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   1914篇
  免费   98篇
  国内免费   3篇
耳鼻咽喉   17篇
儿科学   75篇
妇产科学   32篇
基础医学   173篇
口腔科学   46篇
临床医学   141篇
内科学   369篇
皮肤病学   37篇
神经病学   153篇
特种医学   35篇
外科学   436篇
综合类   48篇
一般理论   9篇
预防医学   135篇
眼科学   35篇
药学   172篇
中国医学   22篇
肿瘤学   80篇
  2024年   2篇
  2023年   16篇
  2022年   67篇
  2021年   85篇
  2020年   49篇
  2019年   75篇
  2018年   70篇
  2017年   38篇
  2016年   45篇
  2015年   54篇
  2014年   85篇
  2013年   98篇
  2012年   160篇
  2011年   135篇
  2010年   91篇
  2009年   81篇
  2008年   105篇
  2007年   107篇
  2006年   98篇
  2005年   93篇
  2004年   71篇
  2003年   63篇
  2002年   59篇
  2001年   40篇
  2000年   47篇
  1999年   21篇
  1998年   11篇
  1997年   8篇
  1996年   9篇
  1995年   9篇
  1994年   11篇
  1993年   6篇
  1992年   14篇
  1991年   17篇
  1990年   14篇
  1989年   7篇
  1988年   2篇
  1987年   8篇
  1986年   7篇
  1985年   4篇
  1984年   5篇
  1983年   5篇
  1982年   2篇
  1981年   3篇
  1979年   3篇
  1978年   4篇
  1973年   3篇
  1969年   1篇
  1947年   1篇
  1946年   1篇
排序方式: 共有2015条查询结果,搜索用时 15 毫秒
1.
Lucio phenomenon is an atypical reaction of leprosy, characterized by vasculitic lesions that can mimic antiphospholipid syndrome (APS) clinically. Distinguishing the two can be difficult as antiphospholipid autoantibodies may be present in patients with leprosy. We report on a 32‐year‐old female patient presenting with a sudden onset of fever, hemorrhagic bullae, and skin necrosis on her lower legs. She was treated for APS due to the presence of antiphospholipid antibodies but had an inadequate response. A skin biopsy revealed thrombotic vasculopathy and necrotizing vasculitis associated with aggregation of foam cells in the perivascular area and subcutis, with acid‐fast bacilli in the histiocytes and blood vessel walls. Direct immunofluorescence showed IgM, C3, and fibrinogen deposition in the superficial and deep dermal blood vessels. The pathology confirmed the diagnosis of Lucio phenomenon, and appropriate therapy was given. It is essential to evaluate the patient comprehensively, including clinical, serological, and pathological aspects, to obtain the correct diagnosis.  相似文献   
2.
Arsenic (As) and cadmium (Cd) have recently emerged as major health concerns owing to their strong association with diabetes mellitus (DM). We aimed to investigate the heavy metals exposure towards incidence of DM at various enzymatic and hormonal levels. Additionally, association of As and Cd with Zinc (Zn, essential metal) was also evaluated. Spot urine samples were collected to assess As, Cd and Zn through ICP-OES. Serum was analyzed by assay method for fasting blood glucose, liver and renal function biomarkers. ELISA was performed to investigate the impact of heavy metals on HbA1c, α-amylase, DPP-IV, IGF-1, leptin, GSH, MDA, SOD, HDL, FFA, TG and interleukin (IL)-6. Association of heavy metals with DM was measured by odds ratio (OR) and level of significance was assessed by Chi-squared test. Unpaired student's t-test was used to compare DM-associated risk factors in heavy metals-exposed and unexposed participants. As and Cd were detectable in 75.4% and 83% participants with mean concentration of 75.5 ppb and 54.5 ppb, respectively. For As exposure, OR in the third quartile was maximum ie 1.34 (95% CI, 0.80 to 2.23), however the result was not statistically significant (P > .05). For Cd exposure, OR in the fourth quartile was considerably high, 1.62 (95% CI, 1.00 to 2.61), with a significant probability value (P < .05). Urinary Cd was negatively associated with Zn. As and Cd exposure increases the incidence of DM in the general population. Impaired hormonal and enzymatic levels in diabetic and non-diabetic exposed participants reflect the multiple organ damage by heavy metal exposure.  相似文献   
3.
Histamine‐2 receptor antagonists are a class of drugs used to treat the acid‐related gastrointestinal diseases such as ulcer and gastro‐oesophageal reflux disease. Although such drugs, especially ranitidine and famotidine, are still widely used, their effects on semen quality, and hence on male infertility, is still unclear. This MiniReview systematically addresses and summarizes the effect of histamine‐2 receptor antagonists (cimetidine, ranitidine, nizatidine and famotidine) on semen quality, particularly, on sperm function. Cimetidine appears to have adverse effects on semen quality. While the effects of ranitidine and nizatidine on semen quality are still controversial, famotidine does not appear to change semen quality. Therefore, additional studies will be required to clarify whether histamine‐2 receptor‐independent effects of these drugs play a role in semen quality as well as further clinical studies including direct comparison of the histamine‐2 receptor antagonists.  相似文献   
4.
The aim of this study was to examine the predictors of long-term survival (>24 months) in patients with gall bladder cancer. A retrospective review of 117 cases of gall bladder cancer resected between 1989 and 2000. The resections included 80 simple cholecystectomies and 37 extended procedures. Patients with survival >24 months (n=44) were compared with those having survival <24 months (n=73) for 17 prognostic factors. Overall median survival was 16 months with a 5-year survival of 27%. T status (P=.000) and adjuvant chemoradiotherapy (P=.001) were independent predictors of long-term survival. Survival advantage was seen in T3N+ve disease (P=.007) with extended procedures. Complete (R0) resection was attained in 30 patients with a 5-year survival advantage of 30% as compared with incomplete (R1) resection (P=.0002). Adjuvant chemoradiotherapy improved survival in simple cholecystectomy group (P=.0008) but no advantage was seen after extended procedures. Stage III (P=.001) and node-positive disease (P=.0005) had significant benefit with adjuvant therapy. Poor differentiation and vascular invasion were associated with poor long-term survival. R0 resection was associated with prolonged survival. Extended procedures improved survival in patients with T3N+ve disease. Addition of chemoradiotherapy made significant improvement in long-term survival in stage III and node-positive lesions and in patients undergoing simple cholecystectomy. R0 resection predicted long-term survival in gall bladder cancer. T3 N+ve disease had better survival after extended procedures. Adjuvant chemoradiotherapy improved survival in stage III and node-positive disease. Poor differentiation and vascular invasion were adverse predictors of survival.  相似文献   
5.
6.
Duodenogastric reflux (DGR) has been implicated in several disease processes. The present study was carried out to document the incidence and evaluate the clinical significance of DGR after choledochoduodenostomy (CDD). A total of 13 patients who had undergone cholecystectomy with a standard side-to-side CDD for choledocholithiasis or chronic pancreatitis were studied by symptom evaluation, scintigraphy, endoscopy, and gastric mucosal histology at least 6 months after surgery. The scintigraphic findings were then compared with those of 10 patients who had undergone cholecystectomy alone. Only two patients (15%) had mild dyspeptic symptoms. The incidence of DGR after CDD was 69% compared to 20% in the cholecystectomy alone group (P < 0.05). In the majority of patients the DGR was only mild to moderate and the severity correlated well with the degree of endoscopic gastritis, but not with the clinical symptoms or histological findings. These results indicate that while CDD is associated with a high incidence of DGR, its occurrence does not produce significant clinical symptoms.  相似文献   
7.
We report an African infant with Ellis‐van Creveld (EVC) syndrome. EVC syndrome is a chondral and ectodermal dysplasia with autosomal recessive transmission. The baby presented with polydactyly, short limbs and atrioventricular septal defect, but was withdrawn from clinical follow up for the first year of life. Initial hematological abnormalities could not be explained and normalized later. EVC syndrome was confirmed by genetic analysis that showed two pathogenic mutations in the EVC2 gene, c.653_654del, p.Val218Glyfs*12 in exon 5, and c.2710C>T, p.Gln904* in exon 16. The variant c.653_654del; p.Val218Glyfs*12 in exon 5 has not been described before. Our review of medical literature suggested this is the first molecularly confirmed case of EVC syndrome in sub‐Saharan Africa.  相似文献   
8.
Calcifying aponeurotic fibroma is a rare benign fibrous tumor with typical radiological and histopathological features seen in young children and adolescents. It commonly involves the extremities and is characterized by a very high chance of local recurrence. A complete excision of the tumor is considered to be the treatment of choice. We report a case of the tumor involving the substance of achilles tendon and extending up till its insertion in the calcaneum. To the best of our knowledge, this is the largest reported case of calcifying fibroma, with the tumor measuring 10 cm in its largest diameter. The tumor was excised in toto followed by reconstruction of the tendon defect with V-Y plasty of the native tendon and supplemented with semitendinosus and gracilis graft. There was no evidence of recurrence during the follow up period of 1 year.  相似文献   
9.
The mutagenic and toxic effects of trifluoperazine and bleomycin on Drosophila were investigated in the progenies of males injected with 0.2 microliter of bleomycin and/or trifluoperazine. The Muller-5 method was used to study the induction of complete- and mosaic-sex-linked recessive lethals induced by 0.1 microgram/ml bleomycin and/or 0.1 mM trifluoperazine in the five successive broods, mainly representing the different stages of spermatogenesis. Trifluoperazine increased the induction rate of sex-linked recessive mutations above the spontaneous rates of the control, but these increases were not statistically significant at the 5% level27 in any of the five different broods. Contrary to trifluoperazine, bleomycin significantly (5% level)27 increased the induction rate of the complete sex-linked recessive lethals over those of the control in the meiotic and premeiotic broods C and D, and the meiotic brood E. As with the separate treatment with bleomycin, the frequencies of the complete sex-linked recessive lethals induced by the simultaneous combination treatment of 0.1 microgram/ml bleomycin and 0.1 mM trifluoperazine were significantly higher than those of the control at the 5%27 level, only in the meiotic and premeiotic broods, but they were not significantly higher than those induced by bleomycin treatment alone19. Treatments with 0.1 mM trifluoperazine enhanced the toxicity, sterility and the number of mutated clusters induced by 0.1 mM bleomycin but did not significantly increase the rates of induced lethals over the additive effects of both drugs in the meiotic and premeiotic stages, suggesting no potentiation effects for trifluoperazine over those of bleomycin in Drosophila. Higher concentrations of the two drugs could not be used due to their high toxicity and sterility effects.  相似文献   
10.

Correspondence

Someone should write a letter  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