全文获取类型
收费全文 | 363篇 |
免费 | 25篇 |
国内免费 | 10篇 |
专业分类
398篇 |
出版年
2023年 | 6篇 |
2022年 | 5篇 |
2021年 | 17篇 |
2020年 | 14篇 |
2019年 | 13篇 |
2018年 | 8篇 |
2017年 | 12篇 |
2016年 | 15篇 |
2015年 | 11篇 |
2014年 | 20篇 |
2013年 | 25篇 |
2012年 | 18篇 |
2011年 | 16篇 |
2010年 | 15篇 |
2009年 | 28篇 |
2008年 | 26篇 |
2007年 | 16篇 |
2006年 | 17篇 |
2005年 | 12篇 |
2004年 | 9篇 |
2003年 | 7篇 |
2002年 | 5篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 8篇 |
1995年 | 8篇 |
1994年 | 6篇 |
1993年 | 6篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1990年 | 6篇 |
1989年 | 5篇 |
1988年 | 2篇 |
1987年 | 6篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 1篇 |
排序方式: 共有398条查询结果,搜索用时 0 毫秒
81.
目的 探讨微生态制剂对肝硬化肝性脑病患者的辅助治疗及对肠道菌群的影响,为该病的治疗提供参考。 方法 选择2016年2月至2019年2月我院门诊及住院病房收治的肝硬化肝性脑病患者70例,参照随机数字表法分为对照组和研究组,各35例。对照组患者接受临床常规治疗,研究组患者在对照组治疗方案基础上加用双歧杆菌四联活菌片治疗。所有患者均持续治疗2周。对比两组患者的治疗效果及血氨、肝功能指标[总胆红素(TBil)、谷草转氨酶(AST)、谷丙转氨酶(ALT)]、肠道黏膜屏障功能指标[内毒素、二胺氧化酶、D 乳酸]水平和肠道菌群分布的差异,记录患者治疗期间药物相关不良反应情况。 结果 治疗后,研究组患者治疗有效率高于对照组患者(94.29% vs 77.14%,χ2=4.200,P=0.040)。研究组患者血氨、TBil、AST、ALT、内毒素、二胺氧化酶、D 乳酸水平均低于对照组(均P结论 双歧杆菌四联活菌片在改善肝硬化肝性脑病患者病情方面具有积极作用,可能与其优化肠道菌群的作用密切相关。 相似文献
82.
<正>Liver cirrhosis is the pathologic end stage of multiple liver diseases.The major complications of liver cirrhosis,such as hepatic encephalopathy,spontaneous bacterial peritonitis and esophageal variceal bleeding are characterized by remarkable changes of the gut microbiota,which indicates that enteric dysbiosis might play an important role in the progression of liver cirrhosis[1,2].The human gastrointes- 相似文献
83.
Jean-Louis Wayenberg Valrie Ransy Danile Vermeylen Eliane Damis Serge P. Bottari 《Free radical biology & medicine》2009,47(7):975-982
Reactive nitrogen species (RNS) have been shown to play a major role in the pathophysiology of hypoxic–ischemic cerebral injury. Using a novel sensitive ELISA allowing the quantification of nitrated albumin (nitroalbumin) in plasma, we tested the hypothesis that perinatal asphyxia increases nitrating RNS generation by verifying whether the concentration of one of its target proteins is correlated with the clinical outcome. We assayed nitroalbumin in 114 plasma samples collected during the first hour, at day 1, and at day 4 of life from 48 term newborns suffering from perinatal asphyxia and correlated this marker with neurological and systemic neonatal outcomes. Nitroalbumin levels at day 1, but not at days 0 and 4, were significantly increased in patients who developed moderate or severe encephalopathy compared to those who had a normal neurological evolution or developed mild encephalopathy (median: 14.4 ng/ml versus 7.3 ng/ml, respectively). In contrast, nitroalbumin concentration at day 1 was not associated with systemic complications. First-hour and fourth-day nitroalbumin concentrations did not differ with respect to the neonatal neurological course. At day 0, nitroalbumin levels also correlated with circulating leukocytes. We conclude that plasma nitroalbumin seems to be a specific marker of neurological injury after perinatal asphyxia and may serve as a secondary end-point in neuroprotective clinical trials. 相似文献
84.
目的:探讨可溶性细胞间粘附分子-1(ICAM-1)在新生儿缺氧缺血性脑病(HIE)血清中的表达及其与病情严重程度的关系。方法:采用酶联免疫吸附双抗体夹心法(ELISA)检测45例HIE新生儿和50例健康新生儿血清中可溶性ICAM-1水平。结果:HIE组血清可溶性ICAM-1浓度为(159.25±25.62)ng/ml,对照组血清可溶性ICAM-1浓度为(53.35±12.42)ng/ml,两组相比较有显著性并差异(P〈0.05);轻、中、重度HIE患儿血清可溶性ICAM-1浓度与对照组比较显著升高(P〈0.05),在HIE各组中可溶性ICAM-1浓度为重度〉中度〉轻度,各组相比较有显著性差异(P〈0.05);HIE患儿血清可溶性ICAM-1水平与临床分度呈正相关相关(r=0.652,P〈0.01)。结论:可溶性ICAM-1在HIE新生儿血清中呈高表达,可溶性ICAM-1的水平与病情严重程度密切相关。可溶性ICAM-1在新生儿缺氧缺血性脑损伤中起着重要作用: 相似文献
85.
David C. Krakauer Paolo M. de A. Zanotto Mark Pagel 《Journal of molecular evolution》1998,47(2):133-145
Modification of the cellular prion protein has been correlated with the acquisition of several neurodegenerative diseases,
including kuru, scrapie, bovine spongiform encephalopathy (BSE), and Creutzfeldt–Jakob disease (CJD). Sequence conservation
and amino acid identity are known to influence the efficacy of interspecific transmission. We analyzed patterns of interspecific
genetic variation with a view toward identifying features related to disease transmission. The reconstructed gene trees and
amino acid tree were compared with the species tree, and all discordances observed were related to the species barrier of
disease transmission. The rates of synonymous substitution, nonsynonymous substitution, and nucleotide content were determined
for the protein-coding gene. Substitutions implicated in each of the prion diseases were found to occur in regions of the
protein that are least variable across all species—opposite to the pattern of variability expected from interaction with an
infectious pathogen. Amino acid residues related to the species barrier form a single cluster associated with the first alpha-helical
domain of the protein. Residues related to sporadic and hereditary human prion disease form two separate clusters, associated
with the second and third alpha-helical domains. Taken together, these results are consistent with the view that prion diseases
arise from accidents in protein folding, rather than infection with an undiscovered virus-like particle. We speculate that
the differences in disease phenotype between transmissable and hereditary forms could result from interactions between different
parts of the protein during propagation.
Received: 18 April 1997 / Accepted: 17 October 1997 相似文献
86.
目的 探讨双歧杆菌三联活菌胶囊对肝性脑病患者肠屏障功能及血氨的影响。方法 选取100例确诊为肝性脑病的患者,随机分为对照组和治疗组各50例。对照组患者给予肝性脑病常规综合治疗,治疗组在常规综合治疗的基础上同时口服双歧杆菌三联活菌胶囊进行治疗。治疗前及治疗两周后分别检测两组患者肠黏膜屏障功能及血氨水平并比较其变化。结果 治疗前两组患者肠屏障功能及血氨水平差异无统计学意义(P>0.05);治疗2周后,治疗组患者的血氨水平、血清二胺氧化酶(DAO)水平、血清内毒素水平(LPS)及肿瘤坏死因子-α(TNF-α)水平较治疗前显著降低,且较对照组治疗后的水平亦有明显的降低(P<0.05)。结论 肝性脑病患者在常规综合治疗的基础上,加用双歧杆菌三联活菌胶囊可以明显改善患者肠黏膜屏障功能,减少肠源性血氨的生成,临床疗效确切。 相似文献
87.
Watanabe Y Hiraoka W Shimoyama Y Horiuchi M Kuwabara M Inanami O 《Biochemical and biophysical research communications》2008,366(1):244-249
We examined the influence of D177N (D178N in humans) mutation on the conformational stability of the S2 region of moPrPC with varying pHs by using the SDSL-ESR technique. The ESR spectrum of D177N at pH 7.5 was narrower than that of Y161R1, referred to as WT∗. The ESR spectrum of D177N did not change when pH in the solution decreased to pH 4.0. Our results suggested that the disappearance of a salt bridge (D177-R163) induced the increase in the instability of S2 region. Moreover, the line shape of the ESR spectrum obtained from H176S neighboring the salt bridge linked to the S2 region was similar to D177N. These results indicate that the protonation of H176 is strongly associated with the stability of S2 region. These findings are important for understanding the mechanism by which the disruption of the salt bridge in the S2 region forms the pathogenic PrPSc structure in hereditary prion disease. 相似文献
88.
Kawashima H Morishima T Togashi T Yokota S Yamanaka G Ioi H Kashiwagi Y Takekuma K Hoshika A Watanabe Y 《Neurochemical research》2004,29(8):1537-1540
The correlation between the glutamate-glutamine cycle and nitric oxide (NO) production in the central nervous system (CNS) of a new type of influenza-associated encephalopathy in children is discussed. When measurements of several amino acids and NOx (nitrite/nitrate) levels in the cerebrospinal fluid (CSF) using HPLC-fluorescence and -UV methods, respectively, were made. the CSF glutamate levels of patients with the new type of encephalitis were significantly lower, and both glutamine and NOx levels were significantly higher than those of the control group and the patients of the meningitis group. Results indicate that the turnover rate of glutamate in CNS, particularly in the brain, increases in the influenza-associated encephalopathy. The high mortality in the disease may correlate with the hyperactivity of supra-spinal glutamate neurons and the subsequent high activity levels of NOx in CNS. 相似文献
89.
过去认为神经元受损伤后难以再生.近年发现神经干细胞(neuralstemcells,NSC)主要存在于胚胎和成熟个体的中枢神经系统(CNS)中,具有增殖和分化的潜能.NSC成为神经学科的热点课题,是神经发育和疾病研究的重要平台,作为新生神经细胞的“种子”,它为治疗缺血缺氧性脑病提供了新策略,尤其是中枢神经细胞的治疗性再生和基因治疗.对NSC的发育、组织学特点、增殖分化的调控及治疗前景进行了阐述. 相似文献
90.
目的:探讨弥散加权成像、1H磁共振波谱诊断新生儿缺氧缺血性脑病的应用价值。方法:以本院收治的缺氧缺血性脑病新生儿37例为研究组,另选择健康新生儿40例作为对照组,两组新生儿均接受弥散加权成像及1H磁共振波谱检查,观察研究组新生儿普通MRI与弥散加权成像检查结果,对比研究组和对照组新生儿的脑代谢化合物相对浓度。结果:与普通MRI检出率相比,研究组患儿的弥散加权成像信号明显升高,差异存在统计学意义(P0.05)。研究组NAA/Cr比值低于对照组,Cho/Cr、MI/Cr、Glu-Gln/Cr、Lac/Cr比值高于对照组,差异存在统计学意义(P0.05)。结论:临床上诊断新生儿缺氧缺血性脑病时,弥散加权成像与1H磁共振波谱的联合应用可提升诊断准确率,通过对代谢物浓度的分析有利于评价缺氧缺血导致脑组织损害的严重程度。 相似文献