Evaluation of Heating Protocols and Body Regions with Graphene Heater for Cold Protective Clothing

학위논문 (석사)-- 서울대학교 대학원 : 의류학과, 2017. 2. 이주영.The purpose of this study was to evaluate the effects of intermittent and continuous heating protocols using graphene heated clothing and identify the more effective body region for heating in a cold environment. The current study consisted of three parts. First, we examined the permissible temperature of graphene heater on the chest, upper back, respectively for human application. Two young males participated in two experiments consisted of chest heating and upper back heating at an air temperature of 0.4oC with 41%RH. The temperature of graphene heater was increased by controlling the voltage. The permissible temperature of graphene heater for human application was decided to be around 45oC considering pain sensation, subjective perceptions and the prevention of skin burn injury. Second, we developed intermittent heating protocol according to electric power consumption. Electric power was set at 0.18, 0.71, 1.61, and 2.86 W with the voltage of 5, 10, 15, and 20 V per graphene heater, respectively. Tests were conducted at an air temperature of 30oC with 10%RH. Five intermittent heating protocols were developed with different electric power consumptions. For the continuous heating protocol (CP), 20 V during 60 min generated an electric power of 8.58 W from three graphene heaters. For the intermittent heating protocols, electric power was 5.28, 5.49, 2.49, 5.10, and 2.94 W for IP-1, IP-2, IP-3, IP-4, and IP-5, respectively. The results showed that the electric power consumption of the IP-3 (2.49 W) was conserved by 71% compared to the continuous protocol (8.58 W). Based on the results, IP-3 was selected for the following human wear trials. Lastly, we evaluated in the following five graphene heating protocols in human wear trials: no heating, continuous heating the chest, continuous heating the back, intermittent heating the chest, and intermittent heating the back. Eight males participated in the experimental protocol consisting of 10 min rest on a chair at an air temperature of 25oC with 28%RH and 60 min cold exposure at an air temperature of 0.6oC with 40%RH. Rectal temperature, cardiovascular and respiratory responses showed no significant differences among the five heating conditions while heating the back showed more beneficial effects on skin temperatures than heating the chest. In summary, to keep a balance between saving electric power and minimizing thermal discomfort in cold environments, intermittent heating the back is recommended.Chapter 1. Introduction 1 Chapter 2. Theoretical Background 4 2.1. Graphene and graphene heater 4 2.2. Necessity of electric heated cold protective clothing 5 2.3. Intermittent heating protocol 5 2.4. Optimal body region for heating 6 2.5. Factors affecting cold responses 7 Chapter 3. Materials and Methods 8 3.1. Production of electrothermal graphene thin film 9 3.2. Permissible temperature of graphene heater for human application 11 3.3. Developing intermittent heating protocol 14 3.4. Evaluation of graphene heating protocols in human wear trials 14 Chapter 4. Results 20 4.1. Permissible temperature of graphene heater for human application 20 4.2. Intermittent heating protocols 22 4.3. Evaluation of heating protocols in human wear trials 24 Chapter 5. Discussion 36 5.1. Advantages in intermittent heating protocol 36 5.2. Advantages of heating the back than the chest 38 5.3. Heating effects on psychological responses 39 Chapter 6. Limitations and Suggestions 41 Chapter 7. Conclusions 42 References 43 Appendix 50 초록 60Maste

Metabotropic glutamate receptor 5 in the nucleus accumbens promotes resilience in various animal models of stress : in vivo assessment adopting knockout mice and viral mediated gene transfer

Dept. of Medical Science/박사Although there is a substantial causal relationship between the occurrence of stressful life events and the subsequent onset of depression, stress per se is not sufficient to the development of depression. Resilience, the ability to avoid deleterious behavioral changes in response to extreme stress, plays a central role in determining 2 whether stress can cause depression. Metabotropic glutamate receptor 5 (mGluR5) has been suggested as a potential pharmacologic target for the depression. However, the possible role of mGluR5 activity in mediating resilience to stress has not been explored. In this study, I found that mGluR5-/- mice exhibited increased behavioral vulnerability to stress, including enhanced helplessness, social withdrawal, and decreased sucrose preference after various stressful events. Lentiviral rescue of mGluR5 in the nucleus accumbens shell reversed the stress-induced depressive-like behaviors of mGluR5-/- mice. Furthermore, induction of ∆FosB in the nucleus accumbens upon stress, an important molecular event for promoting resilience, was impaired in mGluR5-/- mice. Notably, targeted activation of mGluR5 in the nucleus accumbens shell increased the expression of ∆FosB. Taken together, these results demonstrate that mGluR5 is an essential molecule for promoting resilience to stress and defects in mGluR5 signaling in the nucleus accumbens may be a predisposition that interacts with stress to increase vulnerability for depression.prohibitio

Acute physical stress induces the alteration of the serotonin 1A receptor density in the hippocampus.

Stress affects the serotonergic system, which is associated with depression. Previous research has showed that chronic stress causes the deactivation of the limbic system. However, the influence of the acute physical stress on the serotonergic system in vivo was primarily unclear. The purpose of this research is to elucidate the effects of the acute physical stress in vivo using PET. For quantification of the 5-HT1A receptors in the brain, we measured [(18)F]Mefway uptake in the two experiment groups (control and despair rats). The despair group was subjected to the external stressful situation (i.e., forced swimming) and total duration time of immobility, refers to the despair severity, and was analyzed. In the intercomparison experiment, the resulting PET images of [(18)F]Mefway in the despair rat displayed a significant reduction of radioactivity in the hippocampus (HP) compared with the control. The nondisplaceable binding potential (BPND ) refers to the ratio of the concentration of radioligand in the receptor-rich region (i.e., HP) to the concentration of that in the receptor-free region (i.e., cerebellum). The hippocampal uptake and the BPND in the despair group were respectively about 25 and 18% lower than those of the control group. The ratio of specific binding to nonspecific binding in the despair group was 18% lower than that of the control. In the intracomparison experiments, the BPND and immobility in the despair group showed a strong negative correlation. Taken together, the data illustrates that an acute physical stress induces the change in the serotonergic system that correlates with the behavioral despair.ope

GPR30 mediates anorectic estrogen-induced STAT3 signaling in the hypothalamus

OBJECTIVE: Estrogen plays an important role in the control of energy balance in the hypothalamus. Leptin-independent STAT3 activation (i.e., tyrosine(705)-phosphorylation of STAT3, pSTAT3) in the hypothalamus is hypothesized as the primary mechanism of the estrogen-induced anorexic response. However, the type of estrogen receptor that mediates this regulation is unknown. We investigated the role of the G protein-coupled receptor 30 (GPR30) in estradiol (E2)-induced STAT3 activation in the hypothalamus. MATERIALS/METHODS: Regulation of STAT3 activation by E2, G-1, a specific agonist of GPR30 and G-15, a specific antagonist of GPR30 was analyzed in vitro and in vivo. Effect of GPR30 activation on eating behavior was analyzed in vivo. RESULTS: E2 stimulated pSTAT3 in cells expressing GPR30, but not expressing estrogen receptor ERα and ERβ. G-1 induced pSTAT3, and G-15 inhibited E2-induced pSTAT3 in primary cultures of hypothalamic neurons. A cerebroventricular injection of G-1 increased pSTAT3 in the arcuate nucleus of mice, which was associated with a decrease in food intake and body weight gain. CONCLUSIONS: These results suggest that GPR30 is the estrogen receptor that mediates the anorectic effect of estrogen through the STAT3 pathway in the hypothalamus.ope

mGluR5 in the nucleus accumbens is critical for promoting resilience to chronic stress

Resilience to aversive events has a central role in determining whether stress leads to the development of depression. mGluR5 has been implicated in the pathophysiology of depression, but the effect of mGluR5 activity on stress resilience remains unexplored. We found that mGluR5(-/-) (also known as Grm5(-/-)) mice displayed more depression-like behaviors (for example, learned helplessness, social withdrawal and anhedonia) than control mice following exposure to various stressful stimuli. Lentiviral 'rescue' of mGluR5 in the nucleus accumbens (NAc) decreased these depression-like behaviors in mGluR5(-/-) mice. In the NAc, ΔFosB, whose induction promotes stress resilience, failed to be upregulated by stress in mGluR5(-/-) mice. Notably, targeted pharmacological activation of mGluR5 in the NAc increased ΔFosB expression. Our findings point to an essential role for mGluR5 in promoting stress resilience and suggest that a defect in mGluR5-mediated signaling in the NAc may represent an endophenotype for stress-induced depression.ope