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   515篇
  免费   11篇
  国内免费   3篇
耳鼻咽喉   14篇
儿科学   39篇
妇产科学   2篇
基础医学   39篇
口腔科学   33篇
临床医学   38篇
内科学   87篇
皮肤病学   45篇
神经病学   5篇
特种医学   20篇
外科学   130篇
综合类   9篇
预防医学   10篇
眼科学   22篇
药学   19篇
中国医学   2篇
肿瘤学   15篇
  2022年   4篇
  2021年   6篇
  2020年   2篇
  2019年   8篇
  2018年   10篇
  2017年   10篇
  2016年   10篇
  2015年   7篇
  2014年   16篇
  2013年   24篇
  2012年   37篇
  2011年   36篇
  2010年   21篇
  2009年   17篇
  2008年   52篇
  2007年   47篇
  2006年   44篇
  2005年   36篇
  2004年   37篇
  2003年   24篇
  2002年   21篇
  2001年   13篇
  2000年   16篇
  1999年   12篇
  1998年   1篇
  1996年   1篇
  1995年   1篇
  1991年   4篇
  1990年   1篇
  1989年   4篇
  1988年   3篇
  1986年   1篇
  1984年   1篇
  1978年   1篇
  1970年   1篇
排序方式: 共有529条查询结果,搜索用时 46 毫秒
1.
2.
Bilateral germ cell tumours of the testis are rare but a rise in their incidence is expected since with the new therapeutic possibilities a significant improvement in prognosis has been achieved even in patients with advanced metastatic spread. Of the 210 patients treated for malignent germ cell tumours at our Department, six (2.9%) developed a contralateral testicular tumour. All patients had metachronous tumours and the second tumours occurred after an interval ranging between 1 and 22 years. The epidemiology, histology, diagnosis, therapy and prognosis are discussed, and the significance of regular self-examination of the remaining testis in patients with testicular tumour is emphasized.  相似文献   
3.
A methodological approach to the classification of dermoscopy images.   总被引:2,自引:0,他引:2  
In this paper a methodological approach to the classification of pigmented skin lesions in dermoscopy images is presented. First, automatic border detection is performed to separate the lesion from the background skin. Shape features are then extracted from this border. For the extraction of color and texture related features, the image is divided into various clinically significant regions using the Euclidean distance transform. This feature data is fed into an optimization framework, which ranks the features using various feature selection algorithms and determines the optimal feature subset size according to the area under the ROC curve measure obtained from support vector machine classification. The issue of class imbalance is addressed using various sampling strategies, and the classifier generalization error is estimated using Monte Carlo cross validation. Experiments on a set of 564 images yielded a specificity of 92.34% and a sensitivity of 93.33%.  相似文献   
4.
5.
Gynaecomastia in adolescents is a benign glandular proliferation of the male breast. Secondary causes of gynaecomastia in adolescents are relatively rare and may result from a wide variety of rare pathological conditions. Among these, klinefelter syndrome, complete androgen resistance, adrenal tumours and oestrogen-secreting testicular tumours, hypogonadism, hyperthyroidism, kidney disease and medications play a role in aetiology. The aim of our study is to review the demographic characteristics, hormone profile, aetiological characteristics of paediatric gynaecomastia patients admitted to a single center and to determine the frequency of pathological gynaecomastia. Forty-three male patients with gynaecomastia who applied to the paediatric endocrinology outpatient clinic were included in our study. Demographic characteristics, physical examination findings, hormone profile, breast ultrasonography and karyotype results of the patients were recorded. There were 43 male patients in our study. Thirty-six (83.7%) of the patients were pubertal gynaecomastia, 7 (16.2%) were pathological gynaecomastia. Three of the patients with pathological gynaecomastia were prepubertal gynaecomastia, 2 had klinefelter syndrome, 1 had hypergonadotropic hypogonadism after acute lymphoblastic leukaemia treatment and 1 had gynaecomastia after spirololactone use. Careful evaluation of patients with gynaecomastia is especially important in detecting pathological types. We reported the rare prepubertal gynaecomastia and klinefelter frequency in our study.  相似文献   
6.
7.
Transient left ventricular apical ballooning syndrome is characterized by reversible left ventricular wall motion abnormalities, chest pain or dyspnea, ST-segment elevation, and mild elevation of cardiac enzyme levels in the absence of obstructive coronary artery disease. The pathophysiology of the syndrome is still unknown. The probable mechanism is supposed to be a catecholamine discharge. We report the case of a 66-year-old woman with recently diagnosed pheochromocytoma who presented with chest pain and ST-segment elevation. Coronary angiography revealed normal coronaries and apical dyskinesia at ventriculography. A similar episode of chest pain occurred 4 years ago with same angiographic findings and reversible inferobasal akinesia. In-hospital course was uneventful and the patient was discharged from the hospital 4 days later with treatment of aspirin 1 × 100 mg, metoprolol 1 × 50 mg, lisinopril 1 × 10 mg, and atorvastatin 1 × 20 mg. At 2 years follow-up after the event, the patient remained asymptomatic.  相似文献   
8.
Objectives

The aim of this study was to analyze the amount of root resorption of maxillary lateral incisors by relating the position, location, and angulation of the impacted canine using cone-beam computed tomography (CBCT).

Materials and methods

The study sample consisted of panoramic and CBCT radiographs of 46 patients with a unilateral impacted canine (16 males and 30 females; mean age: 19.53 ± 6.66 and 19.44 ± 5.77 years, respectively). Sector location and canine angulation were measured in panoramics. All tomographs were obtained using CBCT (NewTom 5G, QR, Verona, Italy) and three-dimensional (3D) reconstructions of the maxillary laterals assessed by Mimics 14.01 image analysis software.

Results

Upper lateral incisor volume was smaller on the impacted side (401.95 ± 83.69 mm3) than on the nonimpacted side (433.54 ± 92.6 mm3, P < 0.05). There were no significant differences of lateral root resorption volume when comparing the impacted canines being on the labial or palatal sides (P > 0.05), but impacted canine angulation was significantly steeper on the labial side (70.85°) than on the palatal side (46.09°, P < 0.05). The volume of root resorption of laterals when comparing the various positions of the canine in different sectors or canine angulation in 30o intervals was not statistically significantly different (P > 0.05).

Conclusions

The impacted canines caused root resorption of lateral incisors. The angulation of the canine was steeper on the labial side than on the palatal side but root resorption of adjacent laterals was not different. There were no statistically significant differences in the amount of root resorption of the laterals when the canine was evaluated according to localization and angulation.

  相似文献   
9.
Objective: Penetrating colonic injuries are amongst the most discussed intra-abdominal injuries because of the complexity of their management and the severe complications. Penetrating colonic injuries can be managed by either primary repair or diversion. There is a debate over which procedure has to be used under which circumstances. In this retrospective study we analyzed our experience to contribute to the answer.

Patients and methods: The records of patients with penetrating colonic injury between January 1995 and December 2006 at the General Surgery Department of Atatürk University School of Medicine, were reviewed retrospectively. Results: One hundred and forty-one patients were included in the study. Ten patients did not need any surgical treatment. Seventy-nine patients (56%) were treated without formation of a stoma and fifty-two patients (36.8%) with formation of a stoma. The overall complication rate was 50.3% (71 patients). The rate of septic complications was 33.3%.

Conclusion: There is an ongoing debate whether formation of a stoma is indicated in penetrating colonic injury or not. Our clinical experience showed that severe faecal contamination, shock at presentation, and high CIS grades are associated with increased postoperative complications and mortality. Therefore the treatment of penetrating colonic injury in the presence of these risk factors should be stoma formation rather than primary repair.  相似文献   
10.

Background

A prospective study was performed to evaluate the effect of inguinal hernia repairs on the genitofemoral nerve (GFN), and to compare postoperative electrophysiologic changes in the GFN of patients who had undergone either open or laparoscopic surgery.

Methods

Seventy patients with a mean age of 6.48 ± 3.49 were enrolled in the study. Either open or laparoscopic techniques were used to operate on the patients' inguinal hernias. In all cases, bilateral GFN motor responses were investigated electrophysiologically using surface electrodes on three occasions: preoperatively, in the first month, and third month postoperatively. t-Tests were used to compare changes in the GFN.

Results

Preoperative mean latency of the GFN in all groups was found to be significantly prolonged on the hernia side, compared with the non-hernia side (P = 0.01). Although no difference was observed in the latency levels of the GFN on the operated side at the preoperative and early postoperative stages, GFN latency levels decreased significantly in the late postoperative period in the laparoscopic group (P < 0.05). In the late postoperative period, amplitudes of GFN motor responses were significantly higher in the laparoscopic group than the open repair group (0.91 ± 0.11 mV and 0.57 ± 0.053 mV, respectively; P < 0.05).

Conclusion

Preoperative prolonged latency of GFN on the hernia side is likely to occur due to the pressure on the nerve caused by the hernia mass. By surgically removing the hernia mass, this buildup of pressure is prevented, decreasing the latency of the GFN. The significantly higher motor response amplitudes and decreased latency in the late postoperative stage for the laparoscopic group may be due to the fact that this technique is less invasive.  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