• Journal of Dairy Science and Biotechnology
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• 제39권3호
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• pp.113-120
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• 2021

Although the number of incidences of illness caused by ingestion of the bacterial pathogen Enterobacter sakazakii (Cronobacter spp.) has dramatically declined, there remains a need for a robust isolation method to recover this microbe from powdered infant formula (PIF). The current method described in the FDA's Bacteriological Analytical Manual requires multiple steps, and 3-4+ days for complete analysis of PIF isolated E. sakazakii (Cronobacter spp.). We describe a bacteriological method including a one-step enrichment followed by plating on chromogenic agar for presumptive identification of E. sakazakii (Cronobacter spp.). Suspected colonies are confirmed by either biochemical analyses, or a Real-Time PCR-based assay. Using this method, E. sakazakii (Cronobacter spp.) in PIF can be isolated and identified within one day (24 hours).

• Journal of Preventive Medicine and Public Health
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• 제47권1호
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• pp.7-17
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• 2014

Risk assessment considers the situations and characteristics of the exposure environment and host. Various physiological variables of the human body reflects the characteristics of the population that can directly influence risk exposure. Therefore, identification of exposure factors based on the Korean population is required for appropriate risk assessment. It is expected that a handbook about general exposure factors will be used by professionals in many fields as well as the risk assessors of the health department. The process of developing the exposure factors handbook for the Korean population will be introduced in this article, with a specific focus on the general exposure factors including life expectancy, body weight, surface area, inhalation rates, amount of water intake, and soil ingestion targeting the Korean population. The researchers used national databases including the Life Table and the 2005 Time Use Survey from the National Statistical Office. The anthropometric study of size in Korea used the resources provided by the Korean Agency for Technology and Standards. In addition, direct measurement and questionnaire surveys of representative samples were performed to calculate the inhalation rate, drinking water intake, and soil ingestion.

• ALGAE
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• 제35권1호
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• pp.61-78
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• 2020

Species belonging to the dinoflagellate genus Prorocentrum are known to cause red tides or harmful algal blooms. To understand the dynamics of a Prorocentrum sp., its growth and mortality due to predation need to be assessed. However, there are only a few Prorocentrum spp. for which heterotrophic protist predators have been reported. We explored feeding by the common heterotrophic dinoflagellates Gyrodinium dominans, Oxyrrhis marina, Pfiesteria piscicida, Oblea rotunda, and Polykrikos kofoidii and the naked ciliate Strombidinopsis sp. (approx. 90 ㎛ cell length) on the planktonic species Prorocentrum triestinum, P. cordatum, P. donghaiense, P. rhathymum, and P. micans as well as the benthic species P. lima and P. hoffmannianum. All heterotrophic protists tested were able to feed on the planktonic prey species. However, O. marina and O. rotunda did not feed on P. lima and P. hoffmannianum, while G. dominans, P. kofoidii, and Strombidinopsis sp. did. The growth and ingestion rates of G. dominans and P. kofoidii on one of the seven Prorocentrum spp. were significantly different from those on other prey species. G. dominans showed the top three highest growth rates when it fed on P. triestinum, P. cordatum, and P. donghaiense, however, P. kofoidii had negative growth rates when fed on these three prey species. In contrast, P. kofoidii had a positive growth rate only when fed on P. hoffmannianum. This differential feeding on Prorocentrum spp. between G. dominans and P. kofoidii may provide different ecological niches and reduce competition between these two common heterotrophic protist predators.

• 한국환경보건학회지
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• 제49권5호
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• pp.262-274
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• 2023

Background: Exposure levels for heavy metals such as lead (Pb), mercury (Hg), and cadmium (Cd) have increased due to human activities. They are known to be a public health concern. Objectives: This study aimed to determine the exposure levels to heavy metals in the blood and urine of South Korean adults and to present the contribution rate of exposure pathways using an exposure algorithm for men aged 19~64, women aged 19~64, and all seniors aged 65 or older. Methods: We analyzed data from the Korean National Environmental Health Survey (KoNEHS) Cycle 4 (2018~2020). A total of 2,646 participants aged ≥19 years were included. Multiple regression analysis was performed to determine the factors affecting heavy metal concentrations. The contribution rate was calculated by applying three exposure algorithms for ingestion, inhalation, and dermal exposure. Results: Factors that commonly affect heavy metal concentrations in blood and urine were gender and age. The main influencing factors for Pb and Cd were education level and smoking status, while frequency of fish consumption and of alcohol consumption were indicated to be the main influencing factors for mercury. The contribution rates of lead and cadmium from food ingestion were 78.03~79.62% and 88.39~92.89%, respectively. Additionally, the highest contribution for mercury was accounted for by food at 81.69~85.77%. As a result of the risk assessment, cadmium was found to pose a potential health risk a with total cancer risk (TCR) of more than 1×10^-6. Conclusions: The KoNEHS could be an important study for determining the level of exposure to heavy metals and their influencing factors. Integrated exposure to heavy metals could assess the main exposure pathways, and this methodology could be applied to exposure management of heavy metals.

• ALGAE
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• 제31권4호
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• pp.351-362
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• 2016

We investigated a possible reduction in $CO_2$ uptake rate by phototrophic red tide dinoflagellates arising from mixotrophy. We measured the daily ingestion rates of Prorocentrum minimum by Prorocentrum micans over 5 days in 10 L experimental bottles, and the uptake rates of total dissolved inorganic carbon ($C_T$) by a mixture of P. micans and P. minimum(mixotrophic growth), and for the predator P. micans (phototrophic growth; control) and prey P. minimum (phototrophic growth; control) alone. To account for the effect of pH on the phototrophic growth rates of P. micans and P. minimum, measurements of $C_T$ and pH in the predator and prey control bottles were continued until the pH reached the same level (pH 9.5) as that in the experimental bottles on the final day of incubation. The measured total $C_T$ uptake rate by the mixture of P. micans and P. minimum changed from 123 to $161{\mu}mol\;C_T\;kg^{-1}\;d^{-1}$ over the course of the experiment, and was lower than the $C_T$ uptake rates shown by P. micans and P. minimum in the predator and prey control bottles, respectively, which changed from 132 to $17{\mu}mol\;C_T\;kg^{-1}\;d^{-1}$ over the course of the experiment. The reduction in total $C_T$ uptake rate arising from the mixotrophy of P. micans was 7-31% of the daily $C_T$ uptake rate seen during photosynthesis. The results suggest that red tide dinoflagellates take up less $C_T$ during mixotrophy.

• 한국양식학회지
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• 제18권2호
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• pp.86-91
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• 2005

I. galbana, P. parvum 및 P. patelliferum 등 3종의 착편모조를 각각 먹이로서 급이 하면서 각각의 먹이에 따른 해산 요각류 T. japonicus의 nauplius 및 copepodid 유생의 개체수 증식 양상과 재포란 암컷의 개체수 변화 양상, 그리고 배양 도중 사망한 성체 암컷의 개체수를 서로 비교하였으며, 또한 각 계수일에 측정한 배 양수내의 먹이로서 급이한 3종의 착편모조의 세포수 변화 양상을 관찰하였다. 비교구로서 먹이를 전혀 공급하지 않은 실험구의 T. japonicus는 고압 멸균한 자연 해수만을 이용하여 배양하였다. 실험 결과 3종의 착편모조 중 I. galbana를 급이한 경우에는 T. japonicus의 정상적인 유생 발생과 함께 적극적인 I. galbana의 섭이를 관찰할 수 있었으나, P. parvum과 P. patelliferum을 급이한 경우에는 갓 부화한 nauplius 유생이 거의 100% 사망하였고 암컷 성체의 재포란율 또한 거의 0 (zero)임이 관찰되었다. 더욱이 15일간의 실험기간 중에 암컷 성체의 사망을 관찰하였다. 위와 같은 일련의 실험 결과로 볼 때, 독성을 가지며 적조의 원인종으로 알려진 착편모조 P. parvum과 P. patelliferum은 요각류 T. japonicus에 대해서 유해함을 알 수 있었다.

• Environmental Analysis Health and Toxicology
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• 제26권
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• pp.8.1-8.9
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• 2011

Objectives: This study assessed the health risks for children exposed to phthalate through several pathways including house dust, surface wipes and hand wipes in child facilities and indoor playgrounds. Methods: The indoor samples were collected from various children's facilities (40 playrooms, 42 daycare centers, 44 kindergartens, and 42 indoor-playgrounds) in both summer (Jul-Sep, 2007) and winter (Jan-Feb, 2008). Hazard index (HI) was estimated for the non-carcinogens and the examined phthalates were diethylhexyl phthalate (DEHP), diethyl phthalate (DEP), dibutyl-n-butyl phthalate (DnBP), and butylbenzyl phthalate (BBzP). The present study examined these four kinds of samples, i.e., indoor dust, surface wipes of product and hand wipes. Results: Among the phthalates, the detection rates of DEHP were 98% in dust samples, 100% in surface wipe samples, and 95% in hand wipe samples. In this study, phthalate levels obtained from floor dust, product surface and children's hand wipe samples were similar to or slightly less compared to previous studies. The $50^{th}$ and $95^{th}$ percentile value of child-sensitive materials did not exceed 1 (HI) for all subjects in all facilities. Conclusions: For DEHP, DnBP and BBzP their detection rates through multi-routes were high and their risk based on health risk assessment was also observed to be acceptable. This study suggested that ingestion and dermal exposure could be the most important pathway of phthalates besides digestion through food.

• Asian-Australasian Journal of Animal Sciences
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• 제5권4호
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• pp.699-707
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• 1992

Three goats were fed with $^{15}N$-labelled rice straw to study the characteristics of digestion, assimilation, metabolism and excretion of C and N compounds from rice straw. It was shown that the amount of $^{15}N$ assimilated into the bodies of the two slaughtered goats accounted for 38.5 and 23.6% of the total amount of $^{15}N$ ingestion in the experimental diet by each goat. The $^{15}N$ excreted via the feces and urine for the three goats accounted for 34.8, 33.2 and 33.9% of the total amount of $^{15}N$ ingested in the feed of the 3 goats. The recoveries of $^{15}N$ from the two slaughtered goats were 73.3 and 57.5%, with the corresponding rates of $^{15}N$ loss 26.7 and 42.5% respectively. The amino acids digestibilities were 68.7 and 54.0%, while the digestibilities of carbohydrates were 74.8 and 67.7% respectively for goats 1 and 3.

• 대한임상독성학회지
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• 제14권2호
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• pp.136-143
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• 2016

Purpose: In patients with altered mentality caused by drugs or unknown causes, ammonia is checked to facilitate differential diagnosis or diagnose hepatic coma. This helps early prevention and treatment of brain damage due to hyperammonemia. This study was conducted to evaluate clinical characteristics of intoxicated adult patients with hyperammonemia. Methods: We evaluated 95 patients with hyperammonemia among intoxicated patients above the age of 15 who visited our ED from January 2013 to December 2015. We analyzed the demographic characteristics and type of poisoning substance, reason for ingestion, toxicological characteristics such as elapsed time from ingestion to hospital visit, lab, clinical progression and complications. Data were evaluated using the student's t test or Mann-Whitney U test for continuous variables, and Chi-square test and Fisher's exact test for frequency analysis of categorical variables. Results: When compared to healthy individuals, patients with hyperammonemia showed statistical significance on their SOFA score (p=0.016) and poison severity score (p<0.001). Additionally, patients with hyperammonemia showed significantly different initial serum AST level (p=0.012) and maximum serum AST level during the hospital stay (p=0.026) when compared to healthy individuals. Moreover, individuals with sustained hyperammonemia compared to transient hyperammonemia showed clinically significant SOFA scores (p<0.001), poison severity scores (p=0.007), mortality rates in the ICU (p=0.021), as well as different duration of hospital stay (p=0.037), serum creatinine level (p=0.002), erythrocyte sedimentation rate (p=0.025), and serum myoglobin (p=0.015). Conclusion: Most poisoning-induced hyperammonemia cases were transient and recovered without special treatment. Therefore, hyperammonemia is almost non-specific among poisoning patients.

• 한국양식학회지
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• 제15권4호
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• pp.253-260
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• 2002

To find the optimal rearing conditions for Saxidomus purpuratus juvenile, filtering activity was estimated as functions of algal concentration and temperature by measuring the rates of clearance (CR) and ingestion (IR), when S. purpuratus was feeding. The clams were fed on unialgal diet of Isochrysis galbana at 6 algal concentrations (4.6$\times$$10^4$~2.6$\times$$10^6$ cells/ml) and at 6 temperatures (5, 10, 15, 20, 25, and 30^{\circ}C ). Algal concentration significantly affected the CR and the IR at all temperatures. At lower algal concentrations, CR increased, but decreased beyond a particular concentration. The maximum CR ($CR_{max}$) at 5, 10, 15, 20, 25, and 30^{\circ}C were 0.30, 1.73, 5.95, 15.17, 21.12, and 0.33 $l/g/h$, respectively. Below the level of 5.6$\times$10$^{5}$ cells/ml, IR increased as algal concentration increased, but was saturated at higher concentrations. To maintain high growth rate of S. purpuratus, I. galbana should be supplied with more than 5.6$\times$10$^{5}$ cells/ml. The maximum IR ($IR_{max}$) at 5, 10, 15, 20, 25 and30^{\circ}C were $2.2$\times$10^8, $1.5\times$10^9, 3.4$\times$10^9, 4.9$\times$10^9, 5.3$\times$10^9, and 1.0$\times$10^8$ cells/g/h, respectively. As for temperature, both $CR_max$ and $IR_max$ increased remarkably with raising temperature from 5 to 25^{\circ}C, but rapidly decreased at 30^{\circ}C. Between 15 and 25^{\circ}C $CR_{max} and IR_{max}$ were higher and most stable, At this temperature range, the $Q_{10}/s for CR_{max} and IR_{max}$ were 3.5 and 1.6, respectively. Therefore the optimal thermal range for the juvenile is 15~$25^{\circ}C$. The annual variation in IR$_{max}$ predicted by natural seawater temperature shows that inactive period (with lower $IR_max$) lasts for 5 months (from December to April). To ensure higher growth of juvenile during this inactive period at hatcheries, rearing temperature should be elevated to $15^{\circ}C$.>.