BIOPHYSICAL JOURNAL
·
2021
·
IF 4.033
Erika Aloi,Jin-Hua Guo,Rita Guzzi,Ren-Wang Jiang,Lucy Kate Ladefoged,Derek Marsh,Mikael Esmann,Rosa Bartucci,Natalya U. Fedosova
Spin labels based on cinobufagin, a specific inhibitor of the Na,K-ATPase, have proved valuable tools to characterize the binding site of cardiotonic steroids (CTSs), which also constitutes the extracellular cation pathway. Because existing literature suggests variations in the physiological responses caused by binding of different CTSs, we extended the original set of spin-labeled inhibitors to the more potent bufalin derivatives. Positioning of the spin labels within the Na,K-ATPase site was defined and visualized by molecular docking. Although the original cinobufagin labels exhibited lower affinity, continuous-wave electron paramagnetic resonance spectra of spin-labeled bufalins and cinobufagins revealed a high degree of pairwise similarity, implying that these two types of CTS bind in the same way. Further analysis of the spectral lineshapes of bound spin labels was performed with emphasis on their structure (PROXYL vs. TEMPO), as well as length and rigidity of the linkers. For comparable structures, the dynamic flexibility increased in parallel with linker length, with the longest linker placing the spin label at the entrance to the binding site. Temperature-related changes in spectral lineshapes indicate that six-membered nitroxide rings undergo boat-chair transitions, showing that the binding-site cross section can accommodate the accompanying changes in methyl-group orientation. D 2 O-electron spin echo envelope modulation in pulse-electron paramagnetic resonance measurements revealed high water accessibilities and similar polarity profiles for all bound spin labels, implying that the vestibule leading to steroid-binding site and cation-binding sites is relatively wide and water-filled.
研究领域:
生物物理学
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药理学
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DOI
PubMed
高影响因子
Food Chemistry-X
·
2026
·
IF 9.2
Pengyuan Wei,Jingjing Lun,Yihang Ding,Jinying Wang,Linshang Zhang,Cong Sun,Kaizhou Yang
Auto-oxidation occurs during pan-frying of hand-grasp pancakes. • Hydrolysis was observed during the pan-frying process. • Lipid degradation was detected in hand-grasp pancakes during pan-frying. • The content of unsaturated fatty acids decreased following pan-frying. • The levels of unsaturated triacylglycerols declined post pan-frying. This study investigated the effects of pan-frying on fat quality in hand-grasp pancakes. The results demonstrated that fats exhibited significant quality deterioration: acid value increased by 50%–85%, peroxide value rose by 175%–490%, and p-anisidine value elevated by 65%–430%. The increments of conjugated diene value and conjugated triene value ranged from 20% to 50% and 35% to 73%, respectively. Meanwhile, the DPPH radical scavenging capacity decreased by 3%–30%, indicating a remarkable decline in antioxidant activity. Statistical analysis revealed consistent compositional changes in post-frying fats: the average free fatty acid (FFA) content in fats of the six brands of hand-grasp pancakes increased by 113.04%, whereas the average contents of unsaturated fatty acid (UFA) and unsaturated triacylglycerol (UUU) decreased by 1.81% and 4.82%, respectively. Electron paramagnetic resonance (EPR) measurements confirmed the presence of alkyl radicals (R•) in pancake fats verifying that autooxidation served as the primary oxidation pathway of fats in hand-grasp pancakes. This study provides theoretical foundations for the development of dedicated fats and quality improvement of hand-grasp pancake products.
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DOI
高影响因子
Journal of Energy Chemistry
·
2022
·
IF 13.599
Xianwen Zhang,Zheng Li,Bin Zeng,Can Li,Hongxian Han
Understanding the processes of charge generation, transfer and capture is important for the design and synthesis of efficient photocatalysts. In this work, light-induced charge separation and effect of O 2 on electron transfer processes in SrTiO 3 were investigated by electron paramagnetic resonance (EPR). It was found that photoinduced electron transfer from O 2− to Ti 4+ produced Ti 3+ and O − redox radical pairs under vacuum condition. Under oxygen atmosphere, however, surface bound superoxide radicals O 2 − were formed by electron reduction of adsorbed oxygen at initial photoirradiation stage, and quenched by the reverse electron transfer to Ti 4+ upon further photoirradiation. Formation of long-lived charge separation associated [Ti 3+ ---O − ] species and the reversibility of surface bound superoxide radicals mediating the processes of photogenerated electrons may be accountable for the high activity of SrTiO 3 in photocatalytic water splitting reaction.
研究领域:
材料科学
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物理化学
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DOI
高影响因子
ACS Nano
·
2024
·
IF 15.8
Di Liu,Na Lu,Fengchao Zang,Mingze Lu,Jingyue Zhang,Ying Zhao,Hao Wan,Mengjun Wang,Qian-Qian Li,Fei Wang,Shouhua Luo,Ming Ma,Fangfang Shi,Haoan Wu,Jing Tu,Yu Zhang
Even though the enhanced permeability and retention (EPR) effect is applicable for the passive targeting of solid tumors, many nanodrugs have failed to achieve meaningful clinical outcomes due to the heterogeneity of EPR effect. Therefore, understanding the mechanism of the EPR effect is crucial to overcome the obstacles nanomedicines face in clinical translation. The aim of this study was to establish a reliable method to increase awareness of the critical influencing factors of nanoparticle (NP) transport into tumors based on the EPR effect using a combined radiogenomics and clinical magnetic resonance imaging (MRI) technique and gene set pathway enrichment analysis. Employing poly(lactic-co-glycolic acid) (PLGA)-coated Fe3O4 NPs as the contrast agent, the monolayer and multilayer distribution of the NPs were observed and quantitatively analyzed by MRI, improving the accuracy of evaluating vascular permeability by MRI. By performing Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of genes and pathways, we identified a variety of genes affecting vascular permeability, such as Cldn1, Dlg2, Bves, Prkag3, Cldn10, and Cldn8, which are related to tight junctions and control the permeability of blood vessels in tumors. The method presented here provides an MRI-supported approach to increase the breadth of data collected from genetic screens, reveals genetic evidence of the presence of NPs in tumors and lays a foundation for clinical patient stratification and personalized treatment.
研究领域:
医学影像学
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肿瘤学
·
基因组学
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DOI
PubMed
高影响因子
RSC Advances
·
2024
·Vol. 14
·期 38
·27789-27798
·
IF 3.9
Zhipeng Xu,Yongliang Qin,Dongdong Wei,Jie Jin,Long Zheng,Jie Xu,Hui Liu,Ranran Chen,Di Wang
The study of the magnetism of tightly arranged nitronyl nitroxide (NN) radicals via Au–S self-assembly is interesting. In this study, a series of radicals (S-NN, D-NN, BS-NN, BD-NN) along with two types of nanomaterials (S-NPs, D-NPs) were synthesized. NN was chosen for the magnetic units. Their structures have been successfully synthesized and analyzed. The spin magnetic properties were characterized by electron paramagnetic resonance (EPR) and superconducting quantum interference device (SQUID) measurement. The analysis revealed that the self-assembled NN formed via Au–S bonds exhibits high packing density. Furthermore, it was gratifying to observe that the AuNPs exhibit ferromagnetism after the surface modification by NN. This results in strong ferromagnetic exchange interactions of S-NPs and D-NPs : JS-NPs = +279.715 K and JD-NPs = +254.913 K, respectively.
研究领域:
材料科学
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磁学
·
化学合成
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DOI
PubMed
高影响因子
MACROMOLECULES
·
2017
·
IF 5.835
Jiaxing Zhang,Hongying Shen,Wenguang Song,Guowei Wang
A series of novel linear and hyperbranched copolymers with different topological structures and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) radical distributions were synthesized, and their paramagnetic property was systematically investigated. Based on the ring-opening polymerization (ROP) mechanism of GTEMPO, glycidol (Gly) or ethylene oxide (EO) monomers, the linear Poly(EO-co-GTEMPO) and hyperbranched Poly(Gly-co-GTEMPO) copolymers were obtained from a bifunctional 2,2-dimethyl-1,3-propanediol initiator and a tetrafunctional pentaerythritol initiator, respectively. Alternatively, from the multifunctional macroinitiator of hyperbranched polyglycerol (HPG), the hyperbranched HPG-g-Poly(Gly-co-GTEMPO) and HPG-g-PGTEMPO copolymers were also targeted. The copolymers were characterized by GPC, DSC, and UV–vis analysis. The paramagnetic property of the copolymers was studied and compared by EPR analysis at different concentrations of copolymers and temperatures. The results displayed that the concentrations of copolymers majorly manipulated the signal intensity of EPR spectra, and the temperature majorly modulated the shape of EPR spectra. Essentially, the TEMPO radical distributions in copolymers played an important role: the higher regional density tended to give the EPR spectra with intense, broad peaks, while the lower one led to the regular, well-pronounced EPR spectra. The difference was rationalized to different intramolecular spin–spin exchange and dipole–dipole interaction modulated by the topological structures and the corresponding TEMPO radical distributions.
研究领域:
高分子化学
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材料科学
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DOI
高影响因子
Chemical & Biomedical Imaging
·
2025
·
IF 5.7
Jiaxing Lv,Ying Jiang,Hui Feng,Guozhong Lu,Xiaobing Lou,Bingwen Hu
The practical application of all-solid-state lithium metal batteries (ASSLBs) based on Li6PS5Cl (LPSC) is severely hindered by uncontrolled lithium (Li) dendrite penetration, which ultimately leads to soft short circuits and catastrophic battery failure. To address this critical challenge, this work proposes a Li10GeP2S12–Li6PS5Cl (LGPS-LPSC) composite solid electrolyte interlayer between the composite cathode layer and the LPSC bulk layer, which effectively prevents lithium dendrites from penetrating the electrolyte and then enhances the long-term cycling stability. Electrochemically, Li|Li symmetric cells integrated with this composite electrolyte achieve stable operation for 2000 h at a current density of 0.5 mA cm–2, while Li|LiCoO2 full cells with composite electrolyte exhibit excellent cycling stability, retaining 69.51% of their initial capacity after 900 cycles at a rate of 1 C. Via 3D electron paramagnetic resonance (EPR) imaging, in situ 2D EPR imaging, and nanoindentation measurements, it is revealed that the LGPS-LPSC composite electrolyte exerts a dual function: it not only enhances the mechanical strength of the electrolyte system to physically block Li dendrite penetration but also tailors ionic conductivity pathways to facilitate uniform Li plating at the Li metal anode interface.
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高影响因子
ANALYTICAL CHEMISTRY
·
2025
·
IF 6.7
Yi Liu,Xiang Wu,Xiaobing Lou,Chao Li,Ming Shen,Fushan Geng,Bingwen Hu
Electron paramagnetic resonance (EPR), a sensitive probe for unpaired electron spins, has been widely used in the investigation of various electrochemical systems. Despite its success in studying electrochemical processes involving radicals or other species with narrow line widths, interpreting EPR results for systems with broad featureless signals, particularly ions in solid materials, remains challenging. In this work, we develop a quantitative operando EPR method to study redox-active ions in electrode materials. The relationship between the variation in absolute spin amounts and electron transfer amounts is established to assign the signals. Four conversion-type electrode materials, MnO, MnF2, Mn2O3, and MnF3, are used as typical representatives of Kramers and non-Kramers ions to exemplify this method. The results accurately reveal the electrode processes, including redox mechanisms, local structural variations, and transition metal dissolution. It offers a new strategy for properly interpreting the broad featureless signals from ions in electrode materials, paving the way for understanding electrochemical processes in critical systems such as cathode materials.
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DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Hongxia Zhao,Xiuying Chen,Xintong Li,Chen Shen,Baocheng Qu,Jingsuo Gao,Jingwen Chen,Xie Quan
Metal oxide nanocomposites with photocatalytic activity have the potential for many applications in environmental remediation and biomedicine. In this study, we investigated the formation and stabilization of electrons/holes from three metal oxide–silica nanocomposites (CuO–SiO 2 , Fe 2 O 3 –SiO 2 and ZnO–SiO 2 ) under irradiation by electron paramagnetic resonance (EPR) technology. The characteristic EPR signals with g = 2.00070–2.00105, Δ H p-p = 2.17–2.37 G were determined, which corresponded to lattice-trapped electrons. Moreover, the generation of active species from CuO–SiO 2 , Fe 2 O 3 –SiO 2 and ZnO–SiO 2 in aqueous solution under irradiation was also systematically studied. The results showed that all the three nanocomposites could generate hydroxyl radical, singlet oxygen and electron. CuO–SiO 2 was more effective than Fe 2 O 3 –SiO 2 and ZnO–SiO 2 in producing hydroxyl radical and electrons, while ZnO–SiO 2 was the most efficient in generating singlet oxygen. In addition, CuO–SiO 2 exhibited most obviously photocatalytic activity toward degradation of bisphenol A, followed by Fe 2 O 3 –SiO 2 and ZnO–SiO 2 . These findings will provide vital insights into photocatalytic mechanisms and potentially photoinduced toxicity of metal oxide–silica nanocomposites.
研究领域:
环境科学
·
材料科学
·
生物医学
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DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2017
·
IF 4.217
Chaoqun Tan,Yujie Dong,Lei Shi,Qin Chen,Shengwei Yang,Xiaoyu Liu,Jinfeng Ling,Xuefeng He,Dafang Fu
The degradation of Orange II (Org II) by ferrous activated peroxymonosulfate (PMS) was inspected. The maximum degradation efficiency of 62.3% in 90 min occurred at 0.286 mM [PMS] 0 , corresponding to 1:1 molar ratio of Fe 2+ : PMS. Results show that poor recovery of Fe 2+ accounts for poor degradation in the slow stage. The species of reactive radicals were determined through indirect way by quenching agents, as well as directly by in situ EPR spin trapping tests. Results indicated that hydroxyl radicals instead of sulfate radicals were responsible for Org II degradation. The removal of Org II degradation would increase to 93.3% in 90 min as reaction temperature increased to 60 °C. The activation energy for PMS and Fe 2+ /PMS alone was calculated to be 77.2 kJ/mol and 34.7 kJ/mol, respectively. The removal efficiency of total organic carbon (TOC) was 11.0% and 43.8% when [Fe 2+ ] 0 :[PMS] 0 :[Org II] 0 was 5:5:1 and 34:34:1, respectively. The main degradation products of Org II in system were supposed to be heterocyclic compounds containing a five-atom ring. Results demonstrated that Fe 2+ /PMS technology is promising technology for water pollution.
研究领域:
环境科学
·
化学工程
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高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Yuxiang Tang,Zeliang Wu,Hang Hu,Dianwen Yu,Chaohong Liu,Huiwen Jiang,Wenjing Luo,Heng Mei,Rong Xu,Yu Hu
Effective EPR and tumor penetration are bottlenecks in current nanomedicine therapy. Comosol software was utilized to analyze the motion process of nanoparticles (NPs) with different shapes, from blood vessels to tumor tissue, to address this. By calculation, urchin-like NPs experienced higher drag forces than spherical NPs, facilitating their EPR and tumor penetration effects. Thus, urchin-like indocyanine green-loaded hydroxyethyl starch-cholesterol (ICG@HES-CH) NPs were prepared by leveraging the instability of ICG responding to near-infrared light (NIR). Upon NIR exposure, ICG degraded and partly disintegrated ICG@HES-CH NPs, and its morphology transformed from spherical to urchin-like. Vincristine (VC), as a model drug, was loaded in urchin-like ICG@HES-CH NPs for the treatment of lymphoma. A20 lymphoma cells and 3T3-A20 tumor organoids were employed to investigate the influence of shape on NPs' cellular uptake, penetration pathway, and cytotoxicity. It demonstrated that urchin-like ICG@HES-CH NPs mainly transport across the extracellular matrix through intercellular pathways, easily reaching the deep tumor sites and achieving higher cytotoxicity. In vivo VC distribution and anti-tumor results indicated that urchin-like NPs increased VC EPR and penetration ability, lowering VC neurotoxicity and superior anti-tumor effect. Therefore, urchin-like ICG@HES-CH NPs have great translational potential to be used as chemotherapeutic nanocarriers in anticancer therapy.
研究领域:
药剂学
·
肿瘤学
·
生物医学工程
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产品关联
DOI
PubMed
高影响因子
Current Research in Food Science
·
2026
·
IF 7.7
Yue Chen,Yong Zhu,Likang Qin,Xiaoling Yang,Qizhi Long,Bo Zhou,Haiyan Zhong
Phenolic compounds have been serving as primary antioxidants in retarding lipid oxidation, however, the conventional method for screening phenolic candidates is time-consuming and costly. In this study, phenolics were selected in accordance with the bond dissociation energy (BDE) of O−H and the Gibbs free energy change (ΔG) of the scavenging reaction via quantum chemistry calculation, the efficiency of selected phenolics was subsequently assessed by free energy barrier (ΔG‡), eventually, the suppression efficiency of the candidates was verified by using electron paramagnetic resonance (EPR) determination. Among six catechinic compounds, (−)-gallocatechin gallate (GCG) and (−)-epigallocatechin gallate (EGCG) were identified as the most promising candidates, both of which showed potential efficiency for scavenging alkyl peroxyl (•OOR), alkoxyl (•OR), oleic acid (•OA-C11) and linoleic acid (•LA-C11) radicals. In the thermally-induced camellia oil model (180 °C, 20 min), the inhibition rates of EGCG against alkyl (•R), alkoxyl (•OR) and DMPO oxidative free radicals (•X) were 60.06 ± 0.38 %, 59.74 ± 2.57 % and 92.05 ± 1.70 %, respectively, analogously, the efficiencies of GCG scavenging these radicals ranged from 68.40 ± 0.82 % to 94.27 ± 0.33 %. This indicates that the proposed methodology can effectively screen lipid antioxidants, furthermore, both GCG and EGCG are capable of retarding oxidation in camellia oil.
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产品关联
DOI
PubMed
高影响因子
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