全文获取类型
收费全文 | 3139031篇 |
免费 | 266541篇 |
国内免费 | 13877篇 |
专业分类
耳鼻咽喉 | 43528篇 |
儿科学 | 96401篇 |
妇产科学 | 81033篇 |
基础医学 | 504852篇 |
口腔科学 | 86188篇 |
临床医学 | 279937篇 |
内科学 | 543744篇 |
皮肤病学 | 84848篇 |
神经病学 | 271936篇 |
特种医学 | 125281篇 |
外国民族医学 | 196篇 |
外科学 | 492756篇 |
综合类 | 101267篇 |
现状与发展 | 24篇 |
一般理论 | 2177篇 |
预防医学 | 265201篇 |
眼科学 | 71256篇 |
药学 | 216063篇 |
22篇 | |
中国医学 | 9109篇 |
肿瘤学 | 143630篇 |
出版年
2021年 | 54532篇 |
2020年 | 34803篇 |
2019年 | 57689篇 |
2018年 | 69966篇 |
2017年 | 53272篇 |
2016年 | 58809篇 |
2015年 | 73258篇 |
2014年 | 107348篇 |
2013年 | 172328篇 |
2012年 | 83080篇 |
2011年 | 80954篇 |
2010年 | 113273篇 |
2009年 | 118896篇 |
2008年 | 68257篇 |
2007年 | 70479篇 |
2006年 | 81726篇 |
2005年 | 77377篇 |
2004年 | 79890篇 |
2003年 | 71135篇 |
2002年 | 60775篇 |
2001年 | 83979篇 |
2000年 | 76126篇 |
1999年 | 79983篇 |
1998年 | 63076篇 |
1997年 | 61540篇 |
1996年 | 59275篇 |
1995年 | 54817篇 |
1994年 | 49151篇 |
1993年 | 45979篇 |
1992年 | 57344篇 |
1991年 | 54596篇 |
1990年 | 51800篇 |
1989年 | 51390篇 |
1988年 | 48170篇 |
1987年 | 47076篇 |
1986年 | 44882篇 |
1985年 | 45480篇 |
1984年 | 43538篇 |
1983年 | 40216篇 |
1982年 | 40250篇 |
1981年 | 38095篇 |
1980年 | 36017篇 |
1979年 | 36877篇 |
1978年 | 33506篇 |
1977年 | 30831篇 |
1976年 | 28035篇 |
1975年 | 26555篇 |
1974年 | 27677篇 |
1973年 | 26594篇 |
1972年 | 25031篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Summary Of the 105 great cormorants (Phalacrocorax carbo sinensins) from northern Poland (the Vistula Lagoon and Masurian Lake District), examined in 2000–2001, 67 proved hosts of the nematode
Syncuaria squamata (Linstow, 1883). The prevalence, mean intensity, and intensity range amounted to 63.8 %, 36.2 specimens, and 1–120 specimens,
respectively. The infection was heavier in the immature birds (84.6 %, 40.9 inds, and 1–120 inds) than in the adults (3.7
%, 1 ind.). The nematodes were dominated by gravid females (n=1846), followed by males (n=157), immature females (n=79), and
L4 larvae (n=2). Measurements of the parasite are provided. S. squamata is a new species for the parasite fauna of Poland. 相似文献
992.
993.
994.
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
995.
Holl P. Gortzalez R. Ksa M. Horvth A. 《世界核心医学期刊文摘》2006,2(3):14-15
背景:浴光疗同步治疗银屑病的有效性与UVB和死海盐的多靶点作用有关,同步治疗能够起到协同功效。目的:本回顾性研究的目的:①评价浴光疗同步治疗各种临床类型银屑病的有效性;②观察治疗反应有无不同;③获得更多数据以预测对不同类型银屑病的治疗效果,以便针对患者的类型选择治疗效果良好的方法。方法:根据Regensburg计划,患者接受了一个包括35次治疗的基础同步浴光疗疗程,随后又接受了一个包括25次治疗的维持治疗疗程。治疗中每周进行PASI评分以评价患者的皮肤状态。对373例按计划完成基础疗程的患者和其中78例完成维持疗程的患者的治疗… 相似文献
996.
Mark W Woolrich Peter Chiarelli Daniel Gallichan Joanna Perthen Thomas T Liu 《Magnetic resonance in medicine》2006,56(4):891-906
The study of brain function using MRI relies on acquisition techniques that are sensitive to different aspects of the hemodynamic response contiguous to areas of neuronal activity. For this purpose different contrasts such as arterial spin labeling (ASL) and blood oxygenation level dependent (BOLD) functional MRI techniques have been developed to investigate cerebral blood flow (CBF) and blood oxygenation, respectively. Analysis of such data typically proceeds by separate, linear modeling of the appropriate CBF or BOLD time courses. In this work an approach is developed that provides simultaneous inference on hemodynamic changes via a nonlinear physiological model of ASL data acquired at multiple echo times. Importantly, this includes a significant contribution by changes in the static magnetization, M, to the ASL signal. Inference is carried out in a Bayesian framework. This is able to extract, from dual-echo ASL data, probabilistic estimates of percentage changes of CBF, R(2) (*), and the static magnetization, M. This approach provides increased sensitivity in inferring CBF changes and reduced contamination in inferring BOLD changes when compared with general linear model approaches on single-echo ASL data. We also consider how the static magnetization, M, might be related to changes in CBV by assuming the same mechanism for water exchange as in vascular space occupancy. 相似文献
997.
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
998.
999.
1000.