• Journal of Korean Ophthalmic Optics Society
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• v.10 no.3
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• pp.193-203
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• 2005

Highly c-axis oriented nanocrystalline ZnO thin films on silica glass substrates were prepared by spin coating-pyrolysis process with a zinc naphthenate precursor. Only the XRD intensity peak of (002) phase was observed for all samples. With an increase in heat treatment temperature, the peak intensity of (002) phase increases. No significant aggregation of particle was present. From scanning probe microscopy analyses, three-dimensional grain growth, which was thought to be due to inhomogeneous substrate surface and c-axis oriented grain growth of the ZnO phase, was independent on heal-treatment temperature. Highly homogeneous surface of the highly-oriented ZnO film was observed at $800^{\circ}C$. All the films exhibited a high transmittance (above 80%) in visible region except film heat treated at $1000^{\circ}C$, and showed a sharp fundamental absorption edge at about $0.38{\sim}0.40{\mu}m$. The estimated energy band gap for all the films were within the range previously reported for films and single crystal. ZnO films, consisting of densely packed grains with smooth surface morphology were obtained by heat treatment at $600^{\circ}C{\sim}800^{\circ}C$, expected to be ideal for practical application, such as transparent conductive film and optical device.

• Journal of Korean Ophthalmic Optics Society
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• v.10 no.3
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• pp.185-191
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• 2005

Photo-reactive $TiO_2$ thin films on soda-lime-silica slide glass were prepared by spin coating technique with a Ti-naphthenate precursor. Optical, structural and photo-catalytic properties of the films after annealing at $500^{\circ}C{\sim}600^{\circ}C$ were evaluated. As increase with annealing temperature, absorption bands and total transmittance of the films showing an average transmittance (about 80%) at visible spectra range were shifted to UV spectra range and slightly decreased. Refractive index and thickness of the films were increased from 2.16 to 2.63 and decreased from 484 nm to 439 nm, respectively, with increase of annealing temperature. Anatase phase was visible at all annealing temperature. More rougher surface structure was obtained at $600^{\circ}C$ than those of films annealed at $500^{\circ}C$ and $550^{\circ}C$. The hydrophilic conversion was found within 45 min by UV stimulation and optical activation was UVC>UVA>UVB at the case of $500^{\circ}C{\sim}550^{\circ}C$ and UVA>UVC>UVB at the annealing temperature of $600^{\circ}C$. The lowest initial contact angle was obtained at $600^{\circ}C$.

• Pediatric Infection and Vaccine
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• v.22 no.2
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• pp.81-90
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• 2015

Purpose: Group A rotavirus (RV) is most common etiologic agent of acute gastroenteritis (AGE) in children worldwide. Recently, vaccination has been introduced in several countries to reduce the disease burden caused by RV infections, but continuous surveillance of RV strains is necessary to detect the emergence of potential variants induced by vaccine-immune pressure. This study aimed to investigate the changing pattern of RV genotypes in children with AGE, following the introduction of vaccination in Korea. Methods: Genotyping of RVs by RT-PCR on the basis of VP7 and VP4 gene segment sequence was carried out on 201 rotavirus-positive stool samples, from children hospitalized with AGE between August 2009 and June 2013. We have directly sequenced PCR products and analyzed the phylogenetic tree. Results: The most prevalent G genotype was G9 (33.3%), followed by G1 (22.4%), G3 (15.9%), G2 (6.0%), G4 (3.0%), G10 (1.5%), and mixed G-type (15.4%), with some nontypeable cases (2.5%). The detected P genotypes were P[4] (45.3%), P[8] (43.8%), mixed P-type (10.4 %), and P[2] (0.5%). The G9P[4] genotype was predominantly observed in hospitalized cases in Seoul in 2010/2011, however G1P[8] has been re-emerged as the predominant genotype in the following season (P =0.004). Conclusions: It seems that the periodic fluctuation in predominance of the G1, G3, and G9 strains occurred in Korea during 2009-2013, following the introduction of RV vaccination.

• Journal of Trauma and Injury
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• v.24 no.1
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• pp.12-17
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• 2011

Purpose: A rib fracture secondary to blunt thoracic trauma continues to be an important injury with significant complications. Unfortunately, there are no definite treatment guidelines for severe multiple rib fractures. The purpose of this study was to evaluate the result of early operative stabilization and to find the risk factors of surgical fixation in patients with bilateral multiple rib fractures or flail segments. Methods: From December 2005 to December 2008, the medical records of all patients who underwent operative stabilization of ribs for severe multiple rib fractures were reviewed. We investigated patients' demographics, preoperative comorbidities, underlying lung disease, chest trauma, other associated injuries, number of surgical rib fixation, combined operations, perioperative ventilator support, and postoperative complications to find the factors affecting the mortality after surgical treatment. Results: The mean age of the 96 patients who underwent surgical stabilization for bilateral multiple rib fractures or flail segments was 56.7 years (range: 22 to 82 years), and the male-to-female ratio was 3.6:1. Among the 96 patients, 16 patients (16.7%) underwent reoperation under general or epidural anesthesia due to remaining fracture with severe displacement. The surgical mortality of severe multiple rib fractures was 8.3% (8/96), 7 of those 8 patients (87.5%) dying from acute respiratory distress syndrome or sepsis. And the other one patient expired from acute myocardial infarction. The risk factors affecting mortality were liver cirrhosis, chronic obstructive pulmonary disease, concomitant severe head or abdominal injuries, perioperative ventilator care, postoperative bleeding or pneumonia, and tracheostomy. However, age, number of fractured ribs, lung parenchymal injury, pulmonary contusion and combined operations were not significantly related to mortality. Conclusion: In the present study, surgical fixation of ribs could be carried out as a first-line therapeutic option for bilateral rib fractures or flail segments without significant complications if the risk factors associated with mortality were carefully considered. Furthermore, with a view of restoring pulmonary function, as well as chest wall configuration, early operative stabilization of the ribs is more helpful than conventional treatment for patients with severe multiple rib fractures.

• The Korean Journal of Pain
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• v.18 no.2
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• pp.165-170
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• 2005

Background: It is difficult to treat tourniquet-induced hypertension despite adequate anesthesia, and the mechanism of that is not known. And it may be possible that intraoperative continuous infusion of opioid induces preemptive analgesia postoperatively. We investigated the effect of intraoperative continuous i.v. fentanyl on tourniquet induced cardiovascular changes and postoperative preemptive analgesia in total knee replacements. Methods: Sixty patients were randomly assigned to two groups; In study group ($1.5{\mu}g/kg$ loading and $0.5{\mu}g/kg/hr$ continuous infusion of fentanyl before skin incision and tourniquet inflation) and control group (no treatment). Anesthesia was maintained with enflurane (1-2 MAC) and 50% nitrous oxide in oxygen. Arterial pressure and heart rate were compared between two groups. They received postoperative pain treatment with patient-controlled analgesia (PCA) with fentanyl during the postoperative 48 hours after total knee replacement. Visual analog scale (VAS) scores at either rest or movement were used to assess pain. Total fentanyl dose delivered, number of PCA requests, supplemental analgesics, overall satisfaction score and adverse events were evaluated. Results: There were no significant differences between the two groups on cardiovascular changes by tourniquet induced pain effect. VAS, PCA delivered dose and PCA demands at movement in the 24-48 hour decreased in study group compared with control group (P < 0.05). But there were no significant differences between the two groups on the other time periods except 24-48 hour's patient satisfaction and adverse events. Conclusions: We suggest that intraoperative continuous i.v. fentanyl infusion dose not affect cardiovascular change by tourniquet induced pain. But it may induce preemptive analgesia postoperatively.

• The Korean Journal of Pharmacology
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• v.30 no.1
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• pp.39-48
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• 1994

The present study was aimed at establishing what changes occur in the dopamine levels and pattern of TH-immunoreactive neurons of certain areas of rat brain during food intake suppression produced by intraperitoneally administration of CCK-8. CCK-8 in dose of $10\;{\mu}g/kg$ was injected intraperitoneally to 48 h food-deprived rats. In the fasted group, the contents of dopamine were decreased in the frontal, striatum, hypothalamus and amygdala as compared to those of the fed control group. The administration of CCK-8 showed significant decrease on the dopamine levels of the hypothalamus, in comparison to those of the sated and starved group. During deprived condition, the density and number of TH-immunoreactive neurons in the paraventricular nucleus, arcuate nucleus, median eminence and substantia nigra were lower than those of the fed control group. After administration of CCK-8, the pattern and distribution of TH-positive neouons in the hypothalamic areas and substantia nigra were increased when compared to those of the starved group. It is concluded that the results demonstrate the partial involvement of hypothalamic dopamine-containing neurons in the feeding inhibition of CCK-8. Furthermore, the results indicate that TH-immunoreactive neurons play on important role in the hypothalamus and substantia nigra for eating behavior

• Science of Emotion and Sensibility
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• v.15 no.4
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• pp.527-540
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• 2012

We examined the effect of delayed and immediate rewards on short- and long-term memory performance depending on the level of stress. It has been demonstrated that delaying feedback during memory tasks could lead to better retention than presenting it immediately (a.k.a., feedback delay benefit or delay-retention effect). In this study, we manipulated stress level(high-stress or low-stress), reward-timing(delayed or immediate reward), reward-existence(500 or 0 won) and retrieval-timing(delayed or immediate memory test). On the high-stress learning condition, one week later, the number of correct answers with delayed-rewards were significantly more than that of delayed-no-rewards but there was not any difference between immediate-rewards and immediate-no-rewards. On the other hand, in the high-stressful immediate memory test, immediate-rewards only had a positive effect on memory performance. The results indicated that delayed rewards improved long-term memory performance by promoting memory consolidation and the sensitivity to rewards was higher under the high-stress condition.

• Science of Emotion and Sensibility
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• v.15 no.4
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• pp.441-452
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• 2012

Recently, various researches have been attempted to effectively display pseudo-aural senses to the hearing-impaired or the deaf, using vibro-tactile stimulus as well as visual sense. Particularly, it is reported that as complementary senses to support the visual sense, tactile senses displayed by either speakers or vibration motors improve the reality sense significantly but do not nearly improve the emotional sense. Thus, in this study, the thermal sense is selected as another complementary sense to support the pseudo-aural sense display and it is investigated whether the thermal sense could generate a pseudo-aural sense or not. For this purpose, a thermal display module which could effectively display the desired thermal sense is implemented. Then, experiments have been conducted to subjects, which provide them with various types of stimuli combined with the aural, the vibrotactile, and the thermal stimuli along with the visual information. It can be confirmed, through statistical analysis on the data collected from experiments, that subjects could feel a pseudo-thermal sense closer to the real thermal sense which the normal subject feel from both the visual and the aural information, particularly either i) with the thermal stimulus along with the visual information or ii) with both the thermal and the vibrotactile stimuli along with the visual information than only with the visual information. Conclusively, it can be confirmed that the thermal stimulus applied to the skin of the subjects could play a role of effectively displaying pseudo-aural sense related to the thermal sense, as an complementary media for the pseudo-aural display.

• Journal of Food Hygiene and Safety
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• v.32 no.1
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• pp.70-74
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• 2017

Recently, the area of marine resources has become concerned with sources for the next generation of the bio-industry. Until present, development of the marine resources has remained limited, although a large number of these resources are considered to have potential for various significant biological activities. Most marine sponges, marine algae and coral could be used to create specific compounds for survival against a harsh environment. Therefore, it was necessary that these materials needed to be elucidated with biological activities, such as like anti-inflammatory, anti-viral or anti-cancer effects for their utilization in the bio-industry. In this study, we screened extracts of marine resources for their anti-cancer effect on human colorectal cancer cells. These resources were collected at Kosrae of Micronesia on April, 2013 and extracted with methanol. Cytotoxicity of marine resources was observed. Of a total of 20 specimens, three specimens dose-dependently demonstration inhibition of cell viability. Furthermore, cells treated with these specimens for 48h were induced p53, p21, Bax and caspase-3. The results suggest that they involved p53-mediated apoptosis. Two positive specimens (1304KO-327 and 1304KO-329) were verified as the identical materials, which are Hyrtios sp. Unfortunately 1304KO-207 was not yet classified and needed to identify in the further study. There results suggested that marine resources with positive potential in anticancer effect would be good candidates as useful bio-resources.

• Korean Journal of Head & Neck Oncology
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• v.27 no.2
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• pp.177-182
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• 2011

Backgrounds : Head and neck cancer is one of the most prevalent cancers in the world. It tends to remain localized at the primary site and regional lymph nodes, but if distant metastasis occurs, it has a poor prognosis. This study was performed to evaluate the prevalence of distant metastasis and to determine the risk factor in locally advanced head and neck cancer after induction chemotherapy followed locoregional control therapy. Methods : A retrospective review was performed in 420 patients with locally advanced head and neck cancer who treated with induction chemotherapy followed locoregional control therapy from January 2001 to December 2010. Among them, 31 patients who had distant metastasis as first relapse within 2 years after termination of therapy were analyzed for clinical features and the risk factors of distant metastasis. Results : The overall incidence of distant metastasis was 7.3%. The bone, lung, and liver were the most frequent metastatic organs. In univariate analysis, nodal stage, nasopharyngeal cancer, laryngeal cancer, G3/G4 neutropenia during induction chemotherapy, and concurrent chemoradiotherapy were the influencing factors for distant metastasis. In multivariate analysis, advanced N stage and nasopharynx were the risk factors of distant metastasis, and grade 3/4 neutropenia during induction chemotherapy was considered to decrease distant metastasis. Conclusion : This study suggests that the advanced N stage is the risk factor of distant metastasis and Grade 3/4 neutropenia during induction chemotherapy can be beneficial against distant metastasis in locally advanced head and neck cancer patients treated with induction chemotherapy followed locoregional control therapy.