• Journal of Microbiology and Biotechnology
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• v.30 no.12
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• pp.1937-1943
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• 2020

Although classical metabolic engineering strategies have succeeded in developing microbial strains capable of producing desired bioproducts, metabolic imbalance resulting from extensive genetic manipulation often leads to decreased productivity. Thus, abiotic strategies for improving microbial production performance can be an alternative to overcome drawbacks arising from intensive metabolic engineering. Herein, we report a promising abiotic method for enhancing lycopene production by UV-C irradiation using a radiation-resistant ΔcrtLm/crtB+dxs+ Deinococcus radiodurans R1 strain. First, the onset of UV irradiation was determined through analysis of the expression of 11 genes mainly involved in the carotenoid biosynthetic pathway in the ΔcrtLm/crtB+dxs+ D. radiodurans R1 strain. Second, the effects of different UV wavelengths (UV-A, UV-B, and UV-C) on lycopene production were investigated. UV-C irradiation induced the highest production, resulting in a 69.9% increase in lycopene content [64.2 ± 3.2 mg/g dry cell weight (DCW)]. Extended UV-C irradiation further enhanced lycopene content up to 73.9 ± 2.3 mg/g DCW, a 95.5% increase compared to production without UV-C irradiation (37.8 ± 0.7 mg/g DCW).

• Journal of Adhesion and Interface
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• v.21 no.3
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• pp.93-100
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• 2020

3D printing technology enables proper objects to be made through an additive manufacturing method, but resulting in dimension deviation of the product due to contraction phenomenon as cooling melted filament resin injected from high-temperature use environment. In this research, we studied on acrylic adhesives for 3D printer build sheet in order to fabricate high-quality products with a precise shape and to well-mount without distortion. The solvent-free UV-curable acrylic adhesive formulation was designed by adding 4-acryloylmorpholine (ACMO) with high adhesion, toughness, glass transition temperature so that adhesion properties are stable at high temperature and products are easily mounted/detached from the adhesives. The designed formulation was polymerized through two-steps using post-addition of monomers. Using this, the acrylic adhesive was coated to make a film and then analyzed using various experimental techniques. As a result, the fabricated adhesive exhibited high glass transition temperature and there was little gap in peel strength before and after thermal treatment. Moreover, it was confirmed by rheological analysis that this adhesive can provide great bonding/debonding ability without distortion. We demonstrated the fabrication of a rectangular product using a 3D printing method using our acrylic adhesive as a build sheet. Mounting ability and workability were satisfactory and dimension deviation of the product was tiny. Because the product is easily detachable from the acrylic adhesive developed here than conventional build sheets, it is expected that this will provide work convenience to users who use the 3D printer.

• Journal of Bio-Environment Control
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• v.12 no.4
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• pp.252-258
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• 2003

This experiment was performed to investigate the effect of UV-B (4 kJ${\cdot}m^{-2}{\cdot}d^{-1}$) irradiation and growth inhibitor (50 mg${\cdot}L^{-1}$ diniconazole, 500 mg${\cdot}L^{-1}$) treatment on the overgrowth retardation and the growth and yield afterplanting in plug-grown cucumber, tomato, and hot pepper sedlings. Stem length of UV-B-irradiated and iniconazole-treated seedlings was shortened by 38 and 35%^ in cucumber, 37 and 41% in tomato, and 23 and 23% in hot pepper, respectively, compared with non-treated seedlings. While retarding effect ofhexaconazole waslower that that of UV-B or diniconazle. Leaf area and dry weight alson decreased but ldaf thickness increased in UV-B irradiated or growth-inhibitor-treated seedlings. Even thouth the plant height and leaf area of UV-B-irradiated seedlings ant seedling stage were shorter and smaller that those ofnon-treatedd seedlings, they were recovered to the similar level to the growth of non-treated seedlings 20to 30days after trasplantin. The diconazole-and hexaconazole-treated seedlings were delayed recovery to their normal growth, Fruit yiedl of UV-V-irradiated hot pepper and tomato slightly increased but UV-B irradiated cucumer had similar yield to growth-inhibitor-treated one. It suggested that the use of UV-B irradiation could become a reliable tool of overgrowth retardation of plug-grown vegetable seedlings in greenhouse.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.3 s.47
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• pp.361-367
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• 2004

In this study, a different UV (ultra-violet) ray absorption system is presented in which butyl methoxydiben-zoylmethane (BMDM, a model UV-A absorbent, 320$\~$400 nm) is stabilized in phase-controlled poly(methyl methacrylate) (PMMA) microspheres. The photochemistry of BMDM in the microspheres was investigated considering its phase characteristics therein. The analysis of a differential scanning calorimeter and X-ray diffractometer showed that the BMDM in the microspheres was present with a non-crystalline state. The phase control of BMDM in the polymer microsphere has an excellent ability to protect UV-A with maintaining its photo- and thermal stability. The results obtained in this study illustrate well that the phase control of the UV absorbents in the polymer microspheres is another key factor that de-termines its photochemistry and photostability in the final formulations.

• Korean journal of food and cookery science
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• v.18 no.2
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• pp.173-178
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• 2002

Fresh Shiitake mushrooms were irradiated by UV-B or dried by using hot air to increase the vitamin D$_2$content. Vitamin D$_2$content was determined by high-performance liquid chromatography Irradiating the inside of the mushroom cap was more effective in increasing vitamin D$_2$content than irradiating the outside of the mushroom cap. Irradiation of UV-B at 0, 2.5, 5.0, 7.5 and 10 J/㎠ increased the content of vitamin D$_2$in the mushroom to 21.51, 120.78, 144.38, 168.08, and 187.69 $\mu\textrm{g}$/g, respectively. Vitamin D$_2$content of Shiitake mushrooms with irradiation of 10 J/㎠ decreased from 187.69 to 98.78 $\mu\textrm{g}$/g by 6 hours of hot-air drying. When three kinds of drying method (UV-B irradiation followed by hot-air drying, hot-air drying, and sunlight drying) were compared, the combination of UV-B irradiation and hot-air drying was the most effective in terms of increasine the vitamin D$_2$content in the mushroom.

• Conservation Science in Museum
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• v.26
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• pp.25-34
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• 2021

3D printing technology has been actively applied for the restoration of cultural properties. However, its application to the restoration of glass cultural properties has not yet been reported and thus requires further study. In this study, 3D printing technology was used to restore a defective part of a glass sarira bottle that forms an element of a series of sarira reliquaries commissioned by Yi Seonggye (known as King Taejo after founding the Joseon Dynasty) that was excavated from Geumgangsan Mountain (designated as Treasure No. 1925) and is currently housed at the National Museum of Korea. The defective area was reproduced using 3D printing and the printed reproduction was reproduced again using an epoxy resin. This latter piece was used as the restoration component rather than the 3D printed element. After the completion of the conservation treatment, the materials used for the 3D printing were compared with transparent materials used to restore ceramics to evaluate their usability and stability. A total of five specimens were produced, including from photocurable resin made by a stereo lithography apparatus (SLA), epoxy resin, acrylic resin, and more. They were exposed to UV for 96 hours to test for yellowing. Of the two specimens made of photocurable resins and exposed to UV, one was sprayed with a UV blocking agent but the other was exposed as-is. The UV exposure test showed that the specimen made by the SLA and sprayed with a UV blocking agent and the specimen made of epoxy resin were stable in terms of yellowing with a change in the b-value was less than 1. They are thus considered to be suitable materials for the restoration of glass cultural properties. Such glass cultural properties are often diverse in shape and their restoration can be difficult as they generally consist of a range of complex parts that hamper restoration. In this regard, diverse materials should be considered when selecting materials for the restoration of glass cultural properties.

• Korean Journal of Poultry Science
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• v.18 no.3
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• pp.161-166
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• 1991

This study was conducted to investigate the synthesis of previtamin D$_3$(PreD$_3$), lumisterol$_3$($L_3$) and vitamin $D_3$ ($D_3$) in dorsal skin of 8 week-old broiler chicks irradiated by UV light. The Hubbard line day-old broiler chicks were fed with vitamin D-depleted ration (or 3 weeks and with medium broiler diet for 5 weeks. The 3$\times$3cm area of dorsal skin was defeathered one day before the experiment. The 310nm UV light was utilized to irradiate the dorsal skin, which was separated into epidermis and dermis after irradiation. The irradiated epidermis was extracted with 60% ethyl acetate in n-hexane and PreD$_3$, $L_3$, D$_3$ and 7-dehydrocholesterol (7-DHC) were analyzed by HPLC. When UV light was treated for 0, 90 or 150min. the L$_3$ content in the separated epidermis was 219, 298 or 248ng/$\textrm{cm}^2$, respectively. The irradiation for 90min produced 79ng/$\textrm{cm}^2$ of L$_3$, and the synthesizing rate was 0.9ng/$\textrm{cm}^2$/min. The PreD$_3$ content was 23, 33 or 12ng/$\textrm{cm}^2$ when exposed for 0, 60 or 150min The 10ng/$\textrm{cm}^2$ of PreD$_3$ was produced for 60min. The D$_3$ was generated by 27ng/$\textrm{cm}^2$ when exposed for 90min. The 7-DHC contents were decreased gradually from initial 123 to 35ng/$\textrm{cm}^2$ when exposed for 150 min, showing the rate of disappearance as 0.6ng/$\textrm{cm}^2$/min.

• Korean Journal of Materials Research
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• v.23 no.8
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• pp.447-452
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• 2013

Recently, products that a have 3-dimensional(3D) micro structure have been in wide use. To fabricate these 3D micro structures, several methods, such as stereo lithography, reflow process, and diffuser lithography, have been used. However, these methods are either very complicated, have limitations in terms of patterns dimensions or need expensive components. To overcome these limitations, we fabricated various 3D micro structures in one step using a pair of diffusers that diffract the incident beam of UV light at wide angles. In the experiment, we used positive photoresist to coat the Si substrate. A pair of diffusers(ground glass diffuser, opal glass diffuser) with Gaussian and Lambertian scattering was placed above the photomask in the passage of UV light in the photolithography equipment. The incident rays of UV light diffracted twice at wider angles while passing through the diffusers. After exposure, the photoresist was developed fabricating the desired 3D micro structure. These micro structures were analyzed using FE-SEM and 3D-profiler data. As a result, this dual diffuser lithography(DDL) technique enabled us to fabricate various microstructures with different dimensions by just changing the combination of diffusers, making this technology an efficient alternative to other complex techniques.

• Journal of Environmental Science International
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• v.5 no.5
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• pp.635-642
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• 1996

Rice plants, cv. Koshihikari, were subjected to the biologically effective ultraviolet-B(UV-BBE) radiation {daily dose : 0.0 (control) and 11.5 (enhanced UV-B) KJ m-2} to investigate the effect of enhanced UV-B radiation on lipid peroxidation and to determine whether carotenoids and polyamines are involved in protection mechanism against enhanced UV-B radiation. Enhanced UV-B radiation significantly depressed plant dW weight. Malondialdehyde (MDA) content in rice leaves was increased by about 30% after 6 days of UV-B irradiation. Total carotenoid contents tended to slightly decrease with the UV-B irradiation, even though there was no significance. In rice leaves, 3 major polyamines, putrescine, spermidine and spermine are observed. All of the polyamine contents were increased with UV-B irradiation. The results suggest that enhanced UV- B radiation caused oxidative stress on lipids and that polyamines may serve as a biochemiral protectant against increased UV-B radiation in rice plants.

• Animal Bioscience
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• v.36 no.10
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• pp.1536-1545
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• 2023

Objective: The objective was to evaluate the effects of UV-B irradiated vitamin D-enriched yeast supplementation on milk yield, milk composition, vitamin D in milk, milk fatty acids, blood chemistry, and 25(OH)D status in dairy cows. Methods: Six Thai Friesian cows (milk production, 11.2±2.0 kg/d; body weight, 415.0±20.0 kg; and days in milk, 90.0±6.0) were allocated to each treatment in a 3×3 Latin square design, with three treatments and three periods. Each period of the Latin square lasted 49 days consisting of 14 days for diet adaptation and 35 days for sample collection. Dairy cows were randomly assigned to one of three treatments: i) feeding a basal diet without yeast (CON); ii) basal diet + 5 g of live yeast (75 IU/head/d of vitamin D₂; LY); and iii) basal diet + 5 g of UV-B irradiated vitamin D enriched yeast (150,000 IU/head/d of vitamin D₂; VDY). Feed intake and milk production were recorded daily, milk sample collection occurred on days 14 and 35 of each collection period, and blood plasma was collected on days 0, 7, 14, 21, 28, and 35 of each collection period. Results: The results show that after a trial period of 14 and 35 days, the VDY group had significantly higher vitamin D content in milk than the LY and CON groups (376.41 vs 305.15, 302.14 ng/L and 413.46 vs 306.76, 301.12 ng/L, respectively). At days 7, 14, 21, 28, and 35 of the experiment, cows fed the VDY group had significantly higher 25(OH)D₂ status in blood than the CON and LY groups (51.07 vs 47.16, 48.05 ng/mL; 54.96 vs 45.43, 46.91 ng/mL; 56.16 vs 46.87, 47.16 ng/mL; 60.67 vs 44.39, 46.17 ng/mL and 63.91 vs 45.88, 46.88 ng/mL), respectively. Conclusion: In conclusion, UV-B irradiated vitamin D-enriched yeast supplementation could improve vitamin D content in the milk and 25(OH)D status in dairy cows during the lactation period.