Organic free radicals as circularly polarized luminescence

Chiroptical properties of two chiral atropisomers of propeller‐like trityl‐based radical derivatives have been analyzed. A new absolute configuration (AC) assignment has been made, according to the combination of experimental and theoretical data. In this sense, their ACs have been determined through the comparison of the Cotton effects recorded by electronic circular dichroism (ECD) with the theoretical ECD of the open shell structures obtained by TD‐DFT calculations. Finally, their circularly polarized luminescence (CPL) responses have been addressed. Remarkably, this is the first description of organic free radicals as intrinsic CPL emitters. Opposite signed CPL has been detected for each pair of conformers, with acceptable luminescent dissymmetry factors (|glum|≈0.5–0.8×10−3) considering their pure organic nature. In fact, highly efficient chiral emissions have been demonstrated, according to the comparison of |glum| with their respective absorption anisotropy factors (|gabs|). This pioneering study lays the foundations for the optimization of new magnetically active organic chiral emitters.The authors are grateful for the financial support received from: MOTHER (MAT2016-80826-R) granted by the DGI (Spain), GenCat (2017-SGR-918) financed by DGR (Catalunya) and the Spanish Ministry of Economy and Competitiveness, through the “Severo Ochoa” Programme for Centres of Excellence in R&D (SEV-2015-0496) and through the “Proyecto interdisciplinar de frontera“, FIP-2018 HECTIC-PTM. We acknowledge the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (ERC-2015-STG-677023). This study has been also supported by the Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), an initiative funded by the VI National R&D&I Plan 2008-2011, Iniciativa Ingenio 2010, Consolider Program, CIBER Actions and financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund. P. M. B. gratefully acknowledges financial support from the Juan de la Cierva-Formación 2015 programme (FJCI-2015-23577) supported by MINECO. A. G. C. also thanks RyC-2013-12943 contract from MINECO. We also acknowledge Prof. O. Trapp for kindly suppling the DCxplorer software

An Enantiopure Propeller‐Like Trityl‐Brominated Radical: Bringing Together a High Racemization Barrier and an Efficient Circularly Polarized Luminescent Magnetic Emitter

A new persistent organic free radical has been synthetized with Br atoms occupying the ortho‐ and para‐positions of a trityl core. After the isolation of its two propeller‐like atropisomers, Plus (P) and minus (M), their absolute configurations were assigned by a combination of theoretical and experimental data. Remarkably, no hints of racemization were observed up to 60 °C for more than two hours, due to the higher steric hindrance imposed by the bulky Br atoms. Therefore, when compared to its chlorinated homologue (t1/2=18 s at 60 °C), an outstanding stability against racemization was achieved. A circularly polarized luminescence (CPL) response of both enantiomers was detected. This free radical shows a satisfactory luminescent dissymmetry factor (|glum(592 nm)|≈0.7×10−3) despite its pure organic nature and low luminescence quantum yield (LQY). Improved organic magnetic CPL emitters derived from the reported structure can be envisaged thanks to the wide possibilities that Br atoms at para‐positions offer for further functionalization.The authors are grateful for the financial support received from: MOTHER project (MAT2016-80826-R) granted by the DGI (Spain), GenCat (2017-SGR-918) financed by DGR (Catalunya) and the Spanish Ministry of Economy and Competitiveness (PGC2018-095808-B-I00 and PGC2018-101181-B-I00 projects) and through the “Severo Ochoa” Programme for Centres of Excellence in R&D (SEV-2015-0496) and through the “Proyecto Interdisciplinar de Frontera“, FIP-2018 HECTIC-PTM. We acknowledge the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (ERC-2015-STG-677023). This study has been also supported by the Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), an initiative funded by the VI National R&D&I Plan 2008-2011, Iniciativa Ingenio 2010, Consolider Program, CIBER Actions and financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund. P. M. B. gratefully acknowledges financial support from the Juan de la Cierva-Formación 2015 programme (FJCI-2015-23577) supported by MINECO and, together with J.V, A. G. C. also thanks RyC-2013-12943 contract from MINECO. We also thankthe Servei de Ressonància Magnètica Nuclear, Universitat Autònoma de Barcelona, for allocating instrument time to this project

Understanding the apparent superiority of over-sampling through an analysis of local information for class-imbalanced data

Data plays a key role in the design of expert and intelligent systems and therefore, data preprocessing appears to be a critical step to produce high-quality data and build accurate machine learning models. Over the past decades, increasing attention has been paid towards the issue of class imbalance and this is now a research hotspot in a variety of fields. Although the resampling methods, either by under-sampling the majority class or by over-sampling the minority class, stand among the most powerful techniques to face this problem, their strengths and weaknesses have typically been discussed based only on the class imbalance ratio. However, several questions remain open and need further exploration. For instance, the subtle differences in performance between the over- and under-sampling algorithms are still under-comprehended, and we hypothesize that they could be better explained by analyzing the inner structure of the data sets. Consequently, this paper attempts to investigate and illustrate the effects of the resampling methods on the inner structure of a data set by exploiting local neighborhood information, identifying the sample types in both classes and analyzing their distribution in each resampled set. Experimental results indicate that the resampling methods that produce the highest proportion of safe samples and the lowest proportion of unsafe samples correspond to those with the highest overall performance. The significance of this paper lies in the fact that our findings may contribute to gain a better understanding of how these techniques perform on class-imbalanced data and why over-sampling has been reported to be usually more efficient than under-sampling. The outcomes in this study may have impact on both research and practice in the design of expert and intelligent systems since a priori knowledge about the internal structure of the imbalanced data sets could be incorporated to the learning algorithms

Correlación existente entre los tipos de fibras musculares, el ph y la capacidad de retención de agua de la carne en el cerdo chato murciano.

Mediante análisis de correlación se valora la influencia que los tipos de fibras I, IIA y IIX tienen sobre el pH y la capacidad de retención de agua en el músculo longísimo lumbar del cerdo “Chato Murciano”. Los resultados demuestran que los tipos de fibras no influyen sobre el pH a los 45’, pero sí durante la caída del mismo a las 24 h del sacrificio. Por otra parte, nuestros resultados indican que la capacidad de retención de agua está relacionada negativamente con el tamaño de las fibras tipo IIA

Diferenciación y desarrollo postnatal de los tipos de fibras musculares en el cerdo chato murciano

Mediante la técnica que detecta la actividad de la enzima ATPasa miosínica se analiza el tamaño y porcentajes de los distintos tipos de fibras que integran el músculo longísimo lumbar del cerdo “Chato Murciano”, desde el nacimiento hasta los 120 días de edad. Al nacimiento, el músculo longísimo está conformado por un 5,5% de fibras tipo I, de gran tamaño y un 94,5% de fibras tipo II, de menor tamaño. Durante el primer mes de vida postnatal las fibras tipo II se irán diferenciando en nuevas fibras tipo I y subtipos IIA y IIX. A partir de los dos meses tiene lugar un aumento del diámetro fibrilar (hipertrofia) y una distribución fibrilar que recuerda a la de animales adultos. Aunque la hipertrofia observada afecta a los tres tipos de fibras evaluados, parece claro que el crecimiento y conformación muscular en el cerdo chato murciano está muy asociado al notable incremento en diámetro que experimentan las fibras IIX, ya que éstas crecen más rápidamente que las tipo I y IIA

The IL-2/IL-2-Receptor Complex in the Maturation of Rat T-Cell Progenitors

On the basis of both the interleukin-2-receptor (IL-2R) α-chain expression on 16-day-old fetal rat thymocytes and the occurrence of interleukin-2 (IL-2) mRNA-containing cells early during rat thymus ontogeny, we have investigated the possible role of IL-2/IL-2R complex in rat T-cell maturation. For this purpose, we analyzed the effects of the addition of either recombinant rat IL- 2 or anti-CD25 (OX-39)-blocking monoclonal antibodies to fetal thymus organ cultures (FTOC), established from 16-day-old rat embryos. IL-2 stimulated the growth of thymocytes and, as a result, induced T-cell differentiation, whereas OX-39 mAb blocked the maturation of thymic-cell progenitors. Accordingly, these results support the involvement of IL-2/IL-2R complex in rat Tcell development

Psychosocial factors related to physical activity in frail and prefrail elderly people

Background: Increased physical activity (PA) is a very important factor in a healthy aging lifestyle. Psychosocial factors have also a main role in the initiation and maintenance of this behavior, but nowadays its implications for frailty elderly people are unknown, therefore, the aim of this study was to identify the psychosociological variables of behavior change that influence the practice of (PA) in frail and prefrail elderly. Methods: A total of 103 frail and pre-frail elderly people (72 females) participated in this cross-sectional study, on the framework of the EXERNET-Elder3.0 project. Age ranged from 68–94 years (mean = 80.4 ± 5.9 years). Individualized face-to-face interviews according to the constructs of the Transtheoretical Model of Change (TTM) (decisional balance (DB) and self-efficacy (SE)], social support (SS) (family and friends) and outcome expectations (OE) were administered to all participants. Results: Significant differences were found in DB, perceived benefits (PBn), SE, family-related SS and OE as a function of stages of change (SoC) (p < 0.005), but no significant were found in perceived barriers (PBrr) (p = 0.259) and friends-related SS (p = 0.068). According to the Scheffé post-hoc test, those in advanced SoC (Action-Maintenance), scored higher than those in lower SoC (Precontemplation-Contemplation and Preparation). Conclusion: The scores obtained from the study variables differed according to the SoC, supporting the external validity for the use of the TTM in frailty elderly. Further research is needed to determine the impact of PBrr and friends-related SS on this people, as well as to identify the validity of this model in the long-term in this population

Relación entre las acciones técnicas y los requerimientos físicos en baloncesto y la influencia que en ellos tiene la fatiga

P. 199-206El Baloncesto como deporte colectivo se basa en una serie de dominios técnicos que interactúan con una serie de cualidades físicas. El complemento de ambos factores nos dará el rendimiento futuro de ese jugador. Con este trabajo lo que se pretende es comprobar en qué medida las cualidades físicas pueden influir en los dominios técnicos de los jugadores, en este caso en el tiro, de cara a un futuro rendimiento. También pretendemos observar cuál es la influencia de la fatiga tanto en las cualidades físicas como en los dominios técnicos. Utilizaremos una serie de pruebas que nos darán el estado de forma de los jugadores, para después llevarlos a un circuito específico que refleja los requerimientos específicos del baloncesto, donde podremos obtendremos las conclusiones al respect