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   650篇
  免费   16篇
  国内免费   4篇
耳鼻咽喉   14篇
儿科学   52篇
妇产科学   22篇
基础医学   46篇
口腔科学   45篇
临床医学   45篇
内科学   111篇
皮肤病学   45篇
神经病学   9篇
特种医学   25篇
外科学   164篇
综合类   9篇
预防医学   12篇
眼科学   25篇
药学   23篇
中国医学   2篇
肿瘤学   21篇
  2023年   4篇
  2022年   6篇
  2021年   12篇
  2020年   10篇
  2019年   11篇
  2018年   15篇
  2017年   14篇
  2016年   18篇
  2015年   16篇
  2014年   21篇
  2013年   29篇
  2012年   44篇
  2011年   45篇
  2010年   28篇
  2009年   26篇
  2008年   56篇
  2007年   58篇
  2006年   53篇
  2005年   42篇
  2004年   44篇
  2003年   25篇
  2002年   25篇
  2001年   13篇
  2000年   16篇
  1999年   14篇
  1998年   1篇
  1996年   3篇
  1995年   4篇
  1994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670条查询结果,搜索用时 171 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.
A model system of a paramagnetic lymphotropic MR contrast agent (Gd-DTPA labeled polyglucose associated macrocomplex, PGM) for T1-weighted MR imaging of lymph nodes in rats and rabbits was evaluated. Pharmacokinetic (tissue accumulation) and MR imaging data (optimal dose and timing parameters) were obtained in normal rats (n = 88) after subcutaneous (SC) injection of paramagnetic, radiolabeled [111In]Gd-DTPA-PGM. A rabbit model of lymph node metastases (n = 8) was ultimately used to demonstrate the potential of MR imaging with Gd-DTPA-PGM for nodal tumor detection. Maximum concentrations of Gd-DTPA-PGM were found in popliteal and paraaortic lymph nodes within 24 h after SC administration, and highest lymph node SNR values were obtained by MR imaging at this time point. The optimum imaging dose was 6–12 μmol Gd/kg. Tumor-lymph node contrast increased from 0.0 ± 1.2 precontrast to 19.2 ± 6.5 (spoiled gradient echo sequence, TR 50/TE 7/flip angle 60°) postcontrast and conspicuity of nodal metastases was improved. Gd-DTPA-PGM accumulates in lymph nodes after SC administration and significantly enhances lymph node signal intensity of normal animals but not metastatic lymph nodes.  相似文献   
5.
6.
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   
7.
8.
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   
9.
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   
10.
Hemophilia is a hereditary disease with impaired blood coagulation due to a genetic deficiency of blood coagulation factors. The development of inhibitors further complicates the course of the disease and management. The case is here reported of a haemophilia patient who presented with coexisting development of high titer inhibitor with Gastrointestinal Stromal Tumor (GIST) diagnosis and was admitted with upper gastrointestinal system bleeding. The patient had no prior history of inhibitor presence. During all procedures including surgery, excellent hemostasis was achieved with rFVIIa treatment and no hemorrhagic complication was observed. To the best of our knowledge, this constitutes the first reported case of GIST associated with inhibitor development in a hemophilia A patient.  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