• Journal of Veterinary Clinics
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• v.37 no.5
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• pp.261-269
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• 2020

The purpose of this study is to investigate the clinical effects of carboxymethyl chitosan (CMC) and adipose-derived mesenchymal stem cells (MSCs) on osteoarthritis (OA). Thirty New Zealand white rabbits were used as cranial cruciate ligament transection and partial meniscectomy models. The rabbits were divided into five groups (n = 6) according to the intra-articular injection materials: the control group with PBS, the HA group with hyaluronic acid, the CMC group with CMC, the MSC group with MSCs emerged in PBS, and the MSC+CMC group with CMC and MSCs. Knee thickness, extension angle, gross morphology, histopathology and immunohistochemistry were performed to evaluate the effects of CMC and MSCs on rabbit OA. On the morphologic and histologic examination, the articular surfaces of the femur and tibia were markedly damaged in control group with higher Mankin score and lower cartilage surface thickness. However, OA related cartilage defects were alleviated by the treatment of MSC and/or CMC. The expressions of apoptotic and inflammatory cytokines were decreased and cartilage extracellular matrix (ECM) related collagens I and II were enhanced by the treatment of MSC and/or CMC. In conclusion, this study showed that CMC and MSC treatments have a beneficial effects on OA via the protection of cartilage damage, the stimulation of ECM, and the inhibition of inflammatory and apoptotic reaction.

• Archives of Pharmacal Research
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• v.26 no.1
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• pp.76-82
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• 2003

Drug releasing porous poly($\varepsilon$-caprolactone) (PCL)-chitosan matrices were fabricated for bone regenerative therapy. Porous matrices made of biodegradable polymers have been playing a crucial role as bone substitutes and as tissue-engineered scaffolds in bone regenerative therapy. The matrices provided mechanical support for the developing tissue and enhanced tissue formation by releasing active agent in controlled manner. Chitosan was employed to enhance hydrophilicity and biocompatibility of the PCL matrices. PDGF-BB was incorporated into PCL-chitosan matrices to induce enhanced bone regeneration efficacy. PCL-chitosan matrices retained a porous structure with a 100-200 $\mu$m pore diameter that was suitable for cellular migration and osteoid ingrowth. $NaHCO_3$ as a porogen was incorporated 5% ratio to polymer weight to form highly porous scaffolds. PDGF-BB was released from PCL-chitosan matrices maintaining therapeutic concentration for 4 week. High osteoblasts attachment level and proliferation was observed from PCL-chitosan matrices. Scanning electron microscopic examination indicated that cultured osteoblasts showed round form and spread pseudopods after 1 day and showed broad cytoplasmic extension after 14 days. PCL-chitosan matrices promoted bone regeneration and PDGF-BB loaded matrices obtained enhanced bone formation in rat calvarial defect. These results suggested that the PDGF-BB releasing PCL-chitosan porous matrices may be potentially used as tissue engineering scaffolds or bone substitutes with high bone regenerative efficacy.

• Journal of the Korean Ceramic Society
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• v.48 no.3
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• pp.217-221
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• 2011

Glass-ceramic materials, which consist of glass matrix phase containing crystalline ${\beta}-Ca_3(PO_4)_2$ and ${\beta}-Ca_2P_2O_7$, have been prepared by heating at $750-900^{\circ}C$ of calcium phosphate invert glasses in the silica-free $CaO-P_2O_5-TiO_2-Na_2O$, system. With increasing heating temperature from 750 to $900^{\circ}C$, the crystallite size of precipitated ${\beta}-Ca_3(PO_4)_2$ in glass with $55CaO{\cdot}35P_2O_5{\cdot}3TiO_2{\cdot}7Na_2O$ (mol%) composition increased from 48 to 91 nm. With the extension of the immersion time in dilute acetic acid solution (pH = 5) to ${\geq}$200 min, the degree of dissolution of $Ca^{2+}$ and $P^{5+}$ ions in the glass-ceramics was linearly increased and the solution was constantly maintained at pH = ~7. Biomimetic nanostructured (62-88 nm in average dia.), sphere-shaped hydroxyapatite was homogeneously formed on the surface of the glass-ceramics when socked for 7-14 days in a Hanks' solution, indicating bioactivity of the prepared glass-ceramics.

• Perspectives in Nursing Science
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• v.11 no.1
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• pp.1-9
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• 2014

Purpose: The purpose of this study was to demonstrate a two-year global health project to improve maternal and child health (MCH) in Ethiopia. Methods: This is a descriptive case study. The target area is Kilte Awlaelo Woreda in Tigray Regional State, Ethiopia. A baseline survey was conducted to identify the needs of community residents and health care professionals. A MCH program was developed according to a project design matrix that included: infrastructure renovation of health centers; continuing education for midwives, nurses, and health extension workers (HEWs); and improvement of residents' MCH awareness. Project evaluation will examine the structure, process, and outcomes of the program. Results: The baseline survey showed low rates of family planning (31%) and antenatal and postnatal care use (36.1% and 69%, respectively). The institutional birth rate was 13.5%. Midwives and nurses received 2~4 educational programs about family planning and perinatal care. HEWs were also given practical education. Water and electrical infrastructure of all five health centers in the Kilte Awlaelo Woreda were renovated. Additionally, medical supplies and equipment were provided. Community health education on perinatal care, family planning, and personal hygiene was presented. Conclusion: This study highlights the role of nursing in global health and provides basic information on the development and outcomes of the global health project.

• Journal of the Korean Ceramic Society
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• v.21 no.2
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• pp.149-155
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• 1984

The effect of $ZrO_2$ dispersed phase on the mechanical properties in $Al_2O_3$-$ZrO_2$system has been studied. There are both metastable tetragonal phase and stable monoclinic phase of $ZrO_2$particles diespersed in Al2O3 matrix at room temperature. Metastable tetragonal $ZrO_2$ changes to the stable monoclinic structure within the stress field of the crack. And microcracks are formed by the expansion of $ZrO_2$during the tetragonal-monoclinic transformation on cooling. Therefore stress-induced phase transformation and inclusion-induced microcracking contribute to the mec-hanical properties of $Al_2O_3$-$ZrO_2$system. Sintered composites containing 10m/o $ZrO_2$ yield KiC values of 6.5MN/$m^{3/2}$ much greater than that of pure $Al_2O_3$ This increase results from microcrack extension and stress-induced phase transformation absor-bing energy by crack propagation. Flexural strength of composites is decreased considerably in comparison with pure $Al_2O_3$ This decrease results from microcrack as a crack former and higher porosity than pure $Al_2O_3$.

• The Plant Pathology Journal
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• v.23 no.1
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• pp.13-21
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• 2007

Sweet potato feathery mottle virus(SPFMV) is one of the most prevalent viruses infecting sweet potatoes and occurs widely in sweet potato cultivating areas in Korea. To assess their genetic variation, a total of 28 samples infected with SPFMV were subjected to restriction fragment length polymorphism(RFLP) analysis using DNAs amplified by RT-PCR with specific primer sets corresponding to the coat protein(CP) region of the virus. The similarity matrix by UPGMA procedure indicated that 28 samples infected with SPFMV were classified into three groups based on the number and size of DNA fragments by digestion of CP-encoding regions with 7 enzymes including SalI, AluI, EcoRI, HindIII, FokI, Sau3AI, and DraI bands. Four primer combinations out of 5 designed sets were able to differentiate SPFMV and sweet potato virus G infection, suggesting that these specific primers could be used to differentiate inter-groups of SPFMV. Sequence analysis of the CP genes of 17 SPFMV samples were 97-99% and 91-93% identical at the intra-group and inter-groups of SPFMV, respectively. The N-terminal region of the CP is highly variable and examination of the multiple alignments of amino acid sequences revealed two residues(residues 31 and 32) that were consistently different between SPFMV-O and SPFMV-RC.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.380-380
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• 2010

Currently, organic light-emitting diodes (OLEDs) have been proven of their readiness for commercialization in terms of lifetime and efficiency. In accordance with emerging new technologies, enhancement of light efficiency and extension of application fields are required. Particularly inverted structures, in which electron injection occurs at bottom and hole injection on top, show crucial advantages due to their easy integration with Si-based driving circuits for active matrix OLED as well as large open area for brighter illumination. In order to get better performance and process reliability, usually a proper buffer layer for carrier injection is needed. In inverted top emission OLED, the buffer layer should protect underlying organic materials against destructive particles during the electrode deposition, in addition to increasing their efficiency by reducing carrier injection barrier. For hole injection layers, there are several requirements for the buffer layer, such as high transparency, high work function, and reasonable electrical conductivity. As a buffer material, a few kinds of transition metal oxides for inverted OLED applications have been successfully utilized aiming at efficient hole injection properties. Among them, we chose 2 nm of $WO_3$ between NPB [N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine] and Au (or Al) films. The interfacial energy-level alignment and chemical reaction as a function of film coverage have been measured by using in-situ ultraviolet and X-ray photoelectron spectroscopy. It turned out that the $WO_3$ interlayer substantially reduces the hole injection barrier irrespective of the kind of electrode metals. It also avoids direct chemical interaction between NPB and metal atoms. This observation clearly validates the use of $WO_3$ interlayer as hole injection for inverted OLED applications.

• The Journal of Korean Medicine
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• v.39 no.4
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• pp.86-113
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• 2018

Objectives: We examined the effects of a mixed formula consisting of dried pomegranate concentrate powder (PCP) and the aqueous extracts of Eucommiae cortex (EC) and Achyranthis radix (AR) in rats with surgically induced osteoarthritis (OA). Methods: Two weeks after OA-inducing surgery, a PCP:EC:AR 5:4:1 (g/g) combination or single formula was orally administered. Changes in body weight, knee thickness, maximum knee extension angle, bone mineral density of the knee joints, femoral and tibial articular surfaces, and compressive strength of the femoral and tibial articular cartilage (AC) were assessed, along with the prostaglandin E2 level, 5-lipoxygenase, matrix metalloproteinase (MMP)-2 and MMP-9 activity, and chondrogenic gene mRNA expression in the femoral and tibial AC with the synovial membrane (SM). In addition, the number of cleaved poly(ADP-ribose) polymerase, cyclooxygenase and tumor necrosis factor-${\alpha}$-immunoreactive cells in the femoral and tibial AC with SM were monitored, and the rate of cell proliferation was determined with a 5-bromo-2'-deoxyuridine uptake assay. Results : The signs of surgically induced OA in rats were significantly inhibited by both PCP, EC and AR combined and single formulas. In particular, the combination formula-treated OA model rats showed dose-dependent, significantly increased inhibitory activity against all tested criteria compared with single formula-treated rats. Conclusions: Taken together, our results suggest that the combination formula synergistically increased the anti-OA effects of its components through anti-inflammatory and chondrogenic activity in rats with surgically induced OA. In addition, 200, 100 and 50 mg/kg combination formula treatments showed dose-dependent inhibitory activity against all of the tested criteria.

• Composites Research
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• v.22 no.4
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• pp.20-26
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• 2009

In the current study, thermoforming and compression analysis were carried out for the woven composite egg-box panel with the non-orthogonal constitutive material model, which is proposed by Xue et al. The material model is implemented in commercial engineering software, LS-DYNA, with a user subroutine. Directional properties in non-orthogonal coordinates are determinedusing the deformation gradient tensor and the material modulus matrix in local coordinate is updated at eaeh corresponding time step. After the implemented non-orthogonal constitutive model is verified by the bias extension test, the egg-box panel simulations are performed. The egg-box panel simulations are divided into two categories: thermoforming (draping) and crushing. The finite element model for crushing analysiscan be obtained using the displacement result of thermoforming process.

• The Journal of the Convergence on Culture Technology
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• v.9 no.4
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• pp.437-443
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• 2023

We investigates MICE participants's evaluation on the application of smart tourism technology by comparing their importance and performance. Date were collected from MICE participants who had attended in hybrid MICE in recent five years, The three dimensions of smart tourism technology were event management, extension of contents, and community. We found that event management and community affected on overall satisfaction of MICE participants. The result of paired t-test revealed that there were significant differences in audience interaction, webinar, virtual showcase, communication by social hub, virtual marketplace, and matchmaking The importance-performance matrix also indicated that matchmaking, virtual marketplace, audience interaction, communication by social hub, and webinar were major weakness and should be improved in the future.