全文获取类型
收费全文 | 1493篇 |
免费 | 80篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 13篇 |
妇产科学 | 70篇 |
基础医学 | 199篇 |
口腔科学 | 40篇 |
临床医学 | 152篇 |
内科学 | 268篇 |
皮肤病学 | 6篇 |
神经病学 | 159篇 |
特种医学 | 23篇 |
外科学 | 139篇 |
综合类 | 67篇 |
预防医学 | 115篇 |
眼科学 | 46篇 |
药学 | 194篇 |
中国医学 | 23篇 |
肿瘤学 | 79篇 |
出版年
2023年 | 5篇 |
2022年 | 19篇 |
2021年 | 29篇 |
2020年 | 19篇 |
2019年 | 27篇 |
2018年 | 46篇 |
2017年 | 17篇 |
2016年 | 35篇 |
2015年 | 46篇 |
2014年 | 58篇 |
2013年 | 72篇 |
2012年 | 86篇 |
2011年 | 131篇 |
2010年 | 64篇 |
2009年 | 56篇 |
2008年 | 102篇 |
2007年 | 100篇 |
2006年 | 85篇 |
2005年 | 94篇 |
2004年 | 81篇 |
2003年 | 75篇 |
2002年 | 60篇 |
2001年 | 54篇 |
2000年 | 36篇 |
1999年 | 20篇 |
1998年 | 17篇 |
1997年 | 18篇 |
1996年 | 12篇 |
1995年 | 8篇 |
1994年 | 10篇 |
1993年 | 12篇 |
1992年 | 18篇 |
1991年 | 12篇 |
1990年 | 8篇 |
1989年 | 8篇 |
1988年 | 10篇 |
1987年 | 10篇 |
1986年 | 16篇 |
1985年 | 8篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1977年 | 1篇 |
1973年 | 3篇 |
排序方式: 共有1602条查询结果,搜索用时 0 毫秒
11.
To die or not to die for neurons in ischemia,traumatic brain injury and epilepsy: a review on the stress-activated signaling pathways and apoptotic pathways 总被引:22,自引:0,他引:22
After a severe episode of ischemia, traumatic brain injury (TBI) or epilepsy, it is typical to find necrotic cell death within the injury core. In addition, a substantial number of neurons in regions surrounding the injury core have been observed to die via the programmed cell death (PCD) pathways due to secondary effects derived from the various types of insults. Apart from the cell loss in the injury core, cell death in regions surrounding the injury core may also contribute to significant losses in neurological functions. In fact, it is the injured neurons in these regions around the injury core that treatments are targeting to preserve. In this review, we present our cumulated understanding of stress-activated signaling pathways and apoptotic pathways in the research areas of ischemic injury, TBI and epilepsy and that gathered from concerted research efforts in oncology and other diseases. However, it is obvious that our understanding of these pathways in the context of acute brain injury is at its infancy stage and merits further investigation. Hopefully, this added research effort will provide a more detailed knowledge from which better therapeutic strategies can be developed to treat these acute brain injuries. 相似文献
12.
Tseng CJ Chen SF Liou SI Lu SC Chen JM Sun CF Chang SD Cheng PJ Liou JD Chu DC 《Annals of clinical and laboratory science》2004,34(2):154-158
Clinical features of Peutz-Jeghers syndrome (PJS), an autosomal dominant disorder, include clusters of melanotic spots on the lips and limbs, polyposis of the gastrointestinal (GI) tract, and propensity to develop neoplasms of the GI tract, ovaries, testes, and other sites. We report twin sisters with PJS who were found to be homozygous, based on analyses of 9 DNA markers containing short tandem repeats (STR). Aberrant expression of a putative tumor suppressor gene, STK11, which encodes a serine threonine kinase, has been suggested as the etiologic factor in PJS. In both of the twin sisters with PJS, mRNA analyses by RT-PCR demonstrated a complete lack of STK11 gene expression. These results provide direct evidence that STK11 gene expression is abnormal in PJS. Detecting abnormal expression of the STK11 gene may serve as a molecular approach to the diagnosis of PJS and may facilitate genotype-phenotype correlations in PJS patients. 相似文献
13.
Chan HL Chou WS Chen SW Fang SC Liou CS Hwang YS 《Journal of medical engineering & technology》2005,29(5):227-234
Spectral analysis of heart rate variability provides a probe to assess the function of the sympathetic and parasympathetic nervous systems. Time-frequency analysis of heart rate variability is useful for investigating autonomic nervous function in patients with syncope or non-sustained ventricular tachycardia, or in anaesthesia, etc. In this paper, we developed an algorithm for continuous and online analysis of heart rate variability. The algorithm was simulated and evaluated in MATLAB, and implemented on the digital signal processor. The electrocardiogram signals from MIT/BIH arrhythmia database and one patient with syncope demonstrate the capability of the proposed method in the continuous and online analysis of heart rate variability. 相似文献
14.
15.
16.
17.
18.
19.
Jau-Cheng Liou Yun-Ching Cheng Kai-Hsiang Kang Yuan-Ping Chu Chen-Chung Yang Long-Sen Chang 《Toxicon》2004,43(3):341-346
In the present study, Xenopus nerve-muscle cultures were used to explore the functional roles of A chain (a phospholipase A(2) subunit) and B chain (a non-phospholipase A(2) subunit) of Bungarus multicinctus beta-bungarotoxin. It was found that beta-bungarotoxin induced an increment of the frequency of spontaneous synaptic currents (SSCs) in the nerve-muscle cultures. Modification of beta-bungarotoxin with pyridoxal-5'-phosphate or substitution of Ca(2+) with Ba(2+) in buffer abolished the phospholipase A(2) activity of beta-bungarotoxin and the facilitatory phase of SSC as well. Antibodies that were directed specifically against A chain or B chain effectively inhibited phospholipase A(2) activity, and as a consequence the SSC frequency was not greatly different from the control rate. These results suggest that both A and B chains are indispensable parts of beta-bungarotoxin for inducing the facilitation of SSC frequency with Xenopus nerve-muscle cultures. 相似文献
20.
Long-Sen Chang Pei-Fung Wu Jau-Cheng Liou Wen-Hsien Chiang-Lin Chen-Chung Yang 《Toxicon》2004,44(5):491-497
Notexin, a presynaptic phospholipase A2 (PLA2) neurotoxin isolated from Notechis scutatus scutatus venom, was inactivated by arginine-specific reagents, phenylglyoxal and 1,2-cyclohexanedione. Kinetic analyses of the modification reaction revealed that the inactivation of notexin followed pseudo-first order kinetics and the loss of PLA2 activity was correlated with the incorporation of one molecule of modification reagent per toxin molecule. However, the results of amino acid analysis and sequence determination revealed that two arginine residues at positions 43 and 79 of notexin were modified simultaneously. Modification of the arginine residues was accompanied with a decrease in the ability to inhibit the indirectly evoked contraction of chick biventer cervicis muscle and bind with synaptic membranes. The secondary structure of the toxin molecule did not significantly change after modification with phenylglyoxal as revealed by the CD spectra. The modified derivative retained its affinity for Ca2+, indicating that the modified arginine residues did not participate in Ca2+ -binding. Together with the notion that Arg-43 and Arg-79 of notexin are located in the proximity of its catalytic site and toxic site, respectively, our results suggest that modification of Arg-43 and Arg-79 should differently contribute to the observed decrease in the PLA2 activity and neurotoxic effect of notexin. 相似文献