• 대한수의학회지
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• 제45권1호
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• pp.131-137
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• 2005

To assess anesthetic depth using quantitative electroencephalography (q-EEG), we recorded processed EEG (raw EEG) till 100 minutes in beagle dogs anesthetized for 60 minutes with tiletamine/zolazepam (n=5, TZ group), xylazine/ketamine (n=5, XK group) and propofol (n=5, PI group) by intermittent bolus injection. Raw EEG was converted into 95% spectral edge frequency (SEF) and median frequency (MF) through fast fourier transformation (FFT) method. 95% SEF value of TZ group was significantly higher (p<0.05) than the XK group from 10 minutes to 100 minutes. 95% SEF value of PI group was significantly higher (p<0.05) than the XK group from 10 minutes to 40 minutes, and significantly low (p<0.05) than XK group at 90 and 100 minutes. MF was significantly higher (p<0.05) in TZ group from 60 minutes to 100 minutes. Based on these results, using dissociative agent with ${\alpha}_2$-adrenergic agent is more potent in CNS depressed than using dissociative agent alone, and low doses of propofol has a disinhibitory effect on CNS.

• 시큐리티연구
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• 제35호
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• pp.125-149
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• 2013

본 연구에서는 경호경비현장에서 이루어지고 있는 실제적인 경호경비원들의 경계근무와 CCTV 모니터링 요원들의 스트레스를 확인하고, 비교 평가하기 위해 심박동변이(heart rate variability)를 통하여 생체리듬의 변화를 관찰하였다. K대학교 경호학과 학생 9명을 대상으로 실제 근무와 유사한 환경에서 경계근무와 CCTV 모니터링근무를 150분간 실시하였다. 30분 간격으로 자율신경검사를 관찰한 결과 HRT는 모니터링 근무가 경계근무 보다 더 낮게 나타났으며, 안정시, 근무 30분과 60분보다 90분, 120분, 150분은 낮게 나타났다. SDNN은 모니터링 근무가 더 높게 나타났으며, 근무 30분과 60분 보다 근무 150분에서 더 낮게 나타났다. 자율신경검사에서는 TP는 근무형태에 따른 집단 간 차이는 나타나지 않았으며, 근무 30분 보다 근무 150분에 더 높은 시기적 차이를 보였다. 근무형태와 근무시간의 상호작용은 나타났다. LF는 근무 60분 보다 근무 150분에 높은 시기간의 차이를 보였다. HF는 모니터링 근무 집단에 높게 나타났으며, 근무 30분 보다 근무 120분과 150분에서 더 높게 나타났다. 근무형태와 근무시간의 상호작용도 나타났다. LF/HF ratio는 경계근무 집단이 더 높게 나타났으며, 시기 간에 차이와 함께 근무형태와 근무시간의 상호작용도 나타났다. 모니터링 근무가 경계근무보다 부교감신경활동이 더 활발함에 따라 더 낮은 심기능 활동을 보였다. 매일 반복되는 장기간의 모니터링 근무는 VDT증후군이나 신경피로에 노출될 가능성이 더 높은 것으로 나타났다.

• 한국환경생태학회지
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• 제38권2호
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• pp.217-226
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• 2024

본 연구는 공기 중 음이온이 미세먼지(PM10, PM2.5) 정화에 미치는 영향을 파악하고, 식물이 공기 중 음이온 발생과 미세먼지 정화에 미치는 영향을 평가하기 위하여 음이온 발생요인별 음이온 발생량을 측정하고, 각 요인별, 식물 용적별 미세먼지 저감 모형을 구축하여 비교하였다. 음이온 발생요인별 특성은 Type N.I(Negative ion generator; 204,133.33ea/cm³) > Type P₃₀(Plant Vol. 30%; 362.55ea/cm³) > Type C(Control; 46.22ea/cm³)의 순으로 음이온 발생량을 살펴보면 무처리구에 비하여 음이온 발생기 처리구에서 약 4,417배, 식물 배치구에서 약 8배 많았다. 이에 따른 음이온 발생원별 미세먼지 저감 특성은 PM10에서 Type NI가 Type C에 비하여 정화효율이 2.52배, Type P30이 1.46배 높았으며, PM2.5의 경우, Type NI가 Type C에 비하여 정화효율이 2.26배, Type P30이 1.31배 높은 것으로 분석되었다. 식물의 용적별 미세먼지 정화 효율은 Type P₂₀(84.60분) > Type P₃₀(106.50분) = Type P₂₅(115.50분) = Type P₁₅(117.60분) > Type P₅(125.25분) = Type P₁₀(129.75분)의 순이었으며, 초미세먼지의 경우 Type P₂₀ (104.00분) > Type P₃₀(133.20분) = Type P₂₅(144.00분) = Type P₁₅(147.60분) > Type P₅(161.25분) = Type P₁₀ (168.00분)의 순이었다. 이렇게 음이온의 미세먼지 정화 능력과 식물의 미세먼지 정화능력을 정량적으로 분석하였으며, 향후 미세먼지 정화를 고려한 녹지계획 및 식물식재에 고려해야할 사항을 제안하였다.

• 대한수의학회지
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• 제41권4호
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• pp.597-602
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• 2001

This study was carried out to investigate the effectiveness of active biotelemetry to monitor stress response, and the effects of acute stressor (raising a hind foot of a standing animal) on body temperature (BT) and heart rate (HR) in comparison heifer group (n=4) with cow group (n=3). Both parameters were recorded by active telemetry. Cortisol assay was used to compare the result of active biotelemetry. The stressor consisted in restraining the cows for hoof treatments. Body temperature and heart rate were measured at 0, 10, 20, 30, 40, 50, 60, 90, 120, 180 and 360 minutes during the experiments, and also cortisol assay at 0, 0.5, 1, 2, 3, 12 and 24 hours. Base line for these animals was set in there accustomed environment at -24hrs and -30 mins before the beginning of experiments. The results obtained in this study were as follows: 1. In the BT, heifer group showed no significant difference from cow group, but were observed slightly higher BT than cow group during restraint stress for 30 minutes. 2. The both groups showed directly significant increase of HR immediately after the beginning of the restraint stress (P<0.01), but in the required time for the recovery of HR after finishing the stress, heifer group was 40 minutes and cow group 60 minutes. 3. In the cortisol assay, the both groups increased from 30 to 120 minutes after the beginning of experiment (i.e, from 0 to 90 minutes after finishing the restraint stress), showing significant difference from before the beginning of the stress (P<0.01), but heifer group showed great increase of the cortisol level from 30 to 60 minutes after the beginning of the stress, while cow group was observed at 60 minutes. In conclusion, we suppose that care is required to decrease psychological stress in cattle when they suffer from a series of procedures for diagnosis and treatment, especially in heifers rather than in cows. Also BT and HR obtained by active biotelemetry are reliable indicators of stress in cattle.

• 한국자원식물학회지
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• 제36권6호
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• pp.562-570
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• 2023

The droplet-vitrification technique for cryopreservation has proven successful across a diverse range of germplasm, ensuring safe and effective long term preservation. In this study, we investigate an effective cryopreservation protocol using the droplet-vitrification technique for shoot tips of Freesia hybrida cultivars 'Sunny Gold' and 'Sweet Lemon'. To determine optimal conditions for Freesia cryopreservation, we employed a carefully selected standard procedure along with additional treatments and alternative solutions. For 'Sunny Gold', the highest regrowth rate of 24% was achieved when shoot tips underwent dehydration with PVS3 solution for 120 minutes before direct immersion in liquid nitrogen (LN) for 1 hour, coupled with a standard protocol involving a two-step preculture with 0.3 M - 0.5 M sucrose, loading with C4 for 40 minutes, and unloading with 0.8 M sucrose for 40 minutes. In the case of 'Sweet Lemon,' regrowth of cryopreserved shoot tips was observed with dehydration treatments, including PVS2 (A3) for 60 minutes and PVS3 (B1) for 60 minutes, as well as longer exposure. The results reflect the distinct sensitivity of shoot tips to chemical toxicity and osmotic stress in these two genotypes. This study provides valuable evidence to consistently enhance the effectiveness of cryopreservation methods for the long-term conservation of Freesia germplasm.

• Safety and Health at Work
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• 제10권4호
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• pp.470-475
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• 2019

Background: There is a lack of statistical analysis investigating the relationship between sleep problems and commute time in Korea. We aimed to analyze the association between representative health symptoms, sleep disturbances, and commute time according to working hours in Korea. Methods: The 4th Korean Working Conditions Survey data were used for analysis, and unpaid family workers and workers who work fewer than three days in a week were excluded. Commute time, working hours, and sleep hours were assessed using self-reported questionnaires. Odds ratios (ORs) with 95% confidence intervals (CIs) for sleep problems were calculated using a multivariate logistic regression model with ≤10 min commute time as the reference group. Results: Among a total of 28,804 workers (men = 14,945, women = 13,859), 2.6% of men and 3.2% of women experienced sleep problems. In both sexes, long commute time (51-60 minutes and >60 minutes) showed an increased OR [men, 2.03 (CI = 1.32-3.13) and 2.05 (CI = 1.33-3.17); women, 1.58 (CI = 1.05-2.39) and 1.63 (CI = 1.06-2.50), respectively]. In stratification analysis of working hours, long commute time (51-60 and > 60 minutes) showed an increased OR in men working >40 hours/week [2.08 (CI = 1.16-3.71) and 1.92 (CI = 1.08-3.41), respectively]. Furthermore, long commute time (41-50, 51-60, and >60 minutes) showed an increased OR in women working >40 hours/week [2.40 (CI = 1.27-4.55), 2.28 (CI = 1.25-4.16), and 2.19 (CI = 1.17-4.16), respectively]. Moreover, commute time >60 minutes showed an increased OR in women working ≤40 hours/week [1.96 (CI = 1.06-3.62)]. Conclusion: This large cross-sectional study highlights that long commute time is related to sleep problems in both sexes. Shorter commute times and decreased working hours are needed to prevent sleep problems in workers.

• Journal of the Korean Wood Science and Technology
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• 제37권1호
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• pp.56-64
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• 2009

본 연구의 목적은 콩기름을 오존 산화 처리하여 기능기를 도입하고 이를 바탕으로 친환경 목재 접착제를 개발하는 것이다. 시판용 콩기름을 시간당 약 7.13 g의 오존을 발생시켜 15분, 30분, 60분, 120분간 오존산화 처리한 후 FT-IR, $^1H$-NMR, MALDI-TOF MS, GC/MS 측정하여 구조변화를 분석하였다. 기기분석 결과 오존산화처리에 의하여 콩기름의 불포화 이중결합이 개열되어 카르복실기 또는 알데하이드기가 생성됨을 확인하였다. 오존산화콩기름 변성 pMDI 접착제의 접착력은 오존처리 정도와 pMDI의 혼합비율에 따라 달라지며, KS F 3101 보통합판기준 내수 접착강도를 안정적으로 만족 시키는 조건은 오존산화 처리시간 30분~60분, pMDI와 1:1로 혼합한 경우이며, 준내수 접착강도를 만족시키는 범위는 오존산화 처리시간 30분~60분, pMDI의 혼합비 0.5이상, 상태접착강도를 만족시키는 범위는 오존산화 처리시간 15분~60분, pMDI의 혼합비 0.25 이상임을 알 수 있었다. 위의 실험결과를 종합하여 볼 때, 오존산화 처리한 식용유는 오존처리시간 및 pMDI의 혼합비율을 조절하면 상태접착력 뿐만 아니라 내수접착력이 요구되는 목질복합재료 제조용 접착제 제조가 가능함을 확인할 수 있었다.

• Safety and Health at Work
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• 제7권1호
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• pp.32-37
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• 2016

Background: Previous research has shown that paramedics are exposed to risks in the form of injuries to the musculoskeletal system. In addition, there are studies showing that they are also at increased risk of cardiovascular disease, cancer, and psychiatric diseases, which can partly be explained by their constant exposure to stress. The aim of this study is to evaluate whether the use of shoulder straps decreases physical effort in the form of decreased heart rate and cortisol concentration. Methods: A stretcher with a dummy was carried by 20 participants for 400 m on two occasions, one with and one without the shoulder straps. Heart rate was monitored continuously and cortisol samples were taken at intervals of 0 minutes, 15 minutes, 30 minutes, 45 minutes, and 60 minutes. Each participant was her or his own control. Results: A significant decrease in heart rate and cortisol concentration was seen when shoulder straps were used. The median values for men (with shoulder straps) at 0 minutes was 78 bpm/21.1 nmol/L (heart rate/cortisol concentration), at 15 minutes was 85 bpm/16.9 nmol/L, and at 60 minutes was 76 bpm/15.7 nmol/L; for men without shoulder straps, these values were 78 bpm/21.9 nmol/L, 93 bpm/21.9 nmol/L, and 73 bpm/20.5 nmol/L. For women, the values were 85 bpm/23.3 nmol/L, 92 bpm/20.8 nmol/L, and 70 bpm/18.4 nmol/L and 84 bpm/32.4 nmol/L, 100 bpm/32.5 nmol/L, and 75 bpm/25.2 nmol/L, respectively. Conclusion: The use of shoulder straps decreases measurable physical stress and should therefore be implemented when heavy equipment or a stretcher needs to be carried. An easy way to ensure that staff use these or similar lifting aids is to provide them with personalized, well-adapted shoulder straps. Another better option would be to routinely sewn these straps into the staff's personal alarm jackets so they are always in place and ready to be used.

• Journal of Chest Surgery
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• 제18권4호
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• pp.759-770
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• 1985

This study was experimentally undertaken to evaluate the effect of hypothermic oxygenated cardioplegic solution on myocardial protection during prolonged aortic cross clamping under cardiopulmonary bypass. Dogs were divided into two groups control group [received hypothermic unoxygenated cardioplegic solution] and experimental group [received hypothermic oxygenated cardioplegic solution]. Coronary sinus effluent was obtained at once and 30, 60, 90 minutes after cross-clamping for the determination of pH, PCO2,PO2 and lactate level during the infusion of cardioplegic solution and myocardial biopsies were obtained after cessation of 90 minutes of aortic cross-clamping. The results obtained were as follows: 1. There was no significant differences in the pH and PCO2 between the oxygenated and unoxygenated cardioplegic solution but the PO2 of the oxygenated solution was 4 times greater than unoxygenated solution, and also the oxygenated solution had a significantly greater oxygen content [2.020.05 ml 02/min] and had much more oxygen delivery than unoxygenated solution. 2. The myocardial oxygen consumption and the myocardial oxygen extraction in oxygenated group were 1.63 ml 02/100 ml and 67.32% respectively, which was greater than those in unoxygenated group. 3. Regarding to pH and PCO2 of coronary sinus effluent, there was no significant differences between two groups in early period of infusion of cardioplegic solution, but the pH shifted to acidosis from 60 minutes, PCO2 increased from 90 minutes of aortic cross-clamping, and PO2 markedly decreased from 90 minutes of aortic cross-clamping in unoxygenated group. 4. The lactate concentration of coronary sinus effluent revealed relatively normal in both groups, but showed slight increase up to 27.54.56 mg/100 ml at 90 minutes of aortic cross-clamping in unoxygenated group. 5. On electron microscopic study, the ultrastructural integrity of myocardial cells in oxygenated group was well preserved within 90 minutes. Slight swelling and deformity of mitochondria, interfibrillar widening, and disarrangement of myofibrils were observed at 90 minutes after aortic cross-clamping in unoxygenated group. From these results, the use of hypothermic oxygenated cardioplegic solution seemed to be effective and better method for the preservation of ischemic myocardium during the prolonged aortic cross-clamping.

• 한국임상수의학회지
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• 제13권2호
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• pp.177-183
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• 1996

This study was performed to investigate the effects of xylazine on the motility of abomasum and proximal colon in cattle. Bipolar electrodes were implanted in the subserosa of the abomasum and colon. Electromyogram of the motility was recorded by polygraph after intramuscular administration of xylazine at the doses of 0.1 and 0.2 mg/kg. The mtility of abomasum was completely inhibited at 5~11 minutes after xylazine administration. However, that of the abomasum was reappeared at 15 minutes and greatly increased to supranormal motility at 41~51 minutes, then recovered to normal activity at 70~123 minutes. Meanwhile, the motility of proximal colon was completely inhibited at 3~10 minutes and reappeared at 60~150 minutes after xylazine administration, then recovered gradually to normal pattern at 240 minutes. Our data indicate that xylazine (0.1~0.2 mg/kg) affect on the abomasal motility in a biphasic manner, initial inhibition and following activation, but on the colon motility in a monophasic inhibition.