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   2706篇
  免费   138篇
  国内免费   24篇
耳鼻咽喉   77篇
儿科学   84篇
妇产科学   140篇
基础医学   236篇
口腔科学   105篇
临床医学   227篇
内科学   589篇
皮肤病学   64篇
神经病学   195篇
特种医学   96篇
外科学   538篇
综合类   41篇
一般理论   1篇
预防医学   88篇
眼科学   112篇
药学   106篇
中国医学   3篇
肿瘤学   166篇
  2024年   8篇
  2023年   21篇
  2022年   29篇
  2021年   46篇
  2020年   35篇
  2019年   54篇
  2018年   57篇
  2017年   69篇
  2016年   86篇
  2015年   101篇
  2014年   127篇
  2013年   160篇
  2012年   204篇
  2011年   222篇
  2010年   111篇
  2009年   108篇
  2008年   194篇
  2007年   248篇
  2006年   201篇
  2005年   187篇
  2004年   137篇
  2003年   116篇
  2002年   101篇
  2001年   45篇
  2000年   49篇
  1999年   27篇
  1998年   9篇
  1997年   11篇
  1996年   10篇
  1995年   3篇
  1993年   2篇
  1992年   8篇
  1991年   8篇
  1990年   6篇
  1989年   6篇
  1988年   4篇
  1987年   4篇
  1986年   2篇
  1985年   2篇
  1984年   2篇
  1982年   4篇
  1981年   6篇
  1979年   2篇
  1978年   2篇
  1977年   3篇
  1973年   4篇
  1972年   5篇
  1970年   5篇
  1968年   2篇
  1967年   3篇
排序方式: 共有2868条查询结果,搜索用时 15 毫秒
61.
62.
Double orifice mitral valve (DOMV) is an uncommon congenital heart defect. The isolated occurrence of this anomaly is very rare and, more often, is associated with another congenital malformation, dominated by atrioventricular canal defects (AVCD). Mitral insufficiency and/or stenosis may complicate this malformation. Treatment may be summarized as abstention, surgical valve repair, or valve replacement. In here, we report three cases with DOMV. The first patient was an 18-month-old boy who was operated for severe mitral valve stenosis and mild insufficiency (in 1980s), the second was a 47-year-old female, who was operated recently for mitral valve replacement (MVR) under cardiopulmonary bypass due to severe mitral valve insufficiency. This patient had been operated due to the secundum-type atrial septal defect in our institution previously. The last one, a 3-year-old boy, with DOMV and three papillary muscles, was on clinical follow-up because he had no symptoms.  相似文献   
63.
64.
Tear tumor necrosis factor alpha (TNF-alpha), transforming growth factor beta 1 (TGF-beta1), and epidermal growth factor (EGF) levels were determined in patients with inactive trachoma, and a possible relation between these cytokines and conjunctival cicatrization severity was investigated. Forty-four patients with inactive trachoma who were admitted to the Department of Ophthalmology at the Harran University, Sanliurfa, Turkey, were included in this study. The control group consisted of 20 age- and sex-matched healthy subjects. The levels of cytokines in tears were measured by ELISA. Tear samples were collected from the conjunctival cul-de-sac by means of blunted-tip glass capillary tubes. Eyes with inactive trachoma were classified into three subgroups with respect to conjunctiva cicatrization: mild, moderate, and severe. In 44 patients with inactive trachoma, conjunctival cicatrization was found, including mild (n = 15), moderate (n = 16), and severe (n = 13) cases. In patients with inactive trachoma, decreases in tear EGF (p = 0.000) concentrations and increases in tear TGF-beta1 (p = 0.006) and TNF-alpha (p = 0.046) levels with respect to the control group were found to be concordant with conjunctival cicatrization severity. Statistically significant correlations in tear TNF-alpha (p = 0.018), TGF-beta1 (p = 0.007), and EGF (p = 0.043) levels were found between mild and severe cicatrization groups. TNF-alpha and TGF-beta1 have been implicated in the fibrogenic process. Elevated tear levels of inflammatory/fibrogenic cytokines may play an important role in scar formation in trachoma. It is possible that decreased tear levels of EGF, which may be important for the maintenance of corneal epithelial integrity, are related to fibrosis in the lacrimal gland ductules.  相似文献   
65.
BACKGROUND: Progress has been made in the design of bioabsorbable implants, with reduced complication rates and slower degradation times. PURPOSE: To report on complications related to use of poly-L-lactic acid implants after arthroscopic shoulder stabilization procedures. STUDY DESIGN: Retrospective cohort study. METHODS: Between 1997 and 1999, 52 patients underwent arthroscopic stabilization at one institution with an average of 2.2 poly-L-lactic acid tacks. Ten patients (19%), with an average age of 30 years, developed delayed onset of symptoms at an average of 8 months after surgery, including pain in all 10 and progressive stiffness in 6. The patients underwent magnetic resonance imaging and arthroscopic evaluation and debridement. RESULTS: Nine patients had gross implant debris. Evidence of glenohumeral synovitis was seen arthroscopically in all 10 patients. Three patients had significant full-thickness chondral damage on the humeral head. All preexisting labral lesions were healed. One year after arthroscopic debridement, loose body removal, and synovectomy, seven patients reported no or minimal pain and full return of motion. Two patients continued to have persistent pain and stiffness, and one patient reported discomfort with overhand throwing; all three had chondral lesions. CONCLUSIONS: Patients with symptoms of delayed pain and progressive stiffness after arthroscopic stabilization with poly-L-lactic acid implants should be evaluated for synovitis and chondral injury. Arthroscopic treatment provides a significant decrease in symptoms and increased range of motion.  相似文献   
66.
Lipoma arborescens; successfully treated by yttrium-90 radiosynovectomy   总被引:1,自引:0,他引:1  
Although radiosynovectomy (RS) applications have been carried out for many years, clinical indications of this non-invasive procedure is thought to be limited probably due to the lack of information of clinicians. Clinicians' preferential indication for RS is the treatment-resistant synovitis of individual joints, i.e. despite systemic pharmacotherapy and intra-articular steroid injections. We present here a case of "lipoma arborescens" treated by yttrium-90, which is a rare intra-articular lesion characterized by villous proliferation of the synovial membrane and hyperplasia of subsynovial fat. The results of clinical, biochemical and hematological examinations, magnetic resonance (MR) imaging, arthroscopy and histological analysis have shown that the etiology was lipoma arborescens in a female patient, aged 36 having swelling and sometimes associating pain at her right knee for 4 years. We have applied to our patient's right knee RS with 185 MBq yttrium-90 colloid together with 40 mg of methylprednisolone acetate, although in our literature survey we have not met any similar case being treated with such indication. Even a year after the application, the patient has absolutely benefited from the treatment clinically, and this was also confirmed by comparative MR images (pre- and post-treatment). Consequently, we consider that Y-90 treatment might be applicable in suitable cases with lipoma arborescens.  相似文献   
67.
The aim of the present study was to evaluate the possibility that aminophylline could serve as a potential myocardial protectant by measuring cardiac troponin T (TnT) and troponin I (TnI) during coronary artery bypass grafting (CABG). Twenty patients were randomly divided into two groups. Ten patients received aminophylline, 200 mg orally per day for 3 days preoperatively (aminophylline group, AG), and 10 patients received placebo (control group, CG). Blood samples were collected before induction of anesthesia (T0), after 30 min of aortic cross clamping (ACC) (T1), and 1, 24, and 48 h postoperatively (T2, T3, T4). Serum concentrations of TnT, TnI, and creatine kinase-MB (CK-MB) were measured. Perioperative hemodynamic data were recorded and cardiac hemodynamics were evaluated by echocardiography preoperatively and 5-7 days after surgery. There were no adverse events in either group. Preoperative serum levels of TnT and TnI were similar. Their concentrations increased after T1 and, peaked at T2 (0.50+/-0.30 vs. 0.30+/-0.40 ng/ml, and 0.50+/-0.30 vs. 7.90+/-2.70 ng/ml, respectively, P<0.001), and progressively declined until T4. The CK-MB levels of both groups also supported these results. After completion of cardiopulmonary bypass (CPB), the serum concentrations of all enzymes in both groups were significantly higher than before CPB (P<0.001), and serum TnT and TnI levels were significantly lower at T1, T2, T3, and T4 in AG (P<0.001). There was no significant difference in echocardiographic data, cardiac index, ejection fraction or any other hemodynamic parameter between the groups. Fewer patients needed inotropic support (one vs. three patients) (P=0.6) and experienced atrial fibrillation (AF) (one vs. four patients) (P=0.3) in the AG after surgery, although not statistically significant. Although there was no statistically valid evidence to indicate that aminophylline improved clinical outcome in this study, several biochemical endpoints suggested that it reduced I-R damage at the cellular level, and such subtle improvement could be clinically significant in high-risk patients.  相似文献   
68.
We report a case of isolated nasopharyngeal aspergillosis in a 52-year-old woman with Hashimoto's thyroiditis. We found the nasopharyngeal lesion incidentally while evaluating bilateral cervical lymphadenopathy, which we had discovered during a routine follow-up examination pursuant to the patient's thyroid problem. Biopsy analysis of the nasopharyngeal lesion revealed the presence of a mycelium made up of septate hyphae and associated oxalosis. Mycologic examination confirmed that Aspergillus flavus was the responsible pathogen. No systemic involvement or involvement of other head and neck sites was found. The patient had been exposed to a considerable amount of dust during the construction of her house, and this may have been the precipitating factor in the development of her infection. We treated the patient with a 4-week course of itraconazole. At the end of therapy, she exhibited no evidence of A flavus on physical and mycologic examinations.  相似文献   
69.
Whether nasopharyngeal content passes into the middle ear in patients without any head and neck pathology during the recovery phase of anesthesia is shown with an objective and prospective method. Thirty-eight patients, 21 female and 17 male, aged between 17 and 76, were included in the study. During the recovery phase of general anesthesia, 10 ml of 5 mCi Tc-99m-MAA was administered intranasally to the patients with a 10-F catheter. A manometer-adapted cuffed intubation tube was placed in the nasal passage so that the cuff was located at the choana. The pressure changes reflecting to the nasopharynx were recorded. The patients were extubated 10 min after the radionuclide was applied. The scintigraphic evaluation was done at the end of the 1st hour of the application of radionuclide. Transmission and emission views were taken with a gamma camera. Passage of nasopharyngeal content into the middle ear via the eustachian tube was not a statistically significant observation. The mean value of maximum pressure reflecting from the nasopharynx did not differ significantly between patients. Our study does not support the hypothesis that nasopharyngeal content passes directly through the eustachian tube into the middle ear and causes deleterious effects.  相似文献   
70.
Echinococcosis is the most widespread, serious human cestode infection in the world. Isolated retrovesical cyst hydatid is extremely rare in children and mostly causes symptoms because of its pressure on adjacent organs. We report on the case of an 8-year-old girl with an isolated retrovesical cyst hydatid. Final diagnosis was established after histological examination, whereas imaging techniques failed to establish the diagnosis.  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