• 대한인간공학회지
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• 제30권6호
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• pp.765-773
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• 2011

Objective: This study aims towards exploring a model of the HCI evaluation methods to improve the usability of mobile device, based on a case of a Mobile PDA system in a Museum context. Background: Mobile PDA systems in a Museum context is widely utilized for the educational purposes, but it is criticized for low usability that the device only play a role in textbooks on legs without any interactive educational activities. Therefore, the usability improvements on the mobile PDA system should be considered. Method 1: This model was developed with a combination of the expert review and the user testing, and with a combination of the qualitative and quantitative studies. In more details, first of all, a qualitative study was conducted as a combination of three different methods: 1) expert review with heuristics, 2) interviews with persons working in a museum, and 3) contextual enquiry. Results 1: The experts review provided with critical usability issues, and the semi-constructive interview helped to understand the background of the mobile device. Lastly, the contextual enquiry showed user experience problems and directions of improving the device from user's perspective. Method 2: Based on the results of the qualitative study, a questionnaire was designed. Results 2: The analysis of the quantitative study was conducted to generalize the problems, and prioritize the direction of improving the device within the limitation of the cost and time in a museum. Conclusion: This study has implications in developing an example of a HCI evaluation model to improve the user experience of the mobile device as well as finding problems and directions of how to improve the mobile PDA systems in the museum. Application: In fact, most of the studies related to the evaluation of the mobile device have been conducted in a laboratory context due to the cost and time. This paper, however, attempted to apply to various HCI research techniques from different constituents in real context.

• 대한의생명과학회지
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• 제15권1호
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• pp.1-8
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• 2009

Human genomic DNA is continuously attacked by oxygen radicals originated from cellular metabolic processes and numerous environmental carcinogens. 2-deoxyribonolactone (dL) is a major type of oxidized abasic (AP) lesion implicated in DNA strand scission, mutagenesis, and formation of covalent DNA-protein crosslink (DPC) with DNA polymerase (Pol) ${\beta}$. We show here that human DNA polymerase (Pol)${\iota}$ and mitochondrial $Pol{\gamma}$ give rise to stable DNA-protein crosslink (DPC) formation that is specifically mediated by dL lesion. $Pol{\gamma}$ mediates DPC formation at the incised dL residue by its 5'-deoxyribose-5-phosphate (dRP) lyase activity, while $Pol{\gamma}$ cross links with dL thorough its intrinsic dRP lyase and AP lyase activities. Reactivity in forming dL-mediated DPC was significantly higher with $Pol{\gamma}$ than with $Pol{\iota}$. DPC formation by $Pol{\gamma}$, however, can be reduced by an accessory factor of $Pol{\gamma}$ holoenzyme that may attenuate deleterious effects of crosslink adducts on mitochondrial DNA. Comparative kinetic analysis of DPC formation showed that the rate of DPC formation with either $Pol{\iota}$ or $Pol{\gamma}$ was lower than that with $Pol{\beta}$. These results revealed that the activity of catalytic lyase in DNA polymerases determine the efficiency of DPC formation with dL damages. Irreversible crosslink formation of such DNA polymerases by dL lesions may result in a prolonged strand scission and a suicide of DNA repair proteins, both of which could pose a threat to the genetic and structural integrity of DNA.

• 대한의생명과학회지
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• 제26권2호
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• pp.66-74
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• 2020

This study was carried out to investigate the protective effect of crude saponin from Platycodon grandiflorum on Clinical chemical parameters in male rats acutely exposed to 2,3,7,8-tetrachlorodibenzo-ρ-dioxin (TCDD). Crude saponin was prepared from Korean Platycodon grandiflorum with Diaion HP-20 adsorption chromatography after extraction of 80% ethanol at 75℃. The crude saponin was confirmed by thin layer chrmatography. When compared with ginseng saponins, the crude saponin had both a few number of saponins and a broad distribution. Forty male rats (200±20 g) were divided into 4 groups. Normal control (NC) group received vehicle and saline; TCDD-treated (TT) group received TCDD (40 ㎍/kg, single dose) intraperitoneally; Platycodon grandiflorum saponin (PG5 and PG10) groups received crude saponin 5 mg/kg and 10 mg/kg (p.o), respectively, for 2 weeks before 1 week of TCDD-exposure. Increase of body weight was retarded greatly by TCDD-exposure. Body weight of animals in TT group was significantly decrease after 2 days of TCDD-exposure. However, body weights of animals in PG groups increased through the experimental perimental period, although the increasing rate was slower than that of NC group. Increases in contents of blood glucose, total cholesterol and triglyceride (TG) and activities of amylase, lipase, AST, ALT and LDH by toxic action of TCDD were significantly attenuated by crude saponin from Platycodon grandiflorum (P<0.05). In conclusion, these results suggest that crude saponin prepared from Korean Platycodon grandiflorum might be a member of useful protective agents against TCDD, which is one of the environmental hormones.

• BMB Reports
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• 제44권6호
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• pp.410-414
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• 2011

Chana series are new chalcone derivatives. To evaluate the possibility of Chana series as therapeutic agents of type 2 diabetes, the inhibitory effects of Chana series on the activities of ${\alpha}$-glucosidase and DPP-4 were investigated using in vitro enzyme assays, and their effects on adipocyte differentiation were investigated in C3H10T1/2 cells. Chana 1 and Chana 7 among the Chana series showed significant inhibition of ${\alpha}$-glucosidase activity. In DPP-4 enzyme assay, Chana 1 exhibited the highest inhibitory activity while Chana 7 did not. In MTT assay, Chana 1 did not show significant cytotoxicity up to a concentration of $250{\mu}M$, whereas cytotoxicity was observed with Chana 7 at a concentration of $300{\mu}M$. In addition, Chana 1 induced adipocyte differentiation. Therefore, Chana 1 showed inhibitory effects on ${\alpha}$-glucosidase and DPP-4 as well as a stimulatory effect on adipocyte differentiation, suggesting that Chana 1 may be a potential beneficial agent for the treatment of type 2 diabetes.

• BMB Reports
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• 제51권4호
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• pp.200-205
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• 2018

Exercise and resveratrol supplementation exhibit anti-obesity functions in the long term but have not been fully investigated yet in terms of their early potential effectiveness. Mice fed with high-fat diet were categorized into control (Cont), exercise (Ex), resveratrol supplementation (Res), and exercise combined with resveratrol supplementation (Ex + Res) groups. In the four-week period of weight loss, exercise combined with resveratrol supplementation exerted no additional effects on body weight loss but significantly improved whole-body glucose and lipid homeostasis. The combined treatment significantly decreased intrahepatic lipid content but did not affect intramyocellular lipid content. Moreover, the treatment significantly increased the contents of mtDNA and cytochrome c, the expression levels of peroxisome proliferator-activated receptor gamma coactivator-1 alpha and its downstream transcription factors, and the activities of ATPase and citrate synthase. However, exercise, resveratrol, and their combination did not promote myofiber specification toward slow-twitch type. The effects of exercise combined with resveratrol supplementation on weight loss could be partly due to enhanced mitochondrial biogenesis and not to fiber-type shift in skeletal muscle tissues.

• Journal of Ginseng Research
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• 제42권3호
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• pp.379-388
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• 2018

Background: Ginsenosides are the main ingredients of Korean Red Ginseng. They have extensively been studied for their beneficial value in neurodegenerative diseases such as Parkinson's disease (PD). However, the multitarget effects of Korean Red Ginseng extract (KRGE) with various components are unclear. Methods: We investigated the multitarget activities of KRGE on neurological dysfunction and neurotoxicity in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD. KRGE (37.5 mg/ kg/day, 75 mg/kg/day, or 150 mg/kg/day, per os (p.o.)) was given daily before or after MPTP intoxication. Results: Pretreatment with 150 mg/kg/day KRGE produced the greatest positive effect on motor dysfunction as assessed using rotarod, pole, and nesting tests, and on the survival rate. KRGE displayed a wide therapeutic time window. These effects were related to reductions in the loss of tyrosine hydroxylase-immunoreactive dopaminergic neurons, apoptosis, microglial activation, and activation of inflammatory factors in the substantia nigra pars compacta and/or striatum after MPTP intoxication. In addition, pretreatment with KRGE activated the nuclear factor erythroid 2-related factor 2 pathways and inhibited phosphorylation of the mitogen-activated protein kinases and nuclear factor-kappa B signaling pathways, as well as blocked the alteration of blood-brain barrier integrity. Conclusion: These results suggest that KRGE may effectively reduce MPTP-induced neurotoxicity with a wide therapeutic time window through multitarget effects including antiapoptosis, antiinflammation, antioxidant, and maintenance of blood-brain barrier integrity. KRGE has potential as a multitarget drug or functional food for safe preventive and therapeutic strategies for PD.

• Archives of Pharmacal Research
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• 제19권1호
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• pp.52-59
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• 1996

The in vitro activity of LB20304 was evaluated against clinical isolates and compared with those of Q-35, ciprofloxacin, sparfloxacin, lomefloxacin and ofloxacin. LB20304 demonstrated 16-to 64-fold more potent activity than ciprofloxacin against gram-positive bacteria. LB20304 inhibited 90% of the isolates of methicillin-susceptible Staphylococcus aureus(MSSA) at a concentration of $0.016\mug/ml\; (MIC_{90}). MIC_{90}$ values of LB20304 against methicillin-resistant Staphylococcus aureus (MRSA), methicillin-susceptible Staphylococcus epidermidis (MSSE), methicillin-resistant S. epidermidis (MRSE) and Streptococcus pneumoniae were $2\mug/ml,\; 0.016\mug/ml,\; 0.5\mug/ml \;and\; 0.031\mug/ml,$ respectively. LB20304 was also very active against gram-negative bacteria. Against Escherichia coli, Klebsiella pneumoniae, Serratia marcescens, Pseudomonas aeruginosa and Acinetobacter calcoaceticus, $MIC_{90}s of\; LB20304 were\; 0.031\mug/ml,\; 0.25\mug/ml,\; 2\mug/ml,\; 8\mug/ml\; and\; 0.5\mug/ml$, respectively. Its activity was comparable to that of ciprofloxacin but much better than those of Q-35, sparfloxacin, ofloxacin and lomefloxacin. LB20304 also exhibited the most potent acitvity among quinolones tested against laboratory standard strains, ofloxacin-resistant strains, .betha.-lactamase-producing strains and anaerobic strains. The inhibitory effect$ (IC_{50)$ of LB20304 on DNA gyrase from Micrococcus luteus, determined by the supercoiling assay, was 8-fold more potent than that of ciprofloxacin. LB20304 did not induce topoisomerase-associated DNA cleavage even at a concentration of 10 mg/ml, although ciprofloxacin induced DNA cleavage at a concentration of 1 mg/ml.

• 천문학회보
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• 제37권2호
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• pp.236.1-236.1
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• 2012

We conducted simultaneous 22GHz water maser and 44GHz class I methanol maser surveys of newly-identified 282 H2 emission features from the $2.122{\mu}m$ H2 narrowband image survey in the Galactic plane (UWISH2 project) using Korea VLBI Network (KVN) 21-m radio telescopes. We detected 16 and 13 new water and methanol maser sources, respectively. This result indicates that at least ~5% of the H2 emission features originate from young stellar objects (YSOs) that are in the right physical condition to produce the water and methanol masers. The masers are closely related to the current outflow activities in the Galactic plane. The power sources of these 23 diffused/collimated H2 emission features (six sources are detected for both masers) are likely to be intermediate-to high-mass YSOs, based on a comparison with the maser luminosities of other well-studied YSOs. Both maser velocities are mostly close to their own systemic velocities within 5 km/s, even though water masers generally show larger variabilities in the line intensities, velocities, and shapes than methanol masers. We also discovered three new water maser sources with high-velocity components: ~25 km/s red-shifted CMHO019, ~50 km/s blue-shifted CMHO132, and ~120 km/s blue-shifted CMHO182. In particular, we propose that the dominant blue-shifted water maser of CHMO182 could become a unique laboratory for the study of high-mass stellar jet and their accelerations.

• Journal of Ginseng Research
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• 제35권2호
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• pp.243-249
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• 2011

Korean red ginseng (KRG), the steamed root of Panax ginseng Meyer, has a variety of biological properties, including anti-inflammatory, antioxidant and anticancer effects. Aflatoxin $B_1$ ($AFB_1$) produced by the Aspergillus spp. causes acute hepatotoxicity by lipid peroxidation and oxidative DNA damage, and induces liver carcinoma in humans and laboratory animals. This study was performed to examine the protective effects of KRG against hepatotoxicity induced by $AFB_1$ using liver-specific serum marker analysis, histopathology, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling. In addition, to elucidate the possible mechanism of hepatoprotective effects, superoxide dismutase, catalase, glutathione peroxidase, and malondialdehyde were analyzed. Rats were treated with 250 mg/kg of KRG (KRG group) or saline ($AFB_1$ group) for 4 weeks and then received 150 ${\mu}g/kg$ of $AFB_1$ intraperitoneally for 3 days. Rats were sacrificed at 12 h, 24 h, 48 h, 72 h, or 1 wk after $AFB_1$ treatment. In the KRG pre-treatment group, serum alanine aminotransferase, aspartate aminotransferase, and malondialdehyde levels were low, but superoxide dismutase, catalase, and glutathione peroxidase activities were high as compared to the $AFB_1$ alone group. Histopathologically, $AFB_1$ treatment induced necrosis and apoptosis in hepatocytes, and led to inflammatory cells infiltration in the liver. KRG pre-treatment ameliorated these changes. These results indicate that KRG may have protective effects against hepatotoxicity induced by $AFB_1$ that involve the antioxidant properties of KRG.

• 한국전문물리치료학회지
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• 제20권4호
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• pp.32-39
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• 2013

Abdominal curl-up exercise may excessively increased superficial neck flexor such as sternocleidomastoid (SCM) muscle. Also, the muscle activity of the abdominal muscles haven't investigated during abdominal curl-up with craniocervical flexion (CCF). Therefore, the purpose of our study was to determine the effect of CCF on the muscle activity of the abdominal and SCM muscles during abdominal curl-up. Twelve healthy subjects (six men and six women) with no history of abdominal or lower back pain within 6 weeks were recruited. Surface electromyographic signals were collected on SCM, rectus abdominis (RA), internal oblique (IO), and external oblique (EO) muscles bilaterally during performing the traditional abdominal curl-up and the abdominal curl-up with CCF. Paired t-tests were used to compare the differences in the muscle activity of the bilateral SCM, RA, EO, and IO muscles between the traditional abdominal curl-up and the abdominal curl-up with CCF (p<.05). There was significantly lower electromyogram (EMG) activity of the both SCMs during the abdominal curl-up with CCF (Right SCM, $39.50{\pm}15.29%MVIC$; Left SCM, $38.24{\pm}17.31%MVIC$) than with the traditional abdominal curl-up (Right SCM, $54.85{\pm}20.05%MVIC$; Left SCM, $53.18{\pm}26.72%MVIC$) (p<.05). The activity of abdominal muscles were not significantly different between the traditional abdominal curl-up and the abdominal curl-up with CCF. The abdominal curl-up with CCF requires significantly less muscle activity of SCM. Consequently, the abdominal curl-up with CCF is recommended to prevent excessive activation of superficial cervical flexors during abdominal curl-up exercise.