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https://www.readbyqxmd.com/read/27929465/using-multi-fluorinated-bile-acids-and-in-vivo-magnetic-resonance-imaging-to-measure-bile-acid-transport
#1
Jessica Felton, Kunrong Cheng, Anan Said, Aaron C Shang, Su Xu, Diana Vivian, Melissa Metry, James E Polli, Jean-Pierre Raufman
Along with their traditional role as detergents that facilitate fat absorption, emerging literature indicates that bile acids are potent signaling molecules that affect multiple organs; they modulate gut motility and hormone production, and alter vascular tone, glucose metabolism, lipid metabolism, and energy utilization. Changes in fecal bile acids may alter the gut microbiome and promote colon pathology including cholerrheic diarrhea and colon cancer. Key regulators of fecal bile acid composition are the small intestinal Apical Sodium-dependent Bile Acid Transporter (ASBT) and fibroblast growth factor-19 (FGF19)...
November 27, 2016: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/27928893/outsmarted-by-nooptropics-an-investigation-into-the-thermal-degradation-of-modafinil-modafinic-acid-adrafinil-crl-40-940-and-crl-40-941-in-the-gc-injector-formation-of-1-1-2-2-tetraphenylethane-and-its-tetra-fluoro-analog
#2
Geraldine Dowling, Pierce V Kavanagh, Brian Talbot, John O'Brien, Gary Hessman, Gavin McLaughlin, Brendan Twamley, Simon D Brandt
2-[(Diphenylmethyl)sulfinyl]acetamide (modafinil) is commonly prescribed for the treatment of narcolepsy and increasing popularity and off-label use as a cognitive enhancer resulted in a reputation as an intelligence boosting 'wonder drug'. Common alternatives available from online shops and other retail outlets include 2-[(diphenylmethyl)sulfinyl]-N-hydroxyacetamide (adrafinil), 2-{[bis(4-fluorophenyl)methyl]sulfinyl}acetamide (CRL-40,940), 2-{[bis(4-fluorophenyl)methyl]sulfinyl}-N-hydroxyacetamide (CRL-40,941) and N-methyl-4,4-difluoro-modafinil (modafiendz), respectively...
December 8, 2016: Drug Testing and Analysis
https://www.readbyqxmd.com/read/27928466/metabolic-positron-emission-tomography-imaging-of-cancer-pairing-lipid-metabolism-with-glycolysis
#3
EDITORIAL
Sandi A Kwee, John Lim
The limitations of fluorine-18 fluorodeoxy-D-glucose (FDG) in detecting some cancers has prompted a longstanding search for other positron emission tomography (PET) tracers to complement the imaging of glycolysis in oncology, with much attention paid to lipogenesis based on observations that the production of various lipid and lipid-containing compounds is increased in most cancers. Radiolabeled analogs of choline and acetate have now been used as oncologic PET probes for over a decade, showing convincingly improved detection sensitivity over FDG for certain cancers...
November 28, 2016: World Journal of Radiology
https://www.readbyqxmd.com/read/27926846/alamethicin-supramolecular-organization-in-lipid-membranes-from-19-f-solid-state-nmr
#4
Evgeniy S Salnikov, Jesus Raya, Marta De Zotti, Ekaterina Zaitseva, Cristina Peggion, Gema Ballano, Claudio Toniolo, Jan Raap, Burkhard Bechinger
Alamethicins (ALMs) are antimicrobial peptides of fungal origin. Their sequences are rich in hydrophobic amino acids and strongly interact with lipid membranes, where they cause a well-defined increase in conductivity. Therefore, the peptides are thought to form transmembrane helical bundles in which the more hydrophilic residues line a water-filled pore. Whereas the peptide has been well characterized in terms of secondary structure, membrane topology, and interactions, much fewer data are available regarding the quaternary arrangement of the helices within lipid bilayers...
December 6, 2016: Biophysical Journal
https://www.readbyqxmd.com/read/27926844/intracellular-requirements-for-passive-proton-transport-through-the-na-k-atpase
#5
Kevin S Stanley, Dylan J Meyer, Craig Gatto, Pablo Artigas
The Na(+),K(+)-ATPase (NKA or Na/K pump) hydrolyzes one ATP to exchange three intracellular Na+ (Na(+)i) for two extracellular K+ (K(+)o) across the plasma membrane by cycling through a set of reversible transitions between phosphorylated and dephosphorylated conformations, alternately opening ion-binding sites externally (E2) or internally (E1). With subsaturating [Na(+)]o and [K(+)]o, the phosphorylated E2P conformation passively imports protons generating an inward current (IH), which may be exacerbated in NKA-subunit mutations associated with human disease...
December 6, 2016: Biophysical Journal
https://www.readbyqxmd.com/read/27926665/clinicopathological-analysis-and-risk-factors-of-advanced-colorectal-neoplasms-incidentally-detected-by-18f-fdg-pet-ct
#6
Seung Min Chung, Kyeong Ok Kim, Ihn Ho Cho, Tae Nyeun Kim
BACKGROUND: As the clinical use of fluorine-18-fluorodeoxyglucose PET-computed tomography (F-FDG PET-CT) has increased, the incidental finding of F-FDG uptake with subsequent diagnosis of advanced neoplasm at colorectum has increased. The aim of this study is to analyze the characteristics and risk factors of advanced colorectal neoplasm incidentally detected by F-FDG PET-CT. PATIENTS AND METHODS: Patients who underwent colonoscopy because of an incidental finding of F-FDG uptake at the colorectum from January 2006 to January 2015 at Yeungnam University Hospital were reviewed retrospectively...
December 6, 2016: European Journal of Gastroenterology & Hepatology
https://www.readbyqxmd.com/read/27924330/access-to-functionalized-thienopyridines-via-a-reagent-capsule-assisted-coupling-thiolation-and-cyclization-cascade-sequence
#7
Jialing Cai, Shuo Huang, Ruenfa He, Lu Chen, Donghan Chen, Shaohua Jiang, Bin Li, Yibiao Li
Thienopyridines and related heterocycles were prepared in a straightforward manner in moderate to good yields and under mild conditions by palladium-catalysed cross-coupling of ortho-fluorinated iodopyridines and terminal alkynes, followed by a reagent-capsule-assisted thiolation cyclization process. By applying paraffin wax capsules to prevent catalyst poisoning and undesired side reactions, the separation and purification processes were reduced.
December 7, 2016: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/27922086/photoelectrochemical-detection-of-alpha-fetoprotein-based-on-zno-inverse-opals-structure-electrodes-modified-by-ag2s-nanoparticles
#8
Yandong Jiang, Dali Liu, Yudan Yang, Ru Xu, Tianxiang Zhang, Kuang Sheng, Hongwei Song
In this work, a new photoelectrochemical biosensor based on Ag2S nanoparticles (NPs) modified macroporous ZnO inverse opals structure (IOs) was developed for sensitive and rapid detection of alpha fetal protein (AFP). Small size and uniformly dispersed Ag2S NPs were prepared using the Successive Ionic Layer Adsorption And Reaction (SILAR) method, which were adsorbed on ZnO IOs surface and frame work as matrix for immobilization of AFP. The composite structure of ZnO/Ag2S expanded the scope of light absorption to long wavelength, which can make full use of the light energy...
December 6, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27921286/-18-f-fdg-pet-ct-to-differentiate-malignant-necrotic-lymph-node-from-benign-cystic-lesions-in-the-neck
#9
Peymaneh Abadi, Allan Johansen, Christian Godballe, Oke Gerke, Poul Flemming Høilund-Carlsen, Anders Thomassen
OBJECTIVE: Patients presenting with cystic lesions in the neck without obvious signs of malignancy constitute a diagnostic challenge since fine needle aspiration is often insufficient and a diagnosis may not be reached until surgical resection/biopsy is performed. The differential diagnosis of a cystic cervical mass comprises a variety of benign conditions, but malignancy must be ruled out. We examined the diagnostic performance of fluorine-18 fluorodeoxyglucose ((18)F-FDG) PET/CT to identify malignancy...
December 5, 2016: Annals of Nuclear Medicine
https://www.readbyqxmd.com/read/27918030/solvation-behavior-of-carbonate-based-electrolytes-in-sodium-ion-batteries
#10
Arthur V Cresce, Selena M Russell, Oleg Borodin, Joshua A Allen, Marshall A Schroeder, Michael Dai, Jing Peng, Mallory P Gobet, Steven G Greenbaum, Reginald E Rogers, Kang Xu
Sodium ion batteries are on the cusp of being a commercially available technology. Compared to lithium ion batteries, sodium ion batteries can potentially offer an attractive dollar-per-kilowatt-hour value, though at the penalty of reduced energy density. As a materials system, sodium ion batteries present a unique opportunity to apply lessons learned in the study of electrolytes for lithium ion batteries; specifically, the behavior of the sodium ion in an organic carbonate solution and the relationship of ion solvation with electrode surface passivation...
December 5, 2016: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/27917506/comparative-in-vitro-toxicity-assessment-of-perfluorinated-carboxylic-acids
#11
Cecon T Mahapatra, Nur P Damayanti, Samuel C Guffey, Jennifer S Serafin, Joseph Irudayaraj, Maria S Sepúlveda
Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are synthetic fluorinated compounds that are highly bioaccumulative and persistent organic pollutants. Perfluorooctanoic acid (PFOA), an eight-carbon chain perfluorinated carboxylic acid, was used heavily for the production of fluoropolymers, but concerns have led to its replacement by shorter carbon chain homologues such as perfluorohexanoic acid (PFHxA) and perfluorobutanoic acid (PFBA). However, limited toxicity data exist for these substitutes. We evaluated the toxicity of PFOA, PFHxA and PFBA on a zebrafish liver cell line and investigated the effects of exposure on cell metabolism...
December 5, 2016: Journal of Applied Toxicology: JAT
https://www.readbyqxmd.com/read/27917024/efficient-light-induced-phase-transitions-in-halogen-bonded-liquid-crystals
#12
Francisco Fernandez-Palacio, Mikko Poutanen, Marco Saccone, Antti Siiskonen, Giancarlo Terraneo, Giuseppe Resnati, Olli Ikkala, Pierangelo Metrangolo, Arri Priimagi
Here, we present a new family of light-responsive, fluorinated supramolecular liquid crystals (LCs) showing efficient and reversible light-induced LC-to-isotropic phase transitions. Our materials design is based on fluorinated azobenzenes, where the fluorination serves to strengthen the noncovalent interaction with bond-accepting stilbazole molecules, and increase the lifetime of the cis-form of the azobenzene units. The halogen-bonded LCs were characterized by means of X-ray diffraction, hot-stage polarized optical microscopy, and differential scanning calorimetry...
November 22, 2016: Chemistry of Materials: a Publication of the American Chemical Society
https://www.readbyqxmd.com/read/27916947/preparation-of-a-bis-gma-free-dental-resin-system-with-synthesized-fluorinated-dimethacrylate-monomers
#13
Shuzhen Luo, Wenbin Zhu, Fang Liu, Jingwei He
With the aim of reducing human exposure to Bisphenol A (BPA) derivatives in dentistry, a fluorinated dimethacrylate monomer was synthesized to replace 2,2-bis[4-(2-hydroxy-3-methacryloy-loxypropyl)-phenyl]propane (Bis-GMA) as the base monomer of dental resin. After mixing with reactive diluent triethyleneglycol dimethacrylate (TEGDMA), fluorinated dimethacrylate (FDMA)/TEGDMA was prepared and compared with Bis-GMA/TEGDMA in physicochemical properties, such as double bond conversion (DC), volumetric shrinkage (VS), water sorption (WS) and solubility (WSL), flexural strength (FS) and modulus (FM)...
December 1, 2016: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/27914299/the-effects-of-fluorine-substitution-on-the-chemical-properties-and-inhibitory-capacity-of-donepezil-anti-alzheimer-drug-density-functional-theory-and-molecular-docking-calculations
#14
Azita Khosravan, Safora Marani, Mohammad Sadegh Sadeghi Googheri
Drug fluorination has the potential to reproduce useful drugs with decreasing the side effect of them. Identifying the effect of this improvement on the chemical properties and biological interactions of drug symbolizes a meaningful progress in drug design. Here the fluorination of Donepezil as an anti-Alzheimer drug, including 7 fluorinated derivatives of it, was investigated computationally. In the first part of our calculations, the most important chemical properties of drug that affects the drug efficiency were investigated by applying the M06/6-31g (d, p) and M062X/6-31g (d, p) levels of theories...
November 25, 2016: Journal of Molecular Graphics & Modelling
https://www.readbyqxmd.com/read/27912115/self-assembled-hemispherical-nanowell-arrays-for-superhydrophobic-antireflection-coatings
#15
Cheng-Yen Lin, Kun-Yi Andrew Lin, Ting-Wei Yang, Ying-Chu Chen, Hongta Yang
The present study reports an inexpensive and simple bottom-up technology for fabricating superhydrophobic antireflection coatings with highly ordered hemispherical nanowell structures, which are assembled by a scalable Langmuir-Blodgett technology. The subwavelength gratings lead to a gradual change in the effective refractive index, substantially suppressing specular reflection over the entire visible wavelength range. After surface modification with fluorinated silane, the resulting nanowell arrays exhibit superhydrophobic surface with high static water contact angle (154°) and low water contact angle hysteresis (7°)...
November 21, 2016: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/27911800/an-%C3%AE-%C3%AE-hydrolase-fold-protein-in-the-biosynthesis-of-thiostrepton-exhibits-a-dual-activity-for-endopeptidyl-hydrolysis-and-epoxide-ring-opening-macrocyclization
#16
Qingfei Zheng, Shoufeng Wang, Panpan Duan, Rijing Liao, Dandan Chen, Wen Liu
Thiostrepton (TSR), an archetypal bimacrocyclic thiopeptide antibiotic that arises from complex posttranslational modifications of a genetically encoded precursor peptide, possesses a quinaldic acid (QA) moiety within the side-ring system of a thiopeptide-characteristic framework. Focusing on selective engineering of the QA moiety, i.e., by fluorination or methylation, we have recently designed and biosynthesized biologically more active TSR analogs. Using these analogs as chemical probes, we uncovered an unusual indirect mechanism of TSR-type thiopeptides, which are able to act against intracellular pathogens through host autophagy induction in addition to direct targeting of bacterial ribosome...
November 23, 2016: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/27911050/tuning-the-reactivity-of-graphene-by-surface-phase-orientation
#17
Jan Plsek, Petr Kovaricek, Vaclav Vales, Martin Kalbac
Tuning the local reactivity of graphene is a subject of paramount importance. Among the available strategies, the activation/passivation of graphene by copper substrate is very promising, because it enables to influence the properties of graphene without any transfer procedure as graphene can be grown directly on copper. Here, we demonstrate that the reactivity of graphene towards fluorination is strongly influenced by the face of the surface of the copper substrate. We probed graphene on the copper foil with identified grain orientations...
December 2, 2016: Chemistry: a European Journal
https://www.readbyqxmd.com/read/27911033/regioselective-synthesis-of-%C3%AE-fluorinated-cyclopentenones-via-organocatalytic-difluorocyclopropanation-and-fluorine-directed-and-activated-nazarov-cyclization
#18
Kohei Fuchibe, Ryo Takayama, Takaharu Yokoyama, Junji Ichikawa
Silyl dienol ethers, prepared from α,β-unsaturated ketones, underwent proton sponge-catalyzed difluorocyclopropanation with trimethylsilyl 2,2-difluoro-2-fluorosulfonylacetate (TFDA) in a regioselective manner, leading to 1,1-difluoro-2-siloxy-2-vinylcyclopropanes in good yields. The cyclopropanes thus obtained were in turn subjected to fluoride ion-catalyzed ring opening to afford 1-fluorovinyl vinyl ketones (i.e., Nazarov precursors). Treatment of the precursors with Me3Si+ B(OTf)4- regioselectively promoted the Nazarov cyclization, whose rate and regioselectivity were drastically enhanced by the fluorine substituent, thereby facilitating efficient synthesis of biologically promising α-fluorocyclopentenone derivatives...
December 2, 2016: Chemistry: a European Journal
https://www.readbyqxmd.com/read/27910833/cu-ii-and-zn-ii-%C3%AE-diketonate-coordination-polymers-based-on-pyrimidin-2-amine-pyrazine-and-1-2-bis-4-pyridyl-ethane
#19
Franc Perdih
Copper(II) and zinc(II) bis(4,4,4-trifluoro-1-phenylbutane-1,3-dionato) compounds with pyrimidin-2-amine (pyr2a), pyrazine (pyz) and 1,2-bis(4-pyridyl)ethane (dpet) were prepared and solid-state structures of coordination polymers [M(tfpb)2(pyr2a)]∞ [M = Cu (1), Zn (2); tfpb = 4,4,4-trifluoro-1-phenylbutane-1,3-dionate], [M(tfpb)2(pyz)]∞ [M = Cu (3), Zn (4a, 4b)] and [Cu(tfpb)2(dpet)]∞ (5), respectively, were determined by single-crystal X-ray analysis. The coordination of metal centers in all compounds is octahedral with nitrogen ligands occupying the axial positions...
December 1, 2016: Acta Crystallographica Section B, Structural Science, Crystal Engineering and Materials
https://www.readbyqxmd.com/read/27910419/design-and-fabrication-of-a-window-for-the-gas-cherenkov-detector-3
#20
V E Fatherley, D A Bingham, M D Cartelli, R A DiDomizio, J R Griego, H W Herrmann, F E Lopez, J A Oertel, M J Pollack
The gas Cherenkov detector 3 was designed at Los Alamos National Laboratory for use in inertial confinement fusion experiments at both the Omega Laser Facility and the National Ignition Facility. This instrument uses a low-Z gamma-to-electron convertor plate and high pressure gas to convert MeV gammas into UV/visible Cherenkov photons for fast optical detection. This is a follow-on diagnostic from previous versions, with two notable differences: the pressure of the gas is four times higher, and it allows the use of fluorinated gas, requiring metal seals...
November 2016: Review of Scientific Instruments
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