• Journal of dental hygiene science
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• v.15 no.2
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• pp.232-237
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• 2015

The water supplied from dental unit water systems (DUWS) in dentistry may be heavily contaminated with bacteria and thus may be a potential source of infection for both practice staff and patients. The aim of this study was to evaluate the level of heterotrophic bacteria and to confirm the presence of opportunistic pathogens from DUWS in student clinical simulation laboratory of college of dentistry. Water samples were collected from 36 ultrasonic scalers in student clinical simulation laboratory. The levels of heterotrophic bacteria in water samples were quantified by counting colony forming units (CFUs) on R2A agar media. In addition, opportunistic pathogens were detected by using the polymerase chain reaction (PCR) method. The mean CFUs were 16,095 CFU/ml for water samples and all of water samples exceeded current American Dental Association recommendations of 200 CFU/ml. Pseudomonas species and non-tuberculous Mycobacterium species were detected in the one sample and two samples, respectively, among the 36 water samples by the PCR with specific primers for these bacteria. Our study indicated that DUWS in student clinical simulation laboratory can cause potential infection in students and participants. This study suggested the dental unit water line management and wearing personal protective equipment in student clinical simulation laboratory will be needed to reduce bacterial contamination.

• Food Science and Preservation
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• v.11 no.4
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• pp.431-436
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• 2004

Associated with microbial decontamination and quarantine treatment of dried red pepper, the samples was gamma-irradiated (5, 10 kGy) and fumigated (methyl bromide/MeBr, phosphine/$PH_3$) to compare their Hunter's color (L, a, b, ${\Delta}E$) and sensory properties by types (whole, powder, pericarp, seed) during storage under room conditions($18{\pm}12^{\circ}C$). Whole pepper maintained higher lightness (L value) than other groups, while powdered pepper showed higher redness (a value) during storage. Immediately after treatments there was little difference in the overall color difference (${\Delta}E$) among the groups. After 8 months, a higher redness was observed in $PH_3$ group of whole pepper and 5 kGy group of powdered pepper, respectively(p<0.05). Redness of irradiated pericarps was apparently reduced following 8 months of storage and a similar pattern was found in fumigated samples. The yellowness (b value) of pepper seed was lowest in 10 kGy sample (p<0.05), but insignificant difference was observed among treatment groups with storage time. Sensory properties of whole and powdered peppery were little changed by both treatments under commercial conditions. Sensory scores of irradiated or fumigated samples were higher than that of non-treated control with storage time, which was more significant in the powdered than in the whole samples.

• Journal of Pharmaceutical Investigation
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• v.36 no.5
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• pp.331-338
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• 2006

A rapid, selective and sensitive reverse-phase HPLC methods for the determination of atenolol and chlorthalidone in human serum and whole blood were validated, and applied to the pharmacokinetic study of atenolol and chlorthalidone combination therapy. Atenolol and an internal standard, pindolol, were extracted from human serum by liquid-liquid extraction, and analyzed on a $\mu$-Bondapak C18 $10-{\mu}$ column in a mobile phase of methanol-0.01 M potassium dihydrogenphosphate(30:70, v/v, adjusted to pH 3.5) and fluorescence detection(emission: 300 nm, excitation: 224 nm). Chlorthalidone and an internal standard, probenecid, were extracted form human whole blood by liquid-liquid extraction, and analyzed on a Luna C18 $5-{\mu}$ column in a mobile phase of acetonitrile containing 77% 0.01 M sodium acetate and UV detection at 214 nm. These analysis were performed at three different laboratories using the same quality control(QC) samples. The chromatograms showed good resolution, sensitivity, and no interference by human serum and whole blood, respectively. The methods showed linear responses over a concentration range of 10-1,000 ng/mL for atenolol and 0.05-20 ${\mu}g/mL$ for chlorthalidone, with correlation coefficients of greater than 0.999 at all the three laboratories. Intra- and inter-day assay precision and accuracy fulfilled international requirements. Stability studies(freeze-thaw, short-, long-term, extracted sample and stock solution) showed that atenolol and chlorthalidone were stable. The lower limit of quantitation of atenolol and chlorthalidone were 10 ng/mL and 0.05 ${\mu}g/mL$, respectively, which was sensitive enough for pharmacokinetic studies. These methods were applied to the pharmacokinetic study of atenolol and chlorthalidone in human volunteers following a single oral administration of Hyundai $Tenoretic^{\circledR}$ tablet(atenolol 50 mg and chlorthalidone 12.5 mg) at three different laboratories.

• Food Science and Preservation
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• v.15 no.1
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• pp.9-14
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• 2008

This study compared microbial load, texturre, histological properties, and sensory characteristics of gamma-irradiated (20 kGy) Kimchi and freeze-dried Kimchi under condition; of long-tenn storage. immediately after irradiation, no aerobic bacteria were detected, but microbial load of freeze-dried Kimchi decreased by only 1 log cycle in comparision with the nonirradiated control sample. The firmness of irradiated Kimchi was significantly higher than that of rehydrated freeze-dried Kimchi (p<0.05). Scanning electron microscopy showed collapse of the microstructure in epidermis tissues of rehydrated Kimchi. 'The sensory scores for color, texture, and taste of irradiated Kimchi were higher than those for rehydrated freeze-dried Kimchi.

• Korean Journal of Poultry Science
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• v.42 no.3
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• pp.215-221
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• 2015

Chicken breast meat samples were injected with marinade solution (salt, sugar, phosphate, monosodium glutamate, and nucleic acid) with or without 2% citrus peel extract (CPE), and then a subset were irradiated with a 1 or 2 kGy electron beam (EB) and/or subjected to high-pressure (HP) at 300 or 400 MPa. The initial total aerobic bacterial (TAB) count of the control sample was 4.57 log CFU/g and reached 7.17 log CFU/g after 3 days of storage at $4^{\circ}C$. The 2 kGy EB reduced the TAB count to 4.61 log CFU/g after 7 days. The 400 MPa HP treatment was also effective in reducing the TAB count, but the effect was slightly less than that noted with the 2 kGy EB. The CPE, in combination with the EB and HP, decreased the TAB count by 1.71 and 1.32 log CFU/g at the initial stage and further decreased the count during storage. The 2 kGy EB and the HP (300 and 400 MPa) increased the thiobarbituric acid-reactive substances value, whereas the CPE did not show an antioxidative effect. The EB and HP caused no difference in the sensory qualities. In contrast, the CPE decreased all sensory qualities tested. Sensory panelists commented that the samples with CPE were not in the "rejection" category but were "unfamiliar" for chicken breast meat. In conclusion, the EB was more effective than HP in improving the microbial quality of marinated chicken breast meat. The use of CPE in the marinade solution may synergistically increase the shelf life; however, it is necessary to develop an appropriate formulation to ensure that the sensory qualities are maintained.

• The Journal of Internal Korean Medicine
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• v.41 no.3
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• pp.306-325
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• 2020

Objectives: The aim of this study is to investigate the effect of a Dachaihu decoction for hyperlipidemic acute pancreatitis (HLAP) by systematic review and meta-analysis of Chinese clinical studies. Methods: China National Knowledge Infrastructure (CNKI) was utilized as the major search engine. The date of the literature search was March 7, 2020. Randomized controlled trials (RCTs) about using a Dachaihu decoction for HLAP were included in this study. Meta-analysis was performed by synthesizing outcome data, including total effective rate, abdomen pain relief time, first bowel movement time, blood amylase recovery time, and triglyceride (TG) levels (mmol/L). The selected literature was assessed using Cochrane's risk of bias (RoB). Results: Twelve of 44 RCTs met the inclusion criteria. Most studies were evaluated with RoB as having unclear risk. The total effective rate of herbal medicine treatment based on the Dachaihu decoction was significantly higher than that of symptomatic supportive treatment in 10 articles (risk ratio=1.15, 95% CI: 1.08 to 1.21, p<0.00001, I²=0%). Herbal medicine treatment based on a Dachaihu decoction was significantly more effective than symptomatic supportive treatment in terms of reducing abdomen pain relief time (in all articles; mean difference=-1.70, 95% CI: -1.91 to -1.41, p<0.00001, I²=45%), first bowel movement time (in 7 articles; mean difference=-1.46, 95% CI: -1.86 to -1.05, p<0.00001, I²=73%), blood amylase recovery time (in 8 articles; mean difference=-1.48, 95% CI: -2.04 to -0.92, p<0.00001, I²=90%), and TG levels (in 8 articles; mean difference=-1.59, 95% CI: -2.28to -0.91, p<0.00001, I²=90%). Only one article reported side effects of treatment among the intervention group and control group, citing pancreatic ulcer and pancreatic pseudocyst formation. Conclusions: This study suggests that herbal medicine treatment based on a Dachaihu decoction could yield higher efficacy for HLAP than symptomatic supportive treatment alone. However, the results might be somewhat biased because of the poor quality and small sample size of the included RCTs. Well-qualified clinical studies are needed to prove the effectiveness of Dachaihu decoction therapy for HLAP.

• Journal of Soil and Groundwater Environment
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• v.19 no.4
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• pp.62-69
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• 2014

In the results of monitoring nitrate concentration in more than 8,000 groundwater wells around agro-livestock, the average and maximum nitrate concentration was 9.4 mg/L and 101.2 mg/L, respectively. Since about 31% of the monitoring wells was exceed the quality standard for drinking water, nitrate control such as remediation or source regulation is required to conserve safe-groundwater in South Korea. Typical nitrate-treatment technologies include ion exchange, reverse osmosis, and biological denitrification. Among the treatment methods, biological denitrification by indigenous microorganism has environmental and economic advantages for the complete elimination of nitrate because of lower operating costs compared to other methods. Major mechanism of the process is microbial reduction of nitrate to nitrite and nitrogen gas. Three functional genes (nosZ, nirK, nirS) that encode for the enzyme involved in the pathway. In this work, we tried to develop simple process to determine possibility of natural denitrification reaction by monitoring the functional gene. For the work, the functional genes in nitrate-contaminated groundwater were monitored by using PCR with specific target primers. In the result, functional genes (nosZ and nirK) encoding denitrification enzymes were detected in the groundwater samples. This method can help to determine the possibility of natural-nitrate degradation in target groundwater wells without multiplex experimental process. In addition, for field-remediation application we selected nitrate-contaminated site where 200~600 mg/L of nitrate is continuously detected. To determine the possibility of nitrate-degradation by stimulated-natural attenuation, groundwater was sampled in two different wells of the site and nitrate concentration of the samples was 300 mg/L and 616 mg/L, respectively. Fumarate for different C/N ratio was added into microcosm bottles containing the groundwater to examine denitrification rate depending on carbon concentration. In the result, once 1.5 times more than amount of fumarate stoichiometry required was added, the 616 mg/L of nitrate and 300 mg/L of nitrate were completely degraded in 8 days and 30 days. The nitrite, byproduct of denitrification process, was also completely degraded during the experimental period.

• Food Engineering Progress
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• v.15 no.4
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• pp.376-381
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• 2011

The baking performance of Cudrania tricuspidata leaf powder as a value-added food ingredient was investigated in a model system of sponge cakes. Cudrania tricuspidata leaf powder was incorporated into cake batter at 5 levels (0, 5, 10, 15, and 20%, w/w) by adding equivalent amount based on total weight of wheat flour. The specific volume, height, moisture content, volume index, and symmetry index of sponge cakes decreased significantly with the increase in Cudrania tricuspidata leaf powder content (p < 0.05). Sponge cakes became darker and firmer with increase in Cudrania tricuspidata leaf powder content (p < 0.05), as indicated by decrease in the $L^*$ and increase in the firmness measured by the texture measuring instrument. Total polyphenol content also increased gradually as the Cudrania tricuspidata leaf powder content increased. Finally, the consumer acceptance test indicated that addition of Cudrania tricuspidata leaf powder up to 10% in the formulation of sponge cakes did not significantly influence the consumers' acceptability with respect to taste and flavor. In addition, the overall acceptability was not different from each other for control and 5% sample (p > 0.05).

• Korean Journal of Materials Research
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• v.28 no.12
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• pp.732-737
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• 2018

We develop a purification process of $Hg_2Br_2$ raw powders using a physical vapor transport(PVT) process, which is essential for the fabrication of a high performance acousto-optic tunable filter(AOTF) module. Specifically, we characterize and compare three $Hg_2Br_2$ powders: $Hg_2Br_2$ raw powder, $Hg_2Br_2$ powder purified under pumping conditions, and $Hg_2Br_2$ powder purified under vacuum sealing. Before and after purification, we characterize the powder samples through X-ray diffraction and X-ray photoelectron spectroscopy. The corresponding results indicate that physical properties of the $Hg_2Br_2$ compound are not damaged even after the purification process. The impurities and concentration in the purified $Hg_2Br_2$ powder are evaluated by inductively coupled plasma-mass spectroscopy. Notably, compared to the sample purified under pumping conditions, the purification process under vacuum sealing results in a higher purity $Hg_2Br_2$ (99.999 %). In addition, when the second vacuum sealing purification process is performed, the remaining impurities are almost removed, giving rise to $Hg_2Br_2$ with ultra-high purity. This high purification process might be possible due to independent control of impurities and $Hg_2Br_2$ materials under the optimized vacuum sealing. Preparation of such a highly purified $Hg_2Br_2$ materials will pave a promising way toward a high-quality $Hg_2Br_2$ single crystal and then high performance AOTF modules.

• Korean Journal of Food Science and Technology
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• v.53 no.3
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• pp.321-328
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• 2021

Brownies containing whey powder (WP) with different levels of substitutions for wheat flour (0, 10, 20, 30, and 40% substitution for WP 0, WP 10, WP 20, WP 30, and WP 40, respectively) were prepared, and their properties were compared. Regarding appearance, the collapse of the sample surface noticeably started from WP 30. The moisture content was higher in samples containing WP than in the control (WP 0), and the weight of the brownie increased with WP content. As the WP amount increased, both the total and specific volumes of the brownies decreased. Regarding texture, a higher amount of WP resulted in a decrease in hardness, whereas adhesiveness increased significantly. The antioxidant activity also increased with increasing WP amount (from 35.28 to 51.47%). Regarding sensory characteristics, 20 or 30% WP in brownies increased mouth-feel properties, taste, and overall preference. Based on the above results, WP could improve the quality of brownies, and a substitution level of 20% could be the most appropriate.