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The abnormal innate immune response is a prominent feature underlying autoimmune diseases. One emerging factor that can trigger dysregulated immune activation is cytosolic mitochondrial double-stranded RNAs (mt-dsRNAs). However, the mechanism by which mt-dsRNAs stimulate immune responses remains poorly understood. Here, we discover SRA stem-loop interacting RNA binding protein (SLIRP) as a key amplifier of mt-dsRNA-triggered antiviral signals. In autoimmune diseases, SLIRP is commonly upregulated, and targeted knockdown of SLIRP dampens the interferon response. We find that the activation of melanoma differentiation-associated gene 5 (MDA5) by exogenous dsRNAs upregulates SLIRP, which then stabilizes mt-dsRNAs and promotes their cytosolic release to activate MDA5 further, augmenting the interferon response. Furthermore, the downregulation of SLIRP partially rescues the abnormal interferon-stimulated gene expression in autoimmune patients' primary cells and makes cells vulnerable to certain viral infections. Our study unveils SLIRP as a pivotal mediator of interferon response through positive feedback amplification of antiviral signaling.
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Transformational leadership is important to the hotel industry where employees play a critical role in delivering the service. Transformational leadership is a leadership style that causes changes in employees by sharing the organization's vision and goals, providing necessary resources, promoting intellectual stimulation, and expecting high performance. This study uses four dimensions of transformational leadership to investigate how the dimensions influence employees' organizational identification, creativity, and task performance. In order to test the proposed model, data were gathered from employees of six hotels in South Korea. The data were analyzed with SmartPLS 4.0 program. The finding shows that four dimensions of transformational leadership have different effects on organizational identification and creativity. While core transformational leadership and supportive leader behavior enhance employees' organizational identification, which affects creativity and task performance, intellectual stimulation has an impact on creativity, which influences task performance. The post hoc analysis shows that organizational identification fully mediates the relationship between two dimensions of transformational leadership and creativity. This study contributes to the existing literatures of leadership theory and social identification theory by expanding the knowledge on the role of transformational leadership on employees. Some theoretical and practical implications are offered.
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This study considers seven residential environment elements and examines their effect on residents' place attachment (place dependence and place identity), satisfaction, word-of-mouth behavior, and pro-environmental behavior. The study also examines whether gender moderates the proposed relationships. The data were collected from 603 respondents who owned a condominium in Seoul, South Korea. We analyzed the data using structural equation modeling with SmartPLS 4. The finding shows that all seven elements of the residential environment have a significant impact on either dimension of place attachment, except for the insignificant effect of social environment on place dependence. Both dimensions of place attachment have a significant effect on satisfaction, WOM, and pro-environmental behavior except for the insignificant effect of place dependence on pro-environmental behavior. The interaction effect test of gender shows that males consider eco-friendly materials and green/recreational areas more than females. On the other hand, females are found to weigh and social environments more heavily than males. The finding shows that pro-environmental behavior is influenced by place identity (not by place dependence) and satisfaction, indicating a key role of affective response.
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In this study, a new digital technique for the analysis of the mechanical aperture and contact area of rock fractures under various normal stresses is proposed. The technique requires point cloud data of the upper and lower fracture surfaces, pressure film image data of the fracture, and normal deformation data of the fracture as input data. Three steps of algorithms were constructed using these input data: (1) a primary matching algorithm that considers the shape of the fracture surfaces; (2) a secondary matching algorithm that uses pressure film images; and (3) a translation algorithm that considers the normal deformation of a fracture. The applicability of the proposed technique was investigated using natural fracture specimens sampled at an underground research facility in Korea. In this process, the technique was validated through a comparison with the empirical equation suggested in a previous study. The proposed technique has the advantage of being able to analyze changes in the mechanical aperture and contact area under various normal stresses without multiple experiments. In addition, the change in the contact area on the fracture surface according to the normal stress can be analyzed in detail.
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This study investigates the effect of CSR activities on business performance of small- and medium-sized enterprises (SMEs) in South Korea setting. Based on upper echelons theory and stakeholder theory, the study further examines CEO tenure as a potential moderator between CSR activities and business performance. The study considers four dimensions of CSR (economic, legal, ethical, and philanthropic) and two types of business performance (financial and non-financial). To test the moderating effect of CEO tenure, we divided the sample into two groups: companies with short-term tenured CEOs and long-term tenured CEOs. The data were collected from 443 CEOs of SMEs in South Korea. We used a multi-group analysis with SmartPLS 4. The study finds that CEO tenure moderates the relationship between dimensions of CSR and business performance. More specifically, the study finds that CEOs in early-stage tenure focus on philanthropic activities to drive financial performance, while their counterparts focus on economic/legal dimension. CEOs, regardless of the length of tenure, consider the philanthropic dimension helpful for improving both financial and non-financial performance. This study expands prior research by examining the relationship between CSR and business performance in SMEs, considering the impact of the CEO tenure. The findings of this study make contributions to the literature by demonstrating that CEO tenure is an important factor in linking CSR to business performance. This research also adds evidence to the CSR literature that economic and legal dimensions are considered mandatory responsibilities, and CEOs of SMEs view them as interconnected. For practical implications, this study identifies different predictors of financial performance for companies with short-term vs. long-term CEO tenure. Short-term CEOs focus on philanthropy to improve financial performance, and both long- and short-term CEOs believe that philanthropy affects the company's financial and non-financial performance.
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This research examines which of the sub-dimensions of intra entrepreneurship (innovativeness, pro-activeness, risk-taking), and corporate social responsibility (CSR) support affects employee engagement (organizational and job engagement), which leads to employee creativity. The study uses survey data from SME employees in South Korea and applies the Structural Equation Modeling (SEM)-Artificial Neural Network (ANN) approach, to find that innovativeness and CSR support affect creativity through mediating roles of organizational engagement and job engagement, where job engagement plays a mediating role in the relationship between organizational engagement and creativity. The study also examines how employee gender and marital status effects the relative importance of intra entrepreneurship, organizational engagement, and job engagement on creativity. Findings of ANN analysis evaluates the effects per group (male-unmarried, male-married, female-unmarried, female-married) and shows how the importance of organizational engagement, job engagement, CSR support and innovativeness differ for each group. Contribution to theory and practice are discussed.
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Pore-scale modeling with a reconstructed rock microstructure has become a dominant technique for fluid flow characterization in rock thanks to technological improvements in X-ray computed tomography (CT) imaging. A new method for the construction of a pore channel model from micro-CT image analysis is suggested to improve computational efficiency by simplifying a highly complex pore structure. Ternary segmentation was applied through matching a pore volume experimentally measured by mercury intrusion porosimetry with a CT image voxel volume to distinguish regions denoted as "apparent" and "indistinct" pores. The developed pore channel model, with distinct domains of different pore phases, captures the pore shape dependence of flow in two dimensions and a tortuous flow path in three dimensions. All factors determining these geometric characteristics were identified by CT image analysis. Computation of an interaction flow regime with apparent and indistinct pore domains was conducted using both the Stokes and Brinkman equations. The coupling was successfully simulated and evaluated against the experimental results of permeability derived from Darcy's law. Reasonable agreement was found between the permeability derived from the pore channel model and that estimated experimentally. However, the model is still incapable of accurate flow modeling in very low-permeability rock. Direct numerical simulation in a computational domain with a complex pore space was also performed to compare its accuracy and efficiency with the pore channel model. Both schemes achieved reasonable results, but the pore channel model was more computationally efficient.
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OBJECTIVE: The aim of this work was to investigate the cardiorespiratory responses of patients with subacute stroke to exercise stress tests with aquatic and land treadmills. DESIGN: Twenty-one consecutive patients who presented with first-ever subacute stroke in 2013-2015. All subjects underwent symptom-limited incremental exercise testing with aquatic and land treadmills. Land treadmill speed started at 1.5 km/h and increased 0.5 km/h every 1 to 2 minutes until maximal tolerable speed was achieved. Thereafter, the grade was elevated by 2% every 2 minutes. In the aquatic treadmill test, subjects were submerged to the xiphoid in 28°C water. Treadmill speed started at 1.5 km/h and was increased 0.5 km/h every 2 minutes thereafter. Cardiorespiratory responses were recorded with aquatic and land treadmills. RESULTS: Compared to land treadmill exercise, aquatic treadmill exercise achieved significantly better peak VO2 (22.0 vs 20.0; P = 0.02), peak metabolic equivalents (6.3 vs 5.8; P = 0.02), and peak rating of perceived exertion (17.6 vs 18.4, P = 0.01). Heart rate and VO2 correlated significantly during both tests (land treadmill: r = 0.96, P < 0.001; aquatic treadmill: r = 0.99, P < 0.001). CONCLUSIONS: Aquatic treadmill exercise elicited significantly better peak cardiorespiratory responses than land treadmill exercise and may be as effective for early intensive aerobic training in subacute stroke patients.
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Capacidad Cardiovascular/fisiología , Prueba de Esfuerzo/métodos , Consumo de Oxígeno/fisiología , Esfuerzo Físico/fisiología , Accidente Cerebrovascular/fisiopatología , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Inmersión , Masculino , Persona de Mediana Edad , Satisfacción del Paciente , Rehabilitación de Accidente CerebrovascularRESUMEN
OBJECTIVE: To assess the effects of guidance force (GF) and gait speed (GS) on cardiorespiratory responses and energy cost in subacute dependent ambulatory patients with stroke. DESIGN: Cross-sectional study. SETTING: University rehabilitation hospital. PARTICIPANTS: Patients with subacute stroke (N=10; mean age, 64.50±19.20y) who were dependent ambulators (functional ambulation category ≤2). INTERVENTIONS: Patients participated in cardiorespiratory tests during robot-assisted gait training. Subjects walked at a fixed percentage (50%) of body weight support and various percentages of GF (100%, 80%, and 60%) and GS (1.4 and 1.8km/h). The therapist encouraged patients to maximize their locomotor ability. MAIN OUTCOME MEASURES: During the cardiorespiratory tests, oxygen consumption (VËo2), heart rate, and respiratory exchange ratio were measured continuously to assess cardiometabolic demands. RESULTS: There were no significant differences in cardiometabolic demands according to GS (1.4 vs 1.8km/h). There were no significant differences in cardiometabolic demands according to GF at a GS of 1.4km/h. However, lowering GF decreased VËo2 when comparing GFs of 100% (6.89±2.38mL/kg/min), 80% (6.46±1.73mL/kg/min), and 60% (5.77±1.71mL/kg/min) at a GS of 1.8km/h (P=.03). CONCLUSIONS: Lowering the GF of robot-assisted gait training at a higher GS cannot induce a sufficient cardiometabolic demand for subacute dependent ambulatory patients with stroke. This implies that it is important to take the patient's functional ability into consideration when choosing training protocols.
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Metabolismo Energético/fisiología , Prueba de Esfuerzo/métodos , Trastornos Neurológicos de la Marcha/metabolismo , Trastornos Neurológicos de la Marcha/rehabilitación , Aptitud Física/fisiología , Robótica/métodos , Rehabilitación de Accidente Cerebrovascular/métodos , Accidente Cerebrovascular/metabolismo , Accidente Cerebrovascular/fisiopatología , Actividades Cotidianas , Adulto , Anciano , Anciano de 80 o más Años , Estudios Transversales , Deambulación Dependiente , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Persona de Mediana Edad , Consumo de Oxígeno/fisiologíaRESUMEN
The paired immunoglobulin-like type 2 receptor (PILR) family consists of two functionally opposite members, inhibitory PILRα and activating PILRß receptors. PILRs are widely expressed in various immune cells and interact with their ligands, especially CD99 expressed on activated T cells, to participate in immune responses. Here we investigated whether PILR-derived agonists inhibit ß1 integrin activity as ligands for CD99. PILR-derived peptides as well as PILR-Fc fusion proteins prevented cell adhesion to fibronectin through the regulation of ß1 integrin activity. Especially, PILRpep3, a representative 3-mer peptide covering the conserved motifs of the PILR extracellular domain, prevented the clustering and activation of ß1 integrin by dephosphorylating FAK and vinculin, which are major components of focal adhesion. In addition, PILRpep3 inhibited transendothelial migration of monocytes as well as endothelial cell tube formation. Furthermore, upon intraperitoneal injection of PILRpep3 into mice with collagen-induced arthritis, the inflammatory response of rheumatoid arthritis was strongly suppressed. Taken together, these results suggest that PILR-derived agonist ligands may prevent the inflammatory reactions of rheumatoid arthritis by activating CD99.
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Artritis Reumatoide/tratamiento farmacológico , Integrina beta1/metabolismo , Péptidos/administración & dosificación , Receptores Inmunológicos/agonistas , Proteínas Recombinantes de Fusión/farmacología , Animales , Artritis Reumatoide/inmunología , Adhesión Celular/efectos de los fármacos , Línea Celular , Modelos Animales de Enfermedad , Fibronectinas/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Inyecciones Intraperitoneales , Células MCF-7 , Ratones , Péptidos/química , Péptidos/farmacología , Receptores Inmunológicos/químicaRESUMEN
[Purpose] The aim of this study was to evaluate the efficacy of mechanical massage via Endermologie(®) after total knee arthroplasty in reducing edema and pain and improving knee range of motion, in the early postoperative period. [Subjects and Methods] Eighteen patients with knee edema following total knee arthroplasty were randomly assigned to the intervention group (n=8) or the control group (n=10). The intervention group received mechanical massage therapy using Endermologie(®) and the control group received conventional physical therapy for 20 minutes a day, 5 times a week from the seventh day postsurgery. Clinical assessments included active knee flexion and extension range of motion, knee pain using a numeric rating scale, the operated limb circumference, the soft tissue cross-sectional area using ultrasonography, the extracelluar fluid volume, and single frequency bioimpedance analysis at 5 kHz using bioelectrical impedance spectroscopy. [Results] Both groups showed significant reduction in edema and pain, and improvement in active knee flexion at the end of treatment. There were no significant inter-group differences before or after treatment. [Conclusion] Mechanical massage could be an alternative way of managing knee edema after total knee arthroplasty in early postoperative recovery.
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Type 2 superior labral anterior to posterior (SLAP) lesion is a common cause of shoulder pain requiring surgical operation. SLAP tears are often associated with paralabral cysts, but they rarely cause nerve compression. However, we experienced two cases of type 2 SLAP-related paralabral cysts at the spinoglenoid notch which were confirmed as isolated nerve entrapment of the infraspinatus branch of the suprascapular nerve by electrodiagnostic assessment and magnetic resonance imaging. In these pathological conditions, comprehensive electrodiagnostic evaluation is warranted for confirmation of neuropathy, while surgical decompression of the paralabral cyst combined with SLAP repair is recommended.
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OBJECTIVE: To identify the potential predictors of ambulatory function in subacute stroke patients, and to determine the contributing factors according to gait severity. METHODS: Fifty-three subacute stroke patents were enrolled. Ambulatory function was assessed by gait speed and endurance. Balance function was evaluated by the Berg Balance Scale score (BBS) and the Timed Up and Go test (TUG). The isometric muscular strengths of bilateral knee extensors and flexors were measured using an isokinetic dynamometer. Cardiovascular fitness was evaluated using an expired gas analyzer. Participants were assigned into the household ambulator group (<0.4 m/s) or the community ambulator group (≥0.4 m/s) based on gait severity. RESULTS: In the linear regression analyses of all patients, paretic knee isometric extensor strength (p=0.007) and BBS (p<0.001) were independent predictors of gait endurance (R(2)=0.668). TUG (p<0.001) and BBS (p=0.037) were independent predictors of gait speed (R(2)=0.671). Paretic isometric extensor strength was a predictor of gait endurance (R(2)=0.340, p=0.008). TUG was a predictor of gait speed (R(2)=0.404, p<0.001) in the household ambulator group, whereas BBS was a predictive factor of gait endurance (R(2)=0.598, p=0.008) and speed (R(2)=0.713, p=0.006). TUG was a predictor of gait speed (R(2)=0.713, p=0.004) in the community ambulator group. CONCLUSION: Our results reveal that balance function and knee extensor isometric strength were strong predictors of ambulatory function in subacute stroke patients. However, they work differently according to gait severity. Therefore, a comprehensive functional assessment and a different therapeutic approach should be provided depending on gait severity in subacute stroke patients.
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The airway management for patients with critical airway problems continues to be a challenge to the anesthesiologist. In general cases, conventional ventilation techniques have been used successfully. These include fiberoptic bronchoscope guided intubation, supraglottic airway, endotracheal or endobronchial intubation at operative field, high frequency jet ventilation, etc. However, patients with near-fatal airway obstruction or severely depressed pulmonary function that is refractory to conventional ventilation methods also present. In these cases, cardiopulmonary bypass or extracorporeal membrane oxygenation (ECMO) can be used. Although these situations are uncommon indications for ECMO, ECMO can be a potential option for these life threatening conditions. Especially, venovenous (VV) ECMO can be used for pure pulmonary support. We describe three cases of airway surgery requiring ECMO. VV ECMO was established in all cases. ECMO provided adequate temporary pulmonary support and all patients weaned from ECMO successfully without any complication.
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Ozone is an air pollutant that damages a variety of biomolecules. We investigated ozone-induced inactivation of three major antioxidant enzymes. Cu/Zn superoxide dismutase was inactivated by ozone in a concentration-dependent manner. The concentration of ozone for 50% inactivation was approximately 45 microM when 10 microM Cu/Zn superoxide dismutase was incubated for 30 min in the presence of ozone. SDS-polyacrylamide gel electrophoresis (PAGE) showed that the enzyme was randomly fragmented. Both ascorbate and glutathione were very effective in protecting Cu/Zn superoxide dismutase from ozone-induced inactivation. The other two enzymes, catalase and glutathione peroxidase, were much more resistant to ozone than Cu/Zn superoxide dismutase. The ozone concentrations for 50% inactivation of 10 microM catalase and glutathione peroxidase were 500 and 240 microM, respectively. SDS-PAGE demonstrated that ozone caused formation of high molecular weight aggregates in catalase and dimerization in glutathione peroxidase. Glutathione protected catalase and glutathione peroxidase from ozone but the effective concentrations were much higher than that for Cu/Zn superoxide dismutase. Ascorbate was almost ineffective. The result suggests that, among the three antioxidant enzymes, Cu/Zn superoxide dismutase is a major target for ozone-induced inactivation and both glutathione and ascorbate are very effective in protecting the enzyme from ozone.