• Journal of the Korean Applied Science and Technology
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• v.26 no.1
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• pp.45-50
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• 2009

Three-dimensional, statistical-mechanical formulations of problems are usually untractable analytically, and therefore they are commonly solved numerically. However, their one-dimensional counterparts are always to be solved analytically. In general analytical solutions sheds more insights to the problems than numerical solutions. Hence, solutions of one-dimensional problems may provide key properties to the problems, when they are extended to three dimensions. In this article, thermodynamic properties of one-dimensional fluid comprising molecules of rigid rods are analyzed statistical-mechanically. Molecules of rigid rods are characterized with repulsive or excluded volume effect. It is observed that this feature is well reflected in thermodynamic functions such as Helmholtz free energy. volumetric equation of state. chemical potential, entropy, etc.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.04a
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• pp.127-129
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• 1997

The high pretilt angles in nematic liquid crystals (NLCs) have been generated on robbed polythiophene (PTP) surfaces with alkyl chain lengths. The pretilt angle of the NLC was observed on unidirectionally rubbed PTP surfaces with alkyl chains with more than 9 carbon atoms. We obtained the Pretilt angle of 15~40$^{\circ}$ on rubbed PTP surfaces with 10 carbon atoms in the a1ky1 chain. Also, the pretilt angles of 65~80$^{\circ}$ of NLC were obtained on rubbed PTP surfaces with 11 and 12 carbon atoms in the alkyl chain. We suggest that this high pretilt angle generation in NLC is due to the surface-excluded volume effect by the alkyl chain lengths between. the LCs and the PTP surfaces. Finally, we conclude the odd-even effect on rubbed PTP surfaces is clearly contributed to the pretilt angle generation.

• Annals of Hepato-Biliary-Pancreatic Surgery
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• v.27 no.4
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• pp.394-402
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• 2023

Backgrounds/Aims: Acute pancreatitis is an emergency presentation, which can range from mild to life threatening. Intravenous fluids are the cornerstone of management. Although the WATERFALL trial described the optimal fluid rate in mild/moderate pancreatitis, this trial excluded patients with moderate-severe/severe pancreatitis. The aim of this study was to establish clinical practice regarding intravenous fluid administration in acute pancreatitis and assess its effect on mortality. Methods: Prospective multi-centre audit of patients with acute pancreatitis was conducted. Data were collected regarding intravenous fluid administration within 72 hours of admission. The primary outcome was 30-day mortality. Multivariable logistic regression was used to identify predictors of 30-day mortality. Results: Those with severe pancreatitis received more fluid; median 5.7 L versus 4 L in 72 hours (p = 0.003). Participants with severe pancreatitis who died within 30 days received a median of 2,750 mL in the first 24 hours, compared to 4,000 mL in those who survived. The following factors were significant predictors of 30-day mortality: age, Glasgow score, C-reactive protein, ischaemic heart disease, and pancreatitis aetiology. Overall, volume of intravenous fluid was not associated with mortality. However, the effect of intravenous fluid volume on mortality differed significantly depending on pancreatitis severity. In severe pancreatitis, increased volume of intravenous fluid was associated with significant reductions in mortality (odds ratio = 0.655; 0.459-0.936; p = 0.020). Conclusions: In severe pancreatitis, more aggressive fluid prescription was associated with decreased mortality; however, this was not the case in milder disease. Further prospective trials guiding fluid resuscitation in severe pancreatitis are needed, as the impact of fluid on this population appears to differ from that in those with milder disease.

• Bulletin of the Korean Chemical Society
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• v.22 no.11
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• pp.1255-1260
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• 2001

The expansion of two different kinds of hydrodynamic size of polymethyl methacrylate (PMMA Mw: 1.56- 2.04 ${\times}$ 106 g/mol) has been measured by dynamic light scattering and viscometry above the Flory $\theta$ temperature of the variou s solvents such as n-butyl chloride, 3-heptanone, and 4-heptanone. The expansion of PMMA chains was analyzed in terms of universal temperature parameters and also compared with previous results of polystyrene (PS) system. First it was found that simple $\tau/{\tau}c$ parameter no longer had its universality for the expansion behavior of hydrodynamic size in the chemically different linear polymer chains. However after modifying ${\tau}/{\tau}c$ parameter into $(Mw/Ro2)3}2(\tau/\tauc)$, we observed a much better universality for both PMMA and PS systems. Here Mw, Ro, $\tau[=(T-{\theta}$)/${\theta}$]$, and ${\tau}c[=({\theta}-Tc)/Tc]$ are defined as the weight average molecular weight, the unperturbed end-to-end distance, the reduced temperature and the reduced critical temperature, respectively.

• Environmental and Resource Economics Review
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• v.13 no.2
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• pp.195-218
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• 2004

This paper explores the impact of pollution abatement cost on trade balance. First, We derive price pressure of spending pollution abatement cost using I-O table. Then the analysis is extended to the impact on trade balance by manufacturing sectors. The paper explicitly includes indirect effect of pollution abatement cost that is the effect through the change of the other sector prices and excluded in the previous studies. The results show that the impact of pollution abatement cost on trade balance is 0.30~0.46% of total trade volume of Korea. This is lower than that of the United States in 1970's.

• Journal of radiological science and technology
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• v.33 no.3
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• pp.239-243
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• 2010

Even though clinical use DRE, PSA and TRUS for screening while diagnosing prostate cancer early, however, we cannot achieve to diagnose it accurately by one method. Thus, mutual supplements are strongly required in diagnosis. It means that we should identify relationship between prostate volume and serum PSA under different ages for better diagnosis. The subjects(405 men) visited the department of diagnostic radiology in a general university hospital from January 2008 to December 2008, who was going to take the prostatic evaluation by TRUS. 13 men, who did definite diagnosis of prostate cancer before through biopsy, were excluded in this study. All data were expressed as mean and standard deviations by using SPSS 14.0 package programs and were analyzed by using one-way ANOVA to evaluate the effect of different ages. And Scheffe Post hoc comparison is accomplished in order to make significant difference in prostate volume, PSA and PSAD according to ages. Pearson correlation was used for ages, prostate volume, PSA and PSAD. According to examination, the subjects' prostate volume and serum PSA level increase as person's age. We can see significant difference between group over 70 years and group from 40 and 50 years. Moreover, age, prostate volume and serum PSA have significant positive correlation. Even though we can get variations in serum PSA level by changing prostate volume according to ages, it is worthwhile to mention that more strong association for prostate volume is observed than ages in elevation of serum PSA. Therefore, it is strongly recommended to consider prostate volume weightly when it comes to evaluate for men with elevated PSA level. Finally, TRUS is an excellent extra equipment to diagnose prostate cancer because it can contribute to early diagnose and pertinent treatment of prostate cancer.

• Journal of Microbiology
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• v.40 no.4
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• pp.319-326
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• 2002

Cellular DNA in prokaryotes is organized in nucleic acid-protein self-assemblies referred to as the nucleoid. The physical forces responsible for its stability inside the poor solvent properties of the cytoplasm and their functional implications are not understood. Studies on the organisation and functioning of the cytosol of cells largely rely on experimental protocols performed in highly dilute solutions using biochemically purified molecules, which is not a reliable substitute for the situation existing in vivo. Our current research interest is focused on the characterization of biological and physical forces determining the compaction and phase separation of DNA in Escherichia coli cytoplasm. We have emphasized the effect of excluded volume in solutions with high macromolecular concentrations (macromolecular crowding) upon self-association patterns of reactions. The prokaryotic cytosol was simulated by addition of inert polymer polyethylene glycol (PEG) (average molecular weight 20000), as an agent which afterwards facilitates the self-association of macromolecules. Fluorescence microscopy was used for direct visualization of nucleoids in intact cells, after staining with DAPI (4',6-diamidino-2-phenylindole dihydrochloride). Addition of the crowding agent PEG 20,000, in increasing concentrations generated progressively enhanced nucleoid compaction, the effect being stronger in the presence of 0.2 M NaCl and 5 mM MgCl$\_$2/. Under these conditions, the nucleoids were compacted to volumes of around 2 ㎛$\^$3/ or comparable sizes with that of living cells.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.12 no.1
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• pp.69-74
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• 1999

We have investigated that the high pretilt angle of the NLC, 4-n-pentyl-4-cyanobiphenyl (5CB), was observed on rubbed polythiophene (PTP) surfaces with alkyl chains with more than 10 carbon atoms; it is attributed to the surface-excluded volume effect by the alkyl chain lengths between the LCs and the PTP surfaces. Next, we investigated that the odd-even effect of the polar anchoring strength in 5CB on rubbed PTP surfaces with alkyl chain lengths has been successfully evaluated. The anchoring strength of 5CB for rubbed PTP surfaces with odd-number is weak compared with even-number up to the 6 carbon atoms in the alkyl chain; however, odd-number is strong compared with even-number above 7 carbon atoms. The weak anchoring strength of 5CB is approximately $1\times10^{-3} (J/m^2$) on rubbed PTP surface with 7 carbon atoms; it is relatively strong anchoring strength. Consequently, we conclude that the odd-even effects of the polar anchoring strength in NLCs are strongly related to the characteristics of the polymer and observed clearly for short alkyl chain lengths.

• Journal of Environmental Health Sciences
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• v.40 no.3
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• pp.204-214
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• 2014

Objectives: Vehicular emissions are one of the main sources of air pollution in urban areas. Correlation analysis was conducted between air pollutants and traffic volume in order to identify causes of air pollution in Gwangju. Methods: Using traffic volumes and air quality monitoring data from 2002 to 2012 from nine stations (seven urban areas, two roadside areas), especially at three sites where traffic volumes were high, the correlation coefficients were obtained between air pollutants as PM-10 (particulate matter), $NO_2$, $SO_2$, CO and $O_3$ at the stations and traffic volumes near the air monitoring stations. Results: Due to traffic volume and distance between the station and the traffic road, concentrations of pollutants at roadside areas were higher than at urban areas, with the exception of $O_3$. The concentration of $O_3$ showed statistically significance with those of other gas materials as $NO_2$, $SO_2$, and CO in winter (p<0.001) and spring (p<0.05). During the period of October 7 to 20, 2012, excluding periods of yellow dust, smog and rainy season, the ratio of $NO/(NO+NO_2)$ showed the highest value 0.57 and 0.40 at Unam and Chipyeong of two roadside stations, followed by 0.35 at Nongseong with vehicular effects. The correlation coefficient between traffic volume and $O_3$, CO, $NO_2$ became higher when the data on mist and haze days were excluded, than when all hourly data were used in that period, at the three sites of Unam, Chipyeong, and Nongseong. Conclusions: Air quality showed a considerable effect from vehicles at roadside areas compared to in urban areas. Air pollutant diminishment strategies need to be aggressively adopted in order to protect atmospheric environment.

• Biomolecules & Therapeutics
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• v.18 no.3
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• pp.308-315
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• 2010

Essential oil-excluded Artemisia princeps Pamp var Ssajuarissuk (AP) was fermented with Lactobacillus brevis K-1, which was isolated from cabbage Kimchi, and the anti-inflammatory effects of AP and fermented AP (FAP) on lipopolysaccharide (LPS)-induced inflammatory response in peritoneal macrophages were investigated. AP and FAP inhibited LPS-induced TNF-$\alpha$, IL-$1{\beta}$, COX-2, iNOS and COX-2 expression, as well as NF-${\kappa}B$ activation. AP and FAP also reduced ear thickness, inflammatory cytokine (TNF-$\alpha$, IL-$1{\beta}$ and IL-6) expression and NF-${\kappa}B$ activation with 12-O-tetradecanoylphorbol-13-acetate (TPA) induced dermatitis in mice. Furthermore, AP and FAP also reduced exudate volume, cell number, protein amount, inflammatory cytokines (TNF-$\alpha$, IL-$1{\beta}$ and IL-6) expression and NF-${\kappa}B$ activation in carrageenan-induced air pouch inflammation in mice. The inhibitory effects of FAP were more potent than those of non-fermented AP. Based on these findings, we propose that FAP can improve inflammatory diseases, such as dermatitis, by inhibiting the NF-${\kappa}B$ pathway.