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https://www.readbyqxmd.com/read/28641175/atmospheric-dust-deposition-on-soils-around-an-abandoned-fluorite-mine-hammam-zriba-ne-tunisia
#1
Chaima Djebbi, Fredj Chaabani, Oriol Font, Ignasi Queralt, Xavier Querol
The present study focuses on the eolian dispersion and dust deposition, of major and trace elements in soils in a semi-arid climate, around an old fluorite (CaF2) and barite (BaSO4) mine, located in Hammam Zriba in Northern Tunisia. Ore deposits from this site contain a high amount of metal sulphides constituting heavy metal pollution in the surrounding environment. Samples of waste from the surface of mine tailings and agricultural topsoil samples in the vicinity of the mine were collected. The soil samples and a control sample from unpolluted area, were taken in the direction of prevailing northwest and west winds...
June 19, 2017: Environmental Research
https://www.readbyqxmd.com/read/28636820/experimental-and-theoretical-study-of-ionic-pair-dissociation-in-lithium-ion-linear-polyethyleneimine-polyacrylonitrile-blend-for-solid-polymer-electrolytes
#2
Fernando Pignanelli, Mariano Romero, Ricardo Faccio, Álvaro W Mombrú
Herein, we report the preparation and characterization of novel polymeric blend between linear polyethylene imine (PEI) and polyacrylonitrile (PAN), with the purpose to facilitate the dissociation of lithium perchlorate salt (LiClO4) and thus to enhance Li-ion transport. It is a joint theoretical and experimental procedure for evaluating and thus demonstrating, the lithium salt dissociation. The procedure implies the correlation between theoretical pair distribution function (PDF) and conventional X-rays diffraction (XRD) by means of molecular dynamics (MD) approach...
June 21, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28636705/inflammation-in-the-neurocircuitry-of-obsessive-compulsive-disorder
#3
Sophia Attwells, Elaine Setiawan, Alan A Wilson, Pablo M Rusjan, Romina Mizrahi, Laura Miler, Cynthia Xu, Margaret Anne Richter, Alan Kahn, Stephen J Kish, Sylvain Houle, Lakshmi Ravindran, Jeffrey H Meyer
Importance: For a small percentage of obsessive-compulsive disorder (OCD) cases exhibiting additional neuropsychiatric symptoms, it was proposed that neuroinflammation occurs in the basal ganglia as an autoimmune response to infections. However, it is possible that elevated neuroinflammation, inducible by a diverse range of mechanisms, is important throughout the cortico-striato-thalamo-cortical circuit of OCD. Identifying brain inflammation is possible with the recent advance in positron emission tomography (PET) radioligands that bind to the translocator protein (TSPO)...
June 21, 2017: JAMA Psychiatry
https://www.readbyqxmd.com/read/28636380/a-free-radical-promoted-copper-catalyzed-decarboxylative-alkylation-of-%C3%AE-%C3%AE-unsaturated-carboxylic-acids-with-ich2cf3-and-its-analogues
#4
Yan Zhu, Juwen Gong, Yonghui Wang
A novel and efficient free radical promoted copper-catalyzed decarboxylative alkylation of α,β-unsaturated carboxylic acids with ICH2CF3 and its analogues has been developed. This methodology provides with a convenient access to the synthesis of allylic trifluoromethyl and β-CF3 ketone containing compounds as well as other biologically useful fluorinated molecules and materials.
June 21, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28636362/corey-chaykovsky-reactions-of-nitro-styrenes-enable-cis-configured-trifluoromethyl-cyclopropanes
#5
Katharina J Hock, Renè Hommelsheim, Lucas Mertens, Junming Ho, Thanh Vinh Nguyen, Rene M Koenigs
Trifluoromethyl-substituted cyclopropanes are an attractive family of building blocks for the construction of pharmaceutical and agrochemical agents. This work demonstrated the utilization of fluorinated sulfur ylides as versatile reagents for Corey-Chaykovsky cyclopropanation reactions of nitro styrenes. This protocol favored the synthesis of cis-configured trifluoromethyl cyclopropanes on a broad range of substrates with excellent yields and good diastereoselectivity.
June 21, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28636233/green-synthesis-of-small-nanoparticles-of-a2sif6-a-li-cs-using-ionic-liquids-as-solvent-and-fluorine-source-a-novel-simple-approach-without-hf
#6
Jacob Olchowka, Markus Suta, Claudia Wickleder
In this communication, nanoparticles of the fluoridosilicates A2SiF6 (A= Li, Na, K, Rb, Cs), which are extremely promising host lattices for future LEDs, are presented for the first time. The preparation method we introduces here is a very simple and energy and time saving one, moreover the usage of toxic HF or elemental fluorine is avoided. In detail, the ionic liquid [Bmim]PF6 was used both as solvent and fluoride source in an ionothermally assisted microwave synthesis. The small size of the so obtained nanoparticles is of huge relevance for their applications as thin films or coverage of surfaces for, e...
June 21, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28634058/apoptotic-gene-expression-profiles-and-dna-damage-levels-in-rat-liver-treated-with-perfluorooctane-sulfonate-and-protective-role-of-curcumin
#7
Dilek Eke, Ayla Çelik, Bertan Yilmaz, Nurcan Aras, Sabriye Kocatürk Sel, Davut Alptekin
Perfluorinated compounds (PFCs) such as PFOS and PFOA, are xenobiotics that can be detected worldwide in the environment and humans. PFOS (C8F17SO3(-)) is a fluorinated organic compound has been used for decades in industrial and commercial products. We investigated the genotoxic and apoptotic impact of PFOS in rat liver using comet assay, micronucleus test and apoptotic gene expression methods for caspase 3, caspase 8 and the protective role of curcumin on the PFOS- induced damage under chronic exposure. In this study, rats were treated either with three different PFOS doses only (0...
June 17, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28632273/a-model-for-c-f-activation-by-electrophilic-phosphonium-cations
#8
Ian Mallov, Timothy C Johnstone, Darcy C Burns, Douglas W Stephan
The synthesis of the electrophilic phosphonium cation (EPC) salt [C10H6(CF3)PF(C6F5)2][B(C6F5)4] 4 was achieved via oxidation of phosphine [C10H6(CF3)P(C6F5)2] 2 with XeF2 to form phosphorane [C10H6(CF3)PF2(C6F5)2] 3 and subsequent fluoride ion abstraction. Structural and spectroscopic characterization of 4 provides evidence of an interaction between the CF3 functionality and the phosphonium centre. AIM and NBO analyses also support donation from a lone pair on a fluorine atom of the CF3 group to the P-F σ* orbital of the fluorophosphonium unit, consistent with previously proposed mechanisms for main group C-F bond activations...
June 20, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28631468/pyrene-tagged-ionic-liquids-separable-organic-catalysts-for-sn2-fluorination
#9
Abu Taher, Kyo Chul Lee, Hye Ji Han, Dong Wook Kim
We prepared pyrene-substituted imidazolium-based ionic liquids (PILs) as organic catalysts for the SN2 fluorination using alkali metal fluoride (MF). In this system, the PIL significantly enhanced the reactivity of MF due to the phase-transfer catalytic effect of the imidazolium moiety as well as the metal cation-π (pyrene) interactions. Furthermore, this homogeneous catalyst PIL was easily separated from the reaction mixture using reduced graphene oxide by π-π stacking with the pyrene of PIL.
June 20, 2017: Organic Letters
https://www.readbyqxmd.com/read/28631080/comparison-of-volumetric-and-functional-parameters-in-simultaneous-cardiac-pet-mr-feasibility-of-volumetric-assessment-with-residual-activity-from-prior-pet-ct
#10
C Lücke, B Oppolzer, P Werner, B Foldyna, P Lurz, T Jochimsen, B Brenneis, L Lehmkuhl, B Sattler, M Grothoff, H Barthel, O Sabri, M Gutberlet
OBJECTIVE: To compare cardiac left ventricular (LV) parameters in simultaneously acquired hybrid fluorine-18-fluorodeoxyglucose ([18F] FDG) positron emission tomography/magnetic resonance imaging (PET/MRI) in patients with residual tracer activity of upstream PET/CT. METHODS: Twenty-nine patients (23 men, age 58±17 years) underwent cardiac PET/MRI either directly after a non-cardiac PET/CT with homogenous cardiac [18F] FDG uptake (n=20) or for viability assessment (n=9)...
June 19, 2017: European Radiology
https://www.readbyqxmd.com/read/28628301/the-effect-of-fluorine-substitution-on-the-molecular-interactions-and-performance-in-polymer-solar-cells
#11
In-Bok Kim, Soo-Young Jang, Yeong-A Kim, Rira Kang, In-Sik Kim, Do-Kyeong Ko, Dong-Yu Kim
Fluorine (F) substitution on conjugated polymers in polymer solar cells (PSCs) has a diverse effect on molecular properties and device performance. We present a series of three D-A type conjugated polymers (PBT, PFBT and PDFBT) based on dithienothiophene and benzothiadiazole units with different numbers of F atoms to explain the influence of F substitution by comparing the molecular interac-tions of the polymers and the recombination kinetics in PSCs. The pre-aggregation behavior of PFBT and PDFBT in o-DCB at the UV-Vis absorption spectra proves that both polymers have strong intermolecular interactions...
June 19, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28627530/ionic-liquids-containing-tricyanomethanide-anions-physicochemical-characterisation-and-performance-as-electrochemical-double-layer-capacitor-electrolytes
#12
Vitor L Martins, Anthony J R Rennie, Roberto M Torresi, Peter J Hall
We investigated the use of fluorine free ionic liquids (ILs) containing the tricyanomethanide anion ([C(CN)3]) as an electrolyte in electrochemical double-layer capacitors (EDLCs). Three cations were used; 1-butyl-3-methylimidazolium ([Im1,4]), N-butyl-N-methylpyrrolidinium ([Pyr1,4]) and N-butyl-N-methylpiperidinium ([Pip1,4]). Their physicochemical properties are discussed alongside with their performance as electrolytes. We found that the cyano-based ILs present higher ionic conductivity (9.4, 8.7 and 4...
June 19, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28625080/in-vivo-pet-imaging-of-the-activated-immune-environment-in-a-small-animal-model-of-inflammatory-arthritis
#13
Benjamin L Franc, Sam Goth, John MacKenzie, Xiaojuan Li, Joseph Blecha, Tina Lam, Salma Jivan, Randall A Hawkins, Henry VanBrocklin
BACKGROUND: Evolving immune-mediated therapeutic strategies for rheumatoid arthritis (RA) may benefit from an improved understanding of the complex role that T-cell activation plays in RA. This study assessed the potential of fluorine-18-labeled 9-β-d-arabinofuranosylguanine ([(18)F]F-AraG) positron emission tomography (PET) imaging to report immune activation in vivo in an adjuvant-induced arthritis (AIA) small animal model. METHODS: Using positron emission tomography-computed tomography imaging, uptake of [(18)F]F-AraG in the paws of mice affected by arthritis at 6 (acute) and 20 (chronic) days following AIA induction in a single paw was assessed and compared to uptake in contralateral control paws...
January 1, 2017: Molecular Imaging
https://www.readbyqxmd.com/read/28624195/fluorinated-nucleotide-modifications-modulate-allele-selectivity-of-snp-targeting-antisense-oligonucleotides
#14
Michael E Østergaard, Josh Nichols, Timothy A Dwight, Walt Lima, Michael E Jung, Eric E Swayze, Punit P Seth
Antisense oligonucleotides (ASOs) have the potential to discriminate between subtle RNA mismatches such as SNPs. Certain mismatches, however, allow ASOs to bind at physiological conditions and result in RNA cleavage mediated by RNase H. We showed that replacing DNA nucleotides in the gap region of an ASO with other chemical modification can improve allele selectivity. Herein, we systematically substitute every position in the gap region of an ASO targeting huntingtin gene (HTT) with fluorinated nucleotides...
June 16, 2017: Molecular Therapy. Nucleic Acids
https://www.readbyqxmd.com/read/28620761/medicinal-chemistry-of-%C3%AF-1-receptor-ligands-pharmacophore-models-synthesis-structure-affinity-relationships-and-pharmacological-applications
#15
Frauke Weber, Bernhard Wünsch
In the first part of this chapter, we summarize the various pharmacophore models for σ1 receptor ligands. Common to all of them is a basic amine flanked by two hydrophobic regions, representing the pharmacophoric elements. The development of computer-based models like the 3D homology model is described as well as the first crystal structure of the σ1 receptor. The second part focuses on the synthesis and biological properties of different σ1 receptor ligands, identified as 1-9. Monocyclic piperazines 1 and bicyclic piperazines 2 and 3 were developed as cytotoxic compounds, thus the IC50 values of cell growth and survival inhibition studies are given for all derivatives...
June 16, 2017: Handbook of Experimental Pharmacology
https://www.readbyqxmd.com/read/28619538/synthesis-and-biological-evaluation-of-2-3-4-dimethoxyphenyl-6-2-18-f-fluoroethoxy-benzothiazole-18-f-fedbt-for-pet-imaging-of-breast-cancer
#16
Geng-Ying Li, Daria D Vaulina, Jia-Je Li, Olga S Fedorova, Hsin-Ell Wang, Ren-Shyan Liu, Raisa N Krasikova, Chuan-Lin Chen
Given the ever-present demand for improved PET radiotracer in oncology imaging, we have synthesized 2-(3,4-dimethoxyphenyl)-6-(2-[(18)F]fluoroethoxy)benzothiazole ([(18)F]FEDBT), a fluorine-18-containing fluoroethylated benzothiazole to explore its utility as a PET imaging tracer. [(18)F]FEDBT was prepared via kryptofix-mediated nucleophilic substitution of the tosyl group precursor. Fractionated ethanol-based solid-phase (SPE cartridge-based) purification afforded [(18)F]FEDBT in 60% radiochemical yield (EOB), with radiochemical purity in excess of 98% and the specific activity was 35GBq/μmol...
May 26, 2017: Bioorganic & Medicinal Chemistry Letters
https://www.readbyqxmd.com/read/28618171/highly-fluorinated-polymers-with-sulfonate-sulfamide-and-n-n-diethylamino-groups-for-the-capillary-electromigration-separation-of-proteins-and-steroid-hormones
#17
Dzema Daria, Kartsova Liudmila, Emelianov Gennady
Highly fluorinated polymers are promising materials in separation methods due to combination of high chemical and thermally stability, hydro- and oleophobicity and weak intermolecular forces. However, application of these polymers in chromatography is limited because of their low solubility in aqueous-organic solvents. In our research, the highly fluorinated water soluble polymers with -SO3(-) N(Et)4(+) , -SO2 NH2 and -N(Et)2 terminal groups were synthesized and applied as additives to the background electrolyte for the separation of steroid hormones and proteins by capillary electromigration methods...
June 15, 2017: Journal of Separation Science
https://www.readbyqxmd.com/read/28617672/comparison-of-pd-electron-beam-induced-deposition-using-two-precursors-and-an-oxygen-purification-strategy
#18
Catalina Mansilla, Yannick Zondag, Hans Mulders, Piet Trompenaars
Focused electron beam induced deposition (FEBID) allows the creation of nanoscale structures through dissociation of an organo-metallic precursor by electrons at the beam impact point. The deposition of Pd can be interesting for its catalytic behavior and ability to contact carbon based materials. Two precursors were investigated - Pd(hfac)<sub>2</sub> and (Cp)Pd(allyl) - and two deposition methods: with and without an in-situ oxygen purification process. The deposition parameters can be tuned for the Pd(hfac)<sub>2</sub> precursor to provide a deposition with 23±2 at...
June 15, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28614945/selective-and-fast-adsorption-of-perfluorooctane-sulfonate-from-wastewater-by-magnetic-fluorinated-vermiculite
#19
Ziwen Du, Shubo Deng, Siyu Zhang, Wei Wang, Bin Wang, Jun Huang, Yujue Wang, Gang Yu, Baoshan Xing
A novel magnetic fluorinated adsorbent with selective and fast adsorption of perfluorooctane sulfonate (PFOS) was synthesized via a simple ball milling of Fe3O4 and vermiculite loaded with a cationic fluorinated surfactant. The loaded Fe3O4 nanoparticles increased the dispersibility of fluorinated vermiculite (F-VT) in water and allowed the magnetic separability. The nano-sized Fe3O4 was homogeneously embedded into the adsorbent surfaces, improving the hydrophilicity of F-VT external surface, and this hybrid adsorbent still kept the hydrophobic fluorinated interlayer structure...
June 15, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28614009/the-combined-use-of-calcitonin-doubling-time-and-18-f-fdg-pet-ct-improves-prognostic-values-in-medullary-thyroid-carcinoma-the-clinical-utility-of-18-f-fdg-pet-ct
#20
Ji H Yang, Cléber P Camacho, Susan C Lindsey, Flavia O F Valente, Danielle M Andreoni, Lilian Y Yamaga, Jairo Wagner, Rosa Paula M Biscolla, Rui M B Maciel
OBJECTIVE: Calcitonin and carcinoembryonic antigen (CEA) doubling times are established prognostic markers in medullary thyroid cancer (MTC). On the other hand, positron emission tomography with fluorine-18 fluorodeoxyglucose ((18)F-FDG PET/CT) shows an increased rate of detection with high blood tumor marker levels in several cancers. This study aims to analyze the ability of (18)F-FDG PET/CT to determine prognosis in the followup of patients with MTC. METHODS: Medical records of 17 patients with MTC who underwent (18)F-FDG PET/CT were analyzed retrospectively...
June 14, 2017: Endocrine Practice
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