bluuebunny/crossref_metadata_2025 huggingface dataset:
Contribution of hydrogen and/or covalent bonds on reinforcement of natural rubber latex films with surface modified silica
Authors: Somaratne M. Chandani Wasantha , Liyanage N. M. Vinitha Kalyani , Walpalage Shantha
Published: January 2014

A macromolecular coupling agent containing hydrophilic and hydrophobic groups is made to react with precipitated silica. Interfacial interactions between OH groups of silica and COOH groups of macromolecule are found to be created through either hydrogen bonds alone or through hydrogen bonds and covalent bonds. Aqueous dispersions of unmodified and modified silica are prepared and the colloidal stability and particle size distribution of the dispersions are observed. The dispersions at neutral pH are incorporated into vulcanized/unvulcanized natural rubber latex. The formation of hydrogen bonds and/or covalent bonds is studied via FTIR spectroscopy and their contribution in encouraging filler‐rubber interactions is emphasized through mechanical and swelling properties. Uniform distribution and dispersion of modified filler particles throughout the rubber matrix is confirmed by the microstructures of the latex films cast from filler added natural rubber latex. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40380.
Cr(III)‐containing Fe3O4/mercaptopropanoic acid‐poly(2‐hydroxyethyl acrylate) nanocomposite: Highly active magnetic catalyst for direct hydroxylation of benzene
Authors: Zamani Farzad , Kianpour Sahar , Nekooei Behshad
Published: January 2014

In this study, polymer‐grafted magnetic nanoparticles containing chromium(III) ions incorporated onto Fe3O4/mercaptopropanoic acid‐poly(2‐hydroxyethyl acrylate) was prepared via a simple and in situ method. The obtained magnetic nanocomposite exhibited high catalytic activity and excellent selectivity in direct hydroxylation of benzene in the presence of hydrogen peroxide under solvent‐free condition. The magnetic catalyst could be also separated by an external magnet and reused seven times without any significant loss of activity/selectivity. Due to the Lewis acidity of the Fe3+ groups in the structure of magnetic nanoparticles, the high efficiency of this catalyst is possibly due to the synergetic effect of Cr3+ and Fe3+ groups in the structure of magnetic nanocomposite. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40383.
Synthesis and characterization of a drug‐delivery system based on melamine‐modified poly(vinyl acetate‐co‐maleic anhydride) hydrogel
Authors: Shafaghi Samira , Moghadam Peyman Najafi , Fareghi Amir Reza , Baradarani Mohammad Mehdi
Published: January 2014

Three‐dimensional polymeric networks, which quickly swell by imbibing a large amount of water or deswell in response to changes in their external environment, are called hydrogels. These types of polymeric materials are good potential candidates for drug‐delivery systems. In this study, we first synthesized poly(vinyl acetate‐co‐maleic anhydride) by free‐radical copolymerization. Then, they were modified with different molar ratios of melamine to prepare hydrogels that could be used in drug‐delivery systems. The hydrogels were characterized by Fourier transform infrared spectroscopy, 1H‐NMR, differential scanning calorimetry, and scanning electron microscopy. In the second step, Ceftazidime antibiotic was loaded on selected hydrogels. The in vitro drug release was investigated and compared in three different media (HCl solution at pH = 3 and buffer solutions at pH 6.1and pH 8). © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40389.
Extended Conjugated Donor–Acceptor Molecules with E‐(1,2‐Difluorovinyl) and Diketopyrrolopyrrole (DPP) Moieties toward High‐Performance Ambipolar Organic Semiconductors
Authors: Cai Zhengxu , Luo Hewei , Chen Xin , Zhang Guanxin , Liu Zitong , Zhang Deqing
Published: January 2014

Two diketopyrrolopyrrole (DPP)‐based donor–acceptor (D–A) conjugated molecules, DPP‐F and DPP‐2F, which contain E‐(1,2‐difluorovinyl) moieties, are reported. The LUMO energies of DPP‐F and DPP‐2F were estimated to be −3.49 and −3.70 eV, respectively, based on their redox potentials and absorption spectral data; these values were clearly lowered because of the incorporation of electron‐withdrawing E‐(1,2‐difluorovinyl) moieties. Organic field‐effect transistors (OFETs) with thin films of DPP‐F and DPP‐2F were successfully fabricated with conventional techniques. Based on the respective transfer and output characteristics measured in an inert atmosphere, thin films of DPP‐2F display ambipolar semiconducting behavior with hole and electron mobilities reaching 0.42 and 0.80 cm2 V−1 s−1, respectively. The as‐prepared OFET of DPP‐2F already shows high hole and electron mobilities that are not influenced remarkably by thermal annealing. For thin films of DPP‐F, only p‐type semiconducting behavior was observed in both an inert atmosphere and air, and the hole mobility increased to 0.1 cm2 V−1 s−1 after thermal annealing. XRD and AFM studies were performed with thin films of DPP‐F and DPP‐2F after annealing at different temperatures.
The effects on students' emotional and behavioural difficulties of teacher–student interactions, students' social skills and classroom context
Authors: Poulou Maria
Published: January 2014

Children's emotional and behavioural difficulties are the result of multiple individual, social and contextual factors working in concert. The current paper proposes a theoretical framework for interpreting students' emotional and behavioural difficulties in classrooms, by taking into consideration teacher–student interactions, students' social skills and classroom context. Based on Bronfenbrenner's model, according to which process, person and context are the main sources of children's development, the current paper combines three theoretical approaches: firstly, in terms of process, the systems communication approach, which refers to teacher–student interactions; secondly, in terms of person, social and emotional learning, which refers to children's social skills; and thirdly, in terms of classroom context, the achievement goal theory, with its emphasis on the mastery of classroom goal structure. Empirical support for the framework resulted in the administration of four instruments to 962 primary students: (a) QTI for teacher–student interactions, (b) MESSY for students' social skills; (c) CGS for classroom context; and (d) SDQ for students' emotional and behavioural difficulties. It was found that students' possession of social skills had a prominent role in the prediction of emotional and behavioural difficulties, while teacher–student interactions and classroom context also affected students' emotional and behavioural difficulties. This perspective provides educators with a theoretical and practical tool for understanding emotional and behavioural difficulties.
Keeping on track: Performance profiles of low performers in academic educational tracks
Authors: Reed Helen C. , van Wesel Floryt , Ouwehand Carolijn , Jolles Jelle
Published: January 2014

In countries with high differentiation between academic and vocational education, an individual's future prospects are strongly determined by the educational track to which he or she is assigned. This large‐scale, cross‐sectional study focuses on low‐performing students in academic tracks who face being moved to a vocational track. If more is understood about these students, measures could be taken to improve their performance and keep them within academic education. The study investigates performance patterns in academic tracks in the first three years of secondary school in the Netherlands. By identifying patterns that reveal how competence levels in different domains are related at different stages of development and by comparing low performers with other students, the study sheds light on individual and educational aspects that may be amenable to intervention. School grades were analysed for 1596 students. School performance was found to reflect three domains—languages (language of schooling and modern foreign languages), social studies and science and math—that appear to interact in a process of co‐construction. General language skills were robustly related to performance in other domains—particularly social studies—throughout the first three years of secondary school. By comparison, proficiency specifically in the language of schooling was less strongly related to social studies and science and math performance after the first year. Suggestions are given as to how educators and curriculum developers could use these insights to accommodate individual and developmental differences and to develop learning materials that may help low performers keep on track.
Sphinganine‐Like Biogenesis of (E)‐1‐Nitropentadec‐1‐ene in Termite Soldiers of the Genus Prorhinotermes
Authors: Jirošová Anna , Majer Pavel , Jančařík Andrej , Dolejšová Klára , Tykva Richard , Šobotník Jan , Jiroš Pavel , Hanus Robert
Published: January 2014

In 1974, (E)‐1‐nitropentadec‐1‐ene, a strong lipophilic contact poison of soldiers of the termite genus Prorhinotermes, was the first‐described insect‐produced nitro compound. However, its biosynthesis remained unknown. In the present study, we tested the hypothesis that (E)‐1‐nitropentadec‐1‐ene biosynthesis originates with condensation of amino acids with tetradecanoic acid. By using in vivo experiments with radiolabeled and deuterium‐labeled putative precursors, we show that (E)‐1‐nitropentadec‐1‐ene is synthesized by the soldiers from glycine or L‐serine and tetradecanoic acid. We propose and discuss three possible biosynthetic pathways.
Characterization of a Galactosynthase Derived from Bacillus circulans β‐Galactosidase: Facile Synthesis of D‐Lacto‐ and D‐Galacto‐N‐bioside
Authors: Li Chao , Kim Young‐Wan
Published: January 2014

Glycosynthases—retaining glycosidases mutated at their catalytic nucleophile—catalyze the formation of glycosidic bonds from glycosyl fluorides as donor sugars and various glycosides as acceptor sugars. Here the first glycosynthase derived from a family 35 β‐galactosidase is described. The Glu→Gly mutant of BgaC from Bacillus circulans (BgaC‐E233G) catalyzed regioselective galactosylation at the 3‐position of the sugar acceptors with α‐galactosyl fluoride as the donor. Transfer to 4‐nitophenyl α‐D‐N‐acetyl‐glucosaminide and α‐D‐N‐acetylgalactosaminide yielded 4‐nitophenyl α‐lacto‐N‐biose and α‐galacto‐N‐biose, respectively, in high yields (up to 98 %). Kinetic analysis revealed that the high affinity of the acceptors contributed mostly to the BgaC‐E233G‐catalyzed transglycosylation. BgaC‐E233G showed no activity with β‐(1,3)‐linked disaccharides as acceptors, thus suggesting that this enzyme can be used in “one‐pot synthesis” of LNB‐ or GNB‐containing glycans.
From Bare to Covered
Authors: Butera Gianfranco , Manica João Luiz Langer , Marini Davide , Piazza Luciane , Chessa Massimo , Filho Raul Ivo Rossi , Sarmento Leite Rogério E. , Carminati Mario
Published: January 2014

Background

Bare stents has become the first line therapy for aortic coarctation. Covered stents has been reported more recently in clinical practice.

Objectives

The present study, reports comparatively 15‐year experience of bare and covered stent implantation for aortic coarctation in a single tertiary referral center.

Methods

From 1997 to 2011, 143 patients with native or postoperative aortic coarctation were treated at our institution. Seventy‐one subjects (median age 17 years (range from 4 to 70 years) underwent bare stent implantation (Group 1) while 72 patients (median age of 17.5 years (range from 6 to 68 years) underwent covered stent implantation (Group 2).

Results

Success rate in the whole group was 95%. More complex and tighter coarctations were treated using covered stents. Incidence of related‐procedure adverse events was higher in Group 1 than in group 2 (21.1% vs. 8.3%P = 0.035). Aortic wall complications occurred in 7% of patients in Group 1 (one death) and 0% in Group 2 (P = 0.028). Subjects in Group 1 had a longer follow‐up (median 85 vs. 35 months;P < 0.001). Independent predictors associated with reintervention included the presence of complex lesions (HR: 2.70; CI: 1.15–6.32), balloon diameter used <14 mm (HR: 3.76; CI: 1.48–9.55), and immediate residual gradient >10 mm Hg (HR: 4.30; CI: 1.96–9.47).

Conclusions

Both bare and covered stent implantation for aortic coarctation is a safe and efficacious treatment. By using covered stent implantation the spectrum of patients treated has increased with lower rates of acute and late complications. © 2014 Wiley Periodicals, Inc.
Percutaneous stenting of interrupted aortic arch to treat compressive myelopathy
Authors: Moorthy Nagaraja , Ananthakrishna Rajiv , Nanjappa Manjunath C.
Published: January 2014

Neurological complications of coarctation of aorta include spontaneous SAH, intracerebral hemorrhage, and cerebral abscess. Interrupted aortic arch (IAA) present as compressive myelopathy is not known. We describe an adult male presenting to neurology department with progressive paraparesis and was detected to have IAA with intraspinal collaterals causing compressive myelopathy. He was successfully treated with percutaneous stenting of IAA with dramatic improvement in paraparesis. © 2014 Wiley Periodicals, Inc.
Designing Cyclometalated Ruthenium(II) Complexes for Anodic Electropolymerization
Authors: Friebe Christian , Schulze Benjamin , Görls Helmar , Jäger Michael , Schubert Ulrich S.
Published: January 2014

The anodic electropolymerization of thiophene‐functionalized cyclometalated ruthenium(II) complexes is shown for the first time. Oxidative decomposition reactions can be overcome by modification of the involved redox potentials through the introduction of electron‐withdrawing substituents, namely nitro groups, at the cyclometalating phenyl ring. The generated functionalized ruthenium(II) complexes allow the electrochemical preparation of thin polymer films, which show a broad UV/Vis absorption as well as reversible redox switchability. The presented complexes are promising candidates for future photovoltaic applications based on photo‐redox‐active films.
Chemoselective and Direct Functionalization of Methyl Benzyl Ethers and Unsymmetrical Dibenzyl Ethers by Using Iron Trichloride
Authors: Sawama Yoshinari , Goto Ryota , Nagata Saori , Shishido Yuko , Monguchi Yasunari , Sajiki Hironao
Published: January 2014

Methyl and benzyl ethers are widely utilized as protected alcohols due to their chemical stability, such as the low reactivity of the methoxy and benzyloxy groups as leaving groups under nucleophilic conditions. We have established the direct azidation of chemically stable methyl and benzyl ethers derived from secondary and tertiary benzyl alcohols. The present azidation chemoselectively proceeds at the secondary or tertiary benzylic positions of methyl benzyl ethers or unsymmetrical dibenzyl ethers and is also applicable to direct allylation, alkynylation, and cyanation reactions, as well as the azidation. The present methodologies provide not only a novel chemoselectivity but also the advantage of shortened synthetic steps, due to the direct process without the deprotection of the methyl and benzyl ethers.
Supramolecular ssDNA Templated Porphyrin and Metalloporphyrin Nanoassemblies with Tunable Helicity
Authors: Sargsyan Gevorg , Leonard Brian M. , Kubelka Jan , Balaz Milan
Published: January 2014

Free‐base and nickel porphyrin–diaminopurine conjugates were formed by hydrogen‐bond directed assembly on single‐stranded oligothymidine templates of different lengths into helical multiporphyrin nanoassemblies with highly modular structural and chiroptical properties. Large red‐shifts of the Soret band in the UV/Vis spectroscopy confirmed strong electronic coupling among assembled porphyrin–diaminopurine units. Slow annealing rates yielded preferentially right‐handed nanostructures, whereas fast annealing yielded left‐handed nanostructures. Time‐dependent DFT simulations of UV/Vis and CD spectra for model porphyrin clusters templated on the canonical B‐DNA and its enantiomeric form, were employed to confirm the origin of observed chiroptical properties and to assign the helicity of porphyrin nanoassemblies. Molar CD and CD anisotropy g factors of dialyzed templated porphyrin nanoassemblies showed very high chiroptical anisotropy. The DNA‐templated porphyrin nanoassemblies displayed high thermal and pH stability. The structure and handedness of all assemblies was preserved at temperatures up to +85 °C and pH between 3 and 12. High‐resolution transition electron microscopy confirmed formation of DNA‐templated nickel(II) porphyrin nanoassemblies and their self‐assembly into helical fibrils with micrometer lengths.
Design of Ratiometric Fluorescent Probes Based on Arene–Metal‐Ion Interactions and Their Application to CdII and Hydrogen Sulfide Imaging in Living Cells
Authors: Takashima Ippei , Kinoshita Miyuki , Kawagoe Ryosuke , Nakagawa Saika , Sugimoto Manabu , Hamachi Itaru , Ojida Akio
Published: January 2014

Non‐coordinative interactions between a metal ion and the aromatic ring of a fluorophore can act as a versatile sensing mechanism for the detection of metal ions with a large emission change of fluorophores. We report the design of fluorescent probes based on arene–metal‐ion interactions and their biological applications. This study found that various probes having different fluorophores and metal binding units displayed significant emission redshift upon complexation with metal ions, such as AgI, CdII, HgII, and PbII. X‐ray crystallography of the complexes confirmed that the metal ions were held in close proximity to the fluorophore to form an arene–metal‐ion interaction. Electronic structure calculations based on TDDFT offered a theoretical basis for the sensing mechanism, thus showing that metal ions electrostatically modulate the energy levels of the molecular orbitals of the fluorophore. A fluorescent probe was successfully applied to the ratiometric detection of the uptake of CdII ions and hydrogen sulfide (H2S) in living cells. These results highlight the utility of interactions between arene groups and metal ions in biological analyses.
Rhodium(III)‐Catalyzed CH Activation and Indole Synthesis With Hydrazone as an Auto‐Formed and Auto‐Cleavable Directing Group
Authors: Zheng Liyao , Hua Ruimao
Published: January 2014

An efficient, practical, and external‐oxidant‐free indole synthesis from readily available aryl hydrazines was developed, by using hydrazone as a directing group for RhIII‐catalyzed CH activation and alkyne annulation. The hydrazone group was formed by in situ condensation of hydrazines and CO source, whereas its NN bond was served as an internal oxidant, for which we termed it as an auto‐formed and auto‐cleavable directing group (DGauto). This method needs no step for pre‐installation and post‐cleavage of the directing group, making it a quite easily scalable approach to access unprotected indoles with high step economy. The DGauto strategy was also applicable for isoquinoline synthesis. In addition, synthetic utilities of this chemistry for rapid assembly of π‐extended nitrogen‐doped polyheterocycles and bioactive molecules were demonstrated.
α‐Fe2O3 Cubes with High Visible‐Light‐Activated Photoelectrochemical Activity towards Glucose: Hydrothermal Synthesis Assisted by a Hydrophobic Ionic Liquid
Authors: Xu Li , Xia Jiexiang , Wang Leigang , Qian Jing , Li Huaming , Wang Kun , Sun Kaiyong , He Minqiang
Published: January 2014

A liquid/liquid interfacial reaction system was designed to fabricate α‐Fe2O3 cubes. The reaction system uses a hydrophobic ionic liquid containing iron ions ([(C8H17)2(CH3)2N]FeCl4) for manufacturing α‐Fe2O3 cubes by a novel and environmentally friendly hydrothermal method under low‐temperature conditions (140 °C). The iron‐containing ionic liquid is hydrophobic and can form a liquid/liquid interface with water, which is vital for fabrication of the α‐Fe2O3 cubes. Nanomaterials synthesized from hydrophobic iron‐containing ionic liquids show good crystallinity, well‐developed morphology, and uniform size. The effect of different ionic liquids on the morphology of α‐Fe2O3 was investigated in detail. [(C8H17)2(CH3)2N]FeCl4 is assumed to perform the triple role of forming a liquid/liquid interface with water and acting as reactant and template at the same time. The effect of the reaction temperature on the formation of the α‐Fe2O3 cubes was also studied. Temperatures lower or higher than 140 °C are not conducive to formation of the α‐Fe2O3 cubes. Their photoelectrochemical properties were tested by means of the transient photocurrent response of electrodes modified with as‐prepared α‐Fe2O3 cubes. The photocurrent response of an α‐Fe2O3 cubes/indium tin oxide electrode is high and stable, and it shows great promise as a photoelectrochemical glucose sensor with high sensitivity and fast response, which are beneficial to practical applications of nanosensors.
Trifluoroacetic Acid in 2,2,2‐Trifluoroethanol Facilitates SNAr Reactions of Heterocycles with Arylamines
Authors: Carbain Benoit , Coxon Christopher R. , Lebraud Honorine , Elliott Kristopher J. , Matheson Christopher J. , Meschini Elisa , Roberts Amy R. , Turner David M. , Wong Christopher , Cano Celine , Griffin Roger J. , Hardcastle Ian R. , Golding Bernard T.
Published: January 2014

Small‐molecule drug discovery requires reliable synthetic methods for attaching amino compounds to heterocyclic scaffolds. Trifluoroacetic acid‐2,2,2‐trifluoroethanol (TFA‐TFE) is as an effective combination for achieving SNAr reactions between anilines and heterocycles (e.g., purines and pyrimidines) substituted with a leaving group (fluoro‐, chloro‐, bromo‐ or alkylsulfonyl). This method provides a variety of compounds containing a “kinase‐privileged fragment” associated with potent inhibition of kinases. TFE is an advantageous solvent because of its low nucleophilicity, ease of removal and ability to solubilise polar substrates. Furthermore, TFE may assist the breakdown of the Meisenheimer–Jackson intermediate by solvating the leaving group. TFA is a necessary and effective acidic catalyst, which activates the heterocycle by N‐protonation without deactivating the aniline by conversion into an anilinium species. The TFA‐TFE methodology is compatible with a variety of functional groups and complements organometallic alternatives, which are often disadvantageous because of the expense of reagents, the frequent need to explore diverse sets of reaction conditions, and problems with product purification. In contrast, product isolation from TFA‐TFE reactions is straightforward: evaporation of the reaction mixture, basification and chromatography affords analytically pure material. A total of 45 examples are described with seven discrete heterocyclic scaffolds and 2‐, 3‐ and 4‐substituted anilines giving product yields that are normally in the range 50–90 %. Reactions can be performed with either conventional heating or microwave irradiation, with the latter often giving improved yields.
ChemInform Abstract: Structure, Sintering and Electrical Properties of New Ionic Conductor Ag4Co7(AsO4)6.
Authors: Marzouki R. , Guesmi A. , Georges S. , Zid M. F. , Driss A.
Published: January 2014

Ag4Co7(AsO4)6 is prepared by solid state reaction of a stoichiometric mixture of AgNO3, Co(NO3)2, and As2O5 (1.
ChemInform Abstract: Substitution of Conventional High‐Temperature Syntheses of Inorganic Compounds by Near‐Room‐Temperature Syntheses in Ionic Liquids.
Authors: Groh Matthias F. , Mueller Ulrike , Ahmed Ejaz , Rothenberger Alexander , Ruck Michael
Published: January 2014

The preparation of 16 halogenides in the Lewis‐acidic room temperature ionic liquids [bmimm]Cl·xAlCl3 (x: 1.3, 2, 4.8) demonstrates that this resource‐efficient, low‐temperature one‐pot method can successfully replace high‐temperature solid state syntheses.
ChemInform Abstract: Cadmium‐Proline Catalyzed Direct Asymmetric Michael and Aldol Reactions in Water.
Authors: Thingom Bhavna , Moirangthem Soniya D. , Laitonjam Warjeet S.
Published: January 2014

Cd L‐prolinate appears to be a useful catalyst for Michael addition reactions of unmodified ketones to nitrostyrene as well as aldol reactions of unmodified ketones with aryl aldehydes.
ChemInform Abstract: Strain‐Promoted Retro‐Dieckmann‐Type Condensation on [2.2.2]‐ and [2.2.1]Bicyclic Systems: A Fragmentation Reaction for the Preparation of Functionalized Heterocycles and Carbocycles.
Authors: Moreno‐Clavijo Elena , Moreno‐Vargas Antonio J. , Carmona Ana T. , Robina Inmaculada
Published: January 2014

The ring strain of (7‐hetero)norbornene and (7‐hetero)norbornane systems is exploited in the opening of (7‐hetero)bicyclic skeletons containing a β‐ketosulfone/ester functionality through a retro‐Dieckmann type reaction.
ChemInform Abstract: Mild Palladium‐Catalyzed Regioselective Direct Arylation of Azoles Promoted by Tetrabutylammonium Acetate.
Authors: Bellina Fabio , Lessi Marco , Manzini Chiara
Published: January 2014

A simple and efficient method to prepare several 5‐arylated azoles is presented.
ChemInform Abstract: Mild Allylic Defluorination of 3,3‐Difluorobut‐1‐ene Derivative Activated by a Phenylsulfonyl Group.
Authors: Hong Youn Young , Kim Ju Hee , Choi Su Jeong , Jeong In Howa
Published: January 2014

Allylic defluorination is observed when title compounds of type (IV) or (XIV) are reacted with thiolates or alkoxides formed in situ from (V), or with Grignard reagents (VIII) or (XI), or when reacted with t‐butylamine (XI).
ChemInform Abstract: Straightforward and Highly Efficient Synthesis of α‐Acetoxy Ketones Through Gold‐Catalyzed Intermolecular Oxidation of Terminal Alkynes.
Authors: Wu Chao , Liang Zhiwu , Yan Dong , He Weimin , Xiang Jiannan
Published: January 2014

A protocol for the direct synthesis of 2‐acyloxyketones is developed using the Au‐catalyzed oxidative addition of carboxylic acids to a variety of terminal alkynes.
ChemInform Abstract: Study of the Kulinkovich Synthesis of 1‐Methylcyclopropanol and Its Conversion into 1‐Methylcyclopropyl 4‐Nitrophenyl Carbonate.
Authors: Wright Stephen W. , Darout Etzer , Stevens Benjamin D.
Published: January 2014

A carefully designed process for the scalable synthesis of 1‐methylcyclopropanol (III) is developed as well as the optimized conversion to the mixed carbonate (V).
ChemInform Abstract: A Highly Stereoselective Diels—Alder Cycloaddition of Enones with Chiral Cyclic 2‐Amidodienes Derived from Allenamides.
Authors: Fang Li‐Chao , Hsung Richard P. , Ma Zhi‐Xiong , Presser William R.
Published: January 2014

The Lewis acid promotes highly regioselective and diastereoselective Diels‐Alder reaction giving access to optically enriched [2.2.2]‐bicyclic manifolds.
ChemInform Abstract: Capture of in situ Generated Diazo Compounds or Copper Carbenoids by Triphenylphosphine: Selective Synthesis of trans‐Alkenes and Unsymmetric Azines via Reaction of Aldehydes with Ketone‐Derived N‐Tosylhydrazones.
Authors: Sha Qiang , Ling Yifei , Wang Wenyong , Wei Yunyang
Published: January 2014

The reaction of tosylhydrazones with aldehydes affords unsymmetrical azines (III) and (V).
ChemInform Abstract: Synthesis of Biaryl Imino/Keto Carboxylic Acids via Aryl Amide Directed C—H Activation Reaction.
Authors: Zhang Nana , Yu Qingzhen , Chen Ruixue , Huang Jianhui , Xia Yeqing , Zhao Kang
Published: January 2014

A scalable method for the synthesis of the title compounds by utilization of the cheap oxidant tBuOOH is presented.
ChemInform Abstract: Suzuki Cross‐Coupling of Aryl Halides with Phenylboronic Acid Catalyzed by an Amidoxime Fibres‐Nickel(0) Complex.
Authors: Wu Zhi‐Chuan , Lu Ye‐Neng , Ren Yi‐Ming , Chen Zhi‐Ming , Tao Ting‐Xian
Published: January 2014

A polymer‐supported Ni(0)‐amidoxime complex exhibits excellent catalytic activity in promoting the Suzuki reaction (15 examples).
ChemInform Abstract: A Synthesis of γ‐Trifluoromethyl α,β‐Unsaturated γ‐Butyrolactones Using CF3SiMe3 as a Trifluoromethylating Agent.
Authors: Masusai Chonticha , Soorukram Darunee , Kuhakarn Chutima , Tuchinda Patoomratana , Pakawatchai Chaveng , Saithong Saowanit , Reutrakul Vichai , Pohmakotr Manat
Published: January 2014

A general synthesis of title compounds such as (V) and (VIII) is described.
ChemInform Abstract: Gold(I)‐Catalyzed Enantioselective Bromocyclization Reactions of Allenes.
Authors: Miles Dillon H. , Veguillas Marcos , Toste F. Dean
Published: January 2014

N‐Bromolactams are used as tunable electrophiles to achieve the first asymmetric bromofunctionalization of allenes yielding a wide range of pyrrolidines, isoxazolidine (XI), and pyrazolidine (XIII) in high yields and enantioselectivities.
ChemInform Abstract: Boric Acid Promoted Convenient Synthesis of Bis(indolyl)methane in Aqueous Medium.
Authors: Meshram H. M. , Rao Nalajala Nageswara , Thakur Pramod B. , Reddy Bandi Chennakesava , Ramesh P.
Published: January 2014

A highly efficient and convenient synthesis of bis(indolyl)methanes (III) (10 examples) via boric acid promoted reaction of indoles with various aromatic and heteroaromatic aldehydes in an environmentally benign medium is developed.
ChemInform Abstract: Expedient Base‐Mediated Desulfitative Dimethylamination, Oxidation, or Etherification of 2‐(Methylsulfanyl)‐3,5‐dihydro‐4H‐imidazol‐4‐one Scaffolds.
Authors: Khan Shahnawaz , Tyagi Vikas , Mahar Rohit , Bajpai Vikas , Kumar Brijesh , Chauhan Prem M. S.
Published: January 2014

The desulfitative dimethylamination of imidazolones (I) is achieved with DMF under optimized microwave conditions.
ChemInform Abstract: Lewis Acid‐Promoted Cascade Reaction of Primary Amine, 2‐Butynedioate, and Propargylic Alcohol: A Convenient Approach to 1,2‐Dihydropyridines and 1H‐Pyrrolo[3,4‐b]pyridine‐5,7(2H,6H)‐diones.
Authors: Yin Guangwei , Zhu Yuanxun , Wang Ningning , Lu Ping , Wang Yanguang
Published: January 2014

A new BF3‐mediated cascade reaction yielding the title compounds is presented.
ChemInform Abstract: Selective Catalytic Hydrodefluorination as a Key Step for the Synthesis of Hitherto Inaccessible Aminopyridine Derivatives.
Authors: Podolan Gabriel , Lentz Dieter , Reissig Hans‐Ulrich
Published: January 2014

The starting compounds are accessible by nucleophilic aromatic substitution of fluorinated pyridines.
ChemInform Abstract: Synthesis of Phenanthridinones from N‐Methoxybenzamides and Aryltriethoxysilanes Through RhIII‐Catalyzed C—H and N—H Bond Activation.
Authors: Senthilkumar Natarajan , Parthasarathy Kanniyappan , Gandeepan Parthasarathy , Cheng Chien‐Hong
Published: January 2014

The one‐pot synthesis of substituted phenanthridinones involves a rhodium‐catalyzed dual C—H bond activation and annulation reactions.
ChemInform Abstract: Stereoselective Synthesis of Chiral Pyrrolidine Derivatives of (+)‐α‐Pinene Containing a β‐Amino Acid Moiety.
Authors: Vega‐Penaloza Alberto , Sanchez‐Antonio Omar , Escudero‐Casao Margarita , Tasnadi Gabor , Fueloep Ferenc , Juaristi Eusebio
Published: January 2014

The (+)‐α‐pinene derived N‐protected amino acid (I) is used in the synthesis of several constrained pyrrolidine derivatives.
ChemInform Abstract: Melt Infiltration: An Emerging Technique for the Preparation of Novel Functional Nanostructured Materials
Authors: de Jongh Petra E. , Eggenhuisen Tamara M.
Published: January 2014

Review: 184 refs.
ChemInform Abstract: Review of CVD Synthesis of Graphene
Authors: Munoz Roberto , Gomez‐Aleixandre Cristina
Published: January 2014

Review: 158 refs.
ChemInform Abstract: New Method for the Temperature‐Programmed Desorption (TPD) of Ammonia Experiment for Characterization of Zeolite Acidity: A Review
Authors: Niwa Miki , Katada Naonobu
Published: January 2014

Review: ca. 150 refs.
Enantioselective Organocatalytic Oxaziridination of N‐Tosyl Aldimine Catalyzed by Cinchona Alkaloid‐Ester Derivatives
Authors: Jin Ying , Zhang Tianyi , Zhang Wei , Chang Sheng , Feng Bo
Published: January 2014

A series of cinchona alkaloid‐ester derivatives was synthesized and applied to catalyze the enantioselective oxaziridination of aryl aldimines with m‐CPBA. The (R,R)‐oxaziridines were obtained in good yields with high enantiomeric excess (ee) values (up to 98%). Chirality 26:150–154, 2014. © 2014 Wiley Periodicals, Inc.
Perspective on CFD studies of coronary artery disease lesions and hemodynamics: A review
Authors: Zhang Jun‐Mei , Zhong Liang , Su Boyang , Wan Min , Yap Jinq Shya , Tham Jasmine P. L. , Chua Leok Poh , Ghista Dhanjoo N. , Tan Ru San
Published: January 2014

Coronary artery disease (CAD) is the most common cardiovascular disease. Early diagnosis of CAD's physiological significance is of utmost importance for guiding individualized risk‐tailored treatment strategies. In this paper, we first review the state‐of‐the‐art clinical diagnostic indices to quantify the severity of CAD and the associated invasive and noninvasive imaging technologies in order to quantify the anatomical parameters of diameter stenosis, area stenosis, and hemodynamic indices of coronary flow reserve and fractional flow reserve. With the development of computational technologies and CFD methods, tremendous progress has been made in applying image‐based CFD simulation techniques to elucidate the effects of hemodynamics in vascular pathophysiology toward the initialization and progression of CAD. So then, we review the advancements of CFD technologies in patient‐specific modeling, involving the development of geometry reconstruction, boundary conditions, and fluid–structure interaction. Next, we review the applications of CFD to stenotic sites, in order to compute their hemodynamic parameters and study the relationship between the hemodynamic conditions and the clinical indices, to thereby assess the amount of viable myocardium and candidacy for percutaneous coronary intervention. Finally, we review the strengths and limitations of current researches of applying CFD to CAD studies. Copyright © 2014 John Wiley & Sons, Ltd.
Constant hue bands in boundary colors discovered using a new appearance model
Authors: Adams Louis W. , Jennings Carl
Published: January 2014

Boundary colors are observed when light from a scene is dispersed by a prism or diffraction grating. We discovered that patterns with repeating black and white stripes can produce repeating bands of boundary colors with two hues. These hues are virtually constant as measured by chromaticity or CIELAB. We found seven cases of this kind using a new appearance model for boundary colors. The model correctly predicts that green and magenta bands recur as stripe widths and dispersion strength vary. The first green/magenta case in the sequence traces out an accurate ellipse in XYZ color space. Green and magenta bands are prominent in supernumerary rainbows and interference rings, and we explain why that might be the case. The explanation is based on an interesting property of the visible spectrum. In addition to the green/magenta cases, the other cases are orange/cyan, yellowish‐green/purple, and yellow/violet. The success of the boundary color appearance model implies that bands are perceived as if the wavelength responses of the cones were essentially independent, which contradicts the actual behavior of cones. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 135–146, 2015
Quantum Breathing Mode of Trapped Particles: From Nanoplasmas to Ultracold Gases
Authors: Abraham J. W. , Bonitz M.
Published: January 2014

Particles spatially confined in trapping potentials have attracted increasing interest over the recent decade. Of particular importance are systems of charged particles, such as non‐neutral plasmas, nanoplasmas, electrons in metal clusters, electrons in quantum‐confined semiconductor structures (“artificial atoms”), electrons on the surface of liquid helium, ions in traps or highly charged particles (grains) in dusty plasmas. A second example of recent interest are systems with other kinds of pair interactions, including dipole interaction, which is important for excitons in quantum wells or ultracold Fermi and Bose gases in traps and optical lattices.

Trapped systems are fundamentally different from macroscopic systems since they are dominated by strong spatial inhomogeneity and finite size effects (the properties depend on the exact particle number). Furthermore, by changing the strength of the confinement potential, the many‐particle state of the system can be externally controlled—from weak coupling (gas‐like) to strong coupling (crystal‐like). While trapped classical particles are meanwhile well understood and accessible to first‐principle computer simulations, their quantum counterparts still pose big challenges, both for experiment and theory. Therefore, collective properties that can be easily measured or computed and allow to diagnose the many‐particle state of the system are of prime importance. It has been found that the quantum breathing mode (monopole oscillation) is one of the most important such properties. In recent years a number of theoretical studies has demonstrated that the quantum breathing mode is ideally suited to measure the coupling strength (the degree of nonideality) of a trapped system, its kinetic and interaction energy and other key observables. This give rise to a novel kind of “spectroscopy” of trapped systems.

In this review these developments are summarized. The quantum breathing mode is studied for trapped fermions and bosons with Coulomb and dipole interaction, respectively. A systematic description of collective oscillations and especially the breathing mode is provided. Making use of time‐dependent perturbation theory, it is shown how the corresponding breathing frequencies are connected to the properties of the initial equilibrium system. This gives rise to the application of the quantum mechanical sum rules. It is demonstrated how an improved version of the conventional sum rule formulas is suitable for an accurate description of the breathing mode in small systems. Finally, the dependence of the breathing mode on the particle number N is analyzed and the limit of large N is studied for one‐dimensional and two‐dimensional systems. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Orthogonal superimposed training design for block transmission over frequency‐selective fading channels
Authors: Dou Gaoqi , He Chunquan , Li Congying , Gao Jun
Published: January 2014

Channel estimation for single‐carrier block transmission over frequency‐selective fading channel using superimposed training is addressed. A novel affine precoding model based on orthogonal polyphase sequence set is designed to decouple channel estimation from symbol detection. The orthogonal constraints on the training and precoding matrices ensure the separation of superimposed signals and accurate channel estimation with less training overheads as compared with time‐multiplexed scheme. Simulation results show that the proposed scheme exhibits good performance and outperforms another data‐dependent superimposed training scheme, especially for compact constellations or channel with long delay‐spread. Copyright © 2014 John Wiley & Sons, Ltd.
Exposure to natural pathogens reveals costly aphid response to fungi but not bacteria
Authors: Barribeau Seth M. , Parker Benjamin J. , Gerardo Nicole M.
Published: January 2014

Immune responses are costly, causing trade‐offs between defense and other host life history traits. Aphids present a special system to explore the costs associated with immune activation since they are missing several humoral and cellular mechanisms thought important for microbial resistance, and it is unknown whether they have alternative, novel immune responses to deal with microbial threat. Here we expose pea aphids to an array of heat‐killed natural pathogens, which should stimulate immune responses without pathogen virulence, and measure changes in life‐history traits. We find significant reduction in lifetime fecundity upon exposure to two fungal pathogens, but not to two bacterial pathogens. This finding complements recent genomic and immunological studies indicating that pea aphids are missing mechanisms important for bacterial resistance, which may have important implications for how aphids interact with their beneficial bacterial symbionts. In general, recent exploration of the immune systems of non‐model invertebrates has called into question the generality of our current picture of insect immunity. Our data highlight that taking an ecological approach and measuring life‐history traits to a broad array of pathogens provides valuable information that can complement traditional approaches.
Bet‐hedging as a complex interaction among developmental instability, environmental heterogeneity, dispersal, and life‐history strategy
Authors: Scheiner Samuel M.
Published: January 2014

One potential evolutionary response to environmental heterogeneity is the production of randomly variable offspring through developmental instability, a type of bet‐hedging. I used an individual‐based, genetically explicit model to examine the evolution of developmental instability. The model considered both temporal and spatial heterogeneity alone and in combination, the effect of migration pattern (stepping stone vs. island), and life‐history strategy. I confirmed that temporal heterogeneity alone requires a threshold amount of variation to select for a substantial amount of developmental instability. For spatial heterogeneity only, the response to selection on developmental instability depended on the life‐history strategy and the form and pattern of dispersal with the greatest response for island migration when selection occurred before dispersal. Both spatial and temporal variation alone select for similar amounts of instability, but in combination resulted in substantially more instability than either alone. Local adaptation traded off against bet‐hedging, but not in a simple linear fashion. I found higher‐order interactions between life‐history patterns, dispersal rates, dispersal patterns, and environmental heterogeneity that are not explainable by simple intuition. We need additional modeling efforts to understand these interactions and empirical tests that explicitly account for all of these factors.
A Viable Route for Lithium Ion Detection
Authors: Gulino Antonino , Lupo Fabio , Cristaldi Domenico A. , Pappalardo Sebastiano , Capici Calogero , Gattuso Giuseppe , Notti Anna , Parisi Melchiorre F.
Published: January 2014

Invited for the cover of this issue is the Gulino group at the University of Catania, Italy, with collaborators at the University of Messina. The cover image shows the mechanism of the reversible lithium‐sensing monolayer system.
Synthesis and Identification of Solution‐Stable Sulfenic Acids: Perfluoroalkanesulfenic Acids
Authors: Li Xiao‐Bo , Xu Ze‐Feng , Liu Li‐Juan , Liu Jin‐Tao
Published: January 2014

Taking advantage of the strong electron‐withdrawing effect of perfluoroalkyl groups, solution‐stable perfluoroalkanesulfenic acids were synthesized for the first time by Cope‐type elimination of the corresponding imines; the acids were identified by 1H NMR, 19F NMR, and IR spectroscopy and mass spectrometry. Trapping reagents were utilized to capture the in situ generated sulfenic acids, which provided further experimental evidence for the formation of these fluorinated sulfenic acids.
Synthetic Routes towards Fluorine‐Containing Amino Sugars: Synthesis of Fluorinated Analogues of Tomosamine and 4‐Amino‐4‐deoxyarabinose
Authors: Albler Christopher , Schmid Walther
Published: January 2014

Fluorinated analogues of bioactive amino sugars are of high interest in medicinal chemistry. We developed a straightforward synthetic route towards this class of carbohydrates by applying a titanium‐mediated aldol addition. Thus, two‐carbon chain elongations of serine‐ and threonine‐derived aldehydes with a chiral fluoroacetyl‐oxazolidinone could be achieved in good yields and excellent diastereoselectivities to generate a fluorohydrin‐containing carbon skeleton. A short deprotection sequence subsequently furnished the pyranoid forms of various 4‐amino‐2‐fluoropentoses and ‐hexoses, respectively. The versatility of this strategy was demonstrated by the stereoselective synthesis of naturally abundant 4‐amino‐4‐deoxyarabinose and 4‐amino‐4,6‐dideoxygalactose (tomosamine).
Gold(I)‐Catalysed Tandem Cyclisation of Propargyl Acetals and Vinyl Esters
Authors: Siah Huey‐San Melanie , Kaur Maya , Iqbal Naseem , Fiksdahl Anne
Published: January 2014

The results of our previous comparative study of chemoselective gold(I)‐catalysed alkene cycloadditions of propargyl substrates demonstrated that propargyl acetals react by different cyclisation pathways from the corresponding esters, and that they also have significantly higher reactivities. To increase understanding of the chemistry of propargyl acetals and to explore the possibilities of generating new compounds through gold(I)‐catalysed reactions, a range of reactions of propargyl acetals with vinyl esters have been carried out. A new type of cyclopropyl–cyclopentenyl products, (1,3‐dimethoxy‐4,5‐diphenylcyclopent‐2‐en‐1‐yl)‐cyclopropyl ester derivatives, was obtained. A plausible mechanism, including sequential [1+2] and [2+3] cycloadditions, is proposed for these highly regio‐ and stereoselective gold(I)‐catalysed reactions. The cyclopentenylation took place stereoselectively, whereas cis/trans mixtures of diastereoisomers were formed in the cyclopropanation step, with the selectivity being controlled by the bulkier vinylic substituent. The tandem reaction allows the construction of polysubstituted and highly functionalised bicyclic compounds.
Sarsolenane and Capnosane Diterpenes from the Hainan Soft Coral Sarcophyton trocheliophorum Marenzeller as PTP1B Inhibitors
Authors: Liang Lin‐Fu , Kurtán Tibor , Mándi Attila , Gao Li‐Xin , Li Jia , Zhang Wen , Guo Yue‐Wei
Published: January 2014

Two new sarsolenane diterpenes, dihydrosarsolenone (2), methyl dihydrosarsolenoneate (3), and two new capnosane diterpenes, sarsolilides B (5) and C (6), were isolated together with the known analogue, sarsolilide A (4), from the Hainan soft coral Sarcophyton trocheliophorum Marenzeller. Their structures were elucidated by detailed spectroscopic analysis and by comparison with reported data, leading to a structure revision of sarsolenone (1). The absolute configurations of 2 and 5 were determined by TDDFT ECD calculations, and they could be used as ECD reference compounds in the determination of the absolute configuration of their related derivatives. Compounds 4 and 5 exhibited inhibitory activity in vitro against protein tyrosine phosphatases 1B (PTP1B), representing the first report of PTP1B inhibitory activity for capnosane diterpenes.
An ITO Based Disposable Biosensor for Ultrasensitive Analysis of Retinol Binding Protein
Authors: Şimşek Çiğdem Sayıklı , Teke Mustafa , Sezgintürk Mustafa Kemal
Published: January 2014

A highly sensitive electrochemical biosensor based on anti‐RBP biorecognition capable to analyze concentrations of retinol binding protein (RBP) was developed. The construction of the biosensor interfaces was carefully characterized by techniques such as electrochemistry, EIS, and scanning electron microscopy. In order to characterize impedance data, Kramers‐Kronig Transform was performed on the experimental impedance data. Besides, for an immunosensor system the Single Frequency Impedance technique was firstly used for the characterization of the interaction between RBP and anti‐RBP. Finally, artificial serum samples spiked with RBP were analyzed by the proposed ITO based immunosensor to investigate the usefulness of the biosensor for early biomarker diagnosis.