全文获取类型
收费全文 | 10926篇 |
免费 | 711篇 |
国内免费 | 82篇 |
专业分类
耳鼻咽喉 | 131篇 |
儿科学 | 283篇 |
妇产科学 | 351篇 |
基础医学 | 1330篇 |
口腔科学 | 295篇 |
临床医学 | 967篇 |
内科学 | 2495篇 |
皮肤病学 | 192篇 |
神经病学 | 491篇 |
特种医学 | 340篇 |
外国民族医学 | 1篇 |
外科学 | 1605篇 |
综合类 | 311篇 |
一般理论 | 7篇 |
预防医学 | 751篇 |
眼科学 | 358篇 |
药学 | 1024篇 |
中国医学 | 113篇 |
肿瘤学 | 674篇 |
出版年
2023年 | 146篇 |
2022年 | 369篇 |
2021年 | 499篇 |
2020年 | 327篇 |
2019年 | 447篇 |
2018年 | 482篇 |
2017年 | 346篇 |
2016年 | 350篇 |
2015年 | 304篇 |
2014年 | 468篇 |
2013年 | 575篇 |
2012年 | 828篇 |
2011年 | 843篇 |
2010年 | 486篇 |
2009年 | 378篇 |
2008年 | 594篇 |
2007年 | 622篇 |
2006年 | 499篇 |
2005年 | 468篇 |
2004年 | 409篇 |
2003年 | 341篇 |
2002年 | 306篇 |
2001年 | 155篇 |
2000年 | 144篇 |
1999年 | 141篇 |
1998年 | 67篇 |
1997年 | 41篇 |
1996年 | 47篇 |
1995年 | 47篇 |
1994年 | 48篇 |
1993年 | 34篇 |
1992年 | 73篇 |
1991年 | 66篇 |
1990年 | 82篇 |
1989年 | 64篇 |
1988年 | 64篇 |
1987年 | 63篇 |
1986年 | 62篇 |
1985年 | 46篇 |
1984年 | 40篇 |
1983年 | 25篇 |
1982年 | 23篇 |
1980年 | 24篇 |
1979年 | 32篇 |
1977年 | 27篇 |
1976年 | 23篇 |
1974年 | 15篇 |
1973年 | 18篇 |
1970年 | 19篇 |
1969年 | 16篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
A rapid assay is described for the simultaneous determination of emetine and cephaeline in ipecacuanha and its preparations, based upon the different fluorescence intensities of the alkaloids at pH 1 and pH 12. The assay involves the measurement of fluorescence at 317 nm of dilutions of the sample in 0.1 M hydrochloric acid (pH 1) and 0.01 M sodium hydroxide (pH 12) with an excitation wavelength of 283 nm. Concentrations of the individual alkaloids are calculated using two simultaneous equations derived from the experimentally determined coefficients of fluorescence of solutions (1 μg/ml) of emetine and cephaeline at pH 1 and pH 12. The procedure, which has been shown to be accurate, precise and sensitive, requires only 1 ml of a liquid sample and less than 0.5 g of powdered root. There was reasonable agreement between the total concentrations of alkaloids in tinctures and liquid extracts of ipecacuanha determined by the spectrofluorimetric method and by the titrimetric procedure of the British Pharmacopoeia. The fluorimetric procedure gave higher levels of alkaloids in the powdered root than did the B.P. method; this difference is explained by incomplete extraction of the alkaloids in the B.P. procedure for powdered ipecacuanha root. 相似文献
92.
Hasan M. Tasdik Hossain Sahadat Gupta Rajat Das Podder Vivek Mowri Naima Afroz Ghosh Anindita Mahmood Hassan Rushekh Ahmmed Faisal Khatun M. S. T. Halima Nodi Rhedeya Nury Koly Kamrun Nahar Yasmeen Sharmeen Islam Nazrul 《Zeitschrift fur Gesundheitswissenschaften》2022,30(2):465-473
Journal of Public Health - Depression is a major morbidity and the most common mental disorder among the medical students in medical schools globally. Undergraduate students suffer stress more due... 相似文献
93.
Radhouene Doggui Hanin Al-Jawaldeh Jalila El Ati Rawhieh Barham Lara Nasreddine Nawal Alqaoud Hassan Aguenaou Laila El Ammari Jana Jabbour Ayoub Al-Jawaldeh 《Nutrients》2021,13(5)
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
94.
Ahmed Hassan Albelbeisi Ali Albelbeisi Abdel Hamid El Bilbeisi Mahmoud Taleb Amirhossein Takian Ali Akbari-Sari 《Ethiopian journal of health sciences》2021,31(1):73
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
95.
Wong Jasin Kallish Natasha Crown Deborah Capraro Pamela Trierweiler Robert Wafford Q. Eileen Tiema-Benson Laurine Hassan Shahzeb Engel Edeth Tamayo Christina Heinemann Allen W. 《Journal of occupational rehabilitation》2021,31(3):474-490
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
96.
Shayan Taheri Farshid Davoodi Abbas Raisi Amir Zakian Asghar Rajabzadeh Mohammad Hassan Hablolvarid Abdolrahman khezri Hassan Ahmadvand 《Andrologia》2021,53(6):e14049
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
97.
Ali Asghar Ghafarizadeh Mahdi Malmir Samira Naderi Noreini Tayebeh Faraji Zeynab Ebrahimi 《Andrologia》2021,53(1):e13891
Induction of oxidative stress during the sperm preparation process for assisted reproductive techniques (ART) in men can weaken sperm parameters. Vitamin E (VE) is considered a factor in boosting male fertility. This experimental study (in vitro) aimed to assess the impact of VE supplementation on sperm quality and lipid peroxidation during sperm sampling at different times. For this mention, semen samples were collected from 50 asthenoteratozoospermic men. Samples were divided into control and test groups for 2, 4 and 6 hr that the test group was incubated with VE (2 mM). In two groups, total motility, progressive motility and viability based on the WHO 2010 criteria were assessed. Moreover, malondialdehyde (MDA) levels were evaluated in each group. In the control group, total and progressive motility and sperm viability were decreased significantly after 2 hr; however, MDA levels were increased significantly after 6 hr. Also, in the test group, sperm parameters were increased significantly after 2 hr, and MDA levels were decreased significantly after 6 hr compared to the control group. In outcome, in vitro VE supplementation may protect spermatozoa from the adverse effect of oxidative stress during sperm preparation via preservation antioxidant processes in normal condition. 相似文献
98.
99.
100.
Fahimeh-Sadat Jafarian Hassan Barati Ebrahim Sadeghi-Demneh 《Journal of hand therapy》2021,34(1):127-130
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