Factors affecting quality of life in patients with rheumatoid arthritis in South Korea: a cross-sectional study.

INTRODUCTION: Rheumatoid arthritis (RA) is a chronic inflammatory disease that significantly reduces the quality of life (QOL) of affected patients. Many studies have emphasized the deterioration of QOL during the treatment of patients with RA, but factors that affect this phenomenon in Koreans with RA remain unclear. METHODS: In this cross-sectional study, 166 Korean patients with RA were enrolled, and their general characteristics, disease-related characteristics, fatigue, feelings of depression, self-efficacy, social support, and QOL were assessed. RESULTS: The overall mean score for RA-specific QOL was 5.8 out of 10. Fatigue, depression, self-efficacy, and social support were found to be significantly associated with the QOL of patients with RA. Notably, self-efficacy was found to be the most significant predictor of QOL. CONCLUSIONS: Compared to patients with RA in Western countries, Korean patients with RA, even those with better physical function, seem to have a lower QOL. Identification of the relevant physical, psychological, and social factors affecting QOL in Koreans with RA is beneficial for clinical practice. Incorporation of strategies to address these factors, such as cognitive behavioral therapy, should be considered for the holistic management of RA. Key Points • Korean patients with RA report lower levels of QOL. • Factors associated with the QOL of patients with RA were fatigue, depression, self-efficacy, and social support. • Self-efficacy was the strongest factor affecting QOL in this population; thus, it would be beneficial for clinical practitioners to incorporate cognitive-behavioral approaches into patient education to enhance self-management. • Our findings suggest that QOL and psychological factors should also be regularly evaluated for the holistic management of patients with RA.

Self-assembly of core-shell structures driven by low doping limit of Ti in LiCoO2: first-principles thermodynamic and experimental investigation.

Introducing additives is a general method of performance improvement in materials engineering, but details regarding whether the additive is doped in the host crystal or present as a secondary phase are usually examined from experimental experience, with a systematic theoretical prediction lacking, which sometimes causes controversy on the role of additives. In this study, the dopability of Ti in crystalline LiCoO2 (LCO) is investigated by a first-principles simulation method, and the doping limit is quantitatively calculated. The probability of Ti substitution for Co is examined and related to point-defect formation in LCO as a function of the general experimental variables of temperature and gas-phase partial pressures, enabling practical use of the theoretical model for real experiments. It was found that Ti substitution for Co, accompanied by the formation of a Li vacancy, is the most probable Ti doping form in LCO, but the doping limit is very low and most Ti would segregate into secondary phases. The theoretical prediction showed good agreement with the experimental results. Based on theoretical predictions, particles having LCO cores and Ti-rich shells are obtained from a simple sol-gel route followed by one-step firing without additional surface treatment. The high-voltage cyclability of LCO is greatly improved. The method demonstrated in this study may be a useful tool for screening suitable coating or doping elements for various material systems and provide a guide for designing simple spontaneous coating processes, as in this study.