bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies on Chemical Modification of Porous Silicon‐Based Graded‐Index Optical Microcavities for Improved Stability Under Alkaline Conditions
Authors: Jalkanen T. , Mäkilä E. , Suzuki Y.‐I. , Urata T. , Fukami K. , Sakka T. , Salonen J. , Ogata Y. H. 
Published: May 2012

AbstractPreparation of graded‐index optical microcavities based on porous silicon is demonstrated, and chemical modifications for obtaining improved stability under alkaline conditions are studied. Four surface modification methods for stabilizing the samples are examined, and the effects on the optical properties are verified. Two different thermal carbonization treatments resulting in hydrophilic and hydrophobic surfaces are employed. In addition, modification with undecylenic acid is performed on as‐prepared and thermally hydrocarbonized porous silicon surfaces. Stability and sensing capabilities of the modified samples are examined by subjecting them to different concentrations of methylamine and trimethylamine vapors. Vapor induced changes in the reflectance spectra are used for evaluating sensitivity and stability. Sensitivity towards ethanol vapor is also measured in order to compare the sensitivity to a normal organic solvent. The results show that the two carbonization treatments and the undecylenic acid functionalization of the hydrocarbonized surface result in greatly improved stability. In contrast, derivatization of as‐prepared porous silicon with undecylenic acid does not protect the surface sufficiently against oxidation under the highly basic conditions produced by the amine vapors. Surface chemistry is also shown to have a large effect on sensitivity towards the examined vapors. X‐ray photoelectron spectroscopy was used to assess changes in elemental composition of sample surface. The results suggest that thermally promoted addition of undecylenic acid on hydrocarbonized porous silicon is an effective method for producing highly stable optical structures with a carboxyl group functionalization.
Chirality of Metal Nanoparticles in Chiral Mesoporous Silica
Authors: Xie Junjie , Duan Yingying , Che Shunai 
Published: May 2012

AbstractChiroptical properties of pure inorganic material have been achieved by dispersing small amounts of achiral Ag nanoparticles into highly ordered chiral mesoporous silica. There are three types of chirality in chiral mesoporous silica: i) the helical hexagonal surface, ii) the helical pore orientation, and iii) the helical arrangement of aminopropyl groups on the surface of the mesopores, all of which impart plasmonic circular dichroism and have been investigated by introducing Ag nanoparticles into the as‐made, calcined and extracted chiral mesoporous silica, respectively. The three types of optical response originate from asymmetric plasmon‐plasmon interactions of achiral Ag nanoparticles in three types of chiral environments. Among the three sources of chirality, the helical pore orientation was considered to be predominantly responsible for the optical response owing to the high efficiency of nanoscale chirality. Interestingly, large Ag nanoparticles aggregation as a result of calcination still resulted in a strong optical activity, even the chiral mesostructure was destroyed completely. Rather than the pitch length, the length of helical channel was more effective for increasing the intensity of plasmonic circular dichroism due to longitudinal propagation of Ag nanoparticles along helical channel. Such novel chiral inorganic material will bring new opportunities in non‐linear optics, biosensors and chiral recognition.
The Electrochemical Flow Capacitor: A New Concept for Rapid Energy Storage and Recovery
Authors: Presser Volker , Dennison Christopher R. , Campos Jonathan , Knehr Kevin W. , Kumbur Emin C. , Gogotsi Yury 
Published: May 2012

AbstractAvailability of grid‐scale electric energy storage systems with response rates on the order of seconds plays a key role in wide implementation of renewable energy sources. Here, a new concept called the electrochemical flow capacitor (EFC) is presented. This new concept shares the major advantages of both supercapacitors and flow batteries, providing rapid charging/discharging while enabling the decoupling of the power and energy ratings. Like in supercapacitors, energy is stored in the electric double layer of charged carbon particles. A flowable carbon‐electrolyte mixture is employed as the active material for capacitive energy storage, and is handled in a similar fashion to flow or semi‐solid batteries (i.e., for charging/discharging, it is pumped into an electrochemical cell, and for storage, it is pumped into reservoirs). This study presents the proof‐of‐concept of this technology and reports initial EFC performance data obtained under static and intermittent flow operations.
Definition of a critical genetic interval related to kidney abnormalities in the Potocki–Lupski syndrome
Authors: Goh Elaine Suk‐Ying , Perez Irene C. , Canales Cesar P. , Ruiz Phillip , Agatep Ron , Yoon Grace , Chitayat David , Dror Yigal , Shago Mary , Goobie Sharan , Sgro Michael , Walz Katherina , Mendoza‐Londono Roberto 
Published: May 2012

AbstractPotocki–Lupski syndrome is a genomic disorder caused by duplication of 17p11.2. It is characterized by failure to thrive, intellectual disability, hypotonia, and behavioral difficulties. Structural renal anomalies have been observed in <10% of affected individuals. We present detailed clinical and molecular data on six patients with Potocki–Lupski syndrome, two of whom had renal abnormalities, and investigate the prevalence of kidney abnormalities in the mouse model for the syndrome. In contrast to affected humans, the mouse model does not demonstrate a renal phenotype. Comparison of the duplicated segment in patients with Potocki–Lupski syndrome and the renal phenotype and the syntenic duplicated region in the mouse model allowed us to suggest a 0.285 Mb critical region, including the FLCN gene that may be important for development of renal abnormalities in patients with this duplication. © 2012 Wiley Periodicals, Inc.
Miscibility study of chitosan/polyethylene glycol fumarate blends in dilute solutions
Authors: Doulabi Azadehsadat Hashemi , Mirzadeh Hamid , Imani Mohammad 
Published: May 2012

AbstractSolution miscibility of chitosan/polyethylene glycol fumarate blends dissolved in acetate buffer solution was investigated in different blend compositions by viscosity, density, and refractive index measurement techniques at 30, 40, and 50°C. In order to quantify the miscibility of the polymer pair, degree of miscibility was studied by means of two criteria known as interaction parameters i.e., μ and α. On the basis of the sign convention involved in these criteria, these values revealed that the blend solution was miscible when the chitosan content was more than 80% (w/w) of the composition. The results were confirmed by density, and refractive index measurements. Furthermore, the results showed that the miscibility window of chitosan/polyethylene glycol fumarate blends was independent with respect to the changes in solution temperature. Therefore, these results suggested due to intermolecular hydrogen‐bonding interaction between amino and hydroxy groups of chitosan and hydroxy groups of polyethylene glycol fumarate which play an important role in the formation of miscible phase. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Layer double hydroxides for enhanced poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) crystallization
Authors: Dagnon Koffi L. , Robinson Clark , Chen Hua H. , Garrett David C. , Innocentini‐Mei Lucia H. , D'Souza Nandika A. 
Published: May 2012

AbstractEnabling the widespread utilization of poly[(3‐hydroxybutyrate)‐co‐(3‐hydroxyvalerate)] (PHBV) is strongly associated with enhancing its crystallization kinetics. In this article, we utilize a highly surface active (one reactive group per nanometer square) anion exchanged layered‐double hydroxide (LDH) functionalized by stearic acid to probe the crystallization kinetics of PHBV. Our prior work has shown that the addition of LDH decreases the cold crystallization and induces a melt recrystallization peak in PHBV. Since the melt‐recrystallization temperature shifted to higher temperature and its corresponding enthalpy increased with increasing LDH loading, this article is focused on understanding the effect of LDH on kinetics and energetics of PHBV crystallization. Both Avrami and Lauritzen–Hoffman modeling are utilized to develop a comprehensive understanding of thermal history effects through differential scanning calorimetry and polarized optical microscopy measurements. Five concentrations by weight of LDH are used: 1, 3, 5, and 7%. The results show that the addition of LDH promoted both primary and secondary nucleation at low concentrations but additional LDH resulted in primary nucleation alone. The crystallization rate and activation energy show a significant increase, which is accompanied by a decrease in the nucleation constant, the surface energy and the work of chain folding for PHBV crystallization. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2013
Pressurized water pellets and supercritical nitrogen in injection molding
Authors: Cabrera Eusebio Duarte , Mulyana Rachmat , Castro Jose M. , Lee L. James , Min Yong 
Published: May 2012

AbstractIn this article, a novel approach to decrease cycle time without compromising part dimensional stability developed in our group is compared with the use of supercritical nitrogen in injection molding. In this new approach, water is pre‐pressurized into the polymer pellets containing water carrier particles such as activated carbon (AC), thus no molding equipment modifications are required. Because of its high porosity, AC can trap water inside the particle, thus improving water compatibility with hydrophobic polymers for less water loss during handling and in the barrel during injection molding. After mixing, the polymer with the water carrier, the pellets are batch pressurized with water at a controlled temperature and pressure. The water containing pellets are then fed into the hopper of the injection molding machine. Parts with similar densities were molded and mechanical properties and warpage for both processes compared. It was found that the warpage and mechanical properties of the method presented here are comparable with the use of supercritical nitrogen, which is used in microcellular injection molding. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Amphiphilic and biocompatible properties of poly (EA‐MAA)
Authors: Luo Xiadan , Zhu Aiping , Dai Sheng 
Published: May 2012

AbstractThe amphiphilic and biocompatible behaviors of Poly (acetate‐methylacrylic acid) Poly(EA‐MAA) were investigated in this study. The aggregation behavior of Poly(EA‐MAA) in aqueous media was investigated by steady‐state fluorescence spectroscopy and surface tensiometry. The critical aggregation concentration (cac) of Poly(EA‐MAA) was determined to be ∼0.03 mg/mL. Ultraviolet spectrum (UV) and fluorescence spectrum results indicated that there are interactions form between Poly(EA‐MAA) and bovine serum albumin (BSA). And β‐sheet can be changed into α‐helix of BSA in Poly(EA‐MAA) solution effectively revealed by Circular dichroism (CD), which is driven by the H‐bond and hydrophobic interactions. The good cell‐compatibility of Poly(EA‐MAA) makes it great potential in the biomedical fields. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Arctigenin Anti‐Tumor Activity in Bladder Cancer T24 Cell Line Through Induction of Cell‐Cycle Arrest and Apoptosis
Authors: Yang Shucai , Ma Jing , Xiao Jianbing , Lv Xiaohong , Li Xinlei , Yang Huike , Liu Ying , Feng Sijia , Zhang Yafang 
Published: May 2012

AbstractBladder cancer is the most common neoplasm in the urinary system. This study assesses arctigenin anti‐tumor activity in human bladder cancer T24 cells in vitro and the underlying molecular events. The flow cytometry analysis was used to detect cell‐cycle distribution and apoptosis. Western blotting was used to detect changes in protein expression. The data showed that arctigenin treatment reduced viability of bladder cancer T24 cells in a dose‐ and time‐dependent manner after treatment with arctigenin (10, 20, 40, 80, and 100 μmol/L) for 24 hr and 48 hr. Arctigenin treatment clearly arrested tumor cells in the G1 phase of the cell cycle. Apoptosis was detected by hoechst stain and flow cytometry after Annexin‐V‐FITC/PI double staining. Early and late apoptotic cells were accounted for 2.32–7.01% and 3.07–7.35%, respectively. At the molecular level, arctigenin treatment decreased cyclin D1 expression, whereas CDK4 and CDK6 expression levels were unaffected. Moreover, arctigenin selectively altered the phosphorylation of members of the MAPK superfamily, decreasing phosphorylation of ERK1/2 and activated phosphorylation of p38 significantly in a dose‐dependent manner. These results suggest that arctigenin may inhibit cell viability and induce apoptosis by direct activation of the mitochondrial pathway, and the mitogen‐activated protein kinase pathway may play an important role in the anti‐tumor effect of arctigenin. The data from the current study demonstrate the usefulness of arctigenin in bladder cancer T24 cells, which should further be evaluated in vivo before translation into clinical trials for the chemoprevention of bladder cancer. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.
Predicting protein dynamic binding capacity from batch adsorption tests
Authors: Carta Giorgio 
Published: May 2012

AbstractThe dynamic binding capacity (DBC) and its dependence on residence time influence the design and productivity of adsorption columns used in protein capture applications. This paper offers a very simple approach to predict the DBC of an adsorption column based on a measurement of the equilibrium binding capacity (EBC) and of the time needed to achieve one‐half of the EBC in a batch adsorption test. The approach is based on a mass transfer kinetics model that assumes pore diffusion with a rectangular isotherm; however, the same approach is also shown to work for other systems where solute transport inside the particle occurs through other transport mechanisms.
NEIL1 Binding to DNA Containing 2′‐Fluorothymidine Glycol Stereoisomers and the Effect of Editing
Authors: Onizuka Kazumitsu , Yeo Jongchan , David Sheila S. , Beal Peter A. 
Published: May 2012

AbstractThymine glycol (Tg), one of the oxidized bases formed in DNA by reactive oxygen species, is repaired by the DNA glycosylases such as NEIL1, NTH1 and Endo III. In our recent studies, we showed that NEIL1's catalytic efficiency and lesion specificity are regulated by an RNA‐editing adenosine deamination reaction. In this study, we synthesized oligodeoxynucleotides containing 2′‐fluorothymidine glycol with either ribo or arabino configuration and investigated the binding of these modified DNAs with the unedited and edited forms of human NEIL1 along with E. coli Endo III. For the two forms of hNEIL1, binding affinities to FTg‐containing DNA were similar indicating that the editing effect is more subtle than to simply alter substrate affinity. While the NEIL1‐binding to FTg‐containing DNAs was largely insensitive to C5 and 2′ stereochemistry, a preference was observed for the FTg–G pair over the FTg–A pair. In addition, we found that optimal binding is observed with Endo III and duplex DNA with riboFTg(5S) paired with dG. The modified DNAs reported here will provide useful tools for further characterizing the interaction between DNA repair glycosylases and thymine glycol containing DNA.
Catalytic Asymmetric Synthesis of Chromene Derivatives by Iminium Ion Catalysis
Authors: Rueping Magnus , Merino Estíbaliz , Sugiono Erli 
Published: May 2012

AbstractThe diarylprolinol TMS ether catalyzed enantioselective addition–acetalization cascade reaction of 1,3‐diketones with α,β‐unsaturated aldehydes provides access to biologically active hydroxychromenone derivatives. These chromenones can be converted into the corresponding lactones, oxadecalinones, and benzopyranes in good yields without loss of enantiomeric excess. The usefulness of this newly developed methodology was demonstrated in the synthesis of the core structure of a Δ9‐tetrahydrocannabinol analog.
A Mechanistic Study on the Nucleation and Growth of Au on Pd Seeds with a Cubic or Octahedral Shape
Authors: He Guannan , Zeng Jie , Jin Mingshang , Zhang Hui , Lu Ning , Wang Jinguo , Kim Moon J. , Xia Younan 
Published: May 2012

AbstractThis article reports a systematic study on the seed‐mediated growth of Pd–Au bimetallic nanocrystals with a variety of controlled morphologies. The key to the success of this synthesis is to manipulate the reaction kinetics by controlling a set of experimental parameters, which include the amount of ascorbic acid used as a reductant, the amount of HAuCl4 as a precursor to elemental Au, the reaction temperature, and the type of seeds employed. Starting from Pd nanocubes of 18 nm in edge length, Pd–Au bimetallic nanocrystals with a number of morphologies, which includes hybrid dimers, core–shell nanocubes with flat faces, and core–shell nanocubes with concave faces could all be obtained by simply speeding up the reduction of HAuCl4. The same synthesis and control could also be extended to seeds based on Pd octahedrons. For the first time, it was possible to generate Pd@Au core–shell nanocubes and octahedrons with concave faces. The Pd@Au core–shell nanocubes with concave faces exhibited enhanced activity in catalyzing the oxidization of ascorbic acid relative to their counterparts with flat faces or the cubic Pd seeds.
ChemInform Abstract: Cu2ZnGeSe4 Nanocrystals: Synthesis and Thermoelectric Properties.
Authors: Shavel Alexey , et al. et al. 
Published: May 2012

AbstractThe title nanocrystals with narrow size distributions are prepared by injecting a solution of SeO2 in octadecene into a mixture of CuCl, ZnO, GeCl4, hexadecylamine, n‐tetradecylphosphonic acid, and octadecene at 295 °C (5 min, rapid cooling).
ChemInform Abstract: Growth of Single‐Crystal Ca10(Pt4As8) (Fe1.8Pt0.2As2)5 Nanowhiskers with Superconductivity up to 33 K.
Authors: Wang Hua‐Bing , et al. et al. 
Published: May 2012

AbstractThe title nanowhiskers are prepared from mixtures of FeAs, Fe, Pt, and CaAs as a flux (h‐BN cell, Ta capsule, 380 MPa, followed by heating at 1000 °C for 72 h).
ChemInform Abstract: Superionic Phase Transition in Silver Chalcogenide Nanocrystals Realizing Optimized Thermoelectric Performance.
Authors: Xiao Chong , Xu Jie , Li Kun , Feng Jun , Yang Jinlong , Xie Yi 
Published: May 2012

AbstractThe thermoelectric properties of Ag2S, Ag2Se, and Ag4SeS nearly monodisperse nanocrystals are investigated across the semicondutor—superionic conductor transition.
ChemInform Abstract: Synthesis of Highly Crystalline In2Ge2O7(En) Hybrid Sub‐Nanowires with Ultraviolet Photoluminescence Emissions and Their Selective Photocatalytic Reduction of CO2 into Renewable Fuel.
Authors: Liu Qi , Zhou Yong , Ma Yue , Zou Zhigang 
Published: May 2012

AbstractThe new ultrathin title nanowires with general diameters of 2—3 nm and lengths up to hundreds of nanometers are solvothermally synthesized from GeO2 and In(OAc)3 in mixtures of H2O and en (autoclave, 180 °C, 24 h).
ChemInform Abstract: Asymmetric [3 + 2] Annulation of Allenes with Maleimides Catalyzed by Dipeptide‐Derived Phosphines: Facile Creation of Functionalized Bicyclic Cyclopentenes Containing Two Tertiary Stereogenic Centers.
Authors: Zhao Qianyi , Han Xiaoyu , Wei Yin , Shi Min , Lu Yixin 
Published: May 2012

AbstractA highly enantioselective synthesis of title compounds (III) and (V) is presented.
ChemInform Abstract: Site‐ and Enantioselective Formation of Allene‐Bearing Tertiary or Quaternary Carbon Stereogenic Centers Through NHC—Cu‐Catalyzed Allylic Substitution.
Authors: Jung Byunghyuck , Hoveyda Amir H. 
Published: May 2012

AbstractThe reactions of di‐ or trisubstituted allylic phosphates with allenylboronic ester (III) proceed with exclusive addition of the allenyl unit to give chiral SN2′ products.
ChemInform Abstract: E‐Factor Minimized Protocols for the Polystyryl‐BEMP Catalyzed Conjugate Additions of Various Nucleophiles to α,β‐Unsaturated Carbonyl Compounds.
Authors: Bonollo Simona , Lanari Daniela , Longo Julien M. , Vaccaro Luigi 
Published: May 2012

AbstractMichael and hetero‐Michael addition of carbon, nitrogen, and sulfur nucleophiles to α,β‐unsaturated carbonyl compounds (I) is carried out in the presence of the title catalyst.
ChemInform Abstract: A Catalytic Version of Hypervalent Aryl‐λ3‐iodane‐induced Hofmann Rearrangement of Primary Carboxamides: Iodobenzene as an Organocatalyst and m‐Chloroperbenzoic Acid as a Terminal Oxidant.
Authors: Miyamoto Kazunori , Sakai Yuuta , Goda Shunsuke , Ochiai Masahito 
Published: May 2012

AbstractThe first catalytic version of a hypervalent aryl‐λ3‐iodane‐induced Hofmann rearrangement of primary carboxamides is developed (19 examples).
ChemInform Abstract: A Short and Faster Entree to N‐Oxides: Transition Metal Acetylacetonates Promoted Aerobic Oxidative Transformation of Tertiary Nitrogen Compounds to N‐Oxides.
Authors: Dongre Rajendra , Sheikh Javed , Ghugal Dinesh , Ali Parvez , Meshram Jyotsana , Ramteke D. S. 
Published: May 2012

AbstractThe system iPr‐CHO/O2 in the presence of catalytic amounts of Fe(acac)2 provides a simple, efficient and convenient method for the oxidation of tertiary nitrogen compounds to corresponding N‐oxides under mild conditions.
ChemInform Abstract: Electrostatic Immobilization of an Olefin Metathesis Pre‐Catalyst on Iron Oxide Magnetic Particles.
Authors: Byrnes Matthew J. , Hilton Andrew M. , Woodward Clint P. , Jackson William R. , Robinson Andrea J. 
Published: May 2012

AbstractThe quaternary ammonium Hoveyda—Grubbs olefin metathesis pre‐catalyst affecting the ring closing metathesis of diethyl diallylmalonate (I) is readily accessed in one step from second generation Grubbs catalyst and immobilized onto magnetically separable nanosized iron oxide particles.
ChemInform Abstract: Enantioselective α‐Tosyloxylation of Ketones Catalyzed by Spirobiindane Scaffold Based Chiral Iodoarenes.
Authors: Yu Jun , Cui Jian , Hou Xue‐Sen , Liu Shan‐Shan , Gao Wen‐Chao , Jiang Shan , Tian Jun , Zhang Chi 
Published: May 2012

AbstractA series of enantiomerically pure spirobiindane is prepared and investigated as catalysts in the tosyloxylation reaction of ketone (I) using MCPBA as a stoichiometric oxidant.
ChemInform Abstract: Al(OTf)3: An Efficient Recyclable Catalyst for Direct Nucleophilic Substitution of the Hydroxy Group of Propargylic Alcohols with Carbon‐ and Heteroatom‐Centered Nucleophiles to Construct C—C, C—O, C—N and C—S Bonds.
Authors: Gohain Mukut , Marais Charlene , Bezuidenhoudt Barend C. B. 
Published: May 2012

AbstractIndependent of the nucleophile used, the reactions are finished within a few hours.
ChemInform Abstract: Pd‐Catalyzed Dehydrogenative Cross‐Coupling of Polyfluoroarenes with Heteroatom‐Substituted Enones.
Authors: Chen Fei , Feng Zhang , He Chun‐Yang , Wang Hao‐Yang , Guo Yin‐long , Zhang Xingang 
Published: May 2012

AbstractThis reaction provides a rapid access to a wide range of α‐fluoroarylated enones, which are of interest in life science.
ChemInform Abstract: Facile Catalyst‐Free Pseudo Five‐Component Domino Reactions in the Expedient Synthesis of 5‐Aroyl‐1,3‐diarylhexahydropyrimidines.
Authors: Muthusaravanan Sivasubramanian , Perumal Subbu , Almansour Abdulrahman I. 
Published: May 2012

AbstractThe reaction conditions are optimized, especially with respect to the stoichiometric ratio of the reactants.
ChemInform Abstract: Oxidative Rearrangement of Spiro Cyclobutane Cyclic Aminals: Efficient Construction of Bicyclic Amidines.
Authors: Murai Kenichi , Komatsu Hideyuki , Nagao Ryu , Fujioka Hiromichi 
Published: May 2012

AbstractTreatment of spirocyclic cyclobutane aminals like (III) with NBS or NCS allows a new and efficient access to bicyclic amidines and related compounds.