1,953 research outputs found
Boron-doped diamond by 9 MeV microbeam implantation: Damage and recovery
Diamond properties can be tuned by doping and ion-beam irradiation is one of the most powerful techniques to do it in a controlled way, but it also produces damage and other aftereffects. Of particular interest is boron doping which, in moderate concentrations, causes diamond to become a p-type semiconductor and, at higher boron concentrations, a superconductor. Nevertheless, the preparation of superconducting boron-doped diamond by ion implantation is hampered by amorphization and subsequent graphitization after annealing. The aim of this work was to explore the possibility of creating boron-doped diamond superconducting regions and to provide a new perspective on the damage induced in diamond by MeV ion irradiation. Thus, a comprehensive analysis of the damage and eventual recovery of diamond when irradiated with 9 MeV B ions with different fluences has been carried out, combining Raman, photoluminescence, electrical resistivity, X-ray diffraction and Rutherford Backscattering/Ion-channeling. It is found that, as the B fluence increases, carbon migrates to interstitial sites outside of the implantation path and an amorphous fraction increases within the path. For low fluences (∼1015 ions/cm2), annealing at 1000 °C is capable to fully recovering the diamond structure without graphitization. However, for higher fluences (≥5 × 1016 ions/cm2), those required for superconductivity, the recovery is important, but some disorder still remains. For high fluences, annealing at 1200 °C is detrimental for the diamond lattice and graphite traces appear. The incomplete healing of the diamond lattice and the interstitial location of B can explain that optimally doped samples do not exhibit superconductivityThis work has been partially supported by the Ministerio de Ciencia e
Innovacion ´ of Spain (Project grants PID2020-112770RB-C22/MCIN/
AEI/10.13039/501100011033, PID2021-127033OB-C21/MCIN/AEI/
10.13039/501100011033, and PID2021-127498NB-I00/AEI/FEDER/
10.13039/501100011033). We also acknowledge financial support
from MCIN/AEI/10.13039/501100011033, through the “María de
Maeztu” Programme for Units of Excellence in R&D (CEX2018-000805-
M), as well as from the Autonomous Community of Madrid through
program S2018/NMT-4321 (NANOMAGCOST-CM
Monitoring of airborne biological particles in outdoor atmosphere. Part 1: Importance, variability and ratios
The first part of this review ("Monitoring of airborne biological particles in outdoor atmosphere. Part 1: Importance, variability and ratios") describes the current knowledge on the major biological particles present in the air regarding their global distribution, concentrations, ratios and influence of meteorological factors in an attempt to provide a framework for monitoring their biodiversity and variability in such a singular environment as the atmosphere. Viruses, bacteria, fungi, pollen and fragments thereof are the most abundant microscopic biological particles in the air outdoors. Some of them can cause allergy and severe diseases in humans, other animals and plants, with the subsequent economic impact. Despite the harsh conditions, they can be found from land and sea surfaces to beyond the troposphere and have been proposed to play a role also in weather conditions and climate change by acting as nucleation particles and inducing water vapour condensation. In regards to their global distribution, marine environments act mostly as a source for bacteria while continents additionally provide fungal and pollen elements. Within terrestrial environments, their abundances and diversity seem to be influenced by the land-use type (rural, urban, coastal) and their particularities. Temporal variability has been observed for all these organisms, mostly triggered by global changes in temperature, relative humidity, et cetera. Local fluctuations in meteorological factors may also result in pronounced changes in the airbiota. Although biological particles can be transported several hundreds of meters from the original source, and even intercontinentally, the time and final distance travelled are strongly influenced by factors such as wind speed and direction
Monitoring of airborne biological particles in outdoor atmosphere. Part 2: Metagenomics applied to urban environments
The air we breathe contains microscopic biological particles such as viruses, bacteria, fungi and pollen, some of them with relevant clinic importance. These organisms and/or their propagules have been traditionally studied by different disciplines and diverse methodologies like culture and microscopy. These techniques require time, expertise and also have some important biases. As a consequence, our knowledge on the total diversity and the relationships between the different biological entities present in the air is far from being complete. Currently, metagenomics and next-generation sequencing (NGS) may resolve this shortage of information and have been recently applied to metropolitan areas. Although the procedures and methods are not totally standardized yet, the first studies from urban air samples confirm the previous results obtained by culture and microscopy regarding abundance and variation of these biological particles. However, DNA-sequence analyses call into question some preceding ideas and also provide new interesting insights into diversity and their spatial distribution inside the cities. Here, we review the procedures, results and perspectives of the recent works that apply NGS to study the main biological particles present in the air of urban environments
Tailoring of AlAs/InAs/GaAs QDs Nanostructures via Capping Growth Rate
The use of thin AlA capping layers (CLs) on InAs quantum dots (QDs) has recently received considerable attention due to improved photovoltaic performance in QD solar cells. However, there is little data on the structural changes that occur during capping and their relation to different growth conditions. In this work, we studied the effect of AlA capping growth rate (CGR) on the structural features of InAs QDs in terms of shape, size, density, and average content. As will be shown, there are notable differences in the characteristics of the QDs upon changing CGR. The Al distribution analysis in the CL around the QDs was revealed to be the key. On the one hand, for the lowest CGR, Al has a homogeneous distribution over the entire surface, but there is a large thickening of the CL on the sides of the QD. As a result, the QDs are lower, lenticular in shape, but richer in In. On the other hand, for the higher CGRs, Al accumulates preferentially around the QD but with a more uniform thickness, resulting in taller QDs, which progressively adopt a truncated pyramidal shape. Surprisingly, intermediate CGRs do not improve either of these behaviors, resulting in less enriched QDs
Metformin reduces macrophage HIF1α-dependent proinflammatory signaling to restore brown adipocyte function in vitro
© 2021 The Authors.Therapeutic potential of metformin in obese/diabetic patients has been associated to its ability to combat insulin resistance. However, it remains largely unknown the signaling pathways involved and whether some cell types are particularly relevant for its beneficial effects. M1-activation of macrophages by bacterial lipopolysaccharide (LPS) promotes a paracrine activation of hypoxia-inducible factor-1α (HIF1α) in brown adipocytes which reduces insulin signaling and glucose uptake, as well as β-adrenergic sensitivity. Addition of metformin to M1-polarized macrophages blunted these signs of brown adipocyte dysfunction. At the molecular level, metformin inhibits an inflammatory program executed by HIF1α in macrophages by inducing its degradation through the inhibition of mitochondrial complex I activity, thereby reducing oxygen consumption in a reactive oxygen species (ROS)-independent manner. In obese mice, metformin reduced inflammatory features in brown adipose tissue (BAT) such as macrophage infiltration, proinflammatory signaling and gene expression, and restored the response to cold exposure. In conclusion, the impact of metformin on macrophages by suppressing a HIF1α-dependent proinflammatory program is likely responsible for a secondary beneficial effect on insulin-mediated glucose uptake and β-adrenergic responses in brown adipocytes.This work was funded by grants RTI2018-094052-B-100 (MCIN/AEI/10.13039/501100011033/FEDER) , S2017/BMD-3684 (Comunidad de Madrid, Spain), Fundación Ramón Areces (Spain) and CIBERdem (ISCIII) to A.M.V., grant S2010/BMD-2423 (Comunidad de Madrid, Spain) to M.J.O. and A.M.V., PID2019-106371RB-I00 (MCIN/ AEI /10.13039/501100011033/ FEDER) to J.A and PI16/00789 (ISCIII, Spain) to M.A.F.-M. We also acknowledge all members of AMV's laboratory for helpful discussions. M.F. and B.V were supported by Inserm, CNRS, Université de Paris, and Région Ile-de-France. We also acknowledge the EFSD Albert Reynolds travel grant fellowship to V.F
Functional consequences of microbial shifts in the human gastrointestinal tract linked to antibiotic treatment and obesity
The microbiomes in the gastrointestinal tract (GIT) of individuals receiving antibiotics and those in obese subjects undergo compositional shifts, the metabolic effects and linkages of which are not clearly understood. Herein, we set to gain insight into these effects, particularly with regard to carbohydrate metabolism, and to contribute to unravel the underlying mechanisms and consequences for health conditions. We measured the activity level of GIT carbohydrate-active enzymes toward 23 distinct sugars in adults patients (n = 2) receiving 14-d β-lactam therapy and in obese (n = 7) and lean (n = 5) adolescents. We observed that both 14 d antibiotic-treated and obese subjects showed higher and less balanced sugar anabolic capacities, with 40% carbohydrates being preferentially processed as compared with non-treated and lean patients. Metaproteome-wide metabolic reconstructions confirmed that the impaired utilization of sugars propagated throughout the pentose phosphate metabolism, which had adverse consequences for the metabolic status of the GIT microbiota. The results point to an age-independent positive association between GIT glycosidase activity and the body mass index, fasting blood glucose and insulin resistance (r2 ≥ 0.95). Moreover, antibiotics altered the active fraction of enzymes controlling the thickness, composition and consistency of the mucin glycans. Our data and analyses provide biochemical insights into the effects of antibiotic usage on the dynamics of the GIT microbiota and pin-point presumptive links to obesity. The knowledge and the hypotheses generated herein lay a foundation for subsequent, systematic research that will be paramount for the design of “smart” dietary and therapeutic interventions to modulate host-microbe metabolic co-regulation in intestinal homeostasis
A retrospective, multicenter study of the efficacy of lapatinib plus trastuzumab in HER2-positive metastatic breast cancer patients previously treated with trastuzumab, lapatinib, or both: the Trastyvere study
[Purpose]: To evaluate the efficacy and safety of lapatinib (L) and trastuzumab (T) combination in HER2-positive metastatic breast cancer (MBC) patients previously treated with T and/or L.[Materials and methods]: We conducted a retrospective, post-authorized, multicenter study including patients with HER2-positive MBC or locally advanced breast cancer (ABC) treated with the combination of L–T. Concomitant endocrine therapy, as well as brain metastasis and/or prior exposure to L, were allowed.[Results]: One hundred and fifteen patients from 14 institutions were included. The median age was 59.8 years. The median number of prior T regimens in the advanced setting was 3 and 73 patients had received a prior L regimen. The clinical benefit rate (CBR) was 34.8% (95% CI 26.1–43.5). Among other efficacy endpoints, the overall response rate was 21.7%, and median progression-free survival (PFS) and overall survival were 3.9 and 21.6 months, respectively. Heavily pretreated and ≥ 3 metastatic organ patients showed lower CBR and PFS than patients with a low number of previous regimens and < 3 metastatic organs. Moreover, CBR did not significantly change in L-pretreated compared with L-naïve patients (31.5% versus 40.5% for L-pretreated versus L-naïve). Grade 3/4 adverse events were reported in 19 patients (16.5%).[Conclusion]: The combination of L–T is an effective and well-tolerated regimen in heavily pretreated patients and remains active among patients progressing on prior L-based therapy. Our study suggests that the L–T regimen is a safe and active chemotherapy-free option for MBC patients previously treated with T and/or L.This work was supported by GlaxoSmithKline plc (GSK) through a contract with Medica Scientia Innovation Research (MedSIR), an academic research organization focused on independent clinical research development
Crustal structure of the Spanish Central System: Constraints from ambient noise autocorrelation and controlled source data
This presentation provides an image of the crustal structure underneath the Central System, in the Central Iberian Zone, by means of seismic noise autocorrelation and wide angle seismic dat
Campaña de sensibilización para el proyecto Ciudad Amigable con los mayores en Guadalajara, Jalisco: Equipo de producción
El presente reporte se enfoca en la creación de materiales audiovisuales para transformar la percepción actual de las y los adultos mayores, esto a partir de un eje rector que fue la diversidad en las formas de envejecer. El objetivo fue crear una campaña de sensibilización a partir de contenidos que se habían hecho en periodos anteriores del PAP, y con estos, mostrar una imagen digna de las y los adultos mayores para generar una transformación de los estereotipos que giran en torno a ellos. El trabajo se realizó a partir de un diagnóstico para conocer las formas en que se estaban siendo representados los adultos mayores en distintos medios de comunicación; y a partir de ahí se identificaron los recursos y elementos que ayudaban a generar una imagen digna e íntegra de ellos y los que no para usar como referencia de lo que se debía hacer y lo que no. Dentro de los resultados, encontramos distintos productos audiovisuales y gráficos que forman parte de una campaña de sensibilización y en los que se construye una imagen digna de los adultos mayores teniendo en cuenta las distintas formas de envejecer.ITESO, A.C
El regadío del Ebro en Aragón: clasificación, contaminación y gobernanza
Grupo operativo Partenariado del Agua del Ebro-Aragó
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