• Journal of Microbiology and Biotechnology
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• v.30 no.5
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• pp.762-769
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• 2020

Vitamin K2 (menaquinone) is an essential vitamin existing in the daily diet, and menaquinone-7 (MK-7) is an important form of it. In a recent work, we engineered the synthesis modules of MK-7 in Bacillus subtilis, and the strain BS20 could produce 360 mg/l MK-7 in shake flasks, while the methylerythritol phosphate (MEP) pathway, which provides the precursor isopentenyl diphosphate for MK-7 synthesis, was not engineered. In this study, we overexpressed five genes of the MEP pathway in BS20 and finally obtained a strain (BS20DFHG) with MK-7 titer of 415 mg/l in shake flasks. Next, we optimized the fermentation process parameters (initial pH, temperature and aeration) in an 8-unit parallel bioreactor system consisting of 300-ml glass vessels. Based on this, we scaled up the MK-7 production by the strain BS20DFHG in a 50-l bioreactor, and the highest MK-7 titer reached 242 mg/l. Here, we show that the engineered strain BS20DFHG may be used for the industrial production of MK-7 in the future.

• Molecules and Cells
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• v.40 no.10
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• pp.731-736
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• 2017

Taste sensitivity to sugars plays an essential role in the initiation of feeding behavior. In Drosophila melanogaster, recent studies have identified several gustatory receptor (Gr) genes required for sensing sweet compounds. However, it is as yet undetermined how these GRs function as taste receptors tuned to a wide range of sugars. Among sugars, fructose has been suggested to be detected by a distinct receptor from other sugars. While GR43A has been reported to sense fructose in the brain, it is not expressed in labellar gustatory receptor neurons that show taste response to fructose. In contrast, the Gr64a-Gr64f gene cluster was recently shown to be associated with fructose sensitivity. Here we sought to decipher the genes required for fructose response among Gr64a-Gr64f genes. Unexpectedly, the qPCR analyses for these genes show that labellar expression levels of Gr64d and Gr64e are higher in fructose low-sensitivity flies than in high-sensitivity flies. Moreover, gustatory nerve responses to fructose in labellar sensilla are higher in Gr64d and Gr64f mutant lines than in mutant flies of the other Gr64a-Gr64f genes. These data suggest the possibility that deletion of GR64D or GR64F may indirectly induce enhanced fructose sensitivity in the labellum. Finally, we conclude that response to fructose cannot be explained by a single one of the Gr64a-Gr64f genes.

• Journal of Radiation Protection and Research
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• v.42 no.3
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• pp.141-145
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• 2017

Background: The concrete walls inside the vaults of cyclotron facilities are activated by neutrons emitted by the targets during radioisotope production. Reducing the amount of radioactive waste created in such facilities is very important in case they are decommissioned. Thus, we proposed a strategy of reducing the neutron activation of the concrete walls in cyclotrons during operation. Materials and Methods: A polyethylene plate and B-doped Al sheet (30 wt% of B and 2.5 mm in thickness) were placed in front of the wall in the cyclotron room of a radioisotope production facility for pharmaceutical use. The target was Xe gas, and a Cu block was utilized for proton dumping. The irradiation time, proton energy, and beam current were 8 hours, 30 MeV, and $125{\mu}A$, respectively. To determine a suitable thickness for the polyethylene plate set in front of the B-doped Al sheet, the neutron-reducing effects achieved by inserting such sheets at several depths within polyethylene plate stacks were evaluated. The neutron fluence was monitored using an activation detector and 20-g on de Au foil samples with and without 0.5-mm-thick Cd foil. Each Au foil sample was pasted onto the center of a polyethylene plate and B-doped Al sheet, and the absolute activity of one Au foil sample was measured as a standard using a Ge detector. The resulting relative activities were obtained by calculating the ratio of the photostimulated luminescence of each foil sample to that of the standard Au foil. Results and Discussion: When the combination of a 4-cm-thick polyethylene plate and B-doped Al sheet was employed, the thermal neutron rate was reduced by 78%. Conclusion: The combination of a 4-cm-thick polyethylene plate and B-doped Al sheet effectively reduced the neutron activation of the investigated concrete wall.

• Journal of Society of Preventive Korean Medicine
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• v.14 no.3
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• pp.107-115
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• 2010

Objectives : The purpose of this study is to investigate the efficacy of growth exercise program based on Korean medicine. Methods : We recruited fifty two elementary students in a rural area, and measured height, weight, BMI, WHR, and bone age. Questionnaire on sleep, exercise, symptoms based on Korean medicine was performed. Students exercised TaeGuk(太極) Health Gigong(氣功), a growth exercise program 11 times in 6 weeks. Results : Height, weight, BMI and WHR of the subject students were lower than those in the Korean CDC(Center for Disease Control and Prevention) growth chart. There was significantly negative correlation between time of sleep and bone age(p=0.028), but no correlation between time of exercise and bone age(p=0.668). According to diagnosis based on Korean medicine, many students were in weakness of spleen and lung, and bone age according to deficiency of organ showed no significant difference(p=0.774). Satisfaction, impact on time of exercise after program, ideal time for program and impact on reparticipation of program were strong in the questionnaire after growth exercise program(TaeGuk(太極) Health Gigong(氣功)). Conclusions : Korean medicine promotion of health has a salutary effect on elementary school students in rural area by collecting growth and health data and educating easy exercise based on Taichi.

• 한국노년학
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• v.27 no.2
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• pp.487-502
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• 2007

An objective of this study is to verify factor of exercise adherence of the elder who have carried on exercise for many years at non-commercial sports center. To achieve the objective, I used ethnography, a method of qualitative study. The subjects for this study were 5 members of non-commercial sports center. They have been attending lesson which I have been running Taichi for more than 2 years and carried on exercise for more than 5 years. Main results of this study are as follows. First, the elder who have kept on with exercise showed the eagerness to participate and capacity of self-management through their exercise adherence for many years. Second, various factors such as social, environmental, and social psychological on had a strong effect on a continuous exercise performance. The most remarkable thing of results of this study is a close human connection among instructors, manager and companion is the most effectual factor of the elder's exercise adherence.