全文获取类型
收费全文 | 782篇 |
免费 | 62篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 58篇 |
妇产科学 | 6篇 |
基础医学 | 72篇 |
口腔科学 | 43篇 |
临床医学 | 76篇 |
内科学 | 149篇 |
皮肤病学 | 29篇 |
神经病学 | 18篇 |
特种医学 | 227篇 |
外科学 | 38篇 |
综合类 | 34篇 |
预防医学 | 45篇 |
眼科学 | 4篇 |
药学 | 21篇 |
肿瘤学 | 45篇 |
出版年
2019年 | 5篇 |
2018年 | 9篇 |
2017年 | 7篇 |
2016年 | 11篇 |
2015年 | 11篇 |
2014年 | 17篇 |
2013年 | 13篇 |
2012年 | 8篇 |
2011年 | 11篇 |
2010年 | 24篇 |
2009年 | 25篇 |
2008年 | 24篇 |
2007年 | 20篇 |
2006年 | 21篇 |
2005年 | 8篇 |
2004年 | 14篇 |
2003年 | 9篇 |
2002年 | 5篇 |
2001年 | 12篇 |
2000年 | 13篇 |
1999年 | 14篇 |
1998年 | 40篇 |
1997年 | 45篇 |
1996年 | 40篇 |
1995年 | 35篇 |
1994年 | 23篇 |
1993年 | 31篇 |
1992年 | 20篇 |
1991年 | 19篇 |
1990年 | 16篇 |
1989年 | 23篇 |
1988年 | 29篇 |
1987年 | 46篇 |
1986年 | 25篇 |
1985年 | 16篇 |
1984年 | 8篇 |
1983年 | 12篇 |
1982年 | 14篇 |
1981年 | 20篇 |
1980年 | 17篇 |
1979年 | 8篇 |
1978年 | 6篇 |
1977年 | 9篇 |
1976年 | 22篇 |
1975年 | 10篇 |
1934年 | 4篇 |
1933年 | 3篇 |
1930年 | 4篇 |
1927年 | 4篇 |
1926年 | 4篇 |
排序方式: 共有866条查询结果,搜索用时 15 毫秒
91.
P Dutta U Mitra DR Saha SK Niyogi B Manna SK Bhattacharya 《Acta paediatrica (Oslo, Norway : 1992)》1999,88(8):822-826
A hospital-based case-control study was carried out to clarify the characteristics of mucoid presentation of acute enterocolitis in children. One hundred sixty-eight cases of acute mucoid enterocolitis (study population) were compared with 200 cases of watery diarrhoea and 118 cases of blood dysentery (control groups) on the basis of clinical characteristics and findings on stool examination. Study and control groups were comparable with respect to age, body weight and nutritional status. There was no significant difference in clinical characteristics (duration of diarrhoea, stool frequency, presence of vomiting, fever and dehydration) between patients suffering from mucoid enterocolitis and blood dysentery. However, watery diarrhoea patients had significantly high frequencies of vomiting (p = 0.00001) and dehydration (p 相似文献
92.
DR Brewster MJ Manary IS Menzies EV O'Loughlin RL Henry 《Archives of disease in childhood》1997,76(3):236-241
Intestinal permeability can be assessed non-invasively using the lactulose-rhamnose (L-R) test, which is a reliable measure of small intestinal integrity. AIMS: To determine risk factors for abnormal intestinal permeability in kwashiorkor, and to measure changes in L-R ratios with inpatient rehabilitation. DESIGN: A case-control study of 149 kwashiorkor cases and 45 hospital controls. The L-R test was adapted to study kwashiorkor in Malawi, with testing at weekly intervals during nutritional rehabilitation. Urine sugars were measured by thin layer chromatography in London. RESULTS: The initial geometric mean L-R ratios (x100) (with 95% confidence interval) in kwashiorkor were 17.3 (15.0 to 19.8) compared with 7.0 (5.6 to 8.7) for controls. Normal ratios are < 5, so the high ratios in controls indicate tropical enteropathy syndrome. Abnormal permeability in kwashiorkor was associated with death, oliguria, sepsis, diarrhoea, wasting and young age. Diarrhoea and death were associated with both decreased L-rhamnose absorption (diminished absorptive surface area) and increased lactulose permeation (impaired barrier function) whereas nutritional wasting affected only L-rhamnose absorption. Despite, clinical recovery, mean L-R ratios improved little on treatment, with mean weekly ratios of 16.3 (14.0 to 19.0), 13.3 (11.1 to 15.9) and 14.4 (11.0 to 18.8). CONCLUSION: Abnormal intestinal permeability in kwashiorkor correlates with disease severity, and improves only slowly with nutritional rehabilitation. 相似文献
93.
94.
Cerebral blood flow relationships associated with a difficult tone recognition task in trained normal volunteers 总被引:2,自引:2,他引:0
Holcomb HH; Medoff DR; Caudill PJ; Zhao Z; Lahti AC; Dannals RF; Tamminga CA 《Cerebral cortex (New York, N.Y. : 1991)》1998,8(6):534-542
Tone recognition is partially subserved by neural activity in the right
frontal and primary auditory cortices. First we determined the brain areas
associated with tone perception and recognition. This study then examined
how regional cerebral blood flow (rCBF) in these and other brain regions
correlates with the behavioral characteristics of a difficult tone
recognition task. rCBF changes were assessed using H2(15)O positron
emission tomography. Subtraction procedures were used to localize
significant change regions and correlational analyses were applied to
determine how response times (RT) predicted rCBF patterns. Twelve trained
normal volunteers were studied in three conditions: REST, sensory motor
control (SMC) and decision (DEC). The SMC-REST contrast revealed bilateral
activation of primary auditory cortices, cerebellum and bilateral inferior
frontal gyri. DEC-SMC produced significant clusters in the right middle and
inferior frontal gyri, insula and claustrum; the anterior cingulate gyrus
and supplementary motor area; the left insula/claustrum; and the left
cerebellum. Correlational analyses, RT versus rCBF from DEC scans, showed a
positive correlation in right inferior and middle frontal cortex; rCBF in
bilateral auditory cortices and cerebellum exhibited significant negative
correlations with RT These changes suggest that neural activity in the
right frontal, superior temporal and cerebellar regions shifts back and
forth in magnitude depending on whether tone recognition RT is relatively
fast or slow, during a difficult, accurate assessment.
相似文献
95.
96.
97.
98.
99.
数据来源:检索MEDLINE数据库从1970年1月至2003年10月出版的所有文献.并手工检索参考文献中的相关文献。纳入标准:以人为对象的临床试验或观察性研究,且以英语发表的文献。数据提取和合成:由3位作者分别提取数据,意见不同则由讨论解决。记录一系列指标:菌斑指数(PI)、牙石指数、牙龈指数(GI)、探诊出血指数(BOP)、牙周探诊深度(PPD)、临床附着丧失(CAL)、牙龈退缩、牙周指数和骨丧失指数。用血液中糖化血红蛋白百分浓度显示糖尿病控制与否。评估各牙周参数的整体差异,并应用固定效应模型或随机效应模型计算相应的95%CI。用Q检验进行同质性检验。用漏斗图检测发表偏倚。结果:18个横断面对照研究、3个前瞻性队列研究和2个临床试验的基线资料入选。 相似文献
100.