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   2949篇
  免费   119篇
  国内免费   32篇
耳鼻咽喉   18篇
儿科学   34篇
妇产科学   61篇
基础医学   340篇
口腔科学   27篇
临床医学   341篇
内科学   770篇
皮肤病学   50篇
神经病学   278篇
特种医学   126篇
外科学   427篇
综合类   7篇
一般理论   2篇
预防医学   120篇
眼科学   14篇
药学   247篇
中国医学   3篇
肿瘤学   235篇
  2024年   3篇
  2023年   10篇
  2022年   29篇
  2021年   70篇
  2020年   27篇
  2019年   46篇
  2018年   59篇
  2017年   46篇
  2016年   46篇
  2015年   67篇
  2014年   89篇
  2013年   115篇
  2012年   237篇
  2011年   240篇
  2010年   113篇
  2009年   111篇
  2008年   229篇
  2007年   250篇
  2006年   197篇
  2005年   211篇
  2004年   221篇
  2003年   197篇
  2002年   167篇
  2001年   19篇
  2000年   10篇
  1999年   25篇
  1998年   47篇
  1997年   36篇
  1996年   26篇
  1995年   33篇
  1994年   19篇
  1993年   12篇
  1992年   9篇
  1991年   11篇
  1990年   12篇
  1989年   8篇
  1988年   5篇
  1987年   3篇
  1986年   8篇
  1985年   7篇
  1984年   7篇
  1983年   7篇
  1982年   5篇
  1981年   8篇
  1978年   2篇
  1977年   1篇
排序方式: 共有3100条查询结果,搜索用时 0 毫秒
51.
52.
Amiodarone-induced thyrotoxicosis (AIT) is a common complication of amiodarone therapy. Although permanent withdrawal of amiodarone is recommended due notably to the risk of worsening of tachyarrhythmias, some patients may require the reintroduction of amiodarone several months after normalizing their thyroid function. We, retrospectively, assessed the effects of (131)I therapy to prevent recurrence of AIT in euthyroid patients requiring reintroduction of amiodarone. SUBJECTS AND METHODS: Amiodarone was required in 10 cases of recurrent symptomatic paroxysmal atrial fibrillation (AF) and in 5 cases of ventricular tachycardia (VT) (M = 12, F = 3, mean age: 63 +/- 14). The underlying heart disease was dilated cardiomyopathy (n = 4), ischaemic heart disease (n = 4), hypertensive heart disease (n = 2), arrhythmogenic right ventricular dysplasia (n = 27) and valvulopathy (n = 1). Two patients had idiopathic paroxysmal AF. RESULTS: A mean (131)I dose of 579 +/- 183 MBq was administered 34 +/- 37 after the episode of AIT. Amiodarone was reintroduced in 14 of 15 patients after a mean interval of 103 +/- 261 d. Fourteen patients developed definite hypothyroidism necessitating l-thyroxine but we observed no late recurrence of AIT. After a mean follow-up of 22 +/- 16 months, tachyarrhythmias were controlled in 12 of 14 patients. CONCLUSION: (131)I therapy appears to be an effective and safe approach to prevent the recurrence of AIT in a patient requiring the reintroduction of amiodarone for tachyarrhythmias.  相似文献   
53.
The aim of this study was to assess resting energy expenditure in patients with chronic pancreatitis; 33 patients with alcohol-related chronic pancreatitis (group 1: 13 normal weight, group 2: 20 underweight) and 11 undernourished patients without identifiable disease (group 3) were studied. Body composition was determined by bioelectric impedance analysis and energy expenditure by indirect calorimetry. The percentage of body weight occupied by fat-free mass was similar among the three groups (76.4±1.5%, 78.6±1.3% and 76.8±2.1% for groups 1, 2, and 3, respectively). The measured resting energy expenditure (REE) was higher than the predicted EE (Harris and Benedict formula and Cunningham's equation) for the underweight patients with chronic pancreatitis (group 2) (P<0.05), but not for the two other groups. According to Cunningham's equation, 65% of the group 2 patients were hypermetabolic (REE>110% of predicted EE) versus 23.1% and 20% in groups 1 and 3. When adjusted for fat free mass, REE was significantly (P<0.01) higher in group 2 (35.0±0.9 kcal/kg/24 hr) than in the other two groups (30.1±0.7 kcal/kg/24 hr and 30.8±1.4 kcal/kg/24 hr in groups 1 and 3, respectively). During chronic pancreatitis, weight loss is accompanied by hypermetabolism, which should be taken into consideration during nutritional support.  相似文献   
54.
Monitoring airway inflammation by means of induced sputum cell counts seems to improve the management of asthma. We sought to assess whether such monitoring at the end of periods at and away from work combined with the monitoring of PEF could improve the diagnosis of occupational asthma. We enrolled subjects suspected of having occupational asthma. Serial monitoring of PEF was performed during 2 weeks at and away from work. At the end of each period, induced sputum was collected. Specific inhalation challenge was subsequently performed. PEF graphs were interpreted visually by five independent observers. Forty-nine subjects, including 23 with positive specific inhalation challenge, completed the study. The addition of sputum cell counts to the monitoring of PEF increased the specificity of this test, respectively, by 18 (range [r] 13.7-25.5) or 26.8% (r 24.8-30.4) depending if an increase of sputum eosinophils greater than 1 or 2% when at work was considered as significant. The sensitivity increased by 8.2% (r 4.1-13.4) or decreased by 12.3% (r 3.1-24.1) depending on the cutoff value in sputum eosinophils chosen (greater than 1 or 2%, respectively). The addition of sputum cell counts to PEF monitoring is useful to improve the diagnosis of occupational asthma.  相似文献   
55.
Outcome and treatment of Bartonella endocarditis   总被引:5,自引:0,他引:5  
BACKGROUND: Endocarditis caused by Bartonella species is a potentially lethal infection characterized by a subacute evolution and severe valvular lesions. OBJECTIVES: To evaluate the outcome of patients with Bartonella endocarditis and to define the best antibiotic regimen using the following measures: recovery, relapse, or death. METHODS: We performed a retrospective study on 101 patients who were diagnosed in our laboratory as having Bartonella endocarditis between January 1, 1995, and April 30, 2001. Bartonella infection was diagnosed using immunofluorescence with a 1:800 cutoff, polymerase chain reaction amplification of DNA, and/or culture findings of Bartonella species from whole blood, serum, and/or valvular biopsy specimens. A standardized questionnaire was completed by investigators for each patient. RESULTS: Twelve of the 101 patients died and 2 relapsed. Patients receiving an aminoglycoside were more likely to fully recover (P =.02), and those treated with aminoglycosides for at least 14 days were more likely to survive than those with shorter therapy duration (P =.02). CONCLUSION: Effective antibiotic therapy for Bartonella endocarditis should include an aminoglycoside prescribed for a minimum of 2 weeks.  相似文献   
56.
Recent studies have suggested that esophageal human papillomavirus infection could be a risk factor for esophageal squamous cell carcinoma. The aim of this study was to evaluate the prevalence of human papillomavirus DNA sequences in the esophagus of French patients with esophageal squamous cell carcinoma. Multiplex polymerase chain reactions with consensus primers directed to the L1 gene or specific primers for human papillomavirus types 6, 11, 16, 18, 31, and 33 directed to E6 gene (40 cycles followed by restriction mapping of the amplified products) were used to determine the presence of human papillomavirus DNA sequences in esophageal squamous cell carcinoma (n = 75), normal adjacent mucosa (n = 49), and metastatic lymphadenopathies (n = 5). As an internal control, a target located in the embryonic myosin heavy-chain gene was used in each reaction. Human papillomavirus DNA sequences could not be detected in any of the tumoral samples, the normal adjacent mucosa, or the metastatic lymphadenopathies. Human papillomavirus seems not to be implicated in esophageal carcinogenesis, at least in French patients, because the viral genomes are not associated with esophageal squamous cell carcinomas.  相似文献   
57.
Background: Ki-ras mutation analysis from material collected during ERCP has been claimed to improve the diagnosis of pancreatic and bile duct carcinomas as compared with conventional cytology. Our aim was to study the relative contribution of both Ki-ras analysis and brush cytology in patients with a significant stricture at ERCP. Methods: Brushings were collected in duplicate for both analyses in 142 patients in whom a definitive diagnosis was obtained by histology or a minimal follow-up of 6 months. Results: For pancreatic strictures, sensitivity, specificity, and accuracy of Ki-ras analysis vs. cytology in detecting malignancy were 81% vs. 66%, 72% vs. 100%, and 70% vs. 74%, respectively. For biliary strictures, they were 25% vs. 42%, 100% vs. 100%, and 35% vs. 43%, respectively. The combination of the two methods only marginally increased their sensitivity and accuracy in both types of strictures. Conclusion: Ki-ras analysis is a sensitive method for diagnosing pancreatic but not biliary carcinoma. However, its specificity is lowered by a high frequency of Ki-ras mutations in patients with chronic pancreatitis (25%) who did not manifest cancer development within a 6-month follow-up period. In pancreatic duct strictures, brush cytology appears to be more specific in detecting malignancy; specificity for Ki-ras and cytology are equivalent for the diagnosis of malignant bile duct strictures. Therefore, making a clinical decision on the sole basis of Ki-ras analysis is probably not justified in the majority of the cases. (Gastrointest Endosc 1998;47:479-85.)  相似文献   
58.
METHODS: Forty-one consecutive patients with Crohn's disease who underwent long-term seton drainage for high transsphincteric, suprasphincteric, or extrasphincteric anal fistula from 1985 to 1993 were reviewed. The subsequent associated procedure was simple seton removal (18), secondary fistulotomy (7), rectal flap advancement (3), and proctectomy (2). Eleven patients still had the seton in place. RESULTS: Recurrence developed in seven patients (39 percent) undergoing simple seton removal and in one patient undergoing rectal flap advancement. None of the patients treated by secondary fistulotomy developed a recurrence. At the end of follow-up, five patients (12 percent) required proctectomy mainly for severe proctitis, and five patients (12 percent) developed anal incontinence, which was severe in two. CONCLUSION: Long-term seton drainage for high anal fistula in Crohn's disease is efficacious in both treating sepsis and preserving anal sphincter function.  相似文献   
59.
Introduction: The number of grown-up congenital heart disease (GUCH) patients is steadily increasing. Unfortunately, the majority of these patients suffer from late sequelae, with heart failure being the most common cause of death. Exercise training is beneficial and safe in patients with acquired heart failure, as well as in asymptomatic GUCH patients. However, its effect remains unknown in symptomatic GUCH patients. This could cause reticence on positive sports advice, with possible counterproductive effects.

Areas covered: A review of current literature was performed to evaluate the effect of exercise training in symptomatic (NYHA≥2) GUCH patients. The search yielded a mere three studies including symptomatic patients, and another six studies including also patients in NYHA 1 without making clear distinction between the NYHA subgroups.

Expert commentary: Suboptimal trial designs, low patient numbers, and homogeneity of investigated cardiac anomalies make this review insufficient to draw definite conclusions. However, all studies describe overall positive effects of exercise training in symptomatic GUCH patients in terms of exercise capacity and quality of life. There were no safety concerns. Larger-scaled, randomized controlled trials are needed to obtain certainty.  相似文献   

60.
Leka, a New Platelet Antigen Absent in Glanzmann''s Thrombasthenia   总被引:1,自引:0,他引:1  
The serum of a patient who developed a posttransfusion purpura contained antibodies directed against a previously undescribed platelet antigen Lek a. The antiplatelet activity was present in the IgG fraction and was detected by immunofluorescence, 51Cr lysis and 14C-serotonin release. The frequency of the Lek a phenotype in the French population is 98.18%. Lek a does not appear to be sex-linked and seems to be closely related to the Bak a antigen. The Lek a antigen is not expressed on thrombasthenic platelets but is found on platelets from patients with the Bernard-Soulier syndrome which suggests that this antigen is carried by platelet glycoproteins IIb and/or IIIa.  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