全文获取类型
收费全文 | 2375917篇 |
免费 | 195179篇 |
国内免费 | 4214篇 |
专业分类
耳鼻咽喉 | 34272篇 |
儿科学 | 72798篇 |
妇产科学 | 62977篇 |
基础医学 | 335116篇 |
口腔科学 | 67581篇 |
临床医学 | 215616篇 |
内科学 | 468834篇 |
皮肤病学 | 47942篇 |
神经病学 | 200871篇 |
特种医学 | 95999篇 |
外国民族医学 | 886篇 |
外科学 | 360524篇 |
综合类 | 56268篇 |
现状与发展 | 1篇 |
一般理论 | 978篇 |
预防医学 | 190740篇 |
眼科学 | 55490篇 |
药学 | 177577篇 |
4篇 | |
中国医学 | 4372篇 |
肿瘤学 | 126464篇 |
出版年
2018年 | 24259篇 |
2016年 | 20614篇 |
2015年 | 23319篇 |
2014年 | 33586篇 |
2013年 | 50893篇 |
2012年 | 68820篇 |
2011年 | 72362篇 |
2010年 | 42536篇 |
2009年 | 40920篇 |
2008年 | 68843篇 |
2007年 | 73155篇 |
2006年 | 74077篇 |
2005年 | 72111篇 |
2004年 | 69388篇 |
2003年 | 67056篇 |
2002年 | 66286篇 |
2001年 | 112469篇 |
2000年 | 116550篇 |
1999年 | 98352篇 |
1998年 | 27873篇 |
1997年 | 25529篇 |
1996年 | 25460篇 |
1995年 | 24616篇 |
1994年 | 23171篇 |
1993年 | 21568篇 |
1992年 | 79396篇 |
1991年 | 76400篇 |
1990年 | 73583篇 |
1989年 | 70851篇 |
1988年 | 65855篇 |
1987年 | 64804篇 |
1986年 | 61341篇 |
1985年 | 58403篇 |
1984年 | 44226篇 |
1983年 | 37662篇 |
1982年 | 22887篇 |
1981年 | 20335篇 |
1980年 | 19036篇 |
1979年 | 41305篇 |
1978年 | 28986篇 |
1977年 | 24347篇 |
1976年 | 22833篇 |
1975年 | 23968篇 |
1974年 | 29641篇 |
1973年 | 28042篇 |
1972年 | 26228篇 |
1971年 | 24153篇 |
1970年 | 22753篇 |
1969年 | 21090篇 |
1968年 | 19136篇 |
排序方式: 共有10000条查询结果,搜索用时 17 毫秒
41.
42.
J. Smolen 《Zeitschrift für Rheumatologie》2006,65(2):92
Ohne Zusammenfassung
Endpunkt- und Verlaufsmessungen bei entzündlichen rheumatischen Erkrankungen in Studien und Praxis相似文献
43.
B Sedgmen C McMahon D Cairns R J Benzie R L Woodfield 《Ultrasound in obstetrics & gynecology》2006,27(3):245-251
OBJECTIVE: To explore the impact of timing and type of ultrasound, particularly three-dimensional (3D), exposure on maternal-fetal attachment and maternal health behavior during pregnancy. METHODS: Subjects were 68 women aged 18 years or older expecting their first child who presented for a routine ultrasound scan at around either 12 or 18 weeks' gestation in Nepean Hospital, Western Sydney. Women completed questionnaires assessing maternal-fetal attachment and health behavior, and were then allocated arbitrarily to either two-dimensional (2D) or 3D ultrasound examination. Repeat questionnaires were completed 1 week later. RESULTS: Maternal-fetal attachment increased after both 2D and 3D ultrasound exposure, and the effect was moderated by the timing of exposure, with women receiving their first ultrasound examination at around 12 weeks showing the greatest change. Alcohol consumption was the only behavior to show significant change following ultrasound exposure, with a reduction in the reported average number of drinks per week. There was no significant difference in the pattern of change for 2D compared with 3D ultrasound exposure, and no effect of ultrasound exposure on maternal perception of the fetus. CONCLUSIONS: Ultrasound has a positive impact on maternal-fetal attachment, particularly in the first trimester. 3D ultrasound did not offer enhanced benefits. Associations between ultrasound exposure and alcohol consumption warrant further investigation. Larger samples are needed to clarify the moderating effects of gestational age and type of ultrasound exposure. 相似文献
44.
H J Kim C H Kang Y T Kim S-W Sung J H Kim S M Lee C-G Yoo C-T Lee Y W Kim S K Han Y-S Shim J-J Yim 《The European respiratory journal》2006,28(3):576-580
Although surgical lung resection could improve prognosis in some patients with multidrug-resistant tuberculosis (MDR-TB), there are no reports on the optimal candidates for this surgery. The aim of the present study was to elucidate the prognostic factors for surgery in patients with MDR-TB. Patients who underwent lung resection for the treatment of MDR-TB between March 1993 and December 2004 were included in the present study. Treatment failure was defined as greater than or equal to two of the five cultures recorded in the final 12 months of treatment being positive, any one of the final three cultures being positive, or the patient having died during treatment. The variables that affected treatment outcomes were identified through univariate and multivariate logistic regression analysis. In total, 79 patients with MDR-TB were included in the present study. The treatment outcomes of 22 (27.8%) patients were classified as failure. A body mass index <18.5 kg x m(-2), primary resistance, resistance to ofloxacin and the presence of a cavitary lesion beyond the range of the surgical resection were associated with treatment failure. Low body mass index, primary resistance, resistance to ofloxacin and cavitary lesions beyond the range of resection are possible poor prognostic factors for surgical lung resection in multidrug-resistant tuberculosis patients. 相似文献
45.
M Müller J Grunewald C Olgart H?glund B Dahlén A Eklund H Stridh 《The European respiratory journal》2006,28(3):513-522
The increased number of lymphocytes in airways during an asthmatic response is believed to be the result of increased recruitment of these cells. However, it is possible that a decreased apoptotic rate could also contribute to the increased number. The aim of the present study was to investigate whether allergen airway provocation influences the apoptotic phenotype of lung and peripheral blood lymphocytes (PBL) in subjects with atopic asthma. Bronchoalveolar lavage (BAL) lymphocytes and PBL from 12 asthmatic subjects previously challenged with allergen (n = 7) or saline (n = 5) were exposed to the apoptotic stimulus tributyltin (TBT) in vitro and assayed for apoptosis. Airway allergen provocation resulted in decreased sensitivity of BAL lymphocytes to TBT-induced apoptosis, with 42.2% (range 33.9-62.5%) apoptotic cells before challenge versus 23.5% (range 15.3-42.4%) after challenge, while PBL were unaffected. The increased apoptosis resistance correlated with higher numbers of Bcl-2-expressing lymphocytes. Interestingly, baseline caspase-3-like activity was significantly elevated in viable BAL lymphocytes compared with viable PBL, and was unaltered by allergen exposure. In conclusion, allergen inhalation renders bronchoalveolar lavage lymphocytes more resistant to apoptosis while peripheral blood lymphocytes were not influenced at all, indicating that the apoptotic phenotype of airway lymphocytes may play a role in asthmatic inflammation. 相似文献
46.
47.
48.
49.
Parupudi V J Sriram Guduru V Rao Nageshwar D Reddy 《Indian journal of gastroenterology》2006,25(1):39-41
Endoscopic clips have been used mainly for control of gastrointestinal (GI) bleeding and occasionally for closure of GI perforations. However, closure of spontaneous esophageal perforation (Boerhaave's syndrome) by clipping has not been reported. We described successful non-surgical closure of spontaneous esophageal perforation by endoscopic clipping in a patient with bilateral pyopneumothorax and septicemia. 相似文献
50.