Spin transition in arrays of gold nanoparticles and spin crossover molecules.

We investigate if the functionality of spin crossover molecules is preserved when they are assembled into an interfacial device structure. Specifically, we prepare and investigate gold nanoparticle arrays, into which room-temperature spin crossover molecules are introduced, more precisely, [Fe(AcS-BPP)2](ClO4)2, where AcS-BPP = (S)-(4-{[2,6-(dipyrazol-1-yl)pyrid-4-yl]ethynyl}phenyl)ethanethioate (in short, Fe(S-BPP)2). We combine three complementary experiments to characterize the molecule-nanoparticle structure in detail. Temperature-dependent Raman measurements provide direct evidence for a (partial) spin transition in the Fe(S-BPP)2-based arrays. This transition is qualitatively confirmed by magnetization measurements. Finally, charge transport measurements on the Fe(S-BPP)2-gold nanoparticle devices reveal a minimum in device resistance versus temperature, R(T), curves around 260-290 K. This is in contrast to similar networks containing passive molecules only that show monotonically decreasing R(T) characteristics. Backed by density functional theory calculations on single molecular conductance values for both spin states, we propose to relate the resistance minimum in R(T) to a spin transition under the hypothesis that (1) the molecular resistance of the high spin state is larger than that of the low spin state and (2) transport in the array is governed by a percolation model.

Estudio de dos sistemas de transporte para mantener la viabilidad de bacterias de interés clínico / Study of the ability of two swab transport systems to maintain viability of clinically important bacteria / Estudo de dois sistemas de transporte para manter a viabilidade de bactérias de interesse clínico

Se compararon dos dispositivos de conservación de muestras tomadas por hisopado con cepas de referencia de Streptococcus pyogenes, Haemophilus influenzae, Neisseria gonorrhoeae y Streptococcus pneumoniae (ambos con medio de Stuart). El dispositivo Copan Venturi Transystem« (Copan Italia Spa, Brescia, Italia) resultó ser significativamente más efectivo que el Eurotubo (Deltalab, Rubí, Barcelona, España) probablemente porque la estrangulación que presenta al comienzo de la columna semisólida (sistema tipo Venturi) permitiría una mejor conservación de los microorganismos.(AU)

Two extendedly-used swab transport devices with Stuart medium using Streptococcus pyogenes, Haemophilus influenzae, Neisseria gonorrhoeae and Streptococcus pneumoniae reference strains, were compared. Copan Venturi Transystem« (Copan Italia Spa, Brescia, Italy) was significantly more effective than Eurotubo (Deltalab, Rubí, Barcelona, Spain), probably because the narrowing of the tube, just at the beginning of the semisolid column (Venturi system), would yield a better conservation of diffrerent organisms.(AU)

Foram comparados dois dispositivos de conservaþÒo de amostras tomadas por swab com cepas de referÛncia de Streptococcus pyogenes, Haemophilus influenzae, Neisseria gonorrhoeae e Streptococcus pneumoniae (ambos com meio de Stuart). O dispositivo Copan Venturi Transystem« (Copan Italia Spa, Brescia, Itália) resultou ser significativamente mais efetivo que o Eurotubo (Deltalab, Rubí, Barcelona, Espanha) provavelmente porque o estrangulamento que apresenta no início da coluna semi-sólida (sistema tipo Venturi) permitiria uma melhor conservaþÒo dos microorganismos.(AU)

Estudio de dos sistemas de transporte para mantener la viabilidad de bacterias de interés clínico / Study of the ability of two swab transport systems to maintain viability of clinically important bacteria / Estudo de dois sistemas de transporte para manter a viabilidade de bactérias de interesse clínico

Se compararon dos dispositivos de conservación de muestras tomadas por hisopado con cepas de referencia de Streptococcus pyogenes, Haemophilus influenzae, Neisseria gonorrhoeae y Streptococcus pneumoniae (ambos con medio de Stuart). El dispositivo Copan Venturi Transystem® (Copan Italia Spa, Brescia, Italia) resultó ser significativamente más efectivo que el Eurotubo (Deltalab, Rubí, Barcelona, España) probablemente porque la estrangulación que presenta al comienzo de la columna semisólida (sistema tipo Venturi) permitiría una mejor conservación de los microorganismos.

Two extendedly-used swab transport devices with Stuart medium using Streptococcus pyogenes, Haemophilus influenzae, Neisseria gonorrhoeae and Streptococcus pneumoniae reference strains, were compared. Copan Venturi Transystem® (Copan Italia Spa, Brescia, Italy) was significantly more effective than Eurotubo (Deltalab, Rubí, Barcelona, Spain), probably because the narrowing of the tube, just at the beginning of the semisolid column (Venturi system), would yield a better conservation of diffrerent organisms.

Foram comparados dois dispositivos de conservação de amostras tomadas por swab com cepas de referência de Streptococcus pyogenes, Haemophilus influenzae, Neisseria gonorrhoeae e Streptococcus pneumoniae (ambos com meio de Stuart). O dispositivo Copan Venturi Transystem® (Copan Italia Spa, Brescia, Itália) resultou ser significativamente mais efetivo que o Eurotubo (Deltalab, Rubí, Barcelona, Espanha) provavelmente porque o estrangulamento que apresenta no início da coluna semi-sólida (sistema tipo Venturi) permitiria uma melhor conservação dos microorganismos.