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The sweet-tasting protein brazzein is a candidate sugar substitute owing to its sweet, sugar-like taste and good stability. To commercialize brazzein as a sweetener, optimization of fermentation and purification procedure is necessary. Here, we report the expression conditions of brazzein in the yeast Kluyveromices lactis and purification method for maximum yield. Transformed K. lactis was cultured in YPGlu (pH 7.0) at 25 °C and induced by adding glucose:galactose at a weight ratio of 1:2 (%/%) during the stationary phase, which increased brazzein expression 2.5 fold compared to the previous conditions. Cultures were subjected to heat treatment at 80 °C for 1 h, and brazzein containing supernatant was purified using carboxymethyl-sepharose cation exchange chromatography using 50 mM NaCl in 50 mM sodium acetate buffer (pH 4.0) as a wash buffer and 400 mM NaCl (pH 7.0) for elution. The yield of purified brazzein under these conditions was 2.0-fold higher than that from previous purification methods. We also determined that the NanoOrange assay was a suitable method for quantifying tryptophan-deficient brazzein. Thus, it is possible to obtain pure recombinant brazzein with high yield in K. lactis using our optimized expression, purification, and quantification protocols, which has potential applications in the food industry.

Enforcement of an air quality standard for PM 2.5 in the Seoul metropolitan area (SMA) was enacted in 2015. From May to June of 2016, an international airborne and surface measurement campaign took place to investigate air pollution mechanisms in the SMA. The total and speciated PM 2.5 concentrations since 2008 have been measured at an intensive monitoring site for the SMA operated by the National Institute of Environmental Research (NIER). To gain insight on the trends and sources of PM 2.5 in the SMA in May, we analyze PM 2.5 concentrations from 2009 to 2013 using the measurements and simulations from a 3-dimensional global chemical transport model, GEOS-Chem and its adjoint. The model is updated here with the latest regional emission inventory and diurnally varying NH 3 emissions. Monthly average PM 2.5 concentration measured by β-ray attenuation ranges from 28 (2010) to 45 (2013) μg/m 3 , decreased from 2009 to 2010, and then continuously increased until 2013. The model shows good agreement with the measurements for the daily average PM 2.5 concentrations (R ≥ 0.5), and reproduces 10 out of 17 measured episodes exceeding the daily air quality standard (50 μg/m 3 ). Using the GEOS-Chem adjoint model, we find that anthropogenic emissions from the Shandong region have the largest modeled influence on PM 2.5 in Seoul in May. Average contributions to the high PM 2.5 episodes simulated by the model are 39% from the Shandong region, 16% from the Shanghai region, 14% from the Beijing region, and 15% from South Korea. Anthropogenic SO 2 emissions from South Korea are negligible with 90% of the total contribution originating from China. Findings from this study may guide interpretation of observations obtained in the KORUS-AQ measurement campaign., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

This paper presents a power-efficient implantable optogenetic interface using a wireless switched-capacitor based stimulating (SCS) system. The SCS efficiently charges storage capacitors directly from an inductive link and periodically discharges them into an array of micro-LEDs, providing high instantaneous power without affecting wireless link and system supply voltage. A custom-designed computer interface in LabVIEW environment wirelessly controls stimulation parameters through the inductive link, and an optrode array enables simultaneous neural recording along with optical stimulation. The 4-channel SCS system prototype has been implemented in a 0.35-μm CMOS process and combined with the optrode array. In vivo experiments involving light-induced local field potentials verified the efficacy of the SCS system. An implantable version of the SCS system with flexible hermetic sealing is under development for chronic experiments.

Background: Although the 1,927-nm thulium fiber fractional laser is effective and safe for treating photoaging, clinical data regarding this modality remain limited., Objective: To investigate the efficacy and safety of the 1,927-nm thulium fiber fractional laser for treating photoaging and melasma in Asians., Methods: Twenty-five participants received three laser treatments (at 3-week intervals) on the half of the face with more-severe photoaging and melasma. Independent investigators evaluated clinical improvement 2 and 6 months after the final treatment. Improvement in melasma was evaluated using the Melasma Area and Severity Index. Subjective satisfaction rates were also evaluated. Adverse events were assessed, and pain was scored using a visual analog scale (VAS). Histologic changes were observed using immunohistochemical staining., Results: Clinical improvement of photodamaged facial skin was remarkable on the treatment side. Most participants reported that their subjective satisfaction rate was greater than slight satisfaction. Downtime for healing required approximately 1 week. No severe adverse events occurred. Mean VAS score during treatment was 4.8. Collagen regeneration and melanin decrease were observed histologically., Conclusion: The 1,927-nm thulium fiber fractional laser is a safe, effective treatment for photoaging and melasma in Asians., (© 2013 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.)