• Journal of Practical Engineering Education
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• v.15 no.2
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• pp.459-466
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• 2023

This study was conducted to investigate the mediating effect of academic stress on the relationship between smartphone overdependence and the communication competence of nursing students. The research subjects were nursing students in cities A and Y. The research period was from March 2 to March 9, 2023, and the number of subjects analyzed was 139. Descriptive statistics, Pearson correlation were analyzed using SPSS/WIN 26.0, Process macro program the collected data. The results of the mediating effect of academic stress on the relationship between smartphone dependence and communication competence showed that academic stress (β=.226, p=.005) mediated the effect on the relationship between smartphone dependence and communication competence(Z=-3.131, p=.002). As a result, the combined explanatory power of the variables on nursing student's communication competence was 15.4%. In addition, in order to reduce nursing students' smartphone overdependence, it is necessary to educate them about smartphone use and develop self-control, provide interventions to cope with academic stress, and develop intervention programs to improve communication competence.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.4
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• pp.427-439
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• 2021

Objectives: This study aims to investigate differences in microbial contamination according to the duration and environment of mask wearing. Methods: Forty-five participants were recruited from workers in an offices, multi-purpose facilities, and a schools. After wearing of KF94 mask for two. four, and six hours, the microorganisms adsorbed on the outer and inner layers of the mask were inoculated on BAP(Blood Agar Plate), Chocolate agar, and SDA plates. The bacterial count (CFUs: colony-forming units) cultured in each plate was measured and analyzed for changes in filtration efficiency. Results: The microbial contamination of masks worn in classrooms, offices, and multi-purpose facilities showed a significant difference depending on the environment (p<0.000). The measured CFUs increased significantly according to the time wearing the mask. The difference between the inner and outer layers of the mask was also significant (p<0.05). However, there was no statistical difference in the filtration efficiency of the masks by duration time (p=0.515). Conclusions: Masks worn by workers in the offices, multi-purpose facilities, and schools showed an increase of microbial contamination with the amount of time wearing the mask. The results indicate that the masks used in daily life may have adverse health effects if they are worn for a long time or reused over several days without the realizing that the masks can be contaminated with biological hazards. Guidelines on the safe threshold time for mask use should be established through further research.

• Applied Biological Chemistry
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• v.39 no.1
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• pp.89-94
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• 1996

Three sesquiterpene ortho-naphthoquinones were isolated from the methanolic extract of root bark of Ulmus davidiana Planch whose stem and root bark have been used as an oriental medicine for the treatment of edema, mastitis, gastric cancer and inflammation. The structures of these compounds were established on the basis of spectral data obtained from UV-vis, IR, HR-EIMS and NMR spectrometry, including the pulse field gradient (PFG)-HMQC and HMBC techniques. Their structures were determined as 2,3-dihydro-3,6,9-trimethylnaphtho(1,8-b,c)pyran-7,8-dione, 3,6,9-trimethylnaphtho(1,8-b,c)pyran-7,8-dione and 2,3-dihydro-4-hedroxy-3,6, 9-trimethylnaphtho(1,8-b,c)pyran-7,8-dione, which were identified as mansonones E. F and H, respectively. These compounds have originally been isolated from Mansonia altissima Chev, but have never been isolated from Ulmus davidiana Planch. Especially, mansonone H was isolated for the first time from Ulmaceae. The mismatched carbon chemical shifts of mansonones E and F in the reported literature were corrected by the aid of the PFG-HMBC spectral data.

• Journal of Life Science
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• v.32 no.7
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• pp.491-500
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• 2022

HK shiitake mushroom mycelium (HKSMM), containing 14% β-glucan, is a health functional food ingredient individually approved by the Korea Ministry of Food and Drug Safety for liver health. The anti-inflammatory effect of a 50% aqueous ethanol extract of HKSMM (designated HKSMM50) was studied in RAW 264.7 macrophage cells treated with lipopolysaccharide (LPS). An active hexose correlated compound (AHCC) was used as a positive control. LPS-activated RAW 264.7 cells were treated with HKSMM50 and AHCC (0, 20, 100, 500 ㎍/ml) and cultured for 24 hr. Inflammation-related elements in the supernatant were measured using enzyme-linked immunosorbent assay (ELISA) kits, and the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins in the cells was analyzed by Western blotting. The HKSMM50 lowered iNOS and COX-2 protein expressions, and nuclear factor-kappa B (NF-κB), nitric oxide (NO) and prostaglandin E₂ (PGE₂) contents in a concentration-dependent manner as compared to LPS treatment. Similarly, the HKSMM50 lowered the content of pro-inflammatory cytokines interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), interleukin-4 (IL-4) and interleukin-6 (IL-6) contents and increased the activity of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT). The efficacy of the AHCC treatment was similar to that of the HKSSM50 treatments. These results indicate that HKSMM50 showed an anti-inflammatory effect in LPS-treated RAW 264.7 cells by down-regulation of NF-κB signaling and suggest that HKSMM could be used as a health functional food ingredient to help improve immune function.

• The Korea Journal of Herbology
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• v.21 no.4
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• pp.109-113
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• 2006

Objectives : In this study, anti-oxidant activity of Taraxacum platycarpum is confirmed to investigate cosmeceutical activity for utilization as a cosmetic ingredients. Methods : In the anti-oxidant and whitening effect experiment, the electron donating ability of Taraxacum platycarpum extracts, their SOD-like activity, and the inhibitory activity of xanthine oxidase, tyrosinase were examined. Results : Radical-scavenging activity of water and ethanol extract was examined using ${\alpha},{\alpha}-diphenyl-{\beta}-picrylhydrazyl$ (DPPH). Water and ethanol extract from Taraxacum platycarpum showed 62.9% and 54.7% at 500 ppm concentration in DPPH radical inhibition, respectively. In the test of superoxide dismutase (SOD)-like activity, water extract showed 63.4% at 1,000 ppm concentration, while ethanol extract showed 49% at 1,000 ppm concentration. In the test of xanthine oxidase inhibition, ethanol extract showed 66.8% at 1,000 ppm concentration. Tyrosinase inhibition effect related to whitening effect showed 36.3% and 54.2% in ethanol extract and water extract at 1,000 ppm concentration, respectively. Conclusion : According to these results, it is possible that the extract of Taraxacum platycarpum can be used as a new natural material of cosmetic industry.

• The Korea Journal of Herbology
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• v.20 no.3
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• pp.19-27
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• 2005

Objectives : The antioxidant activities of Yeonkyo-san and its ingredient were investigated for industrial application. Methods : We experimented radical scavenging effect, superoxide dismutase and cytotoxicity effect of various cancer cell. Results : The result were obtained as follows : Primary testing of cytotoxicity of Yeonkyo-san and ingredient was done for G361. B16F10, MDA and A549 cell lines. Yeonkyo-san and ingredient water extract, ethanol extract showed cytotoxicity of over 90% respectively against cell line. The electron donating ability(EDA) of water extract from the Yeonkyo-san was higher than 60%, ethanol extract from the Yeonkyo-san was over 80% at 1000 ppm. The electron donating ability(EDA) of water extract and ethanol extract from the Yeonkyo-san ingredients were increased as well. SOD-like activity was high as 75% in 700 ppm, it was increased. All the other samples showed less than 40% SOD-like activity. Conclusions : The results indicated that water extract and ethanol extract of Yeonkyo-san and ingredient can be used as a natural ingredient with biological functions in cosmetic and food composition.

• Korean Journal of Pharmacognosy
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• v.38 no.4
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• pp.312-320
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• 2007

The screening of anti-cancer activity for the MeOH extracts of 163 natural sources, which were registered as edible plants by Korea Food & Drug Administration, exhibited 9 extracts to have significant inhibitory effects on farnesyl-protein transferase (FPTase) and phosphatase of regenerating liver-3 (PRL-3). In order to confirm the inhibitory activity of these active extracts, the activity assay was repeated for some fractions obtained from the active extracts using Medium Pressure Liquid Chromatography (MPLC). Some fractions of Carya illinoensis, Chlorella vulgaris, Panicum miliaceum, Perilla frutescens, Rosmarinus officinalis showed over 50% inhibitory activity on FPTase as well as those of Capsella bursa-pastoris, C. illinoensis, C. vulgaris, Coix lacrymajobi, Myristica fragrans, P. miliaceum, R. officinalis did over 50% inhibitory activity on PRL-3.

• The Korea Journal of Herbology
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• v.34 no.4
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• pp.9-18
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• 2019

Objectives : It has been known to be correlated between phlegm and dementia from the perspective of oriental medicine, but it is unexplored whether herbal medicines to treat phlegm have pharmacological actions on Alzheimer's disease (AD). The aim of this study was to evaluate and to compare effects of herbal medicines to treat phlegm against AD in vitro. Methods : We selected 11 herbal medicines which treat phlegm and obtained each extract by boiling in 10-fold distilled water for 2 h. And we performed the assay of acetylcholinesterase (AChE) inhibitory effects of 11 herbal extracts. Next, we evaluated neuroprotective effects of them against amyloid $beta_{25-35}$ ($A{\beta}_{25-35}$) plaque-induced toxicity in HT22 mouse hippocampal neuronal cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. To investigate whether they show the anti-inflammatory effects against lipopolysaccharide (LPS), we also measured the levels of nitric oxide (NO) in BV2 microglia cells using griess reagent assay. Results : We found that Gamiyeongsin-hwan (GYH) and Cheonghunhwadam-tang (CHT) exhibited remarkable AChE inhibitory effects. In HT22 cells, Arisaematis Rhizoma, Trichosanthis Semen and Fritillariae Thunbergii Bulbus suppressed $A{\beta}_{25-35}$ plaque-induced neuronal cell death. In BV2 cells, Cheongung-hwan significantly inhibited the increase of NO contents induced by LPS and GYH and CHT showed a tendency to inhibit LPS-induced NO generation. Conclusions : These results suggest that several herbal medicines to treat phlegm showed the significant effects on AChE inhibition, neuroprotection against $A{\beta}_{25-35}$ plaque-induced toxicity, and inhibition of NO generation. Therefore, we demonstrate the possibility that herbal medicines with treating phlegm has effects against AD.

• The Korea Journal of Herbology
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• v.31 no.5
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• pp.47-53
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• 2016

Objectives : Mori Follium (Morus alba L. leaf) has been cultivated in many Asian countries. Especially, mulberry leaf has been used as an anti-diabetic remedy in oriental medicine. However, anti-obesity effect of mulberry has not been unknown. In this study, our objectives of study is to investigate the anti-adipogenic effect of mulberry water extract (MLE) and to reveal potential molecular anti-obesity mechanism in 3T3-L1 adipocytes differentiation model.Methods : The cytotoxicity of MLE in 3T3-L1 was examined by MTT assay. Anti-adipogenic effect of MLE was evaluated by Oil Red O (ORO) staining. To elucidate the molecular mechanism, inhibitor assay was employed. The mRNA expression levels of adipogenic transcriptional factors such as PPARγ and fatty acid synthase (FAS) were analyzed by reverse transcription-polymer chain reaction (RT-PCR) analysis.Results : The MLE treatment for 24 h did not affect to the 3T3-L1 cells at concentrations of 1, 10, 100, 200, 400, 800 and 1,000 ㎍/㎖. Thus, non-toxic concentration rages of MLE were used during adipogenesis period (day -2 to 7). Intracellular lipid accumulation in MLE-treated 3T3-L1 adipocytes (day 6) were quantitatively evaluated by ORO staining. The MLE treatment significantly and dose-dependently suppressed 3T3-L1 adipogenesis by 60.42%, 38.24%, and 5.97% at 10, 100, and 200 ㎍/㎖, respectively. In addition, our inhibitor assay and RT-PCR analysis revealed that the MLE-inhibited 3T3-L1 adipogenesis through inhibition of PPARγ mediated by Wnt/β-catenin signaling pathway.Conclusions : In conclusion, these findings indicate that the MLE could be used in prevent and/or treatment of obesity-related diseases.

• Korean Journal of Acupuncture
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• v.21 no.2
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• pp.69-79
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• 2004

Objective : Acupuncture has been used for treatment of numerous disorders, especially for pain control in Oriental Medicine. However, the mechanism of pain control by acupuncture was not clear until now. This study was performed to prove analgesic mechanism of acupuncture treatment at acupoint $ST_{36}$ by observing the changes of abdominal pain and c-Fos expression in the thalamus. Methods : Abdominal pain was induced by acetic acid, and the changes of writhing reflex after acupuncture treatment on $ST_{36}$ and non-acupoints were measured. c-Fos immunohistochemistry was also performed to study the changes of the neuronal activity in the thalamus. Results : The writhing reflex decrease significantly after acupuncturing at $ST_{36}$ compared with control group(p<0.05). The changes of the writhing reflex by non-acupoint acupuncture treatment also showed significant decrease compared with control group(p<0.05). c-Fos expression in the thalamus, especially periventricular part was significantly decreased after acupuncturing as $ST_{36}$ compared with control groups(p<0.05). Conclusion : This study shows that the acupuncture has the analgesic effect in the abdominal pain induced by acetic acid and the thalamus might be a important area for this mechanism.