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   12071篇
  免费   772篇
  国内免费   88篇
耳鼻咽喉   137篇
儿科学   314篇
妇产科学   358篇
基础医学   1416篇
口腔科学   334篇
临床医学   980篇
内科学   2788篇
皮肤病学   219篇
神经病学   548篇
特种医学   363篇
外国民族医学   2篇
外科学   1893篇
综合类   334篇
一般理论   8篇
预防医学   786篇
眼科学   487篇
药学   1111篇
中国医学   128篇
肿瘤学   725篇
  2023年   137篇
  2022年   301篇
  2021年   574篇
  2020年   362篇
  2019年   492篇
  2018年   515篇
  2017年   374篇
  2016年   356篇
  2015年   331篇
  2014年   530篇
  2013年   622篇
  2012年   918篇
  2011年   919篇
  2010年   530篇
  2009年   417篇
  2008年   668篇
  2007年   701篇
  2006年   569篇
  2005年   535篇
  2004年   514篇
  2003年   423篇
  2002年   375篇
  2001年   164篇
  2000年   165篇
  1999年   156篇
  1998年   74篇
  1997年   43篇
  1996年   52篇
  1995年   53篇
  1994年   56篇
  1993年   36篇
  1992年   73篇
  1991年   73篇
  1990年   89篇
  1989年   71篇
  1988年   69篇
  1987年   71篇
  1986年   76篇
  1985年   50篇
  1984年   43篇
  1983年   28篇
  1982年   26篇
  1981年   17篇
  1980年   24篇
  1979年   31篇
  1977年   28篇
  1976年   23篇
  1974年   16篇
  1973年   17篇
  1970年   19篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
The Eastern Mediterranean Region (EMR) is experiencing a nutrition transition, characterized by the emergence of overnutrition and micro-nutrient deficiencies. No previous study has comparatively examined nutrient intake in adults across countries in the EMR. This review examined the adequacy of nutrients in adults living in the EMR. Moreover, it analyzed the food balance sheets (FBS) for 1961–2018 to identify the trajectory of energy supply from macro-nutrients in the EMR. A systematic search was conducted from January 2012 to September 2020. Only observational studies were retained with a random sampling design. An assessment of the methodological quality was conducted. Levels of nutrient daily intake and their adequacy compared to the daily reference intake of the Institute of Medicine were reported across the region. No studies were identified for half of the region’s countries. Although nutrient energy intake was satisfactory overall, fat and carbohydrate intake were high. Intake of vitamin D, calcium, potassium, zinc, and magnesium were below that recommended. The analysis of the FBS data allowed for the identification of four linear patterns of trajectories, with countries in the EMR best fitting the ‘high-energy-supply from carbohydrate’ group. This systematic review warrants multi-sectorial commitment to optimize nutrient intake.  相似文献   
102.
Modelling and simulation methods can play an important role in guiding public health responses to infectious diseases and emerging health threats by projecting the plausible outcomes of decisions and interventions. The 2003 SARS epidemic marked a new chapter in disease modelling in Canada as it triggered a national discussion on the utility and uptake of modelling research in local and pandemic outbreaks. However, integration and application of model-based outcomes in public health requires knowledge translation and contextualization. We reviewed the history and performance of Pan-InfORM (Pandemic Influenza Outbreak Research Modelling), which created a national infrastructure in Canada with a mandate to develop innovative knowledge translation methodologies to inform policy makers through modelling frameworks that bridge the gaps between theory, policy, and practice. This review demonstrates the importance of a collaborative infrastructure as a “Community of Practice” to guide public health responses, especially in the context of emerging diseases with substantial uncertainty, such as the COVID-19 pandemic. Dedicated resources to modelling and knowledge translation activities can help create synergistic strategies at the global scale and optimize public health responses to protect at-risk populations and quell socioeconomic and health burden.  相似文献   
103.
BackgroundDespite the huge numbers of the universally produced and employed protocols, the adherence with them is still low to moderate in the healthcare settings. This study was employed to assess the attitudes of Palestinian healthcare professionals in Gaza Strip to health education and counseling on healthy behaviours protocol (WHO-PEN Protocol 2), for patients with non-communicable diseases in the Ministry of Health primary healthcare centers.MethodsThis cross-sectional study was conducted with a census sample of all governmental family physicians and nurses (n=175). The study questionnaire was developed based on Cabana theoretical framework. The Arabic version questionnaire was developed based on the cross-cultural adaptation framework. The psychometric properties of the Arabic version questionnaire was finally evaluated.ResultsThe psychometric properties of the Arabic version questionnaire showed good construct validity and internal consistency reliability. The overall adherence level to WHO-PEN Protocol 2 was 70.0, SD=6.9. The main perceived barriers were lack of incentive, patients'' factors, and lack of time. In general, most of healthcare professional respondents had a positive attitude toward the protocol, but this attitude was not predictor to protocol adherence.ConclusionThe good validity and reliability of the questionnaire can provide support for the accuracy of the study results. Varied implementation strategies targeting the major barriers derived from the study are extremely required for addressing the lack of incentives, patients'' factors and time constraints.  相似文献   
104.
Journal of Occupational Rehabilitation - Purpose We aimed to identify job accommodations that help persons with physical disabilities maintain or return to work and explore the barriers and...  相似文献   
105.
Testicular torsion/detorsion is one of the important emergencies that requires fast surgical intervention. This study aimed to investigate the effects of Salvia miltiorrhiza hydroalcoholic extract combined with verapamil on testicular ischaemia/reperfusion damage in Wistar albino rats. All animals were distributed in 3 groups (n = 8), including the sham-operated group, torsion/detorsion (TD) group and torsion/detorsion + pretreatment with 200 mg/kg Salvia miltiorrhiza extract combined with 0.3 mg/kg verapamil (SMV) group. Oxidative stress biomarkers (MDA, GPx, CAT and TAC) both in plasma and testicular tissue, sperm parameters (motility, vitality, concentration and morphology) and histopathological parameters (MSTD, GECT, Johnson's score, Cosentino's score and testicular cell thickness) were assessed in all groups. Ischaemia/reperfusion significantly increased MDA and decreased GPx, CAT and TAC levels (p < .05). Pretreatment with SMV significantly increased GPx, CAT and TAC levels (p < .05). SMV group increased progressive sperm motility and vitality and reduced non-progressive motility of spermatozoon (p < .05). Testicular torsion significantly decreased all histopathological parameters compared to the sham group (p < .05). SMV pretreatment remarkably increased MSTD, GECT and Cosentino's score in comparison with the TD group (p < .05). A combination of Salvia miltiorrhiza with verapamil could reduce damages triggered by testicular torsion detorsion and improve sperm functionality parameters and oxidative stress defence systems.  相似文献   
106.
107.
108.
IntroductionThe Patient-Rated Tennis Elbow Evaluation (PRTEE) is designed to evaluate pain and disability in subjects with lateral elbow tendinopathy. This questionnaire is available in Swedish, Italian, and some other languages. A Persian language version of the questionnaire is needed for both research and clinical purposes.Purpose of the StudyThe purpose of this study was to translate and cross-culturally adapt the PRTEE questionnaire into the Persian language and to determine its validity and reliability.MethodsThe PRTEE was translated and culturally adapted from English into Persian (PRTEE-P) according to the established guidelines. The PRTEE-P was completed by 68 Iranian subjects (44 women, 24 men) diagnosed with chronic lateral elbow tendinopathy. To assess test-retest reliability, all subjects filled out the PRTEE-P on a second admission within one week. The intraclass correlation coefficient (ICC) and Cronbach's alpha were measured to report reliability. The validity was determined by correlating the PRTEE-P questionnaire with the Persian version of the Disabilities of the Arm, Shoulder, and Hand questionnaire.ResultsThe Persian version of the PRTEE showed a high internal consistency with a Cronbach's alpha of 0.99, demonstrating good test-retest reliability (ICC = 0.99). It was well correlated with Disabilities of the Arm, Shoulder, and Hand (r = 0.80).ConclusionThe PRTEE-P is a reliable and valid tool designed for measuring pain and disability in subjects with lateral elbow tendinopathy.  相似文献   
109.

This study aimed to examine the side effects of selected neonicotinoids (Acetamiprid, Aceta, and Imidacloprid, Imid) on Oreochromis niloticus juveniles. The acute toxicity, Probit method, revealed an LC50 of 195.81 and 150.76 ppm for Aceta/96 h and Imid/72 h respectively. The fish were divided into three groups that were exposed, for 21 days (n?=?5/replicate), to 1/10 of the LC50 of either neonicotinoids, however, the third was an unexposed control group. Results of erythrocytic micronucleus (MN), and nuclear abnormalities (NA) showed that Aceta and Imid exposure caused a significant (p?<?0.05) increase in MN by?~?2.2 and?~?10 folds, respectively relative to control. NAs occurred at the order of kidney-shaped?>?budding?>?binucleated in Aceta, however, budding?>?binucleated?>?kidney-shaped was noticed in the Imid group. Histopathological changes in gills, liver, and muscles were observed significantly in both exposed groups with more severity in the Imid group. Collectively, Aceta and Imid have potential genotoxicity and histopathological alterations in O. niloticus.

  相似文献   
110.

Wastewater irrigation is becoming a massive challenge for sustainable agriculture. Particularly, copper (Cu) presence in wastewater poses a great threat to the food chain quality. Thus, scientists need to address this issue by using chemical and organic soil amendments to restore the soil ecosystem. Therefore, this study aims to examine the efficacy of sulphur, compost, acidified animal manure and sesame straw biochar for Cu immobilization, adsorption and Brassica growth in wastewater irrigated soil. The current findings presented that all the soil amendments prominently improved brassica yield and significantly minimized the Cu uptake by Brassica shoots and roots in sesame straw biochar (SB) (64.2% and 50.2%), compost (CP) (48% and 32.5%), acidified manure (AM) (37% and 23.2%) and Sulphur (SP) (16% and 3.1%) respectively relative to untreated soil. In addition, Cu bioavailability was reduced by 51%, 34%, 16.6%, and 7.4% when SB, CP, AM, and SP were incorporated in wastewater irrigated polluted soil. The Cu adsorption isotherm results also revealed that SB treated soil has great potential to increase Cu adsorption capacity by 223 mg g??1 over control 89 mg g??1. Among all the treatments, SB and CP were considered suitable candidates for the restoration of Cu polluted alkaline nature soil.

  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