C_xN_y : new carbon nitride organic photocatalysts

The search for metal-free and visible light-responsive materials for photocatalytic applications has attracted the interest of not only academics but also the industry in the last decades. Since graphitic carbon nitride (g-C3N4) was first reported as a metal-free photocatalyst, this has been widely investigated in different light-driven reactions. However, the high recombination rate, low electrical conductivity, and lack of photoresponse in most of the visible range have elicited the search for alternatives. In this regard, a broad family of carbon nitride (CxNy) materials was anticipated several decades ago. However, the attention of the researchers in these materials has just been awakened in the last years due to the recent success in the syntheses of some of these materials (i.e., C3N3, C2N, C3N, and C3N5, among others), together with theoretical simulations pointing at the excellent physico-chemical properties (i.e., crystalline structure and chemical morphology, electronic configuration and semiconducting nature, or high refractive index and hardness, among others) and optoelectronic applications of these materials. The performance of CxNy, beyond C3N4, has been barely evaluated in real applications, including energy conversion, storage, and adsorption technologies, and further work must be carried out, especially experimentally, in order to confirm the high expectations raised by simulations and theoretical calculations. Herein, we have summarized the scarce literature related to recent results reporting the synthetic routes, structures, and performance of these materials as photocatalysts. Moreover, the challenges and perspectives at the forefront of this field using CxNy materials are disclosed. We aim to stimulate the research of this new generation of CxNy-based photocatalysts, beyond C3N4, with improved photocatalytic efficiencies by harnessing the striking structural, electronic, and optical properties of this new family of materials

Washing machine dynamic model to prevent tub collision during transient state

In horizontal-axis washing machines, the front gasket as well as the damping system are crucial owing to the possible collision of the tub with the housing during the transient period. However, most dynamic models for predicting tub motion focus on the steady state and consider only the suspension system without including the gasket. We conducted an experimental study to analyze the effect of the gasket on the transient motion of the tub. The results obtained indicate the necessity of implementing the gasket in the multibody model of a washing machine to accurately predict the tub behavior during this period. The gasket model is formed by a combination of Voigt elements. Stiffness parameters are determined using a load cell, and damping factors are estimated using a process that integrates Adams/View, Matlab optimization algorithms, and displacement measurements that are taken using accelerometers. A D-optimal design used to predict the effect of the gasket parameters reveals that the tub displacement is most sensitive to the changes in linear stiffness in the transversal direction. Finally, the model of the gasket provides a better approach for predicting the tub movement during resonance that can be used in the design phase to avoid tub collision

Mn (II) sub-nanometric sites stabilization in noble, N-doped carbonaceous materials for electrochemical CO₂ reduction

The preparation of stable and efficient electrocatalysts comprising abundant and non-critical row-materials is of paramount importance for its industrial implementation. Herein, we present a simple synthetic route to prepare Mn(II) sub-nanometric active sites over a highly N-doped noble carbonaceous support. This support not only promotes a strong stabilization of the Mn (II) sites, improving its stability against oxidation, but also provides a convenient coordination environment in the Mn (II) sites able to produce CO, HCOOH and CH3COOH from the electrochemically CO2 reduction

Cu^II/Cu^I decorated N-doped carbonaceous electrocatalysts for the oxygen reduction reaction

The oxygen reduction reaction (ORR) that for instance takes place at the cathode of fuel cells is one of the most examined model reactions of energy conversion. The ORR presents sluggish reaction kinetics, thus limiting the overall efficiency of these cells. Pt-based catalysts are still the widest choice though they exhibit important drawbacks such as long-term instability and intolerance to methanol crossover. In this context, engineering transition metals in the form of nano- and subnano-sites on carbonaceous supports has the potential of becoming an alternative to scarce noble metal-based catalysts. Herein, we describe a simple synthetic route towards CuII/CuI decorated N-doped carbonaceous ORR electrocatalysts. CuII/CuI nanosites are obtained by calcination in air of an ionic liquid derived noble carbonaceous support impregnated with copper(ii) acetate. The strong interaction between the copper and the noble support foster the co-formation of CuII/CuI nanosites. Larger amounts of copper(ii) acetate translate into larger amounts of CuI and lower Tafel slopes. The material with 4 wt% of copper catalyzes the selective reduction of oxygen through a 4-electron transfer pathway and exhibits a lower Tafel slope than commercial platinum, a minimal overpotential, and a higher limiting current density. Moreover, all materials show promising durability and high methanol stability, which makes them promising to replace noble metals for the ORR

Combination of exosomes and near-infrared responsive gold nanoparticles: new selective and specific therapeutic vehicle

P602 Exosomes are extracellular vesicles (50 -150 nm of diameter) considered key elements for the intercellular communication. Although they are proposed to be ideal vehicles for the targeting of novel therapies, very little is known about the selectiveness and specificity of the transference processes involving exosomes released from different cells. PEGylated Hollow gold nanoparticles (PEG-HGNs) are near-infrared (NIR) responsive nanoparticles (NPs) which are able to generate localized heat by the use of NIR light leading to cell death when applying optical hyperthermia. In this study, we demonstrate the selectivity of in vitro exosomal transfer between certain cell types and how this phenomenon can be exploited to develop new specific vectors for advanced therapies. Firstly, PEG-HGNs were successfully incorporated in the exosome biogenesis pathway of placental stem cells (MSCs) and they were released as PEG-HGNs-loaded exosomes (PEGHGNs_ MSCs_EXOs). Exosomes were characterized by confocal microscopy, western blot, nanosight, zeta potential and electronic microscopy. Afterwards, time lapse microscopy and atomic emission spectroscopy demonstrated the selective transfer of the ..

Isolation of exosomes from whole blood by a new microfluidic device: proof of concept application in the diagnosis and monitoring of pancreatic cancer

Background: Exosomes are endocytic-extracellular vesicles with a diameter around 100 nm that play an essential role on the communication between cells. In fact, they have been proposed as candidates for the diagnosis and the monitoring of different pathologies (such as Parkinson, Alzheimer, diabetes, cardiac damage, infection diseases or cancer). Results: In this study, magnetic nanoparticles (Fe3O4NPs) were successfully functionalized with an exosome-binding antibody (anti-CD9) to mediate the magnetic capture in a microdevice. This was carried out under flow in a 1.6 mm (outer diameter) microchannel whose wall was in contact with a set of NdFeB permanent magnets, giving a high magnetic field across the channel diameter that allowed exosome separation with a high yield. To show the usefulness of the method, the direct capture of exosomes from whole blood of patients with pancreatic cancer (PC) was performed, as a proof of concept. The captured exosomes were then subjected to analysis of CA19-9, a protein often used to monitor PC patients. Conclusions: Here, we describe a new microfluidic device and the procedure for the isolation of exosomes from whole blood, without any need of previous isolation steps, thereby facilitating translation to the clinic. The results show that, for the cases analyzed, the evaluation of CA19-9 in exosomes was highly sensitive, compared to serum samples

Nitrogen-doped carbon nanodots deposited on titania nanoparticles: unconventional near-infrared active photocatalysts for cancer therapy

Cancer represents a major public health issue and a primary cause of death for the mankind and the search for alternative cancer treatments that assist or alleviate the drawbacks of current cancer therapies remains imperative. Nanocatalytic medicine represents a new discipline that aims at exploiting the unique response of heterogeneous catalysts exposed to unconventional conditions such as those encountered in the tumor microenvironment (TME). Photo-triggered cancer therapies using light-activable catalytic materiales can stimulate and activate multiple biological processes and represent a very promising field of study. Herein, we evaluate the use of carbon nanodots with different composition (CNDs) retrieved by laser pyrolysis as potential near-infrared (NIR) photosensitizers able to activate P25 semiconductor nanostructured photocatalysts. We describe the enhanced photocatalytic response towards glucose conversion and reactive oxygen species (ROS) generation upon irradiation with NIR-LEDs when CNDs doped with heteroatoms were tested. The most active photocatalysts were evaluated in the presence of cancer cells and revealed a promising photodynamic effect under NIR irradiation. This work represents one of the scarce examples of a conventional inorganic photocatalyst containing TiO2 that is translated into a biomedical application with a successful outcome

Factores del retardo de consolidación en fracturas de antebrazo pediátricas

El objetivo de este estudio es determinar factores para el retardo de curación en fracturas pediátricas diafisarias de antebrazo. Presentamos un estudio caso-control de todas las fracturas pediáticas de antebrazo tratadas en el Hospital Universitario Miguel Servet, desde 2003 hasta 2009, y que presentaron retardo de consolidación, con un seguimiento mínimo de 12 meses. Los criterios de exclusión fueron fractura-luxación, infección, osteosíntesis insuficiente, fractura en tallo verde, abierta, patológica y asociada a fractura de cabeza radial, así como pacientes sin el seguimiento mínimo establecido. El cálculo estadístico incluyó análisis de regresión lineal bivariante y multivariante. Resultados: Durante este periodo se trataron 441 fracturas de antebrazo completas, de ambos huesos: 14 de ellas (3.2%) sufrieron retardo de consolidación; y 63 controles cumplieron los criterios de inclusión y fueron seleccionados aleatoriamente. El análisis bivariante mostró diferencias significativas entre los grupos "retardo de consolidación" y "control" en edad, necesidad de tratamiento quirúrgico, reducción abierta frente a cerrada y tiempo hasta retirada del material. Si embargo, la reducción abierta de la fractura, más frecuente en el grupo "retardo de consolidación", fue la única variable que permaneció asociada en el análisis multivariante. Conclusiones: El factor predictivo más importante para el retardo de consolidación en fracturas pediátricas de antebrazo es la reducción abierta.The aim of this study was to assess predictive factors for delayed healing in forearm paediatric fractures. This is a case-control study of all paediatric shaft fractures of forearm presenting delayed union in follow-up period of 12 months or more, from 2003 through 2009, treated in Miguel Servet University Hospital. Exclusion criteria were fracture-dislocations, infection, suboptimal osteosynthesis, greenstick, open, pathologic and associated radial head fractures, as well as patients without stablished period of follow up. Statistical assessment included bivariant and multivariant linear regression analysis. Results: During the study period 441 complete both-bone forearm fractures were treated: 14 of them (3.2%) were identified as suffering delayed union; and 63 controls fulfilling inclusion criteria were randomly selected. Bivariant analysis showed significant differences between "delayed union" and "control" groups in age, need of surgical treatment, open versus closed reduction and mean time to hardware removal. However, open reduction of the fracture, more frequent in the "delayed union" group, was the only variable which remained associated in the multivariant analysis. Conclusions: The strongest predictor of union delay in paediatric forearm fractures is open reduction