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https://www.readbyqxmd.com/read/28340462/assessment-of-arsenic-and-fluorine-in-surface-soil-to-determine-environmental-and-health-risk-factors-in-the-comarca-lagunera-mexico
#1
Yareli A Sariñana-Ruiz, Jorge Vazquez-Arenas, Fabiola S Sosa-Rodríguez, Israel Labastida, Ma Aurora Armienta, Antonio Aragón-Piña, Miguel A Escobedo-Bretado, Laura S González-Valdez, Patricia Ponce-Peña, Hugo Ramírez-Aldaba, René H Lara
Total, bioaccessible and mobile concentrations of arsenic and fluorine are determined in polluted surface soil within the Comarca Lagunera region using standardized protocols to obtain a full description of the environmental behavior for these elements. The composition of mineral phases associated with them is evaluated with microscopic and spectroscopic techniques. Mineralogical characterizations indicate that ultra-fine particles (<1-5 μm) including mimetite-vanadite (Pb5(AsO4)3Cl, Pb5(AsO4, VO4)3Cl)-like, lead arseniate (Pb3(AsO4)2)-like and complex arsenic-bearing compounds are main arsenic-bearing phases, while fluorite (CaF2) is the only fluorine-bearing phase...
March 10, 2017: Chemosphere
https://www.readbyqxmd.com/read/28340419/photolytic-degradation-of-the-%C3%AE-blocker-nebivolol-in-aqueous-solution
#2
Alaa Salma, Holger V Lutze, Torsten C Schmidt, Jochen Tuerk
Nebivolol (NEB) is one of the top-sold prescription drugs belonging to the third generation of beta-blockers. However, so far, occurrence data in the environment are lacking. Within this study NEB has been found for the first time in effluent samples of wastewater treatment plants in Germany with an average concentration of 13 ng L(-1). Its photodegradation behavior in the environment and in technical processes is largely unknown. To fill this gap, three different UV treatment procedures (UV-C at 254 nm, UV-B at 312 nm and UV-A at 365 nm) were investigated in three different matrices: pure water, pure water in presence of the hydroxyl radical (OH) scavenger tert...
March 13, 2017: Water Research
https://www.readbyqxmd.com/read/28339189/polymerization-induced-self-assembly-pisa-control-over-the-morphology-of-19f-containing-polymeric-nano-objects-for-cell-uptake-and-tracking
#3
Wei Zhao, Hang Thu Ta, Cheng Zhang, Andrew Keith Whittaker
Fluorine-containing polymeric materials are receiving increasing attention as imaging probes in fluorine-19 magnetic resonance imaging (19F MRI), for example to enable quantitative in vivo detection of cells. Here we describe the one-pot polymerization synthesis of 19F-containing functional poly(OEGA-co-TFEA)-b-poly(St-co-VBA) copolymers as a new class of fluorinated MRI agent. A range of nanoparticle morphologies, including spheres, worm-like particles and vesicles were formed as a consequence of polymerization-induced self-assembly (PISA)...
March 24, 2017: Biomacromolecules
https://www.readbyqxmd.com/read/28335208/the-influence-of-fluorination-on-nano-scale-phase-separation-and-photovoltaic-performance-of-small-molecular-pc71bm-blends
#4
Zhen Lu, Wen Liu, Jingjing Li, Tao Fang, Wanning Li, Jicheng Zhang, Feng Feng, Wenhua Li
To investigate the fluorination influence on the photovoltaic performance of small molecular based organic solar cells (OSCs), six small molecules based on 2,1,3-benzothiadiazole (BT), and diketopyrrolopyrrole (DPP) as core and fluorinated phenyl (DFP) and triphenyl amine (TPA) as different terminal units (DFP-BT-DFP, DFP-BT-TPA, TPA-BT-TPA, DFP-DPP-DFP, DFP-DPP-TPA, and TPA-DPP-TPA) were synthesized. With one or two fluorinated phenyl as the end group(s), HOMO level of BT and DPP based small molecular donors were gradually decreased, inducing high open circuit voltage for fluorinated phenyl based OSCs...
April 21, 2016: Nanomaterials
https://www.readbyqxmd.com/read/28335199/highly-efficient-plasmon-enhanced-dye-sensitized-solar-cells-created-by-means-of-dry-plasma-reduction
#5
Van-Duong Dao, Ho-Suk Choi
Plasmon-assisted energy conversion is investigated in a comparative study of dye-sensitized solar cells (DSCs) equipped with photo-anodes, which are fabricated by forming gold (Au) and silver (Ag) nanoparticles (NPs) on an fluorine-doped tin oxide (FTO) glass surface by means of dry plasma reduction (DPR) and coating TiO₂ paste onto the modified FTO glass through a screen printing method. As a result, the FTO/Ag-NPs/TiO₂ photo-anode showed an enhancement of its photocurrent, whereas the FTO/Au-NPs/TiO₂ photo-anode showed less photocurrent than even a standard photo-anode fabricated by simply coating TiO₂ paste onto the modified FTO glass through screen printing...
April 14, 2016: Nanomaterials
https://www.readbyqxmd.com/read/28334530/morphology-and-doping-engineering-of-sn-doped-hematite-nanowire-photoanodes
#6
Mingyang Li, Yi Yang, Yichuan Ling, Weitao Qiu, Fuxin Wang, Tianyu Liu, Yu Song, Xiao-Xia Liu, Ping-Ping Fang, Yexiang Tong, Yat Li
High temperature activation has been commonly used to boost the photoelectrochemical (PEC) performance of hematite nanowires for water oxidation, by inducing Sn diffusion from fluorine-doped tin oxide (FTO) substrate into hematite. Yet, hematite nanowires thermally annealed at high temperature suffer from two major drawbacks that negatively affect their performance. First, the structural deformation reduces light absorption capability of nanowire. Second, this "passive" doping method leads to non-uniform distribution of Sn dopant in nanowire and limits the Sn doping concentration...
March 23, 2017: Nano Letters
https://www.readbyqxmd.com/read/28333846/prognostic-value-of-fluorine-18-fluorodeoxyglucose-uptake-of-bone-marrow-on-positron-emission-tomography-computed-tomography-for-prediction-of-disease-progression-in-cervical-cancer
#7
Jeong Won Lee, Seob Jeon, Seong Taek Mun, Sang Mi Lee
OBJECTIVE: This study aimed to evaluate the prognostic value of fluorine-18 fluorodeoxyglucose (FDG) uptake of bone marrow (BM) on positron emission tomography (PET)/computed tomography in patients with uterine cervical cancer. METHODS: One hundred forty-five patients with cervical cancer who underwent staging FDG PET/computed tomography and subsequent surgical resection or chemoradiotherapy were retrospectively enrolled in the study. Mean BM FDG uptake (BM standardized uptake value [SUV]) and BM-to-liver uptake ratio of FDG uptake (BLR) were measured...
March 23, 2017: International Journal of Gynecological Cancer
https://www.readbyqxmd.com/read/28332836/direct-approach-to-n-substituted-2-fluoroindoles-by-sequential-construction-of-c-n-bonds-from-gem-difluorostyrenes
#8
Bin Zhang, Xiaofei Zhang, Jian Hao, Chunhao Yang
A mild and efficient synthesis of N-substituted-2-fluoroindole derivatives was achieved via Buchwald-Hartwig couplings and a sequential, base-promoted intramolecular nucleophilic reaction-β-fluorine elimination. By employing easily obtained gem-difluorostyrenes and primary arylamines, the scope, advantages, and limitations of this reaction were well investigated. Furthermore, this strategy distinguishes itself by high modularity, operational simplicity, and a wide substrate scope, giving rise to a broad array of 2-fluoroindole derivatives in moderate to excellent yields...
March 23, 2017: Organic Letters
https://www.readbyqxmd.com/read/28332816/fluorinated-and-thermo-crosslinked-polyhedral-oligomeric-silsesquioxanes-new-organic-inorganic-hybrid-materials-for-high-performance-dielectric-application
#9
Jiajia Wang, Jing Sun, Junfeng Zhou, Kaikai Jin, Qiang Fang
A fluorinated and thermo-crosslinked polyhedral oligomeric silsesquioxane (POSS) has been successfully synthesized by thermal polymerization of a fluorinated POSS monomer having an inorganic silsesquioxane core and organic side chains bearing thermo-crosslinkable trifluorovinyl ether groups. This new inorganic-organic hybrid polymer shows high thermostability with a 5 wt% loss temperature of 436 C, as well as good transparency (a sheet with an average thickness of 1.5 mm shows high transmittance of 92% varying from 400 to 1,100 nm)...
March 23, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28332450/nuclear-medicine-in-patients-with-net-radiolabeled-somatostatin-analogues-and-their-brothers
#10
Vincenzo Cuccurullo, Maria Rosaria Prisco, Giuseppe Danilo Di Stasio, Luigi Mansi
Although Somastostatin (SS) scintigraphy (SRS) has been introduced many years ago, it remains the most diffuse radionuclide diagnostic tool in patients with neuroendocrine tumours (NETs). Being SS receptors (SSTR) expressed in the majority of NETs, radiolabeled SS analogues (SS-A) provide high diagnostic accuracy, mainly in patients with gastro-entero-pancreatic (GEP) tumors. SSTR are the best target for radiotracers used either for diagnostic and therapeutic purposes in NETs due to their presence on the surface of neoplastic cells of clinical interest...
March 23, 2017: Current Radiopharmaceuticals
https://www.readbyqxmd.com/read/28332403/time-resolved-spectroscopic-study-of-the-defluorination-and-cyclization-reactions-of-lomefloxacin-in-water
#11
Tao Su, Ming-De Li, Jiani Ma, David Lee Phillips
The mechanism of the defluorination reaction(s) of lomefloxacin (LF) upon light illumination was investigated by using ultrafast laser flash photolysis combined with transient resonance Raman spectroscopy in near neutral water solution. The zwitterionic configuration of LF was determined to be the main species present in the near neutral water solution and was the species that was photoexcited to initiate the photochemical reaction. Femtosecond transient absorption revealed that the first excited singlet state (S1) of LF did not appreciably undergo intersystem crossing (ISC) and instead partially decayed to the ground state via fluorescence emission and partially underwent the cleavage of the carbon-fluorine bond at position 8 to produce a singlet LF aryl cation intermediate...
March 23, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28332244/a-fluorine-18-radiolabelling-method-enabled-by-rhenium-i-complexation-circumvents-the-requirement-of-anhydrous-conditions
#12
Mitchell Ashley Klenner, Giancarlo Pascali, Bo Zhang, Tiffany Russel Sia, Lawson Kyle Spare, Anwen M Krause-Heuer, Janice Aldrich-Wright, Ivan Greguric, Adam Guastella, Massimiliano Massi, Benjamin Hugh Fraser
Azeotropic distillation is typically required to achieve fluorine-18 radiolabelling during the production of positron emission tomography (PET) imaging agents. However, this time consuming process also limits fluorine-18 incorporation, due to radioactive decay of the isotope and its adsorption to the drying vessel. In addressing these limitations, we herein report the fluorine-18 radiolabelling of one model rhenium(I) complex, which is significantly improved under conditions that do not require azeotropic drying...
March 22, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28331174/development-of-customized-18-f-fluoride-elution-techniques-for-the-enhancement-of-copper-mediated-late-stage-radiofluorination
#13
Andrew V Mossine, Allen F Brooks, Naoko Ichiishi, Katarina J Makaravage, Melanie S Sanford, Peter J H Scott
In a relatively short period of time, transition metal-mediated radiofluorination reactions have changed the PET radiochemistry landscape. These reactions have enabled the radiofluorination of a wide range of substrates, facilitating access to radiopharmaceuticals that were challenging to synthesize using traditional fluorine-18 radiochemistry. However, the process of adapting these new reactions for automated radiopharmaceutical production has revealed limitations in fitting them into the confines of traditional radiochemistry systems...
March 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28329162/the-value-of-fluorine-18-deoxyglucose-positron-emission-tomography-scans-in-patients-with-ventricular-assist-device-specific-infections%C3%A2
#14
Alexander M Bernhardt, Mustafa A Pamirsad, Chantal Brand, Daniel Reichart, Milena Tienken, Markus J Barten, Andreas Schaefer, Hanno Grahn, Meike Rybczynski, Tobias Deuse, Hermann Reichenspurner, Florian M Wagner
BACKGROUND: Infections are major complications in patients with ventricular assist devices (VAD). Positron emission tomography with deoxyglucose marked by fluorine-18 ( 18 F-FDG PET/CT) is a diagnostic tool to scan for tissue with high metabolism as present in infections. The specificity of 18 F-FDG PET/CT to discriminate between infection and an aseptic reaction of the implanted device is not defined and its evaluation is the aim of this retrospective analysis. METHODS: Until September 2015 a total of 100 patients underwent VAD implantations in our institution...
February 20, 2017: European Journal of Cardio-thoracic Surgery
https://www.readbyqxmd.com/read/28328026/alternative-mass-reference-standards-for-direct-analysis-in-real-time-mass-spectrometry
#15
Robert B Cody, A John Dane
RATIONALE: Mass spectra were acquired with the Direct Analysis in Real Time (DART®) ion source for an amine-terminated polyether used as positive-ion mass reference standards and for several fluorinated materials commonly used as negative-ion reference standards for mass spectrometry. METHODS: A commercial time-of-flight mass spectrometer equipped with a DART ion source was used for all measurements. Mass reference standards deposited onto the sealed end of a glass melting point tube were suspended in the DART gas stream for analysis...
May 30, 2016: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28326754/supporting-imaging-modalities-for-improving-diagnosis-of-prosthesis-endocarditis-preliminary-results-of-a-single-center-experience-with-fluorine-18-fluorodeoxyglucose-positron-emission-tomography-computed-tomography
#16
Anna Kokalova, Angelo M Dell'AQUILA, Nemanja Avramovic, Sven Martens, Christian Wenning, Jürgen R Sindermann
AIM: The aim of current study was to evaluate the role of PET-CT in the diagnosis of prosthetic valve endocarditis (PVE). METHODS: This is a single-center study including 13 PET/CT examinations performed between February 2009 and March 2016 in 13 patients (76.9% men, mean age 68.1 years, IQR 11.1) because of suspect of PVE. Median interval time between first operation and PET/CT examination was 19.02 months (lQR 85.5). Final diagnosis was made according to pathological criteria (histological and microbiological) of the Duke classification...
March 21, 2017: Minerva Medica
https://www.readbyqxmd.com/read/28324644/synthesis-of-the-t-705-ribonucleoside-and-ribonucleotide-and-studies-on-the-chemical-stability
#17
Johanna Huchting, Matthias Winkler, Hiba Nasser, Chris Meier
T-705 (favipiravir) is a fluorinated hydroxypyrazine carboxamide that exhibits antiviral activities against a variety of RNA viruses. Due to the lack of potent agents to combat these infections caused by a large number of these high-impacting pathogens, huge emphasis has been put on the studies of T-705's antiviral properties and its mechanism of action. T-705 acts as a nucleobase analogue; hence, it is metabolized to the corresponding ribonucleoside triphosphate intracellularly. We herein report a reliable synthesis of T-705-ribonucleoside and its 5'-monophosphate...
March 21, 2017: ChemMedChem
https://www.readbyqxmd.com/read/28323424/toward-a-comprehensive-global-emission-inventory-of-c4-c10-perfluoroalkane-sulfonic-acids-pfsas-and-related-precursors-focus-on-the-life-cycle-of-c8-based-products-and-ongoing-industrial-transition
#18
Zhanyun Wang, Justin M Boucher, Martin Scheringer, Ian T Cousins, Konrad Hungerbuehler
Here a new global emission inventory of C4-C10 perfluoroalkanesulfonic acids (PFSAs) from the life cycle of perfluorooctanesulfonyl fluoride (POSF)-based products in 1958-2030 is presented. In particular, we substantially improve and expand the previous frameworks by incorporating missing pieces (e.g., emissions to soil through land treatment, overlooked precursors) and updating parameters (e.g., emission factors, degradation half-lives). In 1958-2015, total direct and indirect emissions of perfluorooctanesulfonic acid (PFOS) are estimated as 1228-4930 tonnes, and emissions of PFOS precursors are estimated as 1230-8738 and approximately 670 tonnes for x-perfluorooctanesulfonamides/sulfonamido ethanols (xFOSA/Es) and POSF, respectively...
March 21, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28322560/subphthalocyanines-axially-substituted-with-a-tetracyanobuta-1-3-diene-aniline-moiety-synthesis-structure-and-physicochemical-properties
#19
Kim A Winterfeld, Giulia Lavarda, Julia Guilleme, Michael Sekita, Dirk M Guldi, Tomas Torres, Giovanni Bottari
A 1,1,4,4-tetracyanobuta-1,3-diene (TCBD)-aniline moiety has been introduced, for the first time, at the axial position of two subphthalocyanines (SubPcs) peripherally substituted with hydrogen (H12SubPc) or fluorine atoms (F12SubPc). Single-crystal X-ray analysis of both SubPc-TCBD-aniline systems showed that each conjugate is a racemic mixture of two atropisomers resulting from the almost orthogonal geometry adopted by the axial TCBD unit, which were separated by chiral HPLC. Remarkably, the single-crystal X-ray structure of one atropisomer of each SubPc-TCBD-aniline conjugate has been solved allowing to unambiguously assign the atropisomers' absolute configuration, something, to the best of our knowledge, unprecedented in TCBD-based conjugates...
March 21, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28322043/-sup-18-sup-f-fluoro-hydroxyphenethylguanidines-efficient-synthesis-and-comparison-of-two-structural-isomers-as-radiotracers-of-cardiac-sympathetic-innervation
#20
Yong-Woon Jung, Keun Sam Jang, Guie Gu, Robert A Koeppe, Phillip S Sherman, Carole A Quesada, David M Raffel
Fluorine-18 labeled phenethylguanidines are currently under development in our laboratory as radiotracers for quantifying regional cardiac sympathetic nerve density using PET imaging techniques. In this study, we report an efficient synthesis of <sup>18</sup>F-hydroxyphenethylguanidines consisting of nucleophilic aromatic [<sup>18</sup>F]fluorination of a protected diaryliodonium salt precursor followed by a single deprotection step to afford the desired radiolabeled compound. This approach has been shown to reliably produce 4-[<sup>18</sup>F]fluoro-<i>m</I>-hydroxyphenethylguanidine ([<sup>18</sup>F]4F-MHPG, [<sup>18</sup>F]<b>1</b>) and its structural isomer 3-[<sup>18</sup>F]fluoro-<i>p</i>-hydroxyphenethylguanidine ([<sup>18</sup>F]3F-PHPG, [<sup>18</sup>F]<b>2</b>) with good radiochemical yields...
March 21, 2017: ACS Chemical Neuroscience
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