• Title/Summary/Keyword: Physiological conditions

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Two Types of Vanadate-sensitive Microsomal ATPases in Tracheal Epithelial Cells

  • Jung Sakong;Kim, Young-Kee
    • Proceedings of the Korean Biophysical Society Conference
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    • 1997.07a
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    • pp.22-22
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    • 1997
  • The physiological activity of tracheal epithelial cells is closely related with the ionic conditions of cytosol, specially the concentration of cytosolic Ca$\^$2+/. We have prepared microsomes in these cells and the molecular mechanisms of ionic regulations were investigated.(omitted)

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Effect of Driver's Cognitive Distraction on Driver's Physiological State and Driving Performance

  • Kim, Jun-Hoe;Lee, Woon-Sung
    • Journal of the Ergonomics Society of Korea
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    • v.31 no.2
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    • pp.371-377
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    • 2012
  • Objective: The aim of this study is to investigate effect of driver's cognitive distraction on driver's physiological state and driving performance, and then to determine parameters appropriate for detecting the cognitive distraction. Background: Driver distraction is a major cause of traffic accidents and poses a serious threat to traffic safety due to ever increasing use of in-vehicle information systems and mobile phones during driving. Cognitive distraction, among four different types of distractions, prevents a driver from processing traffic information correctly and adapting to change in surround vehicle behavior in time. However, the cognitive distraction is more difficult to detect because it normally does not involve significant change in driver behavior. Method: A full-scale driving simulator was used to create virtual driving environment and situations. Participants in the experiment drove the driving simulator in three different conditions: attentive driving with no secondary task, driving and conducting secondary task of adding numbers, and driving and conducting secondary task of conversing with an experimenter. Parameters related with driver's physiological state and driving performance were measured and analyzed for their change. Results: The experiment results show that driver's cognitive distraction, induced by secondary task of addition and conversation during driving, increased driver's cognitive workload, and indeed brought change in driver's physiological state and degraded driving performance. Conclusion: The galvanic skin response, pupil size, steering reversal rate, and driver reaction time are shown to be statistically significant for detecting cognitive distraction. The appropriate combination of these parameters will be used to detect the cognitive distraction and estimate risk of traffic accidents in real-time for a driver distraction warning system.

Secretory Expression, Functional Characterization, and Molecular Genetic Analysis of Novel Halo-Solvent-Tolerant Protease from Bacillus gibsonii

  • Deng, Aihua;Zhang, Guoqiang;Shi, Nana;Wu, Jie;Lu, Fuping;Wen, Tingyi
    • Journal of Microbiology and Biotechnology
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    • v.24 no.2
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    • pp.197-208
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    • 2014
  • A novel protease gene from Bacillus gibsonii, aprBG, was cloned, expressed in B. subtilis, and characterized. High-level expression of aprBG was achieved in the recombinant strain when a junction was present between the promoter and the target gene. The purified recombinant enzyme exhibited similar N-terminal sequences and catalytic properties to the native enzyme, including high affinity and hydrolytic efficiency toward various substrates and a superior performance when exposed to various metal ions, surfactants, oxidants, and commercial detergents. AprBG was remarkably stable in 50% organic solvents and retained 100% activity and stability in 0-4 M NaCl, which is better than the characteristics of previously reported proteases. AprBG was most closely related to the high-alkaline proteases of the subtilisin family with a 57-68% identity. The secretion and maturation mechanism of AprBG was dependent on the enzyme activity, as analyzed by site-directed mutagenesis. Thus, when taken together, the results revealed that the halo-solvent-tolerant protease AprBG displays significant activity and stability under various extreme conditions, indicating its potential for use in many biotechnology applications.

Physiological Response of parrot fish (Oplegnathus fasciantus) and bivalve (Gomphina melanaegis) by Lowing Water Temperature Exposure (저수온 노출에 따른 돌돔(Oplegnathus fasciantus)과 민들조개(Gomphina melanaegis)의 생리활성 변화 연구)

  • YOON, Sung Jin;CHIN, Byung Sun;PARK, Gyung Soo
    • Journal of Fisheries and Marine Sciences Education
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    • v.28 no.1
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    • pp.1-13
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    • 2016
  • Physiological response of fish and bivalve was estimated to identify the physiological changes of test species by lowering water temperature due to the abrupt stop of cooling water discharge from power plant. The experiment was conducted by two conditions; fall and winter by decreasing water temperature ($2^{\circ}C$/2 days) from $26^{\circ}C$ to $17^{\circ}C$ for fall scenario and from $15^{\circ}C$ to $9^{\circ}C$ for winter scenario, respectively. Test organisms were parrot fish (Oplegnathus fasciantus) and bivalve (Gomphina melanaegis), and end points were mortality for both species, hematocrit and cortisol for fish, and hemolymph and superoxide dismutase(SOD) for bivalve. 48/96hr mortality test revealed no mortality for fish and 47% mortality for bivalve at 96hr/$26^{\circ}C$ only. Significant increases of hematocrit and cortisol were found at fishes exposed to $26^{\circ}C$ (high temperature) and lower temperature ($9{\sim}13^{\circ}C$), respectively. Hemolymph and SOD for bivalve tended to decrease by lowering water temperature from 15 to $9^{\circ}C$ (winter scenario) and no changes from 26 to $17^{\circ}C$ (fall scenario). Fall scenario (from 15 to $9^{\circ}C$) showed more significant changes of physiological response than winter cases (26 to $17^{\circ}C$).

Comparison of the Impact of an Optimized Ice Cooling Vest and a Paraffin Cooling Vest on Physiological and Perceptual Strain

  • zare, Mansoor;dehghan, Habibollah;yazdanirad, Saeid;khoshakhlagh, Amir hossein
    • Safety and Health at Work
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    • v.10 no.2
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    • pp.219-223
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    • 2019
  • Background: Ice cooling vests can cause tissue damage and have no flexibility. Therefore, these two undesirable properties of ice cooling vest were optimized, and the present study was aimed to compare the impact of the optimized ice cooling vest and a commercial paraffin cooling vest on physiological and perceptual strain under controlled conditions. Methods: For optimizing, hydrogel was used to increase the flexibility and a layer of the ethylene vinyl acetate foam was placed into the inside layer of packs to prevent tissue damage. Then, 15 men with an optimized ice cooling vest, with a commercial paraffin cooling vest, and without a cooling vest performed tests including exercise on a treadmill (speed of 2.8 km/hr and slope of %0) under hot ($40^{\circ}C$) and dry (40 %) condition for 60 min. The physiological strain index and skin temperature were measured every 5 and 15 minutes, respectively. The heat strain score index and perceptual strain index were also assessed every 15 minutes. Results: The mean values of the physiological and perceptual indices differed significantly between exercise with and without cooling vests (P < 0.05). However, the difference of the mean values of the indices except the value of the skin temperature during the exercises with the commercial paraffin cooling vest and the optimized ice cooling vest was not significant (P > 0.05). Conclusions: The optimized ice cooling vest was as effective as the commercial paraffin cooling vest to control the thermal strain. However, ice has a greater latent heat and less production cost.

Screening Methods for Anti-senescence Activity in Dermal Fibroblasts under Pyruvate-deprivation Conditions

  • Kil, In Sup;Shim, Jinsup;Cho, Gayoung;Choi, Sowoong;Son, Eui Dong;Kim, Hyoung-June
    • Korea Journal of Cosmetic Science
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    • v.1 no.1
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    • pp.1-9
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    • 2019
  • The identification of compounds with anti-senescence activity in cell culture system is a first step in aging research. Given that pyruvate can be used energy source by conversion to acetyl-CoA in mitochondria, and protects cultured cell from various stress-induced cell damage and cell death, synthetic media (e.g., DMEM) often includes 1 mM pyruvate, which is very higher than the pyruvate concentration in human blood (approximately 30 ��M). However, the use of medium containing high concentration of pyruvate is not suitable for screening anti-senescence compounds, because pyruvate also protects against the cellular senescence of primary human dermal fibroblasts (NHDFs) through NAD+ generated during conversion to lactate. In this study, four extracts, i.e., Sprouted seed and fruit complex, Poncirus trifoliata fruit extract, Jaum balancing complex, and Prunus mume extract were used for evaluation of different anti-senescence effect in the absence or presence of 0.1 mM pyruvate, similar to the physiological pyruvate concentration. The senescence in NHDFs cultured with DMEM in the presence of 0.1 mM pyruvate (approximately the physiological concentration in human blood) is accelerated, as observed in pyruvate deprivation conditions. The cytotoxicity of the Poncirus trifoliata fruit extract was protected by pyruvate, and Jaum balancing complex and Prunus mume extract had anti-senescence activity in the presence of 0.1 mM pyruvate, but not in the absence of pyruvate. Given that pyruvate is a powerful protector against both cytotoxicity and cellular senescence, the screening of candidate agents for anti-senescence in high pyruvate conditions using an in vitro cell culture system is not valid. Therefore, we recommend the use of a low concentration of pyruvate to evaluate the anti-senescence effects of candidates, which is more similar to in vivo aging conditions than excessive stress-induced senescence models, to exclude the effect of excessive pyruvate in vitro.

Effects of Design and Material Change of Firefighter Station Uniform on Thermal Physiological and Subjective Responses (소방 기동복의 디자인과 소재 변화가 착용자의 온열생리 반응 및 주관적 감각에 미치는 영향)

  • Kim, Hee-Eun;Kim, Seong-Suk;Son, Su-Young
    • Journal of the Korean Society of Clothing and Textiles
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    • v.44 no.4
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    • pp.776-787
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    • 2020
  • This study investigated physiological and subjective responses to different types of firefighter station uniforms made with various designs and materials. Six healthy males participated in this study that consisted of 20 min of rest, 30 min of treadmill exercise, and 30 min of recovery in a hot and humid environment (34℃ and 65%RH). The experimental clothing conditions were as follows. 1) a fitted T-shirt and trouser made of 100% polyester (FC-Uniform), and 2) flame retardant T-shirts made of acrylic and cotton as well as trousers with aramid and polyester, designed for overfitting (Control). There were no significant differences in the body temperature, and sweat rate between the two conditions; however, the heart rate with the FC-Uniform was significantly lower than Control (p=.025). The clothing microclimate temperature at the chest of the FC-Uniform was significantly lower than the Control (p=.037), and a difference of 1℃ was maintained until the recovery was complete. There were no significant differences in the subjective responses; however, participants experienced a humidity sensation faster with FC-Uniform in the recovery phase. The results indicate that changes in the design and material of firefighter station uniforms may have a positive influence on reducing the thermal stress of firefighters.