• Title/Summary/Keyword: Screening limits

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Comparision of TTC-II and disk assay method for the detection of antibiotic residues in milk (우유내 잔류물질 검사방법인 TTC-II법 및 Disk assay법의 비교시험)

  • 이정아;이은미;이성해;도재철;박영구
    • Korean Journal of Veterinary Service
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    • v.22 no.1
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    • pp.93-101
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    • 1999
  • This test process on screening method for the detection of residual antibiotics in milk is simple, economic, sensitive to residual antibiotics and was given approval international organs. Thus, this study was carried out the comparison of Disk assay method and TTC-II method for sensitivity and minimum detectable range of antibiotics in raw milk. The results of this study was summarized as follows ; 1. The number of samples requested for treatment of mastitis was 198 samples. Comparison or analytical results among the methods of TTC-II, disk assay and Delve sp was that TTC-II 37 samples(18.6% ), Disk assay 125samples(63.1%), Delve SP 130 samples(65.7% ) reacted positively. Conformity rate of Delve SP and Disk assay was 70%. 2. Detectable limits of disk assay method in some antibiotics were more sensitive than those of official method(0.05-0.0025ppm in the $\beta$-lactams, 1ppm in two aminoglycoside, 0.2 ppm in one tetracycline, similar in one macrolide) 3. For sensitivity of residual sulfonamides TTC-II was much more sensitive than disk assay. Detectable limits of sulfamethazine and sulfadimethoxine were 30 to 50ppm levels. 4. The best medium preservation period is 1-2 days. 5. Concentration of brome cresol purple related to resistance for B stearothermophilus culture was 24ppm/ml. These results show that disk assay method for screening detection of antibiotics residuces in milk is worthy of use.

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Residual Multi Pesticides Screening of Dead Birds by Orbitrap High Resolution Mass Spectrometry (오비트랩 고분해능 질량분석기를 이용한 폐사 조류 중 다성분 잔류 농약 스크리닝 기법)

  • Lee, Doo-Hee;Kim, Bo-Kyong;Wang, Seung-Jun;Son, Ki-Dong;Jung, Hyen-Mi;Choi, Jong-Woo
    • Korean Journal of Environmental Agriculture
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    • v.36 no.4
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    • pp.269-278
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    • 2017
  • BACKGROUND: The objective of this study was to evaluate screening method of residual multi pesticides in dead birds by Orbitrap high resolution mass spectrometry (HRMS) to identify the cause of death for birds. METHODS AND RESULTS: Extraction and clean-up method of residual pesticides in liver of dead birds was used QuEChERS (Quick Easy Cheap Effective Rugged and Safe) and method validations was conducted using liquid chromatography and gas chroamtography with triple-quadrupole mass spectrometer (LC/MS/MS and GC/MS/MS) Also, we were evaluated screening method for the determination of residual pesticides in liver of dead birds by LC and GC Orbitrap Mass Spectrometry. Results of method validations, Correlation coefficients of the matrix matched calibration curves were >0.978, and the method detection limits (MDLs) and limits of quantitation (LOQ) were 2.8~72.1 ng/g (18.4 ng/g on average) and 9.0~230 ng/g (58.5 ng/g on average). The accuracy ranged from 69.1%to 130% (103% on average), and the precision values were less than 14.8%(3.8%on average). The screening of residual pesticides in liver of dead birds by LC and GC Orbitrap HRMS was detected monocrotophos, carbofuran, carbosulfan, deltametrin, benfuracarb, carbofuran, phosphamidon, prochloraz in investigated samples. CONCLUSION: This results showed that accurate mass were extraction of residual pesticides in dead birds by Orbitrap HRMS. It suggested that this screening method is applicable to the residual pesticide analysis for the cause of death as a main tool.

Detection of Human Papillomavirus DNA in Routine Cervical Scraping Samples: Use for a National Cervical Cancer Screening Program in a Developing Nation

  • Othman, Norodiyah;Othman, Nor Hayati
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.5
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    • pp.2245-2249
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    • 2014
  • Background: Human papillomavirus is a well-established cause of the development of a variety of epithelial lesions in the cervix. However, as yet, incorporation of HPV testing into cervical cancer screening either as an adjunct or stand alone test is limited due to its cost. We therefore here ascertained the presence and type specificity of human papilloma virus (HPV) DNA in routine cervical scrapings. Materials and Methods: Cervical scrapings were collected from women attending clinics for routine Pap smear screening. HPV-DNA was detected by PCR using MY09/11 and GP5+/GP6+ primer sets and genotyping was accomplished by cycle-sequencing. Results: A total of 635 women were recruited into the study with $mean{\pm}SD$ age of $43{\pm}10.5$ years. Of these 92.6% (588/635) were reported as within normal limits (WNL) on cytology. The presence of HPV infection detected by nested MY/GP+-PCR was 4.4% (28/635). The overall prevalence of high-risk HPV (HR-HPV) in abnormal Pap smears was 53.8% (7/13). HPVs were also seen in 3.1% (18/588) of smears reported as WNL by cytology and 5.9% (2/34) in smears unsatisfactory for evaluation. Conclusions: The overall percentage of HPV positivity in routine cervical screening samples is comparable with abnormal findings in cytology. Conventional Pap smear 'missed' a few samples. Since HPV testing is expensive, our results may provide valuable information for strategising implementation of effective cervical cancer screening in a country with limited resources like Malaysia. If Pap smear coverage could be improved, HPV testing could be used as an adjunct method on cases with ambiguous diagnoses.

A Study on Magnitude Scaling Factors and Screening Limits of Liquefaction Potential Assessment in Moderate Earthquake Regions (중진지역에 적합한 액상화 평가 생략기준 및 지진규모 보정계수에 관한 연구)

  • Park Keun-Bo;Park Young-Geun;Choi Jae-Soon;Kim Soo-Il
    • Journal of the Korean Geotechnical Society
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    • v.20 no.7
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    • pp.127-140
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    • 2004
  • Conventional methods for the assessment of liquefaction potential were primarily for areas of severe earthquake zones (M=7.5) such as North America and Japan. Detailed earthquake related researches in Korea started in 1997, including development of the seismic design standards for port and harbour structures, which was later completed in 1999. Because most contents in the guidelines were quoted through literature reviews from North America and Japan, which are located in strong earthquake region, those are not proper in Korea, a moderate earthquake region. This requires further improvement of the present guidelines. Considering earthquake hazard data in Korea, use of laboratory tests based on irregular earthquake motion appears to be effective to reflect the dynamic characteristics of soil more realistically than those using simplified regular loading. In this study, cyclic triaxial tests using irregular earthquake motions are performed with different earthquake magnitudes, relative densities, and fines contents. Assessment of liquefaction potential in moderate earthquake regions is discussed based on various laboratory test results. Effects of these components on dynamic behavior of soils are discussed as well. From the test results, screening limits and magnitude scaling factors to determine the soil liquefaction resistance strength in seismic design were re-investigated and proposed using normalized maximum stress ratios under real irregular earthquake motions.

On the Method for Hot-Fire Modeling of High-Frequency Combustion Instability in Liquid Rocket Engines

  • Sohn, Chae-Hoon;Seol, Woo-Seok;Valery P. Pikalov
    • Journal of Mechanical Science and Technology
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    • v.18 no.6
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    • pp.1010-1018
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    • 2004
  • This study presents the methodological aspects of combustion instability modeling and provides the numerical results of the model (sub-scale) combustion chamber, regarding geometrical dimensions and operating conditions, which are for determining the combustion stability boundaries using the model chamber. An approach to determine the stability limits and acoustic characteristics of injectors is described intensively. Procedures for extrapolation of the model operating parameters to the actual conditions are presented, which allow the hot-fire test data to be presented by parameters of the combustion chamber pressure and mixture (oxidizer/fuel) ratio, which are customary for designers. Tests with the model chamber, based on the suggested scaling method, are far more cost-effective than with the actual (full-scale) chamber and useful for injector screening at the initial stage of the combustor development in a viewpoint of combustion instabilities.

Studies on the Antifungal Action of Leather in Korea (Part. 2) (한국에서의 피혁방미에 관한 연구 2)

  • 김종협;장건형;최춘언
    • Korean Journal of Microbiology
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    • v.3 no.1
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    • pp.18-23
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    • 1965
  • It seems like that the characteristics and drug-resistances of fungi are respectively different in various circumstances. Scores of chemicals were applicated to the leather-fungi in this study. M-dinitrobenzene, 2, 4-dinitrochlorobenzene and phenyl mercuric acetate inhibited the growth of Aspergilli which were isolated from Korean-leather. The minimum fungicidal limits of p-nitrophenol, 8-hydroxyquinoline and sodium-pentachlorophenolate against the Korean-originated strains are different from that of other country. In the mass-screening of fungicides, artificial "Leather-extracts media" have been designed and used, and the media contributed to screening-tests. Fat and oils which are the materials of fat-liquoring in leather manufacture affects the drugresistance of the leather-fungi. It is found that the accelerating-method on malt-agar plate is effective to determinate the fungicidal action of chemicals in short time.hort time.

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A Mathematical Model to Evaluate the Radiological Risks for the Reuse of Decommissioning Site (원자력시설 해체부지의 재이용을 위한 방사선학적 리스크 평가모델)

  • Cheong, Jae-Hak
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.4 no.4
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    • pp.353-363
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    • 2006
  • In order to evaluate the potential radiological risks for the reuse of the site after decommissioning of nuclear facilities, a mathematical model was developed and materialized into the Microsoft $Excel{\circledR}$ spreadsheets frame. A set of input parameter values was proposed, which is useful in the preliminary risk screening step before the detailed evaluation with the site-specific data. It appeared that the screening levels calculated by the present model was agreed with the derived concentration guideline limits resulted from RESRAD Ver.6.2 and the German dose criteria for releasing a nuclear site from regulatory control.

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The National Cancer Screening Program for Breast Cancer in the Republic of Korea: Is it Cost-Effective?

  • Kang, Moon Hae;Park, Eun-Cheol;Choi, Kui Son;Suh, MiNa;Jun, Jae Kwan;Cho, Eun
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.3
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    • pp.2059-2065
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    • 2013
  • This goal of this research was to evaluate the cost-effectiveness of the National Cancer Screening Program (NCSP) for breast cancer in the Republic of Korea from a government expenditure perspective. In 2002-2003 (baseline), a total of 8,724,860 women aged 40 years or over were invited to attend breast cancer screening by the NCSP. Those who attended were identified using the NCSP database, and women were divided into two groups, women who attended screening at baseline (screened group) and those who did not (non-screened group). Breast cancer diagnosis in both groups at baseline, and during 5-year follow-up was identified using the Korean Central Cancer Registry. The effectiveness of the NCSP for breast cancer was estimated by comparing 5-year survival and life years saved (LYS) between the screened and the unscreened groups, measured using mortality data from the Korean National Health Insurance Corporation and the National Health Statistical Office. Direct screening costs, indirect screening costs, and productivity costs were considered in different combinations in the model. When all three of these costs were considered together, the incremental cost to save one life year of a breast cancer patient was 42,305,000 Korean Won (KW) (1 USD=1,088 KW) for the screened group compared to the non-screened group. In sensitivity analyses, reducing the false-positive rate of the screening program by half was the most cost-effective (incremental cost-effectiveness ratio, ICER=30,110,852 KW/LYS) strategy. When the upper age limit for screening was set at 70 years, it became more cost-effective (ICER=39,641,823 KW/LYS) than when no upper age limit was set. The NCSP for breast cancer in Korea seems to be accepted as cost-effective as ICER estimates were around the Gross Domestic Product. However, cost-effectiveness could be further improved by increasing the sensitivity of breast cancer screening and by setting appropriate age limits.

Preliminary Evaluation of the Activity Concentration Limits for Consumer Goods Containing NORM

  • Jang, Mee;Chung, Kun Ho;Ji, Young Yong;Lim, Jong Myung;Kang, Mun Ja;Choi, Guen Sik
    • Journal of Radiation Protection and Research
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    • v.41 no.2
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    • pp.101-104
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    • 2016
  • Background: To protect the public from natural radioactive materials, the 'Act on safety control of radioactive rays around living environment" was established in Korea. There is an annual effective dose limit of 1 mSv for products, but the activity concentration limit for products is not established yet. Materials and Methods: To suggest the activity concentration limits for consumer goods containing NORM, in this research, we assumed the "small room model" surrounding the ICRP reference phantom to simulate the consumer goods in contact with the human bodies. Using the Monte Carlo code MCNPX, we evaluate the effective dose rate for the ICRP reference phantom in a small room with dimension of phantom size and derived the activity concentration limit for consumer goods. Results and Discussion: The consumer goods have about 1600, 1200 and $19000Bq{\cdot}kg^{-1}$ for $^{226}Ra$, $^{232}Th$ and $^{40}K$, and the activity concentration limits are about six times comparing with the values of building materials. We applied the index to real samples, though we did not consider radioactivity of $^{40}K$, indexes of the some samples are more than 6. However, this index concept using small room model is very conservative, for the consumer goods over than index 6, it is necessary to reevaluate the absorbed dose considering real usage scenario and material characteristics. Conclusion: In this research, we derived activity concentration limits for consumer goods in contact with bodies and the results can be used as preliminary screening tool for consumer goods as index concept.