• PNF and Movement
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• 제20권1호
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• pp.51-58
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• 2022

Purpose: The purpose of this study was to investigate the effect of thoracic-lumbar dissociation motion and slump motion on thoracic-lumbar erector spinae and rectus abdominis muscle activity. Methods: Seventeen healthy adult volunteers participated in this study. All participants performed two motions (thoracic-lumbar dissociation motion, slump motion). Muscle activation during the two motions was measured using a surface electromyography device. The data from this were collected from the iliocostalis thoracis, iliocostalis lumborum, and rectus abdominis. The activities of these muscles before and after each motion were then compared. Results: The iliocostalis thoracis activation was significantly greater during the thoracic-lumbar dissociation motion than during the slump motion (p <0.05). The iliocostalis lumborum activation was greater during the slump motion than during the thoracic-lumbar dissociation motion (p <0.05). The rectus abdominis activation was lesser during the slump motion than during the thoracic-lumbar dissociation motion (p <0.05). Conclusion: This study confirmed that individual contraction of the erector spinae muscles is possible during thoracic-lumbar dissociation motion, which increases the stability of the thoracic spine. In addition, this motion could improve control of the rectus abdominis. Therefore, thoracic-lumbar dissociation motion should be considered for rehabilitation programs for patients with kyphosis and back pain.

• 대한가정학회지
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• 제36권8호
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• pp.95-104
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• 1998

PET microfiber fabric dissociation reactions by ethylene glycol (EG) catalayzed by the corresponding EG anions were examined to provide an empirical basis for the improvement of a PET microfiber fabrics. The alkoxide ions, monosodium ethylene glycolate in ethylene glycol solution(MSEG-EG) are prepared by the reaction between NaH and the EG respectively. The dissociation reactions were carried out until the sample PET microfiber fabrics dissociate up to 80%. Temperature used ranged 100~$160^{\circ}C$. The kinetic behaviors of the dissociated PET microfiber fabrics were examined. The results are as follows : 1. In all cases, it was found that the PET-alkoxide dissociation rate constants increased exponentially with increasing temperature. The activation energies (Ea) of the reactions were 23.31kcal/mol in PET-EG system respectively. The calculated enthalpies of the activated [PET-EG] complexes from the corresponding Ea values were 22.53 ~ 22.61 kcal/mol, and the entropies were -19.03 ~ -19.24 kcal/mol/k respectively. 2. The kinetic behavior of the PET-alkoxide dissociation reactions examined was explained by the transition state theory. PET-alkoxide transition state is believed to be formed during the ester interchange mechanism between PET and MSEG-EG in the course of the PET dissociation reactions.

• EDISON SW 활용 경진대회 논문집
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• 제3회(2014년)
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• pp.347-358
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• 2014

본 논문에서는 양자 역학적 분자 동역학(Quantum Mechanical/Molecular Mechanical-Molecular Dynamics, QM/MM-MD)을 통해 수용액에 녹아 있는 Potassium Thiocyanate의 dynamics를 연구했다. Umbrella sampling technique을 활용하여 association/dissociation에 해당하는 Free energy surface를 구했다. 두 개의 Free energy minimum이 녹아 있는 두 이온의 center of mass 사이의 거리가 $4{\AA}$일 때와 $5{\sim}6{\AA}$ 부근일 때 나타났으며 $4{\AA}$일 때 더 안정 했다. 본 논문에서는 $4{\AA}$일 때를 Contact Ion Pair(CIP) $6{\AA}$일 때를 Dissociation Ion Pair(DlP)라고 칭했다. 이 minimum들이 무엇인 지를 밝혀 내기 위해 추가 연구를 수행하였다. Free energy 상에서 가장 안정 할 때(CIP) solute인 Potassium thiocyanate의 구조를 살펴 봤더니 Potassium ion은 Thiocyanate ion의 Sulfur보다 Nitrogen side를 선호하였다. 그 원인을 알아보기 위해 salvation shell의 구조를 Radial distribution function을 통해 살펴 봤더니 물 분자가 Nitrogen보다 Sulfur와 더 강한 상호작용을 하고 있었다. 그로 인해 Potassium ion이 Nitrogen을 선호한단 결과가 나온 것이다. 한편, 두 번째 minimum은 물 분자가 Potassium 이온과 Thiocyanate 이온 사이에 flexible하게 bridging을 하는 구조였다. 또한 단순 양자 계산을 통해서도 비슷한 구조를 얻을 수 있었다. 그러나 QM 계산은 0K에서 수행하는 것이기 때문에 엔트로피 효과가 없는 계산이지만 본 연구는 온도 300K로 실제 용매와 가깝게 수행함으로써 고정되어 있는 구조가 아니라 엔트로피와 엔탈피가 균형적으로 존재하는 실제 용액 속에서의 구조를 처음으로 보여주는 것이다.

• 한국염색가공학회지
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• 제5권3호
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• pp.216-220
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• 1993

Dissociation constants and heat of dissociation of dimers of 3, 3'-diethyl-thiacarbocyanine dye(Dye 2) have been studied. At $10~40^{\circ}C$, absorption spectra of 2 vol% aqueous ethanol solutions of Dye 2 showed monomer and dimer bands. From the temperature dependence of monomer absorbance, dissociation constants K and ${\Delta}H$ were estimated to be $6.2(10^{\circ}C)-10.6(40^{\circ}C)mon/\ell$ and 3kcal/mol, respectively. These K valus are about one half of those for 3,3'-diethyl-2,2'-cyanine dye with one methine carbon, indication a higher dimer stability than that of 3,3-diethyl-2,2'-cyanine dye.

• Journal of Radiation Protection and Research
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• 제45권1호
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• pp.11-15
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• 2020

Background: There have been various studies to investigate the mechanisms of DNA damage from low-energy electrons. To understand the mechanism of these strand breaks, it is necessary to investigate the dissociation mechanism of the DNA constituents, that is, bases, sugars, and phosphates. Materials and Methods: We studied the dissociation of thymine base upon interaction with low-energy electrons. For this experiment, thymine powder was pressed onto the indium base and irradiated by 5 eV electrons. Results and Discussion: Non-irradiated and irradiated thymine samples were compared and analyzed using the X-ray photoelectron spectroscopic technique to analyze the dissociation patterns of the molecular bonds after low-energy electron irradiation of thymine. Conclusion: With 5 eV electron irradiation, C-C and N-C = O bonds are the primary dissociations that occur in thymine molecules.

• 대한불안의학회지
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• 제18권2호
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• pp.72-79
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• 2022

Objective : Any traumatic event can be a risk factor, for subsequent mental disorder. However, childhood trauma, especially in interpersonal nature, is associated with later development of complex symptom patterns. This study examined the role of dissociation as a mediator between childhood trauma and symptom complexity. Methods : A pooled data of 369 psychiatric outpatients at a university-affiliated hospital was analyzed for descriptive statistics, group differences, and bivariate correlation analysis to verify a structural model. The questionnaires included the Symptom Checklist-90-Revised, the Trauma History Screen, the Dissociative Experiences Scale-Taxon, the Beck Depression Inventory, the Beck Anxiety Inventory, and the Abbreviated PTSD checklist. Results : When other trauma variables were controlled, childhood interpersonal trauma had significant correlation with symptom complexity (r=0.155, p=0.003). Among the paths analyzed, that of childhood interpersonal trauma and dissociation showed the greatest impact on symptom complexity (b=9.34, t=5.75, p<0.001). Based on the significance of the indirect impact, the results suggest a complete mediation impact of dissociation on symptom complexity. Conclusion : This study validated that childhood interpersonal trauma impacts symptom complexity, through the sequential mediating impact of dissociation. Thus, clinicians should understand childhood interpersonal trauma, dissociation, and symptom patterns in a complex and interacting mode, and develop effective pertinent treatment strategies.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.63.2-63.2
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• 2015

Controlling and sensing spin states of magnetic molecules such as metallo-porphyrins at the single molecule level is essential for spintronic molecular device applications. Axial coordinations of diatomic molecules to metallo-porphyrins also play key roles in dynamic processes of biological functions such as blood pressure control and immune response. However, probing such reactions at the single molecule level to understand their physical mechanisms has been rarely performed. Here we present on our single molecule association and dissociation experiments between diatomic and metallo-porphyrin molecules on Au(111) describing its adsorption structures, spin states, and dissociation mechanisms. We observed bright ring shapes in NO adsorbed metallo-porphyrin compelxes and explained them by considering tilted binding and precession motion of NO. Before NO exposure, Co-porphryin showed a clear zero-bias peak in scanning tunneling spectroscopy, a signature of Kondo effect in STS, whereas after NO exposures it formed a molecular complex, NO-Co-porphyrin, that did not show any zero-bias feature implying that the Kondo effect was switched off by binding of NO. Under tunneling junctions of scanning tunneling microscope, both positive and negative energy pulses. From the observed power law relations between dissociation rate and tunneling current, we argue that the dissociations were inelastically induced with molecular orbital resonances. Our study shows that single molecule association and dissociation can be used to probe spin states and reaction mechanisms in a variety of axial coordination between small molecules and metallo-porphyrins.

• 한국결정성장학회지
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• 제10권3호
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• pp.185-188
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• 2000

CdTe 단결정에서 중성 받게에 구속된 엑시톤 해리를 PL 스펙트럼의 온도의존성을 측정하여 조사하였다. 12 K에서 CdTe 단결정의 자유 엑시톤의 결합 에너지는 10 meV이고,중성받게에 구속된 결합 에너지는 7.17 meV 이며, 또 중성주게에 구속된 결합 에너지는 14 meV이였다. 또한 ($A^{\circ}$, X)의 활성화 에너지의 값으로부터($A^{\circ}$, X)의 해리는 자유 엑시톤에서 해리됨을 알 수 있었다.

• Molecules and Cells
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• 제24권1호
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• pp.119-124
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• 2007

TLR4 together with CD14 and MD-2 forms a pattern recognition receptor that plays an initiating role in the innate immune response to Gram-negative bacteria. Here, we employed the surface plasmon resonance technique to investigate the kinetics of binding of LPS to recombinant CD14, MD-2 and TLR4 proteins produced in insect cells. The dissociation constants ($K_D$) of LPS for immobilized CD14 and MD-2 were $8.7{\mu}m$, and $2.3{\mu}m$, respectively. The association rate constant ($K_{on}$) of LPS for MD-2 was $5.61{\times}10^3M^{-1}S^{-1}$, and the dissociation rate constant ($K_{off}$) was $1.28{\times}10^2S^{-1}$, revealing slow association and fast dissociation with an affinity constant $K_D$ of $2.33{\times}10^6M$ at $25^{\circ}C$. These affinities are consistent with the current view that CD14 conveys LPS to the TLR4/MD-2 complex.

• 대한치과의사협회지
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• 제38권4호통권371호
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• pp.378-384
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• 2000