• Korean Chemical Engineering Research
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• v.55 no.2
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• pp.270-274
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• 2017

Formic acid has been known as one of key sources of hydrogen. Among various monometallic catalysts, hydrogen can be efficiently produced on Pd catalyst. However, the catalytic activity of Pd is gradually reduced by the blocking of active sites by CO, which is formed from the unwanted indirect oxidation of formic acid. One of promising solutions to overcome such issue is the design of alloy catalyst by adding other metal into Pd since alloying effect (such as ligand and strain effect) can increase the chance to mitigate CO poisoning issue. In this study, we have investigated formic acid deposition on the bimetallic $Pd/Pd_3Fe$ core-shell nanocatalyst using DFT (density functional theory) calculation. In comparison to Pd catalyst, the activation energy of formic acid dehydrogenation is greatly reduced on $Pd/Pd_3Fe$ catalyst. In order to understand the importance of alloying effects in catalysis, we decoupled the strain effect from ligand effect. We found that both strain effect and ligand effect reduced the binding energy of HCOO by 0.03 eV and 0.29 eV, respectively, compared to the pure Pd case. Our DFT analysis of electronic structure suggested that such decrease of HCOO binding energy is related to the dramatic reduction of density of state near the fermi level.

• Journal of the Korean Society for Heat Treatment
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• v.22 no.5
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• pp.290-297
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• 2009

In case of using Asymmetric Bipolar Pulsed DC (ABPD) power generator, thin film is efficiently deposited as ions are getting higher energy by suppressing target poisoning and electric arc. In this article, the mechanical properties of CNx thin films deposited on the STS 316L were compared with DC and ABPD power generators. The CNx thin films deposited with ABPD clearly improved wear resistance by higher ratio of sp3CN as compared with DC. Nb interlayer affected to increase the value of 10N of adhesion between CNx thin films and substrate. But, CNx thin films deposited with ABPD couldn't endure to wear load and decreased wear resistance as the films were too thinner than substrate. Nevertheless the higher substrate bias energy applied to perform the dense films, it wasn't shown benefits about the wear properties from DC sputtering. But, in case of using ABPD sputtering, the wear resistance was largely improved without changing morphology despite of thin films.

• Food Science of Animal Resources
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• v.40 no.4
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• pp.512-526
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• 2020

Synthetic nitrite is considered an undesirable preservative for meat products; thus, controlling synthetic nitrite concentrations is important from the standpoint of food safety. We investigated 1,000 species of microorganisms from various kimchi preparations for their potential use as a starter culture for the production of nitrites. We used 16S rRNA gene sequence analysis to select a starter culture with excellent nitrite and nitric oxide productivity, which we subsequently identified as Staphylococcus hominis subspecies hominis WiKim0113. That starter culture was grown in NaCl (up to 9%; w/v) at 10℃-40℃; its optimum growth was observed at 30℃ at pH 4.0-10.0. It exhibited nonproteolytic activity and antibacterial activity against Clostridium perfringens, a bacterium that causes food poisoning symptoms. Analysis of Staphylococcus hominis subspecies hominis WiKim0113 with an API ZYM system did not reveal the presence of β-glucuronidase, and tests of the starter culture on 5% (v/v) sheep blood agar showed no hemolytic activity. Our results demonstrated the remarkable stability of coagulase-negative Staphylococcus hominis subspecies hominis WiKim0113, especially in strain negative for staphylococcal enterotoxins and sensitive to clinically relevant antibiotics. Moreover, Staphylococcus hominis subspecies hominis WiKim0113 exhibited a 45.5% conversion rate of nitrate to nitrite, with nitrate levels reduced to 25% after 36 h of culturing in the minimal medium supplemented with nitrate (200 ppm). The results clearly demonstrated the safety and utility of Staphylococcus hominis subspecies hominis WiKim0113, and therefore its suitability as a starter culture.

• Archives of Reconstructive Microsurgery
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• v.5 no.1
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• pp.128-136
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• 1996

Radial nerve injury is caused by variety of etiologies, mainly traumatic. It is primarily a motor nerve and loss of it's function leads to a significant disability. Surgical treatments of radial nerve comprise of neurolysis(internal or external), neurorrhaphy(eineural, perineural or epi-perineural), nerve graft and tendon transfer. However, there is still controversies in treatment methods and time of operation. Authors experienced 23 cases of radial nerve injuries who were treated by operative methods and followed up over 1 year's duration. The male to female ratio was 18 to 5 and mean age was 30.7 years old. The causes were 13 cases in fractures, 5 cases in crushing injury, 3 cases in laceration, 1 case in CO poisoning and 1 case in unknown cause. The summary of the study were as follows ; 1. Excellent or good results were obtained in overall 16 cases among 23 cases; 5 of 9 cases in neurolysis, 3 of 3 cases in neurorrhaphy, 2 of 3 cases in nerve graft and 6 of 8 cases in tendon transfer. 2. In cases of neurorrhaphy and nerve graft, primary or delayed repair showed excellent or good results and neurolysis performed before 6 months leads to better results. But there was no correlations between the time of injury and operation in tendon transfer. 3. The radial nerve injury associated with extensive soft tissue defect or any conditions that leads to nerve ischemia results poor prognosis. 4. The patients aged under 40 years showed better prognosis in clinical results according to the age of surgical treatment. 5. If the surgeon decide the method and the time of operation through the exact evaluation of the factors which influencing the end result such as age of the patient, level and type of injury, extent of nerve lesion and the associated tissue injury, good result could be expected.

• Journal of Microbiology and Biotechnology
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• v.29 no.12
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• pp.1916-1924
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• 2019

Outbreaks of staphylococcal food poisoning (SFP) causing serious human diseases and economic losses have been reported globally. Furthermore, the spread of Staphylococcus aureus with increased resistance to multiple antimicrobial agents has become a major concern in the food industries and medicine. Here, we isolated an endolysin LysSAP8, as one of the peptidoglycan hydrolases, derived from the bacteriophage SAP8 infecting S. aureus. This endolysin was tagged with a 6×His at the C-terminal of the target protein and purified using affinity chromatography. LysSAP8 demonstrated lytic activity against a broad spectrum of bacteria, which included a majority of the staphylococcal strains tested in this study as well as the methicillin-resistant S. aureus (MRSA); however, no such activity was observed against other gram-positive or gram-negative bacteria. Additionally, LysSAP8 could maintain bactericidal activity until 0.1 nM working concentration and after heat treatment at 37℃ for 30 min. The ability of LysSAP8 to lyse cells under varying conditions of temperature (4-43℃), pH (3-9), and NaCl concentrations (0-1,000 mM), and divalent metal ions (Ca²⁺, Co²⁺, Cu²⁺, Mg²⁺, Mn²⁺, Hg²⁺, and Zn²⁺) was examined. At the optimized condition, LysSAP8 could disrupt approximately 3.46 log CFU/ml of the planktonic cells in their exponential phase of growth within 30 min. In this study, we have suggested that LysSAP8 could be a potent alternative as a biocontrol agent that can be used to combat MRSA.

• Applied Chemistry for Engineering
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• v.16 no.1
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• pp.139-143
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• 2005

We evaluated grapefruit seed extract for antibacterial activity at varying time intervals and concentration levels against heat tolerant and spore-forming Bacillus stearothermophilus, mesophilic Bacillus subtilis, and food poisoning Staphylococcus aureus. Grapefruit seed extract showed growth inhibitory activity against B. stearothemophilus and B. subtilis, and S. aureus at the level of 0.01 tp 0.03% in nutrient broth. However, when applied to soymilk in a market, grapefruit seed extract at the level above 0.2% effectively inhibited the growth of B. stearothermophilus, However, it failed to completely sterilize the test organisms. On the other hand, B. subtilis and S. aureus were completely sterilized at the level of 0.2% within 48 hrs and 72 h, respectively. The higher concentration of grapefruit seed extracts showed more effective antibacterial activities against the test organisms, but caused deteriorated organoleptic quality and emulsion stability. We could conclude, by applying grapefruit seed extract (0.015%) with thermal treatment (10 min at $121^{\circ}C$) that the microbial stability of commercial soymilk was enhanced greatly.

• The Journal of Internal Korean Medicine
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• v.16 no.1
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• pp.1-16
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• 1995

This study was done in order to investigate the etiology and pathology of dementia in the variety literature. Dementia in elderly persons(above the age of 60) mainly classfied Alzheimer disease and Cerebral vascular dementia. The results were as follows: 1. Dementia patients have abnormal mental function, who have no mental weakness but defects of memory, verbal disturbance, behavior disturbance and loss of intellectual function. 2. Dementia regard as 'me-beng(?病)', 'jeon-gwang(癲狂)', and 'heo-ro(虛勞)' in oriental medicine and the symptom is a silence with no response, mixing, a crying or a laugh, a stranger behavior and a amnesia; disturbances of speech, emotion, behavior. 3. Dementia caused by Alzheimer disease, Multi infarct dementia, Parkinson's disease, sequelae of acute CO poisoning, head injury and alcoholism(occidental medically) and the 'Dam(痰) and Damhwa(痰火), weakness of heart and spleen(心脾虛) caused by pent up anger of seven emotions(七情鬱結), the weakness of liver and kidney(肝腎不足)(oriental medically). 4. The causes of Alzheimer disease are various; a heredity factor, a morphological factor of brain tissues, a psychological factor and a biochemical factor (occidental medically) ; the 'Dam(痰) and Damhwa(痰火) caused by weakness of the internal organs and disturbance of the emotions(oriental medically). 5. Cerebral vascular dementia caused by loss of the certain cerebral neurons and oriental medically caused by obstruction of 'dam(痰)' or 'eo heul(瘀血)'. It is recommended that further study of many sided investigations, specially against a weakness of spiritual functions and a certain neurotoxin in the future.

• The Korean Journal of Nuclear Medicine
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• v.27 no.1
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• pp.104-111
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• 1993

Trace elements are important components in the biological system, as a structural material and metabolic controller. Neutron activation analysis (NAA) with high neutron flux and high energy resolution Ge (Li) detector coupled to multichannel analyzer (MCA) has been one of the most accurate method for the determination of ultra-trace level components, and is applicable to biological material. In human body, the NAA can be used for quantitation of trace elements in various organs and tissue with endocrinological and metabolic disease and industrial metal poisoning. In this study, Triga Mark III nuclear reactor in Korea Atomic Research Institute was used for quantitation of trace eleement in human lung cancer tissues by neutron activation analysis. In the squamous cell carcinoma tissues, Br, Hg, La, Sb, Sc, Cl, Fe and I content were lower than normal lung tissues, and K, Rb and Se content were higher. In the adenocarcinoma tissues, Fe, Au, La, Sc and Zn content were lower than normal lung tissues, and Rb, Co and Se content were higher. Rb content was higher in the adenocarcinoma tissues than in the squamous cell carcinoma tissues. Fe and Na content were higher in the squamous cell carcinoma tissues than in the adenocarcinoma tissues.

• Korean Journal of Community Nutrition
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• v.11 no.5
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• pp.618-628
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• 2006

The purpose of this study was to examine the donators' characteristics and donative foods of both government-dominant and non-governmental food bank program, to understand the problems and benefits of food bank program, and to find the solutions to activate food bank program. The questionnaires were distributed to 120 food bank operators and 3 donators were selected from each food bank for the survey from April 2002 to May 2002. 118 sheets (32.8%) from government-dominant food bank and 53 sheets (20.1%) from non-governmental food bank were collected. The main results of this study were as follows: The largest donators to either government-dominant or non-governmental food bank programs were bakery and confectionery companies 31.4% and 45.3% respectively. The majority of donated foods were 'goods in stock' (55.6%) and frequency of donation were largely on a daily basis (27.1% for government-dominant and 22.6% for non-governmental). Some of the donators who had more donative food did not donate, and the reasons were closeness to expiration date of food (67.3%), lack of legal protection in the event of food poisoning (54.5%), and poor public image of food related accidents (52.3%).

• Journal of the Korean Institute of Gas
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• v.20 no.6
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• pp.89-94
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• 2016

The number of camping population and sites are rapidly increasing with to the expansion of camping culture and the advancement of leisure culture. It is necessary to develop an effective strategy of safety management, as a lot of accidents occur due to the increase of population and sites for camping. Particular attention needs to be paid for accident prevention in the increasing accidents of explosion awing to the overheating of bytane gas, and carbon monoxide poisoning due to the use of non-ventilated areas. In this study, the direction of safety management strategy is analyzed by a survey and analysis of risk factors in campsite about gas facilities and gas appliances in camp site. Accordingly, some directions are suggested. Conclusively, it is expected that the results of this study could help to improve efficiency management for camping.