4-n-butylresorcinol inhibits melanogenesis by enhancing proteolytic degradation of tyrosinase as well as competitive binding to tyrosinase. These findings will help to develop new, effective and safe chemicals for the treatment of hyperpigmentation disorders.

No abstract

In South Korea, the evaluation criteria for installing shading devices are defined by regulations, but the standards of design methods are not clearly established. The installation of shading devices has become mandatory for some public buildings due to revised regulations. Therefore, a design of horizontal shading device is required, and indoor environmental problems which may occur due to their installation should also be taken into consideration. This research aimed to propose a design which takes into account the energy consumption which may occur if the horizontal shading device is installed and suggests an improved design method of horizontal shading devices when they are installed. Consequently, it was confirmed that as the protrusion of the horizontal shading device becomes longer, the incoming daylight is reduced and the indoor intensity of illumination becomes lower, and thus more lighting energy may be consumed in a room where the shading device is installed than in the one where it is not. Therefore, annual energy consumption was calculated by applying the lighting control and it was found that the total energy consumption decreased by the reduction of air-conditioning and fans and lighting energy consumption.

No abstract

Transglutaminase 2 (TG2) is a Ca 2+ -dependent enzyme, which regulates various cellular processes by catalyzing protein crosslinking or polyamination. Intracellular TG2 is activated and inhibited by Ca 2+ and GTP binding, respectively. Although aberrant TG2 activation has been implicated in the pathogenesis of diverse diseases, including cancer and degenerative and fibrotic diseases, the structural basis for the regulation of TG2 by Ca 2+ and GTP binding is not fully understood.Here, we produced and analyzed a Ca 2+ -containing TG2 crystal, and identified two glutamate residues, E437 and E539, as Ca 2+ -binding sites. The enzymatic analysis of the mutants revealed that Ca 2+ binding to these sites is required for the transamidase activity of TG2. Interestingly, we found that magnesium (Mg 2+ ) competitively binds to the E437 and E539 residues. The Mg 2+ binding to these allosteric sites enhances the GTP binding/hydrolysis activity but inhibits transamidase activity. Furthermore, HEK293 cells transfected with mutant TG2 exhibited higher transamidase activity than cells with wild-type TG2. Cells with wild-type TG2 showed an increase in transamidase activity under Mg 2+ -depleted conditions, whereas cells with mutant TG2 were unaffected. These results indicate that E437 and E539 are Ca 2+ -binding sites contributing to the reciprocal regulation of transamidase and GTP binding/hydrolysis activities of TG2 through competitive Mg 2+ binding.

The objective of this study was to propose a stratification control method for the minimum air flow of a variable air volume (VAV) terminal unit. The minimum air flow rate of the VAV terminal unit is the key factor affecting thermal comfort, indoor air quality (IAQ), stratification and energy consumption depending on the operating mode of the VAV system. Therefore, selecting the proper minimum air flow is very important. In this study, a building simulation was conducted to evaluate the indoor thermal comfort, stratification, IAQ and energy consumption according to the fixed minimum air flow rate of the VAV terminal units. In addition, an algorithm was proposed considering the stratification and variable minimum air flow rate depending on the indoor load. The results of the fixed minimum air flow rate simulation showed that the minimum air flow rate considering stratification satisfies all the conditions of indoor thermal comfort, IAQ and without stratification. The proposed method was found to be more effective than the existing control method. The energy comparison with the existing control method showed that the proposed method reduces the energy consumption.

Abstract:The objective of this study was to propose a control method with a ventilation requirement of variable air volume (VAV) system in multi-zone. In order to control the VAV system inmulti-zone, it is essential to control the terminal unit installed in each zone. A VAV terminal unit with conventional control method using a fixed minimum air flow can cause indoor air quality (IAQ) issues depending on the variation in the number of occupants. This research proposes a control method with a ventilation requirement of the VAV terminal unit and AHU inmulti-zone. The integrated control method with an air flow increase model in the VAV terminal unit, AHU, and outdoor air intake rate increase model in the AHU was based on the indoor CO 2 concentration. The conventional and proposed control algorithms were compared through a TRNSYS simulation program. The proposed VAV terminal unit control method satisfies all the conditions of indoor temperature, IAQ, and stratification. An energy comparison with the conventional control method showed that the method satisfies not only the indoor thermal comfort, IAQ, and stratification issue, but also reduces the energy consumption.

Quantum dot (QD) as a color converting material in the form of patterned film can effectively improve the optical efficiency of displays. Since all of the light passing through the QD film cannot be fully down‐converted, however, novel structure or materials are required to improve the light down‐converting efficiency in the QD film. TiO2 and wrinkled silica particles are respectively applied as scattering nanoparticles which can increase optical path of light in this study. From experimental results, it was confirmed that optical efficiencies of red and green light in white OLED prepared with QD and TiO2 were enhanced further by 57.3% and 17.5%, respectively. In addition, the QD‐converting efficiency to green light from blue µ‐LED was increased using wrinkled silica‐QD hybrid particles, resulting in the enhanced luminous efficacy of 13.1lm/W with 15wt% QD concentration.