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https://www.readbyqxmd.com/read/28525267/the-supernatant-from-hepatocyte-cultures-with-drugs-that-cause-idiosyncratic-liver-injury-activates-macrophage-inflammasomes
#1
Ryuji Kato, Jack Uetrecht
There is increasing evidence that most idiosyncratic drug-induced liver injury (IDILI) is immune mediated, and in most cases reactive metabolites appear to be responsible for induction of this immune response. Reactive metabolites can cause cell damage with the release of damage-associated molecular patterns (DAMPs), which is thought to be involved in immune activation. Presumably the reason that the liver is a common target of idiosyncratic drug reactions is because it is the major site of drug metabolism and reactive metabolite formation...
May 19, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/28523850/n-aryl-groups-are-ubiquitous-in-cross-dehydrogenative-couplings-because-they-stabilize-reactive-intermediates
#2
Althea S-K Tsang, A Stephen K Hashmi, Peter Comba, Marion Kerscher, Bun Chan, Matthew Todd
The mechanism of cross-dehydrogenative coupling (CDC) reactions has been examined by experimental and computational means. We have provided a rationale for the ubiquity of the N-aryl group in these reactions. The aryl substituent stabilizes two intermediates and the high-energy transition state that connects them, which together represent the rate-determining step. This knowledge has enabled us to predict new CDC substrates that react either well or poorly.
May 18, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28522751/targeting-fbw7-as-a-strategy-to-overcome-resistance-to-targeted-therapy-in-non-small-cell-lung-cancer
#3
Mingxiang Ye, Yong Zhang, Xinxin Zhang, Jian-Bin Zhang, Pengyu Jing, Liang Cao, Nan Li, Xia Li, Libo Yao, Jian Zhang, Jian Zhang
Inhibition of epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) signaling is highly effective in a subgroup of non-small cell lung cancer (NSCLC) patients with distinct clinicopathological features. However, resistance to EGFR and ALK inhibitors inevitably occurs, and the molecular mechanism underlying resistance is not fully understood. In this study, we report a PI3K/Akt- and MEK/Erk-independent resistance mechanism by which loss of the E3 ubiquitin ligase F-box and WD repeat domain containing 7 (FBW7α) leads to targeted therapy resistance via stabilization of anti-apoptotic protein MCL-1...
May 18, 2017: Cancer Research
https://www.readbyqxmd.com/read/28516986/single-layer-mos2-formation-by-sulfidation-of-molybdenum-oxides-in-different-oxidation-states-on-au-111
#4
Norberto Salazar, Igor Beinik, Jeppe V Lauritsen
The sulfidation of a MoO3 precursor into MoS2 is an important step in the preparation of catalysts for the hydrodesulfurization process that is widely utilized in oil refineries. Molybdenum oxides are also the most commonly used precursors for MoS2 growth in, e.g., the synthesis of novel two-dimensional materials. In the present study, we investigate the transformation of MoOx into MoS2 on a model Au(111) surface through sulfidation in H2S gas atmosphere using in situ scanning tunneling microscopy and X-ray photoemission spectroscopy...
May 18, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28515795/a-theoretical-investigation-on-co-oxidation-by-single-atom-catalysts-m1-%C3%AE-al2o3-m-pd-fe-co-and-ni
#5
Tao Yang, Ryoichi Fukuda, Saburo Hosokawa, Tsunehiro Tanaka, Shigeyoshi Sakaki, Masahiro Ehara
Single-atom catalysts have attracted much interest recently because of their excellent stability, high catalytic activity, and remarkable atom efficiency. Inspired by the recent experimental discovery of a highly efficient single-atom catalyst Pd1/γ-Al2O3, we conducted a comprehensive DFT study on geometries, stabilities and CO oxidation catalytic activities of M1/γ-Al2O3 (M=Pd, Fe, Co, and Ni) by using slab-model. One of the most important results here is that Ni1/Al2O3 catalyst exhibits higher activity in CO oxidation than Pd1/Al2O3...
April 7, 2017: ChemCatChem
https://www.readbyqxmd.com/read/28514646/heparin-removal-by-ecteola-cellulose-pre-treatment-enables-the-use-of-plasma-samples-for-accurate-measurement-of-anti-yellow-fever-virus-neutralizing-antibodies
#6
Ana Carolina Campi-Azevedo, Vanessa Peruhype-Magalhães, Jordana Grazziela Coelho-Dos-Reis, Christiane Costa-Pereira, Anna Yoshida Yamamura, Sheila Maria Barbosa de Lima, Marisol Simões, Fernanda Freire Campos Nunes, Aline de Castro Zacche Tonini, Elenice Moreira Lemos, Ricardo Cristiano Brum, Tatiana Guimarães de Noronha, Marcos da Silva Freire, Maria de Lourdes Sousa Maia, Luiz Antônio Bastos Camacho, Maria Rios, Caren Chancey, Alessandro Romano, Carla Magda Domingues, Andréa Teixeira-Carvalho, Olindo Assis Martins-Filho
Technological innovations in vaccinology have recently contributed to bring about novel insights for the vaccine-induced immune response. While the current protocols that use peripheral blood samples may provide abundant data, a range of distinct components of whole blood samples are required and the different anticoagulant systems employed may impair some properties of the biological sample and interfere with functional assays. Although the interference of heparin in functional assays for viral neutralizing antibodies such as the functional plaque-reduction neutralization test (PRNT), considered the gold-standard method to assess and monitor the protective immunity induced by the Yellow fever virus (YFV) vaccine, has been well characterized, the development of pre-analytical treatments is still required for the establishment of optimized protocols...
May 14, 2017: Journal of Immunological Methods
https://www.readbyqxmd.com/read/28513753/two-step-conversion-of-carboxylic-esters-into-distally-fluorinated-ketones-via-ring-cleavage-of-cyclopropanol-intermediates-application-of-sulfinate-salts-as-fluoroalkylating-reagents
#7
Yulia A Konik, Marina Kudrjashova, Nele Konrad, Sandra Kaabel, Ivar Järving, Margus Lopp, Dzmitry G Kananovich
Tertiary cyclopropanols easily available from carboxylic esters have been used in the synthesis of distally fluorinated ketones. Cyclopropane ring cleavage reactions in methanol with aqueous tert-butyl hydroperoxide in the presence of a copper(ii) acetate catalyst and sodium triflinate (Langlois reagent) afford β-trifluoromethyl ketones in 16-74% isolated yields. Sodium triflinate serves as a precursor of reactive trifluoromethyl copper species, enabling ring-opening trifluoromethylation, as evidenced by mechanistic studies...
May 17, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28511011/iron-hydroperoxide-intermediate-in-superoxide-reductase-protonation-or-dissociation-first-mm-dynamics-and-qm-mm-metadynamics-study
#8
Rolf David, Helene Jamet, Vincent Niviere, Yohann Moreau, Anne Milet
Superoxide reductase is a mononuclear iron enzyme involved in superoxide radical detoxification in some bacteria. Its catalytic mechanism is associated with the remarkable formation of a ferric hydroperoxide Fe3+-OOH intermediate, which is specifically protonated on its proximal oxygen to generate the reaction product H2O2. Here we present a computational study of the protonation mechanism of the Fe3+ OOH intermediate, at different level of theory. This was performed on the whole system (solvated protein) using well-tempered metadynamics at the QM/MM (B3LYP/AmberFF99SB) level...
May 16, 2017: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/28510696/autologous-adipose-derived-tissue-matrix-part-ii-implantation-biology
#9
Stephen A Schendel
Background: In part 1 of this study it was shown that liposuctioned fat could be a sufficient source of autologous collagen for use as a filler or in reconstruction. The collagen composition in liposuctioned fat was shown to form a cross-linked helical matrix composed of types II, III, and IV. Additionally, viable adipocytes and fibroblasts among other cells were found. Objectives: The purpose of this research was to study the biology of this matrix after subsequent implantation compared to Juvederm (Allergan, Parsippany, NJ) common soft tissue filler...
May 16, 2017: Aesthetic Surgery Journal
https://www.readbyqxmd.com/read/28510487/origin-of-the-ttc-values-for-compounds-that-are-genotoxic-and-or-carcinogenic-and-an-approach-for-their-re-evaluation
#10
Alan Boobis, Paul Brown, Mark Timothy David Cronin, James Edwards, Corrado Lodovico Galli, Jay Goodman, Abigail Jacobs, David Kirkland, Mirjam Luijten, Cyril Marsaux, Matthew Martin, Chihae Yang, Heli Miriam Hollnagel
The threshold of toxicological concern (TTC) approach is a resource-effective de minimis method for the safety assessment of chemicals, based on distributional analysis of the results of a large number of toxicological studies. It is being increasingly used to screen and prioritize substances with low exposure for which there is little or no toxicological information. The first step in the approach is the identification of substances that may be DNA-reactive mutagens, to which the lowest TTC value is applied...
May 16, 2017: Critical Reviews in Toxicology
https://www.readbyqxmd.com/read/28510305/reactive-precipitation-of-anhydrous-alkali-sulfide-nanocrystals-with-concomitant-abatement-of-hydrogen-sulfide-and-co-generation-of-hydrogen
#11
Yongan Yang, Xuemin Li, Yangzhi Zhao, Alice Brennan, Miranda McCeig, Colin A Wolden
Anhydrous alkali sulfide (M2S, M = Li and Na) nanocrystals (NCs) are important materials central to the development of next generation cathodes and solid state electrolytes for advanced batteries, but not commercially available at present. This work reports an innovative method to directly synthesize M2S-NCs through alcohol-mediated reactions between alkali metals and hydrogen sulfide (H2S). In the first step, the alkali metal is complexed with alcohol in solution, forming metal alkoxide (ROM) and releasing hydrogen (H2)...
May 16, 2017: ChemSusChem
https://www.readbyqxmd.com/read/28509543/exploring-the-gas-phase-activation-and-reactivity-of-a-ruthenium-transfer-hydrogenation-catalyst-by-experiment-and-theory-in-concert
#12
Fabian S Menges, Johannes Lang, Yevgeniy Nosenko, Christian Kerner, Maximilian Gaffga, Leila Taghizadeh Ghoochany, Werner Richard Thiel, Christoph Riehn, Gereon Niedner-Schatteburg
This study elucidates structures, activation barriers and the gas phase reactivity of cationic ruthenium transfer hydrogenation catalysts of the structural type [(η6-cym)RuX(pympyr)]+. In these complexes, the central ruthenium(+II) ion is coordinated to a η6-bound p-cymene (η6-cym), a bidentate 2-R-4-(2-pyridinyl)pyrimidine ligand (pympyr) with R = NH2 or N(CH3)2, and an anion X = I-, Br-, Cl-, or CF3SO3-. We present Infrared Multiple-Photon Dissociation (IR-MPD) spectra of precursors (before HCl loss) and of activated complexes (after HCl loss) which elucidates a C-H activation as the key step in the activation mechanism...
May 16, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28508041/mitochondrial-protein-linked-dna-breaks-perturb-mitochondrial-gene-transcription-and-trigger-free-radical-induced-dna-damage
#13
Shih-Chieh Chiang, Martin Meagher, Nick Kassouf, Majid Hafezparast, Peter J McKinnon, Rachel Haywood, Sherif F El-Khamisy
Breakage of one strand of DNA is the most common form of DNA damage. Most damaged DNA termini require end-processing in preparation for ligation. The importance of this step is highlighted by the association of defects in the 3'-end processing enzyme tyrosyl DNA phosphodiesterase 1 (TDP1) and neurodegeneration and by the cytotoxic induction of protein-linked DNA breaks (PDBs) and oxidized nucleic acid intermediates during chemotherapy and radiotherapy. Although much is known about the repair of PDBs in the nucleus, little is known about this process in the mitochondria...
April 2017: Science Advances
https://www.readbyqxmd.com/read/28507666/in-situ-observation-of-reactive-oxygen-species-forming-on-oxygen-evolving-iridium-surfaces
#14
Verena Pfeifer, Travis E Jones, Juan J Velasco Vélez, Rosa Arrigo, Simone Piccinin, Michael Hävecker, Axel Knop-Gericke, Robert Schlögl
Water splitting performed in acidic media relies on the exceptional performance of iridium-based materials to catalyze the oxygen evolution reaction (OER). In the present work, we use in situ X-ray photoemission and absorption spectroscopy to resolve the long-standing debate about surface species present in iridium-based catalysts during the OER. We find that the surface of an initially metallic iridium model electrode converts into a mixed-valent, conductive iridium oxide matrix during the OER, which contains O(II-) and electrophilic O(I-) species...
March 1, 2017: Chemical Science
https://www.readbyqxmd.com/read/28505382/facile-phenylphosphinidene-transfer-reactions-from-carbene-phosphinidene-zinc-complexes
#15
Chris Slootweg, Tetiana Krachko, Mark Bispinghoff, Aaron Tondreau, Daniel Stein, Matthew Baker, Andreas Ehlers, Hansjörg Grützmacher
Phosphinidenes [R-P] are convenient P1 building blocks for the synthesis of a plethora of organophosphorus compounds. Thus far, transition-metal complexed phosphinidenes have been used for their singlet ground-state reactivity, promoting selective addition and insertion reactions. One disadvantage of this approach is that after transfer of the P1 moiety to the substrate a challenging demetallation step is required to provide the free phosphine. Here we report a simple method which allows the Lewis acid-promoted transfer of phenylphosphinidene, [PhP], from NHC=PPh adducts (NHC = N-heterocyclic carbene) to various substrates to produce directly uncoordinated phosphorus heterocycles that are difficult to obtain otherwise...
May 15, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28504171/tuneable-catechin-functionalisation-of-carbohydrate-polymers
#16
Susan Oliver, Aziidah Jofri, Donald S Thomas, Orazio Vittorio, Maria Kavallaris, Cyrille Boyer
In this contribution, we present a strategy to functionalise three natural carbohydrate polymers (dextran - a neutral polymer, sodium alginate - an anionic polymer and chitosan - a cationic polymer) with catechin with excellent degrees of functionality. In a first step, the carbohydrate polymers were oxidised by sodium periodate to yield aldehyde functionalised carbohydrate polymers. The presence of aldehyde groups was exploited to attach catechin by an acid catalysed nucleophilic reaction. The degree of catechin functionalisation could be easily tuned by varying the acid concentration in the reaction mixture, achieving catechin functionalisation levels of up to 48% for dextran aldehyde catechin, 35% for chitosan-aldehyde-catechin and 22% for sodium alginate aldehyde catechin...
August 1, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28501996/application-of-hydrogel-nanoparticles-for-the-capture-concentration-and-preservation-of-low-abundance-biomarkers
#17
Ruben Magni, Alessandra Luchini
In the recent years, a lot of emphasis has been placed on the discovery and detection of clinically relevant biomarkers. Biomarkers are crucial for the early detection of several diseases, and they play an important role in the improvement of current treatments, thus reducing patient mortality rate. Because biofluids account to 60% of the body mass, they represent a goldmine of significant biomarkers. Unfortunately, because of their low concentration in body fluids, their lability, and the presence of high abundance proteins (i...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28501672/combining-reactive-triblock-copolymers-with-functional-cross-linkers-a-versatile-pathway-to-disulfide-stabilized-polyplex-libraries-and-their-application-as-pdna-vaccines
#18
Philipp Heller, Dominika Hobernik, Ulrich Lächelt, Meike Schinnerer, Benjamin Weber, Manfred Schmidt, Ernst Wagner, Matthias Bros, Matthias Barz
Therapeutic nucleic acids such as pDNA hold great promise for the treatment of multiple diseases. These therapeutic interventions are, however, compromised by the lack of efficient and safe non-viral delivery systems, which guarantee stability during blood circulation together with high transfection efficiency. To provide these desired properties within one system, we propose the use of reactive triblock copolypept(o)ides, which include a stealth-like block for efficient shielding, a hydrophobic block based on reactive disulfides for cross-linking and a cationic block for complexation of pDNA...
May 10, 2017: Journal of Controlled Release: Official Journal of the Controlled Release Society
https://www.readbyqxmd.com/read/28499580/transient-receptor-potential-trp-channels-as-molecular-targets-in-lung-toxicology-and-associated-diseases
#19
REVIEW
Alexander Dietrich, Dirk Steinritz, Thomas Gudermann
The lungs as the gateways of our body to the external environment are essential for gas exchange. They are also exposed to toxicants from two sides, the airways and the vasculature. Apart from naturally produced toxic agents, millions of human made chemicals were produced since the beginning of the industrial revolution whose toxicity still needs to be determined. While the knowledge about toxic substances is increasing only slowly, a paradigm shift regarding the proposed mechanisms of toxicity at the plasma membrane emerged...
April 26, 2017: Cell Calcium
https://www.readbyqxmd.com/read/28499032/development-of-a-new-tool-for-systematic-observation-of-nursing-home-resident-and-staff-engagement-and-relationship
#20
A Lynn Snow, M Lindsey Jacobs, Jennifer A Palmer, Patricia A Parmelee, Rebecca S Allen, Nancy J Wewiorski, Michelle M Hilgeman, Latrice D Vinson, Dan R Berlowitz, Anne D Halli-Tierney, Christine W Hartmann
Purpose of Study: To develop a structured observational tool, the Resident-centered Assessment of Interactions with Staff and Engagement tool (RAISE), to measure 2 critical, multi-faceted, organizational-level aspects of person-centered care (PCC) in nursing homes: (a) resident engagement and (b) the quality and frequency of staff-resident interactions. Design and Methods: In this multi-method psychometric development study, we conducted (a) 120 hr of ethnographic observations in one nursing home and (b) a targeted literature review to enable construct development...
May 11, 2017: Gerontologist
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