4,840 research outputs found
Chronic rhinosinusitis with nasal polyps in older adults : clinical presentation, pathophysiology, and comorbidity
Purpose of Review Chronic rhinosinusitis and nasal polyps (CRSwNP) is a common condition that significantly affects patients' life. This work aims to provide an up-to-date overview of CRSwNP in older adults, focusing on its aging-related clinical presentations, pathophysiology, and comorbidity associations including asthma. Recent Findings Recent large population-based studies using nasal endoscopy have shown that CRSwNP is a mostly late-onset disease. Age-related changes in physiologic functions, including nasal epithelial barrier dysfunction, may underlie the incidence and different clinical presentations of CRSwNP in older adults. However, there is still a paucity of evidence on the effect of aging on phenotypes and endotypes of CRSwNP. Meanwhile, late-onset asthma is a major comorbid condition in patients with CRSwNP; they frequently present with type 2 inflammatory signatures that are refractory to conventional treatments when they are comorbid. However, as they are more commonly non-atopic, causative factors other than classical atopic sensitization, such as Staphylococcus aureus specific IgE sensitization, are suggested to drive the type 2 inflammation. There are additional comorbidity associations in older patients with CRSwNP, including those with chronic otitis media and head and neck malignancy. Age is a major determinant for the incidence and clinical presentations of CRSwNP. Given the heterogeneity in phenotypes and endotypes, longitudinal investigations are warranted to elucidate the effects of aging on CRSwNP
Single Molecule and Nanoparticle Imaging in Biophysical, Surface, and Photocatalysis Studies
Single molecule and nanoparticle imaging has become a very important tool to investigate many biological and chemical processes. This dissertation presents the applications of single molecule and nanoparticle imaging in biophysical, surface, and photocatalysis studies using far-field optical microscopy. The work was mainly carried out under a differential interference contrast (DIC) microscope and a total internal reflection (TIR) microscope.
First, a DIC microscopy-based single particle orientation and rotational tracking technique that allows for resolving the full three-dimensional (3D) orientation of single gold nanorod (AuNR) probes has been developed. The angular degeneracy was overcome by combining DIC polarization anisotropy with the image pattern recognition technique. The usefulness of this technique in biophysical studies was further verified by real time tracking of rotational motions of single AuNRs rotating on live cell membranes. Therefore, it is expected that this method will enable us to elucidate the comprehensive interaction mechanisms between the functionalized nanocargoes and the membrane receptors in live cells. Detailed in situ conformational information on how they bind on the cell membrane and how they move and rotate in live cells at single particle level would provide new avenues for the development of new generation of high efficient drug and gene delivery carriers.
Second, a high-throughput focused orientation and position imaging (FOPI) technique with 3D orientation resolvability for single AuNRs deposited on a gold film has been developed for surface studies. The FOPI method presented in this dissertation provides a new approach using the interaction of AuNRs with their surrounding environment for resolving the 3D orientation of single AuNRs. Therefore, it is expectedthat this method can be used as a tool to study interactions of functionalized nanoparticles with functional gold surfaces.
Last, single molecule TIRF imaging was successfully employed in photocatalysis study to reveal the nature and photocatalytic properties of the surface active sites on single Au-CdS hybrid nanocatalysts. Single-molecule photocatalysis with high-resolution super-localization imaging allowed us to reveal two distinct, incident energy-dependent charge separation mechanisms in single Au-CdS heterostructures. This finding will help us design and develop better metal-semiconductor heterostructures that are highly active for photocatalytic reactions under visible light. Furthermore, the finding will enable us to potentially engineer the direction of energy flows on the heterostructured nanomaterials at the nanoscale. Therefore, it is expected that the results presented in this dissertation have a potential impact on the development of better photocatalyst structures
Viable stretchable plasmonics based on unidirectional nanoprisms
Well-defined ordered arrays of plasmonic nanostructures were fabricated on stretchable substrates and tunable plasmon-coupling-based sensing properties were comprehensively demonstrated upon extension and contraction. Regular nanoprism patterns consisting of Ag, Au and Ag/Au bilayers were constructed on the stretchable polydimethylsiloxane substrate. The nanoprisms had the same orientation over the entire substrate (3 x 3 cm(2)) via metal deposition on a single-crystal microparticle monolayer assembly. The plasmonic sensor based on the Ag/Au bilayer showed a 6-fold enhanced surface enhanced Raman scattering signal under 20% uniaxial extension, whereas a 3-fold increase was observed upon 6% contraction, compared with the Au nanoprism arrays. The sensory behaviors were corroborated by finite-difference time-domain simulation, demonstrating the tunable electromagnetic field enhancement effect via the localized surface plasmon resonance coupling. The advanced flexible plasmonic-coupling-based devices with tunable and quantifiable performance herein suggested are expected to unlock promising potential in practical bio-sensing, biotechnological applications and optical devices.11Ysciescopu
The Use of Pluripotent Stem Cell for Personalized Cell Therapies against Neurological Disorders
Although there are a number of weaknesses for clinical use, pluripotent stem cells are valuable sources for patient-specific cell therapies against various diseases. Backed-up by a huge number of basic researches, neuronal differentiation mechanism is well established and pluripotent stem cell therapies against neurological disorders are getting closer to clinical application. However, there are increasing needs for standardization of the sourcing pluripotent stem cells by establishing stem cell registries and banking. Global harmonization will accelerate practical use of personalized therapies using pluripotent stem cells
MiR-9 Controls Chemotactic Activity of Cord Blood CD34⁺ Cells by Repressing CXCR4 Expression
Improved approaches for promoting umbilical cord blood (CB) hematopoietic stem cell (HSC) homing are clinically important to enhance engraftment of CB-HSCs. Clinical transplantation of CB-HSCs is used to treat a wide range of disorders. However, an improved understanding of HSC chemotaxis is needed for facilitation of the engraftment process. We found that ectopic overexpression of miR-9 and antisense-miR-9 respectively down- and up-regulated C-X-C chemokine receptor type 4 (CXCR4) expression in CB-CD34+ cells as well as in 293T and TF-1 cell lines. Since CXCR4 is a specific receptor for the stromal cell derived factor-1 (SDF-1) chemotactic factor, we investigated whether sense miR-9 and antisense miR-9 influenced CXCR4-mediated chemotactic mobility of primary CB CD34+ cells and TF-1 cells. Ectopic overexpression of sense miR-9 and antisense miR-9 respectively down- and up-regulated SDF-1-mediated chemotactic cell mobility. To our knowledge, this study is the first to report that miR-9 may play a role in regulating CXCR4 expression and SDF-1-mediated chemotactic activity of CB CD34+ cells
Intrahousehold discrepancy regarding food insecurity within intermarried couples of Vietnamese wives and Korean husbands in South Korea
Our previous studies have demonstrated the inadequate nutritional status of Vietnamese female marriage immigrants in Korea. Major possible reasons include food insecurity due to economic problems as well as a lack of adjustment to unfamiliar Korean foods and limited access to Vietnamese foods; however, no study has investigated food insecurity among such intermarried couples. This study was performed to investigate the prevalence of food insecurity in Korean-husband-Vietnamese-wife couples and to determine whether they exhibit an intrahousehold discrepancy regarding food insecurity. A cross-sectional analysis of the Cohort of Intermarried Women in Korea study was performed with 84 intermarried couples. Among the 84 Vietnamese immigrants, 48.8% and 41.7% had food insecurity due to economic problems and a lack of foods appealing to their appetite, respectively. There was a marked discrepancy in reporting food insecurity between Vietnamese wives (22.6-38.1%) and their Korean husbands (6.0-15.5%). Vietnamese wives were five and two times more food-insecure due to economic problems and no foods appealing to their appetite, respectively, than their Korean spouses. A follow-up study is needed to investigate the causes of this discrepancy and ways of reducing food insecurity among female marriage immigrants living in low-income, rural communities
Comparative expression patterns and diagnostic efficacies of SR splicing factors and HNRNPA1 in gastric and colorectal cancer
BACKGROUND: Serine/arginine-rich splicing factors (SRSFs) and HNRNPA1 have oncogenic properties. However, their proteomic expressions and practical priority in gastric cancer (GC) and colorectal cancer (CRC) are mostly unknown. To apply SFs in clinics, effective marker selection and characterization of properties in the target organ are essential. METHODS: We concurrently analyzed SRSF1, 3, and 5–7, and HNRNPA1, together with the conventional tumor marker carcinoembryonic antigen (CEA), in stomach and colorectal tissue samples (n = 420) using semiquantitative immunoblot, subcellular fractionation, and quantitative real-time polymerase chain reaction methods. RESULTS: In the semiquantitative immunoblot analysis, HNRNPA1 and SRSF7 levels were significantly higher in GC than in gastric normal mucosa, and SRSF7 levels were higher in intestinal-type compared with diffuse-type of gastric adenocarcinoma. Of the SFs, only HNRNPA1 presented greater than 50 % upregulation (cancer/normal mucosa > 2-fold) incidences and CEA-comparable, acceptable (>70 %) detection accuracy (74 %) for GC. All SF protein levels were significantly higher in CRC than in colorectal normal mucosa, and HNRNPA1 levels were higher in low-stage CRC compared with high-stage CRC. Among the SFs, HNRNPA1 and SRSF3 presented the two highest upregulation incidences (88 % and 74 %, respectively) and detection accuracy (90 % and 84 %, respectively) for CRC. The detection accuracy of HNRNPA1 was comparable to that of CEA in low (≤ II)-stage CRC but was inferior to that of CEA in high (>II)-stage CRC. Extranuclear distributions of HNRNPA1 and SRSF6 (cytosol/microsome) differed from those of other SRSFs (membrane/organelle) in both cancers. In an analysis of the six SF mRNAs, all mRNAs presented unacceptable detection accuracies (≤70 %) in both cancers, and all mRNAs except SRSF6 were disproportionate to the corresponding protein levels in GC. CONCLUSION: Our results provide a comprehensive insight into the six SF expression profiles in GC and indicate that, among the SFs, HNRNPA1, but not HNRNPA1 mRNA, is the most effective, novel GC marker. Regardless of the good to excellent detection accuracy of SRSF3 and HNRNPA1 in CRC, the SFs have lower practical priority than CEA, especially for high-stage CRC detection
Brain-Driven Representation Learning Based on Diffusion Model
Interpreting EEG signals linked to spoken language presents a complex
challenge, given the data's intricate temporal and spatial attributes, as well
as the various noise factors. Denoising diffusion probabilistic models (DDPMs),
which have recently gained prominence in diverse areas for their capabilities
in representation learning, are explored in our research as a means to address
this issue. Using DDPMs in conjunction with a conditional autoencoder, our new
approach considerably outperforms traditional machine learning algorithms and
established baseline models in accuracy. Our results highlight the potential of
DDPMs as a sophisticated computational method for the analysis of
speech-related EEG signals. This could lead to significant advances in
brain-computer interfaces tailored for spoken communication
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