1.Comparative tensile bond strength of heat-cured, cold-cured, and light cured denture base resins bonded to continuous: pressure injection type denture base resin.
Seung Woo WHANG ; Moon Kyu CHUNG
The Journal of Korean Academy of Prosthodontics 1993;31(3):385-393
No abstract available.
Denture Bases*
;
Dentures*
2.THE PHYSCIAL PORPERTIES OFY Y2O3-CONTAINING GLASS INFILTRATED ALUMINA CORE MADE BY PRESSURELESS POWDER PACKING METHOD.
Seung Woo WHANG ; Keun Woo LEE
The Journal of Korean Academy of Prosthodontics 1997;35(1):221-243
The objective of this study was to characterize the mechanical properties of Y2O3-containing glass infiltrated ceramic core material, which was made by pressureless powder packing method. A pure alumina powder with a grain size of about 4micrometer was packed without pressure is silicon mold to form a bar shaped sample, and applied PVA solution as a binder. Samples were sinterd at 1350degrees C for 1 hour. After cooling, Y2O3-containing glass (SiO2, Y2O3, B2O3, Al2O3, ect) was infiltrated to the sinterd samples at 1300degrees C for 2 hours and cooled. Six different proportions Y2O3 of were used to know the effect of the mismatch of the thermal expansion coefficient between alumina powder and glass. The samples were ground to 3x3x30 mm size and polished with 1microneter diamond paste. Flexural strength, fracture toughness, hardness and other physical properties were obtained, and the fractured surface was examined with SEM and EPMA. Ten samples of each group were tested and compared with In-Ceram(TM) core materials of same size made in dental laboratory. The results were as follows : 1. The flexural strengths of group 1 and 3 were significantly not different with that of In-Ceram, but other experimental groups were lower than In-Ceram. 2. The shrinkage rate of samples was 0.42% after first firing, and 0.45% after glass infiltration. Total shrinkage rate was 0.87%. 3. After first firing, porosity rate of experimental groups was 50%, compared with 22.25% of In-Ceram. After glass infiltration, porosity rate of experimental groups was 2%, and 1% in In-Ceram. 4. There was no statistical difference in hardness between two materials tested, but in fracture toughness, group 2 and 3 were higher than In-Ceram. 5. The thermal expansion coefficients of experimental groups were varied to 4.51~5.35x10-6/degrees C according to glass composition, also the flexural strengths of samples were varied. 6. In a view of SEM, many microparticles about 0.5microneter diameter and 4microneter diameter were observed in In-Ceram. But in experimental group, the size of most particles was about 4microneter, and a little microparticles was observed. The results obtained in this study showed that the mismatch of the thermal expansion coefficients between alumina powder and infiltrated glass affect the flexural strength of alumin/glass composite. The Y2O3-containing glass infiltrated ceramic core made by powder packing method will takes less time and cost with sufficient flexural strength similar to all ceramic crown made with slip casting technique.
Aluminum Oxide*
;
Ceramics
;
Edible Grain
;
Crowns
;
Diamond
;
Fires
;
Fungi
;
Glass*
;
Hardness
;
Laboratories, Dental
;
Porosity
;
Silicones
3.The Effect of Contact Precautions and Active Surveillance Culture on the Methicillin-Resistant Staphylococcus aureus Reduction in an Intensive Care Unit.
Seung Mae CHOI ; Jae Sim JEONG ; Dong Hee WHANG ; Jun Hee WOO
Korean Journal of Nosocomial Infection Control 2010;15(2):112-119
BACKGROUND: This study investigated the effectiveness of reinforced contact precautions and active surveillance cultures (ASCs) in reducing the incidence of methicillin-resistant Staphylococcus aureus (MRSA) and other healthcare-associated infections (HAIs). METHODS: A before- and after-experimental study was performed at the intensive care unit (ICU) in a university-affiliated hospital. Reinforced contact precautions were applied to all patients, and ASCs for MRSA were performed for newly admitted patients at the time of admission and once a week thereafter. The HAIs were investigated in accordance with the National Nosocomial Infections Surveillance (NNIS) definitions and compared before and after the interventions. The data were analyzed using descriptive statistics. RESULTS: The number of HAIs caused by MRSA decreased from 2.2 to 0.5 per 100 patients discharged (P=0.02) and from 3.6 to 1.0 per 1,000 patient-days (P=0.032). The number of overall HAIs decreased from 7.6 to 4.0 per 100 patients discharged (P=0.011) and from 12.7 to 7.3 per 1,000 patient-days (P=0.034). The invasive device-associated infections caused by MRSA and other pathogens decreased, but the decrease was not statistically significant. CONCLUSION: Reinforced contact precautions and ASCs were effective in decreasing both MRSA infections and overall HAIs in the ICU. Further, it was assumed that the incidence of device-associated infections would have decreased if the intervention period was extended.
Cross Infection
;
Humans
;
Incidence
;
Critical Care
;
Intensive Care Units
;
Methicillin Resistance
;
Methicillin-Resistant Staphylococcus aureus
4.Traumatic Pseudoaneurysm of Posterior Tibial Artery in a Child: A Case Report.
Tai Seung KIM ; Kuhn Sung WHANG ; Woo Young SEO
Journal of the Korean Fracture Society 2007;20(1):83-85
Pseudoaneurysm is one of the complications of arterial injuries by trauma. The case report in children is rare, although not in adult. A 7-year and 10-month girl was visited with the complaints of pain and a mass in her right leg. At first, the radiograph of right tibia showed a remarkable cortical erosion from without, suggesting mass effect by a soft tissue tumor. She had a history of fracture of right tibia, and then manipulative reduction and K-wire fixation at 11 months ago. Arteriography showed a formation of the pseudoaneurysm originated from the posterior tibial artery. The operation was done through the ligation of artery at proximal and distal to pseudoaneurysm, and then excision of mass. At 5 year follow-up, the configuration and function of right foot was normal. Eventually, the cause of the mass formation is thought by the trauma of fracture fragment at the time of accidents, but the possibility of penetrated injuries by K-wire should be ruled out, which is used frequently in children's fracture. We experienced a case of traumatic pseudoaneurysm of posterior tibal artery with tibial fracture, especially occurred in pediatric patient, and presented the result of long-term follow-up.
Adult
;
Aneurysm, False*
;
Angiography
;
Arteries
;
Child*
;
Female
;
Follow-Up Studies
;
Foot
;
Humans
;
Leg
;
Ligation
;
Tibia
;
Tibial Arteries*
;
Tibial Fractures
5.Variation of Attenuation Value of Pancreas at Dual Phase MDCT: Comparison of the Bolus-tracking Technique vs. the Fixed Scan Delay Protocol.
Eunhye YOO ; Myeong Jin KIM ; Seung Woo PARK ; Woo Jung LEE ; Ki Whang KIM
Journal of the Korean Radiological Society 2007;56(3):267-272
PURPOSE: To clarify the difference between the bolus-tracking technique and a fixed scan delay protocol in the achievement of the optimal pancreatic phase of the pancreas with MDCT. MATERIALS AND METHODS: 526 patients underwent pancreatic and portal venous phase imaging of the pancreas using 16-channel MDCT. All the examinations were randomized into either scanning using a bolus-tracking technique with a scan delay of 20s after the aorta was enhanced > 100 HU (groups 1 and 2) or scanning with a scan delay of 38 s from the beginning of the injection (groups 3 and 4). A contrast material of 300 mgI/mL (groups 1 and 3) or 370 mgI/mL (groups 2 and 4) at an injection speed of 3 mL/sec was injected at 2 mL/kg body weight. The pancreatic CT attenuation values were compared. RESULTS: The scan delay times of the pancreatic phase in groups 1 and 2 were 38+/-3.8s and 37.4+/-3.4s, respectively. At the pancreatic phase, the pancreatic attenuation values of groups 1 and 2 were slightly higher than those of groups 3 and 4 (115.5+/-15.4 vs 111.7+/-15.1HU; p=0.093, 128.3+/-17.1 vs 119+/-17.1HU; p=0.003). There was no significant difference between groups at the portal venous phase. CONCLUSION: The use of a bolus-tracking technique in the optimal pancreatic phase of pancreatic CT does not significantly improve the pancreatic enhancement but does at higher iodine concentrations.
Aorta
;
Body Weight
;
Humans
;
Iodine
;
Pancreas*
6.The accuracy of chest P-A interpretation by practicing familyphysician.
Cheol Kyun LIM ; Whan Sik WHANG ; Cheol Hwan KIM ; Tai Woo YOO ; Bong Yul HUH ; Chang Yup KIM ; Jeong Suk KIM ; Seung Pil JUNG
Journal of the Korean Academy of Family Medicine 1992;13(6):516-522
No abstract available.
Thorax*
7.A survey of externally recognizable genitourinary anomalies in Korean newborns.
Hwang CHOI ; Kwang Myung KIM ; Sung Kun KOH ; Kwang Sae KIM ; Young Nam WOO ; Jong Byung YOON ; Seung Kang CHOI ; Si Whang KIM
Journal of Korean Medical Science 1989;4(1):13-21
To estimate the incidence of externally recognizable genitourinary anomalies and associated anomalies in the newborns in Korea, retrospective and prospective studies have been performed. Thirty eight of 48 urology training hospitals participated in this nationwide survey. In this study we have included minor defects or variations in the anomaly to evaluate the incidence of the recognizable genitourinary conditions in the newborns. The incidence of genitourinary anomaly in 1,000 newborn delivery in a year was 11.0 in the prospective study and this figure is about three times higher than the retrospective study and is considered to be close to the true incidence. The incidence of genitourinary anomaly in 1,000 male newborn was 20.4. Hydrocele, cryptorchidism and hypospadias were most commonly observed. The incidence of hydrocele in 1,000 male newborn was 9.89 and the incidence of cryptorchidism was 7.26 and the incidence of hypospadias was 2.13. The incidence of associated anomaly in 100 genitourinary anomaly was 7.9. Congenital heart diseases and anorectal anomalies were commonly associated anomalies. In the newborns with genitourinary anomalies, premature infants account larger portion than is usually reported in total delivery.
Birth Weight
;
Congenital Abnormalities/epidemiology
;
Female
;
Gestational Age
;
Humans
;
Infant, Newborn
;
Korea
;
Male
;
*Urogenital Abnormalities
8.A case of lymphangioma in the jejunal mesentery preoperatively diagnosed by lipoprotein electrophoresis.
Soo Young KIM ; Hyo Jin PARK ; Sung Woo CHOI ; Sang In LEE ; Ki Whang KIM ; Seung Ho CHOI
Korean Journal of Medicine 2003;64(1):101-104
More than 95% of all cases of lymphangioma occur in head, neck and axilla. But, intraabdominal lymphangioma is rare. The etiology of intraabdominal lymphangioma is thought to be related with the congenital malfomation of lymphatics. It is more common in children than in adults and most of them are known to be cystic lymphangioma in pathology. The clinical symptoms of mesenteric lymphangioma seem to be related with the size and location of the tumor. We report a case of lymphangioma which was diagnosed preoperatively by lipoprotein electrophoresis in a 21-year-old woman with periumblical pain.
Adult
;
Axilla
;
Child
;
Electrophoresis*
;
Female
;
Head
;
Humans
;
Jejunum
;
Lipoproteins*
;
Lymphangioma*
;
Lymphangioma, Cystic
;
Mesentery*
;
Neck
;
Pathology
;
Young Adult
9.A Case of Essential Thrombocythemia Complicated by Acute Myocardial Infarction.
Seung Woon RHA ; Sang Won PARK ; Sang Chil LEE ; Kyo Seung WHANG ; Jung Cheon AHN ; Woo Hyuk SONG ; Do Sun LIM ; Chang Gyu PARK ; Young Hoon KIM ; Hong Seog SEO ; Wan Joo SHIM ; Dong Joo OH ; Young Moo RO
Korean Circulation Journal 1998;28(1):97-102
Essential thrombocythemia, a subcategory of chronic myeloproliferative disorder, is characterized by absolute thrombocytosis due to excessive clonal proliferation of platelets, hyperaggregability of platelets and increased incidence of thrombosis and hemorrhage. Essential thrombocythemia may cause frequent vascular thrombosis, but it can be a rare cause of acute ischemic heart diseases such as acute myocardial infarction without atherosclerosis, unstable angina and angina pectoris. We report a case of essential thrombocythemia complicated by acute myocardial infarction. A patient with a previous history of vascular thrombotic complications (such as transient ischemic attack and deep vein thrombosis) was managed with 2.8 million units of intravenous urokinase, antiplatelet agent, ACEI, antianginal medications and hydroxyurea. There were clinically remarkable improvements and no further episodes of thrombotic ischemic vascular complications, including acute myocardial infarction.
Angina Pectoris
;
Angina, Unstable
;
Atherosclerosis
;
Hemorrhage
;
Humans
;
Hydroxyurea
;
Incidence
;
Ischemic Attack, Transient
;
Myeloproliferative Disorders
;
Myocardial Infarction*
;
Myocardial Ischemia
;
Thrombocythemia, Essential*
;
Thrombocytosis
;
Thrombosis
;
Urokinase-Type Plasminogen Activator
;
Veins
10.Brain Abscess Caused by Vancomycin-Resistant Enterococci.
SulKi LEE ; Sang Won HA ; Un Kyu YUN ; In Ha WHANG ; Sang Woo HAN ; Seung Min KIM ; YoungSoon YANG ; Jeoung Ho HAN ; Inho OH ; Choon Kwan KIM
Journal of the Korean Neurological Association 2017;35(2):108-110
No abstract available.
Brain Abscess*
;
Brain*
;
Vancomycin-Resistant Enterococci*