• Journal of Chest Surgery
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• 제21권6호
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• pp.979-983
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• 1988

Calcium channel blockers may prevent myocardial injury during cardioplegia and reperfusion. This study was done to evaluate the effects of diltiazem cardioplegia on myocardial protection during ischemic arrest and recovery of myocardial function after reperfusion. Four formulations of crystalloid cardioplegic solutions, GIK solution[group I, n=12], diltiazem[lug/ml GIK] in GIK solution[group II, n=7], ],diltiazem[2ug/ml GIK] in GIK solution[group III, n=6] and diltiazem[4ug/ml GIK] in GIK solution[group IV, n=6] were compared in isolated working rat heart subjected to a long period [2 hours] of hypothermic arrest with multi-dose infusion. Diltiazem cardioplegia[group II, III and IV]was found to be superior in nearly all aspects. Diltiazem cardioplegia showed faster recovery of regular rhythm and lower incidence of ventricular fibrillation than group I did. In comparing mechanical function in all experimental hearts, the mean postischemic recoveries of aortic flow, cardiac output, peak aortic pressure, stroke volume and stroke work[expressed as a percentage of its preischemic control] were significantly greater in group II, III and IV[diltiazem cardioplegia] than in group I. The infused amount of cardioplegic solution was more increased by the addition of diltiazem to GI K solution. [p < 0.01] Creatine kinase leakage tended to be lower in hearts receiving diltiazem cardioplegia, especially in group III and IV[p<0.05] than in those receiving GIK solution only[group I]. Diltiazem cardioplegia results in the increased flow of cardioplegic solution and the decreased ischemic injury of myocardium during ischemic arrest and the improved recovery of myocardial function after reperfusion, and a dose-response relation must be established before clinical use.

• Nutritional Sciences
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• 제8권3호
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• pp.189-195
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• 2005

To assess the effect of pinitol supplementation and strength training for two weeks on the anaerobic capacity during and after exercise, and improvement of glucose metabolism during the recovery period of muscular fatigue with repeated acute bouts of cycling exercise, a total of 24 healthy young men were recruited and randomly and equally divided into three groups; pinitol supplementation group (PSG), placebo group (PLG), and control group (CON). Using a randomized double-blinded design, subjects in PSG were provided pinitol supplement, consumed orally 1.2 g/day, and participated in the resistance exercise program and cycling exercise for two weeks. Subjects in PLG underwent the same protocol as those in PSG but consumed the same amount of placebo. No supplementation and exercise program was given to CON. Before and after the intervention, all subjects were tested for their anaerobic capacities evaluated by Wingate test twice separated by 30 min. During the test, peak anaerobic power (PP), mean anaerobic power, total work, and fatigue index were evaluated During resting and recovery, blood samples were drawn and plasma pinitol, myo-inositol, chiro-inositol, insulin, free fatty acid, glucose, and lactate levels were analyzed After two weeks, PP and relative PP of the second biking were improved from the first biking in PSG only (p<0.05). No changes were found in all other variables of Wingate test in all groups. No statistical differences between groups and pre- and post-intervention were observed in concentrations of pinitol, myo-inositol, and chiro-inositol, but pinitol concentration was higher during recovery compared to the baseline in all groups and testings (p<0.05). Lactate level during recovery was higher than the resting level, but no other blood parameters were significantly changed. In conclusion, two weeks of pinitol supplementation in conjunction with short duration of anaerobic training in healthy young men did not induce any obvious benefits in terms of anaerobic capacity and energy metabolism Individual and/or population susceptibility may be one factor responsible for adopting pinitol supplementation.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.996-1001
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• 2009

The purposes of this work were suggested and validated the methods of heat recovery from dyeing wastewater exhausted in Sihwa and Banwol dyeing industrial park. We analyzed the present conditions of heat supplies and demands. So it was made a selection of the system combined heat exchanger for waste heat recovery and the high temperature heat pump. We decided the specifications of the heat recovery facilities. After this, economical assessment is performed to this system. The payback periods are within 4 years, 20 years and 5 years in case of K company, S company and A company. In addition, when they are produced the heat of same capacity, quantities of pollutants from used fuels were calculated.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.942-943
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• 2008

The boost converter is usually used in power factor correction. The dynamic losses of its output diode are produced during the reverse recovery time. The power efficiency is decreased due to the losses and also it generates the noise. These disadvantages have been remarkably improved by ZCS and ZVS techniques of power factor improvement circuit. Some benefits lead to the achievement of higher power density and the development cost can be decreased. In this paper work, the reverse recovery suppression(RS) PFC method is used. A inductor and a diode are added into the conventional circuit. The switching device, MOSFET is turned off after the reverse recovery current has come to the zero level. The Zero Current Switching(ZCS) is implemented at that time. This power conversion technique improves the efficiency to about 1% and reduces the noise obviously. And the additional inductor can be designed using an original filter core in the circuit. The converter size is reduced effectively.

• 한국산업보건학회지
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• 제5권1호
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• pp.104-118
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• 1995

This study was performed to evaluate factors affecting desorption of organic solvents collected on charcoal tube and to find out the optimum condition. Desorption efficiency for polar analytes was improved when several polar desorption solvents such as methanol, dimethylformamide(DMF), 2-(2-butoxyethoxy)ethanol were added to carbon disulfide($CS_2$). The best improvement was achieved when 10% dimethylformamide(DMF) in $CS_2$ was used as desorption solvent. During storage of polar analytes, recovery was greatly reduced. Especially, the recovery of cyclohexanone was decreased to 18.1 % after a month storage at $34^{\circ}C$. After two weeks storage, recovery of polar analytes was sharply decreased. Water adsorbed on charcoal interfered the recovery of polar analytes but didn't interfere that one of nonpolar solvent, toluene. When 10% DMF in $CS_2$ was used as desorption solvent, the effect of water on recovery was decreased, comparing with Desorption efficiency increased when analyte loading increased, and usage of 10% DMF in $CS_2$ decreased the loading effect. Increasing volume of desorption solvent was not effective to improve desorption efficiency of analytes when 10% DMF was used. Continuous shaking and sonication is not helpful to increase the desorption efficiency of analytes except cyclohexanone using 10% DMF. When silica gel used as adsorbent, methanol was better desorbent than dimethylsulfoxide. Analytes adsorbed on silica gel showed high recovery in low concentration and less affected by humidity. On the basis of this study, the following conclusions have been drawn. To improve the recovery of polar organic materials in air samples, it is necessary to analyze samples as soon as possible after they were collected. Otherwise, samples must be stored at low temperature. Using two components of desorption solvents, such as 10% DMF in $CS_2$, the effects of loading and humidity decreased for polar analytes such as methyl ethyl ketone and methyl isobutyl ketone. When work place has high humidity with low concentration of polar organic solvents, silica gel can be used as adsorbent, because it produces quantitative recovery for polar analytes at this condition. But it should be noted that high humidity makes breakthrough easy in silica gel samples.

• Safety and Health at Work
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• 제8권2호
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• pp.162-168
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• 2017

Background: Pelvic ring fractures (PRFs) may influence the daily activities and quality of life of the injured. The aim of this retrospective study was to explore the functional outcomes and factors related to return to work (RTW) after PRF. Methods: During the years 2003-2012, 282 injured individuals aged 20-55 years on the date of the accident, were hospitalized and treated for PRFs in a large tertiary hospital in Athens, Greece. One hundred and three patients were traced and contacted; 77 who were on paid employment prior to the accident gave their informed consent to participate in the survey, which was conducted in early 2015 through telephone interviews. The questionnaire included variables related to injury, treatment and activities, and the Majeed pelvic score. Univariate and multiple regression analyses were used for statistical assessment. Results: Almost half of the injured (46.7%) fully RTW, and earning losses were reported to be 35% after PRF. The univariate analysis confirmed that RTW was significantly related to accident site (labor or not), the magnitude of the accident's force, concomitant injuries, duration of hospitalization, time to RTW, engagement to the same sport, Majeed score, and complications such as limp and pain as well as urologic and sexual complaints (p < 0.05 for all). On multiple logistic regression analysis, the accident sustained out of work (odds ratio: 6.472, 95% confidence interval: 1.626-25.769) and Majeed score (odds ratio: 3.749, 95% confidence interval: 2.092-6.720) were identified as independent predictive factors of full RTW. Conclusion: PRFs have severe socioeconomic consequences. Possible predictors of RTW should be taken into account for health management and policies.

• 한국물환경학회지
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• 제21권1호
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• pp.84-91
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• 2005

$TiO_2-catalyst$ suspensions work efficiently in Photocatalytic oxidation (PCO) for wastewater treatment. Nevertheless, once photocatalysis is completed, separation of the catalyst from solution becomes the main problem. The PCO of Cu(II)-EDTA was studied to determine the reusability of the titanium dioxide catalyst. Aqueous solutions of $10^{-4}M$ Cu(II)-EDTA were treated using illuminated $TiO_2$ particles at pH 6 in a circulating reactor. $TiO_2$ was reused in PCO system for treatment of Cu(II)-EDTA comparing two procedures: reuse of water and $TiO_2$ and reuse of the entire suspension after PCO of Cu(II)-EDTA. The results are as follows; (i) Photocatalytic efficiency worsens with successive runs when catalyst and water are reused without separation and filtration, whereas, when $TiO_2$ is separated from water, the reused $TiO_2$ is not deactivated. (ii) The $TiO_2$ mean recovery (%) with reused $TiO_2$ was 86.4%(1.73g/L). Although the mean initial degradation rate of Cu(II)-EDTA and Cu(II) was lower than that using fresh $TiO_2$, there was no significant change in the rate during the course of the three-trial experiment. It is suggested that Cu(II)-EDTA could be effectively treated using an recycling procedure of PCO and catalyst recovery. (iii) However, without $TiO_2$ separation, the loss of efficiency of the PCO in the use of water and $TiO_2$ due to Cu(II), DOC remained from previous degradation and Cu(II)-EDTA added to the same suspension was observed after 2 trials, and resulted in the inhibition of the Cu(II)-EDTA, Cu(II) and DOC destruction.

• 한국산업보건학회지
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• 제16권3호
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• pp.211-221
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• 2006

This study was performed to compare with desorption efficiency and storage stability of CSC and CMS tubes for Ketones in workplace air. 1. The best desorbing solution for CSC tube was 1 % or 3 % dimethylformamide(DMF) in carbon disulfide($CS_2$). The desorption efficiencies were 96.40 % for cyclohexanone, 94.86 % for acetone, 96.96 % for methyl ethyl ketone(MEK), 103.44 % for methyl isobutyl ketone(MIBK), 100.17 % for methyl amyl ketone(MAK), 100.43 % for methyl butyl ketone(MBK), 97.01 % for toluene and 99.33 % for trichloroethylene(TCE). 2. The best desorbing solution for CMS tube was 1 % or 3 % DMF in $CS_2$. The desorption efficiencies were 96.42 % for cyclohexanone, 98.53 % for acetone, 99.67 % for MEK, 105.48 % for MIBK, 100.13 % for MAK, 100.13 % for MBK, 95.42 % for toluene and 98.15 % for TCE. 3. In the storage condition at room temperature($20^{\circ}C$), the recovery rates of cyclohexanone and MEK on CSC tube were rapidly decreased 30.9 % and 50.9 % after 4 weeks, respectively. The recovery rates of all of 6 ketones and 2 nonpolar solvents were shown over 80 % after 1 week in the storage condition of refrigerate temperature($-4^{\circ}C$), and were kept over 80 % after 4 weeks in the storage condition of freezer temperature($-20^{\circ}C$). 4. The recovery rates of cyclohexanone on CMS tube were 80.6 % for 1 week after and 60.5 % for 4 weeks after at room temperature($20^{\circ}C$). The recovery rates of cyclohexanone were shown 80.6 % for 1 week after and 60.5 % for 4 weeks after at $-4^{\circ}C$, and of 6 ketones and 2 non-polar solvents were kept stable over 85 % at $-4^{\circ}C$ and over 97 % at $-20^{\circ}C$ for 4 weeks after. In conclusion, the best desorbing solution was 1 % or 3 % DMF in $CS_2$ and more appropriate sorbent tube for ketones and non-polar solvents was CMS than CSC. We recommend CSC tube would be useful if the samples analyzed within 1 week because CMS tubes are more expensive than CSC tubes. However, if the storage time is needed more than 3 weeks, CMS tubes should be suitable and the storage condition should be below $-20^{\circ}C$.

• 대한의생명과학회지
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• 제21권2호
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• pp.92-102
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• 2015

This work aimed to study whether rice bran extract fermented with Lactobacillus plantarum (LW) promotes functional recovery and reduces cognitive impairment after ischemic brain injury. Ischemic brain injury was induced by middle cerebral artery occlusion (MCAO) in rats. Four groups were studied, namely the (1) sham, (2) vehicle, (3) donepezil, and (4) LW groups. Animals were injected with LW once a day for 7 days after middle cerebral artery occlusion. LW group showed significantly improved neurological function as compared to the vehicle group, as well as enhanced learning and memory in the Morris water maze. The LW group showed the greatest functional recovery. Moreover, the LW group showed an enhanced more survival cells anti-apoptotic effect in the cortex and neural cell densities in the hippocampal DG and CA1. In addition, this group showed enhanced expression of neurotrophic factors, antioxidant genes, and the acetylcholine receptor gene, as well as synaptophysin (SYP), Fox-3 (NeuN), doublecortin (DCX), and choline acetyltransferase (ChAT) proteins. Our findings indicate that LW treatment showed the largest effects in functional recovery and cognitive improvement after ischemic brain injury through stimulation of the acetylcholine receptor, antioxidant genes, neurotrophic factors, and expression of NeuN, SYP, DCX, and ChAT.

• 한국환경과학회지
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• 제24권2호
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• pp.245-251
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• 2015

The main objective of this study is to recovery valuable metals with metal particle size distributions in waste cell phone PCBs(Printed Circuit Boards) by means of pulverization and nitric acid process. The particle size classifier also was evaluated by specific metal contents. The PCBs were pulverized by a fine pulverizer. The particle sizes were classified by 5 different sizes which were PcS1(0.2 mm below), PcS2(0.20~0.51 mm), PcS3(0.51~1.09 mm), PcS4(1.09~2.00 mm) and PcS5(2.00 mm above). Non-magnetic metals in the grinding particles were separated by a hand magnetic. And then, Cu, Co and Ni were separated by 3M nitric acid. Particle diameter of PCBs were 0.388~0.402 mm after the fine pulverizer. The sorting coefficient were 0.403~0.481. The highest metal content in PcS1. And the bigger particle diameter, the lower the valuable metals exist. The recovery rate of the valuable metals increases in smaller particle diameter with same leaching conditions. For further work, it could improve to recovery of the valuable metals effectively by means of individual treatment, multistage leaching and different leaching solvents.