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91.
Manuel Rubio‐Arroyo Federico Jimnez‐Cruz Guadalupe Prez‐Caballero Simn Hernndez‐Ortega 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(8):1028-1029
The crystal structure of the title compound, C19H16N2O2, displays a trans configuration of the azo moiety, which forms an intramolecular O—H?N=N hydrogen bond. The H?N and O?N distances are 1.81 (3) and 2.581 (4) Å, respectively. The azobenzene moiety is approximately planar, and has a dihedral angle of ca 23° with the substituted phenyl group. 相似文献
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93.
Encarnación Caballero‐Díaz Christian Pfeiffer Lena Kastl Pilar Rivera‐Gil Bartolome Simonet Miguel Valcárcel Javier Jiménez‐Lamana Francisco Laborda Wolfgang J. Parak 《Particle & Particle Systems Characterization》2013,30(12):1079-1085
A set of three types of silver nanoparticles (Ag NPs) are prepared, which have the same Ag cores, but different surface chemistry. Ag cores are stabilized with mercaptoundecanoic acid (MUA) or with a polymer shell [poly(isobutylene‐alt‐maleic anhydride) (PMA)]. In order to reduce cellular uptake, the polymer‐coated Ag NPs are additionally modified with polyethylene glycol (PEG). Corrosion (oxidation) of the NPs is quantified and their colloidal stability is investigated. MUA‐coated NPs have a much lower colloidal stability than PMA‐coated NPs and are largely agglomerated. All Ag NPs corrode faster in an acidic environment and thus more Ag(I) ions are released inside endosomal/lysosomal compartments. PMA coating does not reduce leaching of Ag(I) ions compared with MUA coating. PEGylation reduces NP cellular uptake and also the toxicity. PMA‐coated NPs have reduced toxicity compared with MUA‐coated NPs. All studied Ag NPs were less toxic than free Ag(I) ions. All in all, the cytotoxicity of Ag NPs is correlated on their uptake by cells and agglomeration behavior. 相似文献
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96.
We have designed, grown and fabricated InAs/InP quantum dot (QD) waveguides as the gain materials of mode-locked lasers (MLLs). Passive InAs/InP QD MLLs based on single-section Fabry-Perot (F-P) cavities with repetition rates from 10 GHz to 100 GHz have been demonstrated in the C- and L-band. Femtosecond (fs) pulses with pulse duration of 295 fs have been achieved. The average output power is up to 50 mW at the room temperature of 18 °C. By using the external fiber mixed cavities fs pulse train with a repetition rate of 437 GHz has been generated. We have also discussed the working principles of the developed QD MLLs. 相似文献
97.
Jesus F. Almeida Manuel Grande Joaquín R. Moran Josefa Anaya Ma Luisa Mussons Ma Cruz Caballero 《Tetrahedron: Asymmetry》1993,4(12):2483-2494
The enantioselective synthesis of the potentially nootropic compounds 3–6 is reported. Derivative 3 was obtained from the readily available L-tartaric acid, by reduction of the imide 8 prepared with methyl glycinate. The other derivatives 4–6 were obtained from the dihydroxylactam 11. Protection of one of the hydroxyl groups and a Mitsunobu reaction or triflate displacement of the other group produces the remaining stereoisomers. Aminoderivatives 25 and 27 were obtained by displacement with sodium azide and reduction. 相似文献
98.
M Arenas A Bilbao R Caballero T Gómez M V Rodríguez F Ruiz 《The Journal of the Operational Research Society》2002,53(4):387-396
In this paper, a Goal Programming model is developed in order to study the possibility of decreasing the length of stay on the waiting list of a hospital that belongs to the Spanish Health Service. First, a problem is solved to determine the optimal planning for one year, so as to make the maximum waiting time decrease to six months (at present, some operations have a waiting list of more than a year). Afterwards, two other problems are solved in order to determine the impact that a further reduction of the waiting time (four months) would have on the requirements of extra resources for the hospital. The particular problem for the Trauma service is described in detail, but global results are shown and commented. 相似文献
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100.
The preconcentration and separation of copper, cadmium, cobalt and nickel 8-quinolinolates in solutions of high salinity including synthetic sea water is studied with phenolphthalein or 2-naphthol as collector and octadecylamine as surfactant. A simplex optimization is applied. Yields > 90% are achieved for Ni, Co and Cd with both collectors, but the copper yield is low. Flame atomic absorption spectrometry is used for the final measurements. 相似文献