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   393篇
  免费   13篇
  国内免费   3篇
儿科学   17篇
妇产科学   4篇
基础医学   50篇
口腔科学   35篇
临床医学   17篇
内科学   58篇
皮肤病学   1篇
神经病学   49篇
特种医学   8篇
外科学   29篇
综合类   1篇
预防医学   60篇
眼科学   15篇
药学   44篇
中国医学   2篇
肿瘤学   19篇
  2023年   1篇
  2021年   5篇
  2020年   3篇
  2019年   6篇
  2018年   9篇
  2017年   4篇
  2016年   8篇
  2015年   8篇
  2014年   11篇
  2013年   13篇
  2012年   29篇
  2011年   29篇
  2010年   17篇
  2009年   15篇
  2008年   26篇
  2007年   45篇
  2006年   36篇
  2005年   37篇
  2004年   31篇
  2003年   30篇
  2002年   27篇
  2001年   2篇
  1999年   2篇
  1997年   2篇
  1996年   3篇
  1991年   1篇
  1989年   1篇
  1988年   1篇
  1978年   1篇
  1976年   2篇
  1975年   1篇
  1974年   2篇
  1968年   1篇
排序方式: 共有409条查询结果,搜索用时 15 毫秒
51.
AIMS: Diabetic dyslipidaemia with decreased high-density lipoprotein-cholesterol (HDL-C) concentration plays a key role in enhanced atherosclerosis. The antioxidant effect of HDL is due to the influence of human paraoxonase 1 (PON1) and several authors have described decreased activity of this enzyme in Type 2 diabetics and subjects with metabolic syndrome. The goal of this study was to examine the effect of daily ciprofibrate on serum PON1 and lipoprotein concentrations in patients with metabolic syndrome. METHODS: Fifty-one patients with metabolic syndrome were enrolled into the study. We examined the effect of 100 mg day(-1) ciprofibrate treatment on lipid concentrations, oxidized low-density lipoprotein (LDL), PON1 concentrations and activity. We also investigated the calculated size of LDL-cholesterol (LDL-C). RESULTS: During the 3-month study, it was observed that following treatment with ciprofibrate, the serum triglyceride concentration decreased significantly (from 2.76 +/- 0.9 mmol l(-1) to 2.27 +/- 1.6 mmol l(-1); -18%; P < 0.001), while HDL-C increased significantly (from 0.95 +/- 0.2 mmol l(-1) to 1.2 +/- 0.3 mmol l(-1); 26%; P < 0.001). The oxidatively modified LDL-C concentration decreased significantly (from 137 +/- 19 U l(-1) to 117 +/- 20 U l(-1); P < 0.001), while HDL-associated apolipoprotein A1 significantly increased (from 1.35 +/- 0.2 g l(-1) to 1.75 +/- 0.3 g l(-1); P < 0.001). The LDL-C/LDL-apoB ratio, which reflects the size of LDL, increased significantly (from 0.96 +/- 0.05 to 1.05 +/- 0.06; P < 0.05). Serum PON1 activity was significantly elevated (from 108 +/- 34 U l(-1) to 129 +/- 31 U l(-1); P < 0.05), while standardized values for HDL-C remained significantly unchanged (PON1/HDL-C) (from 114 +/- 21 to 107 +/- 20; NS). CONCLUSION: Three months of treatment with ciprofibrate favourably affected the lipid profile, increased LDL resistance to oxidation and improved antioxidant status by increasing serum paraoxonase activity in these patients.  相似文献   
52.
The Traumatology Department of the University of Debrecen Medical and Health Science Center and that of the Kenezy Gyula Hospital of Hajdu Bihar County guarantees 24 hour service for outpatient trauma patients, which makes up around one hundred thousand cases per year. A very important element of the quality control is the continual assessment and supervision of the specialist performance, and the indicator is the change in the number of selected, incorrectly treated cases. The supervised cases make up a total of 24% of the total outpatient turnover. In 2003, 24313 injury cases, and in 2004, 23705 cases were examined with respect to documentation, and x-ray films. During the supervision, the treatment of the chosen cases are assessed weekly and discussed in conference. The case discussion is one of the valuable pillars of residence training. Our method contributes to the safeguarding of an appropriate standard for specialist work in an outpatient setting, and for this reason we wish to present it.  相似文献   
53.
54.
Salivary mucus and amylase have an anti-bacterial nature. Bacterial endotoxin is considered to decrease mucus secreting cell activity by nitric oxide-dependent mechanisms. In this study, the actions of endotoxin on amylase secreting cell activity have been studied. Endotoxin (Escherichia coli lipopolysaccharide; 3 mg/kg, i.v., 5 h) evoked nitric oxide synthase 2 (NOS2) induction in the rat whole parotid tissue (assessed by Western blot and the citrulline assay) and in rat isolated parotid acinar cells (assessed by Western blot and immunohistochemistry), and reduced basal and acetylcholine-stimulated amylase secretion from these isolated cells. However, N(G)-nitro-L-arginine methyl ester (0.1 mg/ml, 4 days in drinking water, yielding a dose of 25 mg/kg/day) did not affect amylase release under basal or acetylcholine-stimulated conditions, either in control acinar cells or those from endotoxin challenged rats. Thus, basal, acetylcholine-evoked or endotoxin-decreased cellular amylase secretion from rat isolated parotid acinar cells does not appear to be modulated by endogenous nitric oxide.  相似文献   
55.
PURPOSE: To examine the keratan sulfate content of the stroma and to assess its correlation with the healing process (epithelialization and keratocyte density) after photorefractive keratectomy (PRK). METHODS: Using an Aesculap Meditec MEL 70(G-scan) excimer laser, -6.0 diopters (6.0-mm diameter, 82 microm photoablation depth), PRK was carried out on the right eye of 32 New Zealand pigmented rabbits. After enucleation (at days 1, 4, 7, 14, and 28 and months 2, 3, and 7; sub-groups of 4 animals), fluorescent immunohistochemistry was performed on sections from the central comea using monoclonal mouse anti-keratan-sulfate antibody, immunohistochemistry with proliferative cell nuclear antigen antibody, and hematoxylin-eosin histology. The left, untreated eyes served as controls. Cellular morphology and spatial distribution of keratan sulfate were recorded, stromal thickness measured, and keratocyte density calculated. RESULTS: Keratan sulfate was found on the surface of migrating epithelial cells in the early stage (from days 1 to 7). In the stroma, three phases were noted. (Phase 1) Day 1 to 14, intense granular fluorescence appeared in the anterior stroma with hypocellularity. (Phase 2) Month 1 to 2, newly synthesized lamellar keratan sulfate restored the repopulating anterior stroma. Endothelial cells became keratan sulfate positive, while in the posterior stroma, lamellar-form keratan sulfate increased from week 1 and peaked at month 1 (100% increase). (Phase 3) Month 2 to 7, remodeling and deposition of keratan sulfate was noted, which was produced in phase 2. CONCLUSIONS: Keratan sulfate was found in the epithelium, stroma, and endothelium. By controlling the interlamellar spacing, keratan sulfate plays a role in postoperative edema, remodeling of the corneal stroma, and simultaneous regulation of inflammation after PRK.  相似文献   
56.
BACKGROUNDS/AIMS: To assess the age- and gender-specific anthropometric parameters and blood pressure in Hungarian adolescents. METHODS: A cross-sectional study was performed between 1997 and 2000. Altogether 6,345 secondary school students (aged 15-18 years) were involved in the study. The representative sampling sites were selected randomly. In the capital city 3-stage and in the counties 4-stage stratified groups were assigned for the studies. Statistical analysis was performed using SPSS for Windows 9.0. RESULTS: The age- and gender-specific percentile distributions are given with regard to body weight, body height, body mass index (BMI), waist circumference, waist-to-hip ratio and arterial blood pressure values. Elevated blood pressure values were found at the first recording in 14.1% of the boys and in 2.5% of the girls. Since it is well known that the arterial blood pressure (ABP) may exhibit considerable intra- individual fluctuation with time, we therefore categorized normotensive and hypertensive students on the basis of the mean ABP values calculated from data obtained during the course of the three separate consecutive measurement periods at least 2 weeks apart. After that, the incidence of high blood pressure was 7.5% in boys and 1.1% in girls. CONCLUSION: The age- and gender-specific cutoff values thus formed may serve as reference values to assess the risk of developing nutrition-related noninfectious diseases in the future on the basis of the present percentile distribution of BMI. The present study also provides data on the prevalence of hypertension in the 15- to 18-year-old age group.  相似文献   
57.
The inner membrane of the ATP-producing organelles of endosymbiotic origin, mitochondria, has long been considered to be poorly permeable to cations and anions, since the strict control of inner mitochondrial membrane permeability is crucial for efficient ATP synthesis. Over the past 30 years, however, it has become clear that various ion channels—along with antiporters and uniporters—are present in the mitochondrial inner membrane, although at rather low abundance. These channels are important for energy supply, and some are a decisive factor in determining whether a cell lives or dies. Their electrophysiological and pharmacological characterisations have contributed importantly to the ongoing elucidation of their pathophysiological roles. This review gives an overview of recent advances in our understanding of the functions of the mitochondrial potassium channels identified so far. Open issues concerning the possible molecular entities giving rise to the observed activities and channel protein targeting to mitochondria are also discussed.  相似文献   
58.
Chronic obstructive pulmonary disease (COPD) is a complex, multifactorial inflammatory disease of the airways and the pulmonary parenchyme, caused by infection, air pollution and particles. 4-7% of the adult population is involved. COPD is the 4th-6th common cause of death throughout the world. The main aetiological factor is smoking. Bacteria, such as bacteria from the oral cavity, could play a keyrole in the progression of the disease. Epidemiologic studies have noted a relationship between poor oral hygiene or periodontal bone loss and chronic obstructive pulmonary disease. The prevalence and mortality of the disease is increasing worldwide, the treatment is expensive, the efficiency of the present pharmacotherapy is poor, so the importance of prevention should be increasing. Patients with chronic obstructive pulmonary disease (COPD) are prone to frequent exacerbations which are a significant cause of morbidity and mortality. This review is a short summary of studies about the possible relationship between periodontitis and COPD.  相似文献   
59.
The bacterial pneumonia is one of the most frequent complications leading to death among hospitalized patients. The morbidity and mortality of pneumonia is extremely high in the intensive care units and in chronic nursing stations, especially in institutes dealing with old patients. The most common form of lung infection is the aspiration pneumonia. Periodontal diseases play an evident role in the etiology of aspiration pneumonia due to their effect to alter the oral bacterial flora. Authors review the significance of pathogen microorganisms originating from the oral cavity in the development of bacterial pneumonia. The extent of the affected population is discussed and the importance of their oral hygiene and bacterial flora is also specified. The bacterial, enzymatic and molecular pathomechanisms leading to aspiration pneumonia are described, and high risk populations and treatment types are determined. The possibilities of prevention methods for aspiration pneumonia are fully explained and recent directions of actual researches and proposals to minimize the incidence of this disease are summarized.  相似文献   
60.
On the contrary to hyposalivation/xerostomia there is a little attention paid in the literature for discussing the problem of the patient having too much saliva. In most of cases, pathogenesis of sialorrhea is not known. Due to the small number of patients involved in the studies it is difficult to get exact data. In addition to that, there is no consensus either on the terminology of sialorrhea or a preferable method which should be used to achieve the best diagnostic and therapeutic approaches. Sialorrhea may occur in all age groups of population either as a consequence of increased salivary gland secretion or oral incontinence and impaired swallowing. Based on a recently published paper hypersalivation should be considered as the primary form of sialorrhea, and drooling corresponds to its secondary form. Each condition may seriously affect the physical activity, the functioning of different organs, communication, the psychosocial status of the patients. Based on a wide horizon of published data this review is focused on the terminology, methods of assessment, etiology, frequency, symptoms, and therapy of sialorrhea with special emphasis on its dental aspects.  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