• Journal of Biomedical Engineering Research
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• v.14 no.3
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• pp.273-282
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• 1993

This study is concerned with the temperature dependence characteristics of ultrasound parameters in biological tissues, which are basic on the noninvasive deep body temperature estimation. Used parameters are ultrasonic attenuation coefficient and sound velocity In order to accomplishment our purpose, several signal processing methods were used. Attenua4iorl coefficient was estimated by spectral difference method and sound velocity was estimated by P-P method. And we also examined these methods through a series of IN VITRO experi mentis that used tissue-mimicking phantom samples and biological tissue samples. In order to imitate the biological soft tissue two kinds of phantom samples are used, one is agar phantom sample which is composed of agar, graphite, N-propyl alcohol and distilled water, and the other is fat phantom sample which is composed of pure animal fat. And the ultrasound transmission mode and reflection mode experiments are performed on the pig's spleen, kidney and fat. As a result, it is found that the temperature characteristics are uniform in case of phan- tom samples but not in biological tissues because of complicate wave propagation within them. Consequently, the possibility of temperature measurement using ultrasound on biological tissue is confirmed and its results may contribute to the establishment of reference values of internal temperature measurement of biological tissues.

• The Plant Pathology Journal
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• v.37 no.6
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• pp.521-532
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• 2021

Knowledge and better understanding of functions of the microbial community are pivotal for crop management. This study was conducted to study bacterial structures including Acidovorax species community structures and diversity from the watermelon cultivated soils in different regions of South Korea. In this study, soil samples were collected from watermelon cultivation areas from various places of South Korea and microbiome analysis was performed to analyze bacterial communities including Acidovorax species community. Next generation sequencing (NGS) was performed by extracting genomic DNA from 92 soil samples from 8 different provinces using a fast genomic DNA extraction kit. NGS data analysis results revealed that, total, 39,367 operational taxonomic unit (OTU), were obtained. NGS data results revealed that, most dominant phylum in all the soil samples was Proteobacteria (37.3%). In addition, most abundant genus was Acidobacterium (1.8%) in all the samples. In order to analyze species diversity among the collected soil samples, OTUs, community diversity, and Shannon index were measured. Shannon (9.297) and inverse Simpson (0.996) were found to have the highest diversity scores in the greenhouse soil sample of Gyeonggi-do province (GG4). Results from NGS sequencing suggest that, most of the soil samples consists of similar trend of bacterial community and diversity. Environmental factors play a key role in shaping the bacterial community and diversity. In order to address this statement, further correlation analysis between soil physical and chemical parameters with dominant bacterial community will be carried out to observe their interactions.

• Journal of Environmental Health Sciences
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• v.9 no.2
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• pp.1-10
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• 1983

The purpose of this study was to analyze general ingredient of bean cured on the market and to examine its exposure to bacterial contamination. For this study, 17 samples (each 9 samples for general bean curd, soft bean curd, and uncurdled bean curd) were randomly collected from nine areas in Seoul from the beginning of April, 1983 to the beginning of June, 1983. The result of ingredient analysis of moisture, ash, and protein of bean curd was compared with the standard set by the Ministry of Health & Social Affairs. In order to find out exposure of bean curd on the market to bacterial contamination, total biological bacteria and coliform group were examined. Experimental results were shown as follows 1) Results of ingredient analysis of moisture, ash, and protein of general bean curd showed that total samples in both moisture and protein met the standard set by the Ministry of Health & Social Affairs but 44.4% of the samples in ash was below the above standard, indicating average 82.0%, 0.9% and 9.6% in moisture, ash, and protein order. 2) Experimental results of moisture, ash, and protein of soft bean curd demonstrated 90.2%, 0.5% and 4.3% respectively total samples in both moisture and protein satisfied the self-criteria set by the Soft Food Co-operative Association of Seoul City but 11.1% of the samples in ash didn't meet the self-criteria. 3) Total samples of uncurdled bean curd satisfied the self-criteria set by the above association, indicating average 92.0%, 0.4%, and 3.5% in moisture, ash, and protein order. 4) Total biological bacteria and coliform group detected in general bean curd showed that more than 10$^5$/g in total biological bacteria accounted for 88.8% of the samples and that 10$^4$/g or more in coliform group accounted for 77.7% of the samples. The result proves that general bean curd has been exposured to a severe bacterial contamination. 5) Result of total biological bacteria and coliform group detected in such packed bean curd as uncurdled bean curd and soft bean curd showed that 61.6% of the samples exceeded 10$^6$/g in total biological bacteria and 27.7% of the samples exceeded 10$^3$/g in coliform group. 6) According to the change with time and temperatures in total biological bacteria and coliform group of general bean curd, general bean curd began to decay around 72 hours at 4$\circ$C and around 48 hours at 23$\circ$C and around 24 hours at 37$\circ$C and, at that time, total biological bacteria approached 10$^6$/g while coliform group did 10$^6$/g. The result indicates that temperature has a great effect on bacteria counts and decay.

• Journal of Applied Biological Chemistry
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• v.51 no.3
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• pp.128-135
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• 2008

A total of 142 samples comprising vegetables, soil, and water collected from different agricultural farms (five provinces) were analyzed for total aerobic bacteria (aerobic plate count [APC]), Bacillus cereus, Escherichia coli, Listeria monocytogenes, Salmonella spp., and Staphylococcus aureus. The average of total APC in all the samples ranged from $4.72{\times}10^5$ to $8.62{\times}10^8\;CFU/g$ (mL). The prevalence of B. cereus, E. coli, L. monocytogenes, S. spp., and S. aureus for all samples was 17.60%, 2.11 %, 1.4%, 0%, and 2.11 % respectively, and their counts averaged to $4.87{\times}10^4\;CFU/g$ (mL), $4.34{\times}10^3\;CFU/g$ (mL), $2.15{\times}10^2\;CFU/g$, 0 CFU/g, and $3.12{\times}10^3\;CFU/g$ respectively. Among the 3 different types of samples, 6 vegetables (10.34%), 24 soil (38.70%), and 3 water (13.64%) samples were found to be positive for bacterial pathogens. The result showed that the occurrence of bacterial pathogen in the samples analyzed was low. Further time to time monitoring and need to wash of raw agricultural products is recommended.

• Journal of Species Research
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• v.1 no.1
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• pp.87-99
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• 2012

Before the construction of Hantangang dam, we surveyed vertebrate fauna along the Hantangang River and collected samples. We collected 248 specimens (1,394 individuals) of 41 fish species from 10 families in four orders, including 17 endemic species and 5 endangered species. In our herpetofauna survey, we collected 47 amphibian samples of 10 species from 5 families in 2 orders, and 19 reptile samples of 5 species from 2 families in 1 order. We observed 25 species of bird (6 orders, 14 families) inclulding collection of 51 bird specimens (10 species from 5 families in 1 order). We collected 91 mammals of 6 species, and identified 7 species from field sign and direct observation from a total of 10 families in 5 orders. This collection and list comprise the final vertebrate faunal survey of the Hantangang region, and will provide basic scientific information for future research on conservation and restoration of the region.

• Journal of the Korean Chemical Society
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• v.37 no.9
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• pp.800-805
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• 1993

An analytical method has been developed to determine trace elements in biological samples. The biological samples are added to a laboratory-bulit Teflon bomb together with nitric acid-hydrogen peroxide mixture and enriched stable isotopes. The samples are decomposed in a microwave oven. The decomposed sample solutions are analyzed by isotope dilution inductively coupled plasma mass spectrometry. The analytical results of the biological samples agree well with the reference values.

• Macromolecular Research
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• v.17 no.1
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• pp.44-50
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• 2009

Rigid polyurethane foams (PUF)s were synthesized with environmentally friendly blowing agents such as a cyclopentane/distilled water (10.0/1.0, pphp) mixture and distilled water only for four different silicone surfactants having different silicone/polyether ratios. An attempt was made to reduce the thermal conductivities of the PUF samples by varying the concentration and the silicone/polyether ratio of the various silicone surfactants. The scanning electron microscopy (SEM) results indicated an optimum concentration of the silicone surfactant of about 1.5 to 2.5 phpp for various surfactants to reduce the cell size and lower the thermal conductivity. The silicone surfactant having a higher silicone/polymer ratio showed a smaller cell size and, therefore, demonstrated the lower thermal conductivity of the PUF samples. From the relation between the thermal conductivity and the cell size of the PUF samples, the smaller cell size improved the thermal insulation property of the rigid PUF for both the PUF samples blown by the cyclopentane/distilled water (10.0/1.0, pphp) mixture and distilled water only. If the blowing agent is fixed, then the cell size is an important factor to decrease the thermal conductivity of the PUF samples. These results indicated that rigid PUF samples having lower thermal conductivity can be obtained by choosing a silicone surfactant containing a higher silicone/polyether ratio, as well as an optimum content of the surfactant.

• Archives of Pharmacal Research
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• v.17 no.5
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• pp.360-363
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• 1994

Column--swtiching technique with a reversed-phase high performance liquid chromatographic method has been developed for the routine analysis of radioiodinated insulin and its degadation products in biological fluids. The diluted biological samples were loaded onto a precolumn packed with LiChrosorb RP-8 $(25-40{\;}{\mu}m)$ using 0.1% trifuoroacetic acid (TFA) in water as a washing solvent. After valve switching, the concentrated insulins were eluted in the back-flush mode and separated by a W-Porex $C_{18}$ column with a gradient of 0.1% TFA in water and 0.1% TFA in acetonitrile as the mobile phase. The method showed good precision, accuracy and speed with the detection limit of 20 pg/ml. Total analysis time per sample was about 40 min and the coefficients of variation were less than 8, 2%.

• Applied Biological Chemistry
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• v.3
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• pp.17-18
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• 1962

A study on fungus flora of 8 paddy field soil samples including 5 AKIOCHI soils has been made. Samples were taken from Chung-nam area. Fungi of 5 Genera and 19 species were identified; Aspergillus, Penicillium, Spicaria, Curvularia, Trichodema, were the 5 genera and the 19 speciec consristed of 4 Aspergilli, 12 Penicilli, and the each one of the others. Variations of fungus flora among those soil samples were noticed without the ecologieal explanation.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2293-2298
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• 2007

In this study, a dithizone extraction technique involving purge & trap GC-MS was developed for the determination of methylmercury in biological samples, especially blood and fish. After alkaline digestion, methylmercury in biological samples was extracted into dithizone and back-extracted into aqueous sulfide solution. The extracted methylmercury was converted to the volatile ethyl derivative, purged and trapped onto a solid-phase collection medium, and then introduced into the GC-MS system. The determined MDLs of the established method were 0.9 ng·g?1 for biological samples and its accuracy and precision were found to be 93% and 3.8%, respectively. The method was validated by analysis of CRMs such as SRM 966, BCR 463 and IAEA 407 and all analytical results were within certified ranges with average RSDs of less than 6%. The analytical results of field-sampled fish also showed that the method can be successfully used as an alternative for commonly used distillation method followed by GC-CVAFS detection.