• Environmental Mutagens and Carcinogens
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• v.16 no.1
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• pp.35-42
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• 1996

Aragonite is one of polymorphs of calcium carbonate of which main form is calcite. We found that white precipitate is formed in much amount by boiling underwater of Inchon, Korea and confirmed that it is aragonite. This study is to evaluate the dimensional characteristics, solubility, acid resistance of aragonite and the cytotoxicity, cell division disturbance and cell transforming ability of it on BALB/3T3 cells. The results are as follows: Lengths of the aragonite were reduced to the 72.7% and 22.7% respectively after 5 months and 7 months of intrapleurai injection to the Sprague-Dawley rat. Strong acid such as 1M HCl dissolved the aragonite instantly but weaker acid pH 2.0 or more could not dissolved aragonite easily. The result of cell growth inhibition showed that cell numbers were decreased as log-doses of treatment of the aragonite were increased 24 hours, 48 hours, and 72 hours later. Cell plating efficiency after the aragonite treatment also showed dose-dependent decrease. Multinuclear giant cell formation was increased in the aragonite treated cells until ID$_{50}$ and after the dose the multinucleate cells were decreased, but remained much higher than negative control cells. Morphological transformation assay showed that the aragonite did not induce transformation in all treated doses.

• Journal of Nutrition and Health
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• v.29 no.2
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• pp.159-165
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• 1996

This study was performed to investigate the effects of concentration and degree of unsaturation of fatty acids on cellular proliferation and lipid peroxide production, using primary skin fibroblasts from neonate rats Fibroblasts (CPD : 2.8-5.4). Cells were cultured either in control medium (Dulbecco's modified Eagle's medium supplement with 10% fetal bovine serum) or in media supplemented with various kinds (stearic, oleic, linoleic, arachidonic, linolenic, eicosapentaenoic acid) and amounts (5, 10, 25, 50, 100, 150uM)of fatty acids. Cellular proliferation ratio and lipid peroxice production were measured and morphological changes were observed. Cellular proliferation was inhibited and morphological changes were observed. Cellular proliferation was inhibited and morphological changes were observed in cells grown in stearic containing media. Oleic, arachidonic, and eicosapentaenoic aicd tend to stimulate cellualar proliferation, and linolenic acid had no effects. Lipid peroxide concentrations in fibroblasts increased in proportion to the contents and unsaturation of fatty acids in media. Especially supplementation of arachidonic acid accelerated cellualr lipid peroxidation. Free radicals may cause severs damage to biological molecules, so lipid peroxidation probably contributes cellular membrane damages. However there were little relationship between lipid peroxide production and cellular proliferation in this study. (Korean J Nutrition 29(2) : 159~165, 1996)

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.10 no.2
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• pp.102-118
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• 1999

In this study, the author developed a new animal model to examine morphological changes and functional recoveries after vertical hemilaryngeal transplantation in the canine. Seven vertical hemilaryngeal transplantations were carried out in the canine. After preparing the host dog removing right sided hemilarynx, hemilarynx of the donor dog was transplanted by hooking up the arteries, veins, nerves and hypopharyngeal mucosa. Especially, recurrent laryngeal nerve was anastomosed at the branch level(anterior and posterior) respectively. After 7 days, for the first evaluation of the transplantation, four out of seven dogs were considered successful. Three dogs survived more than one month, which is the critical period to evaluate the functional recovery after transplantations. After EMG examination, two dogs(#3, #5 dog) showed some functional recoveries. The five-transplanted hemilarynges were sectioned at the arytenoid cartilage region to examine the morphological changes. The results showed that the transplanted hemilarynx appeared normal as control in #5 dog. In addition, #2 dog showed fairly good condition even though died from asphyxia after 9 days out of transplantation. The other. three dogs(#3, #6, #7) showed various levels of atrophy and disappearance of the muscles and cartilages in their larynges. It can be suggested that this model could contribute an advance to preparing human laryngeal transplantation in the future.

• The Plant Pathology Journal
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• v.38 no.4
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• pp.304-312
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• 2022

Boxwood is a representative ornamental shrub that is widely used in landscaping horticulture. After pruning, damaged leaves or stems of boxwoods are unavoidably vulnerable to infection by various plant pathogens. Several boxwood diseases caused by fungi, such as Volutella blight and Macrophoma leaf spot, have been reported worldwide including Republic of Korea. In this study, we isolated and identified fungal pathogens of boxwood diseases that occurred in Korea and characterized their morphological and taxonomic characteristics. Boxwood samples showing blight symptoms were collected in Seoul, Republic of Korea, and the putative fungal pathogens Pseudonectria buxi, P. foliicola, and Neofusicoccum buxi were successfully identified. Investigation of the morphological features of the field isolates, including mycelial growth and conidial morphology, and phylogenetic analysis of multiple DNA barcode loci revealed that there were some morphological and genetic variations among isolates, but all of the analyzed isolates were closely related to the corresponding reference strains. We also found that P. foliicola strains were more virulent than P. buxi, and the N. buxi strains isolated in this study were weak pathogens or saprophytes. The results of our study will contribute to the development of control strategies for boxwood diseases caused by fungi and accelerate research on the complex ecology of boxwood diseases.

• Restorative Dentistry and Endodontics
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• v.47 no.3
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• pp.28.1-28.12
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• 2022

Objectives: Metalloproteinase-inhibiting agents, such as chitosan, can prevent collagen degradation in demineralized dental substrates, thereby improving the adhesive interface. This study evaluated the bond strength (BS) and chemical and morphological characterization of the adhesive interface after applying chitosan solution to demineralized dentin. Materials and Methods: The 80 third molars were selected. Forty teeth underwent caries induction using the pH cycling method. The teeth were divided according to the treatment: distilled water (control) and 2.5% chitosan solution. The surfaces were restored using adhesive and composite resins. Half of the specimens in each group were aged, and the other half underwent immediate analyses. The teeth were sectioned and underwent the microtensile bond strength test (µTBS), and chemical and morphological analyses using energy-dispersive spectroscopy and scanning electron microscopy, respectively. Data analysis was performed using 3-way analysis of variance. Results: For µTBS, sound dentin was superior to demineralized dentin (p < 0.001), chitosan-treated specimens had higher bond strength than the untreated ones (p < 0.001), and those that underwent immediate analysis had higher values than the aged specimens (p = 0.019). No significant differences were observed in the chemical or morphological compositions. Conclusions: Chitosan treatment improved bond strength both immediately and after aging, even in demineralized dentin.

• The korean journal of orthodontics
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• v.31 no.4 s.87
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• pp.439-445
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• 2001

The Purpose of this study was to compare the dento-skeletal characteristics between functional and skeletal anterior cross-bite patients. Twenty-eight functional anterior cross-bite patients and thirty-one skeletal anterior cross-bite patients were selected as a test and a control group. Mean ages of the test and the control group were $9.6{\pm}1.8$ and $9.9{\pm}1.9$, respectively. Lateral cephalograms were taken. Forty-nine cephalometric variables were measured and statistical analysis was performed to find the morphological differences between the groups. Statistically significant differences were found in the cephalometric variables of cranial deflection, maxillary depth, ANB, convexity, NPo-AB, APDI, Mx 1-SN, Mx 1-NA angle, Mx 1-NA, Md 1-NB angle and Md 1-NB. The test group showed more Class III growth potential, more protruded maxilla, lesser maxillo-mandibular difference, more uprighted and retruded maxillary central incisor, more labially tipped and protruded mandibular central incisor.

• Korean Journal of Veterinary Research
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• v.36 no.1
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• pp.209-219
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• 1996

This study examined the effect of alcohol(AL) and/or paraquat(PQ) on serum TSH, thyroid hormones and enzyme activities, and the protective effect of selenium(SE) againse alcohol and/or paraquat-induced thyroid toxicity in guinea pigs. The experomental group consisted of control, 15% alcohol(AL), 4ppm sodium selentite(SE), 200ppm paraquat(PQ), AL+PQ, AL+SE, PQ+SE and AL+PQ+SE mixed in drinking water-fed guinea pigs for 4 weeks. The morphological changes of thyroid gland were studies on paraffin-embedded sections stained with H-E stain. Body weight losses, high serum concentration in TSH and cholesterol, and low values on triiodothyronine($T_3$), thyrozine($T_4$), free $T_4$ and alkaline phosophatase(ALP) were produced in the groups fed AL and/or PQ. We also noted that AL+PQ-fed group was marked increase in serum TSH. In AL or AL+PQ-fed groups when cpmpared to control group had increased the ratio of thyroid weight to body weight(ratio Twt/Bwt), whereas the ratio Twt/Bwt was decresed in SE or PQ-fed groups. However, the serum TSH, $T_3$,$T_4$ free $T_4$ and cholesterol values, and the ratio Twt/Bwt were reversed in groups given the combination of SE, compared with AL and/or Pq-fed groups, also ALP values were reversed in groups given the combination of SE, compared with AL or AL+PQ-fed groups. In microscope, morphological changes showed a remarkable between the AL or PQ-fed group and controls. In AL+PQ+SE-fed guinca pig, follicular colloid is high density in thyroid follicle and increased in connective tissue around the thyroid cells, and thyroidal epithelia were composed of cuboidal or columnar epithelium. The indicated that the morphological changes of thyroid were direct action in the thyroid cell. The results of this study confirmed that the toxic effect of AL or PQ on thyroid occur independently of changes in liver function, and that SE confers marked protection against AL or PQ-induced thyroid toxicity.

• Design & Manufacturing
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• v.17 no.2
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• pp.55-61
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• 2023

With femtosecond (fs) laser pulse irradiation on metals, various types of nano- and micro-scale structures can be naturally induced at the surface through laser-matter interaction. Two notable structures are laser-induced periodic surface structures (LIPSSs) and cone/spike structures, which are known to significantly modify the optical and physical properties of metal surfaces. In this work, we irradiate fs laser pulses onto various types of metals, cold-rolled steel, pickled & oiled steel, Fe-18Cr-8Ni alloy, Zn-Mg-Al alloy coated steel, and pure Cu which can be useful for precise molding and imprinting processes, and adjust the morphological profiles of LIPSSs and cone/spike structures for clear structural coloration and a larger range of surface wettability control, respectively, by changing the fluence of laser and the speed of raster scan. The periods of LIPSSs on metals used in our experiments are nearly independent of laser fluence. Accordingly, the structural coloration of the surface with LIPSSs can be optimized with the morphological profile of LIPSSs, controlled only by the speed of the raster scan once the laser fluence is determined for each metal sample. However, different from LIPSSs, we demonstrate that the morphological profiles of the cone/spike structures, including their size, shape, and density, can be manipulated with both the laser fluence and the raster scan speed to increase a change in the contact angle. By injection molding and imprinting processes, it is expected that fs laser-induced surface structures on metals can be replicated to the plastic surfaces and potentially beneficial to control the optical and wetting properties of the surface of injection molded and imprinted products.

• International Journal of Control, Automation, and Systems
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• v.2 no.4
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• pp.509-515
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• 2004

In this paper we present the linear combination of a fuzzy opening and closing filter with locally adaptive structuring elements that can preserve the geometrical features of an image. Based on the adaptation algorithm of linear combination of the fuzzy opening and closing filter, the optimal structuring element for image representation is obtained. The optimal structuring element is an indicator of the shape and direction of an object's image, which is useful in filtering, multi resolution, segmentation, and recognition of an image.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.603-608
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• 2003

Recently, personal robots and home robots are developing by many companies and research groups. It is considered that a general effective interface for user of those robots is speech or voice. In this paper, Japanese speech based man-machine interface system is discussed for reflecting the fuzziness of natural language on robots, by using fuzzy reasoning. The present system consists of the derivation part of action command and the modification part of the derived command. In particular, a unique problem of Japanese is solved by applying the morphological analyzer ChaSen. The proposed system is applied for the motion control of a robot manipulator. It is proved from the experimental results that the proposed system can easily modify the same voice command to the actual different levels of the command, according to the current state of the robot.