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Inside Cover: Quinone‐Rich Poly(dopamine) Magnetic Nanoparticles for Biosensor Applications (ChemPhysChem 17/2014) 下载免费PDF全文
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Catalytic Enantioselective Synthesis of N,Cα,Cα‐Trisubstituted α‐Amino Acid Derivatives Using 1H‐Imidazol‐4(5H)‐ones as Key Templates 下载免费PDF全文
Julen Etxabe Joseba Izquierdo Dr. Aitor Landa Prof. Mikel Oiarbide Prof. Claudio Palomo 《Angewandte Chemie (International ed. in English)》2015,54(23):6883-6886
1H‐Imidazol‐4(5H)‐ones are introduced as novel nucleophilic α‐amino acid equivalents in asymmetric synthesis. These compounds not only allow highly efficient construction of tetrasubstituted stereogenic centers, but unlike hitherto known templates, provide direct access to N‐substituted (alkyl, allyl, aryl) α‐amino acid derivatives. 相似文献
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In a series of seminal papers, Thomas J. Stieltjes (1856-1894) gave an elegant electrostatic interpretation for the zeros of classical families of orthogonal polynomials, such as Jacobi, Hermite and Laguerre polynomials. More generally, he extended this approach to the zeros of polynomial solutions of certain second-order linear differential equations (Lamé equations), the so-called Heine-Stieltjes polynomials.In this paper, a class of electrostatic equilibrium problems in R, where the free unit charges x1,…,xn∈R are in presence of a finite family of “attractors” (i.e., negative charges) z1,…,zm∈C?R, is considered and its connection with certain class of Lamé-type equations is shown. In addition, we study the situation when both n→∞ and m→∞, by analyzing the corresponding (continuous) equilibrium problem in presence of a certain class of external fields. 相似文献
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Changlong Wang Dr. Roberto Ciganda Dr. Lionel Salmon Dr. Danijela Gregurec Dr. Joseba Irigoyen Dr. Sergio Moya Dr. Jaime Ruiz Prof. Didier Astruc 《Angewandte Chemie (International ed. in English)》2016,55(9):3091-3095
A ligand design is proposed for transition metal nanoparticle (TMNP) catalysts in aqueous solution. Thus, a tris(triazolyl)‐polyethylene glycol (tris‐trz‐PEG) amphiphilic ligand, 2 , is used for the synthesis of very small TMNPs with Fe, Co, Ni, Cu, Ru, Pd, Ag, Pt, and Au. These TMNP‐ 2 catalysts were evaluated and compared for the model 4‐nitrophenol reduction, and proved to be extremely efficient. High catalytic efficiencies involving the use of only a few ppm metal of PdNPs, RuNPs, and CuNPs were also exemplified in Suzuki–Miyaura, transfer hydrogenation, and click reactions, respectively. 相似文献
6.
Andrade X Alberdi-Rodriguez J Strubbe DA Oliveira MJ Nogueira F Castro A Muguerza J Arruabarrena A Louie SG Aspuru-Guzik A Rubio A Marques MA 《J Phys Condens Matter》2012,24(23):233202
Octopus is a general-purpose density-functional theory (DFT) code, with a particular emphasis on the time-dependent version of DFT (TDDFT). In this paper we present the ongoing efforts to achieve the parallelization of octopus. We focus on the real-time variant of TDDFT, where the time-dependent Kohn-Sham equations are directly propagated in time. This approach has great potential for execution in massively parallel systems such as modern supercomputers with thousands of processors and graphics processing units (GPUs). For harvesting the potential of conventional supercomputers, the main strategy is a multi-level parallelization scheme that combines the inherent scalability of real-time TDDFT with a real-space grid domain-partitioning approach. A scalable Poisson solver is critical for the efficiency of this scheme. For GPUs, we show how using blocks of Kohn-Sham states provides the required level of data parallelism and that this strategy is also applicable for code optimization on standard processors. Our results show that real-time TDDFT, as implemented in octopus, can be the method of choice for studying the excited states of large molecular systems in modern parallel architectures. 相似文献
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Joseba Irigoyen Lulu Han Irantzu Llarena Zhenwei Mao Changyou Gao Sergio E. Moya 《Macromolecular rapid communications》2012,33(22):1964-1969
Responsive polyelectrolyte multilayers (PEMs) of poly(diallyl dimethyl ammonium chloride) (PDADMAC) and poly(styrene sodium sulfonate) (PSS) with thicknesses between 350 and 400 nm for 11 deposited polyelectrolyte layers were fabricated assembling the polyelectrolytes at 3 M NaCl. When the 3 M NaCl bulk solution is replaced by water, the PEMs release water, approximately a 46% of the total mass, and experience a thickness reduction of more than 200 nm. Changes in thickness and water content are fully reversible. The film recovers its original thickness and water content when it is exposed again to a 3 M NaCl solution. A responsive polymer film is achieved with the capability of swelling at high ionic strength and collapsing in water with variations in thickness of hundred of nanometers. 相似文献
8.
Maria M. Orive Blanca Gallo Rosa M. Alonso Francisca Vicente Jean C. Viré Gaston J. Patriarche 《Mikrochimica acta》1989,97(3-4):181-190
The acid-base behaviour of midazolam, a psychotropic drug derived from imidazobenzodiazepine family, has been studied spectro-photometrically. This compound hydrolyzes at pH values lower than 4. Reversible cleavage of the azomethine bond takes place and the open-ring compound is in equilibrium with the closed-ring compound (protonated form of the parent drug). Absorbance-time data (measured at 225 nm and for different pH values) have been evaluated by a pseudo-first order logarithmic approach, leading to different apparent kinetic constants, depending on pH and temperature. A simple mechanism of hydrolysis, corresponding to fast protonation and slow hydrolysis with opening of the ring is in good agreement with the kinetic results. From data obtained at pH values greater than 4, the deprotonation constant of the nitrogen atom at position 2 of the imidazole ring has been calculated and a pKa value of 5.50 ± 0.05 obtained. In addition, a Spectrophotometric method has been developed which allows the determination of midazolam at concentrations from 1.23 × 10–6
M to 3.38 × 10–5
M. This method has been applied to a pharmaceutical formulation midazolam; the Dormicum error, in terms of relative standard deviation, was lower than 1.5%. 相似文献
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Design and Synthesis of Aviram–Ratner‐Type Dyads and Rectification Studies in Langmuir–Blodgett (LB) Films 下载免费PDF全文
Dr. Govindasamy Jayamurugan Dr. Vijayendran Gowri David Hernández Prof. Dr. Santiago Martin Dr. Alejandro González‐Orive Dr. Cagatay Dengiz Dr. Oliver Dumele Prof. Dr. Francesc Pérez‐Murano Dr. Jean‐Paul Gisselbrecht Prof. Dr. Corinne Boudon Dr. W. Bernd Schweizer Dr. Benjamin Breiten Dr. Aaron D. Finke Prof. Dr. Gunnar Jeschke Dr. Bruno Bernet Prof. Dr. Laurent Ruhlmann Prof. Dr. Pilar Cea Prof. Dr. François Diederich 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(30):10539-10547
The design and synthesis of Aviram–Ratner‐type molecular rectifiers, featuring an anilino‐substituted extended tetracyanoquinodimethane (exTCNQ) acceptor, covalently linked by the σ‐spacer bicyclo[2.2.2]octane (BCO) to a tetrathiafulvalene (TTF) donor moiety, are described. The rigid BCO spacer keeps the TTF donor and exTCNQ acceptor moieties apart, as demonstrated by X‐ray analysis. The photophysical properties of the TTF‐BCO‐exTCNQ dyads were investigated by UV/Vis and EPR spectroscopy, electrochemical studies, and theoretical calculations. Langmuir–Blodgett films were prepared and used in the fabrication and electrical studies of junction devices. One dyad showed the asymmetric current–voltage (I–V) curve characteristic for rectification, unlike control compounds containing the TTF unit but not the exTCNQ moiety or comprising the exTCNQ acceptor moiety but lacking the donor TTF part, which both gave symmetric I–V curves. The direction of the observed rectification indicated that the preferred electron current flows from the exTCNQ acceptor to the TTF donor. 相似文献
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Doris Grumelli Dr. Carolina Vericat Dr. Guillermo Benítez Dr. José M. Ramallo‐López Dr. Lisandro Giovanetti Dr. Félix Requejo Dr. M. Sergio Moreno Dr. Alejandro González Orive Alberto Hernández Creus Dr. Roberto C. Salvarezza Dr. 《Chemphyschem》2009,10(2):370-373
Attractive combination: Biopolymer‐modified nanoparticles which combine magnetic properties with biocompatibility are prepared and delivered following a three‐step strategy (see figure): i) Adsorption of thiol‐capped metal nanoparticles on graphite, ii) electrochemical modification, iii) potential‐induced delivery of the modified nanoparticles to the electrolyte.