• Journal of the Korea Convergence Society
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• v.11 no.10
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• pp.139-146
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• 2020

Kastle-Meyer (KM) test is one of presumptive tests used to detect latent blood in crime scenes. While this method is more sensitive than others, false positive reaction can be shown where blood does not exist. In this study, we tried to suggest a new application method to solve this problem. Reaction time and aspect of reaction of this new method was compared with two conventional methods in order to identify the effectiveness and identifiability. As a result, there was no statistically significant difference in sensitivity between the methods. In addition, in case of blood with a dilution ratio of 5000:1 or less, positive reaction showed immediately, making it easy to distinguish the reaction from false positive reaction. However, it became difficult to distinguish them with the reaction time as the dilution ratio increased, and this phenomenon could be supplemented observing aspect of the reaction when using the new method. Therefore, this study suggested a new method for KM test that can be used more accurately in the field.

• Journal of Environmental Health Sciences
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• v.42 no.4
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• pp.266-273
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• 2016

Objectives: This study evaluated the virucidal efficacy against avian influenza virus (AIV) of a disinfectant spray containing 0.25% grapefruit seed extract, 0.2% citric acid, 0.0625% malic acid and 0.0125% benzalkonium chloride. Methods: The disinfectant spray was diluted several times with hard water (HW) and organic matter (OM). Two point five mL of each diluent was added into each test tube, and 2.5 mL of AIV suspension was inserted into each test tube. After 30 minutes of virus-disinfectant contact reaction at $4^{\circ}C$, 2.5 mL of 10% inactivated fetal bovine serum was added into each test tube to neutralize the sanitizer efficacy. The neutralized solutions were serial 10-fold dilutions with phosphate buffer solution, and 0.2 mL of the diluents was injected into the allantoic cavity of five ten-day-old-chickens per dilution time. After incubation of the embryos for five days, the viability of the AIV was examined by hemagglutination titer. The valid dilution of the disinfectant spray was estimated according to the dilution time that the virus titer was inactivated more than $10^4$ 50% egg-infective dose (EID50)/mL compared with pathogen control. Results: In HW and OM conditions, the valid dilutions of the disinfectant spray against AIV were seven- and three-fold dilutions, respectively. The AIV titer of the pathogen control was more than 6.1 log10EID50/mL, and there was no embryonic toxicity. Conclusion: The present study showed that this disinfectant spray has effective virucidal activity against AIV.

• The Journal of the Korean Society for Microbiology
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• v.9 no.1
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• pp.25-31
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• 1974

A comparative study was performed with 176 cultures of Salmonella organisms on tetracyline, neomycin and colistin in order to find out the relationship between the results obtained from the Ericsson's single disk method and the tube dilution method of antibiotic sensitivity tests which may be carried out in many hospital laboratories. With tetracycline, thirty-three out of 163 cultures of Salmonella typhi were found to be either sensitive or moderate sensitive by means of the disk method and thirty one(ca 94%) out of the thirty three cultures showed less than 1.0 ${\mu}g$ of the Minimal Inhibitory Concentretions(MIC) in the tube-dilution tests, which mean that there were a quite good agreement between the two methods. With neomycin, a hundred and five out of 163 S.typhi were appeared to be either sensitive or moderate sensitive by means of Ericsson's single disk method, among which 103 cultures showed less than 10.0 ${\mu}g$ MIC in the tubedilution method. And also there was a quite correlative pat. terns observed in the result of testing with 13 salmonella cultures other than S. typhi. With colistin, it was hard to observe any particular tendency in the distribution of plotting for 148 cultures showing less the 18 mm in the inhibiting zone diameters between MIC and disk sensitivity patterns except the fifteen, cultures out of 176 salmonella, which appeared to be sensitive in the single disk method and showed less than 1.0 ${\mu}g$ MIC in the tube dilution method.

• Korean Journal of Clinical Laboratory Science
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• v.45 no.1
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• pp.21-25
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• 2013

Acinetobacter baumannii is an aerobic, gram-negative and glucose-non-fermenting bacterium, which has emerged as a serious opportunistic pathogen. Many clinical microbiology laboratories use the Vitek 2 system for the routine antimicrobial susceptibility testing process, including testing on A. baumannii isolates. However, in case of amikacin, it is now recommended to perform additional antimicrobial susceptibility testing for A. baumannii strains due to the relatively lower minimum inhibitory concentration (MIC) in the Vitek 2 system compared to conventional reference methods. In our study, we assessed MIC for amikacin susceptibility testing of A. baumannii isolates in the Vitek 2 system, the agar dilution, Etest, and disk diffusion method. We collected 40 gentamicin-resistant, A. baumannii strains (amikacin MIC by Vitek 2:${\leq}2{\mu}g/mL$, 2 isolates; $4{\mu}g/mL$, 34 isolates; $8{\mu}g/mL$, 4 isolates) from a University hospital and compared the Vitek 2 system to other reference methods for testing susceptibility to amikacin. The Vitek 2 system showed major errors in all of the 40 isolates, yielding a low MIC. The results of our study strongly suggested that the Vitek 2 system was not a reliable method to test the MICs of gentamicin; ranging from ${\geq}16{\mu}g/mL$ for amikacin susceptibility. Other tests, such as agar dilution, Etest, or disk diffusion methods, should be paralleled to determine the MIC of amikacin in A. baumannii.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.254-257
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• 2017

As a part of the development of aircraft gas turbines, combustion performance tests have been conducted in the single combustor sector. The effects of change in the amount of air supplied to the main combustion zone to the performance of the combustor, such as a pollutant emission, a liner temperature distribution and an exit temperature patterns, were studied. Emissions of CO and NOx increased with the main air-ratio and exit temperature pattern was improved. When changing the pattern of the dilution holes, it was shown that the temperature patterns on the exit plane of the combustor and the surface of liner changed depending on the main flame structure and mixing with diluent air. These observations will be applied to combustor liner designs to improve combustor durability and emissions reduction performance.

• YAKHAK HOEJI
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• v.43 no.5
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• pp.606-613
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• 1999

To survey the possibility of replacing the pyrogen test with Limulus Amebocyte Lysate(LAL) test and to find out a standard methods suitable to our blood products made in Korea, 100 samples of 20% human serum albumin were tested by commercial LAL test kits and results of those were compared with rabbit pyrogen test. The LAL test is used both dinetic-chromogenically and kinetic-turbidimetrically. Both methods equally showed broad detection range (5.0~0.005 EU/ml), excellent sensitivity ($\geq$ 0.005 EU/ml) and predominant recovery rate within valid dilution range, but kinetic-turbidimetric method seemed to be more reproducible than kinetic-chromogenic method(kinetic-chromogenic method : S.D. = 15.88, kinetic-turbidimetric method : S.D. = 8.12). After heating the sample at 75$^{\circ}C$ for 15 min, the results showed a little elevated recovery rate with both methods. After performing the test on 100 albumin samples with both kits, the results were analysed using the USP standard (1.33 EU/ml). 7% of samples in kinetic-chromogenic methods and 1% of samples in kinetic-turbidimetric method exceeded the limit of endotoxin levels regulated for blood products in USA. Because this phenomenon was not observed in both methods at the same time and both methods have high sensitivity ($\geq$0.005 EU/ml), these results seemed to depend on nonspecific reaction. Considering its sensitivity and reproducibility, we could assure that LAL test is proper to detecting pyrogenic with good sensitivity.

• Korean Journal of Veterinary Service
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• v.21 no.3
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• pp.313-323
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• 1998

In order to establish a sensitive and specific diagnostic method for detection of antibody to Salmonella pullorum, a enzyme-linked immunosorbent assay(ELISA) was designed and standardized. The diagnostic efficacy of the established ELISA was compared with that of the serum plate agglutination test and immunodiffusion test for pullorum disease. 1. The chicken hyperimmune sera to Salmonella pullorum, S gallinarum, S typhimurium and S typhi were shown the cross reaction to S pullorum antigen by serum plate agglutination test. 2. When compared the cross reaction titer of microplate agglutination test for chickens hyperimmune sera, it was found that the titer were 64 in S pullorum, 32 in S gallinarum, 4 in S typhimurium and 8 in S typhi, respectively. 3. When compared the specificity of various antigen(HA, EA, PA and SA) by the immunodiffusion test, the most suitable antigen was phenol-treated bactrium. 4. The optimal concentration of S pullorum antigen for ELISA was 1 : 160 dilution of bacterium. 5. The efficacy of the ELISA for detection of S pullorum antibody was compared with serum Plate agglutination test and immunodiffusion test in chickens infected with S pullorum. The antibody was first detected at 6 days after infection using three tests examined. The antibody was alldetected at 9 days by ELISA, at 12 days by serumplate agglutination test, at 15 days by immunodiffusion test.

• Journal of the Korean Society of Radiology
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• v.10 no.8
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• pp.619-627
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• 2016

The purpose of this study is to investigate the effect of CT contrast agent and MRI contrast agent on the area dose in the body when using automatic exposure control system in general radiography. After making rectangular holes in the center of the abdominal thickness paraffin phantom, CT contrast agent and MRI contrast agent were respectively diluted with physiological saline solution for contrast medium dilution ratio of 10:0, 9:1, 8:2, 7:3, 6:4, 5:5, 4:6, 3:7, 2:8, 1:9, 0:10%. Each experiment was set to 78 kVp, 320 mA, which is the proper condition for KUB photography, and thereafter a total of 30 inspections were made for each dilution ratio using an automatic exposure control device, and the area dose corresponding to the dilution ratio of each contrast agent, Average comparison and correlation analysis were performed on the exposure index. As a result, the CT contrast agent and the MRI contrast agent appeared different in area dose according to the dilution ratio(p<0.05), and as the dilution ratio increased, the area dose increased for CT contrast agent and MRI contrast agent(P<0.05). In each test, the exposure index showed the manufacturer's recommendation of 200-800 EI value, and the exposure index and area dose increased as the area dose increased(p<0.05). In conclusion, CT contrast agent and MRI contrast agent confirmed to increase the area dose by general imaging test using all automatic exposure control device. Therefore, it is considered that it is necessary to perform it after the contrast medium has been excreted sufficiently when using usual imaging test after using the contrast agent in CT and MRI examination.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.451-454
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• 2000

Recently, the antiwashout underwater concrete has been increasingly used for underwater structure such as high strength massive concrete structures. However, Concrete has poor quality ad durability due to dilution with separating cementitious material. In this study, specimens were made with antiwashout underwater concrete replaced with mineral admixtures to improve their properties and were placed in air, water, and salt water. To estimation the chloride ion permeation in concrete, ASTM C 1202 Test was performed. The experimental results demonstrate that the increase of the admixtures improved the properties of antiwashout underwater concrete.

• The Korean Journal of Food And Nutrition
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• v.1 no.2
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• pp.31-36
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• 1988

An adaptive on-line optimization method has been applied to test the ability to maximize the cellular productivity of a continuous methylotroph culture system which was simulated by a variable yield Monod-type model. Optimum dilution rate and productivity were successively obtained and maintained at all times by the algorithm that utilizes steepest descent technique as optimization method and recursive least-square method with forgetting factor as dynamic model identification.