• Journal of Technologic Dentistry
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• v.8 no.1
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• pp.37-43
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• 1986

The purpose of this study is to evalute the effects of melting and casting procedures on the castability of some N-Cr and Ag-Pd alloys. One Ag-Pd alloy and two Ni-Cr alloys were chosen for study, and the first casting group of these alloys were used as the control, and with which the castability of the first recase group and the mixture group of the first recast and as much amount of the first casting alloy was compared. The results of this study were as follows: 1. The castability of the first recast alloys veried significantly depending upon the presence or abscence of the first casting alloy and the kind of alloys. 2. When the first recast alloy was mixed with as much amount of the first casting alloy, there was no significant difference in castabilityh between the first recast group and the first casting group. 3. When the first recast alloy was used alone, the castability veried significantly depending upon the kind of alloys, i.e., the castability of Rexillium III and Palliag M was decreased significantly when compared with that of the first casting groups, while that of C & B Alloy was not.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.1
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• pp.17-28
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• 2008

Purpose: It was well known that cerebral blood perfusion is normal or diffusely decreased in the majority of patients with Parkinson's disease (PD). Actually we interpreted brain perfusion SPECT images of PD patients in the clinical situation, we observed various cerebral perfusion patterns in patients with PD. So we performed brain perfusion SPECT to know the brain perfusion patterns of PD patients and the difference of perfusion patterns according to the sex and the age. Also we classified PD patients into small groups based on the brain perfusion pattern. Methods and Materials: Two hundred nineteen patients (M: 70, F: 149, mean age: $62.9{\pm}6.9$ y/o) who were diagnosed as PD without dementia clinically and 55 patients (M:15, F:40, mean age: $61.4{\pm}9.2$ y/o) as normal controls who had no past illness history were performed $^{99m}Tc$-HMP AO brain perfusion SPECT and neuropsychological test. Results: At first, we compared all patients with PD and normal controls. Brain perfusion in left inferior frontal gyrus, left insula, left transverse temporal gyrus, left inferior parietal lobule, left superior parietal lobule, right precuneus, right caudate tail were lower in patients with PD than normal controls. Secondly, we compared male and female patients with PD and normal controls, respectively. Brain perfusion SPECT showed more decreased cerebral perfusion in left hemisphere than right side in both male and female patients compared to normal controls. And there was larger hypoperfusion area in female patients compared with male. Thirdly, we classified patients with PD and normal controls into 4 groups according to the age and compared brain perfusion respectively. In patient below fifties, brain perfusion in both occipitoparietal and left temporal lobe were lower in PD group. As the patients with PD grew older, hypoperfusion area were shown in both frontal, temporal and limbic lobes. Fourthly, We were able to divide patients into small groups based on cerebral perfusion pattern. There was normal cerebral blood perfusion in 32 (14.7%) of 219 patients with PD, decreased perfusion on the frontal lobe in 45 patients (20.6%), the temporal lobe in 39 patients (17.4%), the parietal lobe in 39 patients (17.9%), the occipital lobe in 40 patients (18.3%), diffuse area in 14 patients (6.4%) and unclassified in 10 patients (4.6%). Fifthly, we compared the results of the neuropsychological test and cerebral perfusion pattern. There was no correlation between two tests except visuospatial function. Conclusion: Various perfusion state were found in patients with PD according to the age and sex. Also we were able to classify perfusion state into several groups and compare the neuropsychological test with cerebral perfusion.

• Journal of the Korean Ceramic Society
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• v.40 no.10
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• pp.973-980
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• 2003

The effects of additives in n-type semiconducting SnO$_2$-based gas sensors on oxidizing gases were investigated. The resistivity of SnO$_2$ sensors decreased when exposed to reducing gases, which act as electronic donors. However, the resistivities of the SnO$_2$ sensors increased when exposed to oxidizing gases, which act as electronic accepters. The products formed from the reaction of oxidizing gases ever SnO$_2$-based powders were analyzed by gas chromatography as compared with those formed from the reaction of reducing gases of alcohols. The SnO$_2$ sensors doped with PdCl$_2$ or A1$_2$O$_3$ showed unique dual response patterns toward oxidizing gases of $CH_3$CN and $CH_3$NO$_2$ depending on the operating temperature. The combination of these two sensors along with proper pattern recognition technique could enhance the selectivity for the gases with electron-accepting groups.

• The Journal of Korean Academy of Prosthodontics
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• v.29 no.3
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• pp.111-119
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• 1991

This study was performed to investigate the effect of gold electrodepositoin on porcelain color of palladium-silver alloy. The specimens were made by firing porcelain on the metal plates cast respectively in Au-Pt alloy, and Pd-Ag alloy. In the case of Pd-Ag alloy specimens, porcelain were fired under three different conditions of the metal plate: 1) without gold coating, 2) firing opaque beforehand on one side, gold coating on the other side, 3) gold coating on both sides of the metal plate. Color change was measured with fiber-optic colorimeter(Model TC-6FX, Tokyo Denshoku Co., Japan). The obtained results were as follows: 1. In the group of firing opaque beforehand on one side and gold coating on the other side, there was no significant differences in their color in comparison to the color of the control group of the Au-Pt alloys. 2. In the group of gold coating on both sides on metal plate, there were no significant differences except their value to the group of firing poaque beforehand on one side and gold coating on the other side.

• YAKHAK HOEJI
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• v.59 no.3
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• pp.127-134
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• 2015

The aim of this study was to investigate the correlation among age, symptoms and initial medication (IM), and the tolerance duration of IM in Korean people with Parkinson's disease (PD). We studied 60 patients with untreated early PD who were initially diagnosed in our hospital between Jun 2006 and Sep 2014. We collected data on sex, age at diagnosis, symptom duration until diagnosis, main motor symptoms, frequency and duration of IM through electronic medical records. We divided patients into groups depending on the number of drugs (MONO/COMBI) and whether to contain dopaminergic property (DOPA/NDOPA). We analyzed the correlation between age and symptoms in each two groups and calculated the mean tolerance duration of IM in each of the groups. The mean symptom duration until diagnosis was 12.2 months. The most frequent drug was levodopa formulations (80%) compared to dopamine agonists (58.3%). The number of patients in the COMBI group (63.3%) was more than that in the MONO group (36.7%). Half of the patients in the COMBI group were taking LDF+DA (50%). Except for tremor, no other symptom showed a significant correlation between with IM. The mean tolerance duration of IM was within 200 days. The mean duration for COMBI group (342.7 days) was longer than that for MONO group (209.8 days). Among regimens, the mean tolerance duration of DOPA group (293.3 days) was longer than for NDOPA group (251.4 days). There was no difference in survival curves between any of the two groups. We found that patients experienced symptoms for over a year in Korea. This indicates that diagnosis time is faster than reported in other previous studies. The longest tolerance duration among IM was for dopaminergic combination therapy. More research is needed to design the most appropriate treatment for PD in Korean patients.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.4
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• pp.539-554
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• 2002

To identify the trend of pediatric dentistry in USA and Japan, closely related to Korean pediatric dentistry. The Japanese Journal of Pediatric Dentistry(JJPD) and The Journal of the American Academy of Pediatric Dentistry(PD) were reviewed. We collected the bibliographical data of the articles published in the two journals from 1991 to 2000. We analyzed thematic distributions and chronological changes, and then compare those of two groups. The following results were obtained: 1. The 869 articles were published in JJPD and 672 in PD. This was about 30% more in JJPD. 2. In both JJPD and PD, the case reports were a quarter of scientific articles in quantity. 3. The studies on the systemic diseases had the highest proportion in both JJPD and PD. The studies on the dental caries and restorative materials also had high proportion in both journals. 4. The studies on the sedation and biochemical survey had high proportion in PD when had low proportion in JJPD. To the contrary, The studies on the behavior science in JJPD were about double of those in PD. 5. There was no statistically significant difference in quantity between JJPD and PD in the studies on the dental caries, prevention of dental caries, community dental survey, conservative treatment, restorative materials, pulp treatment, diagnosis and treatment of malocclusion, oral pathology and minor surgery, local anesthesia and nerve tissue, traumatic injuries. 6. There was statistically significant increase in the studies on the dental equipment in JJPD and in those on restorative materials in PD. 7. There was statistically significant decrease in the studies on the prevention of dental caries and local anesthesia and nerve tissue in JJPD, and those on conservative treatment in PD.

• Journal of Life Science
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• v.13 no.6
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• pp.849-855
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• 2003

Nitric oxide (NO) plays an important role as a signaling molecule in the proliferation of placenta trophoblasts. In this study, we investigated the effect of NO on the activation of phospholipase C (PLC) in BeWo cells, choriocar-cinoma cell line. Sodium nitroprusside (SNP), an agent to produce NO spontaneously in cells, alone increased $［^3H］$ thymidine incorporation of BeWo cells, indicating NO stimulates proliferation of the cells. NO-induced proliferation of BeWo cells was blocked by U73122, an inhibitor of PLC, suggesting that NO-induced PLC activation is involved in the cell proliferation. NO also stimulated extracellular signal-regulated kinase (ERK) in BeWo cells, indicated by increased phosphorylation of ERK1/2 in Western blotting using anti-phospho-ERK1/2 antibody. NO-induced phos-phorylation of ERK1/2 was not abrogated by U73122. $PLC\gamma_1$l but not$PLC\gamma_2$ was tyrosine phosphorylated by SNP in immunoprecipitation assay using anti-$PLC\gamma_1$/$PLC\gamma_2$ antibodies, and SNP-induced phosphorylation of $PLC\gamma_1$ was abrogated by pre-treatment of cells with genistein and PD98059, indicating that NO induced-phosphorylation of $PLC\gamma_1$ is mediated by ERK. These results suggest that NO stimulates the proliferation of BeWo cells through ERK and $PLC\gamma_1$.

• Korean Journal of Pharmacognosy
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• v.49 no.3
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• pp.231-239
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• 2018

Parkinson's disease (PD), one of common neurodegenerative diseases, is caused by the death of dopaminergic neurons in the substantia nigra pars compacta. The loss of dopaminergic neurons in PD is associated with oxidative stress and mitochondrial dysfunction. Hyperoside (quercetin 3-O-${\beta}$-D-galactopyranoside) was reported to have protective properties against oxidative stress by reducing intracellular reactive oxygen species (ROS) and increasing antioxidant enzyme activity. In this study, we examined the neuroprotective effect of hyperoside against 1-methyl-4-phenyl pyridinium ($MPP^+$)-induced cell model of PD and the underlying molecular mechanisms. Hyperoside significantly decreased $MPP^+$-induced cell death, accompanied by a reduction in poly ADP-ribose polymerase (PARP) cleavage. Furthermore, it attenuated $MPP^+$-induced intracellular ROS and disruption of mitochondrial membrane potential (MMP), with the reduction of Bax/Bcl-2 ratio. Moreover, hyperoside significantly increased the phosphorylation of Akt, but it has no effects on $GSK3{\beta}$ and MAPKs. Pharmacological inhibitor of PI3K/Akt abolished the cytoprotective effects of hyperoside against $MPP^+$. Taken together, these results demonstrate that hyperoside significantly attenuates $MPP^+$-induced neurotoxicity through PI3K/Akt signaling pathways in SH-SY5Y cells. Our findings suggest that hyperoside might be one of the potential candidates for the treatment of PD.

• Physical Therapy Korea
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• v.16 no.1
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• pp.70-78
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• 2009

This study was designed to examine a 3-week modified constraint-induced movement therapy (CIMT) to the less-affected arm of patients with Parkinson's disease (PD) would improve function of the more-affected arm in PD. The subjects were 6 institutional older adults with PD and clients of the social welfare facilities. The subjects (2 men, 4 women) ranged in age from 66 to 90 years (mean age 77.2 yrs). Three clinical tests were used to determine the improvement of functional activity between before and after modified CIMT. The tests included Unified Parkinson's Disease Rating Scale (UPDRS). Wolf Motor Function Test (WMFT), and Action Research Arm Test (ARAT). There were significantly differences after the modified CIMT for time performance in WMFT and pinch in ARAT (p<.05), No significant difference was noted after the modified CIMT for UPDRS and functional ability scale in WMFT. Therefore, the modified CIMT might improve time performance and is available to therapeutic program helping them improve functional ability for upper extremity in Parkinson's disease.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.124-124
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• 2010

Diagnostic tests were performed on six high voltage motors. These tests included ac current, dissipation factor(tan6) and partial discharge(PD) magnitude. The rewind of motor stator insulation at rated voltage is assessed by the results of these tests. After completing the diagnostic tests, the stator windings of motors were subjected to gradually increasing ac voltage, until the insulation punctured. No. 1 and No.2 motors(4.16 kV) failed near rated voltage of 12.3 kV and 14.2 kV, respectively. The breakdown voltage of No.3 and No.4 motors(6.6 kV) was 17.6 kV and 17.8 kV, respectively. These motors are higher that expected for good quality coils in 6.6 kV class motors.