The crystal structure of L-glutamine is stabilized by a three-dimensional network of intermolecular hydrogen bonds.We utilize plane-wave density functional theory lattice-dynamics calculations within the generalized-g...The crystal structure of L-glutamine is stabilized by a three-dimensional network of intermolecular hydrogen bonds.We utilize plane-wave density functional theory lattice-dynamics calculations within the generalized-gradient approximation（GGA）, Perdew–Burke–Ernzerhof（PBE）, PBE for solids（PBEsol）, PBE with Wu–Cohen exchange（WC）, and dispersion-corrected PBE, to investigate the effect of these intermolecular contacts on the absorption spectra of glutamine in the terahertz frequency range. Among these calculations, the solid-state simulated results obtained using the WC method exhibit a good agreement with the measured absorption spectra, and the absorption features are assigned with the help of WC. This indicates that the vibrational modes of glutamine were related to the combination of intramolecular and intermolecular motions, the intramolecular modes were dominated by rocking or torsion involving functional groups; the intermolecular modes mainly result from the translational motions of individual molecules, and the rocking of the hydrogenbonded functional groups.展开更多
目的:研究心力衰竭患者血清脑钠肽(Brain Natriuretic Peptide,BNP)与氨基末端B型脑钠肽前体(N terminal pro B type natriuretic peptide,NT-proBNP)水平变化与心功能分级的相关性。方法:选取2021年3月-2024年4月期间本院收治的心力衰...目的:研究心力衰竭患者血清脑钠肽(Brain Natriuretic Peptide,BNP)与氨基末端B型脑钠肽前体(N terminal pro B type natriuretic peptide,NT-proBNP)水平变化与心功能分级的相关性。方法:选取2021年3月-2024年4月期间本院收治的心力衰竭患者91例纳入试验组。另选取同期于本院体检中心行体检的健康者90例纳入对照组。检测并比较对照组、试验组血清BNP、NT-proBNP水平。根据美国纽约心脏病学会心功能分级标准(New York Heart Association,NYHA)对试验组进行分级并比较不同心功能分级患者的BNP、NT-proBNP水平。分析试验组血清BNP、NT-proBNP与NYHA分级的相关性。结果:观察组血清BNP、NT-proBNP水平均显著高于对照组(P<0.05)。试验组心功能分级结果显示:Ⅰ级17例、Ⅱ级44例、Ⅲ级21例、Ⅳ级9例。试验组BNP、NT-proBNP水平比较:Ⅳ级>Ⅲ级>Ⅱ级>Ⅰ级(P<0.05)。血清BNP、NT-proBNP水平与NYHA分级均呈正相关(P<0.05)。结论:心力衰竭患者血清BNP与NT-proBNP水平与心功能分级呈正相关性,BNP与NT-proBNP水平随着心功能分级增加而升高。展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61302007 and 60977065)the Fundamental Research Funds for the Central Universities of China(Grant No.FRF-SD-12-016A)the Engineering Research Center of Industrial Spectrum Imaging of Beijing,China
文摘The crystal structure of L-glutamine is stabilized by a three-dimensional network of intermolecular hydrogen bonds.We utilize plane-wave density functional theory lattice-dynamics calculations within the generalized-gradient approximation（GGA）, Perdew–Burke–Ernzerhof（PBE）, PBE for solids（PBEsol）, PBE with Wu–Cohen exchange（WC）, and dispersion-corrected PBE, to investigate the effect of these intermolecular contacts on the absorption spectra of glutamine in the terahertz frequency range. Among these calculations, the solid-state simulated results obtained using the WC method exhibit a good agreement with the measured absorption spectra, and the absorption features are assigned with the help of WC. This indicates that the vibrational modes of glutamine were related to the combination of intramolecular and intermolecular motions, the intramolecular modes were dominated by rocking or torsion involving functional groups; the intermolecular modes mainly result from the translational motions of individual molecules, and the rocking of the hydrogenbonded functional groups.
文摘目的:研究心力衰竭患者血清脑钠肽(Brain Natriuretic Peptide,BNP)与氨基末端B型脑钠肽前体(N terminal pro B type natriuretic peptide,NT-proBNP)水平变化与心功能分级的相关性。方法:选取2021年3月-2024年4月期间本院收治的心力衰竭患者91例纳入试验组。另选取同期于本院体检中心行体检的健康者90例纳入对照组。检测并比较对照组、试验组血清BNP、NT-proBNP水平。根据美国纽约心脏病学会心功能分级标准(New York Heart Association,NYHA)对试验组进行分级并比较不同心功能分级患者的BNP、NT-proBNP水平。分析试验组血清BNP、NT-proBNP与NYHA分级的相关性。结果:观察组血清BNP、NT-proBNP水平均显著高于对照组(P<0.05)。试验组心功能分级结果显示:Ⅰ级17例、Ⅱ级44例、Ⅲ级21例、Ⅳ级9例。试验组BNP、NT-proBNP水平比较:Ⅳ级>Ⅲ级>Ⅱ级>Ⅰ级(P<0.05)。血清BNP、NT-proBNP水平与NYHA分级均呈正相关(P<0.05)。结论:心力衰竭患者血清BNP与NT-proBNP水平与心功能分级呈正相关性,BNP与NT-proBNP水平随着心功能分级增加而升高。
