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   1059篇
  免费   25篇
  国内免费   47篇
耳鼻咽喉   14篇
儿科学   47篇
妇产科学   23篇
基础医学   87篇
口腔科学   43篇
临床医学   83篇
内科学   270篇
皮肤病学   26篇
神经病学   69篇
特种医学   11篇
外科学   251篇
综合类   1篇
预防医学   97篇
眼科学   4篇
药学   51篇
肿瘤学   54篇
  2023年   20篇
  2022年   39篇
  2021年   51篇
  2020年   35篇
  2019年   16篇
  2018年   16篇
  2017年   11篇
  2016年   26篇
  2015年   17篇
  2014年   21篇
  2013年   26篇
  2012年   42篇
  2011年   39篇
  2010年   34篇
  2009年   87篇
  2008年   51篇
  2007年   65篇
  2006年   50篇
  2005年   45篇
  2004年   43篇
  2003年   25篇
  2002年   22篇
  2001年   34篇
  2000年   18篇
  1999年   37篇
  1998年   26篇
  1997年   25篇
  1996年   16篇
  1995年   25篇
  1994年   18篇
  1993年   12篇
  1992年   16篇
  1991年   17篇
  1990年   9篇
  1989年   15篇
  1988年   15篇
  1987年   8篇
  1986年   5篇
  1985年   13篇
  1984年   6篇
  1983年   6篇
  1981年   3篇
  1979年   3篇
  1978年   2篇
  1974年   2篇
  1973年   4篇
  1971年   2篇
  1970年   2篇
  1968年   2篇
  1967年   2篇
排序方式: 共有1131条查询结果,搜索用时 15 毫秒
41.
42.
Cardiac masses diagnosis and treatment are a true challenge, although they are infrequently encountered in clinical practice. They encompass a broad set of lesions that include neoplastic (primary and secondary), non-neoplastic masses and pseudomasses. The clinical presentation of cardiac tumors is highly variable and depends on several factors such as size, location, relation with other structures and mobility. The presumptive diagnosis is made based on a preliminary non-invasive diagnostic work-up due to technical difficulties and risks associated with biopsy, which is still the diagnostic gold standard. The findings should always be interpreted in the clinical context to avoid misdiagnosis, particularly in specific conditions (e.g., infective endocarditis or thrombi). The modern multi-modality imaging techniques has a key role not only for the initial assessment and differential diagnosis but also for management and surveillance of the cardiac masses. Cardiovascular magnetic resonance (CMR) allows an optimal non-invasive localization of the lesion, providing multiplanar information on its relation to surrounding structures. Moreover, with the additional feature of tissue characterization, CMR can be highly effective to distinguish pseudomasses from masses, as well as benign from malignant lesions, with further differential diagnosis of the latter. Although histopathological assessment is important to make a definitive diagnosis, CMR plays a key role in the diagnosis of suspected cardiac masses with a great impact on patient management. This literature review aims to provide a comprehensive overview of cardiac masses, from clinical and imaging protocol to pathological findings.  相似文献   
43.
The integrated clinical, laboratory and ultrasound approach is essential for the diagnosis, evaluation and monitoring of the patient's therapy in coronavirus disease 2019 pneumonia. The ideal imaging approach in this context is not yet well defined. Chest X-ray is characterized by low sensitivity in identifying earlier lung changes. The "bedside" pulmonary ultrasound has an undeniable series of advantages in the patient at high infectious risk and can provide incremental data in the respiratory intensive care for the serial control of the individual patient as well as for the home delivery of the stabilized subjects. Pulmonary computed tomography shows high sensitivity but should not be routinely performed in all patients, because in the first 48 h it can be absolutely negative and in the late phase the imaging findings may not change the therapeutic approach. Echocardiography should be limited to patients with hemodynamic instability to assess ventricular function and pulmonary pressures.  相似文献   
44.
45.
Liver transplant(LT) outcomes have markedly improved in the recent decades,even if long-term morbidity and mortality are still considerable.Most of late deaths are independent from graft function and different comorbidities,including complications of metabolic syndrome and de novo neoplasms,seem to play a key role in determining long-term outcomes in LT recipients.This review discusses the main factors associated with late mortality and suggests possible strategies to improve long-term managemen...  相似文献   
46.
47.
BACKGROUND Drug toxicity is a common and even serious problem in the gastrointestinal tract that is thought to be caused by a broad spectrum of agents.Although withdrawal of the causative agent would cure the disease knowledge is scarce and mostly derives from case reports and series.AIM To investigate potential triggers of drug-induced colitis(DiC).METHODS We conducted a retrospective,observational case control study.Patients were assigned to DiC or one of two age-and gender-matched control groups(noninflammatory controls and inflammatory colitis of another cause)based on histopathological findings.Histopathology was reassessed in a subset of patients(28 DiC with atherosclerosis,DiC without atherosclerosis and ischaemic colitis each)for validation purposes.Medical history was collected from the electronic database and patient records.Statistical analysis included chi-squared test,t-test,logistic and multivariate regression models.RESULTS Drug-induced colitis was detected in 211 endoscopically sampled biopsy specimens of the colon mucosa(7%of all screened colonoscopic biopsy samples);a total of 633 patients were included equally matched throughout the three groups(291 males,mean age:62.1±16.1 years).In the univariate analysis,DiC was associated with diuretics,dihydropyridines,glycosides,ASS,platelet aggregation inhibitors,nonsteroidal anti-inflammatory drugs(NSAIDs),statins and fibrates,and with atherosclerosis,particularly coronary heart disease,and hyperlipoproteinaemia.Echocardiographic parameters did not show substantial differences.In the multivariate analysis only fibrates[odds ratio(OR)=9.1],NSAIDs(OR=6.7)and atherosclerosis(OR=2.1)proved to be associated with DiC.Both DiC reassessment groups presented milder inflammation than ischaemic colitis.The DiC patients with atherosclerosis exhibited histological features from both DiC without atherosclerosis and ischaemic colitis.CONCLUSION Several drugs indicated for the treatment of cardiovascular and related diseases are associated with DiC.Atherosclerosis and microcirculatory disturbances seem to play an important pathogenetic role.  相似文献   
48.
The coronavirus disease 2019(COVID-19) pandemic has imposed a radical change in daily life and work routine. In this context, health systems have suffered important and serious repercussions in all fields. Among the changes brought about by the state of global health emergency, adjustments to guidelines, priorities, structures, professional teams, and epidemiological data stand out. In light of this, the oncological field has witnessed several changes in the approach to cancer, whether due to de...  相似文献   
49.
50.
The aim of the present experiment was to assess the effect of the administration of the NSAID flurbiprofen (Froben®) on tissue healing after periodontal surgery. Sites from patients with the same treatment modality (modified Widman flap) but receiving a placebo drug and sites within each patient not exposed to surgery served as controls. Nineteen patients suffering from moderate to severe periodontal disease were recruited and they signed informed consent forms. These patients required periodontal surgery as assessed at the periodontal re-evaluation. The sites chosen for the study were all diagnosed with PPD ≥ 5 mm and were bleeding on probing. During the healing phase 10 patients received 50 mg Froben® 3 times per day for 30 d whereas 9 patients received a placebo drug. Two sites with PPD ≥ 5 mm after initial therapy and bleeding on probing served as surgical sites, whereas 2 similar sites were not exposed to surgery. The study design was set up double-blind. The radiographic examination consisted of 2–4 standardized vertical bitewings obtained at the periodontal re-evaluation (BL) at 1, 3 and 6 months post-surgically for digital subtraction and computer assisted densitometric image analysis (CADIA). The regions of interest analysed were mesial or distal crestal sites. Minimal remodelling activity was observed radiographically after periodontal surgery in both patient groups. There were no statistically significant differences between the four groups of sites regarding the mean changes in density when analysing the pairs of radiographs 0–1, 0–3, 0–6 months. A frequency analysis was performed to list the number of sites with different ranges of density change. No differences in the distributions of the numbers of sites were observed when comparing the 4 site groups (Kolmogorov-Smirnov, p > 0.05). A significant reduction of the probing pocket depth and a significant amount of clinical attachment gain was noted at the surgically treated sites irrespective of whether the patients had used flurbiprofen or placebo. Whereas the pathways leading to bone resorption in periodontally diseased sites have been shown, in other studies, to be influenced by NSAID, the results of the present study could not justify general administration of Froben® for the purpose of reduction of bone resorption after periodontal surgical procedures in patients with adult periodontitis.  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