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Laser fenton

Shuyan Song, Yang Liu, Wenyao Zhen, Yinghui Wang, Jianhua Liu, Longhai Jin, Tianqi Zhang, Songtao Zhang, Ying Zhao, Yang Yang, Hongjie Zhang, Chengyu Li, Junjie Zhu
Stringent reaction condition of effective Fenton reaction (the pH range of 3-4) hinders its further application in cancer therapy. Therefore, how to improve the efficiency of Fenton reaction in tumor site has been the main obstacle of chemodynamic therapy (CDT). Herein, we report biocompatible one-dimensional (1D) ferrous phosphide nanorods (FP NRs) with ultrasound (US)- and photothermal (PT)-enhanced Fenton properties and excellent photothermal conversion efficiency (56.6%) in the NIR II window, showing remarkably synergistic therapeutic properties...
January 2, 2019: Angewandte Chemie
Peng Liu, Yurui Wang, Lu An, Qiwei Tian, Jiaomin Lin, Shiping Yang
Synergistic treatment strategies for cancer have attracted increasing attention owing to their enhanced therapeutic effects compared with monotherapy. Chemodynamic therapy (CDT) is an emerging and thriving in situ treatment for cancer owing to its high regioselectivity and activation only by endogenous substances. However, the therapeutic effects of CDT are hindered by low reaction speeds. Here, ultrasmall WO3- x @γ-poly-l-glutamic acid (WO3- x @γ-PGA) nanoparticles (NPs) with good photoacoustic and photothermal properties were prepared, and their chemodynamic performance based on a Fenton-like reaction was explored due to its good catalytic effect...
November 5, 2018: ACS Applied Materials & Interfaces
Yang Liu, Wenyao Zhen, Longhai Jin, Songtao Zhang, Guoying Sun, Tianqi Zhang, Xia Xu, Shuyan Song, Yinghui Wang, Jianhua Liu, Hongjie Zhang
Despite regulation of the reactive oxygen species (ROS) level is an intelligent strategy for cancer therapy, the therapeutic effects of ROS-mediated therapy (including photodynamic therapy (PDT) and chemodynamic therapy (CDT)) are limited by oxygen reliance, inherent flaws of traditional photosensitizers, and strict reaction conditions of effective Fenton reaction. Herein, we reported biocompatible copper ferrite nanospheres (CFNs) with enhanced ROS production under irradiation with a 650 nm laser through direct electron transfer and photoenhanced Fenton reaction and high photothermal conversion efficiency upon exposure to an 808 nm laser, exhibiting a considerable improved synergistic treatment effect...
May 22, 2018: ACS Nano
Sally A M Fenton, Aamer Sandoo, George S Metsios, Joan L Duda, George D Kitas, Jet J C S Veldhuijzen van Zanten
BACKGROUND: Sedentary behaviour is linked to increased cardiovascular disease risk in Rheumatoid Arthritis (RA), but the biological processes underlying this relationship are not understood. OBJECTIVES: To investigate the cross-sectional associations of habitual sedentary behaviour, with endothelial function in RA. METHODS: Sixty-eight RA patients (Mage = 55 ± 12 years) underwent Laser Doppler Imaging with iontophoresis, to assess microvascular endothelium-dependent (acetylcholine, ACh) and endothelium-independent (sodium nitroprusside, SNP) function...
May 2018: Microvascular Research
D Fabio Mercado, Larisa L B Bracco, Antonio Arques, Mónica C Gonzalez, Paula Caregnato
Flusilazole is an organosilane fungicide used for treatments in agriculture and horticulture for control of diseases. The reaction kinetics and mechanism of flusilazole with sulfate and hydroxyl radicals were studied. The rate constant of the radicals with the fungicide were determined by laser flash photolysis of peroxodisulfate and hydrogen peroxide. The results were 2.0 × 109 s-1 M-1 for the reaction of the fungicide with HO and 4.6 × 108  s-1  M-1 for the same reaction with SO4 - radicals. The absorption spectra of organic intermediates detected by laser flash photolysis of S2 O8 2- with flusilazole, were identified as α-aminoalkyl and siloxyl radicals and agree very well with those estimated employing the time-dependent density functional theory with explicit account for bulk solvent effects...
January 2018: Chemosphere
Teng Zhang, Ming-Jun Zhu
A study on the synergistic pretreatment of sugarcane bagasse (SCB) using Fenton reaction and NaOH extraction was conducted. The optimized process conditions for Fenton pretreatment were 10% (w/w) of H2O2, 20mM of Fe(2+), pH 2.5, pretreatment time 6h, and pretreatment temperature 55°C. Sequential pretreatments were performed in combination with NaOH extraction (NaOH 1% (w/w), 80°C, 5% of solid loading, 1h). Among all the pretreatments, Fenton pretreatment followed by NaOH extraction had the highest efficiency of 64...
August 2016: Bioresource Technology
James M Hodges, Julie L Fenton, Jennifer L Gray, Raymond E Schaak
Tetrapod-shaped ZnO nanocrystals exhibit exceptional optoelectronic properties, including intense ultraviolet photoluminescence emission, that make them attractive for applications that include lasers, sensors, and photocatalysts. However, synthetic methods that produce ZnO tetrapods typically include high-temperature vapor-deposition approaches that do not readily achieve characteristic dimensions of less than 100 nm or colloidal methods that require added metal dopants, which modify the inherent properties of ZnO...
October 28, 2015: Nanoscale
O Fenton, S Vero, T G Ibrahim, P N C Murphy, S C Sherriff, D Ó hUallacháin
Elucidation of when the loss of pollutants, below the rooting zone in agricultural landscapes, affects water quality is important when assessing the efficacy of mitigation measures. Investigation of this inherent time lag (t(T)) is divided into unsaturated (t(u)) and saturated (t(s)) components. The duration of these components relative to each other differs depending on soil characteristics and the landscape position. The present field study focuses on tu estimation in a scenario where the saturated zone is likely to constitute a higher proportion of t(T)...
November 2015: Journal of Contaminant Hydrology
Cuiping Li, Hailin Wang
Oxidatively generated DNA damage is considered to be a significant contributing factor to cancer, aging, and age-related human diseases. It is important to detect oxidatively generated DNA damage to understand and clinically diagnosis diseases caused by oxidative damage. In this study, using selective enzymatic cleavage and quantum dot (QD) labeling, we developed a novel capillary electrophoresis-laser induced fluorescence method for the sensitive detection of oxidized DNA bases. First, oxidized DNA bases are recognized and removed by one DNA base excision repair glycosylase, leaving apurinic and apyrimidinic sites (AP sites) at the oxidized positions...
August 7, 2015: Journal of Chromatography. A
Fábio Gozzi, Silvio C Oliveira, Renato F Dantas, Volnir O Silva, Frank H Quina, Amilcar Machulek
BACKGROUND: Due to contamination of the environment by pesticides and their mishandling, there is the need for treatment of contaminated sites and correct disposal of materials containing them. Thus, studies with advanced oxidation processes are expanding and can determine the rate constant of the hydroxyl radical with organic compounds of great importance in environmental contamination. In this context, the use of laser flash photolysis has been shown to be viable for the determination of these constants...
March 30, 2016: Journal of the Science of Food and Agriculture
Roeland Jozef Gentil De Moor, Jeroen Verheyen, Andrii Diachuk, Peter Verheyen, Maarten August Meire, Peter Jozef De Coster, Filip Keulemans, Mieke De Bruyne, Laurence James Walsh
The use of optical radiation for the activation of bleaching products has not yet been completely elucidated. Laser light is suggested to enhance the oxidizing effect of hydrogen peroxide. Different methods of enhancing hydrogen peroxide based bleaching are possible. They can be classified into six groups: alkaline pH environment, thermal enhancement and photothermal effect, photooxidation effect and direct photobleaching, photolysis effect and photodissociation, Fenton reaction and photocatalysis, and photodynamic effect...
2015: TheScientificWorldJournal
Marek Rác, Michal Křupka, Svatopluk Binder, Michaela Sedlářová, Zuzana Matušková, Milan Raška, Pavel Pospíšil
The exposure of human cells to oxidative stress leads to the oxidation of biomolecules such as lipids, proteins and nuclei acids. In this study, the oxidation of lipids, proteins and DNA was studied after the addition of hydrogen peroxide and Fenton reagent to cell suspension containing human leukemic monocyte lymphoma cell line U937. EPR spin-trapping data showed that the addition of hydrogen peroxide to the cell suspension formed hydroxyl radical via Fenton reaction mediated by endogenous metals. The malondialdehyde HPLC analysis showed no lipid peroxidation after the addition of hydrogen peroxide, whereas the Fenton reagent caused significant lipid peroxidation...
2015: PloS One
Kristin Zschörnig, Jürgen Schiller
Oxidized (phospho)lipids are of paramount interest from different reasons: beside their significant in vivo relevance, these products are often needed in the laboratory to study the response of selected cells to oxidized lipids. Unfortunately, the commercial availability of oxidized lipids is limited and scientists interested in studying the physiological impact of oxidized lipids are normally forced to prepare the required compounds by themselves. We will show here that chain-shortened products of oxidized phosphatidylcholines (PCs) such as aldehydes and carboxylic acids can be easily (and in nearly quantitative yields) generated by the Fenton reaction (H2O2+Fe(2+)) or the KMnO4-induced oxidation of the PC...
December 2014: Chemistry and Physics of Lipids
G Lagori, J P Rocca, N Brulat, E Merigo, P Vescovi, C Fornaini
The purpose of this study was to perform a preliminary in vitro test on the possible use of two different laser wavelengths, 405 and 532 nm, to improve the dental bleaching results. To perform the test, the degradation of a dye, rhodamine B, under the effects of hydrogen peroxide was used. One hundred and twenty vials were divided into four groups of 30 samples each and, while three of them were irradiated with different wavelengths, 365 nm (reference), 405 nm and 532 nm, the fourth was the non-irradiated control group...
April 2015: Lasers in Medical Science
Urmi Bandyopadhyay, Wayne A Fenton, Arthur L Horwich, Maria Nagy
Preparation of high-quality RNA from cells of interest is critical to precise and meaningful analysis of transcriptional differences among cell types or between the same cell type in health and disease or following pharmacologic treatments. In the spinal cord, such preparation from motor neurons, the target of interest in many neurologic and neurodegenerative diseases, is complicated by the fact that motor neurons represent <10% of the total cell population. Laser capture microdissection (LMD) has been developed to address this problem...
2014: Journal of Visualized Experiments: JoVE
M R Wasielewski, J M Fenton, Govindjee
Photosystem I particles containing 30-40 chlorophyll a molecules per primary electron donor P700 were subjected to 1.5 ps low density laser flashes at 610 nm resulting in excitation of the antenna chlorophyll a molecules followed by energy transfer to P700 and subsequent oxidation of P700. Absorbance changes were monitored as a function of time with 1.5 ps time resolution. P700 bleaching (decrease in absorbance) occurred within the time resolution of the experiment. This is attributed to the formation of (1)P700...
January 1987: Photosynthesis Research
Magdalena Górska-Czekaj, Wojciech Borucki
Heavy metal stress affects both, nodulation and nitrogen fixation of legumes. Mercury triggers disturbances in cellular structure and metabolism but its influence on ROS generation is poorly understood. Copper is redox active metal which in opposition to mercury is an essential micronutrient for plants. Excess of copper is cytotoxic, as it participates in ROS generation via Fenton-type reaction. The present work describes changes in hydrogen peroxide (H₂O₂) accumulation in response to monthly stress caused by mercury (6 mg/L HgCl₂) or copper (60 mg/L CuCl₂) in root nodules...
September 2013: Micron: the International Research and Review Journal for Microscopy
Christian Langelueddecke, Eleni Roussa, Robert A Fenton, Frank Thévenod
The lipocalin 2//NGAL/24p3 receptor (NGAL-R/24p3-R) is expressed in rodent distal nephron where it mediates protein endocytosis. The mechanisms of apical endocytosis and transcytosis of proteins and peptides in the intestine are poorly understood. In the present study, the expression and localization of rodent 24p3-R (r24p3-R) and human NGAL-R (hNGAL-R) was investigated in intestinal segments by immunofluorescence and confocal laser scanning microscopy, immunohistochemistry and immunoblotting. r24p3-R/hNGAL-R was also studied in human Caco-2 BBE cells and CHO cells transiently transfected with r24p3-R by immunofluorescence microscopy, RT-PCR and immunoblotting of plasma membrane enriched vesicles (PM)...
2013: PloS One
Eric B Monroe, Michael L Heien
The use of hydroxyl radicals to covalently label the solvent-exposed surface of proteins has been shown to be a powerful tool to examine the structure of proteins and intermolecular interfaces. Current methods to generate hydroxyl radicals for footprinting experiments rely on the laser photolysis of H2O2 or the synchrotron radiolysis of water, which adds significant costs and/or complexity to the experiments. In this work, we develop the electro-Fenton reaction as a means to generate hydroxyl radicals for structural footprinting mass spectrometry experiments to complement current laser and synchrotron-based methods, while reducing the costs and complexity of initiating such experiments...
July 2, 2013: Analytical Chemistry
Matthias Lechner, Garrett M Frampton, Tim Fenton, Andrew Feber, Gary Palmer, Amrita Jay, Nischalan Pillay, Martin Forster, Maureen T Cronin, Doron Lipson, Vincent A Miller, Timothy A Brennan, Stephen Henderson, Francis Vaz, Paul O'Flynn, Nicholas Kalavrezos, Roman Yelensky, Stephan Beck, Philip J Stephens, Chris Boshoff
BACKGROUND: Human papillomavirus positive (HPV+) head and neck squamous cell carcinoma (HNSCC) is an emerging disease, representing a distinct clinical and epidemiological entity. Understanding the genetic basis of this specific subtype of cancer could allow therapeutic targeting of affected pathways for a stratified medicine approach. METHODS: Twenty HPV+ and 20 HPV- laser-capture microdissected oropharyngeal carcinomas were used for paired-end sequencing of hybrid-captured DNA, targeting 3,230 exons in 182 genes often mutated in cancer...
2013: Genome Medicine
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