bluuebunny/crossref_metadata_2025_split huggingface dataset:
An eco‐friendly direct spectrofluorimetric method for the determination of irreversible tyrosine kinase inhibitors, neratinib and pelitinib: application to stability studies
Authors: Maher H.M. , Alzoman N.Z. , Shehata S.M. 
Published: June 2016

AbstractA new rapid and simple stability‐indicating spectrofluorimetric method has been developed for the determination of two irreversible tyrosine kinase inhibitors (TKIs), neratinib (NER) and pelitinib (PEL). The method is based upon measurement of the native fluorescence intensity of both drugs at λex 270 nm in aqueous borate buffer solutions (pH 10.5). The fluorescence intensity recorded at 545 nm (NER) and 465 nm (PEL) were rectilinear over the concentration range of 0.1–10 μg/mL for both drugs with a high correlation coefficient (r > 0.999). The proposed method provided low limits of detection and of quantitation of 0.07, 0.11 μg/mL (NER) and 0.02, 0.05 μg/mL (PEL), respectively. The method was successfully applied for the determination of NER and PEL in bulk powder. The proposed methods were fully validated as per the International Conference on Harmonisation (ICH) guidelines. The application of the method was extended to stability studies of both NER and PEL under different forced‐degradation conditions (acidic‐induced, base‐induced, oxidative, wet heat, and photolytic degradation). Moreover, the kinetics of the base‐induced and oxidative degradation of both drugs was investigated and the pseudo‐first‐order rate constants and half‐lives were estimated at different temperatures. Also, an Arrhenius plot was applied to predict the stability behaviour of the two drugs at room temperature. Copyright © 2016 John Wiley & Sons, Ltd.
A supported liquid extraction LC–MS/MS method for determination of concentrations of GDC‐0425, a small molecule Checkpoint kinase 1 inhibitor, in human plasma
Authors: Ding Xiao , Chen Yuan , Sahasranaman Srikumar , Shi Yifan , McKnight Janine , Dean Brian 
Published: June 2016

AbstractA liquid chromatography–tandem mass spectrometry (LC–MS/MS) method for the determination of GDC‐0425 concentrations in human plasma has been developed and validated. Supported liquid extraction was used to extract plasma samples (50 μL) and the resulting samples were analyzed using reverse‐phase chromatography and mass spectrometry coupled with a turbo‐ionspray interface. The mass analysis of GDC‐0425 was performed using multiple reaction monitoring transitions in positive ionization mode. The method was validated over the calibration curve range of 1.00–1000 ng/mL using linear regression and 1/x2 weighting. Within‐run relative standard deviation ranged from 0.8 to 5.1%, while between‐run RSD varied from 1.9 to 4.7% for QCs. The accuracy ranged from 90.0 to 101.0% of nominal for within‐run and from 94.0 to 100.0% of nominal for between‐run. Overall extraction recovery was 87.4% for GDC‐0425 and 87.9% for GDC‐0425‐d9. Stability of GDC‐0425 was established in human plasma for 374 days at −20 and −70 °C and established in reconstituted sample extracts for 88 h when stored at 2–8 °C. Stable‐labeled internal standard was used to minimize matrix effects. This assay was used to characterize the pharmacokinetics of GDC‐0425 in cancer patients.
Beyond main effects of gene‐sets: harsh parenting moderates the association between a dopamine gene‐set and child externalizing behavior
Authors: Windhorst Dafna A. , Mileva‐Seitz Viara R. , Rippe Ralph C. A. , Tiemeier Henning , Jaddoe Vincent W. V. , Verhulst Frank C. , van IJzendoorn Marinus H. , Bakermans‐Kranenburg Marian J. 
Published: June 2016

AbstractBackgroundIn a longitudinal cohort study, we investigated the interplay of harsh parenting and genetic variation across a set of functionally related dopamine genes, in association with children's externalizing behavior. This is one of the first studies to employ gene‐based and gene‐set approaches in tests of Gene by Environment (G × E) effects on complex behavior. This approach can offer an important alternative or complement to candidate gene and genome‐wide environmental interaction (GWEI) studies in the search for genetic variation underlying individual differences in behavior.MethodsGenetic variants in 12 autosomal dopaminergic genes were available in an ethnically homogenous part of a population‐based cohort. Harsh parenting was assessed with maternal (n = 1881) and paternal (n = 1710) reports at age 3. Externalizing behavior was assessed with the Child Behavior Checklist (CBCL) at age 5 (71 ± 3.7 months). We conducted gene‐set analyses of the association between variation in dopaminergic genes and externalizing behavior, stratified for harsh parenting.ResultsThe association was statistically significant or approached significance for children without harsh parenting experiences, but was absent in the group with harsh parenting. Similarly, significant associations between single genes and externalizing behavior were only found in the group without harsh parenting. Effect sizes in the groups with and without harsh parenting did not differ significantly. Gene‐environment interaction tests were conducted for individual genetic variants, resulting in two significant interaction effects (rs1497023 and rs4922132) after correction for multiple testing.ConclusionOur findings are suggestive of G × E interplay, with associations between dopamine genes and externalizing behavior present in children without harsh parenting, but not in children with harsh parenting experiences. Harsh parenting may overrule the role of genetic factors in externalizing behavior. Gene‐based and gene‐set analyses offer promising new alternatives to analyses focusing on single candidate polymorphisms when examining the interplay between genetic and environmental factors.
Tecto‐GIRz: Engineered Group I Ribozyme the Catalytic Ability of Which Can Be Controlled by Self‐Dimerization
Authors: Tanaka Takahiro , Matsumura Shigeyoshi , Furuta Hiroyuki , Ikawa Yoshiya 
Published: June 2016

AbstractRNA is a promising biomaterial for self‐assembly of nano‐sized structures with a wide range of applications in nanotechnology and synthetic biology. Several RNA‐based nanostructures have been reported, but most are unrelated to intracellular RNA, which possesses modular structures that are sufficiently large and complex to serve as catalysts to promote sophisticated chemical reactions. In this study, we designed dimeric RNA structures based on the Tetrahymena group I ribozyme. The resulting dimeric RNAs (tecto group I ribozyme; tecto‐GIRz) exhibit catalytic ability that depended on controlled dimerization, by which a pair of ribozymes can be activated to perform cleavage and splicing reactions of two distinct substrates. Modular redesign of complex RNA structures affords large ribozymes for use as modules in RNA nanotechnology and RNA synthetic biology.
Hepatocyte growth factor‐induced differentiation of bone mesenchymal stem cells toward hepatocyte‐like cells occurs through nuclear factor‐kappa B signaling in vitro
Authors: Yang Tongxi , Wang Yi , Jiang Shasha , Liu Xiaoping , Yu Zhongjie 
Published: June 2016

AbstractHepatocyte growth factor (HGF) is multifaceted cytokine that regulates proliferation, differentiation, morphology, and motility within numerous stem cells. More recently, HGF has been reported to induce the differentiation of bone mesenchymal stem cells (BMSCs) into mature hepatocytes, but the underlying biochemical and molecular signaling is largely unknown. We isolated BMSC from the bone marrow of rats, which were then cultured and exposed to HGF for 15 days. We subsequently assayed these cells for liver functionality and markers, and blocked NF‐кB signaling at various stages of the pathway. The present results demonstrate that HGF induces the differentiation of BMSCs toward hepatocyte‐like cells through the NF‐кB signaling. More specifically, HGF upregulated the translocation of NF‐кB to the nucleus.
Immunoglobulin G4‐related disease: a rare disease with an unusual presentation
Authors: Khan Muhammad Waqas , Hadley Terrance , Kesler Melissa , Gul Zartash 
Published: June 2016

Key Clinical MessageIgG4‐RD can also present in the skeletal muscle, mimicking several other diseases. It is unusual for this relatively new classification of diseases to present in the muscles and can be mistakenly diagnosed as other autoimmune diseases rendering a delay in the appropriate management and progression of the disease.
Synthesis, Optical Properties, and Electronic Structures of Tetrakis(pentafluorophenyl)tetrathiaisophlorin Dioxide
Authors: Mishra Vijay Lakshmi , Furuyama Taniyuki , Kobayashi Nagao , Goto Kenta , Miyazaki Takaaki , Yang Jye‐Shane , Shinmyozu Teruo 
Published: June 2016

AbstractThe synthesis, structure, optical and redox properties, and electronic structure of tetrakis(pentafluorophenyl)tetrathiaisophlorin dioxide (12) are reported. Oxidation of tetrakis(pentafluorophenyl)tetrathiaisophlorin (11) with dimethyldioxirane afforded the oxidized product, which was the tetrathiaisophlorin with two thiophene 1‐oxide moieties (12). More significant nonplanarity and greater bond length alternation in 12 than those of 11 were observed by X‐ray structural analysis. The absorption spectrum of 12 contains two bands at λ=348 and 276 nm, with a weak tail that extends to λ≈650 nm. Analysis of the magnetic circular dichroism spectrum of 12, based on Michl's 4N‐perimeter model and molecular orbital calculations, indicate that the broad band at λ=348 nm appears to contain N2 and P2 bands, and 12 is classified as a 4nπ system, similar to 11. The nuclear‐independent chemical shift values and 1H NMR spectroscopy data indicate that 12 has more antiaromatic character than 11.
Azlactone Reaction Developments
Authors: de Castro Pedro P. , Carpanez Arthur G. , Amarante Giovanni W. 
Published: June 2016

AbstractAzlactones (also known as oxazolones) are heterocycles usually employed in the stereoselective synthesis of α,α‐amino acids, heterocycles and natural products. The versatility of the azlactone scaffold arises from the numerous reactive sites, allowing its application in a diversity of transformations. This review aims to cover classical and recent applications of oxazolones, especially those involving stereoselective processes. After a short introduction on their structures and intrinsic reactivities, dynamic kinetic resolution (DKR) processes as well as reactions involving stereoselective formation of a new σ C−C bond, such as alkylation/allylation/arylation, aldol, ene, Michael and Mannich reactions will be exposed. Additionally, cycloadditions, Steglich rearrangement and sulfenylation reactions will also be discussed. Recent developments of the well‐known Erlenmeyer azlactones will be described. For the most examples, the proposed mechanism, activation modes and/or key reaction intermediates will be exposed to rationalize both the final product and the observed stereochemistry. Finally, this review gives an overview of the synthetic utility of oxazolones.
Hermetically Coated and Well‐Separated Co3O4 Nanophase within Porous Graphitic Carbon Nanosheets: Synthesis, Confinement Effect, and Improved Lithium‐Storage Capacity and Durability
Authors: Zhang Jingfei , Ren Wangyu , Zhou Yunyun , Li Pei , Xu Lin , Sun Dongmei , Wu Ping , Zhou Yiming , Tang Yawen 
Published: June 2016

AbstractConsiderable lithium‐driven volume changes and loss of crystallinity on cycling have impeded the sustainable use of transition metal oxides (MOs) as attractive anode materials for advanced lithium‐ion batteries that have almost six times the capacity of carbon per unit volume. Herein, Co3O4 was used as a model MO in a facile process involving two pyrolysis steps for in situ encapsulation of nanosized MO in porous two‐dimensional graphitic carbon nanosheets (2D‐GCNs) with high surface areas and abundant active sites to overcome the above‐mentioned problems. The proposed method is inexpensive, industrially scalable, and easy to operate with a high yield. TEM revealed that the encaged Co3O4 is well separated and uniformly dispersed with surrounding onionlike graphitic layers. By taking advantage of the high electronic conductivity and confinement effect of the surrounding 2D‐GCNs, a hierarchical GCNs‐coated Co3O4 (Co3O4@GCNs) anode with 43.5 wt % entrapped active nanoparticles delivered a remarkable initial specific capacity of 1816 mAh g−1 at a current density of 100 mA g−1. After 50 cycles, the retained capacity is as high as 987 mAh g−1. When the current density was increased to 1000 mA g−1, the anode showed a capacity retention of 416 mAh g−1. Enhanced reversible rate capability and prolonged cycling stability were found for Co3O4@GCN compared to pure GCNs and Co3O4. The Co3O4@GCNs hybrid holds promise as an efficient candidate material for anodes due to its low cost, environmentally friendly nature, high capacity, and stability.
Periodic Mesoporous Organosilica Nanoparticles with Controlled Morphologies and High Drug/Dye Loadings for Multicargo Delivery in Cancer Cells
Authors: Croissant Jonas G. , Fatieiev Yevhen , Omar Haneen , Anjum Dalaver H. , Gurinov Andrey , Lu Jie , Tamanoi Fuyuhiko , Zink Jeffrey I. , Khashab Niveen M. 
Published: June 2016

AbstractDespite the worldwide interest generated by periodic mesoporous organosilica (PMO) bulk materials, the design of PMO nanomaterials with controlled morphology remains largely unexplored and their properties unknown. In this work, we describe the first study of PMO nanoparticles (NPs) based on meta‐phenylene bridges, and we conducted a comparative structure–property relationship investigation with para‐phenylene‐bridged PMO NPs. Our findings indicate that the change of the isomer drastically affects the structure, morphology, size, porosity and thermal stability of PMO materials. We observed a much higher porosity and thermal stability of the para‐based PMO which was likely due to a higher molecular periodicity. Additionally, the para isomer could generate multipodal NPs at very low stirring speed and upon this discovery we designed a phenylene–ethylene bridged PMO with a controlled Janus morphology. Unprecedentedly high payloads could be obtained from 40 to 110 wt % regardless of the organic bridge of PMOs. Finally, we demonstrate for the first time the co‐delivery of two cargos by PMO NPs. Importantly, the cargo stability in PMOs did not require the capping of the pores, unlike pure silica, and the delivery could be autonomously triggered in cancer cells by acidic pH with nearly 70 % cell killing.
Facile Fabrication of Well‐Dispersed Pt Nanoparticles in Mesoporous Silica with Large Open Spaces and Their Catalytic Applications
Authors: Liu Xianchun , Chen Dashu , Chen Lin , Jin Renxi , Xing Shuangxi , Xing Hongzhu , Xing Yan , Su Zhongmin 
Published: June 2016

AbstractIn this paper, a facile strategy is reported for the preparation of well‐dispersed Pt nanoparticles in ordered mesoporous silica (Pt@OMS) by using a hybrid mesoporous phenolic resin‐silica nanocomposite as the parent material. The phenolic resin polymer is proposed herein to be the key in preventing the aggregation of Pt nanoparticles during their formation process and making contributions both to enhance the surface area and enlarge the pore size of the support. The Pt@OMS proves to be a highly active and stable catalyst for both gas‐phase oxidation of CO and liquid‐phase hydrogenation of 4‐nitrophenol. This work might open new avenues for the preparation of noble metal nanoparticles in mesoporous silica with unique structures for catalytic applications.
Enhancing Tumor Cell Response to Chemotherapy through the Targeted Delivery of Platinum Drugs Mediated by Highly Stable, Multifunctional Carboxymethylcellulose‐Coated Magnetic Nanoparticles
Authors: Medříková Zdenka , Novohradsky Vojtech , Zajac Juraj , Vrána Oldřich , Kasparkova Jana , Bakandritsos Aristides , Petr Martin , Zbořil Radek , Brabec Viktor 
Published: June 2016

AbstractThe fabrication of nanoparticles using different formulations, and which can be used for the delivery of chemotherapeutics, has recently attracted considerable attention. We describe herein an innovative approach that may ultimately allow for the selective delivery of anticancer drugs to tumor cells by using an external magnet. A conventional antitumor drug, cisplatin, has been incorporated into new carboxymethylcellulose‐stabilized magnetite nanoparticles conjugated with the fluorescent marker Alexa Fluor 488 or folic acid as targeting agent. The magnetic nanocarriers possess exceptionally high biocompatibility and colloidal stability. These cisplatin‐loaded nanoparticles overcome the resistance mechanisms typical of free cisplatin. Moreover, experiments aimed at the localization of the nanoparticles driven by an external magnet in a medium that mimics physiological conditions confirmed that this localization can inhibit tumor cell growth site‐specifically.
Evidence of Splitting 1,2,3‐Triazole into an Alkyne and Azide by Low Mechanical Force in the Presence of Other Covalent Bonds
Authors: Khanal Ashok , Long Fei , Cao Bin , Shahbazian‐Yassar Reza , Fang Shiyue 
Published: June 2016

AbstractThe cycloaddition reaction of an alkyne and azide to form a 1,2,3‐triazole is widely used in many areas. However, the stability of the triazole moiety under mechanical stress is unclear. To see if a triazole could be selectively split into an alkyne and azide in the presence of other typical covalent bonds, a mica surface functionalized with a molecule containing a triazole moiety in the middle and an activated ester at the end was prepared. An atomic force microscope (AFM) tip with amino groups on its surface was ramped over the mica surface at predefined locations, which could temporarily link the tip to the surface through amide bond formation. During retraction, the triazole or another bond in the linkage broke, and a force was recorded. The forces varied widely at different ramps from close to 0 pN to 860 pN due to nonspecific adhesions and to the inherent inconsistency of single bond rupture. If some of the forces were from triazole cycloreversion, there would be alkynes at the predefined ramping locations. The surface was reacted with an azide carboxylic acid followed by labeling with amino Au nanoparticles (AuNPs). AFM imaging revealed AuNPs at the predicted locations, which provided evidence that under certain conditions triazole could be split selectively in the presence of other bonds at forces below 860 pN.
Study on the Ultrahigh Quantum Yield of Fluorescent P,O‐g‐C3N4 Nanodots and its Application in Cell Imaging
Authors: Rong Mingcong , Cai Zhixiong , Xie Lei , Lin Chunshui , Song Xinhong , Luo Feng , Wang Yiru , Chen Xi 
Published: June 2016

AbstractGraphitic carbon nitride nanodots (g‐C3N4 nanodots), as a new kind of heavy‐metal‐free quantum dots, have attracted considerable attention because of their unique physical and chemical properties. Although various methods to obtain g‐C3N4 nanodots have been reported, it is still a challenge to synthesize g‐C3N4 nanodots with ultrahigh fluorescence quantum yield (QY). In this study, highly fluorescent phosphorus/oxygen‐doped graphitic carbon nitride (P,O‐g‐C3N4) nanodots were prepared by chemical oxidation and hydrothermal etching of bulk P‐g‐C3N4 derived from the pyrolysis of phytic acid and melamine. The as‐prepared P,O‐g‐C3N4 nanodots showed strong blue fluorescence and a relatively high QY of up to 90.2 %, which can be ascribed to intrinsic phosphorus/oxygen‐containing groups, and surface‐oxidation‐related fluorescence enhancement. In addition, the P,O‐g‐C3N4 nanodots were explored for cell imaging with excellent stability and biocompatibility, which suggest that they have great potential in biological applications.
Breakthrough in Xenon Capture and Purification Using Adsorbent‐Supported Silver Nanoparticles
Authors: Deliere Ludovic , Coasne Benoit , Topin Sylvain , Gréau Claire , Moulin Christophe , Farrusseng David 
Published: June 2016

AbstractRare gas capture and purification is a major challenge for energy, environment, and health applications. Of utmost importance for the nuclear industry, novel separation processes for Xe are urgently needed for spent nuclear fuel reprocessing and nuclear activity monitoring. The recovered, non‐radioactive Xe is also of high economic value for lighting, surgical anesthetic, etc. Here, using adsorption and breakthrough experiments and statistical mechanics molecular simulation, we show the outstanding performance of zeolite‐supported silver nanoparticles to capture/separate Xe at low concentrations (0.087–100 ppm). We also establish the efficiency of temperature swing adsorption based on such adsorbents for Xe separation from Kr/Xe mixtures and air streams corresponding to off‐gases generated by nuclear reprocessing. This study paves the way for the development of novel, cost‐efficient technologies relying on the large selectivity/capacity of adsorbent‐supported silver nanoparticles which surpass all materials ever tested.
Nucleophilicity of Alkyl Zirconocene and Titanocene Precatalysts, and Kinetics of Activation by Carbenium Ions and by B(C6F5)3
Authors: Berionni Guillaume , Kurouchi Hiroaki , Eisenburger Lucien , Mayr Herbert 
Published: June 2016

AbstractKinetics of activation of methyl and benzyl metallocene precatalysts by benzhydrylium ions, tritylium ions, and triarylborane B(C6F5)3were measured spectrophotometrically. The rate constants correlate linearly with the electrophilicity parameterEof the benzhydrylium and tritylium ions employed, allowing us to determine the σ‐nucleophilicities of the metal–carbon bond of several zirconocenes and titanocenes. Bridging, substitution, metal, and ligand effects on the rates of metal–alkyl bond cleavage (M=Zr, Ti) were studied and structure–reactivity correlations were used to predict the kinetics of generation of metallocenium ions pairs, which are active catalysts in polymerization reactions and are highly electrophilic Lewis acids in frustrated Lewis pair catalysis.
Desymmetrization of an Octahedral Coordination Complex Inside a Self‐Assembled Exoskeleton
Authors: Johnstone Mark D. , Schwarze Eike K. , Ahrens Jennifer , Schwarzer Dirk , Holstein Julian J. , Dittrich Birger , Pfeffer Frederick M. , Clever Guido H. 
Published: June 2016

AbstractThe synthesis of a centrally functionalized, ribbon‐shaped [6]polynorbornane ligand L that self‐assembles with PdII cations into a {Pd2L4} coordination cage is reported. The shape‐persistent {Pd2L4} cage contains two axial cationic centers and an array of four equatorial H‐bond donors pointing directly towards the center of the cavity. This precisely defined supramolecular environment is complementary to the geometry of classic octahedral complexes [M(XY)6] with six diatomic ligands. Very strong binding of [Pt(CN)6]2− to the cage was observed, with the structure of the host–guest complex {[Pt(CN)6]@Pd2L4} supported by NMR spectroscopy, MS, and X‐ray data. The self‐assembled shell imprints its geometry on the encapsulated guest, and desymmetrization of the octahedral platinum species by the influence of the D4h‐symmetric second coordination sphere was evidenced by IR spectroscopy. [Fe(CN)6]3− and square‐planar [Pt(CN)4]2− were strongly bound. Smaller octahedral anions such as [SiF6]2−, neutral carbonyl complexes ([M(CO)6]; M=Cr, Mo, W) and the linear [Ag(CN)2]− anion were only weakly bound, showing that both size and charge match are key factors for high‐affinity binding.