• Korean Journal of Childcare and Education
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• v.6 no.1
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• pp.157-176
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• 2010

The purpose of this study was to estimate the effect of "The unsafe food program" designed for improving children's biased eating habits coming from defenceless exposure to the instant food, fast food and adulterated food with MSG and artificial additives with analyzing the current condition of children's biased eating habits and preference for the unsafe foods. This program was performed for 5 year old children who was attending the kindergarten run by the author every day for two months. "The unsafe food program" consisted of the surveys on the parents' attitude towards food and health and children's eating habits, and of programs that was designed to attract children's attention to their daily food intake and to provide physical fitness, information about differences between wholesome food and junk food, and junk food's bad impacts on human body for children. In order to see the changes of children's body through this program, two physical examinations was preformed: SH pharmaceutical company's hair test to measure the accumulation level of toxic metal in children's hair and children's nutrition level before starting the program, and Ilsan Health Center's 'INBODY' test to analyze children's body composition such as body weight, skeletal muscle mass, body fat mass, BMI, body fat percentage and so on before and after the program. The results from this program follow as below. First, the unsafe foods were excluded from children's diet after parents came to recognize the negative effects of the unsafe foods. Second, children became highly interested in their daily diet through the course of gathering information by themselves and discussions together while testing and analyzing foods, and children demonstrated more self-restraint on fast food and instant food. Third, children's body constitution turned out to be improved by physical fitness in addition to this program. Fourth, children formed a good habit of eating well-balanced diet consisting of vegetables, staple food and fruits through this program designed to improve children's biased eating habits. From the results of this study it was confirmed that "the unsafe food project" had effects on improving children's eating habits.

• Journal of Chest Surgery
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• v.35 no.5
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• pp.329-335
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• 2002

Background: The surgical technique for biventricular assist device(BVAD) implantation has mainly consisted of cannulation procedures. A median sternotomy has been the technique of choice as it gives a surgeon an excellent exposure of the heart. However, considering that most patients require a future sternotomy or already have a previous sternotomy, sternotomy-related complication remains a major concern in BVAD implantation. Based on this consideration as well as the clinical experiences of conventional heart surgery, the authors have hypothesized that the cardiac chambers for BVAD cannulation can be approached from the right side of the heart. The purpose of this studs to develop a novel surgical technique of right thoracotomy for BVAD implantation in an animals study. Material and Method: For last two years, 16 (11 calves, 3 canines, and 2 sheep) out of 30 experimental animals with AnyHeart implantation underwent a right thoracotomy. The device was used as an implantable BVAD in 14 animals, a wearable BVAD in 1, and an implantable LVAD in 1. The chest cavity was entered through the 4th intercostal space or the 5th periosteal bed. As for the BVAD use, a right inflow cannula was inserted into the right atrial free wall and a right outflow cannula was grafted onto the main pulmonary artery. A left inflow cannula was inserted into the interatrial groove and a left outflow cannula was grafted on the innominate artery of the ascending aorta. The connecting tubes were brought out through the thoracotomy wound and connected to the pump located in the subcutaneous pocket at the right flank. Result: Except for the 5 animals for a lilting test or during the early learning curve, all recovered smoothly from the procedures. The inflow drainage allowed the pump output 6.5 L/min at the maximum with 3-3.5 L/min in an average. Of the survivors, there noted no procedure-related mortality or morbidity. Necropsy findings demonstrated the well-positioned cannula tips in the each cardiac chamber

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.4
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• pp.634-643
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• 2005

The aim of this study is to evaluate the effects of blue light emitting diode (LED) Light Curing Units (FreeLight 2, L.E.Demetron I, Ultra-Lume 5) on the microhardness of three resin composites (Z250, Point 4, Dyract AP) and to determine their optimal curing time. Samples were made using acrylic molds $(2.0mm{\times}3mm)$ of each composite. All samples were prepared over a Mylar strip placed on a flat glass surface. After composite placement on the molds, the top surface was covered with another Mylar strip and a glass slab was gently pressed over it. The times of irradiation were as follows: Elipar TriLight, 40 s; Elipar FreeLight 2. L.E.Demetron I, and Ultra-Lume 5, 10s, 20s, 40s, respectively. Mean hardness values were calculated at the top and bottom for each group. ANOVA and Sheffe's test were used to evaluate the statistical significance of the results. Results showed that FreeLight 2, Ultra-Lume 5, and L.E.Demetron I were able to polymerize point 4 in 20 seconds to a degree equal to that of the halogen control at 40 seconds. FreeLight 2 and L.E.Demetron I were able to polymerize Z250 in 10 seconds to a degree equal to that of the halogen control at 20 seconds. FreeLight 2 and L.E.Demetron I were able to polymerize Dyract AP in 10 seconds to a degree equal to that of the halogen control at 40 seconds. The commercially available LED curing lights used in this study showed an adequate microhardness with less than half of the exposure time of a halogen curing unit.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.1
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• pp.21-28
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• 2006

Since the usage of tributyltin(TBT) has been banned, many chemicals including Sea-Nine 211, Cu-pyrithione, and Zn-pyrithione were developed to use as antifouling agents for ships and coastal structures. However, the toxicity of these antifouling chemicals have not been systematically evaluated in ecotoxicological and biological studies. In this study, we investigated the effect of four antifouling substances on survival of estuarine rockfish, Sebastes schlegeli and amphipod, Monocorophium acherusicum. Survival of S. schlegeli and M. acherusicum during the 96-h exposure period were used to estimate the median lethal concentrations(LC50s) of test chemicals for each test species. Among antifouling agents, Cu-pyrithione($56{\mu}g{\cdot}1^{-1}$;96-h LC50) was most toxic to S. schlegeli, followed by $TBT(73{\mu}g{\cdot}1^{-1}),\;Sea-Nine(184{\mu}g{\cdot}1^{-1})\;and\;Zn-pyrithione(l707{\mu}g{\cdot}1^{-1})$, while TBT($26{\mu}g{\cdot}1^{-1}$) was most toxic to M. acherusicum followed by Sea-Nine($49{\mu}g{\cdot}1^{-1}$), Cu-pyrithione($119{\mu}g{\cdot}1^{-1}$) and Zn-pyrithione($334{\mu}g{\cdot}1^{-1}$). Effect concentrations of the antifouling chemicals estimated in this study can be used when assessing the potential risks of these substances, of which usage is increasing in the coastal environment.

• Korean journal of applied entomology
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• v.54 no.3
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• pp.151-158
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• 2015

Chlorine dioxide ($ClO_2$) can be used as a fumigant to kill insects. However, some insects can exhibit an evasive behavior from chlorine dioxide. This evasive behavior decreases the efficiency of the insecticidal activity of chlorine dioxide. This study tested a hypothesis that heat treatment suppresses the evasive behavior and synergizes the control efficacy of chlorine dioxide. Chlorine dioxide fumigation killed the red flour beetle, Tribolium castaneum, under direct exposure condition to the chemical for 12 h with median lethal concentrations of 383.67 ppm (153.63 - 955.78 ppm: 95% confidence interval) for larvae and 397.75 ppm (354.46 - 446.13 ppm: 95% confidence interval) for adults. However, when they were treated with enough diet flour, they exhibited an evasive behavior by entering the diet, which significantly decreased the control efficacy of the fumigant. To clarify the evasive behavior, the choice test of the adults were performed in Y tube arena. The test adults significantly avoided the diet treated with chlorine dioxide, while the antennatectomized adults lost the avoidance behavior. Heat treatment using $46^{\circ}C$ for 6 h killed only 10% or less of T. castaneum. Interestingly, most adults were observed to come out of the diet under the heat treatment. Chlorine dioxide treatment even at 400 ppm for 6 h did not kill any T. castaneum. However, the combined treatment of chlorine dioxide with the heat treatment for 6 h resulted in 95% mortality. These results indicated that heat treatment suppressed the evasive behavior of T. castaneum and synergized the control efficacy of the chlorine dioxide fumigant.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.3
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• pp.369-378
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• 2003

Statement of Problem: Recently, resin cements have become more widely used and have been accepted as prominent luting cements. Current resin cements exhibit less microleakage than conventional luting cements. However, the constant contact with water and exposure to occlusal forces increase microleakage even in resin cements inevitably. Most bonding resins have been modified to contain a hydrophilic resin such as 2-hydroxyethylmethacrylate (HEMA) to overcome some of the problems associated with the hydrophobic nature of bonding resins. By virtue of these modifications, bonding resins absorb a significant amount of water, and there may also be significant stresses at bonding interfaces, which may adversely affect the longevity of restorations. Therefore the reinforcement of water stability of resin cement is indispensable in future study. Purpose: This study was conducted to examine the influence of water retention on microleakage of two resin cements over the period of 6 months. Materials and Methods: 32 extracted human teeth were used to test the microleakage of a single full veneer crown. Two resin cements with different components and adhesive properties - Panavia F (Kuraray Co., Osaka, Japan) and Super-Bond C&B (Sun Medical Co., Kyoto, Japan)- were investigated. The storage medium was the physiological saline solution changed every week for 1 month, 3 months, and 6 months. One group was tested after storage for 1 day. At the end of the each storage period, all specimens were exposed to thermocycling from $5^{\circ}C$ to $55^{\circ}C$ of 500 cycles and chewing simulation of 50,000 cycles, and then stained with 50% silver nitrate solution. The linear penetration of microleakage was measured using a stereoscopic microscope at ${\times}40$ magnification and a digital traveling micrometer with an accuracy of ${\pm}3{\mu}m$. Values were analyzed using two-way ANOVA test, Duncan's multiple range tests (DMRT). Results : Statistically significant difference of microleakage was shown in the 3-month group compared with the1-day or 1-month group in both systems (p<0.05) and there were statistically significant differences in microleakage between the 3-month group and the 6-month group in both systems (p<0.05). The two systems showed different tendency in the course of increased microleakage during 3 months. In Panavia F, microleakage increased slowly throughout the periods. In Super-Bond C&B, there was no significant increase of microleakage for 1 month, but there was statistically significant increase of microleakage for the next 2 months. For the mean microleakage for each period, in the 3-month group, microleakage of Super-Bond C&B was significantly greater than that of Panavia F. On the other hand, in the 6-month group, microleakage of Panavia F was significantly greater than that of Super-Bond C&B (p<0.05). Conclusion: Within the limitation of this study, water retention of two different bonding systems influence microleakage of resin cements. Further studies with the longer observation periods in viro are required in order to investigate water stability and the bonding durability of the resin cement. CLINICAL IMPLICATIONS Microleakage at the Cement-tooth interfaces did not necessarily result in the failure of the crowns. But it is considered to be a major factor influening the longerity of restorations. Further clinical approaches for decreasing the amount of microleakage are required.

• Journal of Preventive Medicine and Public Health
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• v.9 no.1
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• pp.11-24
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• 1976

This study was a part of large scale of a prospective study on attitudes of professional students in medicine, nursing and teaching toward population related issues in Korea. The study was first conducted in May 1974 and then in May 1975 for the 1974 class cohot using a questionaire consisted of attitude scales and other items developed by Lee. The purpose of stuay was twohold, namely, to determine the difference in students among specializations on one hand and between the first and second years in the 1974 class cohot regarding tile subject matter. A one-way analysis of variance was used for attitude scale, and absolute and relative frequency were computed for the analysis of non-attitude scale items by employing Fishers' Ratio and Duncan's multiple range test at 5% level and chi square test at 5% level as significance tests. The hypothesis 'students in health profession are more likely to have positive attitudes toward population related issues progressively as class year advances than students in teaching profession' was tested and the following results were obtained: 1) Nursing students were more likely to display favarable attitudes toward family planning than medical or teaching students although the class cohot showed slightly negative improvement in the second year. Medical and teaching students apperaed to have slightly improved attitudes in the second year. 2) Respondents in general perceived national family planning program as a means of population control and this tendency was more true among nursing students as the class year advances than two other professional groups of students. Students in teaching profession appeared to perceive it more as a means to improve individual family welfare while health students were likely to see as to improve maternal and child health. This tendency was progressively improved as the class year advanced. 3) The majority of students regardless of their respective specializations believed that family planning program should be directed toward the improvement of individual family welfare. No progressive changes in the class cohot were observed. 4) About the plan to use contraceptives in future, no singnificant differences were observes among different specializations nor in different class years. However, the majority was confirmed to have a plan to use contracepives in future. An increasing proportion of the undecided category was observed, as class year advanced among health students. 5) Students in health profession were found to be more favorable about 'more leisure opportunities' as motive for limiting number of children whereas education students indicated the reasons as 'facilitate ambitions' and 'economic base' The progressive changes toward positive direction in both groups were observed as the class years advanced. 6) Attitudes toward induced abortions of the health students were observed to be positively related to class years while an inverse relationship was found in teaching students who showed much less favor in the subject matter than health students. This phenomenon may be due to the different exposure to learning environments unique to respective specializations. 7) Health students were found to have more favorable attitudes toward population education in general than the teaching students. The teaching students appeared to have changed more to the negative direction when they became the second year while no such development was observed in health students. The teaching students seemed to hold a very conservative position with regard to sex education in schools. 8) About the equality of sexes, the nursing group was found to be most favorable while the reverse was true in the teaching group. A change in the negative direction as the class year advanced was found in the teaching group. 9) About questions related to fertility values-the 10 percent of respondents regardless of specialization indicated that they would maintain their single status in future, however no change was observed in the second year. The desired number of children was found to be two by the majority of students in nursing, medicine and teaching in order of high proportion. No changes in a different class year were observed. The childless marriage was seen by nursing students as a problem more than other students, but a slight change in positive direction was found when the nursing students became the second year. In summing, as data supported in the above, students in health profession demonstrated more favorable attitudes toward population related issues than the teaching students and this tendency became more apparent in the second year. It was noticed that health students were more conscious about the health aspect of population and family planning program while the teaching students gave more attention to the socioeconomic aspect. The sex variable seemed to have operated in the item related to the equality of sexes. In conclusion, as data presented in the above, the hypothesis of this study was accepted except in the few items. It should be noted that the limitation of this study is the short duration of the observation in measuring the possible attitude changes. It should include curriculum analysis for the respective specializations in order to indentify the area of curriculum impact on students in future study.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.24 no.3
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• pp.97-106
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• 2018

This study aimed at examining the suitability of $Tenax^{(R)}$ for the migration testing of food packaging materials, which is currently approved in the EU as a dry food simulant. The results are used as a basis to examine the feasibility of introducing $Tenax^{(R)}$ to Korean regulation. The OMVs of test specimen into various solvents (diethyl ether, ethanol, pentane, and acetone) after exposure to $100^{\circ}C$ for 1 hr were compared. Diethyl ether showed the highest OMV ($1.33mg/dm^2$) among the solvents tested. When the tests were conducted with different amounts of $Tenax^{(R)}$ of 2, 4, or 8 g per specimen, the OMVs were 0.75, 1.33 and $1.40mg/dm^2$, respectively. The OMV obtained with a closed system after wrapping with aluminum foil showed a significantly higher OMV ($1.61mg/dm^2$) than that without aluminum wrapping ($1.318mg/dm^2w$) and an open system without lid ($1.06mg/dm^2$). The specific migration rates of surrogates spiked in the polyethylene test film and paper samples into $Tenax^{(R)}$ were compared with those into liquid food simulants including 95% ethanol and n-heptane, and actual foods such as starch, skim milk, and sugar. In general, the specific migration levels of surrogates into $Tenax^{(R)}$ were similar compared with n-heptane, however those were significantly higher than into actual foods. These results suggest that $Tenax^{(R)}$ may be used as a food simulant for the long-term preservation of dried foods and paper products. However, more studies need to be conducted to investigate the factors influencing the migration into $Tenax^{(R)}$, such as the types of foods and packaging materials tested, migration conditions, and surrogates properties etc.

• Conservation Science in Museum
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• v.26
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• pp.25-34
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• 2021

3D printing technology has been actively applied for the restoration of cultural properties. However, its application to the restoration of glass cultural properties has not yet been reported and thus requires further study. In this study, 3D printing technology was used to restore a defective part of a glass sarira bottle that forms an element of a series of sarira reliquaries commissioned by Yi Seonggye (known as King Taejo after founding the Joseon Dynasty) that was excavated from Geumgangsan Mountain (designated as Treasure No. 1925) and is currently housed at the National Museum of Korea. The defective area was reproduced using 3D printing and the printed reproduction was reproduced again using an epoxy resin. This latter piece was used as the restoration component rather than the 3D printed element. After the completion of the conservation treatment, the materials used for the 3D printing were compared with transparent materials used to restore ceramics to evaluate their usability and stability. A total of five specimens were produced, including from photocurable resin made by a stereo lithography apparatus (SLA), epoxy resin, acrylic resin, and more. They were exposed to UV for 96 hours to test for yellowing. Of the two specimens made of photocurable resins and exposed to UV, one was sprayed with a UV blocking agent but the other was exposed as-is. The UV exposure test showed that the specimen made by the SLA and sprayed with a UV blocking agent and the specimen made of epoxy resin were stable in terms of yellowing with a change in the b-value was less than 1. They are thus considered to be suitable materials for the restoration of glass cultural properties. Such glass cultural properties are often diverse in shape and their restoration can be difficult as they generally consist of a range of complex parts that hamper restoration. In this regard, diverse materials should be considered when selecting materials for the restoration of glass cultural properties.

• Journal of the Korean Orthopaedic Association
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• v.56 no.2
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• pp.125-133
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• 2021

Purpose: The clinical outcomes were investigated to determine if arthroscopic management is a useful method for 19 hips with iliopsoas tendon impingement (IPI) after total hip arthroplasty (THA). Materials and Methods: Eighteen patients (19 hips), who complained of groin pain and flexion pain that persisted after THA from September 2013 to December 2019, were the subjects of this investigation. The mean time to manifestation after THA was four months (range, 1-9 months) in patients of an average age of 60 years (range, 50-69 years). Thirteen out of 18 patients underwent THA using the direct anterior approach and five by the lateral approach. IPI was diagnosed by the medical history, physical examination, blood test, radiographic examination using X-ray and computed tomography, and topical injection therapy. All patients underwent arthroscopic treatment and a dynamic arthroscopic physical examination after exposure to the iliopsoas tendon revealed impingement. Tenotomy was then performed on the muscle portion through the total tendon portion. Symptoms and pain levels of preoperative, postoperative and follow-up period were investigated and compared. Results: The Western Ontario and McMaster Universities Osteoarthritis Index score decreased from an average of 58.4 (range, 40-88) before surgery to an average of 35.0 (range, 15-76) after surgery. Similarly, the visual analogue scale decreased from an average of 4.0 (range, 2-6) before surgery to an average of 1.4 (range, 0-4) after surgery. Sixteen patients (88.9%) showed pain relief and improvement in the straight leg raise test, and two patients showed postoperative muscle weakness and sustained pain. In the follow-up period, muscle weakness improved. One patient underwent arthroscopic iliopsoas tenotomy at the lesser trochanteric level but the symptoms persisted. The clinical symptoms were improved after one more tenotomy at the joint level. Conclusion: Arthroscopic iliopsoas tenotomy performed in patients with IPI after THA showed good clinical results.