• Journal of the Korean Society for Precision Engineering
• /
• v.23 no.8 s.185
• /
• pp.171-177
• /
• 2006

This study was performed as a part of the research on the development of a maskless and electroless process for fabricating metal micro/nanostructures by using a nanoindenter and an electroless deposition technique. $2-{\mu}m$-deep indentation tests on Ni and Cu samples were performed. The elastic recovery of the Ni and Cu was 9.30% and 9.53% of the maximum penetration depth, respectively. The hardness and the elastic modulus were 1.56 GPa and 120 GPa for Ni and 1.51 GPa and 104 GPa for Cu. The effect of single-point diamond machining conditions such as the Berkovich tip orientation (0, 45, and $90^{\circ}$ ) and the normal load (0.1, 0.3, 0.5, 1, 3, and 5 mN), on both the deformation behavior and the morphology of cutting traces (such as width and depth) was investigated by constant-load scratch tests. The tip orientation had a significant influence on the coefficient of friction, which varied from 0.52-0.66 for Ni and from 0.46- 0.61 for Cu. The crisscross-pattern sample showed that the tip orientation strongly affects the surface quality of the machined are a during scratching. A selective deposition of Cu at the pit-like defect on a p-type Si(111) surface was also investigated. Preferential deposition of the Cu occurred at the surface defect sites of silicon wafers, indicating that those defect sites act as active sites for the deposition reaction. The shape of the Cu-deposited area was almost the same as that of the residual stress field.

• Elastomers and Composites
• /
• v.38 no.3
• /
• pp.273-280
• /
• 2003

Elastic responses on both pure natural rubber melts with different molecular weights and the rubber compounds mixed with various types of carbon blacks were investigated in this study. Furthermore, the degree of bound rubber was measured for various carbon blacks with different sizes and structures in order to study the interaction between the rubber and carbon blacks, and to study the correlation between the interaction and the elastic responses. As a loading amount of carbon black increased, the degree of bound rubber became higher, particularly far carbon-black particles with smaller sizes and higher structures. The elastic responses of the rubber melt filled with carbon black remarkably improved, as compared with those of unfilled rubber melt, specially in carbon black showing higher contents of bound rubber. Stress relaxation was more delayed and recovery behavior became more elastic, as the molecular weight of the rubber melt increased and the size of carbon-black particles was decreased. Permanent set became higher, as the molecular weight of the rubber melts decreased and the size of carbon-black particles increased.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.16 no.1
• /
• pp.130-140
• /
• 2003

Objectives : Lately the oriental medical treatment of Bell's palsy is various. In various treatments. this study reports the effect of our clinical treatment using aqua-acupuncture with hominis placenta and electroacupuncture treatment for Bell's palsy, The other purpose of this study is to compare the outcome of inpatient group with that of outpatient group. Materials and Methods : From March 1, 2003 to June 30, 2003, we observe 25 patients who visited to the department of oriental medical surgery, ophthalmology & otolaryngology, in oriental medicine hospital Sang-ji university with Bell's palsy. limited to patients who receive treatment more than 5th times and 4 weeks poured aqua-acupunture with homonis placenta both inpatient group and outpatient group, Inpatient group used electroacupunture treatment after 1 week after onset and outpatient group used electroacupunture treatment after 4 weeks after onset. Results and Conclusions : 40$\%$ were male and 60$\%$ female. Of 25 cases. 30's and 50's were 24$\%$ respectively, 40's, 60's and over 70 were 16$\%$ respectively, 20's were 4$\%$. 50$\%$ of male and 60$\%$ of female had the affected side at left side and right occured at 50$\%$ of male and 40$\%$ of female. The most common cause of Bell's palsy was nonspecific 36$\%$, followed by labor 28$\%$, stress 20$\%$, In 48$\%$ of all cases, 2~3 days were spent before a patient visited the hospital after onset, followed by 4~7 days (24$\%$), 44$\%$ were treated 11~20 times followed by those who received 21~30 times (28$\%$). The results of treatment with aqua-acupunture wth hominis placenta and electroacupunture treatment showed that 21 of 25(84$\%$) patients achived fair or more recovery. the overall therapeutic rate of inpatient group was 90.9$\%$, which was higher than that of outpatient group(78.6$\%$).

• Genes and Genomics
• /
• v.40 no.11
• /
• pp.1225-1235
• /
• 2018

Hypoxia seriously affects the innate immune system of fish. However, the roles of suppressor of cytokine signaling (SOCS), pivotal anti-inflammatory genes, in response to hypoxia/reoxygenation remain largely unexplored. The primary objective of this study was to elucidate the function of SOCS genes under acute hypoxia and reoxygenation in pufferfish (Takifugu fasciatus). In the present study, SOCS1, 2 and 3 were identified in T. fasciatus referred to as TfSOCS1, 2 and 3. Then, qRT-PCR and western blot analysis were employed to assess their expressions at both the mRNA and protein levels. Tissue distribution demonstrated that the three SOCS genes were predominantly distributed in gill, brain and liver. Under hypoxia challenge ($1.63{\pm}0.2mg/L$ DO for 2, 4, 6 and 8 h), the expressions of TfSOCS1 and 3 in brain and liver at the mRNA and protein levels were significantly decreased, while their expressions showed an opposite trend in gill. Different from the expressions of TfSOCS1 and 3, the expression of TfSOCS2 was inhibited in gill, along with its increased expression in brain and liver. After normoxic recovery ($7.0{\pm}0.3mg/L$ of DO for 4 and 12 h), most of TfSOCS genes were significantly altered at R4 (reoxygenation for 4 h) and returned to the normal level at R12 (reoxygenation for 12 h). SOCS genes played vital roles in response to hypoxia/reoxygenation challenge. Our findings greatly strengthened the relation between innate immune and hypoxia stress in T. fasciatus.

• The Plant Pathology Journal
• /
• v.35 no.2
• /
• pp.178-187
• /
• 2019

Plants are exposed to biotic stresses caused by pathogen attack and complex abiotic stresses including heat and drought by dynamic climate changes. To alleviate these stresses, we investigated two bacterial stains, H26-2 and H30-3 in two cultivars ('Ryeokkwang' and 'Buram-3-ho') of Chinese cabbage in plastic pots in a greenhouse. We evaluated effects of bacterial strains on plant growth-promotion and mitigation of heat and drought stresses; the role of exopolysaccharides as one of bacterial determinants on alleviating stresses; biocontrol activity against soft rot caused by Pectobacterium carotovorum subsp. carotovorum PCC21. Strains H26-2 and H30-3 significantly increased fresh weights compared to a $MgSO_4$ solution; reduced leaf wilting and promoted recovery after re-watering under heat and drought stresses. Chinese cabbages treated with H26-2 and H30-3 increased leaf abscisic acid (ABA) content and reduced stomatal opening after stresses treatments, in addition, these strains stably colonized and maintained their populations in rhizosphere during heat and drought stresses. As well as tested bacterial cells, exopolysaccharides (EPS) of H30-3 could be one of bacterial determinants for alleviation of tested stresses in Chinese cabbages, however, the effects were different to cultivars of Chinese cabbages. In addition to bacterial activity to abiotic stresses, H30-3 could suppress incidence (%) of soft rot in 'Buram-3-ho'. The tested strains were identified as Bacillus aryabhattai H26-2 and B. siamensis H30-3 based on 16S rRNA gene sequence analysis. Taken together, H26-2 and H30-3 could be candidates for both plant growth promotion and mitigation of heat and drought stresses in Chinese cabbage.

• Biomolecules & Therapeutics
• /
• v.27 no.1
• /
• pp.71-77
• /
• 2019

Previous studies have shown that spinosin was implicated in the modulation of sedation and hypnosis, while its effects on learning and memory deficits were rarely reported. The aim of this study is to investigate the effects of spinosin on the improvement of cognitive impairment in model mice with Alzheimer's disease (AD) induced by $A{\beta}_{1-42}$ and determine the underlying mechanism. Spontaneous locomotion assessment and Morris water maze test were performed to investigate the impact of spinosin on behavioral activities, and the pathological changes were assayed by biochemical analyses and histological assay. After 7 days of intracerebroventricular (ICV) administration of spinosin ($100{\mu}g/kg/day$), the cognitive impairment of mice induced by $A{\beta}_{1-42}$ was significantly attenuated. Moreover, spinosin treatment effectively decreased the level of malondialdehyde (MDA) and $A{\beta}_{1-42}$ accumulation in hippocampus. $A{\beta}_{1-42}$ induced alterations in the expression of brain derived neurotrophic factor (BDNF) and B-cell lymphoma-2 (Bcl-2), as well as inflammatory response in brain were also reversed by spinosin treatment. These results indicated that the ameliorating effect of spinosin on cognitive impairment might be mediated through the regulation of oxidative stress, inflammatory process, apoptotic program and neurotrophic factor expression,suggesting that spinosin might be beneficial to treat learning and memory deficits in patients with AD via multi-targets.

• Journal of Korean Academy of Nursing
• /
• v.49 no.4
• /
• pp.398-410
• /
• 2019

Purpose: This study used a system dynamics methodology to identify correlation and nonlinear feedback structures among factors affecting adolescent cyberbullying victims (CV) in Korea and to construct and verify a simulation model. Methods: Factors affecting CV were identified by reviewing a theoretical background in existing literature and referencing various statistical data. Related variables were identified through content validity verification by an expert group, after which a causal loop diagram (CLD) was constructed based on the variables. A stock-flow diagram (SFD) using Vensim Professional 7.3 was used to establish a CV model. Results: Based on the literature review and expert verification, 22 variables associated with CV were identified and the CLD was prepared. Next, a model was developed by converting the CLD to an SFD. The simulation results showed that the variables such as negative emotions, stress levels, high levels of conflict in schools, parental monitoring, and time spent using new media had the strongest effects on CV. The model's validity was verified using equation check, sensitivity analysis for timestep and simulation with 4 CV adolescent. Conclusion: The system dynamics model constructed in this study can be used to develop intervention strategies in schools that are focused on counseling that can prevent cyberbullying and assist in the victims' recovery by formulating a feedback structure and capturing the dynamic changes observed in CV. To prevent cyberbullying, it is necessary to develop more effective strategies such as prevention education, counseling and treatment that considers factors pertaining to the individual, family, school, and media.

• Korean Journal of Pharmacognosy
• /
• v.53 no.4
• /
• pp.213-225
• /
• 2022

Schisandra chinensis is widely known to regulate fatigue recovery, lowering blood pressure, and contains several bioactive compounds such as schizadran. In this study, we obtained basic data for the development of health food by measuring the schizandrin content, antioxidant activity, anti-inflammatory, antibacterial activity, and enzyme activity of the hot water extract (SCW) and 40% ethanol extract (SCE) of S. chinensis grown in Sunchang-gun, Korea. Schizandrin content was measured as 7.87 ± 0.01 mg/g for SCW and 10.38 ± 0.05 mg/g for SCE. SCE had higher DPPH and ABTS radical scavenging activity than SCW, and the total polyphenol and flavonoid contents were also higher. Both SCW and SCE (500 ㎍/mL) exhibited more than 55% protective effects against oxidative stress in HepG2 cell lines. Anti-inflammatory efficacy was assessed using RAW 264.7 and Caco-2 cells and both SCW and SCE do not have cytotoxic effects. Anti-inflammatory results showed concentration-dependent NO activity and pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) inhibition. The antibacterial activity increased with increasing dose concentrations of SCW and SCE, and the MIC was 25 mg/mL for L. monocytogenes, S. typhimurium, and 75 mg/mL for H. pylori. In addition, amylase and protease enzyme activity was observed in both SCW and SCE.

• Journal of Veterinary Clinics
• /
• v.40 no.1
• /
• pp.25-30
• /
• 2023

The ventral midline approach (VMA) and right flank approach (RFA) are common procedures for the sterilization of bitches. This study compared the different parameters viz. total duration of surgery, recovery time, and length of the incision as well as body temperature, heart rate, respiration rate, and SpO2 in each approach. Twenty (20) bitches were divided randomly for the RFA and VMA. Meloxicam (0.2 mg/kg) was administered subcutaneously half an hour before the induction to provide preemptive analgesia. Diazepam and ketamine were administered intravenously at dose rates of 0.25 mg/kg and 2.5 mg/kg, and 0.17 mg/kg and 3.33 mg/kg, respectively to produce and maintain anesthesia. Each parameter was recorded at the pre-operative, operative and post-operative times. The average duration of surgery and length of incision of RFA (16.1 ± 5.13 min and 2.44 ± 0.83 cm) were significantly lower (p < 0.05) than the VMA (21.3 ± 5.48 min and 3.53 ± 0.7 cm). The operated bitches showed hypothermia (p < 0.05) at 1 hour compared to baseline and 24 hours of surgery. Heart and respiration rates increased significantly (p < 0.05) during traction and severing of ovarian ligaments in bitches within the RFA group, but there was no significant difference within VMA approaches. The sedation score was significantly higher (p < 0.05) at 1 hour after surgery in both approaches. Based on the duration of surgery and length of incision RFA approach was quick and minimal skin wound. Further studies on bitches considering molecular investigations of surgical stress are imperative.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.65 no.3
• /
• pp.57-67
• /
• 2023

A flash drought is a rapid-onset drought that develops over a short period of time as weather and environmental factors change rapidly, unlike general droughts, due to meteorological abnormalities. Abnormally high evapotranspiration rates and rapid declines in soil moisture increase vegetation stress. In addition, crop yields may decrease due to flash droughts during crop growth and may damage agricultural and economic ecosystems. In this study, Flash Drought Intensity Index (FDII) based on soil moisture data from Gravity Recovery Climate Experiment (GRACE) was used to analyze flash drought. FDII, which is calculated using soil moisture percentile, is expressed by multiplying two factors: the rate of intensification and the drought severity. FDII was developed for domestic flash drought events from 2014 to 2018. The flash drought that occurred in 2018, Chungcheongbuk-do showed the highest FDII. FDII was higher in heat wave flash drought than in precipitation deficit flash drought. The results of this study show that FDII is reliable flash drought analysis tool and can be applied to quantitatively analyze the characteristics of flash drought in South Korea.