bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optical‐Resolution Photoacoustic Microscopy for Volumetric and Spectral Analysis of Histological and Immunochemical Samples
Authors: Zhang Yu Shrike , Yao Junjie , Zhang Chi , Li Lei , Wang Lihong V. , Xia Younan 
Published: June 2014

AbstractOptical‐resolution photoacoustic microscopy (OR‐PAM) is an imaging modality with superb penetration depth and excellent absorption contrast. Here we demonstrate, for the first time, that this technique can advance quantitative analysis of conventional chromogenic histochemistry. Because OR‐PAM can quantify the absorption contrast at different wavelengths, it is feasible to spectrally resolve the specific biomolecules involved in a staining color. Furthermore, the tomographic capability of OR‐PAM allows for noninvasive volumetric imaging of a thick sample without microtoming it. By immunostaining the sample with different chromogenic agents, we further demonstrated the ability of OR‐PAM to resolve different types of cells in a coculture sample with imaging depths up to 1 mm. Taken together, the integration of OR‐PAM with (immuno)histochemistry offers a simple and versatile technique with broad applications in cell biology, pathology, tissue engineering, and related biomedical studies.
Bioinspired Total Synthesis of Sespenine
Authors: Sun Yu , Chen Pengxi , Zhang Deliang , Baunach Martin , Hertweck Christian , Li Ang 
Published: June 2014

AbstractThe first total synthesis of sespenine, a rare indole sesquiterpenoid from a mangrove endophyte, has been accomplished. A bioinspired aza‐Prins/Friedel–Crafts/retro Friedel–Crafts cascade reaction assembles the bridged tetrahydroquinoline core. Further investigations on the aza‐Prins cyclization imply that the C3 configuration of the hydroxyindolenine intermediate is crucial to the biosynthesis of sespenine and its congener xiamycin A.
Bio‐reduction of Redox‐Sensitive Albumin Conjugates in FcRn‐Expressing Cells
Authors: Brülisauer Lorine , Valentino Gina , Morinaga Sakura , Cam Kübra , Thostrup Bukrinski Jens , Gauthier Marc A. , Leroux Jean‐Christophe 
Published: June 2014

AbstractDisulfide‐containing IgG‐, Fc‐, or albumin‐based prodrugs that rely on FcRn‐trafficking by endothelial cells for prolonged circulation in the body might be hampered by premature bio‐reduction processes during FcRn‐mediated recycling events. A detailed bio‐reduction analysis of redox‐sensitive albumin conjugates in two FcRn‐expressing cell lines has been performed. The obtained results indicate that the FcRn‐mediated recycling pathway is not (or is only poorly) bio‐reducing.
Iridium‐Catalyzed Regioselective Silylation of Aromatic and Benzylic CH Bonds Directed by a Secondary Amine
Authors: Li Qian , Driess Matthias , Hartwig John F. 
Published: June 2014

AbstractReported herein is an iridium‐catalyzed, regioselective silylation of the aromatic CH bonds of benzylamines and the benzylic CH bonds of 2,N‐dialkylanilines. In this process, (hydrido)silyl amines, generated in situ by dehydrogenative coupling of benzylamine or aniline with diethylsilane, undergo selective silylation at the CH bond γ to the amino group. The products of this silylation are suitable for subsequent oxidation, halogenation, and cross‐coupling reactions to deliver benzylamine and arylamine derivatives.
Trifluoromethylation of Alkenes with Concomitant Introduction of Additional Functional Groups
Authors: Egami Hiromichi , Sodeoka Mikiko 
Published: June 2014

AbstractThe trifluoromethyl group is found in many synthetic bioactive compounds, and the difunctionalization of a CC bond, as a powerful strategy for the construction of compounds with various functional groups, has been intensively investigated. Therefore, the difunctionalizing trifluoromethylation of alkenes has attracted growing interest because of the potential of the products as building blocks for bioactive molecules. In this review, we focus on recent advances in the trifluoromethylation of alkenes with concomitant introduction of additional functional groups.
Strategies for the Synthesis of Functional Naphthalene Diimides
Authors: Suraru Sabin‐Lucian , Würthner Frank 
Published: June 2014

AbstractNaphthalene diimides, which have for a long time been in the shadow of their higher homologues the perylene diimides, currently belong to the most investigated classes of organic compounds. This is primarily due to the initial synthetic studies on core functionalization that were carried out at the beginning of the last decade, which facilitated diverse structural modifications of the naphthalene scaffold. Compounds with greatly modified optical and electronic properties that can be easily and effectively modulated by appropriate functionalization were made accessible through relatively little synthetic effort. This resulted in diverse interesting applications. The electron‐deficient character of these compounds makes them highly valuable, particularly in the field of organic electronics as air‐stable n‐type semiconductors, while absorption bands over the whole visible spectral range through the introduction of core substituents enabled interesting photosystems and photovoltaic applications. This Review provides an overview on different approaches towards core functionalization as well as on synthetic strategies for the core expansion of naphthalene diimides that have been developed mainly in the last five years.
Electrochemically Generated Gradients
Authors: Krabbenborg Sven O. , Huskens Jurriaan 
Published: June 2014

AbstractThis review surveys recent developments in the field of electrochemically generated gradients. The gradual variation of properties, which is a key characteristic of gradients, is of eminent importance in technology, for example, directional wetting, as well as biology, for example, chemotaxis. Electrochemical techniques offer many benefits, such as the generation of dynamic solution and surface gradients, integration with electronics, and compatibility with automation. An overview is given of newly developed methods, from purely electrochemical techniques to the combination of electrochemistry with other methods. Electrochemically fabricated gradients are employed extensively for biological and technological applications, such as high‐throughput screening, high‐throughput deposition, and device development, all of which are covered herein. Especially promising are developments towards the study and control of dynamic phenomena, such as the directional motion of molecules, droplets, and cells.
Chemical‐Shift‐Resolved 19F NMR Spectroscopy between 13.5 and 135 MHz: Overhauser–DNP‐Enhanced Diagonal Suppressed Correlation Spectroscopy
Authors: George Christy , Chandrakumar Narayanan 
Published: June 2014

AbstractOverhauser–DNP‐enhanced homonuclear 2D 19F correlation spectroscopy with diagonal suppression is presented for small molecules in the solution state at moderate fields. Multi‐frequency, multi‐radical studies demonstrate that these relatively low‐field experiments may be operated with sensitivity rivalling that of standard 200–1000 MHz NMR spectroscopy. Structural information is accessible without a sensitivity penalty, and diagonal suppressed 2D NMR correlations emerge despite the general lack of multiplet resolution in the 1D ODNP spectra. This powerful general approach avoids the rather stiff excitation, detection, and other special requirements of high‐field 19F NMR spectroscopy.
Transition‐Metal‐Free Tunable Chemoselective N Functionalization of Indoles with Ynamides
Authors: Hentz Alexandre , Retailleau Pascal , Gandon Vincent , Cariou Kevin , Dodd Robert H. 
Published: June 2014

AbstractTwo unprecedented N functionalizations of indoles with ynamides are described. By varying the electron‐withdrawing group on the ynamide nitrogen atom, either Z‐indolo‐etheneamides or indolo‐amidines can be selectively obtained under the same metal‐free reaction conditions. The scope and synthetic potential of these reactions, as well as some mechanistic insights provided by DFT calculations, are reported.
The Total Synthesis of (−)‐Nitidasin
Authors: Hog Daniel T. , Huber Florian M. E. , Mayer Peter , Trauner Dirk 
Published: June 2014

AbstractNitidasin is a pentacyclic sesterterpenoid with a rare 5‐8‐6‐5 carbon skeleton that was isolated from the Peruvian folk medicine “Hercampuri”. It belongs to a small class of sesterterpenoids that feature an isopropyl trans‐hydrindane moiety fused to a variety of other ring systems. As a first installment of our general approach toward these natural products, we report the total synthesis of the title compound. Our stereoselective, convergent route involves the addition of a complex alkenyl lithium compound to a trans‐hydrindanone, followed by chemoselective epoxidation, ring‐closing olefin metathesis, and redox adjustment.
Mesoporous silica nanoparticles with different pore sizes for delivery of pH‐sensitive gallic acid
Authors: Rashidi Ladan , Vasheghani‐Farahani Ebrahim , Rostami Khosrow , Ganji Fariba , Fallahpour Masoud 
Published: June 2014

ABSTRACTIn this study, mesoporous silica nanoparticles (MSN) with different pore diameters were used for encapsulation of gallic acid (GA). All nanoparticles were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, N2 adsorption isotherms, scanning electron microscopy, X‐ray diffraction, and z‐potential analysis for determination of their characterizations. The effects of different pore sizes of nanoparticles on loading of GA and its release from GA‐loaded nanoparticles into simulated gastric fluid (SGF, pH 1.2), simulated intestinal and colon fluids (SIF and SCF, pHs 6.8 and 7.4, respectively), simulated body fluid (SBF, pH 7.4), and simulated gastrointestinal tract fluid (SGITF) were investigated. The pore size increased with the increase of mixing time of mesitylene as a swelling agent. GA is an unstable molecule that decomposes in alkaline pH. The imidazole buffer is the best for investigation of GA release into the alkaline media. The increase of nanoparticles pore size made the enhancement of GA loading. The released GA from GA‐loaded nanoparticles into SGF was slower than that into SIF and SBF. Release of GA was strongly pH dependent on the selected media. The antioxidant activity, based on the 1,1‐diphenyl‐2‐picrylhydrazyl assay, of released GA into SGITF and SBF was conserved and correlated strongly with its content in the selected media. © 2014 Curtin University of Technology and John Wiley & Sons, Ltd.
Nitrile functionalized benzoxazine/bismaleimide blends and their glass cloth reinforced laminates
Authors: Zhang Jing , Zhu Chunli , Geng Pengfeng , Wei Yanze , Lu Zaijun 
Published: June 2014

ABSTRACTA novel high‐performance resin blend composed of nitrile functionalized benzoxazine (CNBZ) and bismaleimide (4,4′‐bismaleimidodiphenyl methane) (BMI) was prepared via solvent method. Its curing behaviors, thermal properties, and mechanical properties were studied by differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FTIR), dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), and universal testing machine, respectively. The results showed that the addition reaction between phenolic hydroxyl group and the double bond occurred except for the homopolymerization of CNBZ and BMI. When BMI content was more than 40%, the cured CNBZ/BMI blends exhibited higher glass transition temperatures (Tgs) than CNBZ and BMI homopolymers, which reached up to 334°C. Meanwhile, when BMI content was 40%, the tensile strength, flexural strength, and shearing strength reached up to 69, 235, and 12.9 MPa, respectively, which exhibited the comparable mechanical properties with BT resin. Furthermore, the glass cloth (GF) reinforced laminates based on these blends were prepared. The results showed that when BMI content was 40%, their tensile strength, flexural strength, and impact strength reached up to 334 MPa, 593 MPa, and 145 KJ m−2, respectively. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41072.
Lignin valorization by forming thermally stimulated shape memory copolymeric elastomers—Partially crystalline hyperbranched polymer as crosslinks
Authors: Li Hui , Sivasankarapillai Gopakumar , McDonald Armando G. 
Published: June 2014

ABSTRACTLignin based thermal‐responsive elastomers were produced by a melt polycondensation reaction with a long alkyl chain hyperbranched poly(ester‐amine‐amide) (B3‐A2‐CB31). The effect of lignin content on elastomers properties was investigated. The thermal and mechanical properties of the copolymers were characterized by DMA, DSC, and TGA. The morphology of the copolymer was examined by SEM. Tensile properties were dominated by HBP <25% lignin content while lignin dominated >25% content. The copolymers glass transition temperature (Tg) increased with lignin content. The elastomer with 30% lignin content demonstrated optimal mechanical properties (tensile strength 5.3 MPa, Young's modulus 8.9 MPa, strain at break 301%, and toughness 1.03 GPa). Thermally stimulated dual shape memory effects (SME) of the copolymers were quantified by cyclic thermomechanical tests. The transition temperature (Ttrans) of the polymer was able to be controlled (room to body temperature) by varying the amount of lignin added which broadens the range to medical applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41103.
Platinum and Palladium Nanotubes Based on Genetically Engineered Elastin–Mimetic Fusion Protein‐Fiber Templates: Synthesis and Application in Lithium‐O2 Batteries
Authors: Guo Guilue , Truong Thi Hong Anh , Tan Huiteng , Ang Huixiang , Zhang Wenyu , Xu Chen , Rui Xianghong , Hu Zhaolong , Fong Eileen , Yan Qingyu 
Published: June 2014

AbstractThe coupling of proteins with self‐assembly properties and proteins that are capable of recognizing and mineralizing specific inorganic species is a promising strategy for the synthesis of nanoscale materials with controllable morphology and functionality. Herein, GPG‐AG3 protein fibers with both of these properties were constructed and served as templates for the synthesis of Pt and Pd nanotubes. The protein fibers of assembled GPG‐AG3 were more than 10 μm long and had diameters of 20–50 nm. The as‐synthesized Pt and Pd nanotubes were composed of dense layers of ∼3–5 nm Pt and Pd nanoparticles. When tested as cathodes in lithium‐O2 batteries, the porous Pt nanotubes showed low charge potentials of 3.8 V, with round‐trip efficiencies of about 65 % at a current density of 100 mA g−1.
Copper‐Catalyzed Synthesis of 1,1‐Diborylalkanes through Regioselective Dihydroboration of Terminal Alkynes
Authors: Lee Sumin , Li Dingxi , Yun Jaesook 
Published: June 2014

AbstractThe copper‐catalyzed sequential hydroboration of terminal alkynes with pinacolborane to prepare 1,1‐diborylalkanes directly from alkynes was studied. Protected propargyl amines, propargyl alcohol derivatives, and simple alkynes regioselectively produced the desired 1,1‐diborylalkanes in good yields with a copper/xantphos catalyst.
Salting‐out‐assisted liquid–liquid extraction with acetonitrile for the determination of trimetazidine in rat plasma using liquid chromatography–mass spectrometry
Authors: Xiong Xin , Yang Li. 
Published: June 2014

AbstractA high‐throughout bioanalytical method based on salting‐out‐assisted liquid/liquid extraction (SALLE) method with acetonitrile and mass spectrometry‐compatible salts followed by LC‐MS/MS analysis of trimetazidine in rat plasma is presented. It required only 50 μL of plasma and allows the use of minimal volumes of organic solvents. The seamless interface of SALLE and LC‐MS eliminated the drying‐down step and the extract was diluted and injected into an LC‐MS/MS system with a cycle time of 2.5 min/sample. The retention times of trimetazidine and IS were approximately 1.1 and 1.7 min, respectively. Calibration curves were linear over the concentration range of 0.1–100 ng/mL, which can be extended to 500 ng/mL by dilution. The intra‐ and inter‐batch precision, accuracy and the relative standard deviation were all <15%. This method was successfully applied to determine trimetazidine concentrations in rat plasma. Copyright © 2014 John Wiley & Sons, Ltd.
Rapid and sensitive determination of levofloxacin in microsamples of human plasma by high‐performance liquid chromatography and its application in a pharmacokinetic study
Authors: Aguilar‐Carrasco José Carlos , Hernández‐Pineda Jessica , Jiménez‐Andrade Juan Miguel , Flores‐Murrieta Francisco Javier , Carrasco‐Portugal Miriam del Carmen , López‐Canales Jorge Skiold 
Published: June 2014

AbstractA rapid, sensitive and simple high‐performance liquid chromatographic assay with ultraviolet detection was developed for the quantification of levofloxacin in microsamples (100 μL) of human plasma. The extraction procedure included a protein precipitation technique and a short chromatographic running time (4.5 min). Analyses were carried out on a Symmetry C18 column using a mixture of acetonitrile and 0.01 m potassium dihydrogen aqueous solution (pH 3.4; 14:86 v/v) as mobile phase. The method provided specificity and was linear (r ≥ 0.9992) over the concentration range 0.1–12 µg/mL. The average absolute recovery was 93.59%. The intra‐ and inter‐day coefficients of variation were <6%. Additionally, levofloxacin was stable in all evaluations. The usefulness of this method was demonstrated in a pharmacokinetic study of levofloxacin in healthy adult volunteers. The present method offers two main advantages: (a) the use of microsamples reduces the total volume of blood to be collected from patients; and (b) it provides a good cost–effectiveness ratio. It is concluded that the method is rapid, simple, sensitive, economical and suitable for the determination of levofloxacin in human plasma using a small volume of sample. Copyright © 2014 John Wiley & Sons, Ltd.
The highly sensitive brain: an fMRI study of sensory processing sensitivity and response to others' emotions
Authors: Acevedo Bianca P. , Aron Elaine N. , Aron Arthur , Sangster Matthew‐Donald , Collins Nancy , Brown Lucy L. 
Published: June 2014

AbstractBackgroundTheory and research suggest that sensory processing sensitivity (SPS), found in roughly 20% of humans and over 100 other species, is a trait associated with greater sensitivity and responsiveness to the environment and to social stimuli. Self‐report studies have shown that high‐SPS individuals are strongly affected by others' moods, but no previous study has examined neural systems engaged in response to others' emotions.MethodsThis study examined the neural correlates of SPS (measured by the standard short‐form Highly Sensitive Person [HSP] scale) among 18 participants (10 females) while viewing photos of their romantic partners and of strangers displaying positive, negative, or neutral facial expressions. One year apart, 13 of the 18 participants were scanned twice.ResultsAcross all conditions, HSP scores were associated with increased brain activation of regions involved in attention and action planning (in the cingulate and premotor area [PMA]). For happy and sad photo conditions, SPS was associated with activation of brain regions involved in awareness, integration of sensory information, empathy, and action planning (e.g., cingulate, insula, inferior frontal gyrus [IFG], middle temporal gyrus [MTG], and PMA).ConclusionsAs predicted, for partner images and for happy facial photos, HSP scores were associated with stronger activation of brain regions involved in awareness, empathy, and self‐other processing. These results provide evidence that awareness and responsiveness are fundamental features of SPS, and show how the brain may mediate these traits.
Fe2O3–Ag Porous Film Anodes for Ultrahigh‐Rate Lithium‐Ion Batteries
Authors: Zhang Dan , Li Yong , Yan Mi , Jiang Yinzhu 
Published: June 2014

AbstractFe2O3 is a candidate material for anodes in Li‐ion batteries due to its high theoretical capacity. However, the practical application of Fe2O3 is still limited by its sluggish conversion reactions. In this work, porous Fe2O3 films with homogeneously dispersed Ag nanoparticles are fabricated using a facile one‐step electrostatic spray deposition technique. Both the unique, highly porous structure and the conducting Ag metal contribute to the outstanding electrochemical performance of the anode. The Fe2O3–Ag composite anode retains stable capacities of 1042 (0.1 C), 961 (1 C) and 857 mA h g−1 (5 C) over 100 cycles. When cycled at even higher rates, competitive capacities of 555 (15 C) and 509 mA h g−1 (20 C) are still acquired. This work might present opportunities to develop an oxide–metal anode with high capacity, long cycling life and good rate capability for Li‐ion batteries.
Boron‐Doped Diamond Functionalization by an Electrografting/Alkyne–Azide Click Chemistry Sequence
Authors: Yeap Weng Siang , Murib Mohammed Sharif , Cuypers Wim , Liu Xianjie , van Grinsven Bart , Ameloot Marcel , Fahlman Mats , Wagner Patrick , Maes Wouter , Haenen Ken 
Published: June 2014

AbstractA straightforward protocol for the covalent functionalization of boron‐doped diamond electrodes with either ferrocene or single‐stranded deoxyribonucleic acid (DNA) is reported. The functionalization method is based on a combination of diazonium salt electrografting and click chemistry. An azide‐terminated organic layer is first electrografted onto the diamond surface by electrochemical reduction of 4‐azidophenyldiazonium chloride. The azidophenyl‐modified surface then reacts rapidly and efficiently with molecules bearing a terminal alkyne moiety by means of CuI‐catalyzed alkyne–azide cycloaddition. Covalent attachment of ferrocene moieties was analyzed by X‐ray photoelectron spectroscopy and cyclic voltammetry, whereas impedance spectroscopy was applied for the characterization of the immobilized DNA.
Impact of the Counter‐Electrode Material on Redox Processes in Resistive Switching Memories
Authors: Tappertzhofen Stefan , Waser Rainer , Valov Ilia 
Published: June 2014

AbstractCation‐based resistive‐switching memories rely on the injection and drift of metal ions in nanoscale thin films. In insulators that do not initially contain mobile cations, such as SiO2, Ta2O5, and so forth, water redox reactions occurring at the counter electrode (CE) were found to be essential in enabling the dissolution of the active electrode and to keep electroneutrality. In this study, we report on the impact of the CE on redox processes prior to resistive switching. Potentiodynamic measurements for various electrode materials revealed that the catalytic activity of the CE towards the water redox process determines the concentration of dissolved ions within the oxide and influences the rate of the total cell reaction. This trend can be used as an indicator for the design of both cation‐ and anion‐conducting oxide‐based resistive‐switching random‐access memories.
A Tetrathiafulvalene (TTF)‐Conjugated Microporous Polymer Network
Authors: Bildirir Hakan , Paraknowitsch Jens Peter , Thomas Arne 
Published: June 2014

AbstractConjugated microporous polymer networks have been prepared from the strong electron donor tetrathiafulvalene (TTF) and 1,3,5‐triethynylbenzene (TEB) by using the Sonogashira–Hagihara cross‐coupling reaction. Optimization of reaction conditions yields polymers with surface areas of up to 434 m2 g−1. The strong electron‐donating properties of the network can be proven by iodine exposure. Structural and electronic changes due to formation of the charge‐transfer salt from TTFs in the porous network and iodine within the pores are investigated.