We report on a blinded analysis of low-energy electronic recoil data from the first science run of the XENONnT dark matter experiment. Novel subsystems and the increased 5.9 ton liquid xenon target ...reduced the background in the (1, 30) keV search region to (15.8±1.3) events/(ton×year×keV), the lowest ever achieved in a dark matter detector and ∼5 times lower than in XENON1T. With an exposure of 1.16 ton-years, we observe no excess above background and set stringent new limits on solar axions, an enhanced neutrino magnetic moment, and bosonic dark matter.
We report on the first search for nuclear recoils from dark matter in the form of weakly interacting massive particles (WIMPs) with the XENONnT experiment, which is based on a two-phase time ...projection chamber with a sensitive liquid xenon mass of 5.9 ton. During the (1.09±0.03) ton yr exposure used for this search, the intrinsic ^{85}Kr and ^{222}Rn concentrations in the liquid target are reduced to unprecedentedly low levels, giving an electronic recoil background rate of (15.8±1.3) events/ton yr keV in the region of interest. A blind analysis of nuclear recoil events with energies between 3.3 and 60.5 keV finds no significant excess. This leads to a minimum upper limit on the spin-independent WIMP-nucleon cross section of 2.58×10^{-47} cm^{2} for a WIMP mass of 28 GeV/c^{2} at 90% confidence level. Limits for spin-dependent interactions are also provided. Both the limit and the sensitivity for the full range of WIMP masses analyzed here improve on previous results obtained with the XENON1T experiment for the same exposure.
The inappropriate use of antibiotics and the inadequate control of infections have led to the emergence of drug-resistant strains. In recent years, metallo-pharmaceutics and metallic nanoparticles ...have been proposed as potential alternative antimicrobials due to their broad-spectrum antimicrobial properties. Moreover, recent findings have shown that combinations of transition metal compounds can exhibit synergistic antimicrobial properties. Therefore, the synthesis and design of bimetallic nanoparticles is a field worth exploring to harness the interactions between groups of metals and organic complex structures found in different microbial targets, towards the development of more efficient combinatorial antimicrobials composed of synergistic metals. In this study, we present a green synthesis of Ag-Fe bimetallic nanoparticles using an aqueous extract from the leaves of Gardenia jasminoides. The characterization of the nanoparticles demonstrated that the synthesis methodology produces homogenously distributed core-shell Ag-Fe structures with spherical shapes and average diameter sizes of 13 nm (± 6.3 nm). The Ag-Fe bimetallic nanoparticles showed magnetic and antimicrobial properties; the latter were evaluated against six different, clinically relevant multi-drug-resistant microbial strains. The Ag-Fe bimetallic nanoparticles exhibited an antimicrobial (bactericidal) synergistic effect between the two metals composing the bimetallic nanoparticles compared to the effects of the mono-metallic nanoparticles against yeast and both Gram-positive and Gram-negative multidrug-resistant bacteria. Our results provide insight towards the design of bimetallic nanoparticles, synthesized through green chemistry methodologies, to develop synergistic combinatorial antimicrobials with possible applications in both industrial processes and the treatment of infections caused by clinically relevant drug-resistant strains.
Aging is a physiological decline process. The number of older adults is growing around the world; therefore, the incidence of cognitive impairment, dementia, and other diseases related to aging ...increases. The main cellular factors that converge in the aging process are mitochondrial dysfunction, antioxidant impairment, inflammation, and immune response decline, among others. In this context, these cellular changes have an influence on the kynurenine pathway (KP), the main route of tryptophan (Trp) catabolism. KP metabolites have been involved in the aging process and neurodegenerative diseases. Although there are changes in the metabolite levels with age, at this time, there is no study that has evaluated cognitive decline as a consequence of Trp catabolism fluctuation in aging. The aim of this study was to evaluate the relation between the changes in Trp catabolism and cognitive impairment associated with age through KP metabolites level alterations in women over 50 years of age. Seventy-seven nondemented women over 50 years old were examined with a standardized cognitive screening evaluation in Spanish language (Neuropsi), Beck anxiety inventory (BAI), and the geriatric depression scale (GDS). Also, serum levels of Trp, kynurenine (Kyn), kynurenic acid (KYNA), and 3-hydroykynurenine (3-HK) and the glutathione ratio (GSH/GSSG) were measured. Results showed a negative correlation between age and Trp levels and a positive correlation between age and KYNA/Trp and 3-HK/Trp ratios. The level of cognitive impairment showed a significant positive association with age and with kynurenine pathway activation and a significant negative correlation with Trp levels. The GSH/GSSG ratio correlated positively with Trp levels and negatively with Kyn/Trp and 3-HK/Trp ratios. The depression score correlated negatively with Trp and positively with the 3-HK/Trp ratio. We concluded that KP activation increases with age and it is strongly associated with the level of cognition performance in nondemented women over 50 years of age.
This work proposed a controlled method to modify the physicochemical properties of corn starch through heating and cooling extrusion (HCE) cycles. It was used native corn starch adjusted to 60% ...moisture. It was then subjected to 5 HCE cycles at 100 and 125 °C, at 10 rpm. Water absorption index (WAI), water solubility index (WSI), resistant starch (RS), thermal properties, viscosity, FTIR, and X-ray were evaluated. For WAI and WSI, a gradual increase was observed on each HCE cycle. Thermal properties shown that enthalpy decrease with each HCE cycles due to more gelatinization. Viscosity properties shown a thermally stable starch conditions being directly proportional to HCE cycles. The RS increased for each 5 HCE. XRD revealed that HCE cycle changed the starch structure from an orthorhombic structure to V-type crystalline structure. Finally, it was concluded that HCE cycles is a method to produce corn starch with controlled physicochemical properties.
•Extrusion heating-cooling cycles (EHCC) change and sharpen the crystalline structure of corn starch.•HCE cycle modifies the resistant starch (RS) percentage.•HCE cycle increases the starch's water absorption and solubility indexes.•HCE cycles decreased the gelatinization enthalpy.•HCE cycles produced a retrograded thermally stable starch.
•A novel room-temperature, one-step, high-yield and green route of Al-doped HfO2 NPs.•Viability and survival of normal human prostate epithelial cells exposed to c-HfO2.•c-HfO2 and Al-doped HfO2 NPs ...are non-toxic for normal prostate tissue.
Al-doped HfO2 nanoparticles were prepared at room-temperature using a novel one-step, straightforward, high-yield, efficient and green process. It includes a mechanically activated metathesis reaction that promotes the direct crystallization of cubic HfO2 (c-HfO2) in milling. Al-cation was used as dopant, achieving c-HfO2 stabilization at low content (5% mol). The c-HfO2 is stable up to 380 °C without exhibiting transformation from the cubic to monoclinic polymorph. The c-HfO2 showed spherical-like morphology with diameter below 7 nm. Human Prostate Epithelial Cells (HPrEC) were used to evaluate nanoparticles toxicity. Cells viability and survival were determined performing MTS and colony formation assays. Nanoparticles were found harmless for cells metabolic activity at concentrations up to 1000 μg/mL. A decrease of ~30% on HPrEC plating efficiency was observed at the highest concentration.
Abstract Major depression might originate from both environmental and genetic risk factors. The environmental chronic mild stress (CMS) model mimics some environmental factors contributing to human ...depression and induces anhedonia and helplessness. Mice heterozygous for the synaptic vesicle protein (SVP) vesicular glutamate transporter 1 (VGLUT1) have been proposed as a genetic model of deficient glutamate function linked to depressive-like behaviour. Here, we aimed to identify, in these two experimental models, gene expression changes in the frontal cortex, common to stress and impaired glutamate function. Both VGLUT1+/− and CMS mice showed helpless and anhedonic-like behavior. Microarray studies in VGLUT1+/− mice revealed regulation of genes involved in apoptosis, neurogenesis, synaptic transmission, protein metabolic process or learning and memory. In addition, RT-PCR studies confirmed gene expression changes in several glutamate, GABA, dopamine and serotonin neurotransmitter receptors. On the other hand, CMS affected the regulation of 147 transcripts, some of them involved in response to stress and oxidoreductase activity. Interestingly, 52 genes were similarly regulated in both models. Specifically, a dowregulation in genes that promote cell proliferation (Anapc7), cell growth (CsnK1g1), cell survival (Hdac3), and inhibition of apoptosis (Dido1) was observed. Genes linked to cytoskeleton (Hspg2, Invs), psychiatric disorders (Grin1, MapK12) or an antioxidant enzyme (Gpx2) were also downregulated. Moreover, genes that inhibit the MAPK pathways (Dusp14), stimulate oxidative metabolism (Eif4a2) and enhance glutamate transmission (Rab8b) were upregulated. We suggest that these genes could form part of the altered “molecular context” underlying depressive-like behaviour in animal models. The clinical relevance of these findings is discussed.
The main aim of the present study was to characterize banana starch films reinforced with nanoparticles from plantain rachis. Nanoparticles were obtained by acid hydrolysis and sonication, exhibiting ...a mean hydraulic diameter of about 60 nm. Scanning electron microscopy micrographs showed that the nanoparticle thickness ranged between 9.8 and 22.3 nm. The thermal gravimetric analysis showed that nanoparticles are thermally stable for temperatures up to 340 °C. Films were made for different fractions of nanoparticles (0.0, 1.75, 2.5, and 4.0%) relative to total solids, and glycerol was used as a plasticizer. The influence of the addition of nanoparticles to starch films on the morphology, water vapor permeability (WVP), and mechanical properties of the nanocomposites films was explored. Cellulose nanoparticles reduced the WVP, and increased the tensile strength and flexibility of the starch films. FTIR analysis of films was used to show that nanoparticles improved the molecular organization of starch chains. It was proposed that nanoparticles acted as a crosslinked for starch chains via hydrogen bonding effects.
•Cellulose nanoparticles size from banana rachis (61 nm) were comparable to commercial cellulose nanoparticles (50–143 nm).•Nanoparticles enhanced mechanical properties of starch films.•FTIR showed that OH binding of nanoparticles and starch chains are likely occurring.
Purpose: To evaluate the effect of three concentrations of bismuth trioxide (Bi2O3) on the biological and physicochemical properties of an experimental mineral trioxide aggregate-type (MTA-type) ...cement at different time points.Methods: Three experimental groups with white Portland cement containing 15, 20, or 25 wt% of Bi2O3 were assessed. Cellular proliferation in human periodontal ligament fibroblasts was evaluated with an MTT assay. Radiopacity, dimensional stability, pH, and compressive strength were evaluated at different time points.Results: Bismuth trioxide induced cell proliferation in the Bi15 and Bi25 groups in a time-dependent manner; pH was similar in all groups. Compressive strength was associated with time and bismuth concentration. Bi25 had significantly contracted at day 7 and expanded at day 14 (ANOVA P < 0.05, post hoc Tukey test P < 0.05).Conclusion: A higher Bi2O3 concentration had a negative effect on the physical properties of the cement at all time points.
Atmospheric aerosol particles that can nucleate ice are referred to as ice-nucleating particles (INPs). Recent studies have confirmed that aerosol particles emitted by the oceans can act as INPs. ...This very relevant information can be included in climate and weather models to predict the formation of ice in clouds, given that most of them do not consider oceans as a source of INPs. Very few studies that sample INPs have been carried out in tropical latitudes, and there is a need to evaluate their availability to understand the potential role that marine aerosol may play in the hydrological cycle of tropical regions.
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