全文获取类型
收费全文 | 1582篇 |
免费 | 147篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 114篇 |
妇产科学 | 20篇 |
基础医学 | 189篇 |
口腔科学 | 40篇 |
临床医学 | 240篇 |
内科学 | 295篇 |
皮肤病学 | 28篇 |
神经病学 | 36篇 |
特种医学 | 327篇 |
外科学 | 142篇 |
综合类 | 21篇 |
预防医学 | 125篇 |
眼科学 | 9篇 |
药学 | 63篇 |
肿瘤学 | 78篇 |
出版年
2023年 | 7篇 |
2021年 | 12篇 |
2020年 | 9篇 |
2019年 | 14篇 |
2018年 | 22篇 |
2017年 | 9篇 |
2016年 | 16篇 |
2015年 | 21篇 |
2014年 | 23篇 |
2013年 | 40篇 |
2012年 | 25篇 |
2011年 | 29篇 |
2010年 | 37篇 |
2009年 | 33篇 |
2008年 | 25篇 |
2007年 | 54篇 |
2006年 | 38篇 |
2005年 | 48篇 |
2004年 | 44篇 |
2003年 | 26篇 |
2002年 | 25篇 |
2001年 | 37篇 |
2000年 | 22篇 |
1999年 | 43篇 |
1998年 | 98篇 |
1997年 | 79篇 |
1996年 | 84篇 |
1995年 | 60篇 |
1994年 | 61篇 |
1993年 | 65篇 |
1992年 | 34篇 |
1991年 | 28篇 |
1990年 | 24篇 |
1989年 | 63篇 |
1988年 | 45篇 |
1987年 | 54篇 |
1986年 | 37篇 |
1985年 | 40篇 |
1984年 | 35篇 |
1983年 | 32篇 |
1982年 | 26篇 |
1981年 | 29篇 |
1980年 | 31篇 |
1979年 | 17篇 |
1978年 | 19篇 |
1977年 | 28篇 |
1976年 | 21篇 |
1975年 | 17篇 |
1974年 | 10篇 |
1971年 | 6篇 |
排序方式: 共有1740条查询结果,搜索用时 15 毫秒
1.
S Chinn S H Downs J M Anto M W Gerbase B Leynaert R de Marco C Janson D Jarvis N Künzli J Sunyer C Svanes E Zemp U Ackermann-Liebrich P Burney 《The European respiratory journal》2006,28(4):763-771
The incidence of asthma has been reported to be associated with obesity. An alternative analysis, of net change in prevalence, does not require exclusion of those with asthma at baseline. Follow-up data were obtained from 9,552 participants in the European Community Respiratory Health Survey and the Swiss cohort Study on Air Pollution and Lung Disease in Adults. Incidence of asthma was analysed by proportional hazards regression, and net changes in symptoms and asthma status by generalised estimating equations, by obesity group. Incidence and net change in ever having had asthma were greater in females than in males, and in participants who remained obese compared with those who were never obese (hazard ratio 2.00, 95% confidence interval 1.25-3.20; excess net change 2.8%, 0.4-5.3% per 10 yrs). The effect of being obese on net change in diagnosed asthma was greater in females than in males, but for net change in wheeze without a cold it was greater in males. The present results are consistent with asthma being more frequently diagnosed in females, especially obese females. These findings may help to explain the reports of a stronger association between asthma and obesity in females than in males. 相似文献
2.
Needle-localized breast biopsy: why do we fail? 总被引:10,自引:0,他引:10
3.
Spleen sizing by ultrasound in polycythaemia and thrombocythaemia: comparison with SPECT 总被引:3,自引:1,他引:2
M. Messinezy L. M. MacDonald T. O. Nunan N. B. Westwood S. Chinn & T. C. Pearson 《British journal of haematology》1997,98(1):103-107
Detection of non-palpable early splenic enlargement may aid diagnosis of primary polycythaemia (PP) and primary thrombocythaemia (PT). In this study linear spleen sizing by ultrasound has been compared with spleen volume estimation by single photon emission computerized tomography (SPECT) in 26 patients. Spleen length by ultrasound correlated well with SPECT volume estimation.
Ultrasound spleen length was also measured in 60 normal control subjects where the upper limit of the 95% reference range was 11.6 cm. Changes in spleen length with both age and body weight were substantial and overshadowed the imperfect reproducibility of this method. Therefore, interpretation of an individual's measured spleen length should be in relation to that predicted for adults of the same age and weight, particularly at the extremes of the younger, heavier patients and also the older, lighter patients.
Ultrasound spleen lengths of different patient groups (21 PP, 26 PT, 17 idiopathic erythrocytosis, 12 secondary polycythaemia, nine apparent polycythaemia) were compared both using the measured overall reference range and the differences from the values predicted for their age and weight. The comparison showed that almost all patients with PP whose spleens were not palpable had spleen lengths greater than the upper limit for the normal control group, but separation from the other patient groups was incomplete.
Detection of non-palpable splenomegaly by ultrasound length should remain a 'minor' criterion amongst the 'proposed modified diagnostic criteria' of PP. 相似文献
Ultrasound spleen length was also measured in 60 normal control subjects where the upper limit of the 95% reference range was 11.6 cm. Changes in spleen length with both age and body weight were substantial and overshadowed the imperfect reproducibility of this method. Therefore, interpretation of an individual's measured spleen length should be in relation to that predicted for adults of the same age and weight, particularly at the extremes of the younger, heavier patients and also the older, lighter patients.
Ultrasound spleen lengths of different patient groups (21 PP, 26 PT, 17 idiopathic erythrocytosis, 12 secondary polycythaemia, nine apparent polycythaemia) were compared both using the measured overall reference range and the differences from the values predicted for their age and weight. The comparison showed that almost all patients with PP whose spleens were not palpable had spleen lengths greater than the upper limit for the normal control group, but separation from the other patient groups was incomplete.
Detection of non-palpable splenomegaly by ultrasound length should remain a 'minor' criterion amongst the 'proposed modified diagnostic criteria' of PP. 相似文献
4.
5.
Ketai LH; Williamson MR; Telepak RJ; Levy H; Koster FT; Nolte KB; Allen SE 《Radiology》1994,191(3):665
6.
7.
荧光原位杂交技术分析人结肠菌群方法研究 总被引:2,自引:0,他引:2
建立荧光原位杂交技术分析人体内结肠菌群的方法。取受试者新鲜粪便 ,选用 5种特异性的 16SrRNA寡核苷酸探针 ,检测粪便样本收集后的保存时间、温度 ,离心条件及样本固定液存放时间对杂交计数结果的影响。结果建立最佳实验条件为 :粪便样本收集后应尽快在 4℃下保存 ,放置时间不要超过 12小时即作处理 ;样本的适宜离心条件为 70 0g 2分钟 ;样本用多聚甲醛固定后在 - 80℃下存放时间不要超过 5个月。该方法具有较好的稳定性 ,可以有效地检出个体之间结肠菌群的差异。 相似文献
8.
9.
10.