Kureha (Japan)

Sixteen strains of basidiomycetous yeasts were evaluated for their capability to produce ergothioneine (EGT), an amino acid derivative with strong antioxidant activity. The cells were cultured in either two synthetic media or yeast mold (YM) medium for 72 h, after which cytosolic constituents were extracted from the cells with hot water. After analyzing the extracts via liquid chromatography-mass spectrometry (LC-MS), we found that all strains produced varying amounts of EGT. The EGT-producing strains, including Ustilago siamensis, Anthracocystis floculossa, Tridiomyces crassus, Ustilago shanxiensis, and Moesziomyces antarcticus, were subjected to flask cultivation in YM medium. U. siamensis CBS9960 produced the highest amount of EGT at 49.5 ± 7.0 mg/L after 120 h, followed by T. crassus at 30.9 ± 1.8 mg/L. U. siamensis was also cultured in a jar fermenter and produced slightly higher amounts of EGT than under flask cultivation. The effects of culture conditions, particularly the addition of precursor amino acids, on EGT production by the selected strains were also evaluated. U. siamensis showed a 1.5-fold increase in EGT production with the addition of histidine, while U. shanxiensis experienced a 1.8-fold increase in EGT production with the addition of methionine. These results suggest that basidiomycetous yeasts could serve an abundant source for natural EGT producers.

We investigated the evolution of the γ-phase spherulites of poly(vinylidene fluoride) (PVDF) added to 1 wt% of tetrabutylammonium hydrogen sulfate during the isothermal crystallization at 165 °C through polarized optical microscopy and light scattering measurements. Optically isotropic domains grew, and then optical anisotropy started to increase in the domain to yield spherulite. Double peaks were seen in the time variation of the Vv light scattering intensity caused by the density fluctuation and optical anisotropy, and the Hv light scattering intensity caused by the optical anisotropy started to increase during the second increase in the Vv light scattering intensity. These results suggest the two-stage evolution of the γ-phase spherulites, i.e., the disordered domain grows in the first stage and ordering in the spherulite increases due to the increase in the fraction of the lamellar stacks in the spherulite without a change in the spherulite size in the second stage. Owing to the characteristic crystallization behavior, the birefringence in the γ-phase spherulites of the PVDF/TBAHS was much smaller than that in the α-phase spherulites of the neat PVDF.

Herein, we measure the Ca isotope ratios (44Ca/42Ca and 43Ca/42Ca) in serum and bone samples collected from rats with chronic kidney disease (CKD) or diabetes mellitus (DM). For the serum samples, the isotope ratios are lower for the CKD (δ44Ca/42Caserum = 0.16 ± 0.11‰; 2SD, n = 6) and the DM (δ44Ca/42Caserum = -0.11 ± 0.25‰; 2SD, n = 7) rats than that for the control rats (δ44Ca/42Caserum = 0.25 ± 0.04‰; 2SD, n = 7). Bone samples from two distinct positions of 20 rats in total, namely, the center and proximal parts of the tibial diaphysis, are subject to Ca isotope analysis. The resulting δ44Ca/42Ca values for the bone of the proximal part are about 0.3‰ lower than that for the serum samples from the same rats. The larger isotope fractionations between the serum and bone are consistent with previously reported data for vertebrate animals (e.g., Skulan and DePaolo, 1999), which suggests the preferential incorporation of lighter Ca isotopes through bone formation. For the bones from the control and CKD rats, there were no differences in the δ44Ca/42Ca values between the positions of the bone. In contrast, the δ44Ca/42Ca values of the bone for the DM rats were different between the positions of the bone. Due to the lower bone turnover rate for the DM rats, the δ44Ca/42Ca for the middle of the diaphysis can reflect the Ca isotopes in the bone formed prior to the progression of DM states. Thus, the resulting δ44Ca/42Ca values show a clear correlation with bone mineral density (BMD). This can be due to the release of isotopically lighter Ca from the bone to the serum. In the present study, our data demonstrate that the δ44Ca/42Ca value for serum can be used as a new biomarker for evaluating changes in bone turnover rate, followed by changes in bone volume.

Abstract Demand for hydrocarbons is continuing to grow, leading to an increase in the stage count of hydraulic fracturing in unconventional reservoirs. The plug-and-perf system is a typical stimulation method that uses frac plugs for zone isolation. Conventionally, the plugs must be milled out to recover the flow path for hydrocarbons after fracturing is complete. Fully degradable frac plugs would eliminate the need for milling out, and this in turn allows for longer wellbores in the lateral direction, lower costs, and reduced risk in well completion. A key material for fully degradable frac plugs is a sufficiently degradable rubber with good sealing properties for the seal elements of the plugs. This paper presents the fundamental properties of degradable rubbers developed in a comprehensive materials study. The degradation behaviors of the degradable rubbers were investigated under various temperature and fluid media conditions. The mechanical strength was compared with that of conventional nitrile rubber. Nonlinear, three-dimensional multi-body contact analysis and qualification testing were integrated to estimate the sealing performance of seal elements made of the degradable rubbers.

Remediation of materials contaminated with a radioactive material such as 137Cs is important for public health and environmental concerns. Here, we report the effectiveness of aqueous sodium metasilicate (SMC) prepared using a microbubble crushing process for the removal of radioactive 137Cs from contaminated materials. We have already reported that almost 80 % 137Cs removal was achieved for a nonwoven cloth sample in which multiple washings using low SMC concentrations were effective. In addition, the volume of the waste solution can be reduced by neutralizing the SMC and using gelation to remove the radioactive material. We also attempt to clarify the mechanism of SMC operation by measuring its electrical properties. Decontamination is shown to be more efficient with SMC than with sodium hydroxide, even for washing granule conglomerates.

Introduction: Chronic kidney disease (CKD) is a crucial risk factor for cardiovascular disease (CVD), and combined CKD and CVD further increases morbidity and mortality. Therefore, the prevention of kidney injury is essential for the improvement of prognosis of patients with CVD. Among the many factors, increased oxidative stress plays a role for the pathogenesis of CKD and CVD. Hypothesis: AST-120, which is an oral charcoal adsorbent, may prevent kidney injury by reducing one of the uremic toxins, indoxyl sulfate (IS) and oxidative stress in a rat myocardial infarction (MI) model. Methods: At 10 weeks of age, male spontaneously hypertensive rats (SHR) were divided into 3 groups: SHR (n=6), MI (n=8) and MI+AST-120 groups (n=8) and the administration of AST-120 was started at 11 weeks of age. MI was induced by the ligation of the left coronary artery in the MI and MI+AST-120 groups at 10 weeks of age. At 18 weeks of age, rats were sacrificed, and blood and urine analyses, mRNA expression analysis, renal histological analysis, and echocardiography were performed in these groups. Results: At 18 weeks of age, though there were no significant differences in blood pressure and kidney function, serum IS levels and urinary IS excretion were reduced in the AST-120 groups compared to the MI groups. Urinary 8-hydroxydeoxyguanosine (8-OHdG) excretion, serum tissue growth factor beta (TGF-β) levels, serum neutrophil gelatinase-associated lipocalin (NGAL) levels, serum kidney injury molecular-1 (KIM-1) levels and serum,L-type fatty acid binding protein (L-FABP) levels were also decreased in the MI+AST-120 group compared to the other two groups. The mRNA expressions of NADPH oxidase and NF-kappa B, connective tissue growth factor (CTGF) in the kidney were significantly decreased in the MI+AST-120 group compared to the MI group. In vitro data using LCC-PK1 cells also supported the influence of IS on kidney injury. Further immunohistological analysis revealed that intrarenal oxidative stress was reduced by AST-120 administration. Conclusions: Our data showed that IS increased after MI and AST-120 is suggested to have protective effects on kidney injury after MI through the suppression of oxidative stress.