全文获取类型
收费全文 | 311篇 |
免费 | 22篇 |
专业分类
儿科学 | 23篇 |
妇产科学 | 4篇 |
基础医学 | 126篇 |
口腔科学 | 3篇 |
临床医学 | 18篇 |
内科学 | 70篇 |
皮肤病学 | 2篇 |
神经病学 | 34篇 |
特种医学 | 7篇 |
外科学 | 14篇 |
综合类 | 2篇 |
预防医学 | 1篇 |
眼科学 | 11篇 |
药学 | 9篇 |
肿瘤学 | 9篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 8篇 |
2021年 | 9篇 |
2020年 | 8篇 |
2019年 | 10篇 |
2018年 | 10篇 |
2017年 | 4篇 |
2016年 | 7篇 |
2015年 | 9篇 |
2014年 | 11篇 |
2013年 | 22篇 |
2012年 | 25篇 |
2011年 | 26篇 |
2010年 | 17篇 |
2009年 | 18篇 |
2008年 | 19篇 |
2007年 | 15篇 |
2006年 | 13篇 |
2005年 | 10篇 |
2004年 | 7篇 |
2003年 | 6篇 |
2002年 | 6篇 |
2001年 | 4篇 |
2000年 | 8篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 4篇 |
1996年 | 1篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1991年 | 10篇 |
1990年 | 6篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 5篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1983年 | 1篇 |
排序方式: 共有333条查询结果,搜索用时 15 毫秒
31.
32.
33.
Neocortical layer 5 (L5) pyramidal cells have at least two spike initiation zones: Na(+) spikes are generated near the soma, and Ca(2+) spikes at the apical dendritic tuft. These spikes interact with each other and serve as signals for synaptic plasticity. The present computational study explores the implications of having two spike-timing-dependent plasticity (STDP) signals in a neuron, each with its respective regional population of synaptic "pupils." In a detailed model of an L5 pyramidal neuron, competition emerges between synapses belonging to different regions, on top of the competition among synapses within each region, which characterizes the STDP mechanism. Interregional competition results in strengthening of one group of synapses, which ultimately dominates cell firing, at the expense of weakening synapses in other regions. This novel type of competition is inherent to dendrites with multiple regional signals for Hebbian plasticity. Surprisingly, such interregional competition exists even in a simplified model of two identical coupled compartments. We find that in a model of an L5 pyramidal cell, the different synaptic subpopulations "live in peace" when the induction of Ca(2+) spikes requires the back-propagating action potential (BPAP). Thus we suggest a new key role for the BPAP, to maintain the balance between synaptic efficacies throughout the dendritic tree, thereby sustaining the functional integrity of the entire neuron. 相似文献
34.
Min Shen Idan Menashe Lindsay M. Morton Yawei Zhang Bruce Armstrong Sophia S. Wang Qing Lan Patricia Hartge Mark P. Purdue James R. Cerhan Andrew Grulich Wendy Cozen Meredith Yeager Theodore R. Holford Claire M. Vajdic Scott Davis Brian Leaderer Anne Kricker Richard K. Severson Shelia H. Zahm Nilanjan Chatterjee Nathaniel Rothman Stephen J. Chanock Tongzhang Zheng 《British journal of haematology》2010,151(3):239-244
Genetic variations in DNA repair genes are thought to play an important role in the pathogenesis and development of non‐Hodgkin lymphoma (NHL). To further explore this hypothesis, we genotyped 319 tag single nucleotide polymorphisms (SNPs) in 27 DNA repair gene regions in 1946 cases and 1808 controls pooled from three population‐based case‐control studies of NHL in the US and Australia. Relative risks of NHL and NHL subtypes in relation to SNP genotypes were assessed using logistic regression. Associations of gene regions and pathways with NHL or NHL subtypes were explored using the minP and tail‐strength statistics, respectively. Overall, genetic polymorphisms within the DNA repair pathway were associated with NHL (P = 0·005). Similar associations were seen with the double‐strand break repair (P = 0·02) and nucleotide excision repair (P = 0·04) pathways. Five SNPs (BLM rs441399, RAD50 rs2237060, FAM82A2 rs2304583, ERCC3 rs4150506, and XRCC4 rs13178127) were particularly noteworthy because their gene regions were significantly associated with NHL or NHL subtypes (minP ≤ 0·05), or because of high level of statistical significance (P ≤ 0·005) and consistent findings across the three studies. These results support the hypothesis that common genetic polymorphisms in human DNA repair genes may modify the risk of NHL. 相似文献
35.
Safir Margarita Hecht Idan Sharon Tal Einan-Lifshitz Adi Belkin Avner 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》2022,260(9):2981-2990
Graefe's Archive for Clinical and Experimental Ophthalmology - The study aims to review the efficacy, safety, and technique of Nd:YAG laser vitreolysis for the management of malignant glaucoma... 相似文献
36.
37.
38.
Neuroimaging studies of individuals with brain damage seek to link brain structure and activity to cognitive impairments, spontaneous recovery, or treatment outcomes. To date, such studies have relied on the critical assumption that a given anatomical landmark corresponds to the same functional unit(s) across individuals. However, this assumption is fallacious even across neurologically healthy individuals. Here, we discuss the severe implications of this issue, and argue for an approach that circumvents it, whereby: (i) functional brain regions are defined separately for each subject using fMRI, allowing for inter-individual variability in their precise location; (ii) the response profile of these subject-specific regions are characterized using various other tasks; and (iii) the results are averaged across individuals, guaranteeing generalizabliity. This method harnesses the complementary strengths of single-case studies and group studies, and it eliminates the need for post hoc “reverse inference” from anatomical landmarks back to cognitive operations, thus improving data interpretability. 相似文献
39.