• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2019.08a
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• pp.281-282
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• 2019

• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.283-287
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• 2004

Persimmons suffer from such physiological disorders as flesh softening, peel blackening, and flesh browning, which occur rapidly particularly when exposed to ambient temperature after storage at low temperature, In this study causes of these disorders were examined in terms of respiration and ethylene production of the fruits. Jelly-like flesh softening, considered as symptom of chilling injury, rapidly developed within 3 days of exposure to ambient temperature without modified atmosphere (MA) packaging after low temperature storage. Disorder development was more suppressed at $30^{\circ}C$ than at $20^{\circ}C$; such temperature dependence is closely connected to ethylene production rate of fruits at both temperatures. Inhibition of ethylene production through MA packaging effectively reduced disorder development, which indicates ethylene production is closely related to jelly-like flesh softening disorder. Development of black-staining on peels occurs in fruits exposed directly to ambient temperature, but not in those packaged with thick PE-film. Flesh browning developed only under anaerobic respiration condition of high temperature and MA packaging with thick PE film, and occurred at quick reduction of available oxygen inside MA package at high temperature.

• Horticultural Science & Technology
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• v.31 no.5
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• pp.538-543
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• 2013

During summer in Korea, the excessively high temperature causes growth retardation and quality reduction in cut roses grown in greenhouse. Mist treatments were conducted to reduce the temperature and avoid quality reduction of cut roses. The temperature change in the greenhouse, growth and quality of cut roses, and injuries caused by insects or fungi were investigated during mist treatment. Daily maximum temperature reduced as the number of mist treatment increased, resulting in $6^{\circ}C$ reduction by mist treatment for 10 seconds at 5 min interval. This temperature reduction occurred only when maximum temperature was over $40^{\circ}C$ in greenhouse, and not when it was less than $40^{\circ}C$ or rainy and/or cloudy day. Plant height and fresh weight of the cut roses were increased at the range of 10-20% by mist treatment. As frequency of mist treatment increased, however, malformed flowers increased and vase life of cut rose was largely shortened. The injuries by insects like as beet armyworm larvae and scale insect increased as well. In conclusion, it is recommended that mist treatment must be used when the daily maximum temperature in a green house is over $40^{\circ}C$ and forecasting for disease or insects should be conducted as well.

• Korean Journal of Weed Science
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• v.32 no.1
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• pp.35-43
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• 2012

The objective of this research was to confirm the difference in physiological responses to environmental stresses such as chilling, high temperature, NaCl, and chemical stress (paraquat) in Protox inhibitor resistant-transgenic rice (MX, PX, and AP37) and its non-transgenic counterpart (WT). Transgenic and non-transgenic rice plants were exposed to a chilling temperature of $5^{\circ}C$ for 1 day or a high temperature of $45^{\circ}C$ for 4 days and allowed to recover at $25^{\circ}C$ for 6 days after the chilling treatment or 8 days after the high temperature treatment. Leaf injury, shoot fresh weight, porphyrin biosynthesis substances, and chlorophyll content were investigated in transgenic and non-transgenic rice at 6 days after 0.5% and 1% NaCl treatments or at 5 days after 0~300 ${\mu}M$ paraquat treatments. No significant difference in leaf injury and shoot fresh weight were observed between transgenic and non-transgenic rice during chilling and recovery. Plant height and shoot fresh weight were also similar between transgenic and non-transgenic rice during the high temperature and recovery period (0~5 days). However, plant height and shoot fresh weight in transgenic rice line MX and PX were lower than in non-transgenic rice at 6 days for recovery. Leaf injury, chlorophyll, and Mg-Proto IX ME contents had no significant difference between transgenic rice and non-transgenic rice after NaCl treatment, but Proto IX content for AP37 and shoot fresh weight for PX and AP37 in 0.5% NaCl treatment were significantly reduced compared with non-transgenic rice. There was no difference in leaf injury and shoot fresh weight when comparing transgenic rice and non-transgenic rice after paraquat treatment. Although transgenic rice and non-transgenic rice showed a little difference at a particular measurement period in certain environmental stresses, there was generally no difference in physiological responses between transgenic rice and non-transgenic rice.

• Restorative Dentistry and Endodontics
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• v.44 no.1
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• pp.3.1-3.10
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• 2019

Objectives: It was the aim of this study to evaluate the effect of cooling water temperature on the temperature changes in the pulp chamber and at the handpiece head during high-speed tooth preparation using an electric handpiece. Materials and Methods: Twenty-eight intact human molars received a standardized occlusal preparation for 60 seconds using a diamond bur in an electric handpiece, and one of four treatments were applied that varied in the temperature of cooling water applied (control, with no cooling water, $10^{\circ}C$, $23^{\circ}C$, and $35^{\circ}C$). The temperature changes in the pulp chamber and at the handpiece head were recorded using K-type thermocouples connected to a digital thermometer. Results: The average temperature changes within the pulp chamber and at the handpiece head during preparation increased substantially when no cooling water was applied ($6.8^{\circ}C$ and $11.0^{\circ}C$, respectively), but decreased significantly when cooling water was added. The most substantial drop in temperature occurred with $10^{\circ}C$ water ($-16.3^{\circ}C$ and $-10.2^{\circ}C$), but reductions were also seen at $23^{\circ}C$ ($-8.6^{\circ}C$ and $-4.9^{\circ}C$). With $35^{\circ}C$ cooling water, temperatures increased slightly, but still remained lower than the no cooling water group ($1.6^{\circ}C$ and $6.7^{\circ}C$). Conclusions: The temperature changes in the pulp chamber and at the handpiece head were above harmful thresholds when tooth preparation was performed without cooling water. However, cooling water of all temperatures prevented harmful critical temperature changes even though water at $35^{\circ}C$ raised temperatures slightly above baseline.

• Journal of Korean Neurosurgical Society
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• v.29 no.9
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• pp.1161-1170
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• 2000

Objective : The transverse hippocampal slice is one of the most commonly studied in vitro models of mammalian brain physiology. However, despite its broad usage, there has been no standardization of slice preparation techniques or recording condition. It is well known that variations in recording conditions can result in profound different effects to neuronal responses. Evoked field potentials, recorded extracellularly, were used to investigate the effects of variations in hippocampal slice preparation protocol on hypoxia responses of CA1 neurones. Material & Methods : Before hypoxic injury, hippocampal slices were incubated for 4 hours. During incubation period, the slices were placed in a incubation chamber($21^{\circ}C$) for recovery from preparation injury and then transferred to recording chamber($34^{\circ}C$) for more recovery and baseline electric recording with current stimulation(0.1Hz). Various time periods in incubation chamber and recording chamber were applied to each experimental group(group 1=60min : 180min, group 2=90min : 150min, group 3=180min : 60min, time in incubation chamber : time in recording chamber) before 10 min hypoxia produced by replacing 95% $O_2$+5% $CO_2$ mixed gas to 95% $N_2$+5% $CO_2$ gas. Calcium, Magnesium ions and several drugs effecting on glutamate receptor also were studied. Recoveries from hypoxic injury of hippocampal slices were estimated by percent recovery of population spike(PS). Statistic analysis of study were performed using paired t-test. Results : The percent recovery of PS after 10min hypoxia was considerably enhanced by increasing the period of current stimulation during incubation period before hypoxic injury. Temperature effect on the result of this experiment was also studied(group 4) but the result from this showed no statistic significance. Low magnesium ion concentration of artificial CSF(Mg-free aCSF) during incubation period enhanced the recovery of PS but low calcium (calcium-free) and high magnesium ion concentration(2mM) reduced it after hypoxic injury. L-glutamate($100{\mu}M$) and AP-5($50{\mu}M$) had no effect on the recovery of PS but CNQX($10{\mu}M$) in artificial CSF during incubation period markedly enhanced the recovery of PS. Co-treatment of AP-5($50{\mu}M$), CNQX($10{\mu}M$) and high magnesium concentration(2mM) enhanced recovery of PS in immediate following period of hypoxic injury but the effect of cotreatment after then decayed rapidly and lost statistic significance. Conclusions : Judging from above results, the condition of baseline recording is important in observing the recovery of population spike after hypoxia, and the time and the condition should be controled more strictly to obtain reliable results.

• Journal of Korean Neurosurgical Society
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• v.38 no.3
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• pp.215-220
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• 2005

Objective : Many researchers believe that the hypothermia shows neuro-protective effect on brain injury. To understand the molecular mechanism of the hypothermic treatment, this study investigated its effects on the expression of cell death or survival related proteins such as p53, Bcl-2 and Bax in the rat traumatic brain injury[TBI] model. Methods : Twenty rats [Spraque Dawley, $200{\sim}250g$] were subjected to the brain injury of moderate severity [$2.4{\sim}2.6atm$] using the fluid percussion injury device and five rats were received only same surgery as controls. During 30minutes after the brain injury, the hypothermia group was maintained the body temperature around $34^{\circ}C$ while the control group were maintained that of $36^{\circ}C$. Five rats in each group were sacrificed 12h or 24h after brain injury and their brain sections was analyzed for physical damages by H-E stains and the extent of apoptosis by TUNEL assay and immunohistochemical stains. The tissue damage after TBI was mainly observed in the ipsilateral cortex and partly in the hippocampus. Results : Apoptosis was observed by TUNEL assay and the Bax protein was detected in both sample which harvested 12h and 24h after TBI. In the hypothermia treatment group, tissue damage and apoptosis were reduced in HE stains and TUNEL assay. In hypothermia treatment group rat shows more expression of the Bcl-2 protein and shows less expression of the Bax protein, at both 12h and 24h after TBI. Conclusion : These results show that the hypothermia treatment is an effective treatment after TBI, by reducing the apoptotic process. Therefore, it could be suggested that hypothermia has a high therapeutic value for treating tissue damages after TBI.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup1
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• pp.37-43
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• 2001

Object : The rapid and early oxygen delivery to brain tissue was a common therapeutic method in the treatment of severe head injury patients. The purpose of this study was to investigate the effect of increased fraction of inspired oxygen in early stage of severe head injury. Methods : The parameters of research were CSF(cerebral spinal fluid) oxygen pressure($PcsfO_2$), lactate, pH, temperature, and CSF carbon dioxide pressure($PcsfCO_2$). We selected 28 patients with head trauma whose the Glasgow Coma Scale(GCS) score was less than 8 point at admission. All patients were mechanically ventilated and monitored with the commercial ICP monitoring device. Each of parameters was compared as increased fraction of inspired oxygen. In experimental cohort of 14 patients, the mean $PcsfO_2$ level was increased to $314.93{\pm}259.15mmHg$ by raising the $FiO_2$ from 40% to 100% for nine hours(p<0.05). And the mean CSF lactate level was decreased to $2.96{\pm}1.98mmol/L$ on 100% $FiO_2$ as compared with $5.98{\pm}3.25mmol/L$ on 40% $FiO_2$ in control group(p<0.05). The only above two parameters were showed statistically meaningful outcome. Conclusions : Although this study was performed in small cohort and short period, these results supports that increased inspired oxygen therapy in severe head injuried patients was recommended as a modality of treatment in future through the continuous survey.

• Journal of Veterinary Clinics
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• v.17 no.1
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• pp.138-144
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• 2000

The studies were carried out to investigate the effects of esophageal thermal tube for rewarming in the hypothermia in rabbits. Thiry-one rabbits were continuously cooled with femoral arterio-venous bypass circulation to 25.0${\pm}$0.3$^{\circ}C$(profound hypothermia) of rectal temperature. The experiment was consisted with 3 esophageal thermal tube groups perfused with circulation water at 38${\pm}$1$^{\circ}C$(low, n=12), 42${\pm}$1$^{\circ}C$(medium, n=12), and 45${\pm}$1$^{\circ}C$(high, n=7). Esophageal thermla tube specially constructed double-lumen esophageal tube with circulating warm water at respective htermal grade. With this device, rewarming of the rabbits as follows; High-esophageal thermal tube group(45${\pm}$1$^{\circ}C$)had a more effect on mean arterial pressure(MAP), heart rate(HR), esophageal temperature, and rectal temperature than others groups, but the circulation water at 45$\pm$1$^{\circ}C$ may cause thermal injuries in the esophagus because esophageal temperature increased to 41.1$^{\circ}C$. Medium-esophageal thermal tube group(42${\pm}$1$^{\circ}C$) had a more effect on RR than others groups, but the circulation water at 42${\pm}$1$^{\circ}C$ may also cause thermal injuries in the esophagus if the temperature exceeds 42$^{\circ}C$ for an extended period of time because its esophageal temperature increased to 39.4$^{\circ}C$. Low-esophageal thermal tube group(38${\pm}$1$^{\circ}C$) had a more effect on MAP, RR, and esophageal temperature than others groups. In conclusion, rewarming of the central core in the treatment of profound hypothermia using the esophageal thermal tube perfused with circulation water at 38${\pm}$1$^{\circ}C$ appears to be a ideal alternative safety zone of the temperature of circulation water avoiding thermal injury in esophagus causing by out of order or lower precise thermostat of water bath to that of others groups.

• Asian Journal of Turfgrass Science
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• v.3 no.1
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• pp.24-33
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• 1989

This study was conducted to investigate the effect of paclobutrazol [(2 RS , 3 RS )1-(4- chlor-ophenyl )-4, 4- dimethyl -2- (1, 2, 4- triazol -1- yl )- pentan -3-01] on the tolerance of hi-gh temperature and drought stress as related to growth retardation , iranspiration rate , soil water content , nitrogen level and photosynthetic rate in perennial ryegrass ( Loliurn perenne L . ' Omega H , ). Plants were given a 30 ml soil drench of paclohutrazol at the concentrations of 0, 0.01, 0.1, 1.0, 10.. 0, mg / 6 .5cm- diameter pot . The rcsults were as follows : 1. Increasing concentrations of paclohutrazul reduced plant height , leaf area , fresh weight and dry weight , hut increased chlorophyll content per unit area . The number of tillers and leaf width were not affected hy the paclobutrazol concentrations . 2. The proper concentration of paclohatrazol on growth retardation in perennial ryegrass was about I mq /pot , hut leaf deformity and severe growth retardation were shown at high concentration of 10 mq / pot . 3. Perennial ryegrasses grown at 30˚C were shown significantly short plant height and low leaf nitrogen level compared with those grown at 20˚C. Increasing concentrations of paclohutrazol at 20˚C increased nitrogen level hut it could not increase nitrogen level at 30˚C . 4. During the drought stress , increasing temperatures significantly promoted transpiration rate and wilting time . It took about 5 days at 20˚C and 3 days at 30˚C to reach wilting time of leaves from water stress treatment . Soil water contents at wilting time of non-treated controls were averaged 6. 871% at 20˚C and 6. 17% at 30˚C 5. Paclohutrazol reduced transpiration rate at high temperature and drought stress . Wilting appeared at the lower water content of soil according to increasing concentrations of paclobutrazol at 30˚C hut there were no differences among concentrations of at 20˚C. 6.Paclohutrazol treatment at 1 rag /pot reduced injury rate of leaves from 67.1 % and 100 % in control plants to 15.7% and 80% at 20˚C and 3010, respectively. 7. Photosynthetic rate per unit area was significantly reduced at high temperature . Paclohutrazol stimulated photosynthetic rate with increase of concentrations at 20˚C but there was no increasing effect at 30˚C.