Vertical flow immunoassay (VFA) biosensor for a rapid one-step immunoassay.

Oh, Young Kyoung,Joung, Hyou-Arm,Kim, Sanghyo,Kim, Min-Gon Royal Society of Chemistry 2013 Lab on a chip Vol.13 No.5

<P>A highly rapid, one-step immunoassay of high sensitivity C-reactive protein (hsCRP) using a biosensor with a vertical flow immunoassay (VFA) was developed. The VFA biosensor was primarily composed of a sample pad, conjugate pad, FTH film and nitrocellulose (NC) membrane, which were all vertically stacked upon one another. Anti-hsCRP and secondary antibodies were consecutively immobilized on the NC membrane at the position below the holes. Gold nanoparticles (AuNPs) conjugated with another anti-hsCRP antibody were encapsulated in the conjugation pad. Various assay conditions, including the size of the hole and the sample volume, were optimized. Under optimized conditions, hsCRP concentrations from 0.01 to 10 μg mL(-1) were detected within 2 min. In comparison with a lateral flow assay (LFA) system, the VFA sensor showed a gradual increase of signal in a concentration-dependent manner without a hook effect in the tested range.</P>

Use of Antimicrobial Food Additives as Potential Dipping Solutions to Control Pseudomonas spp. Contamination in the Frankfurters and Ham

Mi Hwa Oh,Beom Young Park,Hyun Ji Jo,Soo Min Lee,Hee Young Lee,Kyoung Hee Choi,Yo Han Yoon 한국축산식품학회 2014 한국축산식품학회지 Vol.34 No.5

This study evaluated the effect of sodium diacetate and sodium lactate solutions for reducing the cell count of Pseudomo-nas spp. in frankfurters and hams. A mixture of Pseudomonas aeruginosa (NCCP10338, NCCP10250, and NCCP11229),and Pseudomonas fluorescens (KACC10323 and KACC10326) was inoculated on cooked frankfurters and ham. The inoc-ulated samples were immersed into control (sterile distilled water), sodium diacetate (5 and 10%), sodium lactate (5 and10%), 5% sodium diacetate + 5% sodium lactate, and 10% sodium diacetate + 10% sodium lactate for 0-10 min. Inoculatedfrankfurters and ham were also immersed into acidified (pH 3.0) solutions such as acidified sodium diacetate (5 and 10%),and acidified sodium lactate (5 and 10%) in addition to control (acidified distilled water) for 0-10 min. Total aerobic platecounts for Pseudomonas spp. were enumerated on Cetrimide agar. Significant reductions (ca. 2 Log CFU/g) in Pseudomo-nas spp. cells on frankfurters and ham were observed only for a combination treatment of 10% sodium lactate + 10% sodiumdiacetate. When the solutions were acidified to pH 3.0, the total reductions of Pseudomonas spp. were 1.5-4.0 Log CFU/g. The order of reduction amounts of Pseudomonas spp. cell counts was 10% sodium lactate > 5% sodium lactate ≥ 10%sodium diacetate > 5% sodium diacetate > control for frankfurters, and 10% sodium lactate > 5% sodium lactate > 10%sodium diacetate > 5% sodium diacetate > control for ham. The results suggest that using acidified food additive antimicro-bials, as dipping solutions, should be useful in reducing Pseudomonas spp. on frankfurters and ham.

Pulse Oximetry and Skin Temperature Gradient as Diagnostic Tools of Successful Caudal Block

Duk Kyung Kim,Kyoung Min Lee,Won Kyoung Kwon,Chung Sik Oh,Sung Whan Jang 대한마취과학회 2007 Korean Journal of Anesthesiology Vol.53 No.6

Background: Though caudal block is a relative simple technique, it has not been widely used in adults because of a high failure rate. We assumed that any tests to quantify the changes of sympathetic tone in the affected areas would be excellent indicators of successful block. We tested the usefulness of two candidates (pulse oximetry plethysmographic waveform amplitude measured at 5th toe and calf minus 5th toe skin temperature gradient) as indicators of successful caudal block. Methods: In 45 adult patients undergoing anal surgery with caudal block, these two variables were simultaneously measured at 2-min intervals for 20 min. A two-fold increase in the plethysmographic waveform amplitude from baseline and skin temperature gradient of 0°C were predefined as test criteria of successful block. Results: While the sensitivity, specificity, positive predictive value, and negative predictive value of the skin temperature gradient test were 45.9%, 100%, 100%, and 9.1%, those of the plethysmographic waveform test were 86.5%, 100%, 100%, and 28.6%. The plethysmographic waveform test showed a significantly higher discriminative capacity than the skin temperature gradient test (94.9% vs. 48.7%, P < 0.05) Conclusions: Unlike the skin temperature gradient test, the plethysmographic waveform test showed a considerably high validity in detecting successful block. Considering its simple and real time monitoring potentials together with a high failure rate of caudal block in adults, we cautiously recommend it as a supplemental diagnostic tool to predict successful block, especially when verbal communication with patient is difficult. (Korean J Anesthesiol 2007; 53: S 19∼25)

Studies on Lytic, Tailed Bacillus cereus-specific Phage for Use in a Ferromagnetoelastic Biosensor as a Novel Recognition Element

( In Young Choi ),( Joo Hyeon Park ),( Kyoung Min Gwak ),( Kwang-pyo Kim ),( Jun-hyun Oh ),( Mi-kyung Park ) 한국미생물생명공학회(구 한국산업미생물학회) 2018 Journal of microbiology and biotechnology Vol.28 No.1

This study investigated the feasibility of the lytic, tailed Bacillus cereus-specific phage for use in a ferromagnetoelastic (FME) biosensor as a novel recognition element. The phage was immobilized at various concentrations through either direct adsorption or a combination of 11-mercapto-1-undecanoic acid (11-MUA) and [N-(3-dimethylaminopropyl)-N’-carbodiimide hydrochloride and N-hydroxysuccinimide (EDC/NHS)]. The effects of time and temperature on its lytic properties were investigated through the exposure of B. cereus (4 and 8 logCFU/ml) to the phage (8 logPFU/ml) for various incubation periods at 22°C and at various temperatures for 30 and 60 min. As the phage concentration increased, both immobilization methods also significantly increased the phage density (p < 0.05). SEM images confirmed that the phage density on the FME platform corresponded to the increased phage concentration. As the combination of 11-MUA and EDC/NHS enhanced the phage density and orientation by up to 4.3-fold, it was selected for use. When various incubation was conducted, no significant differences were observed in the survival rate of B. cereus within 30 min, which was in contrast to the significant decreases observed at 45 and 60 min (p < 0.05). In addition, temperature exerted no significant effects on the survival rate across the entire temperature range. This study demonstrated the feasibility of the lytic, tailed B. cereus-specific phage as a novel recognition element for use in an FME biosensor. Thus, the phage could be placed on the surface of foods for at least 30 min without any significant loss of B. cereus, as a result of the inherent lytic activity of the B. cereus-specific phage as a novel recognition element.

사각형 마이크로 스트립 선열 안테나의 설계에 관한 연구

오승엽,민경일 충남대학교 공업교육연구소 1984 論文集 Vol.7 No.2

The purpose of this study is to provide an equivalent network and design procedure for square and rectangular shaped linear array microstrip antennas. First, the characteristics of microstrip-line are described. Second, the antenna parameters. such as equivalent admittance, radiation pattern, resonant frequency and directivity of single slot are derived. Third, a design procedure for open-ciruit half-wave resonator and for high gain microstrip linear array antennas are considered. Finally, X-Band antennas of single-element, four-element and sixteen-element linear array with same resonant frequency are built by photo-etching techniqes and tested. The measured gain is 18[dB] and the side-lobe level was measured to 11[dB] for the sixteen-element two dimensional array. Its gain is increased 11[dB] and its beam-width is decreased 22° than those of single-element. The results show that the method presented in this paper has sufficient generality and accuracy to be applicable to design problems of microstrip array antennas.

폐부종과 심정지가 발생한 페노바비탈 중독환자

오동렬,이운정,박규남,김세경,김영민,이환,유은영,최경호,정시경 大韓應急醫學會 1999 대한응급의학회지 Vol.10 No.2

Phenobarbital is a long-acting barbiturate causing generalized depression of neuronal activity in the brain. Its effect is primarily achieved through enhanced GABA-mediated synaptic inhibition. Its use as an antiepileptic agent was first described in 1912. Before the introduction of phenytoin, phenobarbital is used as sedative-hypnotics. It is used for the treatment of epilepsy and status epilepticus. All barbiturates, including phenobarbital, have a high potential for abuse. They were frequently used for suicide attempts in the past, but they have in large part been replaced by benzodiazepines. The onset of symptoms depends on the drug and the route of administration. Mild to moderate barbiturate intoxication resembles ethanol inebriation with slurred speech, ataxia, and lethargy. Severe acute barbiturate intoxication is life threatening. Early deaths are generally cardiovascular-related. Hypotension, shock, pulmonary edema, and cardiac arrest that occurs with large doses are caused by depression of central sympathetic tone and as well as by direct depression of cardiac contractility. The potentially fatal oral dose of phenobarbital is 6-10g. We describe an 23-year-old woman with pulmonary edema, and cardiac arrest ingestion of 18grams of phenobarbital. She was completely recovered by successful cardiopulmonary resuscitation and homoperfusion. We report a case with literature review.

치과 재료용 NiTi 합금의 특성에 대한 Ag 첨가의 영향

오근택,박기호,심형민,황충주,김경남 大韓齒科器材學會 2001 대한치과재료학회지 Vol.28 No.4

Equiatomic and near-equiatomic nickel-titanium alloys have shape memory effect and superelasticity. However nickel-titanium alloys are extremely sensitive to the precise nickel-titanium ratio and alloying additions. There are many reports on the alloying additions such as Fe, Al, Cr, Co, V, Pt, Pd, Zr, Hf, Nb and Cu. The purpose of this study was to investigate the effect of silver addition to nickel-titanium alloy for dental and medical application.Arc melting process was used to fabricate nickel-titanium alloys. The casts were heat-treated in a vacuum furnace at 950℃ for 72 hours to homogenize their composition. Subsequently, they were hot-rolled at 950℃ to obtain the plate samples and annealed in a vacuum furnace at 950℃. To investigate the properties of nickel-titanium alloys, phases, transformation temperature, compositions, corrosion resistance and hardness were evaluated using X-ray diffractometer, differential scanning calorimeter, energy dispersive spectroscopy or atomic absorption spectroscopy, potentiostat and micro-vickers hardness tester, respectively. NiTiAg alloys showed the low silver recovery rate for the cast due to its low evaporation temperature, and showed low silver solubility to NiTi alloy. Silver addition to NiTi alloy increased transition temperature range (TTR) above 100℃ and stabilized martensitic phase(monoclinic structure) at room temperature because Ms temperature was above room temperature. Martensitic and austenitic phase existed in x-ray diffraction pattern of solution annealed NiTiAg alloys. The Silver addition is considered to improve corrosion resistance and change largely the mechanical properties depending upon the amount of alloying addition and types of addition elements.

Ti-Ag 합금의 인공타액 내에서의 전기화학적 특성

심형민,오근택,김경남 大韓齒科器材學會 2003 대한치과재료학회지 Vol.30 No.4

Titanium and its alloys are widely used in biomedical and dental fieds because of their excellent corrosion resistance, biocompatibility, high strength to weight ratio and good fatigue properties. It is well known that titanium is protected from corrosion due to the stability of passive film that controls and determines the corrosion resistance of titanium. The stability of passive film can also determine biocompatibility of titanium and its alloys. The purpose of this study was to evaluate the electrochomical properties of Ti-Ag alloys and the stavility of passive film in artificial saliva. We designed Ti-Ag alloys with silver contents ranging from zero to 5.0 at% in steps of 0.5 at%. The alloys were arc-melted, homogenized, hot-rolled to 2 mm in thickness, and finally solution heat-treated for 1hour and quenched in water. Potentiodynamic and poteniostatic testing were performed and open circuit potential of the Ti-Ag alloys was measured in artificial saliva 37℃. Passive film of the Ti-Ag alloys was analyzed by XPS(x-ray photoelectron spectroscopy). Ti-Ag alloys showed low passive current density and electrochemically stable behavior in the artificial saliva and passive film of the Ti-Ag alloys was composed of TiO_2, Ti_2O_3 and TiO. As Ag content increased, TiO_2 fraction increased and titanium oxide layer of the Ti-Ag alloys formedthicker than that of titanium.It is thought that Ti-Ag alloys can be adopted and used safely with good biocompatibility for dental application.

한국 재래종 벼 품종의 이삭특성 및 형태

강희경,오민교,박용진 한국국제농업개발학회 2003 韓國國際農業開發學會誌 Vol.15 No.3

우리나라 재래종 벼 197품종과 생태형이 다른 자포니카 7품종, 인디카 3품종 및 통일형 5품종의 벼를 공시하여 각 품종의 이삭 특성을 밝히고 이들 형질간의 상관관계를 검토하였으며 특성에 따른 이삭형태의 분류를 실시하였다. 1. 재래종 벼 품종의 이삭 길이는 22.4 .05㎝, 현미의 천립중은 21.7 .35g로 자포니카와 비교하여 천립중은 같았으나 이삭 길이는 1.6㎝ 더 길었다. 2. 재래종 벼 품종의 1차지경 착생립수와 비율은 67.5 1.9립과 43.7 .14%이었고, 2차지경 착생립수와 비율은 91.2 0.7립과 56.3 .14%이었으며, 총립수는 158.1 5.8립으로 자포니카보다 44립 정도 더 많았다. 3. 재래종 벼 품종 현미의 장폭비는 1.70 .19로 자포니카와 유사하였으며 장립종도 몇 품종 존재하였다. 4. 1차지경 평균착생립수 각 절위별 2차지경수 및 2차지경 평균착생립수에 의한 재래종 벼 품종의 이삭형태를 분류한 결과 2차지경립 착생 하위우세형인 Ⅰ형에 2%, Ⅱ형에 10.7%, 중위우세형인 Ⅲ형에 67.5%, Ⅳ형에 18.3% 및 상위우세형인 Ⅴ형에 1.5%가 분포하였으며, 특히 1차지경 평균착생립수 5.1-5.5개의 Ⅲ형에 가장 많이 분포하였다. 5. 각 형질간의 상관관계에서 총립수와 2차지경 착생립수(0.921), 착립밀도와 평균 2차지경수(0.635)간에는 고도로 유의한 정의 상관이 인정되었다. The traits related to panicle are very important in improving the grain yield in cereals including rice. Characterization of panicle traits was conducted using 197 rice varieties of Korean landrace, 7 cultivars of Japonica, 3 cultivars of Indica and 5 cultivars of Tongil type to classify panicle types by distribution patterns of grains on panicle. In Korean landrace, average length of panicle and 1000-grains' weight of brown rice was 22.4±2.05㎝ and 21.7±2.35 g, respectively. Compare with Japonica. Iandrace was similar in 1000 grains' weight, but with a more longer panicle. Higher number of grains on each panicle (44 grains), was observed in landrace relative to the Japonica of rice. Panicle type was classified into five groups according to the number of grains on the primary rachis-branch, number of grain on the secondary rachis-branch and number of the secondary rachis-branches. According to panicle type based on distribution of grains, landrace was classified into five types. Most of the landrace grouped into panicle type Ⅲ, which is characterized as having many grains on the secondary rachis-branch in the middle position of panicle. Especially, frequency of panicle type Ⅲ which have 5.1-5.5 grains on the primary rachis-branch was higher than any other panicle type. In the case of correlation coefficient among panicle traits, highly positive significant correlations were observed in number of grain per panicle versus number of grains on the secondary rachis-branch(0.921) and in density of grain per unit panicle length versus number of secondary rachis-branch(0.635)

흰쥐에서 심정지후 Pentoxifylline이 뇌의 허혈-재관류 손상에 미치는 효과

정시경,김영민,오동렬,최경호,박승현,이운정,박규남,유은영,이원재,김세경 大韓應急醫學會 1999 대한응급의학회지 Vol.10 No.2

Background: Two major events occurring in the cerebral hemodynamics after successful resuscitation from cardiac arrest are reactive hyperemia and postischemic hypoperfusion. In this study, we examined the effect of Pentoxifylline(PTX) on the rat brain following cardiac arrest. Methods: Fourteen rats were anesthetized and artificially ventilated. Cardiac arrest was produced by chest compression and clamping of tracheal tube for 3 minutes in ketamine anesthetized rats. Circulation was restored by standard cardiopulmonary resuscitation methods. In 7 rats, PTX 10mg/kg was infused at 10min after cardiac arrest(PTX group). In the other 7 rats, same amount of normal saline was infused(control group). Results: In both groups, hemodynamic variables, neurologic deficit(ND) score and histopathologic findings of hippocampal CA1 neurons were observed. Hemodynamic variables and ND score were not significantly different between two groups. Delayed ischemic neurons of hippocampal CA1 were decreased in PTX group(2.2±2.4%) compared with control group(9.1±1.2%). Conclusions: We conclude that PTX prevented development of delayed ischemic neurons in hippocampal CA1 after cardiac arrest. PTX may be useful in emergency situations following cardiac arrest.