bluuebunny/crossref_metadata_2025 huggingface dataset:
A Viable Hydrogen Storage and Release System Based on Cesium Formate and Bicarbonate Salts: Mechanistic Insights into the Hydrogen Release Step
Authors: Sordakis Katerina , Dalebrook Andrew F. , Laurenczy Gábor
Published: June 2015

Aqueous solutions of cesium formate and bicarbonate represent an effective hydrogen storage–delivery couple that undergoes either release or take up of hydrogen in the presence of {RuCl2(mTPPTS)2}2 (TPPTS=triphenylphosphine trisulfonate) and excess mTPPTS ligand, with no other additives required. Cesium salt solutions offer the advantage of improved volumetric and gravimetric H2 density compared to their sodium and potassium analogs, owing to their high water solubility. Details of the equilibrium between formate and bicarbonate, which constitutes an important parameter for the applicability of this H2 storage/release cycle, were determined. H2 production is readily tunable by controlling the operating pressure. This behavior was also rationalized through the identification of catalytic intermediates under various conditions. High concentration formate and bicarbonate solutions were used during the tests and the bidirectional catalytic system could be recycled without loss of activity or replacement of solvent. A tentative mechanism is proposed for the formate dehydrogenation step. Among the identified hydride species, the pentacoordinated [RuH(H2O)(TPPTS)3] complex was indispensable for promoting the formate dehydrogenation reaction.
Macrocyclic Gd3+ Complexes with Pendant Crown Ethers Designed for Binding Zwitterionic Neurotransmitters
Authors: Oukhatar Fatima , Meudal Hervé , Landon Céline , Logothetis Nikos K. , Platas‐Iglesias Carlos , Angelovski Goran , Tóth Éva
Published: June 2015

A series of Gd3+ complexes exhibiting a relaxometric response to zwitterionic amino acid neurotransmitters was synthesized. The design concept involves ditopic interactions 1) between a positively charged and coordinatively unsaturated Gd3+ chelate and the carboxylate group of the neurotransmitters and 2) between an azacrown ether appended to the chelate and the amino group of the neurotransmitters. The chelates differ in the nature and length of the linker connecting the cyclen‐type macrocycle that binds the Ln3+ ion and the crown ether. The complexes are monohydrated, but they exhibit high proton relaxivities (up to 7.7 mM−1 s−1 at 60 MHz, 310 K) due to slow molecular tumbling. The formation of ternary complexes with neurotransmitters was monitored by 1H relaxometric titrations of the Gd3+ complexes and by luminescence measurements on the Eu3+ and Tb3+ analogues at pH 7.4. The remarkable relaxivity decrease (≈80 %) observed on neurotransmitter binding is related to the decrease in the hydration number, as evidenced by luminescence lifetime measurements on the Eu3+ complexes. These complexes show affinity for amino acid neurotransmitters in the millimolar range, which can be suited to imaging concentrations of synaptically released neurotransmitters. They display good selectivity over non‐amino acid neurotransmitters (acetylcholine, serotonin, and noradrenaline) and hydrogenphosphate, but selectivity over hydrogencarbonate was not achieved.
How to Make Weak Noncovalent Interactions Stronger
Authors: Xu Jiang‐Fei , Chen Linghui , Zhang Xi
Published: June 2015

By employing noncovalent interactions, chemists have constructed a variety of molecular aggregates with well‐defined structures and fascinating properties. In fabricating stable and large molecular assemblies, noncovalent interactions with high binding strength are needed. This Concept summarizes some strategies to modify and optimize the structures of building blocks for making weak noncovalent interactions stronger. The strategies include: 1) Preorganization of binding sites; 2) spatial confinement effects; 3) multivalent enhancement; 4) synergistic binding with multiple forces. Examples of the fabrication of supramolecular architectures by utilizing these strategies are presented and discussed. Guidance is offered in the construction and fabrication of stable molecular assemblies and supramolecular materials.
Electrochemical Properties of Fiber‐in‐Tube‐ and Filled‐Structured TiO2 Nanofiber Anode Materials for Lithium‐Ion Batteries
Authors: Cho Jung Sang , Hong Young Jun , Kang Yun Chan
Published: June 2015

Phase‐pure anatase TiO2 nanofibers with a fiber‐in‐tube structure were prepared by the electrospinning process. The burning of titanium‐oxide‐carbon composite nanofibers with a filled structure formed as an intermediate product under an oxygen atmosphere produced carbon‐free TiO2 nanofibers with a fiber‐in‐tube structure. The sizes of the nanofiber core and hollow nanotube were 140 and 500 nm, respectively. The heat treatment of the electrospun nanofibers at 450 and 500 °C under an air atmosphere produced grey and white filled‐structured TiO2 nanofibers, respectively. The initial discharge capacities of the TiO2 nanofibers with the fiber‐in‐tube and filled structures and the commercial TiO2 nanopowders were 231, 134, and 223 mA h g−1, respectively, and their corresponding charge capacities were 170, 100, and 169 mA h g−1, respectively. The 1000th discharge capacities of the TiO2 nanofibers with the fiber‐in‐tube and filled structures and the commercial TiO2 nanopowders were 177, 64, and 101 mA h g−1, respectively, and their capacity retentions measured from the second cycle were 89, 82, and 52 %, respectively. The TiO2 nanofibers with the fiber‐in‐tube structure exhibited low charge transfer resistance and structural stability during cycling and better cycling and rate performances than the TiO2 nanofibers with filled structures and the commercial TiO2 nanopowders.
Palladium‐Catalyzed Mono‐α‐arylation of Acetone at Room Temperature
Authors: MacQueen Preston M. , Chisholm Alicia J. , Hargreaves Breanna K. V. , Stradiotto Mark
Published: June 2015

The first examples of acetone mono‐α‐arylation at room temperature are described, enabled by use of a [Pd(cinnamyl)Cl]2/JosiPhos catalyst system. (Hetero)aryl chloride, bromide, and iodide electrophiles featuring or lacking ortho‐substitution, and comprising a range of functionalities (e.g., alkoxy, cyano, fluoro, trifluoromethyl, or alkenyl) and heteroaryl motifs (e.g., pyrrole, pyridine, isoquinoline, quinoline, quinaldine, (benzo)thiophene, benzothiazole, or benzodioxole) were successfully accommodated. Proof‐of‐principle experiments confirm that other (hetero)aryl methyl ketones can also be employed in such room temperature mono‐α‐arylations. The established substrate scope is the most extensive reported to date for acetone mono‐α‐arylation under any conditions, and more generally represents the first room temperature ketone mono‐α‐arylations employing a structurally diverse set of (hetero)aryl chlorides.
Moving toward Ylide‐Stabilized Carbenes
Authors: Borthakur Bitupon , Phukan Ashwini K.
Published: June 2015

The effect of ylide substitution at the α position to the carbene carbon (Cc) atom on the stability and σ‐donating ability of a number of cyclic carbenes has been studied theoretically. The stabilities of all of the carbenes were investigated from an evaluation of their singlet–triplet energy gaps and stabilization energies. All carbenes were found to have a stable singlet state. The energy of the σ‐symmetric lone‐pair orbital at the Cc atom increases as a result of the introduction of ylide centers near to the Cc atom. This indicates an enhanced σ‐donating ability of the ylide‐containing carbenes. The calculated carbonyl‐stretching frequencies of the corresponding rhodium complexes, proton affinities, and nucleophilicity index values correlate well with the σ basicity of the carbenes.
Pyridyl‐Functionalised 3H‐1,2,3,4‐Triazaphospholes: Synthesis, Coordination Chemistry and Photophysical Properties of Low‐Coordinate Phosphorus Compounds
Authors: Sklorz Julian A. W. , Hoof Santina , Rades Nadine , De Rycke Nicolas , Könczöl László , Szieberth Dénes , Weber Manuela , Wiecko Jelena , Nyulászi László , Hissler Muriel , Müller Christian
Published: June 2015

Novel conjugated, pyridyl‐functionalised triazaphospholes with eithertBu or SiMe3substituents at the 5‐position of the N3PC heterocycle have been prepared by a [3+2] cycloaddition reaction and compared with structurally related, triazole‐based systems. Photoexcitation of the 2‐pyridyl‐substituted triazaphosphole gives rise to a significant fluorescence emission with a quantum yield of up to 12 %. In contrast, the all‐nitrogen triazole analogue shows no emission at all. DFT calculations indicate that the 2‐pyridyl substituted systems have a more rigid and planar structure than their 3‐ and 4‐pyridyl isomers. Time‐dependent (TD) DFT calculations show that only the 2‐pyridyl‐substituted triazaphosphole exhibits similar planar geometry, with matching conformational arrangements in the lowest energy excited state and the ground state; this helps to explain the enhanced emission intensity. The chelating P,N‐hybrid ligand forms a ReIcomplex of the type [(N^N)Re(CO)3Br] through the coordination of nitrogen atom N2to the metal centre rather than through the phosphorus donor. Both structural and spectroscopic data indicate substantial π‐accepting character of the triazaphosphole, which is again in contrast to that of the all‐nitrogen‐containing triazoles. The synthesis and photophysical properties of a new class of phosphorus‐containing extended π systems are described.
Mechanistic Insights on the Iodine(III)‐Mediated α‐Oxidation of Ketones
Authors: Beaulieu Samuel , Legault Claude Y.
Published: June 2015

The synthesis of α‐substituted carbonyl compounds is of great importance due to their ubiquity in both natural and man‐made biologically active compounds. The field of hypervalent iodine chemistry has been a great contributor to access these molecules. For example, the α‐oxidation of carbonyl compounds has been one of the most investigated iodine(III)‐mediated stereoselective transformations. Yet, it is also the transformation that has met the most challenge in terms of achieving high stereoselectivities. The different mechanistic pathways of the iodine(III)‐mediated α‐tosyloxylation of ketones have been investigated. The calculations suggest an unprecedented iodine(III)‐promoted enolization process. Indications that iodonium intermediates could serve as proficient Lewis acids are reported. This concept could have broad impact and foster new developments in the field of hypervalent iodine chemistry.
Tunable Molecular Logic Gates Designed for Imaging Released Neurotransmitters
Authors: Klockow Jessica L. , Hettie Kenneth S. , Secor Kristen E. , Barman Dipti N. , Glass Timothy E.
Published: June 2015

Tunable dual‐analyte fluorescent molecular logic gates (ExoSensors) were designed for the purpose of imaging select vesicular primary‐amine neurotransmitters that are released from secretory vesicles upon exocytosis. ExoSensors are based on the coumarin‐3‐aldehyde scaffold and rely on both neurotransmitter binding and the change in environmental pH associated with exocytosis to afford a unique turn‐on fluorescence output. A pH‐functionality was directly integrated into the fluorophore π‐system of the scaffold, thereby allowing for an enhanced fluorescence output upon the release of labeled neurotransmitters. By altering the pH‐sensitive unit with various electron‐donating and ‐withdrawing sulfonamide substituents, we identified a correlation between the pKa of the pH‐sensitive group and the fluorescence output from the activated fluorophore. In doing so, we achieved a twelvefold fluorescence enhancement upon evaluating the ExoSensors under conditions that mimic exocytosis. ExoSensors are aptly suited to serve as molecular imaging tools that allow for the direct visualization of only the neurotransmitters that are released from secretory vesicles upon exocytosis.
Comparative Study of Halogen‐ and Hydrogen‐Bond Interactions between Benzene Derivatives and Dimethyl Sulfoxide
Authors: Zheng Yan‐Zhen , Deng Geng , Zhou Yu , Sun Hai‐Yuan , Yu Zhi‐Wu
Published: June 2015

The halogen bond, similar to the hydrogen bond, is an important noncovalent interaction and plays important roles in diverse chemistry‐related fields. Herein, bromine‐ and iodine‐based halogen‐bonding interactions between two benzene derivatives (C6F5Br and C6F5I) and dimethyl sulfoxide (DMSO) are investigated by using IR and NMR spectroscopy and ab initio calculations. The results are compared with those of interactions between C6F5Cl/C6F5H and DMSO. First, the interaction energy of the hydrogen bond is stronger than those of bromine‐ and chlorine‐based halogen bonds, but weaker than iodine‐based halogen bond. Second, attractive energies depend on 1/rn, in which n is between three and four for both hydrogen and halogen bonds, whereas all repulsive energies are found to depend on 1/r8.5. Third, the directionality of halogen bonds is greater than that of the hydrogen bond. The bromine‐ and iodine‐based halogen bonds are strict in this regard and the chlorine‐based halogen bond only slightly deviates from 180°. The directional order is iodine‐based halogen bond>bromine‐based halogen bond>chlorine‐based halogen bond>hydrogen bond. Fourth, upon the formation of hydrogen and halogen bonds, charge transfers from DMSO to the hydrogen‐ and halogen‐bond donors. The CH3 group contributes positively to stabilization of the complexes.
Antagonistic Functionalized Nucleation and Oxidative Degradation in Combustive Formation of Pyrene‐Based Clusters Mediated by Triplet O and O2: Theoretical Study
Authors: Maranzana Andrea , Tonachini Glauco
Published: June 2015

Polycyclic aromatic hydrocarbons (PAHs) and carbonaceous nanoparticles can be oxidized right from their inception and all through their growth. Oxidation can also promote their degradation. This modelistic density functional theory (DFT) study explores, in a descriptive manner, if oxidation can mediate the earliest stages of nucleation (“functionalized nucleation”), though contrasted by mass declension triggered by oxidation itself. Initial O (3P) attack onto pyrene, chosen as a representative of a generic small PAH or nascent soot lamella, forms an oxyl diradical intermediate that can evolve into an open‐shell epoxide, phenol, or ketone species or, alternatively, undergo mass depletion from the beginning (without impeding further additions). Open‐shell intermediates can add O or O2 (3Σg−) and ethyne, in any order, and open the way, through formation of carbon and oxygen bridges, to the addition of a second molecule of pyrene, whereas formation of direct carbon–carbon links between the two PAH‐like parts might also occur.
Highly Stable Na2/3(Mn0.54Ni0.13Co0.13)O2 Cathode Modified by Atomic Layer Deposition for Sodium‐Ion Batteries
Authors: Kaliyappan Karthikeyan , Liu Jian , Lushington Andrew , Li Ruying , Sun Xueliang
Published: June 2015

For the first time, atomic layer deposition (ALD) of Al2O3 was adopted to enhance the cyclic stability of layered P2‐type Na2/3(Mn0.54Ni0.13Co0.13)O2 (MNC) cathodes for use in sodium‐ion batteries (SIBs). Discharge capacities of approximately 120, 123, 113, and 105 mA h g−1 were obtained for the pristine electrode and electrodes coated with 2, 5, and 10 ALD cycles, respectively. All electrodes were cycled at the 1C discharge current rate for voltages between 2 and 4.5 V in 1 M NaClO4 electrolyte. Among the electrodes tested, the Al2O3 coating from 2 ALD cycles (MNC‐2) exhibited the best electrochemical stability and rate capability, whereas the electrode coated by 10 ALD cycles (MNC‐10) displayed the highest columbic efficiency (CE), which exceeded 97 % after 100 cycles. The enhanced electrochemical stability observed for ALD‐coated electrodes could be a result of the protection effects and high band‐gap energy (Eg=9.00 eV) of the Al2O3 coating layer. Additionally, the metal‐oxide coating provides structural stability against mechanical stresses occurring during the cycling process. The capacity, cyclic stability, and rate performance achieved for the MNC electrode coated with 2 ALD cycles of Al2O3 reveal the best results for SIBs. This study provides a promising route toward increasing the stability and CE of electrode materials for SIB application.
Molecular Engineering of Organic Dyes with a Hole‐Extending Donor Tail for Efficient All‐Solid‐State Dye‐Sensitized Solar Cells
Authors: Lu Jianfeng , Chang Yu‐Cheng , Cheng Hsu‐Yang , Wu Hui‐Ping , Cheng Yibing , Wang Mingkui , Diau Eric Wei‐Guang
Published: June 2015

We report a new concept for the design of metal‐free organic dyes (OD5–OD9) with an extended donor–π–acceptor (D–π–A) molecular framework, in which the donor terminal unit is attached by a hole‐extending side chain to retard back electron transfer and charge recombination; the π‐bridge component contains varied thiophene‐based substituents to enhance the light‐harvesting ability of the device. The best dye (OD9) has a D–A–π–A configuration with the hexyloxyphenylthiophene (HPT) side chain as a hole‐extension component and a benzothiadiazole (BTD) internal acceptor as a π‐extension component. The co‐sensitization of OD9 with the new porphyrin dye LW24 enhanced the light‐harvesting ability to 800 nm; thus, a power conversion efficiency 5.5 % was achieved. Photoinduced absorption (PIA) and transient absorption spectral (TAS) techniques were applied to account for the observed trend of the open‐circuit voltage (VOC) of the devices. This work provides insights into the molecular design, photovoltaic performance, and kinetics of charge recombination.
Teens that fear screams: A comparison of fear conditioning, extinction, and reinstatement in adolescents and adults
Authors: Den Miriam Liora , Graham Bronwyn M. , Newall Carol , Richardson Rick
Published: June 2015

This study investigated differences between adolescents and adults on fear conditioning, extinction, and reinstatement (i.e., the recovery of conditioned fear following re‐exposure to the unconditioned stimulus [US] post‐extinction). Participants underwent differential conditioning (i.e., the Screaming Lady) where one neutral face (CS+) was followed by the same face expressing fear and a loud scream (US) while another neutral face (CS−) remained neutral. Extinction involved non‐reinforced presentations of both CSs, after which participants were reinstated (2xUSs) or not. On two self‐report measures, both ages showed conditioning, good extinction learning and retention, and reinstatement‐induced relapse. However, only adolescents showed conditioning, extinction, and reinstatement on the eye tracking measure; relapse on this measure could not be assessed in adults given they did not show initial conditioning. Lastly, higher levels of depression predicted stronger conditioning and weaker extinction in adolescents only. These findings are discussed in terms of their implications for adolescent anxiety disorders. © 2015 Wiley Periodicals, Inc. Dev Psychobiol 57: 818–832, 2015.
Potential of Gelatin‐Zinc Oxide Nanocomposite as Ascorbic Acid Sensor
Authors: Rawat Kamla , Sharma Anshu , Solanki Pratima R. , Bohidar H. B.
Published: June 2015

We report on the studies relating to fabrication of gelatin B (GB) and zinc oxide (ZnO) based nanocomposite (GB‐ZnO) film deposited on indium‐tin‐oxide (ITO) glass plate, and used for the immobilization of ascorbate oxidase (AsOx) which was further used for ascorbic acid (AA) detection. The structural and morphological studies of GB‐ZnO, and AsOx/GB‐ZnO/ITO bioelectrodes were carried out using XRD, SEM and FTIR techniques. This bioelectrode showed a broad range of linearity (5–500 mg/dL), low detection limit (1 mg/dL), higher sensitivity (0.106 µA mg/dLcm−2) and low value of the apparent MichaelisMenten constant (Kmapp=0.35 mg/dL) for AA. Efforts are being made to utilize this electrode for sensing AA in real samples in a bid to develop a strip based sensor.
A Layer‐by‐Layer Biosensing Architecture Based on Polyamidoamine Dendrimer and Carboxymethylcellulose‐Modified Graphene Oxide
Authors: Borisova Boryana , Ramos Javier , Díez Paula , Sánchez Alfredo , Parrado Concepción , Araque Elena , Villalonga Reynaldo , Pingarrón José M.
Published: June 2015

A novel nanostructured architecture for the construction of electrochemical enzyme biosensors is here described. It implies the electrostatic layer‐by‐layer assembly of four‐generation ethylenediamine core polyamidoamine G‐4 dendrimers on glassy carbon electrodes coated with a graphene oxide‐carboxymethylcellulose hybrid nanomaterial. This modified surface was further employed for the covalent immobilization of the model enzyme tyrosinase through a glutaraldehyde‐mediated cross‐linking. The prepared enzyme electrode allowed the amperometric detection of catechol in the 2–400 nM range. The biosensor showed excellent analytical performance with high sensitivity of 6.3 A/M and low detection limit of 0.9 nM. The enzyme electrode retained over 93 % of the initial activity after 40 days at 4 °C.
Direct Electrochemistry of Glucose Oxidase at Reduced Graphene Oxide and β‐Cyclodextrin Composite Modified Electrode and Application for Glucose Biosensing
Authors: Palanisamy Selvakumar , Devasenathipathy Rajkumar , Chen Shen‐Ming , Ajmal Ali M. , Karuppiah Chelladurai , Balakumar V. , Prakash P. , Elshikh Mohamed S. , Al‐Hemaid Fahad M. A.
Published: June 2015

A simple glucose biosensor has been developed based on direct electrochemistry of glucose oxidase (GOx) immobilized on the reduced graphene oxide (RGO) and β‐cyclodextrin (CD) composite. A well‐defined redox couple of GOx appears with a formal potential of ∼−0.459 V at RGO/CD composite. A heterogeneous electron transfer rate constant (Ks) has been calculated for GOx at RGO/CD as 3.8 s−1. The fabricated biosensor displays a wide response to glucose in the linear concentrations range from 50 µM to 3.0 mM. The sensitivity and limit of detection of the biosensor is estimated as 59.74 µA mM−1 cm−2 and 12 µM, respectively.
Click‐Conjugation of Nanogold‐Functionalized PAMAM Dendrimer: Toward a Novel Electrochemical Detection Platform
Authors: Tang Ying , Zhang Jin , Tang Dianyon , Teng Liumei , Lv Jing , Tang Dianping
Published: June 2015

This work reports a new electrochemical monitoring platform for sensitive detection of Cu2+ coupling click chemistry with nanogold‐functionalized PAMAM dendrimer (AuNP‐PAMAM). The system involved an alkyne‐modified carbon electrode and an azide‐functionalized AuNP‐PAMAM. Initially, the added Cu2+ was reduced to Cu+ by the ascorbate, and then the azide‐modified AuNP‐PAMAM was covalently conjugated to the electrode via Cu+‐catalyzed azide‐alkyne click reaction. The carried AuNPs accompanying PAMAM dendrimer could be directly monitored by stripping voltammetry after acidic pretreatment. By introduction of high‐loading PAMAM dendrimer with gold nanoparticles, as low as 2.8 pM Cu2+ (ppt) could be detected, which was 125‐fold lower than that of gold nanoparticle‐based labeling strategy. The method exhibited high specificity toward target Cu2+ against other potentially interfering ions, and was applicable for monitoring Cu2+ in drinking water with satisfactory results.
Potentiostatic Electrochemical Preparation of Bismuth Nanoribbons and its Application in Biologically Poisoning Lead and Cadmium Heavy Metal Ions Detection
Authors: Devasenathipathy Rajkumar , Karthik Raj , Chen Shen‐Ming , Mani Veerappan , Vasantha V. S. , Ali M. Ajmal , Elshikh Mohamed S. , Lou Bih‐Show , Al‐Hemaid Fahad M. A.
Published: June 2015

A simple and elegant electrochemical potentiostatic method has been described for the preparation of highly stable and electrocatalytically active bismuth nanoribbons (BiNRs). The average length and width of the BiNRs were of 100±50 nm and 10±5 µm, respectively. Here, disodium ethylene diamine tetraacetate was employed as a scaffold for the growth of BiNRs. The formation of BiNRs was confirmed by surface morphological, elemental and cyclic voltammetric analyses. The BiNRs exhibited excellent electrocatalytic ability in detecting biologically poisoning heavy metal ions such as lead and cadmium. The described BiNRs based sensor presents good linear dependence on lead and cadmium ions in the concentration range of 1–50 µg/L for both metal ions with a detection limit of 0.104 µg/L for lead and 0.145 µg/L for cadmium.
Experimental Study on Anode and Cathode Pressure Difference Control and Effects in a Proton Exchange Membrane Fuel Cell System
Authors: Li Yankun , Zhao Xingqiang , Tao Shiyong , Li Qi , Chen Weirong
Published: June 2015

In a proton exchange membrane fuel cell (PEMFC) system, controlling the pressure balance between the anode and the cathode reactants is very important, especially for transient processes involving big load changes. Unreasonable pressure following the control may lead to pressure imbalance, which may result in damage to the thin membranes inside the fuel cell stack. A pressure difference control method for maintaining the pressure difference on both sides of the membrane within a reasonable scope is proposed in this paper. This method is also applied in an actual PEMFC system for pressure‐balance control. In the experiments involving a 14.4 kW PEMFC system with 100 A current jumps, the pressure difference between the anode hydrogen and cathode air could be controlled within allowable values. The results reveal that the proposed method can be used to control the anode inlet pressure more simply and rapidly following the cathode pressure changes, which could be more effective for membrane protection.
Alisporivir plus ribavirin, interferon free or in combination with pegylated interferon, for hepatitis C virus genotype 2 or 3 infection
Authors: Pawlotsky Jean‐Michel , Flisiak Robert , Sarin Shiv K. , Rasenack Jens , Piratvisuth Teerha , Chuang Wan‐Long , Peng Cheng‐Yuan , Foster Graham R. , Shah Samir , Wedemeyer Heiner , Hézode Christophe , Zhang Wei , Wong Kelly A. , Li Bin , Avila Claudio , Naoumov Nikolai V. ,   on behalf of the VITAL‐1 study team
Published: June 2015

Alisporivir is a cyclophilin inhibitor with pan‐genotypic anti–hepatitis C virus (HCV) activity and a high barrier to viral resistance. The VITAL‐1 study assessed alisporivir as interferon (IFN)‐free therapy in treatment‐naïve patients infected with HCV genotype 2 or 3. Three hundred forty patients without cirrhosis were randomized to: arm 1, alisporivir (ALV) 1,000 mg once‐daily (QD); arm 2, ALV 600 mg QD and ribavirin (RBV); arm 3, ALV 800 mg QD and RBV; arm 4, ALV 600 mg QD and pegylated IFN (Peg‐IFN); or arm 5, Peg‐IFN and RBV. Patients receiving IFN‐free ALV regimens who achieved rapid virological response (RVR) continued the same treatment throughout, whereas those with detectable HCV RNA at week 4 received ALV, RBV, and Peg‐IFN from weeks 6 to 24. Overall, 300 patients received ALV‐based regimens. In arm 1 to arm 4, the intent‐to‐treat rates of sustained virological response (SVR) 24 weeks after treatment (SVR24) were from 80% to 85%, compared with 58% (n = 23 of 40) with Peg‐IFN/RBV. Per‐protocol analysis showed higher SVR24 rates in patients who received ALV/RBV, IFN‐free after RVR (92%; n = 56 of 61) than with ALV alone after RVR (72%; n = 13 of 18) or with Peg‐IFN/RBV (70%; n = 23 of 33). Both RVRs and SVRs to ALV IFN‐free regimens were numerically higher in genotype 3– than in genotype 2–infected patients. Viral breakthrough was infrequent (3%; n = 7 of 258). IFN‐free ALV treatment showed markedly better safety/tolerability than IFN‐containing regimens. Conclusions: ALV plus RBV represents an effective IFN‐free option for a proportion of patients with HCV genotype 2 or 3 infections, with high SVR rates for patients with early viral clearance. Further investigations of ALV in IFN‐free combination regimens with direct‐acting antiviral drugs deserve exploration in future trials. (Hepatology 2015;62:1013‐1023)
A Tale of Two Mounts: The History of Chemistry at the Hebrew University of Jerusalem
Authors: Shaik Sason
Published: June 2015

This is the story of the establishment of the Hebrew University (HU), and within it, the sub‐story of the first school of chemistry in the Land of Israel, from 1923. It spans more than 100 years, from the publication of the pamphlet, Eine Jüdische Hochschule, in 1902, all the way to 2015. The story starts with a dream, almost in the realm of science fiction, the audacious vision of building a university in a stateless and impoverished region, and all the way to an Institute of Chemistry of HU that has served as the mother of chemistry in the State of Israel.
The effect of an alginate carrier on bone formation in a hydroxyapatite scaffold
Authors: Coathup Melanie J. , Edwards Thomas C. , Samizadeh Sorousheh , Lo Wei‐Jen , Blunn Gordon W.
Published: June 2015

This study investigated the osteoconductive properties of a porous hydroxyapatite (HA) scaffold manufactured using a novel technique similar to the bread‐making process, alone and in combination with an alginate polysaccharide fiber gel (HA/APFG putty) and autologous bone marrow aspirate (BMA). The hypothesis was that the HA/APFG putty would be as osteoconductive as granular HA and that the presence of BMA would further enhance bone formation in an ovine femoral condyle critical defect model. Thirty‐six defects were created and either (1) porous HA granules, (2) HA/APFG putty, or (3) HA/APFG putty + BMA were implanted. After retrieval at 6 and 12 weeks, image analysis techniques were used to quantify bone apposition rates, new bone area, bone–HA scaffold contact, and implant resorption. At 6 weeks postsurgery, significantly lower bone apposition rates were observed in the HA/APFG putty group when compared to the HA (p = 0.014) and HA/APFG putty + BMA (p = 0.014) groups. At 12 weeks, significantly increased amounts of new bone formation were measured within the HA scaffold (33.56 ± 3.53%) when compared to both the HA/APFG putty (16.69 ± 2.7%;p = 0.043) and the defects containing HA/APFG putty + BMA (19.31 ± 3.8%;p = 0.043). The use of an APFG gel as a carrier for injectable CaP bone substitute materials delayed bone formation in this model compared to HA granules alone which enhanced bone formation especially within the interconnected smaller pores. Our results also showed that the addition of autologous BMA did not further enhance its osteoconductive properties. Further study is required to optimize the degradation rate of this APFG binding agent before using as a directly injectable material for repair of bone defect. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1328–1335, 2016.
Reliability of the INSTI® rapid test for the diagnosis of HIV‐1 non‐B subtypes and recombinant variants
Authors: Goupil de Bouillé Jeanne , Le Moal Gwénaël , Hocqueloux Laurent , Guigon Aurélie , Plainchamp David , Giraudeau Geneviève , Theillay Aurélie , Languille Anne , Bélec Laurent , Prazuck Thierry
Published: June 2015

Data regarding the efficacy of Rapid HIV tests (RHTs) in detecting non‐B subtype HIV‐1 are limited. We evaluated the sensitivity of the INSTI® test for the detection of HIV‐1 antibodies for the diagnosis of HIV‐1 non‐B subtypes and recombinant variants. We identified adults with HIV‐1 infection due to non‐B subtypes and recombinant variants. The participants were re‐tested with INSTI® test. We included 258 patients. Overall, the INSTI® test sensitivity was 98.4% (95%CI: 96.9–99.9%). For the major CRF_02AG subtype, the sensitivity was 99.0% (95%CI: 97.1–100%). The HIV INSTI® test is reliable for the detection of various non‐B HIV‐1 antibodies. J. Med. Virol. 88:180–183, 2016. © 2015 Wiley Periodicals, Inc.
Etiology of aseptic meningitis and clinical characteristics in immune‐competent adults
Authors: Han Su‐Hyun , Choi Hye‐Yeon , Kim Jeong‐Min , Park Kwang‐Ryul , Youn Young Chul , Shin Hae‐Won
Published: June 2015

Viral meningitis is the most common cause of aseptic meningitis. Use of the polymerase chain reaction (PCR) has increased the ability to determine the etiology of viral meningitis. This study used PCR analysis to evaluate the etiology of aseptic meningitis in 177 previously healthy adults over a 5‐year period, as well as analyzing the clinical characteristics, cerebrospinal fluid (CSF) findings, and prognosis according to each etiology. The most frequent cause of aseptic meningitis was enterovirus (EV), followed by varicella zoster virus (VZV). Patients with EV meningitis were significantly younger than those with VZV meningitis. The percentage of lymphocytes in white blood cell counts and protein concentrations in the CSF differed significantly among patients with EV, VZV and meningitis of undetermined etiology. Younger age and lower percentage of lymphocyte and protein level in CSF analysis may be suggestive of EV meningitis. Further prospective studies are warranted to identify the correlations between the clinical characteristics and the etiologies of meningitis. J. Med. Virol. 88:175–179, 2016. © 2015 Wiley Periodicals, Inc.
Accumulation of γ‐aminobutyric acid in soybean by hypoxia germination and freeze–thawing incubation
Authors: Yang Runqiang , Feng Li , Wang Shufang , Yu Nanjing , Gu Zhenxin
Published: June 2015

BACKGROUND

γ‐Aminobutyric acid (GABA) can be synthesised by the GABA shunt and polyamine degradation pathway in plants under hypoxia stress and lower temperature. The hypoxia germination freeze–thawing incubation was used as a new technique for accumulating more GABA in soybean.

RESULTS

Results showed that glutamate decarboxylase (GAD) and diamine oxidase (DAO) activity as well as GABA content increased during germination within 24 h under hypoxia. However, the contents of dry matters and protein decreased. When the hypoxia‐treated sprouts were frozen at −18 °C for 12 h and thawed at 25 °C for 6 h, GABA content increased drastically to 7.21‐fold of the non‐frozen sprouts. Subsequently, the freeze–thawing sprouts were ground into homogenates and incubated. GABA content was 14.20‐fold of the only‐soaked seeds when homogenates was incubated at 45 °C for 80 min within 400 µmol L−1 pyridoxine (VB6) (pH 6.5).

CONCLUSION

The hypoxia germination freeze–thawing incubation was an effective method for accumulating GABA in soybean. During incubation, DAO was more important for GABA formation in homogenate of germinated soybean compared with GAD. © 2015 Society of Chemical Industry
Comparative analysis of the antioxidant and anticancer activities of chestnut inner shell extracts prepared with various solvents
Authors: Jung Byeong Su , Lee Na‐Kyoung , Na Da Som , Yu Hwan Hee , Paik Hyun‐Dong
Published: June 2015

BACKGROUND

The chestnut inner shell (CIS) has long been used as a medicinal herb for strengthening the antioxidant in the cosmetic industry. However, little is known about the antioxidant and anticancer effects of the CIS.

RESULTS

The antioxidant and anticancer effects of CIS extracts (CISEs) were investigated by the use of various methods and cancer cell lines, respectively. The total polyphenol content of CISEs using ethanol, methanol, butanol, ethyl acetate and water were 53.30, 43.98, 32.16, 26.79 and 11.53 mg gallic acid equivalents g−1, respectively. The CISEs using ethanol and methanol exhibited high antioxidant activities in the 1,1‐diphenyl‐2‐picrylhydrazyl radical scavenging activity, β‐carotene bleaching and ferric reducing ability of plasma assays; the effects were equivalent to those of butylated hydroxytoluene. All CISEs at 2.5 mg mL−1 were shown to have a cytotoxic effect over 50%, and the CISE using ethyl acetate at 0.6 mg mL−1 was proved to have 90% cytotoxic effect against the tested cancer cells.

CONCLUSION

The ethanol and methanol CISEs had potent antioxidant effects, and the ethyl acetate CISE had the highest cytotoxicity. These results suggest that CISEs could be used as functional ingredients for antioxidant and anticancer effects in foods as extraction solvents. © 2015 Society of Chemical Industry
Robotic liver resection for malignancy: Current status, oncologic outcomes, comparison to laparoscopy, and future applications
Authors: Ocuin Lee M. , Tsung Allan
Published: June 2015

Utilization of robotic techniques for resection of the liver is slowly gaining acceptance in specific situations and is now being applied to more challenging endeavors, such as major hepatectomy for cancer. This review provides a summary of robotic applications in liver surgery, with specific attention perioperative outcomes, oncologic outcomes, cost, and comparison to conventional laparoscopic techniques of liver resection. We also discuss future applications of robotic‐assisted liver surgery. J. Surg. Oncol. 2015; 112:295–301. © 2015 Wiley Periodicals, Inc.
Composite Beads Based on Chitosan and a Synthetic Polycation with Sorption Properties Modulated by the Cross‐Linking Strategy
Authors: Dragan Ecaterina Stela , Cocarta Ana Irina
Published: June 2015

A comparative study on the relation between the cross‐linking strategy and binding capacity of Cu2+, and Ni2+, of some novel composite beads based on chitosan (CS) and poly(vinylamine) (PVAm), is presented in the paper. The equilibrium sorption capacity of the metal ions onto the CS/PVAm composite beads was strongly depending on the cross‐linking strategy, and on the metal ion. Thus, the maximum sorption capacity values obtained by fitting the Langmuir isotherm on the data at 25 °C were 192.57 mg Cu2+/g, and 175.05 mg Ni2+/g, for the in‐situ cross‐linked beads, and 166.55 mg Cu2+/g, and 130.97 mg Ni2+/g, for the post‐cross‐linked beads.
Crosslinking Copolymerization of Vinyl Monomers Using Non‐Vinyl Crosslinker: Morpholine Substituted Poly (vinyl methyl ketone)
Authors: Ince Ahmet , Bicak Niyazi
Published: June 2015

Morpholine substituted poly(vinyl methyl ketone) (MSP) is presented as non‐vinyl crosslinker forming insoluble polymers in polymerization of vinyl monomers. In this process, crosslinking occurs via double bonds in situ formed by thermal de‐amination of MSP above 70 °C as demonstrated in polymerization of methylmethacrylate (MMA), styrene and 4‐vinyl pyridine (4‐VP) monomers.
Polymerization of Aniline in Microemulsion by Catalytic Air Oxidation
Authors: Kumru Baris , Bicak Niyazi
Published: June 2015

A copper catalyzed air oxidation process is presented for polymerization of aniline in a microemulsion constituting with cetyltrimethylammonium chloride (CTAC) and n‐butanol. The process was demonstrated to give stable and pitch‐dark emulsions of Emeraldine base in molecular weights of 33800 Da, as inferred from the capillary viscometer. A fairly linear viscosity‐conversion relation was noted in each case up to 95.0% of conversion. Differential light scattering (DLS) measurements showed 70 nm of average particle size for the polyaniline (PANI) in the emulsion. Conductivities measured by four‐ point probe technique indicated conductivities 8.3×10−8 and 9.8 Scm−1 for un‐doped and doped PANI.
The Synthesis of Bio‐Based Flame‐Retarded Epoxy‐Precursors
Authors: Keglevich György , Bagi Péter , Rapi Zsolt , Bakó Péter , Drahos László , Szolnoki Beáta , Marosi György
Published: June 2015

The synthesis of phosphorylated di‐ and triallyl glucopyranosides was elaborated that may be regarded as precursors of bio‐based monomers having potential flame‐retardant properties. In a separate series of experiments, the phosphorylation of methyl‐α‐d‐glucopyranoside was also investigated.
Preparation of the Poly(styrene) Based Imidazole Containing Quaternary Chloroacetamide Modified Sorbent for Removal of Phenol
Authors: Bildik Fatih , Yavuz Erdem , Sismanoglu Tuba , Filiz Senkal Bahire
Published: June 2015

Crosslinked copolymer beads were prepared by suspension polymerization of 4‐vinylbenzyl chloride (VBC) and ethyleneglycole dimethacrylate (EGDMA) mixtures. The resulting copolymer beads with quaternary amide functions were prepared in two steps: (1) modification of imidazole with PVBC and (2) quaternization of imidazole modified beads with chloroacetamide. The resulting polymer resin, which had a chloroacetamide content of 4.50 mmol/g, was effective in extracting phenol from aqueous solutions. The phenol sorption capacity was around 0.208 g phenol/g resin in non‐buffered conditions. The adsorption conditions (initial phenol concentration and pH) were varied to evaluate the mechanism of adsorption of phenol on the prepared resin. This resin is also able to remove phenol completely even from highly diluted aqueous phenol solutions.
Semicontinuous Emulsion Copolymerization of Vinyl acetate and Butyl acrylate with Nonionic Surfactants (Triton X Series)
Authors: Karacetin Gülsüm , Sarac Ayfer
Published: June 2015

In this study, the copolymerization of vinyl acetate (VAc) and butyl acrylate (BuA) in water semicontinuous emulsions made with the nonionic surfactants, Triton Xs, was studied as a function number of ethylene oxide (EO, X) and their concentrations. The copolymerization of VAc and BuA was initiated by peroxide at proper temperature in order to improve the efficiency of droplet nucleation and maintain the stability of the emulsion. The effects of EO's in the surfactant structure and surfactant concentration on latex colloidal and physicochemical properties were investigated.
A new biopolymer substrate‐based compact monopole antenna covering RFID, WiMAX, and C/X‐band
Authors: Ahsan Md Rezwanul , Islam Mohammad Tariqul , Ullah Mohammad Habib
Published: June 2015

A simple design, compact size, multiband monopole antenna comprises of wide arcs and square slots on its radiating element is proposed in this article. After successful completion of the numerical simulation, the proposed antenna has been fabricated with its optimum parameters on 1.0 mm thick 24 × 17 mm2 custom‐made biopolymer substrate with relative dielectric constant εr = 10.0 and loss tangent 0.002. The experimental results obtained from the antenna prototype have been validated with numerical results and they are well matched. The measured data confirms the bandwidth for S11 <−10 dB are of 712 MHz (90.3%), 1.38 GHz (41.3%), 2.46 GHz (30.7%) at 0.788, 3.34, and 8.01 GHz band, respectively. The antenna prototype shows almost symmetrical radiation patterns with maximum measured gain of 1.37, 2.8, and 3.56 dBi for lower, middle, and highest frequency band, respectively. Based on the excellent matching, wide bandwidth, stable radiation, and acceptable gain performance, the compact size monopole antenna finds its potential application in RFID, WiMAX, and C/X‐band applications. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2002–2005, 2015
Bandwidth enhancement in compact dual open‐loop antenna for UHF near‐field RFID reader
Authors: Chen Hua‐Ming , Lin Yi‐Fang , Chen Chien‐Hung , Hsu Jui‐Chan
Published: June 2015

A compact dual open‐loop antenna is proposed to provide enhanced bandwidth in near‐field applications in the ultra‐high frequency band. The antenna generates a strong and uniform magnetic field in a near‐field zone of the smaller open‐loop antenna. For increased bandwidth, two open loops with individual half‐wavelength perimeters are etched on each side of an FR4 printed circuit board. The antenna was fabricated in a compact overall size (dimensions, 60 × 60 × 0.8 mm3) and achieves an interrogation zone of 50 × 50 mm2 with good impedance matching and uniform magnetic field distribution in a 888–932 MHz band. Performance tests indicate that the proposed antenna has a reading distance of up to 130 mm for near‐field applications and is suitable for radio frequency identification reader applications. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2008–2012, 2015
Rectangular waveguide fed DRA using tapered waveguide section
Authors: Jasmine P. M. , Abdulla P. , Raphika P. M.
Published: June 2015

A novel technique for coupling enhancement of rectangular waveguide fed hemispherical dielectric resonator antenna (DRA) is presented in this article. Waveguide with tapered section at the end is terminated by a thick ground plane and a slot is cut at the center of the ground plane for exciting the DRA. Introduction of tapering at the end of the waveguide provides substantial improvement in matching between the waveguide and DRA. The effects of different antenna parameters on return loss characteristics are studied. The experimental results show reasonable agreement with simulated results. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2025–2028, 2015
The effect of the gate‐drain distance on high frequency and noise performance for AlGaN/GaN HEMT
Authors: Shen Li , Chen Bo , Sun Ling , Gao Jianjun
Published: June 2015

The influence of the gate‐drain distance on high frequency and noise performance of AlGaN/GaN high electron mobility transistors (HEMT) is investigated in this article. AlGaN/GaN HEMTs with three different gate‐drain separation structures are fabricated using 0.25 μm gatelength process, and a detailed comparative study on their device performances is performed. Small signal model parameters are determined from S‐parameter on‐wafer measurement up to 40 GHz, and the noise parameters are determined up to 18 GHz based on 50 Ω noise figure on‐wafer measurement system. The variation of intrinsic small signal model parameters and noise model parameters with different gate‐drain separation is studied. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2020–2023, 2015
High efficiency power amplifier with frequency band selective matching networks
Authors: Jeong Junhyung , Kim Phirun , Jeong Yongchae
Published: June 2015

In this article, a high efficiency power amplifier (PA) with frequency selective matching networks (MNs) that can provide passband impedance matching as well as suppression of out‐of‐band signals simultaneously is proposed. The proposed frequency selective MN consists of a λ/4 length coupled line, a λ/2 length open step‐impedance resonator stub, and a λ/6 length bias line terminated with a bypass capacitor. For experimental validation, the PA with input and output frequency selective MNs is designed and fabricated for the US PCS band (1.93–1.99 GHz). The measurement results show that the output power and power add efficiency are 43 dBm and 70.3%, respectively, at the center frequency of 1.96 GHz, and the out‐of‐band suppression is higher than 32 dB. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2031–2034, 2015
Design of a high‐sensitivity ground radiation antenna for wireless headsets
Authors: Zhang Rui , Liu Yang , Kim Hyunghoon , Kim Hyeongdong
Published: June 2015

A slot‐type ground radiation antenna and a high‐speed digital circuit are modeled within a Bluetooth headset to demonstrate a useful method to reduce high‐speed digital noise. The method of noise reduction is based on the theory of characteristic modes. Modifying the structure of the antenna and thereby changing the characteristic mode excited by the antenna leads to decoupling between the antenna and the circuit, achieving the high‐sensitivity property of the antenna. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2104–2108, 2015
Compact triple band‐notched printed antenna with multislots for UWB applications
Authors: Tang Zhi‐jun , Zhan Jie , Wu Xiao‐feng
Published: June 2015

A novel compact planar printed antenna is designed and analyzed for ultrawideband wireless applications. The proposed antenna is constructed by a circular patch with a circular split‐ring slot gradually varying the width, a U‐shaped slot, a small strip slot, and a segmental ground plane with three slits. To broaden the bandwidth and produce notches, three different type slots are incorporated in the antenna radiating patch, and multiple slits are embedded onto the defected ground plane. The simulated and measured results show that the antenna yields a wider bandwidth ranging from 2.9 to 13.0 GHz (the return loss less than −10 dB) with the three notched bands of 3.30–3.70 GHz (WiMAX band), 4.50–4.83 GHz (Receiving frequency for INSAT/Super‐Extended C‐band), and 6.67–7.15 GHz (Transmitting frequency for INSAT/Super‐Extended C‐band). Furthermore, the proposed antenna has achieved average peak gain of 5.50 dBi and stable quasi‐omnidirectional radiation patterns. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2056–2060, 2015