The Association of Cholesterol Uptake and Synthesis with Histology and Genotype in Cortisol-Producing Adenoma (CPA)

Cortisol-producing adenoma (CPA) is composed of clear and compact cells. Clear cells are lipid abundant, and compact ones lipid poor but associated with higher production of steroid hormones. PRKACA mutation (PRKACA mt) in CPA patients was reported to be associated with more pronounced clinical manifestation of Cushing’s syndrome. In this study, we examined the association of histological features and genotypes with cholesterol uptake receptors and synthetic enzymes in 40 CPA cases, and with the quantitative results obtained by gas chromatography-mass spectrometry (GC-MS) analysis in 33 cases to explore their biological and clinical significance. Both cholesterol uptake receptors and synthetic enzymes were more abundant in compact cells. GC-MS analysis demonstrated that the percentage of compact cells was inversely correlated with the concentrations of cholesterol and cholesterol esters, and positively with the activity of cholesterol biosynthesis from cholesterol esters. In addition, hormone-sensitive lipase (HSL), which catalyzes cholesterol biosynthesis from cholesterol esters, tended to be more abundant in compact cells of PRKACA mt CPAs. These results demonstrated that both cholesterol uptake and biosynthesis were more pronounced in compact cells in CPA. In addition, more pronounced HSL expression in compact cells of PRKACA mt CPA could contribute to their more pronounced clinical manifestation.     

Remarkable effect of ordered mesoporous carbon support in tantalum oxide-catalyzed selective epoxidation of cyclooctene

The olefin epoxidation is one of the most important reactions in chemical industry. Metal oxide supports often cause drawbacks in catalytic activity and selectivity, which has been overcome by introducing hydrophobic organic groups onto the oxide supports. The present study utilizes ordered mesoporous carbon (CMK-3 and CMK-1) as structurally defined hydrophobic catalyst support. Well-dispersed tantalum oxides supported on the ordered mesoporous carbon were prepared. Their application in catalytic epoxidation of cyclooctene demonstrates that the tantalum oxide catalysts on the ordered mesoporous carbon supports show higher performances than those of the catalysts supported on activated carbon and ordered mesoporous silica SBA-15.     

Effect of grain size and density of spray-pyrolyzed hydroxyapatite particles on the sinterability of hydroxyapatite disk

The effect of grain size and density of hydroxyapatite particles, which were prepared by different spray-pyrolysis temperatures, on the sinterability of hydroxyapatite disk was investigated. Calcium phosphate solution (Ca/P ratio of 1.67 and 0.1 M concentration) was prepared by reacting calcium nitrate tetrahydrate and diammonium hydrogen phosphate solutions, and adding nitric acid. Spray-pyrolysis was carried out at 900 °C, 1200 °C, and 1500 °C at a carrier gas flowing rate of 10 L/min. The particles synthesized at 900 °C were large, hollow spheres with a hole at the outer surface, a broad size distribution, but had small grain sizes. Conversely, the particles synthesized at 1500 °C were small, solid spheres with a narrow size distribution, but had large grain sizes. The particles synthesized at 1200 °C had intermediate properties. A sinterability test conducted at 1100 °C for 1 h demonstrated that small and dense particles with large grain sizes showed a higher relative sintered density compared with large and hollow particles with small grain sizes. The results were explained in terms of the grain size and density of a particle, which were inversely and proportionally affected to sinterability. The practical implication of these results is that highly sinterable hydroxyapatite powders can be synthesized through spray-pyrolysis at a high temperature under a fixed initial concentration of calcium phosphate solution and flow rate of carrier gas.     

Bioethanol production from micro-algae, Schizocytrium sp., using hydrothermal treatment and biological conversion

Hydrothermal fractionation for micro-algae, Schizocytrium sp., was investigated to separate sugars, lipids, and proteins. This fractionation process produced protein-rich solid cake and liquid hydrolysates, which contained oligomeric sugars and lipids. Oligomeric sugars and lipids were easily separated by liquid-liquid separation. Sugars in the separated hydrolyzate were determined to be mainly D-glucose and L-galactose. Fractionation conditions were optimized by response surface methodology (RSM). Optimal conditions were found to be 115.5 °C of reaction temperature, 46.7 min of reaction time, and 25% (w/w) of solid loading. The model predicted that maximum oligomeric sugar yield (based on untreated micro-algae weight), which can be recovered by hydrothermal fractionation at the optimum conditions, was 19.4 wt% (based on the total biomass weight). Experimental results were in agreement with the model prediction of 16.6 wt%. Production of bioethanol using micro-algae-induced glucan and E. coli KO11 was tested with SSF (simultaneous saccharification and fermentation), which resulted in 11.8 g-ethanol/l was produced from 25.7 g/l of glucose; i.e. the theoretical maximum ethanol yield based on glucan in hydrolyzate was 89.8%.     

Adhesion properties of UV crosslinked polystyrene-block-polybutadiene-block-polystyrene copolymer and tackifier mixture

The peel and tack properties of mixtures of polystyrene-block-polybutadiene-block-polystyrene (SBS) and a tackifier were investigated after these were crosslinked by ultraviolet (UV) irradiation at various amounts of benzophenone (BP) as a photoinitiator and trimethylolpropane mercaptopropionate (TRIS) as a crosslinking agent.The degree of crosslinking of polybutadiene (PB) block in the SBS mixture was qualitatively estimated from the amount of gel fraction as well as the change in the glass transition temperature of the PB block. The crosslinking of the PB block was done within 3 min after UV irradiation and the peel strength of crosslinked specimens was as low as 45[percnt] of specimens without crosslinking. Nano-tack and bulk tack properties as well as the surface tension of mixtures were measured depending upon amounts of BP and TRIS.     

Recent advancements in bioreactions of cellular and cell-free systems: A study of bacterial cellulose as a model

Conventional approaches of regulating natural biochemical and biological processes are greatly hampered by the complexity of natural systems. Therefore, current biotechnological research is focused on improving biological systems and processes using advanced technologies such as genetic and metabolic engineering. These technologies, which employ principles of synthetic and systems biology, are greatly motivated by the diversity of living organisms to improve biological processes and allow the manipulation and reprogramming of target bioreactions and cellular systems. This review describes recent developments in cell biology, as well as genetic and metabolic engineering, and their role in enhancing biological processes. In particular, we illustrate recent advancements in genetic and metabolic engineering with respect to the production of bacterial cellulose (BC) using the model systems Gluconacetobacter xylinum and Gluconacetobacter hansenii. Besides, the cell-free enzyme system, representing the latest engineering strategies, has been comprehensively described. The content covered in the current review will lead readers to get an insight into developing novel metabolic pathways and engineering novel strains for enhanced production of BC and other bioproducts formation.     

Characterization and catalytic activities of MoMCM‐41

Catalysts consisting of molybdenum incorporated into MCM‐41 mesoporous molecular sieves (MoMCM‐41) were synthesized and characterized by XRD, N₂ adsorption/desorption, ESR, FTIR, and UV‐vis analysis techniques. The MoMCM‐f41 catalysts were synthesized by addition of Na₂MoO₄·2H₂O as molybdenum source at the initial step of synthesis; the framework Mo in MoMCM‐41 catalysts could be confirmed by ESR, FTIR and UV‐vis. As the molybdenum content is increased, the structure of MoMCM‐41 changed from hexagonal to amorphous. Molybdenum loading up to ca. 10% was a maximum concentration that was obtained in this study. The MoMCM‐41 catalysts showed a catalytic activity for propylene oxidation. This revised version was published online in July 2006 with corrections to the Cover Date.     

Digital screening methodology for the directed evolution of transglycosidases

Engineering of glycosidases with efficient transglycosidasesactivity is an alternative to glycosyltransferases or glycosynthasesfor the synthesis of oligosaccharides and glycoconjugates. However,the engineering of transglycosidases by directed evolution methodologiesis hampered by the lack of efficient screening systems for sugar-transferactivity. We report here the development of digital imaging-basedhigh-throughput screening methodology for the directed evolutionof glycosidases into transgalactosidases. Using this methodology,we detected transglycosidase mutants in intact Escherichia colicells by digital imaging monitoring of the activation of non-or low-hydrolytic mutants by an acceptor substrate. We screenedseveral libraries of mutants of β-glycosidase from Thermusthermophilus using this methodology and found variants withup to a 70-fold overall increase in the transglycosidase/hydrolysisactivity ratio. Using natural disaccharide acceptors, thesetransglycosidase mutants were able to synthesise trisaccharides,as a mixture of two regioisomers, with up to 76% yield.     

Boron Nitride-Based Overcoat Thick Films for MoSi2 Planar Heating Elements

This work first reports a boron nitride-based dielectric system that is designed for MoSi₂–based planar heating elements patterned on a regular 96% alumina substrate. The dielectric system is expected to function as an overcoat layer mainly to protect the printed heating elements from environments and to reduce thermal stress induced during thermal heating through improved heat dissipation. The boron nitride (BN) pastes mixed with a low softening glass of calcium barium aluminoborosilicate were screen printed onto MoSi₂ thick films and then fired at a temperature of 900°C. The addition of BN was found to increase the thermal conductivity considerably without detrimental chemical reactions with glass constituents. For instance, the thick film containing 30 wt% BN was regarded as a promising composition from the supporting evidences of good adhesion with MoSi₂, an increased thermal conductivity of ∼31 W·(m·K)⁻¹, and a high electrical resistance of 4.7 × 10¹⁰Ω.     

Characteristics of selective adsorption using D-phenylalanine imprinted terpolymer beads

A D-Phenylalanine (Phe) imprinted terpolymer, Polyacrylonitrile-Poly(acrylic acid)-Poly(acryl amide) (Poly(AN-AA-AAm)) bead was prepared by the wet-phase inversion method. Acrylamide (AAm) and acrylic acid (AA) were used as the functional monomer and acrylonitrile (AN) was used as a physical cross linker. The characteristics of selective adsorption by the D-Phe imprinted terpolymer beads were investigated at high concentrations of Phe racemate solution, 1 g Phe/L, and 10 g Phe/L. The adsorption selectivity of the D-Phe imprinted terpolymer beads prepared by anin-situ implanting method reached 0.82 and 0.8 at 1.0 g and 10 g Phe/L racemate solution, respectively, and almost all of the adsorbed D-Phe and about 43% of the adsorbed L-Phe were desorbed by 4% acetic acid. The uptake capacities of the terpolymer beads were maintained for several repeated batches.