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   4312篇
  免费   435篇
  国内免费   23篇
耳鼻咽喉   52篇
儿科学   177篇
妇产科学   165篇
基础医学   448篇
口腔科学   120篇
临床医学   321篇
内科学   980篇
皮肤病学   198篇
神经病学   150篇
特种医学   417篇
外国民族医学   6篇
外科学   618篇
综合类   125篇
预防医学   291篇
眼科学   61篇
药学   351篇
中国医学   27篇
肿瘤学   263篇
  2023年   13篇
  2022年   74篇
  2021年   151篇
  2020年   102篇
  2019年   177篇
  2018年   194篇
  2017年   153篇
  2016年   153篇
  2015年   187篇
  2014年   235篇
  2013年   276篇
  2012年   268篇
  2011年   265篇
  2010年   197篇
  2009年   203篇
  2008年   149篇
  2007年   176篇
  2006年   142篇
  2005年   149篇
  2004年   124篇
  2003年   106篇
  2002年   115篇
  2001年   35篇
  2000年   33篇
  1999年   48篇
  1998年   96篇
  1997年   69篇
  1996年   85篇
  1995年   57篇
  1994年   60篇
  1993年   56篇
  1992年   38篇
  1991年   20篇
  1990年   28篇
  1989年   45篇
  1988年   48篇
  1987年   44篇
  1986年   33篇
  1985年   35篇
  1984年   28篇
  1983年   19篇
  1982年   25篇
  1981年   27篇
  1980年   24篇
  1979年   24篇
  1978年   19篇
  1977年   25篇
  1976年   18篇
  1975年   13篇
  1967年   12篇
排序方式: 共有4770条查询结果,搜索用时 125 毫秒
1.
2.
Purpose  Congenital clasped thumb is a deformity that is associated with heterogeneous congenital anomalies and it has been addressed in many congenital syndromes. The aim of this study was to diagnose and evaluate cases of clasped thumb as regards the associated congenital anomalies and syndromes, and evaluation of the results of treatment of such cases. Methods  A prospective study on 40 patients with 73 clasped thumbs was done. All the patients’ data regarding their personal, family, pregnancy and developmental histories were recorded. All the patients were exposed to thorough clinical and radiological examination and genetic assessment. The cases were classified using the Tsuyuguchi et al. (J Hand Surg [Am] 10:613–618, 1985) classification into three types. Conservative treatment was adopted in ten hands, and surgical treatment was performed for 28 hands in 17 patients, with an average follow-up of 26 months. Results  Positive consanguinity was recorded in 57.5% of cases. Associated anomalies were recorded in 77.5% of cases. Type I was the most common one, followed by type III and then type II. Conservative treatment is effective in type I cases when presented early, and all patients were satisfied with the results of surgical treatment. Conclusions  We reported associated anomalies which are to our knowledge have not mentioned before in the literature which include; congenital blindness, radial deviation of the index finger and ventricular septal defect. We found that 68% of the patients had associated syndromes, and this has not been mentioned before. In this study, we found that there were no difference between type II and type III clasped thumb as regards the pathological findings, severity, the operative procedures, the treatment protocol and the operative results. Properly planned treatment gives satisfactory results.  相似文献   
3.
目的 探讨创伤后迟发性脑肿胀的临床特点、发病机制与治疗。方法 回顾性分析1998年1月~2005年6月年收治的17例迟发性脑肿胀患者的临床特点和救治情况。结果 所有颅脑损伤患者采用保守治疗后均有好转,但于伤后5-10d出现恶化,CT复查有脑肿胀,经加强综合脱水等治疗后16例治愈,1例死亡。结论 迟发性脑肿胀好发于对冲性额、颞叶挫裂伤伴明显蛛网膜下腔出血、硬膜下薄层血肿及早期CT有脑肿胀者。其发病机制可能与创伤后的迟发性脑血管痉挛、微循环障碍、静脉回流障碍及甘露醇作用下降等因素有关。此类患者病情隐蔽性强,应加强观察、积极行CT复查,如能早期明确诊断,保守治疗多数效果良好。  相似文献   
4.
Retrorenal colon: implications for percutaneous diskectomy   总被引:1,自引:0,他引:1  
Helms  CA; Munk  PL; Witt  WS; Davis  GW; Morris  J; Onik  G 《Radiology》1989,171(3):864-865
It has been recommended that computed tomography (CT) with the patient prone be performed in every patient undergoing percutaneous diskectomy; this would enable detection of a retrorenal location of the colon, which could interfere with the percutaneous procedure. In this evaluation of 346 prone CT studies, only one patient (0.29%) was found to have retrorenal or retropsoas bowel that would have been perforated at diskectomy. Because of this extremely low prevalence, the performance of prone CT in every patient undergoing percutaneous lumbar diskectomy is not believed to be necessary.  相似文献   
5.
6.
7.
BACKGROUND: Transforming growth factor-beta(1) (TGF-beta(1)) is the major fibrogenic growth factor implicated in the pathogenesis of renal scarring. Proteinuria is a poor prognostic feature for various types of glomerular disease and its toxic action may be related to the activation of tubular epithelial cells towards increased production of cytokines and chemoattractant peptides. In this work we studied the site of synthesis and expression profile of TGF-beta(1) in the renal tissue of patients with heavy proteinuria and examined the relation of this expression with the urinary excretion of TGF-beta(1). METHODS: Twenty-five patients with heavy proteinuria (8.4+/-3.0 g/24 h) were included in the study. All patients underwent a diagnostic kidney biopsy and were commenced on immunosuppressive therapy with corticosteroids and cyclosporin. The sites of synthesis and expression profile of TGF-beta(1) mRNA and protein in the kidney were examined by in situ hybridization and immunohistochemistry. Urinary and plasma TGF-beta(1) levels were determined by ELISA before the initiation of treatment and 6 months later and compared with those of normal subjects and of patients with IgA nephropathy and normal urinary protein excretion. RESULTS: The site of synthesis and expression of TGF-beta(1) in the renal tissue of patients with heavy proteinuria was mainly localized within the cytoplasm of tubular epithelial cells. Interstitial expression was also present but glomerular TGF-beta(1) expression was found only in patients with mesangial proliferation. Urinary TGF-beta(1) excretion was significantly higher in nephrotic patients compared with normal subjects and with patients with IgA nephropathy and normal urinary protein excretion (783+/-280 vs 310+/-140 and 375+/-90 ng/24 h, respectively; P<0.01). In patients with remission of proteinuria after immunosuppressive therapy, urinary TGF-beta(1) excretion was significantly reduced (from 749+/-290 to 495+/-130 ng/24 h; P<0.01), while in patients with persistent nephrotic syndrome, it remained elevated. CONCLUSIONS: The localization of TGF-beta(1) mRNA and protein within tubular epithelial cells, along with its increased urinary excretion in patients with nephrotic syndrome, suggest the activation of these cells by filtered protein towards increased TGF-beta(1) production.  相似文献   
8.
9.
Eleven patients with portal hypertension due to infection with Schistosoma mansoni underwent splenectomy and devascularization operations. The patients were examined with ultrasound once preoperatively and twice postoperatively over a period of about 6 months. Following surgery there was significant and sequential reduction in the diameter of the portal vein at the hilum and the splenic vein at the pancreas. The liver lengths and index of liver size did not change significantly. No changes in the degree of periportal fibrosis could be detected.  相似文献   
10.
There are significant variations among countries in the incidence of brain abscess. We report here 26 cases of brain abscess treated at the Neurosurgery Department of King Faisal University and Dammam Central Hospital Saudi Arabia over a six year period (1982–1988). This is 2.3% of total admissions to the two neurosurgery departments serving a population of approximately 1.2 million in the same period.Young males were most often affected (M/F ratio 3.3:1; 31% were less than 15 years old, 46% aged between 15–39 years, and 23% older than 40 years). Streptococcus was found to be the most common microorganism (38.4%). Mixed infection was seen in 15.3%, and sterile abscesses were found in 11.5% of the patients after aerobic and anaerobic cultures of the pus. Chronic otitis media and paranasal sinusitis predisposed the patients to abscess formation in 57.6% of the cases. The temporo-parietal area was the commonest site. Epilepsy was a complication in 30.7% of our patients, and the mortality rate was 15.3%.  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