• Asian Pacific Journal of Cancer Prevention
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• v.16 no.3
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• pp.1159-1164
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• 2015

Background: The prevalence of smoking among secondary school children continues to remain unchanged over the last 3 decades even though awareness regarding the health effects of smoking is increasing. Common misconceptions about smoking and parental influence could be factors influencing future intentions to smoke among these students. Hence, we looked at the common misconceptions as well as student perceptions about their future intention to smoke among Form 4 students in Shah Alam, Malaysia. Materials and Methods: This study was conducted by distribution of a questionnaire developed as part of the Global Youth Tobacco Survey to Form 4 student in 3 schools at Shah Alam. Results: Prevalence of smoking (current smokers) was 7.5%. Almost half of the children came from families where one or both parents smoked and a third of the parents had no discussion regarding consequences of smoking with them. A large number of students were classified as "triers" as they had tried smoking and were unsure of whether they would not be smoking in the future. Contrary to our expectations, students generally felt smoking did make one feel more uncomfortable and helped one to reduce body weight. Most students seemed to be aware of the ill-effects of smoking on health. They felt they had received adequate information from school regarding the effects on smoking on health. Conclusions: Our study showed that even though Form 4 students in Shah Alam were knowledgeable about ill-effects of smoking and were taught so as part of their school curriculum, the prevalence of smoking was still high. Students in the "trier group" represent a potential group of future smokers and strategies targeting tobacco control may be aimed at tackling these vulnerable individuals. Efforts are also needed to help educate secondary school children about common misconceptions and dispel myths associated with cigarette smoking.

• Journal of Chest Surgery
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• v.44 no.3
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• pp.225-228
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• 2011

Background: Conventional treatment (i.e. chest tube insertion and chemical pleurodesis) still remains standard for patients with secondary spontaneous pneumothorax because the risk of surgical bullectomy is deemed high in this subset. However, it has been suggested that surgical treatment using thoracoscopy may expedite postoperative recovery and, thus, may reduce hospital stay. Materials and Methods: Retrospective review of 61 patients with secondary spontaneous pneumothorax, who underwent conventional treatment (n=39) or video-assisted thoracoscopic surgery (VATS) (n=22) between January 2007 and December 2009, was performed. Talc was used for chemical pleurodesis in both groups. Results: Hospital stay of conventional treatment group and VATS group was $14.2{\pm}14.2$ days (4~58 days) and $10.6{\pm}5.8$ days (5~32 days), respectively, with statistically significant difference (p=0.033). Recurrence rate of conventional treatment group was also significantly higher (12/39, 30%) compared to VATS group (1/22, 4.5%) (p=0.016). Conclusion: In selected patients with secondary spontaneous pneumothorax with continuous air leak or inadequate lung expansion, thoracoscopic surgery with chemical pleurodesis using talc results in shorter hospital stay and lower recurrence rate compared to conventional approach.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.1
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• pp.275-282
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• 1999

Purpose: The objective of this study was to compare clinical examination of dental caries and secondary caries with panoramic examination. and to examine bone lesions and dental anomaly of unerupted state. Materials and Methods: In this study. clinical records and panoramic radiographs were available for 89 first grade students in elementary school. Dental caries of occlusal surfaces. proximal surfaces. and buccolingual surfaces were examined. Secondary caries was examined too. In addition. the central lesion and dental anomaly of unerupted state were examined in panoramic radiographs. Results: The obtained results were as followed: 1. Carious detectability of clinical examination in occlusal and buccolingual surface was higher than that of panoramic examination. but it is statistically insignificant(p>0.05). In proximal surface. carious detect ability of panoramic examination was higher than that of clinical examination. and it is statistically significant(p<0.01). 2. In contrast to clinical examination only. when the two examination methods were combined. there was additional detection of dental caries(26.7％ in occlusal surface. 48.2％ in proximal surface. 33.3％ in buccolingual surface. and 38.3％ totally). 3. In detection of secondary caries. panoramic examination had lower ability than clinical examination in all three surfaces. but in case that both methods were combined. totally 36.0％ extra carious lesions were detected. 4. In panoramic examination. detectability of secondary caries in upper teeth is lower than lower teeth. 5. In panoramic examination. it was possible to detect the central lesions and dental anomalies of unerupted state which cannot be detected in clinical examination. Conclusion: It is useful to combine the panoramic examination with clinical examination in order to increase carious detectability and to evaluate the central lesions and dental anomalies of unerupted state

• Imaging Science in Dentistry
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• v.41 no.4
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• pp.143-150
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• 2011

Purpose : The aim of this study was to compare the diagnostic accuracy of cone-beam computed tomography (CBCT) images and bitewing images in detection of secondary caries. Materials and Methods : One hundred and twenty proximal slots of Class II cavities were randomly prepared on human premolar and molar teeth, and restored with amalgam (n=60) and composite resin (n=60). Then, artificial secondary caries lesions were randomly created using round steel No. 4 bur. The teeth were radiographed with a conventional bitewing technique and two CBCT systems; Pax-500ECT and Promax 3D. All images were evaluated by five observers. The area under the receiver operating characteristic (ROC) curve ($A_z$) was used to evaluate the diagnostic accuracy. Significant difference was tested using the Friedman test (p value<0.05). Results : The mean $A_z$ values for bitewing, Pax-500ECT, and Promax 3D imaging systems were 0.882, 0.995, and 0.978, respectively. Significant differences were found between the two CBCT systems and film (p=0.007). For CBCT systems, the axial plane showed the greatest $A_z$ value. Conclusion : Based on the design of this study, CBCT images were better than bitewing radiographs in detection of secondary caries.

• Journal of the Korean Electrochemical Society
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• v.3 no.3
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• pp.173-177
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• 2000

The synthetic carbon was coated with tin oxide and copper by fluidized-bed chemical vapor deposition method. $(CH_3)_4Sn\;and\;Cu(hfac)_{2s}$ were employed as the metallic organic precursor, respectively. The modified synthetic carbons were used for lithium secondary battery anode to investigate their coating effects on electrochemical characteristics as alternative anode materials for lithium secondary batteries. The electrode which prepared by the synthetic carbons(MCMB) coated with tin oxide gave the higher capacity than that of raw material. Their capacity decreased with the progress of cycling possibly due to severe volume changes. But the cyclability was improved by coating with copper on the surface of the tin oxide coated carbon, which plays an important role as an inactive matrix buffering volume changes.

• Food Science of Animal Resources
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• v.39 no.5
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• pp.780-791
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• 2019

This study aimed to extend the retention of flavor in coffee-containing milk beverage by microencapsulation. The core material was caramel flavor, and the primary and secondary coating materials were medium-chain triglyceride and maltodextrin, respectively. Polyglycerol polyricinoleate was used as the primary emulsifier, and the secondary emulsifier was polyoxyethylene sorbitan monolaurate. Response surface methodology was employed to determine optimum microencapsulation conditions, and headspace solid-phase microextraction was used to detect the caramel flavor during storage. The microencapsulation yield of the caramel flavor increased as the ratio of primary to secondary coating material increased. The optimum ratio of core to primary coating material for the water-in-oil (W/O) phase was 1:9, and that of the W/O phase to the secondary coating material was also 1:9. Microencapsulation yield was observed to be approximately 93.43%. In case of in vitro release behavior, the release rate of the capsules in the simulated gastric environment was feeble; however, the release rate in the simulated intestinal environment rapidly increased within 30 min, and nearly 70% of the core material was released within 120 min. The caramel flavor-supplemented beverage sample exhibited an exponential degradation in its flavor components. However, microcapsules containing flavor samples showed sustained flavor release compared to caramel flavor-filled samples under higher storage temperatures. In conclusion, the addition of coffee flavor microcapsules to coffee-containing milk beverages effectively extended the retention of the coffee flavor during the storage period.

• Korean Journal of Optics and Photonics
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• v.25 no.2
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• pp.78-84
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• 2014

In this paper secondary optics for an LED lamp with a narrow beam angle of $15^{\circ}$ were optimized by using a two-reflector system, to reduce both its size and the occurrence of satellite rings. The conic constant and the curvature of the primary reflector were determined by considering the relation of the source size to the beam angle, and the optimal position and radius of the secondary reflector were found for reducing the occurrence of satellite rings. Luminous flux efficiency was about 80%.

• Nuclear Engineering and Technology
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• v.53 no.8
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• pp.2767-2773
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• 2021

We used the GEANT4 Monte Carlo MC Toolkit to simulate carbon ion beams incident on water, tissue, and bone, taking into account nuclear fragmentation reactions. Upon increasing the energy of the primary beam, the position of the Bragg-Peak transfers to a location deeper inside the phantom. For different materials, the peak is located at a shallower depth along the beam direction and becomes sharper with increasing electron density NZ. Subsequently, the generated depth dose of the Bragg curve is then benchmarked with experimental data from GSI in Germany. The results exhibit a reasonable correlation with GSI experimental data with an accuracy of between 0.02 and 0.08 cm, thus establishing the basis to adopt MC in heavy-ion treatment planning. The Kolmogorov-Smirnov K-S test further ascertained from a statistical point of view that the simulation data matched the experimentally measured data very well. The two-dimensional isodose contours at the entrance were compared to those around the peak position and in the tail region beyond the peak, showing that bone produces more dose, in comparison to both water and tissue, due to secondary doses. In the water, the results show that the maximum energy deposited per fragment is mainly attributed to secondary carbon ions, followed by secondary boron and beryllium. Furthermore, the number of protons produced is the highest, thus making the maximum contribution to the total dose deposition in the tail region. Finally, the associated spectra of neutrons and photons were analyzed. The mean neutron energy value was found to be 16.29 MeV, and 1.03 MeV for the secondary gamma. However, the neutron dose was found to be negligible as compared to the total dose due to their longer range.

• Vascular Specialist International
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• v.34 no.4
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• pp.88-93
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• 2018

Purpose: This study aimed to compare surgical revisions and balloon angioplasty after surgical thrombectomy on thrombosed dialysis access as a first event. Materials and Methods: Records of patients undergoing creation of arteriovenous grafts (AVGs) at the Gachon University Gil Medical Center between March 2008 and February 2016 were reviewed. Among them, patients who underwent treatment on first-time thrombotic occlusion after AVG creation were identified. Outcomes were primary, primary-assisted, and secondary patency. The patency was generated using the Kaplan-Meier method, and patency rates were compared by log-rank test. Results: A total of 59 de novo interventions (n=26, hybrid interventions; n=33, surgical revisions) for occlusive AVGs were identified. The estimated 1-year primary patency rates were 47% and 30% in the surgery and hybrid groups, respectively. The estimated primary patency rates were not different between the two groups (log-rank test, P=0.73). The Kaplan-Meier estimates of 6 and 12 months for primary-assisted patency rates were 68% and 57% in the surgery group and 56% and 56% in the hybrid group. The Kaplan-Meier estimates of 12 and 24 months secondary patency rates were 90% and 71% in the surgery group and 79% and 62% in the hybrid group. There were no differences in the estimated primary-assisted and secondary patency rates between the two groups. Conclusion: Our results showed no significant difference between the two groups in terms of primary patency (P=0.73), primary-assisted patency (P=0.85), and secondary patency (P=0.78). However, percutaneous transluminal angioplasty can give more therapeutic options for both surgeons and patients.

• Design & Manufacturing
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• v.16 no.1
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• pp.36-42
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• 2022

Globally, as population growth and economic development continue, resource consumption is increasing rapidly. As an alternative to electric vehicles was suggested as the environmental pollution problem emerged, the number of registered electric vehicles in Korea increased by more than 137 times compared to 2013. Secondary batteries are expected to expand into various markets such as small IT devices and electric vehicles, and the most important part of electric vehicles is the battery (secondary battery). Therefore, in this study, to analyze the stability of the CSM (Classifier Separator Mill) grinding disc that crushes secondary battery raw materials, structural analysis and vibration analysis of the 1st to 4th grinding discs and the final model were performed. The change of bending by the weight of the Grinding Disc is at least 0.065㎛ and maximum 0.075㎛, and the change by the standard gravity is judged to be very low. The strain is at least 0.00031㎛/㎛ and maximum 0.00078㎛/㎛, and even if the number of Hamer increases, the change by the weight is judged to be insignificant. When the Grinding Disc rotates at a maximum of 6000rpm, the deformation and deformation rate of the first to third models are similar, but the fourth model (Hamer 10EA) is more than three times and the final model (Hamer 12EA) is about four times. However, the maximum deformation is 28.21㎛, which is considered to be insignificant when the change is 6000rpm. Six modes of natural Frequency analysis of the 1st~4th order and final model of the grinding disc appeared to be bent or twisted.