Exciton tuning and strain imaging in WS2supported on PDMS micropillars

Since the raise of 2D materials, significant research has been dedicated to their strain-dependent electronic and mechanical properties. In this work, we studied exciton energies and low-frequency phonon modes in CVD-grown mono- and few-layer WS2 transferred on PDMS micropillars. The modification of the band structure under strain was investigated by photoluminescence (PL) spectroscopy at room temperature. Machine learning (ML) methods were used to analyze the PL spatial maps and facilitate the spectral deconvolution. For monolayer (1L) WS2, red shift in the exciton energy was detected as a function of the position, which was ascribed to the presence of residual strain. For three-layer (3L) strained WS2, a significant increase in the PL intensity corresponding to direct (K-K) band transition together with a change of exciton energy was observed. From the PL spectra, strain distribution maps were extracted for both studied samples, which strongly resembled the ML clustering results. Finally, the low-frequency Raman modes of WS2 were studied on both Si/SiO2 and PDMS substrates and no significant change of their frequency was observed for the 3L-WS2

Psycho-Neuro-Endocrine-Immunological Basis of the Placebo Effect: Potential Applications beyond Pain Therapy

The placebo effect can be defined as the improvement of symptoms in a patient after the administration of an innocuous substance in a context that induces expectations regarding its effects. During recent years, it has been discovered that the placebo response not only has neurobiological functions on analgesia, but that it is also capable of generating effects on the immune and endocrine systems. The possible integration of changes in different systems of the organism could favor the well-being of the individuals and go hand in hand with conventional treatment for multiple diseases. In this sense, classic conditioning and setting expectations stand out as psychological mechanisms implicated in the placebo effect. Recent advances in neuroimaging studies suggest a relationship between the placebo response and the opioid, cannabinoid, and monoaminergic systems. Likewise, a possible immune response conditioned by the placebo effect has been reported. There is evidence of immune suppression conditioned through the insular cortex and the amygdala, with noradrenalin as the responsible neurotransmitter. Finally, a conditioned response in the secretion of different hormones has been determined in different studies; however, the molecular mechanisms involved are not entirely known. Beyond studies about its mechanism of action, the placebo effect has proved to be useful in the clinical setting with promising results in the management of neurological, psychiatric, and immunologic disorders. However, more research is needed to better characterize its potential use. This review integrates current knowledge about the psycho-neuro-endocrine-immune basis of the placebo effect and its possible clinical applications

Use of the entomopathogenic fungi \u3ci\u3eMetarhizium anisopliae, Cordyceps bassiana\u3c/i\u3e and \u3ci\u3eIsaria fumosorosea\u3c/i\u3e to control \u3ci\u3eDiaphorina citri\u3c/i\u3e (Hemiptera: Psyllidae) in Persian lime under field conditions

The Asian citrus psyllid Diaphorina citri Kuwayama is a destructive insect pest in citriculture, because it is an efficient vector of the proteobacteria ‘Candidatus Liberibacter asiaticus’ (Las), ‘Ca. L. africanus’ (Laf) and ‘Ca. L. americanus’ (Lam). These bacteria cause the ‘huanglongbing’ disease or ‘greening’ or ‘yellow dragon’ disease. The disease kills the plant and reduces fruit production. This insect pest is susceptible to entomopathogenic fungi, and we report the use of different strains of Metarhizium anisopliae, Cordyceps bassiana and Isaria fumosorosea against the nymphs and adults of D. citri under field conditions. The fungi were applied four times using a concentration of 2 £ 1013 conidia/ha with a time interval of 15 days between applications. The percentage of control of Cb 108, Ma 65, Ma 14 and Ifr 4 was 60, 50, 40 and 35% in nymphs, and 50, 50, 42 and 22% in adults, respectively. Metarhizium anisopliae, C. bassiana and I. fumosorosea applied on Persian lime groves are more effective in reducing higher density of nymphs than adults of D. citri

Características físicas de la carne de corderos Katahdín con Pelibuey alimentados a base de forraje y concentrado

Objective: To evaluate the effect of forage and concentrate in diet on physical characteristics of meat of crossed (F1) Katahdin with Pelibuey lambs. Design/methodology/approach: Thirty-six entire male lambs were distributed in a completely randomized design to four treatments: 1) 100% Concentrated food (CF) with 15 % of CP; 2) 70% CF + 30% of Maralfalfa forage (Pennisetum sp); 3) 70% CF + 30% of Mombaza forage (M. maximum); 4) 70% CF + 30% CT-115 forage (P. Purpureum). Results: No effect of diet on carcass traits and physical properties of meat was found (P> 0.05). The average value of pH and temperature ± SD were 5.58 ± 0.12 and 6.38 ± 0.56 o C, respectively. The little loss of water in meat (0.1%), indicates that it retains its physical-chemical characteristics for storage. Limitations on study/implications: Consumer demands of lamb meat are more focused on quality traits than quantity details, so, in order to comply with demands demanded by market, it is necessary to carry out meat quality evaluations, compare between breeds and feeding systems to determine which genotype produces the best meat. Findings/conclusions: Lambs fed diets that include forage have similar physical characteristics of meat to those that received only concentrate food, which indicates that it is possible to produce lamb meat with excellent properties, using diets with good quality forage.Objetivo: Evaluar el efecto del forraje y concentrado en la dieta sobre las características físicas de la carne de corderos cruzados (F1) Katahdín × Pelibuey (KtPb). Diseño/metodología/aproximación: Treinta y seis corderos machos enteros fueron distribuidos mediante un diseño completamente al azar a cuatro tratamientos:1) 100% Alimento concentrado (AC) con 15 % de PC: 2) 70% AC + 30% de pasto Maralfalfa (Pennisetum sp); 3) 70% AC + 30% pasto Mombaza (M. maximum ); 4) 70% AC + 30%   CT-115 (P. Purpureum). Resultados: No se encontró un efecto de la dieta sobre las características de la canal y propiedades físicas de la carne (P>0.05). Los valores promedio para el pH y temperatura ± DE encontrados fueron de 5.58 ± 0.12 y 6.38 ± 0.56 o C, respectivamente. La poca pérdida de agua en la carne (0.1%), indica que esta conservo sus propiedades físico-químicas adecuadas para su almacenamiento Limitaciones del estudio/implicaciones: Las demandas de los consumidores de cortes de cordero se centran más en los rasgos de calidad que en los detalles de cantidad. Para poder cumplir con los estándares que exige el mercado, es necesario realizar evaluaciones de calidad de la carne, comparar entre razas y sistemas de alimentación para conocer cual fenotipo produce la mejor carne. Hallazgos/conclusiones: Los corderos alimentados con dietas que incluyen forraje tienen características físicas de la carne similar a los que recibieron solo concentrado, lo que indica que es posible producir carne de corderos con excelentes propiedades, utilizando dietas con forrajes de buena calidad

Inferior vena cava filters: a review

Venous thromboembolism is an entity that ranges from deep vein thrombosis to pulmonary embolism, both are highly prevalent diseases in our environment and potentially fatal. The intention of this review is to compile information regarding the indications, contraindications, complications and comparison of different therapeutic methods in order to create an algorithm. An exhaustive review was performed with the available literature, using the PubMed, ScienceDirect, Scopus and Cochrane databases from 2004 to 2021. The search criteria were formulated to identify reports related to inferior vena cava filters. Venous thrombosis manifested as deep vein thrombosis or pulmonary embolism is a highly prevalent disease in our setting with high morbidity and mortality. Currently, different therapeutic options have been presented to address this pathology, in this review we focus on the developments regarding the use of vena cava filters. Reviewing the indications for the placement of a vena cava filter, we find absolute indications such as a contraindication to anticoagulation and high risk of massive pulmonary embolism. Pulmonary thromboembolism is a disease with high prevalence and mortality, we have highly effective and novel treatments such as the vena cava filter, patients should be selected carefully always taking into account the absolute and relative indications

Self-sustained coherent phonon generation in optomechanical cavities

Optical forces can set tiny objects in states of mechanical self-sustained oscillation, spontaneously generating periodic signals by extracting power from steady sources. Miniaturized self-sustained coherent phonon sources are interesting for applications such as mass-force sensing, intra-chip metrology and intra-chip time-keeping among others. In this paper, we review several mechanisms and techniques that can drive a mechanical mode into the lasing regime by exploiting the radiation pressure force in optomechanical cavities, namely stimulated emission, dynamical back-action, forward stimulated Brillouin scattering and self-pulsing

Dynamic equivalence between atomic and colloidal liquids

We show that the kinetic-theoretical self-diffusion coefficient of an atomic fluid plays the same role as the short-time self-diffusion coefficient D_S in a colloidal liquid, in the sense that the dynamic properties of the former, at times much longer than the mean free time, and properly scaled with D_S, will indistinguishable from those of a colloidal liquid with the same interaction potential. One important consequence of such dynamic equivalence is that the ratio D_L/ D_S of the long-time to the short-time self-diffusion coefficients must then be the same for both, an atomic and a colloidal system characterized by the same inter-particle interactions. This naturally extends to atomic fluids a well-known dynamic criterion for freezing of colloidal liquids[Phys. Rev. Lett. 70, 1557 (1993)]. We corroborate these predictions by comparing molecular and Brownian dynamics simulations on (soft- and hard-sphere) model systems, representative of what we may refer to as the "hard-sphere" dynamic universality class

Simulation of dimensionality effects in thermal transport

The discovery of nanostructures and the development of growth and fabrication techniques of one- and two-dimensional materials provide the possibility to probe experimentally heat transport in low-dimensional systems. Nevertheless measuring the thermal conductivity of these systems is extremely challenging and subject to large uncertainties, thus hindering the chance for a direct comparison between experiments and statistical physics models. Atomistic simulations of realistic nanostructures provide the ideal bridge between abstract models and experiments. After briefly introducing the state of the art of heat transport measurement in nanostructures, and numerical techniques to simulate realistic systems at atomistic level, we review the contribution of lattice dynamics and molecular dynamics simulation to understanding nanoscale thermal transport in systems with reduced dimensionality. We focus on the effect of dimensionality in determining the phononic properties of carbon and semiconducting nanostructures, specifically considering the cases of carbon nanotubes, graphene and of silicon nanowires and ultra-thin membranes, underlying analogies and differences with abstract lattice models.Comment: 30 pages, 21 figures. Review paper, to appear in the Springer Lecture Notes in Physics volume "Thermal transport in low dimensions: from statistical physics to nanoscale heat transfer" (S. Lepri ed.