• Journal of Industrial Convergence
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• v.21 no.1
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• pp.137-145
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• 2023

The purpose of this study was to find the effects of ethical awareness about pandemic and health beliefs of standard precaution on performance standard precaution of nursing students. The survey was performed on 163 nursing students in three universities. Data were collected using a structured questionnaires and analyzed using t-test, ANOVA, Pearson correlation coefficient, and multiple regression with SPSS 25.0 program. Study findings revealed that performance standard precautions was significantly correlated with ethical awareness about pandemic(r=.17, p=.033), perceived susceptibility(r=.33, p<.001), perceived severity (r=.24, p=.003), perceived benefits(r=.35, p<.001) and perceived obstruction(r=-.31, p<.001). The factors that had the influences on performance standard precaution were the perceived benefits(β=.20, p=.014)) and perceived obstruction(β=-.20, p=.008). And the explanation power of the regression model appeared as being 18.1%(F=8.09, p<.001). It is necessary to develop a systematic infection education program that considers ethical awareness, and perceived severity and obstruction among health beliefs of standard precaution to improve performance standard precaution of nursing students.

• Journal of the Korean Society of Food Culture
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• v.24 no.1
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• pp.69-76
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• 2009

This study was conducted to determine the optimal cooking conditions for brown rice using an electric pressure rice cooker. The effects of steeping conditions and cooking pressure on the hydration, gelatinization, texture and palatable properties of cooked brown rice were evaluated. Based on water uptake and DSC data, the optimal steeping time and temperature for brown rice were determined to be 25 minutes and ${\sim}60^{\circ}C$, respectively. The cooking conditions for brown rice were then divided into the following 6 categories: steeping at $25^{\circ}C$ for 25 minutes and cooking at an atmospheric pressure of 1.7 (25P) or 1.9 (25HP), steeping at $57^{\circ}C$ for 25 minutes and cooking at an atmospheric pressure of 1.7 (57P) or 1.9 (57HP), steeping at $85^{\circ}C$ for 15 minutes and cooking at an atmospheric pressure of 1.7 (85P) or 1.9 (85HP). The susceptibility of cooked brown rice starch to degradation into maltose by ${\alpha}$-amylase, which is related to the degree of gelatinization and in vitro digestibility, were then determined. The amount of maltose produced by cooked brown rice samples was highest in the 57HP group, followed by the 57P and 85HP groups. Storing cooked brown rice at $73^{\circ}C$ for 24 hours resulted in significantly higher amounts of starch being degraded into maltose in the 57P, 57HP and 85HP groups than in the other groups. Textural analysis demonstrated that the 57P, 57HP and 85HP groups had significantly lower gumminess and chewiness values when compared to the other groups, and that 57HP received had the lowest hardness of all treatments. These results were confirmed by the results of the sensory evaluations. Furthermore, the 57P and 57HP groups were found to have a higher glossiness, stickiness aroma and taste score than the other groups. These findings were taken to indicate that steeping conditions and pressure exerted a positive synergistic effect on the cooking quality of brown rice. The texture analyzer also revealed that storing the cooked rice at $73^{\circ}C$ for 24 hours only led to significantly lower scores in gumminess, hardness and chewiness in the 57P and 57HP groups, which indicates that these groups underwent a lesser degree of retrogradation than other groups. Taken together, the results of the present study demonstrate that steeping brown rice at $57^{\circ}C$ for 25 minutes and a higher cooking pressure improved the palatability and in vitro digestibility of brown rice significantly.

• Journal of Nutrition and Health
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• v.56 no.5
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• pp.469-482
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• 2023

Purpose: Obesity has emerged as a critical global public health concern as it is associated with and increases susceptibility to various diseases. This condition is characterized by the excessive enlargement of adipose tissue, primarily stemming from an inequity between energy intake and expenditure. The purpose of this study was to investigate the potential of sweet pumpkin powder in mitigating obesity and metabolic disorders in leptin-deficient obese (ob/ob) mice and to compare the effects of raw sweet pumpkin powder (HNSP01) and heat-treated sweet pumpkin powder (HNSP02). Methods: Leptin-deficient obese mice were fed a diet containing 10% HNSP01 and another containing 10% HNSP02 for 6 weeks. Results: The supplementation of ob/ob mice with HNSP01 and HNSP02 resulted in decreased body weight gain, reduced adipose tissue weight, and a smaller size of lipid droplets in the adipose tissue and liver. Furthermore, the ob/ob-HNSP01 and ob/ob-HNSP02 supplemented groups exhibited lower levels of triglycerides, total cholesterol, low-density lipoprotein cholesterol, fasting blood glucose, and insulin, as well as a reduced atherogenic index in comparison with the control group. Molecular analysis also demonstrated that the intake of HNSP01 and HNSP02 resulted in a diminished activation of factors associated with fatty acid synthesis, including acetyl-CoA carboxylase and fatty acid synthase, while concurrently enhancing factors associated with lipolysis, including adipose triglyceride lipase and hormone-sensitive lipase, in the adipose tissue. Conclusion: Taken together, these findings collectively demonstrate the potential of sweet pumpkin powder as a functional food ingredient with therapeutic properties against obesity and its associated metabolic disorders, such as insulin resistance and dyslipidemia.

• BMB Reports
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• v.57 no.1
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• pp.60-65
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• 2024

The CRISPR-Cas9 system has significantly advanced regenerative medicine research by enabling genome editing in stem cells. Due to their desirable properties, mesenchymal stem cells (MSCs) have recently emerged as highly promising therapeutic agents, which properties include differentiation ability and cytokine production. While CRISPR-Cas9 technology is applied to develop MSC-based therapeutics, MSCs exhibit inefficient genome editing, and susceptibility to plasmid DNA. In this study, we compared and optimized plasmid DNA and RNP approaches for efficient genome engineering in MSCs. The RNP-mediated approach enabled genome editing with high indel frequency and low cytotoxicity in MSCs. By utilizing Cas9 RNPs, we successfully generated B2M-knockout MSCs, which reduced T-cell differentiation, and improved MSC survival. Furthermore, this approach enhanced the immunomodulatory effect of IFN-r priming. These findings indicate that the RNP-mediated engineering of MSC genomes can achieve high efficiency, and engineered MSCs offer potential as a promising therapeutic strategy.

• Biomolecules & Therapeutics
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• v.32 no.4
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• pp.481-491
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• 2024

Paxlovid is the first approved oral treatment for coronavirus disease 2019 and includes nirmatrelvir, a protease inhibitor targeting the main protease (M^pro) of SARS-CoV-2, as one of the key components. While some specific mutations emerged in M^pro were revealed to significantly reduce viral susceptibility to nirmatrelvir in vitro, there is no report regarding resistance to nirmatrelvir in patients and animal models for SARS-CoV-2 infection yet. We recently developed xenograft tumors derived from Calu-3 cells in immunodeficient mice and demonstrated extended replication of SARS-CoV-2 in the tumors. In this study, we investigated the effect of nirmatrelvir administration on SARS-CoV-2 replication. Treatment with nirmatrelvir after virus infection significantly reduced the replication of the parental SARS-CoV-2 and SARS-CoV-2 Omicron at 5 days post-infection (dpi). However, the virus titers were completely recovered at the time points of 15 and 30 dpi. The virus genomes in the tumors at 30 dpi were analyzed to investigate whether nirmatrelvir-resistant mutant viruses had emerged during the extended replication of SARS-CoV-2. Various mutations in several genes including ORF1ab, ORF3a, ORF7a, ORF7b, ORF8, and N occurred in the SARS-CoV-2 genome; however, no mutations were induced in the M^pro sequence by a single round of nirmatrelvir treatment, and none were observed even after two rounds of treatment. The parental SARS-CoV-2 and its sublineage isolates showed similar IC₅₀ values of nirmatrelvir in Vero E6 cells. Therefore, it is probable that inducing viral resistance to nirmatrelvir in vivo is challenging differently from in vitro passage.

• Journal of Food Hygiene and Safety
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• v.39 no.1
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• pp.1-8
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• 2024

Salmonella is widely prevalent in various environments and often detected in poultry. In this study, we investigated the effect of heat treatment on heat resistance via measuring the minimum inhibitory concentration (MIC) values of antibiotics after 3, 6, and 9 min of acclimatization to mild heat treatment (50℃) against 11 strains of Salmonella spp. Most strains were susceptible to chloramphenicol and their MIC values were maintained or decreased after heat treatment compared to the control. Most control and heat-treated strains showed susceptibility or intermediate resistance to ciprofloxacin. All isolates were susceptible to tetracycline, with the MIC increasing after heat treatment for S. Gaminara BAA 711. In the control, three, two, and six strains were susceptible, intermediate resistance, and resistant to gentamicin, respectively. Among them, S. Heidelberg ATCC 8326 had an intermediate MIC breakpoint of 8 ㎍/mL in the control; however, after 3 and 9 min of heat treatment, the MIC value increased to 16 ㎍/mL, indicating it to be resistant. The results of this study revealed the changes in antibiotic resistance in some of the 11 strains after heat treatment. MIC values of ciprofloxacin increased when S. Montevideo BAA 710 was heat treated for 3 and 6 min. MIC values of gentamicin increased after 3 min of heat treatment for S. Enteritidis 109 D1 and after 3 and 9 minutes of heat treatment for S. Heidelberg ATCC 8326. The MIC value of tetracycline increased when S. Gaminara BAA 711 was heat treated for 6 and 9 min.

• Steel and Composite Structures
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• v.50 no.6
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• pp.705-720
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• 2024

Analyzing the collapse behavior of thin-walled steel structures holds significant importance in ensuring their safety and longevity. Geometric imperfections present on the surface of metal materials can diminish both the durability and mechanical integrity of steel shells. These imperfections, encompassing local geometric irregularities and deformations such as holes, cavities, notches, and cracks localized in specific regions of the shell surface, play a pivotal role in the assessment. They can induce stress concentration within the structure, thereby influencing its susceptibility to buckling. The intricate relationship between the buckling behavior of these structures and such imperfections is multifaceted, contingent upon a variety of factors. The buckling analysis of thin-walled steel shell structures, similar to other steel structures, commonly involves the determination of crucial material properties, including elastic modulus, shear modulus, tensile strength, and fracture toughness. An established method involves the emulation of distributed geometric imperfections, utilizing real test specimen data as a basis. This approach allows for the accurate representation and assessment of the diversity and distribution of imperfections encountered in real-world scenarios. Utilizing defect data obtained from actual test samples enhances the model's realism and applicability. The sizes and configurations of these defects are employed as inputs in the modeling process, aiding in the prediction of structural behavior. It's worth noting that there is a dearth of experimental studies addressing the influence of geometric defects on the buckling behavior of cylindrical steel shells. In this particular study, samples featuring geometric imperfections were subjected to experimental buckling tests. These same samples were also modeled using Finite Element Analysis (FEM), with results corroborating the experimental findings. Furthermore, the initial geometrical imperfections were measured using digital image correlation (DIC) techniques. In this way, the response of the test specimens can be estimated accurately by applying the initial imperfections to FE models. After validation of the test results with FEA, a numerical parametric study was conducted to develop more generalized design recommendations for the stainless-steel shell structures with the initial geometric imperfection. While the load-carrying capacity of samples with perfect surfaces was up to 140 kN, the load-carrying capacity of samples with 4 mm defects was around 130 kN. Likewise, while the load carrying capacity of samples with 10 mm defects was around 125 kN, the load carrying capacity of samples with 14 mm defects was measured around 120 kN.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.12
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• pp.1781-1786
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• 2011

This study was conducted to investigate the cause of microbiological contamination in yogurt and evaluate the effect of physicochemical treatment on the growth inhibition of Hanseniaspora uvarum isolated from yogurt. The yeast strain Hanseniaspora uvarum Y1 was subjected to heat and pH treatments. H. uvarum Y1 was killed at $70^{\circ}C$ and $80^{\circ}C$ after 15 min and survived in a wide pH range from pH 2 to 9. However, it did not survive under pH 1 and over pH 10. In a disk diffusion susceptibility test on H. uvarum Y1, a clear zone (5 mm) of growth inhibition was observed upon treatment with electrolyzed water. The effect of ozone gas on the growth of H. uvarum Y1 was evaluated by viable cell count. Initial cell numbers of $10^2$ and $10^3$ CFU/mL of H. uvarum Y1 were completely killed by treatment for 10 and 30 min, respectively. H. uvarum Y1 was also sterilized by microwave treatment for 1 min. When treated with gamma-irradiation, the rate of killing of H. uvarum Y1 was proportional to the irradiation dose. and complete killing occurred at a dose of 50 kGy.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.363-370
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• 2013

Susceptibility of each developmental stage of Phthorimaea operculella (Lepidoptera: Gelechiidae) were investigated using 16 insecticides which are available in the market in Korea. For the eggs and pupae, only spinosad showed a 71.1% inhibition rate for egg hatchability and a 66.7% inhibition rate for emergence. For the 3rd instar larvae, the feeding toxicities were over 90% for fenitrothion ($LC_{50}$ 336.6 ppm), esfenvalerate ($LC_{50}$ 8.6 ppm), ethofenprox ($LC_{50}$ 35.7 ppm), and emamectin benzoate ($LC_{50}$ 0.05 ppm). Furthermore, the contact toxicities were over 90% for esfenvalerate ($LC_{50}$ 0.87 ppm), ethofenprox ($LC_{50}$ 16.5 ppm), emamectin benzoate ($LC_{50}$ 0.53 ppm), and spinosad ($LC_{50}$ 2.48 ppm) at the recommended concentrations. Deltamethrin and spinosad yielded 100% mortality for adult P. operculella 48 h after treatment. The adult female fecundity was inhibited by deltamethrin, esfenvalerate, emamectin benzoate, spinosad and dinotefuran, which were significantly different from the control. The adult longevities (7.3-8.3 days) were reduced by approximately 1-2 days compared with the control (9.3 day). The emamectin benzoate maintained 100% insecticidal activity 14 days after treatment and ethofenprox maintained over 90% activity 7 days after treatment.

• Clinical and Experimental Pediatrics
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• v.46 no.2
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• pp.143-153
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• 2003

Purpose : Infection with Shiga-like toxin (SLT)-producing Escherichia coli, an emerging human pathogen found particularly in young children under 5 years of age, causes a spectrum of illnesses with high morbidity and mortality, ranging from diarrhea to hemorrhagic colitis and hemolytic uremic syndrome. Host mediators play an important role in the pathogenesis of SLT-I toxicity. The experiments described here were designed to investigate the effect of SLT-I on TNF-${\alpha}$ production and to understand the effect of TNF-${\alpha}$ on GB3 expression. We also further examine the relationship between the Gb3 level and the differential susceptibility of cells to the cytotoxic action of SLT-I. Methods : The effect of purified SLT-1 from E. coli O157 : H7 (ATCC 43890) on tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) production in Raw264.7 cells was investigated. Many mediators regulate endothelial cell membrane expression of the glycolipid globotriaosyleramide (Gb3), which serves as the toxin receptor, suggesting that the host response to the toxin or other bacterial products may contribute to pathogenesis by regulating target cell sensitivity to the toxins. Therefore, the relationships between Gb3 expression and cytotoxicity against SLT-I on three types of cells were evaluated. Results : Detectable levels of TNF-${\alpha}$ were produced as early as six hours after induction and continued to increase during 48 hours by SLT-I. It was also found that Vero cells and dendritic cells (DC2.4 cells) expressed high levels of Gb3, 83% and 68%, respectively, and that Raw264.7 cells had a low level of Gb3 (29%) and appeared refractory to cytotoxicity against SLT-I. Vero cells and DC2.4 cells expressing high levels of Gb3 were highly susceptible to SLT-I. Furthermore, macrophages showed a resistance to SLT-I cytotoxicity, despite the fact that Gb3 expression was enhanced. Conclusion : These results strongly suggest that the expression of Gb3 is necessary but not sufficient to confer sensitivity of macrophages to SLT-I and further underpin the important role of SLT-I and its Gb3 receptors in the pathogenesis of E. coli O157 infection.