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BACKGROUND: While the central location is a known adverse prognostic factor in lung cancer, a precise definition of central lung cancer has not yet emerged. PURPOSE: To determine the prognostic significance of central lung cancer (defined by location index) in resected T1-sized early-stage non-small cell lung cancer (NSCLC). MATERIAL AND METHODS: Patients with resected T1-sized early-stage NSCLC between 2010 and 2015 at a single tertiary cancer center were retrospectively reviewed. Central lung cancer was defined by a location index of the second tertile or less. Kaplan-Meier analysis with log-rank test and multivariable Cox regression analysis were performed to analyze the relationship between central lung cancer and the prognosis of relapse-free survival (RFS) and overall survival (OS). Inter-observer agreement was assessed using Cohen's kappa value and intraclass correlation coefficient (ICC). RESULTS: Overall, 289 patients (169 men; median age 65 years; interquartile range 58-70 years) were evaluated. Central lung cancer (defined by location index) was adversely associated with RFS (P = 0.005) and OS (P = 0.01). Multivariable Cox regression analysis showed that central lung cancer was independently associated with poor RFS (adjusted hazard ratio 1.91; 95% confidence interval [CI] 1.12-3.24; P = 0.017) and OS (adjusted hazard ratio 1.69; 95% CI 1.04-2.74; P = 0.033). Location index demonstrated excellent inter-observer agreement (Cohen's kappa value 0.88; 95% CI 0.82-0.93) with a high ICC (0.98; 95% CI 0.97-0.98). CONCLUSION: Central lung cancer defined by a location index of the second tertile or lower is an independent adverse prognostic factor in resected T1-sized early-stage NSCLC.
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Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Carcinoma de Pequenas Células do Pulmão , Masculino , Humanos , Idoso , Neoplasias Pulmonares/patologia , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Prognóstico , Estudos Retrospectivos , Estadiamento de Neoplasias , Recidiva Local de Neoplasia/patologiaRESUMO
Transient global amnesia (TGA) is recognized as a benign memory disorder, with characteristic clinical and imaging features. However, the pathophysiology of TGA remains elusive. This study aims to elucidate the pathophysiological changes underlying TGA by exploring the brain activities. In total, 215 patients with TGA (age: 61.8 ± 7.8 years; women: 146) with MRI (within 7 days) and EEG studies (within 90 days) were recruited. Quantitative EEG (QEEG) power spectra and network analysis were performed by the artificial intelligence EEG analysis platform (iSyncBrain®). Subgroup analyses were conducted for different clinical groups, based on symptom duration, EEG timing after onset, and cytotoxic lesions on the MRI. Compared with 252 age- and sex-matched subjects (age: 64.5 ± 8.3 years, women: 182), TGA patients showed a global decrease in absolute power in all band waves, a relative decrease in alpha waves, a relative increase in theta waves, and atypical compensation activity. These QEEG changes were observed regardless of having cytotoxic lesions in MRI and they were significant up to 1 week after symptom onset. Network analysis showed that TGA was more activated than normal controls in alpha1 band-waves, exhibiting a compensatory process. TGA results in prolonged and widespread alterations of brain activity and connectivity. QEEG provide insight into pathophysiology of TGA.
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Amnésia Global Transitória , Idoso , Amnésia Global Transitória/diagnóstico por imagem , Inteligência Artificial , Eletroencefalografia/métodos , Feminino , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-IdadeRESUMO
Drawing on the moral exclusion theory and resource allocation perspective, we examine the association between supervisor perception of subordinate performance and abusive supervision (AS), and the interaction effects of a supervisor's need for achievement and second-level superiors' close monitoring of first-line supervisors, as key boundary conditions for the performance-AS relationship. We conducted a time-lagged survey with 142 matched reports from supervisors and subordinates who had direct reporting relationships with the supervisors in the South Korea military. The results of this study indicate that subordinate performance, as rated by the supervisor, was negatively associated with AS. Furthermore, a supervisor's need for achievement moderated the relationship between subordinate performance and AS, such that the relationship was more negative under a supervisor who had a higher need for achievement. In addition, second-level superiors' close monitoring of first-line supervisors moderated the effect of the interaction of subordinate performance and a supervisor's need for achievement on AS, such that the existing moderation effect of a supervisor's need for achievement is more pronounced when supervisors are under high close monitoring by their superiors. Our investigation of antecedents of supervisor's abusive behavior could help expand our previous knowledge regarding the mechanism of the performance-AS relationship.
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BACKGROUND: The prevalence of overactive bladder syndrome (OAB) increases with age. Sleep disturbances in elderly individuals with OAB is a common problem. The purpose of this study was to examine the effects of a biofeedback-based sleep improvement (BBSI) program on urinary symptoms and sleep patterns in elderly Korean women with OAB. METHODS: A non-equivalent control group pre-/post-test design was used. Elderly women with OAB were assigned to an intervention group (n = 20) or a control group (n = 18). The BBSI program was implemented in the intervention group for 12 weeks, while two educational sessions of general sleep hygiene and lifestyle modification were provided to the control group. Using SPSS 23.0, the data were analyzed by descriptive analysis using the chi-square test, Fisher's exact test, Mann-Whitney test, and Wilcoxon test. RESULTS: After the 12-week BBSI program, significant improvements were found in the intervention group's the square root of the mean squared differences of successive R-R intervals (p = 0.025), low frequency/high frequency ratio (p = 0.006), and epinephrine (p = 0.039). We also observed a significant difference in urinary symptoms, sleep efficiency, wake after sleep onset, number of awakenings, and number of awakenings within 3 h after sleep onset (p < 0.001, p = 0.004, p = 0.001, p = 0.001, and p = 0.048, respectively). However, no significant changes were found in these variables in the control group. CONCLUSIONS: The BBSI program effectively improved urinary symptoms and sleep patterns of elderly Korean women with OAB. Further longitudinal research is required to investigate the sustainability and effects of the BBSI program. TRIAL REGISTRATION: KCT0003882. Date of registration: 02/05/2019. Retrospectively registered.
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Biorretroalimentação Psicológica , Transtornos do Sono-Vigília/terapia , Bexiga Urinária Hiperativa/terapia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , República da Coreia , Transtornos do Sono-Vigília/etiologia , Bexiga Urinária Hiperativa/complicaçõesRESUMO
Our previous study demonstrated that phlorotannin supplement had a sleep-promoting effect in rodents. In the present study, we investigated whether the phlorotannin supplement could improve sleep in subjects with self-reported sleep disturbances. In a randomized, double-blind, placebo-controlled trial, 24 subjects consumed either a placebo or phlorotannin supplement (500 mg/day) for 1 week, 30-60 min prior to bedtime. Sleep parameters were assessed at baseline and at 1 week with sleep questionnaires and polysomnography. At the end of the treatment period, the complete sets of sleep parameters from 20 subjects. Phlorotannin resulted in a significant increase in "Sleep duration" scores compared to the placebo (p = .044), although there were no significant differences on the total PSQI scores. Polysomnography revealed that wakefulness after sleep onset was significantly lower in the phlorotannin group compared to the placebo group (phlorotannin vs. placebo, -25.5 ± 30.5 vs. -1.7 ± 14.9; p = .045) as well as total wake time (phlorotannin vs. placebo, -0.9 ± 3.0 vs. -6.1 ± 6.8; p = .048). Additionally, the respiratory disturbance index during supine rapid eye movement sleep was significantly lower in the phlorotannin group (p = .035). There were no serious adverse effects in either group. Our data suggest that the phlorotannin supplement improved sleep maintenance (WHO ICTRP: KCT0001892).
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Suplementos Nutricionais/efeitos adversos , Polissonografia/métodos , Distúrbios do Início e da Manutenção do Sono/etiologia , Sono/efeitos dos fármacos , Adulto , Método Duplo-Cego , Feminino , Humanos , Masculino , Autorrelato , Inquéritos e Questionários , Resultado do TratamentoRESUMO
PURPOSE: Recent study suggests that psychological issues and eating habits are closely related. In this study, we aimed to find the association between eating habits and intakes of artificial sweeteners with emotional states of schoolchildren using quantitatively analyzing objective biosignals. METHODS: The study was conducted at the National Standard Reference Data Center for Korean EEG as a cross-sectional study. Three hundred eighteen healthy children who have not been diagnosed with neurologic or psychiatric disorders were evaluated (168 girls and 150 boys; mean age of 11.8 ± 3.6 years). Analysis indicators were a dietary intake checklist for children's nutrition-related behavior score (NBS), consisting of 19 items; food frequency questionnaires (FFQs), consisting of 76 items; the Child Depression Inventory (CDI); State-Trait Anxiety Inventory-State (STAI-S); State-Trait Anxiety Inventory-Trait (STAI-T); electroencephalograph (EEG); and heart rate variability (HRV). RESULTS: Higher scores on the CDI, STAI-S, and STAI-T indicate negative emotions, and these scores were significantly decreased from the first to the fourth quartiles. The HRV results showed that the standard deviation of all normal-to-normal (SDNN) intervals was significantly higher in the first quartile than in the fourth quartile (p < 0.05). The intakes of artificial sweeteners and processed foods such as hamburgers correlate with higher theta/beta ratios, and intakes of natural foods such as legumes and fruits correlate with lower theta/beta ratios (p < 0.05). CONCLUSIONS AND IMPLICATIONS: From this result we confirmed a link between overall nutritional behavior, food additive intakes, and emotion in apparently healthy children and adolescents.
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Ansiedade/epidemiologia , Depressão/epidemiologia , Ingestão de Alimentos , Comportamento Alimentar , Aditivos Alimentares/administração & dosagem , Aditivos Alimentares/efeitos adversos , Adolescente , Ansiedade/induzido quimicamente , Criança , Depressão/induzido quimicamente , Eletroencefalografia , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Masculino , República da CoreiaRESUMO
IL-7 signaling via IL-7Rα and common γ-chain (γc) is necessary for the development and homeostasis of T cells. Although the delicate mechanism in which IL-7Rα downregulation allows the homeostasis of T cell with limited IL-7 has been well known, the exact mechanism behind the interaction between IL-7Rα and γc in the absence or presence of IL-7 remains unclear. Additionally, we are still uncertain as to how only IL-7Rα is separately downregulated by the binding of IL-7 from the IL-7Rα/γc complex. We demonstrate here that 4G3, TUGm2, and 3E12 epitope masking of γc protein are induced in the presence of IL-7, indicating that the epitope alteration is induced by IL-7 binding to the preassembled receptor core. Moreover, the epitope masking of γc protein is inversely correlated with the expression of IL-7Rα upon IL-7 binding, implying that the structural alteration of γc might be involved in the regulation of IL-7Rα expression. The conformational change in γc upon IL-7 binding may contribute not only to forming the functional IL-7 signaling complex but also to optimally regulating the expression of IL-7Rα.
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Epitopos/química , Subunidade gama Comum de Receptores de Interleucina/química , Interleucina-7/metabolismo , Receptores de Interleucina-7/química , Animais , Anticorpos Monoclonais/química , Citocinas/metabolismo , Humanos , Cinética , Camundongos , Camundongos Endogâmicos C57BL , Fosforilação , Ligação Proteica , Domínios Proteicos , Transdução de SinaisRESUMO
OBJECTIVE: This study tested a multilevel model examining the effect of nursing leader's behavioral integrity and intragroup relationship conflict on staff nurses' intent to remain. BACKGROUND: In the challenging situation of nursing shortage, nurse executives are required to focus on the retention of nurses. No previous studies have examined the impact of nursing leader's behavioral integrity and intragroup relationship conflict on nurses' intention to remain. METHODS: A cross-sectional survey of 480 RNs in 34 nursing units of a large public hospital in South Korea was conducted to test the hypothesized multilevel model. RESULTS: Nursing leader's behavioral integrity was positively related to nurses' intention to remain (b = 0.34, P < .001). This relationship was enhanced when the level of intragroup relationship conflict was high (b = 0.21, P < .05). CONCLUSIONS: Nursing leaders assigned to units with a high level of intragroup relationship conflict should endeavor to maintain their behavioral integrity to promote nurses' intention to remain.
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Conflito Psicológico , Relações Interprofissionais , Satisfação no Emprego , Liderança , Enfermeiros Administradores/psicologia , Recursos Humanos de Enfermagem Hospitalar/psicologia , Reorganização de Recursos Humanos/estatística & dados numéricos , Adulto , Atitude do Pessoal de Saúde , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Competência Profissional , República da CoreiaRESUMO
BACKGROUND: The proteasome is a validated anti-cancer target and various small-molecule inhibitors are currently in clinical development or on the market. However, adverse events and resistance associated with those proteasome inhibitors indicate the need for a new generation of drugs. Therefore, we focused on developing an oral proteasome inhibitor with improved efficacy and safety profiles. METHOD: The in vitro inhibition of the 20S proteasome catalytic activities was determined in human multiple myeloma (MM) cellular lysates with fluorogenic peptide substrates specific for each catalytic subunit. Cell cytotoxicity was assessed with the ATP bioluminescence assay using human cell samples from tumor cell lines, MM patients or normal healthy donors. In mice bearing human MM xenografts, a single dose of LC53-0110 was administered orally, and concentration-time profiles of LC53-0110 and the 20S proteasome catalytic activities in plasma, blood, and tumor were determined. The efficacy of repeat-dose compound with regard to tumor growth inhibition in vivo was also evaluated in the same MM xenograft models. RESULTS: LC53-0110 is far more specific for the chymotrypsin-like proteolytic (ß5) site of the 20S proteasome as compared to bortezomib, carfilzomib, or ixazomib. LC53-0110 treatment showed accumulation of ubiquitinated proteins, inhibited cell viability with a low nM range potency in various tumor cell lines, and showed potent activity on CD138(+) cells isolated from MM patients who are resistant/refractory to current FDA-approved drug treatment. When a single dose was administered orally to tumor-bearing mice, LC53-0110 showed both greater maximum and sustained tumor proteasome inhibition as compared with ixazomib in MM xenograft models. The robust pharmacodynamic responses in tumor correlated with tumor growth regression. In addition, LC53-0151, an analog of LC53-0110, in combination with pomalidomide, a third-generation immunomodulatory drug, showed synergistic inhibition of tumor growth both in vitro and in the xenograft mouse model. CONCLUSIONS: In view of the in vitro, in vivo, and ex vivo profiles, further investigation of additional LC compounds in preclinical studies is warranted for the nomination of a clinical development candidate.
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Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Sinergismo Farmacológico , Mieloma Múltiplo/tratamento farmacológico , Inibidores de Proteassoma/administração & dosagem , Idoso , Animais , Antineoplásicos/administração & dosagem , Apoptose/efeitos dos fármacos , Compostos de Boro/administração & dosagem , Bortezomib/administração & dosagem , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Glicina/administração & dosagem , Glicina/análogos & derivados , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Mieloma Múltiplo/patologia , Oligopeptídeos/administração & dosagem , Complexo de Endopeptidases do Proteassoma/efeitos dos fármacos , Talidomida/administração & dosagem , Talidomida/análogos & derivados , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
AIM: This empirical research aimed to identify relationships between nurses' unit tenure, nursing unit tenure diversity and medication errors. BACKGROUND: Research examining medication errors has paid little attention to the effects of multilevel precursors. METHOD: In total, 567 registered nurses (from 36 nursing units) completed a survey questionnaire at a university hospital during September 2012. Of these, 334 (completed by nurses from 22 nursing units) were eligible for multilevel analysis. RESULTS: The average frequency of self-reported medication errors per registered nurse in the preceding 6 months was 0.98. Multilevel analysis showed that medication errors were significantly negatively associated with nurses' unit tenure at individual level (B = -0.64, P = 0.002) and nursing unit tenure diversity at unit level (B = -0.69, P < 0.001). Furthermore, nursing unit tenure diversity moderated the relationship between nurses' unit tenure and medication errors (B = 0.48, P = 0.012). CONCLUSION: This study provided evidence indicating that novice nurses made a higher number of medication errors relative to experienced nurses, and that including a mixture of novice and experienced nurses in a nursing unit attenuated novice nurses' medication errors. IMPLICATIONS FOR NURSING MANAGEMENT: The development of staffing strategies that enhance nursing unit tenure diversity is required.
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Erros de Medicação/enfermagem , Enfermeiras e Enfermeiros/normas , Quartos de Pacientes , Fatores de Tempo , Adulto , Feminino , Hospitais Universitários/organização & administração , Humanos , Relações Interprofissionais , Masculino , Pessoa de Meia-Idade , Análise Multinível , Cultura Organizacional , Quartos de Pacientes/normas , Autorrelato , Inquéritos e Questionários , Recursos HumanosRESUMO
This paper presents empirical research into the relationship between leader-follower value congruence in social responsibility and the level of ethical satisfaction for employees in the workplace. 163 dyads were analyzed, each consisting of a team leader and an employee working at a large manufacturing company in South Korea. Following current methodological recommendations for congruence research, polynomial regression and response surface modeling methodologies were used to determine the effects of value congruence. Results indicate that leader-follower value congruence in social responsibility was positively related to the ethical satisfaction of employees. Furthermore, employees' ethical satisfaction was stronger when aligned with a leader with high social responsibility. The theoretical and practical implications are discussed.
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Dominação-Subordinação , Ética , Satisfação no Emprego , Liderança , Modelos Estatísticos , Responsabilidade Social , Adulto , Códigos de Ética , Pesquisa Empírica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cultura Organizacional , Valores SociaisRESUMO
Owing to the development of Information and Communication Technology (ICT) and the inevitability of telecommuting in the COVID-19 environment, the boundary between working and non-working hours has become blurred. mWork, that is, ICT-based off-hour work, which has increased through the pandemic, affects employees' work attitudes, such as presenteeism. Hence, we designed a study to investigate the antecedents and mechanisms of employee presenteeism from the perspective of the conservation of resources theory. We supported our hypothesis using a sample of 325 Korean office workers obtained through three rounds of time-delay surveys. The results show that presenteeism is higher among employees with high mWork. In addition, employees' mWork increases sleep deprivation and presenteeism, and the exchange ideology of employees reinforces the positive effect of sleep deprivation on presenteeism. Additionally, the higher the level of exchange ideology, the stronger the mediating effect of mWork on presenteeism through sleep deprivation. This study verified the conservation of resources theory by identifying the mechanism by which mWork affects an employee's life, which in turn affects their work, and provides practical implications for managing productivity loss due to presenteeism.
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Presenteísmo , Privação do Sono , Humanos , Comunicação , Tecnologia da Informação , Povo AsiáticoRESUMO
OBJECTIVE: Fatigue is a common, debilitating nonmotor symptom of Parkinson's disease (PD), but its mechanism is poorly understood. We aimed to determine whether electroencephalography (EEG) could objectively measure fatigue and to explore the pathophysiology of fatigue in PD. METHODS: We studied 32 de novo PD patients who underwent EEG. We compared brain activity between 19 PD patients without fatigue and 13 PD patients with fatigue via EEG power spectra and graphs, including the global efficiency, characteristic path length, clustering coefficient, small-worldness, local efficiency, degree centrality, closeness centrality, and betweenness centrality. RESULTS: No significant differences in absolute or relative power were detected between PD patients without or with fatigue (all p > 0.02, Bonferroni-corrected). According to our network analysis, brain network efficiency differed by frequency band. Generally, the brain network in the frontal area for theta and delta bands showed greater efficiency, and in the temporal area, the alpha1 band was less efficient in PD patients without fatigue (p < 0.0001, p = 0.0011, and p = 0.0007, respectively, Bonferroni-corrected). CONCLUSION: Our study suggests that PD patients with fatigue have less efficient networks in the frontal area than PD patients without fatigue. These findings may explain why fatigue is common in PD, a frontostriatal disorder. Increased efficiency in the temporal area in PD patients with fatigue is assumed to be compensatory. Brain network analysis using graph theory is more valuable than power spectrum analysis in revealing the brain mechanism related to fatigue.
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Enhancing corporate accountability in areas such as environment, social, and governance (ESG) has solidified its role in the discussion on improving corporate resilience and growth. ESG management activities not only augment corporate sustainability and risk control but also influence the professional roles and personal lives of members through their perceived ESG. Historically, most ESG research has centered on the interrelation of corporate ESG endeavors and outcomes, while studies focusing on the influence of perceived ESG on members have been sparse. In this light, our investigation, rooted in the conservation of resources theory, aimed to delineate the mechanistic link between perceived ESG and members' psychological well-being. This study employed a stratified random sampling technique and collected data across three waves, each spaced four weeks apart. Our sample comprised 325 Korean employees working in administrative, technical, service, and sales roles. This study recruited 325 Korean employees across three time-lagged phases and found that ESG comprehension enhances job meaningfulness, subsequently amplifying psychological wellness. Intriguingly, as pay satisfaction escalates, the mediating role of job meaningfulness between perceived ESG and well-being intensifies. Our study underscores that for organizations to harness perceived ESG to boost psychological well-being via job meaningfulness, managing pay satisfaction is imperative. These findings highlight a crucial policy implication: policymakers must actively promote ESG awareness and incorporate it into employee compensation strategies. This integration is essential to cultivating a healthier, more engaged workforce and driving long-term organizational success.
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BACKGROUND: Subjective cognitive decline (SCD) refers to the self-reported persistent cognitive decline despite normal objective testing, increasing the risk of dementia compared to cognitively normal individuals. OBJECTIVE: This study aims to investigate the attributes of SCD patients who demonstrated memory function improvement. METHODS: In this prospective study of SCD, a total of 120 subjects were enrolled as part of a multicenter cohort study aimed at identifying predictors for the clinical progression to mild cognitive impairment or dementia (CoSCo study). All subjects underwent 18F-florbetaben PET and brain MRI scans at baseline and annual neuropsychological tests. At the 24-month follow-up, we classified SCD patients based on changes in memory function, the z-score of the Seoul verbal learning test delayed recall. RESULTS: Of the 120 enrolled patients, 107 successfully completed the 24-month follow-up assessment. Among these, 80 patients (74.8%) with SCD exhibited memory function improvements. SCD patients with improved memory function had a lower prevalence of coronary artery disease at baseline and performed better in the trail-making test part B compared to those without improvement. Anatomical and biomarker analysis showed a lower frequency of amyloid PET positivity and larger volumes in the left and right superior parietal lobes in subjects with improved memory function. CONCLUSIONS: Our prospective study indicates that SCD patients experiencing memory improvement over a 24-month period had a lower amyloid burden, fewer cardiovascular risk factors, and superior executive cognitive function. Identifying these key factors associated with cognitive improvement may assist clinicians in predicting future memory function improvements in SCD patients.
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Doença de Alzheimer , Disfunção Cognitiva , Demência , Humanos , Estudos Longitudinais , Estudos de Coortes , Estudos Prospectivos , Disfunção Cognitiva/epidemiologia , Neuroimagem , Testes Neuropsicológicos , Doença de Alzheimer/psicologiaRESUMO
Introduction: This study draws on the conservation of resources theory to investigate whether the loss of sleep can trigger the loss of additional resources that are necessary for work. Methods: Using cross-sectional design of 322 call center employees working at a government-owned public bank in South Korea, we test the study hypotheses using regression and bootstrapping indirect effects analyses. Results: The results of analyses show that insufficient sleep increases employee burnout and that psychological capital mediates this relationship. We also find that insufficient sleep decreases job satisfaction via a serial mediation model such that insufficient sleep reduces psychological capital, which in turn increases burnout, and ultimately results in lower job satisfaction. Discussion: The findings reinforce the previous assessment that although sleep is a non-work factor, its impact spills over to the workplace. Theoretically, this study goes beyond direct effect to uncover the underlying or mediating mechanisms that account for the impact of the sleep-burnout relationship and the sleep-job satisfaction relationship. For managers, the results highlight the significance of sleep to employees' overall health and well-being and thus underscore the need to foster a work culture that recognizes and prioritizes employee sleep needs.
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Esgotamento Psicológico , Privação do Sono , Humanos , Estudos Transversais , Sono , GovernoRESUMO
This study empirically analyzes the role of coaching leadership in enhancing an organization's creative performance, discussing and evaluating important mediating paths of coaching leadership regarding creative performance. As a result of an empirical analysis based on survey data collected from 332 employees of Korean companies, this study first confirms that coaching leadership has a positive effect on both employees' creative performance. We also found that psychological empowerment and constructive voice behavior positively mediated the relationship between coaching leadership and creative performance. Finally, the serial mediating effect of coaching leadership on creative performance was tested through psychological empowerment and constructive voice behavior and confirmed to have a positive effect. This study indicates the importance of leadership as a critical variable that promotes employees' creative performance. In addition, by confirming the serial mediating role of psychological empowerment and constructive voice behavior, this study improves understanding of key mechanism in which coaching leadership leads to creative performance.
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This study explored the effects of trust in a supervisor (TIS) on social loafing behaviors of employees. In addition, this study examined the mediating effect of perceived organizational support (POS) on the relationship between trust in a supervisor and employees' social loafing behaviors. It also examined the moderating effects of perceived organizational politics (POP) on the relationship between TIS and POS, TIS and social loafing behaviors, and POS and social loafing behaviors. Data were collected from local government employees in Korea, and the final sample was 260. Our results indicate that trust in a supervisor has indirect negative effects on social loafing behaviors mediated by POS. In addition, it was found that the effects of TIS on POS and POS on social loafing behaviors were moderated by POP. The results of this study contribute to the extant literature on social loafing behaviors. Moreover, the findings imply that political behaviors in organizations might induce social loafing behaviors.
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Developing reliable biomarkers is important for screening Alzheimer's disease (AD) and monitoring its progression. Although EEG is non-invasive direct measurement of brain neural activity and has potentials for various neurologic disorders, vulnerability to noise, difficulty in clinical interpretation and quantification of signal information have limited its clinical application. There have been many research about machine learning (ML) adoption with EEG, but the accuracy of detecting AD is not so high or not validated with Aß PET scan. We developed EEG-ML algorithm to detect brain Aß pathology among subjective cognitive decline (SCD) or mild cognitive impairment (MCI) population, and validated it with Aß PET. 19-channel resting-state EEG and Aß PET were collected from 311 subjects: 196 SCD(36 Aß +, 160 Aß -), 115 MCI(54 Aß +, 61Aß -). 235 EEG data were used for training ML, and 76 for validation. EEG features were standardized for age and sex. Multiple important features sets were selected by 6 statistics analysis. Then, we trained 8 multiple machine learning for each important features set. Meanwhile, we conducted paired t-test to find statistically different features between amyloid positive and negative group. The best model showed 90.9% sensitivity, 76.7% specificity and 82.9% accuracy in MCI + SCD (33 Aß +, 43 Aß -). Limited to SCD, 92.3% sensitivity, 75.0% specificity, 81.1% accuracy (13 Aß +, 24 Aß -). 90% sensitivity, 78.9% specificity and 84.6% accuracy for MCI (20 Aß +, 19 Aß -). Similar trends of EEG power have been observed from the group comparison between Aß + and Aß -, and between MCI and SCD: enhancement of frontal/ frontotemporal theta; attenuation of mid-beta in centroparietal areas. The present findings suggest that accurate classification for beta-amyloid accumulation in the brain based on QEEG alone could be possible, which implies that QEEG is a promising biomarker for beta-amyloid. Since QEEG is more accessible, cost-effective, and safer than amyloid PET, QEEG-based biomarkers may play an important role in the diagnosis and treatment of AD. We expect specific patterns in QEEG could play an important role to predict future progression of cognitive impairment in the preclinical stage of AD. Further feature engineering and validation with larger dataset is recommended.
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Doença de Alzheimer , Disfunção Cognitiva , Humanos , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/patologia , Encéfalo/metabolismo , Biomarcadores , Algoritmos , Aprendizado de Máquina , Tomografia por Emissão de Pósitrons , Progressão da DoençaRESUMO
Objectives: More than half of patients with acute ischemic stroke develop post-stroke cognitive impairment (PSCI), a significant barrier to future neurological recovery. Thus, predicting cognitive trajectories post-AIS is crucial. Our primary objective is to determine whether brain network properties from electroencephalography (EEG) can predict post-stroke cognitive function using machine learning approach. Methods: We enrolled consecutive stroke patients who underwent both EEG during the acute stroke phase and cognitive assessments 3 months post-stroke. We preprocessed acute stroke EEG data to eliminate low-quality epochs, then performed independent component analysis and quantified network characteristics using iSyncBrain®. Cognitive function was evaluated using the Montreal cognitive assessment (MoCA). We initially categorized participants based on the lateralization of their lesions and then developed machine learning models to predict cognitive status in the left and right hemisphere lesion groups. Results: Eighty-seven patients were included, and the accuracy of lesion laterality prediction using EEG attributes was 97.0%. In the left hemispheric lesion group, the network attributes of the theta band were significantly correlated with MoCA scores, and higher global efficiency, clustering coefficient, and lower characteristic path length were associated with higher MoCA scores. Most features related to cognitive scores were selected from the frontal lobe. The predictive powers (R-squared) were 0.76 and 0.65 for the left and right stroke groups, respectively. Conclusion: Estimating EEG-based network properties in the acute phase of ischemic stroke through a machine learning model has a potential to predict cognitive outcomes after ischemic stroke.