• The Journal of Korean Academy of Prosthodontics
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• v.45 no.6
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• pp.717-723
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• 2007

Statement of problem. Unreasonable distal cantilevered implant-supported prosthesis can mask functional problems of reconstruction temporarily, but it can cause serious strain and stress around its supported implant and surrounding alveolar bone. Purpose. The purpose of this study was to evaluate strain of implants supporting distal cantilevered fixed prosthesis with two different cantilevered length under distal cantilevered static load. Material and methods. A partially edentulous mandibular test model was fabricated with auto-polymerizing resin (POLYUROCK; Metalor technologies, Stuttgart, Swiss) and artificial denture teeth (Endura; Shofu inc., Kyoto, Japan). Two implants-supported 5-unit screw-retained cantilevered fixed prosthesis was made using standard methods with Type III gold alloy (Harmony C&B55; Ivoclar-vivadent, Liechtenstein, Germany) for superstructure and reinforced hard resin (Tescera; Ivoclar-vivadent, Liechtenstein, Germany) for occlusal material. Two strain gauges (KFG-1-120-C1-11L1M2R; KYOWA electronic instruments, Tokyo, Japan) were then attached to the mesial and the distal surface of each standard abutment with adhesive (M-bond 200; Tokuyama, Tokyo, Japan). Total four strain gauges were attached to test model and connected to dynamic signal conditioning strain amplifier (CTA1000; Curiotech inc., Paju, Korea). The stepped $20{\sim}100$ N in 25 N increments, cantilevered static load 8mm apart (Group I) or 16mm apart (Group II), were applied using digital push-pull gauge (Push-Pull Scale & Digital Force Gauge, Axis inc., Seoul, Korea). Each step was performed ten times and every strain signal was monitored and recorded. Results. In case of Group I, the strain values were surveyed by $80.7{\sim}353.8{\mu}m$ in Ch1, $7.5{\sim}47.9{\mu}m/m$ in Ch2, $45.7{\sim}278.6{\mu}m/m$ in Ch3 and $-212.2{\sim}718.7{\mu}m/m$ in Ch4 depending on increasing cantilevered static load. On the other hand, the strain values of Group II were surveyed by $149.9{\sim}612.8{\mu}m/m$ in Ch1, $26.0{\sim}168.5{\mu}m/m$ in Ch2, $114.3{\sim}632.3{\mu}m/m$ in Ch3, and $-323.2{\sim}-894.7{\mu}m/m$ in Ch4. Conclusion. A comparative statistical analysis using paired sample t-test about Group I Vs Group II under distal cantilevered load shows that there are statistical significant differences for all 4 channels (P<0.05).

• Journal of the Korean Society of Safety
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• v.25 no.6
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• pp.169-179
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• 2010

The aim of this study was to investigate occupational and individual risk factors and working conditions in relation to musculoskeletal symptoms in street cleaners. Investigation was conducted through a survey of 395 male street cleaners employed by the government office in Seoul, Gyeonggi and Chung-Nam from July to August of 2009. The control group was comprised of 143 male drivers and security guards. Risk factors for musculoskeletal symptoms in street cleaners were investigated by multiple logistic regression analysis and also evaluated ergonomic risk factors by assessing working conditions of 4 street cleaners. As a result of symptom questionnaires, all of the prevalent rates of musculoskeletal symptoms in street cleaners had significantly higher results than those of the control group(p<0.05). On binary logistic regression analysis of musculoskeletal symptoms, street cleaners showed significant higher odds ratio as 18.84(95%CI: 6.56-54.12) in the arm/elbow, 10.49(95%CI: 4.29-25.65) in the hand/wrist compared to the control group. Both absence of rest breaks and exposure to ergonomic risk factors showed to be important internal risk factors of musculoskeletal symptoms among street cleaners. The exposure levels of QEC(Quick exposures checklist) in street cleaners were revealed to be higher on the shoulder/arm, wrist/hand, and neck than back, or from stress. The findings appear to show that street cleaners were high-risk group of work-related musculoskeletal disorders. Therefore street cleaners require a holistic interventional strategy, including adequate arrangement of rest breaks, improvement of working tools and control of individual risk factors such as obesity and smoking.

• Anxiety and mood
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• v.14 no.1
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• pp.44-52
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• 2018

Objective : The present study had examined the psychiatric symptoms and physical health consequences for the bereaved parents of the high school students who died in the 2014 Sewol ferry accident. Methods : Forty bereaved parents participated in the study. The authors administered self-report questionnaires about the parents' health behaviors and psychiatric symptoms. The authors also conducted laboratory tests to assess the parents' physical health at 18 and 30 months after the accident. Univariate descriptive statistics were performed to report the prevalence and severity of psychiatric symptoms and health-related behaviors. Paired t-test and Mcnemar test were performed to compare the 18-and 30-month findings. Correlation analysis between psychiatric symptoms and laboratory findings were performed to find a relationship between the two variables. Results : At 30 months after the accident, most of the bereaved parents still appeared to suffer from complicated grief (97.5%), post traumatic stress disorder (80%), insomnia (77.5%) and severe depression (62.5%) based on the scores on the Inventory of Complicated Grief (ICG), the PTSD Check List-5 (PCL-5), the Insomnia Severity Index (ISI) and the Patient Health Questionnaire-9 (PHQ-9). One quarter of the bereaved parents reported high-risk drinking, and 47.5% reported increased drinking amount and frequency after the accident. In objective laboratory results, 55% of the bereaved parents were obese as defined by body mass index ${\geq}25$. The parents' mean low-density lipoprotein shows a significant increase over time (118.5 mg/dL at 18 months. vs. 132.5 mg/dL at 30 months. paired t-test t=-4.061, $$p{\leq_-}0.001$$). Total cholesterol and low-density lipoprotein at 30 months after the accident were in clinically borderline high range. In correlation analysis, triglyceride was positively correlated with ISI. Conclusion : The loss of children in the Sewol ferry accident, a disaster caused by human error, continued to have considerable impact on the victims' parents' mental and physical health 18 and 30 months after the accident. A longitudinal study following the parents' physical health would be necessary to investigate the long-term effects of this traumatic experience on physical health.

• The Korea Journal of Herbology
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• v.35 no.4
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• pp.25-36
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• 2020

Objective : Reflux esophagitis is a disease caused by the reflux of gastric acid and inflammation due to unstable gastroesophageal sphincter. The aim of the present study was to clarify the effect of Phellodendri Cortex (PC) on chronic reflux esophagitis (CRE) in rats. Methods : The anti-oxidant activity of PC was measured by total polyphenol, total flavonoid contents, 1, 1-diphenyl-2-picrylhydrazyl (DPPH), and 2, 2'-azinobis-3-ethyl-enzothiazoline-6-sulfonic acid (ABTS) radical scavenging activity. A CRE was established surgically in SD rats. And then CRE rats were treated with water or PC 200 mg/kg body weight for 14 days. Besides, the anti-oxidant and inflammatory protein levels were evaluated using western blotting. Results : PC reduced esophagus tissues injury. The total polyphenol (36.05 ± 0.25 mg/g) and total flavonoid (72.90 ± 0.61 mg/g) of PC showed a high content. PC strongly reduced radical scavenging activities (DPPH IC₅₀ 43.58 ± 1.54 ㎍/㎖; ABTS IC₅₀ 36.75 ± 0.35 ㎍/㎖). Moreover, reactive oxygen species (ROS) and peroxynitrite (ONOO^-) levels in serum, the protein expression of inducible nitric oxide synthases (iNOS) were significantly reduced. In addition, the protein expression of NADPH oxidases related to oxidative stress were significantly reduced in PC compared to CRE control. PC effectively reduced inflammatory factors including, TNF-α, and IL-6 via NF-κBp65 inactivation through the inhibition of p-IκBα and increased anti-oxidant enzyme such as HO-1, SOD, catalase, and GPx-1/2 via Nrf2 activation. Conclusions : Taken together, these results show that PC can alleviate the esophageal mucosal ulcer though the inhibition of NF-κB inflammatory and the enhancement of Nrf2 anti-oxidant pathway.

• Journal of Digital Contents Society
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• v.15 no.1
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• pp.19-27
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• 2014

In order to estimate the life of 2,5 inch HDD which is adopted by PC environment, make the test plan which reflect the failure mode of market, make the test model of accelerated life test which reflect the stress of temperature. after an analysis of the environment of PC using, test procedure was decided that operation was write 50 % and read 50 %, and then access method was sequential 50 % and random 50%. The acceleration life test was executed on condition that temperature was $50^{\circ}C$ and $60^{\circ}C$, performance was 95 % in max performance, test time was 1000 hours. by the test of goodness of fit of anderson-darling of the failure data during test, it was confirmed that the distribution of failure fellow weibull. test for shape and scale was equal, and shape parameter was 0.7177, characteristic life was 429434 hours at normal user condition($30^{\circ}C$) by the analysis of weibull-arrhenius modeling. It made no difference about the statistics when equality test was executed. The activation energy was 0.2775eV. In analyzing between the failure samples of acceleration test and the samples of market return even though there is detail difference about the share of failure mode, the rank of share was almost same. This study suggest the test procedure of acceleration test of 2.5 inch HDD in PC using environment, and help the life estimation at manufacture and user.

• Journal of Life Science
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• v.15 no.4 s.71
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• pp.607-612
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• 2005

Heat shock protein 70 (HSP70) is a multigene family composed of constitutively expressed members(Hsc70) and stress-inducible members (Hsp70). In the mammalian nervous system, a considerable amount of HSPs is also synthesized under normal conditions suggesting that they play an important role in the metabolism of unstressed cells. In this study we examined the expression of Hsp70 in the synapses of rat cerebellar neurons. Immunohistochemistry using specific antibodies revealed that both Hsp70 and Hsc70 are expressed in the cerebellar tissue, with strongest expression in Purkinje cells followed by granule cells. Neurons in deep cerebellar nuclei were also intensely stained by Hsp70 antibody. Immunocytochemical stainings of cultured cerebellar cells showed that Hsp70 is expressed in both Purkinje and granule cells. The expression was punctate in the soma and along dendritic trees, and the punctae were colocalized with those of PSD95, a postsynaptic marker. Immunoblotting also indicates that Hsp70 is associated with the postsynaptic density fraction. Taken together, our results indicate that the Hsp70 is expressed in cerebellar neurons in normal conditions, and that some are localized in the synapses.

• Journal of Korean Biological Nursing Science
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• v.3 no.1
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• pp.1-10
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• 2001

뇌손상이라고 하는 과도한 stress를 받았을 때 free cortisol의 분비되는 양과 urinary free cortisol의 circadian 리듬에 어떻게 영향을 주는지 확인하기 위하여 시도하였다. 연구대상은 대조군은 건강한 젊은 여성 6명과 실험군응 CT상 뇌에 손상을 받은 4명의 여성으로 30대 환자이었다. 담당의사와 중환자실 관리책임자의 동의하에서 시도되었으며, 실험기간은 2000년 7월 1일에서 7월 10일까지였다. 대조군과 실험군의 뇨를 채취하여 뇨중 free cortisol 농도의 circadian rhythm을 알아보기 위해 채뇨 후 분석하였다. 채뇨는 뇌손상을 받고 응급실을 통해 신경외과 중환자실에 입원한 지 5시간 이내에 해당된 환자로 24시간 유지되는 foley catherization 상태하에서 12:00부터 3일동안 72시간을 2시간 간격으로 채뇨하였고, 대조군은 오전 12시부터 24시간 동안 2시간 간격으로 채뇨하였다. 측정방법으로는 cortisol의 정량은 solid-phase radioimmuoassay 방법을 이용하였으며, 분석재료는 Coat-A-Count(R) Cortisol kit(DPC, U.S.A.)을 사용하여 DPC사의 측정방법을 따랐다. 연구대상자의 free cortisol의 총량은 대조군에서는 $42.8{\mu}g$이었고, 실험군은 1일에 $991.2{\mu}g$, 2일에 $809{\mu}g$, 3일에 $544.2{\mu}g$으로 대조군과 통계적으로 유의한 차이를 나타내(p<.05), 실험군에서 현저하게 증가된 양상을 보였고, 시간이 지나면서 점점 감소하는 경향을 나타냈다. 시간별로 t-검정으로 분석한 결과로는 모든 시간대에서 대조군과 실험군의 평균치는 통계적으로 유의한 차이를 나타냈다. Free cortisol의 circadian에서는 대조군에서는 정상인의 cortisol의 circadian의 경우와 같은 리듬을 보였으나, 손상을 받은 실험군의 경우 분비량은 현저하게 증가했음을 보여주었다. 최고치가 제1일에 18:00과 다음날 10:00에 나타나 최고치가 2회 나타났으며, 제2일에도 제1일과 마찬가지로 18:00에 나타났고, 제3일에는 24:00에 나타나 제1일보다 제2일에는 최고치가 한 번 나타난 리듬을 보여주었고, 분비량은 2일에 감소하였다. 제3일에는 최고치가 8시간 지연된 나타난 리듬의 변화를 보여주었다. 최저치는 제1일, 제2일, 제3일 모두 24:00에 나타난 리듬을 보여주었다. 이상의 결과에서 실험군인 뇌손상 환자군에서는 뇌손상이 과도한 stress로 작용하여 환자의 free cortisol 분비량과 circadian 리듬에도 영향을 주는 것으로 나타났다. 그러므로 뇌손상환자를 간호하는 간호사는 스트레스상태인 것을 인지하여 환자 개개인에 필요한 간호를 해야 할 것으로 사료된다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.11
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• pp.1293-1299
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• 2017

Obesity contributes to the development of diseases, such as type II diabetes, hypertension, coronary heart disease, and cancer. In addition, oxidative stress caused by reactive oxygen species (ROS) is recognized widely as a contributing factor in the development of chronic diseases. This study was examined the antioxidant and anti-adipogenic activities of epigallocatechin-3-gallate (EGCG) in 3T3-L1 preadipocytes. 3T3-L1 cells were differentiated with or without EGCG for 6 days. The production of glutathione (GSH) and the activities of the antioxidant enzymes, such as glutathione reductase (GR), glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD) were measured. EGCG inhibited significantly the lipid accumulation and the expression of adipogenic specific proteins including CCAAT/enhancer binding protein ${\alpha}$ and adipocyte fatty acid binding protein. The production of intracellular ROS was decreased significantly by EGCG in 3T3-L1 cells. EGCG increased the GSH production and the activities of GPx, GR, CAT, and SOD. Moreover, EGCG increased the protein expression of glutamate-cysteine ligase and heme oxygenase-1 in 3T3-L1 cells. These results suggest that EGCG increased the activity and expression of antioxidant enzymes and suppressed the lipid accumulation in 3T3-L1 cells. Therefore, the use of phytochemicals that can maintain the GSH redox balance in adipose tissue could be promising for reducing obesity.

• Journal of the Microelectronics and Packaging Society
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• v.23 no.3
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• pp.69-75
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• 2016

This study investigated the effect of heat treatment conditions not only on the Cr surface crack propagation behaviors but also on the Ni/Cr interfacial reaction characteristics in electroless Ni/electroplated Cr double coating layers on Cu substrate. Clear band layer of Ni-Cr solid solutions were developed at Ni/Cr interface after heat treatment at $750^{\circ}C$ for 6 h. Channeling cracks formed in Cr layer after 1 step heat treatment, that is, heat treatment after Ni/Cr plating, while little channeling cracks formed after 2 step heat treatment, that is, same heat treatments after Ni and Cr plating, respectively, due to residual stress relaxation due to crystallization of Ni layer before Cr plating.

• Biomolecules & Therapeutics
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• v.20 no.4
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• pp.406-412
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• 2012

This study was performed to examine the hepatoprotective effect of isorhamnetin-3-O-galactoside, a flavonoid glycoside isolated from Artemisia capillaris Thunberg (Compositae), against carbon tetrachloride ($CCl_4$)-induced hepatic injury. Mice were treated intraperitoneally with vehicle or isorhamnetin-3-O-galactoside (50, 100, and 200 mg/kg) 30 min before and 2 h after $CCl_4$ (20 ${\mu}l/kg$) injection. Serum aminotransferase activities and hepatic level of malondialdehyde were significantly higher after $CCl_4$ treatment, and these increases were attenuated by isorhamnetin-3-O-galactoside. $CCl_4$ markedly increased serum tumor necrosis factor-${\alpha}$ level, which was reduced by isorhamnetin-3-O-galactoside. The levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and heme oxygenase-1 (HO-1) protein and their mRNA expression levels were significantly increased after $CCl_4$ injection. The levels of HO-1 protein and mRNA expression levels were augmented by isorhamnetin-3-O-galactoside, while isorhamnetin-3-O-galactoside attenuated the increases in iNOS and COX-2 protein and mRNA expression levels. $CCl_4$ increased the level of phosphorylated c-Jun N-terminal kinase, extracellular signal-regulated kinase and p38, and isorhamnetin-3-O-galactoside reduced these increases. The nuclear translocation of nuclear factor kappa B (NF-${\kappa}B$), activating protein-1, and nuclear factor erythroid 2-related factor 2 (Nrf2) were significantly increased after $CCl_4$ administration. Isorhamnetin-3-O-galactoside attenuated the increases of NF-${\kappa}B$ and c-Jun nuclear translocation, while it augmented the nuclear level of Nrf2. These results suggest that isorhamnetin-3-O-galactoside ameliorates $CCl_4$-induced hepatic damage by enhancing the anti-oxidative defense system and reducing the inflammatory signaling pathways.