• Restorative Dentistry and Endodontics
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• 제41권3호
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• pp.189-195
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• 2016

Objectives: A variety of root canal sealers were recently launched to the market. This study evaluated physicochemical properties, biocompatibility, and sealing ability of a newly launched resin-based sealer (Dia-Proseal, Diadent) compared to the existing root canal sealers (AHplus, Dentsply DeTrey and ADseal, Metabiomed). Materials and Methods: The physicochemical properties of the tested sealers including pH, solubility, dimensional change, and radiopacity were evaluated. Biocompatibility was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. For microleakage test, single-rooted teeth were instrumented, and obturated with gutta-percha and one of the sealers (n = 10). After immersion in 1% methylene blue solution for 2 weeks, the specimens were split longitudinally. Then, the maximum length of staining was measured. Statistical analysis was performed by one-way analysis of variance followed by Tukey test (p = 0.05). Results: Dia-Proseal showed the highest pH value among the tested sealers (p < 0.05). ADseal showed higher dimensional change compared to AHplus and Dia-Proseal (p < 0.05). The solubility values of AHplus and Dia-Proseal were similar, whereas ADseal had the lowest solubility value (p < 0.05). The flow values of sealer in increasing order were AHplus, DiaProseal, and ADseal (p < 0.05). The radiopacity of AHplus was higher than those of ADseal and Dia-Proseal (p < 0.05). The cell viability of the tested materials was statistically similar throughout the experimental period. There were no significant differences in microleakage values among the tested samples. Conclusions: The present study indicates that Dia-Proseal has acceptable physicochemical properties, biocompatibility, and sealing ability.

• Restorative Dentistry and Endodontics
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• 제45권4호
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• pp.47.1-47.11
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• 2020

Objectives: The aim of this study was to assess the physicochemical properties, cytotoxicity and penetration into dentinal tubules of ChlorCid^TM Surf (3% sodium hypochlorite [NaOCl] with surfactant) in comparison to ChlorCid^TM (3% NaOCl without surfactant). Materials and Methods: The physicochemical properties evaluated were pH, surface tension, free available chlorine (FAC) and contact angle. Cytotoxicity was evaluated in L929 fibroblasts exposed to the solutions by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and neutral red assays. Assessment of penetration into dentinal tubules was performed by staining single-rooted permanent human teeth with crystal violet (n = 9), which were irrigated with the solutions and analyzed in cervical, middle and apical segments. Data were analyzed by one-way analysis of variance (ANOVA) and Tukey's post-test, 2-way ANOVA and Bonferroni's post-test or t-test (α = 0.05). Results: ChlorCid^TM Surf and ChlorCid^TM FAC values were close to those indicated by the manufacturer. ChlorCid^TM Surf showed lower surface tension and contact angle on dentin, and higher pH than ChlorCid^TM (p < 0.05). The penetration of ChlorCid^TM Surf was higher in cervical and middle segments, compared with ChlorCid^TM (p < 0.05). There was no difference in irrigant cytotoxicity (p > 0.05). Conclusions: ChlorCid^TM Surf showed lower surface tension, lower contact angle on root canal dentin, higher penetration into dentinal tubules and more alkaline pH, compared with ChlorCid^TM. However, both solutions showed similar cytotoxicity and FAC content.

• 한국식품영양학회지
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• 제29권5호
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• pp.706-715
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• 2016

Nutritional composition and physicochemical properties changes in mustard leaf kimchi were investigated during fermentation of up to 3 months. The pH decreased, and the titratable acidity gradually increased according to increase of fermentation periods. Fructose and glucose were the major free sugars in mustard leaf kimchi, and their amounts were significantly decreased with fermentation periods (p<0.05). Lactic acid content showed a significant increase with maximum increase at 3 months. All types of kimchi contained 20 amino acids, but the content of most amino acid fluctuated during fermentation. Except for K and Zn, the content of other ingredients including Ca, Fe, Mg, Na, Se were the highest in kimchi fermented for 2 months. The unsaturated fatty acid of mustard leaf kimchi was higher than that of saturated fatty acid, and total fatty acid of kimchi significantly decreased after 2 months (p<0.05). Most vitamin contents showed a tendency to decrease with fermentation, in particular, vitamin B complex except for $B_2$ significantly decreased after 3 months (p<0.05). The results provide fundamental data for determining the appropriate fermentation period to improve the quality of kimchi.

• Safety and Health at Work
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• 제10권4호
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• pp.437-444
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• 2019

Background: Headache/eyestrain symptoms are common health problems that people experience in daily life. Various studies have examined risk factors contributing to headache/eyestrains, and physicochemical exposure was found to be a leading risk factor in causing such symptoms. The purpose of this study was to examine the relationship of headache/eyestrain symptoms with physicochemical exposure among Korean construction workers depended on worksite. Methods: This study used data from the 4th Korean Workers Conditions Survey and selected 1,945 Korean construction workers as participants. Multivariable logistic regression analysis was used to determine the relationship. Results: Exposure to vibrations among all construction workers affected the moderate exposure group [odds ratio (OR) 1.53, 95% confidence interval (CI) 1.01-2.32], the high exposure group (OR 1.77 95%CI 1.17-2.67), and the indoor high exposure group (OR 1.61, 95%CI 1.02-2.55) and among outdoor construction workers, the moderate group (OR 6.61, 95%CI 15.4-28.48) and the high group (OR 6.61, 95%CI 1.56-27.98). When exposed to mist, dust, and fumes, the indoor high exposure group was significantly affected (OR 1.63, 95%CI 1.07-2.47). All construction workers exposed to organic solvents were affected, high exposure group (OR 1.69, 95%CI 1.15-2.49) and indoor high exposure group (OR 1.77, 95%CI 1.08-2.89). The high exposure group in all construction worker (OR 1.70, 95%CI 1.20-2.42) and the indoor high exposure group (OR 1.83, 95%CI 1.17-2.89) also were affected by secondhand smoking exposure. Conclusion: Many physicochemical exposure factors affect headache/eyestrain symptoms among construction workers, especially indoor construction workers, suggesting a deficiency in occupational hygiene and health environments at indoor construction worksites.

• 한국환경복원기술학회지
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• 제11권5호
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• pp.60-71
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• 2008

Through analyzing the specific physicochemical alterations in depth-based soil at reclaimed dredging area, the baseline data were provided for developing the reclaimed dredging area as natural landscape planting sites and ecological-landscape sites based on the soil improvement technology. There was no physical disturbance for 15 to 20 years in Gwangyang Bay reclaimed dredging area after reclamation. Physicochemical examinations of the soil were performed based on the vertical depth. Results of physicochemical analysis such as pH, electric conductivity, total salt contents, silt, clay contents, available phosphorus, calcium, magnesium, sodium, chlorine, and sodium-adsorption ratio showed increasing patterns with the depth while total organic contents, total nitrogen, and sand showed decreasing patterns. Potassium as an exchangeable cation, showed similar distribution patterns between the shallow and deep soil. This result strongly implied that long-term exposure to natural rainfall in reclaimed dredging area altered soil characteristics related to salinity. This research demonstrated that there were no remarkable differences in physicochemical characteristics at soil depth and groundwater table height, suggesting a baseline data for developing reclaimed dredging area. Additional investigation is required for different reclaimed dredging areas. Also, additional monitoring and examination are need on plant communities and time variable alteration in the soil to test the feasibility of reclaimed dredging areas as natural landscape planting sites and ecological-landscape sites.

• Preventive Nutrition and Food Science
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• 제15권3호
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• pp.221-228
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• 2010

The objective of this research was to investigate the changes in the contents of physicochemical properties including $\gamma$-aminobutyric acid (GABA), total dietary fiber (TDF), amylose, protein, and fat content in brown rice through germination for 2 different years. Total phenolic contents and antioxidant activities of DPPH and ABTS radical scavenging capacities were also determined in different solvent extracts. For the physicochemical properties, GABA, TDF, protein, and fat content increased, whereas amylose levels decreased. Specially, GABA and TDF levels showed the greatest variations among cultivars and harvest years. Total phenolic content and antioxidant activity significantly increased. The average total phenolic content at a concentration of 0.5 mg/mL in different extract solvents occurred in this order: methanol>ethylacetate>chloroform>hexane extracts. Additionally, 'Keunnun' exhibited the highest GABA levels, highest total phenolic content, and highest antioxidant activity after germination, with increases of approximately 3.7, 2.0, and 1.9 times, respectively, compared to levels before germination. These results suggest that, because of its high physicochemical contents and strong radical scavenging activities, germinated brown rice can be used as beneficial supplement.

• Journal of Microbiology and Biotechnology
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• 제27권11호
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• pp.2019-2027
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• 2017

Recently, cabbage kimchi has occasionally been associated with the foodborne diseases of enteric viruses such as human norovirus (HuNoV). This study aimed to evaluate the correlation between microbial/physicochemical properties and persistence of HuNoV in experimentally contaminated cabbage kimchi fermented and stored at $4^{\circ}C$ or $10^{\circ}C$ for 28 days. Changes in organic acid content, lactic acid bacteria (LAB), acidity, pH, and salinity were analyzed. The recovery of structurally intact HuNoV was examined for up to 28 days post-inoculation, using a NoV GII.4 monoclonal antibody-conjugated immuno-magnetic separation method combined with quantitative real-time reverse transcription polymerase chain reaction. On day 0, LAB loads were $4.70log_{10}$ colony forming units/g and HuNoV GII.4 titers were $2.57log_{10}\;genomic\;copies/{\mu}l$, at both temperatures. After 28 days, intact HuNoV titers decreased to 1.58 ($4^{\circ}C$) and $1.04(10^{\circ}C)log_{10}\;genomic\;copies/{\mu}l$, whereas the LAB density increased. This correlated with a gradual increase in lactic acid and acetic acid at both temperatures. Our findings support a statistical correlation between changes in physicochemical properties and the recovery of structurally intact HuNoV GII.4. Moreover, we determined that the production of organic acid and low pH could affect HuNoV GII.4 titers in cabbage kimchi during fermentation. However, HuNoV GII.4 was not completely eliminated by microbial/physicochemical factors during fermentation, although HuNoV GII.4 was reduced. Based on this, we speculate that the persistence of HuNoV GII.4 may be affected by the continually changing conditions during kimchi fermentation.

• Asian-Australasian Journal of Animal Sciences
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• 제28권7호
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• pp.1028-1037
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• 2015

Unique organoleptic characteristics such as rich flavors and chewy texture contribute to the higher popularity of native chicken in many Asian areas, while the commercial broilers are well-accepted due to their fast-growing and higher yields of meat. Sensory attributes of foods are often used to evaluate food eating quality and serve as references during the selection of foods. In this study, a three-phase descriptive sensory study was conducted to evaluate the sensory attributes of commercial broiler (BR) and Taiwan native chicken (TNC) breast meat, and investigate correlations between these sensory attributes and instrumental measurements. The results showed that for the first bite (phase 1), TNC meat had significantly higher moisture release, hardness, springiness, and cohesiveness than BR meat. After chewing for 10 to 12 bites (phase 2), TNC meat presented significantly higher chewdown hardness and meat particle size, whereas BR meat had significantly higher cohesiveness of mass. After swallowing (phase 3), TNC meat had higher chewiness and oily mouthcoat and lower residual loose particles than BR meat. TNC meat also provided more intense chicken flavors. This study clearly demonstrates that descriptive sensory analysis provides more detailed and more objectively information about the sensory attributes of meats from various chicken breeds. Additionally, sensory textural attributes vary between BR and TNC meat, and are highly correlated to the shear force value and collagen content which influence meat eating qualities greatly. The poultry industry and scientists should be able to recognize the sensory characteristics of different chicken meats more clearly. Accordingly, based on the meat's unique sensory and physicochemical characteristics, future work might address how meat from various breeds could best satisfy consumer needs using various cooking methods.

• Journal of Microbiology and Biotechnology
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• 제28권9호
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• pp.1517-1526
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• 2018

Investigating bacterial diversity and its metabolic capabilities is crucial for interpreting the ecological patterns in a desert environment and assessing the presence of exploitable microbial resources. In this study, we evaluated the spatial heterogeneity of physicochemical parameters, soil bacterial diversity and metabolic adaptation at meter scale. Soil samples were collected from two quadrats of a desert (Thar Desert, India) with a hot, arid climate, very little rainfall and extreme temperatures. Analysis of physico-chemical parameters and subsequent variance analysis (p-values < 0.05) revealed that sulfate, potassium and magnesium ions were the most variable between the quadrats. Microbial diversity of the two quadrats was studied using Illumina bar-coded sequencing by targeting V3-V4 regions of 16S rDNA. As for the results, 702504 high-quality sequence reads, assigned to 173 operational taxonomic units (OTUs) at species level, were examined. The most abundant phyla in both quadrats were Actinobacteria (38.72%), Proteobacteria (32.94%), and Acidobacteria (9.24%). At genus level, Gaiella represented highest prevalence, followed by Streptomyces, Solirubrobacter, Aciditerrimonas, Geminicoccus, Geodermatophilus, Microvirga, and Rubrobacter. Between the quadrats, significant difference (p-values < 0.05) was found in the abundance of Aciditerrimonas, Geodermatophilus, Geminicoccus, Ilumatobacter, Marmoricola, Nakamurella, and Solirubrobacter. Metabolic functional mapping revealed diverse biological activities, and was significantly correlated with physicochemical parameters. The results revealed spatial variation of ions, microbial abundance and functional attributes in the studied quadrats, and patchy nature in local scale. Interestingly, abundance of the biotechnologically important phylum Actinobacteria, with large proposition of unclassified species in the desert, suggested that this arid environment is a promising site for bioprospection.

• 산업식품공학
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• 제23권3호
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• pp.186-192
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• 2019

본 연구는 팽화스낵에 기능성 및 영양적으로 뛰어난 인삼의 활용도를 높이고자 각 조건별로 팽화스낵을 제조해 품질특성을 조사하였다. 수분함량(1, 4, 7, 10%)을 달리하여 pellet을 제조하고, 백미와 혼합한 뒤 팽화온도(180-220℃)를 달리하여 스낵을 제조하였다. 팽화스낵 제조 시, pellet의 수분함량과 팽화온도가 낮을수록 팽화가 잘 일어나지 않아 딱딱한 질감과 온전하지 않은 모양으로 제조되었다. 색도에서는 pellet의 수분함량과 팽화온도가 높을수록 명도, 적색도, 비체적은 증가하는 경향을 나타내었지만, 조직감에서는 감소하였다. 이에 따라 인삼을 이용한 팽화스낵 제조 시에는 적절한 수분함량과 팽화온도가 필요할 것으로 생각된다.