• BMB Reports
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• v.54 no.9
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• pp.439-450
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• 2021

Translating ribosomes accompany co-translational regulation of nascent polypeptide chains, including subcellular targeting, protein folding, and covalent modifications. Ribosome-associated quality control (RQC) is a co-translational surveillance mechanism triggered by ribosomal collisions, an indication of atypical translation. The ribosome-associated E3 ligase ZNF598 ubiquitinates small subunit proteins at the stalled ribosomes. A series of RQC factors are then recruited to dissociate and triage aberrant translation intermediates. Regulatory ribosomal stalling may occur on endogenous transcripts for quality gene expression, whereas ribosomal collisions are more globally induced by ribotoxic stressors such as translation inhibitors, ribotoxins, and UV radiation. The latter are sensed by ribosome-associated kinases GCN2 and ZAKα, activating integrated stress response (ISR) and ribotoxic stress response (RSR), respectively. Hierarchical crosstalks among RQC, ISR, and RSR pathways are readily detectable since the collided ribosome is their common substrate for activation. Given the strong implications of RQC factors in neuronal physiology and neurological disorders, the interplay between RQC and ribosome-associated stress signaling may sustain proteostasis, adaptively determine cell fate, and contribute to neural pathogenesis. The elucidation of underlying molecular principles in relevant human diseases should thus provide unexplored therapeutic opportunities.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.11 no.1
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• pp.70-78
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• 2000

This study was to develop Korean version of Parenting Stress Scale. Primary research was processed thru Abidin's PSI(Parenting Stress Index) scale. For the pilot primary study, distri-buted questionnaire to the mothers who have three to twelve age children and tried factor analysis with 382 data sheets. At the result, 29 items and 5 factors among the 47 items of child domain, 28 items and 5 factors among the items of parent domain were extracted. At the secondary pilot study survey, reanalyzed the 57 items extracted by primary pilot survey with the 392 data collected from three to six age children's parents. For the item discrimination analysis, calculated item-total correlation and deleted the items under r=.20. For the validity test, reviewed content validity and construct validity. For the verification of construct validity, tried factor analysis. At the result, in child domain area, the four factors, 'Reinforces Parent's, 'Accep-tability', 'Attention Distractiveness', 'Demandingness' and 24 items were extracted. Among the common variance of child domain, 'explained common variance' was 82.05%. In parent domain area, the five factors, 'Restriction of Role', 'Depression', 'Social Isolation', 'Parent Health', 'Spouse Relationship' and 24 items were extracted. Among the common variance of parent domain, 'explained common dominator' was 82.40%. For the verification of reliability, Cronbach's ${\alpha}$ coefficient was calculated and in child domain, .69, .70, .67, .66 were produced by each item, respectively and total reliability coefficient was ${\alpha}$=.81. Reliability coefficient of parent domain was .73, .70, .70, .55, .73 by each item, respectively and total reliability coefficient was ${\alpha}$=.83. This study was processed as a primary research to develop the Korean version of parent stress scale which is originally from U.S.A. version of PSI and apply it to proper Korean culture. Therefore, the necessity of continuous study was discussed with more localized items and factors.

• Journal of Electrical Engineering and Technology
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• v.7 no.5
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• pp.778-783
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• 2012

The synthetic short-circuit making test to adequately stress the circuit breaker has been specified as the mandatory test duty in the IEC 62271-100. The purpose of this test is to give the maximum pre-arcing energy during making operation. And this requires the making operation with symmetrical short-circuit current that is established when the breakdown between contact gap occurs near the crest of the applied voltage. Also, if the interrupting chamber of circuit breakers is designed as the type of common enclosure or the operation is made by the gang operated mechanism that three-phase contacts are operated by one common mechanism, three-phase synthetic making test is basically required. Therefore, several testing laboratories have developed and proposed their own test circuits to properly evaluate the breaker performance. With these technical backgrounds, we have developed the new alternative three-phase making circuit.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.9
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• pp.799-807
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• 2005

The flow characteristics and the heat transfer rate on a surface by the interaction of a pair of vortices are studied numerically. To analyze the common flow up produced by vortex generators in a rectangular channel flow, the pseudo-compressibility viscous method is introduced into the Reynolds-averaged Navier-Stokes equation for 3-dimensional unsteady, incompressible viscous flows. To predict turbulence characteristics, a two-layer $k-\varepsilon$ turbulence model is used on the flat plate 3-dimensional turbulence boundary The computational results predict accurately Reynolds stress, turbulent kinetic energy and flow field generated by the vortex generators. The numerical results, such as thermal boundary layers, skin friction characteristics and heat transfers, are also reasonably close to the experimental data.

• Genomics & Informatics
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• v.7 no.1
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• pp.26-31
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• 2009

Heat shock proteins are a class of molecular chaperones that can be found in nearly all organisms from Bacteria, Archaea and Eukarya domains. Heat shock proteins experience increased transcription during periods of heat induced osmotic stress and are involved in protein disaggregation and refolding as part of a cell's danger signaling cascade. Heat shock protein, Hsp20 is a small molecular chaperone that is approximately 20kDa in weight and is hypothesized to prevent aggregation and denaturation. Hsp20 can be found in several strains of Proteobacteria, which comprises the largest phyla of the Bacteria domain and also contains several medically significant bacterial strains. Genomic analyses were performed to determine a common evolutionary pattern among Hsp20 sequences in Proteobacteria. It was found that Hsp20 shared a common ancestor within and among the five subclasses of Proteobacteria. This is readily apparent from the amount of sequence similarities within and between Hsp20 protein sequences as well as phylogenetic analysis of sequences from proteobacterial and non-proteobacterial species.

• Journal of Preventive Medicine and Public Health
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• v.49 no.5
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• pp.253-259
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• 2016

Objectives: Central obesity plays a major role in the development of many chronic diseases, including cardiovascular disease and cancer. Chronic stress may be involved in the pathophysiology of central obesity. Although several large-scale genome-wide association studies have reported susceptibility genes for central adiposity, the effects of interactions between genes and psychosocial stress on central adiposity have rarely been examined. A recent study focusing on Caucasians discovered the novel gene early B-cell factor 1 (EBF1), which was associated with central obesity-related traits via interactions with stress levels. We aimed to evaluate EBF1 gene-by-stress interaction effects on central adiposity traits, including visceral adipose tissue (VAT), in Korean adults. Methods: A total of 1467 Korean adults were included in this study. We selected 22 single-nucleotide polymorphisms (SNPs) in the EBF1 gene and analyzed their interactions with stress on central adiposity using additive, dominant, and recessive genetic modeling. Results: The four SNPs that had strong linkage disequilibrium relationships (rs10061900, rs10070743, rs4704967, and rs10056564) demonstrated significant interactions with the waist-hip ratio in the dominant model ($p_{int}$<0.007). In addition, two other SNPs (rs6556377 and rs13180086) were associated with VAT by interactions with stress levels, especially in the recessive genetic model ($p_{int}$<0.007). As stress levels increased, the mean values of central adiposity traits according to SNP genotypes exhibited gradual but significant changes (p<0.05). Conclusions: These results suggest that the common genetic variants for EBF1 are associated with central adiposity through interactions with stress levels, emphasizing the importance of managing stress in the prevention of central obesity.

• Restorative Dentistry and Endodontics
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• v.21 no.1
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• pp.339-352
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• 1996

Many dentists have been taken an interest in restoration of severly damaged teeth after endodontic treatment and it is a true that there are lots of studies about it. In these days, although we have used Para-Post, pins, threaded steel post, cast gold post and core, and so on, as a method of restoration frequently, it has been in controversy with the effects of them on the teeth and surrounding periodontal tissue. In this study, we assume that the crown of the upper 1st premolar was severly damaged, and after the root canal therapy, two most common types of restoration were carried out ; 1) coronal-radicular amalgam restoration, 2) after setting up the Para-Post, restore with amalgam core and gold crown. After restoration, in order to present the concentration of stress at internal portion of the tooth and the surrounding periodontal tissue, we doveloped a 2-dimensional finite element model of labiopalatal section, then loaded forces from 2 long perpendicular to the lingual incline of buccal ridge an the middle point, parallel to the long direction axis of tooth at the fossa-were applied. The analyzed results were as follows : 1. Stress of the normal first premolar was concentrated on the most weakest anatomical structure, that is, cervical area, and no stress on the bifurcated area of the canal. 2. Crown restoration after root canal therapy causes large stress concentration on the bifurcated area of the canal. This stress concentration has larger value in case of lateral movement of mandible, and there are decrease in the stress concentration compared with natural tooth. 3. Coronal-radicular amalgam restoration method transports more stress to the tooth structure than restoration using Para-Post. 4. There are more stress concentration around Para-Post in the case of lateral movement, and we have more favo rable result when restored with Para-Post. 5. Generally, stress in the lateral movement is larger than stress in the perpendicular load.

• Journal of Dairy Science and Biotechnology
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• v.38 no.3
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• pp.134-141
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• 2020

Oxidative stress is a cascade reaction characterized by a significant increase in the amount of oxidized components. Free radicals produced by oxidative stress are one of the common features in several experimental models of disease, and contribute to wide range of neurodegenerative diseases, including Alzheimer's disease. Iron (II) species can participate in the Fenton, and Fenton-like reactions, to react with hydrogen peroxide and generate hydroxyl radical. As iron accumulation and oxidative stress are associated with the pathological progression of neurodegenerative diseases, iron chelation and antioxidant therapies have become strategies to combat these diseases. Due to the complexity of the redox system in vivo, a multifaceted approach may be an attractive therapeutic strategy. Further investigations are highly expected for the prevention and treatment of neurodegenerative diseases in future.

• BMB Reports
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• v.47 no.9
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• pp.524-529
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• 2014

Oxidative stress and inflammation are common to many pathological conditions. Defense mechanisms protect cells from oxidative stress, but can become over-activated following injury and inflammation. NF-${\kappa}B$ and Nrf2 transcription factors regulate proinflammatory and antioxidant gene expression, respectively. Studies have shown that many natural dietary compounds regulate NF-${\kappa}B$ and Nrf2, preventing inflammation and oxidative stress. Here, we report major compounds of Prunella vulgaris var. lilacina such as rosmarinic acid, oleanolic acid, ursolic acid and caffeic acid as a potential therapeutic for oxidative stress and inflammation. The major compounds exhibited high anti-inflammatory activity, inhibiting NO, PGE2 production, NF-${\kappa}B$ expression and activating Nrf2 expression. In addition, we examined the effect of major compounds on MafK expression. Among the compounds, oleanolic acid significantly decreased MafK expression and MafK-mediated p65 acetylation. These findings suggest that oleanolic acid as NF-${\kappa}B$ inhibitors can potentially be used in therapeutic applications for the treatment of oxidative stress-induced diseases.

• International Journal of Precision Engineering and Manufacturing
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• v.6 no.1
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• pp.65-72
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• 2005

Drilling process is one of the most common, yet complex operations among manufacturing processes. The performance of a drill is largely dependent upon drilling forces, Many researches focused on the effects of drill parameters on drilling forces. In this paper, an effective theoretical model to predict thrust and torque in drilling is presented. Also, with the predicted forces, the stress analysis of the drill tool is performed by the finite element method. The model uses the oblique cutting model for the cutting lips and the orthogonal cutting model for the chisel edge. Thrust and torque are calculated analytically without resorting to any drilling experiment, only by tool geometry, cutting conditions and material properties. The stress analysis is performed by the commercial FEM program ANSYS. The geometric modeling and the mesh generation of a twist drill are performed automatically. From the study, the effects of the variation of the geometric features of the drill and of the cutting conditions of the drilling on the drilling forces and the stress distributions in the tool are calculated analytically, which can be applicable for designing optimal drill geometry and for improving the drilling process.