• Journal of the Korean Electrochemical Society
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• v.17 no.3
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• pp.164-171
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• 2014

A highly sensitive and selective non-enzymatic glucose sensor has gained great attention because of simple signal transformation, low-cost, easily handling, and confirming the blood glucose as the representative technology. Until now, glucose sensor has been developed by the immobilization of glucose oxidase (GOx) on the surface of electrodes. However although GOx is quite stable compared with other enzymes, the enzyme-based biosensors are still impacted by various environment factors such as temperature, pH value, humidity, and toxic chemicals. Non-enzymatic sensor for direct detecting glucose is an attractive alternative device to overcome the above drawbacks of enzymatic sensor. Many efforts have been tried for the development of non-enzymatic sensors using various transition metals (Pt, Au, Cu, Ni, etc.), metal alloys (Pt-Pb, Pt-Au, Ni-Pd, etc.), metal oxides, carbon nanotubes and graphene. In this paper, we show that Ni-based nano-particles (NiNPs) exhibit remarkably catalyzing capability for glucose originating from the redox couple of $Ni(OH)_2/NiOOH$ on the surface of ITO electrode in alkaline medium. But, these non-enzymatic sensors are nonselective toward oxidizable species such as ascorbic acid the physiological fluid. So, the anionic polymer was coated on NiNPs electrode preventing the interferences. The oxidation of glucose was highly catalyzed by NiNPs. The catalytically anodic currents were linearly increased in proportion to the glucose concentration over the 0~6.15 mM range at 650 mV versus Ag/AgCl.

• Journal of Veterinary Clinics
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• v.21 no.4
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• pp.384-394
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• 2004

This study was carried out to monitor the response of ovaries and cyst according to treatment with GnRH or combination of GnRH and $PGF_2{\alpha}$ in dairy cows with ovarian follicular cysts. Thirty cows were diagnosed as having follicular cysts by rectal palpation, ultrasonography and progesterone (P4) assays. Ten cows were treated with GnRH (control), and the other twenty were treated with $PGF_2{\alpha}$ at 10 days after GnRH treatment. All the animals were re-examined by ultrasonography and blood was collected for the measurement of plasma P4 concentration at day 0 (the day of treatment), day 7, day 10, day 13, day 24 and day 34, respectively. In 30 cows that were diagnosed with follicular cysts, mean plasma P 4 concentrations on day -II and day -I were 0.3 ng/ml and 0.4 ng/ml. On day 10 increased as 2.7$\pm$0.2 ng/ml. Mean cystic wall thickness by ultrasonography on day -11 and day -I were 2.1 mm and 2.2 mm. In 9 cows responded on luteinization of cystic wall, cystic wall thickness was 3.9$\pm$0.5 mm at day 10 after GnRH treatment. The responses of ovaries until day 10 after GnRH treatment included development of corpus luteum in the ovary bearing the cyst or in the contralateral ovary (12 cows), luteinization of cystic wall (6 cows) and clouding of the anechoic antrum of cysts (2 cows). The ovarian responses according to the combination of GnRH and $PGF_2{\alpha}$ included regression of the corpus luteum (12 cows), increase (1 cow) and no change (1 cow) of cyst size until last examination, and complete disappearance on day 13 (6 cows), 23 (6 cows) and 34 (4 cows). Combination treatment group of GnRH and $PGF_2{\alpha}$ showed a higher pregnancy rate within 100 days after initial treatment (40.0 vs 65.0%) and shorter intervals from the treatment to conception (45.4$\pm$25.8 vs 53.5$\pm$31.4 days) compared with control. It was concluded that the administration of $PGF_2{\alpha}$ following GnRH treatment is effective in shortening the interval from treatment to conception in cows with follicular cyst. Also, this study suggested that the response of the cyst according to treatment revealed various types. Therefore, veterinarians should pay attention to monitor of the response of cystic ovaries after treatment, specially no change, slowly decrease or increasement of cyst size after treatment.

• Management & Information Systems Review
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• v.34 no.3
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• pp.79-100
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• 2015

This study is to examine the factors that influence purchasing behavior and decision-making when consumers buy goods through mobile shopping, define purchasing decision-making with the steps of problem recognition, information search, alternative assessment, and purchasing behavior to understand mobile consumer behavior, and investigate how the factors of each step play roles and influence consumers' purchasing decision-making through positive analysis to figure out consumer purchasing behavior in mobile shopping. The study results, First, the user characteristics of information search influence flow. Second, in the relations between the user characteristics in the step of information search and perceived risk in alternative assessment, if recognition on gains is higher, perceived risk for time loss gets lower, and when the level of skills is higher, perceived risk gets higher, and it has been partly adopted that innovativeness does not influence risk perception. Third, in the relations between flow experience and purchasing intention, it has been found to be partially significant that remote presence and challenge do not influence purchasing intention but do influence excitement, attention concentration, and control and also do influence perceived risk and purchasing intention. Fourth, according to the results of analyzing the difference of consumer purchasing behavior by the types of involvement, practical involvement and sensual involvement, user characteristics and flow, and perceived risk differ by the types of products in terms of the search process, thereby changing purchasing intention. Lastly, the significance and limitations of this study was discussed.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.7
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• pp.771-776
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• 2005

In recent days, there is much interest in the biocidal activity of silver since silver is known to be safe and effective as disinfectant and biocidal material against coliforms and viruses. In particular, nano silted silver particles which can be used as effective biocidal material received more attention. Accordingly, it is important to investigate antimicrobial activity and mechanism of nano sized silver particles prepared in a cost-effective manner. In this study, nano sized silver particles were prepared via photoreduction of a silver salt ($AgNO_3$) in the bulk phase of $PEO_{20}-PPO_{70}-PEO_{20}$ (Pluronic 123) block copolymer The antimicrobial efficacy of silver nano particles against E. coli was investigated and compared with that of silver ion as the concentration of silver nano particles, pH ($5.6{\sim}8.2$), temperature ($4^{\circ}C{\sim}35^{\circ}C$) varied in aqueous system. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) was used to examine the nature of damaged microorganism with nano sized silver particles and silver ion. This study showed that antimicrobial efficacy of silver nano particles was approximately one twentieth than that of silver ion. It was more biocidal at higher pH in contrast with silver ion. In addition, nano silver particles was demonstrated to disrupt the outer membrane of E. coli, subsequently causing their aggregation. On the other hand, silver ion diffused into the cell damaging the cytoplasmic membrane without disrupting the outer membrane of E. coli.

• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.67-74
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• 2016

The Prussian Blue Analogue(PBA) has three dimensional structure and the metal - organic framework material, and it has a variety configurations depending on the type of organic ligands. PBA has been receving an attention in the fields of biosensors, optical, catalytic, and hydrogen storage device. Also, it is an environmental friendly substance with a chemical stability. In addition, PBA is widely used in the filed of adsorption art since we can adjust the size of the fine pores. In this study, we synthesized $Mn_3[Fe(CN)_6]_2$, an organometallic framework chains by using a hydrothermal synthesis method. We used $K_4[Fe(CN)_6]$ and $MnCl_2$ as precursors. We also produced a manganese iron oxide, by baking the synthesized material. The effect of the size and shape of the particles was examined by controling pH of the precursor solution, the molar concentration of the precursor, and reaction time as the experimental variables. Synthesized absorbent was analyzed by XRD, SEM, FT-IR, UV-Vis, and TG / DTA to evaluate the adsorption properties of several dyes.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.3-3
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• 2018

For centuries, Panax ginseng Meyer (Korean ginseng) has been widely used as a medicinal herb in Korea, China, and Japan. Ginsenosides are a class of triterpene saponins and recognized as the bioactive components in Korean ginseng. Ginsenosides, which can be classified broadly as protopanaxadiols (PPD), protopanaxatriols (PPT), and oleanolic acids, have been shown to flaunt a vast array of pharmacological activities such as immune-modulatory, anti-inflammatory, anti-tumor, anti-diabetic, and antioxidant effects. In recent years, a number of ginseng and ginsenoside researches have increasingly gained wide attention owing to its unique pharmacological properties. Although good efficacies of ginsenosides have been reported, lack of target specific delivery into tumor sites, low solubility, and low bioavailability due to modifications in gastro-intestinal environments limit their biomedical application in clinical trials. As a result to this major challenge, nanotechnology and drug delivery techniques play a significant role to solve this problematic issue. Thus, we reported the preparation of poly-ethylene glycol (PEG) and glycol chitosan (GC) functionalized to ginsenoside (Compound K and PPD) conjugates via hydrolysable ester bonds with improved aqueous solubility and pH-dependent drug release. In vitro cytotoxicity assays revealed that PEG-CK, and PPD-CK conjugates exhibited lower cytotoxicity compared to bare CK and PPD in HT29 cells. However, GC-CK conjugates exhibited higher and similar cytotoxicity in HT29 and HepG2 cells. Furthermore, GC-CK-treated RAW264.7 cells did not exhibit significant cell death at higher concentration of treatment which supports the biocompatibility of the polymer conjugates. They also inhibited nitric oxide production in lipopolysaccharide (LPS)-induced RAW64.7 cells. In addition to polymer-ginsenoside conjugates, silver (AgNps) and gold nanoparticles (AuNps) have been successfully synthesized by green chemistry using different m. The biosynthesized nanoparticles demonstrated antimicrobial efficacy, anticancer, anti-inflammatory, antioxidant activity, biofilm inhibition, and anticoagulant effect. Special interest on the effective delivery methods of ginsenoside to treatment sites is the focus of metal nanoparticle research.In short, nano-sizing of ginsenoside results in an increased water solubility and bioavailability. The use of nano-sized ginsenoside and P. ginseng mediated metallic nanoparticles is expected to be effective on medical platform against various diseases in the future.

• Korean Chemical Engineering Research
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• v.51 no.4
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• pp.438-442
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• 2013

The study of bioproduct production from inexpensive biomass such as marine biomass has recently attracted considerable attention. Because, marine biomass which compared to land biomass, it can be grown rapidly and is easily cultivated without the need for expensive equipment. In addition, the carbohydrate contents are similar or higher than land biomass such as woody biomass and can be easily converted to chemicals through proper chemical processes. In the production of various biochemicals from marine biomass, levulinic acid is a highly versatile chemical with numerous industrial uses and has the potential to become a commodity chemical. It can be used as a raw material for resins, plasticizers, textiles, animal feed, coatings and antifreeze. In this study, experiments were carried out to determine the optimum conditions of temperature, acid concentration and reaction time for production of levulinic acid from marine biomass, Gelidium amansii, using two-step treatment. In the first hydrolysis step, solid-state cellulose which was used to produce ethanol by fermentation and liquid-state galactose which used to produce bioproduct such as levulinic aicd were obtained through acid soaking. In the second hydrolysis step, the liquid-state galactose was converted into levulinic acid via a high-temperature reaction in a batch reactor. As a result, the overall production yield of Gelidium amansii to levulinic acid in the two-step acid hydrolysis was approximately 20.6% on the initial biomass basis.

• Journal of agricultural medicine and community health
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• v.45 no.3
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• pp.121-129
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• 2020

Purpose: As dementia progresses, cognitive function decreasing leads to memory loss, speech degradation, time and space degradation and judgment degradation, which causes difficulties in carrying out tasks related to daily life. It was said that community-based non-drug intervention therapy for early dementia patients was important to participate in entertainment treatment, including activities such as awareness and exercise therapy, exercise rehabilitation, aerobic exercise, and art. Methods: This study conducted 15 experimental and 15 control groups(experimental group : Fumanet exercise, control group : general occupational therapy) for eight weeks at the Daycare Center in Gyeonggi-do to find out the impact of the Fumanet exercise program on cognitive and depression functions of the elderly. The pre-post evaluation used KGDS, MMSE. Results: There were significant differences between the two groups in the function of menopause, memory recall, attention concentration and calculation, and depression, and no significant results were obtatined in memory registration, language function, understanding and fracture. The Fumanet movement was judged to be effective in improving cognitive function and reducing depression for the elderly with dementia. Conclisions: The Fumanet movement was judged to be effective in improving cognitive function and reducing depression for the elderly with dementia.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.14 no.1
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• pp.3-11
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• 2003

Attention-deficit/Hyperactivity disorder(ADHD) is the most common psychiatric disorder of childhood and among the most prevalent chronic health conditions affecting school-aged children. Children with ADHD experience significant functional problems, such as school difficulties, academic underachievement, troublesome interpersonal relationships with family members and peers, and low self-esteem. The most widely used pharmacological treatments for ADHD are psychostimulants, such as methylphenidate and amphetamine salts. These medications provide clinical efficacy by increasing the availability of catecholamines, primarily dopamine, in the frontal lobe of the brain. immediate-release(IR) formulations of sychostimulants were among the most effective psychotrophic medications in the psychopharmacological treatment. However, there are some limitations of IR formulations：the short half-life and duration of efficacy, which result in the need for multiple daily dosing and the poor compliance. These limitations have led to the development of once-daily, extended-release(ER) formulations of methylphenidate and amphetamine salts. However, these ER formulations may not be as immediately helpful to ADHD children due to delayed onset of action and the acute tolerance which is the failure to sustain the efficacy with the same concentration of drug as the initial stage of medication. OROS-methylphenidate(Concerta$^{\circledR}$) given once a day produces an ascending-pattern plasma drug level generated by the osmotically released, timed drug-delivery system. These new formulations of the psychostimulants have been shown to be a useful alternative to old stimulant medications through the evidence by the clinical trials.

• Journal of Life Science
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• v.26 no.6
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• pp.673-679
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• 2016

The development of safe and effective anti-cancer compounds has been seriously required to prevent and treat development of tumor in recent years. Among them, natural compounds derived traditional medicinal stuffs have been paid to attention as an anti-cancer candidate. In this study, aesculetin is a main component of a widely known as a medicinal stuff. It was reported that aesculetin has various biological effects such as anti-inflammatory and anti-bacterial, but its effect related to cell invasion was not discovered. Therefore, in this study, the effect of aesculetin on antioxidant and matrix metalloproteases (MMPs) was investigated in human fibrosarcoma cells, HT1080. First of all, aesculetin showed the scavenging activity of DPPH radical and reducing power in a dose dependent manner. As a result of cytotoxicity, the nontoxic concentration of aesculetin was below 2 μM in HT1080 cells performed by MTT assay. In addition, aesculetin displayed the inhibitory effect on MMP-9 activity related to cell invasion in experiment carried out by gelatin zymography assay. Furthermore, aesculetin increased the expression level of TIMP-1 but decreased the expression level of MMP-9 stimulated with PMA in western blot assay. Furthermore, aesculetin remarkably inhibited cell invasion related to metastasis a dose dependent manner. Above results suggest that aesculetin could exert chemopreventive effect through inhibition of activity and expression of MMP-9 related to cell invasion.