• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.21 no.1
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• pp.70-82
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• 2008

Objective : The purpose of this study is to examine the effects of Baickbujasan(BB) on the skin damage and depigmentation. Method : The inhibition of tyrosinase activity, melanogenesis and cell viability in cultured B16 melanoma cells were measured. In order to test effects of reduction of melanogenesis, B16 F-10 mouse melanoma stem line was employed to extract melanin from cultured cell, where BB was added or not, and was dissolved in alkali for colorimetric analysis. Also, in order to test skin alteration in C57BL/6 after UV irradiation, the animals were grouped into a UV urradiation group and UV irradiation after BB application group. Dopa oxidase tissue staining was excuted to invesitage the change in the distribution of active melanin cell. The distribution of active melanin cell in inner skin of iNOS after damage from UVB irradiation and the manifestation condition of P53 which takes part in natural death of keratinocyte were examined. Result : The results indicate that BB has significant effects on tyrosinase activity, and melanogenesis in vivo test. BB seems to reduce C57BL/6, external dermatological damage, for instance, erythematous papule, eczema, loss of keratinocyte, reduction in pus, and relieves dermatological damages. Conclusion : BB can be applied externally for UV protection and depigmentation.

• International Journal of Oral Biology
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• v.31 no.4
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• pp.119-125
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• 2006

The importance of phytoestrogens to human health is currently being actively investigated. Hesperidin, abundantly found in citrus fruits, is known to possess antioxidant, anticancer, and anti-inflammatory effects. Recently, it has been reported that hesperidin inhibits bone loss and decreases serum and hepatic lipids in ovariectomized mice. In our study, to determine the possible role of hesperidin in the regulation of bone metabolism, we observed the effects of hesperidin on the proliferation and activity of osteoblasts, as well as the effects of hesperidin on osteoclast generation and activity. We observed that, when treated with hesperidin, the number and viability of osteoblastic cells increased, alkaline phosphatase (ALP) activity of osteoblastic cells increased, and osteoprotegerin (OPG) secretion from MG63 cells decreased. Hesperidin treatment had no effect on the osteoclast generation and activity in the bone marrow cell culture, but decreased the number and resorptive activity of osteoclasts generated from RAW/264.7 cells. Taken together, these results indicate that hesperidin increases the proliferation and activity of osteoblasts, while inhibiting generation and activity of osteoclasts. Although the precise role of hesperidin remains to be elucidated, our study suggests that it is one of the important modulators of bone metabolism.

• Archives of Pharmacal Research
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• v.29 no.8
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• pp.645-650
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• 2006

Tributyltin chloride (TBTC) at concentrations of $0.5-1.0\;{\mu}M$ inhibits dopamine biosynthesis in PC12 cells. In this study, the effects of TBTC on L-3,4-dihydroxyphenylalanine (L-DOPA)-induced cytotoxicity in PC12 cells were investigated. TBTC at concentrations up to $1.0\;{\mu}M$ neither affected cell viability, nor induced apoptosis after 24 or 48 h in PC12 cells. However, TBTC at concentrations higher than $2.0\;{\mu}M$ caused cytotoxicity through an apoptotic process. In addition, exposure of PC12 cells to non-cytotoxic (0.5 and $1.0\;{\mu}M$) or cytotoxic $(2.0\;{\mu}M)$ concentrations of TBTC in combination with L-DOPA (20, 50 and $100\;{\mu}M$) resulted in a significant increase in cell loss and the percentage of apoptotic cells after 24 or 48 h compared with TBTC or L-DOPA alone. The enhancing effects of TBTC on L-DOPA-induced cytotoxicity were concentration- and treatment time-dependent. These data demonstrate that TBTC enhances L-DOPA-induced cytotoxicity in PC 12 cells.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.17 no.3
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• pp.253-263
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• 1995

Microsurgical vascularized bone transfer has the disadvantages of limitation of available donor sites, loss of donor function, and the possibility of donor site defects or deformity. To overcome these shortage of current microsurgical tissue transfer, the method of creating the neovascularized free flap has been introduced. Potentially, this technique must be an innovation in providing the free vascularized bone grafts that are not limited by natural vascular anatomy. But, as could be imagined technique resulted in unavoidable donor bone defect and additional operation for harvesting the autologous bone. The purpose of this study was to evaluate the efficacy of demineralized allogeneic bone as a possible substitute for autologous bone in fabricating the neo-osseous flap. By histologic, microangiographic and radioisotope method, the viability and vascularity of neo-osseous flap, which has been fabricated using allogeneic bone or autologous bone, was assessed in rat model. After 6 weeks, demineralized allogeneic bone showed consistent bone formation and neovascularization. The clinical and microscopic findings of demineralized allogeneic bone group were inferior to those of autogenous bone with regard to bone regeneration. The amount of bone blood floow per dry weight of demineralized allogeneic bone group was significantly higher than that of autogenous bone, even higher that of control intact iliac bone. In conclusion, findings supported that allogeneic bone could be the potential substitute for autologous bone source in creating a prefabricated neo-osseous flap.

• Archives of Plastic Surgery
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• v.37 no.6
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• pp.775-778
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• 2010

Purpose: Reconstruction of soft tissue defects with osteomyelitis in the lower third of the leg represents a challenge to plastic surgeons. Moreover, it is more arduous in multimorbid patients. One excellent option for reconstruction of these defects is to use a delayed distally based sural flap. Methods: We successfully used delayed distally based sural flap with a two-step procedure. During the first operation, radical debridement and elevation of flap were performed. The raised flap was fixed again at the donor site. The delay period ranged from seven to ten days. Between August 2008 and July 2009, we underwent operations for five patients using this technique. The size of flap varied from $10{\times}6\;cm$ to $12{\times}14\;cm$. Results: All flaps successfully survived. Partial skin loss of the grafted site was seen in two patients but no further surgical procedure was required for wound healing. Complaints of hypoesthesia on the lateral part of the foot was observed. In a three month follow-up period, hypoesthesia was resolved spontaneously. Conclusion: Delayed procedure improves the viability of distally based sural flap in high risk, critically multimorbid patients. We recommend that, if a two-stage operative approach is required, the delayed procedure should be considered.

• International Journal of Computer Science & Network Security
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• v.21 no.12
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• pp.9-20
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• 2021

Abstraction applied in computer networking hides network details behind a well-defined representation by building a model that captures an essential aspect of the network system. Two current methods of representation are available, one based on graph theory, where a network node is reduced to a point in a graph, and the other the use of non-methodological iconic depictions such as human heads, walls, towers or computer racks. In this paper, we adopt an abstract representation methodology, the thinging machine (TM), proposed in software engineering to model computer networks. TM defines a single coherent network architecture and topology that is constituted from only five generic actions with two types of arrows. Without loss of generality, this paper applies TM to model the area of network monitoring in packet-mode transmission. Complex network documents are difficult to maintain and are not guaranteed to mirror actual situations. Network monitoring is constant monitoring for and alerting of malfunctions, failures, stoppages or suspicious activities in a network system. Current monitoring systems are built on ad hoc descriptions that lack systemization. The TM model of monitoring presents a theoretical foundation integrated with events and behavior descriptions. To investigate TM modeling's feasibility, we apply it to an existing computer network in a Kuwaiti enterprise to create an integrated network system that includes hardware, software and communication facilities. The final specifications point to TM modeling's viability in the computer networking field.

• Journal of Powder Materials
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• v.25 no.6
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• pp.507-513
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• 2018

This study investigates the viability of using a Na-ion battery with a tin(Sn) anode to mitigate the vulnerability caused by volume changes during discharge and charge cycling. In general, the volume changes of carbon material do not cause any instability during intercalation into its layer structure. Sn has a high theoretical capacity of $847mAh\;g^{-1}$. However, it expands dramatically in the discharge process by alloying Na-Sn, placing the electrode under massive internal stress, and particularly straining the binder over the elastic limit. The repeating strain results in loss of active material and its electric contact, as well as capacity decrease. This paper expands the scope of fabrication of Na-ion batteries with Sn by fabricating the binder as an auxetic structure with a unique feature: a negative Poisson ratio (NPR), which increases the resistance to internal stress in the Na-Sn alloying/de-alloying processes. Electrochemical tests and micrograph images of auxetic and common binders are used to compare dimensional and structural differences. Results show that the capacity of an auxetic-structured Sn electrode is much larger than that of a Sn electrode with a common-structured binder. Furthermore, using an auxetic structured Sn electrode, stability in discharge and charge cycling is obtained.

• Nuclear Engineering and Technology
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• v.54 no.2
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• pp.709-731
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• 2022

Loss of fracture resistance due to thermal aging degradation is a potential limiting factor affecting the long-term (80+ year) viability of nuclear reactors. To evaluate the effects of decades of aging in a practical time frame, accelerated aging must be employed prior to mechanical characterization. In this study, a variety of chemically and microstructurally diverse austenitic stainless steels were aged between 0 and 30,000 h at 290-400 ℃ to simulate 0-80+ years of operation. Over 600 static fracture tests were carried out between room temperature and 400 ℃. The results presented include selected J-R curves of each material as well as K_0.2mm fracture toughness values mapped against aging condition and ferrite content in order to display any trends related to those variables. Results regarding differences in processing, optimal ferrite content under light aging, and the relationship between test temperature and Mo content were observed. Overall, it was found that both the ferrite volume fraction and molybdenum content had significant effects on thermal degradation susceptibility. It was determined that materials with >25 vol% ferrite are unlikely to be viable for 80 years, particularly if they have high Mo contents (>2 wt%), while materials less than 15 vol% ferrite are viable regardless of Mo content.

• Development and Reproduction
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• v.26 no.2
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• pp.79-90
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• 2022

Krüppel-like factor 10 (KLF10) regulates various cellular functions, such as proliferation, differentiation and apoptosis, as well as the homeostasis of several types of tissue. In the present study, we attempted a loss-of-function analysis of zebrafish Klf11a and Klf11b, which constitute human KLF10 homologs. Embryos injected with klf11b-morpholino (MO) showed developmental retardation and cell death, whereas klf11a-MO-injected embryos showed normal development. In klf11b-MO-injected embryos, a dramatic increase in the amount of zebrafish p53 mRNA might be the cause of the increase in that of bax. The degree of apoptosis decreased in the klf11b-MO and p53-MO co-injected embryos. These findings imply that KLF10 is a negative regulator of p53-dependent transcription, suggesting that the KLF10/p53 complex may play an important role in apoptosis for maintenance of tissue homeostasis during embryonic development.

• Food Science of Animal Resources
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• v.43 no.1
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• pp.157-169
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• 2023

Effects of culture supernatants of Lactobacillus reuteri MG5346 (CS-MG5346) on receptor activator of nuclear factor-kappa B ligand (RANKL)-induced osteoclastogenesis were examined. CS-MG5346 treatment up to 400 ㎍/mL significantly reduced tartrate-resistant acid-phosphatase (TRAP) activity, the phenotype biomarker of osteoclast, without affecting cell viability. CS-MG5346 inhibited the expression of osteoclast specific transcriptional factors (c-fos and nuclear factor-activated T cells c1) and their target genes (TRAP, cathepsin, and matrix metallo-proteinase-9) in a dose-dependent manner (p<0.05). The administration of L. reuteri MG5346 (2×10⁸ CFU/day) for 8 wks significantly improved furcation involvement, but no difference was observed in alveolar bone loss in ligature-induced experimental periodontitis rats. The elevated RANKL/osteoprotegerin ratio, the biomarker of periodontitis, was significantly lowered in the gingival tissue by administration of L. reuteri MG5346 (p<0.05). L. reuteri MG5346 showed excellent stability in simulated stomach and intestinal fluids and did not have antibiotic resistance. Based on the results, L. reuteri MG5346 has the potential to be a promising probiotic strain for oral health.