• Title/Summary/Keyword: 동적 평형성

Search Result 113, Processing Time 0.021 seconds

Smoking-Induced Dopamine Release Studied with $[^{11}C]Raclopride$ PET ($[^{11}C]Raclopride$ PET을 이용한 흡연에 의한 도파민 유리 영상 연구)

  • Kim, Yu-Kyeong;Cho, Sang-Soo;Lee, Do-Hoon;Ryu, Hye-Jung;Lee, Eun-Ju;Ryu, Chang-Hung;Jeong, In-Soon;Hong, Soo-Kyung;Lee, Jae-Sung;Seo, Hong-Gwan;Jeong, Jae-Min;Lee, Won-Woo;Kim, Sang-Eun
    • The Korean Journal of Nuclear Medicine
    • /
    • v.39 no.6
    • /
    • pp.421-429
    • /
    • 2005
  • Purpose: It has been postulated that dopamine release in the striatum underlies the reinforcing properties of nicotine. Substantial evidence in the animal studies demonstrates that nicotine interacts with dopaminergic neuron and regulates the activation of the dopaminergic system. The aim of this study was to visualize the dopamine release by smoking in human brain using PET scan with $[^{11}C]raclopride$. Materials and Methods: Five male non-smokers or ex-smokers with an abstinence period longer than 1 year (mean age of $24.4{\pm}1.7$ years) were enrolled in this study $[^{11}C]raclopride$, a dopamine D2 receptor radioligand, was administrated with bolus-plus-constant infusion. Dynamic PET was performed during 120 minutes ($3{\times}20s,\;2{\times}60s,\;2{\times}120s,\;1{\times}180s\;and\;22{\times}300s$). following the 50 minute-scanning, subjects smoked a cigarette containing 1 mg of nicotine while in the scanner. Blood samples for the measurement of plasma nicotine level were collected at 0, 5, 10, 15, 20, 25, 30, 45, 60, and 90 minute after smoking. Regions for striatal structures were drawn on the coronal summed PET images guided with co-registered MRI. Binding potential, calculated as (striatal-cerebellar)/cerebellar activity, was measured under equilibrium condition at baseline and smoking session. Results: The mean decrease in binding potential of $[^{11}C]raclopride$ between the baseline and smoking in caudate head, anterior putamen and ventral striatum was 4.7%, 4.0% and 7.8%, respectively. This indicated the striatal dopamine release by smoking. Of these, the reduction in binding potential in the ventral striatum was significantly correlated with the cumulated plasma level of the nicotine (Spearman's rho=0.9, p=0.04). Conclusion: These data demonstrate that in vivo imaging with $[^{11}C]raclopride$ PET could measure nicotine-induced dopamine release in the human brain, which has a significant positive correlation with the amount or nicotine administered bt smoking.

The Association between Cross-section of Lumbar Regional Muscle analyzed by MRI and Stability, Center of Pressure assessed by Tetrax (요통 환자의 요추 주변 근육 단면적과 신체안정성(Stability), 체중심(Center of Pressure)과의 관련성 : 동적평형검사(Tetrax)를 중심으로)

  • Seong, Ik-Hyun;Lee, Kap-Soo;Jung, Jae Hoon;Kim, Won-Woo;Cho, Chang-Young;Choi, Chul-Woo;Ha, In-Hyuk
    • The Journal of Churna Manual Medicine for Spine and Nerves
    • /
    • v.8 no.2
    • /
    • pp.39-46
    • /
    • 2013
  • Objectives : To identify the association between cross-sectional area of lumbar regional muscle and stability(ST), center of pressure(COP) assessed by tetrax. Methods : Patients(n=55) who had taken L-SPINE MRI and Tetrax(Sunlight, Israel) were analyzed retrospectively. To evaluate the cross-sectional area of lumbar regional muscle, L-SPINE MRI was used. Data of ST, COP were accumulated by using dynamic equilibrium analysis by Tetrax. Of the lumbar regional muscles, the Psoas muscles and the Paraspinalis muscles were examined. Using Pearson correlation, we analyzed COP, ST and the difference between the cross-sectional area of lumbar regional muscles. Results : The variance of cross-sectional area of both sides of Psoas muscle and COP had moderate positive correlation(r=0.621). Between variance of cross-sectional area of both sides of Paraspinalis and lumbar regional muscle and COP there was low positive correlation(r=0.287, r=0.329) ST also had low correlation with variance of cross-sectional area of both sides of Psoas muscle. Conclusion : The variance of cross-sectional area between both sides of Psoas muscle had moderate correlation with COP.

  • PDF

An Outline of Food Ethics (음식윤리 개요)

  • Kim, Suk-Shin
    • Food Science and Industry
    • /
    • v.49 no.2
    • /
    • pp.83-97
    • /
    • 2016
  • This review was performed to outline the food ethics to the professionals in the field of food science and industries. Food ethics is the ethics or ethical consideration concerning food; while, the keywords of food ethics are a life, happiness and the wisdom. The ultimate goal as well as the first principle of food ethics is a sustainable living of human race. In order to reach the goal a coexistence of humans and nature, coexistence of humans and humans, and the fulfillment of essential requirements of a food are needed. The needs yield six categorical imperatives such as a respect for life, preservation of nature, distributive justice without deception or fakes, prior consideration of consumer, moderation and balance neither overs nor shorts, and the assurance of safety. The core principles corresponding to the categorical imperatives include a respect for life, environmental preservation, justice, priority of consumer, dynamic equilibrium, and the priority of safety. The core principles approach is a simple, clear, and practical method in solving ethical issues. The code of food ethics is also based on the core principles.

Explicit Stress-Erection and Ultimate Load Analysis of Unit STRARCH Frame Considering Geometrically and Materially Nonlinear Characteristics (기하학적 재료적 비선형 특성을 고려한 스트라치 단위부재의 명시적 긴장설치 및 극한하중 해석)

  • Lee, Kyoung-Soo;Han, Sang-Eul
    • Journal of Korean Society of Steel Construction
    • /
    • v.23 no.4
    • /
    • pp.429-438
    • /
    • 2011
  • In this study, the explicit numerical algorithm was proposed to simulate the stress erection process and ultimate-load analysis of the strarch (stressed arch) system. The strarch system is a unique and innovative structural system and member prestress comprising prefabricated plane truss frames erected through a post-tensioning stress erection procedure. The flexible bottom chord, which has sleeve and gap details, is closed by the reaction force of the prestressing tendon. The prestress imposed on the tendon will enable the strarch system to be erected. This post-tensioning process is called "stress erection process." During this process, plastic rigid-body rotation occurs to the flexible top chord due to the excessive amount of plastic strain, and the structural characteristic is unstable. In this study, the dynamic relaxation method (DRM) was adopted to calculate the nonlinear equilibrium equation of the system, and a displacement-based finite-element-formulated filament beam element was used to simulate the nonlinear behavior of the top chord sections of the strarch system. The section of the filament beam element was composed by the amount of filaments, which can be modeled by various material models. The Ramberg-Osgood and bilinear kinematic elastic plastic material models were formulated for the nonlinear material behaviors of the filaments. The numerical results that were obtained in the present study were compared with the experiment results of the stress erection and with the results of the ultimate-load analysis of the strarch unit frame. The results of the present studies are in good agreement with the previous experiment results, and the explicit DRM enabled the analysis of the post-buckling behaviors of the strarch unit frame.

Effect of Cosurfactant on Solubilization of Hydrocarbon Oils by Pluronic L64 Nonionic Surfactant Solution (보조계면활성제가 Pluronic L64 비이온 계면활성제에 의한 탄화수소 오일 가용화에 미치는 영향)

  • Bae, MinJung;Kim, DoWon;Cho, Seo-Yeon;Lim, JongChoo
    • Korean Chemical Engineering Research
    • /
    • v.52 no.2
    • /
    • pp.219-225
    • /
    • 2014
  • In this study, effect of cosurfactant on the solubilization rate of n-octane, n-decane and n-dodecane oil was performed by micellar solutions of polymeric nonionic surfactant Pluronic L64($EO_{13}PO_{30}EO_{13}$) at room temperature. It has been found that the solubilization rate of a hydrocarbon oil was enhanced with an increase in both chain length and amount of alcohol added. In case of addition of a short chain alcohol such as 1-butanol, the solubilization rate of a hydrocarbon oil was slightly increased since most of alcohol molecules remained in an aqueous surfactant solution. On the other hand, the addition of a relatively long chain alcohol such as 1-hexanol and 1-octanol produced a big increase in solubilization rate of a hydrocarbon oil mainly due to incorporation of alcohol molecules into micelles and thus producing more flexible micellar packing density. Dynamic interfacial tension measurements showed the same trend found in solubilization rate measurement. Both interfacial tension value at equilibrium and time required to reach equilibrium decreased with an increase in chain length of an alcohol.

Biofilter Model for Robust Biofilter Design: 1. Adsorption Behavior of the Media of Biofilter (강인한 바이오필터설계를 위한 바이오필터모델: 1. 바이오필터 담체의 흡착거동)

  • Lee, Eun Ju;Seo, Kyo Seong;Jeon, Wui-Sook;Lim, Kwang-Hee
    • Korean Chemical Engineering Research
    • /
    • v.50 no.1
    • /
    • pp.149-154
    • /
    • 2012
  • The adsorption and desorption behavior of biofilter-medium was investigated on the performance of an adsorption column. Continuous flow-isothermal adsorption experiments were performed to treat waste air containing such a VOC as ethanol under the same condition of > 90% relative humidity as the condition of the feed to a biofilter process. In case of feeding waste air containing ethanol of 1,000 ppmv (or 2,050 mg ethanol/$m^3$) to the adsorption system at the rate of 2 L/min, the onsets of its breakthrough and reaching the state of dynamic equilibrium at the exit had been delayed 10 and 3 times, respectively, later than those at the 1st stage sampling port. Moreover, in case of 2,000 ppmv (or 4,100 mg ethanol/$m^3$), they had been delayed 9 and 3 times, respectively. Thus, regardless of feeding concentration, the ratios of delaying period were observed to be quite consistent each other at the exit of the adsorption column. With regard to the period of desorption, the ratios of delaying period were consistent each other to be 1.5 for both cases. In addition, the effect of microbial activity and sterilization-process was studied on adsorption equilibrium. The ethanol concentration in the vapor phase of vials packed with sterilized granular activated carbon (GAC) was quite consistent to that with unsterilized GAC. However, the ethanol concentrations in the vapor phase of vials packed with unsterilized compost and the unsterilized mixture of GAC and compost were higher than those with sterilized compost and the sterilized mixture of GAC and compost, respectively.

The High Temperature Deformation Behavior of Mechanically (기계적 합금화된 Al-8wt% Fe분말의 고온 변형거동)

  • Jo, Gwon-Gu;Lee, Do-In;An, In-Seop;Heo, Bo-Yeong;Jo, Jong-Chun;Kim, Seon-Jin;Mun, In-Hyeong
    • Korean Journal of Materials Research
    • /
    • v.3 no.1
    • /
    • pp.50-57
    • /
    • 1993
  • Abstract The sintering behavior of the mechanically alloyed AI-8wt%Fe power during vacuum hot pressing was investigated and high temperature deformation behavior of the sintered specimen was studied through compression tests at various strain rates in the temperature range between 35$0^{\circ}C$ and 45$0^{\circ}C$. In 'addition, thermal stablity of the sintered specimem was examined by hardness measurement after annealing the spcimem for 60 hours in the temperature range of 30$0^{\circ}C$ ~50$0^{\circ}C$. The compressive stress increased rapidly with strain and reached the maximum point at the strain about 3%. With slight decrement after reaching the maximum point, the flow stress became constant up to the strain of 30% and it was considered to be due to equilibrium between work hardening and dynamic recrystallization. The hardness of the 60 hrs annealed specimens began to decrease rapidly at 40$0^{\circ}C$ .

  • PDF

A Study on the Transfer of Amino Acids across the Human Placenta at Term of Pregnancy (임신말 태반을 통한 아미노산 이동에 관한 연구)

  • Ahn, Hong-Seok
    • Journal of Nutrition and Health
    • /
    • v.18 no.3
    • /
    • pp.209-216
    • /
    • 1985
  • The plasma levels of 23 free amino acids in both the umbilical circulation (umbilical vein and artery) and the maternal circulation (antecubital vein, uterine vein and iliac artery ) of 34 pregnant women were measured at delivery by the cesarean section. Each amino acid with the exception of glutamate was found to be in higher concentration in the fetal blood and the cord plasma characterized by hyperaminoacidemia with a marked increase of the lysine and ornithine levels. The linear relationships found between the amino acids concentrations of iliac artery and those of umbilical vein suggest three transport groups across the placental membrane One group consists of neutral amino acids whose slopes are equal to one and the other two groups are characterized by their slopes higher and lower than unity respectivly. This division into three groups is tentatively explained by the result of a dynamic equilibrium between active transport towards the fetus and diffusion back towards the maternal circulation.

  • PDF

Comparison of effects of 12 weeks of Pilates with Mini Ball versus Mat Pilates on strength, endurance, flexibility, and dynamic equilibrium in older adults. (12주간의 미니볼(Mini Ball)을 이용한 필라테스와 매트 필라테스가 노인의 근력, 전신지구력, 유연성, 동적평형성에 미치는 영향을 비교)

  • Myoung-Kwon Kim;Yong-Bum Jung;Eun-Hee Jeon
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
    • /
    • v.29 no.1
    • /
    • pp.33-39
    • /
    • 2023
  • Background: Most Pilates programs for older adults have been based on mat Pilates, and there has been limited research on Pilates with mini-balls. Therefore, this study aims to compare the effects of Pilates with mini-balls and mat Pilates interventions on strength, total body endurance, flexibility, and dynamic equilibrium to determine the differences. Methods: The elderly aged 65 or older living in Gyeongsan, Daegu, were divided into two groups, and the experimental group (n=10) conducted a Pilates exercise program using mini balls for 12 weeks, and the control group (n=10) conducted a mat Pilates exercise program for 12 weeks without mini balls. Strength, endurance, flexibility, and dynamic equlibrium were measured as a pre-test, and post-test was performed in the same way after 12 weeks of application. Results: Comparing the mini-ball Pilates group to the mat Pilates group, there was a significant difference (p<.05) in the 'chair sit and reach' after the intervention. In the within-group comparison, there was a significant increase (p<.05) in 'arm curl right', '30-second chair stand', '2-minute walk', 'back scratch', 'chair sit and reach', and '2.44m up and go' in the experimental group using the mini-ball Pilates program. Mat Pilates program significantly increased the within-group comparisons in '30-second chair stand' and 'chair sit and reach' (p<.05). Conclusion: It is suggested that mini-ball Pilates has a positive effect on the senior fitness and will be a good exercise method for using it as an exercise program for the elderly in the future.

  • PDF

The Study on Improvement Methods for The Seismic Performance of Port Structures (항만 구조물의 내진성능 향상을 위한 배면 지반의 보강방안에 관한 연구)

  • Kim, Byung-Il;Hong, Kang-Han;Kim, Jin-Hae;Han, Sang-Jae
    • Journal of the Korean Geosynthetics Society
    • /
    • v.18 no.4
    • /
    • pp.151-165
    • /
    • 2019
  • In this study, the four types of improvement methods (increase self weight and reducing sliding force etc.) were proposed depending on install location with compaction grouting to improve seismic performance of existing port structure and optimal methods by analyzing the effects of improvement (stability, constructability and economy) by theoretical and numerical methods. From the dynamic time history analysis for artificial seismic waves, the results indicated that the horizontal displacement after improvement decreased compared to before improvement, however the displacement reduction effect among improvement methods was not significantly different. Slope stability based on the strength reduction method and the limit equilibrium analysis method, it is confirmed that the passive pile method is more safe than other methods. It is due to the shear strength at the failure surface is increased. In addition, the analysis of constructability and economy showed that the reduction of earth pressure method (type 02) and the passive pile method (type 03) are excellent. However, in the case of the passive pile method is concerned that there is a shortage of design cases and the efficiency can be reduced depend on various constraints such as ground conditions.