In Vivo Skin Permeation of Sodium Naproxen Formulated in Pluronic F-127 Gels: Effect of Azone® and Transcutol®

The objective of this study was to determine the penetration of sodium naproxen, formulated in Pluronic F-127 (PF-127) gels containing Azone® and Transcutol® as penetration enhancers, through human skin in vivo. It was found that the combination of Azone® and Transcutol® in PF-127 gels enhanced sodium naproxen penetration, with enhancement ratios of up to two fold compared with the formulation containing only Transcutol®. These results were confirmed by TEWL and ATR-FTIR spectroscopy, suggesting a synergic action for Azone® and Transcutol®. Because of the thermo-reversible behavior of Pluronic gels, the influence of the components added to the gel formulations on viscosity, as a function of temperature, was also studied.     

The influence of the stabilizing agent SDS on porosity development in alkali-activated fly-ash based foams

Alkali activated foams (known also as “geopolymer foams”) are formed by the adding of a foaming agent, such as Al powder or H₂O₂, to an alkali activated matrix which can be based on, for example, fly ash, slag or meta-kaolin. The foaming agent decomposes and reacts inside the matrix, resulting in the release of gasses which form pores within the structure. Such pores have to be created before the alkali activated foams harden. In order to prevent the escape of these gasses from the foam, a stabilizing agent can be added to the foam mixture. This paper presents the results of tests involving the pore-foaming process in the case of highly porous, alkali activated, fly-ash based foams. Between 0.5 and 1.5 mass % of H₂O₂ was added to the fly ash precursor as a foaming agent, as well as different amounts (varying from 0.1 to 4.0 mass %) of the selected stabilizing agent, which is known as SDS - sodium dodecyl sulfate. The physical, mechanical, and microstructural properties of the hardened alkali-activated foams were determined. Their pore structures were characterised by SEM, as well as by a three-dimensional (3D) technique, X-ray computed micro-tomography. The advantage of the latter method is that a better insight can be obtained into the characteristics of the hardened pore structure, including information about its homogeneity and the pore size distribution. The influence of the amount of the added foaming agent, as well as that of the amount of the stabilization agent, was evaluated, and optimal addition mass percentages were determined. In the case of the best mixtures, the investigated hardened pore structures showed relatively good mechanical properties, and could therefore be used for various applications in the building industry.     

Effect of the Type of Base and Number of Reaction Steps on the Degree of Quaternization and Molecular Weight of N-Trimethyl Chitosan Chloride

N-Trimethyl chitosan chloride (TMC), a chemically modified derivative of chitosan, is the first chitosan derivative shown to be an effective absorption enhancer for peptide and protein drugs across mucosal epithelia. TMC is synthesized by reductive methylation with methyl iodide in the presence of a strong base such as sodium hydroxide. In this reaction, the primary amino group on the C-2 position of chitosan is changed to a quaternary amino group. The charge density, as determined by the degree of quaternization, and probably also the molecular weight of TMC are important factors that influence the absorption enhancement effect and toxicity of this polymer. The molecular weight of the starting polymer decreases during the synthesis procedure due to factors such as the strong alkaline environment and elevated experimental temperatures. This study investigated the effects of two different bases, sodium hydroxide and dimethyl amino pyridine, together with a varying number and duration of reaction steps, on the degradation and the degree of quaternization of TMC polymers. ¹H-NMR (nuclear magnetic resonance) spectra showed a major increase in the degree of quaternization (21%–59%) of TMC with an increase in the number of reaction steps when sodium hydroxide was used as the base. Intrinsic viscosity values indicated that the use of dimethyl amino pyridine did not cause polymer degradation to the same extent as sodium hydroxide, but that the degree of quaternization of TMC stayed low (7.3%–9.6%) even when the number of reaction steps was increased. A combination of the two bases did not reduce polymer degradation, while the degree of quaternization was limited to relatively low values (12.5%–34.4%).     

Effect of sodium dodecyl benzene sulfonate (SDBS) on the performance of anaerobic co-digestion with sewage sludge,food waste,and green waste

Abstract

The anionic detergent sodium dodecyl benzene sulfonate (SDBS) inhibits anaerobic solid waste fermentation process in mesophilic anaerobic digesters. In this study, the effect SDBS on the performance of anaerobic digestion (AD) of mixture of sewage sludge, food waste, and green waste serving as substrate was investigated. The batch experiments were conducted with five SDBS concentrations namely 0, 0.01, 0.02, 0.05, 0.1, and 0.2?g/g (SDBS/dry sludge) under mesophilic condition (37?±?1?°C) and lasted for 63?days. The results showed that the presence of SDBS remarkably increased the release of protein and carbohydrate, and resulting in the serious accumulation of volatile fatty acids (VFAs), especially for propionate accumulation. Likewise, the observed variations in enzyme activities associated with different stage of AD revealed that methanogenesis was quite sensitive to SDBS and inhibited by the increase of SDBS addition. Meanwhile, the presence of SDBS decreased the pH value and the concentration of free ammonia, but increased the concentration of NH₄⁺-N. Furthermore, the production of biogas was reduced by SDBS. In conclusion, SDBS addition has a negative impact on anaerobic co-digestion. On the one hand, methanogens were severely inhibited and biogas yield decreased remarkably, on the other hand, the accumulation of VFAs was excessive. Thus, the presence of surfactant (SDBS) in the municipal organic waste should be concerned during the waste disposal via anaerobic digestion process.     

Solid-state NaBH4 composites for hydrogen generation: Catalytic activity of nickel and cobalt catalysts

Hydrogen generation from tablets of sodium borohydride with chlorides of nickel and cobalt was studied. The nickel catalysts were shown to be less active in the borohydride hydrolysis than the cobalt catalysts. One of the reasons for the lower activity of the nickel catalyst was the presence of hydrogen on its surface, which hampered the adsorption of reactants. The addition of cobalt to the nickel catalyst increases the hydrogen generation rate. This is due to the introduction of active metal with low adsorption capacity for hydrogen and the higher dispersion of the active component.     

Development of microbiologically safe mung bean sprouts using combination treatment of sodium hypochlorite and gamma radiation

Specific group of people, with impaired immune system, are recommended to consume pathogen‐free foods. In this study, microbiologically safe ready‐to‐eat (RTE) mung bean sprouts were developed using combination treatment (CT) with 200 ppm sodium hypochlorite and 12 kGy dose of gamma radiation. Microbiological analysis of combination‐treated sprout samples showed complete elimination (<10 CFU g^?1 of sprouts) of microbial load in these samples, even during storage at 4 °C up to 12 days. Combination treatment and storage period did not have any significant effect on the sensory qualities of RTE mung bean sprouts. However, reduction in the firmness and vitamin C content of combination‐treated sprout samples, similar to other food processing methods, was observed. These results suggest that CT is effective in sterilisation of mung bean sprouts. These sprouts can be included in the diets of special target groups and thereby improve in their quality of life.     

Poly(acrylic acid)-modified silica nanoparticles as a nonmetal catalyst for NaBH4 methanolysis

In the present work, a SiO₂@PAA catalyst for NaBH₄ methanolysis composed of silica nanoparticles modified with poly(acrylic acid) has been developed. The morphology and composition of the prepared SiO₂@PAA catalyst were analyzed with transmission electron microscopy, Fourier transform-infrared spectroscopy, x-ray photoelectron spectroscopy and thermogravimetric analysis. This catalyst showed excellent catalytic performance for methanolysis of NaBH₄. The NaBH₄ methanolysis reaction catalyzed by SiO₂@PAA showed an average hydrogen generation rate 5.5 times as high as the reaction catalyzed by unmodified SiO₂ and 10.6 times as high as the uncatalyzed reaction, respectively. The activation energy for methanolysis of NaBH₄ catalyzed by this SiO₂@PAA catalyst was 24.03 kJ/mol. Moreover, although the catalytic activity of SiO₂@PAA catalyst partially lost after being used, it could be restored after being regenerated by washing with diluted hydrochloric acid solution.     

Innovative hydrogen release from sodium borohydride hydrolysis using biocatalyst-like Fe2O3 nanoparticles impregnated on Bacillus simplex bacteria

For the first time in this innovative study, microorganisms such as Bacillus simplex bacteria, mostly used in biological activity studies, are used as a bio-supporter agent of iron to release hydrogen from sodium borohydride hydrolysis at 25.0 ± 0.1 °C. The goal is to investigate thoroughly sodium borohydride hydrolysis catalyzed by Fe₂O₃ nanoparticles impregnated on microorganism such as Bacillus simplex (BS) bacteria (Fe₂O₃@BS NPs) known with strong antibacterial properties, which makes innovative them a candidate for hydrolysis reaction. This study was focused on the preparation, identification, and catalytic use of biocatalyst-like Fe₂O₃@BS NPs for hydrogen release from the sodium borohydride hydrolysis at 25.0 ± 0.1 °C. The characterization results made after and before hydrolysis reaction using by SEM/SEM-EDX, FT-IR, XRD, UV–vis, XPS, DLS, ELS Zeta potential, ESR, and TEM techniques reveal the formation of highly active, stable, durable, and long-lived biocatalysts-like Fe₂O₃@BS NPs.     

超声波对工业用水杀菌消毒效果的研究

研究了超声波功率,作用时间以及与次氯酸钠协调作用对工业用水杀菌消毒效果。结果表明:50 W的超声波对藻类叶绿素合成量的抑制率达到了68.75%;低频率超声波对水中微生物团聚体的机械分散性能好于高频率的超声波,超声波与次氯酸钠协同作用既可提高灭菌效果,又可减少75%杀菌剂的使用量。     

Effects of inorganic surface treatment on water permeability of cement-based materials

The permeability of the cement-based materials can be used as an important indicator of their durability. Surface treatment is a simple way to reduce permeability and improve durability of cement-based materials. This paper studied the effects of fluosilicate and sodium silicate surface treatments on the permeability of cement-based materials using the Autoclam water permeability and water absorption testing method. The experimental results showed that both fluosilicate and sodium silicate surface treatments could effectively reduce the permeability of cement-based materials. However, fluosilicate worked within the first 28days after treatment, while sodium silicate showed more obvious effect at later ages. Autoclam water permeability index exhibited an exponential relationship with the water absorption of the cement-based materials. In addition, mercury intrusion porosimetry result suggested that these inorganic surface treatment agents could reduce the porosity of surface layer of cement-based materials.