Intergalactic space is believed to contain nonzero magnetic fields (the Intergalactic Magnetic Field: IGMF), which at scales of megaparsecs would have intensities below 10−9 G. Very high energy (VHE ...> 100 GeV) gamma-rays coming from blazars can produce e+e− pairs when interacting with the extragalactic background light (EBL) and the cosmic microwave background, generating an electromagnetic cascade of megaparsec scale. The IGMF may produce a detectable broadening of the emission beam that could lead to important constrains both on the IGMF intensity and its coherence length. Using the Monte Carlo-based Elmag code, we simulate the electromagnetic cascade corresponding to two detected TeV sources: PKS 2155-304 visible from the south and H1426+428 visible from the north. Assuming an EBL model and intrinsic spectral properties of the sources, we obtain the spectral and angular distribution of photons when they arrive at Earth. We include the response of the next generation Cherenkov telescopes by using simplified models for Cherenkov Telescope Array (CTA)-south and CTA-north based on a full simulation of each array performance. Combining the instrument properties with the simulated source fluxes, we calculate the telescope point-spread function for null and non-null IGMF intensities and develop a method to test the statistical feasibility of detecting IGMF imprints by comparing the resulting angular distributions. Our results show that for the analyzed source PKS 2155-304 corresponding to the southern site, CTA should be able to detect IGMF with intensities stronger than 10−14.5 G within an observation time of ∼100 hr.
Fourier transform infrared spectroscopy is a powerful analytical technique to study organic materials. However, in Cultural Heritage, since the sample under analysis is always a complicated matrix of ...several materials, data analysis performed through peak-by-peak comparisons of sample spectra with those of standard compounds is a tedious method that does not always provide good results. To overcome this problem, a chemometric model based on principal component analysis was developed to classify and identify organic binding media in artworks. The model allows the differentiation of five families of binders: drying oils, waxes, proteins, gums, and resins, taking into account the absorption bands in two characteristic spectral windows: C–H stretching and carbonyl band. This new methodology was applied in the characterization of binders in three kinds of artworks: papers of historical, archeological, and artistic value, easel paintings, and polychromed stone-based sculptures.
Figure
Analysis of the binder in a wallpaper of the 19th century by means of FTIR spectroscopy and chemometrics
Forest fires in Galicia have become a serious environmental problem over the years. This is especially the case in the Pontevedra region, where in October 2017 large fires (>500 hectares) burned more ...than 15,000 Ha. In addition to the area burned being of relevance, it is also very important to know quickly and accurately the different severity degrees that soil has suffered in order to carry out an optimal restoration campaign. In this sense, the use of remote sensing with the Sentinel-2 and Landsat-8 satellites becomes a very useful resource due to the variations that appear in soil after a forest fire (changes in soil cover are noticeably appreciated with spectral information). To calculate these variations, the spectral indices NBR (Normalized Burn Ratio) and NDVI (Normalized Difference Vegetation Index) are used, both before and after the fire and their differences (dNBR and dNDVI, respectively). In addition, as a reference for a correct discrimination between severity degrees, severity data measured in situ after the fire are used to classified at 5 levels of severity and 6 levels of severity. Therefore, this study aims to establish a methodology, which relates remote-sensing data (spectral indices) and severity degrees measured in situ. The R2 statistic and the pixel classification accuracy results show the existing synergy of the Sentinel-2 dNBR index with the 5 severity degrees classification (R2 = 0.74 and 81% of global accuracy) and, for this case, the good applicability of remote sensing in the forest fire field.
Summary
Background
The molecular basis and effects of proton pump inhibitor (PPI) therapy on PPI‐responsive oesophageal eosinophilia (PPI‐REE) and eosinophilic oesophagitis (EoE) remain unknown.
Aim
...To compare symptom‐histological and cytokine gene expression in PPI‐REE and EoE patients, at baseline and after specific treatment.
Methods
In consecutive adult patients with an EoE phenotype (dysphagia/food impaction, typical endoscopic findings and > 15 eos/HPF), gene expression of eotaxin‐3, IL‐13, and IL‐5 were determined in distal and proximal oesophagus, at baseline and after omeprazole 40 mg b.d. for 8 weeks. PPI‐REE was defined by clinicohistological response. PPI nonresponders (EoE) were offered treatment with topical steroids.
Results
Fifty three patients were re‐evaluated on PPI therapy. 23 patients (43%) had PPI‐REE and 30 patients (57%) had EoE. At baseline, eotaxin‐3/IL‐13/IL‐5 gene expression was indistinguishable between EoE and PPI‐REE, excepting increased IL‐5 expression in proximal oesophagus (12.54 vs. 57, P = 0.029). PPI therapy significantly decreased eotaxin‐3/IL‐13 in PPI‐REE, at both oesophageal sites (P ≤ 0.008), and IL‐5 in distal (P = 0.016), but not in proximal oesophagus. Patients with steroid‐responsive EoE also showed a significant decrease in eotaxin‐3/IL‐5 expression at both oesophageal sites. In EoE patients, initial PPI trial significantly decreased distal oesophageal eosinophilia (63.78 to 41.79 eos/HPF, P = 0.025) and led to symptom remission in 16%, but did not influence Th2 markers.
Conclusions
Baseline cytokine gene expression in PPI‐REE was nearly indistinguishable from EoE. PPI therapy significantly downregulated oesophageal eotaxin‐3/Th2‐cytokine gene expression in PPI‐REE, similarly to that seen in steroid‐responsive EoE. A subset of EoE patients showed clinicohistological improvement on PPI therapy.
Purpose
To report the incidence and quantity of silicone oil microbubbles and the relationship with the number of intravitreal anti‐vascular endothelial growth factor (VEGF) injections and evaluate ...if microbubbles induce artefacts on optical coherence tomography (OCT) images.
Methods
Observational, descriptive, cross‐sectional study. Patients with wet age‐related macular degeneration were included who had been treated for 1 year minimally with anti‐VEGF injections repackaged in the hospital pharmacy. Detection and quantification of silicone microbubbles by mydriatic biomicroscopic examination were conducted 1 month after the last injection. The numbers of microbubbles were quantified on a scale of 0–3: 0, none; 1 scarce (1–10 microbubbles); 2 moderate (10–30); or 3 numerous (>30). Shadowing on OCT images was classified as 0–3: 0, none; 1 obscuring some retinal layers; 2 obscuring all retinal layers; or 3 obscuring the retinal thickness.
Results
The study included 142 eyes of 98 patients (mean age, 82.4 years + 7.3; range, 65–97) treated with 2377 injections. Microbubbles were detected in 127 (89.4%) eyes, 62 (43.6%) with numerous microbubbles and 36 (25.4%) and 29 (20.4%), respectively, with scarce and moderate numbers. A positive correlation was found between the numbers of injections and intravitreal silicone (rho, 0.7). Optical coherence tomography (OCT) artefacts were detected in 11 eyes; the artefacts obscured all retinal layers in three eyes. No significant relationship could be established between the appearance of floaters and the microbubbles.
Conclusion
The presence and number of silicone microbubbles were correlated with the number of intravitreal injections. Microbubbles can produce OCT artefacts, which can hinder the treatment decision.
•REY distributions in ashes of a bituminous coal and three sewage sludges were studied.•REY concentrations in sludge ashes are lower than in coal ashes, excepting for La.•Correlations and ...associations between major and minor elements and REY were obtained.
Rare earth elements together with Y and Sc (REY) are essential in the development of technology for clean and efficient use of energy. Apart from the potential of coal and sewage sludge as energy resources, the enrichment of REY in their ashes may provide a feasible source of them. The concentrations of REY in ashes obtained at 800 and 1100°C of a bituminous coal and three types of sewage sludge were determined. Also, their relationships with major and minor elements and minerals were studied. The concentrations of REY, excepting for La, are higher in the coal ashes than those of the sludge ashes. In both types of materials, REY are associated with the inorganic matter, although the associations are different for the coal than for the sludges. In the coal ashes, La, Ce, Pr and Nd are mainly associated with silicates and aluminosilicates in ashes at 800 and 1100°C. The rest of REY (excepting Sm and Yb) are associated with carbonates in ashes at 800°C and with sulphates in ashes at 1100°C. In the sludge ashes, Y is associated with carbonates, while other REY are mainly associated with phosphates, silicates and aluminosilicates.
Detection of molecular recognition processes requires robust, specific, and easily implementable sensing methods, especially for screening applications. Here, we propose the difluoroacetamide moiety ...(an acetamide bioisoster) as a novel tag for detecting by NMR analysis those glycan–protein interactions that involve N‐acetylated sugars. Although difluoroacetamide has been used previously as a substituent in medicinal chemistry, here we employ it as a specific sensor to monitor interactions between GlcNAc‐containing glycans and a model lectin (wheat germ agglutinin). In contrast to the widely employed trifluoroacetamide group, the difluoroacetamide tag contains geminal 1H and 19F atoms that allow both 1H and 19F NMR methods for easy and robust detection of molecular recognition processes involving GlcNAc‐ (or GalNAc‐) moieties over a range of binding affinities. The CHF2CONH‐ moiety behaves in a manner that is very similar to that of the natural acetamide fragment in the involved aromatic‐sugar interactions, providing analogous binding energy and conformations, whereas the perfluorinated CF3CONH‐ analogue differs more significantly.
Monitoring glycan/protein interactions: A simple chemical tag (see figure) that can be used to monitor glycan–protein molecular recognition by NMR spectroscopic analysis has been devised. The chemical nature of the tag permits the easy and straightforward detection of interactions between the partners and allows the glycan binding epitope to be deduced.
Abstract
The radio galaxy M87 is the central dominant galaxy of the Virgo Cluster. Very high-energy (VHE, ≳0.1 TeV) emission from M87 has been detected by imaging air Cherenkov telescopes. Recently, ...marginal evidence for VHE long-term emission has also been observed by the High Altitude Water Cherenkov Observatory, a gamma-ray and cosmic-ray detector array located in Puebla, Mexico. The mechanism that produces VHE emission in M87 remains unclear. This emission originates in its prominent jet, which has been spatially resolved from radio to X-rays. In this paper, we construct a spectral energy distribution from radio to gamma rays that is representative of the nonflaring activity of the source, and in order to explain the observed emission, we fit it with a lepto-hadronic emission model. We found that this model is able to explain nonflaring VHE emission of M87 as well as an orphan flare reported in 2005.
In our search for new neuroprotective agents for stroke therapy to improve the pharmacological profile of the compound quinolylnitrone QN23, we have prepared and studied sixteen new, related and ...easily available quinolylnitrones. As a result, we have identified compounds QN4 and QN15 as promising candidates showing high neuroprotection power in a cellular experimental model of ischemia. Even though they were found to be less active than our current lead compound QN23, QN4 and QN15 provide an improved potency and, particularly for QN4, an expanded range of tolerability and improved solubility compared to the parent compound. A computational DFT-based analysis has been carried out to understand the antioxidant power of quinolylnitrones QN23, QN4 and QN15. Altogether, these results show that subtle, simple modifications of the quinolylnitrone scaffold are tolerated, providing high neuroprotective activity and optimization of the pharmacological potency required for an improved design and future drug developments in the field.
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