• Journal of the Microelectronics and Packaging Society
• /
• v.10 no.4
• /
• pp.61-64
• /
• 2003

The fractography was used to observe the stress profile on a single ion-exchanged glass. In the processing, the temperature was varied during the ion exchange, and then the stress profile on the single ion-exchanged glass was shifted from glass surface to slightly below the glass surface. The hackle mark and mirror surface were varied according to process conditions, and the glass strength was increased with increasing the number of hackle markers. In case of breaking the stress profile by using indenter, the breaking property was similar to the annealed glass.

• The korean journal of orthodontics
• /
• v.24 no.1 s.44
• /
• pp.105-114
• /
• 1994

The movement of teeth during orthodontic treatment requires bone remodeling process of bone formation and bone resolution. To find out the changes occuring in the cell itself, mechanical stress was applied to the cell populations involved in the bone metabolism. Bone tissue cell populations were isolated from fetal rat calvaria and divided into OC and OB groups. Following results were obtained from measuring the changes in acid & alkaline phosphatease activity, cyclic AMP and $PGE_2$ production in time lapse after the application of mechanical stress. 1. In case of the marker enzyme of specific bone tissue cell, acid phosphatase activity was high in OC group and alkaline phosphatase activity was high in OB group. 2. After the mechanical stress was applied, acid phosphatase activity was decreased in both OC and OB groups and alkaline phosphatase activity was increase in OB group. 3. When the mechanical stress was applied for 15, 30 and 60 minutes, the production of $PGE_2$ increased in both OC and OB groups, as the time span increased. 4. When the mechanical stress was applied for 20 and 40 minutes, the production of $PGE_2$ increased in both OC and OB groups, as the time span increased.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.21 no.2
• /
• pp.523-527
• /
• 2007

Previous studies reported that exposure to noise during pregnancy adversely influenced the development of the fetus and neonate. In Oriental medicine, medications based on Angelicae gigantis radix have been known to be of efficacy in the treatment of various diseases. c-Fos, an immediate early gene whose expression is sometimes used as a marker for stimulus-induced changes in the metabolic activity of neurons. In the present study, the influence of postnatal Angelicae gigantis radix administration on c-Fos expression in the each region of hippocampus of offspring rats with prenatal noise stress during pregnancy was investigated. From the present results, exposure to the prenatal stress during pregnancy enhanced c-Fox expression, whereas exposure to postnatal Angelice gigantis radix suppressed c-Fos expression in the offsprings with prenatal noise stress during pregnancy. Based on the present study, Angelicae gigantis radix may provide new therapeutic opportunities as an agent to counteract the effects of prenatal noise stress- induced hippocampal dysfunction, and may be useful in the treatment of psychiatric problems in children of mothers who have experienced noise stress during pregnancy.

• Journal of Oral Medicine and Pain
• /
• v.45 no.4
• /
• pp.89-96
• /
• 2020

Purpose: To investigate the expression of malondialdehyde (MDA), lipid peroxidation marker for oxidative stress (OS), in autoimmune Sjögren's syndrome (SjS) by utilizing the SjS-prone C57BL/6.NOD-Aec1Aec2 (B6DC) mouse and the SjS patient plasma samples. Methods: The MDA concentrations in the lysates of the submandibular gland, liver, and serum samples from the SjS-prone B6DC mouse model were compared with those from the C57BL/6J as a control. A thiobarbituric acid reactive substance (TBARS) assay kit was used to measure MDA. Plasma samples from five SjS patients and five control subjects were also evaluated. Results: The MDA concentrations in experimental animals and controls were not significantly different. There were no significant differences between the plasma of SjS patients and of controls. Conclusions: The expression of MDA was investigated in the organs from the SjS-prone B6DC mouse for the first time and in the plasma samples of SjS patients. No significant differences were observed between SjS and control samples when MDA was the target molecule with the TBARS assay. MDA may not be a reliable marker to measure OS contrary to the published studies involving OS of SjS.

• Annals of Occupational and Environmental Medicine
• /
• v.34
• /
• pp.34.1-34.13
• /
• 2022

Background: This study aimed to investigate the association between lead exposure and serum gamma-glutamyl transpeptidase (γGT) levels as an oxidative stress marker in male steelworkers. Methods: Data were collected during the annual health examination of workers in 2020. A total of 1,654 steelworkers were selected, and the variables for adjustment included the workers' general characteristics, lifestyle, and occupational characteristics. The association between the blood lead level (BLL) and serum γGT level was investigated by multiple linear and logistic regression analyses. The BLL and serum γGT values that were transformed into natural logarithms were used in multiple linear regression analysis, and the tertile of BLL was used in logistic regression analysis. Results: The geometric mean of the participants' BLLs and serum γGT level was 1.36 ㎍/dL and 27.72 IU/L, respectively. Their BLLs differed depending on age, body mass index (BMI), smoking status, drinking status, shift work, and working period, while their serum γGT levels differed depending on age, BMI, smoking status, drinking status, physical activity, and working period. In multiple linear regression analysis, the difference in models 1, 2, and 3 was significant, obtaining 0.326, 0.176, and 0.172 (all: p < 0.001), respectively. In the multiple linear regression analysis stratified according to drinking status, BMI, and age, BLLs were positively associated with serum γGT levels. Regarding the logistic regression analysis, the odds ratio of the third BLL tertile in models 1, 2, and 3 (for having an elevated serum γGT level within the first tertile reference) was 2.74, 1.83, and 1.81, respectively. Conclusions: BLL was positively associated with serum γGT levels in male steelworkers even at low lead concentrations (< 5 ㎍/dL).

• YAKHAK HOEJI
• /
• v.53 no.4
• /
• pp.189-193
• /
• 2009

To investigate the antioxidant effect of lutein on N-nitrosodimethylamine (NDEA)-induced oxidative stress in mice, we measured lipid peroxidation, superoxide dismutase (SOD) and catalase of various tissues. Body weight was almost similar in lutein and control groups during 3 weeks. NDEA increased significantly the activities of typical marker enzymes of liver function (AST, ALT and ALP) in both groups. However, the increase of plasma aminotransferase activity significantly decreased in lutein group. Lipid peroxidation and SOD in various tissues, such as heart, lung, liver, kidney, spleen and plasma were significantly increased by NDEA, which were significantly reduced by lutein at a dose of 50 mg/kg. Catalase activity decreased significantly in control and lutein groups treated with NDEA, the effect being less in lutein group. Lesser effect on SOD and catalase in NDEA-treated lutein group indicates the improvement of protective mechanisms by lutein. Thus, it can be concluded from the present study that lutein can offer a useful protection against NDEA-induced oxidative stress.

• Herbal Formula Science
• /
• v.32 no.3
• /
• pp.263-275
• /
• 2024

Background : Recent studies have shown that stress fundamentally influences the functional modulation of organ and stress-related disease causes high morbidity and mortality rates. Objective : The present research investigated the effect of restraint stress on psychological and physiological responses. Results : Body weight and food intake were changed in stress group. Body weight has continuously decreased, and food intake has been slightly altered. As a result of measuring each tissue's weight, the liver and kidney's weight loss was greater than that of other organs. The lipid profile of stressed animals showed significant increases in cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) levels compared to control. As hepatic marker enzymes, serum glutamic pyruvic transaminase (GPT; alanine aminotransferase), glutamic oxalacetic transaminase (GOT; aspartate aminotransferase), and lactic dehydrogenase (LDH) were increased in the stress group. However, levels of serum cortisol and corticosterone did not affect. Results of the behavioral tests show that the stress group has increased activity, sluggish movements, and anxiety in the central part compared with the control group through the open field test. In the forced swim test, the stress group models had a longer duration of slowing movement, and its rate also increased. Also, in immunoblotting, stress increased the inflammatory factors Inducible Nitric Oxide Synthase (iNOS), cyclooxygenase-2 (COX-2) and activated the mitogen-activated protein kinase (MAPK) pathway. Conclusions : We observed that mouse model were affected behavioral response and liver injury when exposed to restraint stress, indicating the importance of the restraint stress in the development of psychological and physiological processes.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.17
• /
• pp.7105-7112
• /
• 2014

In this study, we investigated oxidative stress and tumor marker levels of polycyclic aromatic hydrocarbons (PAHs) in 136 coke oven workers and in 60 control subjects, and evaluated the correlation between oxidative stress and tumor marker levels. Questionnaires on basic demographic information were also administered. Significant differences in employment time and percentages of alcohol drinkers were observed between the control and exposed groups. PAH exposure was assessed using urinary 1-hydroxy-pyrene (1-OHP) levels and was found to be significantly higher in workers than in the controls. Significant differences (P<0.001) of MDA, GST, LDH, NSE, Cyfra21-1, and of SCC and TNF-a (P<0.0001 and P<0.05, P<0.001, respectively) levels were observed among controls and coke-oven workers, except for bottom coke oven workers. Associations between age and risk of increased TNF-a, smoking and increased GST activities, and drinking with increased MDA concentrations, were marginal (P=0.055, P=0.048, P=0.057, respectively). The association between smoking with MDA (P=0.004), NSE (P=0.005), SCC (P=0.004) andTNF-a (P<0.001), and drinking with TNF-a levels was significant (P=0.012). In addition, a significant positive correlation between oxidative stress and tumor markers was found in the present study. These results suggest that a synergistic increase of oxidative stress and tumor markers induced by PAHs may play a role in toxic responses for PAHs in coke oven workers.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.60 no.4
• /
• pp.401-411
• /
• 2015

Drought stress has detrimental effects on the seedling development, vegetative/ reproductive growth, photosynthesis, root proliferation, anthesis, anthesis-silking interval (ASI), pollination and grain yield in maize. Typically, two weeks before silking through pollination are an important time in maize life. Here we reviewed the effects of drought stress on growth, physiological/ molecular researches for drought tolerance, and breeding to genomics in maize. Drought stress during kernel development increases leaf dying and lodging, decreases grain filling period and grain yield. Physiological factors of drought stress/ effects are water content, water deficits, and water potential. Nowdays molecular marker assisted breeding method is becoming increasingly useful in the improvement of new germplasm with drought stress tolerance.

• Molecules and Cells
• /
• v.39 no.3
• /
• pp.250-257
• /
• 2016

Abiotic stresses such as drought and low temperature critically restrict plant growth, reproduction, and productivity. Higher plants have developed various defense strategies against these unfavorable conditions. CaPUB1 (Capsicum annuum Putative U-box protein 1) is a hot pepper U-box E3 Ub ligase. Transgenic Arabidopsis plants that constitutively expressed CaPUB1 exhibited drought-sensitive phenotypes, suggesting that it functions as a negative regulator of the drought stress response. In this study, CaPUB1 was over-expressed in rice (Oryza sativa L.), and the phenotypic properties of transgenic rice plants were examined in terms of their drought and cold stress tolerance. Ubi:CaPUB1 T3 transgenic rice plants displayed phenotypes hypersensitive to dehydration, suggesting that its role in the negative regulation of drought stress response is conserved in dicot Arabidopsis and monocot rice plants. In contrast, Ubi:CaPUB1 progeny exhibited phenotypes markedly tolerant to prolonged low temperature ($4^{\circ}C$) treatment, compared to those of wild-type plants, as determined by survival rates, electrolyte leakage, and total chlorophyll content. Cold stress-induced marker genes, including DREB1A, DREB1B, DREB1C, and Cytochrome P450, were more up-regulated by cold treatment in Ubi:CaPUB1 plants than in wild-type plants. These results suggest that CaPUB1 serves as both a negative regulator of the drought stress response and a positive regulator of the cold stress response in transgenic rice plants. This raises the possibility that CaPUB1 participates in the cross-talk between drought and low-temperature signaling pathways.