• Korean Journal of Materials Research
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• v.10 no.11
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• pp.755-759
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• 2000

The influence of $O_2$partial presure on saturation magnetization, coercivity and effective permeability(0.5~100MHz) of as-deposited Fe-Sm-O thin films, which were fabricated by RF magnetron reactive sputtering method, were investigated. The nanocrystalline Fe(sub)83.4Sm(sub)3.4O(sub)13.2 thin film fabricated at $O_2$partial pressure of 5% exhibits the best magnetic softness with saturation magnetization of 18kG, coercivity of 0.82 Oe and effective permeability about 2,600 at 0.5~100MHz. $\alpha$-Fe grain size is decreased with increasing $O_2$partial pressure. In case of $O_2$partial pressure of 10%, it is observed that FeO compound is formed and soft magnetic properties are decreased. The electrical resistivity of Fe-Sm-O thin films were increased with increasing $O_2$partial pressure, the electrical resistivity of Fe(sub)83.4Sm(sub)3.4O(sub)13.2 thin film with the best soft magnetic properties was 130 $\mu$$\Omega$cm. Therefore, It is assumed that the good soft magnetic properties of Fe(sub)83.4Sm(sub)3.4O(sub)13.2 thin film results from high electrical resistivity and decreasing $\alpha$-Fe grain size due to precipitation of Sm-Oxide phase.

• Korean Journal of Materials Research
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• v.9 no.7
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• pp.753-759
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• 1999

The microstructure and electrical properties of ZNR that W $O_3$ is added in the range 0.5~4.0mol%, were investigated. The major part of W $O_3$ were segregated at the nodal point and W-rich phase was formed. Three crystalline phases, such as W-rich phase (W $O_3$), Bi-rich phase (B $i_2$W $O_{6}$ ), and spinel phase (Z $n_{2.33}$S $b_{0.67}$ $O_4$) were confirmed to be co-existed at the nodal point The average grain size increased in the range 15.5~29.9$\mu\textrm{m}$ with increasing W $O_3$ additive content. Consequently. W $O_3$ acted as a promotion additive of grain growth. As the W $O_3$ additive content increases. the varistor voltage and the nonlinear exponent decreased in the range 186.82~35.87V/mm and 20.90~3.34, respectively, and the leakage current increased in the range of 22.39~83.01 uh. With increasing W $O_3$ additive content, the barrier height and the density of interface states decreased in the range 1.93~0.43eV and (4.38~1.22)$\times$10$^{12}$ $\textrm{cm}^2$, respectively. W $O_3$ acted as an acceptor additive due to the donor concentration increasing in the range (1.06~0.38)$\times$10$^{18}$ /㎤with increasing W $O_3$ additive content.t.t.

• Journal of Food Hygiene and Safety
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• v.35 no.5
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• pp.477-488
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• 2020

Recently, foodborne illness outbreaks linked to fresh produce are being increasingly reported in the United States, the EU, and Korea as well. Some of this increase may be due to improved surveillance, increase in consumption, change in consumers' habits, and complex distribution systems. Garlic chive is a green, fresh-cut vegetable consumed year-round as a nutrition-rich herb in Korea. It is also prone to contamination with foodborne pathogens during pre-harvest, as amendment with high amounts of livestock manure or compost to soil is required in its cultivation. Our aim in this study was to evaluate microbial contamination of garlic chives, garlic chives cultivation soil, compost, and irrigation water in the southern part of Korea. Samples were collected in A, B, and C regions in 2019 and 2020, and 69, 72, 27, and 40 of garlic chives, soil, compost, and irrigated water, respectively, were analyzed for the presence of sanitary indicator bacteria (total aerobic bacteria, coliforms and Escherichia coli), Bacillus cereus, Staphylococcus aureus, pathogenic E. coli, E. coli O157:H7, Listeria monocytogenes, and Salmonella spp. In A, B, and C regions, levels of total aerobic bacteria, coliform, B. cereus, and S. aureus on all samples were between 1.14 and 8.83 log CFU/g, 0.43 and 5.01 log CFU/g, 0.41 and 5.55 log CFU/g, and 1.81 and 6.27 log CFU/g, respectively. B. cereus isolated from garlic chives and environmental samples showed β-hemolysis activity. Incidence of S. aureus in garlic chive and its production environments in 2020 was different from 2019. In this study, B. cereus and S. aureus were the only pathogenic microorganisms detected in all samples. As a result, this work suggests that continuous monitoring in the production and pre-harvest environment is required to improve hthe hygiene and safety of garlic chive.

• Korean Journal of Materials Research
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• v.11 no.1
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• pp.39-43
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• 2001

Nanocrystalline Fe-Sm-O thin films were prepared by RF magnetron reactive sputtering method in $Ar+O_2$mixed atmosphere with the $O_2$content of 5%. The compositions of the thin films were changed by changing the number of $Sm_2O_3$ chips. The best soft magnetic properties of the thin film with the composition of $Fe_{83.4}Sm_{3.4}O_{13.2}$ were saturation flux density of 18 kG, coercivity of 0.82 Oe and effective permeability about 2,600 at 0.5~100 MHz, respectively. The electrical resistivity of Fe-Sm-O thin films was increased with increasing the amount of Sm and O elements which combined each other, the electrical resistivity of$Fe_{83.4}Sm_{3.4}O_{13.2}$ thin film was $130{\mu}{\Omega}cm$. In case of the small amount of Sm and O elements, the microstructures of Fe-Sm-O thin films showed a precipitated phase of $Sm_2O_3$ on the ${\alpha}-Fe$ phase. With the increase of the amount of Sm and O elements, the microstructures of the Fe- Sm-O thin films were changed into a mixed structure of ${\alpha}-Fe$ crystal-phase and Sm-oxide amorphous phase. The Fe-Sm-O thin films with Fe content in the range of 72~94 at% exhibited the quality factor (Q = $\mu$′/$\mu$") of 7~75 up to 50 MHz.

• Herbal Formula Science
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• v.8 no.1
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• pp.299-318
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• 2000

In order to study on SOD like activity and Electric donor ability of Hedyotis diffusa $W_{ILLD}$, testing antibacterial effect on E. coli O157 which causes infectious inflammatory disease; measunng inhibitory effect on tyrosinase which stimulates melanin formation; and measuring the influence of it to SOD like activity, DPPH and TBARS which are related to ageing and carcinogenesis. The results of these experiments, are as follows. 1. In the antibacterial experiment with the extract of Hedyotis diffusa $W_{ILLD}$ on E. coli O157, there was no change in proliferation from the beginning of culture to two hours after, but proliferation inhibiting effect on E. coli O157 was detected from three hours after the beginning of culture. 2. Tyrosinase inhibitory effect was measured as $0.39{\pm}0.026%$. Compared with the control group, the effect was very slight. 3. The SOD like activity of the extract of Hedyotis diffusa $W_{ILLD}$. was measured as 21.33${\pm}$ 4.264%. Compared with the extracts of several other herbs, it was much more significant. 4. The DPPH of the extract of Hedyotis diffusa $W_{ILLD}$. was $53.3{\pm}0.91%$ when 0.02g was used and $83.5{\pm}1.82% $ when 0.05g was used. The result when 0.05g was used was more significant than 0.02g was used. 5. The TBARS of the extract of Hedyotis diffusa $W_{ILLD}$. was measured as 0.724 ${\pm}$0.O04MDAppm. Compared with the extracts of several other herbs, the result was more significant. From these results, we found that Hedyotis diffusa $W_{ILLD}$. can be used in therapy of dysentery with bloody stool and fever which is caused by infection with E. coli O157 and that it can be also used effectively as age resister or anticarcinogen.

• Journal of Photoscience
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• v.11 no.32
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• pp.71-74
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• 2004

The macrocycle L exhibited a switch on-off behavior through the fluorescent responses by aromatic imine molecule 1 (X=H) / trifluoroacetic acid (TFA). In the 'switch on' state, it was supposed that the aromatic imine molecule 1 is in the cavity of macrocycle L and a photoinduced electron transfer (PET) from the nitrogen of azacrown part to the anthryl group is inhibited by the interaction between the aromatic imine molecule 1 and the azacrown part of macrocycle L. In the 'switch off' state, it was supposed that the protonated imine molecule 1 is induced by the continuous addition of TFA and a repulsion between the protonated azacrown part and the protonated imine molecule 1 is occurred. It was considered that this process induces the intermolecular PET from the protonated imine molecule 1 to the anthryl group of macrocycle L because of a proximity effect between the anthryl group and the protonated imine molecule 1. From the investigation of the transient emission decay curve, the macrocycle L showed three components (3.45 ns (79.72%), 0.61 ns (14.53%), and 0.10 ns (5.75%). When the imine molecule 1 was added in the macrocycle L as molar ratio=1:1, the first main component showed a little longer lifetime as 3.68 ns (82.75%) although the other two components were similar as 0.64 ns (14.28%) and 0.08 ns (2.96%). On the contrary, when the imine molecule 3 (X=C1) was added in the macrocycle L as molar ratio=l:1, all the three components were decreased such as 3.27 ns (69.83%), 0.44 ns (13.24%), and 0.06 ns (16.93%). The fluorescent pH titration of macrocycle L was carried out from pH=3 to pH=9. The macrocycle L and C $U^{2+}$- macrocycle L complex were intersected at about pH=5, while the E $u^{3+}$ -macrocycle L complex was intersected at about pH=5.5. In addtion, we investigated the fluorescence change of macrocycle L as a function of the substituent constant ($\sigma$$_{p}$$^{o}$) showing in the para-substituent with electron withdrawing groups (X=F, Cl) and electron donating groups (X=C $H_3$, OC $H_3$, N(C $H_3$)$_2$), respectively, as well as non-substituent (X=H).).ctively, as well as non-substituent (X=H).

• Food Science of Animal Resources
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• v.33 no.2
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• pp.258-267
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• 2013

This study was conducted to determine the antioxidative and neuroprotective effect of pig skin extracts (PS) and pig skin gelatin hydrolysates (LPS) using a human neuroblastoma cell line (SH-SY5Y). The extraction yield of PS was 3 fold higher than that of LPS. The protein content of PS was about 10 fold higher than that of LPS (p<0.05). Also LPS increased antioxidative activity dose dependently, and the activity was significantly higher than PS at all concentration (p<0.05). DPPH radical scavenging activity of LPS at 50 mg/mL was 92.97%, which was similar to $1{\mu}M$ vitamin C as a positive control. ABTS radical scavenging activity of LPS (20 mg/mL) was 89.83% and oxygen radical absorbance capacity of LPS at 1 mg/mL was $141.39{\mu}M$ Trolox Equvalent/g. No significant change of human neuroblastoma cells was determined by MTT test. Cell death by oxidative stress induced by $H_2O_2$ and amyloid beta 1-42 ($A{\beta}_{1-42}$) was protected by LPS rather than PS. Acetylcholine esterase was significantly inhibited, by up to 33.62% by LPS at 10 mg/mL. Therefore, these results suggest that pig skin gelatin hydrolysates below 3 kDa have potential to be used as anti-oxidative and neuroprotective functional additives in the food industry, while further animal test should be determined in the future.

• Advances in pediatric surgery
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• v.20 no.1
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• pp.1-6
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• 2014

Minimal invasive surgery (MIS) has rapidly gained acceptance for the management of a wide variety of pediatric diseases. A questionnaire was sent to all members of the Korean Association of Pediatric Surgeons. Thirty one members (25.4%) took part in the survey that included data for the year 2012: demographic details, opinion regarding minimal invasive surgery and robotic surgery, spectrum of minimally invasive operations, and quantity of procedures. 48.4% of the respondents had more than 10 years experience, 35.5% less than 10 years experience, and 16.1 % had no experience. The respondents of the recommend MIS and perform MIS for surgical procedures are as follow; inguinal hernia (61.3%), simple appendicitis (87.1%), complicated appendicitis (80.6%), reduction of intussusceptions (83.9%), pyloromyotomy (90.3%), fundoplication (96.8%), biopsy and corrective surgery of Hirschsprung's disease (93.5%/90.3%), imperforate anus (77.4%), congenital diaphragmatic hernia (80.6%), and esophageal atresia (74.2%). The MIS procedures with more than 70% were lung resection (100%), cholecystectomy (100%), appendectomy (96.2%), ovarian torsion (86.7%), fundoplication (86.8%), hiatal hernia repair (82.6%), and splenectomy (71.4%). The MIS procedures with less than 30% were congenial diaphragmatic hernia reapir (29.6%), esophageal atresia (26.2%), correction of malroatation (24.4%), inguinal hernia repair (11.4%), anorectal malformation (6.8%), Kasai operation (3.6%).