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   4079篇
  免费   289篇
  国内免费   24篇
耳鼻咽喉   31篇
儿科学   153篇
妇产科学   115篇
基础医学   458篇
口腔科学   95篇
临床医学   335篇
内科学   921篇
皮肤病学   62篇
神经病学   337篇
特种医学   132篇
外国民族医学   5篇
外科学   726篇
综合类   117篇
一般理论   1篇
预防医学   280篇
眼科学   73篇
药学   278篇
中国医学   33篇
肿瘤学   240篇
  2023年   38篇
  2022年   95篇
  2021年   152篇
  2020年   100篇
  2019年   119篇
  2018年   149篇
  2017年   89篇
  2016年   108篇
  2015年   121篇
  2014年   173篇
  2013年   197篇
  2012年   270篇
  2011年   303篇
  2010年   188篇
  2009年   163篇
  2008年   201篇
  2007年   213篇
  2006年   211篇
  2005年   250篇
  2004年   190篇
  2003年   177篇
  2002年   156篇
  2001年   74篇
  2000年   69篇
  1999年   81篇
  1998年   25篇
  1997年   26篇
  1996年   16篇
  1995年   28篇
  1994年   16篇
  1993年   19篇
  1992年   29篇
  1991年   18篇
  1990年   26篇
  1989年   20篇
  1988年   18篇
  1987年   17篇
  1986年   23篇
  1985年   21篇
  1984年   15篇
  1983年   14篇
  1982年   15篇
  1981年   11篇
  1979年   12篇
  1978年   20篇
  1976年   10篇
  1973年   10篇
  1972年   13篇
  1969年   15篇
  1966年   9篇
排序方式: 共有4392条查询结果,搜索用时 15 毫秒
41.
42.
BACKGROUND: Schistosoma haematobium infection causes severe urinary disease and considerable mortality. The factors that determine disease progression from mild to severe stages are not fully understood. METHODS: Here we describe a cross-sectional epidemiological study of kidney and bladder diseases in 2 Dogon populations with different exposure to S. haematobium infection. RESULTS: Early and high exposure resulted in more-severe disease, especially among young subjects, without clear evidence of a more-rapid development of immunity. Nevertheless, 50%-60% of subjects of all age classes in both villages showed no evidence of disease. Kidney and bladder disease peaked biphasically among young subjects and adults >25 years old. The first peak corresponded with infections of maximum intensity, whereas the second peak occurred among adults with infections of very low intensity. Kidney disease was correlated with circulating anodic antigen concentration in serum, whereas bladder disease was correlated with egg count and eosinophil cationic protein concentration in urine. Kidney and bladder disease did not correlate. Severe kidney disease was more frequent in certain families. CONCLUSIONS: The frequency of urinary disease is increased by infections acquired early during life, is regulated by strong clinical immunity in certain subjects, and may be dependent on hereditary factors. Kidney and bladder disease may involve different mechanisms of pathogenesis, which may differ between children and adults.  相似文献   
43.
44.
45.
46.

Background

The maternal, newborn, and child health (MNCH) indicators of Pakistan depict the deplorable state of the poor and rural women and children. Many MNCH programmes stress the need to engage the poor in community spaces. However, caste and class based hierarchies and gendered social norms exclude the lower caste poor women from accessing healthcare. To find pathways for improving the lives of the excluded, this study considers the social system as a whole and describes the mechanisms of exclusion in the externally created formal community spaces and their interaction with the indigenous informal spaces.

Methods

The study used a qualitative case study design to identify the formal and informal community spaces in three purposively selected villages of Thatta, Rajanpur, and Ghizer districts. Community perspectives were gathered by conducting 37 focus group discussions, based on participatory rural appraisal tools, with separate groups of women and men. Relevant documents of six MNCH programmes were reviewed and 25 key informant interviews were conducted with programme staff.

Results

We found that lower caste poor tenants and nomadic peasants were excluded from formal and informal spaces. The formal community spaces formed by MNCH programmes across Pakistan included fixed, small transitory, large transitory, and emerging institutional spaces. Programme guidelines mandated selection of community notables in groups/committees and used criteria that prevented registration of nomadic groups as eligible clients. The selection criteria and adverse attitude of healthcare workers, along with inadequacy of programmatic resources to sustain outreach activities also contributed to exclusion of the lower caste poor women from formal spaces. The informal community spaces were mostly gender segregated. Infrequently, MNCH information trickled down from the better-off to the lower caste poor women through transitory interactions in the informal domestic sphere.

Conclusion

A revision of the purpose and implementation mechanisms for MNCH programmes is mandated to transform formal health spaces into sites of equitable healthcare.
  相似文献   
47.
BACKGROUND: Chlorofluorocarbons (CFCs) have historically served as the propellants of choice in pressurised metered-dose asthma inhalers, but concern has been raised in recent decades regarding their damaging effect on the ozone layer. Among the alternative propellants being considered is alcohol, which can be used as a co-solvent in asthma inhalers. Healthcare professionals need to be aware of alcohol-containing inhalers, since certain populations may have religious and/or cultural concerns regarding the use of such preparations. OBJECTIVES: To identify pressurised metered-dose asthma inhalers which contain alcohol-based propellants. METHODS: We searched the British National Formulary to identify companies that manufacture asthma treatments and wrote to them to enquire about which of their products contained alcohol and if so in what percentage. These direct contacts were supplemented by searching medical databases and the Internet for additional information. RESULTS: We identified 11 manufacturers of asthma inhalers, seven of which produced pressurised metered-dose inhalers; of these, six were willing to disclose the requested information, and information on the seventh product was obtained from an alternative valid source of information. Most CFC preparations contain alcohol, but CFC- and alcohol-free preparations do exist. CONCLUSIONS: Clinicians need to be aware that the majority of CFC-free inhalers contain alcohol. Alcohol-free, and CFC- and alcohol-free, preparations are available for the delivery of both rescue and preventative treatment and these should be considered for use in those patients who may have concern about alcohol-based treatments.  相似文献   
48.
49.
Over the years, olive mill wastewater (OMW), which is generated from olive oil production has attracted considerable attention as one of the most polluted wastewaters due to its high concentrations of toxic compounds. It is a truism nowadays to guide research towards a novel and efficient technologies in order to treat this hazardous waste.In this paper, detoxification of OMW in an external loop airlift reactor (ALR) by electrocoagulation (EC) powered by photovoltaic solar system as a renewable and sustainable energy source was investigated. The effects of the operating parameters, such as electrolysis time, initial pH, current density (CD), and the axial position of the electrode were studied in continuous flow with two aluminum electrodes. A rate of abatement of about 79.24% for COD, 94.82% for polyphenols and 97.87% for dark color was observed within 40 min of treatment at 32.14 mA/cm2 current density, a position of the electrodes at 35 cm from the bottom of the riser compartment, and initial pH of 5.6. Furthermore, under these optimal conditions, the power supplied by photovoltaic cells led to amount of electrode dissolved (ELC) and specific energy consumption (SEC) of around 0.1118 kg/m3 and 9.86 kWh/m3, respectively. It has been proven that the EC treatment of OMW in ALR coupled with renewable energy source offers a low operation cost (0.2 USD/m3) compared to other treatment processes.  相似文献   
50.
Psychiatric Quarterly - Technology driven capacity building initiatives are the way to break the barrier of shortage of mental health human resources in India. This new path, while is a welcome...  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