Metal single-atom catalysts (SACs) promise great rewards in terms of metal atom efficiency. However, the requirement of particular conditions and supports for their synthesis, together with the need ...of solvents and additives for catalytic implementation, often precludes their use under industrially viable conditions. Here, we show that palladium single atoms are spontaneously formed after dissolving tiny amounts of palladium salts in neat benzyl alcohols, to catalyze their direct aerobic oxidation to benzoic acids without ligands, additives, or solvents. With this result in hand, the gram-scale preparation and stabilization of Pd SACs within the functional channels of a novel methyl-cysteine-based metal–organic framework (MOF) was accomplished, to give a robust and crystalline solid catalyst fully characterized with the help of single-crystal X-ray diffraction (SCXRD). These results illustrate the advantages of metal speciation in ligand-free homogeneous organic reactions and the translation into solid catalysts for potential industrial implementation.
Puerto Rico has played a pivotal role in the building of cultural chronology for the insular Caribbean, and yet little systematic work has been conducted in recent decades to assess the validity of ...the system(s) produced. To resolve this issue, we assembled a radiocarbon inventory comprised of more than a thousand assays, drawn from both published sources and grey literature, which was used to assess and revise (as necessary) the received cultural chronology of Puerto Rico. The application of chronological hygiene protocols and Bayesian modeling of the dates yields an initial arrival of humans to the island more than a millennium earlier than previously established, making Puerto Rico the earliest inhabited island of the Antilles, following Trinidad. The chronology of the different cultural manifestations that have been identified for the island, as grouped by Rousean styles, also is updated, and in some cases heavily modified, as a result of this process. While admittedly limited by several mitigating factors, the image that emerges from this chronological revision suggests a much more complex, dynamic, and plural cultural scenario than has been traditionally assumed, as a result of the myriad of interactions that took place between the different peoples that coexisted in the island through time.
Self-motile Janus colloids are important for enabling a wide variety of microtechnology applications as well as for improving our understanding of the mechanisms of motion of artificial micro- and ...nanoswimmers. We present here micro/nanomotors which possess a reversed Janus structure of an internal catalytic “chemical engine”. The catalytic material (here platinum (Pt)) is embedded within the interior of the mesoporous silica (mSiO2)-based hollow particles and triggers the decomposition of H2O2 when suspended in an aqueous peroxide (H2O2) solution. The pores/gaps at the noncatalytic (Pt) hemisphere allow the exchange of chemical species in solution between the exterior and the interior of the particle. By varying the diameter of the particles, we observed size-dependent motile behavior in the form of enhanced diffusion for 500 nm particles, and self-phoretic motion, toward the nonmetallic part, for 1.5 and 3 μm ones. The direction of motion was rationalized by a theoretical model based on self-phoresis. For the 3 μm particles, a change in the morphology of the porous part is observed, which is accompanied by a change in the mechanism of propulsion via bubble nucleation and ejection as well as a change in the direction of motion.
The specificity and predictability of hybridization make oligonucleotides a powerful platform to program assemblies and networks with logic-gated responses, an area of research which has grown into a ...field of its own. While the field has capitalized on the commercial availability of DNA oligomers with its four canonical nucleobases, there are opportunities to extend the capabilities of the hardware with unnatural nucleobases and other backbones. This Topical Review highlights nucleobases that favor hybridizations that are empowering for assemblies and networks as well as two chiral XNAs than enable orthogonal hybridization networks.
Pocas empresas atesoran en nuestro país un patrimonio publicitario tan intenso y extenso como el de Renfe. La empresa pública de transporte ferroviario celebra precisamente este 2021 sus primeros ...ochenta años de existencia y se han programado acciones a lo largo del ejercicio para conmemorar tan densa trayectoria. Las acciones previstas abarcan desde iniciativas comerciales hasta actos y encuentros institucionales de todo tipo.
Renfe es hoy una operadora ferroviaria de primer nivel y referencia mundial en alta velocidad, con cerca de 15.000 profesionales al servicio de sus clientes y confirmada como uno de los puntales de la movilidad en España merced a sus diferentes actividades de transporte. La compañía está volcada desde hace tiempo en una intensa transformación mediante una apuesta decidida por la innovación, la internacionalización y centrar el foco de toda iniciativa en el cliente, con vistas a afianzarse como un operador integral de movilidad.
As discussed in this review, human cytomegalovirus (HCMV) infection in healthy individuals is associated with a variable and persistent increase of NK cells expressing the CD94/NKG2C activating ...receptor. The expansion of NKG2C+ NK cells reported in other infectious diseases is systematically associated with HCMV co‐infection. The functionally mature NKG2Cbright NK‐cell subset expanding in HCMV+ individuals displays inhibitory Ig‐like receptors (KIR and LILRB1) specific for self HLA class I, and low levels of NKp46 and NKp30 activating receptors. Such reconfiguration of the NK‐cell compartment appears particularly marked in immunocompromised patients and in children with symptomatic congenital infection, thus suggesting that its magnitude may be inversely related with the efficiency of the T‐cell‐mediated response. This effect of HCMV infection is reminiscent of the pattern of response of murine Ly49H+ NK cells against murine CMV (MCMV), and it has been hypothesized that a cognate interaction of the CD94/NKG2C receptor with HCMV‐infected cells may drive the expansion of the corresponding NK‐cell subset. Yet, the precise role of NKG2C+ cells in the control of HCMV infection, the molecular mechanisms underlying the NK‐cell compartment redistribution, as well as its putative influence in the response to other pathogens and tumors remain open issues.
This systematic review and meta-analysis aimed to examine the effects of out-of-school physical activity (PA) interventions, based on Self-Determination Theory (SDT), on basic psychological needs ...(BPN), motivation toward PA, and PA levels in youths.
Systematic review and meta-analyses.
We searched for intervention studies examining the effects of PA interventions based on SDT implemented outside the school published in English and Spanish in six electronic databases up to January 2022.
Outcomes of interest were BPN, motivation, and PA levels. In total, nine studies were included in this review. Seven individual meta-analyses were conducted for each variable, revealing nonsignificant clustered effects for the outcomes autonomy satisfaction (g = 0.12, 95% CI -0.31, 0.55), competence satisfaction (g = 0.02, 95% CI -0.28, 0.32), relatedness satisfaction (g = 0.13, 95% CI -0.43, 0.68), autonomous motivation (g = 0.15, 95% CI -0.38, 0.67), controlled motivation (g = 0.12, 95% CI -0.32, 0.55), amotivation (g = -0.36, 95% CI -0.88, 0.16), and PA behavior (g = 0.02, 95% CI -0.08, 0.12).
Meta-analyses suggest that out-of-school PA interventions based on SDT are not effective in increasing levels of needs satisfaction, types of motivation, and PA levels.
Highlights • NK cells are cytotoxic lymphocytes with potential for cancer immunotherapy. • NK-cell numbers and function are regulated by surface receptors and cytokines. • Inhibitory and activating ...NK-cell receptors can be targeted for cancer immunotherapy. • IL-2 and IL-15 enhance NK-cell anti-tumor function. • Strengthening NK-cell ADCC emerges as a suitable approach for cancer treatment.
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