全文获取类型
收费全文 | 17439篇 |
免费 | 1609篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 152篇 |
儿科学 | 643篇 |
妇产科学 | 584篇 |
基础医学 | 2397篇 |
口腔科学 | 363篇 |
临床医学 | 1874篇 |
内科学 | 2974篇 |
皮肤病学 | 220篇 |
神经病学 | 1833篇 |
特种医学 | 881篇 |
外科学 | 2158篇 |
综合类 | 336篇 |
一般理论 | 21篇 |
预防医学 | 1930篇 |
眼科学 | 336篇 |
药学 | 1399篇 |
中国医学 | 19篇 |
肿瘤学 | 948篇 |
出版年
2021年 | 242篇 |
2020年 | 196篇 |
2019年 | 235篇 |
2018年 | 290篇 |
2017年 | 251篇 |
2016年 | 249篇 |
2015年 | 300篇 |
2014年 | 388篇 |
2013年 | 546篇 |
2012年 | 791篇 |
2011年 | 806篇 |
2010年 | 484篇 |
2009年 | 390篇 |
2008年 | 739篇 |
2007年 | 753篇 |
2006年 | 716篇 |
2005年 | 682篇 |
2004年 | 612篇 |
2003年 | 645篇 |
2002年 | 575篇 |
2001年 | 549篇 |
2000年 | 550篇 |
1999年 | 498篇 |
1998年 | 210篇 |
1997年 | 181篇 |
1996年 | 159篇 |
1995年 | 151篇 |
1994年 | 139篇 |
1992年 | 390篇 |
1991年 | 411篇 |
1990年 | 411篇 |
1989年 | 363篇 |
1988年 | 390篇 |
1987年 | 398篇 |
1986年 | 322篇 |
1985年 | 346篇 |
1984年 | 265篇 |
1983年 | 224篇 |
1982年 | 143篇 |
1979年 | 252篇 |
1978年 | 194篇 |
1977年 | 143篇 |
1976年 | 167篇 |
1974年 | 178篇 |
1973年 | 170篇 |
1972年 | 151篇 |
1971年 | 139篇 |
1970年 | 135篇 |
1969年 | 169篇 |
1968年 | 146篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
Kazumasa Fujitani Jaffer A. Ajani Christopher H. Crane Barry W. Feig Peter W. Pisters Nora Janjan Garrett L. Walsh Stephen G. Swisher Ara A. Vaporciyan David Rice Angela Welch Jackie Baker Josephine Faust Paul F. Mansfield MD 《Annals of surgical oncology》2007,14(4):1305-1311
Background Significant tumor downstaging has been achieved in patients with localized gastric or gastroesophageal adenocarcinoma by induction
chemotherapy and preoperative chemoradiotherapy (CTX–CTXRT). However, the influence of CTX–CTXRT on operative morbidity and
mortality has not yet been clarified. The aim of the present study was to document the frequency and nature of morbidity and
mortality after surgery combined with CTX–CTXRT, and identify factors predictive of postoperative complications in patients
with localized gastric or gastroesophageal adenocarcinoma.
Methods A prospectively collected database on 71 consecutive patients who underwent CTX–CTXRT at M.D. Anderson Cancer Center between
January 1997 and August 2004 was reviewed. Postoperative morbidity and mortality were investigated, and risk factors for overall
complications were identified by multivariate logistic regression analysis.
Results Overall morbidity and mortality rates were 38.0% (27 patients) and 2.8% (2 patients), respectively. Age greater than 60 years
[relative risk 11.3 (95% confidence interval 2.50–50.6)] and body mass index (BMI) of 26 kg/m2 or above [relative risk 4.08 (95% confidence interval 1.08–15.4)] were significant risk factors for overall complications.
Conclusions CTX–CTXRT can be performed safely with an acceptable operative morbidity and a low operative mortality rate in patients with
gastric or gastroesophageal cancer, with careful consideration of added risk associated with age and obesity. 相似文献
52.
BACKGROUND: To investigate vergence adaptation during the incipient phase of presbyopia, when the amplitude of accommodation approaches the level where the first reading addition is required. The study aimed to assess the ability of the vergence system to counteract changes in the component contributions to the overall vergence response with the decline in the amplitude of accommodation in presbyopia, although previous reports on the nature of changes in accommodative, tonic and proximal vergence are equivocal. METHODS: Using a 'flashed' Maddox rod technique, an assessment of vergence adaptation to 6delta base-out and 6delta base-in prism was made for 28 subjects (aged 35-45 years at the commencement of the study). The measurements were taken four times over a 2-year period. RESULTS: Using a repeated measures analysis of variance, the results show that with the decline in amplitude of accommodation, there is a statistically significant reduction in the magnitude of vergence adaptation to both base-out (p < 0.05) and base-in prism (p < 0.01). CONCLUSIONS: This study shows that with ageing, there is a decrease in the ability of the slow vergence mechanism to overcome a change in fusional vergence demand and would suggest that either the fast component of fusional vergence must cope with any change in fusional vergence demand or that the sum of the accommodative, tonic and proximal vergence responses are virtually stable with age. 相似文献
53.
Richard A. Perugini Steven H. Quarfordt Stephen Baker Donald R. Czerniach Demetrius E. M. Litwin John J. Kelly 《Journal of gastrointestinal surgery》2007,11(9):1083-1090
Introduction Obese individuals may have normal insulin–glucose homeostasis, insulin resistance, or diabetes mellitus. Whereas gastric bypass
cures insulin resistance and diabetes mellitus, its effects on normal physiology have not been described. We studied insulin
resistance and β-cell function for patients undergoing gastric bypass.
Methods One hundred thirty-eight patients undergoing gastric bypass had fasting insulin and glucose levels drawn on days 0, 12, 40,
180, and 365. Thirty-one (22%) patients with diabetes mellitus were excluded from this analysis. Homeostatic model of assessment
was used to estimate insulin resistance, insulin sensitivity, and β-cell function. Based on this model, patients were categorized
as high insulin resistance if their insulin resistance was >2.3.
Results Body mass index did not correlate with insulin resistance. Forty-seven (34%) patients were categorized as high insulin resistance.
Correction of insulin resistance for this group occurred by 12 days postoperatively. Sixty (43%) patients were categorized
as low insulin resistance. They demonstrated an increase of β-cell function by 12 days postoperatively, which returned to
baseline by 6 months. At 1 year postoperatively, the low insulin resistance group had significantly higher β-cell function
per degree of insulin sensitivity.
Conclusions Adipose mass alone cannot explain insulin resistance. Severely obese individuals can be categorized by degree of insulin resistance,
and the effect of gastric bypass depends upon this preoperative physiology. 相似文献
54.
55.
56.
Herbert L. Baker 《Journal of the National Medical Association》1993,85(6):468-470
A transoral technique for the excision of primary hypopharyngeal, posterior pharyngeal, and lateral pharyngeal wall tumors using the CO2 or KTP laser and an operating microscope is presented. 相似文献
57.
The prevalence of different measurements of respiratory illness among construction painters was examined and the relation between respiratory illness and employment as a painter assessed in a cross sectional study of current male members of two local affiliates of a large international union of painters. Respiratory illness was measured by questionnaire and spirometry. Longer employment as a painter was associated with increased prevalence of chronic obstructive disease and an interactive effect was observed for smoking and duration of employment as a painter. Multiple regression analysis showed a significant association between years worked as a painter and a decrement in FEV1 equal to about 11 ml for each year worked. This association was larger among painters who had smoked. The prevalence of chronic bronchitis was significantly associated with increased use of spray application methods. 相似文献
58.
59.
Frank Baker Ph.D. David Jodrey Ph.D. James Intagliata Ph.D. Harry Straus Ph.D. 《Community mental health journal》1993,29(4):321-331
A cohort of 729 chronically mentally ill patients receiving community support services (CSS) were followed over a nine-month period. Receiving needed community support services was shown to predict change in client functioning as measured by the Global Assessment Scale (GAS) even after the initial values on the GAS, as well as demographic, psychiatric, residential and medication maintenance variables were considered. Adequacy of social support from family, friends and others also contributed to predicting change in global functioning of the CSS patients.Johns Hopkins UniversityPresented at the American Psychological Association Annual Meeting, Washington, D.C., August 16, 1992. 相似文献
60.
S J Vukelja W J Baker P Jeffreys B A Reeb T Pick 《American journal of clinical oncology》1992,15(6):500-502
Nonbacterial thrombotic endocarditis is an uncommon, but well-described, complication of bone marrow transplantation. We describe a case of nonbacterial thrombotic endocarditis following autologous bone marrow transplantation that was marked by weight gain, hepatomegaly, ascites, and extreme hyperbilirubinemia leading to a clinical diagnosis of hepatic veno-occlusive disease. Autopsy revealed nonbacterial thrombotic endocarditis of the tricuspid and pulmonic valves, and passive congestion of the liver, but there was no evidence of veno-occlusive disease. We discuss the pathophysiology and clinical features of nonbacterial thrombotic endocarditis and review its occurrence in association with bone marrow transplantation. Nonbacterial thrombotic endocarditis is often difficult to detect clinically and should be a diagnostic consideration in patients who develop systemic emboli or congestive heart failure after bone marrow transplantation. 相似文献