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   6146篇
  免费   370篇
  国内免费   33篇
耳鼻咽喉   69篇
儿科学   151篇
妇产科学   123篇
基础医学   1035篇
口腔科学   47篇
临床医学   576篇
内科学   1353篇
皮肤病学   84篇
神经病学   714篇
特种医学   339篇
外科学   871篇
综合类   27篇
一般理论   6篇
预防医学   279篇
眼科学   83篇
药学   414篇
中国医学   6篇
肿瘤学   372篇
  2023年   28篇
  2022年   29篇
  2021年   173篇
  2020年   87篇
  2019年   135篇
  2018年   187篇
  2017年   132篇
  2016年   137篇
  2015年   191篇
  2014年   231篇
  2013年   352篇
  2012年   482篇
  2011年   504篇
  2010年   282篇
  2009年   284篇
  2008年   414篇
  2007年   425篇
  2006年   408篇
  2005年   405篇
  2004年   372篇
  2003年   292篇
  2002年   308篇
  2001年   52篇
  2000年   25篇
  1999年   44篇
  1998年   46篇
  1997年   46篇
  1996年   39篇
  1995年   46篇
  1994年   24篇
  1993年   23篇
  1992年   22篇
  1991年   9篇
  1990年   10篇
  1989年   21篇
  1988年   9篇
  1985年   13篇
  1984年   11篇
  1983年   15篇
  1982年   25篇
  1981年   23篇
  1980年   12篇
  1979年   16篇
  1978年   17篇
  1977年   8篇
  1976年   9篇
  1974年   9篇
  1972年   14篇
  1971年   6篇
  1968年   7篇
排序方式: 共有6549条查询结果,搜索用时 515 毫秒
11.
12.
13.
We assessed whether the range of passive hip motion is reliable for predicting abnormal femoral ante-version. We measured the passive medial and lateral rotation in extension in both hips of 1, 140 children between 8 and 9 years of age. The children were divided into 3 groups: group 1: difference between lateral and medial rotation less than 10° group 2: medial rotation more than 10° greater than the lateral; group 3: lateral rotation more than 10° greater than the medial. Group 1 comprised 90% of the children, whereas 8% belonged to group 2 and 2% to group 3.

The angle of femoral neck anteversion was measured in 57 children from the first group, in 67 from the second and in 24 children from the third group, using biplane radiography. The mean anteversion angles in the 3 groups were 24°, 36° and 14°, respectively. To predict an abnormally high anteversion angle (above mean +2SD), the difference between medial and lateral rotation must be 45° or more, whereas an abnormally low anteversion angle (lower than mean -2SD) could be predicted when the lateral rotation was at least 50° higher than the medial rotation.  相似文献   
14.
Cytochemical analysis of leukemic blasts from 46 patients with acute myeloblastic M2 leukemia (according to the FAB classification) was performed before and after cytostatic therapy, and compared with findings obtained in 20 age- and sex-matched control subjects. Cytochemical findings for myeloperoxidase (MPO), Sudan black B, acid phosphatase and alpha-naphthyl-acetate esterase (ANAE) were related to the achievement of the first complete remission (CR),i.e. data were compared after the patients had been divided into CR and non-CR groups. The analysis clearly showed that a high proportion of myeloperoxidase- and, to a lesser extent, Sudan black B-positive blasts before treatment may have constituted a significantly unfavourable prognostic factor.  相似文献   
15.
16.
The objective of the study was to compare the clinical outcomes at the short-term follow-ups of two novel transobturator mid-urethral sling procedures – the transobturator tape (TOT) procedure and the tension-free vaginal tape (TVT)-obturator procedure. The study cohort consisted two groups of 40 women with urodynamically proven stress urinary incontinence (SUI). The patients in one group underwent the TOT procedure, performed according to Delorme (Prog Urol 11:1306–1313, 2001); those in the second group underwent the TVT-obturator operation, performed according to de Leval (Eur Urol 44:724–730, 2003). Intra-operative diagnostic cystoscopy was not performed with either the TVT-obturator or the TOT procedures. The average follow-up was 12 months. The two patient groups were similar in terms of demographic and therapeutic criteria, except for patient age, which was significantly younger in the TVT-obturator group. Previously reported TVT-related operative complications, such as bladder penetration, intra-operative bleeding, field infection and post-operative pelvic floor relaxation, were not observed in patients of either group. Bowel and urethral injuries were also not recorded. The therapeutic failure rates were 10% for the TOT procedure and 5% for the TVT-obturator procedure. Urinary frequency and urgency post-operatively were reported in 25% of the TOT patients and 19% of the TVT-obturator patients, pelvic or vaginal pain affected 10% of the TOT and 5% of the TVT-obturator patients, while post-operative voiding difficulty was experienced by 12.5% of the TOT and 7.5% of the TVT-obturator patients. None of the above-mentioned differences between the two patient groups were of statistical significance. The TVT-obturator and TOT procedures, both minimally invasive, novel, mid-urethral sling procedures, seem to be safe, easy-to-perform and effective in treating female SUI. The patients of both study groups suffered less intra- and post-operative surgical complications than previously been reported in connection with the TVT operation. The TVT-obturator patients had fewer therapeutic failures, less post-operative urinary frequency and urgency, less pelvic pain and less voiding difficulty. All of these findings, however, had no statistical significance; consequently, long-term comparative data collection will be required before solid conclusions can be drawn on the superiority of either of these two operative techniques.  相似文献   
17.
A monoclonal antibody to the molluscan small cardioactive peptide SCPB and a polyclonal antibody to FMRFamide were used to localize antigens in the stomatogastric nervous system and brain of two species of Cancer. Both antibodies labeled cell bodies, axons, and neuropilar processes in the brain and in the stomatogastric nervous system. All of the SCPB immunoreactive neurons were co-labeled with antibody to FMRFamide. However, antibody to FMRFamide labeled additional neurons of the commissural ganglion and the brain that were not immunoreactive to the monoclonal SCPB antibody.  相似文献   
18.
INTRODUCTION: The change in obstetrical practices over the last decade in favor of trials of labor in patients with uterine scars has resulted in increased incidences of uterine ruptures. Although neither repeat cesarean delivery nor a trial of labor is risk free, evidence from a large multicenter study shows vaginal birth after the cesarean (VBAC) is associated with shorter hospital stays, fewer postpartum blood transfusions, and a decreased incidence of postpartum maternal fever. The uterine rupture remains the most serious complication associated with VBAC. Factors associated with uterine rupture include excessive exposure to oxytocin, dysfunctional labor, and a history of more than 1 cesarean delivery.2 Because uterine rupture may be a life-threatening event, intrapartum surveillance and the ability to perform an emergency surgery are both necessary when trial of labor is allowed. Until now, no early symptoms pathognomonic to uterine rupture had been described. We share our experiences with the novel approach to the problem - an intrapartum endoscopy. MATERIALS AND METHODS: Endoscopic examination was accomplished by using the intraoperational fiberscope (Olympus and Endoview system (Costa Mesa, CA, USA). A gas-sterilized 25-cm long fiberscope is introduced into the amniotic cavity through the cervical canal after rupture of the membranes. The distance between the fiberscope and the object varies from 3 to 50 mm. The fiberscope has a separate channel for the fluid infusion (normal saline) throughout the procedure; the surgeon looks through the eyepiece directly and exhibits control over the flexible scope. The duration of endoscopy is less than 15 minutes. The inserting of the endoscopic device is very similar to that of insertion of an intrauterine pressure catheter. The IRB Committees of both participating institutions approved the study protocol. Twenty-eight patients with an unknown or poorly documented site of the uterine scar were included in the study. An ultrasound examination had been performed on all patients prior to endoscopy to assess fetal wellbeing and placental location. The ages of the patients ranged from 21 to 38 years. Eighteen women had 1 previous cesarean delivery, and 10 had 2. The performance of intrapartum endoscopy did not interfere with fetal monitoring; 21 fetuses were monitored externally, 7 internally. Indications for previous cesarean deliveries were as follows: fetal distress in 11 cases, failure to progress in labor in 8, placenta previa in 2, and unknown in 7. Twenty-one patients delivered vaginally; 7 had had repeat cesarean deliveries. All neonates were born in satisfactory condition. The Apgar scores at 1 minute varied from 7 to 9 and at 5 minutes from 8 to 10. The integrity of the uterine wall was assessed by manual postpartum uterine exploration in each case of vaginal delivery and by visualization and palpation of the scar site in each abdominal delivery. RESULTS: The lower uterine segment and contractile portion of the anterior uterine wall were visualized successfully in all patients. In 25 patients, the presumed scar site looked totally indistinguishable from the rest of the lower uterine segment and anterior uterine wall. Two scars were identified as vertical in 2 patients who were delivered by a repeat abdominal operation. A vertical scar appears as a groove running in a cephalad-caudad direction from the lower uterine segment into the contractile portion of the anterior uterine wall. The usefulness of the intrapartum endoscopy is best demonstrated by the following case reports (2 of 28 study cases).  相似文献   
19.
20.
OBJECTIVE: To determine the efficacy of a new multilevel surgical protocol for obstructive sleep apnea (OSA). STUDY DESIGN AND SETTING: Sixty patients with moderate to severe OSA because of multilevel pharyngeal obstruction were enrolled into this prospective, controlled clinical trial after clinical examination, endoscopy, and polysomnography. Surgery included uvulaflap, tonsillectomy, hyoid suspension, and radiofrequency treatment of the tongue base (group A). A second group did not receive hyoid suspension (group B). In both groups, nasal surgery was performed if necessary. Polysomnography and Epworth Sleepines Scale (ESS) were recorded at baseline and 2 to 15 months after surgery. RESULTS: In group A, the mean apnea-hypopnea index (AHI) decreased significantly after surgery (38.9 +/- 20.0 vs 20.7 +/- 20.6, P < 0.0001), whereas in group B the AHI did not. All secondary variables (minimal oxygen saturation, mean oxygen saturation, arousal index), and the ESS significantly improved in group A with only changes in arousal index and ESS reaching levels of significance in group B. CONCLUSION: The presented protocol including the hyoid suspension proved to be effective in the treatment of OSA, whereas surgery without hyoid suspension was less successful. EBM rating: B-2b.  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