Structural analysis of the non-dialysable urinary glucoconjugates of normal men.

Enzymic methods were employed to analyse the structure of the non-dialysable urinary glucoconjugates of ten healthy males. The excretion of the urinary glucoconjugates was determined from the glucosyl:galactosyl ratio after acid hydrolysis, and a mean value of 0.27 was obtained. The results of the specific actions of alpha- and beta-glucosidases showed that the non-dialysable urinary glucoconjugates contain a branched alpha-glucan fraction with 1,4- and 1,6-glucosidic bonds, and a beta-glucan fraction containing 1,4-glucosidic bonds.     

Stability of vinylidene chloride copolymers containing 4-vinylpyridine units

Vinylidene chloride copolymers are prominent in the barrier plastic packaging industry. These materials display excellent barrier to the transport of oxygen (and other small molecules) as well as flavor and aroma molecules. However, they suffer from a propensity to undergo degradative dehydrochlorination at process temperatures. To scavenge hydrogen chloride formed and prevent its interaction with the metallic components of process equipment, a passive base is usually included as an additive prior to processing. The base is most often an inorganic oxide or salt. These may negatively impact the properties of the polymer, particularly as a film. An organic base that could be covalently incorporated into the copolymer might display better behavior. Accordingly, a series of copolymers containing low levels of 4-vinylpyridine (0.05–3 mole%) have been prepared, characterized, and examined by thermogravimetry to assess thermal stability. In all cases, polymers containing 4-vinylpyridine units are less stable than the polymer containing none of this comonomer. Clearly, the pyridine moiety is a sufficiently strong base to promote E2 elimination of hydrogen chloride to generate dichlormethylene units in the mainchain from which thermal degradation may be initiated.     

Preparation and properties of VO2 thin films by a novel sol–gel process

Vanadium dioxide (VO₂) thin films were fabricated using a simple and novel sol–gel process in which V₂O₅ was used as the vanadium source; oxalic acid was used as the reducing agent; and polyvinyl alcohol was used as the film former to control the viscosity of the VO₂ precursor solution and bond vanadium ions. The microstructure and surface morphology of VO₂ films were studied by X-ray diffraction and scanning electron microscopy, respectively. The results showed that using polyvinyl alcohol forms porous nanostructure of VO₂ films with a uniform grain size of ~25 nm. The measured optical reflectance shows well-defined phase transition as observed by an increase of reflectance upon heating above the transition temperature from ~11 to ~30 % at 1,100 nm. Upon cooling, the expected hysteresis is observed.     

Prediction and optimization of the performance characteristics of CZTS thin film solar cell using band gap grading

The results of the numerical simulation of the performance characteristics of (Cu₂ZnSnS₄) CZTS thin film solar cell due to bandgap grading is presented in this work. The investigation of the performance of this solar cell was carried out using the Analysis of Microelectronics and Photonics software (AMPS-1D). A substrate cell structure FTO/CdS/CZTS/Mo(SLG) was used as the base model. An efficiency of 8.33% was obtained from the simulation with baseline parameters while an intentional grading of the device was carried out on the device both at the front and back interface of the absorber. Front grading was observed to degrade the device performance while significant improvement of the device performance was observed with back grading. An intentional double grading of the device further enhanced the efficiency up to 12.26%.     

关于五阶非线性微分方程一致耗散解的一个结果

Criteria for the existence of uniformly dissipative solutions for a certain fifth order non-linear differential equation are given by means of the frequency domain method.     

Spectroscopic,conformational analysis,structural benchmarking,excited state dynamics,and the photovoltaic properties of Enalapril and Lisinopril

There have been numerous attempts to theoretically design a better photovoltaic property with much interest on how to improved absorption and emission parameters of most reactive compounds in respect to dye – sensitized solar cells (DSSCs). This is regardless of the promising futures of the photovoltaic properties. However, for such effective design, it is necessary to understand the electronic and photophysical properties of the dye systems. Herein detailed density functional theory (DFT) and time – dependent DFT (TD-DFT) investigation of the excited state characteristics and the influence of various solvents: water, acetone, ethanol and chloroform on the photophysical properties of enalapril and lisinopril were investigated along with the experimental spectral (UV–vis and FT-IR) analysis. The electronic structure calculations were conducted using the 6–311++G(d,p) basis set in combination with B3LYP, M06-2X, and ?B97XD DFT functionals for the structural benchmarking investigations of the studied compounds. Results of the excitation electronic analysis of enalapril was observed to have wavelength absorption in the order gas > chloroform > ethanol > water which correspond to 229.19, 228.81, 228.85, 229.03 nm respectively while Lisinopril have the order of chloroform > gas > water > ethanol which present ethanol have the highest transition energy. In all the studied structured, the transition assignment corresponds to π $\to$ π* all corresponding to the Frank -Condon local excitation. It can be inferred from the photovoltaic properties that among the studied compounds in four different phases enalapril have the highest oscillator strength, but the values of light-harvesting efficiency (LHE) varies and show greater stability in Lisinopril. Lisinopril was observed to have the highest value of $V_{OC}$ compared to Enalapril this further confirmed the result obtained from the frontier molecular orbitals.     

Spherical cell approach for the effective viscosity of suspensions

In the present paper, the spherical cell approach is employed for addressing the effective viscosity of suspensions of spherical particles. The proposed derivation is based on the only assumption which constitutes the essence of the spherical cell approach: a representative part of the suspension is a spherical cell which contains a particle surrounded by the continuous phase. In contrast with the previous studies on this topic, no additional assumptions are used in the present analysis. The general method of derivation and the final result, which represents the effective viscosity as a function of the solid-phase volume fraction, are compared with earlier studies where the spherical cell approach was applied for describing the effective viscosity.     

Kinetics of Phenolic Compounds Modification during Maize Flour Fermentation

This study aimed to investigate the kinetics of phenolic compound modification during the fermentation of maize flour at different times. Maize was spontaneously fermented into sourdough at varying times (24, 48, 72, 96, and 120 h) and, at each point, the pH, titratable acidity (TTA), total soluble solids (TSS), phenolic compounds (flavonoids such as apigenin, kaempferol, luteolin, quercetin, and taxifolin) and phenolic acids (caffeic, gallic, ferulic, p-coumaric, sinapic, and vanillic acids) were investigated. Three kinetic models (zero-, first-, and second-order equations) were used to determine the kinetics of phenolic modification during the fermentation. Results obtained showed that fermentation significantly reduced pH, with a corresponding increase in TTA and TSS. All the investigated flavonoids were significantly reduced after fermentation, while phenolic acids gradually increased during fermentation. Among the kinetic models adopted, first-order (R² = 0.45–0.96) and zero-order (R² = 0.20–0.82) equations best described the time-dependent modifications of free and bound flavonoids, respectively. On the other hand, first-order (R² = 0.46–0.69) and second-order (R² = 0.005–0.28) equations were best suited to explain the degradation of bound and free phenolic acids, respectively. This study shows that the modification of phenolic compounds during fermentation is compound-specific and that their rates of change may be largely dependent on their forms of existence in the fermented products.     

Fatty Acid Profile and Antioxidant Capacity of Dabai (Canarium odontophyllum L.): Effect of Origin and Fruit Component

In the present work, the influence of geographical location on the fatty acid profiles, antioxidant potential, as well as cytotoxicity of edible dabai fruit fractions (kernel, skin, and pulp) were analyzed. The fatty acid profiles were determined by Gas Chromatography (GC), and the antioxidant activity was quantified with free 2,2-diphenyl-1-picr/ylhdrazyl, while the cytotoxicity was assessed by the brine shrimp lethality test. The results showed that the samples from Sibu, Serian, and Kapit geographical locations had a high content of the saturated fatty acids, ranging from 46.63% to 53.31% in the three fractions. The highest mono-saturated fatty acids (MUFA) content was found in Sibu. Serian and Kapit kernel fractions MUFA, however, ranged from 21.2% to 45.91%. No fatty acid composition was detected in Bentong and Kanowit. The fatty acid composition and DPPH free radical scavenging antioxidant activity of dabai were statistically independent using a multivariate analysis in different localities in Malaysia. The skin fraction had a more appreciable antioxidant potential and toxicity level than the pulp and kernel fractions. The highest antioxidant activity (EC₅₀ 198.76 ± 1.06 µg/mL) with an LC₅₀ value of 1387.22 µg/mL was obtained from the Sibu skin fraction. Therefore, the fatty acid composition, antioxidant, as well as cytotoxicity analyses of the extracts from different localities indicated that “geographical location” remarkably influenced fatty acid composition, antioxidant activity, and toxicity.