化学•材料最新文献

{"title":"Identification and Characterization of EmNag, a Novel β-1,2-N-Acetylglucosaminidase from Elizabethkingia meningoseptica","authors":"Shaoxian Lyu,&nbsp;Yongliang Tong,&nbsp;Qiange Lin,&nbsp;Yilin Ye,&nbsp;Xinliu Geng,&nbsp;Cuiying Chen,&nbsp;Xinrong Lu,&nbsp;Guiqin Sun,&nbsp;Li Chen","doi":"10.1021/acs.biochem.6c00631","DOIUrl":"https://doi.org/10.1021/acs.biochem.6c00631","url":null,"abstract":"<p>N-Acetylglucosamineexists in various glycoforms and linkage patternswithin organisms, playing a crucial role in numerous vital biologicalprocesses. The signal of β-1,2-N-acetylglucosamine is a keycomponent within complex biantennary N-glycans on the cell surface,leaving related research in its early exploratory stages. Currently,there is a lack of efficient tools and methods capable of directlymodifying terminal N-acetylglucosamine on living cells. In this study,we identified a novel β-N-acetylglucosaminidase from <em>Elizabethkingia meningoseptica</em> FMS-007, which specificallycleaves nonreducing terminal β-1,2-N-acetylglucosamine, enablingdirect removal from native glycoproteins and/or free oligosaccharides.More importantly, we demonstrate for the first time the successfulremoval of β-1,2-N-acetylglucosamine from the living cell surfaceusing this enzyme. Based on its isolation and newly characterizedcell-surface glycan-editing activity, we designated it as EmNag, alsotermed cell-surface glycan-editing N-acetylglucosaminidase (csgeNag).It showed favorable enzymatic stability between pH 5–8 andfrom 4 to 37 °C. Sequence analysis and alanine-scanning mutagenesisidentified a conserved active pocket containing the catalytic residuepair Asp317-Glu318, with Asp317 being essential for activity. In summary,our findings provide an effective and reliable method for the targetedremoval of β-1,2-N-acetylglucosamine from the living cell surface,establishing a foundation for further functional studies and practicalapplications.</p>","PeriodicalId":28,"journal":{"name":"Biochemistry Biochemistry","volume":"65 20","pages":"3206–3216"},"PeriodicalIF":2.7,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149219014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Insight into the Rate Dependent Viscoelastic Behavior of PVDF","authors":"Arthanareeswaran Shubha,&nbsp;Sachin Varma,&nbsp;Payel Bandyopadhyay","doi":"10.1134/S0965545X26600183","DOIUrl":"10.1134/S0965545X26600183","url":null,"abstract":"<p>Polyvinylidene fluoride (PVDF) is widely used in soft piezoelectric devices, where mechanical stability plays a critical role in long-term performance. In this work, the rate-dependent elastic and viscoelastic behavior of pristine PVDF films is investigated using nanoindentation. Experiments are carried out at room temperature with a maximum load of 30 mN using four different loading times (5, 10, 15, and 20 s), corresponding to loading rates of 6, 3, 2, and 1.5 mN/s, while maintaining a constant holding time of 10 s. The results show a clear loading-rate dependence, with the elastic modulus and hardness increasing by approximately 14.7 and 11.7%, respectively, as the loading rate increases. Creep compliance data obtained from the indentation hold segment are analyzed using the three-element Standard Linear Solid (Kelvin–Voigt form) and the four-element Burger model to extract the viscoelastic parameters. Comparative analysis reveals that the instantaneous elastic modulus (<i>E</i>₁) remains independent of loading rate in both models, whereas the delayed elastic modulus (<i>E</i>₂) decreases with increasing loading rate by ~31% in the SLS–K.V model and ~40% in the Burger model. Furthermore, the viscous parameters show significant rate sensitivity, with η₁ decreasing by ~57% and η₂ reducing to nearly half of its initial value at higher loading rates in both models. These results highlight the pronounced rate-dependent viscoelastic response of PVDF and provide insights relevant to the mechanical reliability of PVDF-based piezoelectric devices.</p>","PeriodicalId":738,"journal":{"name":"Polymer Science, Series A","volume":"68 5","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149222691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Toward a Universal Switch for Microbial Granulation: Photogranule Insights to Advance Granular Wastewater Treatment","authors":"Chul Park,Douglas D. Risser,Yasu S. Morita,Klaus Nüsslein,Joseph G. Gikonyo","doi":"10.1021/acs.est.6c05495","DOIUrl":"https://doi.org/10.1021/acs.est.6c05495","url":null,"abstract":"Microbial granulation─the assembly of self-immobilized, spheroidal aggregates─is a transformative approach for high-density, energy-efficient wastewater treatment. By concentrating biomass and enhancing resilience to influent fluctuations, granular systems significantly reduce infrastructure footprints. Current granular technologies primarily leverage upflow continuous reactors or sequencing-batch reactors, where specific external selection pressures are imposed to drive granulation. However, granulation remains neither spontaneous nor reliably predictable, and its fundamental biological drivers are poorly understood. Recent advances in photogranules challenge selection-pressure models. Photogranules form from activated-sludge inocula in hydrostatic and hydrodynamic batches and even in CSTRs where classical selection conditions are weak or absent. Moreover, the recurring emergence of compact spheroidal granules across diverse natural and laboratory systems suggests shared, intrinsic biological drivers rather than purely engineered causes. In this Perspective, we propose that the bacterial second messenger c-di-GMP functions as a conserved, Goldilocks-like molecular switch that integrates diverse environmental cues into a coordinated granulation program. We synthesize transcriptomic, biochemical, and genetic evidence and advance three hypotheses linking c-di-GMP signaling and community physiology to granulation. If validated, targeted modulation of c-di-GMP─by genetic or chemical means─could enable predictable, resilient granulation across a wider range of systems, including the continuous horizontal-flow basins that dominate wastewater infrastructure.","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":"16 1","pages":""},"PeriodicalIF":9.028,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heterogeneous Component Degradation Controls Molecular Evolution and Reactivity of Volatile Organic Compounds during Distiller’s Grains Pyrolysis","authors":"Qiqi Chi,Tingting Li,Yuhan Cao,Weiying Feng,Meiling Xu,Queping Yang,Fanhao Song,Fengchang Wu","doi":"10.1021/acs.est.6c11058","DOIUrl":"https://doi.org/10.1021/acs.est.6c11058","url":null,"abstract":"Biomass pyrolysis is a crucial method of resource utilization, but resulting volatiles may pose environmental concerns due to their impacts on air quality and secondary pollution. However, the mechanisms governing thermal degradation and volatile evolution remain unclear. Herein, we integrate online thermogravimetry–Fourier transform infrared spectroscopy–gas chromatography/mass spectrometry, Gaussian deconvolution, and two-dimensional correlation spectroscopy to elucidate the degradation characteristics and sequential temperature-dependent volatile evolution of distiller’s grains (DG), a protein-rich agro-industrial residue. DG pyrolysis exhibited distinct multistage degradation characteristics governed by coupled decomposition and synergistic interactions of lignocellulosic and protein-derived components. The major volatiles included alcohols/ethers, phenols/esters, hydrocarbons, and aromatics, with pronounced temperature-dependent variations. Volatile and intermediate-volatility organic compounds accounted for 47–60% and 35–52% of total detected organic volatile emissions released during pyrolysis, respectively. Most DG-derived volatiles exhibited reducing characteristics, with average carbon oxidation states below zero, while broad saturation mass concentration distributions reflected substantial chemical heterogeneity. The temperature-dependent evolution sequence of DG-derived volatiles followed alcohols/phenols → aromatics/hydrocarbons → aldehydes/ketones/acids → esters → CO2/CH4/NH3. A DG mechanistic framework was proposed, demonstrating that heterogeneous component degradation regulated dynamic volatile generation and variation. These findings provide mechanistic insight into DG pyrolysis and contribute to sustainable biomass valorization and environmental impact assessment.","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":"56 1","pages":""},"PeriodicalIF":9.028,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Cytosolic Arabidopsis Homologue of Bacterial GppA/PPX Retains Polyphosphate and pppGpp Phosphatase Activities and Regulates Photosynthetic Acclimation","authors":"Takanari Nemoto,&nbsp;Yuto Omata,&nbsp;Masataka Inazu,&nbsp;Shouta Nonoyama,&nbsp;Shinji Masuda","doi":"10.1021/acs.biochem.6c00467","DOIUrl":"https://doi.org/10.1021/acs.biochem.6c00467","url":null,"abstract":"<p>Here, we performed biochemical andgenetic characterizationofa GppA/PPX-family phosphohydrolase from <em>Arabidopsis thaliana</em> (AtGPPA/PPX). Sixteen splice variants of <em>AtGPPA/PPX</em> are deposited in public databases and can beclassified into two types based on differences in their N-terminalsequences. Green fluorescent protein fusions with either N-terminusindicated that neither possesses a transit peptide, suggesting thatall AtGPPA/PPX splice variants localize to the cytosol. Biochemicalanalysis of the long splice variant of AtGPPA/PPX demonstrated phosphataseactivity toward guanosine 5′-triphosphate 3′-diphosphate(pppGpp) and long-chain polyphosphate <em>in vitro</em>, althoughits substrate affinity and catalytic efficiency were lower than thoseof<em>Escherichia coli</em> PPX. Heterologousexpression of AtGPPA/PPX in an<em>Escherichia coli</em><em>gppA</em> mutant reduced intracellular pppGpp levelsrelative to the mutant control, indicating that AtGPPA/PPX possessespppGpp dephosphorylation activity <em>in vivo</em>. Loss-of-functionmutants of AtGPPA/PPX exhibited no overt growth defects under eitherstandard or nitrogen-starvation conditions. However, chlorophyll fluorescenceimaging revealed delayed and attenuated nonphotochemical quenchingafter actinic-light illumination without changes in the PSII quantumyield, suggesting faster electron transport and reduced need for thermaldissipation. Together, these results suggest that the cytosol-localizedAtGPPA/PPX functions as a phosphatase with unknown physiological substrate(s)and plays a key role in photosynthetic acclimation to fluctuatinglight conditions.</p>","PeriodicalId":28,"journal":{"name":"Biochemistry Biochemistry","volume":"65 20","pages":"3273–3285"},"PeriodicalIF":2.7,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149218990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"mRNA Structure Regulates Translation at Every Step","authors":"Alexandra Khitun,&nbsp;Kevin M. Weeks","doi":"10.1021/acs.biochem.6c00561","DOIUrl":"https://doi.org/10.1021/acs.biochem.6c00561","url":null,"abstract":"<p>Precise,context-sensitivecontrol of protein synthesis is criticalin eukaryotic cells, and mRNA structure has emerged as a central mechanismfor achieving this control. mRNA structures influence every stageof translation. During initiation, structures within 5′ untranslatedregions modulate ribosome association with mRNA and the balance betweentranslation of the main open reading frame and use of upstream oralternative start sites. During elongation, structures in the codingsequence govern ribosome pausing in ways that can either protect mRNAstability or trigger decay. During termination, structures downstreamof primary stop codons promote readthrough to generate protein isoformsin a tissue-specific manner. mRNA structures are remodeled by helicaseexpression, post-transcriptional modifications, and translationalprogramming to provide additional layers of regulation. We reviewrecent advances illuminating diverse mechanisms by which RNA structuremodulates translation.</p>","PeriodicalId":28,"journal":{"name":"Biochemistry Biochemistry","volume":"65 20","pages":"3144–3150"},"PeriodicalIF":2.7,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149218992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"More Halogen-Localized, Yet More Strongly Electron Bound: Carbon Cage-Mediated Electron Stabilization in C60X– (X = F, Cl, Br, and I) Anions","authors":"Jianzhi Xu,Junda Li,Zhilong Wu,Hao Li,Zhen-Chao Long,Chang-Feng Zhu,Hong-Guang Xu,Wei-Jun Zheng,Xue-Bin Wang,Gao-Lei Hou","doi":"10.1021/acs.jpclett.6c02657","DOIUrl":"https://doi.org/10.1021/acs.jpclett.6c02657","url":null,"abstract":"Carbon–halogen bonds are central motifs in molecular chemistry, yet how a single C–X linkage behaves on an extended electron-accepting carbon framework remains poorly understood. Here, we combine negative ion photoelectron spectroscopy and theoretical calculations to investigate monohalogenated fullerene anions, C60X– (X = F, Cl, Br, and I), as gas-phase models for examining how local C–X bonding and cage-mediated electron stabilization jointly control electron detachment. From F to I, the C60–X interaction weakens systematically: the C–X bond length increases, orbital overlap decreases, and the excess electron evolves from mixed halogen–cage character in C60F–/C60Cl– to more halogen-centered character in C60Br–/C60I–. However, the electron detachment energies of C60X– lie within a narrow energy range of 3.5–3.7 eV, in contrast to isolated halide anions X–, whose electron detachment energies increase from F to Cl and then decrease from Cl to I. Energy decomposition analysis shows that this apparent contradiction arises from different stabilization of the neutral and anionic fullerene–halogen bonded states by the C60 cage. These results highlight fullerene-cage stabilization as a molecular design principle for stabilizing halogen-centered excess electrons and tuning the C–X bond activation in halogen-functionalized π-carbon materials.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"37 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Psychoactive Pollutant Impacts Baseline Immune Traits but Not Behavior and Microbiome in a Fish","authors":"Gabriel Melhado,Rhiannon V. Eastment,Francine Z. Marques,Upama Aich,Anne Peters,Bob B. M. Wong","doi":"10.1021/acs.est.6c12057","DOIUrl":"https://doi.org/10.1021/acs.est.6c12057","url":null,"abstract":"Pharmaceutical pollution is an increasing global threat to freshwater ecosystems. Psychoactive drugs, such as antidepressants, are of particular concern because they affect evolutionarily conserved neuroendocrine pathways in nontarget organisms. As these pathways regulate interconnected biological systems, understanding the ecological consequences of pharmaceutical exposure requires an integrative approach. Here, we investigated the effects of 28-day exposure to control (freshwater), low (4.2 ± 0.3 ng/L), and high (637.5 ± 173.84 ng/L) fluoxetine concentrations on behaviors, baseline immune traits, and skin mucus microbiome composition in the Murray River rainbowfish (Melanotaenia fluviatilis). Fluoxetine exposure did not impact fish behavior, including activity, freezing behavior, shelter use, or microbiome composition. In contrast, immune traits were significantly altered. Both fluoxetine concentrations reduced total white blood cell (WBC) count, while only fish exposed to the low concentration showed reduced lymphocyte counts and elevated neutrophil counts, consistent with a stress-associated WBC redistribution response. Our findings show that different, but interconnected, biological systems can differ in their sensitivity to pollutants and suggest that immune traits may be an early, sensitive indicator of exposure to psychoactive pharmaceuticals. These findings highlight the importance of integrating multiple biological end points to obtain a more comprehensive understanding of the ecological consequences of pharmaceutical contamination.","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":"22 1","pages":""},"PeriodicalIF":9.028,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Landscape Fire-Sourced PM2.5 and Cause-Specific Renal Hospitalizations: A Multicountry Two-Stage Time-Series Analysis of 12.5 Million Admissions","authors":"Bo Wen,Yao Wu,Rongbin Xu,Gongbo Chen,Pei Yu,Yanming Liu,Wenhua Yu,Tingting Ye,Wenzhong Huang,Zhengyu Yang,Yiwen Zhang,Zhihu Xu,Shuang Zhou,Ke Ju,Simon Hales,Eric Lavigne,Paulo H.N. Saldiva,Micheline S.Z.S. Coelho,Patricia Matus,Kraichat Tantrakarnapa,Wissanupong Kliengchuay,Michael Abramson,Guy Marks,Lidia Morawska,Fay H. Johnston,Jane Heyworth,Geoffrey G. Morgan,Luke Knibbs,Yuming Guo,Shanshan Li","doi":"10.1021/acs.est.6c04677","DOIUrl":"https://doi.org/10.1021/acs.est.6c04677","url":null,"abstract":"Landscape fire-sourced PM2.5 (LFS PM2.5) is increasingly recognized as an important air pollutant, but its short-term contribution to renal hospitalizations remains unclear. Here, we assessed the associations between LFS PM2.5 and renal hospitalizations across 1020 locations in Australia, Brazil, Canada, Chile, New Zealand, and Thailand during 2000–2019 using a two-stage time-series design and estimated the attributable hospitalizations. LFS PM2.5 was associated with increased renal hospitalization risk, with the strongest associations observed for acute kidney injury. A 10 μg/m3 increase in cumulative LFS PM2.5 exposure over lag 0–5 was associated with a 1.1% increase in renal hospitalizations (RR = 1.011, 95% CI: 1.007–1.015). Associations were stronger in warmer areas and differed across levels of GDP per capita. Associations were consistently stronger for LFS PM2.5 than for non-LFS PM2.5. We estimated that LFS PM2.5 contributed to 1.38 renal hospitalizations per 100,000 population annually across the study regions. These findings highlight renal disease as an underrecognized health consequence of landscape fire smoke and support strengthened strategies to reduce wildfire smoke exposure under a changing climate.","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":"73 1","pages":""},"PeriodicalIF":9.028,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Further Insights into the Stereoselective Total Synthesis of Ageliferin via Dearomatizing Diels–Alder Cycloaddition","authors":"Yudai Fujino,Ayami Amano,Taisei Matoba,Keisuke Fukaya,Daisuke Urabe","doi":"10.1021/acs.joc.6c02174","DOIUrl":"https://doi.org/10.1021/acs.joc.6c02174","url":null,"abstract":"We report the total synthesis of ageliferin, focusing on the preparation of substrate for the D-tartrate-tethered cycloaddition and late-stage transformations. A D-tartrate-derived tether was designed to facilitate a challenging intramolecular dearomative Diels–Alder reaction of the hymenidin-derived units. The key cycloaddition proceeded with complete diastereoselectivity to construct the highly functionalized six-membered framework bearing three contiguous stereocenters. Conversion of the cycloadduct to ageliferin required careful adjustment of the reaction sequence, including protecting-group manipulations, introduction of azido groups onto the imidazole rings, cleavage of the N–N bond, and installation of the pyrrole-2-carbonyl units.","PeriodicalId":57,"journal":{"name":"Journal of Organic Chemistry","volume":"11 1","pages":""},"PeriodicalIF":4.354,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149218921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}