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   254篇
  免费   17篇
耳鼻咽喉   10篇
儿科学   2篇
妇产科学   12篇
基础医学   30篇
口腔科学   3篇
临床医学   24篇
内科学   51篇
皮肤病学   4篇
神经病学   11篇
特种医学   3篇
外科学   43篇
综合类   2篇
预防医学   35篇
眼科学   23篇
药学   11篇
中国医学   4篇
肿瘤学   3篇
  2022年   1篇
  2021年   4篇
  2020年   1篇
  2019年   5篇
  2018年   7篇
  2017年   5篇
  2016年   9篇
  2015年   10篇
  2014年   7篇
  2013年   11篇
  2012年   34篇
  2011年   27篇
  2010年   17篇
  2009年   9篇
  2008年   25篇
  2007年   18篇
  2006年   8篇
  2005年   18篇
  2004年   9篇
  2003年   5篇
  2002年   10篇
  2001年   7篇
  2000年   4篇
  1999年   7篇
  1998年   2篇
  1997年   1篇
  1996年   1篇
  1995年   1篇
  1985年   1篇
  1983年   1篇
  1976年   1篇
  1969年   1篇
  1968年   1篇
  1965年   1篇
  1932年   1篇
  1923年   1篇
排序方式: 共有271条查询结果,搜索用时 15 毫秒
1.
Obesity Surgery - Laparoscopic sleeve gastrectomy (LSG) is increasingly playing a key role in obesity management. Such operations, however, carry complications sometimes including leaks. The...  相似文献   
2.
Five new microsatellite loci were described and characterized for use as molecular markers for the identification and genetic differentiation of Candida albicans strains. Following the typing of 72 unrelated clinical isolates, the analysis revealed that they were all polymorphic, presenting from 5 to 30 alleles and 8 to 46 different genotypes. The discriminatory power obtained by combining the information generated by three microsatellites used in a multiplex PCR amplification strategy was 0.99, the highest ever reported. The multiplex PCR was later used to test a total of 114 C. albicans strains, including multiple isolates from the same patient collected from different body locations and along episodes of vulvovaginal infections. Three different scenarios for strain relatedness were identified: (i) different isolates that were revealed to be the same strain, (ii) isolates that were the same strain but that apparently underwent a process of microevolution, and (iii) isolates that corresponded to different strains. Analysis of the microevolutionary changes between isolates from recurrent infections indicated that the genotype alterations observed could be the result of events that lead to the loss of heterozygosity (LOH). In one case of recurrent infection, LOH was observed at the CAI locus, and this could have been related to exposure to fluconazole, since such strains were exposed to this antifungal during treatment. The analysis of microsatellites by a multiplex PCR strategy was found to be a highly efficient tool for the rapid and accurate differentiation of C. albicans strains and adequate for the identification of fine microevolutionary events that could be related to strain microevolution in response to environmental stress conditions.  相似文献   
3.
Unsealed radionuclides have been in clinical therapeutic use for well over half a century. Following the early inappropriate clinical administrations of radium salts in the early 20th century, the first real clinical benefits became evident with the use of (131)I-sodium iodide for the treatment of hypothyroidism and differentiated thyroid carcinoma and (32)P-sodium phosphate for the treatment of polycythaemia vera. In recent years the use of bone seeking agents (89)Sr, (153)Sm and (186)Re for the palliation of bone pain have become widespread and considerable progress has been evident with the use of (131)I-MIBG and (90)Y-somatostatin receptor binding agents. Although the use of monoclonal antibody based therapeutic products has been slow to evolve, the start of the 21st century has witnessed the first licensed therapeutic antibody conjugates based on (90)Y and (131)I for the treatment of non-Hodgkin's lymphoma. The future clinical utility of this form of therapy will depend upon the development of radiopharmaceutical conjugates capable of selective binding to molecular targets. The availability of some therapeutic radionuclides such as (188)Re produced from the tungsten generator system which can produce activity as required over many months, may make this type of therapy more widely available in some remote and developing countries.Future products will involve cytotoxic radionuclides with appropriate potency, but with physical characteristics that will enable the administration of therapeutic doses with the minimal need for patient isolation. Further developments are likely to involve molecular constructs such as aptamers arising from new developments in biotechnology.Patient trials are still underway and are now examining new methods of administration, dose fractionation and the clinical introduction of alpha emitting radiopharmaceutical conjugates. This review outlines the history, development and future potential of these forms of therapy.  相似文献   
4.
To test the hypothesis that cholesterol might suppress the beneficial effect of olive oil in atherosclerosis, we fed apoE KO mice diets containing extra virgin olive oil, either with or without cholesterol, for 10 weeks and assessed the development of atherosclerosis. Within each sex, mice were assigned randomly to one of the following four experimental groups: (1) a standard chow diet, (2) a chow diet supplemented with 0.1% cholesterol (w/w) cholesterol, (3) a chow diet enriched with 20% (w/w) extra virgin olive oil and (4) a chow diet containing 0.1% cholesterol and 20% extra virgin olive oil. On the standard chow diet, average plasma cholesterol levels were higher in males than in females. Olive oil- and cholesterol-enriched diets, separately or in combination, induced hypercholesterolemia in both sexes, and abolished the difference between the sexes in plasma cholesterol levels. The addition of cholesterol to chow or olive oil diets decreased apolipoprotein A-I significantly in females and serum paraoxonase activities in males. The latter activity was higher in females than in males. In both sexes, the size of aortic atherosclerotic lesions was similar in olive oil- and chow-fed animals and smaller than in cholesterol-supplemented groups. Size of aortic lesions were positively correlated with circulating paraoxonase activity, particularly in males, and the relationship remained after adjusting for apolipoprotein A-I and HDL cholesterol levels. Our results demonstrate that the nutritional regulation of paraoxonase is an important determinant of atherosclerotic lesions dependent on sex. They also suggest that the mere inclusion of olive oil in Western diets is insufficient and the adoption of Mediterranean diet would be more effective in retarding the development of atherosclerotic lesions.  相似文献   
5.

Background

The under-5 mortality rate (U5MR) is an important metric of child health and survival. Country-level estimates of U5MR are readily available, but efforts to estimate U5MR subnationally have been limited, in part, due to spatial misalignment of available data sources (e.g., use of different administrative levels, or as a result of historical boundary changes).

Methods

We analyzed all available complete and summary birth history data in surveys and censuses in six countries (Bangladesh, Cameroon, Chad, Mozambique, Uganda, and Zambia) at the finest geographic level available in each data source. We then developed small area estimation models capable of incorporating spatially misaligned data. These small area estimation models were applied to the birth history data in order to estimate trends in U5MR from 1980 to 2015 at the second administrative level in Cameroon, Chad, Mozambique, Uganda, and Zambia and at the third administrative level in Bangladesh.

Results

We found substantial variation in U5MR in all six countries: there was more than a two-fold difference in U5MR between the area with the highest rate and the area with the lowest rate in every country. All areas in all countries experienced declines in U5MR between 1980 and 2015, but the degree varied both within and between countries. In Cameroon, Chad, Mozambique, and Zambia we found areas with U5MRs in 2015 that were higher than in other parts of the same country in 1980. Comparing subnational U5MR to country-level targets for the Millennium Development Goals (MDG), we find that 12.8% of areas in Bangladesh did not meet the country-level target, although the country as whole did. A minority of areas in Chad, Mozambique, Uganda, and Zambia met the country-level MDG targets while these countries as a whole did not.

Conclusions

Subnational estimates of U5MR reveal significant within-country variation. These estimates could be used for identifying high-need areas and positive deviants, tracking trends in geographic inequalities, and evaluating progress towards international development targets such as the Sustainable Development Goals.
  相似文献   
6.
Research suggests that conjugated linoleic acid (CLA) may inhibit atherosclerosis, but there are contradictory results in different animal models fed heterogeneous mixtures of CLA isomers. This study addressed the hypothesis that the individual CLA isomers may exert different atherogenic properties. ApoE(-/-) mice were fed isocaloric, isonitrogenous westernized diets containing 0.15% cholesterol and enriched with 1% (w/w) cis-9,trans-11-CLA (c9,t11-CLA), trans-10,cis-12-CLA (t10,c12-CLA) or linoleic acid (control diet) for 12 weeks. At the end of the dietary intervention, the effects of CLA isomers on the development of atherosclerotic vascular lesions, lipid metabolism, inflammation and oxidative stress were assessed. The t10,c12-CLA diet had a profound pro-atherogenic effect, whereas c9,t11-CLA impeded the development of atherosclerosis. En face aortic lesion assessment showed more dorsal and lumbar extensions presenting atherosclerotic foci after the t10,c12-CLA diet. Furthermore, animals fed t10,c12-CLA had pronounced hyperlipidemia, higher 8-iso-prostaglandin F(2alpha) levels, higher vulnerable atherosclerotic plaque with a lower smooth muscle and fibre contents and higher macrophage content and activation, assayed as plasma chitotriosidase compared to the control or c9,t11-CLA dietary groups. Plasma chitotriosidase activity was more closely associated with the extent of the plaque than with MOMA staining or than monocyte chemoattractant protein-1 levels. Our results demonstrate that CLA isomers differentially modulate the development of atherosclerosis, c9,t11-CLA impedes, whereas t10,c12-CLA promotes atherosclerosis. These opposing effects may be ascribed to divergent effects on lipid, oxidative, inflammatory and fibro muscular components of this pathology. Plasma chitotriosidase is a better indicator of dietary fat interventions that alter plaque monocyte activity in this murine model.  相似文献   
7.
8.
Antiphospholipid syndrome is accepted as one of the most important causes of hypercoagulable states. Thrombotic events in patients with antiphospholipid syndrome, predominantly women, occur at a younger age than in those suffering from atherosclerotic disease. The majority of the thrombotic events affect the deep venous system of the lower limbs and arterial thrombosis predominates in the cerebral territory. The use of anticoagulant therapy prevents recurrent thrombosis but the duration and intensity of treatment remain controversial. Aortic disease is an anecdotal fact in the literature. A case of infrarenal aortic occlusion involving both iliac arteries associated with primary antiphospholipid syndrome is presented.  相似文献   
9.
ApoA-IV is a protein constituent of HDL particles; the gene coding for it is a member of the ApoA-I-ApoC-III-ApoA-IV cluster. To investigate the effects of the quantity and the degree of saturation of dietary lipid on the long-term response of this Apo, and on the hypothetical coordinated regulation of the cluster in vivo, pigs were fed isoenergetic, cholesterol-free, low-lipid or lipid-enriched diets (containing either extra olive oil (rich in MUFA) or sunflower oil (rich in n-6 PUFA)) for 42 d. In animals fed on the control diet, ApoA-IV was mainly associated with plasma lipoproteins. An increase in plasma ApoA-IV concentration, mainly in the lipoprotein-free fraction, was induced by the lipid-enriched diets, independent of the degree of saturation of the fatty acids involved. The latter diets also led to increases in hepatic ApoA-I, ApoA-IV and ApoC-III mRNA levels, more so with the sunflower oil-rich diet. The present results show that porcine plasma ApoA-IV levels and their association with lipoproteins are very sensitive to increases in dietary lipids, independent of the degree of fatty acid saturation. Furthermore, hepatic expression of RNA appears to be coordinated along with that of the other members of the gene cluster.  相似文献   
10.
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