• 여성건강간호학회지
• /
• 제12권4호
• /
• pp.273-281
• /
• 2006

Purpose: The purpose of this study was to provide basic data for nursing programs to reduce fatigue among middle-aged adults by looking at age group differences. Method: The study used a secondary analysis design and participants were 315 middle-aged adults. The data was analyzed using $x^2$-test, ANOVA, Pearson's correlation coefficient analysis, and stepwise multiple regression. Results: The findings revealed significant age group differences in socio-demographic variables for educational level, job, religion, economic status, consumption of cigarettes, experience with disease, satisfaction with spouse and children, and number of children. Scores of fatigue showed a significant difference between age groups. The factors influencing fatigue for subjects in their thirties were depression, level of education and self-efficacy. For those in their forties, factors were stress, depression, and self-efficacy. For those in their fifties, the factor was stress. Conclusion: For people in their thirties, school education or lifelong learning programs are needed to reduce fatigue. A disease prevention program and a family support program for people in their forties and fifties. Nurses need to provide customized nursing programs related to depression, stress and self-efficacy to reduce fatigue among middle-aged adults based on age groups.

• Journal of Ginseng Research
• /
• 제45권2호
• /
• pp.218-227
• /
• 2021

Background: Panax ginseng is one of the most important medicinal plants and is usually harvested after 5 to 6 years of cultivation in Korea. Heavy metal (HM) exposure is a type of abiotic stress that can induce oxidative stress and decrease the quality of the ginseng crop. Siderophore-producing rhizobacteria (SPR) may be capable of bioremediating HM contamination. Methods: Several isolates from ginseng rhizosphere were evaluated by in vitro screening of their plant growth-promoting traits and HM resistance. Subsequently, in planta (pot tests) and in vitro (medium tests) were designed to investigate the SPR ability to reduce oxidative stress and enhance HM resistance in P. ginseng inoculated with the SPR candidate. Results: In vitro tests revealed that the siderophore-producing Mesorhizobium panacihumi DCY119^T had higher HM resistance than the other tested isolates and was selected as the SPR candidate. In the planta experiments, 2-year-old ginseng seedlings exposed to 25 mL (500 mM) Fe solution had lower biomass and higher reactive oxygen species level than control seedlings. In contrast, seedlings treated with 10⁸ CFU/mL DCY119^T for 10 minutes had higher biomass and higher levels of antioxidant genes and nonenzymatic antioxidant chemicals than untreated seedlings. When Fe concentration in the medium was increased, DCY119^T can produce siderophores and scavenge reactive oxygen species to reduce Fe toxicity in addition to providing indole-3-acetic acid to promote seedling growth, thereby conferring inoculated ginseng with HM resistance. Conclusions: It was confirmed that SPR DCY119^T can potentially be used for bioremediation of HM contamination.

• Asian-Australasian Journal of Animal Sciences
• /
• 제31권2호
• /
• pp.263-269
• /
• 2018

Objective: Heat stress (HS) triggers oxidative stress and respiratory alkalosis in pigs. The objective of this experiment was to study whether a short-term supranutritional amount of dietary vitamin E (VE) can mitigate oxidative stress and respiratory alkalosis in heat-stressed pigs. Methods: A total of 24 pigs were given either a control diet (17 IU/kg VE) or a high VE (200 IU/kg VE; HiVE) diet for 14 d, then exposed to thermoneutral (TN; $20^{\circ}C$, 45% humidity) or HS ($35^{\circ}C$, 35% to 45% humidity, 8 h daily) conditions for 7 d. Respiration rate and rectal temperature were measured three times daily during the thermal exposure. Blood gas variables and oxidative stress markers were studied in blood samples collected on d 7. Results: Although HiVE diet did not affect the elevated rectal temperature or respiration rate observed during HS, it alleviated (all p<0.05 for diet${\times}$temperature) the loss of blood $CO_2$ partial pressure and bicarbonate, as well as the increase in blood pH in the heat-stressed pigs. The HS reduced (p = 0.003) plasma biological antioxidant potential (BAP) and tended to increase (p = 0.067) advanced oxidized protein products (AOPP) in the heat-stressed pigs, suggesting HS triggers oxidative stress. The HiVE diet did not affect plasma BAP or AOPP. Only under TN conditions the HiVE diet reduced the plasma reactive oxygen metabolites (p<0.05 for diet${\times}$temperature). Conclusion: A short-term supplementation with 200 IU/kg VE partially alleviated respiratory alkalosis but did not reduce oxidative stress in heat-stressed pigs.

• Archives of Pharmacal Research
• /
• 제19권5호
• /
• pp.374-380
• /
• 1996

Sprague-Dawley male rats (150 g) were chronically treated with 5 v/v % ethanol admixed with nutritionally complete liquid diet and fed ad libitum for 3 weeks. One half of each group was exposed to cold stress at 4 ^{\circ}C either for 24 h (for determination of mRNA by in situ hybridization) or for 48 h (for determination of enzyme activity). Chronic ethanol treatment (ethanol) did not affect tyrosine hydroxylase(TH) mRNA level in locus coeruleus(LC) of brain and adrenal medulla(AM) compared to controls. Cold stress showed strong increase of TH mRNA level in LC and AM compared to controls. Pretreated ethanol reduced the increased TH mRNA level by cold stress in LC and AM. Ethanol did not affect TH activity in LC and adenal glands(adrenals). Cold stress increased TH activity in LC but not in adrenals. Pretreated ethanol did not reduce the increased TH activity by cold stress in LC but this result was not shown in adrenals. Phenylethanolamine-N-methyltransferase(PNMT) activity in $C_{1}$$C_{2}$ and adrenals increased only in ethanol treated group. THese results suggest that ethanol does not affect TH mRNA level and activity in LC and adrenals, but increases PNMT activity in $C_{1}$$C_{2}$ and adrenals in normal rat. It is also suggested that pretreated ethanol reduces the magnitude of cold stress response, that is induction of TH mRNA in LC and AM, and does not reduce the protein activation of TH that is also cold stress response in LC.

• 한국직업건강간호학회지
• /
• 제23권1호
• /
• pp.20-27
• /
• 2014

Purpose: This study was conducted to identify the association between emotional labor and job stress in bus drivers, as well as to propose management strategies for job stress. Methods: The study was conducted in February 2013 and involved 182 bus drivers working in the Gyeonggi area. Results: emotional labor was $9.5{\pm}2.34$ on average, and job stress was higher than the median of the same indicator among Korea's workers in the areas of physical environment, job autonomy, and relationship conflicts. Factors that affected job stress was lower if the subjects' Higher values for emotional labor indicated a higher level of job stress. Conclusion: To reduce among drivers, the following measures are necessary: increase the comfort of the driver's seat within the vehicle, provide adequate rest between bus headways, provide comfortable in-house rest facilities, and establish physical training spaces to reduce musculoskeletal disorders as well as programs for reducing back pain. In addition, relationship conflicts may be relieved by increasing job autonomy as much as possible, by granting autonomous control of working hours and bus headways, as well as by banning long work hours. Moreover, various club activities, exercise programs, and counseling programs that workers can be involved in together may be beneficial. This study is significant in that it identified the relationship of the bus drivers' emotional labor and job stress, which has previously been ignored as a research topic. Through its results, this study provides baseline data for the preparation of management strategies that can address the job stress of bus drivers.

• 지역사회간호학회지
• /
• 제33권3호
• /
• pp.279-289
• /
• 2022

Purpose: This is a descriptive correlation study to confirm the effect of stress and anxiety caused by COVID-19 on the quality of life of small business owners in an area under environment of COVID-19. Methods: The participants were 150 small business owners in an area. The collected data were analyzed by descriptive statistics, an independent t-test, a one-way ANOVA, Pearson's correlation coefficients, and multiple regression with the SPSS 25.0 Program. Results: The stress of small business owners averaged 3.67±0.65 out of 4 points, anxiety of COVID-19 was 2.65±0.52, and quality of life was 75.61±20.26 out of 130 points. The quality of life showed a significant negative correlation with 'fear of infection' (r=-.42, p<.001), 'difficulties caused by social distancing' (r=-.49, p<.001) in the stress subdomain, and anxiety (r=-.61, p<.001). On the other hand, stress, 'fear of infection' (r=.50, p<.001), 'difficulties caused by social distancing' (r=.60 p<.001), 'anger against others' (r=.35, p<.001) and anxiety showed positive correlation. Factors affecting the quality of life of the subjects were 'fear of infection' in the stress subdomain (β=-.23, p=.003), anxiety (β=-.45, p<.001), and residential area (J zone) (β=-.16, p=.030). These factors explained 47.0% of the variance. Conclusion: In order to enhance the quality of life of small business owners in an area, it is required to reduce stress and anxiety. In addition, it is necessary to prepare an intervention program that can reduce stress and anxiety of small business owners.

• 전력전자학회논문지
• /
• 제24권6호
• /
• pp.406-410
• /
• 2019

Three-level (3L) DC-DC converters are appropriate for high-input-voltage applications. Although the voltage stress of TL converter switches can be reduced to half of the input voltage, the primary side has a large circulating current, which degrades efficiency. In this study, a dual half-bridge cascaded TL converter is presented to reduce this circulating current and thus decrease the conduction loss of the primary circuit. Moreover, the proposed converter can reduce the voltage stress of rectifier diodes, thereby reducing their conduction loss. Therefore, efficiency can be improved by reducing the conduction loss of the primary circuit and rectifier diodes.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2000년도 춘계학술대회논문집B
• /
• pp.531-534
• /
• 2000

The objective of this investigation is to find effects of the pulsatile flow on the morphological changes of the endothelial cell(E.C.) in blood vessel. The shear flow experiment system is used to get the morphological changes of the E.C. The shapes of E.C. are simulated by the cosine curves and computer simulation is used to calculate the pressure and shear stress fields on the E.C. The inlet boundary condition is given from the measured velocity data of femoral artery. The endothelial cells reduce their heights in the flow field so as to reduce the pressure and wall shear stress on the surface. As the exposed time increases, the shear stress and pressure on the E.C. are reduced under the pulsatile flow. The shear stresses on the cell surface show the minimum values during the deceleration phase.

• Journal of Electrical Engineering and Technology
• /
• 제9권5호
• /
• pp.1632-1642
• /
• 2014

This paper presents an interleaved resonant converter to reduce the voltage stress of power MOSFETs and achieve high circuit efficiency. Two half-bridge converters are connected in series at high voltage side to limit MOSFETs at $V_{in}/2$ voltage stress. Flying capacitor is used between two series half-bridge converters to balance two input capacitor voltages in each switching cycle. Variable switching frequency scheme is used to control the output voltage. The resonant circuit is operated at the inductive load. Thus, the input current of the resonant circuit is lagging to the fundamental input voltage. Power MOSFETs can be turn on under zero voltage switching. Two resonant circuits are connected in parallel to reduce the current stress of transformer windings and rectifier diodes at low voltage side. Interleaved pulse-width modulation is adopted to decrease the output ripple current. Finally, experiments are presented to demonstrate the performance of the proposed converter.

• 한국간호교육학회지
• /
• 제3권
• /
• pp.7-25
• /
• 1997

Using the self-evaluation test proposed by D. Girdano, et al., the psycological, and biological causes and personality factors of the stress of the nursing students of K university in local county are measured and analyzed. As fundamental data to overcome these kinds of stress, the overall stress profiles are proposed. The results of this study are ; 1) The freshman group is very susceptible to the stress due to the behavior type and anxiety-reactive personality. 2) The sophomore group is very susceptible to the stress due to frustration, the behavior type and anxiety-reactive personality. 3) Two groups are not susceptible to the stress due to diet and noise. Since the stress is the multi-dimensional phenomena, it is necessary to reduce these stress that the life style of each Individual students be changed and the curriculm and the teaching methodology in nursing school be developed.