• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.673-680
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• 2019

This study was conducted to investigate the effects of plasma homocysteine concentration on the brachial-ankle pulse wave velocity between the normal homocysteine group and the asymptomatic high homocysteine group. 435 subjects who visited the general health examination center from April 1 to October 31, 2016, as well as to compare the direct correlation of the brachial-ankle pulse wave velocity, which indirectly reflects the homocysteine test and arterial stiffness, as a predictor of future cardiovascular outcome. As a result of the study, age, waist circumference, BUN, and plasma creatinine were significantly higher, and HDL was significantly lower in the high homocysteine group (> $15{\mu}mol/L$) than in the normal homocysteine group (< $15{\mu}mol/L$) (p=0.05). In addition, homocysteinemia was associated with smoking and drinking (p<0.001) and was significantly higher in males (p<0.001). The right and left brachial-to-ankle pulse wave velocities were significantly higher in the high homocysteine group (right p<0.001, left p=0.003) before calibrating the relevant variables. There was no significant difference between right and left brachial-to-ankle pulse wave velocities after calibrating the relevant variables. Therefore, further studies on the independent association of lowering homocysteine concentration and prevention of cardiovascular disease and the relationship between homocysteine and renal function are needed.

• Proceedings of the KSAR Conference
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• 2001.10a
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• pp.62-62
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• 2001

Development of effective activation protocols is of great importance for improving the success of cloning and subsequent transgenic. Three methods for oocyte activation, including 5μM ionomycin (5 min) alone, ionomycin＋1.9 mM 6-dimetylaminopurine (DMAP, 3 hrs) and ionomycin＋10㎍/㎖ cycloheximide(CHX, 3 hrs) were compared for their effects of pronuclei(PN) formation, development, developmental velocity and ploidy of parthenotes to IVF control in bovine. In group of ionomycin＋DMAP, the oocytes having more 3 PN were significantly(P〈0.05) higher than in groups of ionomycin alone and of ionomycin＋CHX (45.5% vs. 0 and 0%, respectively). Activation with the ionomycin alone, ionomycin＋DMAP and ionomycin＋CHX resulted in cleavage rates of 30, 85.5 and 57.9%, respectively. The blastocysts rate of parthenotes activated by ionomycin＋DMAP treatment was significantly higher (12.3%, P〈0.05) than those of other treated groups. Chromosome analysis shows that ionomycin＋DMAP treatment greatly increases the incidence of chromosomal abnormality of the parthenotes. When compared the developmental velocity at 24 hrs after insemination and activation, 27% eggs in IVF control and 55% in DMAP treatment out of total cleaved eggs developed to 2-cell stage, respectively. Developmental velocity of parthenotes activated by ionomycin ＋DMAP treatment was significantly (P〈0.05) faster than others. From the results, we may conclude that DMAP treatment to the oocytes accelerates developmental velocity resulting in both the higher incidence of chromosome abnormality and of PN formation suggesting that CHX combined with ionomycin is suitable DMAP for the purpose of successful nuclear transplantation.

• Wind and Structures
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• v.27 no.5
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• pp.347-356
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• 2018

In this paper, stress distribution for a structurally stable greenhouse is considered in the present paper with subsequent investigation into the detailed stress distribution contour with the variation of self-weight and wind pressure level designation method under wind velocity of less than 30 m/sec. For reliable analysis, wind pressure coefficients of a single greenhouse unit were modeled and compared with experiment with correlation coefficient greater than 0.99. Wind load level was designated twofold: direct mapping of fluid dynamic analysis and conversion of modeled results into wind pressure coefficients ($C_P$). Finally, design criteria of EN1991-1-4 and NEN3859 were applied in terms of their wind pressure coefficients for comparison. $C_P$ of CFD result was low in the most of the modeled area but was high only in the first roof wind facing and the last lee facing areas. Besides, structural analysis results were similar in terms of stress distribution as per EN and direct mapping while NEN revealed higher level of stress for the last roof area. The maximum stress levels are arranged in decreasing order of mapping, EN, and NEN, generating 8% error observed between the EN and mapping results under 30 m/sec of wind velocity. On the other hand, effect of dead weight on the stress distribution was investigated via variation of high stress position with wind velocity, confirming shift of such position from the center to the forward head wind direction. The sensitivity of stress for wind velocity was less than 0.8% and negligible at wind velocity greater than 20 m/sec, thus eliminating self-weight effect.

• Journal of the Korean Geophysical Society
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• v.4 no.1
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• pp.21-33
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• 2001

Simultaneous inversion of first-arrivals of local earthquakes recorded by the Korea Meteorological Administration(KMA) seismograph network from 1991 to 1998 is made to derive 1D crustal velocity structure of the Korean peninsula. Twenty-nine events with 178 observations are used in the inversion. Average crustal P-wave velocity turns out to be about 6.3 km/sec, and crustal thickness and upper mantle P-wave velocity are estimated as 33 km and 7.9 km/sec, respectively. Results of inversion indicate the possibility of the low velocity layer in the lower crust. Joint inversion is applied to estimate hypocenters, station delays, and velocities simultaneously. Relative station corrections for 11 stations range from zero to about 1.2 sec. Analysis of the synthetic data shows that estimates of hypocenter locations and station corrections as well as averaged crustal structure are reliable for the given data set..

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.2
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• pp.101-108
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• 2023

Purpose : To investigate effects of transcranial directed current stimulus (tDCS) combined with abdominal draw-in maneuver (ADIM) on balance ability and trunk impairment scale of chronic stroke patients. Methods : Twenty-six chronic stroke patients were recruited and twenty-four participated after excluding two patients who met the exclusion criteria. After screening tests, they were randomized through excel program into an experimental group (n = 12) to apply a tDCS combined with ADIM and a control group (n = 12) to apply a sham tDCS with ADIM. The intervention lasted three times a week for six weeks. To compare tDCS intervention effects, trunk impairment scale and balance ability were measured. Comparisons between experimental and control groups were statistically processed using an independent t-test and comparisons within groups were statistically processed using a paired t-test. Results : The experimental group showed significant increases of pre- and post-intervention medial lateral velocity, anterior posterior velocity and area of balance ability, and trunk impairment scale (p<.05). The control group showed significant increases in pre- and post-intervention medial lateral velocity of balance ability and trunk impairment scale (p< .05). The experimental group showed significant increases of medial lateral velocity of balance ability and trunk impairment scale compared to the control group (p<.05). Conclusion : Results of this study suggest that tDCS combined with ADIM for chronic stroke patients can be effective in improving medial lateral velocity of balance ability and trunk impairment scale. Thus, tDCS can be used as an effective treatment protocol for trunk rehabilitation of chronic stroke patients.

• Biomedical Science Letters
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• v.18 no.3
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• pp.260-267
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• 2012

Obesity is associated with cardiovascular risk factors, such as dyslipidemia, hypertension and diabetes. However the presence of the obesity related deranged metabolic profiles varies widely among obese individuals. These individuals, known as 'metabolically healthy obese phenotype (MHO)', despite having excessive body fatness, display favorable metabolic profiles characterized by insulin sensitivity, no hypertension, as well as less dyslipidemia, less inflammation. The purpose of this study was to compare cardiac characterization and clinical profile of MHO and Non-MHO (nonmetabolically healthy obese) subjects in men. We measured treadmill exercise capacity (METs) and maximum blood pressure (BP) in 210 subjects through a medical checkup at J General Hospital. Metabolic syndrome was defined according to the modified Adult Treatment Panel III definition criteria. Both MHO and Non-MHO subjects showed statistically significant changes in the left ventricular mass index (P<.001, P<.01, respectively), A-velocity (P<.01, P<.001, respectively), E/A ratio (P<.01, P<.001, respectively), E'-velocity (P<.001, P<.001, respectively), HOMA-IR (P<.01, P<.001, respectively) and maximum systolic BP (P<.01, respectively) compared with the MH-NO (metabolically healthy non obese) subjects. In conclusion, MHO participants were at increased risk of cardiovascular disease and partly metabolic disorder.

• The Journal of Korean Physical Therapy
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• v.17 no.2
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• pp.126-147
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• 2005

TCD(transcranial doppler, TCD) units is a equipment that measure a blood flow velocity in the middle cerebral artery(MCA), anterior cerebral artery(ACA), posterior cerebral artery(PCA), and vertebral artery(VA). The aim of this study was to determine the influence on cerebral blood flow velocity according to different stimulation frequency of interferential currents. 50 patients who has a cervical pain were participated in this study and randomly divided into one of the three experimental, placebo, and control group: (1)IFS 1; $10{\sim}30Hz$ was applied, (2)IFS 2; $30{\sim}50Hz$ was applied, (3)IFS 3; $50{\sim}100Hz$ was applied, (4)placebo; suction only applied, and (5)control; neither suction nor interferential stimulation applied. In the IFS groups, interferential stimulations were applied through four suction electrodes application from the 5th cervical to the 1st thoracic level. The results were as follow; 1. MCA was statistically significant with IFS 1, IFS 2, IFS 3, and Placebo group(p<0.05), But there was no statistical significance between IFS 1 and IFS 3 group(p>0.05). 2. ACA was statistically significant with IFS 1, IFS 2, and IFS 3 group(p<0.05). And IFS 1 was more statistical significance than IFS 3 group on ACA(p<0.05). 3. PCA was statistically significant with IFS 1, IFS 2, and IFS 3 group(p<0.05). And IFS 1 was more statistical significance than IFS 3 group on PCA(p<0.05). 4. VA was statistically significant with IFS 1, IFS 2, and IFS 3 group(p<0.05). And IFS 1 was more statistical significance than IFS 3 group on VA(p<0.05).

• Journal of the Korean Institute of Gas
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• v.16 no.5
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• pp.7-13
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• 2012

An experimental study has been done to investigate the explosion characteristics of aluminum powders with different sizes and concentrations in a 20 L spherical explosion vessel. Two different sizes of aluminum powder were used : $15.1{\mu}m$ and $34.8{\mu}m$ with a volume mean diameter. The results revealed that $15.1{\mu}m$ Al powder has a Lower explosion limit (LEL) of $40g/m^3$, a maximun explosion pressure ($P_{max}$) of 9.8 bar and a maximum rate of pressure rise ($[dP/dt]_{max}$) of 1852 bar/s, in $34.8{\mu}m$ Al powder, LEL of $70g/m^3$, $P_{max}$ of 7.9 bar and $[dP/dt]_{max}$ of 322 bar/s. The LEL of Al powders tended to increase with the increase of particle size. Also, it was found that the flame velocity calculated from the powder with $15.1{\mu}m$ was about 5 times higher than that of the powder of $34.8{\mu}m$.

• Journal of the Korean Geosynthetics Society
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• v.14 no.1
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• pp.23-32
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• 2015

This paper describes a flow experiment and characteristics of heavy metals based on microfluidics, in order to improve the prefabricated vertical drain system that is possible pollutants removal and soil improvement in soft ground polluted with various pollutants, simultaneously. The result showed that the surface with hydrophobic condition affected large effect on flow velocity pollutants, and pH condition was also influence factor for change of flow velocity. Especially, the flow velocity of lead has risen slightly, when pH was close to basicity in complex heavy metal. This means that lead pollutant can reduce a hydrophobic characteristic in comparison with a copper pollutant.

• The Journal of Internal Korean Medicine
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• v.19 no.1
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• pp.157-167
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• 1998

Background and Purpose : Cerebrovascular reactivity(CVR) can be estimated by measuring the change of cerebral blood flow that occurs during vasostimulation. To estimate the cerebrovascular reactivity, we investigated the change of flow velocity of the middle cerebral artery(MCA) during hyperventilation and hypoventilation with the transcranial doppler. So we studied whether the CVR measured by this method could show a significant difference between the normal and the cerebral infarction subjects and whether the CVR may decrease with age in normal subjects. Methods : Using transcranial doppler, we measured the mean velocity(Vm), the pulsatility index(P.I.) at the resting state, the end of breath-holding and the end of hyperventilation in 36 normal and 10 cerebral infarction subjects, so we calculated the percentile change of mean velocity(%${\Delta}$Vm) and P.I.(%${\Delta}$P.I.) after the vasostimulation. We estimated the change of Vm, P.I., %${\Delta}$Vm and %${\Delta}$P.I. by the age group and compared those parameters between the age-matched normal control and cerebral infarction subjects. Results : The Vm in MCA significantly decreased with age(p<0.05), but there was no significant difference in Vm and P.I. between normal and cerebral infarction subjects. The %${\Delta}$Vm and %${\Delta}$P.I. in response to hyperventilation significantly decreased with age in MCA and there was significant difference in $%{\Delta}Vm$ of MCA after breath-holding between the normal and cerebral infarction subjects. Conclusion : The breath-holding and hyperventilation tests could be non-invasive and useful methods in estimation of the cerebrovascular reactivity and could be applied in the basal and follow-up evaluation of the cerebrovascular reserve of the ischemic stroke patients.