• Journal of Preventive Medicine and Public Health
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• v.39 no.2
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• pp.171-176
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• 2006

Objectives : The objective of this study is to assess the factors influencing biological monitoring of textile coating factory workers exposed to N,N-dimethylformamide(DMF). Methods : We studied 35 workers who were occupationally exposed to DMF from 9 textile coating factories. The study was carried out in two phases; summer and winter. While air concentration of DMF, temperature and humidity were assessed in order to monitor the atmospheric conditions, biological monitoring was done to determine the internal dose by analyzing the N-methylformamide(NMF) collected from urine at the beginning and end of the shift. Questionnaires and medical surveillance were also obtained during the two phases. Results : Median air concentrations of DMF in winter and summer were 1.85 ppm and 2.78 ppm respectively. Also the difference between the urinary NMF concentration at the beginning and end of the shift $({\Delta}NMF)$ was always significant in each season (P < 0.001). The correlations between log DMF in air, log end-of-shift urinary NMF (r=0.555, P < 0.001) and log ${\Delta}NMF$ (r = 0.444, P < 0.001) was statistically significant in summer. The temperature, humidity, a shift system and different styles of clothing worn were significantly different during the two phases. In a multivariate analysis, temperature and the concentration of DMF in the air were the main factors influencing biological monitoring of textile coating factory workers. Conclusions : Concerning more comprehensive prevention measures to reduce exposure for those workers occupationally exposed to DMF, dermal exposure conditions such as temperature and humidity together with the air concentration of DMF should be assessed and biological monitoring is necessary to reduce adverse health effects, especially during the summer.

• Journal of Nutrition and Health
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• v.33 no.7
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• pp.745-754
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• 2000

Effects of oral taurine supplementation (6g/day)for 2-4 weeks on activities of red blood cell(RBC)total superoxide dismutase (SOD) and plasma glutathione peroxidase(GSH-Px) and the level of malondialdehyde(MDA) were evaluated in healthy female adults (23.6$\pm$0.3 years old). Compared to the value for 0 week plasma GSH-Px activity of the subjects was significantly lower after 2 weeks of taurine supplementation(p<0.05) and recovered to the value similar to 0 week after 4 weeks of taurine supplementation. RBC total SOD activity tended to be decreased after 2 weeks of taurine supplmentation compared to the values for 0 week although the difference between the means of the two group was not statistically significant. Plasma MDA level was not significantly decreased by taurine supplementation most probably due to the fact that the subjects participated in the present study were healthy and their antioxidant defense system had been in the 'normal' range. Plasma MDA concentration was negatively correlated with plasma taurine concentration(r=-0.2003m p<0.05) but tended to be positively correlated with plasma cholesterol concentration(r=0.2465, p=0.0645) as expected Plasma GSH-Px activity was positively associated with the percentage of 22:0 (r=0.2892, p<0.05) or 20:4w6(r=0.2939, p<0.05). On the other hand plasma MDA concentration was positively correlated with the percentage of 20:5w3 in plasma total lipids(r=0.2635 p<0.05) and negatively correlated with $\Delta$5 desaturation index of w6 fatty acids(20:3w6⇒20:4w6) in plamsa total lipids(r=-0.2714, p<0.05) as well as in phospholipids(r=-0.2864, p<0.05). From these results protective effect of taurine supplementation against lipid peroxidation and antioxidant defense system in humans appears to be minimal when the subjects are in a relatively healthy state. Further studies concerning the antioxidant efficacy of taurine should be conducted in human subjects under various disease states related to oxidative stress such as diabetes and artheroxclerosis.

• YAKHAK HOEJI
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• v.44 no.6
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• pp.552-557
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• 2000

In order to investigate the effects of Yukmijihwang-Tang on the hepatic microsomal function of Cd-poisoned rats, 3 mg/kg of cadmium (Cd) and 500 mg/kg of Yukmijihwang-Tang extract (YJT), a herbal hepatoprotective medicine, were administered concurrently to rats for 4 weeks. The levels of protein, aniline hydroxylase (AH) and malondialdehyde (MDA) were increased in Cd-treated group. This increase was suppressed by treatment or YJT. The levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), glucose-6-phosphatase (G-6-P) and ${\delta}-aminolevulinic$ acid dehydratase (ALAD) of Cd-treated group were decreased. This decrease was inhibited by treatment of YJT. Treatment with YJT significantly protects cadmium-induced hepatotoxicity.

• Fisheries and Aquatic Sciences
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• v.17 no.1
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• pp.19-25
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• 2014

We investigated the effects of Ecklonia cava ethanol extract (ECE) on sleep architecture and sleep profiles. ECE was orally administered at a dose of 100, 250, or 500 mg/kg to C57BL/6N mice and its effects were measured by recording electroencephalogram (EEG) and electromyogram. Administration of ECE (250 and 500 mg/kg) significantly induced non-rapid eye movement sleep (NREMS) without affecting rapid eye movement sleep. The increase in NREMS by ECE (500 mg/kg) was significant (P < 0.05) during the first 2 h after administration. In addition, ECE had no effect on EEG power density (an indicator of sleep quality) in NREMS. These results suggest that ECE induces NREMS in a manner similar to physiological sleep.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.1
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• pp.5-12
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• 1991

the Chinese cabbage kimchi was fermented with the various submaterials such as hot pep-per garlic ginger leek green onion fermented anchovy juice and sugar according to the average contents of each submaterial described in the 39 kinds of references. And then the effects of each submaterial and lactic acid bacteria such as L. brevis. Leu. mesenteroides. P cerevisiae and L. plantarum on the content of carotenes were investigated, The major carotene in kimchi was $\beta$-carotene. And also $\delta$-carotene and $\alpha$-carotene were detected. Contents of $\beta$-carotene and total carotene were high in the kimchi containing leek red pepper powder green onion and fermented anchovy juice as a submaterial. But the kimchi containing or omitting the other submaterials were litter affected to the contents of carotene. Contents of $\beta$-carotene and total carotene were high in kimchi fermented with Leu. msenteroides L. brevis and P. cerevi-siae as a starter but was low with L plasntarum.

• The Korean Journal of Ceramics
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• v.4 no.2
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• pp.68-71
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• 1998

The effect of Mn and Nb additions on the electrical properties of BaTiO$_3$ has been studied by means of equilibrium electrical conductivity as a function of temperature, oxygen partial pressure(Po$_2$) and composition. If the manganese ion is added to the normal Ti site, i.e. BaTi$_{1-x}Mn_xO_{\delta-6}$, the equilibrium conductivity shows strong evidence of acceptor-doped behavior. The conductivity minimum, corresponding to the transition from oxygen excess, p-type behavior to oxygen deficient, n-type behavior with decreasing Po$_2$, is displaced to lower Po$_2$ and is broadened and flattened. The partial replacement of Mn ion with Nb decreases the acceptor-doped effect and the total replacement exhibits a typical donor-doped behavior. It was confirmed that unlike undoped or other acceptor-doped behavior. It was confirmed that unlike undoped or other acceptor-doped samples, for the p-type region, the electrical conductivity follows the 1/6th power dependence of oxygen partial pressure.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.3
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• pp.164-167
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• 2016

In this study, in order to develop relaxor ferroelectric ceramics for refrigeration device application with large electrocaloric effect, PLZT(8/65/35) composition was fabricated using conventional solid-state method. The Curi temperature of this composition PLZT ceramics was $230^{\circ}C$, and the P-E hysteresis loops of the PLZT ceramics as a fuction of temperature became slim by degrees with higher temperatures. The maximum value of ${\Delta}T$ of $0.243^{\circ}C$ in ambient temperature of $215^{\circ}C$ with 30 kV/cm was appeared. It is considered that PLZT ceramics possess the possibility of refrigeration device application.

• Electrical & Electronic Materials
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• v.6 no.3
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• pp.207-213
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• 1993

Pb(Z $r_{0.54}$, $Ti_{0.46}$) $O_{3}$에 B $i_{2}$ $O_{3}$를 0.0wt%까지 첨가하여 미세구조, 유전, 압전, 성질에 미치는 영향을 고찰하였다. B $i_{2}$ $O_{3}$의 고용범위는 약 0.5~0.7wt%정도 이었고 B $i_{2}$ $O_{3}$ 첨가량이 증가함에 따라서 결정립의 크기가 감소하였다. B $i_{2}$ $O_{3}$첨가량이 증가함에 따라 고용한계까지는 $d_{33}$ , tan .delta., .xi.$_{r}$(분극후)값이 증가하였으며 Qm값과 밀도는 감소하였다. $K_{p}$ 값은 B $i^{3+}$ 가 P $b^{2+}$를 치환하므로 형성되는 Pb공공의 형성에 의해 자발분극이 증가됨에 따라 증가하였다.다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.2
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• pp.269-277
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• 2003

Effects of soy protein concentrate (SPC) containing isoflavone and casein diets on plasma phospholipid (PLs)-fatty acid patterns were investigated in 7-& 40- wk old female rats. Diets containing 16% SPC (soy/young:SY, soy/old: SO) and casein (casein/young : CY, casein/ old: CO) supplemented with 0.5% cholesterol were fed for 4 wks. Fatty acid compositions of plasma PLs were determined by TLC and GLC. Compared to the dietary protein effects, age effects on serum lipids were more profound. The levels of total cholesterol (Chol.), triglyceride, HDL-Chol., (LDL+VLDL)-Chol. and atherogenic index (AI) were higher in older groups (OC & OS) than younger groups (YC &. YS). Soy groups had higher Ell)L-Chol. level and lower (LDL+ VLDL)-Chol. and AI, compared with casein groups. The compositions of C22:0, Cl8:1 $\omega$9 and sum of MUFA in plasma PLs were significantly higher in casein group (CY & CO) than soy group (SY & SO), but those of sum of SFA were higher in soy group. The compositions of C22:0, Cl8:1 $\omega$9, C22:1, Cl8:3$\omega$3 and C22:4$\omega$6 were higher and those of C22:6$\omega$3, sum of $\omega$3, Cl8: 2$\omega$6 C20:4$\omega$6, sum of $\omega$6 and sum of PUFA were lower in plasma PLs of younger rats. The average P/S and $\omega$3/$\omega$6 ratio in older group was higher. The $\Delta$-7 desaturation index (16:0⇒16:1$\omega$7) and $\Delta$-9 desaturation index (18:0⇒18:1$\omega$9) were lower in soy group than casein group, while $\Delta$-6 and $\Delta$-5 desaturation index were not affected by dietary protein. The $\Delta$-4 desaturation index (22:4$\omega$6⇒22:5$\omega$6) were higher and elongation index (20:4$\omega$6⇒22:4$\omega$6) were lower in older group. The ratio of the products of $\omega$3 fatty acid series (Cl8:3) was significantly higher in older group, which indicated that age affected the plasma PUFA metabolism. On the other hand, older rats had higher serum cholesterol level compared with younger rats. Taken together, these changes in fatty acid composition might cause minimal changes in tile membrane fluidity induced by the increase serum cholesterol level.

• Computers and Concrete
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• v.19 no.5
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• pp.537-544
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• 2017

The strength and deformational capacity of slender reinforced concrete (RC) columns greatly rely on their slenderness ratios, while an additional secondary moment (i.e., the $P-{\delta}$ effect) can be induced especially when the RC column members are exposed to fire. To evaluate the fire-resisting performances of RC columns, this study proposed an axial force-flexural moment (i.e., P-M) interaction curve model, which can reflect the fire-induced slenderness effects and the nonlinearity of building materials considering the level of stress and the magnitude of temperature. The P-M interaction model proposed in this study was verified in detail by comparing with the fire test results of RC column specimens reported in literature. The verification results showed that the proposed model can properly evaluate the fire-resisting performances of RC column members.