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Ki Woong Kim

Publications and source records attributed to Ki Woong Kim.

8 recordsLinked to original sources
PubMed2007

Combinatorial approach for ferroelectric material libraries prepared by liquid source misted chemical deposition method.

Combinatorial approach for discovering novel functional materials in the huge diversity of chemical composition and processing conditions has become more important for breakthrough in thin film electronic and energy-conversion devices. The efficiency of combinatorial method depends on the preparation of a reliable high-density composition thin-film library. The physico-chemical properties of each sample on the library should be similar to those of the corresponding samples prepared by one-by-one conventional methods. We successfully developed the combinatorial liquid source misted chemical deposition (LSMCD) method and demonstrated its validity in screening the chemical composition of Bi3.75LaxCe0.25-xTi3O12 (BLCT) for high remanent polarization (Pr). LSMCD is a cheap promising combinatorial screening tool. It can control the composition up to ppm level and produce homogeneous multicomponent library. LSMCD method allows us to prepare BLCT thin-film library at the variation of 0.4 mol% of La. Maximum 2Pr is 35 microC/cm-2 at x=0.21. The intensity of (117) XRD peak is quantitatively related to 2Pr. Newly developed scanning piezoelectric deformation measurement for nano-sized samples using scanning probe microscope (SPM) is also found out to be reliable for determining the relative ranking of Pr value rapidly.

Journal Article↗
PubMed2006

A normative study of the Trail Making Test in Korean elders.

OBJECTIVE: The purpose of this study was to explore the effects of age, education and gender on the performance of the Trail Making Test (TMT) and provide normative information in Korean elders. METHODS: The TMT was administered to 997 community-dwelling volunteers aged 60-90. People with serious neurological, medical and psychiatric disorders, including dementia, were excluded. RESULTS: Education and age had significant effects on both parts of the TMT. Gender also had an effect on part A of the TMT (Trail A). Based on these results, the norms of Trail A stratified by age (four overlapping tables), education (four strata) and gender, and the norms of part B of TMT (Trail B) stratified by age (four overlapping tables) and education (three strata). CONCLUSIONS: Age and educational level had a considerable influence on both Trail A and B. Our normative information on the Trail A will be useful in the elders with poor educational attainment and can be utilized for cross-cultural comparison of the Trail A performance. The fact that a large number of elders fail to complete Trail B indicates a limited applicability of Trail B in elderly population, particularly with poor educational background.

Age Factors↗
PubMed2006

Combination of clinical and neuropsychologic information as a better predictor of the progression to Alzheimer disease in questionable dementia individuals.

OBJECTIVES: This study aimed to examine the clinical outcomes of questionable dementia (QD) elderly subjects after three years of follow-up and to compare the ability of a standardized clinical assessment, neuropsychologic tests, the ApoE genotyping, and possible combinations of these methods to predict their progression to Alzheimer disease (AD). METHODS: One hundred six elderly subjects with QD were evaluated with a standardized clinical assessment, neuropsychologic tests, and ApoE genotyping and followed up annually. The Clinical Dementia Rating Sum of Boxes (CDR-SOB) score was used as a quantitative summary score of the standardized clinical assessment on the overall functioning of the subjects. RESULTS: Among the individuals remaining in the study after the 3-year follow-up period, 8.3% had improved to a state of normal cognition, 72.7% were still in the QD state. and 19.4% had progressed to clinically evident AD. Although each of CDR-SOB, Word List Recall (WLR), and ApoE epsilon4 genotype was predictive for AD, the combination of CDR-SOB and WLR was found to predict AD better than any single variable. However, the addition of the ApoE epsilon4 genotype information to CDR-SOB or WLR did not improve their predictive ability. CONCLUSION: The combination of clinical assessment on function and episodic memory test can improve the predictive ability of each measure for progression to AD in QD individuals. However, ApoE genotyping dose not make an additional contribution to AD prediction in QD individuals when used in combination with clinical assessment or memory test.

Aged↗
PubMed2006

Frontal dysfunction underlies depressive syndrome in Alzheimer disease: a FDG-PET study.

OBJECTIVE: This study aimed to investigate the regional cerebral dysfunction associated with depressive syndrome in patients with Alzheimer disease (AD). METHOD: Twelve patients with AD with depressive syndrome (ADD) and 12 age-, gender-, and severity-matched patients with AD without depressive syndrome (ADND) underwent FDG-PET scanning. The regional cerebral glucose metabolism in the two groups was compared using a voxel-based method. RESULTS: The ADD group showed lower glucose metabolism in the right superior frontal gyrus than the ADND group. CONCLUSIONS: These results indicate that frontal dysfunction, known to be associated with primary or other secondary depressive syndromes, underlies the depressive syndrome of patients with AD patients as well.

Aged↗
PubMed2006

White matter changes associated with psychotic symptoms in Alzheimer's disease patients.

This study explored the relationship between white matter changes seen on magnetic resonance imaging (MRI) and neuropsychiatric symptoms of Alzheimer's disease patients. Fifty-five probable Alzheimer's disease patients were assessed with Behavioral Rating Scale for Dementia (BRSD) and MRI. White matter changes in the bilateral frontal or parieto-occipital region and left basal ganglia significantly corresponded with the score of the Psychotic Symptoms subscale of BRSD. Secondary analyses revealed that white matter changes were not associated with paranoid delusion and hallucination, but only with delusional misidentification. Our results suggest that white matter changes in Alzheimer's disease patients probably contribute to the development of specific psychotic symptoms, namely delusional misidentification.

Aged↗
PubMed2005

Lack of association of cathepsin D genetic polymorphism with Alzheimer's disease in Koreans.

Cathepsin D (CatD) is a good candidate susceptibility marker for Alzheimer's disease (AD), since it was found to be involved in the processing of the amyloid precursor protein and the formation of the hyperphosphorylated tau. And recently, a CatD genetic polymorphism was found to be associated with the risk of Alzheimer's disease (AD) in a German population. However, the CatD T-AD association has not been replicated in a series of the successive independent studies in other races. Therefore, we determined CatD genotypes to examine the possible association of the CatD polymorphism with AD in Koreans. We failed to find significant association between the CatD T allele and AD. In addition, the CatD T--AD association was not significant regardless of the age at onset or the occurrence of the apolipoprotein epsilon4 allele. However, we cannot exclude the possible contribution of the CatD in the development of AD, since the power of the present study was not high enough because of low allelic frequency of the CatD T in Koreans and small sample size. In conclusion, the association between the CatD genetic polymorphism and AD was not found in Koreans, although it waits for further replication in an extended sample.

Aged↗
PubMed2002

The prevalence of dementia in older people in an urban population of Korea: the Seoul study.

OBJECTIVES: To estimate prevalence of dementia and its subtypes in older people in Seoul, a metropolitan area of Korea, and compare these findings with estimates reported for other populations. DESIGN: The study employed a two-stage design for case identification. Initially, the Mini-Mental State Examination in the Korean version (MMSE-KC) of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) assessment packet was administered to all participants. Two hundred seventeen persons sampled from three levels of performance on MMSE-KC underwent the second-stage clinical evaluation based on the Korean Version of the CERAD assessment packet. SETTING: The study was conducted in an urban community setting. PARTICIPANTS: Six hundred forty-three persons aged 65 and over participated in the study. MEASUREMENTS: Dementia was defined using the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition diagnostic features of dementia. RESULTS: Dementia prevalence ranged from 2.6% in persons aged 65 to 69 to 32.6% in persons aged 85 and older. Age-standardized prevalence was 8.2% for dementia, 5.4% for Alzheimer's disease, and 2.0% for vascular dementia. The prevalence estimates, which excluded very mild cases (clinical dementia rating index 0.5), were approximately 5.3% for dementia and 4.3% for Alzheimer's disease. CONCLUSION: The prevalence of dementia in older people in Seoul appears to be somewhat lower than in rural areas of Korea. Considering the difficulties involved in establishing a diagnostic threshold for dementia, actual differences in dementia prevalence between Asian populations are probably minimal.

Aged↗