化学•材料最新文献

{"title":"Bioactivity Profiling of Chemical Mixtures for Hazard Characterization","authors":"Xiaojing Li, Jiarui Zhou, Yaohui Bai, Meng Qiao, Wei Xiong, Tobias Schulze, Martin Krauss, Timothy D. Williams, Ben Brown, Luisa Orsini, Liang-Hong Guo, John K. Colbourne","doi":"10.1021/acs.est.4c11095","DOIUrl":"https://doi.org/10.1021/acs.est.4c11095","url":null,"abstract":"The assessment and regulation of chemical toxicity to protect human health and the environment are done one chemical at a time and seldom at environmentally relevant concentrations. However, chemicals are found in the environment as mixtures, and their toxicity is largely unknown. Understanding the hazard posed by chemicals within the mixture is critical to enforce protective measures. Here, we demonstrate the application of bioactivity profiling of environmental water samples using the sentinel and ecotoxicology model species <i>Daphnia</i> to reveal the biomolecular response induced by exposure to real-world mixtures. We exposed a <i>Daphnia</i> strain to 30 sampled waters of the Chaobai River and measured the gene expression response profiles. Using a multiblock correlation analysis, we establish correlations between chemical mixtures identified in 30 water samples with gene expression patterns induced by these chemical mixtures. We identified 80 metabolic pathways putatively activated by mixtures of inorganic ions, heavy metals, polycyclic aromatic hydrocarbons, industrial chemicals, and a set of biocides, pesticides, and pharmacologically active substances. Our data-driven approach discovered both known bioactivity signatures with previously described modes of action and new pathways linked to undiscovered potential hazards. This study demonstrates the feasibility of reducing the complexity of real-world mixture toxicity to characterize the biomolecular effects of a defined number of chemical components based on gene expression monitoring of the sentinel species <i>Daphnia</i>.","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":"1 1","pages":""},"PeriodicalIF":9.028,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142857937","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":"Magnesium Ferrite Promoting the Purity of Grown Boron Nitride Nanotubes","authors":"Xin Chen, Liyun Wu, Kai Zhang, Qian He, Ying Wang, Haoting Niu, WenTao Zheng, Yagang Yao","doi":"10.1021/acs.jpcc.4c06779","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c06779","url":null,"abstract":"The synthesis of boron nitride nanotubes via the boron oxide chemical vapor deposition process, especially when boron, magnesium oxide, and iron oxide are used as precursors for the synthesis, often encounters the problem of nanotubes doped with impurities, such as nanosheets and fibers. For this reason, this study adopts a novel active component of magnesium ferrite with a defined decomposition temperature and successfully synthesizes high-purity nanotubes. Growth experiments combined with computational fluid dynamics (CFD) simulations were performed to investigate the effects of active component ratio, growth temperature, ammonia flow rate, and boron source velocity on nanotube growth and the differences with that of magnesium oxide-iron oxide. Morphological analysis showed that the nanotubes grown from magnesium ferrite have better purity, effectively preventing the mixing of impurities in nanosheets and nanofibers. Furthermore, it was found that these nanotubes float at a more controlled height in a wider ammonia flow rate and temperature range. These allow for a more efficient collection of purer nanotube products for magnesium ferrite.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"31 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142858029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Machine Learning Prediction of the Corrosion Rate of Zinc-Based Alloys Containing Copper, Lithium, Magnesium, and Silver","authors":"Artur Davletshin, Elena A. Korznikova, Andrey A. Kistanov","doi":"10.1021/acs.jpclett.4c03357","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c03357","url":null,"abstract":"Implementation of machine learning (ML) techniques in materials science often requires large data sets. However, a proper choice of features and regression methods allows the construction of accurate ML models able to work with a relatively small data set. In this work, an extensive, although still limited, experimental data set of corrosion-related properties of Zn-based alloys used in biomedicine was created. On the basis of this data set, a robust and accurate model was built to predict the corrosion behavior of Zn-based alloys. This work highlights the effectiveness of ML methods for assessing the corrosion behavior of Zn-based alloys, which can facilitate their application in bioimplants.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"90 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142858024","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":"Anisotropic Interlayer Force Field for Heterogeneous Interfaces of Graphene and h-BN with Transition Metal Dichalcogenides","authors":"Wenwu Jiang, Reut Sofer, Xiang Gao, Leeor Kronik, Oded Hod, Michael Urbakh, Wengen Ouyang","doi":"10.1021/acs.jpcc.4c05924","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c05924","url":null,"abstract":"An anisotropic interlayer potential (ILP), designed to describe the interlayer interaction in graphene/MX₂ and h-BN/MX₂ (M = Mo, W; X = S, Se) heterostructures, is presented. The ILP is parametrized against density functional theory (DFT) calculations within the Perdew–Burke–Ernzerhof (PBE) generalized-gradient approximation, augmented by nonlocal many-body dispersive (MBD-NL) interactions. The parametrized force field demonstrates excellent agreement with the DFT reference data of binding energy curves and sliding energy surfaces across all heterostructures considered. The transferability of the developed ILP is demonstrated for the phenalenyl (C₁₃H₉)/MoS₂ and B₇N₆H₉/MoS₂ interfaces, which are outside the training set. The force field is then used to study equilibrium interlayer distances, bulk moduli, and phonon spectra by means of molecular dynamics simulations.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"39 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142858027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stabilizing Diketopyrrolopyrrole Radical Cations Through Carbazoles: Substitution Pattern vs Spin Delocalization","authors":"Sanchari Debnath, Jungjin Park, Vithobha Hugar, Ram Kumar Canjeevaram Balasubramanyam, Juwon Oh, Woojae Kim, Satish Patil","doi":"10.1021/acs.jpclett.4c03335","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c03335","url":null,"abstract":"The synthesis of organic radicals continues to garner significant interest due to their fascinating optical, electronic, and magnetic properties. Moreover, the growing demand for chemically stable organic radicals is driven by the rapid expansion of the market for electronic devices utilizing organic semiconductors. In this context, the development of multifaceted approaches for the design of stable organic radicals is of great importance. In this work, we introduce a strategy for generating stable radical cations of diketopyrrolopyrroles (DPP) by modulating the substitution pattern of the electron-donating carbazole substituent. Using electronic, spin resonance, and vibrational spectroscopies, supported by density functional theory, we carefully investigated the electronic structures and chemical stability of the DPP radical cations. Our findings demonstrate that the position of electron-rich heteroatoms and the presence of Clar’s aromatic sextets in donor moieties play a pivotal role in enhancing the chemical stability of DPP radical cations.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"496 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142858021","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":"Quantum Tunneling: History and Mystery of Large Amplitude Motions over a Century","authors":"Ha Vinh Lam Nguyen","doi":"10.1021/acs.jpclett.4c02914","DOIUrl":"https://doi.org/10.1021/acs.jpclett.4c02914","url":null,"abstract":"Large amplitude motions (LAMs), most notably represented by proton tunneling, mark a significant departure from small amplitude vibrations where protons merely oscillate around their equilibrium positions. These substantial displacements require tunneling through potential energy barriers, leading to splittings in, e.g., rotational spectra. Since Hund’s pioneering work in 1927, proton tunneling has offered a unique glimpse into the internal dynamics of gas-phase molecules, with microwave spectroscopy being the key technique for such investigations. The ubiquous LAM type is methyl internal rotation, characterized by 3-fold potentials arising from the interaction between methyl rotors and their molecular frame, with the barrier hindering methyl torsion and the orientation of the torsional axis being defining features. Investigating methyl internal rotations plays a key role in fields ranging from molecular physics, where the methyl rotor serves as a sensitive probe for molecular structures, to atmospheric chemistry and astrophysics, where methyl-containing species have been detected in the Earth’s atmosphere and interstellar environments and even discussed as potential probes for effects beyond the standard model of physics. Despite nearly a century of study, modeling methyl internal rotations with appropriate model Hamiltonians and fully understanding the origins of these motions, particularly the factors that influence torsional barriers, remain partially unresolved, reflecting the enduring mystery of quantum tunneling. This Perspective reviews the history of LAMs, highlights advances in decoding their complex spectra, and explores future research directions aimed at uncovering the remaining mysteries of these fascinating motions.","PeriodicalId":62,"journal":{"name":"The Journal of Physical Chemistry Letters","volume":"13 1","pages":""},"PeriodicalIF":6.475,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142858020","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":"A Tribute to Gustavo E. Scuseria.","authors":"Matthias Ernzerhof, Troy Van Voorhis, Viktor N Staroverov","doi":"10.1021/acs.jpca.4c07208","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c07208","url":null,"abstract":"","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"128 50","pages":"10737-10738"},"PeriodicalIF":2.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142851658","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":"Oxidation of Silicon Carbide with Atomic Oxygen through the Passive-to-Active Transition","authors":"David Z. Chen, Chenbiao Xu, Vanessa J. Murray, Pedro Recio, Chloe Miossec, Nadia Balucani, Piergiorgio Casavecchia, Timothy K. Minton","doi":"10.1021/acs.jpcc.4c05923","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c05923","url":null,"abstract":"The inelastic and reactive scattering dynamics of O(³P) atoms on a 6H-silicon carbide (SiC) surface were investigated as a function of temperature with a molecular beam-surface scattering technique that employed a rotatable mass spectrometer detector. One set of experiments used a pulsed hyperthermal beam that produced ∼8 km s^–1 O atoms, and another set of experiments used a continuous beam that contained O atoms with a nominal velocity of ∼2 km s^–1. When exposed to the relatively low-flux, pulsed hyperthermal O-atom beam, a passive oxide layer on the SiC that formed at lower temperatures decomposed as the temperature increased above 1673 K. Instead of entering an active oxidation regime, a graphitic layer formed on the surface and largely protected the underlying SiC from incoming O atoms. Investigation of the oxide decomposition without O-atom bombardment revealed volatile Si and SiO products at the moment that the oxide decomposed, implying that Si sublimation occurs concurrently with oxide decomposition. In the experiment with the continuous (higher flux) O-atom beam, volatile SiO and CO products were observed after the passive oxide decomposed, indicating that active oxidation was reached. The results of this study provide evidence for the importance of Si sublimation within the active oxidation regime. Above the passive-to-active transition temperature, Si sublimation is an ongoing process, and continuous active oxidation will only occur if sufficient oxygen reacts with the surface to produce SiO more quickly than a graphitic layer can form. Thus, accurate models of SiC ablation by atomic oxygen must account for multiple competing mechanisms that depend on the surface temperature and incident O-atom flux.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"268 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142849765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coarse-Grained Simulation Study of the Association of Selected Dipeptides.","authors":"Mateusz Leśniewski, Emilia Iłowska, Justyna Sawicka, Zihan Li, Chun Tang, Adam Liwo","doi":"10.1021/acs.jpcb.4c06305","DOIUrl":"10.1021/acs.jpcb.4c06305","url":null,"abstract":"<p><p>The association of 55 dipeptides extracted from aggregation-prone regions of selected proteins was studied by means of multiplexed replica-exchange molecular dynamics simulations with the coarse-grained UNRES model of polypeptide chains. Each simulation was carried out with 320 dipeptide molecules in a periodic box at 0.24 mol/dm³ concentration, in the 260-370 K temperature range. The temperature profiles of the degree of association, distributions of dipeptide cluster size, and structures of clusters were examined. It has been found that the dipeptides composed of strongly nonpolar (aromatic or aliphatic) residues associate nearly completely at all temperatures to form tight clusters, while those composed of charged or polar residues exhibited no or residual association. The dipeptides composed of nonpolar and small polar residues and those composed of less hydrophobic residues formed single clusters, gradually dissolving with increasing temperature, while those composed of phenylalanine or tryptophan and polar or charged residues formed multiple irregular clusters with room to accommodate water inside, suggesting the formation of liquid droplets or gels. The logarithms of the average degree of association and the free energy of aggregation per monomer were found to correlate with the dipeptide hydrophobicity.</p>","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":" ","pages":"12403-12415"},"PeriodicalIF":2.8,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142778799","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":"Constructing Predictive Implicit Solvent Models: Insights from Exploring Potential Parameter Space and Property Predictions.","authors":"Dan Zhang, Meng Deng, Chuncheng Li, Qinghua Ren, Zhaochuan Fan","doi":"10.1021/acs.jpcb.4c05190","DOIUrl":"10.1021/acs.jpcb.4c05190","url":null,"abstract":"<p><p>Implicit solvent (IS) models enhance the efficiency of simulating liquid systems, but those based on the potential of mean force calculations using explicit solvent (ES) models often fail to capture the solute structure and assembly dynamics under various conditions. This study examines the relationships between the parameter space of IS models and their predictive capabilities regarding solute structure and assembly dynamics, focusing on NaCl solutions and protein-bound silica colloidal nanoparticles. For NaCl solutions, models developed using concentration-dependent dielectric constants generally lack efficacy, and their effectiveness in predicting high-concentration liquid structures varies based on the ES model used. Adjusting the dielectric constant value or the shape of the short-range potentials can improve the accuracy of these models in predicting liquid structures. For protein-bound silica colloidal nanoparticles, we find that interaction site size and model resolution significantly influence the prediction of nanoparticle assembly dynamics, with different resolutions producing aggregates with distinct structures and connection modes. This study elucidates the complex relationship between parameter space in IS models and liquid structure and assembly kinetics, providing crucial insights for developing more accurate and predictive models.</p>","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":" ","pages":"12517-12532"},"PeriodicalIF":2.8,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142783374","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}