• The Korean Journal of Physiology and Pharmacology
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• 제14권3호
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• pp.157-161
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• 2010

Heat shock proteins (HSPs) are specifically induced by various forms of stress. Hsp70.1, a member of the hsp70 family is known to play an important role in cytoprotection from stressful insults. However, the functional role of Hsp70 in motor function after spinal cord injury (SCI) is still unclear. To study the role of hsp70.1 in motor recovery following SCI, we assessed locomotor function in hsp70.1 knockout (KO) mice and their wild-type (WT) mice via the Basso, Beattie and Bresnahan (BBB) locomotor rating scale, before and after spinal hemisection at T13 level. We also examined lesion size in the spinal cord using Luxol fast blue/cresyl violet staining. One day after injury, KO and WT mice showed no significant difference in the motor function due to complete paralysis following spinal hemisection. However, when it compared to WT mice, KO mice had significantly delayed and decreased functional outcomes from 4 days up to 21 days after SCI. KO mice also showed significantly greater lesion size in the spinal cord than WT mice showed at 21 days after spinal hemisection. These results suggest that Hsp70 has a protective effect against traumatic SCI and the manipulation of the hsp70.1 gene may help improve the recovery of motor function, thereby enhancing neuroprotection after SCI.

• 한국지역사회생활과학회지
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• 제27권3호
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• pp.419-435
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• 2016

The purpose of the present study was to suggest the design requirements for Korean naval duty uniforms by evaluating the physiological and psychological comfort while wearing the uniforms. Two sets of wear trials were conducted with summer uniforms(eight young males) and winter uniforms(seven other young males). The summer wear trial consisted of 10-min rest, 60-min exercise, and 10-min recovery at an air temperature($T_{air} $) of $33^{\circ}C$ and 62%RH, followed by 10-min recovery at a $T_{air} $ of $23^{\circ}C$ and 64%RH(total 90 min). The winter wear trial consisted of 20-min rest at $T_{air} $ $20^{\circ}C$ and 55%RH, 25-min rest, 30-min exercise, and 35-min recovery at a $T_{air} $ of 0oC and 43%RH(total 110 min). Rectal and seven skin temperatures, clothing microclimate, heart rate, oxygen consumption, total sweat rate, and subjective perceptions were measured during the wear trials. By evaluating the experimental results from the wear trials, we extracted the following psycho-physiological design requirements to improve the current Korean naval uniforms: (1) It is important to maintain the skin temperatures within their comfort range, which depends on the body region (higher than $30^{\circ}C$ in winter, but less than $35^{\circ}C$ in summer). (2) In summer, the feet should be protected from the high heat of the ship floor surface. (3) In summer, sweat from the back should be sufficiently absorbed and allowed to dry quickly.

• 한국수산과학회지
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• 제51권3호
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• pp.238-247
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• 2018

This study investigated survival rates and physiological responses in Pacific abalone (Haliotis discus hannai) to 18 days of containment in live fish containers ($8^{\circ}C$, 34 psu). The investigation was divided into three periods: before, during, and recovery after transportation. The overall survival rate was greater than 99%. Glucose, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) rose immediately on the first day of containment, but then gradually returned to normal levels. $NH_3$ continued to rise after the first day, but during the recovery period it decreased to a level not significantly different from that of the control group. $Na^+$ and osmolality did not show any abnormal changes. After recovery, superoxide dismutase (SOD) was not significantly different from control. Abalone in the experimental group had lower glutathione reductase (GR) than control. The hyalinocyte ratio fell immediately after confinement, but then gradually increased until it reached a normal level. The ratios of apoptotic and necrotic cells indicated no specific variations in hemocyte viability. Histological changes in the epidermal layer and muscle layer of the foot were not significantly different from those seen in the control group. The experimental data obtained in this study suggest that live fish containers may be used for transport of Pacific abalone without significantly impacting their physiology or survival rates.

• 한국작물학회지
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• 제46권3호
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• pp.209-214
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• 2001

본 실험은 청수, 반탁수, 탁수에 따른 탁도처리와 관수시간에 따른 광합성, 엽록소형광, 증산량 및 회복능을 분석하여 관수스트레스에 대한 벼의 생리반응을 구명하고자 실시한 결과는 다음과 같다. 1. 광합성은 탁도가 높고, 관수 시간이 경과할수록 감소하였다. 특히 관수 36시간 전까지는 약 25%, 42시간이후에는 약 50%가 감소하였다. 증산량은 탁도 및 관수시간이 증가함에 따라 증가하였으며, 청수에서는 약 30%, 반탁수에서는 약 25%, 탁수에서는 약 20%가 증가하였다. Fv/Fm은 탁도 및 관수시간 증가에 따라 감소하였으며, 청수에서는 48시간이후에, 반탁수 및 탁수에서는 36시간이후 약 20%가 감소하였다. 전질소함량은 관수스트레스에 의해 감소하였고, 탁수처리 36시간이후부터 감소량이 켰다. 2. 관수스트레스에 따른 회복력을 나타내는 건물중은 탁도 리별 차이는 작았으나, 관수시간이 경과할수록 크게 감소하였다. 피해정도는 24시간안에는 약 25%, 42시간이후에는 각 처리구 모두에서 약 50%의 생장감소가 일어났다. 관수 48시간의 반탁수 및 탁수는 고사하였다. 광합성은 탁도에 따라서는 청수에서 약 15%, 반탁수, 탁수에서는 10%가 감소하였고, 특히 42시간이후에는 30-50% 감소하였다. 증산량은 탁도 및 관수시간에 처리간의 차이 없이 약 20%증가하였다. 3. 관수 24시간처리에서 관수처리 시 및 퇴수 후 회복기간에도 광합성과 증산량의 일시적인 감소가 일어났다

• 생명과학회지
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• 제21권3호
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• pp.368-374
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• 2011

식물의 저온 적응 메카니즘에서 아스코브산과 관련된 효소 중 MDHA 환원효소의 활성도와 과산화수소, 아스코브산의 함량, mRNA의 발현수준과의 연관성을 연구한 결과는 다음과 같다. MDHA 환원효소의 활성도 변화는 저온에 노출되는 시간이 길어질수록 증가하였으며 6시간 이후에 엽록체분획과 세포질분획에서 급격하게 증가하는 경향을 보였으나 실온으로 회복시켰을 때 효소의 활성도가 상대적으로 감소하는 경향을 보였다. 저온에 노출된 동안 아스코브산의 함량은 비교적 일정한 경향을 보이다가 실온으로 회복시키면 그 이후에는 급격하게 증가하는 경향을 보였다. 반면 저온에 노출되는 동안 급격히 dehydroascorbate 함량이 감소하였다가 실온으로 회복되면 약간 증가하는 경향을 보였다. 아스코브산의 함량과 엽록체분획과 세포질분획의 MDHA 환원효소의 활성도와의 상관관계는 각각 정의 상관($R^2$=0.9240, 0.9108)을 나타내었으나 디하이드로아스코브산의 함량과 MDHA 환원효소의 활성도 사이에는 각각 부의 상관($R^2$=0.8638, 0.8980)을 나타내었다. MDHA 환원효소 활성도와 과산화수소의 함량과의 상관관계를 과산화수소의 생성량이 증가하면 MDHA 환원효소의 활성도가 증가하는 정의 상관($R^2$=0.9443, 0.9647)을 나타내었다. 저온스트레스 처리 시간이 증가할수록 MDHA 환원효소의 mRNA의 발현 수준과 총 MDHA 환원효소의 활성도가 증가하는 경향을 나타내었다.

• 열처리공학회지
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• 제14권3호
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• pp.160-166
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• 2001

The change of ribbon geometry, microstructure and shape recovery with Mn contents, wheel speed and various annealing temperature have been studied in Fe-X%Mn-5Cr-5Co-4Si (X%=15, 20, 24) shape memory alloy (SMA) ribbons rapidly solidfied by single roll chill-block melt-spinning process. The thickness and width of melt-spun ribbons are reduced, results in refining and uniformalizing grains with increasing wheel speed. In the ribbons melt-spun at a wheel speed of 15m/sec, both ${\varepsilon}$ and ${\alpha}^{\prime}$martensites are formed in ribbon 1 (15.5wt%Mn), while only ${\varepsilon}$ martensite is revealed in ribbon 2 (20.2wt%Mn) and ribbon 3 (23.5wt%Mn). The volume fraction of ${\varepsilon}$ martensite is decreased with increasing Mn contents, and those of ${\varepsilon}$ as well ${\alpha}^{\prime}$martensites are increased due to thermal stress relief and grain growth with increasing annealing temperature. Ms temperatures of the ribbons 1, 2 and 3 are fallen with increasing Mn contents. $M_s$ temperatures of the ribbons 1, 2 and 3 annealed at $300^{\circ}C$ for 3 min are risen abruptly, but are nearly constant even at higher annealing temperature, i.e., 400, 500 and $600^{\circ}C$ for 3 min. Shape recovery of the ribbons 1, 2 and 3 increased 30%, 52% and 69% with Mn contents, respectively. Shape recovery of ribbon 1 (15.5wt%Mn) formed ${\varepsilon}$ and ${\alpha}^{\prime}$martensites decreased because of the presence of ${\alpha}^{\prime}$martensite but those of ribbon 2 (20.2wt%Mn) and ribbon 3 (23.5wt%Mn) formed ${\varepsilon}$ martensite increased with increasing annealing temperature.

• Journal of Chest Surgery
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• 제33권5호
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• pp.398-406
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• 2000

Background: Cardiac atrium is an endocrine gland secreting a family of natriuretic peptides. The secretion of atrial natriuretic peptide(ANP) had been shown to be controlled by variable factors. The change in atrial dynamics have been considered as one of the most prominent stimuli for the stimulation of ANP secretion. Hypoxic stress has been shown to increase cardiac ANP secretion. However, the mechanism by which hypoxia increases ANP secretion cardiac ANP secretions. However, the mechanism by which hypoxia increases ANP secretion has not to be defined. Therefore, the purpose of the present study was tow-fold: to develop a protocol to defined the effect of hypoxia on ANP secretion in perfused beating rabbit atria and to clarify the mechanism responsible for the accentuation by hypoxia of ANP secretion. Material and Method: Experiments have been done in perfused beating rabbit atria. ANP was measured by radioimmunoassay. Result: Hypoxic stimulus with nitrogen decreased atrial stroke volume. The decrease in atrial stroke volume recovered basal level during the period of recovery with oxygen. ANP secretion and the concentration of perfusate ANP in terms of extracellular fluid(ECF) translocation which reflects the rate of myocytic release of ANP were increased by hypoxia and returned to basal levels during the recovery. Changes in ECF translocation paralleled by hypoxia and returned to basal levels during the recovery. Changes in ECF translocation paralleled to that of atrial stroke volume. At the start of recovery in atrial storke volume, ECF tranalocation incrased for several minutes. The above responses were stable and reproducible. Glibenclamide treatment prevented the recovery in atrial stroke volume. Increments by hypoxia of ANP secretion and ANP concentration were suppressed by glibenclamide. Conclusion: These results indicate that hypoxia incrased atrial myocytic ANP release and that the mechanism responsible for the accentuation is partially related to the change in K+ATP channel activity.

• 대한불안의학회지
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• 제12권2호
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• pp.69-78
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• 2016

Objective : Disaster causes psychological distress to a large number of people in a short period of time, by both direct and indirect exposure to traumatic events embedded in various realms of disaster experience. Optimal, well-planned treatment interventions should follow from the early acute period to recovery phase, extending up to several months later. In this context, there is an increasing need for systemic review to gain comprehensive insights for disaster interventions. These need to be added to public policy, and for the prevention and treatment of disaster-related psychopathology. Here, we review the published studies on psychological interventions for disaster-related posttraumatic stress disorder. Methods : Specific psychological interventions regarded as effective treatments for have been selected for this review, such as CBT (Cognitive-Behavior Therapy), Exposure Therapy, EMDR (Eye Movement Desensitization & Reprocessing), SIT (Stress Inoculation Therapy) and Psychoeducation. In addition, natural disasters, industrial disasters, and accidents involving aircraft and ships were also categorized as disasters, along with war and combat trauma. Results : Cognitive behavior therapy and exposure therapy had the strongest research support for effectiveness, and could be considered as the first-choice treatment for disaster-related PTSD. The second line of treatment is EMDR, although this treatment modality has the advantage of reaching certain treatment improvements in fewer sessions. However, the effects of SIT and psychoeducation to the survivors of disasters, remains unclear at this point. Additionally, we propose the possibilities of using virtual reality component and imagery rescripting as modified forms of traditional cognitive behavior therapy and exposure therapy. Conclusion : Cognitive behavior therapy and exposure therapy, deemed effective treatments for various trauma, are considered to be effective for survivors from disasters. However, the efficacy of other interventions has not yet been examined methodologically in well-designed studies, such as randomized controlled trials. In particular, future empirical studies are needed, since it is difficult to conclude that psychological interventions have similar effects on different types of disasters.

• The Korean Journal of Ecology
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• 제19권2호
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• pp.151-163
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• 1996

To investigate the early symptoms of light-chilling, alterations of chlorophyll fluorescence transients were monitored in cucumber (Cucumis sativus L. cv. Ilmichungjang) leaves. During 24 h chilling, decreases in (Fv)m/Fm, qE and qQ, and an increase in Fo were observed. The chilling effects were not recovered at room temperature, and a significant increase in Fo was observed during the recovery period. After 6 h chilling, ‘dip’(D) level of the transients became obscure, and the negative slope after ‘peak’(P) disappeared. The first derivative (dFv/dt) of the fast fluorescence rise curve was used to obtain more accurate information about the changes in the transients. The maximal rate of the fluorescence increase in the D-p rise curve (Fr) has been the most frequently used chilling stress indicator. However, a correct value of Fr could not be measured when the D level became obscure. This problem was overcome by introducing a new indicator, HFr (dFv/dt at Fv = 1/2 (Fv)m), and HFr gave very similar values to Fr. To monitor the changes in curvature around D level, another new parameter, ${\Delta}S$(D-Fr), was also introduced. These three parameters decreased very sensitively during light-chilling. In addition, increases in these parameters were observed during the first 2 h chilling, but this increase in Fr was also observed in pea leaf discs dark-chilled for 15 min, suggesting that this very early change is a common response to chilling in both pea and cucumber leaves. Quenching coefficients were also very sensitive to chilling, especially qE. Discussion on the usage of these parameters as chilling stress indicators is given in the text.

• 한국환경농학회지
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• 제27권4호
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• pp.389-394
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• 2008

The ecophysiological changes occurring upon cold stress were studied using cold tolerant transgenic and wild-type tobacco plants. In a previous study, cold tolerance in tobacco was induced by the introduction of a gene encoding the zinc finger transcription factor, PIF1. Gas-exchange measurements including net photosynthesis and stomatal conductance were performed prior to, in the middle of, and after a cold-stress treatment of $1{\pm}2^{\circ}C$ for 96 h in each of the four seasons. In both transgenic and wild-type plants, gas-exchange parameters were severely decreased in the middle of the cold treatment, but had recovered after 2-3 h of adaptation in a greenhouse. Most t-test comparisons on gas-exchange measurements between the two plant types did not show statistical significance. Wild-type plants had slightly more water-soaked damage on the leaves than the transgenic plants. A light-response curve did not show any differences between the two plant types. However, the curve for assimilation-internal $CO_2$ in wild-type plants showed a much higher slope than that of the PIF1 transgenic plants. This means that the wild-type plant is more capable of regenerating Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and has greater electron transport capacity. In conclusion, cold-resistant transgenic tobacco plants demonstrated a better recovery of net photosynthesis and stomatal conductance after cold-stress treatment compared to wild-type plants, but the ecophysiological recoveries of the transgenic plants were not statistically significant.