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Two-dimensional (2D) transition-metal dichalcogenides such as molybdenum disulfide (MoS2) have received a great deal of attention for high-performance gas sensing applications. Unfortunately, before their translation to commercial use, several scientific problems remain to be solved. The challenges include poor stability in a humid environment, random deposition manner of MoS2 flakes that makes the process unscalable, and incomplete recovery at room temperature. Herein, we report a strategy for the room-temperature volatile organic compound (VOC) sensor using the optical microfiber sensing technology. We demonstrated well-controlled immobilization of MoS2 nanosheets onto the optical sensing region using the optical deposition technique. The experimental results show that the MoS2-functionalized optical microfiber sensor achieves high selectivity to polar aprotic and nonpolar VOCs. The sensor demonstrated high sensitivity of 0.0195, 0.0143, 0.0072, and 0.0058 nm/ppm to acetone, ethyl acetate, cyclohexane, and IPA, respectively. Finally, the repeatability and complete recovery capabilities of the sensor have also been validated in this work. [ABSTRACT FROM AUTHOR]

Usingdensity-functional theory, we performed calculations on asingle-atom catalyst (SAC) comprising an iridium atom on a modifiedgraphene oxide (Ir1-GO) surface to investigate the conversionof CO2and C2H6molecules to propanoicacid. The great catalytic activity of this surface is due to the strongadsorption of C2H6and CO2(−0.92and −0.56 eV adsorption energies, respectively). First, C2H6is dehydrogenated at an oxide site of the surfaceto form C2H5+ OH with a barrier of height 0.63eV; the adsorbed CO2then reacts with ethyl to form C2H5COO or COOC2H5with barriersof 0.95 and 1.70 eV, respectively. Less likely, the adsorbed CO2might be hydrogenated by hydroxyl to form HCOO or COOH, withenergy barriers of 1.34 and 1.49 eV, respectively. We predict thatthe most likely path for the conversion of the adsorbed CO2and ethane molecules on the Ir1-graphene oxide surfacewould involve the formation of propanoic acid (C2H5COOH). To understand the interaction between adsorbates andsurfaces, we calculated and analyzed the local densities of states(LDOS) and the electron localization function (ELF). [ABSTRACT FROM AUTHOR]

This study delves into the green synthesis and multifaceted applications of three types of carbon quantum dots (CQDs), namely, CQDs-1, CQDs-2, and CQDs-3. These CQDs were innovatively produced through a gentle pyrolysis process from distinct plant-based precursors: genipin with glucose for CQDs-1, genipin with extracted gardenia seeds for CQDs-2, and genipin with whole gardenia seeds for CQDs-3. Advanced analytical techniques, including X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FT-IR), were employed to detail the CQDs' structural and surface characteristics, revealing their unique functional groups and surface chemistries. The study further explores the CQDs' bioimaging potential, where confocal fluorescence microscopy evidenced their swift uptake by Escherichia coli bacteria, indicating their suitability for bacterial imaging. These CQDs were also applied in the synthesis of gold nanoparticles (AuNPs), acting as reducing agents and stabilizers. Among these, CQD3-AuNPs were distinguished by their remarkable stability and catalytic efficiency, achieving a 99.7% reduction of 4-nitrophenol to 4-aminophenol in just 10 min and maintaining near-complete reduction efficiency (99.6%) after 60 days. This performance notably surpasses that of AuNPs synthesized using sodium citrate, underscoring the exceptional capabilities of CQD3-AuNPs. These insights pave the way for leveraging CQDs and CQD-stabilized AuNPs in bacterial imaging and catalysis, presenting valuable directions for future scientific inquiry and practical applications., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Metal halide perovskites have attracted great attention for their superior light energy conversion applications. Herein, we demonstrated a facile synthesis of zero-dimensional Sn 2+ perovskite Cs 4- x M x SnBr 6 (M = K + and Rb + ) material through the cation transformation reaction at room temperature. Cs 4 SnBr 6 NCs was mixed with pure metal bromide salts (KBr and RbBr) via the mechanochemical process to successfully synthesize Cs 4- x M x SnBr 6 perovskite where transformation of Cs to mixed Cs/Rb and mixed Cs/K was achieved. By substituting different cations, the bright fluorescence of the Cs 4- x M x SnBr 6 was tuned from dim green to greenish-cyan while achieving the photoluminescence (PL) quantum yield of ∼39%. The crystal structure of Sn based perovskite with the substitution of K + or Rb + cations was determined by X-ray diffraction (XRD). Moreover, the Cs 4- x M x SnBr 6 demonstrated superior air stability and exhibited a better photocatalytic activity for CO 2 reduction reaction (CO 2 RR) with high selectivity of CH 4 gas with a higher yield rate compared to the pristine Cs 4 SnBr 6 NCs.

The aryl hydrocarbon receptor (AhR), a transcription factor mediating xenobiotic detoxification, plays a considerable role in regulatory T cell (Treg) induction. Tregs regulate the immune system, thus suppressing allergies and autoimmune diseases. This study aims to identify new types of antiallergic dietary factors, with focus on the flavonoids with potential AhR agonistic activity. Among 25 dietary flavonoid samples tested using a reporter assay, 8 showed marked induction of AhR-dependent transcriptional activity. The subsequent T cell proliferation suppression assay identified naringenin as the only sample capable of stimulating Treg induction; notably, this induction was eliminated by cotreatment with AhR antagonists. Indeed, naringenin induced CD4(+)Foxp3(+) Tregs, irrespective of the presence of the transforming growth factor-β (TGF-β), indicating that the conventional TGF-β-dependent signaling pathway might not be involved.

Bioactive components in Ganoderma lucidum mainly include polysaccharides (PS-G) and immunomodulatory protein Ling Zhi-8 (LZ-8). These components may have diverse regulatory functions in the immune system. However, the PS-G preparations from different procedures still contained partial LZ-8 residue, indicating that the specific target and regulating function of PS-G and LZ-8 were not fully understood. In the present study, PS-G was subjected to 15% TCA for removing proteins and the LZ-8 detection using anti-LZ-8 monoclonal antibodies showed a remarkable 89.7% protein reduction of the deproteinized PS-G (dpPS-G). The Saccharomyces cerevisiae which expressed recombinant LZ-8 protein (rLZ-8) without glycosylation was generated and then compared with dpPS-G in the induction toward murine primary macrophage and T lymphocytic cells. The peritoneal macrophages from TLR4-deficient and wild type mice revealed that TLR4 was a putative receptor of dpPS-G, mediating the TNF-alpha, IL-1beta and IL-12p70 cytokine production and CD86, MHC II expression on macrophages, while rLZ-8 enhanced the production of IL-1beta, IL-12p70, CD86, and MHC II expression by another obscure route. rLZ-8-treated macrophages enhanced the release of IFN-gamma and IL-2 by murine CD4(+) and CD8(+) T cells, whereas dpPS-G treatment did not enhance the release of IFN-gamma and IL-2. Furthermore, although the direct rLZ-8-treatment conduced dramatic CD154, CD44 expression on CD3(+) T cells and increased IL-2, IFN-gamma secretion on CD4(+) and CD8(+) T cells, the dpPS-G was incapable of priming CD3(+), CD4(+) or CD8(+) T cells unitarily. Taken together, these results demonstrated that LZ-8 could activate murine macrophages and T lymphocytes but PS-G was merely the activator for macrophages, suggesting their diverse roles in activating the innate and adaptive immunity.

Poria cocos is an important Oriental medical fungus with multiple functionalities, yet its bioactive substances and the mechanisms involved have not been fully characterized. A novel immunomodulatory protein (P. cocos immunomodulatory protein; PCP) was purified from the dried sclerotium of P. cocos (Schw.) Wolf using DE-52 cellulose and gel filtration chromatography. Chromatography and electrophoresis results indicated that the native PCP (35.6 kDa) is a disulfide-linked heterodimeric glycoprotein consisting of 14.3 and 21.3 kDa subunits with N- and O-glycosylation. PCP was capable of stimulating RAW 264.7 macrophages in vitro through the induction of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1beta) as well as the regulation of nuclear factor-kappa B (NF-kappaB)-related gene expression. In primary mouse macrophages, PCP directly activated peritoneal cavity macrophages to induce Toll-like receptor 4 (TLR4)-mediated myeloid differentiation factor 88 (MyD88)-dependent signaling. This study demonstrated the cell surface interactions of PCP with TLR4 and the capacity of PCP for TLR4 tyrosine phosphorylation. Results obtained with peritoneal macrophages from TLR4-deficient C57BL/10ScN mice revealed that PCP-induced activation and PCP cell surface binding were significantly attenuated. Moreover, enzymatic deglycosylation decreased PCP-mediated responses, indicating that the glycosylated portion of PCP was a key factor in PCP signaling through TLR4 in peritoneal macrophages. These findings suggest that PCP is a new potential immune stimulator within P. cocos and that TLR4 is primarily responsible for PCP signaling in murine macrophages.