收费全文 | 12342篇 |
免费 | 850篇 |
国内免费 | 42篇 |
耳鼻咽喉 | 115篇 |
儿科学 | 421篇 |
妇产科学 | 299篇 |
基础医学 | 1992篇 |
口腔科学 | 268篇 |
临床医学 | 1337篇 |
内科学 | 2330篇 |
皮肤病学 | 171篇 |
神经病学 | 1379篇 |
特种医学 | 513篇 |
外科学 | 1629篇 |
综合类 | 86篇 |
一般理论 | 4篇 |
预防医学 | 952篇 |
眼科学 | 142篇 |
药学 | 698篇 |
中国医学 | 50篇 |
肿瘤学 | 848篇 |
2023年 | 73篇 |
2022年 | 151篇 |
2021年 | 277篇 |
2020年 | 166篇 |
2019年 | 272篇 |
2018年 | 283篇 |
2017年 | 212篇 |
2016年 | 260篇 |
2015年 | 280篇 |
2014年 | 359篇 |
2013年 | 515篇 |
2012年 | 756篇 |
2011年 | 763篇 |
2010年 | 414篇 |
2009年 | 377篇 |
2008年 | 597篇 |
2007年 | 604篇 |
2006年 | 657篇 |
2005年 | 609篇 |
2004年 | 554篇 |
2003年 | 543篇 |
2002年 | 485篇 |
2001年 | 273篇 |
2000年 | 292篇 |
1999年 | 264篇 |
1998年 | 125篇 |
1997年 | 107篇 |
1996年 | 89篇 |
1995年 | 61篇 |
1994年 | 77篇 |
1993年 | 83篇 |
1992年 | 195篇 |
1991年 | 183篇 |
1990年 | 166篇 |
1989年 | 165篇 |
1988年 | 139篇 |
1987年 | 151篇 |
1986年 | 130篇 |
1985年 | 154篇 |
1984年 | 115篇 |
1983年 | 96篇 |
1982年 | 60篇 |
1981年 | 59篇 |
1979年 | 68篇 |
1978年 | 86篇 |
1974年 | 69篇 |
1973年 | 63篇 |
1972年 | 71篇 |
1971年 | 62篇 |
1970年 | 58篇 |
Methods & Procedures: Eighteen PWA and 20 healthy older adults (HOA) completed a written sentence-picture matching task involving the interpretation of prepositional phrases (PP; the chef is poking the solider with an umbrella) that were ambiguous between high (verb modifier) and low attachment (object noun modifier). Only one interpretation was possible for prime sentences, while both interpretations were possible for target sentences. In Experiment 1, the target was presented immediately after the prime (0-lag). In Experiment 2, two filler items intervened between the prime and the target (2-lag). Within each experiment, the verb was repeated for half of the prime-target pairs, while different verbs were used for the other half. Participants’ off-line picture matching choices and response times were measured.
Results: After reading a prime sentence with a particular interpretation, HOA and PWA tended to interpret an ambiguous PP in a target sentence in the same way and with faster response times. Importantly, both groups continued to show this priming effect over a lag (Experiment 2), although the effect was not as reliable in response times. However, neither group showed lexical (verb-specific) boost on priming, deviating from robust lexical boost seen in the young adults of prior studies.
Conclusions: PWA demonstrate abstract (lexically-independent) structural priming in the absence of a lexically-specific boost. Abstract priming is preserved in aphasia, effectively facilitating not only immediate but also longer-lasting structure-message mapping during sentence comprehension. 相似文献
Methods This investigation, on infants aged from 1 to 6 months, was approved by the institutional ethic committee. Thirty-six otherwise healthy infants due to elective surgery were included in our study The patients were randomly assigned to one of two treatment groups. Group S ( n = 24) was anaesthetised with sevoflurane, Group H was anaesthetised with halothane. ECG recordings were taken before the anaesthesia onset, 15 min after the first contact with the volatile anaesthetic and 60 min after the ending of the volatile gas exposition. QTc interval was calculated using the Bazett's formula ( 5 ).
Results QTc interval was significantly ( P < 0.0002) (Table 1) lengthened 15 min after anaesthesia induction with sevoflurane as well as 60 min ( P < 0.01) after the ending of the gas exposition without any difference in age and gender. The QTc interval in patients anaesthetised with halothane did not show any significant change.
Table 1 相似文献