• Journal of Nutrition and Health
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• 제49권5호
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• pp.367-377
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• 2016

본 연구는 산업체근로자들의 직무스트레스와 카페인 섭취량을 알아보고, 직무스트레스에 따른 카페인 섭취량과의 관련성에 대해 살펴보고자 실시하였다. 연구 대상자의 직무스트레스 총합은 100점 환산 기준으로 $72.7{\pm}6.8$점으로 나타났으며, 연구 대상자들의 직무스트레스 정도에 따라 스트레스를 가장 적게 받는 그룹은 Q1, 스트레스를 적게 받는 그룹은 Q2, 스트레스를 많이 받는 그룹은 Q3, 스트레스를 가장 많이 받는 그룹은 Q4로 구분 하였다. 이들이 느끼는 스트레스는 조직적 관리체계에 대한 스트레스가 $21.9{\pm}3.3$점으로 직무요구도 $19.9{\pm}5.1$점, 보상 부적절 $16.1{\pm}2.5$점, 직무자율성 결여 $14.7{\pm}2.1$점에 비해 가장 높았다. 카페인에 대한 인지도 조사결과 카페인이 건강에 미칠 영향에 대해 스트레스가 가장 높은 군 (Q4)에서 '적당히 마시면 도움이 되고 해롭지 않다' 57.1%, '적게 마실수록 좋다'고 응답한 사람들이 17.3%로 스트레스가 많을수록 카페인은 적당히 섭취하면 도움이 되고 해롭지 않으나 적게 마실수록 좋다고 하였다. 스트레스 정도에 따른 카페인 섭취량을 보면 커피믹스 (1봉 47.51 mg)는 Q3에서 $86.1{\pm}56.4mg$ (p < 0.01), 자판기 커피 (1잔 47.51 mg)는 Q2에서 $62.3{\pm}60.9mg$ (p < 0.05), 커피전문점 커피 (1잔 158.43 mg)는 Q4에서 $40.7{\pm}88.7mg$ (p < 0.001), 녹차 (1티백: 28 mg)는 Q4에서 $18.4{\pm}32.4mg$ (p < 0.01)으로 가장 높게 나타났다. 이에 따른 카페인 일일섭취량은 Q1에서 $172.0{\pm}85.3mg$, Q2에서 $179.0{\pm}83.7mg$, Q3에서 $187.9{\pm}81.4mg$, Q4에서 $214.2{\pm}147.3mg$ 으로 Q4그룹이 유의하게 높았다 (p < 0.05). 본 연구 결과 카페인 최대 일일 섭취권고량 대비 실제 카페인 섭취량 비율은 Q1에서 $43.0{\pm}21.3%$, Q2에서 $44.8{\pm}20.9%$, Q3에서 $47.1{\pm}20.4%$, Q4에서 $53.6{\pm}36.8%$로 일일섭취량과 같이 Q4그룹이 유의하게 높았다 (p < 0.05). 카페인 섭취에 따른 부작용으로는 속이 메슥거리거나 구토와 같은 부작용이 Q4에서 $2.7{\pm}0.8$로 유의하게 높았다 (p < 0.05). 대상자들의 카페인 섭취량은 직무스트레스는 유의한 양의 상관관계를 (r = 0.137, p = 0.009), 평균 근무시간과도 유의한 양의 상관성을 보였으며 (r = 0.122 p = 0.001), 수면시간 역시 유의한 양의 상관성을 보였다 (r = 0.169, p = 0.001). 반면 카페인 섭취량과 근무기간은 유의한 음의 상관관계를 나타냈다 (r = -0.114. p = 0.031). 본 연구의 결과, K 제조공장 근로자들은 스트레스 정도가 높아질수록 섭취하는 카페인 섭취량이 많았고, 스트레스를 많이 받는 군에서는 최대 일일 섭취권고량 대비 실제 카페인 섭취량 비율이 50% 정도로 나타나 한국 20세 성인남자보다 2배 이상 섭취하는 것으로 조사되었다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.285-291
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• 2003

An experimental method to measure Q-parameter in-situ is described. The basic idea comes from the fact that the side necking near a crack tip indicates the loss of stress triaxiality, which can be scaled by Q. From the out-of-plane displacement and the in-plane strain near the surface of side necking, stress field averaged through the thickness is calculated and then Q is determined from the difference between the stress field and the HRR field corresponding to the identical J-integral. To prove the validity, three-dimensional finite element analysis has been performed for a CT configuration with side-groove. Q-value which was calculated directly from the near-tip stress field is compared with that determined by simulating the experimental procedure according to the proposed method, that is, the Q-value determined from the lateral displacement and the inplane strain. Also, the effect of location where the displacement and strain are measured is explored.

• Child Health Nursing Research
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• 제5권1호
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• pp.5-17
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• 1999

This study was designed to determine the schemata and their characteristics of stress experience the subjectivity of stress experience(structure of subjectivity) would be a basic step for the effective clinical education through the stress management for characteristics of these types. Q-methodological method was used for that purpose. The research method statements were collected prior to the study through indepth interviews. For the study, 31 Q-statements were selected. There were 34 nursing students as subjects for the research. The 34 nursing students sorted the 31 statements using the principal of forced normal distribution. The principle of forced normal distribution, which has 9 scales to measure the individual opinions, was called. Q-factor analysis by using PC QUANL program supply the material. According to the outcomes of this study, there were 3 types of special opinion about the stress experience of clinical practice. The first type is called 'Influence of practical atmosphere type'. Members of this type experienced stress by an inadequate orientation and undesirable role model of nursing. The second type is called 'conflict of nursing role type'. Members of this type experienced stress by an inadequate orientation and undesirable role model of nursing. The third type is called 'Lack of confidence type'. Members of this type experienced stress because of a lack of confidence for their own nursing knowledge and skill. As a result, we now need further study to identify individual psychological aspects of stress for clinical practice. The findings will guide the development in effective approaches for clinical education. Finally, the result of the study will provide us the need for developing systematic and integrated practice education program for students and active involvement of clinical instructor.

• The Korean Journal of Ecology
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• 제17권3호
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• pp.241-249
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• 1994

참나무속 식물 6종류의 잎의 확산저항, 기공밀도, 공변세포의 길이 및 털의 밀도를 측정하여 건조스트레스에 대한 이 식물들의 전략을 주성분분석법으로 분석하였다. 상수리나무, 갈참나무 및 졸참나무의 잎의 확산저항은 다른 3종보다 높은 Ψleaf 또는 낮은 WSD에서 빠르게 상승함으로써 수분 스트레스를 회피하였다. 그러나, 신갈나무와 떡갈나무는 낮은 Ψleaf, 낮은 기공밀도, 작은 기공 크기 및 높은 털밀도로 수분스트레스를 회피하였다. 그러나 신갈나무와 떡갈나무는 낮은 Ψleaf에서 기공 확산저항의 상승을 보였다. 건조스트레스에 대한 조정능과 관련된 15변수의 주성분분석에서 참나무속 식물은 2그룹, 즉 건성생육지종인 굴참나무, 신갈나무 및 떡갈나무와 중성생육지종인 상수리 나무, 갈참나무 및 졸참나무로 구별되었고, 건성생육지종인 굴참나무는 높은 털밀도, 낮은 기공밀도 및 높은 LAR에서 신갈나무 및 떡갈나무와 다시 구별되었다. 이 결과는 자연생육지에서 참나무속 식물의 건조에 대한 전략을 잘 설명하고 있다.

• 대한기계학회논문집A
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• 제27권9호
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• pp.1607-1613
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• 2003

An experimental method to measure Q-parameter in-situ is described. The basic idea comes from the fact that the side necking near a crack tip indicates the loss of stress triaxiality, which can be scaled by Q. From the out-of-plane displacement and the in-plane strain near the surface of side necking, stress field averaged through the thickness is calculated and then Q is determined from the difference between the stress field and the HRR field corresponding to the identical J-integral. To prove the validity, three-dimensional finite element analysis has been performed for a CT configuration with side-groove. Q-value which was calculated directly from the near-tip stress field is compared with that determined by simulating the experimental procedure according to the proposed method, that is, the Q-value determined from the lateral displacement and the in-plane strain. In addition, the effect of location where the displacement and strain are measured is explored.

• The Korean Journal of Physiology and Pharmacology
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• 제13권4호
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• pp.321-326
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• 2009

The antioxidant effect of $CoQ_{10}$ on N-nitrosodiethylamine (NDEA)-induced oxidative stress was investigated in mice. Food intake and body weight were similar in both $CoQ_{10}$ and control groups during the 3-week experimental period. NDEA significantly increased the activities of typical marker enzymes of liver function (AST, ALT and ALP) both in control and $CoQ_{10}$ groups. However, the increase of plasma aminotransferase activity was significantly reduced in the $CoQ_{10}$ group. Lipid peroxidation in various tissues, such as heart, lung, liver, kidney, spleen and plasma, was significantly increased by NDEA, but this increase was significantly reduced by 100 mg/kg of $CoQ_{10}$. Superoxide dismutase activity increased significantly upon NDEA-induced oxidative stress in both the control and $CoQ_{10}$ groups with the effect being less in the $CoQ_{10}$ group. Catalase activity decreased significantly in both the control and $CoQ_{10}$ groups treated with NDEA, again with the effect being less in the $CoQ_{10}$ group. The lesser effect on superoxide dismutase and catalase in the NDEA-treated $CoQ_{10}$ group is indicative of the protective effect $CoQ_{10}$. Thus, $CoQ_{10}$ can offer useful protection against NDEA-induced oxidative stress.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.331-340
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• 2009

This study evaluates the relationship between cone tip resistance ($q_c$) and small-strain shear modulus ($G_{max}$) of cemented sand. For this purpose, a series of miniature cone penetration and bender element tests are performed in calibration chamber specimens with various gypsum contents. Experimental results show that both $q_c$ and $G_{max}$ of sand increase with increasing cementation level as well as relative density and vertical confining stress. However, the relative density and vertical confining stress has more significant influence on $G_{max}$ and $q_c$ of uncemented sand than those of cemented sand. It is observed that the $G_{max}/q_c$ ratio of cemented sand decreases with increasing relative density. This result means that state variables have more affect on $q_c$ than $G_{max}$ of cemented sand. Test results also show that the effect of vertical stress on $G_{max}-q_c$ relation is reduced by cementation effect.

• 한국작물학회지
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• 제66권1호
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• pp.8-17
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• 2021

자포니카 벼의 저온 스트레스 내성 증진을 위하여, RIL 계통을 이용하여 저온 스트레스 내성 QTL을 탐색하였다. 이를 통하여 (1) 5, 9번 염색체에서 저온발아에 관련한 '기호벼' 유래 QTL, qLTG5와 qLTG9를 확인하였으며, 7, 9번 염색체에서 저온 발아속도에 관련한 '밀양23호' 및 '기호벼' 유래 QTL, qOGCV7, qOGCV9를 확인하였다. (2) Duncan 검정결과, 그룹VII [qLTG5+qLTG9 (qOGCV9)], 그룹VIII [qLTG5+qOGCV7+qLTG9 (qOGCV9)]의 계통들이 저온 스트레스에 내성이 있는 것으로 확인 되었다. (3) 최근 발표된 RIL 집단 담수내성 계통과 비교한 결과, 저온 스트레스에도 내성이 있으면서 담수발아에도 내성이 있는 것으로 확인된 총 2개의 유망 유전자원을 선발하였다. 본 연구의 결과를 통해 저온 및 혐기 관련 QTL의 집적은 벼의 저온에서의 발아 및 초기 입모율을 높여 저온스트레스 내성 개선에 도움이 되는 것으로 판단 되었으며, 선발된 유망 계통은 향후 직파재배 품종 육성에 유용한 유전자원으로 활용되어 직파재배의 안정성 증대에 기여할 것으로 기대된다.

• 한국치위생학회지
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• 제10권4호
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• pp.595-605
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• 2010

Objectives : A precedent research has documented that occupational stress is closely associated with increased the risk of fatigue and decreased in job satisfaction. This study was conducted in an effort to assess the relationship of occupational stress to self-perceived fatigue and job satisfaction by using job strain model. Methods : The number of respondents was 122 dental hygienist who work in dental clinic and period of the investigation was July 2009 through september 2009. A structured questionnaire was employed to evaluate the participants' sociodemographics, job-related factors, health-related behaviors, occupational stress, job satisfaction and self-perceived fatigue. Occupational stress and self-perceived fatigue were assessed using the Korean Occupational Stress Scale-Short form (KOSS-SF) and the Multidimensional Fatigue Scale (MFS), respectively. Results : In job strain model, the ratio of Q2(High Strain Job) group that more susceptible to disease by stress than other group was 16% and the proportion of high fatigue group(Q3, Q4 group) and low job satisfaction group(Q3, Q4 group) was 48%, 45% respectively. In logistic regression analyses, a High Strain Job group was associated with higher odds of react factor(fatigue, job satisfaction) and the odds was down by 3.3%~7.5% after adjustment for age, smoking, alcohol drinking, regular exercise. So the effective strategy for fatigue, job satisfaction reduction for dental hygienist requires additional program focusing on innovated work environment that provide a enough leisure time and exercise program considering the personality traits. Conclusions : The results of this study suggest that occupational stress is a determinant predictor of self perceived fatigue and job satisfaction. Thus, a stress management program for the reduction of occupational stress, and the promotion of dental hygienist impact assessment health and quality of life is strongly recommended.

• Clinical and Experimental Reproductive Medicine
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• 제48권2호
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• pp.150-155
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• 2021

Objective: Oxidative stress (OS) plays a key role in the etiology of unexplained male infertility. Coenzyme Q10 (CoQ10) is a potent antioxidant that may improve semen quality and OS in infertile men with idiopathic oligoasthenoteratospermia (OAT), but the underlying mechanism is unknown. Therefore, the present study was undertaken to investigate the effect of CoQ10 on OS markers and sperm DNA damage in infertile patients with idiopathic OAT. Methods: This prospective controlled study included 50 patients with idiopathic OAT and 50 fertile men who served as controls. All patients underwent a comprehensive medical assessment. Patients and controls received 200 mg of oral CoQ10 once daily for 3 months. Semen and blood were collected and analyzed for sperm parameters, seminal CoQ10 levels, reactive oxygen species (ROS) levels, total antioxidant capacity, catalase, sperm DNA fragmentation (SDF), and serum hormonal profile. Results: The administration of CoQ10 to patients with idiopathic OAT significantly improved sperm quality and seminal antioxidant status and significantly reduced total ROS and SDF levels compared to pretreatment values. Conclusion: CoQ10, at a dose of 200 mg/day for 3 months, may be a potential therapy for infertile patients with idiopathic OAT, as it improved sperm parameters and reduced OS and SDF in these patients.