• Journal of Microbiology and Biotechnology
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• v.23 no.2
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• pp.246-250
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• 2013

In this study, a loop-mediated isothermal amplification (LAMP) method to rapidly detect Staphylococcus aureus strains was developed and evaluated by extensively applying a large number of S. aureus isolates from clinical and food samples. Six primers were specially designed for recognizing eight distinct sequences on the species-specific femA gene of S. aureus. The detection limits were 100 fg DNA/tube and $10^4$ CFU/ml. The LAMP assay was applied to 432 S. aureus strains isolated from 118 clinical and 314 food samples. Total detection rates for the LAMP and polymerase chain reaction assays were 98.4% (306/311) and 89.4% (278/311), respectively.

• Environmental Engineering Research
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• v.22 no.2
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• pp.216-223
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• 2017

For the prediction of the ventilation rate for removing the non-isothermal concentrated fume from the semi-enclosed space, the computational fluid dynamics (CFD) analysis was done. Securing the proper ventilation conditions in emergency state such as in fire is crucial factor for the protection of the resident in the space. In the analysis for the determining the proper ventilation rate, the experimental study had the limitation for simulating the versatile conditions of fume development. The theoretical and computational method had been chosen as the alternate tool for the experimental analysis. In this study, the CFD analysis was done on the defined model which already had been done the experimental analysis by the previous workers. By comparing the prediction on the plume heights and the ventilation rates by the CFD analysis at, and in the parametric model of $1m^3$ with those of the previous experimental works, the feasibility of the computational analysis was evaluated. For the required ventilation rate analyzed by the CFD analysis was over predicted in 7.1% difference with that of the experimental results depending on the different plume height. With the comparison with the analytical Zukoski model at, the CFD analysis on the ventilation was under predicted in 8.3%. By the verification of the feasibility of the CFD analysis, the extended analysis was done for getting the extra information such as the water vapor distribution and $CO^2$ distribution in the semi-enclosed spaces.

• Korean Journal of Agricultural Science
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• v.47 no.3
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• pp.673-681
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• 2020

Human enteric Adenovirus 41 (HueAdV-41) is a major waterborne virus that causes human gastroenteritis and is classified as a viral group I double-strand DNA virus, Adenoviridae. HueAdV-41 has been detected with the polymerase chain reaction (PCR) in various samples such as ground water. However, the PCR-based diagnostic method has problems such as reaction time, sensitivity, and specificity. Thus, the loop-mediated isothermal amplification (LAMP) assay has emerged as an excellent method for field applications. In this study, we developed a LAMP system that can rapidly detect HueAdV-41 with high specificity and sensitivity. HueAdV-41 specific LAMP primer sets were tested through a specific, non-specific selection and sensitivity test for three prepared LAMP primer sets, of which only one primer set and optimum reaction temperature were selected. The developed LAMP primer set condition was confirmed as 63℃, and the sensitivity was 1 copy. In addition, to confirm the system, a LAMP positive reaction was developed with the restriction enzyme Taq I (T/GCC). The developed method in this study was more specific, rapid (typically within 2 - 3 hours), and highly sensitive than that of the conventional PCR method. To evaluate and verify the developed LAMP assay, an artificial infection test was done with five cDNAs from groundwater samples, and the results were compared to those of the conventional PCR method. We expect the developed LAMP primer set will be used to diagnose HueAdV-41 from various samples.

• Journal of Adhesion and Interface
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• v.13 no.2
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• pp.64-72
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• 2012

Vinyl acetate/alkyl acrylate copolymers were prepared by water-born emulsion copolymerization according to the compositional change of vinyl acetate and various alkyl acrylates such as methyl acrylate (MA), ethyl acrylate (EA), and n-butyl acrylate (BA). Ammonium persulfate (APS) was used as an initiator and poly(vinyl alcohol) (PVA) was used as a protective colloid. The significant result was described as follows. The activation energy determined by an isothermal analysis in the temperature region between $100{\sim}200^{\circ}C$ of the copolymer had the order of PVAc/PMA > PVAc/PEA > PVAc/PBA. The peel strengths before and after the plasma treatment were the order of PVAc/PMA > PVAc/PEA > PVAc/PBA.

• Korean Journal of Materials Research
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• v.11 no.6
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• pp.483-491
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• 2001

The recovery and recrystallization behavior of cold-rolled Zr-based alloys during isothermal annealing at temperatures from $575^{\circ}C$ to $650^{\circ}C$ was studied by thermoelectric power and Vickers microhardness measurement. The recovery and recrystallization resulted in the increase of TEP doe to the extinction of lattice defect, vacancy, dislocation and stacking fault during isothermal annealing after cold- rolling. The completion of recrystallization could be determined much clearly by TEP behavior than by microhardness change in Zr-based alloys. Especially, the recovery and recrystallization were classified separately by TEP behavior in Zr-0.4Nb-xSn alloys. From the analysis of TEP behavior and microhardness, the addition of Sn caused to form the interaction between stain field and dislocation, which resulted in the delay of recovery in Zr-based alloys. The precipitation due the addition of Nb suppressed the grain growth after recrystallization effectively in Zr-based alloys.

• Preventive Nutrition and Food Science
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• v.4 no.4
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• pp.246-250
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• 1999

This study was conducted to develop the fermentation kinetic modeling for the prediction of pH and acidity changes in kimchi at isothermal and nonisothermal fermentation temperatures(0~15$^{\circ}C$) and salt concentrations(1.5~4.0%) using the traditional two-step method and alternative one-step method. The calculations of the two-step method of pH and acidity change during fermentation followed the pattern of the first order and zero order, respectively. The reaction rate constant of pH by the first order was increased from 0.008 {TEX}$day^{-1}${/TEX} to 0.017 {TEX}$day^{-1}${/TEX} by increasing the temperature from $0^{\circ}C$ to 15$^{\circ}C$ at 2.75% of salt concentration, and was decreased from 0.013 {TEX}$day^{-1}${/TEX} to 0.010 {TEX}$day^{-1}${/TEX} by increasing the salt concentration from 1.5% to 4.0% at 5$^{\circ}C$. For the pH and acidity of Kimchi, the zero order had a higher correlation than the first order to the estimate of the kinetics parameters by the one-step method. The {TEX}$E_{a}${/TEX} ranges of pH and acidity were 61.057~66.086 and 62.417~68.772 kJ/mole with different temperatures and salt concentrations. This one-step method had smaller and more realistic estimates of error(p〈0.05). The effective temperatures, {TEX}$T_{eff}${/TEX}, with 0~15$^{\circ}C$ of square function type of 12 hr intervals were 12.85, 11.48 and 12.46$^{\circ}C$ as increasing the salt concentration, 1.50, 2.75 and 4.00%, respectively. The {TEX}$T_{eff}${/TEX} were higher values than the mean temperature(7.5$^{\circ}C$).

• Journal of Microbiology and Biotechnology
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• v.23 no.1
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• pp.1-6
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• 2013

Tetanus is a specific infectious disease, which is often associated with catastrophic events such as earthquakes, traumas, and war wounds. The obligate anaerobe Clostridium tetani is the pathogen that causes tetanus. Once the infection of tetanus progresses to an advanced stage within the wounds of limbs, the rates of amputation and mortality increase manifold. Therefore, it is necessary to devise a rapid and sensitive point-of-care detection method for C. tetani so as to ensure an early diagnosis and clinical treatment of tetanus. In this study, we developed a detection method for C. tetani using loop-mediated isothermal amplification (LAMP) assay, wherein the C. tetani tetanus toxin gene was used as the target gene. The method was highly specific and sensitive, with a detection limit of 10 colony forming units (CFU)/ml, and allowed quantitative analysis. While detecting C. tetani in clinical samples, it was found that the LAMP results completely agreed with those of the traditional API 20A anaerobic bacteria identification test. As compared with the traditional API test and PCR assay, LAMP detection of C. tetani is simple and rapid, and the results can be identified through naked-eye observation. Therefore, it is an ideal and rapid point-of-care testing method for tetanus.

• The Plant Pathology Journal
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• v.32 no.5
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• pp.414-422
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• 2016

Eucalyptus dieback disease, caused by Cylindrocladium scoparium, has occurred in last few years in large Eucalyptus planting areas in China and other countries. Rapid, simple, and reliable diagnostic techniques are desired for the early detection of Eucalyptus dieback of C. scoparium prior to formulation of efficient control plan. For this purpose, three PCR-based methods of nested PCR, multiplex PCR, loop-mediated isothermal amplification (LAMP) were developed for detection of C. scoparium based on factor 1-alpha (tef1) and beta-tubulin gene in this study. All of the three methods showed highly specific to C. scoparium. The sensitivities of the nested PCR and LAMP were much higher than the multiplex PCR. The sensitivity of multiplex PCR was also higher than regular PCR. C. scoparium could be detected within 60 min from infected Eucalyptus plants by LAMP, while at least 2 h was needed by the rest two methods. Using different Eucalyptus tissues as samples for C. scoparium detection, all of the three PCR-based methods showed much better detection results than regular PCR. Base on the results from this study, we concluded that any of the three PCR-based methods could be used as diagnostic technology for the development of efficient strategies of Eucalyptus dieback disease control. Particularly, LAMP was the most practical method in field application because of its one-step and rapid reaction, simple operation, single-tube utilization, and simple visualization of amplification products.

• Korean Journal of Materials Research
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• v.11 no.2
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• pp.132-136
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• 2001

Iron- silicide has been produced by mechanical alloying process and consolidated by hot pressing. As-consolidated iron silicides were consisted of $\beta$-FeSi$_2$ phase, and untransformed mixture of $\alpha$-$Fe_2Si_5$ and $\varepsilon$-FeSi phases. Isothermal annealing has been carried out to induce the transformation to a thermoelectric semiconducting $\beta$-$FeSi_2$ phase. The condition for $\beta$-FeSi$_2$ transformation was investigated by utilizing DTA, SEM, TEM and XRD analysis. The phase transformation was shown to be taken place by a vacuum isothermal annealing at $830^{\circ}C$ for 24 hours. The mechanical and thermoelectric properties of $\beta$-FeSi$_2$ materials before and after isothermal annealing were characterized in this study.

• Korean Journal of Materials Research
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• v.18 no.1
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• pp.38-44
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• 2008

The micro-structural changes, strength characteristics, and micro-fractural behaviors at the joint interface between a Sn-4.0wt%Ag-0.5wt%Cu solder ball and UBM treated by isothermal aging are reported. From the reflow process for the joint interface, a small amount of intermetallic compound was formed. With an increase in the isothermal aging time, the type and amount of the intermetallic compound changed. The interface without an isothermal treatment showed a ductile fracture. However, with an increase in the aging time, a brittle fracture occurred on the interface due mainly to the increase in the size of the intermetallic compounds and voids. As a result, a drastic degradation in the shear strength was observed. From a microshear test by a scanning electron microscope, the generation of micro-cracks was initiated from the voids at the joint interface. They propagated along the same interface, resulting in coalescence with neighboring cracks into larger cracks. With an increase in the aging time, the generation of the micro-structural cracks was enhanced and the degree of propagation also accelerated.