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   3087654篇
  免费   216284篇
  国内免费   4450篇
耳鼻咽喉   43217篇
儿科学   100184篇
妇产科学   83118篇
基础医学   450301篇
口腔科学   85725篇
临床医学   278363篇
内科学   591019篇
皮肤病学   68650篇
神经病学   240739篇
特种医学   117296篇
外国民族医学   676篇
外科学   464405篇
综合类   63118篇
现状与发展   13篇
一般理论   1044篇
预防医学   235508篇
眼科学   72181篇
药学   235359篇
  18篇
中国医学   6537篇
肿瘤学   170917篇
  2019年   24408篇
  2018年   34018篇
  2017年   25919篇
  2016年   29166篇
  2015年   32773篇
  2014年   45976篇
  2013年   68862篇
  2012年   94562篇
  2011年   100642篇
  2010年   59805篇
  2009年   56272篇
  2008年   94267篇
  2007年   100659篇
  2006年   101580篇
  2005年   98270篇
  2004年   94126篇
  2003年   90750篇
  2002年   87831篇
  2001年   145909篇
  2000年   150086篇
  1999年   125924篇
  1998年   35432篇
  1997年   31147篇
  1996年   31456篇
  1995年   29581篇
  1994年   27213篇
  1993年   25665篇
  1992年   96981篇
  1991年   94307篇
  1990年   92447篇
  1989年   88948篇
  1988年   81538篇
  1987年   79942篇
  1986年   75044篇
  1985年   71541篇
  1984年   52943篇
  1983年   44981篇
  1982年   26248篇
  1979年   48445篇
  1978年   34070篇
  1977年   28973篇
  1976年   26993篇
  1975年   29531篇
  1974年   35031篇
  1973年   33523篇
  1972年   31696篇
  1971年   29946篇
  1970年   27600篇
  1969年   26416篇
  1968年   23983篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
BACKGROUND: Repairing dorsal nasal defects is a frequent challenge for dermatologic surgeons, mainly due to the high frequency of basal cell carcinomas on this site. Obvious scars, mismatched skin and distortion of the nasal contour are the surgical hazards that must be avoided in these cases. AIM: Our aim was to perform surgery involving a simple flap in order to repair medium to large defects on the dorsal side of the nose. METHODS: The dorsal horizontal advancement flap was studied in 12 patients, in order to evaluate the benefits and limits of this surgical procedure. RESULTS: The resulting scars on most of our patients were well-camouflaged among their natural skin lines, and there was neither distortion of the alar contour nor the nostril. CONCLUSIONS: This flap is easy to perform and, in selected cases, provides an outstanding alternative to second-intention healing, full-thickness skin grafts, transposition, rotation and pedicle flaps.  相似文献   
72.
PURPOSE: The aim of this study was to determine if the concomitant use of ketorolac 0.4% and cyclosporin-A improves patient comfort during the induction phase in treating chronic dry eye disease. METHODS: Patients (n = 52) with clinically diagnosed dry eye were randomized to receive either cyclosporin-A monotherapy twice-daily (BID) or a BID adjunctive regimen of ketorolac, followed by the instillation of cyclosporin-A 10 min later. Study visits were at baseline, week 2, and week 6. At each study visit, patients underwent an evaluation for corneal staining, Schirmer's scores, and tear break-up time tests. Patients were asked to rate ocular comfort on a 4-point scale and to complete the ocular surface disease index (OSDI). Changes from baseline readings were recorded at week-2 and week-6 visits, and final patient success on treatment regimen was evaluated at week 6. RESULTS: After 6 weeks, the mean ocular comfort score of adjunctive patients improved 2.55 +/- 0.95 points, versus 1.53 +/- 0.91 points for monotherapy (P = 0.309). The adjunctive regimen provided significantly greater corneal staining reductions versus monotherapy, mean reduction in staining of 1.74 +/- 0.9, versus 1.27 +/- 0.56 (P = 0.044). CONCLUSIONS: Concurrent ketorolac 0.4% use with cyclosporin-A significantly reduced corneal staining and increased comfort in the induction phase.  相似文献   
73.
74.
Primary chemotherapy administered to breast cancer patientsis the best model to identify baseline features able to predictwhich patients may be most likely to benefit or not from a cytotoxicregimen. In the March issue of Annals of Oncology two papersevaluated the predictive role of immunohistochemical p53 expressionon  相似文献   
75.
76.
CONTEXT: Although the nonmedical use of stimulant drugs such as cocaine and methamphetamine is increasingly common in many rural areas of the United States, little is known about the health beliefs of people who use these drugs. PURPOSE: This research describes illicit stimulant drug users' views on health and health-related concepts that may affect their utilization of health care services. METHODS: A respondent-driven sampling plan was used to recruit 249 not-in-treatment, nonmedical stimulant drug users who were residing in 3 rural counties in west central Ohio. A structured questionnaire administered by trained interviewers was used to collect information on a range of topics, including current drug use, self-reported health status, perceived need for substance abuse treatment, and beliefs about health and health services. FINDINGS: Participants reported using a wide variety of drugs nonmedically, some by injection. Alcohol and marijuana were the most commonly used drugs in the 30 days prior to the interview. Powder cocaine was used by 72.3% of the sample, crack by 68.3%, and methamphetamine by 29.7%. Fair or poor health status was reported by 41.3% of the participants. Only 20.9% of the sample felt they needed drug abuse treatment. Less than one third of the sample reported that they would feel comfortable talking to a physician about their drug use, and 65.1% said they preferred taking care of their problems without getting professional help. CONCLUSIONS: Stimulant drug users in rural Ohio are involved with a range of substances and hold health beliefs that may impede health services utilization.  相似文献   
77.
OBJECTIVE: To assess the effect of glucose control on the rate of growth of fetuses in women with pregestational diabetes mellitus (Types 1 and 2). METHODS: All pregestational diabetic women booked at Mater Mothers' Hospital, Brisbane, Australia, between 1 January 1994 and 31 December 2002, were included. Pregnancies with congenital fetal anomalies, multiple pregnancies, and pregnancies terminated prior to 20 weeks' gestation were excluded. Dating scans were performed before 14 weeks' gestation and serial scans were performed at 18, 24, 28, 32 and 36 weeks. Fetal parameters, including biparietal diameter, femur length and abdominal circumference, were recorded. The daily growth rates for biparietal diameter, femur length, and fetal abdominal area were calculated and compared with those in a low-risk (non-diabetic) population. The growth rates in fetuses of women with satisfactory diabetic control (HbA1c < 6.5%) and unsatisfactory control (HbA1c > or = 6.5%) in the three trimesters were compared. RESULTS: A total of 174 diabetic pregnancies were included and a total of 997 ultrasound scans were performed. The growth rates for fetuses of mothers with diabetes mellitus were significantly higher than for those in the low-risk population. The z-scores for biparietal diameter, femur length, and fetal abdominal area were 0.18, 0.59 and 1.44, respectively. Fetuses of diabetic mothers with high HbA1c in the first trimester had significantly greater fetal abdominal area growth rate than those with normal HbA1c (fetal abdominal area z-score of 1.7 vs. 0.75, P = 0.009). Although the fetal abdominal area z-scores in fetuses of diabetic mothers with high HbA1c in the second or third trimesters were also higher than those with normal HbA1c levels, the differences did not reach statistical significance. Maternal obesity did not influence the fetal growth rate. CONCLUSION: The rate of growth of fetuses of diabetic mothers differs from that of the normal population. Growth acceleration persists until the late third trimester. Moreover, periconceptional glucose control appears to have a significant effect on accelerated growth of the fetal abdominal area.  相似文献   
78.
79.
80.
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