Pseudomonas aeruginosa is one of the most worrisome infectious bacteria due to its intrinsic and acquired resistance against several antibiotics and the recalcitrance of its infections; hence, the ...development of novel antimicrobials effective against multidrug‐resistant P. aeruginosa is mandatory. In this work, silver nanoparticles obtained by green synthesis using a leaf extract and fungi were tested against a battery of clinical strains from cystic fibrosis, pneumonia and burnt patients, some of them with multidrug resistance. Both nanoparticles showed a potent antibacterial effect, causing severe damage to the cell wall, membrane and DNA, and inducing the production of reactive oxygen species. Moreover, the nanoparticles derived from fungi showed synergistic antibacterial effects with the antibiotics meropenem and levofloxacin for some clinical strains and both kinds of nanoparticles were nontoxic for larvae of the moth Galleria mellonella, encouraging further research for their implementation in the treatment of P. aeruginosa infections.
Significance and Impact of the Study: The continuous rise of antibiotic resistance in bacteria such as Pseudomonas aeruginosa is a serious threat to human health, hence it is mandatory to identify novel ways to combat its infections. In this work, silver nanoparticles were synthesized in a green way using leaves and fugal extracts and its antibacterial effects were tested against clinical strains. The nanoparticles killed the strains due severe cellular damage affecting the membranes, the DNA and generating reactive oxygen species, in addition they were nontoxic and displayed synergy with some antibiotics; therefore, being a promising alternative to treat MDR P. aeruginosa infections.
Abstract
Submolecular charge distribution significantly affects the physical-chemical properties of molecules and their mutual interaction. One example is the presence of a π-electron-deficient ...cavity in halogen-substituted polyaromatic hydrocarbon compounds, the so-called π-holes, the existence of which was predicted theoretically, but the direct experimental observation is still missing. Here we present the resolution of the π-hole on a single molecule using the Kelvin probe force microscopy, which supports the theoretical prediction of its existence. In addition, experimental measurements supported by theoretical calculations show the importance of π-holes in the process of adsorption of molecules on solid-state surfaces. This study expands our understanding of the π-hole systems and, at the same time, opens up possibilities for studying the influence of submolecular charge distribution on the chemical properties of molecules and their mutual interaction.
Abstract
We present the first results of the Chandra Cool Targets (CCT) survey of the Second Bologna Catalog (B2CAT) of powerful radio sources, aimed at investigating the extended X-ray emission ...surrounding these sources. For the first 33 sources observed in the B2CAT CCT survey, we performed both imaging and spectral X-ray analysis, producing multiband Chandra images, and compared these images with radio observations. To evaluate the presence of extended emission in the X-rays, we extracted surface flux profiles comparing them with simulated ACIS point-spread functions. We detected X-ray nuclear emission for 28 sources. In addition, we detected eight regions of increased X-ray flux originating from radio hot spots or jet knots, and a region of decreased flux, possibly associated with an X-ray cavity. We performed X-ray spectral analysis for 15 nuclei and found intrinsic absorption significantly larger than the Galactic values in four of them. We detected significant extended X-ray emission in five sources, and fitted their spectra with thermal models with gas temperatures ∼2 keV. In the case of B2.1 0742+31, the surrounding hot gas is compatible with the intracluster medium of low-luminosity clusters of galaxies, while the X-ray diffuse emission surrounding the highly disturbed wide-angle-tailed radio galaxy B2.3 2254+35 features a luminosity similar to those of relatively bright galaxy groups, although its temperature is similar to those of low-luminosity galaxy clusters. These results highlight the power of low-frequency radio selection, combined with short Chandra snapshot observations, for investigating the properties of X-ray emission from radio sources.
A body mass index (BMI) ≥30 kg/m(2) and a waist circumference (WC) ≥80 cm in women (WCF) or ≥90 cm in men (WCM) are reference cardiometabolic risk markers (CMM) for Mexicans adults. However, their ...reliability to predict other CMM (index tests) in young Mexicans has not been studied in depth.
A cross-sectional descriptive study evaluating several anthropometric, physiological and biochemical CMM from 295 young Mexicans was performed. Sensitivity (Se), specificity (Sp) and Youden's index (J) of reference BMI/WC cutoffs toward other CMM (n = 14) were obtained and their most reliable cutoffs were further calculated at Jmax.
Prevalence, incidence and magnitude of most CMM increased along the BMI range (p < 0.01). BMI explained 81 % of WC's variance Se (97 %), Sp (71 %), J (68 %), Jmax (86 %), BMI = 30 kg/m(2) and 4-50 % of other CMM. The five most prevalent (≥71 %) CMM in obese subjects were high WC, low HDL-C, and three insulin-related CMM Fasting insulin, HOMA-IR, and QUICKI. For a BMI = 30 kg/m(2), J ranged from 16 % (HDL-C/LDL-C) to 68 % (WC), being moderately reliable (Jmax = 61-67) to predict high uric acid (UA), metabolic syndrome (MetS) and the hypertriglyceridemic-waist phenotype (HTGW). Corrected WCM/WCF were moderate-highly reliable (Jmax = 66-90) to predict HTGW, MetS, fasting glucose and UA. Most CMM were moderate-highly predicted at 27 ± 3 kg/m(2) (CI 95 %, 25-28), 85 ± 5 cm (CI 95 %, 82-88) and 81 ± 6cm (CI 95 %, 75-87), for BMI, WCM and WCF, respectively.
BMI and WC are good predictors of several CMM in the studied population, although at different cutoffs than current reference values.
Abstract We recently built the G4Jy-3CRE catalog of extragalactic radio sources. This catalog lists 264 powerful radio sources selected with similar criteria to those of the revised Third Cambridge ...Catalog, but visible from the Southern Hemisphere. A literature search revealed that 119 sources in the G4Jy-3CRE catalog (i.e., 45%) lack a firm spectroscopic redshift measurement. Here, we present a campaign aimed at acquiring optical spectra of G4Jy-3CRE sources and measuring their redshifts. We used single-slit observations obtained with the Víctor Blanco Telescope, the New Technology Telescope, the Southern Astrophysical Research Telescope, and the 2.1 m telescope of the Observatorio Astronómico Nacional at San Pedro Mártir, Mexico. In addition, we analyzed Very Large Telescope/MUSE archival observations. From these observations, we report the spectra and redshifts of 93 sources, 42 of which are the first optical spectra and redshift determinations for the respective sources. With our new data, approximately 71% of the sources in the G4Jy-3CRE catalog now have firm spectroscopic redshift measurements. This data set will be the basis of our future analysis of the optical properties of the G4Jy-3CRE catalog.
Abstract
We recently constructed the G4Jy-3CRE, a catalog of extragalactic radio sources based on the GLEAM 4-Jy (G4Jy) sample, with the aim of increasing the number of powerful radio galaxies and ...quasars with similar selection criteria to those of the revised release of the Third Cambridge Catalog (3CR). The G4Jy-3CRE consists of a total of 264 radio sources mainly visible from the Southern Hemisphere. Here, we present an initial X-ray analysis of 89 G4Jy-3CRE radio sources with archival X-ray observations from the Neil Gehrels Swift Observatory. We reduced a total of 624 Swift observations, for about 0.9 Ms of integrated exposure time. We found X-ray counterparts for 59 radio sources belonging to the G4Jy-3CRE, nine of them showing extended X-ray emission. The remaining 30 sources do not show any X-ray emission associated with their radio cores. Our analysis demonstrates that X-ray snapshot observations, even if lacking uniform exposure times, as those carried out with Swift, allow us to (i) verify and/or refine the host galaxy identification; (ii) discover the extended X-ray emission around radio galaxies of the intracluster medium when harbored in galaxy clusters, as the case of G4Jy 1518 and G4Jy 1664; and (iii) detect X-ray radiation arising from their radio lobes, as for G4Jy 1863.
Abstract
Since the early sixties, our view of radio galaxies and quasars has been drastically shaped by discoveries made thanks to observations of radio sources listed in the Third Cambridge Catalog ...and its revised version (3CR). However, the largest fraction of data collected to date on 3CR sources was performed with relatively old instruments, rarely repeated and/or updated. Importantly, the 3CR contains only objects located in the Northern Hemisphere, thus having limited access to new and innovative astronomical facilities. To mitigate these limitations, we present a new catalog of powerful radio sources visible from the Southern Hemisphere, extracted from the GLEAM 4 Jy (G4Jy) catalog and based on equivalent selection criteria as the 3CR. This new catalog, named G4Jy-3CRE, where the E stands for “equivalent,” lists a total of 264 sources at decl. below −5° and with 9 Jy limiting sensitivity at ∼178 MHz. We explored archival radio maps obtained with different surveys and compared them with optical images available in the Pan-STARRS, DES, and DSS databases to search for optical counterparts of their radio cores. We compared mid-infrared counterparts, originally associated in the G4Jy, with the optical ones identified here, and we present results of a vast literature search carried out to collect redshift estimates for all G4Jy-3CRE sources resulting in a total of 145 reliable
z
measurements.
In our previous analysis we investigated the large-scale environment of two samples of radio galaxies (RGs) in the local universe (i.e., with redshifts zsrc ≤ 0.15), classified as FR I and FR II on ...the basis of their radio morphology. The analysis was carried out using (i) extremely homogeneous catalogs and (ii) a new method, known as cosmological overdensity, to investigate their large-scale environments. We concluded that, independently of the shape of their radio extended structure, RGs inhabit galaxy-rich large-scale environments with similar characteristics and richness. In the present work, we first highlight additional advantages of our procedure, which does not suffer cosmological biases and/or artifacts, and then we carry out an additional statistical test to strengthen our previous results. We also investigate properties of RG environments using those of the cosmological neighbors. We find that large-scale environments of both FR Is and FR IIs are remarkably similar and independent of the properties of central RG. Finally, we highlight the importance of comparing radio sources in the same redshift bins to obtain a complete overview of their large-scale environments.
We present the analysis of nine radio sources belonging to the Third Cambridge Revised catalog (3CR) observed with Chandra during Cycle 20 in the redshift range between 1.5 and 2.5. This study ...completes the 3CR Chandra Snapshot Survey thus guaranteeing the X-ray coverage of all 3CR sources identified to date. This sample lists two compact steep spectrum sources, four radio galaxies, and three quasars. We detected X-ray emission from all nuclei, with the only exception of 3C 326.1 and 3C 454.1 and from radio lobes in six out of nine sources at a level of confidence larger than ∼5 . We measured X-ray fluxes and luminosities for all nuclei and lobes in the soft (0.5-1 keV), medium (1-2 keV), and hard (2-7 keV) X-ray bands. Since the discovered X-ray extended emission is spatially coincident with the radio structure in all cases, its origin could be due to inverse Compton (IC) scattering of the cosmic microwave background (CMB) occurring in radio lobes.
The prevalence of symptomatic adverse reactions to gluten and adherence to gluten-free diet in Latin American countries is unknown. These measurements are strongly linked to gluten-related disorders. ...This work aimed to estimate the prevalence of adverse reactions to oral gluten and the adherence to gluten-free diet in the adult Mexican population. To reach this aim, a self-administered questionnaire was designed and tested for clarity/comprehension and reproducibility. Then, a self-administered questionnaire-based cross-sectional study was conducted in the Mexican population. The estimated prevalence rates were (95% CI): 11.9% (9.9-13.5) and 7.8 (6.4-9.4) for adverse and recurrent adverse reactions to gluten respectively; adherence to gluten-free diet 3.7% (2.7-4.8), wheat allergy 0.72% (0.38-1.37); celiac disease 0.08% (0.01-0.45), and NCGS 0.97% (0.55-1.68). Estimated pooled prevalence of self-reported physician-diagnosis of gluten-related disorders was 0.88% (0.49-1.5), and 93.3% respondents reported adherence to gluten-free diet without a physician-diagnosis of gluten-related disorders. Symptom comparisons between those who reported recurrent adverse reactions to gluten and other foods showed statistically significant differences for bloating, constipation, and tiredness (p < 0.05). Gluten-related disorders may be underdiagnosed in the Mexican population and most people adhering to a gluten-free diet are doing it without proper diagnostic work-up of these disorders, and probably without medical/dietician advice.
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