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   162篇
  免费   4篇
儿科学   3篇
妇产科学   8篇
基础医学   24篇
口腔科学   10篇
临床医学   5篇
内科学   34篇
皮肤病学   1篇
神经病学   2篇
特种医学   1篇
外科学   7篇
综合类   6篇
预防医学   40篇
眼科学   2篇
药学   13篇
肿瘤学   10篇
  2023年   2篇
  2022年   5篇
  2021年   18篇
  2020年   10篇
  2019年   16篇
  2018年   10篇
  2017年   12篇
  2016年   9篇
  2015年   10篇
  2014年   8篇
  2013年   9篇
  2012年   9篇
  2011年   4篇
  2010年   4篇
  2009年   15篇
  2008年   10篇
  2007年   3篇
  2006年   1篇
  2005年   3篇
  2004年   4篇
  1997年   1篇
  1996年   1篇
  1993年   1篇
  1992年   1篇
排序方式: 共有166条查询结果,搜索用时 15 毫秒
1.
The interaction between MDMA and Nicotine affects multiple brain centres and neurotransmitter systems (serotonin, dopamine and glutamate) involved in motor coordination and cognition. In this study, we have elucidated the effect of prolonged (10 days) MDMA, Nicotine and a combined Nicotine-MDMA treatment on motor-cognitive neural functions. In addition, we have shown the correlation between the observed behavioural change and neural structural changes induced by these treatments in BALB/c mice. We observed that MDMA (2 mg/Kg body weight; subcutaneous) induced a decline in motor function, while Nicotine (2 mg/Kg body weight; subcutaneous) improved motor function in male periadolescent mice. In combined treatment, Nicotine reduced the motor function decline observed in MDMA treatment, thus no significant change in motor function for the combined treatment versus the control. Nicotine or MDMA treatment reduced memory function and altered hippocampal structure. Similarly, a combined Nicotine-MDMA treatment reduced memory function when compared with the control. Ultimately, the metabolic and structural changes in these neural systems were seen to vary for the various forms of treatment. It is noteworthy to mention that a combined treatment increased the rate of lipid peroxidation in brain tissue.  相似文献   
2.
ObjectiveTo assess the association between the employment status of human immunodeficiency virus (HIV)-infected individuals and adherence to antiretroviral therapy (ART).MethodsWe searched the Medline, Embase and Cochrane Central Register of Controlled Trials databases for studies reporting ART adherence and employment status published between January 1980 and September 2014. Information from a wide range of other sources, including the grey literature, was also analysed. Two independent reviewers extracted data on treatment adherence and study characteristics. Study data on the association between being employed and adhering to ART were pooled using a random-effects model. Between-study heterogeneity and sources of bias were evaluated.FindingsThe meta-analysis included 28 studies published between 1996 and 2014 that together involved 8743 HIV-infected individuals from 14 countries. The overall pooled odds ratio (OR) for the association between being employed and adhering to ART was 1.27 (95% confidence interval, CI: 1.04–1.55). The association was significant for studies from low-income countries (OR: 1.85, 95% CI: 1.58–2.18) and high-income countries (OR: 1.33, 95% CI: 1.02–1.74) but not middle-income countries (OR: 0.94, 95% CI: 0.62–1.42). In addition, studies published after 2011 and larger studies showed less association between employment and adherence than earlier and small studies, respectively.ConclusionEmployed HIV-infected individuals, particularly those in low- and high-income countries, were more likely to adhere to ART than unemployed individuals. Further research is needed on the mechanisms by which employment and ART adherence affect each other and on whether employment-creation interventions can positively influence ART adherence, HIV disease progression and quality of life.  相似文献   
3.
Sleep and Breathing - Obesity is a common risk factor for polycystic ovary syndrome (PCOS) and obstructive sleep apnoea (OSA). Both PCOS and OSA are associated with increased risk of type 2...  相似文献   
4.
The Principles of Green Chemistry was employed for the preparation of organic antiseptic soaps with improved skin sensitivity, reduced skin toxicity and improved biodegradability. Non-conventional and lesser known tropical seeds of Momordica charantia were used as the source of oil for the saponification processes. The fatty acid methyl esters of the oil were prepared via transesterification and subjected to GC–MS analysis to obtain the fatty acid composition of the oil and saponified products were subjected to various physicochemical and antimicrobial evaluations. The results indicated that stearic acid (18:0) and eleostearic acid (18:3) were the most abundant fatty acids making up 37.60% and 39.16%, respectively. Palmitic acid (16:0) 12.36%, oleic acid (18:1) 8.71%, linoleic acid (18:2) 0.67% and gamolenic acid (18:3) 1.50% were present in smaller amount in the oil. The oil is a viable source of polyunsaturated fatty acid which is required as essential fatty acids in the human body. The prepared soaps containing only natural additives (such as honey and shear butter) and components showed appreciable degree of hardness comparable to commercial Dudu Osun and the synthetic Lux soaps used as standards. This work demonstrates the probability of the preparation of green antiseptic soaps from the underutilized tropical seed of M. charantia. The seed oil and the allied products obviously have great potential for further advancement, development, research and applications in health and cosmetics sectors. The adopted approach could also assist maintaining a safe and healthy biotic and abiotic environment.  相似文献   
5.
Risk factors for ectopic pregnancy in Lagos, Nigeria   总被引:14,自引:0,他引:14  
BACKGROUND: Ectopic pregnancy is an important cause of maternal deaths in Nigeria and in other developing countries. In Lagos, Nigeria, it is responsible for 8.6% of maternal deaths, and has a case fatality rate of 3.7%. The purpose of this study was to determine the risk factors for ectopic pregnancy in Lagos. METHODS: A case-control study of 100 patients and 280 controls was performed in the three hospitals--Lagos University Teaching Hospital, Ayinke House Maternity Hospital, and Lagos Island Maternity Hospital--in Lagos from June 1999 to December 1999. Data were analyzed by using logistic regression. RESULTS: The incidence was 23.1/1000 (1 : 43) deliveries and was responsible for 48.5% of gynecologic emergencies. Age, marital status, socioeconomic status, and parity were not the significant risk factors for ectopic pregnancy. An early age of sexual debut increased the risk of ectopic pregnancy almost two-fold (adjusted OR = 1.93; 95% CI = 1.71-2.93), whereas a late age of sexual debut was protective (adjusted OR = 0.37; 95% CI = 0.19-0.59). History of multiple lifetime sexual partners, induced abortions, pelvic inflammatory disease, sexually transmitted disease (STD), miscarriage, and pelvic surgery independently and significantly increased the risk of ectopic pregnancy. Induced abortion and STD increased the risk 14-fold and nine-fold, respectively. Previous use of intrauterine contraceptive device increased the risk almost four-fold (adjusted OR = 3.76; 95% CI = 2.12-6.69), whereas the use of condoms was protective (adjusted OR = 0.35; 95% CI = 0.17-0.71). CONCLUSIONS: Proper sex education, prevention of unwanted pregnancy, and prevention and proper treatment of sexually transmitted infections will reduce the incidence of ectopic pregnancy.  相似文献   
6.
PURPOSE: To evaluate black to white differences in treatment for colorectal cancer. METHODS: Only whites or blacks diagnosed with colon or rectal cancer between 1988 and 1997 were identified from SEER database. RESULTS: A total of 106,377 (91.3% white, 50.5% male) patients formed the study population. The vast majority of these patients received standard cancer treatment. Although the number of subjects who did not receive such treatment was small, their proportion was higher among blacks than among whites. The odds of non-receipt of surgical treatment was higher among blacks than whites for stage I (OR = 2.08, 95% CI, 1.41, 3.03 among males; OR = 2.38, 95% CI, 1.69, 3.45 among females) and stage IV colon cancer (OR = 1.25, 95% CI, 1.01, 1.56 among males; OR = 1.41; 95% CI, 1.14, 1.72 among females). A similar pattern was also seen for most stages of rectal cancer. CONCLUSIONS: Most black and white colorectal cancer patients received standard treatment. Although the number of subjects without standard treatment was small, their proportion was higher among blacks than among whites. Blacks were also more likely to refuse recommended treatment. Efforts in educating black patients about the benefits of treatment may help to eliminate the remaining racial disparity.  相似文献   
7.
OBJECTIVE: Hypertension may result from changes in dietary quality and nutrient intake. We therefore sought to determine the epidemiological association between tooth loss and hypertension in South African adults. METHODS: This is a secondary data analysis of a cross-sectional survey of a nationally representative sample of adults aged 25 - 70 years who participated in the South African Demographic and Health Survey during 1998 (N = 9 098). The primary data were collected using a validated questionnaire, which included information on past experience of tooth loss (partial or complete), use of dental services, tobacco use and other known risk factors for hypertension. Hypertension was defined as having a measured average blood pressure (BP) > or = 160/95 mmHg and/or taking antihypertensive medication. RESULTS: The prevalences of hypertension, any tooth loss and complete edentulousness were 18.1%, 72.2% and 9.4% respectively. Tooth loss was more common among overweight/obese respondents than among those with a normal body mass index (76.7% v. 66.7%; p < 0.01). Compared with the fully dentate respondents, the completely edentulous respondents had mean systolic and diastolic BPs that were respectively 12 mmHg and 5 mmHg higher. After adjusting for known risk factors for hypertension in a multiple logistic regression model, being completely edentulous remained significantly associated with hypertension (odds ratio 1.35, 95% confidence interval 1.02 - 1.78). The estimated population-attributable fraction of hypertension resulting from complete edentulousness was 10%. CONCLUSIONS: The findings suggest that complete edentulousness is a risk indicator for hypertension in South Africa and highlights the importance of primary care practitioner involvement in oral health promotion.  相似文献   
8.

Background  

Violence against women, especially by intimate partners, is a serious public health problem that is associated with physical, reproductive and mental health consequences. Even though most societies proscribe violence against women, the reality is that violations against women's rights are often sanctioned under the garb of cultural practices and norms, or through misinterpretation of religious tenets.  相似文献   
9.

Background

Graph theoretical methods are extensively used in the field of computational chemistry to search datasets of compounds to see if they contain particular molecular sub-structures or patterns. We describe a preliminary application of a graph theoretical method, developed in computational chemistry, to geographical epidemiology in relation to testing a prior hypothesis. We tested the methodology on the hypothesis that if a socioeconomically deprived neighbourhood is situated in a wider deprived area, then that neighbourhood would experience greater adverse effects on mortality compared with a similarly deprived neighbourhood which is situated in a wider area with generally less deprivation.

Methods

We used the Trent Region Health Authority area for this study, which contained 10,665 census enumeration districts (CED). Graphs are mathematical representations of objects and their relationships and within the context of this study, nodes represented CEDs and edges were determined by whether or not CEDs were neighbours (shared a common boundary). The overall area in this study was represented by one large graph comprising all CEDs in the region, along with their adjacency information. We used mortality data from 1988–1998, CED level population estimates and the Townsend Material Deprivation Index as an indicator of neighbourhood level deprivation. We defined deprived CEDs as those in the top 20% most deprived in the Region. We then set out to classify these deprived CEDs into seven groups defined by increasing deprivation levels in the neighbouring CEDs. 506 (24.2%) of the deprived CEDs had five adjacent CEDs and we limited pattern development and searching to these CEDs. We developed seven query patterns and used the RASCAL (Rapid Similarity Calculator) program to carry out the search for each of the query patterns. This program used a maximum common subgraph isomorphism method which was modified to handle geographical data.

Results

Of the 506 deprived CEDs, 10 were not identified as belonging to any of the seven groups because they were adjacent to a CED with a missing deprivation category quintile, and none fell within query Group 1 (a deprived CED for which all five adjacent CEDs were affluent). Only four CEDs fell within Group 2, which was defined as having four affluent adjacent CEDs and one non-affluent adjacent CED. The numbers of CEDs in Groups 3–7 were 17, 214, 95, 81 and 85 respectively. Age and sex adjusted mortality rate ratios showed a non-significant trend towards increasing mortality risk across Groups (Chi-square = 3.26, df = 1, p = 0.07).

Conclusion

Graph theoretical methods developed in computational chemistry may be a useful addition to the current GIS based methods available for geographical epidemiology but further developmental work is required. An important requirement will be the development of methods for specifying multiple complex search patterns. Further work is also required to examine the utility of using distance, as opposed to adjacency, to describe edges in graphs, and to examine methods for pattern specification when the nodes have multiple attributes attached to them.  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