We present intermediate-resolution spectroscopy of the optical counterpart to the black hole X-ray transient MAXI J1820+070 (=ASASSN-18ey) obtained with the OSIRIS spectrograph on the 10.4 m Gran ...Telescopio Canarias. The observations were performed with the source close to the quiescent state and before the onset of renewed activity in 2019 August. We make use of these data and K-type dwarf templates taken with the same instrumental configuration to measure the projected rotational velocity of the donor star. We find vrot sin i = 84 5 km s−1 (1 ), which implies a donor to the black hole mass ratio for the case of a tidally locked and Roche-lobe filling donor star. The derived dynamical masses for the stellar components are and . The use of q, combined with estimates of the accretion disk size at the time of the optical spectroscopy, allows us to revise our previous orbital inclination constraints to 66° < i < 81°. These values lead to 95% confidence level limits on the masses of 5.73 < M1(M ) < 8.34 and 0.28 < M2(M ) < 0.77. Adopting instead the 63° 3° orientation angle of the radio jet as the binary inclination leads to and (1 ).
Micro- and nanotechnology are tools being used strongly in the area of food technology. The electrospray technique is booming because of its importance in developing micro- and nanoparticles ...containing an active ingredient as bioactive compounds, enhancing molecules of flavors, odors, and packaging coatings, and developing polymers that are obtained from food (proteins, carbohydrates), as chitosan, alginate, gelatin, agar, starch, or gluten. The electrospray technique compared to conventional techniques such as nanoprecipitation, emulsion–diffusion, double-emulsification, and layer by layer provides greater advantages to develop micro- and nanoparticles because it is simple, low cost, uses a low amount of solvents, and products are obtained in one step. This technique could also be applied in the agrifood sector for the preparation of controlled and/or prolonged release systems of fertilizer or agrochemicals, for which more research must be conducted.
Evaluate the bispectral index (BIS) monitoring to detect delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH).
A single-center prospective study in patients with aSAH. BIS ...monitoring was recorded during 25–120 min in two periods, within the initial 72 h (BIS1) and between days 4 and 6 (BIS2) from admission. The median for each exported BIS parameter was analyzed. Transcranial Doppler (TCD) sonography was simultaneously performed with BIS1 (TCD1) and BIS2 (TCD2) monitoring. A multivariate logistic regression model was built to identify the variables associated with DCI.
Sixty-four patients were included and 16 (25%) developed DCI. During BIS2 monitoring, significant differences were found in BIS value (left, p = 0.01; right, p = 0.009), 95% spectral edge frequency (left and right, p = 0.04), and total power (left and right, p = 0.04). In multivariable analysis, vasospasm on TCD2 (OR 42.8 95% CI 3.1–573; p = 0.005), a median BIS2 value <85 in one or both sides (OR 6.2 95% CI 1.28–30; p = 0.023), and age (OR 1.08 95% CI 1.00–1.17; p = 0.04) were associated with the development of DCI.
BIS value is the most useful BIS parameter for detecting DCI after aSAH. Pending further validation, BIS monitoring might be even more accurate than TCD.
•BIS monitoring may help detect delayed cerebral ischemia after aneurysmal SAH.•A BIS value lesser than 85 in the right and/or left side was the best predictor.•BIS might be more accurate in the detection of clinical DCI than TCD.•Asymmetry index failed to detect delayed cerebral ischemia.
ABSTRACT
MAXI J1305-704 has been proposed as a high-inclination candidate black hole X-ray binary in view of its X-ray properties and dipping behaviour during outburst. We present photometric and ...spectroscopic observations of the source in quiescence that allow us to reveal the ellipsoidal modulation of the companion star and absorption features consistent with those of an early K-type star ($T_{\rm eff}=4610^{+130}_{-160}\, {\rm K}$). The central wavelengths of the absorption lines vary periodically at $P_{\rm orb}=0.394\pm 0.004\, {\rm d}$ with an amplitude of $K_2=554\pm 8\, {\rm km \, s^{-1}}$. They imply a mass function for the compact object of $f(M_1)=6.9\pm 0.3\, {\rm M}_\odot$, confirming its black hole nature. The simultaneous absence of X-ray eclipses and the presence of dips set a conservative range of allowed inclinations $60\, {\rm deg}\lt i\lt 82\, {\rm deg}$, while modelling of optical light curves further constrain it to $i=72^{+5}_{-8}\, {\rm deg}$. The above parameters together set a black hole mass of $M_1= 8.9_{-1.0}^{+1.6}\, {\rm M}_{\odot }$ and a companion mass of $M_2= 0.43\pm 0.16\, {\rm M}_{\odot }$, much lower than that of a dwarf star of the observed spectral type, implying it is evolved. Estimates of the distance to the system ($d=7.5^{+1.8}_{-1.4}\, {\rm kpc}$) and space velocity ($v_{\rm space}=270\pm 60 \, {\rm km\, s^{-1}}$) place it in the Galactic thick disc and favour a significant natal kick during the formation of the BH if the supernova occurred in the Galactic Plane.
Autoimmune comorbidity in achalasia patients Romero-Hernández, Fernanda; Furuzawa-Carballeda, Janette; Hernández-Molina, Gabriela ...
Journal of gastroenterology and hepatology
33, Številka:
1
Journal Article
Recenzirano
Idiopathic achalasia is a rare esophageal motor disorder. The disease state manifests local and systemic inflammation, and it appears that an autoimmune component and specific autoantibodies ...participate in the pathogenesis. The study aims to determine the prevalence of autoimmune and chronic inflammatory diseases in patients with achalasia and compare the results with those from patients with gastroesophageal reflux disease (GERD).
It was a cross-sectional and included 114 patients with idiopathic achalasia and 114 age-matched and sex-matched control patients with GERD. Data on the presence of autoimmune and inflammatory diseases, the time of presentation, and any family history of autoimmune disease were obtained from the hospital's medical records.
Seventy three (64%) were female patients (mean age: 42.3 ± 15.5; median disease duration: 12 months). We identified the presence of autoimmune disease in 19 patients with achalasia (16.7%), hypothyroidism was the main diagnosis, and it was present in 52.6% of patients compared with 4.2% in controls. Thirteen of the 19 achalasia patients (68.4%) with autoimmune disease had history of familial autoimmunity. We identified 11 achalasia (9.6%) and 5 GERD patients (4.16%) with an inflammatory condition. Compared with the GERD, the achalasia group was 3.8 times more likely to have an autoimmune disease (95% CI: 1.47-9.83), 3.0 times more likely to have thyroidopathies (95% CI: 1.00-9.03), and 3.02 times more likely to suffer from any chronic inflammatory disease (95% CI: 1.65-6.20).
The non-negligible number of patients with autoimmune diseases identified among the patients with idiopathic achalasia supports the hypothesis that achalasia has an autoimmune component.
Rationale
The jumbo squid Dosidicus gigas is a fishery resource of considerable economic and ecological importance in the Mexican Pacific. Studies on its habitat preferences are needed to understand ...recent fluctuations in the abundance and availability of the species. Stable isotope analysis allows us to infer ecological aspects such as spatial distribution and trophic preferences.
Methods
We used an isotope ratio mass spectrometer, automated for carbonate analysis, and coupled to an elemental analyzer, to determine the isotopic composition of statoliths (δ18O and δ13C values) and beaks (δ13C and δ15N values) from 219 individuals caught over two fishing seasons (2007 and 2009) off the coast of Santa Rosalía, in the central Gulf of California. We used these isotopic ratios to assess variation in spatial and trophic preferences by sex, size, and fishing season.
Results
In the 2009 group, we observed significant differences in statolith δ13C values and beak δ13C and δ15N values between males and females. Between size groups, we observed significant differences in statolith δ18O and δ13C values in 2007 and in beak δ13C and δ15N values during both seasons. Both seasons were characterized by high overlap in δ18O and δ13C values between sexes and in 2009 between size groups. We observed low trophic overlap between sexes in 2009 and between size groups during both seasons.
Conclusions
The isotopic ratios from statoliths and beaks indicate that D. gigas has changed its spatial and trophic preferences, a shift that is probably related to changes in the species' diet. This intraspecific variation in preferences could be related to characteristics such as size, which may influence squid distribution preferences.
ABSTRACT
We present a new method to derive binary inclinations in quiescent black hole (BH) X-ray transients (XRTs), based on the depth of the trough (T) from double-peaked H α emission profiles ...arising in accretion discs. We find that the inclination angle (i) is linearly correlated with T in phase-averaged spectra with sufficient orbital coverage (≳50 per cent) and spectral resolution, following i(deg) = 93.5 × T + 23.7. The correlation is caused by a combination of line opacity and local broadening, where a leading (excess broadening) component scales with the deprojected velocity of the outer disc. Interestingly, such scaling allows to estimate the fundamental ratio M1/Porb by simply resolving the intrinsic width of the double-peak profile. We apply the T–i correlation to derive binary inclinations for GRO J0422+32 and Swift J1357−0933, two BH XRTs where strong flickering activity has hindered determining their values through ellipsoidal fits to photometric light curves. Remarkably, the inclination derived for GRO J0422+32 (i = 55.6 ± 4.1○) implies a BH mass of $2.7^{+0.7}_{-0.5}$ M⊙ thus placing it within the gap that separates BHs from neutron stars. This result proves that low-mass BHs exist in nature and strongly suggests that the so-called ‘mass gap’ is mainly produced by low number statistics and possibly observational biases. On the other hand, we find that Swift J1357−0933 contains a $10.9^{+1.7}_{-1.6}$ M⊙ BH, seen nearly edge on ($i=87.4^{+2.6}_{-5.6}$ deg). Such extreme inclination, however, should be treated with caution since it relies on extrapolating the T–i correlation beyond i ≳ 75○, where it has not yet been tested.
The growth in our knowledge of the diversity of the herpetofauna of Mexico has occurred over the period of approximately 445 years from the work of Francisco Hernández to that of a broad ...multinational array of present-day herpetologists. The work of this huge group of people has established Mexico as one of the most significant centers of herpetofaunal biodiversity in the world. This status is the result of a complex orography, in addition to diverse habitats and environments and the biogeographic history of Mexico. The current herpetofauna consists of 1,421 native and introduced species, allocated to 220 genera, and 61 families. This figure is comprised of 1,405 native species and 16 non-native species (as of April 2023). The non-native species include two anurans, 13 squamates, and one turtle. The level of endemism is very high, presently lying at 63%, with this level expected to increase with time. Species richness varies among the 32 federal entities in the country, from a low of 50 in Tlaxcala to a high of 492 in Oaxaca. Amphibian species richness by state-level can be envisioned as comprising three levels of low, medium, and high, with the lowest levels occurring in the Peninsula of Baja California, a group of seven states in north-central and central Mexico, and a group of three states in the Yucatan Peninsula, with the highest levels occupying the southern states of Guerrero, Puebla, Veracruz, Oaxaca, and Chiapas, and the medium level in the remaining states of the country. Reptile species richness also can be allocated to three categories, with the lowest level occupying Baja California Sur, a group of central states, and the states of the Yucatan Peninsula, and the highest level found in a cluster of the states of Veracruz, Guerrero, Oaxaca, and Chiapas. Knowledge of the Mexican herpetofauna will continue to grow with additional studies on systematics, conservation, and the construction of checklists at various levels.
We identified the main changes in serum metabolites associated with severe (n = 46) and mild (n = 19) COVID-19 patients by gas chromatography coupled to mass spectrometry. The modified metabolic ...profiles were associated to an altered amino acid catabolism in hypoxic conditions. Noteworthy, three α-hydroxyl acids of amino acid origin increased with disease severity and correlated with altered oxygen saturation levels and clinical markers of lung damage. We hypothesize that the enzymatic conversion of α-keto-acids to α- hydroxyl-acids helps to maintain NAD recycling in patients with altered oxygen levels, highlighting the potential relevance of amino acid supplementation during SARS-CoV-2 infection.
In this study the mechanical behavior of FeB and Fe2B layers formed at the surface of AISI D2 steels was estimated by the Berkovich nanoindentation technique. The boriding of AISI D2 steels was ...developed by the powder-pack method at temperatures of 1223, 1273 and 1323K with exposure times of 3–7h for each temperature. The mechanical characterization was performed to determine the effect of the set of experimental parameters of the boriding process with three experimental procedures: first, nanoindentation was performed along the depth of the surface layers at a constant load of 250mN to determine the hardness gradient and the state of the thermal residual stresses in the boride layers; then, loads in the range of 10 to 300mN were applied to the “pure” zone of the FeB layer at a distance of 10μm from the surface, and in the “pure” zone of the Fe2B layer (40μm), respectively. Finally, the fracture toughness, compressive residual stresses, and brittleness of the boride layers were evaluated using the length of the cracks that originated from the corners of the Berkovich nanoindentation site after the application of loads ranging from 300 to 500mN.
For a constant load of 250mN, the results showed that the state of thermal residual stresses and the hardness of both the FeB and Fe2B layers were a function of the temperature and exposure time of the process. Moreover, the presence of the indentation size effect (ISE) in the FeB and Fe2B layers was verified in the range of applied loads (10–300mN), in which the apparent or real hardness was estimated by the elastic recovery (ER) model according to the boriding experimental parameters. Finally, the estimated values of the fracture resistance and brittleness of the boride layers fell within the range of 1.48–3.02MPam and 2.01–4.65MPam, with the presence of compressive stresses in the range of 428 to 1604MPa for the FeB and Fe2B layers, respectively.
► Mechanical properties of the FeB and Fe2B layers were evaluated by nanoindentation. ► The thermal residual stresses across the boride layers were compressive. ► The presence of the indentation size effect was verified in both FeB and Fe2B layers. ► The FeB layer showed low fracture resistance with high brittleness.
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