1.THE EFFECT OF PLASMA-TREATED POLYETHYLENE FIBER ON THE FLEXURAL STRENGTH OF COMPOSITE RESIN IN VARIOUS APPLIED PORTIONS.
Yong Jin OH ; Nam Shik OH ; Keun Woo LEE
The Journal of Korean Academy of Prosthodontics 1997;35(2):401-412
There has been many researches aimed at reinforcing the strength of resin, and these have led to the development and use of numerous materials in recent years. A case in point, is the recent development of plasma-treated polyyethylene fiber which has been used mainly in fixed provisional restoration to reduce the incidence of fractures. This study aims at assessing whether plasma-treated polyethylene fiber as applied to composite resin is effective in increasing the flexural strength and how applied portions affect this. Twenty-four applied and eight unapplied composite resin bars were fabricated. Twenty-four applied specimens were divided into three groups. Plasma treated polyethylene fiber was applied to the groups each with different portions of composite resin. In the first group, plasma-treated polyethylene fiber was not applied. In the second group, fiber was applied to the compression side of composite resin. Fiber was applied to the tension side in the third group, while fiber was embedded in the tension side of the compositeresin in the fourth group. Each specimen was tested by use of a three-point bending strength test with an instron testing machine, and the flexural strength was calculated. The following results were obtained. : 1. Under the conditions of this study, the third and fourth groups demonstrated a statistically greater flexural strength compared to the first and second groups. 2. But there was no statiscally significant difference, not only between the first group and the second group, but also between the third group and the fourth group. Taken together, it can be concluded that plasma-treated polyethylene fiber applied to composite resin is an effective method in increasing flexural strength, and the best way of increasing the flexural strength is by application of plasma-treated polyethylene fiber to the tension side, or the embedding of same in composite resin. It must be mentioned however that this test used a static single-load test method. This method determined the maximum stresses that could be tolerated, but this might not be valid where the prediction of clinical failure is concerned. In order therfore to clinically utilize plasma-treated polyethylene fiber to reinforce the composite resin, it is suggested that a further study which considers the various loads be undertaken.
Incidence
;
Plasma
;
Polyethylene*
2.A Case of Congenital Anterior Urethral Diverticulum.
Young Ho LEE ; Gyu Jeon SONG ; Woo Yeong CHUNG ; Moo Young OH ; Soon Yong LEE
Journal of the Korean Pediatric Society 1987;30(4):431-434
No abstract available.
Diverticulum*
3.Medullary carcinoma of the breast: Imaging findings characteristics vs histologic classification.
Chang Soo AHN ; Ki Keun OH ; Choon Sik YOON ; Woo Hee CHUNG ; Yong Hee LEE
Journal of the Korean Radiological Society 1993;29(5):1071-1079
It is well known that the medullary carcinoma of the breast is one of the special types of breast carcinoma with a good prognosis. At present, the medullary carcinoma of the breast is subclassified into 3 types: typical medullary, atypical medullary and nonmedullary carcinoma. Among them, the former has the best prognosis. We reviewed the film mammographic and ultrasonomammographic findings of 13 patients according to the reevaluated histopathologic diagnosis. Typical medullary carcinoma shows a well circumscribed mass with surrounding halo on film mammogram, and well defined mass with central intermediate echogenicity and peripheral low echogenicity and posterior acoustic enhancement on ultrasonomammogram. Atypical medullary carcinoma shows relatively well circumscribed mass with partial marginal obliteration on film mammogram, and irregular bordered mass with inhomogeneous echogenicity due to focal necrosis in the mass and associated findings of thick boundary, asymetrical lateral shadowing on ultrasonomammogram. Nonmedullary carcinoma shows lobulated mass with surrounding parenchymal distortion and skin thickening on film mammogram, and relatively well defined lobulating mass with surrounding parenchymal distortion and marked heterogeneous internal echogenicity on ultrasonomammogram. Therefore, differentiation between typical medullary carcinoma with good prognosis and atypical medulary or nonmedullary carcinoma with poor prognosis, may be possible by various diagnostic imaging modalities preoperatively. But further collective study shall be needed in near future.
Acoustics
;
Breast Neoplasms
;
Breast*
;
Carcinoma, Medullary*
;
Classification*
;
Diagnosis
;
Diagnostic Imaging
;
Humans
;
Necrosis
;
Prognosis
;
Shadowing (Histology)
;
Skin
4.The Structural Properties of Israeli Carp ( Cyprinus carpio L. ) Immunoglobulin.
Sang Hoon CHOI ; Jong Kyu WOO ; Yong Suk JANG ; Chan Ho OH
Korean Journal of Immunology 1999;21(1):85-92
Serum immunoglobulins from Israeli carp (I. carp) were purified using affinity chromatography. Fish were immunized with purified mouse IgG, and the specific fish antibodies purified from the immune serum on a mouse IgG-immobilized agarose gel. Rabbit anti-carp Ig (Raclg) antibodies were produced following hyperimmunization with mlgG specific I. Carp Ab. SDS-PAGE analysis under reducing condition showed that I. carp Ig (clg) were composed of two u-like heavy chains with about 82 and 50 kD, respectively and one light chain with about 25 kD. On immunoblotting analysis, however, Raclg failed to react with light chain. When both protein A and protein G purified normal clg were compared with mlgG specific clg, no significant structural differences among them were observed. To investigate if there is any homology between other fish Ig molecules, cross-reactivity of Raclg against Ig molecules from 6 different fish sera and mouse control serum was checked on immunoblotting analysis. As a result, Raclg responded to only carp and tilapia Ig molecules, indicating that both tilapia and carp are very closely associated, especially, in the genetic basis of immunoglobulin structure. In flow cytometry study, Raclg appeared to recognize 45.8% of carp Ig+, 14.5% of catfish Ig+ and <5% of tilapia Ig+ cells. The result suggest the heterogeniety between receptor immunoglobulins on B-like lymphocytes and soluble immunoglobulins in serum. It is crucial to obtain pure fish immunoglobulins to produce reagent antibodies as tools for the study of their specific immune response.
Animals
;
Antibodies
;
Carps*
;
Catfishes
;
Chromatography, Affinity
;
Electrophoresis, Polyacrylamide Gel
;
Flow Cytometry
;
Immunoblotting
;
Immunoglobulin G
;
Immunoglobulins*
;
Lymphocytes
;
Mice
;
Sepharose
;
Staphylococcal Protein A
;
Tilapia
5.Clinical study on kyphoscoliosis complicating pregnancy.
Young Min KIM ; Joon Hyung KIM ; Yong Woo LEE ; Won Seob OH
Korean Journal of Obstetrics and Gynecology 1991;34(3):348-352
No abstract available.
Pregnancy*
6.Change of Clinical Feature of Typhoid Fever in Children.
Sung Oh KIM ; Yong Joo KIM ; Woo Kill LEE ; Chong Moo PARK
Journal of the Korean Pediatric Society 1988;31(5):566-576
No abstract available.
Child*
;
Humans
;
Typhoid Fever*
7.A case of Hutchinson Gilford Progeria Syndrome.
Myung Ho CHO ; Yong Woo CHOI ; Wan Seob KIM ; Oh Kyung LEE ; Myung Ho LEE
Journal of the Korean Pediatric Society 1986;29(5):106-110
No abstract available.
Progeria*
8.Changes of Quantitative EEG after Donepezil Treatment in Alzheimer's Disease.
Yong Tae KWAK ; Il Woo HAN ; Oh Young BANG
Journal of the Korean Neurological Association 2001;19(3):245-250
BACKGROUND: Though symptomatic improvements after treatment of donepezil is well documented in Alzheimer's disease (AD), the electrophysiological change have not yet been elucidated. Among the parameters of quantitative electroen-cephalography (q-EEG), high frequency activity, especially gamma rhythm, may play a role in normal cognitive function including the integration of sensory processing, association, coupling or selective attention, which are characteristically impaired in AD. METHODS: In order to define the profile of q-EEG changes including gamma rhythm after donepezil treatment, we followed 17 AD patients for 12 weeks. We analyzed the spectra power taken from 16 derivations by averaging twenty-2-sec epoch in normal controls and AD patients. After logarithmic transformation of spectra power, statistical test was done and the effect of donepezil treatment on q-EEG profile was analyzed during follow up period. RESULTS: Before medication of donepezil, AD patients had a significantly lower alpha spectra power as well as a significant higher delta spectra power, compared with normal control. After medication of donepezil in AD patients, compared to base-line q-EEG, gamma spectra power was significantly increased, whereas delta spectra power was significantly reduced. Compared to absolute power, relative power was more sensitive in detecting change of EEG after donepezil treatment. CONCLUSIONS: This study suggests that donepezil significantly change delta and gamma spectra power in q-EEG, and the increase in gamma rhythm may be correlated with the clinical improvements after donepezil treatment. (J Korean Neurol Assoc 19(3):245~250, 2001)
Alzheimer Disease*
;
Electroencephalography*
;
Follow-Up Studies
;
Humans
9.A study of teenage obstetrics complications.
Hyun Kyung KIM ; Jae Chern SONG ; Man Chul PARK ; Yong Woo LEE ; Won Sup OH
Korean Journal of Obstetrics and Gynecology 1993;36(7):2117-2123
No abstract available.
Obstetrics*
10.A Case of (21q 21q) Translocation Down Syndrome Inherited from a t(21q 21q) Balanced Carrier Mother.
Byeong Gie YEO ; Chong Woo BAE ; Yong Mook CHOI ; Chang Il AHN ; Bo Hoon OH
Journal of the Korean Pediatric Society 1990;33(7):1004-1008
No abstract available.
Down Syndrome*
;
Humans
;
Mothers*