Advanced Materials Research Vols. 781-784

Abstract: Using X-ray power diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR), the chemical composition of urinary nanocrystallites from 3 calcium phosphate (CaP) stone-formers were investigated and compared with that from healthy subjects. The main components of nanocrystallites in urine of CaP stone formers were uric acid and CaP, while that in healthy urine was mainly uric acid, which indicated a significant difference. This study purposed an accurate detection method of urinary nanocrystallites, namely washing the urinary crystallites samples with double distilled water, which can avoid the interference of soluble components (such as NaCl, uric acid, and urea) that were precipitated from urine during sample preparation.

Abstract: Flow chemistry, as a rapidly emerging technology, is exploited to provide a safe and scalable route for the pharmaceutically interesting coumarin. Here, a continuous flow approach for the generation of coumarin is reported, which relies on the two connected coil reactors design. The synthesis of coumarin has been performed successfully in high conversion on small scale and can be scaled up substantially.

Abstract: A new method of determination of malachite green (MG) in sediment has been developed by high performance liquid chromatography with fluorescence detection (HPLC-FLD). It is based on use of a deoxidation reaction which converts malachite green (MG) into LMG in the process of extraction. The sediment samples were extracted with a solution of formic acid and acetonitrile. Clean up and isolation was performed on MCX solid phase extraction (SPE) column. Chromatographic separation was achieved by using C₁₈ column with an isocratic mobile phase consisting of acetonitrile and ammonium acetate buffer (0.05 M, pH 4.5) (80:20, v/v). High performance liquid chromatography with fluorescence detector (λex=265 nm and λem=360 nm) was used for the determination of LMG. The recovery values of MG in sediment samples fortified with MG were determined by measuring the amount of MG in the samples, after carrying out deoxidation reaction with potassium borohydride, which converts the MG into LMG. Under the optimized conditions, the average recoveries of MG from sediment at three levels (1.0, 10 and 50 μg/kg) were 85.0% (range from 80.8 to 87.6%). Relative standard deviations (RSD) of recoveries at all fortification levels were less than for 9.57% for MG. The method detection limit obtained for MG was 0.5 μg/kg.

Abstract: Four different concentrations of alkaline solution for pretreatment of Paulownia biomass were comparatively studied. The extracted celluloses were characterized using Fourier Transform Infrared spectra (FTIR) for changes of the chemical group, as well as X-ray Diffraction (XRD), Scanning Electron Microscope (SEM). The four samples were untreated biomass, treated with 2%, 4% and 6%peroxide alkaline, and thena comparison between alkaline and dilute acid pretreatment on those indexes were conducted. FTIR spectra results suggested that NaOH could mainly work on lignin of the raw material while the dilute acid work on hemicellulose. The CrI of acid pretreatment and alkaline pretreatment increased to 0.5467 and 0.6395 respectively comparing with the value of 0.4347 of raw material. The XRD results suggested that both of them could act on amorphous region firstly. The SEM micrographs showed the visual structure changes of this progress. The results of enzyme hydrolysis showed 93.3% and 90.6% of the potential glucose and xylose were recovered in the pretreated biomass at 6% NaOH that proved the effects of the NaOH on cellulose structural.

Abstract: Lignin-modified amino-sulfonic acid-based dispersant LMA was synthesized by using soda lignin to substitute part of phenol. Effect of LMA on ceramic slurry performance was studied and compared with inorganic salt dispersant. The addition of LMA endows ceramic slurry with lower viscosity, better fluidity and stability. Particle size of ceramic slurry blended with LMA is clearly decreased and grinding efficiency improves. LMA can enhance particle electro-negativity by complexing high valence cations and polymeric anion-adsorbing on ceramic particles surface by hydrogen bonds. The dispersive effect of LMA to ceramic particles is the combined action of steric effect and electrostatic repulsion.

Abstract: The quantitative determination of glutamate is very important for diagnostic of many diseases of the nervous system, severity of stroke of the brain and also for determination glutamate in the food stuffs [1,2]. To the present days for quantitative determination of glutamate is wide used to the enzyme preparation of glutamate dehydrogenase (GDh) from bovine liver. However the application of GDh has the next serious disadvantages: high lability of this preparation and many substances strong change the activity of GDh. For example there are nucleotides, amino acid, steroid and metal ions. As the results the application of GDh preparation dont give reliable determination of quantity of glutamate. Thus there is the high necessity to propose another enzyme preparation for quantitative determination of glutamate without above mentioned disadvantages. In this reason we propose absolutely new enzyme preparation for this aim. In the laboratory of the enzyme structure and regulation of the Institute of the molecular biology and biochemistry of the Ministry of the education and science of the Republic of Kazakhstan was discovered the new enzyme complex (EC), which consists of malate dehydrogenase (MDh) and glutamate-oxaloacetate aminotransferase (GOAT) and used it for quantitative determination of glutamate concentration [3].

Abstract: Production of fructose from glucose isomerisation process using commercial immobilized glucose isomerase (IGI) was conducted in a fixed-bed bioreactor. A semi-empirical kinetic model based on the mechanism of the glucose isomerisation process has been proposed. The values of maximum rate of reaction, V_m ,g L^-1 min^-1 are (1.82, 1.86, 1.93 and 0.37), for Michaelis-Menten constant K_m, g L^-1 the values are (1.04, 1.11, 1.24 and 0.35). In this modified model, known as MM3 the variation of temperature, pH, and initial substrate concentration, feed flow rates have been taken into account. The validation of the models with experimental data was checked in terms of AAE and R². The values of correlation coefficient, R² (> 0.95) indicated that MM3 model was well fitted to the experimental data.

Abstract: This paper aims to study the root activity of wheat and radish seeds with seven plant growth regulators in room through seed soaking. The results show that it mainly affects the stem height of wheat seed when it was 1000 dilution of the 7 plant growth regulators, but it mainly affects the main root length of wheat seed when it was 5000 dilution. when we treat radish seeds in 1000 and 5000 dilution , there were obvious effect on stem height and main root length, this study is helpful for field planting.

Abstract: Quaternary ammonium salt of chitosan (HACC) was synthesized by the reaction of chitosan(CTS) and 2, 3-epoxypropyltrimethyl- ammonium chloride(GTA) in isopropanol. The influence factors of the degree of substitution of synthetic reaction, such as the molar ratio of reactants, the reaction time, temperature and so on were discussed by single factor experiments.The results showed that the optimal conditions for the preparation were nGTA: nCTS=4:1, the reaction time 8h, the reaction temperature 75°C, the reaction pH value 7, the alkalization time 14h, the molecular weight of chitosan 320000g/mol, the moisture of reaction system 20%. The structures of HACC and CTS were characterized by infrared spectrum, the appearances of morphology of HACC and CTS were researched by scanning electron microscopy, the thermal stabilities of HACC and CTS were studied by thermogravimetry. The results showed that the substitution reaction mainly occurs on the N element, modified derivatives had significant changes in appearance and size, and lower thermal stability.

Abstract: Bamboo vinegar and sulfuric acid are used as acidifier and the method of precipitation is adopted to synthesize the antibacterial white carbon black. Orthogonal experiment was carried out to investigate the influence of reaction temperature, the amount of bamboo vinegar, additive amount of polyethylene glycol, the concentration of sodium silicate and amount of priming water on the oil absorption value of white carbon black. The analysis of orthogonal experimental results shows that influence of temperature, amount of priming water and the additive amount of PEG on oil absorption value is extremely remarkable. The influence of the amount of bamboo vinegar is remarkable, but the concentration of sodium silicate is indistinctive. It is verified through experiments that the specific surface area and oil absorption value of product is high, and its antibacterial effect is good.