• Bulletin of the Korean Chemical Society
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• v.18 no.12
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• pp.1274-1280
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• 1997

The photodissociation dynamics of CH2I2 has been studied at 304 nm by state-selective photofragment translational spectroscopy. Velocity distributions, anisotropy parameters, and relative quantum yields are obtained for the ground I(2P3/2) and spin-orbit excited state I*(2P1/2) iodine atoms, which are produced from photodissociation of CH2I2 at this wavelength. These processes are found to occur via B1 ← A1 type electronic transitions. The quantum yield of I*(2P1/2) is determined to be 0.25, indicating that the formation of ground state iodine is clearly the favored dissociation channel in the 304 nm wavelength region. From the angular distribution of dissociation products, the anisotropy parameters are determined to be β(I)=0.4 for the I(2P3/2) and β(I*)=0.55 for the I*(2P1/2) which substantially differ from the limiting value of 1.13. The positive values of anisotropy parameter, however, show that the primary processes for I and I* formation channels proceed dominantly via a transition which is parallel to I-I axis. The above results are interpreted in terms of dual path formation of iodine atoms from two different excited states, i.e., a direct and an indirect dissociation via curve crossing between these states. The translational energy distributions of recoil fragments reveal that a large fraction of the available energy goes into the internal excitation of the CH2I photofragment; < Eint > /Eavl=0.80 and 0.82 for the I and I* formation channels, respectively. The quantitative analysis for the energy partitioning of available energy into the photofragments is used to compare the experimental results with the prediction of direct impulsive model for photodissociation dynamics.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.589-589
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• 2015

물은 인간생활에 있어 반드시 필요한 존재이다. 용수 수요량은 도시화로 인한 인구증가와 기상 이상화 현상으로 인해 점증되고 있는 실정이다. 특히 우리나라의 연평균강우량 2/3가 6, 7, 8월에걸쳐 3개월 동안의 강우량에 따라 가뭄빈도가 잦아지고 있어 이에 대한 피해는 앞으로 증가될 것으로 예상되어지고 있다. 실제로 2012년 5 ~ 6월 충남 서부지역에서는 예년평균의 20%로 관측되어 전국최대의 가뭄피해가 발생하였다. 이러한 문제점들을 해결하기 위한 방법으로 수자원의 안정적인 확보와 하천의 효율적인 이용 및 보전계획 등에 대한 관심이 증가되어지고 있다. 이러한 실정을 고려하여 한국건설기술연구원과 SEI-B(Stockholm Environment Institute-Boston Center)가 공동으로 개발한 통합수자원평가계획모형인 K-WEAP(Korea-Water Evaluation And Planning System) 을 이용하여 물수지 분석하였다. 본 연구에서는 K-WEAP 모형을 이용하여 금강유역의 물수지 분석을 기존 수자원장기종합계획의 중권역 단위의 물수지 분석에서 시군 행정구역단위로 분석을 통한 구체적인 공급방안 제시하였다. 이 때 이용된 권역별 유출량 자료는 강우-유출 모형인 Tank 모형을 통해 산정하였으며, 네트워크는 시군 행정구역단위 모의 목적에 따라 구현하여 적용하였다. 물수지 계산시간 간격은 최대 갈수년 1967년을 설정하여 목표연도 2025년까지 총 45년간 반순단위로 물수지 분석을 수행하였다. 개선된 물수급 분석 방안에 의한 산정결과 생공용수의 지역적 물수급 불균형과 농업용수의 월별 물부족량이 발생하는 것으로 검토되어 가뭄에 대비한 중장기적 이수전략, 다양한 수원을 이용한 수자원 안정성을 확보하는데 필요한 참고자료로 활용이 가능할 것으로 판단된다.

• Physical Therapy Rehabilitation Science
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• v.3 no.1
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• pp.69-75
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• 2014

Objective: We developed a Motor-Assisted Rowing Machine (MARM) for Spinal Cord Injury (SCI), by modification of the Concept II rowing machine, so that the seats could be operated automatically in a backward and forward direction by a motor. Design: Case report. Methods: Motor rowing consisted of a chair with inclination control, a motor system, control button, monitor, program, leg supporter, safety belt, and seat. The patients were 2 men rowing athletes with SCI, classified as American Spinal Injury Association class B, participated in the study. Level of thoracic injury ranged from T8 to T10. The subjects rowed at a self-selected stroke rate with 50 watts. Two different rowing methods (static rowing without movement of the seat, dynamic rowing using MARM) were assigned to each participant during 10 minutes; 34 reflective markers were attached to their full bodies. Kinematic data were collected using the Vicon motion analysis system. Based on the full body model provided as a default by the equipment. In the rowing exercise, the rowing motions were divided into Drive Phase and Recovery Phase. Results: The two rowing methods differ in handle range, seat range, handle and seat ratio, handle velocity, and seat velocity during static and dynamic rowing. The rowing exercise using a rowing machine developed MARM increased tendency to the range of motion in the dynamic method compared to the static method. Conclusions: The newly developed MARM could be a useful whole body exercise for people with SCI.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.3
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• pp.177-187
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• 2021

Metabolic syndrome (MBS) is a widespread disease that has strongly related to unhealthy diet and low physical activity, which initiate more serious conditions such as obesity, cardiovascular diseases and type 2 diabetes mellitus. This study aimed to examine the therapeutic effects of morin, as one of the flavonoids constituents, which widely exists in many herbs and fruits, against some metabolic and hepatic manifestations observed in MBS rats and the feasible related mechanisms. MBS was induced in rats by high fructose diet feeding for 12 weeks. Morin (30 mg/kg) was administered orally to both normal and MBS rats for 4 weeks. Liver tissues were used for determination of liver index, hepatic expression of glucose transporter 2 (GLUT2) as well as both inflammatory and fibrotic markers. The fat/muscle ratio, metabolic parameters, systolic blood pressure, and oxidative stress markers were also determined. Our data confirmed that the administration of morin in fructose diet rats significantly reduced the elevated systolic blood pressure. The altered levels of metabolic parameters such as blood glucose, serum insulin, serum lipid profile, and oxidative stress markers were also reversed approximately to the normal values. In addition, morin treatment decreased liver index, serum liver enzyme activities, and fat/muscle ratio. Furthermore, morin relatively up-regulated GLUT2 expression, however, down-regulated NF-κB, TNF-α, and TGF-β expressions in the hepatic tissues. Here, we revealed that morin has an exquisite effect against metabolic disorders in the experimental model through, at least in part, antioxidant, anti-inflammatory, and anti-fibrotic mechanisms.

• BMB Reports
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• v.52 no.3
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• pp.220-225
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• 2019

We have identified a mechanism to diminish the proliferative capacity of cells during cell expansion using human adipose-derived stromal cells (hAD-SCs) as a model of replicative senescence. hAD-SCs of high-passage numbers exhibited a reduced proliferative capacity with accelerated cellular senescence. Levels of key bioactive sphingolipids were significantly increased in these senescent hAD-SCs. Notably, the transcription of sphingosine kinase 1 (SPHK1) was down-regulated in hAD-SCs at high-passage numbers. SPHK1 knockdown as well as inhibition of its enzymatic activity impeded the proliferation of hAD-SCs, with concomitant induction of cellular senescence and accumulation of sphingolipids, as seen in high-passage cells. SPHK1 knockdown-accelerated cellular senescence was attenuated by co-treatment with sphingosine-1-phosphate and an inhibitor of ceramide synthesis, fumonisin $B_1$, but not by treatment with either one alone. Together, these results suggest that transcriptional down-regulation of SPHK1 is a critical inducer of altered sphingolipid profiles and enhances replicative senescence during multiple rounds of cell division.

• Korean Journal of Acupuncture
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• v.36 no.2
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• pp.93-103
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• 2019

Objectives : The aim of this study is to review the current trends in experimental studies on the acupuncture moxibustion treatment for visceral hypersensitivity. Methods : PubMed was searched for experimental studies about visceral hypersensitivity and acupuncture/moxibustion. Data were extracted and tabulated from the selected articles about experimental method, intervention, result and mechanism. Results : Total 23 articles were reviewed. Chronic visceral hypersensitivity animal model was applied in 17 studies (74%). Visceral hypersensitivity was measured by abdominal withdrawal reflex scoring or/and abdominal electromyogram. Acupoints like ST25, ST36, ST37, BL25, LI11, BL32 and PC6 were treated by electroacupuncture or moxibustion. All articles reported that electroacupuncture or moxibustion treatment is significantly effective in reducing visceral hypersensitivity. Treatment mechanisms were studied, related to mast cell, serotonin (5-HT) and receptor (5-HT3R and 5-HT4R), substance P (SP), vasoactive intestinal polypeptide (VIP), c-fos positive cell, corticotropin-releasing hormone (CRH), purinergic 2X (P2X)2, P2X3, P2X4, P2X7, N-methyl-D-aspartate (NMDA) receptor (NR1 and NR2B), prokinectin (PK) 1 and PK2. Conclusions : Evidences on acupuncture/moxibustion treatment for visceral hypersensitivity in animal studies warrant more research on effective acupoins, electro-acupuncture methods and treatment durations.

• Advances in concrete construction
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• v.7 no.3
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• pp.151-166
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• 2019

This paper introduces a new efficient analytical method, based on shear deformations obtained with 2D elasticity theory approach, to perform an explicit closed-form solution for calculation the interfacial shear and normal stresses in plated RC beam. The materials of plate, necessary for the reinforcement of the beam, are in general made with fiber reinforced polymers (Carbon or Glass) or steel. The experimental tests showed that at the ends of the plate, high shear and normal stresses are developed, consequently a debonding phenomenon at this position produce a sudden failure of the soffit plate. The interfacial stresses play a significant role in understanding this premature debonding failure of such repaired structures. In order to efficiently model the calculation of the interfacial stresses we have integrated the effect of shear deformations using the equilibrium equations of the elasticity. The approach of this method includes stress-strain and strain-displacement relationships for the adhesive and adherends. The use of the stresses continuity conditions at interfaces between the adhesive and adherents, results pair of second-order and fourth-order coupled ordinary differential equations. The analytical solution for this coupled differential equations give new explicit closed-form solution including shear deformations effects. This new solution is indented for applications of all plated beam. Finally, numerical results obtained with this method are in agreement of the existing solutions and the experimental results.

• Molecules and Cells
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• v.44 no.2
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• pp.79-87
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• 2021

Chromatin dynamics is essential for maintaining genomic integrity and regulating gene expression. Conserved bromodomain-containing AAA+ ATPases play important roles in nucleosome organization as histone chaperones. Recently, the high-resolution cryo-electron microscopy structures of Schizosaccharomyces pombe Abo1 revealed that it forms a hexameric ring and undergoes a conformational change upon ATP hydrolysis. In addition, single-molecule imaging demonstrated that Abo1 loads H3-H4 histones onto DNA in an ATP hydrolysis-dependent manner. However, the molecular mechanism by which Abo1 loads histones remains unknown. Here, we investigated the details concerning Abo1-mediated histone loading onto DNA and the Abo1-DNA interaction using single-molecule imaging techniques and biochemical assays. We show that Abo1 does not load H2A-H2B histones. Interestingly, Abo1 deposits multiple copies of H3-H4 histones as the DNA length increases and requires at least 80 bp DNA. Unexpectedly, Abo1 weakly binds DNA regardless of ATP, and neither histone nor DNA stimulates the ATP hydrolysis activity of Abo1. Based on our results, we propose an allosteric communication model in which the ATP hydrolysis of Abo1 changes the configuration of histones to facilitate their deposition onto DNA.

• Journal of Audiology & Otology
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• v.25 no.3
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• pp.146-151
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• 2021

Background and Objectives: The relationship between hearing aid (HA) use and improvement in cognitive function is not fully known. This study aimed to determine whether HAs could recover temporal resolution or hearing in noise functions. Materials and Methods: We designed a prospective study with two groups: HA users and controls. Patients older than 45 years, with a pure tone average threshold of worse than 40 dB and a speech discrimination score better than 60% in both ears were eligible. Central auditory processing tests and hearing in noise tests (HINTs) were evaluated at the beginning of the study and 1, 3, 6, and 12 months after the use of a monaural HA in the HA group compared to the control group. The changes in the evaluation parameters were statistically analyzed using the linear mixed model. Results: A total of 26 participants (13 in the HA and 13 in the control group) were included in this study. The frequency (p<0.01) and duration test (p=0.02) scores showed significant improvements in the HA group after 1 year, while the HINT scores showed no significant change. Conclusions: After using an HA for one year, patients performed better on temporal resolution tests. No improvement was documented with regard to hearing in noise.

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.2
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• pp.145-153
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• 2022

Purpose : This study aimed to investigate the effects of blended learning on learning satisfaction in nursing students. Methods : This study was conducted with 160 current nursing students in the department of nursing at K university located in city B. All students included in the study understood the purpose of the study and provided informed consent to participate. Data were collected between May 3 and July 9, 2021 and analyzed using SPSS/WIN 22.0. The frequency, percentage, mean, and standard deviation were created, and t-test, ANOVA, and Scheffé test for post hoc analysis were performed. Correlations were analyzed using Pearson's correlation coefficient. The factors influencing learning satisfaction were analyzed using multiple regression. Results : Significant differences were observed for academic stress according to the online classes environmental satisfaction (F=4.10, p=.001), online classes experience (t=4.11, p=.001) and self-directed learning ability according to the grade (F=4.10, p=.001), online classes environmental satisfaction (t=4.11, p=.001). The academic stress of nursing students who experienced blended learning was significantly negatively correlated with self-directed learning ability (r=-.480, p<.001), and learning satisfaction (r=-.236, p<.001). self-directed learning ability showed a significant positive correlation with learning satisfaction (r=.524, p<.001). The regression model for the factors affecting the learning satisfaction of the subjects was statistically significant (F= 3.027, p<.001). The major influential factors of learning satisfaction were grade (𝛽=.154, p=.013), satisfaction with school life (𝛽=.168, p=.032), and satisfaction with non-contact learning environment (𝛽=-.141, p=.028). The explanatory power was 28 %. Conclusion : These results indicate that it is necessary to reduce academic stress and increase self-directed learning ability to enhance learning satisfaction in nursing students through blended learning. In addition, the development and operation of a tailored intervention program is required to help improve learning satisfaction.