early postoperative deaths, three due to infection and one due to heart failure, secondary to intraoperative heart block. The remaining 11 animals remained healthy, gained weight, and survived to termination at 5 months. An initial definite-sized valve conduit was implanted, followed by inserting a single size TPV, which allowed a more accurate physiological assessment of any chosen valve. Our developed adult sheep model for percutaneous TPV implantation for right ventricular outflow tract lesions was successful for long-term assessment by utilizing our preoperative, surgical, and postoperative techniques.  相似文献   
20.
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