• 한국의류학회지
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• 제26권11호
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• pp.1672-1681
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• 2002

To evaluate the thermal environments and the workload of farmers in the rice field in summer, this study investigated rice farmers' physiological, psychological responses, work postures, work clothes, air temperature and air humidity during the spraying pesticide in the rice field. Five career farmers (3 males, 2 females) volunteered as the subjects. During the spraying pesticide in the rice field, physiological responses were monitored continuously. The results were as follows. l. Farmers wore only raincoats not pesticide-proof clothing. 2. The value of WBGT, rectal temperature($T_{re}$), mean skin temperature(${\={T}}_{sk}$) were $24.9∼28.9^{\circ}C,\;37.8({\pm}0.3)^{\circ}C\;and\;33.6({\pm}0.6)^{\circ}C$, respectively. Clothing microclimate temperature($T_{cl}$) on the chest and back were $32.5({\pm}2.6)^{\circ}C\;and\;33.6({\pm}2.6)^{\circ}C$, respectively(p<0.00l). Humidity inside of the clothing ($H_{cl}$) was over 80%RH and heart rate(HR) was 112(${\pm}27$)bpm. We evaluated that the spraying pesticide was 'heavy work' by the Tre and HR. To four subjective questionnaires, all farmers expressed 'hard, hot, humid and uncomfortable' without individual difference at the end of works. We suggested that 1) the spraying pesticide in the rice field was a heavy work, 2) because the workload of farmers in the raincoat/pesticide-proof clothing can't be evaluated by only WBGT, assessors should measure physiological, psychological responses as well as thermal environments, 3) to alleviate farmers' heat strain, clothing manufacturers must consider not only the improvement of textile materials and clothing weight but also the designing of personal cooling equipment.

• International Journal of Oral Biology
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• 제41권3호
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• pp.141-147
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• 2016

Reactive oxygen species (ROS) and nitrogen species (RNS) are both important signaling molecules involved in pain transmission in the dorsal horn of the spinal cord. Xanthine oxidase (XO) is a well-known enzyme for the generation of superoxide anions ($O_2^{\bullet-}$), while S-nitroso-N-acetyl-DL-penicillamine (SNAP) is a representative nitric oxide (NO) donor. In this study, we used patch clamp recording in spinal slices of rats to investigate the effects of $O_2^{\bullet-}$ and NO on the excitability of substantia gelatinosa (SG) neurons. We also used confocal scanning laser microscopy to measure XO- and SNAP-induced ROS and RNS production in live slices. We observed that the ROS level increased during the perfusion of xanthine and xanthine oxidase (X/XO) compound and SNAP after the loading of 2',7'-dichlorofluorescin diacetate ($H_2DCF-DA$), which is an indicator of intracellular ROS and RNS. Application of ROS donors such as X/XO, ${\beta}-nicotinamide$ adenine dinucleotide phosphate (NADPH), and 3-morpholinosydnomimine (SIN-1) induced a membrane depolarization and inward currents. SNAP, an RNS donor, also induced membrane depolarization and inward currents. X/XO-induced inward currents were significantly decreased by pretreatment with phenyl N-tert-butylnitrone (PBN; nonspecific ROS and RNS scavenger) and manganese(III) tetrakis(4-benzoic acid) porphyrin (MnTBAP; superoxide dismutase mimetics). Nitro-L-arginine methyl ester (NAME; NO scavenger) also slightly decreased X/XO-induced inward currents, suggesting that X/XO-induced responses can be involved in the generation of peroxynitrite ($ONOO^-$). Our data suggest that elevated ROS, especially $O_2^{\bullet-}$, NO and $ONOO^-$, in the spinal cord can increase the excitability of the SG neurons related to pain transmission.

• 전기전자학회논문지
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• 제27권1호
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• pp.122-126
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• 2023

본 논문에서는 복합 미생물 배양기의 제어시스템을 제안하였다. 제안하는 제어시스템은 복합 미생물 배양기의 제어부, 통신부, 전원부, 제어시스템 등으로 구성된다. 복합 미생물 배양기의 제어부는 아날로그 신호와 디지털 신호의 변환, LCD 패널을 이용한 디스플레이, 수위센서, 온도센서, pH 농도센서 등과 같은 센서들의 신호 제어를 하도록 설계 및 제작한다. 사용하는 수위센서는 기존 수위센서가 거품과 같은 이물질 등으로 인해 측정이 어려운 문제점을 해결하고자 직진성이 우수한 IR 레이저 방식을 사용하여 정확한 수위 측정이 가능하도록 설계 및 제작한다. 온도센서는 열 저항 원리를 사용하여 측정함으로써, 높은 정확도와 누적 저항 오차가 없도록 설계하여 사용한다. 통신부는 2개의 LAN 포트와 1개의 RS-232 포트로 구성하여 복합 미생물 배양기에서 사용되는 LCD 패널, PCT 패널, 로드셀 컨트롤러 등의 신호를 제어부에 전달할 수 있도록 설계 및 제작한다. 전원부는 제어부와 통신부가 원활하게 동작할 수 있도록 24V, 12V 5V 등 3개의 전압 공급 단자로 구성하여 전원을 공급하도록 설계 및 제작한다. 복합 미생물 배양기의 제어시스템은 PLC를 사용하여 pH 농도센서, 온도센서, 수위센서 등의 센서값과 배양에 사용되는 써큘레이션 펌프, 써큘레이션 밸브, 로터리 펌프와 인버터 로드셀 등의 동작을 제어한다. 제안된 복합 미생물 배양기의 제어시스템의 성능을 평가하기 위하여 공인인증기관에서 실험한 결과는 수위 측정감도의 범위가 -0.41mm~1.59mm로, 물 온도의 변화 폭이 ±0.41℃로 현재 상용으로 판매되는 제품들 성능보다 우수한 성능으로 동작됨이 확인되었다. 따라서, 본 논문에서 제안한 복합 미생물 배양기의 제어시스템의 효용성이 입증되었다.

• Restorative Dentistry and Endodontics
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• 제36권4호
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• pp.306-312
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• 2011

연구목적: 본 임상 연구의 목적은 15% 과산화수소를 함유한 전문가용 치아 미백제의 광활성화 여부에 따른 미백효과와 안전성에 관해 평가하는 것이다. 연구 재료 및 방법: 33명의 지원자를 광조사를 하는 실험군(n = 17)과 광조사를 하지 않는 대조군(n = 16)으로 무작위로 나누고 Zoom2 미백제(15% $H_2O_2$, Discus Dental)로 총 45분간 치료하였다. Vitapan Classical shade guide와 Shadepilot (DeguDent)을 이용해 스크리닝 검사 시, 미백직후, 미백 종료 1달 및 3달 후 색조측정을 시행하였다. 통계분석을 위해 t-test, repeated measure ANOVA 와 카이제곱 검정을 시행하였다. 결과: Zoom2 미백제는 미백 전후를 비교할 때 실험군과 대조군 모두에서 뚜렷한 색조 변화를 가져왔다. 하지만, 두 군 사이의 색조 변화량을 비교했을 때 통계학적으로 유의성 있는 차이는 관찰되지 않았다(p > 0.05). 또한 미백 종료 3달 후에도 치아의 색조 회귀는 관찰되지 않았다. 미백 후 일시적인 지각과민증은 전체 환자의 39.4%에서 보고되었지만, 두 군간의 차이는 보이지 않았다(p > 0.05). 결론: 광조사로 인해 부가적인 미백효과의 증가는 물론 어떠한 부작용 증가도 관찰되지 않았다.

• Radiation Oncology Journal
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• 제20권2호
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• pp.155-164
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• 2002

목적 : Ginkgo biloba extract (GBE)는 혈액순환개선효과가 있어 기존의 방사선민감제와 달리 혈류저항이 높은 악성종양에서 저산소세포 분획을 줄일 수 있으나 아직까지는 실제 임상에서 사용되는 저선량 분할 방사선조사시에도 GBE가 방사선조사 효과의 증대를 나타내는지 밝혀지지 않았다. 이에 본 연구에서는 저선량 분할 방사선조사시 GBE가 방사선조사효과증대를 나타내는지, 또한 정상조직과 악성종양의 혈류량 분포에 어떠한 영향을 미치는지 알아보고자 하였다. 대상 및 방법 : 통상적인 범위의 저산소세포 분획을 가진 C3H 마우스의 섬유육종(FSall)을 마우스 우측하지에 이식한 후 종양직경이 7 mm에 도달하였을 때 마우스 체중 kg당 100 mg의 GBE를 방사선조사 25시간 전과 매회 1시간 전에 복강내 투여 후 방사선을 조사하였다. 3 Gy 내지 12 Gy의 방사선을 일회 조사시 GBE투여군과 방사선단독조사군의 종양성장지연기간을 비교하여 GBE에 의한 방사선효과 증강율을 구하였다. 3 Gy씩 10회의 분할 방사선조사시 방사선 단독조사군의 방사선량-종양성장지연기간(tumor growth delay, TGD)의 관계식을 구하여 두 실험군의 선형회귀직선 기울기의 비율, 즉 GBE에 의한 방사선효과 증강율을 구하였다. 같은 종양을 이용하여 레이저 도플러 혈류측정기로 정상근육과 종양의 혈류량을 측정함으로써 저혈류 분포의 차이가 존재하는지 확인하였고, GBE 투여에 의한 혈류량분포의 변화 여부를 관찰하였다. 결과 : 3 Gy 내지 12 Gy의 방사선을 일회 조사시 GBE투여군의 종양성장지연기간이 방사선단독조사군에 비하여 의미있게 증가되었으며(p<0.05), GBE에 의한 방사선효과 증강율은 3일 종양성장지연 기준으로 1.16이었다. 3 Gy씩 10회의 분할 방사선조사시 방사선 단독조사군의 방사선량-종양성장지연기간(tumor growth delay, TGD)의 관계는 TGD $(days)=0.26{\times}D$ (Gy)+0.13, GBE 병용군의 경우 TGD $(days)=0.30{\times}D$ (Gy)+0.13이었고 두 실험군의 직선 기울기의 비율, 즉 GBE에 의한 방사선효과 증강율은 1.19 ($95\%$ 신뢰구간: $1.13\~1.27$)로 나타났다. 같은 종양을 이용하여 레이저 도플러 혈류측정기로 혈류량을 측정한 결과, 혈류량의 분포는 모두 Poisson 분포와 비슷한 양상을 보였다. 정상근육의 혈류량은 평균 10.15 mL/100 g/min, 종양의 혈류량은 평균 7.78 mL/100 g/min으로 종양의 평균 혈류량이 근육에 비하여 낮게 나타났고(p=0.001), 2 mL/100 g/min 이하의 저혈류 분포는 정상근육에 비하여 종양에서 높게 나타났다($0.5\%$ 대 $5.2\%$, p=0.005). 정상근육에서는 GBE 투여에 의하여 혈류량 분포에 큰 변화가 없었던 반면, 종양에서는 2 mL/100 g/min 이하의 저혈류량 분포가 감소하였고, 평균 혈류량은 $23.5\%$ 증가되었다(p=0.0004). 결론 : GBE는 방사선 일회 조사시 뿐만 아니라 분할조사시에도 방사선치료의 효과를 유의하게 증가시켰다. 또한 정상근육에 비하여 종양의 혈류량을 선택적으로 증가시킴이 확인되었다.

• 대한수의학회지
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• 제12권1호
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• pp.127-132
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• 1972

Experimental studies on the water content of muscles and the histological changes of muscles, digestive tract and kidney, influenced by forced oral administration of excessive tap water, were performed by using 10 Korean bulls. Experimental animals were divided into two groups, five heads for test group and five for control group. All of the bulls used in this experiment were weighing between 250 kg and 300 kg and 3 and 4 years of age. In each test animal, a total of 140 litters of tap water was passed in the forestomach by means of catheterization within 12 to 18 hours. And each of them was slaughtered immediately after the animals showing symptoms of respiratory distress. In control group, the animals were allowed to drink tap water normally. From test and control animals after slaughter, each 10 gm of M. biceps femoris, M. satorius, M. adductor, M. gluteous supercialis, M. iliocostalis lumborum, and M. transversus costarum were taken from definite parts in order to measure water content. In the histopathological studies tissues of rumen, reticulum, omasum, abomasum, duodenum, colon and kidney were taken as wall as the above mentioned muscles. The results obtained were as follows; 1. Increase of water content in the muscles of test group were 4.6% in M. satorius, 4.24% in M. transversus costarum, 4.14% in M. gluteous supercialis, 4.02% in M. adductor, 3.88% in M. biceps femoris, and 2.46% in M. iliocostalis lumborum respectively. The highest increase was found in M. satorius and the lowest in M. iliocostalis lumborum. 2. In test animal, average increasing value of water content in muscles was 3.9% and shown highly significant (p<0.01). 3. On the microscopical findings of carcass, marked watery edema was observed all of the subcutaneous tissues and intermuscular connective tissues. 4. Microscopically, the epimysium, perimysium and endomysium were widened, and the muscle fibers were lacerated. The cells of stratum lucidum in the epithelium of rumen and reticulum were shown marked vacuolization. In the kidney, dilatation of Bowman's spaces and proximal tubles was observed.

• Journal of Ecology and Environment
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• 제35권1호
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• pp.1-7
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• 2012

To calculate and predict soil carbon budget and cycle, it is important to understand the complex interrelationships involved in soil respiration rate (Rs). We attempted to reveal relationships between Rs and key environmental factors, such as soil temperature, using a laboratory incubation method. Soil samples were collected from mature deciduous (MD), mature coniferous (MC), immature deciduous (ID), and immature coniferous (IC) forests. Prior to measure, soils were pre-incubated for 3 days at $25^{\circ}C$ and 60% of maximum water holding capacity (WHC). Samples of gasses were collected with 0, 2, and 4 h interval after the beginning of the measurement at soil temperatures of 5, 15, 25, and $35^{\circ}C$ (at 60% WHC). Air samples were collected using a syringe attached to the cap of closed bottles that contained the soil samples. The $CO_2$ concentration of each gas sample was measured by gas chromatography. Rs was strongly correlated with soil temperature (r, 0.93 to 0.96; P < 0.001). For MD, MC, ID, and IC soils taken from 0-5 cm below the surface, exponential functions explained 90%, 82%, 92%, and 86% of the respective data plots. The temperature and Rs data for soil taken from 5-10 cm beneath the surface at MD, MC, ID, and IC sites also closely fit exponential functions, with 83%, 95%, 87%, and 89% of the data points, respectively, fitting an exponential curve. The soil organic content in mature forests was significantly higher than in soils from immature forests (P < 0.001 at 0-5 cm and P < 0.005 at 5-10 cm) and surface layer (P = 0.04 at 0-5 cm and P = 0.12). High soil organic matter content is clearly associated with high Rs, especially in the surface layer. We determined that the incubation method used in this study have the possibility for comprehending complex characteristic of Rs.

• Journal of Animal Science and Technology
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• 제58권8호
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• pp.31.1-31.8
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• 2016

Background: Plasma protein hydrolysates have been shown to possess antioxidant activity. However, no report has yet to examine the antioxidant effects of injection of plasma protein hydrolysates on meat quality. Therefore, in this study, the effects of injection of hydrolysis plasma protein solution on meat quality and storability were investigated in porcine M. longissimus lumborum. Methods: Twelve pigs were randomly selected at a commercial slaughter plant and harvested. Dissected loins were injected with one of five solutions: C- control (untreated), T1- 10 mM phosphate buffer solution (PBS), T2- 10 mM PBS with 0.01 % butylated hydroxytoluene, T3- 10 mM PBS with 5 % plasma proteins, and T4- 10 mM PBS with 5 % hydrolysis plasma proteins. Results: T3 and T4 induced greater reduction in protein content of the loin muscle than other treatments. T2 resulted in the lowest pH as well as highest cooking loss. After a storage period of 3-7 days, both lightness and redness of meat were unaffected by all injection treatments. However, yellowness was significantly elevated by treatment with T4 relative to the control. T4 also resulted in the lowest shear force (a measure of meat toughness), suggesting improvement of texture or tenderness. Further, T4 resulted in the most stable TBARS values during storage, indicating that this treatment might retard rancidity in meat. Conclusion: Injection of porcine M. longissimus lumborum with hydrolysis plasma protein solution could improve overall pork quality, including tenderness and storability.

• International Journal of Ocean System Engineering
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• 제2권1호
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• pp.50-56
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• 2012

This study investigates flow fields and energy dissipation due to regular wave interaction with a perforated vertical breakwater, through velocity data measurement in a two-dimensional wave tank. As the waves propagate through the perforated breakwater, the incoming wave energy is reflected back to the ocean, dissipated due to very turbulent flows near the perforations and inside the chamber, and transmitted through the perforations of the breakwater. This transmitted energy is further reduced due to the presence of the perforated back wall. Hence most of the energy is either reflected or dissipated in the vicinity of the structure, and only a small amount of the incoming wave energy is transmitted through the structure. In this study, particle image velocimetry (PIV) technique was employed to measure two-dimensional instantaneous velocity fields in the vicinity of the structure. Measured velocity data was treated statistically, and used to calculate mean flow fields, turbulence intensity and turbulent kinetic energy. For investigation of the flow pattern, time-averaged mean velocity fields were examined, and discussed using the cross-sections through slot and wall for comparison. Flow fields were obtained and compared for various cases with different regular wave conditions. In addition, turbulent kinetic energy was estimated as an approach to understand energy dissipation near the perforated breakwater. The turbulent kinetic energy was distributed against wave height and wave period to see the dependence on wave conditions.

• 한국약용작물학회지
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• 제28권6호
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• pp.463-470
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• 2020

Background: Evaluation of transpiration is required for agricultural and environmental management applications, as crop yields and plant growth are primarily water limited. This study aimed to determine the transpiration and carbon accumulation of Cnidium officinale. Methods and Results: The transpiration of C. officinale was evaluated using weighing lysimeter. The relationship between transpiration and factors such as solar radiation, air temperature, and leaf area was assessed. Transpiration increased as the leaf area increased with the growth stage. Furthermore, daily transpiration per unit leaf area was 0.69 ± 0.16 g·cm-2·day-1 and there were no significant differences in daily transpiration during the cultivation period. The maximum transpiration was 620.6 g m-2·h-1 and diurnal changes in transpiration were highly correlated with solar radiation although the maximum transpiration was observed at the air temperatures of 20℃ - 26℃. The ratio of carbon accumulation to transpiration was 0.12%. Conclusions: Our results indicated that the transpiration of C. officinale is primarily regulated by solar radiation energy on clear days and that 97% of the water is discharged through transpiration for heat dissipation. Therefore, weighing lysimeters can measure transpiration accurately and may be useful in interpreting plant growth.