• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.119-119
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• 2017

Growth related to morphological and proteome response under waterlogging stress in sorghum has not yet been elucidated. Understanding how plants respond to waterlogging, the present study was conducted in seedlings leaf of the Nam-pung chal cultivar. Regarding 3-leaf stage of sorghum, stem length and plant height were slightly decreased in the treatments during ten days of waterlogging, and chlorophyll contents were also significantly different from 7 days of waterlogging treatment. The results observed from the present study were considered to be influenced by the waterlogging stress more in the $5^{th}$ leaf stage of the growth period of the sorghum, and as the waterlogging treatment progressed, the waterlogging stress gradually influenced the growth difference between the control and the treatment respectively. Using 2-DE method, a total of 74 differentially expressed protein spots were analyzed using LTQ-FT-ICR MS. Of these proteins, 45 proteins were up-regulated in the treatment group, and 32 proteins were down-regulated. Analysis of LTQ-FI-ICR MS showed that about 50% of the proteins involved in carbohydrate metabolic process, metabolic process, and cellular metabolic compound salvage were affected by stress. Malate dehydrogenase protein and Glyceraldehyde-3-phosphate dehydrogenase protein related to carbohydrate metabolic process increased the level of protein expression in both 3 and 5-leaf stage under waterlogging stress. The increased abundance of these proteins may play an active role in response to waterlogging stress. These results provide new insights into the morphological alteration and modulation of differentially expressed proteins in sorghum cultivar.

• Molecules and Cells
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• v.47 no.1
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• pp.100004.1-100004.11
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• 2024

Insulin is essential for maintaining normoglycemia and is predominantly secreted in response to glucose stimulation by β-cells. Incretin hormones, such as glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide, also stimulate insulin secretion. However, as obesity and type 2 diabetes worsen, glucose-dependent insulinotropic polypeptide loses its insulinotropic efficacy, whereas GLP-1 receptor (GLP-1R) agonists continue to be effective owing to its signaling switch from Gs to Gq. Herein, we demonstrated that endoplasmic reticulum (ER) stress induced a transition from Gs to Gq in GLP-1R signaling in mouse islets. Intriguingly, chemical chaperones known to alleviate ER stress, such as 4-PBA and TUDCA, enforced GLP-1R's Gq utilization rather than reversing GLP-1R's signaling switch induced by ER stress or obese and diabetic conditions. In addition, the activation of X-box binding protein 1 (XBP1) or activating transcription factor 6 (ATF6), 2 key ER stress-associated signaling (unfolded protein response) factors, promoted Gs utilization in GLP-1R signaling, whereas Gq employment by ER stress was unaffected by XBP1 or ATF6 activation. Our study revealed that ER stress and its associated signaling events alter GLP-1R's signaling, which can be used in type 2 diabetes treatment.

• Structural Engineering and Mechanics
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• v.14 no.4
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• pp.455-472
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• 2002

The paper involves the study on the elastic and elasto-plastic stress wave propagation in the 1-D and 2-D solid media. The Smooth Particle Hydrodynamics equations governing the elastic and elasto-plastic large deformation dynamic response of solid structures are presented. The proposed additional stress points are introduced in the formulation to mitigate the tensile instability inherent in the SPH approach. Both incremental rate approach and leap-frog algorithm for time integration are introduced and the new solution algorithm is developed and implemented. Two examples on stress wave propagation in aluminium bar and 2-D elasto-plastic steel plate are included. Results from the proposed SPH approach are compared with available analytical values and finite element solutions. The comparison illustrates that the stress wave propagation problems can be effectively solved by the proposed SPH method. The study shows that the SPH simulation is a reliable and robust tool and can be used with confidence to treat transient dynamics such as linear and non-linear transient stress wave propagation problems.

• Journal of Korean Medicine Rehabilitation
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• v.20 no.1
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• pp.119-132
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• 2010

Objectives : The purpose of this study is to compare interrelations between stress and muscles of neck through stress response inventory(SRI), 7 zone diagnostic system and surface electromyography(sEMG). Methods : This study was carried out with the data from SRI, 7 zone diagnostic system and sEMG. First subjects were divided into two group according to the SRI points. subjects in group A had points of SRI in which lower than 30 points. Subjects in group B had points of SRI in which higher than 30 points. And subjects were divided into nonstress group(Group C) and stress grouop(Group D) according to the result of 7 zone diagnostic system. Then we investigated how to differentiate the muscle contraction, fatigue, recovery and asymmetry ratio on sEMG for each groups. Results : In this study, the muscle contraction of both upper trapezius muscle and left sternocleidomastoid muscle and left scalene muscle in stress group were higher than nonstress group significantly. And the muscle recovery of left sternocleidomastoid muscle and left scalene muscle in stress group were higher than nonstress group significantly. Conclusions : This results show that the stress was associated with muscle condition.

• Biomedical Science Letters
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• v.12 no.4
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• pp.435-438
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• 2006

In eukaryotes, ER stress induces UPR (unfolded protein response) via IRE1 activation which sends a molecular signal for XBP1 mRNA splicing in the cytosol. During this mRNA splicing, 23 nt removed in which contains PstI site and then resulting XBP1 product is not digested with PstI restriction enzyme. In this study, using this XBP1 mRNA splicing mechanism, the effect of heat shock on thyrocytes is studied, because heat shock response in the thyrocytes needs more study to understand thyroid physiology under alternative environments. ER inducible drugs (tunicamycin, DTT, $Ca^{2+}$ ionopore A23187, BFA) induce ER stress in the thyrocytes. From 3 hours after heat shock, ER stress is induced and which is reversible when heat shock is without. While $Ca^{2+}$ ionopore A23187 is reversible from ER stress by washing out the drug, thapsigagin is irreversible. Other ER inducible drugs are not so sensitive to ER stress repairing. XBP1 mRNA splicing in a cell is very available method to detect ER stress. It needs only a small quantity of total RNA and processing also very easy.

• Biomolecules & Therapeutics
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• v.20 no.5
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• pp.482-486
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• 2012

Cerebral monoamines play important roles as neurotransmitters that are associated with various stressful stimuli. Some components such as ginsenosides (triterpenoidal glycosides derived from the Ginseng Radix) may interact with monoamine systems. The aim of this study was to determine whether ginsenoside Rb1 can modulate levels of the monoamines such as dihydroxyphenylalanine (DOPA), dopamine (DA), norepinephrine (NE), epinephrine (EP), 3,4-dihydroxyphenylacetic acid (DOPAC), 5-hydorxytryptamine (5-HT), 5-hydroxindole-3-acetic acid (5-HIAA), and 5-hydroxytryptophan (5-HTP) in mice frontal cortex and cerebellum in response to immobilization stress. Mice were treated with ginsenoside Rb1 (10 mg/kg, oral) before a single 30 min immobilization stress. Acute immobilization stress resulted in elevation of monoamine levels in frontal cortex and cerebellum. Pretreatment with ginsenoside Rb1 attenuated the stress-induced changes in the levels of monoamines in each region. The present findings showed the anti-stress potential of ginsenoside Rb1 in relation to regulation effects on the cerebral monoaminergic systems. Therefore, the ginsenoside Rb1 may be a useful candidate for treating several brain symptoms related with stress.

• Journal of Ginseng Research
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• v.44 no.2
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• pp.267-273
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• 2020

Background: Continuous exposure to high temperatures can lead to heat stress. This stress response alters the expression of multiple genes and can contribute to the onset of various diseases. In particular, heat stress induces oxidative stress by increasing the production of reactive oxygen species. The liver is an essential organ that plays a variety of roles, such as detoxification and protein synthesis. Therefore, it is important to protect the liver from oxidative stress caused by heat stress. Korean ginseng has a variety of beneficial biological properties, and our previous studies showed that it provides an effective defense against heat stress. Methods: We investigated the ability of Korean Red Ginseng and Korean black ginseng extracts (JP5 and BG1) to protect against heat stress using a rat model. We then confirmed the active ingredients and mechanism of action using a cell-based model. Results: Heat stress significantly increased gene and protein expression of oxidative stress-related factors such as catalase and SOD2, but treatment with JP5 (Korean Red Ginseng extract) and BG1 (Korean black ginseng extract) abolished this response in both liver tissue and HepG2 cells. In addition, JP5 and BG1 inhibited the expression of inflammatory proteins such as p-NF-κB and tumor necrosis factor alpha-α. In particular, JP5 and BG1 decreased the expression of components of the NLRP3 inflammasome, a key inflammatory signaling factor. Thus, JP5 and BG1 inhibited both oxidative stress and inflammation. Conclusions: JP5 and BG1 protect against oxidative stress and inflammation induced by heat stress and help maintain liver function by preventing liver damage.

• Journal of the Korea Convergence Society
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• v.6 no.6
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• pp.139-146
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• 2015

The purpose of this study is to determine the general characteristics and work-related characteristics of call center workers and learn the relationship between the subjects of emotional labor levels, stress response levels and turnover. Target the K's Call Center employees 300 people of telecommunications companies in Korea 2015 July 15 to August 31. Results of the study was higher the level of emotional labor of the subjects underlying factors which are somatization of stress reactions, depression, anger is rising, which also showed an increase in turnover. It is necessary to develop and measures to reduce the degree of turnover Intention of call center workers prepare measures are needed that can mitigate the stress response reduces the level of emotional labor.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.2
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• pp.108-115
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• 2015

Electro-mechanical actuator installed on aircraft consists of a decelerator which magnifies the torque in order to rotate an axis connected with aircraft control surface, a control section which controls the motor assembly through receiving orders from cockpit and a motor assembly which rotates the decelerator. Electro-mechanical actuator controls aircraft altitude, position, landing, takeoff, etc. It is an important part of a aircraft. Aircraft maneuvering causes vibrations to electro-mechanical actuator. Vibrations may result in structural fatigue. For that reason, it is necessary to analyze the system structural safety. In order to analyze the system structural safety. It is needed reasonable finite element model and structural response stress closed to real value. In this paper, analytic model is derived by using the simplified finite element model, and damping ratio which is closely related to response stress is derived by using modal test. So, we developed analytic model in less than 10 % error rate, compared with modal test. Vibration response stress close to real value was estimated from analytic model modified with modal experimental damping ratio. Estimation method for damping ratio with empirical formula was suggested partly. Finally, It was proved that electro-mechanical actuator had reasonable structure margin of safety at environmental random $3{\sigma}$ stress during life cycle.

• Journal of the Korea Institute of Military Science and Technology
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• v.26 no.1
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• pp.1-9
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• 2023

The skin structure of sensor pod mounted on the exterior of aircraft can be exposed to the acoustic dynamic load and static load such as aerodynamic pressure and inertial load during flight. Fatigue life prediction of structural model under acoustic load should be performed and also differential stiffness of model modified by static load should be considered. The acoustic noise test spectrum of MIL-STD-810G was applied to the structural model and the stress response power spectral density (PSD) was calculated. The frequency response analysis was performed with or without prestress induced by inplane static load, and the response spectrum was compared. Time series data was generated using the calculated PSD, and the time and frequency domain fatigue life were predicted and compared. The variation of stress response spectrum due to static load and predicted fatigue life according to the different structural model considering mean stress were examined and decreasing fatigue life was observed in the model with prestress of compressive static load.