Tuning photoluminescence of organic rubrene nanoparticles through a hydrothermal process

Light-emitting 5,6,11,12-tetraphenylnaphthacene (rubrene) nanoparticles (NPs) prepared by a reprecipitation method were treated hydrothermally. The diameters of hydrothermally treated rubrene NPs were changed from 100 nm to 2 μm, depending on hydrothermal temperature. Photoluminescence (PL) characteristics of rubrene NPs varied with hydrothermal temperatures. Luminescence of pristine rubrene NPs was yellow-orange, and it changed to blue as the hydrothermal temperature increased to 180°C. The light-emitting color distribution of the NPs was confirmed using confocal laser spectrum microscope. As the hydrothermal temperature increased from 110°C to 160°C, the blue light emission at 464 to approximately 516 nm from filtered-down NPs was enhanced by H-type aggregation. Filtered-up rubrene NPs treated at 170°C and 180°C exhibited blue luminescence due to the decrease of intermolecular excimer densities with the rapid increase in size. Variations in PL of hydrothermally treated rubrene NPs resulted from different size distributions of the NPs

Lomerizine inhibits LPS-mediated neuroinflammation and tau hyperphosphorylation by modulating NLRP3, DYRK1A, and GSK3α/β

IntroductionLomerizine is a calcium channel blocker that crosses the blood–brain barrier and is used clinically in the treatment of migraines. However, whether lomerizine is beneficial in modulating neuroinflammatory responses has not been tested yet.MethodsTo assess the potential of lomerizine for repurposing as a treatment for neuroinflammation, we investigated the effects of lomerizine on LPS-induced proinflammatory responses in BV2 microglial cells, Alzheimer’s disease (AD) excitatory neurons differentiated from induced pluripotent stem cells (iPSCs), and in LPS-treated wild type mice.ResultsIn BV2 microglial cells, lomerizine pretreatment significantly reduced LPS-evoked proinflammatory cytokine and NLRP3 mRNA levels. Similarly, lomerizine pretreatment significantly suppressed the increases in Iba-1, GFAP, proinflammatory cytokine and NLRP3 expression induced by LPS in wild-type mice. In addition, lomerizine posttreatment significantly decreased LPS-stimulated proinflammatory cytokine and SOD2 mRNA levels in BV2 microglial cells and/or wild-type mice. In LPS-treated wild-type mice and AD excitatory neurons differentiated from iPSCs, lomerizine pretreatment ameliorated tau hyperphosphorylation. Finally, lomerizine abolished the LPS-mediated activation of GSK3α/β and upregulation of DYRK1A, which is responsible for tau hyperphosphorylation, in wild-type mice.DiscussionThese data suggest that lomerizine attenuates LPS-mediated neuroinflammatory responses and tau hyperphosphorylation and is a potential drug for neuroinflammation- or tauopathy-associated diseases

Analysis of spike protein variants evolved in a novel in vivo long-term replication model for SARS-CoV-2

IntroductionThe spectrum of SARS-CoV-2 mutations have increased over time, resulting in the emergence of several variants of concern. Persistent infection is assumed to be involved in the evolution of the variants. Calu-3 human lung cancer cells persistently grow without apoptosis and release low virus titers after infection.MethodsWe established a novel in vivo long-term replication model using xenografts of Calu-3 human lung cancer cells in immunodeficient mice. Virus replication in the tumor was monitored for 30 days and occurrence of mutations in the viral genome was determined by whole-genome deep sequencing. Viral isolates with mutations were selected after plaque forming assays and their properties were determined in cells and in K18-hACE2 mice.ResultsAfter infection with parental SARS-CoV-2, viruses were found in the tumor tissues for up to 30 days and acquired various mutations, predominantly in the spike (S) protein, some of which increased while others fluctuated for 30 days. Three viral isolates with different combination of mutations produced higher virus titers than the parental virus in Calu-3 cells without cytopathic effects. In K18-hACE2 mice, the variants were less lethal than the parental virus. Infection with each variant induced production of cross-reactive antibodies to the receptor binding domain of parental SARS-CoV-2 S protein and provided protective immunity against subsequent challenge with parental virus.DiscussionThese results suggest that most of the SARS-CoV-2 variants acquired mutations promoting host adaptation in the Calu-3 xenograft mice. This model can be used in the future to further study SARS-CoV-2 variants upon long-term replication in vivo

Remote Biosensing with Polychromatic Optical Waveguide Using Blue Light‐Emitting Organic Nanowires Hybridized with Quantum Dots

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/107498/1/adfm201304039.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/107498/2/adfm201304039-sup-0001-S1.pd

Peritoneal Cells Mediate Immune Responses and Cross-Protection Against Influenza A Virus

Intraperitoneal inoculation with live influenza A virus confers protection against intranasal infections in mice and ferrets. However, the responses of peritoneal cells to influenza A virus have not been investigated. Here we show that intraperitoneal inoculation with A/WSN/1933 (H1N1) virus induced virus-reactive IgG production in the peritoneal cavity in mice. The infection resulted in substantial but transient B cell and macrophage depletion along with massive neutrophil infiltration, but virus growth was not detected. Influenza A viruses bound to α-2,6-linked sialic acids of B cells and macrophages and induced apoptotic death of peritoneal cavity cells. However, re-infection with A/WSN/1933 virus did not have adverse effects on immune cells most likely because of the neutralizing antibodies produced in response to the first exposure. Infection of BALB/c mice with A/WSN/1933 induced cross-protection against an otherwise lethal intraperitoneal dose of A/Hongkong/4801/2014 (H3N2) virus. This information suggests that immunological responses in the peritoneal cavity can induce effective defense against future virus infection. Considering the unexpected potent immunoregulatory activity of the peritoneal cells against influenza viruses, we suggest that comparative studies on various immune reactions after infection through different routes may contribute to better selection of vaccination routes in development of efficacious influenza vaccines

Characteristics of subclinical tuberculosis compared to active symptomatic tuberculosis using nationwide registry cohort in Korea: prospective cohort study

ObjectiveThe clinical manifestations of tuberculosis (TB) range from asymptomatic to disseminated depending on the microbiological and immunological status, making the diagnosis challenging. To improve our understanding of the disease progression mechanism, we aimed to identify the characteristics of subclinical TB and important predictors of symptom development.MethodsFrom July 2018 to June 2019, we systemically collected data from the National Surveillance System of South Korea on patients with pulmonary TB, and compared the characteristics of subclinical and active symptomatic TB patients.ResultsA total of 4,636 patients with pulmonary TB were included, and the prevalence of subclinical TB was 37.1% (1,720/4,636). In subclinical TB patients, the positivity rates of acid-fast bacilli (AFB) smear and culture were 16.2 and 50.2%, respectively. Subclinical TB patients were younger (55.6 ± 19.2 vs. 60.7 ± 19.5, P < 0.001), had a higher body mass index (21.7 ± 3.1 vs. 21.0 ± 3.5, P < 0.001), less under Medicaid support, and had lower rates of chronic lung disease, AFB smear and culture positivity, and bilateral disease. Regarding the characteristic differences of individual TB-related symptoms, age was positively associated with dyspnoea and general weakness but negatively associated with chest pain, haemoptysis, and weight loss. Male patients were more prone to weight loss. Chronic lung disease was related to symptoms including cough/phlegm, dyspnoea, and haemoptysis, while autoimmune diseases were associated with fever and weight loss.ConclusionsThe development of TB-related symptoms was associated with microbiological burden and clinical characteristics including underlying comorbidities, which should be evaluated carefully

Do Consumers Intend to Use Indoor Smart Farm Restaurants for a Sustainable Future? The Influence of Cognitive Drivers on Behavioral Intentions

Smart farms are eco-friendly and sustainable agriculture practices that also play a crucial role in the foodservice industry. This study investigated cognitive drivers, which included biospheric value, environmental concern, problem awareness, and ascription of responsibility, in order to form consumers’ behavioral intentions in the context of indoor smart farm restaurants. The current study also investigated the differences among the four sub-dimensions of cognitive drivers, which are based on the respondents’ demographic factors. This study was performed using data from 310 participants. The study conducted multiple linear regression to test the causal relationships and t-test and one-way ANOVA to test the demographic differences. The results of the data analysis revealed that all four sub-dimensions of the cognitive drivers aid in regard to increasing behavioral intentions. Furthermore, the data analysis results showed that age and marital status were associated with differences in biospheric value, and gender was associated with differences in environmental concern and problem awareness. This study empirically identified the direct effect of cognitive drivers on consumers’ pro-environmental behavior and their demographic differences, and it also presents practical suggestions from the perspective of green marketing

Relationships among Experience Economy, Tour Quality, Tour Satisfaction, and Word-of-Mouth in the Senior Tourism Context in Korea: The Moderating Role of Tour Guiding Services

The senior tourist market is growing, because the number of elderly people is increasing in Korea. It is widely accepted that experience in travel is more important than any other factor. Thus, the aim of this study was to examine the importance of the experience economy and its impact on outcome variables with the moderating role of tour guiding services in the senior tourism industry. This study more specifically proposed that there is a positive relationship between the four dimensions of the experience economy, which include education, entertainment, aesthetics, and escapism, and tour quality. In addition, it was proposed that tour quality has a positive influence on tour satisfaction and word-of-mouth. Lastly, this study investigated the moderating role of a tour guide service in the relationship between the experience economy and tour quality. The data were collected from 323 seniors who had experienced an overseas package tour in Korea. In order to test the proposed model, this study employed confirmatory factor analysis and structural equation modeling analysis. The data analysis results indicated that entertainment and aesthetics play a significant role in the formation of tour quality. The results of the data analysis also showed that tour quality has a positive influence on tour satisfaction, which in turn positively affects word-of-mouth. Furthermore, a tour guide service moderated the relationship between aesthetics and tour quality

Are Customers Willing to Pay More for Eco-Friendly Edible Insect Restaurants? Focusing on the Internal Environmental Locus of Control

This study examines the effect of the internal environmental locus of control, which includes green consumers, environmental activists, environmental advocates, and recyclers, in regard to the green image of edible insect restaurants. This study additionally investigates how the green image of edible insect restaurants affects the willingness to pay more. Lastly, this study explores the differences of the internal environmental locus of control, which were based on the demographic characteristics. A total of 448 samples were used for the final statistical analysis. The results of the data analysis indicate that two dimensions of the internal environmental locus of control, which include recyclers and environmental activists, have a positive influence on the green image of edible insect restaurants, and they in turn positively affect the willingness to pay more. In terms of difference analysis, all four concepts of INELOC indicated statistical differences according to age. In addition, significant differences of the mean value of recyclers and environmental advocates were found in age. There were also significant differences in the education level for the groups of green consumers. There were significant differences in green consumers, environmental advocates, and environmental activists based on marital status. Lastly, there were significant differences of the mean values of environmental advocates in monthly income