• Archives of Plastic Surgery
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• v.49 no.2
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• pp.258-265
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• 2022

Background Chitosan (CS) is a well-known antimicrobial dressing material. Moreover, widely used amniotic membranes contain growth factors beneficial for wound healing. Herein, we created a novel amnion-conjugated CS-alginate membrane dressing and tested its wound healing potency in a diabetic swine model. Methods The bovine amniotic powder growth factor contents were evaluated by protein assay, and the powder's wound healing effects were assessed in vitro by HaCaT cell scratch closure. In vivo, two minipigs developed streptozotocin-induced diabetes. Serial serum glucose measurements and intravenous glucose tolerance tests were performed to confirm their diabetic status. Twelve square-shaped wounds created on each pig's back were randomly divided into control (n = 4), CS (n = 4), and amnion-CS (AC; n = 4) groups and treated accordingly with different dressings. Wound healing in each group was assessed by measuring wound contraction over time, capturing wound perfusion with indocyanine green (ICG) angiography, and histologically analyzing inflammatory markers. Results Amniotic powder elution promoted HaCaT cell migration in the scratch wound model, suggesting its beneficial in vitro wound healing effects. In vivo, the CS and AC groups showed earlier wound contraction initiation and reepithelialization and earlier wound perfusion improvement by ICG angiography than the control group. Additionally, the wound size of the AC group at week 3 was significantly smaller than those in the control group. There was no significant difference in the numbers of acute and chronic inflammatory cells between the groups. Conclusion The amnion-conjugated CS-alginate membrane, as well as CS dressing alone, could be a favorable dressing option for diabetic wounds.

• Composites Research
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• v.20 no.5
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• pp.56-63
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• 2007

An approach using complex potentials is presented for analysis of composite plate with an elliptical hole or a rectilinear crack. Composite structure is susceptible to encounter impact damages, which lead to considerable decrease in its residual strength. Such impact damages could be modeled as an equivalent elliptical hole or notch-like crack. Even though finite element method is widely used to analyze stresses or fracture mechanics parameters around such damage, it is tedious to make successive FE-modeling for damage tolerance assessment under fatigue loadings. In this point of view, the solutions based on complex potentials are very simple and easy to use. The computed results are also compared and discussed with those from FEA.

• Transactions of Materials Processing
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• v.32 no.6
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• pp.311-320
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• 2023

Recently, lightweight of automotive parts has been required to solve environmental problems caused by global warming. Accordingly, research and development are proceeded on manufacturing of parts using aluminum that can replace steel for lightweight of the automotive parts. In addition, high strength aluminum can be applied to body parts in order to meet both requirements of lightening and improving crash safety of vehicle. In this study, hot blow forming of roof side rail is employed to manufacturing of the automotive parts with high strength aluminum tube. In hot blow forming, longer forming times and excessive thinning can be occurred as compared with conventional manufacturing processes. So optimization of process conditions is required to prevent excessive thinning and to uniformize thickness distribution with fast forming time. Mechanical properties of high strength aluminum are obtained from tensile test at high temperature. These properties are used for finite element(FE) analysis to investigate the effect of strain rate on thinning and thickness distribution. Variation of thickness was firstly investigated from the result of FE analysis according to tube diameter, where the shapes at cross section of roof side rail are compared with allowable dimensional tolerance. Effective tube diameter is determined when fracture and wrinkle are not occurred during hot blow forming. Also FE analysis with various pressure-time profiles is performed to investigate the their effects on thinning and thickness distribution which is quantitatively verified with thinning factor. As a results, optimal process conditions can be determined for the manufacturing of roof side rail using high strength aluminum.

• Anatomy and Cell Biology
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• v.56 no.4
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• pp.552-561
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• 2023

The endocrinology of type 2 diabetes (T2D) and its predisposing factors have been studied extensively while its skeletal effects have received negligible research despite this being a global disease. The cellular and molecular association between proximal humeral fractures and T2D has not been fully elucidated. We aimed to study bone cell quantities and immunolabel osteogenic and antiosteogenic cytokines. The study used 12-week-old rats (23 males) consisting of 8 Sprague Dawley (SD) and 15 Zucker Diabetic Sprague Dawley (ZDSD). Weekly mass measurements were taken while fasting blood glucose levels were recorded every 2 weeks with oral glucose tolerance tests conducted once every 4 weeks. Upon termination at the age of 28 weeks, humeri were fixed in 10% buffered formalin, prior to decalcification in ethylenediaminetetraacetic acid. The bone samples were then processed in ascending grades of alcohol using an automatic processor before embedding in paraffin wax. Sections were cut at 5 ㎛ thickness in a series for Haematoxylin and Eosin stain, and immunohistochemistry was performed with the anti-tartrate-resistant acid phosphatase (TRAP), anti-alkaline phosphatase (ALP), anti-bone morphogenetic protein 3 (BMP3), anti-transforming growth factor beta 1 (TGFβ1), anti-aged glycation end product (AGE) antibodies in the sequence. ZDSD rats had more adipocytes, BMP3 and AGEs expression with higher numbers of TRAP positive osteocytes and fewer ALP cells although no differences were found in TGFβ1 immunopositivity. We also found that T2D increases the number of AGEs immuno-positive cells, as well as its extracellular expression, thus providing a conducive environment for the interaction of the osteogenic cytokine and its antagonist to suppress osteoblastogenesis. ZDSD groups had higher adipocyte numbers therefore increased marrow adiposity in T2D.

• Journal of Microbiology and Biotechnology
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• v.34 no.4
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• pp.871-879
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• 2024

Our group had isolated Bifidobacterium breve strain BS2-PB3 from human breast milk. In this study, we sequenced the whole genome of B. breve BS2-PB3, and with a focus on its safety profile, various probiotic characteristics (presence of antibiotic resistance genes, virulence factors, and mobile elements) were then determined through bioinformatic analyses. The antibiotic resistance profile of B. breve BS2-PB3 was also evaluated. The whole genome of B. breve BS2-PB3 consisted of 2,268,931 base pairs with a G-C content of 58.89% and 2,108 coding regions. The average nucleotide identity and whole-genome phylogenetic analyses supported the classification of B. breve BS2-PB3. According to our in silico assessment, B. breve BS2-PB3 possesses antioxidant and immunomodulation properties in addition to various genes related to the probiotic properties of heat, cold, and acid stress, bile tolerance, and adhesion. Antibiotic susceptibility was evaluated using the Kirby-Bauer disk-diffusion test, in which the minimum inhibitory concentrations for selected antibiotics were subsequently tested using the Epsilometer test. B. breve BS2-PB3 only exhibited selected resistance phenotypes, i.e., to mupirocin (minimum inhibitory concentration/MIC >1,024 ㎍/ml), sulfamethoxazole (MIC>1,024 ㎍/ml), and oxacillin (MIC >3 ㎍/ml). The resistance genes against those antibiotics, i.e., ileS, mupB, sul4, mecC and ramA, were detected within its genome as well. While no virulence factor was detected, four insertion sequences were identified within the genome but were located away from the identified antibiotic resistance genes. In conclusion, B. breve BS2-PB3 demonstrated a sufficient safety profile, making it a promising candidate for further development as a potential functional food.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.5
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• pp.53-68
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• 2014

This study is aimed at analyzing the factors that affect the behaviors of employee's investment, such as a decision making process in a variety of views and proving the extent of how those factors influence on their investment. The basic assumption is that the preceding factors that can be determined by the personal investment propensity, a psychological factor asserted by Behavior Financial Theory and financial-economic and social environment. This study uses Hershey's Investment Behavior Model(2007) as the main analysis tool to explain the investment behavior of individuals and deals with personal investment inclination in the psychological perspective of overconfidence, self-control and the risk tolerance propensity and add the financial and economic factors in terms of financial literacy and economic distress. Also the new preceding social environmental factors like social interaction and the effect of reference group are added to make this research to be more precise. This study analyze the adjustment effect of professional invest-consulting service that affect the fluctuation influence between the individual variables(those factors) and subordination variable(the level of investment satisfaction). The study reveals that overconfidence and self-control in direct ways have a positive effect on the level of investment satisfaction in terms of investment behavior and economic distress has a negative effect on the level of investment satisfaction. The adjustment effect provided by financial experts in investment consulting service is affirmed as the critical factor that increase the influence between self-control and the level of investment satisfaction. To conclude, the research reveals that the psychological factors are the main criteria when the workers as employees have to make investment decisions. To make investors be reasonable, a systematic financial education system provided by experts is needed from the early adolescent stages and financial companies should develop the relevant services of consulting service department as a key financial sector and financial investment products and consulting program and marketing tool pertinent to investors ages, vocational traits and their inclinations.

• Management & Information Systems Review
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• v.35 no.4
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• pp.99-122
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• 2016

The social networking services (SNSs) have become popular among smartphone users, and one of the most popular services. In order to explain users' motivations toward SNS, this study considers uses and gratification theory which can explain individuals' motivations to select certain media channels. The purposes of this study is to investigate the relationships between motivations and addiction of SNS, and between addiction of SNS and decline in the subjective wellbeing. We examine moderating effects of social tie based on the social capital theory in the relationships between SNS addiction and decline in the subjective wellbeing. The motivations of SNS are subdivided into emotional motive (entertainment and fantasy) and cognitive motive (information share burden and challenge burden) based on the use and gratifications theory. The addiction of SNS is subdivided into time tolerance, withdrawal symptoms, interruption, and barrier of living. The data used in this study were collected from 286 SNS users through surveys. The data analysis in this study was performed using AMOS 17.0, and we used SEM(Structural Equation Modeling) methods in order to test the research model. The result shows that the emotional motive(entertainment and fantasy) and cognitive motive(information share burden and challenge burden) have an effect on the addiction of SNS. Especially emotional motive such as entertainment and users' fantasy toward SNS is an important factor that can cause SNS addiction. The addiction of SNS such as time tolerance, withdrawal symptoms, interruption, and barrier of living has an effect on the decline in the subjective wellbeing. Our result show that social tie partially moderates the relationship SNS addiction and decline in the subjective wellbeing. In addition, social tie between interruption of SNS and decline in the subjective wellbeing is an important moderating factor. The results focuses on the understanding toward relationship between SNS addiction based on the online and decline in the subjective wellbeing in the real world. The findings of this study also provides theoretical as well as practical implications which reflect the major features of SNS, and moderating effects of social tie based on the social capital.

• Journal of Aquaculture
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• v.21 no.4
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• pp.265-271
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• 2008

Upper temperature tolerance of the turbot Scophthalmus maxim us, one of the popular aquaculture species in European community and China, was evaluated in terms of survival and growth at $20^{\circ}C$, $23^{\circ}C$, $26^{\circ}C$, or $29^{\circ}C$. Best growth was achieved at temperature $20^{\circ}C$ in this experiments. The fish exposed to $20^{\circ}C$ or $23^{\circ}C$ were comparable in survival, condition factor and feed conversion efficiency reminiscent of the latter temperature to be agreeable for the fish. The temperature over $23^{\circ}C$ appeared to be the temperatures beyond the fish can tolerate. For instance, the fish exposed to 26 showed mortality of 60.9% by day 60; none of the fish exposed to $29^{\circ}C$ survived beyond day 7. Culture densities between 80 and $200\;fish/m^2$ did not influence the survival, growth, condition factor and specific growth rate of the fish. The final production of the culture density experiment was $10\;kg/m^2$ on average. These results imply that the location where water temperature remains lower than $25^{\circ}C$ during summer can be a candidate site for the turbot aquaculture.

• Clinical and Experimental Pediatrics
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• v.48 no.11
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• pp.1239-1243
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• 2005

Purpose : Iron accumulation interferes with hepatic insulin extraction and affects insulin synthesis and secretion. The purpose of this study is to investigate the correlation between serum ferritin and type 2 diabetes mellitus. Methods : We compared the serum ferritin level among 18 patients in an impaired glucose tolerance (IGT) group, 36 in a type 1 diabetes group, eight in a type 2 diabetes group and 29 in a healthy control group. The correlation between serum ferritin levels and sex, body mass indices(BMI), blood pressure(BP), serum fasting sugar level and serum fasting insulin level were also analyzed. Results : The mean log ferritin were $1.33{\pm}0.32$(healthy control group), $1.63{\pm}0.19$(IGT group) and $1.90{\pm}0.30$(type 2 diabetes group). In the IGT group, log ferritin was higher than in the healthy control group(P=0.001). The log ferritin of the type 2 diabetes group was higher than that of the healthy control group(P=0.001). Comparing log ferritin to other factors, log ferritin had a significant positive correlation with body mass indices(P<0.001), systolic blood pressure(P=0.001), and fasting glucose(P=0.001), fasting insulin(P=0.002). Conclusion : Compared to the normal healthy group, serum ferritin concentrations were significantly higher in the IGT group and the type 2 diabetes group. The elevation of serum ferritin concentration may be a risk factor of type 2 diabetes mellitus.

• Spatial Information Research
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• v.14 no.4 s.39
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• pp.363-377
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• 2006

Mean annual soil loss was calculated and critical soil erosion areas were identified for the Congaree River Basin in South Carolina, USA using the Revised Universal Soil Loss Equation (RUSLE) model. In the RUSLE model, the mean annual soil loss (A) can be calculated by multiplying rainfall-runoff erosivity (R), soil erodibility (K), slope length and steepness (LS), crop-management (C), and support practice (P) factors. The critical soil erosion areas can be identified as the areas with soil loss amounts (A) greater than the soil loss tolerance (T) factor More than 10% of the total area was identified as a critical soil erosion area. Among seven subwatersheds within the Congaree River Basin, the urban areas of the Congaree Creek and the Gills Creek subwatersheds as well as the agricultural area of the Cedar Creek subwatershed appeared to be exposed to the risk of severe soil loss. As a prototype model for examining future effect of human and/or nature-induced changes on soil erosion, the RUSLE model customized for the area was embedded into ESRI ArcGIS ArcMap 9.0 using Visual Basic for Applications. Using the embedded model, users can modify C, LS, and P-factor values for each subwatershed by changing conditions such as land cover, canopy type, ground cover type, slope, type of agriculture, and agricultural practice types. The result mean annual soil loss and critical soil erosion areas can be compared to the ones with existing conditions and used for further soil loss management for the area.