• Polymer(Korea)
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• v.32 no.3
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• pp.206-212
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• 2008

Alginate obtained from marine brown algae, is a copolymer with repeating units of $\alpha$-($1{\rightarrow}4$)-L-guluronic acid(G) and $\beta$-($1{\rightarrow}4$)-D-mannuronic acid(M). It has good properties such as biocompatibility, non-toxicity. and hydrophilicity. However, alginate alone cannot be electrospun due to high viscosity and conductivity. To solve this problem. electro spinning of sodium alginate(SA) was performed by blending with poly(ethylene oxide)(PEO) and poly(vinyl alcohol)(PVA) in this study. Characteristics of SA/PEO nanofibers and SA/PVA nanofibers were estimated by SEM and XRD analyses. Optimal nanofiber webs are obtained from 2/2 wt% of SA/PEO and 2/7 wt% of SA/PVA. SA/PEO and SA/PVA nanofiber webs may have potentials for tissue engineering scaffold and wound dressing.

• Journal of Environmental Health Sciences
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• v.19 no.3
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• pp.1-16
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• 1993

This paper describes an investigation to determine whether the activated sludge (AS) process could be used for the treatment of wastewater at the Union Carbide Coporation (UCC) plant in Seadrift, Texas. This plant presently utilizes a waste stabilization pond (WSP) system for treatment of the wastewater. The treatment system consists of an in-plant primary WSP and two off-plant WSPs (secondary and tertiary WSPs), run in series. The total hydraulic detention time of the WSP system is approximately 150 days. Several laboratory-based treatability studies have been conducted to evaluate the performace of the WSP system and the degradability of specific chemical compounds. From an additional study, it was determined that the WSP system was stressed and occasionally operating near the limit of its treatment capacity. The existing primary WSP plays an important role in the overall treatmemt system, because it not only functions as a pH and organic-strength equalization basin, but also serves as a "preconditioning" basin by fermenting high strength organic wastes to volatile organic acids for subsequent degradation in the escondary WSP. However, in view of pending RCRA legislatin conerning the "proposed organic toxicity characteristics limits" (40 CFR Part261: Federal Register, July, 1988), it is possible that the primary WSP will have to be abandoned in favor of alternative treatment options. Therefore the main purpose of this study was to perform activated sludge treatability evaluations for the development of an alternative to the existing primary WSP treatment ststem. In addition, another purpose was to determine the degradability of bis(2-chloroethyl)ether (Chlorex or CX) and benzene(BZ) in the activated sludge process. The presence of these two chemicals in the wastewater of the plant prompted the question of whatedether they could be degraded in an activated sludge system.

• Journal of Embryo Transfer
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• v.31 no.1
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• pp.13-17
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• 2016

The purpose of this study was to examine the effects of taurine and vitamin E on sperm characteristics damaged by bromopropane (BP) in pig. We evaluated toxicity of BP on viability, membrane integrity and mitochondrial activity of spermatozoa. 1-BP (0, 2.5, 5.0, 10, and $50{\mu}M$), 2-BP (0, 2.5, 5.0, 10, and $50{\mu}M$), taurine (0, 5.0, 10, and $25{\mu}M$) and vitamin E (0, 50, 100, and $200{\mu}M$) were treated in fresh boar semen for 6 h. 10 and $50{\mu}M$ of 1-BP and 2-BP inhibited sperm viability, membrane integrity and mitochondrial activity in fresh boar semen (P<0.05). $25{\mu}M$ of taurine increased sperm viability and membrane integrity (P<0.05), $100{\mu}M$ of vitamin E enhanced viability and mitochondrial activity of sperm (P<0.05). Finally, $10{\mu}M$ of 1-BP and 2-BP was co-treated with taurine ($25{\mu}M$) and vitamin E ($100{\mu}M$) in the fresh boar semen. The co-treated samples did affected viability, membrane integrity and mitochondrial activity of sperm. In conclusion, taurine and vitamin E can improve and maintain sperm quality in fresh boar semen.

• Korean Journal of Community Nutrition
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• v.9 no.3
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• pp.303-314
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• 2004

We studied daily micronutrient intake from vitamin-mineral supplements, health-related life style, clinical case of diseases and food frequency of the Korean middle-aged (40-59 yr, n = 404) to compare the characteristics of non-user (n = 270) and user (n = 134) of vitamin-mineral supplements. Rate of supplement use of the middle-aged was 33.2% and there was significant difference in education level (p = 0.0084) and family income (p = 0.0476) of user and nonuser. Smoking habit (p = 0.0844) and drinking frequency (p = 0.0606) tended to be lower in a supplement user than a non-user. The medical history of a case was significantly higher in users (67.9%) than in non-users (44.4%) (p = 0.001), which suggests that medical history is one of the important motivations of supplement use. Supplement users had the medical history of digestive disease (34.1%), anemia (11.0%) and hypertension (9.9%) in order. Vitamin C was the most frequently supplemented nutrient (81.3%) among vitamin-mineral supplement, and the next orders were vitamins E (73.1%), B$_2$(68.7%) and B$_{6}$ (60.4%). Mean intakes of vitamin B$_1$, iron, selenium, vitamin E, and vitamin C from supplement was 4,260%, 4,030%, 1,660% and 1,330% of RDA, respectively. The supplement users tended to consume most food items including milk ＆ milk products (p ＜ 0.01), rice (p ＜ 0.01), grains (p ＜ 0.05) and cookies (p ＜ 0.01) less frequently than non-users. Conclusively, nutrient intake of vitamin B$_1$, iron, selenium, vitamin E, and vitamin C from supplement was excessively high compared to RDA. We suggest that the toxic effect of excessive supplementation should he informed to supplement user and nutritional education should be focused on the optimal supplement dose.e.

• Journal of Korean Medical Science
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• v.33 no.45
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• pp.283.1-283.10
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• 2018

Background: The role of sorafenib in patients with hepatocellular carcinoma (HCC) recurrence after liver transplantation (LT) has been rarely studied. The aim of this study was to evaluate the efficacy of sorafenib in post-LT era. Methods: Consecutive patients with post-transplant HCC recurrence not eligible to resection or locoregional therapy were included. Patients receiving best supportive care (BSC) until 2007 were compared with those treated by sorafenib thereafter. Results: Of a total of 65 patients, 20 patients received BSC and 45 received sorafenib. Clinical characteristics were similar between two groups except that sorafenib group received tacrolimus and mammalian target-of-rapamycin inhibitors more frequently than BSC group. Treatment with sorafenib conferred a survival advantage as compared with BSC for survival after recurrence (median, 14.2 vs. 6.8 months; P = 0.01). In multivariate analyses, high serum ${\alpha}$-fetoprotein level, synchronous intrahepatic recurrence and distant metastasis at the time of recurrence, and BSC were independently associated with poorer survival after recurrence. Sorafenib treatment was associated with better survival after recurrence as compared with BSC (hazard ratio, 0.25; 95% confidence interval, 0.10-0.62; P = 0.002). In addition, sorafenib group showed tolerable toxicity in the post-transplant setting. Conclusion: Sorafenib may be beneficial in patients with post-transplant HCC recurrence.

• The Journal of the Convergence on Culture Technology
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• v.5 no.4
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• pp.445-450
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• 2019

Recently, consumers using cosmetics have a great interest in raw material safety. Among them, interest in natural preservatives is increasing, and as the demand for cosmetics excluding paraben preservatives increases, a method of replacing synthetic preservatives with antibacterial essential oils is being considered. The antibacterial effect of essential oils depends on the components, concentrations and interactions between the main active compounds. Effective preservatives should have antimicrobial activity against a wide range of strains even at minimal concentrations. All preservatives should be considered to increase skin concentration and cause skin irritation and allergic reactions. Consumers recognize that essential oils from nature are safe, but some should be careful because they can cause contact allergies or phototoxic reactions. As such, it is important to balance natural preservatives with maximum preservative effects and low toxicity. This paper describes the characteristics of essential oils focused on antibacterial properties, efficacy and safety as cosmetic preservatives.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.4
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• pp.46-58
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• 2010

Hydrogen peroxide(HP) and liquid methane have deserved renewed considerations as green propellants in recent years, because main design concerns in the development of the new generation propulsion system for spacecrafts are concentrated on low operation cost and environmental cleanness. Although HP has a long history of application to aerospace propulsion systems due to high density, mono-propellant characteristics and low toxicity, it had been replaced by hydrazine and liquid oxygen due to extreme performance requirement during the cold war. But HP has received a renewed interest due to its increased stability and many researches have been conducted to develop high performance LREs(Liquid Rocket Engines) using HP. Liquid methane has also received a new interest in rocket propulsion system for the future space exploration according to its possibility of ISRU(In-Situ Resource Utilization).

• Nuclear Engineering and Technology
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• v.37 no.4
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• pp.363-374
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• 2005

A heterogeneous thorium-based Kyung Hee Thorium Fuel (KTF) assembly design was assessed for application in the APR-1400 to study the feasibility of using thorium fuel in a conventional pressurized water reactor (PWR). Thermal hydraulic safety was examined for the thorium-based APR-1400 core, focusing on the Departure from Nucleate Boiling Ratio (DNBR) and Large Break Loss of Coolant Accident (LBLOCA) analysis. To satisfy the minimum DNBR (MDNBR) safety limit condition, MDNBR>1.3, a new grid design was adopted, that enabled grids in the seed and blanket assemblies to have different loss coefficients to the coolant flow. The fuel radius of the blanket was enlarged to increase the mass flow rate in the seed channel. Under transient conditions, the MDNBR values for the Beginning of Cycle (BOC), Middle of Cycle (MOC), and End of Cycle (EOC) were 1.367, 1.465, and 1.554, respectively, despite the high power tilt across the seed and blanket. Anticipated transient for the DNBR analysis were simulated at conditions of $112\%$ over-power, $95\%$ flow rate, and $2^{\circ}C$ higher inlet temperature. The maximum peak cladding temperature (PCT) was 1,173K for the severe accident condition of the LBLOCA, while the limit condition was 1,477K. The proliferation resistance potential of the thorium-based core was found to be much higher than that of the conventional $UO_2$ fuel core, $25\%$ larger in Bare Critical Mass (BCM), $60\%$ larger in Spontaneous Neutron Source (SNS), and $155\%$ larger in Thermal Generation (TG) rate; however, the radio-toxicity of the spent fuel was higher than that of $UO_2$ fuel, making it more environmentally unfriendly due to its high burnup rate.

• Journal of The Korean Society of Clinical Toxicology
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• v.6 no.2
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• pp.117-122
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• 2008

Purpose: Surveys on poisoning usually involves intoxication rather than inhalation, skin contact, etc. Therefore, we examined the characteristics of patients who visited the emergency department in an industrial complex after acute industrial exposure to toxic materials. Methods: Medical records of patients exposed to toxic materials in the work places from April, 2006, to March, 2008, were analyzed retrospectively. Inhalation patients due to fire were excluded. Results: Subjects included 66 patients, with a mean age of $35.4{\pm}10.9$ years, mostly men (91%). Toxicity occurred in 51 patients (77%) by contact, 15 patients (23%) by inhalation, and none by oral ingestion. For toxic materials, 10 patients were exposed to hydrofluoric acid, 8 to hydrochloric acid, 7 to sodium hydroxide, 7 to metals, and others. The face and hands were the most frequent exposure site by contact. Most exposures were caused by accidents, with 29 cases (42%) exposed because of carelessness or not wearing protective equipment. Most complaints were pain on exposure site, but 7 of the inhalation patients complained of dyspnea. The majority of patients with contact exposure were discharged after wound care or observation. After inhalation exposure, 1 patient died and 5 patients were admitted to the intensive care unit. Conclusion: Major causes of workplace exposure were not wearing protective equipment or carelessness. Although contact exposures are usually benign, cautious observation and management are required in patients with inhalation exposure.

• Journal of the Korean Applied Science and Technology
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• v.38 no.5
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• pp.1265-1272
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• 2021

This study was intended to investigate the potential of Astragalus membranaceus ethanol extract(AM) and Astragalus membranaceus bioconversion extract(AMB) as functional cosmetic materials. To confirm the antioxidant effect, polyphenol and flavonoid contents were measured, and a study was conducted on skin cell toxicity and skin cell aging through cell experiments. As a result of the antioxidant experiment, the content of polyphenols and flavonoids increased in a concentration-dependent manner in the effects of polyphenols and flavonoids, and it was confirmed that the ethanol extracts were higher than the bioconversion extracts. It was confirmed that the AM and AMB increased the MMP1 expression inhibitory effect in a concentration-dependent manner in HDF cells. Therefore, this study is considered to be very useful as a functional cosmetic material in terms of antioxidant and skin aging prevention when using AM and AMB as functional cosmetic materials.