Precision die-casting of optical MU/SC conversion sleeve

The performance of MU/SC conversion sleeve produced by bulk metallic glass (Zr₅₅Al₁₀Ni₅Cu₃₀) was examined. A precision die-casting method was applied to improve size accuracy. The size accuracy of the conversion sleeve produced by the precision die-casting method was ±1 μm, and optical insertion loss (Li) was less than 0.3 dB for a standard value. The wear resistance of metallic glass is improved by surface oxidation treatment in air at 673 K. The MU/SC conversion sleeve produced from bulk metallic glass has superior characteristics for optical parts.     

Recombinant Long-Acting Thioredoxin Ameliorates AKI to CKD Transition via Modulating Renal Oxidative Stress and Inflammation

An effective strategy is highly desirable for preventing acute kidney injury (AKI) to chronic kidney disease (CKD) transition. Thioredoxin-1 (Trx), a redox-active protein that has anti-oxidative and anti-inflammatory properties, would be a candidate for this but its short half-life limits its clinical application. In this study, we examined the renoprotective effect of long-acting Trx that is comprised of human albumin and Trx (HSA-Trx) against AKI to CKD transition. AKI to CKD mice were created by renal ischemia-reperfusion (IR). From day 1 to day 14 after renal IR, the recovery of renal function was accelerated by HSA-Trx administration. On day 14, HSA-Trx reduced renal fibrosis compared with PBS treatment. At the early phase of fibrogenesis (day 7), HSA-Trx treatment suppressed renal oxidative stress, pro-inflammatory cytokine production and macrophage infiltration, thus ameliorating tubular injury and fibrosis. In addition, HSA-Trx treatment inhibited G2/M cell cycle arrest and apoptosis in renal tubular cells. While renal Trx protein levels were decreased after renal IR, the levels were recovered by HSA-Trx treatment. Together, HSA-Trx has potential for use in the treatment of AKI to CKD transition via its effects of modulating oxidative stress and inflammation.     

Identification of Tumor Suppressive Genes Regulated by miR-31-5p and miR-31-3p in Head and Neck Squamous Cell Carcinoma

We identified the microRNA (miRNA) expression signature of head and neck squamous cell carcinoma (HNSCC) tissues by RNA sequencing, in which 168 miRNAs were significantly upregulated, including both strands of the miR-31 duplex (miR-31-5p and miR-31-3p). The aims of this study were to identify networks of tumor suppressor genes regulated by miR-31-5p and miR-31-3p in HNSCC cells. Our functional assays showed that inhibition of miR-31-5p and miR-31-3p attenuated cancer cell malignant phenotypes (cell proliferation, migration, and invasion), suggesting that they had oncogenic potential in HNSCC cells. Our in silico analysis revealed 146 genes regulated by miR-31 in HNSCC cells. Among these targets, the low expression of seven genes (miR-31-5p targets: CACNB2 and IL34; miR-31-3p targets: CGNL1, CNTN3, GAS7, HOPX, and PBX1) was closely associated with poor prognosis in HNSCC. According to multivariate Cox regression analyses, the expression levels of five of those genes (CACNB2: p = 0.0189; IL34: p = 0.0425; CGNL1: p = 0.0014; CNTN3: p = 0.0304; and GAS7: p = 0.0412) were independent prognostic factors in patients with HNSCC. Our miRNA signature and miRNA-based approach will provide new insights into the molecular pathogenesis of HNSCC.     

DNA promotes the activation of oxygen molecules by binuclear cobalt(II) compounds

We have observed that binuclear cobalt(II) compounds with H(HPTP), Co₂(HPTP)(CH₃COO)(ClO₄)₂ and Co₂(HPTP)Cl(ClO₄)₂, react with oxygen molecules when DNA is present in the solution, cleaving the DNA (H(HPTP) denotes N,N,N′,N′-tetrakis(2-pyridylmethyl)-1,3-diaminopropane-2- ol).     

Comparative characterisation of dioxane-soluble lignins released by ball milling and by sheep digestion from forage grasses

Faecal soluble lignin (FSL), extracted from the faeces of sheep that received orchardgrass and timothy, were compared with 90% dioxane-soluble lignins released by ball milling (MHL) and by subsequent enzymatic hydrolysis (EHL) from the same grasses. FSL contained much less carbohydrate and esterified p-coumaric and ferulic acids than MHL and EHL. Although no considerable differences were found in the yields of vanillin and syringaldehyde produced by nitrobenzene oxidation, the molar ratio of syringaldehyde to vanillin was higher for FSL than for MHL and EHL. Such differences in chemical properties among the lignin preparations were confirmed by ¹³C-NMR spectroscopy. FSL had a lower molecular size compared with MHL and EHL. Results indicated that syringyl-rich lignin fragments with less phenolic acid esters, probably depolymerisation products of the grass lignins, were released by digestion in sheep from the forage grasses.     

Detection of tris(2,4-di-tert-butylphenyl)phosphite (Irgafos 168, antioxidant in plastics) and its oxide in commercial frozen vegetables

Two peaks, A and B, detected in chromatograms of commercial frozen vegetable extracts during analysis of organophosphorus pesticide residues by GC-FPD, were identified as tris(2,4-ditert-butylphenyl)phosphite (Irgafos 168) and Irgafos 168 oxide, respectively, from their mass spectra. Irgafos 168 is used as an antioxidant in plastics, and there has been no report of its detection in foods. We analyzed Irgafos 168 and its oxide in 38 samples of commercial frozen vegetables, and they were detected from 4 samples (0.02-0.80 microgram/g as total amount of Irgafos 168 and its oxide).     

Inhibitory effect of high concentrations of ferric ions on the activity of Acidithiobacillus ferrooxidans

The influence of high concentrations of ferric ions on the biochemical activity of Acidithiobacillus ferrooxidans was studied using intact cells. The specific oxidation rate of ferrous ions decreased with increasing ferric ion concentration. Lineweaver-Burk plots revealed typical competitive inhibition kinetics, because the slopes varied with the ferric ion concentration. A linear relationship between the slope and the square of the ferric ion concentration revealed that the iron-oxidizing enzyme system of A. ferrooxidans was competitively inhibited by about two molecules of ferric ion. The kinetic equation based on this inhibition model agreed with the experimental observation at a high ferric ion concentration where the bacterium is usually exposed in bioleaching and biooxidation plants.     

Polysulfide reduction using sulfate-reducing bacteria in a photocatalytic hydrogen generation system

A hydrogen generation process using photocatalytic reactions has been proposed. In this process, hydrogen sulfide is a source of hydrogen and is turned into polysulfide. In order to establish the cyclic operation of a photocatalytic hydrogen generation system, it is necessary to convert polysulfide back into hydrogen sulfide with a small energy input. This paper proposes the use of sulfate-reducing bacteria (SRB) for the regeneration of hydrogen sulfide. Batch cultivation of natural source SRB samples were carried out using a culture medium containing polysulfide as the only sulfur compound source. SRB produced hydrogen sulfide from several kinds of polysulfide sources, including a photocatalytic hydrogen generation-produces solution. Production lag phase and production rate of hydrogen sulfide were affected by initial polysulfide concentration. SRB activity was inhibited at high initial polysulfide concentrations. SRB enrichment culture T2, exhibited the highest hydrogen sulfide production rate, and was able to utilize several kinds of organic matter as the electron donor. The results suggest the possibility of using large biomass sources, such as sewage sludge and the raw garbage in a hydrogen generation system. We developed speculative estimates that an SRB based hydrogen generation system is feasible.     

CoCl(2) inhibits neural differentiation of retinoic acid-treated embryoid bodies

The effects of CoCl(2) on retinoic acid (RA)-treated embryoid bodies (EBs) were investigated. Four-day EBs were treated with 5x10(-6) M of RA for 4 d, then subjected to attached culturing for 7 d in the presence of CoCl(2) at 0, 20, and 100 microM. Differentiation into MAP2- and GFAP-immunopositive cells was inhibited by CoCl(2) in a dose-dependent manner. Next, RA-treated EBs were dissociated into single cells and cultured for 7 d at an initial cell density of 1x10(3)/cm(2). The number of cells increased in a CoCl(2)-dose dependent fashion. In cultures with 100 microM of CoCl(2), more than 90% of the cells were immunopositive for nestin and nestin-immunopositive cells formed clusters, while there were few cells immunopositive for MAP2 or GFAP. These results suggest that CoCl(2) inhibits neural differentiation of RA-treated EB cells and promotes the proliferation of nestin-immunopositive cells, i.e., embryonic stem (ES)-derived neural stem-like cells.