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31.
Numerous scientific studies have confirmed the beneficial therapeutic effects of phenolic acids. Among them gentisic acid (GA), a phenolic acid extensively found in many fruit and vegetables has been associated with an enormous confirmed health benefit. The present study aims to evaluate the antidiabetic potential of gentisic acid and highlight its mechanisms of action following in silico and in vitro approaches. The in silico study was intended to predict the interaction of GA with eight different receptors highly involved in the management and complications of diabetes (dipeptidyl-peptidase 4 (DPP4), protein tyrosine phosphatase 1B (PTP1B), free fatty acid receptor 1 (FFAR1), aldose reductase (AldR), glycogen phosphorylase (GP), α-amylase, peroxisome proliferator-activated receptor gamma (PPAR-γ) and α-glucosidase), while the in vitro study studied the potential inhibitory effect of GA against α-amylase and α-glucosidase. The results indicate that GA interacted moderately with most of the receptors and had a moderate inhibitory activity during the in vitro tests. The study therefore encourages further in vivo studies to confirm the given results.  相似文献   
32.
A series of chalcone analogues (1–15) were synthesized by Claisen-Schmidt condensation in good yields (70–95%) and characterized by FT-IR, 1H NMR and mass spectral methods. Additionally, compounds 3 and 7 were characterized by 13C NMR. Antitubercular and antioxidant activities of the chalcones were evaluated by MABA and DPPH free radical assays. In MABA assay analogues 3 (MIC = 14 ± 0.11 µM) and 11 (MIC = 14 ± 0.17 µM) bearing fluorine and methoxy groups at para and meta positions were 1.8-times more active than the standard pyrazinamide (MIC = 25.34 ± 0.22 µM). The chalcone analogues such as compound 7 (IC50 = 4 ± 1 µg/mL) containing electron releasing groups such as OH at ortho position had slightly more antioxidant activity than Gallic acid (IC50 = 5 ± 1 µg/mL). The potential compounds 3, 7, 9 and 11 were less selective and toxic against human live cell lines-LO2. Further, molecular docking results of chalcones against anti-tubercular drug target isocitrate lyase (PDB ID: 1F8M) revealed that compound 3 and 11 shown least binding energies as ?7.6, and ?7.5 kcal/mol are in line with in vitro MABA assay, suggesting that these compounds 3 and 11 are strong inhibitor of isocitrate lyase. SwissADME programme estimated the drug likeliness properties of compounds 3, 7, 9 and 11. The lead molecules arisen through this study helps to develop new antitubercular and antioxidant agents.  相似文献   
33.
针对近红外光谱应用,提出了一种基于高斯过程(GP)模型的波长选择算法,即联合区间高斯过程(synergy interval gaussian process,siGP)算法。首先将全光谱区域划分为一系列无重复且间距相等的区间,再选取最优的若干个区间联合建立GP模型,由于GP模型具有非线性处理能力,因此该方法可以减少非线性的影响。以红曲菌固态发酵过程中过程参数水分含量和pH值的检测为例,新算法对水分含量、pH值的预测集相关系数(rp)分别为0.956 4和0.977 3,预测均方根误差(RMSEP)分别为0.012 7和0.161 0,参与建模的数据点由全谱的1 500个分别减少到225个、375个,在对独立样本的预测上,表现出较好的精度。与传统联合区间偏最小二乘(siPLS)波长选择算法对比,siGP算法预测效果更好:对水分含量和pH值,rpGP模型预测时提高了3.37%和3.51%,RMSEP在GP模型预测时提高了29.4%和34.8%。表明siGP结合GP模型能够有效选择波长区间以及提高近红外模型的准确性,对进一步实现近红外光谱技术在线检测具有参考价值。  相似文献   
34.
We construct exact stationary solutions to the one-dimensional coupled Gross-Pitaevskii equations for the two-species Bose-Einstein condensates with equal intraspecies and interspecies interaction constants. Three types of complex solutions as well as their soliton limits are derived. By making use of the SU(2) unitary symmetry, we further obtain analytical time-evolving solutions. These solutions exhibit spatiotemporal periodicity.  相似文献   
35.
We have computed γ-ray exposure buildup factors (EBF) of some building materials; glass, marble, flyash, cement, limestone, brick, plaster of paris (POP) and gypsum for energy 0.015–15 MeV up to 40 mfp (mfp, mean free path) penetration depth. Also, the macroscopic effective removal cross-sections (ΣR) for fast neutron were calculated. We discussed the dependency of EBF values on photon energy, penetration depth and chemical elements. The half-value layer and kinetic energy per unit mass relative to air of building materials were calculated for assessment of shielding effectiveness. Shielding thicknesses for glass, marble, flyash, cement, limestone and gypsum plaster (or Plaster of Paris, POP) were found comparable with ordinary concrete. Among the studied materials limestone and POP showed superior shielding properties for γ-ray and neutron, respectively. Radiation safety inside houses, schools and primary health centers for sheltering and annual dose can be assessed by the determination of shielding parameters of common building materials.  相似文献   
36.
本文涉及多步 Runge-Kutta方法关于多延迟微分方程系统的渐近稳定性 .在本文中我们证明了在适当条件下常微多步 Runge-Kutta方法的 A-稳定性等价于相应求解多延迟微分方程系统的GPk-稳定性 .  相似文献   
37.
Absorption spectroscopic measurements of effective particle number densities of excited Xe, Ne, Cl, and H performed on a small scale discharge with well-defined current and voltage pulses are compared with the results of model calculations over a wide range of discharge parameters. The reaction kinetic pathways determining the ionization and dissociative attachment rates have been verified by the good agreement obtained during the quasi-steady-state phase of the discharge for Xe and H. To reproduce the rise times of the excited Xe particle number densities during the ignition phase, the electron collision excitation cross sections of ground state Xe published by Puech and Mizzi [1] had to be enhanced by about 25%. From the Ne measurements it is concluded that the electron collision excitation cross sections of ground state Ne published by Puech and Mizzi [1] may be too large near the threshold. Measurements of excited Cl particle number densities are unsuitable to check the attachment kinetics of HCl, because these densities are mainly determined by reactions not involving the formation of Cl ions.  相似文献   
38.
The ‘Congruence Conjecture’ was developed by the second author in a previous paper [So3]. It provides a conjectural explicit reciprocity law for a certain element associated to an abelian extension of a totally real number field whose existence is predicted by earlier conjectures of Rubin and Stark. The first aim of the present paper is to design and apply techniques to investigate the Congruence Conjecture numerically. We then present complete verifications of the conjecture in 48 varied cases with real quadratic base fields.  相似文献   
39.
基于GP4020的GPS接收机软件设计   总被引:4,自引:4,他引:4  
介绍了一种基于ARM的GPS接收机的开发过程,对接收机的软件设计和信号处理技术进行了详细的阐述,给出了软件结构和程序流程图。为了能够快速地对扩频信号进行捕获跟踪,采用了四相鉴频器、符号叉积频率跟踪算法和科斯塔斯环混合进行载波跟踪的变带宽跟踪策略。实验证明,采用本方案设计的GPS接收机能较好地完成信息提取与处理任务。  相似文献   
40.
With the rapid development of rubber industry, it becomes more and more important to improve the performance of the quality control system of rubber mixing process. Unfortunately, the large measurement time delay of Mooney viscosity, one of the most important quality parameters of mixed rubber, badly blocks the further development of the issue. The independent component regression‐Gaussian process (ICR‐GP) algorithm is used to solve such typical nonlinear “black‐box” regression problem for the first time to predict Mooney viscosity. In the ICR‐GP method, the non‐Gaussian information is extracted by the independent component regression method firstly, and then the residual Gaussian information is extracted by the Gaussian process method. Meanwhile, both the linear and nonlinear relationships between the input and output variables can be extracted through the ICR‐GP method. With the fact that there is no need to optimize parameters, the ICR‐GP method is especially suitable for “black‐box” regression problems. The highest prediction accuracy was achieved at M = 0.8765 (the root mean square error), which was high enough considering the measuring accuracy (M = ±0.5) of the Mooney viscometer. It is by using the online‐measured rheological parameters as the input variables that the measurement time delay of Mooney viscosity could be dramatically decreased from about 240 to 2 min. Consequently, such Mooney‐viscosity prediction model is very helpful for the development of the rubber mixing process, especially of the emerging one‐step rubber mixing technique. The practical applications performed on the rubber mixing process in a large‐scale tire factory strongly proved the outstanding regression performance of this ICR‐GP Mooney‐viscosity prediction model. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
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