• Polymer(Korea)
• /
• v.37 no.1
• /
• pp.100-112
• /
• 2013

It is found that the commercialization of nylon 66/Cloisite 93A nanocomposite by applying melt intercalation is possible in the composite production facilities of the pilot scale which has been generalized today. The strength and modulus under tensile and flexural stress have been improved with the introduction of Cloisite 93A in nylon 66. Furthermore, it is found through the analysis of morphologic and crystallization behavior that the elements such as content of Cloisite 93A, viscosity of nylon 66 and the crystallization behavior have significantly influences on the characteristics of nanocomposite.

• Restorative Dentistry and Endodontics
• /
• v.40 no.3
• /
• pp.241-248
• /
• 2015

Variation in root canal morphology, especially in maxillary first molar presents a constant challenge for a clinician in their detection and management. This case report describes the successful root canal treatment of a three rooted right maxillary first molar presenting with three canals each in the mesiobuccal and distobuccal roots and one canal in the palatal root. The clinical detection of this morphologic aberration was made using a dental operating microscope, and the canal configuration was established after correlating and computing the clinical, radiographic and cone-beam computed tomography (CBCT) scan findings. CBCT images confirmed the configuration of the canals in the mesiobuccal and distobuccal roots to be Al-Qudah and Awawdeh type (3-2) and type (3-2-1), respectively, whereas the palatal root had a Vertucci type I canal pattern. This report reaffirms the importance of careful examination of the floor of the pulp chamber with a dental operating microscope and the use of multiangled preoperative radiographs along with advanced diagnostic aids such as CBCT in identification and successful management of aberrant canal morphologies.

• The Korean Journal of Pain
• /
• v.26 no.2
• /
• pp.154-159
• /
• 2013

Femoroacetabular Impingement (FAI) arises from morphological abnormalities between the proximal femur and acetabulum. Impingement caused by these morphologic abnormalities induces early degenerative changes in the hip joint. Furthermore, FAI patients complain of severe pain and limited range of motion in the hip, but a guideline for treatment of FAI has not yet been established. Medication, supportive physical treatment and surgical procedures have been used in the treatment of the FAI patients; however, the efficacies of these treatments have been limited. Here, we report the diagnosis and treatment for 3 cases of FAI patients. Intra-articular (IA) steroid injection of the hip joint was performed in all three patients. After IA injection, pain was reduced and function had improved for up to three months.

• Restorative Dentistry and Endodontics
• /
• v.19 no.1
• /
• pp.85-96
• /
• 1994

In this study, 24 curved resin blocks were prepared by one of the following four methods: 1) Conventional technique using K-flexo files 2) Step-back technique using K-flexo files 3) Crown-down technique using K-flexo files 4) Canal Master instrumentation using Canal Master Resin blocks were sectioned, photographed, and evaluated the mean centering ratio and the mean area of dentin removed before and after the instrumentation. The results were as follows : I. the mean centering ratio 1. In the level 1 and level 3, there was no significant difference in the mean centering ratio. 2. In the level 2, Step-back technique showed the worst mean centering ratio among the tested groups(p<0.001) and there was no significant difference between the other three groups. 3. In the level 4, Canal Master instrumentation and Step-back technique showed better mean centering ratio than the other two techniques(p<0.001) and there was no significant difference between the two techniques. II. the mean area of dentin removed 1. In the level l and level 3, there was no significant difference in the mean area of dentin removed. 2. In the level 2, Canal Master instrumentation removed less dentin than the other three techniques(P<0.01). 3. In the level 4, Crown-down technique removed less dentin than the other three techniques(P<0.05).

• Macromolecular Research
• /
• v.11 no.1
• /
• pp.2-8
• /
• 2003

The self-assembly of polymers can lead to supramolecular systems and is related to the their functions of material and life sciences. In this article, self-assembly of Langmuir-Blodgett (LB) films, polymer micelles, and polymeric nanoparticles, and their biomedical applications are described. LB surfaces with a well-ordered and layered structure adhered more cells including platelet, hepatocyte, and fibroblast than the cast surfaces with microphase-separated domains. Extensive morphologic changes were observed in LB surface-adhered cells compared to the cast films. Amphiphilic block copolymers, consisting of poly(${\gamma}$-benzyl L-glutamate) (PBLG) as the hydrophobic part and poly(ethylene oxide) (PEO) [or poly(N-isopropylacrylamide) (PNIPAAm)] as the hydrophilic one, can self-assemble in water to form nanoparticles presumed to be composed of the hydrophilic shell and hydrophobic core. The release characteristics of hydrophobic drugs from these polymeric nanoparticles were dependent on the drug loading contents and chain length of the hydrophobic part of the copolymers. Achiral hydrophobic merocyanine dyes (MDs) were self-assembled in copolymeric nanoparticles, which provided a chiral microenvironment as red-shifted aggregates, and the circular dichroism (CD) of MD was induced in the self-assembled copolymeric nanoparticles.

• Archives of Plastic Surgery
• /
• v.34 no.4
• /
• pp.493-494
• /
• 2007

Purpose: Nevus sebaceous is a distinctive growth commonly found on the scalp, forehead and retroauricular region. Nevus sebaceous has age-related changes in morphologic and histologic appearance. Secondary neoplasm including basal cell carcinoma is found in 20% of the nevus sebaceous which were not treated properly. So, we report a case of basal cell carcinoma that is arising in nevus sebaceous but has no malignant appearance. Methods: A 38 year-old female patient wanted to excise the lesion on scalp. It looked like typical nevus sebaceous because we didn't find any malignant appearances. We excised the lesion including minimal normal tissue. Results: After the excision of the lesion, pathologist reported the nevus sebaceous with multifocal basal cell carcinoma. Conclusion: Many patients want to excise the nevus sebaceous that stands out to other people. But they don't know the potency of malignant changes. So, plastic surgeons have to notify the potency and make plan for proper treatment.

• The Journal of Internal Korean Medicine
• /
• v.30 no.1
• /
• pp.1-8
• /
• 2009

Objective : The aims of this study were to observe how body weight and gastric morphology were changed and whether gastric emptying was impaired in rats with partial pyloric obstruction. and to evaluate whether electroacupuncture was able to restore delayed gastric emptying. Methods : Partial pyloric obstruction was induced by wrapping a nonabsorbable rubber ring around the 1st portion of the duodenum for 2 weeks. Body gain and morphologic changes of stomach were investigated and compared with normal intact rats. Gastric emptying was measured by numbering expelled glass of beads in rats. Rats were divided into 4 groups(non-acupuncture, manual acupuncture. 3Hz-electroacupuncture. 60Hz-electroacupuncture). Stimulus intensity in two electroacupuncture groups was 1.2 times of pain threshold. Results : Partial pyloric obstruction produced a significant loss of body weight and induced a significant increase of gastric surface area. The 60Hz electroacupuncture-stimulated group significantly restored the delayed gastric emptying compared to the other groups of rats with partial pyloric obstruction. Conclusion : 60Hz electroacupuncture stimulation on Zusanli(ST36) showed significant restoration of delayed gastric emptying in rats with partial pyloric obstruction.

• Parasites, Hosts and Diseases
• /
• v.44 no.2 s.138
• /
• pp.117-125
• /
• 2006

Genetic diversity of 18 Acanthamoeba isolates from ocean sediments was evaluated by comparing mitochondrial (mt) DNA RFLP, 18S rDNA sequences and by examining their cytopathic effects on human corneal epithelial cells versus reference strains. All isolates belonged to morphologic group II. Total of 16 restriction phenotypes of mtDNA from 18 isolates demonstrated the genetic diversity of Acanthamoeba in ocean sediments. Phylogenetic analysis using 18s rDNA sequences revealed that the 18 isolates were distinct from morphological groups I and III. Fifteen isolates showed close relatedness with 17 clinical isolates and A. castellanii Castellani and formed a lineage equivalent to T4 genotype of Byers' group. Two reference strains from ocean sediment, A. hatchetti BH-2 and A. griffini S-7 clustered unequivocally with these 15 isolates. Diversity among isolates was also evident from their cytopathic effects on human corneal cells. This is the first time describing Acanthamoeba diversity in ocean sediments in Korea.

• Journal of Preventive Medicine and Public Health
• /
• v.16 no.1
• /
• pp.79-88
• /
• 1983

There has been some evidence concerning the fact that trihalomethanes(THMs), toxic chlorinated compounds, may be present in drinking water. One of the important methodologies to evaluate the toxicity of THMs is to determine enzyme alteration in experimental animal tissues after treatment. This study was intended to investigate how lactic dehydrogenase(LDH) of rat tissues is affected by administration of chloroform($CHCl_3$) and dichloromonobromomethane($CHCl_2\;Br$). THMs, high dose(1/10 LD50) or low dose(1/50 LD50) of $CHCl_3$ or $CHCl_{2}Br$ were administered orally to experimental rats for 4 or 8 weeks. The treated groups of rats were sacrificed to determine LDH specific activity and isozyme pattern in various organs which were liver, thigh muscle, kidney and brain. The conclusions were obtained as follows: 1. Alteration of LDH activities and isozyme patterns were revealed before morphologic changes in tissues. 2. The LDH specific activities were increased significantly in liver and brain after administration of high concentrations of $CHCl_3$ and $CHCl_{2}Br$ for 4 weeks respectively. Otherwise, they were decreased significantly in liver, muscle and kidney after administration for 8 weeks. 3. The isozyme activities of LDH-4 and LDH-5 were increased in muscle, brain, and especially the liver. 4. It was more distinct for the decrement of LDH H-type isozyme than the increment of M-type isozyme in muscle.

• Proceedings of the KAIS Fall Conference
• /
• 2011.12a
• /
• pp.322-325
• /
• 2011

본 연구는 넓은잎 딱총나무 잎으로부터 유도된 캘러스의 형태학적 특성과 효능에 관한 것이다. 딱총나무에서 유도된 캘러스 내의 세포들을 촬영한 표면주사현미경 사진에서 분열능이 높은 세포의 특성을 보여주었다. 유도된 넓은잎 딱총나무 캘러스를 생물반응기 내에서 배양시켜 얻은 딱총나무 식물세포배양 추출물은 DPPH 제거 및 $PPAR{\alpha}$ 활성 실험결과에서 자유라디컬 제거능 및 항염증 효능이 높게 나타났다. 이러한 딱총나무 캘러스 세포 배양 추출물은 화장품의 항노화 신소재로서 응용될 수 있다.