• 반도체디스플레이기술학회지
• /
• 제17권1호
• /
• pp.35-39
• /
• 2018

This paper deals with the relaxation of singular stresses developed in an epoxy adhesive at high temperature. The interface stresses are analyzed using BEM. The adhesive employed in this study is an epoxy which can be cured at room temperature. The adhesive is assumed to be linearly viscoelastic. First, the distribution of the interface stresses developed in the adhesive layer under the uniform tensile stress has been calculated. The singular stress has been observed near the interface corner. Such singular stresses near the interface corner may cause epoxy layer separated from adherent. Second, the interfacial thermal stress has been investigated. The uniform temperature rise can relieve the stress level developed in the adhesive layer under the external loading, which can be viewed as an advantage of thermal loading. It is also obvious that temperature rise reduces the bonding strength of the adhesive layer. Experimental evaluation is required to assess a trade-off between the advantageous and deleterious effects of temperature.

• 대한수의학회지
• /
• 제44권3호
• /
• pp.357-366
• /
• 2004

We studied the effect of propofol (PPF) on the endothelium-dependent vascular responses in isolated rat thoracic aorta. In aortic rings with endothelium, PPF inhibited the phenylephrine (PE)-induced contraction in a concentration-dependent manner. In PE-precontracted preparations, PPF attenuated the endothelium-dependent relaxation by acetylcholine but not by A23187. And PPF did not attenuate the endothelium-independent relaxation by sodium nitroprusside (SNP). The relaxation induced by acetylcholine in PE-precontracted aortic rings was significantly augmented by zaprinast, a cGMP-specific phosphodiesterase inhibitor, and this augmentation was inhibited by PPF. Although SNP-induced relaxation was significantly augmented by zaprinast, this augmentation was not inhibited by PPF. In preparations preconstricted with PE, the PPF-induced relaxation was inhibited by atropine. In addition, PPF attenuated the vasorelaxation by phosphodiesterase inhibitors (IBMX, Ro20-1724 or zaprinast except milrinone). In vivo, the infusion of acetylcholine and SNP showed decreased arterial blood pressure in rats. The pre-injection of PPF inhibited the acetylcholine-induced blood pressure lowering, but not the SNP-induced blood pressure lowering. These results suggest that PPF can attenuate in part the acetylcholine-induced vasorelaxation and blood pressure lowering through the inhibition of the acetylcholine receptor-mediated endothelium-derived relaxing factor by acting on endothelium. It is considered that the inhibitory effect of PPF on the vasorelaxation is due to the decreased level of cGMP which can be attributed to the inhibition of the muscarinic receptor and/or receptor-G-protein interaction.

• 대한한방부인과학회지
• /
• 제31권1호
• /
• pp.43-56
• /
• 2018

Objectives: This study was designed to investigate the basis for developing the herbal decoction that may help promote healthy blood vessels in accordance with the basic principles of Korean medicinal materials. Methods: In this study, we investigated the vascular relaxation effects of fifty herbal decoctions on vascular response in isolated thoracic aorta of phenylephrine-preconracted rats. Results: The results of identify the vascular relaxation effect of fifty herbal decoctions provided by Korea Institute of Korean Medicine, twenty-one herbal decoctions showed vascular relaxation effects. Among them, four herbal decoctions, Mahwang-tang (麻黃湯), Samchulgeonbi-tang (參朮健脾湯), Cheonwangbosim-dan (天王補心丹), and Socheonglyong-tang (小靑龍湯), with showed significantly concentration-dependent vasodilation was examined. Vascular relaxation level are $84.02{\pm}4.70$, $79.39{\pm}13.9$, $51.26{\pm}12.56$, and $54.73{\pm}15.8%$, respectively (P<0.05, 0.01, and 0.001). Conclusions: Thus these results provide a basic data for the treatment of the impairment of vascular function and blood pressure in traditional Oriental medicine.

• Asian Pacific Journal of Cancer Prevention
• /
• 제14권4호
• /
• pp.2237-2242
• /
• 2013

Background: The aim of this study was to determine the impact of applied progressive muscle relaxation training on the levels of depression, anxiety and stress among prostate cancer patients. Materials and Methods: A quasi-experimental study was conducted at the University Malaya Medical Centre (UMMC) and Universiti Kebangsaan Malaysia Medical Centre (UKMMC) over six months. Prostate cancer patients from UMMC received the intervention and patients from UKMMC were taken as controls. The level of depression, anxiety and stress were measured using Depression, Anxiety Stress Scales - 21 (DASS-21). Results: A total of 77 patients from the UMMC and 78 patients from the UKMMC participated. At the end of the study, 90.9% and 87.2% of patients from the UMMC and UKMMC groups completed the study respectively. There were significant improvements in anxiety (p<0.001, partial ${\eta}^2$=0.198) and stress (p<0.001, partial ${\eta}^2$=0.103) at the end of the study in those receiving muscle training. However, there was no improvement in depression (p=0.956). Conclusions: The improvement in anxiety and stress showed the potential of APMRT in the management of prostate cancer patients. Future studies should be carried out over a longer duration to provide stronger evidence for the introduction of relaxation therapy among prostate cancer patients as a coping strategy to improve their anxiety and stress.

• 감성과학
• /
• 제6권2호
• /
• pp.21-28
• /
• 2003

본 연구는 국제정서사진체계(IAPS) 사진 중 이차원 감성을 잘 표현한다고 판단되는 9장의 사진을 선정하고, 이 사진 자극으로 유발된 감성의 변화를 심리ㆍ생리적으로 측정한 후 이차원 감성의 한 축인 각성/이완의 감성변화를 심리ㆍ생리적으로 변별 가능한지를 검증하는 것을 목표로 한다. 각성/이완의 감성변화를 대변하는 Eelectrocardiogram (ECG), Galvanic Skin Response (GSR), Skin Temperature, Respiration 등의 자율신경계 반응을 측정하였다. 자극 제시 후에 주관적 평가를 실시한 바, 각성 〉 불쾌/각성 및 쾌/각성 〉 중립 〉 이완 순서의 4단계로 각성도 감성을 구분할 수 있었다 자율신경계 반응은 각성, 불쾌/각성, 쾌/각성 〉 중립 〉 이완 순서의 3단계로 구분이 가능하였다. 본 연구는 한국인의 이차원 감성을 표현할 수 있는 9장의 사진을 IAPS로부터 선정하였으며, 이차원 감성의 한 축인 각성/이완의 감성 변화를 심리ㆍ생리적평가로부터 변별할 수 있다는 사실을 확인하였다.

• Journal of Ginseng Research
• /
• 제40권4호
• /
• pp.334-343
• /
• 2016

Background: Progressed tissue culture techniques have allowed us to easily obtain mass products of tissue-cultured mountain ginseng over 100 yr old (TCMG-100). We investigated the effects of TCMG-100 extract on erectile function using in vitro and in vivo studies. Methods: To examine the relaxation effects and mechanisms of action of TCMG-100 on rabbit cavernosal strips evaluated in an organ bath. To investigate the long-term treatment effect of TCMG-100, 8-wk administration was performed. After administration of TCMG-100, intracavernosal pressure, cyclic guanosine monophosphate and nitric oxide (NO) levels of cavernosal tissue, serum testosterone level, histological observation of collagen fiber, endothelium, smooth muscle cell, and transforming growth factor-${\beta}1$ were investigated. Results: TCMG-100 extract displayed dose-dependent relaxation effects on precontracted rabbit corporal smooth muscle. The TCMG-100-induced relaxation was significantly reduced by removing the endothelium, and treatment with an NO synthase inhibitor or NO scavenger. Eight weeks of TCMG-100 administration increased intracavernosal pressure in a rat model. The levels of cyclic guanosine monophosphate and NO in the corpus callosum and serum testosterone level were also increased by TCMG-100 treatment. Furthermore, histological evaluation of collagen, smooth muscle, and endothelium showed increases in endothelium and smooth muscle, and a decrease in transforming growth factor-${\beta}1$ expression. Conclusion: These relaxation effects on corporal smooth muscle and increased erectile function suggest that TCMG-100 might be used as an alternative herbal medicine to improve erectile function.

• 대한의용생체공학회:학술대회논문집
• /
• 대한의용생체공학회 1997년도 춘계학술대회
• /
• pp.398-401
• /
• 1997

The EMG signal of spinal cord injured patient is very feeble because that the information from central nervous system is not sufficiently transmitted to molter neuron or muscle fiber. Therefore the observer can not observe contraction and relaxation movement of muscle from the raw EMG signal. In this paper, we propose the muscle contraction and relaxation pattern analysis method of spinal cord injured patient whose EMG signal is composed of the sum of motor unit action potential train with additive white Gaussian noise and impulsive noise. From the EMG model, we denoise impulsive noise using median filter which is a kind of nonlinear filter and the output of median filter is transformed to wavelet transform domain for denoising additive white Gaussian noise using threshold level removal technique. As a result, we can obtain the clear contraction and relaxation pattern.

• Asian Pacific Journal of Cancer Prevention
• /
• 제16권1호
• /
• pp.217-220
• /
• 2015

Background: Breast cancer is the second most common cancer in the world and by far the most frequent cancer among women. Objective: This study was conducted to observe the effect of progressive relaxation exercises on anxiety and comfort level of breast cancer patients receiving chemotherapy. Materials and Methods: A control group pre-test/post-test quasi-experimental model was applied with experimental (30) and control (30) groups, who agreed to participate in this study. Data collection was with the "Personnel Information Form, State-Trait Anxiety Inventory and General Comfort Scale". Results: The average age of the patients that participated in the study was $49.1{\pm}7.96$ years. Eighty-three point three percent (n=25) of the patients in the experiment group and 86.7 (n=26) percent of patients in control group were married. Patient state of anxiety post-test mean scores were $36.2{\pm}8.21$ in the experimental group and $43.4{\pm}7.96$ in the control group, the difference being statistically significant (p<0.05). The general comfort scale post-test mean scores were $149.5{\pm}13.9$ in the experimental group and $137.7{\pm}15.0$ in the control group, again statistically significant (p<0.05). Conclusions: Progressive relaxation exercises positively affect patient comfort and anxiety levels in Turkey.

• 한국정밀공학회지
• /
• 제23권5호
• /
• pp.162-169
• /
• 2006

Steel cord which is used as reinforcement in car tires is produced by wet-drawing process. Recently the quality improvement of the steel cord product is demanded by the tire market. After cold drawing process, produced residual stresses have a harmful effect on the durability of the wire and become the cause which decreases the quality of the product. Therefore, to improve the quality of the steel cord product, the research regarding the method of residual stress relaxation is necessary. To evaluate the quality of the cold drawn wire, it is very important to measure the residual stress, because the residual stress decides a variety of the quality level which is demanded in the cold drawn wire. The aim of this study is to propose residual stress relaxation method in the drawn wire using FE-analysis. The validity of the analysis results was verified by Nano indentation test.

• Structural Engineering and Mechanics
• /
• 제2권4호
• /
• pp.383-393
• /
• 1994

The residual stress distribution in a unidirectional graphite/epoxy laminate induced during the fabrication process is investigated at the microstress level within the scope of linear viscoelasticity. To estimate the residual stresses, the fabrication process is divided into polymerization phase and cool-down phase, and strength of materials approach is employed. Large residual stresses are not generated during polymerization phase because the relaxation modulus is relatively small due to the relaxation ability at this temperature level. The residual stresses increase remarkably during cool-down process. The magnitude of final residual stress is about 80% of the ultimate strength of the matrix material at room temperature. This suggests that the residual stress can have a significant effect on the performance of composite structure.