Charge transport in C60-based dumbbell-type molecules: mechanically induced switching between two distinct conductance states.

Single molecule charge transport characteristics of buckminsterfullerene-capped symmetric fluorene-based dumbbell-type compound 1 were investigated by scanning tunneling microscopy break junction (STM-BJ), current sensing atomic force microscopy break junction (CS-AFM-BJ), and mechanically controlled break junction (MCBJ) techniques, under ambient conditions. We also show that compound 1 is able to form highly organized defect-free surface adlayers, allowing the molecules on the surface to be addressed specifically. Two distinct single molecule conductance states (called high G(H)(1) and low G(L)(1)) were observed, depending on the pressure exerted by the probe on the junction, thus allowing molecule 1 to function as a mechanically driven molecular switch. These two distinct conductance states were attributed to the electron tunneling through the buckminsterfullerene anchoring group and fully extended molecule 1, respectively. The assignment of conductance features to these configurations was further confirmed by control experiments with asymmetrically designed buckminsterfullerene derivative 2 as well as pristine buckminsterfullerene 3, both lacking the G(L) feature.

Comparative adsorption of ciprofloxacin on sugarcane bagasse from Ecuador and on commercial powdered activated carbon.

This work examined the adsorption capacity of sugarcane bagasse (SB) for the removal of ciprofloxacin (CPX) from water using batch experiments and a fixed bed column and compared its adsorption performance with a powdered activated commercial carbon (PAC). Both adsorbents achieved a similar percentage removal of about 78% with doses of 3 g L-1 of SB and 0.3 g L-1 of PAC (20 mg L-1 initial CPX concentration at 30 °C). The maximum removal was obtained at a pH between 6 and 8. SB adsorption isotherms were fitted to the Langmuir, BET and Freundlich models showing a maximum adsorption capacity of 13.6 mg g-1. The kinetic data for both SB and PAC fitted the pseudo second-order model (R2 = 0.99). The adsorption process was faster on the SB (65% of elimination in the first 5 min) than on the PAC. The study of the adsorbent properties shows that SB is a macroporous solid with a specific surface area 250 times smaller than PAC. The thermodynamic results show that SB adsorption was physical and exothermic. The main suggested interactions between CPX and SB are electrostatic attraction, hydrogen bonding and dipole-dipole interactions. The experiments carried out in a fixed bed show that the adsorption capacity at breakthrough increases with the bed height. The adsorption capacity at saturation time was 9.47 mg g-1 at a flow rate of 3 mL min-1, a bed height of 14 cm, and a diameter of 1.5 cm. The experimental data were fitted to the Bohart-Adams model (R2 = 0.98). These results highlight the capacity of sugarcane bagasse to adsorb ciprofloxacin from water, illustrating its potential as a low-cost adsorbent.

El beneficio penitenciario del adelantamiento de la libertad condicional en España. Análisis histórico-evolutivo de la institución / The prison system's benefit of granting parole in advance in Spain. Historical-evolutionary analysis of the Institution / O benefício penitenciário do adiantamento da liberdade condicional na Espanha. Análise histórico-evolutivo da instituição

Se tiene como objetivo analizar la evolución histórica y normativa del beneficio del adelantamiento de la libertad condicional, desde sus orígenes hasta nuestros días, que constituye actualmente un mecanismo fundamental para que la ejecución de la pena cumpla con su función preventiva especial positiva, traducida en la resocialización del penado. Asimismo, se prestará especial atención a las limitaciones y restricciones impuestas por las reformas de los últimos años para su concesión y disfrute. Para ello, se plantea una metodología basada en un estudio sobre los antecedentes internacionales del sistema progresivo de ejecución de condenas, y un análisis evolutivo de la normativa penal y penitenciaria española, abordando la temática de manera analítica, descriptiva y sucinta de la normativa reguladora de la institución, poniendo de manifiesto la constante y creciente rigidez de la normativa punitiva reguladora del beneficio del adelantamiento de la libertad condicional. Y es que un siglo después de que se instaurase la libertad condicional en España, el mecanismo de otorgamiento de su adelantamiento se concibe de extremada, si no imposible, concesión.

The objective here is to analyze the historical and normative evolution of the benefit of granting parole in advance, from its origins to this day. At present it has become an essential mechanism to make sentence enforcement fulfill its special positive function translated into the resocialization of the convicted prisoner. Likewise, particular attention will be given to the limitations and constraints imposed to both parole granting and enjoyment in the past years. For this purpose, a methodology has been proposed on the basis of a study on international backgrounds of the gradual serving of sentences, and an evolutionary analysis of the Spanish criminal and penitentiary normative. The matter is approached in an analytical, descriptive and concise manner, while highlighting the persistent and even growing rigidity of the Institution's punitive regulations governing the benefit of granting an early release from prison. And, notwithstanding benefits, a century after having introduced parole in Spain the advancement of the granting of parole is being deemed to be an extreme -if not impossible- concession.

O objetivo é analisar a evolução histórica e normativa do benefício de adiantamento da liberdade condicional, de suas origens ao tempo atual, que é um mecanismo fundamental para que a execução da pena cumpra sua função preventiva especial positiva, traduzida no ressocialização do punido. Também, prestará atenção especial às limitações e às restrições impostas pelas reformas dos últimos anos para sua concessão e usufruto. Para isso, se considera a metodologia baseada em um estudo sobre os antecedentes internacionais do sistema progressivo da execução das sentenças, e uma análise evolutiva da normativa penal e penitenciária espanhola, abordando a temática de maneira analítica, descritiva e sucinta da normativa reguladora da instituição, mostrando a constante e crescente rigidez da normativa punitiva reguladora do benefício do adiantamento da liberdade condicional. E é que um século depois que a liberdade condicional em Espanha foi restaurada, o mecanismo de conceder de outorgamento do seu adiantamento e concebido do extremada, se não impossível, concessão.