ACS Publications最新文献

{"title":"Ab Initio Structure and Dynamics of Beryllium Monofluoride and Its Anion.","authors":"Jacek Koput","doi":"10.1021/acs.jpca.4c06334","DOIUrl":"10.1021/acs.jpca.4c06334","url":null,"abstract":"<p><p>The accurate potential energy functions of beryllium monofluoride, BeF, and its anion, BeF^-, have been determined from ab initio calculations using the coupled-cluster approach, up to the CCSDTQP level of approximation, in conjunction with the augmented correlation-consistent core-valence basis sets, aug-cc-pCV<i>n</i>Z, up to septuple-zeta quality. The vibration-rotation energy levels of the two species were predicted to near the \"spectroscopic\" accuracy. Changes in the electron density distribution upon formation of the Be-F chemical bond are discussed.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142575439","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":"Molecular Dynamics Investigation of the Influenza Hemagglutinin Conformational Changes in Acidic pH.","authors":"Shadi A Badiee, Vivek Govind Kumar, Mahmoud Moradi","doi":"10.1021/acs.jpcb.4c04607","DOIUrl":"10.1021/acs.jpcb.4c04607","url":null,"abstract":"<p><p>The surface protein hemagglutinin (HA) of the influenza virus plays a pivotal role in facilitating viral infection by binding to sialic acid receptors on host cells. Its conformational state is pH-sensitive, impacting its receptor-binding ability and evasion of the host immune response. In this study, we conducted extensive equilibrium microsecond-level all-atom molecular dynamics (MD) simulations of the HA protein to explore the influence of low pH on its conformational dynamics. Specifically, we investigated the impact of protonation on conserved histidine residues (H106₂) located in the hinge region of HA2. Our analysis encompassed comparisons between nonprotonated (NP), partially protonated (1P, 2P), and fully protonated (3P) conditions. Our findings reveal substantial pH-dependent conformational alterations in the HA protein, affecting its receptor-binding capability and immune evasion potential. Notably, the nonprotonated form exhibits greater stability compared to protonated states. Conformational shifts in the central helices of HA2 involve outward movement, counterclockwise rotation of protonated helices, and fusion peptide release in protonated systems. Disruption of hydrogen bonds between the fusion peptide and central helices of HA2 drives this release. Moreover, HA1 separation is more likely in the fully protonated system (3P) compared to nonprotonated systems (NP), underscoring the influence of protonation. These insights shed light on influenza virus infection mechanisms and may inform the development of novel antiviral drugs targeting HA protein and pH-responsive drug delivery systems for influenza.</p>","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142575460","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":"Inhibition of Human Salivary and Pancreatic α-Amylase by Resveratrol Oligomers.","authors":"Rizliya Visvanathan, Dang Truong Le, Sushil Dhital, Topul Rali, Rohan A Davis, Gary Williamson","doi":"10.1021/acs.jmedchem.4c01042","DOIUrl":"10.1021/acs.jmedchem.4c01042","url":null,"abstract":"<p><p>A key strategy to mitigate postprandial hyperglycemia involves inhibiting α-amylases, which commence the starch digestion process in the gut. This study examined the inhibitory effects of resveratrol and stilbenoid tetramers, vaticanol B, (-)-hopeaphenol, and vatalbinoside A on human salivary and pancreatic α-amylases experimentally and through molecular docking studies. Vaticanol B demonstrated the most potent inhibition with IC₅₀ values of 5.3 ± 0.3 μM for salivary and 6.1 ± 0.5 μM for pancreatic α-amylase (compared to acarbose with IC₅₀ values of 1.2 ± 0.1 μM and 0.5 ± 0.0 μM, respectively). Kinetic analysis suggested a competitive inhibition mode for vaticanol B. Resveratrol and vatalbinoside A were poor inhibitors of human α-amylases, while (-)-hopeaphenol exhibited moderate inhibition. Molecular docking supported the inhibition data, and several aspects of the structural configurations explained the stronger inhibition exerted by vaticanol B. Overall, vaticanol B shows promise as a natural alternative to acarbose for inhibiting α-amylase.</p>","PeriodicalId":46,"journal":{"name":"Journal of Medicinal Chemistry","volume":null,"pages":null},"PeriodicalIF":6.8,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142580832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photooxidation of Nonanoic Acid by Molecular and Complex Environmental Photosensitizers.","authors":"Grace Freeman-Gallant, Emily J Davis, Elizabeth Scholer, Onita Alija, Juan G Navea","doi":"10.1021/acs.jpca.4c05608","DOIUrl":"10.1021/acs.jpca.4c05608","url":null,"abstract":"<p><p>Photochemical aging and photooxidation of atmospheric particles play a crucial role in both the chemical and physical processes occurring in the troposphere. In particular, the presence of organic chromophores within atmospheric aerosols can trigger photosensitized oxidation that drives the atmospheric processes in these interfaces. However, the light-induced oxidation of the surface of atmospheric aerosols, especially those enriched with organic components, remains poorly understood. Herein, we present a gravimetric and vibrational spectroscopy study aimed to investigate the photosensitized oxidation of nonanoic acid (NA), a model system of fatty acids within organic aerosols, in the presence of complex organic photosensitizers and molecular proxies. Specifically, this study shows a comparative analysis of the photosensitized reactions of thin films containing nonanoic acid and four different organic photosensitizers, namely marine dissolved organic matter (m-DOM) and humic acids (HA) as environmental photosensitizers, and 4-imidazolecarboxaldehyde (4IC) and 4-benzoylbenzoic acid (4BBA) as molecular proxies. All reactions show predominant photooxidation of nonanoic acid, with important differences in the rate and yield of product formation depending on the photosensitizer. Limited changes were observed in the organic photosensitizer itself. Results show that, among the photosensitizers examined, 4BBA is the most effective in photooxidizing nonanoic acid. Overall, this work underscores the role of chromophores in the photooxidation of organic thin films and the relevance of such reactions on the surface of aerosols in the marine environment.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142580931","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":"Harnessing CRISPR/Cas12a Activity and DNA-Based Ultrabright FluoroCube for <i>In Situ</i> Imaging of Metabolically Labeled Cell Membrane Glycoproteins.","authors":"Jiajia Liu, Ziyan Zhou, Yifan Bo, Qiming Yan, Xin Su","doi":"10.1021/acs.nanolett.4c03605","DOIUrl":"10.1021/acs.nanolett.4c03605","url":null,"abstract":"<p><p>Fluorescence imaging of cell membrane glycoproteins based on metabolic labeling faces challenges including the sensitivity and spatial specificity and the use of a high concentration of unnatural sugars. To overcome these limitations, we developed a method for <i>in situ</i> imaging of cell membrane glycoproteins by operating Cas12a activity, and employing the ultrabright DNA nanostructure, FluoroCube (FC), as a signal reporter. Following Cas12a activation, we observed stable and intense fluorescence signals within 15 min. The combination of bright FC and Cas12a's amplification capability allows for effective imaging with only 5 μM of unnatural sugars and a brief 24-h incubation. Computational modeling demonstrates that Cas12a specifically cleaves FC in the 11-17 nm range of the glycosylation site, enabling spatially precise imaging. This approach successfully enabled fluorescence imaging of glycoproteins across various cell lines and the detection of changes in glycoprotein levels induced by drugs.</p>","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":null,"pages":null},"PeriodicalIF":9.6,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142520260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"One-Step Gas Foaming Strategy for Constructing Strontium Nanoparticle Decorated 3D Scaffolds: a New Platform for Repairing Critical Bone Defects.","authors":"Yujie Chen, Yucai Li, Xinyi Wang, Xiumei Mo, Yicheng Chen, Zijun Deng, Xiaojian Ye, Jiangming Yu","doi":"10.1021/acsami.4c13119","DOIUrl":"10.1021/acsami.4c13119","url":null,"abstract":"<p><p>The management of critical-sized bone defects poses significant clinical challenges, particularly in the battlefield and trauma-related injuries. However, bone tissue engineering scaffolds that satisfy high porosity and good angiogenic and osteogenic functions are scarce. In this study, 3D nanofiber scaffolds decorated with strontium nanoparticles (3DS-Sr) were fabricated by combining electrospinning and gas foaming. Sodium borohydride (NaBH₄) served a dual role as both a reducing and gas-foaming agent, enabling a one-step process for expansion and modification. <i>In vitro</i> experimental results demonstrated that 3DS-Sr possessed an integrated multilayered porous structure. It promoted angiogenesis by upregulating the expression of hypoxia-inducible factor-1α (HIF-1α) protein and phosphorylation of ERK through the sustained release of Sr²⁺ and created a favorable microenvironment for osteogenesis by activating the Wnt/β-catenin pathway. <i>In vivo</i> experiments indicated that 3DS-Sr promoted cranial bone regeneration by synergistically promoting the effects of vascularization and osteogenesis. In summary, this study proposed a bioactive bone scaffold in a \"one stone, two birds\" manner, providing a promising strategy for bone defect repair.</p>","PeriodicalId":5,"journal":{"name":"ACS Applied Materials & Interfaces","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142542742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stromal Reprogramming Optimizes KRAS-Specific Chemotherapy Inducing Antitumor Immunity in Pancreatic Cancer.","authors":"Qinglian Hu, Jiayu Feng, Lulu Qi, Yuanxiang Jin","doi":"10.1021/acsami.4c10404","DOIUrl":"10.1021/acsami.4c10404","url":null,"abstract":"<p><p>Pancreatic ductal adenocarcinoma (PDAC) is a clinically challenging cancer and is often characterized with rich stroma and mutated KRAS, which determines the tumor microenvironment (TME) and therapy response. Turning immunologically \"cold\" PDAC into \"hot\" is an unmet need to improve the therapeutic outcome. Herein, we propose a programmable strategy by sequential delivery of pirfenidone (PFD) and nanoengineered KRAS specific inhibitor (AMG510) and gemcitabine (GEM) liposomes. PFD could achieve precise reduction of the extracellular matrix (ECM) by reprogramming pancreatic stellate cells (PSCs). Subsequently, targeting the KRAS-directed oncogenic signaling pathway effectively inhibited tumor proliferation and migration, which sensitized a chemotherapeutic drug and promoted immunogenic cell death (ICD). In preclinical mouse models of PDAC, PFD mediated stromal modulation enhanced the deep penetration of nanoparticles and improved their subsequent performance in tumor growth inhibition. The molecular mechanisms elucidated that the stroma intervention and KRAS signal pathway regulation reshaped the immunosuppression of PDAC and optimized cytotoxic T-cell-mediated antitumor immunity with sustained antitumor memory. Overall, our study provides a practical strategy with clinical translational promise for immunologically cold tumor PDAC treatment.</p>","PeriodicalId":5,"journal":{"name":"ACS Applied Materials & Interfaces","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142542745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ionic Liquid-Assisted Strategy for Morphology Engineering of Inorganic Cesium-Based Perovskite Thin Films Toward High-Performance Solar Cells.","authors":"Gulzhan Zhumadil, Menghua Cao, Yu Han, Vladimir Pavlenko, Gaukhar Nigmetova, Zhuldyz Yelzhanova, Hryhorii P Parkhomenko, Zhazira Ergasheva, Damir Aidarkhanov, Mannix P Balanay, Askhat N Jumabekov, Gang Li, Zhiwei Ren, Annie Ng","doi":"10.1021/acsami.4c15880","DOIUrl":"10.1021/acsami.4c15880","url":null,"abstract":"<p><p>The wide bandgap CsPbI₂Br perovskite materials have attracted significant attention due to their high thermal stability and compatibility with narrow bandgap materials in tandem devices. The performance of perovskite solar cells (PSCs) is highly dependent on the quality of the perovskite layer, which is governed by the crystallization process during solution processing. However, the crystallization dynamics of CsPbI₂Br thin films remain less explored compared to conventional organic-inorganic perovskites. Achieving high-quality CsPbI₂Br films with uniform morphology and large perovskite grains remains challenging with standard solution techniques. This study applies the ionic liquid (IL) [EMIM]⁺[PF₆]^- as an additive within the bulk CsPbI₂Br absorber layer. Within our experimental regime, [EMIM]⁺[PF₆]^- accelerates the crystallization process while promoting the formation of large perovskite grains, a feature not commonly observed in previous studies. Our experimental results suggest that the IL acts as heterogeneous nucleation sites, and varying IL incorporation amount significantly impacts the morphology of CsPbI₂Br perovskite films. Consistent UV-vis and photoluminescence (PL) red-shifts are observed in the IL-incorporated CsPbI₂Br films, with X-ray diffraction (XRD) data projecting an influence on the perovskite crystal structure. These findings provide new insights into the role of ILs in controlling crystallization and morphology that have been minimally discussed in the literature. The incorporation of an optimized amount of [EMIM]⁺[PF₆]^- promotes the formation of highly crystalline perovskite thin films with excellent morphology, reducing defect density, enhancing carrier transport, and yielding large grain sizes. As a result, PSCs fabricated with [EMIM]⁺[PF₆]^- achieved a power conversion efficiency (PCE) of 17.11% (stabilized at 15.87%) and an open-circuit voltage (<i>V</i>_OC) of 1.39 V, along with improved stability compared to control devices. This work provides a straightforward approach for producing high-quality CsPbI₂Br thin films with high reproducibility, contributing valuable advancements to Cs-based PSCs.</p>","PeriodicalId":5,"journal":{"name":"ACS Applied Materials & Interfaces","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142542837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fluence-Dependent Photoinduced Charge Transfer Dynamics in Polymer-Wrapped Semiconducting Single-Walled Carbon Nanotubes.","authors":"Zachary X W Widel, James A Alatis, Riley H Stephenson, Francesco Mastrocinque, Alexander C Wilcox, George Bullard, Jean-Hubert Olivier, Yusong Bai, Peng Zhang, David N Beratan, Michael J Therien","doi":"10.1021/jacs.4c11118","DOIUrl":"10.1021/jacs.4c11118","url":null,"abstract":"<p><p>Because an individual single-walled carbon nanotube (SWNT) can absorb multiple photons, the exciton density within a single tube depends upon excitation conditions. In SWNT-based energy conversion systems, interactions between excitons and charges make it possible for multiple types of charge transfer reactions. We exploit a SWNT-molecular donor-acceptor hybrid system (<i>R</i>-PBN(b)-Ph₆-PDI-[(6,5) SWNT]) that fixes spatial organization and stoichiometry of perylene diimide (PDI) electron acceptors on the nanotube surface, to elucidate how excitation fluence affects ultrafast charge separation (CS) and the nature of charge recombination (CR) dynamics triggered upon SWNT near-infrared excitation. Pump-probe data characterizing these photoinduced CS and thermal CR reactions were acquired over excitation fluences that produce ∼5-125 excitons per 700 nm long nanotube. These experiments show that optical excitation gives rise to CS states in which PDI radical anions (PDI^-•) and SWNT hole polarons (SWNT^•+) have geminate and nongeminate spatial relationships. Under low excitation fluences, the observed dynamics reflect CR reactions of these geminate and nongeminate CS states. As excitation fluence increases, persistent excitons, which have not undergone CS, undergo reaction with ([SWNT(^•+)<i>ⁿ</i>]-(PDI^-•)<i>_n</i>) CS states to produce lower-energy CS states that are characterized by hole (SWNT^•+) and electron (SWNT^•-) polarons. When nongeminate SWNT^•+ and SWNT^•- charge carriers are generated, CR dynamics depend on the time scale required for these oppositely charged solvated SWNT polarons to encounter each other. Because SWNT excitons have substantial excited-state reduction (¹<i>E</i>^-/*) and excited-state oxidation (¹<i>E</i>^*/+) potentials, they can drive additional charge transfer reactions involving initially prepared CS states under experimental conditions where excess excitons are present.</p>","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":null,"pages":null},"PeriodicalIF":14.4,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142542886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nanodomain-Enhanced Stable and Multifunctional Probes with Near 100% Quantum Yield for Versatile Biosensing.","authors":"Yu Zhang, Niu Feng, Xiaobo Hu, Xufeng Wang, Jiacheng Tao, Zhenguang Ji, Yue Yang, Jimei Ma, Yiping Chen","doi":"10.1021/acs.nanolett.4c04376","DOIUrl":"10.1021/acs.nanolett.4c04376","url":null,"abstract":"<p><p>The preparation of high quantum yield, stable, and multifunctional fluorescent probes is of great significance in the fields of biomedicine and photoelectric sensing. Here, a triphenylamine-based D-π-A fluorescent molecule (TPA-CN) was designed and prepared, demonstrating a fluorescence quantum yield of 88.84%. With a polystyrene nanosphere as the carrier, TPA-CN was encapsulated inside the nanosphere to form intra-nanosphere confining domains. These nanodomain-enhanced fluorescent nanospheres exhibited a fluorescence quantum yield of 98.21%. Using antigen-antibody specificity and the selective catalytic activity of a bioenzyme, with chloramphenicol as a model target, a dual-signal readout biosensor (in fluorescence and colorimetric modes) was designed for ultrasensitive and instrument-free determination. The detection limit was 24 pg/mL within 30 min in fluorescence mode, 38-fold more sensitive and 10-fold faster than that of enzyme linked immunosorbent assays. The nanodomain-enhanced fluorescent probes and dynamic biosensor provide a robust and versatile solution for public health and environmental monitoring needs.</p>","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":null,"pages":null},"PeriodicalIF":9.6,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142542904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}