全文获取类型
收费全文 | 2147920篇 |
免费 | 148284篇 |
国内免费 | 3980篇 |
专业分类
耳鼻咽喉 | 31515篇 |
儿科学 | 68027篇 |
妇产科学 | 60447篇 |
基础医学 | 303228篇 |
口腔科学 | 62947篇 |
临床医学 | 187976篇 |
内科学 | 409890篇 |
皮肤病学 | 48776篇 |
神经病学 | 168397篇 |
特种医学 | 84351篇 |
外国民族医学 | 595篇 |
外科学 | 327468篇 |
综合类 | 48597篇 |
现状与发展 | 7篇 |
一般理论 | 678篇 |
预防医学 | 153243篇 |
眼科学 | 51402篇 |
药学 | 165722篇 |
10篇 | |
中国医学 | 5062篇 |
肿瘤学 | 121846篇 |
出版年
2018年 | 20757篇 |
2016年 | 18587篇 |
2015年 | 20732篇 |
2014年 | 28829篇 |
2013年 | 43170篇 |
2012年 | 57657篇 |
2011年 | 61103篇 |
2010年 | 36105篇 |
2009年 | 34425篇 |
2008年 | 57543篇 |
2007年 | 62333篇 |
2006年 | 63156篇 |
2005年 | 60597篇 |
2004年 | 58607篇 |
2003年 | 56422篇 |
2002年 | 55082篇 |
2001年 | 104519篇 |
2000年 | 107305篇 |
1999年 | 90254篇 |
1998年 | 24080篇 |
1997年 | 21641篇 |
1996年 | 21144篇 |
1995年 | 19874篇 |
1994年 | 18441篇 |
1993年 | 17349篇 |
1992年 | 69499篇 |
1991年 | 67145篇 |
1990年 | 65989篇 |
1989年 | 64040篇 |
1988年 | 59055篇 |
1987年 | 57922篇 |
1986年 | 55221篇 |
1985年 | 52339篇 |
1984年 | 38919篇 |
1983年 | 33057篇 |
1982年 | 19305篇 |
1981年 | 17406篇 |
1979年 | 36699篇 |
1978年 | 25790篇 |
1977年 | 22629篇 |
1976年 | 20326篇 |
1975年 | 23066篇 |
1974年 | 27242篇 |
1973年 | 26567篇 |
1972年 | 25292篇 |
1971年 | 23683篇 |
1970年 | 22196篇 |
1969年 | 21355篇 |
1968年 | 19698篇 |
1967年 | 17651篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
Sebastian Bonner Thomas Matte Mitchell Rubin Joanne K Fagan Jennifer Ahern David Evans 《The Journal of asthma》2006,43(1):31-35
Although studies have documented underuse of controller medications and overuse of short-acting inhaled ss(2)-agonist among children with persistent asthma in disadvantaged communities, the persistence of oral ss(2)-agonist use in pediatric practice has not been studied since inhaled short-acting ss(2)-agonists became widespread. We describe medications used to treat asthma among children 3 to 5 years of age at 10 Head Start and other subsidized preschool centers in East and Central Harlem, New York City. We interviewed 149 parents/guardians of children who were identified as having probable asthma based on physician's diagnosis, persistent symptoms, hospitalization, and medication use. We classified 86 of the 149 children (58%) as having current persistent asthma. Only 15 of them (17%) were reported to have used controller medications at least 5 days/week in the last 4 weeks-only 2 of whom used inhaled corticosteroids. By contrast, 53 children (62%) used oral ss(2)-agonist in the last 4 weeks, often (72%) in conjunction with nebulized or inhaled short-acting ss(2)-agonist. Use of oral ss(2)-agonist was associated with more severe symptoms. This study documents the continued widespread use of oral ss(2)-agonist for treatment of children in a low-income community with high prevalence of asthma. 相似文献
43.
44.
45.
46.
To determine if impaired energy metabolism might contribute to some aspects of Alzheimer disease (AD), including the vulnerability of the CA1 region of the hippocampal formation and the altered cytoskeleton evident in neurofibrillary tangles, we examined the effects of metabolic poisons on neuronal damage and cytoskeletal disruption in the hippocampal formation. Intrahippocampal injection of 3-nitropropionic acid (3-NP) and malonic acid resulted in neuronal death, particularly in CA1. Cytoskeletal disruption included loss of dendritic MAP2, but sparing of axonal τ. MK-801 (a noncompetitive NMDA receptor antagonist) did not atenuate the lesions produced by intrahippocampal injection of malonate. MK-801, however, was effective against intrastriatal malonate. Acute systemic 3-NP resulted in neuronal damage and cytoskeletal disruption in the CA1 region of the hippocampal formation, including an extensive loss of MAP2 immuno-reactivity, but sparing of τ. The neuronal loss in CA1 was delayed as compared to striatum. Chronic intraventricular infusion of 3-NP produced a different pattern of neuronal damage. Loss of τ-1 immuno-reactivity was observed in CA3 and CA1 s. oriens, whereas MAP2 immunostaining was preserved. These results demonstrate that chronic and acute administration of metabolic inhibitors produce distinct patterns of neuronal damage and cytoskeletal disruption. The results further suggest a differential involvement of the NMDA receptor in malonate-induced neuronal damage in striatum as compared to the hippocampus. The pattern of neuronal damage and cytoskeletal disruption observed following acute metabolic impairment resembled some aspects of neurofibrillary pathology in AD, but did not result in τ hyperphosphorylation. 相似文献
47.
Effects of poor glucose handling on arterial stiffness and left ventricular mass in normal children.
AIM: Cardiovascular risk factors can be present in children and young adults. We previously found abnormal microvascular function in children who had glucose intolerance and insulin resistance. The aim of the present study was to investigate whether they also have abnormalities in left ventricular mass (LVM) and arterial stiffness. METHODS: We measured heart dimensions and LVM using echocardiography, and arterial stiffness using pulse wave analysis in 23 children with good glucose handling (postfeeding glucose: 3.9 to 5 mmol/L) and 21 with poor glucose handling (7.7 to 11.4 mmol/L). RESULTS: The time to pulse reflection was slightly shorter in the poorer glucose handlers (mean+/-SD: 143+/-10 vs 153+/-20 ms, P=0.04), suggestive of increased arterial stiffness. Also in this group, there were significant relationships between intraventricular septal thickness, blood pressure and body mass index, but not in the normal glucose handlers. CONCLUSIONS: We have found that normal children who are in the lowest quintile of glucose tolerance in comparison with their peers are exhibiting the first signs of arterial stiffening. In addition, we have seen the beginnings of a relationship between blood pressure, body mass index and left ventricular enlargement in this group. While these changes may not yet be clinically significant, their emergence might be further evidence of early predisposition to cardiovascular disease. 相似文献
48.
Lorusso F Kong D Jalil A. K. A A. AO 《世界核心医学期刊文摘》2006,2(6):25-26
目的:描述胚胎种植前遗传诊断在1例携带Ⅰ型白细胞黏附缺陷病(LAD-1)携带者并完成健康妊娠夫妇中的应用。设计:病例报道。机构:大学医院生殖中心。患者:1例男女双方都是LAD-1携带者的夫妇,女方CD18基因的外显子4携带有G400A置换,男方的外显子5携带有C562T置换。干预:标准体外受精(IVF)后第3天行卵裂期活检和分裂球遗传分析以检测2处突变以及21号染色体标记物。主要观察指标:1个未罹患LAD-1婴儿的出生。结果:得到15个卵母细胞,其中10个受精。8个胚胎适宜胚胎活组织检查。 相似文献
49.
Philip A. Rozario Nancy L. Morrow-Howell Enola K. Proctor 《Quality of life research》2006,15(4):755-759
Using the SF-12 to measure physical and mental functioning, the authors examine the intra-individual changes in health-related
quality of life (HRQOL) 6 months post-discharge for depressed older adults. In addition, they examine three sets of predictors
that might influence these changes. The sample of depressed older adults was recruited from an inpatient geropsychiatry unit.
Although their physical and mental health scores on the SF-12 were lower than comparable norms, the sample showed an average
increase in their mental functioning but a decrease in the physical functioning over the 6 months. Negative life-events were
significant predictors of people who reported no change in their mental health functioning and decreases in their physical
health functioning. Interestingly, those who experienced positive life events were more likely to report declines and younger
participants were more likely to report no change in their physical functioning. The findings indicate that the effects of
depression on HRQOL can have enduring effects on a sample of previously hospitalized older adults. The significance of life
event changes might signify the importance of taking into account non-traditional areas of medical interventions. Further,
the findings indicate the usefulness of the SF-12 quantifying HRQOL outcomes. 相似文献
50.