1.The psychological influences of shift work by "symptom checklist-90-revision".
Kee Woon CHOI ; Kyung Hwan CHO ; Myung Ho HONG
Journal of the Korean Academy of Family Medicine 1991;12(7):11-21
No abstract available.
2.The psychological influences of shift work by "symptom checklist-90-revision".
Kee Woon CHOI ; Kyung Hwan CHO ; Myung Ho HONG
Journal of the Korean Academy of Family Medicine 1991;12(7):11-21
No abstract available.
3.Clinical Consideration of Coarctation of the Aorta.
Jong Woon CHOI ; Kyung Hee PARK ; Jung Yun CHOI ; Yong Soo YOON
Journal of the Korean Pediatric Society 1990;33(5):651-657
No abstract available.
Aortic Coarctation*
4.A Case of Takayasu's Arteritis.
Yong Woon KIM ; Kyung Sik CHOI ; Jae Ho KIM
Journal of the Korean Ophthalmological Society 1980;21(4):663-666
Takayasu's arteritis is an arterial inflammatory disease of unknown etiology, which most commonly affects the aorta and its large branches, and the pulmonary artery. This pathological condition which is prevalent in. Asian females results in occlusive changes in the lamina, often combined with dilation and secondary thrombus formation. It is associated with four main complications, which is Takayasu's retinopathy. secondary hypertension, aortic regurgitation and aortic or arterial aneurysms. The authors have experienced a case of Takayasu's arteritis (25 years old female) with severe retinopathy, complicated cataract. cyanotic engorged conjunctival vessels and new vessels as a collateral circulation in both eyes.
Aneurysm
;
Aorta
;
Aortic Valve Insufficiency
;
Asian Continental Ancestry Group
;
Cataract
;
Collateral Circulation
;
Female
;
Humans
;
Hypertension
;
Pulmonary Artery
;
Takayasu Arteritis*
;
Thrombosis
5.Clinical and laboratory evaluations of the vertiginous and dizzy patients.
Hyang Woon LEE ; Kee Duk PARK ; Kyung Gyu CHOI
Journal of the Korean Neurological Association 1997;15(1):165-175
Vertigo, a definite rotational sensation, consists of a variety of syndromes. The purpose of this study was to accumulate information on various aspects of vertigo or dizziness. We performed a retrospective study about vertigo patients, who had admitted to our hospital for recent 2 years. From January 1994 to December 1995, 214 patients with the complaints of 'vertigo' and 'dizziness', who admitted to the department of Neurology, Ewha Womans University Hospital, were accepted for this study. All data were recorded on computer-oriented questionnaires in digital forms. The study forms consisted of five parts; (1) history and associated symptoms, (2) physical, neurologic and bedside examinations, (3) laboratory and brain imaging studies, (4) special tests including brainstem auditory evoked potentials and (5) clinical diagnosis. Of these 214 patients, secure diagnosis could be made in 186 patients or 86.9%. Of these, 92 patients had peripheral causes of vertigo, and 94 had central causes. Vestibular disorders accounted for the largest proportion of complaints of vertigo(48/92 or 52%). Of 94 patients with central causes of vertigo, vertebrobasilar insufficiency was the leading cause(25/94 or 27%). The most common site of the brain lesion proved by MRI was cerebellum(23/94 or 25%). BAEP study revealed abnormal findings in 6 cases of the 16 patients with central causes. This study not only offered a clinical information about vertigo, but also could be beneficial for further researches.
Brain
;
Diagnosis
;
Dizziness
;
Evoked Potentials, Auditory, Brain Stem
;
Female
;
Humans
;
Magnetic Resonance Imaging
;
Neuroimaging
;
Neurology
;
Surveys and Questionnaires
;
Retrospective Studies
;
Sensation
;
Vertebrobasilar Insufficiency
;
Vertigo
6.Immunohistochemical study on the distribution of ion channels in rat trigeminal sensory nucleus.
Ho Young PARK ; Gi Woon CHOI ; Ho Young CHOI
Journal of Korean Academy of Conservative Dentistry 2002;27(3):215-231
No abstract available.
Animals
;
Ion Channels
;
Rats
7.The effect of cyanate methacrylate on the shear bond strengths to dentin.
Hyang Kyung KIM ; Kyung Kyu CHOI ; Gi Woon CHOI ; Sang Jin PARK
Journal of Korean Academy of Conservative Dentistry 2007;32(3):236-247
The purpose of this study was to evaluate the effects of cyanate methacylate on the shear bond strengths to bovine dentin surfaces as a dentin primers. Seven experimental adhesives were made with different mass fraction of Isocyanatoetylmethacrylate (IEM), 40wt% HEMA (Wako Pure Chemical Industries Osaka, Japan), 0.6% camphoroquinone, 0.4% amine and ethanol as balance. dentin bonding agents (0, 2, 4, 6, 8, 10, 12%) were made and applied on the surface of bovine dentin specimens of 7 experimental groups. Shear bond strengths were measured using a universal testing machine (Instro 4466). To identify the ratio and modes of cohesive failures, microscopic examinationn was performed. The ultra-structure of resin tags were observed under scanning electron microscope. The results were as follows ; 1) A higher shear bond strengths (33.62 MPa) in group 8% of Cyanate methacrylate to dentin were found, but there were no statistically significancy between Groups (p > 0.05). 2) The higher ratio of cohesive failures mode in group 2, 6, an 10% could be seen than that in any other groups. 3) A shorter resin tags were observed in all experimental groups. This could be resulted that the preventing from the cyanate methacrylate penetrate into dentin owing to reacting it with dentin collagen. Therefore the resin tags were shorter in lengths. Whether the higher bonding strengths of dentin bonding agents can be affected was not been assured with statistic results. The results indicated that the relation between tensile strengths of the dentin adhesives to bovine dentin and resin tags formed into the dentin could not affected. The main reason of increasing the shear bond strength to bovine dentin in experimental groups could not be assured.
Adhesives
;
Chemical Industry
;
Collagen
;
Dentin*
;
Dentin-Bonding Agents
;
Ethanol
;
Tensile Strength
8.The effect of cyanate methacrylate on the shear bond strengths to dentin.
Hyang Kyung KIM ; Kyung Kyu CHOI ; Gi Woon CHOI ; Sang Jin PARK
Journal of Korean Academy of Conservative Dentistry 2007;32(3):236-247
The purpose of this study was to evaluate the effects of cyanate methacylate on the shear bond strengths to bovine dentin surfaces as a dentin primers. Seven experimental adhesives were made with different mass fraction of Isocyanatoetylmethacrylate (IEM), 40wt% HEMA (Wako Pure Chemical Industries Osaka, Japan), 0.6% camphoroquinone, 0.4% amine and ethanol as balance. dentin bonding agents (0, 2, 4, 6, 8, 10, 12%) were made and applied on the surface of bovine dentin specimens of 7 experimental groups. Shear bond strengths were measured using a universal testing machine (Instro 4466). To identify the ratio and modes of cohesive failures, microscopic examinationn was performed. The ultra-structure of resin tags were observed under scanning electron microscope. The results were as follows ; 1) A higher shear bond strengths (33.62 MPa) in group 8% of Cyanate methacrylate to dentin were found, but there were no statistically significancy between Groups (p > 0.05). 2) The higher ratio of cohesive failures mode in group 2, 6, an 10% could be seen than that in any other groups. 3) A shorter resin tags were observed in all experimental groups. This could be resulted that the preventing from the cyanate methacrylate penetrate into dentin owing to reacting it with dentin collagen. Therefore the resin tags were shorter in lengths. Whether the higher bonding strengths of dentin bonding agents can be affected was not been assured with statistic results. The results indicated that the relation between tensile strengths of the dentin adhesives to bovine dentin and resin tags formed into the dentin could not affected. The main reason of increasing the shear bond strength to bovine dentin in experimental groups could not be assured.
Adhesives
;
Chemical Industry
;
Collagen
;
Dentin*
;
Dentin-Bonding Agents
;
Ethanol
;
Tensile Strength
9.The effect of bonding resin on bond strength of dual-cure resin cements.
Duck Su KIM ; Sang Hyuk PARK ; Gi Woon CHOI ; Kyung Kyu CHOI
Journal of Korean Academy of Conservative Dentistry 2007;32(5):426-436
The objective of this study is to evaluate the effect of an additional application of bonding resin on the bond strength of resin luting cements in both the light-cure (LC) and self-cure (SC) modes by means of the microTBS tests. Three combinations of One-Step Plus with Choice, Single Bond with Rely X ARC, and One-Up Bond F with Bistite II were used. D/E resin and Pre-Bond resin were used for the additional application. Twelve experimental groups were made. Three mandibular 3rd molars were used in each group. Indirect composite blocks were cemented on the tooth surface. 1 x 1 mm2 dentin-composite beam for microTBS testing were made and tested. When total-etching dentin adhesives were used, an additional application of the bonding resin increased the bond strength (P < 0.05). However, this additional application didn't influence the bond strength of self-etching dentin adhesives (P > 0.05). In conclusion, the results suggest that an additional application of the bonding resin increases bond strength and enhances quality of bonding when using total-etching dentin adhesives.
Adhesives
;
Dentin
;
Dentin Permeability
;
Molar
;
Resin Cements*
;
Tooth
10.Effect of film thickness of resin cement on bonding efficiency in indirect composite restoration.
Sang Hyuck LEE ; Gi Woon CHOI ; Kyung Kyu CHOI
Journal of Korean Academy of Conservative Dentistry 2010;35(2):69-79
The purpose of this study was to evaluate the effect of film thickness of various resin cements on bonding efficiency in indirect composite restoration by measurement of microtensile bond strength, polymerization shrinkage, flexural strength and modulus, fractographic FE-SEM analysis. Experimental groups were divided according to film thickness (< 50 microm-control, 50 microm-T50, 100 microm-T100, 150 microm-T150) using composite-based resin cements (Variolink II, Duo-Link) and adhesive-based resin cements (Panavia F, Rely X Unicem). The data was analyzed using ANOVA and Duncan's multiple comparison test (p < 0.05). The results were as follows; 1. Variolink II showed higher microtensile bond strength than that of adhesive-based resin cements in all film thickness (p < 0.05) but Duo-Link did not show significant difference except control group (p < 0.05). 2. Microtensile bond strength of composite-based resin cements were decreased significantly according to increasing film thickness (p < 0.05) but adhesive-based resin cements did not show significant difference among film thickness (p > 0.05). 3. Panavia F showed significantly lower polymerization shrinkage than other resin cements (p < 0.05). 4. Composite-based resin cements showed significantly higher flexural strength and modulus than adhesive-based resin cements (p < 0.05). 5. FE-SEM examination showed uniform adhesive layer and well developed resin tags in composite-based resin cements but unclear adhesive layer and poorly developed resin tags in adhesive-based resin cements. In debonded surface examination, composite-based resin cements showed mixed failures but adhesive-based resin cements showed adhesive failures.
Adhesives
;
Polymerization
;
Polymers
;
Resin Cements