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The nano-SiO2 particles modified by silane coupling agent A-1100 were used for preparing the vinyl ester resin (VE) Pickering emulsion. The stable emulsion could be served as the film former of sizing agent for glass fiber (GF). The influence of the wettability and the addition amount of nano-SiO2 on the stability of film former emulsion was explored. The effect of nano-SiO2 Pickering emulsion type sizing agent on the properties of GF was investigated. SEM images show that there existed a layer of sizing agent film with nano-SiO2 particles evenly on the GF surface. The abrasion resistance of the sized GF reached 3,579 times and the stiffness was 69 mm. The strand integrity also performed well. The fracture strength of GF bundles treated by Pickering emulsion type sizing agent increased by 28.6% to 0.504 N/Tex compared with that of the unsized GF bundles. The interlaminar shear strength (ILSS) of GF/VE composites sized by self-made sizing agent which contained nano-SiO2 has improved, compared to the unsized GF reinforced VE composite. POLYM. COMPOS., 37:334-341, 2016. © 2014 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Isothermal extrusion is an important method for ensuring the quality of extruded profiles. On the basis of the actual indirect extrusion process of 7075 aluminum alloy with high strength and toughness, this study used the combination of a finite element model and deep neural network to construct a prediction model for the temperature series of the indirect extrusion outlet. The extrusion velocity–stroke control curves of the isothermal extrusion of aluminum profiles were obtained on the premise of ensuring maximum production efficiency and the absence of defects. Results showed that the constructed model had high robustness and performed well on the validation set with an average error of 1.8% and that the temperature difference at the outlet of the profile obtained through isothermal extrusion would not exceed 5 °C. By using machine learning, finite element simulation or experiments can be omitted from process optimization, and the indirect isothermal extrusion process can be rapidly optimized. Then, consistency along the extrusion direction was proven by microstructure evolution simulation. [ABSTRACT FROM AUTHOR]

Classical swine fever (CSF) is a contagious disease with a high mortality rate and is caused by classical swine fever virus (CSFV). CSFV non-structural protein 4B (NS4B) plays a crucial role in CSFV replication and pathogenicity. However, precisely how NS4B exerts these functions remains unknown, especially as there are no reports relating to potential cellular partners of CSFV NS4B. Here, a yeast two-hybrid (Y2H) system was used to screen the cellular proteins interacting with NS4B from a porcine alveolar macrophage (PAM) cDNA library. The protein screen along with alignment using the NCBI database revealed 14 cellular proteins that interact with NS4B: DDX39B, COX7C, FTH1, MAVS, NR2F6, RPLP1, PSMC4, FGL2, MKRN1, RPL15, RPS3, RAB22A, TP53BP2 and TBK1. These proteins mostly relate to oxidoreductase activity, signal transduction, localization, biological regulation, catalytic activity, transport and metabolism by GO categories. Tank-binding kinase 1 (TBK1) was chosen for further confirmation. The NS4B-TBK1 interaction was further confirmed by subcellular co-location, co-immunoprecipitation and glutathione S-transferase pull-down assays. This study offers a theoretical foundation for further understanding of the diversity of NS4B functions in relation to viral infection and subsequent pathogenesis. [ABSTRACT FROM AUTHOR]

Objectives: To investigate single nucleotide polymorphism (SNP) in the transformation process of phytosterol to valuable steroid intermediates in three steroid-producing Mycobacterium neoaurum strains using deep sequencing and bioinformation analysis. Results: The assembled contig sequences from RNA sequencing of strains producing 9α-hydroxy-4-androstene-3,17-dione (9OHAD), 1,4-androstadiene-3,17-dione (ADD), and 22-hydroxy-23, 24-bisnorchola-1,4-dien-3-one (1,4-BNA) were analyzed for the presence of putative SNPs for steroid catabolism. 413, 375, and 491 SNPs were detected in the coding domain sequences and non-coding domain sequences of RNA sequencing reads of M. neoaurum strains producing 9OHAD, ADD, and BNA, respectively. Special attention was focused on SNPs associated with genes showing differential expression at proteome level, including the genes for sterol catabolism, glycerol catabolic process, signal transduction systems, transport system and energy metabolism. Conclusions: The work facilitates the understanding of underlying genetic changes that may be responsible for steroid accumulation in M. neoaurum and is useful for its targeted genetic engineering. [ABSTRACT FROM AUTHOR]

Mycobacterium neoaurum NwIB-01 exhibits powerful ability to cleave the side chain of soybean phytosterols to accumulate 4-androstene-3,17-dione (AD) and 1,4-androstadiene-3,17-dione (ADD). The difficulty in separation of AD from ADD is one of the key bottlenecks to the microbial transformation of phytosterols in the industry. To enhance ADD quantity in products, 3-ketosteroid Δ-dehydrogenase genes ( kstD and kstD) were obtained from M. neoaurum NwIB-01 and Arthrobacter simplex respectively. Using replicating vector pMV261, kstD and kstD were overexpressed in M. neoaurum NwIB-01. For foreign gene stable expression, the integration vector pMV306 was used for kstD/ kstD overexpression and the relevant sequences of promoter and kanamycin antibiotic resistance gene sequences were amplified by PCR to verify plasmid integrity. The resultant plasmid and mutant strain were verified and the kstD augmentation mutants were good ADD-producing strains. The ADD producing capacity of NwIB-04 and NwIB-05 was 0.1401 and 0.1740 g/l (cultured in shake bottles with 0.4 g/l phytosterols), and the molar ratio of ADD in products was 98.34 and 98.60 %, respectively. This study on the manipulation of the main kstD gene in Mycobacterium sp. provides a feasible way to achieve excellent phytosterol-transformation strains with high product purity. [ABSTRACT FROM AUTHOR]

In this study, a high (R)-enantioselective nitrilase gene from Sphingomonas wittichii RW1 was cloned and overexpressed in Escherichia coli BL21 (DE3). The recombinant nitrilase was purified to homogeneity with a molecular weight of 40 kDa. The pH and temperature optima were shown to be pH 8.0 and 40 °C, respectively. The purified nitrilase was most active toward succinonitrile, approximately 30-fold higher than that for phenylglycinonitrile. Using the E. coli BL21/ReSWRW1 whole cells as biocatalysts, the kinetic resolution for asymmetric synthesis of (R)-phenylglycine was investigated at pH 6.0. A yield of 46 % was obtained with 95 % enantiomeric excess (ee), which made it a promising biocatalyst for synthesis of (R)-phenylglycine. [ABSTRACT FROM AUTHOR]

Diosgenin transformation was studied in Streptomyces virginiae IBL-14, a soil-dwelling bacterium with diosgenin-degrading capacity. All of the derivatives isolated were identified as 4-ene-3-keto steroids. We cloned ChoL, a fragment of a cholesterol oxidase from S. virginiae IBL-14, and used gene-disruption techniques to determine its function in the oxidation of diosgenin to 4-ene-3-keto steroids. Subsequently, the entire open reading frame of ChoL was cloned by chromosome walking, and the His6-tagged recombinant protein was overproduced, purified, and characterized. ChoL consisted of 1,629 nucleotides that encoded a protein of 542 amino acids, including a 34-residue putative signal peptide at the N-terminal. ChoL showed 85% amino acid similarity to ChoA from Streptomyces sp. SA-COO. This enzyme can also oxidize other steroids such as cholesterol, sitosterol, and dehydroepiandrosterone, which showed higher affinity ( Km = 0.195 mM) to diosgenin. The catalytic properties of this enzyme indicate that it may be useful in diosgenin transformation, degradation, and assay. [ABSTRACT FROM AUTHOR]

Abstract: Cobalt-coated Al2O3 and TiC powders were prepared using an electroless method to improve resistance to thermal shock. The mixture of cobalt-coated Al2O3 and TiC powders (about 70wt.% Al2O3–Co+30wt.% TiC–Co) was hot-pressed into an Al2O3–TiC–Co composite. The thermal shock properties of the composite were evaluated by indentation technique and compared with the traditional Al2O3–TiC composite. The composites containing 3.96vol.% cobalt exhibited better resistance to crack propagation, cyclic thermal shock and higher critical temperature difference (ΔT c). The calculation of thermal shock resistance parameters (R parameters) shows that the incorporation of cobalt improves the resistance to thermal shock fracture and thermal shock damage. The thermal physic parameters are changed very little but the flexure strength and fracture toughness of the composites are improved greatly by introducing cobalt into Al2O3–TiC (AT) composites. The better thermal shock resistance of the composites should be attributed to the higher flexure strength and fracture toughness. [Copyright &y& Elsevier]

The whitening effects of the flavonoid constituents of Alpinia officinarum Hance were investigated on melanin biosynthesis in B16 mouse melanoma cells, tyrosinase inhibition and UV absorption. The melanin content was reduced to 1.276 μg /105cell for flavonoid mixture and 1.161 μg /105cell for galangin while the melanin control was 1.632 μg /105cell. Both flavonoid mixture and galangin reduced melanin production with an inhibition of 21.81% and 28.86% at a concentration of 26.5 μ g/mL and 29 μg /mL (107.4 μM), respectively. Tyrosinase inhibition by the flavonoid mixture and galangin were higher at lower concentrations and galangin showed competitive inhibition at a concentration less than 21.23 μg/mL which was soluble. In addition, the flavonoid mixture and galangin showed a broad absorption band at 270 ∼ 290 nm related to the UV-B area. These observations suggest that galangin may be a whitening agent and a promising candidate for prevention of skin cancer. This is the first full scale report on the evaluation of the whitening effect of galangin. [ABSTRACT FROM AUTHOR]

A bioconversion process of producing GM1 (monosialotetrahexosylganglioside) on an industrial scale was developed with a novel sialidase-producing strain Brevibacterium casei. The sialidase hydrolyzed polysialogangliosides to produce GM1 but did not act on GM1. When Brevibacterium casei was cultured in a synthetic medium containing crude pig brain gangliosides (10% w/v) at 30°C for 24 h in a 50 l fermenter, most of the polysialogangliosides were converted to GM1. The content of GM1 was increased from 9% in crude gangliosides to 45% with 70% (w/w) yield. [ABSTRACT FROM AUTHOR]