Histone–DNA interactions were probed computationally at a molecular level, by characterizing the bimolecular clusters constituted by selected amino acid derivatives with polar (asparagine and ...glutamine), nonpolar (alanine, valine, and isoleucine), and charged (arginine) side chains and methylated pyrimidinic (1-methylcytosine and 1-methylthymine) and puric (9-methyladenine and 9-methylguanine) DNA bases. The computational approach combined different methodologies: a molecular mechanics (MMFFs forced field) conformational search and structural and vibrational density-functional calculations (M06-2X with double and triple-ζ Pople’s basis sets). To dissect the interactions, intermolecular forces were analyzed with the Non-Covalent Interactions (NCI) analysis. The results for the 24 different clusters studied show a noticeable correlation between the calculated binding energies and the propensities for protein–DNA base interactions found in the literature. Such correlation holded even for the interaction of the selected amino acid derivatives with Watson and Crick pairs. Therefore, the balance between hydrogen bonds and van der Waals interactions (specially stacking) in the control of the final shape of the investigated amino acid–DNA base pairs seems to be well reproduced in dispersion-corrected DFT molecular models, reinforcing the idea that the specificity between the amino acids and the DNA bases play an important role in the regulation of DNA.
We study the structure and tectonics of the collision zone between the Nazca Ridge (NR) and the Peruvian margin constrained by seismic, gravimetric, bathymetric, and natural seismological data. The ...NR was formed in an on‐ridge setting, and it is characterized by a smooth and broad shallow seafloor (swell) with an estimated buoyancy flux of ~7 Mg/s. The seismic results show that the NR hosts an oceanic lower crust 10–14 km thick with velocities of 7.2–7.5 km/s suggesting intrusion of magmatic material from the hot spot plume to the oceanic plate. Our results show evidence for subduction erosion in the frontal part of the margin likely enhanced by the collision of the NR. The ridge‐trench collision zone correlates with the presence of a prominent normal scarp, a narrow continental slope, and (uplifted) shelf. In contrast, adjacent of the collision zone, the slope does not present a topographic scarp and the continental slope and shelf become wider and deeper. Geophysical and geodetic evidence indicate that the collision zone is characterized by low seismic coupling at the plate interface. This is consistent with vigorous subduction erosion enhanced by the subducting NR causing abrasion and increase of fluid pore pressure at the interplate contact. Furthermore, the NR has behaved as a barrier for rupture propagation of megathrust earthquakes (e.g., 1746 Mw 8.6 and 1942 Mw 8.1 events). In contrast, for moderate earthquakes (e.g., 1996 Mw 7.7 and 2011 Mw 6.9 events), the NR has behaved as a seismic asperity nucleating at depths >20 km.
Key Points
The Nazca Ridge hosts an overthickened lower crust (10–14 km) formed in an on‐ridge setting (hot spot plume near a spreading center)
The Nazca Ridge correlates with a prominent continental slope scarp bounded by a narrow and uplifted continental shelf
The Nazca Ridge has behaved as a seismic asperity for moderate earthquakes (e.g., 1996 Mw 7.7 and 2011 Mw 6.9) nucleating at depths >20 km
In this study, we synthesized and characterized pH-responsive Chitosan–AgCl-doped ZnO hybrid hydrogels and evaluated their potential for loading aquaculture bioactive compounds, and assessed their ...antimicrobial properties against a threatening pathogen associated with disease across a broad spectrum of warm water fish and invertebrates. Hydrogel characterization consisted of assessing morphology via SEM, composition via EDS, hydrogels’ network components interactions via FT-IR and pH response through swelling behavior determinations. The swelling characterization of the synthesized hydrogels demonstrated a pH-responsive behavior, showing that low pH values caused the hydrogel polymeric network to expand and capture more of the aqueous solution. These characteristics make the synthesized hydrogels suitable for the encapsulation and controlled release of drugs and bioactive compounds in aquaculture. Chitosan_ZnO hybrid hydrogels showed great antimicrobial activity against Vibrio harveyi, even better than that of loaded PB hydrogels. Here, we provide evidence for the potential capacity of Chitosan_ZnO hybrid hydrogels for the preventive and curative treatment of diseases that impact aquaculture animal health and prevent drug resistance by bacteria.
Genomics has significantly revolutionized pathogen surveillance, particularly in epidemiological studies, the detection of drug-resistant strains, and disease control. Despite its potential, the ...representation of Latin American countries in the genomic catalogues of Mycobacterium tuberculosis (Mtb), the bacteria responsible for Tuberculosis (TB), remains limited. In this study, we present a whole genome sequencing (WGS)-based analysis of 85 Mtb clinical strains from 17 Mexican states, providing insights into local adaptations and drug resistance signatures in the region. Our results reveal that the Euro-American lineage (L4) accounts for 94% of our dataset, showing 4.1.2.1 (Haarlem, n = 32), and 4.1.1.3 (X-type, n = 34) sublineages as the most prevalent. We report the presence of the 4.1.1.3 sublineage, which is endemic to Mexico, in six additional locations beyond previous reports. Phenotypic drug resistance tests showed that 34 out of 85 Mtb samples were resistant, exhibiting a variety of resistance profiles to the first-line antibiotics tested. We observed high levels of discrepancy between phenotype and genotype associated with drug resistance in our dataset, including pyrazinamide-monoresistant Mtb strains lacking canonical variants of drug resistance. Expanding the Latin American Mtb genome databases will enhance our understanding of TB epidemiology and potentially provide new avenues for controlling the disease in the region.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
Dehydration of the oceanic subducting slab promotes the formation of magmatic arcs, intra-slab intermediate-depth seismicity, and hydration of the overlying mantle wedge. However, the ...complex permeability structure of the overriding plate controls the magma and fluid migration and their accumulation at shallower depths. In this regard, mapping the inner structure of the overriding crust and mantle is crucial to understand the magmatic and hydrological processes in subduction zones. We integrate 3-D P-wave,
$$V_p/V_s$$
V
p
/
V
s
, and electrical resistivity tomographic models of the northern Chilean subduction zone to map the magmatic and fluids derived from the subducting oceanic Nazca plate. Results show a continental crust relatively thick (50–65 km) characterized by a lower zone of high
$$V_p$$
V
p
values (7.2–7.6 km/s), which is interpreted as the presence of plutonic rocks. The mantle lithospheric wedge is weakly hydrated (
$$V_p/V_s$$
V
p
/
V
s
= 1.75–1.8) while the forearc continental crust is traversed by regions of reduced electrical resistivity values (
$$< 10^2$$
<
10
2
$$\Omega m$$
Ω
m
) interpreted as zones of relatively high permeability/fracturing and fluid content. These regions spatially correlate with upper plate trans-lithospheric deformation zones. Ascending melts accumulate preferentially in the back-arc, whereas hydrothermal systems form trenchward of the volcanic arc. The results highlight the complex permeability structure of the upper South American plate.
On 17 August 2017, gravitational waves (GWs) were detected from a binary neutron star merger, GW170817, along with a coincident short gamma-ray burst, GRB 170817A. An optical transient source, Swope ...Supernova Survey 17a (SSS17a),was subsequently identified as the counterpart of this event. We present ultraviolet, optical, and infrared light curves of SSS17a extending from 10.9 hours to 18 days postmerger. We constrain the radioactively powered transient resulting from the ejection of neutron-rich material. The fast rise of the light curves, subsequent decay, and rapid color evolution are consistent with multiple ejecta components of differing lanthanide abundance. The late-time light curve indicates that SSS17a produced at least ~0.05 solar masses of heavy elements, demonstrating that neutron star mergers play a role in rapid neutron capture (r-process) nucleosynthesis in the universe.
Background
Pituitary adenomas (PA) are neoplasms of pituitary adenohypophyseal cell lineage, which are the third most common cause of brain tumors among adults. Due to hormone secretion, PAs are ...closely related to metabolic syndrome (MetS). However, the relationship between these two entities has been scarcely studied to date.
Purpose
This paper aims to evaluate changes in the metabolic status of patients with PA before and after surgical treatment and to look for differences in metabolic outcomes among patients according to the adenoma type and the surgery success rate.
Methods
We assessed patients with PA who went through transsphenoidal surgery for its treatment, documenting metabolic parameters before and after surgery, analyzed whole sample changes, and then stratified them according to adenoma type (nonfunctioning, somatotroph, lactotroph, and corticotroph), and surgery success (total resection, near-total resection, partial resection, subtotal resection).
Results
A total of 214 patients were enrolled for this study. The prevalence of MetS with AACE criteria went from 51.52% before surgery to 28.99% after surgery (
P
< 0.001). Hyperglycemia (HG) was the most beneficial component; it went from 56% pre-surgery to 40.51% post-surgery (
P
= 0.03). The total resection group had the best improvement, with a significant decrease of prevalence in MetS from 83 to 16% (
P
< 0.001), and every component, except hypoalphalipoproteinemia (HA): obesity went from 96 to 67% (
P
< 0.001), arterial hypertension (AH) 59 to 24% (
P
< 0.001), HG 74 to 23% (
P
< 0.001), and hypertriglyceridemia (HTG) from 81 to 54% (
P
< 0.001). According to MetS prevalence, there was no difference in the improvement according to PA type.
Conclusion
Surgical treatment in patients with PA is associated with MetS improvement.
Purpose
The effect of the sodium-glucose 2 (SGLT-2) inhibitors on microvascular complications remains uncertain. We performed a systematic review to determine the efficacy of the SGLT-2 inhibitors on ...microvascular outcomes in patients with type 2 diabetes.
Methods
A comprehensive search was performed using Ovid, MEDLINE, EMBASE, Web of Science, and Scopus from inception to May 2019. Randomized trials comparing SGLT-2 inhibitors with placebo or other medication for type 2 diabetes for ≥ 4 weeks were included. Diabetes-related microvascular complications such as nephropathy, retinopathy, neuropathy, and peripheral vascular disease were evaluated. A random-effect model using mean differences for continuous outcomes and risk ratio for dichotomous outcomes was used to synthesize data. PROSPERO (CRD 42017076460).
Results
A total of 40 RCTs with overall moderate quality of evidence were included. SGLT-2 inhibitors reduced the risk of renal-replacement therapy (0.65; 95% CI 0.54–0.79), renal death (0.57; 95% CI 0.49–0.65), and progression of albuminuria (0.69; 95% CI 0.66–0.73). Conversely, they appeared ineffective in maintaining eGFR (0.33; 95% CI − 0.74 to 1.41) or reducing serum creatinine (− 0.07; 95% CI − 0.26 to 0.11), whereas urine albumin–creatinine ratio (− 23.4; 95% CI − 44.6 to − 2.2) was reduced. Risk of amputation was non-significant (1.30; 95% CI 0.93–1.83). No available data were found regarding neuropathy and retinopathy to perform a quantitative analysis.
Conclusion
SGLT-2 inhibitors may reduce the risk of renal patient-important outcomes but fail to improve surrogate outcomes. Apparently, no increased risk of amputations was observed with these medications. No data were available regarding other microvascular complications.
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•Oxidative desulfurization of model diesel was tested in a biphasic system.•ODS activity was proportional to the V5+/(V4++V5+) values of the catalysts.•Lewis acidity was related to ...vanadium content and catalytic activity.•99.9% DBT was oxidized using 25%V2O5/Ti-MCM-41 at 60°C within 60min.
A series of vanadium oxide supported on Ti-MCM-41 catalysts was synthesized via the incipient impregnation method by varying the vanadia loading from 5wt% to 10, 15, 20 and 25wt%. These catalysts were characterized by a variety of advanced techniques for investigating their crystalline structure, textural properties, and surface chemistry information including surface acidity, reducibility, vanadium oxidation states, and morphological features. The catalytic activities of the catalysts were evaluated in a biphasic reaction system for oxidative desulfurization (ODS) of a model diesel containing 300ppm of dibenzothiophene (DBT) where acetonitrile was used as extraction solvent and H2O2 as oxidant. ODS activity was found to be proportional to the V5+/(V4++V5+) values of the catalysts, indicating that the surface vanadium pentoxide (V2O5) was the active phase. Reaction temperature would influence significantly the ODS efficiency; high temperature, i.e., 80°C, would lead to low ODS reaction due to the partial decomposition of oxidant. All the catalysts contained both Lewis and Brønsted acid sites but the former was predominant. The catalysts with low vanadia loading (5 or 10 wt%V2O5) had many Lewis acid sites and could strongly adsorb DBT molecule via the electron donation/acceptance action which resulted in an inhibition for the reaction of DBT with the surface peroxometallic species. The catalyst with high vanadia loading (25wt%V2O5/Ti-MCM-41) showed the highest catalytic activity and could remove 99.9% of DBT at 60°C within 60min.
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