• Journal of Radiation Industry
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• v.6 no.4
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• pp.289-297
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• 2012

Since Nafion is very expensive and shows the decreased fuel cell performance over $80^{\circ}C$ operating temperature, much work has been carried out in the search for cheaper membrane with high fuel cell performance. Radiation is known to be very useful for the preparation of the polymer electrolyte membranes since it can be effectively used for the introduction of ion conducting functional groups into the commercial film with high mechanical and chemical properties. Here, we summarize the our recent progress in the development of fuel cell membranes by utilizing radiation.

• Journal of Radiation Industry
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• v.5 no.2
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• pp.179-184
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• 2011

In this study, several anion exchange membranes were successfully prepared by radiation grafting of vinylbenzyl chloride (VBC) monomer onto a polyethylene-co-tetrafluoroethylene (ETFE) film and subsequent quaternarization with diamins such as 1,4-diazbicyclo[2,2,2]octane, N,N,N',N'-tetramethyl-1,3-diaminopropane, N,N,N',N'-tetramethyl-1,6-diaminohexane, and trimethylamine. The anion exchange capacities of the prepared membranes were determined by using acid-base titration method. The cross-sectional morphology of the membranes was studied by using SEM instrument. The cross-sectional distribution patterns of the grafted polymers with anion exchange functional groups were also studied by EDX analysis.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.5
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• pp.467-473
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• 2019

In this study, approached to improve durability of the multi-functional nano-pattern fabricated on the curved lens surface using nanoimprint lithography (NIL) was proposed, and the effects of the proposed methods on functionality after wear test were examined. To improve the mechanical property of ultraviolet(UV)-curable resin, UV-NIL was conducted at the elevated temperature around $60^{\circ}C$. In addition, micro/nano hierarchical structures was fabricated on the lens surface with a durable film mold. Analysis on the worn surfaces of nano-hole pattern and hierarchical structures and measurements on the static water contact angle and critical water volume for roll-off indicated that the UV curing process with elevated temperature is effective to maintain wettability by increasing hardness of resin. Also, it was found that the micro-scale pattern is effective to protect nano-pattern from damage during wear test.

• Science of Emotion and Sensibility
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• v.21 no.4
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• pp.103-112
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• 2018

This study aimed to identify specific psychological and brain activation responses relating to the processing of negative emotions in patients with alcohol dependency. The authors hypothesized that patients with alcohol dependency would demonstrate the abnormal functioning of brain regions involved in negative emotions. Eleven male patients diagnosed with alcohol dependence in an inpatient alcohol treatment facility and 13 social drinkers with similar demographics were scanned using functional magnetic resonance imaging (fMRI) as they viewed film clips that evoked negative emotions. During exposure to negative emotional stimuli, the control group evinced significantly greater activity in the right anterior cingulate cortex (ACC) in comparison to patients with alcohol dependency. Correlation analyses demonstrated a negative association in the relationship between beta values from the right ACC and amygdala in participants classified in the control group. No statistically significant relationship was observed for blood oxygenation level-dependent (BOLD) changes between the two regions in the patient group during the elicitation of negative emotions. On the other hand, patients exhibited a greater activation of the amygdala as negative emotions were induced. These results suggest that alcoholism presents pathophysiology of brain activation that is distinct from the responses of healthy individuals functioning as controls.

• Journal of Pharmacopuncture
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• v.25 no.4
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• pp.317-325
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• 2022

Polymers are the major constructive material of pharmaceutical formulations that play a prime role in designing effective drug-delivery systems and releasing drugs at their sites of application. Polymers are composed of multiple repeating units of high molecular mass components with attendant properties. Most synthetic polymers are non-biocompatible, expensive, and extremely inclined to deliver adverse impacts. Meanwhile, edible polymers obtained from natural sources have gained remarkable recognition for their promising use in modern medicine. Moreover, polymers derived from natural sources are generally preferred due to certain of their unique features such as abundant availability, biocompatibility, nontoxicity, economical, safe, and effective functions that fit the purpose. Polysaccharides including starch, cellulose, hemicellulose, pectin, and mucilage are identified as a major class of naturally obtained molecules that have a substantial role as functional polymers. This review summarizes the potential role of polysaccharides derived from vegetable sources such as adhesives, anticaking agents, binders, disintegrants, emulsifiers, film-framing agents, and thickeners. This is simply an opportunity to abandon synthetic excipients that hurt our bodies and think back to nature from where we originate.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.4
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• pp.463-469
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• 2015

Purpose: A hydrogel including alginate and $CaCl_2$ extracted from seaweed was manufactured, and their physical properties were investigated. Also, its applicability as contact lenses was examined. Methods: A film-type sample used in this experiment was manufactured using 2-hydroxyethyl methacrylate (HEMA), which is the raw material of hydrogel contact lenses; azobisiobutyonitile (AIBN), which is an initiator and ethylenglycoldimethacrylate (EGDMA), which is a cross-linking agent. It was hydrated in a PBS solution for 24 hours, and an interpenetrating polymer network (IPN) was formed in 1% and 2% alginate and 1%, 3%, and 5% $CaCl_2$ solutions for 24 hours, respectively. Results: The measurement of the physical properties of the film after the IPN showed that the moisture content was 30.89~36.89%, the refractive index was 1.431~1.441, the contact angle was $62.98{\sim}80.45^{\circ}$, and the tensile strength was 2.378~4.215 ($gf/mm^2$). Also, the physical properties hardly changed as the content of alginate increased, and the moisture content decreased as the content of $CaCl_2$ increased. As a result of the IPN, the moisture content and contact angle decreased compared to those of basic HEMA, but the tensile strength increased. The tensile strength of the second IPN was higher than that of the first IPN. In the case of $CaCl_2$, for the sample polymerized for 24 hours and the second IPN sample with 2% alginate, the contact angle decreased as the content of $CaCl_2$ increased. Conclusions: In this study, the tensile strength increased as the content of $CaCl_2$ increased, and the wettability increased as a result of IPN of alginate and $CaCl_2$. The hydrogel containing the alginate and $CaCl_2$ was confirmed possible utilization as contact lens material.

• Journal of radiological science and technology
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• v.26 no.4
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• pp.27-32
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• 2003

To evaluate usefulness of a functional tracheobronchial phantom for interventional procedure. The functional phantom was made as a actual size with human normal anatomy used silicone and a paper clay mold. A tracheobronchial-shape clay mold was placed inside a square box and liquid silicone was poured. After the silicone was formed, the clay was removed. We measured film density and tracheobronchial angle at the human, animal and phantom, respectively. The film density of trachea part were 0.76(${\pm}0.011$) in human, 0.97(${\pm}0.015$) in animal, 0.45(${\pm}0.016$) in phantom. The tracheobronchial bifurcation part measured 0.51(${\pm}0.006$) in human, 0.65(${\pm}0.005$) in animal, 0.65(${\pm}0.008$) in phantom. The right bronchus part measured 0.14(${\pm}0.008$) in human, 0.59(${\pm}0.014$) in animal and 0.04(${\pm}0.007$) in phantom. The left bronchus were 0.54(${\pm}0.004$) in human, 0.54(${\pm}0.008$) in animal and 0.08(${\pm}0.008$) in phantom. At the stent part were 0.54(${\pm}0.004$) in human, 0.59(${\pm}0.011$) in animal and 0.04(${\pm}0.007$) in phantom, respectively. The tracheobronchial angle of the left bronchus site were $42.6({\pm}2.07)^{\circ}$ in human, $43.4({\pm}2.40)^{\circ}$ in animal and $35({\pm}2.00)^{\circ}$ in phantom, respectively. The right bronchus site were $32.8({\pm}2.77)^{\circ}$ in human, $34.6({\pm}1.94)^{\circ}$ in animal and $50.2({\pm}1.30)^{\circ}$ in phantom, respectively. The phantom was useful for in-vitro testing of tracheobronchial interventional procedure, since it was easy to reproduce.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.688-695
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• 2011

This study was carried out for some survey about soil compaction in the multi-cropping system of paddy field. Investigated sites were 90 farmer's fields in south-eastern part of Korea. The tillage practices season was different according to cropping system of paddy; in spring for mono rice cultivation and in autumn for the multi-cropping field. The average tillage depth in investigated sites was about 25 cm, however, it is different between the farmer's tillage practices and soil characteristics. It is high correlation to tillage deep and minimum resistance of penetration. The reaching soil deep to maximum resistance of penetration was about 27 cm, and average penetration resistance of the deep is 1.8~2.0 MPa for moderately fine-textured soils and more than 3.0 MPa for moderately coarse-textured soils. The difference of penetration resistance between cultivating and compacted layer was in order to sandy loam > clayey loam > clayey, and the difference was lesser in poorly drained soils than somewhat poorly ones. In the rice mono cropping field, the maximum resistance in no-tillage for 15 years was 1.18~1.25 Mpa at 20~25 cm in soil deep, however, the resistance of field with every year tillage practices was 2.03~2.21 Mpa. In the extremely compacted sandy loam textured soils, the penetration resistance at 30 cm in soil depth was drastically reduced by the subsoil from 5.2 Mpa to 3.2 Mpa, and the watermelon root in plastic film house was deep elongated.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.3
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• pp.227-231
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• 2004

A total of 219 polymerase chain reaction tests of genetically modified (GM) DNA sequences in soybean seeds and soybean sprouts were conducted during 2000-2001. No CM gene was found in 96 tests of soybean seeds. However, either a functional CP4EPSPS gene or the 355 promoter gene was found three times in 2000 and eight times in 2001, in between 0.01 and 0.17％ of soybean spout products, in 123 tests. Since the amount of GM genes was much less than the threshold limit of 3％, none of the 11 positive soybean-sprout samples needed to be libeled GM crops. Of these, seven sprout samples were from domestic seeds and four were from seeds imported from China. To find the contamination route, the raw materials, seed surface, floor of the storage room, area around the selection machine, surface of the packaging film and corn powder used in the package were tested. The 35S promoter gene was detected in only two samples of the corn powder (0.1％). Although we could not find the cause of the GM contamination, the sprout package film is one possibility. In total,8.9％ of the soybean sprout tests were GM positive, but the amounts were much less than the threshold of 3％. This means that there are frequent false-positives and these would threaten the sprout industry if GMO were decided qualitatively. Food companies should make their safety data available to the public and make an effort to address people's concerns about GM food more openly. In addition, there is a need to establish a quantitative test for GM genes in sampled water and a sampling method for raw materials.

• Journal of Acupuncture Research
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• v.18 no.3
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• pp.56-68
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• 2001

Objective : Functional brain mapping study on acupuncture stimulation using the [14C]2-deoxyglucose([14C]2-DG) autoradiography provides quantitative data and visualized pathway in central nervous system(CNS). We aimed to investigate the neural pathway and spatial distribution of metabolic activity elicited in CNS on electroacupuncture stimulation using [14C]2-DG autoradiography. Methods : The study were divided into three groups by stimulation times. 45-mins stimulation group according to Sokoloffs method, 5-mins stimulation group according to Duncun's method, and 15-mins stimulation group. ;A venous catheter was equipped into right jugular vein. The rats (Sprague-Dawley rats, 230-260g) were kept fastened loosely on a holding platform without anesthesia. Electroacupuncture stimulation (5 ms, 2 Hz, 1~3 mA) were applied on the left Zusanli (ST36) acupoint and [14C]2-DG ($25{\mu}Ci/rat$) injection was performed through the catheter. After sacrifice, the brain and the spinal cord were made to sections for film image. The film images were digitalized as the isotope concentration based upon comparison of optical densities with that of the standards and normalized by the optical density of corpus callosum. Results : 1. 15-mins stimulation group was most effective among 3 experiments. 2. On 15-mins stimulation group, medial geniculate nucleus, intetpeduncular nucleus intermedius, ventral periolivary nucleus, caudal periolivary nucleus, medial superior olive, lateral paragigantocellular nucleus, including hypothalamic arcuate nucleus were increased by more than 25% (at least, p<0.05) by electroacupuncture stimulation. 3. Especially, the metabolism in hypothalamic arcuate nucleus was increased by 90% (p<0.05). 4. The fact that arcuate nucleus of hypothalamus might play a role of interconnection area between ascending and descending pathway of acupuncture stimulation was demonstrated visually. Conclusions : Advanced study on electroacupuncture stimulation elicited significant increase of metabolic activity in various nuclei of hypothalamus will provide the important experimental basis in research of the relationship between electroacupuncture stimulation and internal visceral functions.