bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of epoxy‐ended hyperbranched polymers with precisely controllable degree of branching by thiol‐ene Michael addition
Authors: Zhang Daohong , Wang Yimei , Xu Zhicai , Cheng Juan , Chen Sufang , Zhang Junheng , Miao Menghe 
Published: August 2016

ABSTRACTEpoxy‐ended hyperbranched polymers (EHPs) have a wide range of applications due to their outstanding performances. Because their microstructures are not positively identified, it is very difficult to ascertain the reinforcing and toughening mechanisms of EHPs and their interface interaction with other matrixes. Controllable synthesis of EHPs with precise degree of branching (DB) remains to be a major challenge. Here, a method for preparing novel nitrogen‐phosphor skeleton epoxy‐ended hyperbranched polymers (NPEHP) with controllable DB by a thiol‐ene Michael addition between thiol‐ended hyperbranched polymers (NPHSH) and glycidyl methacrylate have been firstly reported. NPHSH is synthesized by an esterification between hydroxyl‐ended hyperbranched polymers (NPHOH) and 3‐mercaptopropionic acid. NPHOH is prepared by a thiol‐ene Michael addition between methacrylate group of a monomer and thiol group of linear monomer (AB) and/or branched monomer (AB2). The molar ratio between the AB and AB2 monomers controls the DB of the products. The 1H NMR spectra analysis of NPHOH shows that their experimentally determined DBs are very close to their theoretical values, indicating good controllability of their DBs. The narrow molecular weight distributions of NPHOH, NPHSH, and NPEHP suggest high efficiency of the thiol‐ene Michael addition. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44277.
BaTiO3 incorporation effect on the dielectric properties of polymer from aqueous emulsion: An enhanced dispersion technique
Authors: Zyane Adel , Belfkira Ahmed , Brouillette François , Marchet Pascal , Lucas Romain 
Published: August 2016

ABSTRACTAn economic and environment friendly process was adapted to synthesize new dielectric composite materials. Using ethylene vinyl acetate (EVA)/vinyl ester of versatic acid (VeoVa) terpolymer as an aqueous emulsion provides a homogenous dispersion of BaTiO3 (BT) particles, due to the high viscosity and polarity of the vinyl resin (VR). Composites films were obtained from these dispersions by water evaporation. The evolution of the dielectric properties as a function of the BaTiO3 content, was correctly fitted by a Maxwell‐Garnett model. This fitting of the experimental curve shows a good dispersion of filler in the vinyl resin and the particles separation by a layer of resin as expected for the preparation method used in this study. The VR/BT composites show good synergy between the dielectric properties of the different phases of the composites due to the formation of macrodipoles and to the strong interactions between polar EVA/VeoVa groups and the BaTiO3 particles surface. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44333.
The effects of the concentration‐dependent erythrocyte distribution of TAK‐802, a potent acetylcholinesterase inhibitor, on rat pharmacokinetics
Authors: Kakehi Masaaki , Tagawa Yoshihiko , Goto Akihiko , Kondo Takahiro , Asahi Satoru 
Published: August 2016

AbstractThe purpose of this study was to investigate the effect of the concentration‐dependent erythrocyte distribution of TAK‐802, a potent acetylcholinesterase inhibitor, on rat pharmacokinetics. In an ascending oral dose study, the maximum plasma concentration (Cmax) of TAK‐802 increased in a dose‐dependent manner. The time to reach Cmax decreased as the dose increased, whereas the total clearance was independent of the tested dose range. In this intravenous (i.v.) ascending dose study in rats, the apparent distribution volumes at steady state decreased, and the apparent terminal elimination rate constants increased with TAK‐802 dose escalation. A marked concentration dependency was observed in an associated in vitro erythrocyte distribution study. The in vitro erythrocyte distribution study results and a relationship analysis between the plasma and blood concentrations of TAK‐802 after i.v. dosing revealed that the characteristics of the erythrocyte distribution could be expressed by Langmuir's adsorption formula. The concentration–time profiles of TAK‐802 in plasma and whole blood calculated using a nonlinear pharmacokinetic model incorporating the concentration‐dependent erythrocyte distribution with optimized parameters fit well to the observed plasma and blood concentration profiles obtained from the i.v. ascending dose study. These results indicate that the concentration‐dependent erythrocyte distribution plays a major role in the nonlinear pharmacokinetics of TAK‐802 in rats. Copyright © 2016 John Wiley & Sons, Ltd.
A new validated HPLC method for the determination of quercetin: Application to study pharmacokinetics in rats
Authors: Abdelkawy Khaled S. , Balyshev Mark E. , Elbarbry Fawzy 
Published: August 2016

AbstractA simple, accurate, and reproducible high‐performance liquid chromatography (HPLC) method has been developed and validated for the quantification of quercetin (QR) in rat plasma. The method involves a simple protein precipitation procedure to extract both QR and thymoquinone (TQ), the internal standard. The chromatographic analysis was achieved on a Shimadzu LC 20 A HPLC system equipped with a Supelcosil LC‐18 T C18 column and an isocratic mobile phase consisting of 0.3% trichloroacetic acid in water and acetonitrile HPLC‐grade (50:50, v/v) run at a flow rate of 0.9 mL/min for 13 min. The UV detection wavelength was set at 254 nm. The method exhibited good linearity (R2 > 0.994) over the assayed concentration range (0.10–25 μg/mL) and demonstrated good intra‐day and inter‐day precision and accuracy (relative standard deviations and the deviation from predicted values were <20%). This method was also successfully applied for studying the pharmacokinetics of QR in rats following a single oral dose of QR to evaluate its pharmacokinetic parameters in rats.
Development and validation of an LC–MS/MS quantitative method for endogenous deoxynucleoside triphosphates in cellular lysate
Authors: Chen Xinhui , McAllister Kevin J. , Klein Brandon , Bushman Lane R. , Anderson Peter L. 
Published: August 2016

AbstractThe endogenous deoxynucleoside triphosphate (dNTP) pool includes deoxyadenosine triphosphate (dATP), deoxycytidine triphosphate (dCTP), deoxyguanosine triphosphate (dGTP) and thymidine triphosphate (TTP). The endogenous dNTP pool is regulated by complex enzymatic pathways that can be targeted by drugs, such as antimetabolites. In addition, these components compete with antiviral nucleos(t)ide analog triphosphates, contributing to the mechanism of pharmacologic action. This communication describes the development and validation of a sensitive method to quantify the intracellular dNTP pool in cellular lysates. The extraction process was optimized for dNTPs using an indirect strategy – the separation of mono‐, di‐ and triphosphate moieties by strong anion exchange, dephosphorylation of target fractions to molar equivalent nucleosides – followed by sensitive quantitation using liquid chromatography–tandem mass spectrometry. The validated analytical range was 50–2500 fmol/sample for each dNTP. The assay was used to quantify dNTPs in peripheral blood mononuclear cells from 40 clinical research participants (n = 279 samples). Median (interquartile range) concentrations were 143 (116, 169) for dATP, 737 (605, 887) for dCTP, 237 (200, 290) for dGTP and 315 (220, 456) for TTP, in femtomoles per million cells. This method allows for future studies of endogenous dNTP disposition in subjects receiving antimetabolites or nucleos(t)ide analogs, or for other clinical scenarios.
A fast and sensitive UHPLC–MS/MS method for the determination ofN‐butylscopolamine in human plasma: application in a bioequivalence study
Authors: Suenaga Eunice Mayumi , Val Ligia de Cássia , Tominaga Mineko , Souza Filho José Homero , Soares Gidel , Vioto Monalisa , Nakaie Clovis Ryuichi 
Published: August 2016

AbstractWe have developed and validated a fast and sensitive ultra high‐performance liquid chromatography with positive ion electrospray ionization tandem mass spectrometry method for determining N‐butylscopolamine levels in human plasma using propranolol as an internal standard. The acquisition was set up in the multiple reaction monitoring mode with the transitions m/z 360.3 → 138.0 for N‐butylscopolamine and m/z 260.2 → 116.1 for IS. This method uses a liquid–liquid extraction process with dichloromethane. The analyte and IS were chromatographed on a C18, 50 × 2.1 mm, 1.7 μm column through isocratic elution with acetonitrile–5 mm ammonium acetate (adjusted to pH 3.0 with formic acid). The method was linear in the 1–1000 pg/mL range for N‐butylscopolamine and was selective, precise, accurate and robust. The validated method was successfully applied to perform a bioequivalence study of the reference (Buscopan®, from Boehringer Ingelheim) and the test sample coated‐tablet formulations (from Foundation for Popular Remedy), both containing 10 mg of N‐butylscopolamine bromide administered as a single dose. Using 58 healthy volunteers and accounting for the high intra‐individual variability confirmed by statistical calculations (38%), the two formulations were considered bioequivalent because the rate and extent of absorption (within 80–125% interval), satisfying international requirements.
Mutation and prognostic analyses of PIK3CA in patients with completely resected lung adenocarcinoma
Authors: Song Zhengbo , Yu Xinmin , Zhang Yiping 
Published: August 2016

AbstractPIK3CA mutation represents a clinical subset of diverse carcinomas. We explored the status of PIK3CA mutation and evaluated its genetic variability, treatment, and prognosis in patients with lung adenocarcinoma. A total of 810 patients with completely resected lung adenocarcinoma were recruited between 2008 and 2013. The status of PIK3CA mutation and other three genes, that is, EGFR mutation, KRAS mutation and ALK fusion were examined by reverse transcription‐polymerase chain reaction (RT‐PCR). Survival curves were plotted with the Kaplan–Meier method and log‐rank for comparison. Cox proportional hazard model was performed for multivariate analysis. Among the 810 patients, 23 cases of PIK3CA mutation were identified with a frequency of 2.8%. There were 14 men and 9 women with a median age of 61 years. Seventeen tumors revealed concurrent gene abnormalities of EGFR mutation (n = 12), KRAS mutation (n = 3), and ALK fusion (n = 2). Seven patients with EGFR & PIK3CA mutations recurred and administrated of EGFR‐TKIs yielded a median progression free‐survival of 6.0 months. Among four eviromous‐treated patients, stable disease was observed in three patients with a median Progression‐free survival (PFS) of 3.5 months. Patients with and without PIK3CA mutation had different overall survivals (32.2 vs. 49.6 months, P = 0.003). Multivariate analysis revealed that PIK3CA mutation was an independent predictor of poor overall survival (HR = 2.37, P = 0.017). The frequency of PIK3CA mutation was around 2.8% in the Chinese patients of lung adenocarcinoma. PIK3CA mutation was associated with reduced PFS of EGFR‐TKIs treatment and shorter overall survival.
Idiopathic sclerosing orbital inflammation mimicking a malignant spindle cell tumor in a dog
Authors: Marie Rzechorzek Nina , Smith Colin , Schwarz Tobias , Liuti Tiziana , Elders Richard , Woods Samantha , Lawrence Jessica , Marioni‐Henry Katia 
Published: August 2016

Key Clinical MessageA dog presented with a retrobulbar mass, diagnosed histopathologically as malignant spindle cell neoplasia. Emergence of analogous findings in the contralateral orbit prompted extended immunohistochemistry of the original mass and reassignment to idiopathic sclerosing orbital inflammation. Early incisional biopsy with extended immunohistochemical analysis should be considered for canine orbital tumors.
Right parietal source in Mahjong‐induced seizure: a system epilepsy of focal origin
Authors: Fukuma Kazuki , Ihara Masafumi , Miyashita Kotaro , Motoyama Rie , Tanaka Tomotaka , Kajimoto Katsufumi , Ikeda Akio , Nagatsuka Kazuyuki 
Published: August 2016

Key Clinical MessageMahjong, a game similar to bridge and chess in Western cultures, can cause reflex seizure. We report a case of Mahjong‐induced seizures with the first documentation of ictal electroencephalography (EEG) findings, which showed secondarily generalized partial seizure of the right parietal origin.
Methanation of CO2 over a (Mg,Al)Ox Supported Nickel Catalyst Derived from a (Ni,Mg,Al)‐Hydrotalcite‐like Precursor
Authors: Bette Nadine , Thielemann Jörg , Schreiner Marcus , Mertens Florian 
Published: August 2016

AbstractThe CO2 methanation performance of a Ni catalyst supported on a Lewis basic (Mg,Al)Ox mixed oxide derived from a (Ni,Mg,Al)‐hydrotalcite‐like (HTL) precursor was investigated. The HTL structure of the precursor, synthesized by pH‐controlled coprecipitation, was confirmed by using XRD. Reduction at 900 °C led to metallic Ni particles supported on a spinel‐type (Mg,Al)Ox matrix. Catalytic measurements between 210 and 400 °C revealed a reproducible CO2 conversion into CH4. Kinetic analysis of the data in the lower temperature range resulted in an apparent activation energy of (83±7) kJ mol−1 for this reaction. After a latency period of 10 h, the catalyst showed excellent long‐term stability for up to 50 h on stream under methanation conditions.
Zinc Homeostasis at the Bacteria/Host Interface—From Coordination Chemistry to Nutritional Immunity
Authors: Wątły Joanna , Potocki Sławomir , Rowińska‐Żyrek Magdalena 
Published: August 2016

AbstractZinc is one of the most important metal nutrients for species from all kingdoms, being a key structural or catalytic component of hundreds of enzymes, crucial for the survival of both pathogenic microorganisms and their hosts. This work is an overview of the homeostasis of zinc in bacteria and humans. It explains the importance of this metal nutrient for pathogens, describes the roles of zinc sensors, regulators, and transporters, and summarizes various uptake systems and different proteins involved in zinc homeostasis—both those used for storage, buffering, and signaling inside the cell and those excreted in order to obtain ZnII from the host. The human zinc‐dependent immune system response is explained, with a special focus given to ‘zinc nutritional immunity′, a process that describes the competition between the bacteria or fungus and the host for this metal, during which both the pathogen and host make huge efforts to control zinc availability. This sophisticated tug of war over ZnII might be considered as a possible target for novel antibacterial therapies.
A Blocking Group Scan Using a Spherical Organometallic Complex Identifies an Unprecedented Binding Mode with Potent Activity In Vitro and In Vivo for the Opioid Peptide Dermorphin
Authors: Strack Martin , Bedini Andrea , Yip King T. , Lombardi Sara , Siegmund Daniel , Stoll Raphael , Spampinato Santi M. , Metzler‐Nolte Nils 
Published: August 2016

AbstractHerein, the selective enforcement of one particular receptor‐ligand interaction between specific domains of the μ‐selective opioid peptide dermorphin and the μ opioid receptor is presented. For this, a blocking group scan is described which exploits the steric demand of a bis(quinolinylmethyl)amine rhenium(I) tricarbonyl complex conjugated to a number of different, strategically chosen positions of dermorphin. The prepared peptide conjugates lead to the discovery of two different binding modes: An expected N‐terminal binding mode corresponds to the established view of opioid peptide binding, whereas an unexpected C‐terminal binding mode is newly discovered. Surprisingly, both binding modes provide high affinity and agonistic activity at the μ opioid receptor in vitro. Furthermore, the unprecedented C‐terminal binding mode shows potent dose‐dependent antinociception in vivo. Finally, in silico docking studies support receptor activation by both dermorphin binding modes and suggest a biological relevance for dermorphin itself. Relevant ligand‐protein interactions are similar for both binding modes, which is in line with previous protein mutation studies.
Rhodium‐Catalyzed Dehydrogenative Silylation of Acetophenone Derivatives: Formation of Silyl Enol Ethers versus Silyl Ethers
Authors: Garcés Karin , Lalrempuia Ralte , Polo Víctor , Fernández‐Alvarez Francisco J. , García‐Orduña Pilar , Lahoz Fernando J. , Pérez‐Torrente Jesús J. , Oro Luis A. 
Published: August 2016

AbstractA series of rhodium–NSiN complexes (NSiN=bis (pyridine‐2‐yloxy)methylsilyl fac‐coordinated) is reported, including the solid‐state structures of [Rh(H)(Cl)(NSiN)(PCy3)] (Cy=cyclohexane) and [Rh(H)(CF3SO3)(NSiN)(coe)] (coe=cis‐cyclooctene). The [Rh(H)(CF3SO3)(NSiN)(coe)]‐catalyzed reaction of acetophenone with silanes performed in an open system was studied. Interestingly, in most of the cases the formation of the corresponding silyl enol ether as major reaction product was observed. However, when the catalytic reactions were performed in closed systems, formation of the corresponding silyl ether was favored. Moreover, theoretical calculations on the reaction of [Rh(H)(CF3SO3)(NSiN)(coe)] with HSiMe3 and acetophenone showed that formation of the silyl enol ether is kinetically favored, while the silyl ether is the thermodynamic product. The dehydrogenative silylation entails heterolytic cleavage of the Si−H bond by a metal–ligand cooperative mechanism as the rate‐determining step. Silyl transfer from a coordinated trimethylsilyltriflate molecule to the acetophenone followed by proton transfer from the activated acetophenone to the hydride ligand results in the formation of H2 and the corresponding silyl enol ether.
Green Synthesis of Red‐Emitting Carbon Nanodots as a Novel “Turn‐on” Nanothermometer in Living Cells
Authors: Wang Chuanxi , Jiang Kaili , Wu Qian , Wu Jiapeng , Zhang Chi 
Published: August 2016

AbstractTemperature measurements in biology and medical diagnostics, along with sensitive temperature probing of living cells, is of great importance; however, it still faces significant challenges. Herein, a novel “turn‐on” carbon‐dot‐based fluorescent nanothermometry device for spatially resolved temperature measurements in living cells is presented. The carbon nanodots (CNDs) are prepared by a green microwave‐assisted method and exhibit red fluorescence (λem=615 nm) with high quantum yields (15 %). Then, an on–off fluorescent probe is prepared for detecting glutathione (GSH) based on aggregation‐induced fluorescence quenching. Interestingly, the quenched fluorescence could be recovered by increasing temperature and the CNDs–GSH mixture could behave as an off–on fluorescent probe for temperature. Thus, red‐emitting CNDs can be utilized for “turn‐on” fluorescent nanothermometry through the fluorescence quenching and recovery processes, respectively. We employ MC3T3‐E1 cells as an example model to demonstrate the red‐emitting CNDs can function as “non‐contact” tools for the accurate measurement of temperature and its gradient inside a living cell.
Ate Complexes in Iron‐Catalyzed Cross‐Coupling Reactions
Authors: Parchomyk Tobias , Koszinowski Konrad 
Published: August 2016

AbstractIron‐catalyzed cross‐coupling reactions have an outstanding potential for sustainable organic synthesis, but remain poorly understood mechanistically. Here, we use electrospray‐ionization (ESI) mass spectrometry to identify the ionic species formed in these reactions and characterize their reactivity. Transmetalation of Fe(acac)3 (acac=acetylacetonato) with PhMgCl in THF (tetrahydrofuran) produces anionic iron ate complexes, whose nuclearity (1 to 4 Fe centers) and oxidation states (ranging from −I to +III) crucially depend on the presence of additives or ligands. Upon addition of iPrCl, formation of the heteroleptic FeIII complex [Ph3Fe(iPr)]− is observed. Gas‐phase fragmentation of this complex results in reductive elimination and release of the cross‐coupling product with high selectivity.
First Total Synthesis, Structure Revision, and Natural History of the Smallest Cytochalasin: (+)‐Periconiasin G
Authors: Zaghouani Mehdi , Kunz Caroline , Guédon Laura , Blanchard Florent , Nay Bastien 
Published: August 2016

AbstractThe total synthesis of the smallest cytochalasin isolated so far, periconiasin G, which bears a seven‐membered ring in lieu of the usual macrocycle, has been performed from both enantiomers of citronellal, relying on an intramolecular Diels–Alder reaction in favor of the natural endo stereochemistry. We show that, among the four synthesized stereoisomers, including the exo isomers, the one matching the NMR data of the natural product was not that assigned in the original report, imposing structure revision. The natural product, previously isolated from a plant‐mutualistic fungus, was biologically investigated taking into account its natural history, showing significant effects against the phytopathogenic fungus Botrytis cinerea and thus opening new opportunities in combating this pest.
Intramolecular trans‐Dicarbofunctionalization of Alkynes by a Formal anti‐Carbopalladation/Stille Cascade
Authors: Milde Bastian , Reding Andreas , Geffers Finn J. , Jones Peter G. , Werz Daniel B. 
Published: August 2016

AbstractAn intramolecular Pd‐catalyzed trans‐dicarbofunctionalization of internal alkynes using aryl bromides and aryl stannanes is presented. Tetrasubstituted double bonds embedded in an oligocyclic ring system are obtained in a regio‐ and diastereoselective fashion. The transformation features a broad substrate scope and functional‐group tolerance.
Synergistic Diazo‐OH Insertion/Conia‐Ene Cascade Catalysis for the Stereoselective Synthesis of γ‐Butyrolactones and Tetrahydrofurans
Authors: Hunter Arianne C. , Schlitzer Steven C. , Sharma Indrajeet 
Published: August 2016

AbstractA novel and highly efficient diazo‐OH insertion/Conia‐ene cascade reaction of readily available homopropargylic acids and alcohols with diazo carbonyl compounds is described. The cascade reaction involves a synergistic Rh/Ag/Au catalyst cocktail and proceeds instantly with a variety of substituted diazo compounds and acids/alcohols to provide functionalized γ‐butyrolactones and tetrahydrofurans with complete regio‐ and stereoselectivity. The unprecedented rate‐enhancement, complete stereoselectivity, and the enabling of new Conia‐ene cyclizations suggest a concerted [4+1]‐cycloaddition reaction pathway under synergistic (Rh/Ag/Au)‐catalysis conditions.
Probability‐scale residuals for continuous, discrete, and censored data
Authors: Shepherd Bryan E. , Li Chun , Liu Qi 
Published: August 2016

AbstractWe describe a new residual for general regression models defined as, whereyis the observed outcome andis a random variable from the fitted distribution. This probability‐scale residual (PSR) can be written as, whereas the popular observed‐minus‐expected residual can be thought of as. Therefore the PSR is useful in settings where differences are not meaningful or where the expectation of the fitted distribution cannot be calculated. We present several desirable properties of the PSR that make it useful for diagnostics and measuring residual correlation, especially across different outcome types. We demonstrate its utility for continuous, ordered discrete, and censored outcomes, including current status data, and with various models including Cox regression, quantile regression, and ordinal cumulative probability models, for which fully specified distributions are not desirable or needed, and in some cases suitable residuals are not available. The residual is illustrated with simulated data and real data sets from HIV‐infected patients on therapy in the southeastern United States and Latin America.The Canadian Journal of Statistics44: 463–479; 2016 © 2016 Statistical Society of Canada