• Title/Summary/Keyword: Detection time

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Study on verification of various national standards regarding phthalate testing in industrial products (공산품 중 프탈레이트류 함유량 분석법에 관한 국내외 표준의 검증 연구)

  • Song, Moon-Hwan;Cho, Young-Dal;Choe, Eun-Kyung;Myoung, Young-Chan
    • Analytical Science and Technology
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    • v.25 no.3
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    • pp.178-189
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    • 2012
  • As phthalates classified as toxic to reproduction category 2 and endocrine disrupting chemicals were more strictly regulated as Substances of Very High Concern (SVHC) for authorization in under EU REACH and considered as priority substances in RoHS II, standardization of phthalate testing method is now being proposed in IEC 62321 of IEC TC 111 and the 2nd revision of KS M 1991 is also finished. In order to assist standardization activities related to phthalating testing, solvent extraction part of existing national standards were compared and verified. Recovery of DEHP (diethylhexyl phthalate) from PVC (polyvinyl chloride) by Soxhlet extraction increased in the order of methanol, toluene, dichloromethane and hexane from 46.9% to 95.3% as measured by GC-MS. Optimum extraction time was verified to be 6 hours using hexane. Recovery of DBP (dibutyl phthalate), BBP (butylbenzyl phthalate), and DEHP from different matrixes such as PVC, nitro cellulose, ABS (acrylonitrile butadiene styrene). and EPDM(ethylene propylene diene monomer) rubber were evaluated to be more than 90% up to 99%. The detection limits of phthalates in solvent extraction followed by GC-MS analysis were 0.08~0.3 ${\mu}g/mL$ in solution and 8~30 mg/Kg in polymeric samples. GC-MS analyses of phthalates were carried out using different solvent extraction based on the EN 14372, ASTM D 7083, Japanese test method (MHLW 0906-4) and KS M 1991, proving that equivalent recoveries ranging from 98%~99% were obtained. DBP and DEHP were detected in three consumer products such as a child toy, a power cable and manicure with the amount of 22~1,910 mg/kg.

Residual characteristics of tolclofos-methyl treated by seed dressing in ginseng (인삼 중 종자분의 처리 tolclofos-methyl의 잔류 특성)

  • Noh, Hyun-Ho;Lee, Jae-Yun;Park, So-Hyun;Lee, Kwang-Hun;Park, Hyo-Kyoung;Oh, Jae-Ho;Im, Moo-Hyeog;Kwon, Chan-Hyeok;Lee, Joong-Keun;Woo, Hee-Dong;Kwon, Ki-Sung;Kyung, Kee-Sung
    • The Korean Journal of Pesticide Science
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    • v.16 no.3
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    • pp.217-221
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    • 2012
  • This study was carried out to evaluate residual characteristics of tolclofos-methyl in ginseng and elucidate the reason for its high detection rate from fresh ginseng selling at markets. Seeds of ginseng were sowed after seed dressing with tolclofos-methyl and after a year of growth, the young seedlings were transplanted to field. They were then harvested annually until three-years of growth and the pesticide residue was analyzed in them. LOD and LOQ of the pesticide were 0.001 and 0.003 mg/kg, respectively. Recovery test was carried out to validate the analytical method for tolclofos-methyl in ginseng. The ginseng seedlings were fortified with the test pesticide at the level of LOQ, ten times of LOQ and maximum residue concentration of tolclofos-methyl. Its recovery ranged from 77.37 to 100.16%. Residual concentration of tolclofos-methyl in ginseng seedlings just before transplanting and two-year-old ginseng were from 7.58 to 8.05 and from 6.46 to 6.79 mg/kg, respectively. In case of three-year-old ginseng, it was found to be from 4.18 to 4.35 mg/kg. As a result of annual pesticide residue analysis, concentration of the pesticide was found to decrease time-coursely in ginseng. This may be due to decomposition and increasing of fresh weight of the ginseng during the cultivation periods of three years.

The Comparison of Noise-induced Hearing Loss Evaluation Criteria for Management (소음성난청 관리를 위한 판정기준간의 비교)

  • 남궁원자;원정일
    • Journal of environmental and Sanitary engineering
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    • v.13 no.1
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    • pp.123-134
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    • 1998
  • The study was performed to investigate the differences among various evaluation criteria for noise-induced hearing loss(NIHL). The subjects were 100 workers who had received detailed audiometric examinations after the periodic annual examination for hearing loss. The evaluation criteria included were as follows: The criterion I was NIHL of 50dB or greater at 4,000Hz in either ear which is one of the legal requirements for determining occupational hearing loss in Korea. The criterion II was NIHL of 40dB or greater by 4-divided classification(a+b+c+d/4 at 500Hz(a), 1,000Hz(b), 2,000Hz(c), 4,000Hz(d)) which is also one of the legal requirements for determining occupational hearing loss in Korea. The criterion III was NIHL of 31dB of greater by 6-divided classification(a+2b+2c+d/6) which is the workers' compensation standard. The criterion IV was NIHL of 40dB or greater by 6-divided classification(a+2b+2c+d/6), the criterion used to prohibite workers to be employed in the noisy workplace. The criterion V was NIHL of 40dB or greater by 3-divided classification(a+b+c/3) which is the guideline of the Japanes Labour Department. The results were as follows; 1. The percentage of workers with NIHL by the criterion I was the highest(96%) and covered all workers with NIHL diagnosed by other criteria. Therefore, this criterion was the most sensitive one for early detection of NIHL among various evaluation criteria. 2. The percentage of workers with NIHL by the criterion II was 29% of the subjects, but all of them could be diagnosed as having NIHL by the criterion I and 33.1% of the NIHL by the criterion III could not be covered by the criterion II. Thus, this criterion was not considered suitable as an initial step for determining occupational hearing loss. 3. The percentage of workers with NIHL by the criterion III was 45% of the subjects. This percentage was 46.9% of the NIHL by the criterion I and was estimated to cover 3.6% of all noise exposed workers. 4. The percentage of workers with NIHL by the criterion IV was 28% of the subjects, but 37.8% of the NIHL by the criterion III and 70.8% of the NIHL by the criterion I were not covered by the criterion. Therefore, these workers could have been employed in the noisy workplaces. 5. Employed relocation which was one of the post management methods was an option in the criterion I in Korea and in the criterion V in Japan. The number of NIHL by the criterion I was 6.7times greater than that by the criterion V. Thus, although employee relocation was not used exclusively, many more workers with NIHL could have been relocated. In conclusion, this study revealed that the criteria being used for managing occupational hearing loss showed a lack uniformity among them. In addition, since these criteria are all relied on the total threshold shifts caused by the noise exposure at the time of hearing test with no consideration given to the past noise exposure history nor age, it can be said that they are not an effective tool for occupational hearing loss management. Since legal requirements are usually followed after being diagnosed as having NIHL, it is recommended that a uniform diagnostic criterion should be used to minimize confusion. Pre-employment hearing tests should also be utilized so as to managing occupational hearing loss after employment rather than being used as a legal roadblock of prohibiting workers with mild hearing loss from being employed. Thus, what is needed is an establishment of a rational criterion for occupational hearing loss management rather than for legal requirements.

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Posttransplantation Lymphoproliferative Disorder after Liver Transplantation in Pediatric Patients: Report from a Single-center Over 21 Years (간 이식 소아에서 발생한 이식 후 림프 증식 질환: 단일 기관에서의 21년 경험)

  • Lee, Jung-Hwa;Ko, Jae-Sung;Seo, Jeong-Kee;Yi, Nam-Joon;Suh, Kyung-Suk;Lee, Kuhn-Uk;Kang, Gyeong-Hoon
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.12 no.2
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    • pp.199-206
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    • 2009
  • Purpose: To analyze the clinical spectrum of posttransplantation lymphoproliferative disorder (PTLD) after liver transplantation in children. Methods: From January 1988 to June 2009, we retrospectively reviewed the medical records of 8 PTLD cases among 148 pediatric patients underwent liver transplantation. The age at transplantation, time of presentation after transplantation, clinical manifestations, histologic diagnosis, results of EBV (Epstein-Barr virus) assessments, managements and outcomes of PTLD were investigated. Results: The prevalence of PTLD in liver transplant pediatric recipients was 5.4% (8 of 148). The mean age of patients was 25.4${\pm}$21.3 months (range 10 to 67 months). Seven of 8 patients (87.5%) underwent liver transplantation before 1 year of age. The common clinical presentations were persistent fever (8 of 8, 100%) and bloody diarrhea (6 of 8, 75%). PTLD was diagnosed with gastrointestinal endoscopic biopsies in five patients and surgical biopsies in three. Histologic findings showed early lesion in three patients, polymorphic in two, and monomorphic in three. Burkitt lymphoma and lymphoblastic lymphoma were found in two of 3 monomorphic patients. Seven of 8 patients were found with EBV-positive. Eight patients were treated with dose reduction of immunosuppressants and infusion of ganciclovir. Rituximab was added to four patients. PTLD were successfully managed in all patients except one who died of sepsis during chemotherapy. Conclusion: Major risk factor of PTLD was to undergo liver transplantation before 1 year of age. Continuous monitoring for EBV viral load and gastrointestinal endoscopic biopsy may be useful to early detection of PTLD.

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Comparative Analysis of Signal Intensity and Apparent Diffusion Coefficient at Varying b-values in the Brain : Diffusion Weighted-Echo Planar Image ($T_2^*$ and FLAIR) Sequence (뇌의 확산강조 영상에서 b-value의 변화에 따른 신호강도, 현성확산계수에 관한 비교 분석 : 확산강조 에코평면영상($T_2^*$ 및 FLAIR)기법 중심으로)

  • Oh, Jong-Kap;Im, Jung-Yeol
    • Journal of radiological science and technology
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    • v.32 no.3
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    • pp.313-323
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    • 2009
  • Diffusion-weighted imaging (DWI) has been demonstrated to be a practical method for the diagnosis of various brain diseases such as acute infarction, brain tumor, and white matter disease. In this study, we used two techniques to examine the average signal intensity (SI) and apparent diffusion coefficient (ADC) of the brains of patients who ranged in age from 10 to 60 years. Our results indicated that the average SI was the highest in amygdala (as derived from DWI), whereas that in the cerebrospinal fluid was the lowest. The average ADC was the highest in the cerebrospinal fluid, whereas the lowest measurement was derived from the pons. The average SI and ADC were higher in $T_2^*$-DW-EPI than in FLAIR-DW-EPI. The higher the b-value, the smaller the average difference in both imaging techniques; the lower the b-value, the greater the average difference. Also, comparative analysis of the brains of patients who had experienced cerebral infarction showed no distinct lesion in the general MR image over time. However, there was a high SI in apparent weighted images. Analysis of other brain diseases (e.g., bleeding, acute, subacute, chronic infarction) indicated SI variance in accordance with characteristics of the two techniques. The higher the SI, the lower the ADC. Taken together, the value of SI and ADC in accordance with frequently occurring areas and various brain disease varies based on the b-value and imaging technique. Because they provide additional useful information in the diagnosis and treatment of patients with various brain diseases through signal recognition, the proper imaging technique and b-value are important for the detection and interpretation of subacute stroke and other brain diseases.

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Analysis of 1,000 Cases of Abdominal Ultrasonography Performed by a Pediatrician (소아과 의사에 의해 시행된 복부 초음파 검사 1,000예에 대한 분석)

  • Bae, Sang-In;Park, Jae-Hong
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.10 no.1
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    • pp.28-35
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    • 2007
  • Purpose: The aim of this study was to evaluate the clinical usefulness of ultrasound examination of children performed by a pediatrician. Methods: One thousand children who presented with symptoms of a gastrointestinal disorder and underwent abdominal ultrasound evaluation in the Department of Pediatrics, between January 2003 and June 2006, were included in this study. We analyzed the patient's medical records and ultrasound results retrospectively. Results: Among the 1,000 patients, 58.4% were male and 41.6% were female. The mean age of the patients was $4.7{\pm}4.0$ years. The main reasons for ultrasound were abdominal pain (43.9%), vomiting (17.3%), elevated liver enzymes (11.8%), and jaundice (9.8%). Abnormal ultrasound findings were present in 57.9% of cases. The major abnormal findings were mesenteric lymphadenitis (29.2%), fatty liver (12.1%), hepatitis (6.4%), hepatosplenomegaly (6.2%), and acute appendicitis (4.8%). The time interval between the initial medical evaluation and the ultrasound evaluation was within 24 hours in most cases (78.5%). The main findings in children with abdominal pain were mesenteric lymphadenitis (32.6%), fatty liver (5.9%), intussusception (2.7%), and acute appendicitis (2.7%). The main findings in children with vomiting were mesenteric lymphadenitis (12.7%), hypertrophic pyloric stenosis (10.4%), and acute appendicitis (3.5%). The major ultrasound findings in children with urinary tract diseases were hydronephrosis (45.4%), urolithiasis (21.5%) and cystic renal disease (18.1%). Conclusion: Ultrasound examination played an important role as a non-invasive and prompt screening examination for detection of abdominal diseases. Ultrasound was an important tool for pediatricians to determine timely information for patient management.

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Rice Blast Control and Race Diversity by Mixed-Planting of Two Cultivars ('Hopyeongbyeo'/'Nampyeongbyeo') with Different Susceptibility to Magnaporthe oryzae (호평벼와 남평벼의 혼합재배에 의한 도열병 방제와 레이스 다양성의 변화)

  • Oh, In-Seok;Min, Ji-Young;Cho, Myung-Gil;Roh, Jae-Hwan;Shin, Dong-Bum;Song, Jin;Kim, Myeong-Ki;Cho, Young-Chan;Kim, Byung-Ryun;Han, Seong-Sook
    • Research in Plant Disease
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    • v.14 no.3
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    • pp.143-152
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    • 2008
  • Mixed-planting of two rice cultivars, HP ('Hopyeongbyeo') and NP ('Nampyeongbyeo'), having a dissimilar susceptibility to rice blast was practiced for chemical-free control of rice blast in the field. The HP/NP combination was selected for applying under mechanized agricultural conditions. Because they have similar genetic characteristics such as seed germination and heading time, culm length, rice quality and size of rice grains except susceptibility to blast. Incidence of panicle blast was reduced 50.4 % compare with supposed blast incidence by HP/NP mixed-planting when the seeds of two cultivars were combined 1 to 1 as weight. Supposed blast incidence was estimated from reduction of rice blast caused by addition of a resistant cultivar NP. Race diversity of Magnaporthe oryzae was examined for correlation with control effect of HP/NP mixed-planting on rice blast. The population of dominant race KJ-101 was diminished and replaced with various co-existing races and eleven new races were appeared in mixed-planting plot. Total number of race isolated from mixed-planting plot was not largely different from mono-culture. However, detection frequency of the new race was increased and variation of the population size of each race was decreased in mixed-planting plots. It was shown that a biased community with a dominant race (KJ-101 or KI-181) was altered to a balanced one of coexisting races. From these results, it was supposed that the balanced diversity among co-existing races within a community might be correlated to control effect by HP/NP mixed-planting on rice blast. Further more, it should be studied that genetic characteristics of the individual race including a virulence on cv. HP and NP was examined for verifying a correlation of mixed-planting effect and race diversity.

[ $^{99m}Tc-DISIDA$ ] Scintigraphic Diagnosis Of Extrahepatic Hepatocellular Carcinoma Metastasis : Comparison with Primary Hepatocellular Carcinoma ($^{99m}Tc-DISIDA$ 신티그래피를 이용한 간세포암 간외 전이의 진단 : 원발 간세포암과의 비교)

  • Chung, Soo-Kyo;Kim, Sung-Hoon;Baik, Joon-Hyun;Kim, Young-Joo;Chun, Kyung-Ah;Park, Seog-Hee;Bahk, Yong-Whee;Shin, Kyung-Sub
    • The Korean Journal of Nuclear Medicine
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    • v.29 no.4
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    • pp.484-491
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    • 1995
  • It is well known that hepatobiliary agent are taken up by metastatic hepatocellular carcinoma(HCC) as well as primary HCC. But the reported cases of the extrahepatic metastasis of HCC diagnosed by hepatobiliary scintigraphy are for the most part hematogenous ones. The relation of the uptake pattern of hepatobiliary agent in the primary and metastatic HCC is also still remains unknown. So we undertook this study to evaluate the relation of the hepatobiliary scintigraphic patterns of primary and metastatic HCC with different metastatic routes. Nine patients with primary HCC and twelve cases of metastatic HCC including four lung metastases, one bone metastasis, one right atrial metastasis, one peritoneal wall metastasis, and five lymph node metastases were studied with $^{99m}Tc-DISIDA$ scintigraphy. The images were taken on 10, 30 minutes, 1, 2, 4-6 hours. The overall detection rates of hematogenous metastases(lung and bone) is 60%(3 of 5), direct metastasis(right atrium and peritoneal wall), 100%(2 of 2) and lymphatic metastases, 0%(0 of 5). In four of five metastatic cases demonstrated with hepatobiliary scintigraphy, biliary agent is also taken up by primary HCC lesions. And the appearing time of the radioactivity in the direct metastatic HCC lesioin is same as that of primary HCC and in the cases of hematogenous metastasis, earlier than that of primary HCC. Hepatobiliary scintigraphy is more useful in the diagnosis of the metastatic HCC than primary HCC, in the cases of hematogenous and direct metastasis.

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Report on the Effects Lipemic Specimen in Anti-ds DNA Antibody Test (Anti-ds DNA 항체 검사 시 Lipemic 검체의 영향에 관한 보고)

  • Cheon, Jun Hong;Kim, Whe Jung;Kim, Sung Ho;Moon, Hyoung Ho;Yoo, Seon Hee
    • The Korean Journal of Nuclear Medicine Technology
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    • v.18 no.1
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    • pp.153-157
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    • 2014
  • Purpose: SLE (systemic lupus erythematosus) is an inflammatory autoimmune disease, characterized by various autoantibody. The detection of Anti double-stranded DNA (Anti-ds DNA) is important in the diagnostics of SLE, and include the American College of Rheumatology (ACR) diagnostic criteria for SLE. Also SLE disease activity and correlativity with the level Anti-ds DNA antibody have been reported and Anti-ds DNA antibody quantitative test is very useful for tracing before and after SLE treatment. When These Anti-ds DNA antibody test (Farr assay: $^{125}I$ labeled ds-DNA and bound Anti-ds DNA antibodies complex in serum is precipitated by ammonium sulfate and used to centrifugation, measured it) inhaled supernatant after centrifugation, a lipemic specimen does not facilitate the formation of precipitate and also occurs situation was inhaled with precipitate. To solve these problems, The Influence of the degree of lipemic specimen was evaluated. Materials and Methods: September 2012 to February 2013, We selected lipemic samples (n=81) of specimen commissioned by Anti-ds DNA antibody test. Lipemic samples were done pre-treatment (high-speed centrifugation: 14,000 rpm 5 mins) used a micro-centrifuge (Eppendorf Model 5415D). At the same time lipemic specimen and pre-treatment samples were performed Anti-ds DNA antibody test (Anti-ds DNA kit, Trinity Biotech, Ireland). Statistical analysis were analyzed Pearson's correlation coefficients and regression and paired t-test, and Difference (%). Results: Experimental group 1 (Lipemic Specimen Anti-ds DNA Ab concentration ${\leq}7IU/mL$) at y=0.368X+4.732, $R^2=0.023$, Pearson's correlation coefficient was 0.154, paired t-test (P=0.003), Difference (%) mean 65.7 and showed a statistically significant difference. Experimental group 2 (Lipemic Specimen Anti-ds DNA Ab concentration ${\geq}8IU/mL$) at y=0.983X+0.298, $R^2=0.994$, Pearson's correlation coefficient showed 0.997, paired t-test (P=0.181), Difference (%) mean -5.53 made no statistically significant difference. Conclusion: Lipemic sample of low Anti-ds DNA Ab concentration (2.5-7 IU/mL) and the result is obtained pre-treatment (high-speed centrifugation: 14,000 rpm 5 mins) were made a significant difference statistically. Anti-ds DNA is one of the primary auto-antibodies present in patients with SLE, and remain an important diagnostic test for SLE. Therefore, we recommend preprocessing (high-speed centrifugation: 14,000 rpm 5 mins) in order to exclude the influence of lipemic specimen.

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Perspective on Rapid and Selective Method for Detecting Microbiology in Dairy Industry: A Review (낙농산업에 필요한 미생물 검사방법과 전망: 총설)

  • Chon, Jung-Whan;Kim, Hyun-Sook;Kim, Hong-Seok;Kim, Dong-Hyeon;Song, Kwang-Young;Yim, Jin-Hyuk;Choi, Dasom;Lim, Jong-Soo;Jeong, Dong-Gwan;Kim, Soo-Ki;Seo, Kun-Ho
    • Journal of Dairy Science and Biotechnology
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    • v.33 no.2
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    • pp.119-127
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    • 2015
  • To date, detection of microbial populations in dairy products has been performed using culture media, which is a time-consuming and laborious method. The recently developed chromogenic media could be more rapid and specific than classical culture media. However, the newly developed molecular-based technology can detect microbial populations with greater rapidity and sensitivity than the classical method involving culture media and chromogenic media. This molecular-based technology could provide various options for monitoring the characterization of different states of bacteria and cells. Thus, it could help upgrade the processing system of the dairy industry so as to maintain the safety and quality of dairy foods. Among the various newly developed molecular-based technologies, flow cytometry can potentially be used for monitoring microbiological populations in the dairy industry if official international standards are available for this purpose. When omics technology would have biomarker identification, it could be regarded as the rapid and sensitive analytical methods. Methods based on PCR, which has become a basic technique in microbiological research, can be developed and validated as alternative methods for quantification of dairy microorganisms. This review discusses methods for monitoring microbiological populations in dairy foods and the limitations of these studies, as well as the need for further research on such methods in the dairy industry.

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