25,597 research outputs found
Multi-laboratory assessment of reproducibility, qualitative and quantitative performance of SWATH-mass spectrometry
Recommended from our members
Microgravimetric immunosensor for direct detection of aerosolized influenza A virus particles.
The development and characterization of a quartz crystal microbalance (QCM) sensor for the direct detection of aerosolized influenza A virions is reported. Self-assembled monolayers (SAMs) of mercaptoundecanoic acid (MUA) are formed on QCM gold electrodes to provide a surface amenable for the immobilization of anti-influenza A antibodies using NHS/EDC coupling chemistry. The surface-bound antibody provides a selective and specific sensing interface for the capture of influenza virions. A nebulizer is used to create aerosolized samples and is directly connected to a chamber housing the antibody-modified crystal ("immunochip"). Upon exposure to the aerosolized virus, the interaction between the antibody and virus leads to a dampening of the oscillation frequency of the quartz crystal. The magnitude of frequency change is directly related to virus concentration. Control experiments using aerosols from chicken egg allantoic fluid and an anti-murine antibody based immunosensor confirm that the observed signal originates from specific viral binding on the chip surface. Step-by-step surface modification of MUA assembly, antibody attachment, and antibody-virus interaction are characterized by atomic force microscopy (AFM) imaging analysis. Using the S/N = 3 principle, the limit of detection is estimated to be 4 virus particles/mL. The high sensitivity and real-time sensing scheme presented here can play an important role in the public health arena by offering a new analytical tool for identifying bio-contaminated areas and assisting in timely patient diagnosis
Exploring the Impact of Tourist Motivations on Thailand's Gastronomic Tourism: A Structural Equation Modeling Approach
This study investigates the impact of tourist motivations on Thailand's appeal as a gastronomic tourism destination, addressing a gap in the existing literature by examining the specific factors that attract tourists to the country's culinary offerings. The primary research objective is to identify and analyze the motivations driving tourists to choose Thailand as a gastronomic destination, while also assessing the implications of these motivations for tourism stakeholders. Data was collected from 163 valid participants who had experiences with Thailand's gastronomic tourism. Using a combination of exploratory and confirmatory factor analyses, this study identifies four distinct factors that contribute to tourism motivation in Thailand: social interaction with novelty, relaxation, regression, and escape from boredom. Structural equation modeling is then employed to analyze the relationships between these factors and Thailand's appeal as a gastronomic tourism destination. The results indicate that social interaction with novelty, regression, and escape from boredom have a significant positive effect on Thailand's gastronomic destination, while relaxation is found to have no significant impact. These findings challenge existing assumptions about the role of relaxation in tourists' destination choices and provide valuable insights for tourism stakeholders seeking to capitalize on the growing popularity of gastronomic tourism. This research contributes to the understanding of gastronomic tourism motivations in Thailand, offering valuable insights for tourism stakeholders and paving the way for further exploration and understanding of the factors driving tourists' destination choices in the context of gastronomic tourism
Chromatin-binding protein PHF6 regulates activity-dependent transcriptional networks to promote hunger response
Understanding the mechanisms of activity-dependent gene transcription underlying adaptive behaviors is challenging at neuronal-subtype resolution. Using cell-type specific molecular analysis in agouti-related peptide (AgRP) neurons, we reveal that the profound hunger-induced transcriptional changes greatly depend on plant homeodomain finger protein 6 (PHF6), a transcriptional repressor enriched in AgRP neurons. Loss of PHF6 in the satiated mice results in a hunger-state-shifting transcriptional profile, while hunger fails to further induce a rapid and robust activity-dependent gene transcription in PHF6-deficient AgRP neurons. We reveal that PHF6 binds to the promoters of a subset of immediate-early genes (IEGs) and that this chromatin binding is dynamically regulated by hunger state. Depletion of PHF6 decreases hunger-driven feeding motivation and makes the mice resistant to body weight gain under repetitive fasting-refeeding conditions. Our work identifies a neuronal subtype-specific transcriptional repressor that modulates transcriptional profiles in different nutritional states and enables adaptive eating behavior
Ensuring quality of offshore programmes: views and expectations of key stakeholders in Oman
Developing offshore programmes provided by private higher education institutions through affiliation agreements with international university partners is a key strategy to assure the quality of programmes in the Sultanate of Oman. However, there is limited research on these programmes from the perspectives of Ministry of Higher Education officials, managers, academics and students of private higher education institutions. This study uses gap analysis to explore these key stakeholders’ expectations and perceptions of the quality of offshore programmes in Oman. It reveals that dependence on International University Partners to monitor their offshore programmes compromises quality because local academics have limited involvement in developing programmes and students get limited feedback on their coursework. Students’ lack of English proficiency also makes them struggle with offshore programme requirements. Key stakeholders argue for embedding Omani cultural values in the offshore programmes without compromising their academic qualification credentials and enhancing students’ learning experience to become global citizens
Factorization and Nonfactorization in B Decays
Using NLL values for Wilson coefficients and including the contributions from
the penguin diagrams, we estimate the amount of nonfactorization in two-body
hadronic B decays. Also, we investigate the model dependence of the
nonfactorization parameters by performing the calculation using different
models for the form factors. The results support the universality of
nonfactorizable contributions in both Cabibbo-favored and Cabibbo-suppressed B
decays.Comment: 17 pages, 5 figures, revte
Identification of PLXDC1 and PLXDC2 as the transmembrane receptors for the multifunctional factor PEDF.
Pigment Epithelium Derived Factor (PEDF) is a secreted factor that has broad biological activities. It was first identified as a neurotrophic factor and later as the most potent natural antiangiogenic factor, a stem cell niche factor, and an inhibitor of cancer cell growth. Numerous animal models demonstrated its therapeutic value in treating blinding diseases and diverse cancer types. A long-standing challenge is to reveal how PEDF acts on its target cells and the identities of the cell-surface receptors responsible for its activities. Here we report the identification of transmembrane proteins PLXDC1 and PLXDC2 as cell-surface receptors for PEDF. Using distinct cellular models, we demonstrate their cell type-specific receptor activities through loss of function and gain of function studies. Our experiments suggest that PEDF receptors form homooligomers under basal conditions, and PEDF dissociates the homooligomer to activate the receptors. Mutations in the intracellular domain can have profound effects on receptor activities
Recommended from our members
A Milky Way-like barred spiral galaxy at a redshift of 3
The majority of massive disk galaxies in the local Universe show a stellar barred structure in their central regions, including our Milky Way. Bars are supposed to develop in dynamically cold stellar disks at low redshift, as the strong gas turbulence typical of disk galaxies at high redshift suppresses or delays bar formation. Moreover, simulations predict bars to be almost absent beyond z = 1.5 in the progenitors of Milky Way-like galaxies. Here we report observations of ceers-2112, a barred spiral galaxy at redshift zphot ≈ 3, which was already mature when the Universe was only 2 Gyr old. The stellar mass (M★ = 3.9 × 109 M⊙) and barred morphology mean that ceers-2112 can be considered a progenitor of the Milky Way, in terms of both structure and massassembly history in the frst 2 Gyr of the Universe, and was the closest in mass in the frst 4 Gyr. We infer that baryons in galaxies could have already dominated over dark matter at z ≈ 3, that high-redshift bars could form in approximately 400 Myr and that dynamically cold stellar disks could have been in place by redshift z = 4–5 (more than 12 Gyrs ago)
- …