Detection of cytochrome P450 substrates by using a small-molecule droplet array on an NADH-immobilized solid surface

Seeing below the surface: A small-molecule droplet array platform on an NADH-immobilized solid surface and a biotinylated acetophenone derivative were developed to identify the substrate candidates for soluble P450 enzymes of interest. This methodology is thought to be easily applicable to other class I P450 systems, including those that use NADPH as cofactor.     

Distribution Behavior of Nb,Ta, and Pa as Homologues of Db in Cation Exchange and Solid-Liquid and Liquid-Liquid Extractions by Aliquat 336 from Hydrochloric Acid

Detailed chemical studies on transactinide elements will clarify their characteristic properties caused by strong relativistic effect. In this work, to realize chemical study on transactinide element ₁₀₅Db, cation exchange, and solid-liquid and liquid-liquid extractions of micro amounts of Nb, Ta (homologues of Db), and Pa (pseudo homologue) by Aliquat 336 were performed employing hydrochloric acid. Clearly different chloride complex formations and distribution reaction kinetics were observed among these elements, and the present results are useful for studying the chemical properties of Db. Based on these results, we propose suitable experimental conditions for Db.     

Application of Poly(acetic Acid)–Based Graft Copolymer as a Compatibilizer for Poly(L-lactic Acid)/Poly(butylenesuccinate) Blend System

Poly(L-lactic acid) (PLLA) was blended with poly(butylenesuccinate) (PBS) using a single-screw extruder to modify the poor characteristics of these polymers. Furthermore, when both polymers were blended, the graft copolymer that was synthesized by partially saponified poly(vinyl alcohol) (PSPVA) and ?-caprolactone (?-CL) was used as a novel compatibilizer. The structure of the synthesized compatibilizer was determined by ¹H or ¹³C NMR. From this result, the ring-opening polymerization of the ?-CL occurred at the hydroxyl group of PSPVA. The structures of the PLLA/PBS solvent-cast blended films could be observed via an optical microscope. From the optical microscopic observation, the structures of the solvent-cast blended films with the synthesized compatibilizer were more homogeneous than those of the solvent-cast blended films without the compatibilizer. The mechanical properties of the PLLA/PBS extruded blended films were determined by a tensile test. The result showed the tensile strength of the blended films with the synthesized compatibilizer was greater than that of the blended films without the compatibilizer.     

Promotion of CO2 methanation activity and CH4 selectivity at low temperatures over Ru/CeO2/Al2O3 catalysts

The effect of CeO₂ loading amount of Ru/CeO₂/Al₂O₃ on CO₂ methanation activity and CH₄ selectivity was studied. The CO₂ reaction rate was increased by adding CeO₂ to Ru/Al₂O₃, and the order of CO₂ reaction rate at 250 °C is Ru/30%CeO₂/Al₂O₃ > Ru/60%CeO₂/Al₂O₃ > Ru/CeO₂ > Ru/Al₂O₃. With a decrease in CeO₂ loading of Ru/CeO₂/Al₂O₃ from 98% to 30%, partial reduction of CeO₂ surface was promoted and the specific surface area was enlarged. Furthermore, it was observed using FTIR technique that intermediates of CO₂ methanation, such as formate and carbonate species, reacted with H₂ faster over Ru/30%CeO₂/Al₂O₃ and Ru/CeO₂ than over Ru/Al₂O₃. These could result in the high CO₂ reaction rate over CeO₂-containing catalysts. As for the selectivity to CH₄, Ru/30%CeO₂/Al₂O₃ exhibited high CH₄ selectivity compared with Ru/CeO₂, due to prompt CO conversion into CH₄ over Ru/30%CeO₂/Al₂O₃.     

Agglomeration Characteristics of Aluminum Particles in AP/AN Composite Propellants

Most solid rockets are powered by ammonium perchlorate (AP) composite propellant including aluminum particles. As aluminized composite propellant burns, aluminum particles agglomerate as large as above 100 μm diameter on the burning surface, which in turn affects propellant combustion characteristics. The development of composite propellants has a long history. Many studies of aluminum particle combustion have been conducted. Optical observations indicate that aluminum particles form agglomerates on the burning surface of aluminized composite propellant. They ignite on leaving the burning surface. Because the temperature gradient in the reaction zone near a burning surface influences the burning rate of a composite propellant, details of aluminum particle agglomeration, agglomerate ignition, and their effects on the temperature gradient must be investigated. In our previous studies, we measured the aluminum particle agglomerate diameter by optical observation and collecting particles. We observed particles on the burning surface, the reaction zone, and the luminous flame zone of an ammonium perchlorate (AP)/ammonium nitrate (AN) composite propellant. We confirmed that agglomeration occurred in the reaction zone and that the agglomerate diameter decreased with increasing the burning rate. In this study, observing aluminum particles in the reaction zone near the burning surface, we investigated the relation between the agglomerates and the burning rate. A decreased burning rate and increased added amount of aluminum particles caused a larger agglomerate diameter. Defining the extent of the distributed aluminum particles before they agglomerate as an agglomerate range, we found that the agglomerate range was constant irrespective of the added amount of aluminum particles. Furthermore, the agglomerate diameter was ascertained from the density of the added amount of aluminum particles in the agglomerate range. We concluded from the heat balance around the burning surface that the product of the agglomerate range and the burning rate was nearly constant irrespective of the added amount of aluminum particles. Moreover, the reduced burning rate increased the agglomerate range.     

Diet-induced changes in alginate- and laminaran-fermenting bacterial levels in the caecal contents of rats

Brown algae contain soluble polysaccharides, such as alginic acid, fucoidan and laminaran. To assess the induction of dietary fiber-fermenting bacteria in the intestine, rats were fed diet containing no dietary fiber (control) or 2% w/w of the polysaccharides for 2 weeks. The levels of dietary fiber-fermenting bacteria in caecal contents were determined using decimal dilution culture containing 1% w/v of the fibers. Caecal microbiota in the rats was analyzed using polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE). In the culture method, 4–9 log viable cells/g caecal content of alginate-fermenting bacteria was detected in rats fed alginate, while this was not detected in rats fed the control diet. Although laminaran-fermenting bacteria were detected in control rats (4–9 log viable cells/g), the level observed in rats fed laminaran was 8 or 9 log viable cells/g. On the other hand, fucoidan-fermenting bacteria were not detected in rats fed fucoidan. DGGE analysis showed laminaran administration increased the diversity of bacterial bands. Clostridium spp. and Parabacteroides distasonis were detected as typical species in rats fed alginate and laminaran. The results indicate that the intake of soluble fermentable fibers in edible brown algae can alter the intestinal microbiota and its fermentation capacity.     

Angiotensin I-converting enzyme inhibitory activities of Chinese fermented soypaste and estimation of the inhibitory substances

Angiotensin I-converting enzyme (ACE) inhibitory activities of aqueous extracts of Chinese commercial soypaste were investigated in this work. Six samples from northern China showed potent ACE inhibitory activities with IC₅₀ values less than 40.0 μg/mL. ACE inhibitors in the sample with the strongest activity were purified by ultrafiltration, solid-phase extraction and gradient RP-HPLC. According to spectroscopic methods, a compound (M328.1) was separated as C₁₅H₂₁NO₇. It was supposed to be a conjugate of phenylalanine and glucose generated by Maillard reaction during soypaste production, providing support on the contribution of Maillard reaction products to the ACE inhibitory activity of the sample. Results further indicated that the total ACE inhibition by the sample occurred from the combined function of various bioactive substances, suggesting that Chinese soypaste could be a good source of ACE inhibitors for exploring functional foods or ingredients with antihypertensive effect.     

不同波长UV对副溶血性弧菌光修复反应的影响

低压水银管是常见的灭菌工具,其一般采用的是波长为254 nm的UVC作为灭菌光源。而UVA（365 nm波长）配合发光二极管（light-emitting diodes,LED）也有明显的杀菌效果。本研究从灭菌能力,照射后细菌的光修复能力和再生长能力以及能耗等方面入手,比较短波长的UVC和长波长的UVA/LED对副溶血性弧菌的灭菌效果。结果显示,UVA/LED比UVC有更强的杀菌能力,且在受到UVA/LED照射后,副溶血性弧菌的再生长明显慢于单纯UVC处理后的细菌;对副溶血性弧菌的光修复酶基因表达水平进行检测发现,UVA/LED照射后副溶血性弧菌三种光修复酶基因的表达水平都无激活现象,而UVC处理后的细菌三种基因表达水平明显升高。我们认为UVA/LED可能抑制副溶血性弧菌的光修复现象。但在具备以上优势的同时,UVA/LED的能耗大大高于UVC,因此该技术还有待进一步改进。