• Fibers and Polymers
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• v.6 no.1
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• pp.1-5
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• 2005

In this study, we attempted to evaluate a novel use of sericin-fixed silk fiber (SFx) as an immobilization support of enzyme. Sericin was fixed on the silk fiber using glutaraldehyde as a fixation reagent. After 6 hours of fixation, the degree of fixation increases linearly with linear decrease of the amount of bound $\alpha$-chymotrypsin (CT). This suggests that the increase of the degree of fixation is due to the further crosslinking of free aldehyde groups on the surface of sericin-fixed silk fiber (SFx). Even though perfect fixation was not achieved, sericin did not dissolve seriously and could be removed by further washing. The specific activity did not differ significantly after 6 hours of fixation. The activity of immobilized CT on SFx decreased to its half after 6 hours of incubation at 50$^{\circ}C$. However, it retained $78\%$ of initial activity even after 1 hour of treat­ment with $100\%$ ethanol. As a result, the SFx could be used as an immobilization support of enzyme in non-aqueous media at ambient temperature.

• Journal of Korean Elementary Science Education
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• v.28 no.2
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• pp.187-196
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• 2009

The purpose of this study was to investigate the impact on creativity when the elementary fifth-grade students do the activity with impression writing or the activity with science writing after reading books on science. The subjects for this study were students in two fifth-grade classes in an elementary school that was located in Incheon. The two classes were respectively selected as an experimental group and a comparison group. The comparison group read books on science and did the activity with impression writing for 6 weeks. And, the experimental group also read books on science and did the activity with science writing for 6 weeks. According to the result of the effect on the creativity, the experimental group was better than the comparison group. This study showed that the activity with science writing was more effect than the activity with impression writing to boost the creativity. After a detailed analysis about the creativity, this study showed a boost for all area of subordinate creativity.

• The Journal of Korean Academy of Prosthodontics
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• v.34 no.3
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• pp.574-592
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• 1996

This study investigated the time-dependent dimensional changes of elastomeric impression materials using holographic interferometry. Six commercial impression materials, Permlastic(polysulfide), Xantopren VL (condensation silicone), low and medium viscosity of Exafine, Provil (addition silicone), and Impregum(polyether), were selected. Steel plate was used as custom tray, and each impression specimen was 20 mm in width, 15 mm in length and 3 mm in thickness. Each impression material was evaluated at 30 minutes, 1, 2, 4, 6, 8 and 12 hours after setting using real-time holography. The results were as follow : 1. Xantopren VL and Permlastic showed relatively severe and continuous dimensional changes after setting. Low viscosity of Exafine, Provil, Impregum showed relatively slight dimensional changes with function of time and medium viscosity of Exafine showed almost no dimensional change from 2 hours after setting to 6 hours. 2. On initial dimensional changes within 1 hour, the amount of change in low viscosity of Exafine was the least and Xantopren VL was the largest. 3. On dimensional changes at 4 hours after setting, the amount of change in medium viscosity of Exafine was the least and tile change of Xantopren VL was the largest. 4. In overall dimensional stability during 12 hours, medium viscosity of Exafine was the most stable and Xantopren VL and Permlastic were least stable.

• Korean journal of food and cookery science
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• v.19 no.4
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• pp.403-412
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• 2003

The purpose of this study was to develop methods for foodservice employees to perform by measuring their levels of sanitation and hygiene practices. The employees' sanitation and hygiene competency list for school foodservice was developed on the basis of the job standardization. The competency list was divided into three parts; (1) before starting the work, (2) during the work and (3) after the work. The levels of the employees' sanitation and hygiene practices were evaluated by dietitians and by the employees themselves. Most schools had conventional foodservice systems (83.4%), which were operated by contract management (94.8%). It was found that the highest practice level related to sanitation and hygiene before starting work, with the lowest levels observed after work. The item related to the cleaning and sanitizing of dishes had the lowest practice level score. Employees perceived their sanitation and hygiene practice after work to be worse than before starting and during work. The items of ″Clean and sanitize all large stationary equipment after every use, and record equipment monitoring chart″ and ″Do not clean dishes and utensils in production area″ had the lowest scores by employees. The scores of the employees were similar to the perception of the dietitians.

• Journal of Chest Surgery
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• v.55 no.3
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• pp.243-245
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• 2022

True aneurysms of the coronary artery after aortic root replacement in Marfan syndrome patients are very rare. An anomalous origin of the right coronary artery (RCA) from the left sinus of Valsalva adds complexity during aortic root surgery. We present a case of a 37-year-old male patient with Marfan syndrome who had an RCA anomaly and a 4.5-cm true aneurysm of the common coronary button 14 years after a previous Bentall procedure. A redo Bentall operation and hemi-arch replacement were successfully performed. The anomalous origin of the RCA from the left sinus of Valsalva was safely divided and anastomosed as separate coronary buttons to the prosthetic composite valve graft. To prevent coronary button aneurysms after aortic root surgery in Marfan patients, the coronary buttons and the corresponding side holes on the prosthetic graft must be reduced to the maximum possible extent.

• Korean Journal of Exercise Nutrition
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• v.25 no.1
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• pp.1-6
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• 2021

[Purpose] We determined the effect of partial sleep deprivation (PSD) after an exercise session on exercise performance on the following morning. [Methods] Eleven male athletes performed either a normal sleep trial (CON) or a PSD trial. On the first day (day 1), all subjects performed an exercise session consisting of 90 min of running (at 75% ${\dot{V}}O_{2max}$) followed by 100 drop jumps. Maximal strength (MVC) was evaluated before and after exercise. In the CON trial, the sleep duration was 23:00-7:00, while in the PSD trial, the sleep duration was shortened to 40% of the regular sleep duration. On the following morning (day 2), MVC, the metabolic responses during 20 min of running (at 75% ${\dot{V}}O_{2max}$), and time to exhaustion (TTE) at 85% ${\dot{V}}O_{2max}$ were evaluated. [Results] On day 2, neither the MVC nor ${\dot{V}}O_2$ during 20 min of running differed significantly between the two trials. However, the respiratory exchange ratio was significantly lower in the PSD trial than in the CON trial (p = 0.01). Moreover, the TTE was significantly shorter in the PSD trial than in the CON trial (p = 0.01). [Conclusion] A single night of PSD after an exercise session significantly decreased endurance performance without significantly changing muscle strength or cardiopulmonary response.

• Korea Trade Review
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• v.47 no.3
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• pp.37-55
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• 2022

This paper takes the factors influencing consumers' purchase of organic agricultural products before and after the COVID-19 epidemic as the starting point, decomposes Chinese consumers' purchase behavior of organic agricultural products into questionnaire surveys before and after the COVID-19 epidemic with the help of the theory of planned behavior, and builds structural equation regression models to compare and analyze them respectively. The study investigates whether this change has any impact on consumers' purchasing behavior of organic agricultural products, and proposes rationalized countermeasures from different perspectives based on the results of the study. To this end, this study collected 219 valid questionnaires by combing through domestic and international literature and referring to scholars' mature scales for measurement. The results showed that consumers' attitudes, subjective norms and perceptual behavioral control of organic agricultural products before and after the COVID-19 epidemic had a significant positive effect on consumers' willingness to purchase; however, it can be seen that the intervention of the COVID-19 epidemic event has significantly improved consumers' attitudes, subjective norms and perceptual behavioral control of organic agricultural products.

• Journal of Distribution Science
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• v.22 no.1
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• pp.47-59
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• 2024

Purposes: The study aimed at examining the impact of the COVID-19 pandemic on the shift of online consumer purchasing behavior and whether the new behaviors would be maintained after the epidemic season. The study also aims to investigate how online customers change based on perceived risks. Research design and Methodology: The study investigated purchasing behavior of the same 377 online Vietnamese consumers during two periods: (1) during the period of social distancing and (2) one and half year after that, allowing data to be collected in real time, so that consumers do not have to recall their behavior. Results: Purchasing behavior appeared to be more influenced by gender, age and household size. Aged consumers are more concerned about risks than those in the younger group, who only worry about the risks during the pandemic. Consumers in households with two or more people are more concerned about the risks than those living alone. Female appeared to be more influential in both during and after pandemic than male. Conclusions: The findings contribute to clarify shift of online consumer purchasing behavior, which helps business to develop effective marketing strategies and enhance their presence in the e-commerce sector.

• Hip & pelvis
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• v.34 no.4
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• pp.262-268
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• 2022

A fracture of the affected extremity in patients with Klippel-Trenaunay-Weber syndrome can be fatal due to massive bleeding and show poor results. A 42-year-old male presented with an old fracture of the right femoral shaft with metal failure. We planned an operation to remove the previously fixed plate and to perform re-fixation using an intra-medullary nail. Preoperative angiography was performed and the arteriovenous malformations were embolized in order to reduce the risk of bleeding. After angiography, the previously fixed plate was removed. After the operation, a second angiography was performed immediately and the venous malformation was embolized. One week after the first operation, a second operation was performed in order to reduce the fracture and to perform re-fixation using an intramedullary nail. The patient is being followed without major complication over a period of seven years after surgery. We recommend careful planning of preoperative and postoperative angiography and embolization in order to reduce the risk of bleeding in patients with Klippel-Trenaunay-Weber syndrome.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.25 no.4
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• pp.440-446
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• 2023

Craniotomy is known as a cause of iatrogenic dural cerebral arteriovenous fistula (AVF). However, mixed pial and dural AVFs after craniotomy are extremely rare and require accurate diagnosis and prompt treatment due to their aggressiveness. We present a case of an iatrogenic mixed pial and dural AVF diagnosed 2 years after pterional craniotomy for surgical clipping of a ruptured anterior choroidal aneurysm. The lesion was successfully treated using single endovascular procedure of transvenous coil embolization through the engorged vein of Labbe and the superficial middle cerebral vein. The possibility of the AVF formation after the pterional approach should always be kept in mind because it usually occurs at the middle cranial fossa, which frequently has an aggressive nature owing to direct cortical venous or leptomeningeal drainage patterns. This complication is believed to be caused by angiogenetic conditions due to coagulation, retraction, and microinjuries of the perisylvian vessels, and can be prevented by performing careful sylvian dissection according to patient-specific perisylvian venous anatomy.