• Journal of Korean Foot and Ankle Society
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• v.9 no.1
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• pp.1-8
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• 2005

Purpose: We compared the bony arrangements of the forefoot in 2 different years, 1982 and 2004, to determine any changes with time period of 22 years. Materials and Methods: The radiographs of 200 normal Korean adults, 100 male and 100 female volunteers, were evaluated both in 1982 and 2004. The radiographic results were evaluated with as follows; hallux valgus angle (HVA), intermetatarsal angle (IMA), morphology of metatarsal head and relative anterior protrusion of the metatarsals and the phalanges. The mean ages were 38 years (23-52years) in 1982, and 37 years (24-50years) in 2004. Results: The mean of HVA decreased from 15.6 degrees in 1982 to 14.3 degrees in 2004 (p=0.047), and the mean of IMA increased from 8.0 degrees in 1982 to 9.4 degrees in 2004 (p=0.031). The morphology of metatarsal head and relative anterior protrusion of the metatarsals and the phalanges were not different between the two study years. Conclusion: Comparing with those of 1982 measurements, we found an increase of IMA and a decrease of HVA. A prospective study may be needed to illuminate course of the changes.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3519-3524
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• 2014

Background: Esophageal squamous cell carcinoma (ESCC) is a common cancer with poor prognosis. It has been hypothesized that Oct4 positive radioresistant stem cells may be responsible for tumor recurrence. Hence, we evaluated Oct4 expression in ESCC in pre-treatment, post neo-adjuvant residual and post-surgical recurrent tumours. Materials and Methods: Endoscopic mucosal biopsies were used to study Oct4 expression and the observations were correlated with histological tumor grades, patient data and clinical background. Results: All patients presented with dysphagia with male predominance and a wide age range. Majority of the patients had intake of mixed diet, history of alcohol and tobacco intake was documented in less than half of the patients. Oct 4 expression was significantly higher in poorly differentiated (PDSCC) and basaloid (BSCC) subtypes than the other better differentiated tumor morphology. Oct4 was also expressed by adjoining esophageal mucosa showing low grade dysplasia and basal cell hyperplasia (BCH). Biopsies in PDSCC and BSCC groups were more likely to show a positive band for Oct4 by polymerase chain reaction (PCR). Dysplasia and BCH mucosa also showed Oct4 positivity by PCR. All mucosal biopsies with normal morphology were negative for Oct4. Number of tissue samples showing Oct4 positivity by PCR was higher than that by the conventional immunohistochemistry (p>0.05). Oct4 expression pattern correlated only with tumor grading, not with other parameters including the clinical background or patient data. Conclusions: Our observations highlighted a possible role of Oct4 in identifying putative cancer stem cells in ESCC pathobiology and response to treatment. The implications are either in vivo existence of Oct4 positive putative cancer stem cells in ESCC or acquisition of cancer stem cell properties by tumor cells as a response to treatment given, resulting ultimately an uncontrolled cell proliferation and treatment failure.

• Applied Microscopy
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• v.47 no.2
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• pp.70-74
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• 2017

In the case of genus Nothobranchius, Nothobranchiidae, the morphology of fertilized eggs and ultrastructures of fertilized egg envelopes have been reported in only two fishes. Therefore it is hard for sure to these morphological characteristics show genus specificity because of lower research samples. So, we studied the morphology of fertilized egg, and compared the ultrastructures of outer surface, micropyle, and section of fertilized egg envelopes under the light and electron microscopes from the other two species, Nothobranchius foerschi and Nothobranchius rachovii, Nothobranchiidae to find out whether these structures have the species specificity or not. Both fertilized eggs were spherical, demersal and adhesive, and have a large oil droplet. The adhesive whip-like structures were distributed on the outer surface of egg envelope, and a micropyle located on the animal pole. The fertilized egg envelope consisted of two distinct layers: an outer electron-dense layer with adhesive structures and an inner lamellae layer in both species. The external shapes of fertilized egg and ultrastuctures of outer surface, micropyle, and section of fertilized egg envelope have same structure including results before. Our data indicate that these morphological characteristics of fertilized egg and fertilized egg envelope show genus Nothobranchius specificity.

• Applied Chemistry for Engineering
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• v.17 no.6
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• pp.586-590
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• 2006

As one of electro active polymers for soft smart materials, the ionic polymer metal composites (IPMC) are easy to produce through chemical reduction processing and show high displacements at low voltage. When the IPMC actuates, the deformation depends on a few factors including the structure of based membrane, species and morphology of the metal electrodes, the nature of cations and the level of hydration. As previously published, we have been studying on improvement of actuation through surface electrode modification of IPMC to grasp the effect of electrode morphology on actuation. This study is comparative experiments through the chemical reaction and deposition by ion beam assisted deposition (IBAD) in order to prepare the very thin and homogeneous surface electrode of IPMC. The IPMCs were prepared with different surface roughness of polymer membrane, and the influence of the surface roughness on the actuation was studied. By investigating the electrical properties and driving displacement, the actuating properties of IPMC with different surface roughness were studied.

• Journal of Adhesion and Interface
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• v.5 no.3
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• pp.1-9
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• 2004

Using the methods which described in ISO 4588, ASTM D2651 and the selected literature, we investigated the best conditions of acid treatment for stainless steel and carbon steel. The acid treatments were conducted with four different acid solutions which were prepared for stainless steel and carbon steel specimen. We observed the contact angle and morphology and roughness of the metal surface and the thickness change at various treatment conditions as treatment temperature and time. Also, we investigated the characteristics of the surface aging according to air exposure after surface treatment. As a result, the optimal temperature of the acid treatment for stainless steel and carbon steel were each obtained at $83^{\circ}C$ and $63^{\circ}C$. Also, it was confirmed that the acid treatments for the metal surface were accompanied with the decrease of thickness and the change of surface morphology due to significant erosion that depend on treatment methods. And also, it was characterized that the aspect of surface aging by air exposure was highly depended on the method of acid treatment.

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.4
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• pp.867-886
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• 1996

The purpose of this study was to evaluate the shearbond strength and resin-dentin interface of three different dentinal bonding systems in primary and permanent teeth. Thirty extracted human primary molars and premolars, which were non-carious and free of obvious defect, were selected for this study. All specimens were divided into six groups with two groups allocated for each of the three dentinal bonding system(All-bond 2, Scotchbond Multi-Purpose, Gluma bonding system). After completion of bonding composite to dentin using each tested dentin bonding system, bond strength measurement and histological observation were performed. The results are as follows: 1. All-bond 2 and Scotchbond Multi-Purpose, A good quality hybrid layer was identified, the morphology of which could be equated with the zone of H-E and Brown-Brenn staining. In Gluma bonding system, hybrid layer was very thin, and separated from the solid polymer. 2. All-bond 2 had the highest mean shearbond strength, followed by Scotchbond Multi-Purpose and Gluma bonding system in both primary and permanent teeth. There was no statistically significant difference between All-bond 2 and Scotchbond Multi-Purpose. Statistically significant difference could be found between Gluma bonding system and the other two groups(p<0.05). 3. The fracture patterns observed were mainly the mixture of adhesive failure and dentin dettachment pattern in All-bond 2 and Scotchbond Multi-Purpose while adhesive failure prevailed in Gluma bonding system.

• Polymer(Korea)
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• v.37 no.4
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• pp.547-552
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• 2013

Polyimide (PI) containing carboxyl functional group was prepared and reacted with diaminosiloxane during high temperature film casting. The morphology of resulting film was observed by using transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX), which revealed that globular 100 nm-sized PI domains and continuous polysiloxane phase were formed. X-ray photoelectron spectroscopy (XPS) study indicated that air-film interface mainly consisted of polysiloxane blocks. Poly(imidesiloxane) thin layer was thermostable until $400^{\circ}C$ and its pressure- sensitive adhesive property was retained up to $300^{\circ}C$. The comparative experiments revealed that grafting between carboxyl groups of polyimide and aminosiloxane was crucial for formation of microdomain structure and pressure-sensitive adhesive property.

• ALGAE
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• v.29 no.2
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• pp.57-73
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• 2014

Amphora Ehrenberg ex Kutzing sensu lato is a common and widespread benthic diatom genus with a taxonomy that has been under continual revision, particularly based on molecular analyses. Although Amphora species have been studied using modern microscopy in recent years, there has not been much progress on molecular characterization of the species, especially in Asia. In this study of Amphora, sampling was carried out from September 2009 to August 2010 in Korean coastal waters. The morphological and molecular characteristics of eight Amphora sensu lato were examined: Amphora marina, A. proteus, Halamphora costata, H. coffeaeformis, H. eunotia, H. holsatica, H. terroris, and Halamphora sp. Based on previous accounts, morphology suggested that A. marina and A. proteus belong to the subgenus Amphora Cleve, which have smooth girdle bands and rather coarse and very distinct areolae on the valve. The other species, H. coffeaeformis, H. costata, H. eunotia, H. holsatica, H. terroris, and Halamphora sp. belong to the subgenus Halamphora Cleve, which was recently elevated to generic status by Levkov 2009, have plicate girdle bands, puncta which do not form straight longitudinal lines, valves which have a narrow ventral portion and apices that are generally rostrate-capitate and recurved. In agreement with analysis based on morphological characteristics, phylogenetic analysis based on small subunit rDNA suggested that the eight Amphora sensu lato species were not a monophyletic group as the morphological classification. Also, the results of molecular work and statistical analysis on all these Amphora sensu lato combined with phylogenic analysis on our geographically representative samples give strong evidence that Halamphora Levkov is independent of Amphora Cleve. Furthermore, in this study, Amphora terroris was transferred Halamphora as Halamphora terroris (Ehrenberg) Wang comb. nov. and Amphora marina was recorded for the first time in Korea.

• Korean Chemical Engineering Research
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• v.57 no.6
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• pp.804-811
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• 2019

This study was performed the real motion and DEM simulation of ball motion using three different types of grinding media with different size and materials in media formation for optimization of process conditions in a traditional ball mill (media ball mill). In the simulation, the rotational speed of the mill, the material of the medium, the velocity of the medium, and the coefficient of friction between the media and the wall of pot were fixed into the actual experimental conditions. The motion of various kinds of grinding media was quantitatively measured by setting the grinding zone defined in the present study on the photographs taken and the snapshot images analyzed in the simulation. In addition, we observed the quantitatively measured value and the changed morphology of the sample and examined the correlation. Therefore, it is suggested to optimize the grinding media which has the greatest influence on the grinding zone under specific experimental conditions.

• Journal of Veterinary Science
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• v.23 no.4
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• pp.62.1-62.10
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• 2022

Background: The corneal and limbal morphology relevant to corneal epithelial maintenance in ten different species was examined using histological methods. Objectives: The presence of a Bowman's layer, limbal epithelial cell, and superficial stromal morphology was examined in the following species to evaluate the differences in corneal thickness and epithelium: Java sparrows, frogs, macaws, spoonbills, red pandas, penguins, horses, Dobermans, orangutans, and humans. Methods: Corneal sections (4 ㎛) were obtained from ten ocular globes from three different animal classes: Aves, Amphibia, and Mammalia. All sections were stained with hematoxylin and eosin and periodic acid-Schiff reaction. After microscopy, all stained slides were photographed and analyzed. Results: Significant morphological differences in the corneal and limbal epithelia and their underlying stroma between species were observed. The number of corneal epithelial cell layers and the overall corneal epithelial thickness varied significantly among the species. The presence of a Bowman's layer was only observed in primates (orangutans and humans). Presumed supranuclear melanin caps were noted in four species (orangutans, macaws, red pandas, and horses) in the limbal basal epithelial layer (putative site of corneal epithelial stem cells). The melanin granules covered the apex of the cell nucleus. Conclusions: Supranuclear melanin capping has been described as a process within the epidermis to reduce the concentration of ultraviolet-induced DNA photoproducts. Similarly, there may be a relationship between limbal stem cell melanin capping as a protective mechanism against ultra-violet radiation.