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101.
Eutimio G. Fernández Rodolfo Valdés Yenisley Medina José A. Montero Alejandro Figueroa Williams Ferro Yarysel Guevara Tatiana Álvarez Andrés Tamayo Regla M. Somoza Leonardo Canaán-Haden Jorge L. López 《Chromatographia》2009,70(7-8):1179-1183
Sepharose CL-4B and Sepharose CL-2B with immobilized CB.Hep-1 monoclonal antibody were compared for studying the matrix efficiency in the immunopurification of the recombinant hepatitis B surface antigen (rHBsAg). The elution capacities of both matrices were similar over eight chromatographic cycles, significant differences were only observed in the first purification cycles. A high percentage of the adsorbed rHBsAg was not eluted from both matrices. The rHBsAg purity was not affected by matrix characteristics (pore size and percentage of agarose) and differences between Sepharose CL-4B and Sepharose CL-2B do not provoke differences in the antibody released from the matrices under defined experimental conditions. 相似文献
102.
Árpád Furka 《Structural chemistry》2009,20(5):781-788
The relative enthalpies of organic compounds described in Parts I and II of this series made possible to show the contribution
of the reactants and products to the heat of reactions. First, the meaning of the relative enthalpies is demonstrated. The
components of the heats of reactions are exemplified by a series of reactions: formation of alkyl halides, esters, amides,
acid halides, and anhydrides. Further examples are hydrogenation of alkenes, alkynes, benzene, ethylene oxide, aldehydes,
and nitriles, and addition of chlorine, water, and hydrogen chloride to ethylene. Acetal and hemiacetal formations and cyclization
reactions are also among the examples. 相似文献
103.
Árpád Furka 《Structural chemistry》2009,20(4):587-604
The energies of the following types of compounds are characterized by their calculated relative enthalpies: alkanes and cycloalkanes,
alkenes and cycloalkenes, polyolefins and cyclic polyolefins, aromatic hydrocarbons, alcohols and phenols, ethers, peroxides,
aldehides and ketones, acetals, carboxylic acids esters, and anhydrides. Stabilization energies of conjugated olefins, benzene,
and furan have been estimated. 相似文献
104.
Sara Abalde‐Cela Szushen Ho Benito Rodríguez‐González Dr. Miguel A. Correa‐Duarte Dr. Ramón A. Álvarez‐Puebla Dr. Luis M. Liz‐Marzán Prof. Nicholas A. Kotov Prof. 《Angewandte Chemie (International ed. in English)》2009,48(29):5326-5329
Feature film : Thin films made by exponential layer‐by‐layer growth display high diffusivity and can be readily infiltrated with inorganic nanoparticles. They can sequestrate molecular systems from solution as a function of the composition of their layers, while providing intense surface‐enhanced Raman scattering (SERS) signals (see picture).
105.
Mario Castaño‐Álvarez Ana Fernández‐la‐Villa María Teresa Fernández‐Abedul Agustín Costa‐García 《Electrophoresis》2009,30(11):1943-1948
The interaction between the organic dye, methylene blue and DNA has been studied by MCE with electrochemical detection. Interaction produces two different signals, one corresponding to free methylene blue and other, for the complex methylene blue–DNA. The hybridization between a ssDNA and a complementary sequence, specific to the severe acute respiratory syndrome virus, has been performed and studied in a thermoplastic olefin polymer of amorphous structure CE‐microchip with an end‐channel gold wire detector. Moreover, studies with a longer dsDNA, an expression vector involved in the transitory or stable expression in mammals cells, pFLAG‐CMV4, has also been performed. 相似文献
106.
Francisco Alcaide Garbiñe Álvarez Oscar Miguel María Jesús Lázaro Rafael Moliner Ana López-Cudero José Solla-Gullón Enrique Herrero Antonio Aldaz 《Electrochemistry communications》2009,11(5):1081-1084
Carbon nanofibers synthesized via the thermo catalytic decomposition of methane were investigated for the first time as an electrocatalyst support in PEMFC cathodes. Their textural and physical properties make them a highly efficient catalyst support for cathodic oxygen reduction in low temperature PEMFC. Tests performed in MEAs showed that Pt supported on carbon nanofibers exhibited an enhancement of ca. 94% in power density at 0.600 V, in comparison with a commercial catalyst supported on conventional carbon black, Pt/Vulcan XC-72R. 相似文献
107.
Álvaro Álvarez Ramón Macías Dr. Jonathan Bould Dr. Carmen Cunchillos Fernando J. Lahoz Prof. Dr. Luis A. Oro Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(22):5428-5431
A sensitive cluster : The labile rhodathiaborane [(PPh3)2(H)‐nido‐RhSB9H9(NC5H5)] combines the redox and coordinative flexibility of the {(PPh3)2(H)Rh} fragment with the capability of the 11‐vertex rhodathiaborane cluster to undergo oxidative nido‐to‐closo transformations induced by coordination of alkynes to the metal centre, which leads to hydrogenation of the triple bond, dehydrogenation of the cluster and oxidative addition of sp C? H bonds.
108.
Alfonso Miranda-Molina Agustín López-Munguía María Luisa San Román Jaime Escalante Marco Antonio Leyva Ana María Puebla Edmundo Castillo Laura Álvarez 《Tetrahedron: Asymmetry》2010,21(1):43-50
The monoglucosyl-inositols α-d-glucopyranosyl-(1→4)-4d-myo-inositol 3 and α-d-glucopyranosyl-(1→1)-1d-myo-inositol 4 were synthesized by a combined enzymatic transglucosylation and hydrolysis strategy, using cyclodextrin glucosyl transferase (CGTase) from Thermoanaerobacter sp., followed by hydrolysis with Aspergillus niger glucoamylase. The glucosides were separated by preparative HPLC and fully characterized by extensive 1D and 2D NMR studies. The structure of the regioisomer 4 was confirmed by X-ray crystallography of its perbenzoylated derivative 4a. Both isomers demonstrated in vivo anti-inflammatory activity at comparative levels to corticosterone on mouse ear oedema induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) and in rat hind paw oedema induced by carrageenan. 相似文献
109.
Jorge Antonio Guerrero‐Álvarez Wendy Paloma Mas‐Ku Cesar Garcías‐Morales Armando Ariza‐Castolo 《Magnetic resonance in chemistry : MRC》2010,48(5):356-361
The relative acidities of the cis and trans isomers of a series of 1,5‐oxazaspiro[5.5]undecane derivatives were determined by measuring ΔpK in acid‐base titrations followed by 1 H NMR. Relative structural stabilities were determined by measuring substituent chemical shift and γ‐gauche effects in 13C, 15N, and 17O NMR. Crystallographic characterization of a model spiro[5.5]undecane is presented to support the basicity in solid state. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
110.
Resolution and uniqueness of estimated parameters of a model of thin filament regulation in solution
Srboljub M. Mijailovich Xiaochuan Li Juan C. del Álamo R. Hugh Griffiths Vojislav Kecman Michael A. Geeves 《Computational Biology and Chemistry》2010,34(1):19-33
The estimation of chemical kinetic rate constants for any non-trivial model is complex due to the nonlinear effects of second order chemical reactions. We developed an algorithm to accomplish this goal based on the Damped Least Squares (DLS) inversion method and then tested the effectiveness of this method on the McKillop–Geeves (MG) model of thin filament regulation. The kinetics of MG model is defined by a set of nonlinear ordinary differential equations (ODEs) that predict the evolution of troponin–tropomyosin–actin and actin–myosin states. The values of the rate constants are estimated by integrating these ODEs numerically and fitting them to a series of stopped-flow pyrene fluorescence transients of myosin-S1 fragment binding to regulated actin in solution. The accuracy and robustness of the estimated rate constants are evaluated for DLS and two other methods, namely quasi-Newton (QN) and simulated annealing (SA). The comparison of these methods revealed that SA provides the best estimates of the model parameters because of its global optimization scheme. However it converges slowly and does quantify the uniqueness of the estimated parameters. On the other hand the QN method converges rapidly but only if the initial guess of the parameters is close to the optimum values, otherwise it diverges. Overall, the DLS method proves to be the most convenient method. It converges fast and was able to provide excellent estimates of kinetic parameters. Furthermore, DLS provides the model resolution matrix, which quantifies the interdependence of model parameters thereby evaluating the uniqueness of their estimated values. This property is essential for estimating of the dependence of the model parameters on experimental conditions (e.g. Ca2+ concentration) when it is assessed from noisy experimental data such as pyrene fluorescence from stopped-flow transients. The advantages of the DLS method observed in this study should be further examined in other physicochemical systems to firmly establish the observed effectiveness of DSL vs. the other parameter estimation methods. 相似文献