• Analytical Science and Technology
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• v.25 no.2
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• pp.146-151
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• 2012

An analytical method was developed for the measurement of uranium isotope in ground water using the liquid scintillation counting technique. A LKB Wallac Quantulus 1220 liquid scintillation counter (LSC) equipped with pulse shape analyzer (PSA) and a solvent extraction method were used for the measurement of uranium isotope in ground water samples. The effect of solution volume on the extraction efficiency was evaluated for 100 to 1000 mL solutions using a NIST standard reference material (NIST SRM 4321C). The effect of groundwater pH on the extraction efficiency was also investigated for pH ranging from 0.5 to 10. It was found that the extraction efficiency had a strong dependence on pH showing a maximum at pH 2. In contrast, the effect of groundwater volume on the extraction efficiency was negligible in the range investigated. According to the method, the extraction efficiency of uranium isotopes was near 96% and the lower detection limit for uranium was 0.018 Bq/L with the counting time of 300 min. The result of this study was also verified by the conventional ICP-MS measurement. It is demonstrated that the suggested method is valuable to the determination of the optimum extraction and measurement conditions for uranium in ground water. The method was successfully applied to the ground water at four locations near the Daejeon province. It was found that the uranium content and the isotopic ratio of $^{234}U/^{238}U$ at the locations ranged 0.59~6.69 Bq/L and 0.72~1.40, respectively.

• Korean Chemical Engineering Research
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• v.48 no.5
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• pp.609-614
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• 2010

In this study, emulsion polymerizations for synthesizing acrylic pressure-sensitive adhesive(PSA) were carried out using 2-ethylhexyl acrylate(2-EHA), n-butyl acrylate(n-BA), methyl metacrylate(MMA) as fundamental monomers and acrylic acid(AAc) as a functional monomer in the presence of anionic SLS (sodium lauryl sulfate). To obtain the optimized synthetic condition in the polymerization, we analyzed the polymerization variables such as the effect of surfactant concentration and hydrophilic lipophilic values(HLB). At the same time, the final adhesive properties were also analyzed by the function of the initiator concentration and buffer concentration. In the results, the most stable emulsion was obtained at the surfactant concentrations between 3 and 5 wt%. It was also determined the effect of HLB value of nonionic surfactant and the initiator concentrations on the gel content. Stable emulsion is obtained using the surfactant having HLB value of 12.3. The rate of emulsion polymerization was increased at the initiator concentration greater than 1 wt%, but the stability of the emulsion was decreased. Finally, the effect of the buffer concentrations on the pH and the conversion of the acrylic emulsion product were experimentally measured. At the sodium bicarbonate concentration above 0.4 wt%, the buffer infulence was apparent. The buffer effect was fully acceptable at the concentrations between 0.6 and 0.8 wt% regardless of the monomer composition.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.5
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• pp.2165-2168
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• 2014

Background: Today, survival rate of patients with chronic renal failure/hemodialysis has increased so that chronic illnesses are more likely to occur. Cancer is the main cause of morbidity and mortality in such patients. Aim: In this study, physician attitudes were examined about cancer screening in patients with renal failure. Materials and Methods: This study was done by face to face questionnaire in the $27^{th}$ National Nephrology Congress to determine if the physicians dealing with chronic renal failure, hemodialysis or renal transplanted patients, recommend cancer screening or not and the methods of screening for cervix, prostate, breast and colon cancer. Results: One hundred and fifty six physicians were included in the survey. A total of 105 (67%) participants were male and the age of responders was $48{\pm}9$ years. About 29% were specialists in nephrology, 28% internal medicine, and 5% were other areas of expertise. Some 48% of participants were hemodialysis certified general practitioners. Patients were grouped as compensated chronic renal failure, hemodialysis or renal transplanted. Of the 156 responders, 128 (82%) physicians recommended breast cancer screening and the most recommended subgroup was hemodialysis patients (15%). The most preferred methods of screening were combinations of mammography, self breast examination and physicianbreast examination. 112 (72%) physicians recommended cervix cancer screening, and the most preferred method of screening was pap-smear. Colon cancer screening was recommended by 102 (65%) physicians and prostate screening by 109 (70%) physicians. The most preferred methods of screening were fecal occult blood test and PSA plus rectal digital test, respectively. Conclusions: It is not obvious whether cancer screening in renal failure patients is different from the rest of society. There is a variety of screening methods. An answer can be found to these questions as a result of studies by a common follow-up protocol and cooperation of nephrologists and oncologists.

• Polymer(Korea)
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• v.39 no.2
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• pp.329-337
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• 2015

In this study, multi-walled carbon nanotubes (MWCNTs) were oxidized with a mixture of nitric acid and sulfuric acid. After oxidation, oxidized MWCNTs were treated with thionyl chloride ($SOCl_2$) and 1,4-butanediol (BD) in sequence at room temperature to introduce hydroxyl groups on the surface of MWCNTs. The prepared MWCNT-OH was silanized with 3-methacryloxypropyltrimethoxylsilane (MPTMS) to make MWCNT-MPTMS. The MWCNT-MPTMS was used as fillers in emulsion polymerization to make MWCNT-MPTMS/PMMA composite particles with 3 kinds of emulsifiers, hexadecyltrimethylammoniumbromide (CTAB) as a cationic, sodium dodecylbenzene sulfonate (SDBS) as an anionic and polyethylene glycol tert-octylphenyl ether (Triton X-114) as a nonionic emulsifier. Morphologies of composite emulsions were confirmed by a particle size analyzer (PSA) and a scanning electron microscope (SEM). Morphologies of emulsion polymerized MWCNT-MPTMS/PMMA with SDBS showed more uniform particle size distribution compared to those of other two emulsifiers used emulsions. MWCNT-MPTMS/PMMA showed $3.4^{\circ}C$ higher $T_g$ compared to pristine MWCNT/PMMA due to covalent bond formation at interface of MWCNT-MPTMS and PMMA.

• Elastomers and Composites
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• v.37 no.1
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• pp.21-30
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• 2002

Core-shell polymers of methyl methacrylate/styrene pair were prepared by sequential emulsion polymerization in the presence of sodium dodecyl benzene sulfonate(SDBS) as an emulsifier using ammonium persulfate(APS) as an initiator. The characteristics of these core-shell polymers were evaluated. Core-shell composite latex has the both properties of core and shell components in a particle, where as polymer blonds or copolymers show a combined properties from the physical properties or two homopolymers. This unique behavior of core-shell composite latex can be used in many industrial fields. However, in preparation of core-shell composite latex, several unexpected phenomina are observed, such as, particle coagulation, low degree of polymerization, and formation of new particles during shell polymerization. To solve the disadvantages, we studied the effects of surfactant concentrations, initiator concentrations, and reaction temperature on the tore-shell structure or PMMA/PSt and PSt/PMMA. Particle size and particle size distribution were measured by using particle size analyzer, and the morphology of the core-shell composite latex was observed by using transmission electron microscope. Glass transition temperature($T_g$) was also measured by using differential scanning calorimeter. To identify the core-shell structure, pH of the composite latex solutions were measured.

• Journal of Nutrition and Health
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• v.46 no.2
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• pp.119-125
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• 2013

We studied the anti-diabetic effects of medicinal herb water extracts on expression of hepatic glucokinase (GCK), pyruvate dehydrogenase (PDH), and acetyl-CoA carboxylase (ACC) mRNA. The medicinal herbs used for experiments were Cornus officinalis (CO), Paeonia suffruticosa Andrews (PSA), Discorea japonica Thunb. (DJ), Rehmannia glutinosa (RG), Lycium chinense (LC), and Pyrus pyrifolia (PP). For GCK mRNA expression, CO, RG, and LC water extracts exhibited a more effective activity than other extracts. Cells treated with RG and LC water extracts showed an increase in expression of PDH mRNA to 191% and 124%, respectively, compared to control. Expression of ACC mRNA was significantly higher in LC water extract. These data indicate that CO, RG, and LC water extracts stimulates expression of hepatic GCK, PDH, and ACC mRNA.

• Membrane Journal
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• v.33 no.4
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• pp.222-232
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• 2023

In this study, a hollow fiber support membrane was prepared by a non-solvent induced phase separation (NIPS) method using a polysulfone (PSf). The prepared hollow fiber support membrane was coated with PDMS and Pebax to prepare a hollow fiber composite membrane. The prepared composite membrane was measured for permeance and selectivity for pure CO₂, H₂, O₂ and N₂. Gas separation performance of the module having the highest selectivity (CO₂/H₂) among the prepared composite membrane modules was measured according to the change in stage cut using simulated gas. The composition of the simulated gas used at this time was 70% CO₂ and 30% H₂. In the 1 stage experiment, it was possible to obtain values of about 60% of H₂ concentration and 12% of H₂ recovery. In order to overcome the low H₂ concentration and recovery, 2 stage serial test was performed, and through this, it was possible to achieve 70% H₂ concentration and 70% recovery. Through this, it was possible to derive a separation process configuration for CO₂/H₂ separation.

• Polymer(Korea)
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• v.36 no.3
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• pp.344-350
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• 2012

New pressure sensitive adhesives (PSAs) for polarizer film were prepared by electron beam (e-beam) radiation to acrylic copolymers, and their adhesive properties were investigated. The acrylic copolymers were synthesized by free radical polymerization of $n$-butylacrylate (BA), 2-hydroxyethyl methacrylate (HEMA), and acrylic acid (AA). The acrylic copolymers were coated on PET release films to a thickness of 25 ${\mu}m$, laminated to polarizer films, and then radiated with e-beam at room temperature. Gel fractions of all the acrylic copolymers after e-beam radiation at 50 kGy were higher than 93%, and their crosslinking densities were increased with increasing the content of HEMA units. PSA prepared by e-beam radiation of acrylic copolymer synthesized with a feed ratio of BA/HEMA/AA = 89.5/10/0.5 (w/w/w) at a dose of 50 kGy exhibited the best adhesion performances in terms of peel strength, creep resistance, durability and reliability, and light leakage. It is expected that the preparation method of PSAs via e-beam irradiation will improve the producibility and workability of polarizer film for liquid crystal display.

• Journal of Korea Entertainment Industry Association
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• v.13 no.2
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• pp.253-259
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• 2019

Prostate cancer(PrCa) is a leading cause of cancer-related death in man. Medicinal plants are exploited for many drugs to treat various ailments. The drugs derived from the plants promote health, augmented the resistance of the body against disease. Pueraia lobata(wild) Ohwi(P. Lobata), kudzu, which is a twining perennial woody herb native to China, Korea, Japan, India, and the United States. Plants such as Moringa oleifera, have hypoglycemic properties and other beneficial properties. The objective of the study was to analyze the effects of kadzu and moringa, natural plant products on antioxidant activity and proliferation of the hormone-sensitive prostate cancer LNCaP cells. MTT assay, flow cytometry analysis were employed to investigate the anticancer mechanism and DPPH assay was determined to the antioxidant activity to scavenge free radicals in extract of these. All two extracts showed significantly antioxidant activity at 10 and 50mg/ml of concentration. kadzu and moringa reduced LNCaP cell viability in a dose dependent manner. Specially moringa extract was more potent cytotoxic than kadzu extract. Statistical analyses revealed kadzu and moringa exhibited significantly higher (P < 0.05) cytotoxicity and antioxidant activity in LNCaP. The finding of this study provides a scientific basis for using kadzu and moringa in future development of chemotherapeutic drugs against hormone-sensitive prostate cancer.

• Journal of Embryo Transfer
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• v.33 no.3
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• pp.185-194
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• 2018

The aim of this study was performed to evaluate the effects of ice-binding protein from the arctic yeast Leucosporidium (LeIBP) supplementation on cryopreservation of boar sperm. The collected semen was diluted ($1.5{\times}10^8/ml$) in lactose egg yolk (LEY) and cooled at $5^{\circ}C$ for 3 h. The cooled semen was then diluted ($1{\times}10^8/ml$) in LeIBP containing LEY with 9% glycerol and maintained at $5^{\circ}C$ for 30 min. The semen was divided into six experimental groups (control, 0.001, 0.005, 0.01, 0.05 and 0.1 mg/ml of LeIBP). The straws were kept on above the liquid nitrogen ($LN_2$) vapors for 20 minutes and then plunged into $LN_2$. After thawing, computer-assisted sperm analysis was used for sperm motility and flow cytometry was performed to assess the viability, acrosome integrity (FITC-PSA/PI), ROS (DCF/PI), lipid peroxidation (BODIPY C11/PI) and apoptosis (Annexin V/PI), respectively. No significant responses were observed for sperm motility. However, sperm viability was significantly increased on 0.05 and 0.1 mg/ml of LeIBP groups compared to control (P < 0.05). In addition, acrosome integrity was significantly increases LeIBP groups (P < 0.05) and both ROS and lipid peroxidation level were lower in all LeIBP groups than those of control (P < 0.05). On the other hand, a significant higher apoptosis rate was observed in 0.05 and 0.1 mg/ml of LeIBP groups compared to control (P < 0.05). It can be assumed that a supplementation of LeIBP in boar sperm freezing extender is an effective method to increase the sperm qualities after cryopreservation.