The electrochemical polymerization of polypyrrole nanowires is carried out using potentiodynamic and galvanostatic methods in order to enhance the performance of the modified electrodes as capacitor ...devices. The electrochemical, spectroscopic, and morphological properties are determined through cyclic voltammetry, Raman spectroscopy and scanning electron microscopy, respectively, corroborating the presence of PPy-nw in dimensions of 30 nm in diameter. Characterization as a capacitor revealed that the nanowire structure enhances key parameters such as specific capacitance with 60 times greater value than bulk polymer modification, in addition to a significant increase in stability. In this way, it is verified that electrodes modified with polypyrrole nanowires obtained in situ by electrochemical methods constitute an excellent candidate for the development of capacitors.
Highlights • EGCG favors the survival of newborn neurons in the hippocampus. • EGCG is proneurogenic upon adult hippocampal precursor cells in culture. • EGCG might act through phospho-Akt.
We studied the effect of silymarin and dimercaptosuccinic acid (DMSA), a chelating agent that was administered individually or in combination against lead (Pb) toxicity in rats. Wistar rats (200 ± ...20) were randomly divided into five groups. Group A served as a control. Groups B–E were exposed to 2000 ppm of lead acetate in drinking water for 8 weeks. Group B served as a positive control. Group C received silymarin (100 mg kg−1 orally) for 8 weeks. Group D received DMSA (75 mg kg−1 orally) once daily for the last 5 days of treatment. Group E received DMSA and silymarin as groups C and D, respectively. The effect of Pb was evaluated and accordingly the treatments on blood lead levels (BLLs), renal system, and genotoxic effects were calculated using comet assay. The BLLs were significantly increased following the exposition of lead acetate. The administration of silymarin and DMSA provided reduction in BLLs. Silymarin and DMSA provided significant protection on the genotoxic effect of Pb. The toxic effect of Pb on kidneys was also studied. Our data suggest that silymarin and DMSA improve the renal histopathological lesions.
We present double-differential measurements of antineutrino charged-current quasielastic scattering in the MINERvA detector. This study improves on a previous single-differential measurement by using ...updated reconstruction algorithms and interaction models and provides a complete description of observed muon kinematics in the form of a double-differential cross section with respect to muon transverse and longitudinal momentum. We include in our signal definition zero-meson final states arising from multinucleon interactions and from resonant pion production followed by pion absorption in the primary nucleus. We find that model agreement is considerably improved by a model tuned to MINERvA inclusive neutrino scattering data that incorporates nuclear effects such as weak nuclear screening and two-particle, two-hole enhancements.
This work is focused on the structural, thermal and mechanical studies of direct polycondensation of poly (lactic acid) (PLA) modified with three different chain extenders ...(1,3-phenylene-bis-2-oxazoline, PBO; pyromellitic dianhydride, PMDA; and 1,1′-carbonyl bis caprolactam, CBC). Three concentrations of PBO, PMDA and CBC chain extenders (0.2, 0.5 and 1 wt%) were added during three stages (S): monomer dehydration (80 °C, S1), oligomer polycondensation (130 °C, S2) and melt polycondensation (160 °C, S3). FTIR, Raman and
1
H-NMR spectroscopies revealed the presence of signals produced by interactions between OH and C=O end groups of PLA and reactive functional groups of chain extenders. It was found that the interaction with the PMDA chain extender decreased the PLA crystallinity. Furthermore, data from thermal analysis revealed that the interaction between PLA and chain extenders increased the chain mobility, which represented a decrease in its
T
g
. Enhanced mechanical properties, hardness, elastic modulus and indentation creep were observed with the addition of chain extenders, improving the performance with the addition of 1 wt% of PBO at S3, 1 wt% of PMDA at either S2 or S3 and 0.25 wt% of CBC at either S2 or S3. Additionally to the synthesis, the degradation was mainly influenced by the interaction more than by any specific stage of chain extender addition. Finally, the thermal and structural characterizations revealed that the PLA-PBO, PLA-PMDA and PLA-CBC systems were more resistant than PLA to UV light and humidity during the accelerated weathering test.
Final-state kinematic imbalances are measured in mesonless production of νμ+A→μ-+p+X in the MINERvA tracker. Initial- and final-state nuclear effects are probed using the direction of the μ- - p ...transverse momentum imbalance and the initial-state momentum of the struck neutron. Differential cross sections are compared to predictions based on current approaches to medium modeling. These models underpredict the cross section at intermediate intranuclear momentum transfers that generally exceed the Fermi momenta. As neutrino interaction models need to correctly incorporate the effect of the nucleus in order to predict neutrino energy resolution in oscillation experiments, this result points to a region of phase space where additional cross section strength is needed in current models, and demonstrates a new technique that would be suitable for use in fine-grained liquid argon detectors where the effect of the nucleus may be even larger.
A randomized controlled phase I/II clinical trial was designed to evaluate the safety and efficacy of encapsulated human umbilical cord mesenchymal stem cells in a plasma-derived biomaterial for ...regenerative endodontic procedures (REPs) in mature permanent teeth with apical lesions. The trial included 36 patients with mature incisors, canines, or mandibular premolars showing pulp necrosis and apical periodontitis. Patients were randomly and equally allocated between experimental (REP) or conventional root canal treatment (ENDO) groups. On the first visit, cavity access and mechanical preparation of the root canal were performed. Calcium hydroxide medication was used, and the cavity was sealed. Three weeks later, patients were treated following their assigned protocol of ENDO or REP. Clinical follow-up examinations were performed at 6 and 12 mo. Categorical variables were evaluated by Fisher’s exact test. Quantitative variables were compared using the Mann-Whitney test. The evolution over time of the percentage of perfusion units and the dimensions of lesion and cortical compromise were explored. After the 12-mo follow-up, no adverse events were reported, and the patients showed 100% clinical efficacy in both groups. Interestingly, in the REP group, the perfusion unit percentage measured by laser Doppler flowmetry revealed an increase from 60.6% to 78.1% between baseline and 12-mo follow-up. Sensitivity tests revealed an increase of the positive pulp response in the REP group at 12-mo follow-up (from 6% to 56% on the cold test, from 0% to 28% on the hot test, and from 17% to 50% on the electrical test). We present the first clinical safety and efficacy evidence of the endodontic use of allogenic umbilical cord mesenchymal stem cells encapsulated in a plasma-derived biomaterial. The innovative approach, based on biological principles that promote dentin-pulp regeneration, presents a promising alternative for the treatment of periapical pathology (ClinicalTrials.gov NCT03102879).
Elastic neutrino scattering on electrons is a precisely known purely leptonic process that provides a standard candle for measuring neutrino flux in conventional neutrino beams. Using a total sample ...of 810 neutrino-electron scatters after background subtraction, the measurement reduces the normalization uncertainty on the ν μ NuMI beam flux between 2 and 20 GeV from 7.6 to 3.9%. This is the most precise measurement of neutrino-electron scattering to date, will reduce uncertainties on MINER ν A's absolute cross section measurements, and demonstrates a technique that can be used in future neutrino beams such as long baseline neutrino facility.
•Reliable, cost-effective and high-performance in vitro detection system for COVID-19.•Novel optical multiplexed In-Vitro detection system to identify IgGs, IgMs and IgAs against SARS-COV-2 in serum ...and saliva.•Reliable and rapid tool for screening infected people with or without symptoms.•A real alternative to be used periodically to early detection, surveillance and immunity control of COVID-19.
The standard rapid approach for the diagnosis of coronavirus disease 2019 (COVID-19) is the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA. The detection of specific anti-SARS-CoV-2 immunoglobulins is crucial for screening people who have been exposed to the virus, whether or not they presented symptoms. Recent publications report different methods for the detection of specific IgGs, IgMs, and IgAs against SARS-CoV-2; these methods mainly detect immunoglobulins in the serum using conventional techniques such as rapid lateral flow tests or enzyme-linked immunosorbent assay (ELISA). In this article, we report the production of recombinant SARS-CoV-2 spike protein and the development of a rapid, reliable, cost-effective test, capable of detecting immunoglobulins in serum and saliva samples. This method is based on interferometric optical detection. The results obtained using this method and those obtained using ELISA were compared. Owing to its low cost and simplicity, this test can be used periodically for the early detection, surveillance, detection of immunity, and control of the spread of COVID-19.
Macromolecules are essential cellular components in biological systems responsible for performing a large number of functions that are necessary for growth and perseverance of living organisms. ...Proteins, lipids and carbohydrates are three major classes of biological macromolecules. To predict the structure, function, and behaviour of any cluster of macromolecules, it is necessary to understand the interaction between them and other components through basic principles of chemistry and physics. An important number of macromolecules are present in mixtures with surfactants, where a combination of hydrophobic and electrostatic interactions is responsible for the specific properties of any solution. It has been demonstrated that surfactants can help the formation of helices in some proteins thereby promoting protein structure formation. On the other hand, there is extensive research towards the use of surfactants to solubilize drugs and pharmaceuticals; therefore, it is evident that the interaction between surfactants with macromolecules is important for many applications which includes environmental processes and the pharmaceutical industry. In this review, we describe the properties of different types of surfactants that are relevant for their physicochemical interactions with biological macromolecules, from macromolecules–surfactant complexes to hydrophobic and electrostatic interactions.
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