• Journal of Forest and Environmental Science
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• v.33 no.4
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• pp.322-329
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• 2017

As a result of contemporary environmental concerns, a number of studies from plants' tissues as one of the alternatives to conventional chemicals are increasingly investigated. In tandem with these trends, Lagenaria breviflora (LB) fruit, reputed as antiviral and depilatory agents in the Yoruba folkloric medicine was examined on Vitex doniana wood to ascertain its antifungal activity. Fungicides of 25%, 50%, 75%, and 100% LB fruits formulations (concentrations) were developed through simple one-step mechanical-forming process, including control. In this study, the yield, the chemical compositions, the absorption capacity of the fungicides and wood weight losses (WWL) analysis were evaluated to investigate the antifungal activity of LB fruit on wood. The fruit extract yielded 35.4% of fresh juice weight. LB fruits contained total: alkaloids ($8.78{\pm}0.21mg/mL$), flavonoids ($2.01{\pm}0.02mg/mL$), phenol ($7.42{\pm}0.09mg/mL$), saponins ($11.00{\pm}0.10mg/mL$) and tannins ($5.47{\pm}0.05mg/mL$) contents. All the formulations provided effective protection against the tested wood fungi compared to control. Interestingly, the antifungal activity of 50% and 25% formulations of 6.8% WWL and 9.9% WWL satisfied the excellent fungal resistance class description against white rot fungus (Ganoderma lucidum) and brown rot fungus (Fibroporia vaillantii), respectively according to ASTM D 2017. These results thus, support LB fruit as a strong potential source of natural antifungals for industrial wood production.

• The Journal of the Convergence on Culture Technology
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• v.6 no.1
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• pp.23-29
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• 2020

Since the movements of a machine are driven by a certain principle, there is a fundamental principle that governs the movement of the machine, no matter how complex and diverse it may be. Autonomous movements are a way to avoid repetition, to approach more humane and more natural factors. That's all the more so when it comes to original movements, not cloning. So now, the dynamics of the machine are more multi-sensory by human participation. It is challenging the potential to be expressed and is gradually expanding its sphere of expression in the boundaries of fact and cloning. Theo Jansen's works have changed from period to period to adapt to different circumstances, indicating that his decades-long work has continued to evolve from early to present. The evolution's focus, among other things, can be seen as having the same source of circular motion and horizontal reciprocating motion, which are repeated from the principle of organic coupling between the parts that make up the object.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.2
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• pp.126-136
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• 2020

Recently, unmanned aerial vehicles (UAV, Drone) are highly regarded for their potential in the agricultural field, and research and development are actively conducted for various purposes. Therefore, in this study, to present a framework for tracking research trends in UAV use in the agricultural field, we secured a keyword search strategy and analyzed social network, a methodology used to analyze recent research trends or technological trends as an analysis model applied. This study consists of three stages. As a first step in data acquisition, search terms and search formulas were developed for experts in accordance with the Keyword Search Strategy. Data collection was conducted based on completed search terms and search expressions. As a second step, frequency analysis was conducted by country, academic field, and journal based on the number of thesis presentations. Finally, social network analysis was performed. The analysis used the open source programming language 'Python'. Thanks to the efficiency and convenience of unmanned aerial vehicles, this field is growing rapidly and China and the United States are leading global research. Korea ranked 18th, and bold investment in this field is needed to advance agriculture. The results of this study's analysis could be used as important information in government policy making.

• Bulletin of the Society of Naval Architects of Korea
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• v.23 no.4
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• pp.25-34
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• 1986

A two-dimensional linear method has been developed for the motion and the second-order steady force arising from the hydrodynamic coupling between waves and currents in the presence of a body of arbitrary shape. Interaction between the incident wave and current in the absence of the body lies in the realm beyond our interest. A Fredholm integral equation of the second kind is employed in association with the Haskind's potential for a steadily moving source of pulsating strength located in or below the free surface. The numerical calculations at the preliminary stage showed a significant fluctuation of the hydrodynamic forces on the surface-piercing body. The problem is approximately solved by using the asymptotic Green function for $U^2{\rightarrow}0$. The original Green function, however, is applied for the fully submerged body. Numerical calculations are made for a submerged and for a half-immersed circular cylinder and extensively for the mid-ship section of a Lewis-form. Some of the results are compared with other analytical results without any available experimental data. The current has strong influence on roll motion near resonance. When the current opposes the waves, the roll response are generally negligible in the low frequency region. The current has strong influence on roll motion near resonance. When the current opposes the wave, the roll response decreases. When the current and wave come from the same direction, the roll response increases significantly, as the current speed increases. The mean drift forces and moment on the submerged body are more affected by current than those on the semi-immersed circular cylinder or on the ship-like section in the encounter frequency domain.

• Bulletin of the Korean Chemical Society
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• v.33 no.4
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• pp.1135-1140
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• 2012

An electrochromatographic microchip with carboxyl-group-derivatized mono-disperse silica packing was prepared from the corresponding colloidal silica solution by utilizing capillary action and self-assembly behavior. The silica beads in water were primed by the capillary action toward the ends of cross-patterned microchannel on a cyclic olefinic copolymer (COC) substrate. Slow evaporation of water at the front of packing promoted the self-assembled packing of the beads. After thermally binding a cover plate on the chip substrate, reservoirs for sample solutions were fabricated at the ends of the microchannel. The packing at the entrances of the microchannel was silver coated to fix utilizing an electroless silver-plating technique to prevent the erosion of the packed structure caused by the sudden switching of a high voltage DC power source. The electrochromatographic behavior of the microchip was explored and compared to that of the microchip with bare silica packing in basic borate buffer. Electrophoretic migration of Rhodamine B was dominant in the microchip with the carboxyl-derivatized silica packing that resulted in a migration approximated twice as fast, while the reversible adsorption was dominant in the bare silica-packed microchip. Not only the faster migration rates of the negatively charged FITC-derivatives of amino acids but also the different migration due to the charge interaction at the packing surface were observed. The electrochromatographic characteristics were studied in detail and compared with those of the bare silica packed microchip in terms of the packing material, the separation potential, pH of the running buffer, and also the separation channel length.

• Korean Journal of Agricultural Science
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• v.29 no.1
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• pp.1-7
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• 2002

Postharvest characteristics of 'Pingguoli' fruit produced between China and Korea were compared to find an ecological difference. There was a difference in fresh weight per fruit, thus, fruit weight produced in Korea was much higher than those in China. However, no significant differences were confirmed in the level of soluble solid content and flesh firmness. The acidity of Korean 'Pingguoli' was higher than Chinese ones. The external appearance of Korean 'Pingguoli' was not attractive due to the rough and rugged surface. Thus, the prospect of 'Pingguoli' cultivation in Korea seems not to be promised. The general trend of respiration and ethylene evolution during storage did not significantly differed but the amount of $CO_2$ and ethylene production was higher in fruits produced in China. There was a strong similarity in respiration and ethylene evolution pattern to typical climacteric fruits. Thus, 'Pingguoli' is considered as a climacteric fruit. Even though the rate of ethylene production of 'Pingguoli' was relatively high, the storability of 'Pingguoli' showed a strong potential. The further studies in postharvest physiology of pear using 'Pingguoli' and in its breeding potentials as a source of long storage life are needed.

• The Journal of Advanced Prosthodontics
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• v.2 no.1
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• pp.7-13
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• 2010

Although most researchers agree that platelet-rich plasma (PRP) is a good source of autogenous growth factors, its effect on bone regeneration is still controversial. The purpose of this study was to evaluate whether increasing angiogenic factors in the human PRP to enhance new bone formation through rapid angiogenesis. MATERIAL AND METHODS. In vitro, the human platelets were activated with application of shear stress, $20\;{\mu}g/ml$ collagen, 2 mM $CaCl_2$ and 10U thrombin/$1\;{\times}\;10^9$ platelets. Level of vascular endothelial growth factor (VEGF) and platelet microparticle (PMP) in the activated platelets were checked. In the animal study, human angiogenic factors-enriched PRP was tested in 28 athymic rat's cranial critical bone defects with $\beta$-TCP. Angiogenesis and osteogenesis were evaluated by laser Doppler perfusion imaging, histology, dual energy X-ray densinometry, and micro-computed tomography. RESULTS. In vitro, this human angiogenic factors-enriched PRP resulted in better cellular proliferation and osteogenic differentiation. In vivo, increasing angiogenic potential of the PRP showed significantly higher blood perfusion around the defect and enhanced new bone formation around acellular bone graft material. CONCLUSION. Angiogenic factor-enriched PRP leads to faster and more extensive new bone formation in the critical size bone defect. The results implicate that rapid angiogenesis in the initial healing period by PRP could be supposed as a way to overcome short term effect of the rapid angiogenesis.

• Clinical and Experimental Reproductive Medicine
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• v.37 no.3
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• pp.199-206
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• 2010

Stem-cell therapy has the potential to improve vision in patients with untreatable retinal disease. Various types of cell source including fetal, embryonic and adult stem cells, intrinsic and extrinsic factors for differentiation into retinal progenitors and transplantation mode were discussed in this review. Experimental approaches have successfully induced photoreceptor precursor cells and retinal pigment epithelium. Stem-cell-based therapy is a promising treatment to restore vision in patients with retinal disease, in spite of the challenges.

• Nuclear Engineering and Technology
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• v.52 no.10
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• pp.2410-2414
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• 2020

Heavy ions have a high potential for destroying deep tumors that carry the highest dose at the peak of Bragg. The peak caused by a single-energy carbon beam is too narrow, which requires special measures for improvement. Here, carbon-12 (¹²C) ion with different energies has been used as a source for calculating the dose distribution in the water phantom, soft tissue and bone by the code of Monte Carlobased FLUKA code. By increasing the energy of the initial beam, the amount of absorbed dose at Bragg peak in all three targets decreased, but the trend for this reduction was less severe in bone. While the maximum absorbed dose per bone-mass unit in energy of 200 MeV/u was about 30% less than the maximum absorbed dose per unit mass of water or soft tissue, it was merely 2.4% less than soft tissue in 400 MeV/u. The simulation result showed a good agreement with experimental data at GSI Darmstadt facility of biophysics group by 0.15 cm average accuracy in Bragg peak positioning. From 200 to 400 MeV/u incident energy, the Bragg peak location increased about 18 cm in soft tissue. Correspondingly, the bone and soft tissue revealed a reduction dose ratio by 2.9 and 1.9. Induced neutrons did not contribute more than 1.8% to the total energy deposited in the water phantom. Also during ¹²C ion bombardment, secondary fragments showed 76% and 24% of primary 200 and 400 MeV/u, respectively, were present at the Bragg-peak position. The combined treatment of carbon ions with neutron or electron beams may be more effective in local dose delivery and also treating malignant tumors.

• Journal of Ginseng Research
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• v.44 no.1
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• pp.145-153
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• 2020

Background: Panax ginseng Meyer (Araliaceae) is a highly valued medicinal plant in Asian regions, especially in Korea, China, and Japan. Chemical and biological studies on P. ginseng have focused primarily on its roots, whereas the seeds remain poorly understood. This study explores the phytochemical and biological properties of compounds from P. ginseng seeds. Methods: P. ginseng seeds were extracted with methanol, and 16 compounds were isolated using various chromatographic methods. The chemical structures of the isolates were determined by spectroscopic data. Antiinflammatory activities were evaluated for triterpene and steroidal saponins using lipopolysaccharide-stimulated RAW264.7 macrophages and THP-1 monocyte leukemia cells. Results: Phytochemical investigation of P. ginseng seeds led to the isolation of a novel triterpene saponin, pseudoginsenoside RT₈, along with 15 known compounds. Pseudoginsenoside RT₈ exhibited more potent antiinflammatory activity than the other saponins, attenuating lipopolysaccharide-mediated induction of proinflammatory genes such as interleukin-1β, interleukin-6, inducible nitric oxide synthase, cyclooxygenase-2, and matrix metalloproteinase-9, and suppressed reactive oxygen species and nitric oxide generation in a dose-dependent manner. Conclusion: These findings indicate that pseudoginsenoside RT₈ has a pharmaceutical potential as an antiinflammatory agent and that P. ginseng seeds are a good natural source for discovering novel bioactive molecules.