113 research outputs found

    Parallel plate wet denuder coupled ammonia transfer device-conductivity detector for near-real-time monitoring of gaseous ammonia

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    Gaseous ammonia (NH3) is a primary basic substance in the atmosphere, and its global emission has been increasing in recent decades. It is vital to continuously monitor the atmospheric NH3 to clarify the impact of NH3 on sensitive ecosystems. This paper proposes a simple gaseous NH3 monitor utilizing a parallel plate wet denuder (PPWD) and a conductometric flow injection analysis (FIA) with an ammonia transfer device (ATD). In the present study, water-soluble basic gases, NH3, are selectively detected by the conductivity detector (CD). The ATD-CD ammonium detector requires no coloring reagents commonly used in FIA. Five-day field measurement of ambient NH3 was successfully performed with 30 min time resolution. All the air samples over the observation period (n = 186) contained NH3 above the limit of quantification (11.4 nmol m−3). The NH3 data showed excellent agreement with the values using ion chromatography in the field measurements

    Online monitoring of bromate in treated wastewater: implications for potable water reuse

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    Continuous monitoring of bromate ions, a disinfection by-product of the ozonation of wastewater, may improve the safety of recycled water for potable use. A recently developed elemental analyzer can determine bromate ion concentrations online. However, dissolved organics present in wastewater interfere with the detection of bromate ions. The aim of this study was to develop a nanofiltration (NF) membrane-based pre-treatment system to remove the interfering substances present in treated wastewater prior to the online analysis. The NF pre-treatment system was optimized to ensure the removal of the interfering substances from the membrane bioreactor (MBR)-treated wastewater without altering the bromate ion concentration. We determined a permeate flux of 1 L m−2 h−1 and a feed temperature of 35 °C as optimal pre-treatment conditions for online analysis. Furthermore, the continuous monitoring of MBR-treated wastewater, containing different bromate ion concentrations (0-12 μg L−1), for three days revealed a strong correlation between the concentrations determined using the online analyzer and liquid chromatography coupled with tandem mass spectrometry. Thus, this study demonstrates the potential utility of the online bromate ion analyzer coupled with NF pre-treatment system to monitor the rate of bromate ion formation during ozonation

    Total Synthesis of Zephycarinatines via Photocatalytic Reductive Radical ipso‐Cyclization

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    We report herein a nonbiomimetic strategy for the total synthesis of the plicamine‐type alkaloids zephycarinatines C and D. The key feature of the synthesis is a stereoselective reductive radical ipso‐cyclization using visible‐light‐mediated photoredox catalysis. This cyclization enabled the construction of a 6, 6‐spirocyclic core structure through the addition of a carbon‐centered radical onto the aromatic ring. Biological evaluation of zephycarinatines and their derivatives revealed that the synthetic derivative with a keto group displays moderate inhibitory activity against LPS‐induced NO production. This approach could offer future opportunities to expand the chemical diversity of plicamine‐type alkaloids as well as providing useful intermediates for their syntheses

    The Initiatives Yamanashi Gakuin University’s Writing Support Desk in 2022

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    In Vitro and In Vivo Evaluation of Starfish Bone-Derived -Tricalcium Phosphate as a Bone Substitute Material

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    We evaluated starfish-derived -tricalcium phosphate (Sf-TCP) obtained by phosphatization of starfish-bone-derived porous calcium carbonate as a potential bone substitute material. The Sf-TCP had a communicating pore structure with a pore size of approximately 10 m. Although the porosity of Sf-TCP was similar to that of Cerasorb M (CM)a commercially available -TCP bone fillerthe specific surface area was roughly three times larger than that of CM. Observation by scanning electron microscopy showed that pores communicated to the inside of the Sf-TCP. Cell growth tests showed that Sf-TCP improved cell proliferation compared with CM. Cells grown on Sf-TCP showed stretched filopodia and adhered; cells migrated both to the surface and into pores. In vivo, vigorous tissue invasion into pores was observed in Sf-TCP, and more fibrous tissue was observed for Sf-TCP than CM. Moreover, capillary formation into pores was observed for Sf-TCP. Thus, Sf-TCP showed excellent biocompatibility in vitro and more vigorous bone formation in vivo, indicating the possible applications of this material as a bone substitute. In addition, our findings suggested that mimicking the microstructure derived from whole organisms may facilitate the development of superior artificial bone.ArticleMATERIALS. 12(11):1881 (2019)journal articl

    Possible cross-feeding pathway of facultative methylotroph Methyloceanibacter caenitepidi Gela4 on methanotroph Methylocaldum marinum S8

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    Non-methanotrophic bacteria such as methylotrophs often coexist with methane-oxidizing bacteria (methanotrophs) by cross-feeding on methane-derived carbon. Methanol has long been considered a major compound that mediates cross-feeding of methane-derived carbon. Despite the potential importance of cross-feeding in the global carbon cycle, only a few studies have actually explored metabolic responses of a bacteria when cross-feeding on a methanotroph. Recently, we isolated a novel facultative methylotroph, Methyloceanibacter caenitepidi Gela4, which grows syntrophically with the methanotroph, Methylocaldum marinum S8. To assess the potential metabolic pathways in M. caenitepidi Gela4 co-cultured with M. marinum S8, we conducted genomic analyses of the two strains, as well as RNA-Seq and chemical analyses of M. caenitepidi Gela4, both in pure culture with methanol and in co-culture with methanotrophs. Genes involved in the serine pathway were downregulated in M. caenitepidi Gela4 under co-culture conditions, and methanol was below the detection limit (< 310 nM) in both pure culture of M. marinum S8 and co-culture. In contrast, genes involved in the tricarboxylic acid cycle, as well as acetyl-CoA synthetase, were upregulated in M. caenitepidi Gela4 under co-culture conditions. Notably, a pure culture of M. marinum S8 produced acetate (< 16 μM) during growth. These results suggested that an organic compound other than methanol, possibly acetate, might be the major carbon source for M. caenitepidi Gela4 cross-fed by M. marinum S8. Co-culture of M. caenitepidi Gela4 and M. marinum S8 may represent a model system to further study methanol-independent cross-feeding from methanotrophs to non-methanotrophic bacteria

    Biodiversity-productivity relationships are key to nature-based climate solutions

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    The global impacts of biodiversity loss and climate change are interlinked, but the feedbacks between them are rarely assessed. Areas with greater tree diversity tend to be more productive, providing a greater carbon sink, and biodiversity loss could reduce these natural carbon sinks. Here, we quantify how tree and shrub species richness could affect biomass production on biome, national and regional scales. We find that GHG mitigation could help maintain tree diversity and thereby avoid a 9–39% reduction in terrestrial primary productivity across different biomes, which could otherwise occur over the next 50 years. Countries that will incur the greatest economic damages from climate change stand to benefit the most from conservation of tree diversity and primary productivity, which contribute to climate change mitigation. Our results emphasize an opportunity for a triple win for climate, biodiversity and society, and highlight that these co-benefits should be the focus of reforestation programmes

    Anti-inflammatory effects of cold atmospheric plasma irradiation on the THP-1 human acute monocytic leukemia cell line.

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    Cold atmospheric plasma (CAP) has been studied and clinically applied to treat chronic wounds, cancer, periodontitis, and other diseases. CAP exerts cytotoxic, bactericidal, cell-proliferative, and anti-inflammatory effects on living tissues by generating reactive species. Therefore, CAP holds promise as a treatment for diseases involving chronic inflammation and bacterial infections. However, the cellular mechanisms underlying these anti-inflammatory effects of CAP are still unclear. Thus, this study aimed to elucidate the anti-inflammatory mechanisms of CAP in vitro. The human acute monocytic leukemia cell line, THP-1, was stimulated with lipopolysaccharide and irradiated with CAP, and the cytotoxic effects of CAP were evaluated. Time-course differentiation of gene expression was analyzed, and key transcription factors were identified via transcriptome analysis. Additionally, the nuclear localization of the CAP-induced transcription factor was examined using western blotting. The results indicated that CAP showed no cytotoxic effects after less than 70 s of irradiation and significantly inhibited interleukin 6 (IL6) expression after more than 40 s of irradiation. Transcriptome analysis revealed many differentially expressed genes (DEGs) following CAP irradiation at all time points. Cluster analysis classified the DEGs into four distinct groups, each with time-dependent characteristics. Gene ontology and gene set enrichment analyses revealed CAP-induced suppression of IL6 production, other inflammatory responses, and the expression of genes related to major histocompatibility complex (MHC) class II. Transcription factor analysis suggested that nuclear factor erythroid 2-related factor 2 (NRF2), which suppresses intracellular oxidative stress, is the most activated transcription factor. Contrarily, regulatory factor X5, which regulates MHC class II expression, is the most suppressed transcription factor. Western blotting revealed the nuclear localization of NRF2 following CAP irradiation. These data suggest that CAP suppresses the inflammatory response, possibly by promoting NRF2 nuclear translocation
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