• Dementia and Neurocognitive Disorders
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• v.22 no.2
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• pp.61-68
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• 2023

Background and Purpose: Analyzing brain amyloid positron emission tomography (PET) images to access the occurrence of β-amyloid (Aβ) deposition in Alzheimer's patients requires much time and effort from physicians, while the variation of each interpreter may differ. For these reasons, a machine learning model was developed using a convolutional neural network (CNN) as an objective decision to classify the Aβ positive and Aβ negative status from brain amyloid PET images. Methods: A total of 7,344 PET images of 144 subjects were used in this study. The 18F-florbetaben PET was administered to all participants, and the criteria for differentiating Aβ positive and Aβ negative state was based on brain amyloid plaque load score (BAPL) that depended on the visual assessment of PET images by the physicians. We applied the CNN algorithm trained in batches of 51 PET images per subject directory from 2 classes: Aβ positive and Aβ negative states, based on the BAPL scores. Results: The binary classification of the model average performance matrices was evaluated after 40 epochs of three trials based on test datasets. The model accuracy for classifying Aβ positivity and Aβ negativity was (95.00±0.02) in the test dataset. The sensitivity and specificity were (96.00±0.02) and (94.00±0.02), respectively, with an area under the curve of (87.00±0.03). Conclusions: Based on this study, the designed CNN model has the potential to be used clinically to screen amyloid PET images.

• Journal of Korean Academy of Nursing
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• v.23 no.2
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• pp.299-315
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• 1993

Koreans are one of the fastest growing immigrant groups in America. Stress responses and stressors among this large cultural minority has been rarely been studied by nursing researchers. Adjusting to life in foreign country produces a great deal of stress. Differences in culture, language, expectations and social behavior can lead to misunderstandings between health care providers and clients. These misunderstandings are not well accounted for in health assessment. This study investigated the relationship between life events or / and daily activities as a stressor and the symptoms of stress among a sample of Korean immigrants in America. The symptoms of stress scale (SOS) was used to identify stress responses and open-ended questions were used to identify life events and daily activities considered by the respondents to be stressful. A simple random sample of 283 subjects was selected from the Directory of the Korean Society of Chicago, New York, Los Angeles, Philadelphia and Seattle. Demographically, the subjects ranged in age from 20 to 69 years, and the percentage of women and men was approximately 50% each. Almost ninety percent of the subjects were highly educated, 17% owners of business, 19% white collar professionals, 14% employed in sales or as skilled /unskilled labor, 27% as housewives and students and 3％ had no occupation. The total group SOS mean was 0.8042 ; the SOS men for man was 0.7371, and for women was 0.8713. The stress response of this subject group was high, -the stress response of women higher than that for men. In an earlier study(June, 1992) with another sample, the total mean SOS score was similar to this one. The main stressful life events or / and daily activities were, in order, economic problems (N=97), interpersonal problems (N=68), children care problems (N=258), health problems (N=49), communication problems (N=42), family problems (N=38), worry about future career (N=36), and religious problems (N=25). There was a significant difference in the SOS means between the group that expressed life events or / and daily activities to be stressful and the group that did not. Interpersonal relationships and economic and family problems were stressors for those who complained about peripheral manifestations. cardiopulmonary symptoms, central-neurological symptoms, gastrointestinal symptoms, muscle ten-sion, habitual patterns, depression, anxiety, emotional irritability and cognitive disorganization. In summary, interpersonal relationships and economic and family problems influenced stress response manifestations. Income, the number of people in the family, the year of immigration. the level of education, and marital status were related to physiological and psychosocial stress responses.