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Reactive stepping

Jia Wang, Zhuwei Liao, Jerosha Ifthikar, Lerong Shi, Yunan Du, Jingyi Zhu, Shuang Xi, Zhuqi Chen, Zhulei Chen
A novel strategy for the removal of refractory organic contaminants was realized through sludge-derived biochar (SDBC)/persulfate (PS) system via both adsorption and advanced oxidation process under ambient conditions. SDBC was prepared by one single step of slow pyrolysis of municipal sewage sludge, appeared a porous structure, and contained abundant oxygen-containing functional groups as well as amorphous Fe species. Large surface area and porous structure of SDBC benefitted the adsorption and enrichment of contaminants, while oxygen-containing functional groups and Fe species on the surface were considered as reactive components for the activation of PS...
July 17, 2017: Chemosphere
Wangjia Tang, Dong Xie, Tong Shen, Xiuli Wang, Donghuang Wang, Xuqing Zhang, Xinhui Xia, Jianbo Wu, Jiangping Tu
Exploring advanced anode materials with highly reversible capacity have gained great interests for large-scale lithium storage. Herein, a facile two-step method is developed to synthesize nitrogen-doped carbon coated MoSe2 microspheres via hydrothermal plus thermal polymerization. The MoSe2 microspheres composed of interconnected nanoflakes are homogeneously coated by thin nitrogen-doped carbon (N-C) layer. As an anode for lithium ion batteries, the MoSe2/N-C composite shows better reversibility, smaller polarization and higher electrochemical reactivity as compared to the unmodified MoSe2 microspheres...
July 21, 2017: Chemistry: a European Journal
Satish K Tuteja, Todd Duffield, Suresh Neethirajan
We report the step-by-step fabrication of a 2D MoS2 nanostructure-based disposable electrochemical immunosensor to detect β-hydroxybutyrate (βHBA), a novel subclinical ketosis biomarker. The MoS2 nanosheets were exfoliated in the liquid phase by ultrasonication, and then followed by deposition on gold colloid modified screen-printed electrodes (Au-SPE). The MoS2-modified electrodes were thoroughly characterized by physical, electrochemical as well as spectroscopic techniques, and the obtained results indicate the successful and irreversible electrodeposition of MoS2 nanosheets...
July 21, 2017: Nanoscale
Rohini Handa, Sundeep Upadhyaya, Sanjiv Kapoor, Ramesh Jois, Bimlesh D Pandey, Anuj K Bhatnagar, Ashwani Khanna, Vishal Goyal, Kamal Kumar
India has a huge patient burden of rheumatic diseases (RDs) including rheumatoid arthritis. The use of biologics has transformed the treatment paradigm for RD; however, biologic treatment-related infections (especially tuberculosis [TB]) are an area of potential concern for TB-endemic nations like India. Anti-tumor necrosis factor (TNF) therapy impairs the physiological TNF-mediated signaling and may cause reactivation and dissemination of latent TB infection (LTBI). Careful screening is, thus, crucial in RD patients who are about to commence anti-TNF treatment...
July 21, 2017: International Journal of Rheumatic Diseases
Jon Uranga, Jon M Matxain, Xabier Lopez, Jesus M Ugalde, David Casanova
This work presents the mechanism of the photoinduced generation of reactive oxygen species (ROS) by paramagnetic copper porphyrins in aqueous solution. Electronic structure calculations within the framework of the (time-dependent) density functional theory, (TD)DFT, reveal the details regarding the development of the atomistic and electronic structures of the copper porphyrin in solution along the set of chemical reactions accessible upon photoactivation. This study identifies the key parameters controlling the feasibility of the various reaction pathways that drive the formation of specific reactive oxygen species, ROS, i...
July 21, 2017: Physical Chemistry Chemical Physics: PCCP
Li-Long Jiang, Dong-Sheng Zhao, Ya-Xi Fan, Qiong Yu, Ping Li, Hui-Jun Li
Polygoni Multiflori Radix (PMR) has been commonly used as a tonic in China for centuries. PMR-associated hepatotoxicity has been drawing increasingly more attention in recent years in parallel with its wide utilization. Anthraquinones (AQs) are recognized as the main hepatotoxic components in PMR. However, the exact underlying mechanism of AQs poisoning is still not fully understood. Herein, we proposed a hypothesis that metabolic activation of AQs such as emodin was involved in PMR-induced liver injury, AQs followed to generate the electrophilic reactive metabolites and subsequently formed covalent adduct with cellular nucleophiles in the liver to exert hepatotoxicity...
2017: Frontiers in Pharmacology
Xudan Song, Jiarui Lu, Wenzhen Lai
Herein, we use in-protein quantum mechanical/molecular mechanical (QM/MM) calculations to elucidate the mechanism of dioxygen activation, oxygen atom exchange and substrate epoxidation processes by AsqJ, an Fe(II)/α-ketoglutarate-dependent dioxygenase (α-KGD) using a 2-His-1-Asp facial triad. Our results demonstrated that the whole reaction proceeds through a quintet surface. The dioxygen activation by AsqJ leads to a quintet penta-coordinated Fe(IV)-oxo species, which has a square pyramidal geometry with the oxo group trans to His134...
July 20, 2017: Physical Chemistry Chemical Physics: PCCP
Laurent Bonnet, Joaquin Espinosa-Garcia
The OH + CHD3 reaction is among the largest one ever studied at the high-resolution level permitted by imaging techniques [B. Zhang et al., J. Phys. Chem. A, 2005, 109, 8989]. This process involves eighteen configuration space coordinates, which are large enough to make exact quantum scattering calculations beyond reach. Moreover, freezing some degrees-of-freedom in order to render these calculations feasible may lead to unrealistic predictions. However, we have found it possible to reproduce for the first time the pair-correlated measurements of Zhang et al...
July 20, 2017: Physical Chemistry Chemical Physics: PCCP
C V Neves, F B Scheufele, A P Nardino, M G A Vieira, M G C da Silva, A N Módenes, C E Borba
The aim of this work was an experimental and theoretical investigation of the influence of electrolyte (NaCl) and surfactant (SP), as textile auxiliary agents (TAAs), on the removal of reactive blue 5G dye (RB5G) by applying untreated fish scales (FS) in batch system. For this, kinetic and equilibrium studies were performed aiming the comprehension of the mass transfer mechanisms through a phenomenological modeling. The biosorbent was texturally characterized, not only to investigate the adsorbent's characteristics but especially to support the definition of the assumptions of the models...
July 20, 2017: Environmental Technology
Yuanle Deng, Yali Li, Fangfang Yang, Anqi Zeng, Shuping Yang, Yi Luo, Yiwen Zhang, Yongmei Xie, Tinghong Ye, Yong Xia, Wenya Yin
Prostate cancer is a big threat to male for its poor prognosis and high mortality rate. Natural compounds are important resources of many anticancer drugs. Pomegranate is a kind of antioxidant-rich fruit and its peel and seed has potential anticancer activities. In this study, we aimed to investigate the effects of pomegranate peel extract (PoPx) on the apoptosis and metastasis of prostate cancer cells and the related mechanism. We found that PoPx showed growth inhibition on prostate cancer cells. Nuclei morphological and flow cytometer (FCM) analysis indicated that PoPx could induce prostate cancer apoptosis...
July 14, 2017: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
Nicolas Clavier, Yanis Cherkaski, Julien Martinez, Sophie Costis, Théo Cordara, Fabienne Audubert, Laurent Brissonneau, Nicolas Dacheux
Highly reactive and nanosized Th1-xYxO2-x/2 or Ce0.8Ln0.2O1.9 mixed oxides were prepared through the initial precipitation of hydroxide precursors which were further dried under vacuum. Whatever the chemical system investigated, the characterization of the powdered samples evidenced a rapid aging process leading to hydrated oxides. The thermal behavior of these samples was further investigated and first showed a two-step dehydration process, with the successive departure of adsorbed then constitutive water, both yielding a drastic drop of the powders reactivity (i...
July 19, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
Kamalika Mukherjee, Tak Ian Chio, Han Gu, Abhijit Banerjee, Anthony M Sorrentino, Dan L Sackett, Susan L Bane
Detection and quantification of biomolecule carbonylation, a critical manifestation of oxidative stress, allows better understanding of associated disease states. Existing approaches for such analyses require further processing of cells and tissues, which leads to loss of both spatial and temporal information about carbonylated biomolecules in cells. Live cell detection of these species requires sensors that are nontoxic, sufficiently reactive with the biocarbonyl in the intracellular milieu, and detectable with commonly available instrumentation...
January 27, 2017: ACS Sensors
Artëm E Masunov, Elizabeth Wait, Subith S Vasu
The supercritical carbon dioxide diluent is used to control the temperature and to increase the efficiency in oxycombustion fossil fuel energy technology. It may affect the rates of combustion by altering mechanisms of chemical reactions, compared to the ones at low CO2 concentrations. Here, we investigate potential energy surfaces of the four elementary reactions in the CH3 + O2 reactive system in the presence of one CO2 molecule. In the case of reaction CH3 + O2 → CH2O + OH (R1 channel), van der Waals (vdW) complex formation stabilizes the transition state and reduces the activation barrier by ∼2...
July 19, 2017: Journal of Physical Chemistry. A
Alia Méjri, Fabien Picaud, Mohammed El Khalifi, Tijani Gharbi, Bahoueddine Tangour
The oxidative addition of primary amine on a monocyclic phospholane was studied in confined conditions. This one-step chemical reaction has been investigated using the DFT technique to elucidate the role of confinement in carbon nanotubes on the reaction. Calculations were carried out by a progressive increase of the nanotube diameters from 10 Å to 15 Å in order to highlight the dependence of the reactivity on the nanotube diameter. First, single point investigations were dedicated to the study of reactants, transition states, and products placed in the different nanotubes while keeping their optimized structure as free compounds...
August 2017: Journal of Molecular Modeling
Nicolas Glade, Olivier Bastien, Pascal Ballet
Cellular automata are often used to explore the numerous possible scenarios of what could have occurred at the origins of life and before, during the prebiotic ages, when very simple molecules started to assemble and organise into larger catalytic or informative structures, or to simulate ecosystems. Artificial self-maintained spatial structures emerge in cellular automata and are often used to represent molecules or living organisms. They converge generally towards homogeneous stationary soups of still-life creatures...
July 18, 2017: Theory in Biosciences, Theorie in Den Biowissenschaften
Alan A Wilson, Oleg Sadovski, José N Nobrega, Roger J Raymond, Francis R Bambico, Mina G Nashed, Armando Garcia, Peter M Bloomfield, Sylvain Houle, Romina Mizrahi, Junchao Tong
INTRODUCTION: Few, if any, radiotracers are available for the in vivo imaging of reactive oxygen species (ROS) in the central nervous system. ROS play a critical role in normal cell processes such as signaling and homeostasis but overproduction of ROS is implicated in several disorders. We describe here the radiosynthesis and initial ex vivo and in vivo evaluation of [(11)C]hydromethidine ([(11)C]HM) as a radiotracer to image ROS using positron emission tomography (PET). METHODS: [(11)C]HM and its deuterated isotopologue [(11)C](4) were produced using [(11)C]methyl triflate in a one-pot, two-step reaction and purified by high performance liquid chromatography...
June 1, 2017: Nuclear Medicine and Biology
Jing-Shuang Dang, Wei-Wei Wang, Jia-Jia Zheng, Shigeru Nagase, Xiang Zhao
Although the existence of Stone-Wales (5-7) defect at graphene edge has been clarified experimentally, theoretical study on the formation mechanism is still imperfect. In particular, the regioselectivity of multistep reactions at edge (self-reconstruction and growth with foreign carbon feedstock) is essential to understand the kinetic behavior of reactive boundaries but investigations are still lacking. Herein, by using finite-sized models, multistep reconstructions and carbon dimer additions of a bared zigzag edge are introduced using density functional theory calculations...
July 18, 2017: Journal of Computational Chemistry
Na Li, Shibin Wang, Yuhan Sun, Shenggang Li
First principles calculations using both molecular cluster and periodic slab models were performed to reveal the mechanism for the formation of dimethoxymethane (DMM) from methanol over V2O5/TiO2-based catalysts. Two different pathways were found, and the formation of DMM was predicted to be initiated by methanol chemisorption followed by a dehydration reaction with hemiacetal catalyzed by acidic sites. For unpromoted V2O5/TiO2 catalysts, we predicted the energy barrier for the rate determining step (RDS) to follow the order formaldehyde (FA) > methyl formate (MF) > DMM, consistent with the experimental observation for the preferential formation of DMM at a relatively low temperature and that of MF at a relatively high temperature...
July 17, 2017: Physical Chemistry Chemical Physics: PCCP
Mi Tang, Rengwei Sun, Hao Li, Xinhong Yu, Wei Wang
Reaction of α-amino acids particularly prolines and their derivatives with carbonyl compounds via decarboxylative redox process is a viable strategy for synthesis of structurally diverse nitrogen centered heterocyclics. In these processes, the decarboxylation is the essential driving force for the processes. The realization of the redox process without decarboxy-lation may offer an opportunity to explore new reactions. Herein, we report the discovery of an unprecedented redox Claisen type condensation aromatization cascade reaction of 4-substituted 4-hydroxyproline and its esters with unreactive ketones...
July 17, 2017: Journal of Organic Chemistry
Daniel Helmdach, Polina Yaseneva, Parminder K Heer, Artur M Schweidtmann, Alexei Lapkin
A decision support tool has been developed, which uses global multi-objective optimisation based on: (i) the environmental impacts, evaluated within the framework of full life cycle assessment, and (ii) process costs, evaluated using rigorous process models. This approach is particularly useful in developing the bio renewable-based energy solutions and chemicals manufacturing, where multiple criteria must be evaluated and where the optimisation-based decision making process is particularly attractive. The framework is demonstrated using a case study of conversion of terpenes derived from bio-waste feedstocks into reactive intermediates...
July 17, 2017: ChemSusChem
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