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https://www.readbyqxmd.com/read/28719746/structure-activity-study-of-ghrelin-1-8-resulting-in-high-affinity-fluorine-bearing-ligands-for-the-ghrelin-receptor
#1
Carlie L Charron, Jin-Qiang Hou, Mark S McFarland, Savita Dhanvantari, Michael S Kovacs, Leonard G Luyt
The ghrelin receptor, also known as the growth hormone secretagogue receptor 1a (GHS-R1a), is a G-protein coupled receptor that is differentially expressed in healthy tissue and several cancers, including prostate, testicular, and ovarian. Selectively targeting the ghrelin receptor using fluorine-18 tagged entities would allow localization and visualization of ghrelin receptor expressing carcinomas using PET imaging. The endogenous ligand ghrelin, a 28 amino acid peptide with 3.1 nM affinity, has poor in vivo stability...
July 18, 2017: Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28719195/fluorinated-boronic-acid-appended-pyridinium-salts-and-19f-nmr-spectroscopy-for-diol-sensing
#2
Jörg Axthelm, Sven H C Askes, Martin Elstner, Upendar Reddy Gandra, Helmar Görls, Peter Bellstedt, Alexander Schiller
The identification and discrimination of diols is of fundamental importance in medical diagnostics, such as measuring the contents of glucose in the urine of diabetes patients. Diol sensors are often based on fluorophore-appended boronic acids, but these severely lack discrimination power and their response is one-dimensional. As an alternative strategy, we present the use of fluorinated boronic acid-appended pyridinium salts in combination with 19F NMR spectroscopy. A pool of 59 (bio)analytes was screened, containing monosaccharides, phosphorylated and N-acetylated sugars, polyols, carboxylic acids, nucleotides and amines...
July 18, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28718469/characterization-of-the-thermal-thermal-oxidative-stability-of-fluorinated-graphene-with-various-structures
#3
Wenchuan Lai, Dazhou Xu, Xu Wang, Zaoming Wang, Yang Liu, Xiaojiao Zhang, Xiangyang Liu
Considering practical applications, the thermal/thermal oxidative stability of fluorinated graphene should be given sufficient attention. Herein, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FT-IR) were used to investigate in detail the differences in the thermal stabilities of two types of fluorinated samples, fluorinated graphene (FG) and fluorinated porous graphene (FPG) with various fluorine contents, respectively, as well as the reasons for these differences...
July 18, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28718282/metal-free-three-component-regioselective-aminofluorination-of-styrene-derivatives
#4
Qiao Zhang, Guangfan Zheng, Qian Zhang, Yan Li, Qian Zhang
The first metal-free, three-component radical aminofluorination of styrene derivatives, Selectfluor and triazole derivatives has been developed. This reaction proceeds with high regioselectivity, providing various 1,2-aminofluorination compounds under mild conditions. Mechanistic studies suggest that the aminofluorination process might involve radical fluorination followed by nucleophilic amination.
July 18, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28716641/synthesis-and-evaluation-of-osimertinib-derivatives-as-potent-egfr-inhibitors
#5
Hongying Gao, Zimo Yang, Xinglin Yang, Yu Rao
Osimertinib has been identified as a promising therapeutic drug targeting for EGFR T790M mutant non-small cell lung cancer (NSCLC). A new series of N-oxidized and fluorinated osimertinib derivatives were designed and synthesized. The cellular anti-proliferative activity, kinase inhibitory activity and the activation of EGFR signaling pathways of 1-6 in vitro were determined against L858R/T790M and wild-type EGFR, the antitumor efficacy in NCI-H1975 xenografts in vivo were further studied. Compound 2, the newly synthesized N-oxide metabolite in N,N,N'-trimethylethylenediamine side chain of osimertinib, showed a comparable kinase selectivity in vitro and a slightly better antitumor efficacy in vivo to osimertinib, making it valuable and suitable for the potential lung cancer therapy...
July 8, 2017: Bioorganic & Medicinal Chemistry
https://www.readbyqxmd.com/read/28715453/effects-of-glucose-insulin-and-insulin-resistance-on-cerebral-18f-fdg-distribution-in-cognitively-normal-older-subjects
#6
Kenji Ishibashi, Airin Onishi, Yoshinori Fujiwara, Kiichi Ishiwata, Kenji Ishii
BACKGROUND: Increasing plasma glucose levels and insulin resistance can alter the distribution pattern of fluorine-18-labeled fluorodeoxyglucose (18F-FDG) in the brain and relatively reduce 18F-FDG uptake in Alzheimer's disease (AD)-related hypometabolic regions, leading to the appearance of an AD-like pattern. However, its relationship with plasma insulin levels is unclear. We aimed to compare the effects of plasma glucose levels, plasma insulin levels and insulin resistance on the appearance of the AD-like pattern in 18F-FDG images...
2017: PloS One
https://www.readbyqxmd.com/read/28715369/electrospinning-of-photocatalytic-electrodes-for-dye-sensitized-solar-cells
#7
Nicolò Canever, Fraser Hughson, Thomas J Macdonald, Thomas Nann
This work demonstrates a protocol to fabricate a fiber-based photoanode for dye-sensitized solar cells, consisting of a light-scattering layer made of electrospun titanium dioxide nanofibers (TiO2-NFs) on top of a blocking layer made of commercially available titanium dioxide nanoparticles (TiO2-NPs). This is achieved by first electrospinning a solution of titanium (IV) butoxide, polyvinylpyrrolidone (PVP), and glacial acetic acid in ethanol to obtain composite PVP/TiO2 nanofibers. These are then calcined at 500 °C to remove the PVP and to obtain pure anatase-phase titania nanofibers...
June 28, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/28714902/fluorescence-modulation-of-green-fluorescent-protein-using-fluorinated-unnatural-amino-acids
#8
Jordan K Villa, Hong-Anh Tran, Megha Vipani, Stephanie Gianturco, Konark Bhasin, Brent L Russell, Elizabeth J Harbron, Douglas D Young
The ability to modulate protein function through minimal perturbations to amino acid structure represents an ideal mechanism to engineer optimized proteins. Due to the novel spectroscopic properties of green fluorescent protein, it has found widespread application as a reporter protein throughout the fields of biology and chemistry. Using site-specific amino acid mutagenesis, we have incorporated various fluorotyrosine residues directly into the fluorophore of the protein, altering the fluorescence and shifting the pKa of the phenolic proton associated with the fluorophore...
July 16, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28713230/in-vivo-micro-ct-imaging-of-human-mesenchymal-stem-cells-labeled-with-gold-poly-l-lysine-nanocomplexes
#9
Taeho Kim, Nohyun Lee, Dian R Arifin, Irina Shats, Miroslaw Janowski, Piotr Walczak, Taeghwan Hyeon, Jeff W M Bulte
Developing in vivo cell tracking is an important prerequisite for further development of cell-based therapy. So far, few computed tomography (CT) cell tracking studies have been described due to its notoriously low sensitivity and lack of efficient labeling protocols. We present a simple method to render human mesenchymal stem cells (hMSCs) sufficiently radiopaque by complexing 40 nm citrate-stabilized gold nanoparticles (AuNPs) with poly-L-lysine (PLL) and rhodamine B isothiocyanate (RITC). AuNP-PLL-RITC labeling did not affect cellular viability, proliferation, or downstream cell differentiation into adipocytes and osteocytes...
January 19, 2017: Advanced Functional Materials
https://www.readbyqxmd.com/read/28712295/closing-the-mass-balance-on-fluorine-on-papers-and-textiles
#10
Alix Elizabeth Robel, Kristin Amy Marshall, Margaret Dickinson, David Lunderberg, Craig Butt, Graham F Peaslee, Heather M Stapleton, Jennifer A Field
Papers and textiles that treated with per- and polyfluoroalkyl substances (PFASs) are sources of human and environmental exposure. Data for individual PFASs, such as perfluorooctane sulfonate (PFOS) and perfluroooctanoate (PFOA), are not placed into the context of total fluorine for papers and textiles. Gas chromatography mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) were used to quantify volatile and ionic PFASs, respectively, and the total oxidizable precursor (TOP) assay was used to quantify precursors that form perfluoroalkyl carboxylates...
July 15, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28710238/is-fch-pet-able-to-identify-foci-of-infection-superiorly-to-fdg-pet
#11
Liesel Elisabeth Hardy, Hannah Hessamodini, Michael Wallace, Roslyn Francis
We report a case of a brain abscess identified on fluorine-18 choline (FCH) positron emission tomography (PET) scan, which was not identified on fluorodeoxyglucose (FDG) PET scan. To our knowledge, there are no previous case reports of incidental brain abscess identified by FCH PET imaging. A 51-year-old man, with liver cirrhosis complicated by hepatocellular carcinoma (HCC) was enrolled in a research trial comparing HCC detection in FCH PET versus FDG PET. During the course of the trial, he underwent radiofrequency ablation (RFA) for HCC...
July 14, 2017: BMJ Case Reports
https://www.readbyqxmd.com/read/28709257/monte-carlo-study-of-the-ordering-in-a-strongly-frustrated-liquid-crystal
#12
S George, C Bentham, X Zeng, G Ungar, G A Gehring
We have performed Monte Carlo simulations to investigate the temperature dependence of the ordering of the side chains of the X-shaped liquid crystal molecules which are arranged in a hexagonal array. Each hexagon contains six side chains, one from each side of the hexagon. Each liquid crystal molecule has two, dissimilar, side chains, one that contains silicon and one that contains fluorine. Like chains attract each other more strongly than unlike chains and this drives an order-disorder transition. The system is frustrated because it is not possible to find a configuration in which all the hexagons are occupied by either all silicon or all fluorine chains...
June 2017: Physical Review. E
https://www.readbyqxmd.com/read/28708334/palladium-catalyzed-suzuki-miyaura-cross-coupling-of-secondary-%C3%AE-trifluoromethyl-benzyl-tosylates
#13
Marta Brambilla, Matthew Tredwell
A palladium catalyzed C(sp3)-C(sp2) Suzuki-Miyaura cross-coupling of aryl boronic acids and α-(trifluoromethyl)benzyl tosylates is reported. The reaction uses a readily available, air-stable palladium catalyst to access a wide range of functionalized 1,1-diaryl-2,2,2-trifluoroethanes. Enantioenriched α-(trifluoromethyl)benzyl tosylates were found to undergo cross-coupling to give the corresponding enantioenriched cross-coupled products with an overall inversion in configuration. The crucial role of the CF3 group in promoting this transformation is demonstrated by comparison with non-fluorinated derivatives...
July 14, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28708079/comparison-of-erosion-behavior-and-particle-contamination-in-mass-production-cf%C3%A2-o%C3%A2-plasma-chambers-using-y%C3%A2-o%C3%A2-and-yf%C3%A2-protective-coatings
#14
Tzu-Ken Lin, Wei-Kai Wang, Shih-Yung Huang, Chi-Tsung Tasi, Dong-Sing Wuu
Yttrium fluoride (YF₃) and yttrium oxide (Y₂O₃) protective coatings prepared using an atmospheric plasma spraying technique were used to investigate the relationship between surface erosion behaviors and their nanoparticle generation under high-density plasma (10(12)-10(13) cm(-3)) etching. As examined by transmission electron microscopy, the Y₂O₃ and YF₃ coatings become oxyfluorinated after exposure to the plasma, wherein the yttrium oxyfluoride film formation was observed on the surface with a thickness of 5...
July 14, 2017: Nanomaterials
https://www.readbyqxmd.com/read/28707963/in-vivo-assessment-of-ovarian-tumor-response-to-tyrosine-kinase-inhibitor-pazopanib-by-using-hyperpolarized-13-c-pyruvate-mr-spectroscopy-and-18-f-fdg-pet-ct-imaging-in-a-mouse-model
#15
Murali K Ravoori, Sheela P Singh, Jaehyuk Lee, James A Bankson, Vikas Kundra
Purpose To assess in a mouse model whether early or late components of glucose metabolism, exemplified by fluorine 18 ((18)F) fluorodeoxyglucose (FDG) positron emission tomography (PET) and hyperpolarized carbon 13 ((13)C)-pyruvate magnetic resonance (MR) spectroscopy, can serve as indicators of response in ovarian cancer to multityrosine kinase inhibitor pazopanib. Materials and Methods In this Animal Care and Use Committee approved study, 17 days after the injection of 2 × 10(6) human ovarian SKOV3 tumors cells into 14 female nude mice, treatment with vehicle or pazopanib (2...
July 13, 2017: Radiology
https://www.readbyqxmd.com/read/28704677/hydrated-electron-based-decomposition-of-perfluorooctane-sulfonate-pfos-in-the-vuv-sulfite-system
#16
Yurong Gu, Tongzhou Liu, Hongjie Wang, Huili Han, Wenyi Dong
As one of the most reactive species, hydrated electron (eaq(-)) is promising for reductive decomposition of recalcitrant organic pollutants, such as perfluorooctane sulfonate (PFOS). In this study, PFOS decomposition using a vacuum ultraviolet (VUV)/sulfite system was systematically investigated in comparison with sole VUV and ultraviolet (UV)/sulfite systems. A fast and nearly complete (97.3%) PFOS decomposition was observed within 4h from its initial concentration of 37.2μM in the VUV/sulfite system. The observed rate constant (kobs) for PFOS decomposition in the studied system was 0...
July 10, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28704339/quantitative-analysis-of-normal-and-pathologic-adrenal-glands-with-18f-fdopa-pet-ct-focus-on-pheochromocytomas
#17
Aurélie Moreau, Anne L Giraudet, David Kryza, Françoise Borson-Chazot, Claire Bournaud, Thomas Mognetti, Jean-Christophe Lifante, Patrick Combemale, Francesco Giammarile, Claire Houzard
INTRODUCTION: Many studies have reported the high performance of 6-fluorine-18-fluorodihydroxyphenilalanine (F-FDOPA) PET/CT in the diagnosis of pheochromocytomas but nobody seems to have investigated physiological and pathological adrenal glands from a quantitative point of view. The purpose of the present study was to assess the quantitative F-FDOPA uptake of normal and pathologic adrenal glands and to establish thresholds to characterize pheochromocytomas. We were especially interested in characterizing the remaining adrenal glands captation after an adrenalectomy...
July 12, 2017: Nuclear Medicine Communications
https://www.readbyqxmd.com/read/28702999/correction-to-fluorinated-and-charged-hydrogenated-alkanethiolates-grafted-on-gold-expanding-the-diversity-of-mixed-monolayer-nanoparticles-for-biological-applications
#18
Silvia Bidoggia, Francesca Milocco, Stefano Polizzi, Patrizia Canton, Alessandra Saccani, Barbara Sanavio, Silke Krol, Francesco Stellacci, Paolo Pengo, Lucia Pasquato
No abstract text is available yet for this article.
July 13, 2017: Bioconjugate Chemistry
https://www.readbyqxmd.com/read/28702639/insights-into-the-electron-donating-and-withdrawing-effect-of-the-functional-groups-on-mechanochemical-dehydrochlorination-reactions
#19
Fang Guo, Zhen Wang, Jin-Jing Zhang, Antonino Famulari, Hai-Tao Li, Javier Martí-Rujas
The effect of the withdrawing ability of -CF3 groups in a large and flexible bidentate ligand has been evaluated by monitoring the course of solid-state dehydrochlorination reactions. We demonstrate that the coordination bond formation does not occur by mechanochemical means from a second coordination sphere adduct. Quantum mechanical calculations have shown that frontier molecular orbital energy and net charges at N centers can justify the less reactive nature of the partially fluorinated ligand, corroborating the experimental results...
July 12, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28702622/mechanism-of-ion-transport-in-perfluoropolyether-electrolytes-with-a-lithium-salt
#20
Ksenia Timachova, Mahati Chintapalli, Kevin R Olson, Sue J Mecham, Joseph M DeSimone, Nitash P Balsara
Perfluoropolyethers (PFPEs) are polymer electrolytes with fluorinated carbon backbones that have high flash points and have been shown to exhibit moderate conductivities and high cation transference numbers when mixed with lithium salts. Ion transport in four PFPE electrolytes with different endgroups was characterized by differential scanning calorimetry (DSC), ac impedance, and pulsed-field gradient NMR (PFG-NMR) as a function of salt concentration and temperature. In spite of the chemical similarity of the electrolytes, salt diffusion coefficients measured by PFG-NMR and the glass transition temperature measured by DSC appear to be uncorrelated to ionic conductivity measured by ac impedance...
July 12, 2017: Soft Matter
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