• Proceedings of the Korean Vacuum Society Conference
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.397-397
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• 2010

Bone is considered as hierarchically organized biocomposites of organic (collagen) and inorganic (hydroxyapatite) materials. The precise structural dependence between hydroxyapatite (HAp, $Ca_{10}(PO_4)_6(OH)_2)$ crystals and collagen fibril is critical to unique characteristics of bone. To meet those conditions and obtain optimal properties, it is essential to understand and control the initial growth mechanisms of hydroxyapatite at the molecular level, such as other nano-structured materials. In this study, collagen fibrils were prepared by adsorbing native type I collagen molecules onto hydrophobic surface. Hydrophobicity was introduced on the Si wafer surface by using PECVD (plasma enhanced chemical vapor deposition) method and cyclohexane as a precursor. Biomimetic nucleation and growth of HAp on the self-assembled collagen nanofibrils were occurred through incubation of the sample in SBF (simulated body fluid). Chemical and morphological evolution of HAp nanocrystals was investigated by surface-sensitive analytical techniques such as ToF-SIMS (Time-of-Flight Secondary Ion Mass Spectrometry) and AFM (Atomic Force Microscopy) in the early growth stages (< 24 hrs). The very initial stages (< 12 hrs) of mineralization could be clearly demonstrated by ToF-SIMS chemical mapping of surface. In addition to ToF-SIMS and AFM measurement, scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction analysis were conducted to characterize the HAp layer in the late stages. This study is of great importance in the growth of real bone-like materials with a structure analogous to that of natural bones and the development of biomimetic nanomaterials.

• Animal cells and systems
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• 제16권3호
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• pp.207-214
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• 2012

Burns are one of the most devastating forms of trauma and wound healing is a complex and multicellular process, which is executed and regulated by signaling networks involving numerous growth factors, cytokines, and chemokines. Recombinant human granulocyte macrophage colony-stimulating factor (rhGM-CSF) was specifically produced from rice cell culture through use of a recombinant technique in our laboratory. The effect of rhGM-CSF on promotion of deep second-degree burn wound healing on the back skin of a hamster model was evaluated through a randomized and double-blind trial. As macroscopic results, hamster skins of the experimental groups showed earlier recovery by new epidermis than the control groups. Immunohistochemical reactions of proliferating cell nuclear antigen and transforming growth factor-b1, which are indicators of cell proliferation, were more active in the experimental group, compared with the control group. On electron microscopy, basal cells in the epidermis of the experimental group showed oval nuclei, prominent nucleoli, numerous mitochondria and abundant free ribosomes. In addition, fibroblasts contained well-developed rough endoplasmic reticulum with dilated cisternae. Bundles of collagen fibrils filled the extracellular spaces. Particularly, ultrastructural features indicating active metabolism for regeneration of injured skin at 15 days after burn injury, including abundant euchromatin, plentiful free ribosomes, and numerous mitochondria, were observed. These findings suggest that use of rhGM-CSF could result in accelerated deep second-degree burn wound healing in animal models.

• Biomolecules & Therapeutics
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• 제32권2호
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• pp.224-230
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• 2024

Pinitol (3-O-Methyl-D-chiro-inositol) has been reported to possess insulin-like effects and is known as one of the anti-diabetic agents to improve muscle, liver, and endothelial cells. However, the beneficial effects of pinitol on the skin are not well known. Here, we investigated whether pinitol had effects on human dermal fibroblasts (HDFs), and human dermal equivalents (HDEs) irradiated with ultraviolet A (UVA), which causes various damages including photodamage in the skin. We observed that pinitol enhanced wound healing in UVA-damaged HDFs. We also found that pinitol significantly antagonized the UVA-induced up-regulation of matrix metalloproteinase 1 (MMP1), and the UVA-induced down-regulation of collagen type I and tissue inhibitor of metalloproteinases 1 (TIMP1) in HDEs. Electron microscopy analysis also revealed that pinitol remarkably increased the number of collagen fibrils with regular banding patterns in the dermis of UVA-irradiated human skin equivalents. Pinitol significantly reversed the UVA-induced phosphorylation levels of ERK and JNK but not p38, suggesting that this regulation may be the mechanism underlying the pinitol-mediated effects on UVA-irradiated HDEs. We also observed that pinitol specifically increased Smad3 phosphorylation, which is representative of the TGF-β signaling pathway for collagen synthesis. These data suggest that pinitol exerts several beneficial effects on UVA-induced damaged skin and can be used as a therapeutic agent to improve skin-related diseases.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제15권1호
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• pp.63-79
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• 1993

To repair bony defects with tansplanted bone in the body, fresh autogenous bone is undoubtly, the most effective bone graft for clinical applications. But the demineralized bone has the matrix-induced bone formation which was suggested by Urist in 1965. Many authors assisted that demineralized bone powder induces phenotypic conversion of mesenchymal cells into osteoblasts, with high-density bone formation. The process of inducing differentiated cells becomes osteogenic properties. The purpose of this study was to evaluate the osteoinductive capacity of allogenic freeze-dried demineralized bone block (FDD, $7{\times}7mm$) and to compare FDD with the same sue of deep-frozen allogenic bone(DF), fresh autogenous bone (A) after implantation. The histological and ultrastructural features of tissue responses were examined after 1, 2, 4, 6, 8 weeks implantation of each experimental groups in the operative site of the New Zealand white rabbits. The results were as follows : 1. Inflammatory cell infiltration generally has appeared at 1 week, but reduced at 4 weeks in each group, but most severe in DF group. 2. Osteoblastic activity has increased for 4 weeks, but decreased at 6 weeks in each group and there was no significant difference among experimental groups. 3. New bone formation has begun at 1week, least activations in A groups, and showed the revesal line of bone formation among each group at 6 to 8 weeks. 4. Bone resorption has appeared at 1 week, but disappeared at 4 weeks in both A and DF groups, but more severe in DF than A groups. 5. In ultrastructural changs, the DF group have showed the most remarkable osteoclastic activities among experimental groups. 6. Osteoid or tangled collagen fibrils near the implanted sites were replaced by more mature, lamellated bony trabeculae during bone remodeling. There was little difference among each experimental groups. 7. During the convertion osteoblasts to osteocytes which embedded within the bone matrix, there was organ-less-poor cytoplasm, increased nuclear chromatin, abundant rough endothelial reticulum (RER) in each groups. From the above the findings, the DF group shored more bone resorption and foreign body reaction than FDD and A groups, and FDD group showed more new bone formation or osteoblastic activity than DF and A groups in early stage. There was no significant difference of cellular activities among the FDD DF, and A groups according to the time.

• Applied Microscopy
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• 제39권2호
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• pp.157-165
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• 2009

Here we demonstrate the fine structural characteristics of the spigots on the cribellum and its peculiar sieve-like structure at the aspects of the functional significance. The surface of the cribellum is covered by hundred of tiny spigots which producing numerous cribellate silk fibrils. It has been known that the cribellar silk is considered as a quite different sort of catching silk with dry-adhesive properties. By our fine structural observation using the field emission scanning electron microscopy (FESEM), the titanoecid spiders have a specialized sieve-like plate just in front of the anterior spinnerets. The other types of the silk spigots were identified as follows: ampullate, pyriform and aciniform glands. Two pairs of major ampullate glands send secretory ductules to the anterior spinnerets, and another 1~2 pairs of minor ampullate glands supply the median spinnerets. In addition, the pyriform glands send ductules to the anterior spinnerets, and the aciniform glands feed silk into the median and the posterior spinnerets, respectively. Characteristically, 2 distinct types (A & B types) of the aciniform spigots were identified in this spider, and the spigots of the aciniform B type are always detected at the posterior spinneret, however sexual dimorphism for spigot is unlikely to be exhibited in this species of spider.

• Food Science of Animal Resources
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• 제40권4호
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• pp.588-600
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• 2020

The effect of age (22, 30, 38, and 46 days) on Beijing duck breast myosin gels was investigated. The results showed that the water holding capacity (WHC) and gel strength were markedly improved at the age of 30 days. Differential scanning calorimetry suggested that the myosin thermal ability increased at the age of 30 and 38 days (p<0.05). A compact myosin gel network with thin cross-linked strands and small regular cavities formed at the age of 30 days, which was resulted from the higher content of hydrophobic interactions and disulfide bonds. Moreover, the surface hydrophobicity of myosin extracted from a 30-day-old duck breast decreased significantly under temperature higher than 80℃ (p<0.05). This study illustrated that myosin extracted from a 30-day-old duck's breast enhanced and stabilized the WHC, thermal stability and molecular forces within the gel system. It concluded that age is an essential influencing factor on the myosin thermal stability and gel quality of Beijing duck due to the transformation of fibrils with different myosin character.

• The Korean Journal of Zoology
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• 제28권2호
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• pp.85-98
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• 1985

The present study was carried out light and electron microscopic analysis of the structures of the tritocerebral neurons in butterfly (Pieris rapae Linne) from Insecta. We have summarized our morphological analyses as follows: In insecta, tritocerebrum of butterfly shows tentatively classified 6 neuronal types without any arrangement of cell layers. Type I cells with long oval or spindle shape are the largest out of 6 kinds. The nucleus contains a small amount of chromatin. In the large volume of cytoplasm there contained rich cell organelles except granular endoplasmic reticulum. Type II cells are smaller than type I neurons, but their ultrastructural features are similar to type I neuron. They have well-developed granular endoplasmic reticulum. Type III cells are spherical or triangular and smaller than type I neuron with spherical nuclei. Cell organelles are mostly prominent, esp., mitochondria, ribosomes and fine fibrils which are arranged in periphery of the cytoplasm.

• Journal of the Korean Arthroscopy Society
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• 제5권1호
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• pp.7-12
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• 2001

Purpose : We observed usability of allograft by evaluating the clinical results, second look arthroscopic and histologic findings at last follow up after anterior cruciate ligament(ACL) reconstruction using by fresh frozen Achilles allograft. Materials and Methods : We analyzed in 58 patients(59 cases) by subjective and objective parameters, Telos stress arthrometer and Modified Feagin Scoring System. The average age and follow up period was 25 years(ranging from 18 to 49 years), and 15 months(ranging from 12 to 19 months). Among them we studied second look arthroscopic and histologic findings in 16 patients. Results : The mean Lysholm Score wits improved from 60 to 88.2 as well the anterior translation was improved from 7.1 min to 2.3mm at last follow up. The second look arthroscopic findings were close to normal in ligament thickness, tension and showed revasculization at the holly attachment site. Light microscope(LM) findings showed dense cellularity like a normal ligament. In electron microscope(EM) collagen fibrils showed parallel arrangement longitudinally and unimodal pattern diameter close to normal tissue in the transverse section. Conclusion : We think that the fresh frozen Achilles allograft is a good substitution of autograft in cruciate ligament reconstruction.

• Journal of Environmental Science International
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• 제23권5호
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• pp.895-902
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• 2014

Bacterial cellulose (BC) has played important role as new functional material for food industry and industrial products based on its unique properties. The interest in BC from static cultures has increased steadily in recent years because of its potential for use in medicine and cosmetics. In this study, we investigated culture condition for BC production by Acetobacter sp. F15 in static culture. The strain F15, which was isolated from decayed fruit, was selected on the basis of BC thickness. The optimal medium compositions for BC production were glucose 7%, soytone 12%, $K_2HPO_4$ 0.2%, $NaH_2PO_4{\cdot}_2H_2O$ 0.2%, lactic acid 0.05% and ethanol 0.3%, respectively. The strain F15 was able to produce BC at $26^{\circ}C-36^{\circ}C$ with a maximum at $32^{\circ}C$. BC production occurred at pH 4.5-8 with a maximum at pH 6.5. Under these conditions, a maximum BC thickness of 12.15 mm was achieved after 9 days of cultivation; this value was about 2.3-fold higher than the thickness in basic medium. Scanning electron micrographs showed that BC from the optimal medium was more compact than plant cellulose and was reticulated structure consisting of ultrafine cellulose fibrils. BC from the optimal medium was found to be of cellulose type I, the same as typical native cellulose.

• Journal of Korean Ophthalmic Optics Society
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• 제3권1호
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• pp.93-101
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• 1998

The present study was conducted to investigate the structural changes in rat cornes. Sixty eyes from one-day-old uneyed rats, fourty eyes from 10-weeks-old adult rats were used. With the increase of age, the epithelial layer was thickened by the addition of new successive cellular layers. Then, the new-born rat's epithelial cells formed a pentagonal shape, and the quality of decidual cells showed a high electron-density, although the boundary between cells was distinctive. The newly produced cells showed a low electron-density so that there was the distinctive difference between light and darkness. In Bowman's layer, collagen fibrils demonstrate a regularly arranged structure along with the age. In stroma's layer, the density of keratocytes was decreased and thereby progressively flattened during the development. The collagenous layer of the adult rats was more distinctive than that of the new-born rats in a form of vertical and horizontal parallel alignment running vertically and horizontally. Descemet's membrane changed its structure significantly along with the age. It changed the shape from "banded-layer" to "non-banded layer" gradually. The thickness was also increased along with the age. Regardless of developmental stages, the endothelium is usually monolayer. During the developmental process, endothelial cells disappeared, so the density of endothelium was also decreased. The empty spaces were replaced by the expansion of adjacent cells.