Monolayer hexagonal boron nitride (hBN) is attracting considerable attention because of its potential applications in areas such as nano‐ and opto‐electronics, quantum optics and nanomagnetism. ...However, the implementation of such functional hBN demands precise lateral nanostructuration and integration with other two‐dimensional materials, and hence, novel routes of synthesis beyond exfoliation. Here, a disruptive approach is demonstrated, namely, imprinting the lateral pattern of an atomically stepped one‐dimensional template into a hBN monolayer. Specifically, hBN is epitaxially grown on vicinal Rhodium (Rh) surfaces using a Rh curved crystal for a systematic exploration, which produces a periodically textured, nanostriped hBN carpet that coats Rh(111)‐oriented terraces and lattice‐matched Rh(337) facets with tunable width. The electronic structure reveals a nanoscale periodic modulation of the hBN atomic potential that leads to an effective lateral semiconductor multi‐stripe. The potential of such atomically thin hBN heterostructure for future applications is discussed.
Vapor growth of borazine on a curved Rh surface leads to continuous hexagonal boron nitride (hBN) monolayer coating, under which nanomesh‐quantized Rh(111) terraces and stepped Rh(337) facets segregate, The latter reveals a perfect hBN/Rh interface registry, with all N atoms anchoring at step on‐top positions. This imprints a strong uniaxial anisotropy in the electronic band structure of the hBN monolayer.
Abstract
Background and study aims
Artificial intelligence is currently able to accurately predict the histology of colorectal polyps. However, systems developed to date use complex optical ...technologies and have not been tested in vivo. The objective of this study was to evaluate the efficacy of a new deep learning-based optical diagnosis system, ATENEA, in a real clinical setting using only high-definition white light endoscopy (WLE) and to compare its performance with endoscopists.
Methods
ATENEA was prospectively tested in real life on consecutive polyps detected in colorectal cancer screening colonoscopies at Hospital Clínic. No images were discarded, and only WLE was used. The in vivo ATENEA’s prediction (adenoma vs non-adenoma) was compared with the prediction of four staff endoscopists without specific training in optical diagnosis for the study purposes. Endoscopists were blind to the ATENEA output. Histology was the gold standard.
Results
Ninety polyps (median size: 5 mm, range: 2–25) from 31 patients were included of which 69 (76.7 %) were adenomas. ATENEA correctly predicted the histology in 63 of 69 (91.3 %, 95 % CI: 82 %–97 %) adenomas and 12 of 21 (57.1 %, 95 % CI: 34 %–78 %) non-adenomas while endoscopists made correct predictions in 52 of 69 (75.4 %, 95 % CI: 60 %–85 %) and 20 of 21 (95.2 %, 95 % CI: 76 %–100 %), respectively. The global accuracy was 83.3 % (95 % CI: 74%–90 %) and 80 % (95 % CI: 70 %–88 %) for ATENEA and endoscopists, respectively.
Conclusion
ATENEA can accurately be used for in vivo characterization of colorectal polyps, enabling the endoscopist to make direct decisions. ATENEA showed a global accuracy similar to that of endoscopists despite an unsatisfactory performance for non-adenomatous lesions.
People still drown on beaches in unacceptable numbers due to the lack of knowledge about the risks taking place in them. The proposed methodology forecasts electronic bathing flags in beaches by ...integrating the benefits of metocean operational systems, machine learning and web-based decision support technologies into a 24/7 risk assessment service that could be easily implemented at any beach worldwide with low costs of maintenance. Firstly, a crosscutting analysis between metocean conditions, beach characteristics and flag records was performed. Secondly, an expert system, based on Deep Learning, was developed to obtain electronic bathing flags as an indicator of the dynamic risk of drowning on beaches. The input variables of the Deep Neural Network were significant wave height, mean wave period, wind velocity, marine current velocity, incidence angle, and beach modal state. Finally, the application of the method to the Santa Catarina's beaches (Brazil) conveniently reproduced the status flag of beaches.
Maternal smoking during pregnancy is a major risk factor for adverse health outcomes. The main objective of the study was to assess the impact of in utero tobacco exposure on DNA methylation in ...children born at term with appropriate weight at birth.
Twenty mother-newborn dyads, after uncomplicated pregnancies, in the absence of perinatal illness were included. All mothers were healthy with no cardiovascular risk factors, except for the associated risks among those mothers who smoked. Umbilical cord blood and maternal peripheral venous blood were collected and an epigenome-wide association study was performed using a 450 K epigenome-wide scan (Illumina Infinium HumanMethylation 450BeadChip) with adjustment to normalize the DNA methylation for data cell variability in whole blood.
The maternal plasmatic cotinine levels ranged from 10.70-115.40 ng/ml in the exposed group to 0-0.59 ng/ml in the non-exposed group. After adjusting for multiple comparisons in 427102 probes, statistically significant differences for 31 CpG sites, associated to 25 genes were observed. There was a greater than expected proportion of statistically-significant loci located in CpG islands (Fisher's exact test, p = 0.029) and of those CpG islands, 90.3% exhibit higher methylation levels in the exposed group. The most striking and significant CpG site, cg05727225, is located in the chromosome 11p15.4, within the adrenomedullin gene.
In utero tobacco exposure, even in the absence of fetal growth restriction, may alter the epigenome, contributing to global DNA hypomethylation. Therefore, DNA status can be used as a biomarker of prenatal insults. Considering the possibility to reverse epigenetic modifications, a window of opportunity exists to change the programmed chronic disease.
Tree nuts and peanuts (henceforth, nuts) are nutrient-dense foods rich in neuroprotective components; thus, their consumption could benefit cognitive health. However, evidence to date is limited and ...inconsistent regarding the potential benefits of nuts for cognitive function.
To prospectively evaluate the association between nut consumption and 2-y changes in cognitive performance in older adults at cognitive decline risk.
A total of 6,630 participants aged 55 to 75 y (mean age 65.0±4.9 y, 48.4% women) with overweight/obesity and metabolic syndrome completed a validated semi-quantitative food frequency questionnaire and a comprehensive battery of neuropsychological tests at baseline and a 2-y follow-up. Composite cognitive scores were used to assess global, general, attention, and executive function domains. Nut consumption was categorized as <1, ≥1 to <3, ≥3 to <7, and ≥7 servings/wk (1 serving=30 g). Multivariable-adjusted linear regression models were fitted to assess associations between baseline nut consumption and 2-y cognitive changes.
Nut consumption was positively associated with 2-y changes in general cognitive function (P-trend <0.001). Compared with participants consuming <1 serving/wk of nuts, those categorized as consuming ≥3 to <7 and ≥7 servings/wk showed more favorable changes in general cognitive performance (β z-score 95% CI = 0.06 0.00,0.12 and 0.13 0.06,0.20, respectively). No significant changes were observed in the multivariable-adjusted models for other cognitive domains assessed.
Frequent nut consumption was associated with a smaller decline in general cognitive performance over 2 y in older adults at risk of cognitive decline. Randomized clinical trials to verify our findings are warranted.
Heart failure (HF) is prevalent in advanced ages. Our objective was to assess the impact of frailty on 1-year mortality in older patients with ambulatory HF.
Our data come from the FRAGIC study ...(Spanish acronym for “Study of the impact of frailty and other geriatric syndromes on the clinical management and prognosis of elderly outpatients with heart failure”), a multicenter prospective registry conducted in 16 Spanish hospitals including outpatients ≥ 75 years with HF followed up by cardiology services in Spain.
We included 499 patients with a mean age of 81.4±4.3 years, of whom 193 (38%) were women. A total of 268 (54%) had left ventricular ejection fraction <40%, and 84.6% was in NYHA II functional class. The FRAIL scale identified 244 (49%) pre-frail and 111 (22%) frail patients. Frail patients were significantly older, were more frequently female (both, P <.001), and had higher comorbidity according to the Charlson index (P=.017) and a higher prevalence of geriatric syndromes (P <.001). During a median follow-up of 371 361-387 days, 58 patients (11.6%) died. On multivariate analysis (Cox regression model), frailty detected with the FRAIL scale was marginally associated with mortality (HR=2.35; 95%CI, 0.96-5.71; P=.059), while frailty identified by the visual mobility scale was an independent predictor of mortality (HR=2.26; 95%CI, 1.16-4.38; P=.015); this association was maintained after adjustment for confounding variables (HR=2.13; 95%CI, 1.08-4.20; P=.02).
In elderly outpatients with HF, frailty is independently associated with mortality at 1 year of follow-up. It is essential to identify frailty as part of the comprehensive approach to elderly patients with HF.
La insuficiencia cardiaca (IC) es prevalente en edades avanzadas. Nuestro objetivo es conocer el impacto de la fragilidad en la mortalidad a 1 año en pacientes mayores con IC ambulatorios.
El estudio «Impacto de la fragilidad y otros síndromes geriátricos en el manejo clínico y pronóstico del paciente anciano ambulatorio con insuficiencia cardiaca» (FRAGIC) es un registro prospectivo multicéntrico, realizado en 16 centros españoles, que incluyó pacientes con IC ambulatorios de edad ≥ 75 años seguidos por cardiología en España.
Se incluyó a 499 pacientes (media de edad, 81,4±4,3 años; 193 38% mujeres); 268 (54%) tenían una fracción de eyección del ventrículo izquierdo <40% y el 84,6% estaba en clase funcional II de la NYHA. La escala FRAIL identificó a 244 pacientes prefrágiles (49%) y 111 frágiles (22%). Los pacientes frágiles tenían una media de edad significativamente mayor, eran más frecuentemente mujeres (ambos, p <0,001) y presentaban mayores comorbilidad según el índice de Charlson (p=0,017) y prevalencia de síndromes geriátricos (p <0,001). Tras una mediana de seguimiento de 371 361-387 días, fallecieron 58 pacientes (11,6%). En el análisis multivariado (modelo de regresión de Cox), la fragilidad mediante la escala FRAIL se asoció marginalmente con la mortalidad (HR=2,35; IC95%, 0,96-5,71; p=0,059); la identificada mediante la escala visual de movilidad (HR=2,26; IC95%, 1,16-4,38; p=0,015) fue predictor independiente de mortalidad, cuya asociación se mantuvo tras ajustar por variables confusoras (HR=2,13; IC95%, 1,08-4,20; p=0,02).
En pacientes mayores ambulatorios con IC, la fragilidad es predictor independiente de mortalidad a 1 año de seguimiento. Debe identificarse como parte del abordaje integral de estos pacientes.
DNA molecules containing a 1D silver array may be applied for nanotechnology applications, but first their conducting and photoluminescence behavior must be enhanced. Here we have synthesized and ...characterized three new helical compounds based on stacked silver–mediated cytosine base pairs Ag(mC)2X (mC = N1-methylcytosine; X = NO3 (1), BF4 (2) and ClO4 (3)), that contain uninterrupted polymeric AgI chains that run through the center of the helixes, comparable to related silver-DNA structures. The exposure of nanostructures of Ag(mC)2BF4 (2) to cold hydrogen plasma stimulates the reduction of the prearranged AgI polymeric chains to metallic silver along the material. This solvent-free reduction strategy leads to the compound AgI(mC)2X@Ag0 (2H) that contains uniformly well-distributed silver metallic nanostructures that are responsible for the new conducting and photoluminescence properties of the material. The presence of silver nanostructures alongside compound 2H has been evaluated by means of X-ray photoelectron spectroscopy (XPS), UV-vis spectroscopy, and X-ray powder diffraction (XRPD). The conducting and photoactive properties of 2H were studied by electrostatic force microscopy (EFM) and conducting-AFM (c-AFM), and photoluminescence microscopy (PL), respectively. The results demonstrate that the presence of well-organized metallic silver nanoentities on the material is responsible for the novel conductivity and photoactive properties of the material. This methodology can be employed for the generation of multifunctional silver-DNA related materials with tailored properties.
The development of novel strategies to prevent HIV-1 infection is of outstanding relevance. Metal complexes of Cu2+, Ni2+, Co2+ and Zn2+ derived from sulfonated and carboxylated poly(propylene imine) ...dendrimers with ethylenediamine core were evaluated as tunable antiviral agents against HIV-1. After demonstrating their biocompatibility, specific trends in the antiviral properties were found, related to both the dendritic scaffold (peripheral group, generation) and the bound metal ions (sort, amount). In HEC-1A and VK-2 cell lines, as model of the first barrier against HIV-1 infection, a high preventive inhibitory action was found, which also avoided virus internalization inside cells and inhibited both CCR5 and CXCR4 HIV-1 strains. In peripheral blood mononuclear cells (PBMC), as model of the second barrier, a dual preventive and therapeutic behavior was observed. A rational design of such metallodendrimers opens new avenues for the production of versatile and efficient treatments against HIV-1 infection.
Display omitted
•Polyanionic dendrimers were used as selective metal complexing agents.•Dendrimers and metallodendrimers were biocompatible in Hec-1A, VK-2 and PBMC.•Metallodendrimers showed preventive-therapeutic action against HIV-1 infection.•Trends in the antiviral properties related to the dendritic scaffold and the metal.•Highest inhibition for the lowest metal dose.
Hyperoxia is used in order to counteract hypoxia effects in the TME (tumor microenvironment), which are described to boost the malignant tumor phenotype and poor prognosis. The reduction of tumor ...hypoxic state through the formation of a non-aberrant vasculature or an increase in the toxicity of the therapeutic agent improves the efficacy of therapies such as chemotherapy. Radiotherapy efficacy has also improved, where apoptotic mechanisms seem to be implicated. Moreover, hyperoxia increases the antitumor immunity through diverse pathways, leading to an immunopermissive TME. Although hyperoxia is an approved treatment for preventing and treating hypoxemia, it has harmful side-effects. Prolonged exposure to high oxygen levels may cause acute lung injury, characterized by an exacerbated immune response, and the destruction of the alveolar-capillary barrier. Furthermore, under this situation, the high concentration of ROS may cause toxicity that will lead not only to cell death but also to an increase in chemoattractant and proinflammatory cytokine secretion. This would end in a lung leukocyte recruitment and, therefore, lung damage. Moreover, unregulated inflammation causes different consequences promoting tumor development and metastasis. This process is known as protumor inflammation, where different cell types and molecules are implicated; for instance, IL-1β has been described as a key cytokine. Although current results show benefits over cancer therapies using hyperoxia, further studies need to be conducted, not only to improve tumor regression, but also to prevent its collateral damage.
Current high power laser transmission technology faces two major limitations to improve the efficiency of the photovoltaic receivers: the intrinsic entropic losses associated to low bandgap materials ...(such as GaAs) and the series resistance losses that degrade the device performance at high power densities. The use of high bandgap materials and new architectures for laser power converters (LPC) have been pointed out as alternatives to overcome these limitations. In this work, three silicon carbide polytypes (3C, 4H and 6H) are proposed as base materials for the standard horizontal laser power converter (hLPC) architecture and the Vertical Epitaxial Hetero-Structure Architecture (VEHSA). 3C SiC based hLPCs outperform the power converters based on the other two polytypes, achieving a maximum efficiency of 84.6% at ▪, but suffer from series resistance losses, that deteriorate their efficiency, at higher laser power densities. This issue is solved with 3C SiC 4 cells VEHSAs that demonstrated increasing efficiency with the input power, reaching a maximum of 87.4% at ▪. The VEHSA reduced number of cells minimize the risks of efficiency losses due to current mismatch between cells. These results support the feasibility of a new generation of LPCs capable of efficiently convert ultra-high laser power densities.
•Three silicon carbide (SiC) polytypes are proposed as a base material for ultra-high efficiency laser power converters.•The 1-cell 3C SiC-based laser power converter outperforms the other polytypes, obtaining a peak efficiency of 84.6% at 100 Wcm−2.•3C SiC-based VEHSA devices outperform the one-cell laser power converters, achieving an 87.4% efficiency at 3000 Wcm−2.•Results support the use of high-bandgap materials and advanced architectures to efficiently convert ultra-high laser powers.
PDF
