• Korean Journal of Food Science and Technology
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• v.23 no.1
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• pp.31-36
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• 1991

Cellulase genes from thermophilic alkalophilic Bacillus sp. F204 a potent cellulase complex-producing bacterium, were cloned in Escherichia coli with pUC 19. Plasmids pBC191 and pBC192, isolated from transformants forming yellow zone around colony on the LB agar plate containing 0.5% carboxymethyl cellulose and ampicillin, contained 4.6 Kb and 5.8 Kb HindIII fragments, respectively. The 4.6 Kb insert of pBC191 had single sites for BamHI EcoRI, KpnI and pvuII. DNA hybridization and immunodiffusion studies showed that pBC191-encoded cellulase gene was homologous with that of host strain. pKC231, constructed by inserting 4.6 Kb insert of pBC191 at the HindIII site of pKK223-3, E. coli expression vector, and pGC711, constructed by inserting 4.6 Kb insert of pBC191 at the HindIII site of pGR71, E. coli and B. subtilis shuttle vector, had 3.2 times and 2.8 times as much cellulase activity as pBC191, respectively. Substrate specificity analysis showed that cellulases cloned were CMCase.

• Radiation Oncology Journal
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• v.19 no.2
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• pp.146-152
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• 2001

Purpose : To investigate the regulation of apoptosis and cell cycle in mouse brain irradiation. Materials and Methods : 8-week old male mice, C57B1/6J were given whole body $\gamma-radiation$ with a single dose of 25 Gy using Cobalt 60 irradiator. At different times 1, 2, 4, 8 and 24hr after irradiation, mice were killed and brain tissues were collected. Apoptotic cells were scored by TUNEL assay. Expression of p53, Bcl-2, and Bax and cell cycle regulating molecules; cyclins Bl, Dl, E and cdk2, cdk4, $p34^{cdc2}$ were analysed by Western blotting. Cell cycle was analysed by Flow cytometry. Results : The peak of radiation induced apoptosis is shown at 8 hour after radiation. With a single 25 Gy irradiation, the peak of apoptotic index in C57B1/6J is $24.0{\pm}0.25$ (p<0.05) at 8 hour after radiation. Radiation upregulated the expression of p53/tubulin, Bax/tubulin, and Bcl-2/tubulin with 1.3, 1.1 and 1.45 fold increase, respectively were shown at the peak level at 8 hour after radiation. The levels of cell cycle regulating molecules after radiation are not changed significantly except cyclin D1 with 1.3 fold increase. Fractions of Go-Gl, G2-M and S phase in the cell cycle does not specific changes by time. Conclusion : In mouse brain tissue, radiation induced apoptosis is particularly shown in a specific area, subependyma. These results and lack of radiation induced changes in cell cycle ofter better understanding of radiation response of noraml brain tissue.

• The Korean Journal of Ecology
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• v.19 no.5
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• pp.431-451
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• 1996

The present studwas undertaken to classify and describe the riverside vegetation around Hanchon (36°27’-36°51’N, 128°15’-128°37’E), a tributary in the upper stream area of Nak-tong River, South Korea by methods of the ZM school of phytosociology. As a result the vegetation was divided into twenty three associations and communities belonging to ten classes. Reflecting various human impacts in the past, the associations and communities of the Artemisietea principis were most plentiful there. The vegetation units obtained in the present study were as follows: A. forest vegetation A-1 Fagetea crenatae:Zelkova serrata community, Larix leptolepis community; B. Shrub vegetation B-1 Salicetea sachalinensis:Salicetum gracilistylae, Salicetum graciliglandis assoc. nov., B-2 Rosetea sachalinensis:Salicetum gracilistylae, Salicetum graciliglandis assoc. nov., B-2 Rosetea multiflorae:Stephanandra incisa community, Lycium chinense community; C. Grassland vegetation C-1 Lemnetea minoris:Spirodela polyrhiza-Lemna paucicostata community, C-2 Bidentetea tripartiti:Polygonetum thunbergii, Polygonetum sieboldii-hydropiperis, Panico Polygonetum hydropiperis, Pharagmitetea :Oenantho- Phalaridetum arundinaceae, Phragmitetum japonicae, Miscanthetum sacchariflori, Phragmites australis community, C-4 Artemisietea principis:Artemisia princeps community, Impatiens textori community, Lactuco indicae-Humuletum japonicae, Pueraria lobata-Humulus japonicus community, Pennisetum alopecuroides community, C-5 chenopodietea:Echinochloa crus-galli var. orizicola community, Digitaria adsecendens community, Polygonum nodosum community, C-6 Miscanthetea sinensis: Miscanthus sinensis community, C-7 Plantaginetea:Eragrotis multicaulis-Plantago asiatica community. It is inferred that the endemic vegetation units in the riverside vegetation of Korea are very rare, because most of the vegetation units obtained in the present study are common with those of Japan. Among the above vegetation units, the Salicetum graciliglandis was established as a new association. On the other hand, the associations and communities of classes characterizing the riverside vegetation increased with a decrease of human impacts from the downstream to the upstream in Hanchon, while the number of the naturalized plants was the reverse. Also based on the present phytosociological work, the relation between the vegetation units and their environmental conditions and the restoration ecology and nature conservation of the riverside vegetation were discussed here in detail.

• Journal of Life Science
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• v.27 no.2
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• pp.139-148
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• 2017

The inhibition of tyrosinase, a key enzyme in mammalian melanin synthesis, plays an important role in preventing skin pigmentation and melanoma. Therefore, tyrosinase inhibitors are very important in the fields of medicine and cosmetics. However, only a few tyrosinase inhibitors are currently available because of their toxic effects on skin or lack of selectivity and stability. Therefore, we synthesized a novel series of (E)-2-(substituted benzylidene)-2,3-dihydro-1H-cyclopenta[a]naphthalen-1-one derivatives and evaluated their inhibitory effects on mushroom tyrosinase, with the aim of discovering a novel tyrosinase inhibitor. Among 19 derivatives, MHY3655 ($IC_{50}=0.1456{\mu}M$) showed the strongest inhibitory effect on tyrosinase activity compared to kojic acid ($IC_{50}=17.2{\mu}M$), a well-known tyrosinase inhibitor. In addition, MHY3655 showed competitive inhibition on Lineweaver-Burk plots. We confirmed that MHY3655 strongly interacts with mushroom tyrosinase residues through the docking simulation. Substitutions with a hydroxy group at both R2 and R4 in the phenyl ring indicated that these groups play a major role in the high binding affinity to tyrosinase. Further, MHY3655 did not show cytotoxicity at the concentrations tested in B16F10 melanoma cells. In conclusion, the novel compound MHY3655 potentially shows tyrosinase inhibitory activity, and it could be used as an ingredient in whitening cosmetics.

• Korean Journal of Food Science and Technology
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• v.47 no.1
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• pp.13-19
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• 2015

The effects of electron beam (e-beam) irradiation at up to 10 kGy on the microbiological and physicochemical properties of dried red pepper powders were studied. Samples from Korea, China, and Vietnam were included in this study. In untreated samples, the total number of microbes, such as total aerobic bacteria, yeasts and molds, was in the range of $10^6-10^7CFU/g$. E-beam irradiation at 5 kGy reduced the microbial load by 2-4 log cycles, thus improving the hygienic quality of the samples. Moisture and pH of the samples were unchanged after e-beam irradiation. Reducing sugar content decreased at 1 kGy, followed by a gradual increase at higher radiation doses. At 5 kGy, no significant changes in the content of capsaicinoids were observed between the irradiated and control samples, while a 10 kGy dose led to a significant decrease. The content of pigments did not exhibit apparent changes with increasing dose of irradiation.

• The Journal of Pediatrics of Korean Medicine
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• v.22 no.2
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• pp.81-114
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• 2008

Objectives : The purpose of this study is to investigate the effect of Jeseupwiryeongtang-gagam(JWTG) on atopic dermatitis by in vivo experiment using NC/Nga atopic dermatitis mouse, which has histological and clinical similarities to the atopic dermatitis of human. Methods : To investigate the effect of JWTG on AD, we evaluated atopic dermatitis-like skin lesions by clinical skin index and analyzed immunological parameters in peripheral blood mononuclear cells(PBMCs), splenocytes, draining lymph node(DLN) and performed skin histology in ears and dorsal skin of atopic dermatitis-like skin NC/Nga mouse in vivo. Results and Conclusions : In vivo, clinical skin severity score were significantly lower in JWTG group than control group. IgE, IL-6, $TNF-{\alpha}$, IgM, IgG2a and IgG2b levels in serum were decreased remarkably in JWTG group than control group and $IFN-{\gamma}$ production, secreted in Th1 cell were increased by JWTG. After experiment ended, we analyzed immunological cells ($CD3^+$, $CD19^+$, $CD4^+$, $CD8^+$, $CD3^+$$CD69^+$, $CD4^+$$CD25^+$ and $CD49b^+$) by flow cytometry. It resulted that total absolute number of $CD3^+$, $CD19^+$, $CD4^+$ and $CD8^+$ cells were recovered as normal and $CD3^+$$CD69^+$ were decreased significantly compared with control group in isolated DLN and PBMCs from NC/Nga mouse and total absolute number of $Gr-1^+$, $CD11b^+$ and $CD3^+$ in dorsal skin of NC/Nga mouse were decreased by JWTG. We analyzed ear, DLN, and neck-back skin after biopsy and dyeing by hematoxyline/eosin(H&E) and toluidine staining (mast cells marker) and obtained results that JWTG were effective to histological symptoms (dermal and epidermal thickening, hyperkeratosis and inflammatory cell infiltration). Ear thickness was decreased significantly than the control group and the size of inflammatory lymphocytes cells(ILC) and plasma cells(PC) in DLN were also decreased.

• Journal of the Optical Society of Korea
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• v.19 no.3
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• pp.255-259
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• 2015

We have proposed and experimentally verified a pulse-width modulation (PWM) generator which directly generated a PWM signal in the optical domain. Output waveforms were clear at the repetition rate of 16 MHz; the duty cycle (DC) was from 14.7% to 72.1%; and the DC-control resolution was about 4.399%/dB. The PWM generator' operation principle is based on the injection-locking property of a single-mode Fabry-$P{\acute{e}}rot$ laser diode (SMFP-LD). The SMFP-LD, which has a self-locked mode wavelength at ${\lambda}_{PWM}$, was used to detect the power of the injection-locking signal (optical analog input). If the analog input power is high, the SMFP-LD is locked to the wavelength of the input signal ${\lambda}_a$ and there is no output after an optical bandpass filter (OBF). If the analog input power is low, the SMFP-LD is unlocked and there is output signal at ${\lambda}_{PWM}$ after the OBF. Thus, the SMFP-LD plus the OBF provide digital output for an analog input. The DC of the output PWM signal can be controlled by tuning the power of the analog input.

• Carbon letters
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• v.15 no.3
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• pp.171-179
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• 2014

An attempt was made to investigate the effect of the preparation temperature on the electrocapacitive performance of polypyrrole (PPY)/graphene oxide (GO) nanocomposites (PNCs). For this purpose, a series of PNCs were prepared at various temperatures by the cetyltrimethylammonium bromide-assisted dilute-solution polymerization of pyrrole in presence of GO (wt%) ranging from 1.0 to 4.0 with ferric chloride as an oxidant. The formation of the PNCs was ascertained through Fourier-transform infrared spectrometry, X-ray diffraction spectra, scanning electron microscopy and simultaneous thermogravimetric-differential scanning calorimetry. The electrocapacitive performance of the electrodes derived from sulphonated polysulphone-bound PNCs was evaluated through cyclic voltammetry with reference to Ag/AgCl at a scan rate (V/s) ranging from 0.2 and 0.001 in potassium hydroxide (1.0 M). The incorporation of GO into the PPY matrix at a reduced temperature has a pronounced effect on the electrocapacitive performance of PNCs. Under identical scan rates (0.001 V/s), PNCs prepared at $10{\pm}1^{\circ}C$ render improved specific conductivity (526.33 F/g) and power density (731.19 W/Kg) values compared to those prepared at $30{\pm}1^{\circ}C$ (217.69 F/g, 279.43 W/Kg). PNCs prepared at $10{\pm}1^{\circ}C$ rendered a capacitive retention rate of ~96% during the first 500 cycles. This indicates the excellent cyclic stability of the PNCs prepared at reduced temperatures for supercapacitor applications.

• Journal of the Korean Society of Food Science and Nutrition
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• v.5 no.1
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• pp.53-59
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• 1976

Around 2nd century B. C. two varieties of apple, i. e. 'Nay' and 'Imgum' were already grown in China. It can be suspected that 'Nay' came from the West because of its popular word 'Pyn Por' and 'Imgum' was originated from North East Asia because of its word 'Lii Kiem'. After this time 'Imgum' was called as its popular name 'Sha Guoo' in about 15 th century. In 17th century a new variety of 'Nay' was named as 'Pyng Guoo' and this name was replaced with 'Nay' when the variety was widely supplied. In 19th century a better variety of 'Nay' was developed in the West and it was introduced into China in 20th century which was called 'Western Pyng Guoo'. As a result there were two kinds of 'Pyng Guoo', i. e. 'Chinese Pyng Guoo' and 'Western Pyng Guoo'. However, the 'Western Pyng Guoo' was more supplied and it was said 'Pyng Guoo' which was written as 'Pyng Guoo(?果)' or 'Pyng Guoo (平果)'. At present time apples were classified into 'Sha Guoo' and 'Pyng Guoo'. The old 'Nay' is now called 'Bin Tzyy' which is hardly found. From this study it is suspected that the history of Chinese apples were affected much on our introduction history and its naming.

• KSBB Journal
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• v.19 no.6 s.89
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• pp.462-466
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• 2004

Mycothiol (MSH), a low molecular antioxidant thiol compound, was purified and analyzed from Streptomyns coelicolor A[3]2 by the monobromobimane fluorescence detection method modified by this lab. Through HPLC chromatpgram, MSH fraction was obtained following the elution time of standard MSH (donated by Dr. Robert C. Fahey). That MSH showed the highest concentration among the thiol compounds contained in the cell indicated that MSH was the key thiol compound having antioxidant activity. To understand the role of gene of inositol monophosphatase (I-1-Pase) involved in the MSH biosynthesis, it was isolated from S. coelicolor A(3)2 and cloned and overexpressed in the Escherichia coli. The expressed I-1-Pase was purified through Ni-NTA column. The soluble protein consisted of 281 amino acids, and the molecular weight was 32 kDa. I-1-Pase of S. coelicolor A(3)2 had the sequence homology with those of human and E. coli by 24 and $25\%$, respectively, and had two conserved domains (mofif A and motif B) which were typical of I-1-Pase.