ABSTRACT
We present a reassessment of the radial abundance gradients of He, C, N, O, Ne, S, Cl, and Ar in the Milky Way using the deep optical spectra of 42 H ii regions presented in Arellano-Córdova ...et al. (2020, 2021) and Méndez-Delgado et al. (2020) exploring the impact of: (1) new distance determinations based on Gaia EDR3 parallaxes and (2) the use of Peimbert’s temperature fluctuations paradigm (t2 > 0) for deriving ionic abundances. We find that distances based on Gaia EDR3 data are more consistent with kinematic ones based on Galactic rotation curves calibrated with radio parallaxes, which give less dispersion and uncertainties than those calibrated with spectrophotometric stellar distances. The distances based on the Gaia parallaxes – DR2 or EDR3 – eliminate the internal flattening observed in previous determinations of the Galactic gradients at smaller distances than ∼7 kpc. Abundances and gradients determined assuming t2 > 0 – not only for O but also for the rest of elements – are not affected by the abundance discrepancy problem and give elemental abundances much consistent with the solar ones for most elements. We find that our radial abundance gradient of He is consistent with the most accurate estimates of the primordial He abundance. We do not find evidence of azimuthal variations in the chemical abundances of our sample. Moreover, the small dispersion in the O gradient – indicator of metallicity in photoionized regions – indicate that the gas of the H ii regions is well mixed in the sampled areas of the Galaxy.
There is an increasing interest in using physical factors such as magnetic fields as antimicrobial strategy, with variable results. The current study was aimed to evaluate the influence of extremely ...low-frequency electromagnetic fields (ELF-EMFs) on the axenically-cultured parasite protozoans
and
growth.
Bioassays were developed using
, GT-13 and
IMSS-0989 strains cultured at 37 ºC in TYI-S-33 medium. The following treatment regimens and controls were considered: (a) cells exposed to ELF-EMFs, (b) untreated cells, (c) cells treated with Metronidazole, used as positive controls, and (d) cells co-exposed to ELF-EMFs and Metronidazole. When cultures reached the end of logarithmic phase, they were exposed to ELF-EMFs for 72 h, in a standardized magnetic field exposure facility. For determining cytotoxic effects, trophozoite density was blindly evaluated in a Neubauer chamber.
A significant decrease in trophozoite growth was observed for
, in magnetic field-treated cultures. On the other hand, cultures co-exposed to ELF-EMFs and Metronidazole showed no significant differences when compared with cultures treated with Metronidazole alone. On the contrary, an increased trophozoite density was observed in
cultures after exposure to magnetic fields. An absence of a synergistic or antagonistic effect was observed.
ELF-EMFs induced
and
.
growth alterations, indicating a potential effect in cell cycle progression.
In the present work the results of the mechanism of calcium uptake in nixtamalized corn kernel were studied. The results showed that at a critical time, the calcium uptake in the pericarp suffers a ...drastic change; this fact cannot be associated only to the diffusive mechanism. The SEM analysis of processed corn kernels, taken at 1
h of steeping time illustrates a calcium cluster formation. It means that for short steeping times the calcium uptake in the total kernel is governed by an accumulation process in the most external layers of the pericarp and the diffusion process is not relevant. The apparition of micro-holes for critical time in dependence on the temperature indicates that another mechanism is contributing to the calcium uptake. These holes can pass thought the whole pericarp or form an interconnected lattice to develop a percolation path. The holes formations allow the entrance of water and calcium directly to the outermost layers of the endosperm and now the accumulation of calcium is not the predominant mechanism. It could be implied that, at this critical time the percolation of water and calcium thought these holes is the main mechanism to calcium uptake in the corn kernel and the diffusion process is not relevant.
Functional diversity is the variability in the functional roles carried out by species within ecosystems. Changes in the environment can affect this component of biodiversity and can, in turn, affect ...different processes, including some ecosystem services. This study aimed to determine the effect of forest loss on species richness, abundance and functional diversity of Neotropical bats. To this end, we identified six landscapes with increasing loss of forest cover in the Huasteca region of the state of Hidalgo, Mexico. We captured bats in each landscape using mist nets, and calculated functional diversity indices (functional richness and functional evenness) along with species richness and abundance. We analyzed these measures in terms of percent forest cover. We captured 906 bats (Phyllostomidae and Mormoopidae), including 10 genera and 12 species. Species richness, abundance and functional richness per night are positively related with forest cover. Generalized linear models show that species richness, abundance and functional richness per night are significantly related with forest cover, while seasonality had an effect on abundance and functional richness. Neither forest cover nor season had a significant effect on functional evenness. All these findings were consistent across three spatial scales (1, 3 and 5 km radius around sampling sites). The decrease in species, abundance and functional richness of bats with forest loss may have implications for the ecological processes they carry out such as seed dispersal, pollination and insect predation, among others.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This study aimed to assess the impact of allicin on the course of diabetic nephropathy. Study groups included control, diabetes, and diabetes-treated rats. Allicin treatment (16 mg/kg day/p.o.) ...started after 1 month of diabetes onset and was administered for 30 days. In the diabetes group, the systolic blood pressure (SBP) increased, also, the oxidative stress and hypoxia in the kidney cortex were evidenced by alterations in the total antioxidant capacity as well as the expression of nuclear factor (erythroid-derived 2)-like 2/Kelch ECH associating protein 1 (Nrf2/Keap1), hypoxia-inducible factor 1-alpha (HIF-1α), vascular endothelial growth factor (VEGF), erythropoietin (Epo) and its receptor (Epo-R). Moreover, diabetes increased nephrin, and kidney injury molecule-1 (KIM-1) expression that correlated with mesangial matrix, the fibrosis index and with the expression of connective tissue growth factor (CTGF), transforming growth factor-β1 (TGF-β1), and α-smooth muscle actin (α-SMA). The insulin levels and glucose transporter protein type-4 (GLUT4) expression were decreased; otherwise, insulin receptor substrates 1 and 2 (IRS-1 and IRS-2) expression was increased. Allicin increased Nrf2 expression and decreased SBP, Keap1, HIF-1α, and VEGF expression. Concurrently, nephrin, KIM-1, the mesangial matrix, fibrosis index, and the fibrotic proteins were decreased. Additionally, allicin decreased hyperglycemia, improved insulin levels, and prevented changes in (GLUT4) and IRSs expression induced by diabetes. In conclusion, our results demonstrate that allicin has the potential to help in the treatment of diabetic nephropathy. The cellular mechanisms underlying its effects mainly rely on the regulation of antioxidant, antifibrotic, and antidiabetic mechanisms, which can contribute towards delay in the progression of renal disease.
Abstract
Objectives
The COVID-19 vaccination in autoimmune diseases (COVAD) study aimed to assess short-term COVID-19 vaccination-related adverse events (AEs) in RA patients.
Methods
An online ...self-reported questionnaire (March–December 2021) was used to capture data related to COVID-19 vaccination-related AEs in RA, other autoimmune rheumatic diseases (AIRDs) (excluding RA and inflammatory myositis), non-rheumatic autoimmune diseases (nrAIDs) and healthy controls (HCs). Descriptive and multivariable regression analyses were performed.
Results
Of the 9462 complete respondents, 14.2% (n = 1347) had been diagnosed with RA; they had a mean (s.d.) age of 50.7 (13.7) years, 74.2% were women and 49.3% were Caucasian. In total, 76.9% and 4.2% of patients with RA reported minor and major AEs, respectively. Patients with active and inactive RA had similar AE and hospitalization frequencies. Overall, AEs were reported more frequently by BNT162b2 and mRNA-1273 recipients and less frequently by BBV152 recipients compared with the rest. Major AE and hospitalization frequencies were similar across recipients of different vaccines. Patients receiving methotrexate and hydroxychloroquine reported fewer minor AEs than those patients not on them. Compared with HCs and patients with other AIRDs, patients with RA reported similar total AEs, overall minor AEs, and hospitalizations. Compared with nrAIDs, patients with RA reported lower frequencies of overall AEs, minor AEs (both odds ratio OR = 0.7; 95% CI: 0.5, 0.9), and injection site pain (OR = 0.6; 95% CI: 0.5, 0.8) with similar major AE and hospitalization frequencies.
Conclusion
Despite the differences in AE frequency across different COVID-19 vaccines, all were well tolerated in patients with RA and were comparable to HCs, providing reassurance as to the safety of COVID-19 vaccination.
Since epoxythymols occur in Nature either as scalemic mixtures or as pure enantiomers, the knowledge of their chiral composition and of the absolute configuration (AC) of the dominant enantiomer ...turns out to be mandatory. This task has already been faced using 1,1-bis-2-naphthol (BINOL), as a chiral solvating agent in accurate 1H NMR quantifications to determine the enantiomeric ratio, and vibrational circular dichroism (VCD) to evidence the AC of the dominant enantiomer. We now explore the use of electronic circular dichroism (ECD) to determine the AC of an epoxythymol for which time-expensive DFT calculations would be required unless the AC of a related molecule is already known, from either VCD studies or single-crystal X-ray diffraction analysis, since one could correlate the ECD Cotton effect with the AC because in ECD only chromophores and their neighborhoods are evidenced. This method is now applied by using the epoxythymols from Piptothrix areolare. Known areolal (1) and 10-cinnamoyloxy-8,9-epoxythymol isobutyrate (2) were isolated from the roots, while known 7-acetoxy-10-cinnamoyloxy-8,9-epoxythymol isobutyrate (3) and 10-cinnamoyloxy-7-hydroxy-8,9-epoxythymol isobutyrate (4), as well as the new enantiopure 7-acetoxy-10-cinnamoyloxy-6-hydroxy-8,9-epoxythymol isobutyrate (5) and 10-cinnamoyloxy-8,9-epoxy-6-hydroxy-7-northymol isobutyrate (6), were obtained from the extract of the flowers. Chemical correlation of epoxythymols 1 and 3 was achieved. Compounds 1–4 were obtained as scalemic mixtures, and 5 and 6 as the pure (8S) enantiomers. In addition, the new 10-cinnamoyloxy-7-oxo-8,9-dehydrothymol isobutyrate (7) was isolated from the roots. The structures of 5–7 followed from NMR and HRMS data, while enantiomeric compositions of 1–6 were determined by 1H NMR-BINOL measurements. The AC determination for 2–6 was done by ECD using a sample of 1 to reference the ECD Cotton effect. In turn, the AC of 1 was determined by VCD and extensive DFT calculations. The ECD-BINOL methodology turned out to be some 500 times more sensitive than that combining VCD and 1H NMR-BINOL.
The Resilient Dairy Genome Project (RDGP) is an international large-scale applied research project that aims to generate genomic tools to breed more resilient dairy cows. In this context, improving ...feed efficiency and reducing greenhouse gases from dairy is a high priority. The inclusion of traits related to feed efficiency (e.g., dry matter intake DMI) or greenhouse gases (e.g., methane emissions CH4) relies on available genotypes as well as high quality phenotypes. Currently, 7 countries (i.e., Australia, Canada, Denmark, Germany, Spain, Switzerland, and United States) contribute with genotypes and phenotypes including DMI and CH4. However, combining data are challenging due to differences in recording protocols, measurement technology, genotyping, and animal management across sources. In this study, we provide an overview of how the RDGP partners address these issues to advance international collaboration to generate genomic tools for resilient dairy. Specifically, we describe the current state of the RDGP database, data collection protocols in each country, and the strategies used for managing the shared data. As of February 2022, the database contains 1,289,593 DMI records from 12,687 cows and 17,403 CH4 records from 3,093 cows and continues to grow as countries upload new data over the coming years. No strong genomic differentiation between the populations was identified in this study, which may be beneficial for eventual across-country genomic predictions. Moreover, our results reinforce the need to account for the heterogeneity in the DMI and CH4 phenotypes in genomic analysis.
APOGEE view of the globular cluster NGC 6544 Gran, F; Zoccali, M; Rojas-Arriagada, A ...
Monthly notices of the Royal Astronomical Society,
07/2021, Letnik:
504, Številka:
3
Journal Article
Recenzirano
Odprti dostop
ABSTRACT
The second phase of the APOGEE survey is providing near-infrared (near-IR), high-resolution, high signal-to-noise spectra of stars in the halo, disc, bar, and bulge of the Milky Way. The ...near-IR spectral window is especially important in the study of the Galactic bulge, where stars are obscured by the dust and gas of the disc in its line of sight. We present a chemical characterization of the globular cluster NGC 6544 with high-resolution spectroscopy. The characterization of the cluster chemical fingerprint, given its status of ‘interloper’ towards the Galactic bulge and clear signatures of tidal disruption in its core is crucial for future chemical tagging efforts. Cluster members were selected from the DR16 of the APOGEE survey, using chemodynamical criteria of individual stars. A sample of 23 members of the cluster was selected. An analysis considering the intracluster abundance variations, known as anticorrelations is given. According to the red giant branch (RGB) content of the cluster, the iron content and α-enhancement are Fe/H = −1.44 ± 0.04 dex and α/Fe = 0.20 ± 0.04 dex, respectively. Cluster members show a significant spread in Fe/H and Al/Fe that is larger than expected based on measurement errors. An Al/Fe spread, signal of an Mg–Al anticorrelation is observed and used to constrain the cluster mass budget, along with C, N, Mg, Si, K, Ca, and Ce element variations discussed. Across all the analysed evolutionary stages (RGB and asymptotic giant branch), about ∼2/3 (14 out of 23) show distinct chemical patterns, possibly associated with second-generation stars.
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