• Korean Journal of Materials Research
• /
• v.14 no.2
• /
• pp.141-145
• /
• 2004

Silicon nitride thin films were deposited by atomic layer deposition (ALD) technique in a batch-type reactor by alternating exposures of precursors. XJAKO200414714156408$_4$ or$ SiH_2$$Cl_2$ was used as the Si precursor, $NH_3$ was used as the N precursor, and the deposited films were characterized comparatively. The thickness of the film linearly increased with the number of deposition cycles, so that the thickness of the film can be precisely controlled by adjusting the number of cycles. As compared with the deposition using$ SiCl_4$, the deposition using $SiH_2$$Cl_2$ exhibited larger deposition rate at lower precursor exposures, and the deposited films using $SiH_2$$Cl_2$ had lower wet etch rate in a diluted HF solution. Silicon nitride films with the Si:N ratio of approximately 1:1 were obtained using either Si precursors at $500^{\circ}C$, however, the films deposited using $SiH_2$$Cl_2$ exhibited higher concentration of H as compared with those of the $SiC_4$ case. Silicon nitride thin films deposited by ALD showed similar physical properties, such as composition or integrity, with the silicon nitride films deposited by low-pressure chemical vapor deposition, lowering deposition temperature by more than $200^{\circ}C$.

• The Journal of the Korean bone and joint tumor society
• /
• v.4 no.1
• /
• pp.65-70
• /
• 1998

Osteosarcoma is the most common primary bone tumor except for multiple myeloma. Hematogenous spread of osteosarcoma presents the t1susal route of dissemination. Lung metastasis is the most common, however the lymph node involvement is quite rare. In addition, according to Mirra, radiologically detectable involvement of lymph node is an extremely rare manifestation of osteosarcoma. The authors had experienced a patient with an osteosarcoma of the right distal femur which spread to the right inguinal lymph node and lung. After preoperative chemotheraphy, a limb salvage operation was performed around the lesion of right distal femur and the right inguinal lymph nodes were dissected. A adjuvant postoperative chemotheraphy was performed. After the treatment, there was no recurrence of osteosarcoma or any other metastatic evidence for two years and 8 months.

• Journal of Korean Foot and Ankle Society
• /
• v.5 no.1
• /
• pp.62-68
• /
• 2001

Purpose: to investigate the etiology and the results of surgical treatment of the symptomatic accessory navicular in adults. Materials and Methods: Between 1996 and 2000, 17 cases in 16 adult patients who were older than 20 years were diagnosed as painful accessory na vicular. 11 patients could recall a twisting injury of the ankle, and 8 of them were inversion sprain. 4 patients had tibialis posterior tendon lesions. 13 feet of 12 patients were treated by resection of accessory navicular, the synchondrosis, the medial portion of the navicular and reattachment of tibialis posterior tendon without transposition. 9 feet in 8 patients were followed for more than one year after surgery. In 4 patients with tibialis posterior tendon lesions, additional procedures were performed according to the state of the lesion. Results: All were type II accessory navicular bone which had synchondroses. There was gross motion of the synchondrosis in 'the operating field in all feet. Of the 9 feet which were followed for more than one year after surgery, results were excellent in five and good in four. Conclusion: The painful accessory navicular in adult might be closely associated with inversion ankle sprain, and also with the tibialis posterior tendon lesions. Satisfactory result could be obtained without transposition of the tibialis posterior tendon to the undersurface of the navicular and immediate postoperative weight bearing does not have harmful effect on the result.

• Human Ecology Research
• /
• v.55 no.2
• /
• pp.153-166
• /
• 2017

This study examined the effects of the cognitive and affective country image of Korea on product evaluation and purchase intention for Korean products. The research model was developed from relevant literature based on the halo effect model and data was collected using a self-administered online survey of 772 Southeast Asian consumers from Vietnam, Indonesia, and Malaysia. The major findings are as follows. First, analysis of variance revealed that Vietnam consumers have a significantly positive perception compared to Indonesia and Malaysia, regarding the affective country image and purchase intention towards Korean products. Second, results from structural equation model showed that the affective country image has significantly positive effects on product evaluation and purchase intention, which means the affective country image is directly and indirectly connected to purchase intention towards Korean products. However, cognitive country image only has an indirect effect on purchase intention. Third, the results of comparing path coefficient among three countries showed that the direct effect is more effective for consumers in Indonesia and Malaysia, whereas indirect effect has a stronger effect on consumers in Vietnam. Academically, this study contributes to an expansion of understanding the effects of country image by empirically proving the different roles of cognitive and affective dimensions for country image. This study provides practical implications for developing marketing communication strategies for businesses that hope to penetrate Southeast Asian countries.

• The Korean Journal of Food & Health Convergence
• /
• v.6 no.5
• /
• pp.11-17
• /
• 2020

This study tried to analyze sensual properties by classifying the thermal water extract of the main material used in Ssanghwa tea. Through this study, we wanted to develop popular Ssanghwa tea and further carry out basic research for the development of various menus using it. The ingredients for the Ssanghwa tea were washed under running water, then dehydrated and put in a pot as 2L of purified water. Ssangwha tea were heated at 100℃ for 10 minutes, then lowered the temperature to 75℃ and boiled down to 200 ml for 110 minutes. This study evaluated sensory characteristics of four types of commercial products and the five types manufactured by the description analysis. Quantitative analysis of the commercial Ssanghwa tea showed significant differences between samples in seven of the total 13 sensory characteristics except OG(Smell of grass), OC(Oriental medicine smell), TG(Umami), RT(Thick), RC(Rough) and RS(Tub-Tub) (p<0.05). In particular, differences between samples were evident in CT(Transmittance), CB(Brownness), TW(Sweet taste) and TB(Bitter) (p<0.001), which appeared to be the main differentiated features of appearance, aroma and taste for commercial Ssanghwa tea. This study tried to analyze sensual properties by classifying the thermal water extract of the main material used in Ssanghwa tea. Through, we wanted to develop popular Ssanghwa tea and further carry out basic research for the development of various menus using it.

• Genomics & Informatics
• /
• v.2 no.1
• /
• pp.36-44
• /
• 2004

Astrocytes play supportive roles for neurons in the brain. Recently, they have been accepted to have various functions in the vascular system as well as in the nervous system. We investigated the differential gene expression in rat astrocytes according to the oxygen tension, which is a crucial factor for angiogenesis. A cDNA microarray was performed to find the genes whose expression was sensitive to oxygen tension. We found 26 genes in the astrocyte were found and classified into 4 groups. In order to show the genes' relevancy to angiogenesis, seven of the 26 genes were investigated to see whether they have capabilities of interaction with angiogenesis­related factors in AngioDB. Through this investigation, we found interactions of three proteins with angiogenesis-related factors. These genes were further investigated with a new focus on the vascular endothelial growth factor (VEGF) expression in an astrocyte based on our hypothesis that astrocytes can have effects on endothelial angiogenesis via the release of VEGF. Collectively, we identified several genes whose expressions were dependent on the oxygen concentration of the astrocyte. Furthermore, the relevancy of astrocytes to angiogenesis was investigated using preexisting information of AngioDB, and suggested a possible signaling pathway for VEGF expression in the aspects of brain endothelial angiogenesis by astrocytes.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.6
• /
• pp.1067-1076
• /
• 2016

The gene encoding lipase (Lip98) from Aeromicrobium sp. SCSIO 25071 was cloned and functionally expressed in Escherichia coli. Lip98 amino acid sequence shares the highest (49%) identity to Rhodococcus jostii RHA1 lipase and contains a novel motif (GHSEG), which is different from other clusters in the lipase superfamily. The recombinant lipase was purified to homogeneity with Ni-NTA affinity chromatography. Lip98 showed an apparent molecular mass of 30 kDa on SDS gel. The optimal temperature and pH value for enzymatic activity were recorded at 30℃ and 7.5, respectively. Lip98 exhibited high activity at low temperatures with 35% maximum activity at 0℃ and good stability at temperatures below 35℃. Its calculated activation energy was 4.12 kcal/mol at the low temperature range of 15-30℃. Its activity was slightly affected by some metal ions such as K⁺, Ca²⁺, and Na⁺. The activity of Lip98 was increased by various organic solvents such as DMSO, ethanol, acetone, and hexane with the concentration of 30% (v/v) and retained more than 30% residual activity in neat organic solvent. The unique characteristics of Lip98 imply that it is a promising candidate for industrial application as a nonaqueous biocatalyst and food additive.

• Journal of Intelligence and Information Systems
• /
• v.19 no.2
• /
• pp.21-38
• /
• 2013

The purpose of this study is to investigate the influence of behavioral factors (buyer's tendency to reflect stockout and overstock experiences in ordering decision) on the supply chain performance. This study employs system dynamics to examine the influence of these behavioral factors derived from the interview with several representatives of retailers in South Korea. The results show that different contract can bring different performance (total profit, seller's profit, buyer's profit, order quantity, sales quantity, overstock, and stockout). The results also suggest that these behavioral factors play a significantly influential role in the performance of supply contract. These results imply that supply contract should be established based on the analysis of behavioral factors of supply chain participants.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.111-111
• /
• 2007

Further scaling the semiconductor devices down to low dozens of nanometer needs the extremely shallow depth in junction and the intentional counter-doping in the silicon gate. Conventional ion beam ion implantation has some disadvantages and limitations for the future applications. In order to solve them, therefore, plasma source ion implantation technique has been considered as a promising new method for the high throughputs at low energy and the fabrication of the ultra-shallow junctions. In this paper, we study about the effects of DC bias and base pressure as a process parameter. The diluted mixture gas (5% $PH_3/H_2$) was used as a precursor source and chamber is used for vacuum pressure conditions. After ion doping into the Si wafer(100), the samples were annealed via rapid thermal annealing, of which annealed temperature ranges above the $950^{\circ}C$. The junction depth, calculated at dose level of $1{\times}10^{18}/cm^3$, was measured by secondary ion mass spectroscopy(SIMS) and sheet resistance by contact and non-contact mode. Surface morphology of samples was analyzed by scanning electron microscopy. As a result, we could accomplish the process conditions better than in advance.

• Archives of Plastic Surgery
• /
• v.32 no.5
• /
• pp.625-635
• /
• 2005

In this study, the effects of verapamil on growth rate, apoptosis, production of transforming growth factor (TGF-${\beta}$) and fibronectin were evaluated in keloid and normal human dermal fibroblasts. Both fibroblasts were primarily cultured from earlobe keloids of three female patients and treated with various concentrations of verapamil. Cell toxicity was assessed by MTT assay, growth rate and apoptosis by FACS, and the production of TGF-${\beta}$ and fibronectin by ELISA and Western blot, respectively. In the $MTT_{50}$, the cell growth was more suppressed in keloid fibroblasts. In the $MTT_{90}$, cell growth was more stimulated in normal fibroblasts. No significant effect appeared on TGF-${\beta}$ expression but an increase in extracellular fibronectin secretion was found in keloid fibroblasts. Keloid fibroblasts responded to verapamil more sensitively, and the percentage of apoptosis was higher at the $MTT_{50}$l. In brief, verapamil had growth-inhibitory effect with inducing apoptosis at the $MTT_{50}$, but rather growth-stimulatory effect at the $MTT_{90}$. The biphasic effect of verapamil depending on the dose might explain one of the reasons of relapse after keloid treatment with verapamil. Clinical application with high concentration (2.5 mg/ml) is advised unless excessive dosage is used.