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Aptamer Nanoconstructs Crossing Human Blood???Brain Barrier Discovered via Microphysiological System-Based SELEX Technology
No full textBlood???brain barrier (BBB) remains one of the critical challenges in developing neurological therapeutics. Short single-stranded DNA/RNA nucleotides forming a three-dimensional structure, called aptamers, have received increasing attention as BBB shuttles for efficient brain drug delivery owing to their practical advantages over Trojan horse antibodies or peptides. Aptamers are typically obtained by combinatorial chemical technology, termed Systemic Evolution of Ligands by EXponential Enrichment (SELEX), against purified targets, living cells, or animal models. However, identifying reliable BBB-penetrating aptamers that perform efficiently under human physiological conditions has been challenging because of the poor physiological relevance in the conventional SELEX process. Here, we report a human BBB shuttle aptamer (hBS) identified using a human microphysiological system (MPS)-based SELEX (MPS-SELEX) method. A two-channel MPS lined with human brain microvascular endothelial cells (BMECs) interfaced with astrocytes and pericytes, recapitulating high-level barrier function of in vivo BBB, was exploited as a screening platform. The MPS-SELEX procedure enabled robust function-based screening of the hBS candidates, which was not achievable in traditional in vitro BBB models. The identified aptamer (hBS01) through five-round of MPS-SELEX exhibited high capability to transport protein cargoes across the human BBB via clathrin-mediated endocytosis and enhanced uptake efficiency in BMECs and brain cells. The enhanced targeting specificity of hBS01 was further validated both in vitro and in vivo, confirming its powerful brain accumulation efficiency. These findings demonstrate that MPS-SELEX has potential in the discovery of aptamers with high target specificity that can be widely utilized to boost the development of drug delivery strategies
Process Controlled Ruthenium on 2D Engineered V-MXene via Atomic Layer Deposition for Human Healthcare Monitoring
No full textIn searching for unique and unexplored 2D materials, the authors try to investigate for the very first time the use of delaminated V-MXene coupled with precious metal ruthenium (Ru) through atomic layer deposition (ALD) for various contact and noncontact mode of real-time temperature sensing applications at the human-machine interface. The novel delaminated V-MXene (DM-V2CTx) engineered ruthenium-ALD (Ru-ALD) temperature sensor demonstrates a competitive sensing performance of 1.11% degrees C-1 as of only V-MXene of 0.42% degrees C-1. A nearly threefold increase in sensing and reversibility performance linked to the highly ordered few-layered V-MXene and selective, well-controlled Ru atomic doping by ALD for the successful formation of Ru@DM-V2CTX heterostructure. The advanced heterostructure formation, the mechanism, and the role of Ru have been comprehensively investigated by ultra-high-resolution transmission/scanning transmission electron microscopies coupled with next-generation spherical aberration correction technology and fast, accurate elemental mapping quantifications, also by ultraviolet photoelectron spectroscopy. To the knowledge, this work is the first to use the novel, optimally processed V-MXene over conventionally used Ti-MXene and its surface-internal structure engineering by Ru-ALD process-based temperature-sensing devices function and operational demonstrations. The current work could potentially motivate the development of multifunctional, future, next-generation, safe, personal healthcare electronic devices by the industrially scalable ALD technique
Green Synthesis of Ce Doped Cs3MnBr5 for Highly Stable Violet Light Emitting Diodes
No full textOver the past few decades, wide-bandgap semiconductor materials have been extensively explored for short-wavelength light-emitting diode (LED) owing to their rich technological applications spanning from phototherapy, sensors, and healthcare, to the indoor plantation. However, to date, few papers have reported violet-emitting (< 435 nm) perovskite materials and LEDs. Despite the tunable bandgap property, perovskite researchers are still lagging to achieve efficient violet emitting material. The presence of toxic lead, environment stability, complex synthesis, and achieving a large bandgap emitter have put a constraint on the development of violet perovskite LEDs. To address the abovementioned issues, herein we report a simple water-assisted synthesis of lead-free wide-bandgap perovskite with bright violet emission. No use of other solvent during synthesis makes our process very simple, cost-effective, and eco-friendly. As synthesized Ce doped -Cs3MnBr5 shows a visible blind absorption with an effective optical bandgap of 3.12 eV. Introduction of Ce in -Cs3MnBr5 lattice demonstrate dual violet emission peaks at 387 and 419 nm. Our synthesized -Cs3MnBr5:Ce also shows a good environment stability with narrow full-width half maxima (FWHM). We achieve the violet light with standard chromaticity coordinates of (0.18044, 0.02034) which makes -Cs3MnBr5:Ce a promising candidate for stable violet perovskite LEDs. [GRAPHICS]
Self-Accommodation Induced Electronic Metal-Support Interaction on Ruthenium Site for Alkaline Hydrogen Evolution Reaction
No full textTuning the metal-support interaction of supported metal catalysts has been found to be the most effective approach to modulating electronic structure and improving catalytic performance. But practical understanding of the charge transfer mechanism at the electronic level of catalysis process has remained elusive. Here, it is reported that ruthenium (Ru) nanoparticles can self-accommodate into Fe3O4 and carbon support (Ru-Fe3O4/C) through the electronic metal-support interaction, resulting in robust catalytic activity toward the alkaline hydrogen evolution reaction (HER). Spectroscopic evidence and theoretical calculations demonstrate that electronic perturbation occurred in the Ru-Fe3O4/C, and that charge redistribution directly influenced adsorption behavior during the catalytic process. The Ru-O bond formed by orbital mixing changes the charge state of the surface Ru site, enabling more electrons to flow to H intermediates (H*) for favorable adsorption. The weak binding strength of the Ru-O bond also reinforces the anti-bonding character of H* with a more favorable recombination of H* species into H-2 molecules. Because of this satisfactory catalytic mechanism, the Ru-Fe3O4/C supported nanoparticle catalyst demonstrated better HER activity and robust stability than the benchmark commercial Pt/C benchmark in alkaline media
Superficial white matter across development, young adulthood, and aging: volume, thickness, and relationship with cortical features
No full textSuperficial white matter (SWM) represents a significantly understudied part of the human brain, despite comprising a large portion of brain volume and making up a majority of cortico-cortical white matter connections. Using multiple, high-quality datasets with large sample sizes (N = 2421, age range 5-100) in combination with methodological advances in tractography, we quantified features of SWM volume and thickness across the brain and across development, young adulthood, and aging. We had four primary aims: (1) characterize SWM thickness across brain regions (2) describe associations between SWM volume and age (3) describe associations between SWM thickness and age, and (4) quantify relationships between SWM thickness and cortical features. Our main findings are that (1) SWM thickness varies across the brain, with patterns robust across individuals and across the population at the region-level and vertex-level; (2) SWM volume shows unique volumetric trajectories with age that are distinct from gray matter and other white matter trajectories; (3) SWM thickness shows nonlinear cross-sectional changes across the lifespan that vary across regions; and (4) SWM thickness is associated with features of cortical thickness and curvature. For the first time, we show that SWM volume follows a similar trend as overall white matter volume, peaking at a similar time in adolescence, leveling off throughout adulthood, and decreasing with age thereafter. Notably, the relative fraction of total brain volume of SWM continuously increases with age, and consequently takes up a larger proportion of total white matter volume, unlike the other tissue types that decrease with respect to total brain volume. This study represents the first characterization of SWM features across the large portion of the lifespan and provides the background for characterizing normal aging and insight into the mechanisms associated with SWM development and decline
Development of human-in-the-loop experiment system to extract evacuation behavioral features: A case of evacuees in nuclear emergencies
No full textEvacuation time estimation (ETE) is crucial for the effective implementation of resident protection measures as well as planning, owing to its applicability to nuclear emergencies. However, as confirmed in the Fukushima case, the ETE performed by nuclear operators does not reflect behavioral features, exposing thus, gaps that are likely to appear in real-world situations. Existing research methods including surveys and interviews have limitations in extracting highly feasible behavioral features. To overcome these limitations, we propose a VR-based immersive experiment system. The VR system realistically simulates nuclear emergencies by structuring existing disasters and human decision pro- cesses in response to the disasters. Evacuation behavioral features were quantitatively extracted through the proposed experiment system, and this system was systematically verified by statistical analysis and a comparative study of experimental results based on previous research. In addition, as part of future work, an application method that can simulate multi-level evacuation dynamics was proposed. The proposed experiment system is significant in presenting an innovative methodology for quantitatively extracting human behavioral features that have not been comprehensively studied in evacuation. It is expected that more realistic evacuation behavioral features can be collected through additional experiments and studies of various evacuation factors in the future.(c) 2023 Korean Nuclear Society, Published by Elsevier Korea LLC. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Asymptotic analysis on positive solutions of the Lane-Emden system with nearly critical exponents
No full textWe concern a family {(u(epsilon), v(epsilon))}(epsilon)>0 of solutions of the Lane-Emden system on a smooth bounded convex domain Omega in R-N [GRAPHICS] for N >= 4, max{1, 3/N-2} < p < q(epsilon) and small [GRAPHICS] This system appears as the extremal equation of the Sobolev embedding W-2,W-(p+1)/p(Omega) -> Lq epsilon+1(omega), and is also closely related to the Calderon-Zygmund estimate. Under the natural energy condition, we prove that the multiple bubbling phenomena may arise for the family {(u(epsilon), v(epsilon))}(epsilon)>0, and establish a detailed qualitative and quantitative description. If p < N/N-2, the nonlinear structure of the system makes the interaction between bubbles so strong, so the determination process of the blow-up rates and locations is completely different from that of the classical Lane-Emden equation. If p >= N/N-2, the blow-up scenario is relatively close to that of the classical Lane-Emden equation, and only single-bubble solutions can exist. Even in the latter case, we have to devise a new method to cover all p near N/N-2. We also deduce a general existence theorem that holds on any smooth bounded domains
Ocean-atmosphere interactions: Different organic components across Pacific and Southern Oceans
No full textSea spray aerosol (SSA) particles strongly influence clouds and climate but the potential impact of ocean microbiota on SSA fluxes is still a matter of active research. Here-by means of in situ ship-borne measurements-we explore simultaneously molecular-level chemical properties of organic matter (OM) in oceans, sea ice, and the ambient PM2.5 aerosols along a tran-sect of 15,000 km from the western Pacific Ocean (36 degrees 13 ' N) to the Southern Ocean (75 degrees 15 ' S). By means of orbitrap mass spectrometry and optical characteristics, lignin-like material (24 +/- 5 %) and humic material (57 +/- 8 %) were found to dominate the pelagic Pacific Ocean surface, while intermediate conditions were observed in the Pacific-Southern Ocean waters. In the marine atmosphere, we found a gradient of features in the aerosol: lignin-like material (31 +/- 9 %) dominat-ing coastal areas and the pelagic Pacific Ocean, whereas lipid-like (23 +/- 16 %) and protein-like (11 +/- 10 %) OM controlled the sympagic Southern Ocean (sea ice-influence). The results of this study showed that the OM composition in the ocean, which changes with latitude, affects the OM in aerosol compositions in the atmosphere. This study highlights the impor-tance of the global-scale OM monitoring of the close interaction between the ocean, sea ice, and the atmosphere. Sympagic primary marine aerosols in polar regions must be treated differently from other pelagic-type oceans
Sensor to Machined Surface Image Generation in CFRP Drilling
No full textCarbon-fiber-reinforced plastic (CFRP) is gaining popularity in the aerospace and automotive industries due to its exceptional physical quality. However, CFRP is a difficult-to-cut material with anisotropic properties, necessitating a system to discover defects and delamination, which might impair the product???s life during the millions of drilling hole processing, in real time. Existing studies have taken data-driven approaches that predict the hole quality using sensory data and measure the quality with delamination assessment factors, such as a conventional delamination factor (Fd) and an adjusted delamination factor (Fda), derived from image processing on hole surfaces acquired with optical microscopes. However, the factor needed by the operation may vary depending on its purpose. Because previous studies only predict a single delamination factor (e.g., Fd) at a time, they cannot simultaneously predict other factors (e.g., Fda) despite their needs. Therefore, it is necessary to explore the format of the model output that permits multiple explanations on the hole quality. In this work, an image-to-image translation-based generative model is proposed to predict the machined surface images from the CFRP drilling process. As the proposed model generates the images of the machined surfaces, instead of estimating the numerical value of only the selected delamination factor, multiple factors can be extracted from the generated images to meet diverse requirements in the drilling process. The proposed model is validated using real-world time series data collected from a dynamometer