全文获取类型
收费全文 | 747篇 |
免费 | 41篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 17篇 |
妇产科学 | 28篇 |
基础医学 | 116篇 |
口腔科学 | 11篇 |
临床医学 | 75篇 |
内科学 | 139篇 |
皮肤病学 | 19篇 |
神经病学 | 52篇 |
特种医学 | 14篇 |
外科学 | 87篇 |
综合类 | 10篇 |
预防医学 | 65篇 |
眼科学 | 26篇 |
药学 | 71篇 |
中国医学 | 10篇 |
肿瘤学 | 50篇 |
出版年
2023年 | 13篇 |
2022年 | 26篇 |
2021年 | 53篇 |
2020年 | 42篇 |
2019年 | 42篇 |
2018年 | 40篇 |
2017年 | 35篇 |
2016年 | 38篇 |
2015年 | 37篇 |
2014年 | 38篇 |
2013年 | 51篇 |
2012年 | 67篇 |
2011年 | 58篇 |
2010年 | 36篇 |
2009年 | 31篇 |
2008年 | 32篇 |
2007年 | 35篇 |
2006年 | 22篇 |
2005年 | 23篇 |
2004年 | 17篇 |
2003年 | 11篇 |
2002年 | 12篇 |
2001年 | 10篇 |
2000年 | 7篇 |
1999年 | 5篇 |
1997年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1986年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 2篇 |
排序方式: 共有794条查询结果,搜索用时 15 毫秒
1.
2.
3.
Mitochondrial DNA and Y-Chromosome Variation in the Caucasus 总被引:7,自引:3,他引:7
I. Nasidze E. Y. S. Ling D. Quinque I. Dupanloup R. Cordaux S. Rychkov O. Naumova O. Zhukova N. Sarraf-Zadegan G. A. Naderi S. Asgary S. Sardas D. D. Farhud T. Sarkisian C. Asadov A. Kerimov M. Stoneking 《Annals of human genetics》2004,68(3):205-221
We have analyzed mtDNA HVI sequences and Y chromosome haplogroups based on 11 binary markers in 371 individuals, from 11 populations in the Caucasus and the neighbouring countries of Turkey and Iran. Y chromosome haplogroup diversity in the Caucasus was almost as high as in Central Asia and the Near East, and significantly higher than in Europe. More than 27% of the variance in Y‐haplogroups can be attributed to differences between populations, whereas mtDNA showed much lower heterogeneity between populations (less then 5%), suggesting a strong influence of patrilocal social structure. Several groups from the highland region of the Caucasus exhibited low diversity and high differentiation for either or both genetic systems, reflecting enhanced genetic drift in these small, isolated populations. Overall, the Caucasus groups showed greater similarity with West Asian than with European groups for both genetic systems, although this similarity was much more pronounced for the Y chromosome than for mtDNA, suggesting that male‐mediated migrations from West Asia have influenced the genetic structure of Caucasus populations. 相似文献
4.
Raci Karayigit Alireza Naderi Firat Akca Carlos Janssen Gomes da Cruz Amir Sarshin Burak Caglar Yasli Gulfem Ersoz Mojtaba Kaviani 《Nutrients》2021,13(1)
Caffeine is widely consumed among elite athletes for its well-known ergogenic properties, and its ability to increase exercise performance. However, studies to date have predominantly focused on the anhydrous form of caffeine in male participants. The aim of the study was to investigate the effect of caffeinated coffee ingestion on lower-upper body muscular endurance, cognitive performance, and heart rate variability (HRV) in female athletes. A total of 17 participants (mean ± standard deviation (SD): age = 23 ± 2 years, body mass = 64 ± 4 kg, height = 168 ± 3 cm) in a randomized cross-over design completed three testing sessions, following the ingestion of 3 mg/kg/bm of caffeine (3COF), 6 mg/kg/bm of caffeine (6COF) provided from coffee or decaffeinated coffee (PLA) in 600 mL of hot water. The testing results included: (1) repetition number for muscular endurance performance; (2): reaction time and response accuracy for cognitive performance; (3): HRV parameters, such as standard deviation of normal-to-normal (NN) intervals (SDNN), standard deviation of successive differences (SDSD), root mean square of successive differences (RMSSD), total power (TP), the ratio of low- and high-frequency powers (LF/HF), high-frequency power (HF), normalized HF (HFnu), low-frequency power (LF), and normalized LF (LFnu). A one-way repeated measures ANOVA revealed that 3COF (p = 0.024) and 6COF (p = 0.036) improved lower body muscular endurance in the first set as well as cognitive performance (p = 0.025, p = 0.035 in the post-test, respectively) compared to PLA. However, no differences were detected between trials for upper body muscular endurance (p = 0.07). Lastly, all HRV parameters did not change between trials (p > 0.05). In conclusion, ingesting caffeinated coffee improved lower body muscular endurance and cognitive performance, while not adversely affecting cardiac autonomic function. 相似文献
5.
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
6.
Mina Saeedneja Mohammadreza Zafarghandi Narjes Khalili Vali Baigi Moein Khormali Zahra Ghodsi Mahdi Sharif-Alhoseini Gerard M. O’Reilly Khatereh Naghdi Melika Khaleghi-Nekou Seyed mohammad Piri Vafa Rahimi-Movaghar Somayeh Bahrami Marjan Laal Mahdi Mohammadzadeh Esmaeil Fakharian Habibollah Pirneja Hamid Pahlavanhosseini Payman Salamati Homayoun Sadeghi-Bazargani 《中华创伤杂志(英文版)》2021,24(3):153-158
Purpose: Injuries are one of the leading causes of death and lead to a high social and financial burden. Injury patterns can vary significantly among different age groups and body regions. This study aimed to evaluate the relationship between mechanism of injury, patient comorbidities and severity of injuries.
Methods: The study included trauma patients from July 2016 to June 2018, who were admitted to Sina Hospital, Tehran, Iran. The inclusion criteria were all injured patients who had at least one of the following: hospital length of stay more than 24 h, death in hospital, and transfer from the intensive care unit of another hospital. Data collection was performed using the National Trauma Registry of Iran minimum dataset.
Results: The most common injury mechanism was road traffic injuries (49.0%), followed by falls (25.5%). The mean age of those who fell was significantly higher in comparison with other mechanisms (p < 0.001). Severe extremity injuries occurred more often in the fall group than in the vehicle collision group (69.0% vs. 43.5%, p < 0.001). Moreover, cases of severe multiple trauma were higher amongst vehicle collisions than injuries caused by falls (27.8% vs. 12.9%, p = 0.003).
Conclusion: Comparing falls with motor vehicle collisions, patients who fell were older and sustained more extremity injuries. Patients injured by motor vehicle collision were more likely to have sustained multiple trauma than those presenting with falls. Recognition of the relationship between mechanisms and consequences of injuries may lead to more effective interventions. 相似文献
7.
Zeidabadi Somayeh Abbas Jaffar Mangolian Shahrbabaki Parvin Dehghan Mahlagha 《Sexuality and disability》2022,40(3):567-581
Sexuality and Disability - Sexual problems of hemodialysis patients are one of the most significant factors affecting their quality of life and families. On the other hand, an essential part of the... 相似文献
8.
Anti-oxidant effect of flavonoids on hemoglobin glycosylation 总被引:7,自引:0,他引:7
Asgary S Naderi G Sarrafzadegan N Ghassemi N Boshtam M Rafie M Arefian A 《Pharmaceutica acta Helvetiae》1999,73(5):223-226
A high glucose concentration has been found to lead to the glycosylation of amino groups of lysine residue in proteins. The addition of reducing agent not only prevents this reaction but also reverses it. On the other hand, flavonoids which found in plant sources have antioxidant properties. Since the glycosylation of protein is an oxidation reaction, therefore, antioxidants should be able to prevent this reaction. In this study, the best concentration and time to incubate glucose with hemoglobin was investigated. Then the glycosylation degree of hemoglobin in the presence of flavonoids and their absence was measured by means of a colorimetric method. Different concentration of flavonoids (Quercetin, Rutin, Kaempferol) were used. The preventing effect on hemoglobin glycosylation by the three concentrations; 0.5, 5, 10 micrograms/ml was estimated as follows: for Rutin; 11%, 27%, 42%, Quercetin; 3%, 37%, 52%, Kaempferol; 10%, 12%, 15% respectively. So, the in vivo effect should be investigated and then plants that containing flavonoids can be utilized to prevent or treat complication of diabetes. 相似文献
9.
10.