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https://www.readbyqxmd.com/read/29236176/na18f-accumulates-on-the-compressive-side-of-peri-implant-bone-under-immediate-loading
#1
Miou Yamamoto, Toru Ogawa, Masayoshi Yokoyama, Yoshihito Funaki, Kenta Shobara, Aya Shibamoto, Juan Ramón Vanegas Sáenz, Keiichi Sasaki
This study aimed to examine the dynamic change in bone metabolism by immediate loading in several sites around implants using high-resolution Na18F-PET scan. Two titanium implants (Ø 1.2 mm) were inserted parallel to each other in the right tibiae of Wistar rats (n = 4). The left tibia was set as control side. One day after insertion, closed coil springs of 4.0 N were attached to the expose superior portions of the implants to apply a continuous mechanical stress. The rats with fluorine-18 (18F) ion (5 mCi/rat) intravenously injected were scanned by PET scanner at 4, 7, 14, 28 days after load application...
December 13, 2017: Odontology
https://www.readbyqxmd.com/read/29235212/high-performance-as-cast-nonfullerene-polymer-solar-cells-with-thicker-active-layer-and-large-area-exceeding-11-power-conversion-efficiency
#2
Qunping Fan, Yan Wang, Maojie Zhang, Bo Wu, Xia Guo, Yufeng Jiang, Wanbin Li, Bing Guo, Chennan Ye, Wenyan Su, Jin Fang, Xuemei Ou, Feng Liu, Zhixiang Wei, Tze Chien Sum, Thomas P Russell, Yongfang Li
In this work, a nonfullerene polymer solar cell (PSC) based on a wide bandgap polymer donor PM6 containing fluorinated thienyl benzodithiophene (BDT-2F) unit and a narrow bandgap small molecule acceptor 2,2'-((2Z,2'Z)-((4,4,9,9-tetrahexyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b']dithiophene-2,7-diyl)bis(methanylylidene))bis(3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile (IDIC) is developed. In addition to matched energy levels and complementary absorption spectrum with IDIC, PM6 possesses high crystallinity and strong π-π stacking alignment, which are favorable to charge carrier transport and hence suppress recombination in devices...
December 13, 2017: Advanced Materials
https://www.readbyqxmd.com/read/29235203/selective-c-h-halogenations-with-a-highly-fluorinated-manganese-porphyrin
#3
Gang Li, Andrew Dilger, Peter Cheng, William Ewing, John T Groves
Selective C-H functionalizations of aliphatic molecules remain a challenge in organic synthesis. While radical chain halogenations provide an efficient way to access many halogenated molecules, application of typical protocols to selectively halogenate electron-deficient and strained aliphatic molecules are rare. Herein, we report selective C-H chlorinations and fluorinations that use an electron-deficient manganese pentafluorophenyl porphyrin catalyst, Mn(TPFPP)Cl. This catalyst displays superior properties for aliphatic halogenations of recalcitrant, electron-deficient and strained substrates with unique regio- and stereoselectivity...
December 12, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/29234471/hydrolysis-polarity-and-conformational-impact-of-c-terminal-partially-fluorinated-ethyl-esters-in-peptide-models
#4
Vladimir Kubyshkin, Nediljko Budisa
Fluorinated moieties are highly valuable to chemists due to the sensitive NMR detectability of the 19F nucleus. Fluorination of molecular scaffolds can also selectively influence a molecule's polarity, conformational preferences and chemical reactivity, properties that can be exploited for various chemical applications. A powerful route for incorporating fluorine atoms in biomolecules is last-stage fluorination of peptide scaffolds. One of these methods involves esterification of the C-terminus of peptides using a diazomethane species...
2017: Beilstein Journal of Organic Chemistry
https://www.readbyqxmd.com/read/29234454/pulmonary-injury-associated-with-spray-of-a-water-based-nano-sized-waterproofing-product-a-case-study
#5
Paul T J Scheepers, Lucie Masen-Poos, Frits G B G J van Rooy, Arné Oerlemans, Eline van Daalen, Robbert Cremers, Hera Lichtenbeld, Bonne Biesma, Jorid B Sørli, Ismo K Koponen, Søren Thor Larsen, Peder Wolkoff, Asger W Nørgaard
Background: In most reported cases of lung trauma with water proofing products, volatile organic compounds (VOC) have a prominent role. Here we report on a case involving ten workers exposed to a sprayed product containing nanoparticles in a water solution with only a few percent VOC. Case presentation: Ten workers suffered from respiratory symptoms following spray impregnation of hardwood furniture using a waterproofing product that contained positively charged fluorinated acrylate copolymer solid cores with a median diameter of 70 nm (1...
2017: Journal of Occupational Medicine and Toxicology
https://www.readbyqxmd.com/read/29234239/polymorphism-and-modulation-of-para-substituted-l-phenylalanine
#6
Leyla-Cann Sögütoglu, Martin Lutz, Hugo Meekes, René de Gelder, Elias Vlieg
The crystal structure of para-methyl-l-phenylalanine at 230 K resembles that of the para-fluorinated analogue from the literature but is commensurately modulated with seven molecules in the asymmetric unit (Z' = 7). At 100 K, the superstructure loses its modulation, leading to a unit cell with Z' = 1, with clear disorder in the phenyl ring orientations. The methyl-substituent in para-methyl-l-phenylalanine has, in contrast to fluorine, no polar interactions with protons of neighboring molecules, which might allow for the well-defined modulation of the crystal structure at 230 K...
December 6, 2017: Crystal Growth & Design
https://www.readbyqxmd.com/read/29233265/use-of-carbon-11-labelled-tool-compounds-in-support-of-drug-development
#7
REVIEW
Giulia Boscutti, Mickael Huiban, Jan Passchier
The pharmaceutical industry is facing key challenges to improve return on R&D investment. Positron emission tomography (PET), by itself or in combination with complementary technologies such as magnetic resonance imaging (MRI), provides a unique opportunity to confirm a candidate's ability to meet the so-called 'three pillars' of drug development. Positive confirmation provides confidence for go/no-go decision making at an early stage of the development process and enables informed clinical progression. Whereas fluorine-18 has probably gained wider use in the community, there are benefits to using carbon-11 given the greater flexibility the use of this isotope permits in adaptive clinical study design...
November 2017: Drug Discovery Today. Technologies
https://www.readbyqxmd.com/read/29233264/imaging-the-glutamate-receptor-subtypes-much-achieved-and-still-much-to-do
#8
REVIEW
Stefan Gruber, Simon M Ametamey
Functional imaging of glutamate receptors using PET imaging modality can be used to study numerous CNS disorders and also to select appropriate doses of clinically relevant glutamate-receptor-targeting candidate drugs. Great strides have been made in developing PET imaging probes for the non-invasive detection of glutamate receptors in the brain. This review highlights recent progress made towards the development of glutamatergic PET imaging agents. Focus is placed on PET imaging probes that have been labelled with either carbon-11 or fluorine-18...
November 2017: Drug Discovery Today. Technologies
https://www.readbyqxmd.com/read/29233263/discovery-of-pet-radiopharmaceuticals-at-the-academia-industry-interface
#9
REVIEW
Vadim Bernard-Gauthier, Thomas L Collier, Steven H Liang, Neil Vasdev
Project-specific collaborations between academia and pharmaceutical partners are a growing phenomenon within molecular imaging and in particular in the positron emission tomography (PET) radiopharmaceutical community. This cultural shift can be attributed in part to decreased public funding in academia in conjunction with the increased reliance on outsourcing of chemistry, radiochemistry, pharmacology and molecular imaging studies by the pharmaceutical industry. This account highlights some of our personal experiences working with industrial partners to develop new PET radiochemistry methodologies for drug discovery and neuro-PET research studies...
November 2017: Drug Discovery Today. Technologies
https://www.readbyqxmd.com/read/29233239/perfluorocarbon-in-delayed-recompression-with-a-mixed-gender-swine-model-of-decompression-sickness
#10
William A Cronin, Aaron A Hall, Charles R Auker, Richard T Mahon
INTRODUCTION: Perfluorocarbons (PFC) are fluorinated hydrocarbons that dissolve gases to a much greater degree than plasma and hold promise in treating decompression sickness (DCS). The efficacy of PFC in a mixed gender model of DCS and safety in recompression therapy has not been previously explored. METHODS: Swine (25 kg; N = 104; 51 male and 53 female) were randomized into normal saline solution (NSS) or PFC emulsion treatment groups and subjected to compression on air in a hyperbaric chamber at 200 fsw for 31 min...
January 1, 2018: Aerospace Medicine and Human Performance
https://www.readbyqxmd.com/read/29232496/force-induced-catastrophes-on-energy-landscapes-mechanochemical-manipulation-of-downhill-and-uphill-bifurcations-explains-ring-opening-selectivity-of-cyclopropanes
#11
Miriam Wollenhaupt, Christoph Schran, Martin Krupicka, Dominik Marx
The mechanochemistry of ring-opening reactions of cyclopropane derivatives turns out to be unexpectedly rich and puzzling. After showing that a rare socalled uphill bifurcation in the case of trans-gem-difluorocyclopropane turns into a downhill bifurcation upon substitution of fluorine by chlorine, bromine and iodine in the thermal activation limit, the dichloro derivative is studied systematically in the realm of mechanochemical activation. Detailed exploration of the force-transformed potential energy surface in terms of Dijkstra path analysis unveils a hitherto unknown topological catastrophe where the global shape of the energy landscape is fundamentally changed...
December 12, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
https://www.readbyqxmd.com/read/29232185/18f-fdg-pet-biomarkers-help-detect-early-metabolic-response-to-irreversible-electroporation-and-predict-therapeutic-outcomes-in-a-rat-liver-tumor-model
#12
Xifu Wang, Zhanliang Su, Tianchu Lyu, Matteo Figini, Daniel Procissi, Junjie Shangguan, Chong Sun, Bin Wang, Na Shang, Shanzhi Gu, Quanhong Ma, Andrew C Gordon, Kai Lin, Jian Wang, Robert J Lewandowski, Riad Salem, Vahid Yaghmai, Andrew C Larson, Zhuoli Zhang
Purpose To test the hypothesis that biomarkers of fluorine 18 (18F) fluorodeoxyglucose (FDG) positron emission tomography (PET) can be used for the early detection of therapeutic response to irreversible electroporation (IRE) of liver tumor in a rodent liver tumor model. Materials and Methods The institutional animal care and use committee approved this study. Rats were inoculated with McA-RH7777 liver tumor cells in the left median and left lateral lobes. Tumors were allowed to grow for 7 days to reach a size typically at least 5 mm in longest diameter, as verified with magnetic resonance (MR) imaging...
December 12, 2017: Radiology
https://www.readbyqxmd.com/read/29231247/biocatalysis-in-radiochemistry-enzymatic-incorporation-of-pet-radionuclides-into-molecules-of-biomedical-interest
#13
REVIEW
Eunice S da Silva, Vanessa Gómez-Vallejo, Fernando López-Gallego, Jordi Llop
Biocatalysis is emerging as a new approach to radiolabel biologically active molecules with short half-lived positron emitters for their use in positron emission tomography. Despite the golden era of biocatalysis in radiochemistry occurred in the 70´s and 80´s, advances in enzyme engineering during the last decade have significantly enhanced the toolbox of enzymes available for chemical reactions, which may find application in the context of radiochemistry. In the present review, we intend to give an overview of the biocatalytic approaches that have been reported during the last four decades for the synthesis of PET radiotracers using Nitrogen-13, Carbon-11 and Fluorine-18...
December 12, 2017: Journal of Labelled Compounds & Radiopharmaceuticals
https://www.readbyqxmd.com/read/29228071/associations-between-tau-%C3%AE-amyloid-and-cognition-in-parkinson-disease
#14
Joseph R Winer, Anne Maass, Peter Pressman, Jordan Stiver, Daniel R Schonhaut, Suzanne L Baker, Joel Kramer, Gil D Rabinovici, William J Jagust
Importance: Multiple disease processes are associated with cognitive impairment in Parkinson disease (PD), including Lewy bodies, cerebrovascular disease, and Alzheimer disease. It remains unknown whether tau pathology relates to cognition in patients with PD without dementia. Objective: To compare tau aggregation in patients with PD who are cognitively normal (PD-CN), patients with PD with mild cognitive impairment (PD-MCI), and healthy control participants, and evaluate the relationships between β-amyloid (Aβ), tau, and cognition in patients with PD who did not have dementia...
December 11, 2017: JAMA Neurology
https://www.readbyqxmd.com/read/29227348/quantitative-pet-ct-in-clinical-practice-assessing-the-agreement-of-pet-tumor-indices-using-different-clinical-reading-platforms
#15
Joyce C Mhlanga, Alin Chirindel, Martin A Lodge, Richard L Wahl, Rathan M Subramaniam
OBJECTIVE: The aim of this study was to determine whether various fluorine-18-fluorodeoxyglucose PET/CT-derived parameters used in oncology vary significantly depending on the interpretation software systems used in clinical practice for multiple human solid tumors. PATIENTS AND METHODS: A total of 120 fluorine-18-fluorodeoxyglucose PET/CT studies carried out in patients with pancreatic, lung, colorectal, and head and neck cancers were evaluated retrospectively on two different vendor software platforms including Mirada and MIMVista...
December 8, 2017: Nuclear Medicine Communications
https://www.readbyqxmd.com/read/29223891/fallen-leaves-derived-honeycomb-like-porous-carbon-as-a-metal-free-and-low-cost-counter-electrode-for-dye-sensitized-solar-cells-with-excellent-tri-iodide-reduction
#16
Sung Min Cha, Goli Nagaraju, S Chandra Sekhar, L Krishna Bharat, Jae Su Yu
Utilizing carbon-based counter electrodes (CEs) in dye-sensitized solar cells (DSSCs) have received much attention in recent times, owing to their low cost, good electrochemical activity, natural abundance and eco-friendly nature. Herein, we have facilely prepared quince leaves derived porous carbon (QLPC) using fallen quince leaves (QLs) and it was used as a cost-effective CE for the fabrication of DSSCs. By means of alkali treatment and pyrolysis process (at different temperatures of 700, 800 and 900 °C), the QLs powder undergoes chemical activation and carbonization, which results in a honeycomb-like QLPC with abundant micro/mesopores and large surface area...
December 2, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/29223715/development-of-two-fluorine-18-labeled-pet-radioligands-targeting-pde10a-and-in-vivo-pet-evaluation-in-nonhuman-primates
#17
Vladimir Stepanov, Akihiro Takano, Ryuji Nakao, Nahid Amini, Shotaro Miura, Tomoaki Hasui, Haruhide Kimura, Takahiko Taniguchi, Christer Halldin
INTRODUCTION: Phosphodiesterase 10A (PDE10A) is a member of the PDE enzyme family that degrades cyclic adenosine and guanosine monophosphates (cAMP and cGMP). Based on the successful development of [11C]T-773 as PDE10A positron emission tomography (PET) radioligand, in this study our aim was to develop and evaluate fluorine-18 analogs of [11C]T-773. METHODS: [18F]FM-T-773-d2 and [18F]FE-T-773-d4 were synthesized from the same precursor used for 11C-labeling of T-773 in a two-step approach via 18F-fluoromethylation and 18F-fluoroethylation, respectively, using corresponding deuterated synthons...
October 23, 2017: Nuclear Medicine and Biology
https://www.readbyqxmd.com/read/29223532/new-insights-into-the-influence-of-monofluorination-on-dimyristoylphosphatidylcholine-membrane-properties-a-solid-state-nmr-study
#18
Marie-Claude Gagnon, Erik Strandberg, Anne S Ulrich, Jean-François Paquin, Michèle Auger
Solid-state 19F NMR spectroscopy is a method of choice to study the interactions between lipid membranes and other molecules such as peptides, proteins or drugs. Numerous fluorine-labeled NMR probes have been developed over the last few years, especially fluorine-labeled peptides. In order to develop a new kind of NMR reporter molecule and a complementary approach to fluorine-labeling of peptides, we synthesized six monofluorinated derivatives of the lipid dimyristoylphosphatidylcholine (F-DMPC), with the fluorine atom located along the acyl chain linked to the central glycerol position...
December 6, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/29221762/continuous-infusion-of-cilengitide-plus-chemoradiotherapy-for-patients-with-stage-iii-non-small-cell-lung-cancer-a-phase-i-study
#19
Carole Massabeau, Jonathan Khalifa, Thomas Filleron, Anouchka Modesto, Laurence Bigay-Gamé, Gavin Plat, Lawrence Dierickx, Richard Aziza, Isabelle Rouquette, Carlos Gomez-Roca, Muriel Mounier, Jean-Pierre Delord, Christine Toulas, Pascale Olivier, Etienne Chatelut, Julien Mazières, Elizabeth Cohen-Jonathan Moyal
INTRODUCTION: Because of our previous preclinical results, we conducted a phase I study associating the specific αvβ3/αvβ5 integrin inhibitor cilengitide, given as a continuous infusion, with exclusive chemoradiotherapy for patients with stage III non-small-cell lung cancer. PATIENTS AND METHODS: A standard 3+3 dose escalation design was used. Cilengitide was given as a continuous infusion (dose levels of 12, 18, 27, and 40 mg/h), starting 2 weeks before and continuing for the whole course of chemoradiotherapy (66 Gy combined with platinum/vinorelbine), and then at a dose of 2000 mg twice weekly in association with chemotherapy...
November 21, 2017: Clinical Lung Cancer
https://www.readbyqxmd.com/read/29220174/the-intramolecular-hb-interactions-evidenced-in-dibenzoyl-oxalamide-derivatives-nmr-qtaim-nci-studies
#20
Dhanishta Poshetti, Sandeep Kumar Mishra, Nagarajarao Suryaprakash
Extensive NMR spectroscopic studies revealed information on the occurrence of bifurcated intramolecular hydrogen bond in the dibenzoyl oxalamide derivatives. One dimensional NMR experiments, viz., solvent dilution, temperature perturbation and two dimensional techniques,, such as, 15N-1H HSQC and 19F-1H HOESY have been exploited to derive the unambiguous confirmation for the participation of organic fluorine in the hydrogen bonding interaction. The experimental NMR findings have been ratified by Density Functional Theory (DFT) based calculations, such as, Quantum Theory of Atoms in Molecules (QTAIM) and Non-Covalent Interaction (NCI)...
December 8, 2017: Journal of Physical Chemistry. A
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