Quantum chemical parameters of 10 amino acids with D- and L-configurations were firstly calculated with semi-empirical AM1 method. Furthermore, the relationship between molecular structures of D-, L-amino acids and t...Quantum chemical parameters of 10 amino acids with D- and L-configurations were firstly calculated with semi-empirical AM1 method. Furthermore, the relationship between molecular structures of D-, L-amino acids and their sweetness were observed. The results show that upon different configurations of amino acids, the sweetness is relative with their formation heat, dipole moment, energy gap of frontier orbital and other parameters. The formation heats of the same amino acids possessing D- and L-configurations are different except glycine. The algebraic value of D-amino acid is generally larger than that of corresponding L-configuration with only one except of tyrosine. The dipole moment of D-amino acid is generally larger than that of corresponding L-amino acid except tyrosine and lysine. The lowest unoccupied orbital energy （ELUMO） of D-amino acid is higher than that of corresponding L-configuration except phenylalanine. △E of D-amino acid is larger than that of L-amino acid except histidine, phenylalanine and lysine. The larger gap will have advantage for its matching with frontier orbital energy of human protein acceptor, which strengthens the interaction between D-amino acid and sweet taste acceptor. Besides, the changing rules of these parameters are generally identical.展开更多
目的利用文献计量学方法分析量化小儿心脏术后急性肾损伤(CS-AKI)的研究现状、热点及前沿,为临床工作者和相关研究人员提供参考。方法利用Web of Science检索2005~2024年间小儿CS-AKI相关文献,利用R语言数据包Bibliometrix对文献发表年...目的利用文献计量学方法分析量化小儿心脏术后急性肾损伤(CS-AKI)的研究现状、热点及前沿,为临床工作者和相关研究人员提供参考。方法利用Web of Science检索2005~2024年间小儿CS-AKI相关文献,利用R语言数据包Bibliometrix对文献发表年代、期刊、作者及关键词等进行可视化分析。结果筛选出小儿CS-AKI相关文献558篇,发文量呈逐年上升趋势。发文量前三的期刊为Pediatric Critical Care Medicine、Pediatric Nephrology、Pediatric Cardiology。全球小儿CS-AKI的作者中,Devarajan P、Goldstein SL、Zappitelli M为重要核心作者,且美国生产力最高。高频关键词为小儿CS-AKI的危险因素、病因及发病机制、预后、预测因子及防治措施。结论小儿CS-AKI近年来逐渐被重视,研究热点主要为CS-AKI的危险因素与预后、病因与发病机制及防治措施。未来该领域的预测指标与保护措施仍可能是热门研究方向。展开更多
目的 基于高分辨率磁共振血管壁成像和计算流体动力学技术,探讨大脑中动脉(MCA)粥样硬化性狭窄处斑块陡度与血流动力学的关系。方法收集80例缺血性脑卒中、短暂性脑缺血发作且单侧动脉粥样硬化性MCA狭窄的患者(50%~99%)进行进行常规磁...目的 基于高分辨率磁共振血管壁成像和计算流体动力学技术,探讨大脑中动脉(MCA)粥样硬化性狭窄处斑块陡度与血流动力学的关系。方法收集80例缺血性脑卒中、短暂性脑缺血发作且单侧动脉粥样硬化性MCA狭窄的患者(50%~99%)进行进行常规磁共振扫描及大脑中动脉狭窄处血管壁扫描。获得斑块、血管壁、血管壁剪切力比(WSSR)、狭窄处血管壁剪切力(WSS)的数值。根据有无缺血性脑卒中将患者分为有症状组和无症状组。比较两组在斑块、血管壁和血流动力学方面的差异。计算斑块陡度与血流动力学之间的相关性。结果80例患者中症状组31例,无症状组49例。症状组较无症状组狭窄处管腔面积(LA)较小(2.33±1.12 VS 2.94±1.06,P=0.024),斑块面积(PA)较大(4.36.±2.13 VS 2.87±1.38,P=0.001),重构指数较大(1.13±0.21 VS 0.92±0.19,P=0.001),WSSR(9.93,8.42 VS 5.75,3.68,P=0.009)和WSS(52.41±16.92 VS 38.37±17.26,P=0.018)较高,斑块陡度(1.24,1.17 VS 0.94,0.91,P=0.014)较大。与无症状组相比,症状组有更多的强化斑块(24vs 13,P=0.03),正性重构(23vs20,P=0.001)。斑块陡度与WSSR呈正相关(r=0.879,P<0.001)。结论斑块陡度是MCA粥样硬化斑块的一个重要特征,在以往的研究中未引起足够的重视。大的斑块陡度更容易引起脑卒中。展开更多
文摘Quantum chemical parameters of 10 amino acids with D- and L-configurations were firstly calculated with semi-empirical AM1 method. Furthermore, the relationship between molecular structures of D-, L-amino acids and their sweetness were observed. The results show that upon different configurations of amino acids, the sweetness is relative with their formation heat, dipole moment, energy gap of frontier orbital and other parameters. The formation heats of the same amino acids possessing D- and L-configurations are different except glycine. The algebraic value of D-amino acid is generally larger than that of corresponding L-configuration with only one except of tyrosine. The dipole moment of D-amino acid is generally larger than that of corresponding L-amino acid except tyrosine and lysine. The lowest unoccupied orbital energy （ELUMO） of D-amino acid is higher than that of corresponding L-configuration except phenylalanine. △E of D-amino acid is larger than that of L-amino acid except histidine, phenylalanine and lysine. The larger gap will have advantage for its matching with frontier orbital energy of human protein acceptor, which strengthens the interaction between D-amino acid and sweet taste acceptor. Besides, the changing rules of these parameters are generally identical.
文摘目的 基于高分辨率磁共振血管壁成像和计算流体动力学技术,探讨大脑中动脉(MCA)粥样硬化性狭窄处斑块陡度与血流动力学的关系。方法收集80例缺血性脑卒中、短暂性脑缺血发作且单侧动脉粥样硬化性MCA狭窄的患者(50%~99%)进行进行常规磁共振扫描及大脑中动脉狭窄处血管壁扫描。获得斑块、血管壁、血管壁剪切力比(WSSR)、狭窄处血管壁剪切力(WSS)的数值。根据有无缺血性脑卒中将患者分为有症状组和无症状组。比较两组在斑块、血管壁和血流动力学方面的差异。计算斑块陡度与血流动力学之间的相关性。结果80例患者中症状组31例,无症状组49例。症状组较无症状组狭窄处管腔面积(LA)较小(2.33±1.12 VS 2.94±1.06,P=0.024),斑块面积(PA)较大(4.36.±2.13 VS 2.87±1.38,P=0.001),重构指数较大(1.13±0.21 VS 0.92±0.19,P=0.001),WSSR(9.93,8.42 VS 5.75,3.68,P=0.009)和WSS(52.41±16.92 VS 38.37±17.26,P=0.018)较高,斑块陡度(1.24,1.17 VS 0.94,0.91,P=0.014)较大。与无症状组相比,症状组有更多的强化斑块(24vs 13,P=0.03),正性重构(23vs20,P=0.001)。斑块陡度与WSSR呈正相关(r=0.879,P<0.001)。结论斑块陡度是MCA粥样硬化斑块的一个重要特征,在以往的研究中未引起足够的重视。大的斑块陡度更容易引起脑卒中。
