• Bulletin of the Korean Chemical Society
• /
• v.10 no.2
• /
• pp.191-196
• /
• 1989

We obtained the new complexes, $Fe{\eta}^4-R,R'-TPSCp](CO)_3$(R,R'-TPSCp = 1,1-disubstituted 2,3,4,5-Tetraphenyl-1-Silacyclopenta-2,4-diene; R = Ph, R' = Cl, R = R' = Cl) from the reaction of the corresponding R,R'-TPSCp with ironpentacarbonyl under reflux in toluene. Also, the analogous complexes with R = R' = Me and R = Me, R' = Cl were obtained in an identical manner. We have determined the crystal structure of $Fe[Ph(Cl)-TPSCp](CO_)3$ by using Mo ka, ${\lambda}$ = 0.71069${\AA}$, where the unit cell was found to be monoclinic with a = 9.042 (6)${\AA}$, b = 19.870 (9)${\AA}$, c = 17.426 (9)${\AA}$ and ${\beta}$ = 96.28(4)$^{\circ}$. The butadiene moiety of TPSCp ring is planar and the dihedral angle of the butadiene plane and C4-Si-C25 plane was opened up to 41.8$^{\circ}$. The C-C distances in the butadiene moiety were found to be 1.4346, 1.462, and 1.440 ${\AA}$, respectively. It may be said that the four ${\pi}$-electrons are delocalized over the four carbons in five membered ring through coordination with ironcarbonyl. In this complex Fe is either in distorted tetrahedron environment with the centroid of the four C-atom butadiene moiety and three carbons of the three carbonyls or in distorted square-pyramidal environment with two midpoints of double bonds of the butadiene moiety and two carbons of carbonyl defining the base of the pyramid and the carbon of remaining carbonyl the apex.

• Korean Journal of Metals and Materials
• /
• v.50 no.4
• /
• pp.338-343
• /
• 2012

The early osseointegration of titanium (Ti) dental implants is related to the initial cell morphology. The morphology of the cells (mesenchymal stem cells, MSC) was observed on three different Ti disc surfaces, which were mechanically treated by polishing, blasting, and scratching. A non-directional surface (isotropic texture) was obtained by the blasting of HA grits on cp-Ti discs, and a unidirectional surface (anisotropic texture) was obtained by the scratching of SiC papers. The cell attachment and arrangement in the initial periods were quite similar, but those in the later periods were significantly affected by the texture of the cp-Ti discs. After 1 week, the blasted Ti discs showed non-directional arrangement or spreading of the cells, whereas the scratched cp-Ti discs showed unidirectional properties parallel to the direction of the scratched grooves on the surface. The surface roughness of the cp-Ti discs significantly affects cell proliferation. Cell proliferation on the blasted and scratched surfaces was about 60% and 40% higher compared to the control result (polishing group) after 1 week (P<0.05). Cell proliferation on the blasted and scratched surfaces after 1 week was slightly enhanced with increasing surface roughness. It is believed that the direction of cell attachment and arrangement is closely related to the surface texture of the substrate surfaces, but cell proliferation after a relatively long period of time is directly enhanced by the surface roughness, not by the surface texture.

• Journal of Wetlands Research
• /
• v.23 no.2
• /
• pp.116-121
• /
• 2021

This study is the first official report on the wild habitats of alien species, Yellow-spotted Amazon River Turtle (Podocnemis unifilis) in Republic of Korea. On July 24, 2020, two P.unifilis were observed basking on rocks at 33°30'20.08"N 126°38'0.23"E, Waheul-ri, Jocheon-eup, Jeju-si, Jeju. One individual had a yellow spots on the head where as the other contains black spot. Our observatory site is close to road and easy access to people. Thus, these individuals were believed to be released in the pond after raising as pets. Recently, the number of alien turtles identified in wild(etc. lake, resevoir) is increasing, which is predicted to damage the aquatic ecosystem due to the inflow of exotic turtles. So, it is necessary to improve the people's awareness of alien species through citizen science projects and environmental education. We suggest that research on habitat adaptation, reproduction and management through continuous monitoring is needed in the future.

• Journal of Microbiology and Biotechnology
• /
• v.31 no.1
• /
• pp.16-24
• /
• 2021

Hepatitis B virus (HBV) genome P-encoded protein HBV DNA polymerase (Pol) has long been known as a reverse transcriptase during HBV replication. In this study, we investigated the impact of HBV Pol on host cellular processes, mainly apoptosis, and the underlying mechanisms. We showed a marked reduction in apoptotic rates in the HBV Pol-expressed HepG2 cells compared to controls. Moreover, a series of assays, i.e., yeast two-hybrid, GST pull-down, co-immunoprecipitation, and confocal laser scanning microscopy, identified the host factor eEF1A2 to be associated with HBV Pol. Furthermore, knockdown of eEF1A2 gene by siRNA abrogated the HBV Pol-mediated anti-apoptotic effect with apoptosis induced by endoplasmatic reticulum (ER) stress-inducer thapsigargin (TG), thus suggesting that the host factor eEF1A2 is essential for HBV Pol's anti-apoptosis properties. Our findings have revealed a novel role for HBV Pol in its modulation of apoptosis through integrating with eEF1A2.

• Journal of Forest and Environmental Science
• /
• v.38 no.3
• /
• pp.141-151
• /
• 2022

Soil seed banks as natural storage of plant seeds play an important role in the maintenance and regeneration of watershed. Natural regeneration potential of the soil seed bank of Land use types (LUTs) in Ogun River watershed (ORW) was investigated. ORW was stratified using proportionate sampling technique into Guinea Savannah (GS), Rainforest (RF) and Swamp Forest (SF) Ecological Zones (EZs). Three LUTs: Natural Forest (NF), Disturbed Forest (DF) and Farmland (FL) were purposively selected in GS: GSNF, GSDF, GSFL; RF: RFNF, RFDF, RFFL and SF: SFNF, SFDF, SFFL, respectively. Systematic line transects was used in the laying of the sample plots. Sample plots of 25 m×25 m were established in alternate positions. Ten 1 m×1 m quadrats were randomly laid for soil core sampling from previously randomly selected ten plots. The core samples (10) were pooled per plot in each LUT and placed in individual trays. Ten trays with sterilized soil were used as control. The trays were watered regularly and checked for seedlings emergence fortnightly for 18 months. The experimental design used was 3×3 factorial experiments. ANOVA, Diversity index (H') and Similarity index (SI) were used to analyze the data. There was significant difference in seedling emergence among ecological zones and land use types (p<0.05). A total of 4,400 seedlings emerged from the soil samples. All species were distributed among 32 families. FL in the RF had the highest number of germinated seeds (705±37.33 seedlings) followed by DF in the RF (701±49.6 seedlings). The lowest emergence was in NF of the SF (199±28.41 seedlings). DF in the RF had highest number of species (34) distributed among 22 families. Emergence from soil seed bank of NF in ORW was generally with more of tree species than herbs that were predominant in FL and DF.

• Journal of Trauma and Injury
• /
• v.35 no.2
• /
• pp.92-98
• /
• 2022

Purpose: Critically ill patients are frequently transferred from one point of care to a hospital that can provide a higher level of care. To achieve optimal treatment within the targeted window of time necessary for time-sensitive cases like major trauma, rapid transportation and decision making are essential. Transferred patients have often undergone radiologic imaging at the referring hospital. Examining these outside images is paramount. Therefore, this study was conducted to estimate the upload time of outside images. Methods: This retrospective study was conducted from January to April 2020. Patients transferred from other hospitals with digitally recorded CDs or DVDs of radiologic or diagnostic images were included. When the patients were registered at the emergency department reception desk, the digital images were transmitted to our picture archiving and communication system using transmission software. The time of upload and the numbers of digital images were recorded. The time interval from patient registration to the time of upload was calculated. Results: The median number of images was 688 in the trauma team activation (TTA) group (688 in the TTA group, 281 in the non-TTA trauma group, and 176 in the nontrauma group, respectively; P<0.001). The median upload time was 10 minutes. The longest upload time was 169 minutes. The upload time was more than 20 minutes in 12 cases (19.4%). Conclusions: Patients with major trauma bring more images than patients with other diseases. Unexpected delays (>20 minutes) were noted in approximately 20% of cases. It is necessary to minimize this time.

• Journal of The Korean Society of Integrative Medicine
• /
• v.10 no.1
• /
• pp.109-118
• /
• 2022

Purpose : The study to verify the effectiveness of the Soomchi combined marine healing program by analyzing the physical composition of the subjects, their blood lipids, and the effects of the program on their lung health-related variables, and heart rate variability variables. Methods : In the experiment, the Soomchi combined marine healing program was conducted for 5 hours a day, 5 days a week. on 15 participants. The results of their body composition, blood lipids, lactic acid, blood pressure, PEF, FEV1 and maximum oxygen intake were analyzed before and after the subjects completed the Soomchi program. For the statistical analysis, the mean and standard deviation (M±SD) of each variable were calculated using SPSS version 20 and an independent t-test was conducted to test for the amount of change in the participants before and after the Soomchi combined marine healing program. All significant levels were set to α=.05. As a result of the experiment Results : First, no statistically significant differences were found in the changes in body composition after the 5-day combined marine healing program was completed. Second, regarding the changes in blood component after the program was conducted, statistically significant differences were found in the lactic acid (p<.05). That is, the experimental group showed a significant decrease in lactic acid after the program whereas the control group showed a significant increase. Third, systolic blood pressure decreased significantly and while in PEF and FEV1 increased significantly in the experimental group after the program. Fourth, the LF of the control group significantly decreased after 5 days. Conclusion : After the Soomchi Lung Health Ocean Healing Program, positive physical changes were observed in the lung health variables and heart rate variability of the participants.

• Journal of the Semiconductor & Display Technology
• /
• v.21 no.3
• /
• pp.57-62
• /
• 2022

The plasma resistance of multi-component glasses containing La, Gd, Ti, Zn, Y, Zr, Nb, and Ta was analyzed in this study. The plasma etching was performed via inductively coupled plasma-reactive ion etching (ICP-RIE) using CF₄/O₂/Ar mixed gas. After the reaction, the glass with a low fluoride sublimation temperature and high content of P, Si, and Ti elements showed a high etching rate. On the other hand, the glass containing a high fluoride sublimation temperature component such as Ca, La, Gd, Y, and Zr exhibited high plasma resistance because the etch rate was lower than that of sapphire. Glass with low plasma resistance increased surface roughness after etching or nanoholes were formed on the surface, but glass with high plasma resistance showed little change in surface microstructure. Thus, the results of this study demonstrate the potential for the development of plasma-resistant glasses (PRGs) with other compositions besides alumino-silicate glasses, which are conventionally referred to as plasma-resistant glasses.

• The Korean Journal of Food And Nutrition
• /
• v.36 no.1
• /
• pp.25-32
• /
• 2023

To increase antioxidant activity and physicochemical quality characteristics, four kinds of berries (blueberry (BEB), blackberry (BKB), cranberry (CNB), raspberry (RSB)) with antioxidant activities were used to replace beet (B) in existing ABC juice. In the experimental group, the pH was decreased while the content of soluble solids was increased significantly. Total polyphenol content was significantly increased in all experimental groups compared to that in the control group. The control group had the lowest polyphenol content at 14.723 ㎍ GAE/g, whereas the blackberry replacement group had the highest polyphenol content at 67.12 ㎍ GAE/g. The total flavonoid content was the lowest in the control group at 8.98 ㎍ QE/g but the highest in the blackberry group at 50.47 ㎍ QE/g. All experimental groups showed significantly higher antioxidant activities than the control group. DPPH & ABTS radical scavenging activities were the lowest in the control group at 15.69% and 19.55%, respectively, but the highest in the blackberry group at 48.24% and 59.43%, respectively. SOD-like activity was also the lowest in the control group at 14.12%, but the highest in the blackberry group at 48.18%. When comparing experimental groups, antioxidant activities (DPPH, ABTS, SOD) and antioxidant components (total polyphenols and total flavonoids) were in the order of BKB > CNB > RSB > BEB > Control. In conclusion, the new ABC juice containing four types of berries is enriched in antioxidants with significantly improved antioxidant activities and physicochemical quality characteristics.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2003.11a
• /
• pp.20-20
• /
• 2003

We developed 30 ㎽-AlInGaN based violet laser diodes. The fabrication procedures of the laser diodes are described as follows. Firstly, GaN layers having very low defect density were grown on sapphire substrates by lateral epitaxial overgrowth method. The typical dislocation density was about 1-3$\times$10$^{6}$ /$\textrm{cm}^2$ at the wing region. Secondly, AlInGaN laser structures were grown on LEO-GaN/sapphire substrates by MOCVD. UV activation method, instead of conventional annealing, was conducted to achieve good p-type conduction. Thirdly, ridge stripe laser structures were fabricated. The cavity mirrors were formed by cleaving method. Three pairs of SiO$_2$ and TiO$_2$ layers were deposited on the rear facet for mirror coating. Lastly, laser diode chips were mounted on AlN submount wafers by epi-down bonding method. The lifetime of the laser diodes was over 10,000 hrs at room temperature under automatic power controlled condition. We expect the performance of the LDs to be improved by the optimization of the growth and fabrication process. The detailed characteristics and important issues of the laser diodes will be discussed at the conference.