全文获取类型
收费全文 | 7543篇 |
免费 | 313篇 |
国内免费 | 44篇 |
专业分类
耳鼻咽喉 | 205篇 |
儿科学 | 421篇 |
妇产科学 | 376篇 |
基础医学 | 473篇 |
口腔科学 | 457篇 |
临床医学 | 639篇 |
内科学 | 1706篇 |
皮肤病学 | 143篇 |
神经病学 | 602篇 |
特种医学 | 335篇 |
外科学 | 1418篇 |
综合类 | 81篇 |
一般理论 | 1篇 |
预防医学 | 179篇 |
眼科学 | 293篇 |
药学 | 265篇 |
中国医学 | 10篇 |
肿瘤学 | 296篇 |
出版年
2024年 | 5篇 |
2023年 | 80篇 |
2022年 | 67篇 |
2021年 | 177篇 |
2020年 | 117篇 |
2019年 | 136篇 |
2018年 | 203篇 |
2017年 | 181篇 |
2016年 | 279篇 |
2015年 | 287篇 |
2014年 | 344篇 |
2013年 | 463篇 |
2012年 | 612篇 |
2011年 | 562篇 |
2010年 | 332篇 |
2009年 | 270篇 |
2008年 | 480篇 |
2007年 | 629篇 |
2006年 | 587篇 |
2005年 | 576篇 |
2004年 | 516篇 |
2003年 | 357篇 |
2002年 | 379篇 |
2001年 | 55篇 |
2000年 | 25篇 |
1999年 | 26篇 |
1998年 | 24篇 |
1997年 | 19篇 |
1996年 | 19篇 |
1995年 | 13篇 |
1994年 | 13篇 |
1993年 | 8篇 |
1992年 | 8篇 |
1991年 | 10篇 |
1989年 | 5篇 |
1987年 | 6篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 3篇 |
1971年 | 1篇 |
1970年 | 3篇 |
1969年 | 1篇 |
1963年 | 1篇 |
排序方式: 共有7900条查询结果,搜索用时 15 毫秒
41.
Ay H Ay I Koroshetz WJ Finklestein SP 《Cerebrovascular diseases (Basel, Switzerland)》1999,9(3):131-135
Within the past few years, a growing body of evidence has accumulated indicating that exogenously administered neurotrophic growth factors may limit the extent of acute ischemic neural injury and enhance functional neurorecovery following stroke. One of the most widely studied growth factor in this regard is basic fibroblast growth factor (bFGF). In preclinical studies, bFGF administered intravenously within hours after the onset of ischemia reduces infarct size, presumably due to direct protection of cells at the borders (penumbra) of cerebral infarction. On the other hand, if bFGF is administered intracisternally starting at one day after ischemia, infarct size is not reduced, but recovery of sensorimotor function of the impaired limbs is increased, presumably due to enhancement of new neuronal sprouting and synapse formation in the intact uninjured brain. Clinical trials of the intravenous administration of bFGF as a cytoprotective agent in acute stroke are in progress. Trials of the delayed administration of bFGF as a recovery-promoting agent in subacute stroke are anticipated. 相似文献
42.
Güner Söyletir Ayşegül Eskitürk Günay Kiliç Volkan Korten Nurdan Tözün 《European journal of epidemiology》1996,12(4):391-394
Infection with Clostridium difficile can present with various clinical pictures ranging from an asymptomatic carrier state to pseudomembranous colitis and plays an important part in the etiology of nosocomial diarrhoea. To identify risk factors for C. difficile colonization and diarrhoea in hospitalized subjects, patients admitted to a general medicine ward at Marmara University hospital during a one year period were entered into the study. Of the 202 patients, nosocomial diarrhoea developed in 45 (22.3%). Fourteen patients (6.9%) were colonized with C. difficile during their hospitalization period. Ten of the colonized patients (71.4%) developed diarrhoea and were found to be positive by toxin assay. Pseudomembranous colitis was confirmed endoscopically in 3 of the patients with diarrhoea. Administration of beta lactam agents such as ampicillin and cephalosporins; gastrointestinal manipulations and admission to the intensive care unit were found as major risk factors for C. difficile colonization. 相似文献
43.
Charanjit S. Aulakh James L. Hill Hakan T. Yoney Dennis L. Murphy 《Psychopharmacology》1992,109(4):444-448
Administration of various doses of 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) to rats produced dose-related decreases in 1-h food intake in the food-deprived paradigm. Pretreatment with spiperone (5-HT1A/5-HT2/D2 antagonist), propranolol or CGP361A (-adrenoceptor antagonists that also have binding affinities for 5-HT1A and 5-HT1B sites) and MDL-72222 (5-HT3 antagonist) did not attenuate DOI-induced suppression of food intake. In contrast, pretreatment with metergoline (5-HT1/5-HT2 antagonist) completely blocked whereas mesulergine, mianserin and ritanserin (5-HT1C/5-HT2 antagonists) partially blocked DOI's effect on food intake. On the other hand, pretreatment with MDL-72222 but not with m-chlorophenylpiperazine (m-CPP) significantly potentiated DOI-induced suppression of food intake. Furthermore, the food intake suppressant effects of various doses of DOI were found to be similar in the Fawn-Hooded (FH) rat strain as compared to the Wistar rat strain. These findings suggest that DOI-induced suppression of food intake is mediated by stimulation of both 5-HT1C and 5-HT2 receptors. 相似文献
44.
Cenk Can Buket Demirci Ay?egül Uysal Yasemin Delen Ak?ay Sezen Ko?ay 《Pharmacological research》2003,48(3):223-230
We examined the effects of the phenothiazine derivative, chlorpromazine on thoracic aortic endothelial cell histology (14 h after LPS challenge) in a model of endotoxic shock in rats. Since excessive formation of tumor necrosis factor-alpha (TNF-alpha) and oxygen-derived free radicals contribute to endothelial injury in endotoxemia, we also evaluated the effect of the drug on the activities of antioxidant enzymes superoxide dismutase (SOD) and catalase in liver tissue in this model and tried to find out whether this possible effect was associated with a change in serum TNF-alpha levels (measured 90 min after chlorpromazine administration). Endotoxemia was induced by a single i.p. injection of lipopolysaccharide (LPS) (5 mg kg(-1) in 1.5 ml of saline; LPS from Escherichia coli serotype 055:B5, L-2880, Sigma Chemical Company). Electron microscopic evaluation of the aortas revealed that chlorpromazine (administered 30 min prior to LPS challenge), in smaller doses (3 mg kg(-1)) ameliorated the endothelial cell injury caused by LPS, whereas it caused deterioration of endothelial cell morphology in higher doses (10 and 25 mg kg(-1)). Chlorpromazine administration caused a significant reduction in serum TNF-alpha levels, which was correlated well with an increase in SOD activity in all drug doses (3, 10 and 25 mg kg(-1)). Catalase activity was increased only in the 25 mg kg(-1) chlorpromazine group. 相似文献
45.
46.
Ayse Rodopman Arman Pinar Ay Nese Perdahli Fis Refika Ersu Ahmet Topuzoglu Ugur Isik Meral Berkem 《Acta paediatrica (Oslo, Norway : 1992)》2011,100(3):420-424
Aim: In this population‐based study, we aimed to determine the total sleep duration (TSD), its association with socio‐economic status (SES) and behavioural symptoms among schoolchildren. Methods: A cross‐sectional study was performed among schoolchildren in Istanbul. A structured questionnaire evaluating the sleep schedule variables was filled out by their parents. SES was determined according to the Turkish SES scale. Results: The mean age of 2669 children was 8.2 ± 2.4 years, and 51% of the students were girls. The mean TSD was 10.20 ± 1.04, and the mean bedtime was 21.57 ± 0.56 (both in hours, minutes ± SD). Boys tended to go bed later (p = 0.004) and slept less than girls (p = 0.02). The duration of sleep disruptions increased (p < 0.001), whereas TSD decreased with age (p < 0.001). Multiple linear regression revealed that waking time and TSD decreased significantly (p < 0.05) with higher SES among both girls and boys. Sleep fragmentation was associated with habitual snoring, parasomnias, daytime sleepiness and conduct symptoms. Conclusion: Decreased total sleep duration is more prominent in boys, older children and children among higher socio‐economic status. Insufficient sleep attributed to shortened total sleep duration by age and higher socio‐economic status might have a negative effect on both sleep hygiene and psychological well‐being in schoolchildren. 相似文献
47.
48.
49.
Onur Geckili PhD DDS Hakan Bilhan PhD DDS Emre Mumcu PhD DDS Cagatay Dayan DDS Ali Yabul DDS Necat Tuncer PhD DDS 《Special care in dentistry》2012,32(4):136-141
This study compared two groups of patients who were elderly and edentulous, one group included subjects who had mandibular overdentures supported by two implants (Group I); the other groups wore conventional complete dentures (Group II). This retrospective study included 100 edentulous patients (50 from each group) with an average age of 67.86 years, who had been followed for 4 years. The groups were compared in terms of patient satisfaction, quality of life (QOL), and bite force. The bite force and patient satisfaction scores of Group I were found to be statistically significantly higher than Group II (p < .05). However, no statistically significant difference was found between the two groups’ QOL scores (p > .05) except on the physical pain subscale (p = .013). Based on these results, it can be concluded that after 4 years of function, subjects wearing mandibular overdentures supported by two implants had higher values for bite force and patient satisfaction scores, but similar QOL scores when compared to conventional complete denture‐wearers. 相似文献
50.