The optimization of the localized surface plasmon resonance (LSPR)-decaying channels of hot-electrons is essential for efficient optical and photochemical processes. Understanding and having the ...ability to control chemical interface damping (CID) channel contributions will bring about new possibilities for tuning the efficiency of plasmonic hot-electron energy transfer in artificial devices. In this scanning electron microscopy-correlated dark-field scattering study, the CID was controlled by focusing on the electronic nature of disubstituted benzene rings acting as adsorbates, as well as the effects of sharp tips on gold bipyramids (AuBPs) with similar aspect ratios to those of gold nanorods. The results showed that the sharp tips on single AuBPs, as well as the electronic effects of the adsorbate molecules, increase the interfacial contact between the nanoparticles and adsorbate molecules. Electron withdrawing groups (EWGs) on the adsorbates induce larger homogeneous LSPR line widths compared to those of electron donating groups (EDGs). Depending on the location (ortho, meta, and para) of the EDG, the effect of benzene rings with an EDG, which was considered to be induced by sulfur atoms bound to the nanoparticle surface, is weakened by the back transfer of electrons facilitated by the difference in the availability of the electrons of the EDG. Therefore, this study reports that the CID in the LSPR total decay channels can be tuned by controlling the electron withdrawing and electron donating features of adsorbate molecules with the surface topology of metal.
Gut lactobacilli and bifidobacteria on the immune homeostasis. Therefore, to understand the mechanism in vivo, we selected human fecal Lactobacillus rhamnosus NK210 and Bifidobacterium longum NK219, ...which strongly suppressed the IFN-γ to IL-10 expression (IIE) ratio in lipopolysaccharide-stimulated macrophages. Thereafter, we examined their effects on the endotoxin, antibiotics, or antitumor drug-stimulated immune imbalance in mice. Intraperitoneal injection of lipopolysaccharide and oral gavage of ampicillin increased IFN-γ and TNF-α expression in the spleen, colon, and hippocampus, while IL-10 expression decreased. However, intraperitoneal injection of cyclophosphamide suppressed IFN-γ, TNF-α, and IL-10 expression. LPS exposure induced splenic natural killer cell cytotoxicity against YAC-1 cells (sNK-C) and peritoneal macrophage phagocytosis against Candida albicans (pMA-P) activities, while cyclophosphamide and ampicillin treatments suppressed sNK-C and pMA-P activities. However, LPS, ampicillin, cyclophosphamide all increased IIE and TNF-α to IL-10 expression (TIE) ratios. Oral administration of NK210 and/or NK219 significantly reduced LPS-induced sNK-C, pMA-P, and IFN-γ expression, while cyclophosphamide- or ampicillin-suppressed sNK-C and pMA-P activities, cyclophosphamide-suppressed IFN-γ, TNF-α, and IL-10 expression, and ampicillin-suppressed IL-10 expression increased. Nevertheless, they suppressed LPS-, ampicillin-, or cyclophosphamide-induced IIE and TIE ratios, cognitive impairment, and gut dysbiosis. In particular, NK219, but not NK210, increased the IIE expression ratio in vitro and in vivo, and enhanced sNK-C and pMA-P activities in normal control mice, while cognitive function and gut microbiota composition were not significantly affected. These findings suggest that NK210, Lactobacillus sp, and NK219, Bifidobacterium additively or synergistically alleviate gut dysbiosis, inflammation, and cognitive impairment with immune imbalance by controlling IIE and TIE ratios.
Controlling the morphology and composition of nanocatalysts constructed from metals and conductive polymers has attracted attention owing to their great potential for the development of ...high‐efficiency catalysts for various catalytic applications. Herein, a facile synthetic approach for ultrathin‐polyaniline‐coated Pt–Ni nanooctahedra (Pt‐Ni@PANI hybrids) with controllable PANI shell thicknesses is presented. Pt–Ni nanooctahedra/C catalysts enclosed by PANI shells with thicknesses from 0.6 to 2.4 nm were obtained by fine control over the amount of aniline. The various Pt‐Ni@PANI hybrids exhibited electrocatalytic activity toward the methanol oxidation reaction that is highly dependent on the thickness of the PANI shell. Pt‐Ni@PANI hybrids with the thinnest PANI shells (0.6 nm) showed markedly improved electrocatalytic performance for the methanol oxidation reaction compared with Pt‐Ni@PANI hybrids with thicker PANI shells, Pt–Ni nanooctahedra/C, and commercial Pt/C due to synergistic benefits of ultrathin PANI shells and Pt–Ni alloy.
The thinner the better: Polyaniline‐coated Pt–Ni nanooctahedra (Pt‐Ni@PANI) with controllable PANI shell thicknesses of 0.6 to 2.4 nm were synthesized by direct polymerization of aniline on as‐prepared Pt‐Ni nanooctahedra/C (see figure). The Pt‐Ni@PANI hybrids with the thinnest PANI shells exhibited markedly improved electrocatalytic performance in the methanol oxidation reaction due to synergism of the ultrathin PANI shell and Pt–Ni alloy.
Synthetic data generation addresses the challenges of obtaining extensive empirical datasets, offering benefits such as cost-effectiveness, time efficiency, and robust model development. Nonetheless, ...synthetic data-generation methodologies still encounter significant difficulties, including a lack of standardized metrics for modeling different data types and comparing generated results. This study introduces PVS-GEN, an automated, general-purpose process for synthetic data generation and verification. The PVS-GEN method parameterizes time-series data with minimal human intervention and verifies model construction using a specific metric derived from extracted parameters. For complex data, the process iteratively segments the empirical dataset until an extracted parameter can reproduce synthetic data that reflects the empirical characteristics, irrespective of the sensor data type. Moreover, we introduce the PoR metric to quantify the quality of the generated data by evaluating its time-series characteristics. Consequently, the proposed method can automatically generate diverse time-series data that covers a wide range of sensor types. We compared PVS-GEN with existing synthetic data-generation methodologies, and PVS-GEN demonstrated a superior performance. It generated data with a similarity of up to 37.1% across multiple data types and by 19.6% on average using the proposed metric, irrespective of the data type.
Chemical encapsulation of microbes in threedimensional polymeric microcapsules promises various applications, such as cell therapy and biosensors, and provides a basic platform for studying microbial ...communications. However, the cytoprotection of microbes in the microcapsules against external aggressors has been a major challenge in the field of microbial microencapsulation, because ionotropic hydrogels widely used for microencapsulation swell uncontrollably, and are physicochemically labile. Herein, we developed a simple polydopamine coating for obtaining cytoprotective capability of the alginate capsule that encapsulated Saccharomyces cerevisiae. The resulting alginate/ polydopamine core/shell capsule was mechanically tough, prevented gel swelling and cell leakage, and increased resistance against enzymatic attack and UV‐C irradiation. We believe that this multifunctional core/shell structure will provide a practical tool for manipulating microorganisms inside the microcapsules.
All wrapped up: Alginate/polydopamine core/shell microcapsules that encapsulate yeast Saccharomyces cerevisiae cells prevent gel swelling because of the mechanical durability of the polydopamine shell. Encapsulation enhances cell resistance against external stresses, such as enzymatic attack and UV‐C irradiation, and effectively prevents cell growth and leakage.
The genus Enterococcus is commonly overpopulated in patients with depression compared to healthy control in the feces. Therefore, we isolated Enterococcus faecalis, Enterococcus durans, Enterococcus ...gallinarum, Enterococcus faecium, and Enterococcus mundtii from the feces of patients with comorbid inflammatory bowel disease with depression and examined their roles in depression in vivo and in vitro.
Of these Enterococci, E. mundtii NK1516 most potently induced NF-κB-activated TNF-α and IL-6 expression in BV2 microglia cells. NK1516 also caused the most potent depression-like behaviors in the absence of sickness behaviors, neuroinflammation, downregulated brain-derived neurotrophic factor (BDNF), and serotonin (5-HT) levels in the hippocampus of mice. Furthermore, E. mundtii NK1516 reduced the mRNA expression of Htr1a in the hippocampus. Its capsular polysaccharide (CP), but not cytoplasmic components, also caused depression-like behaviors and reduced BDNF and serotonin levels in the hippocampus. Conversely, this was not observed with E. mundtii ATCC882, a well-known probiotic, or its CP. Orally gavaged fluorescence isothiocyanate (FITC)-conjugated NK1516 CP was detected in the hippocampus of mice. The NK1516 genome exhibited unique CP biosynthesis-related genes (capD, wbjC, WecB, vioB), unlike that of ATCC882. These findings suggest that E. mundtii may be a risk factor for depression.
To circumvent the adverse impacts arising from an excessive use of fossil fuels, bioenergy and chemical production from a carbon neutral resource (biomass) has drawn considerable attention over the ...last two decades. Among various technical candidates, fast pyrolysis of biomass has been considered as one of the viable technical routes for converting a carbonaceous material (biomass) into biocrude (bio-oil). In these respects, three biomass samples (i.e., sawdust, empty fruit bunch, and giant Miscanthus) were chosen as a carbon substrate for the pyrolysis process in this study. A pilot-scale circulating fluidized bed reactor was employed for the pyrolysis work, and biocrude from the fast pyrolysis process at 500 °C were characterized because the maximum yield of biocrude (60 wt% of the original sample mass) was achieved at 500 °C. The physico-chemical properties of biocrude were measured by the international standard/protocol (ASTM D7544 and/or EN 16900 test method) to harness biocrude as bioenergy and an initial feedstock for diverse chemicals. All measurements in this study demonstrated that the heating value, moisture content, and ash contents in biocrude were highly contingent on the type of biomass. Moreover, characterization of biocrude in this study significantly suggested that additional unit operations for char and metal removal must be conducted to meet the fuel standard in terms of biocrude as bioenergy.
•Bio-oil was produced using a pilot-scale circulating fluidized bed reactor.•The maximum yield of bio-oil (60%) was obtained at 500 °C.•The properties of bio-oil was significantly improved via extraction process.
Display omitted
•The sericin contained in silk deteriorates the electrical output characteristics of silk-fabric PENGs.•The crystallinity increases owing to the relative increase in the β-sheet ...component through the degumming process.•The degummed silk-fabric generator exhibits an output voltage approximately 40 Vp-p under pushing conditions of 60 N and 5 Hz.•Silk-fabric PENGs maintain their electrical output characteristics after 10,000 cycles.
This study evaluated the suitability of silk fabric as a piezoelectric nanogenerator (PENG). A PENG with excellent mechanical and electrical properties as well as biocompatibility was fabricated using silk. Silk fibers are composed of sericin and fibroin, and effect of sericin on the piezoelectric properties was evaluated. X-ray diffraction, Raman spectroscopy, and Fourier transform infrared analyses showed that the presence of sericin reduced the piezoelectricity, and its removal (degumming) improved the electrical output characteristics of the specimens. The device output performance exhibited a positive dependence on pressure conditions, such as the load and pushing frequency. The generators prepared from specimens before and after degumming showed power densities of 0.43 and 1.52 μW/cm2, respectively, at an applied stress of 110 N. The electrical properties of the fabricated silk PENG were stable even after 10,000 cycles. Silk-fabric PENGs can be fabricated as low-cost, high-output devices without additional processes, such as electrospinning or coating, and they show significant potential for application in biosensors, medical sensors, and implantable medical devices.
Various source-derived mesenchymal stem cells (MSCs) have been considered for cell therapeutics in incurable diseases. To characterize MSCs from different sources, we compared human bone marrow (BM), ...adipose tissue (AT), and umbilical cord blood-derived MSCs (UCB-MSCs) for surface antigen expression, differentiation ability, proliferation capacity, clonality, tolerance for aging, and paracrine activity. Although MSCs from different tissues have similar levels of surface antigen expression, immunosuppressive activity, and differentiation ability, UCB-MSCs had the highest rate of cell proliferation and clonality, and significantly lower expression of p53, p21, and p16, well known markers of senescence. Since paracrine action is the main action of MSCs, we examined the anti-inflammatory activity of each MSC under lipopolysaccharide (LPS)-induced inflammation. Co-culture of UCB-MSCs with LPS-treated rat alveolar macrophage, reduced expression of inflammatory cytokines including interleukin-1α (IL-1α), IL-6, and IL-8 via angiopoietin-1 (Ang-1). Using recombinant Ang-1 as potential soluble paracrine factor or its small interference RNA (siRNA), we found that Ang-1 secretion was responsible for this beneficial effect in part by preventing inflammation. Our results demonstrate that primitive UCB-MSCs have biological advantages in comparison to adult sources, making UCB-MSCs a useful model for clinical applications of cell therapy.
In this paper, five hydrogen storage systems for automobiles are evaluated using the fuzzy analytic hierarchy process (AHP) in respect to eight criteria. The hydrogen storage systems for automobiles ...to be evaluated are 350 bar compressed gas hydrogen, 700 bar compressed gas hydrogen, liquefied hydrogen, metal hydride and chemical hydride. The selected criteria used in the evaluation of five hydrogen storage systems are weight efficiency, volume efficiency, system cost, energy efficiency, cycle life, refueling time, safety and infrastructure. According to the evaluation, compressed gas hydrogen ranks the highest in classification in Korea. Liquefied hydrogen ranks higher than metal hydride and chemical hydride. If the infrastructure for liquefied hydrogen were good in Korea, liquefied hydrogen may rank the highest in classification. Also, it should be noted that the rank of hydrogen storage systems can be changed according to the future technological developments.
•Five hydrogen storage systems for automobiles are evaluated using the fuzzy analytic hierarchy process.•We describe the hierarchical structure and the relative comparison results on the selected criteria.•According to the evaluation, compressed gas hydrogen ranks the highest in classification in Korea.
PDF
