Plasmodium falciparum is sensitive to oxidative stress in vitro and in vivo, and many drugs such as artemisinin, chloroquine and cercosporin interfere in the parasite's redox system. To minimize the ...damage caused by reactive radicals, antioxidant enzymes and their substrates found in parasites and in erythrocytes must be functionally active. It was shown that P. falciparum synthesizes vitamin E and that usnic acid acts as an inhibitor of its biosynthesis. Vitamin E is a potent antioxidant that protects polyunsaturated fatty acids from lipid peroxidation, and this activity can be measured by detecting its oxidized product and by evaluating reactive oxygen species (ROS) levels.
Here, we demonstrated that ROS levels increased in P. falciparum when vitamin E biosynthesis was inhibited by usnic acid treatment and decreased to basal levels if exogenous vitamin E was added. Furthermore, we used metabolic labelling to demonstrate that vitamin E biosynthesized by the parasite acts as an antioxidant since we could detect its radiolabeled oxidized product. The treatment with chloroquine or cercosporin of the parasites increased the ratio between α-tocopherolquinone and α-tocopherol.
Our findings demonstrate that vitamin E produced endogenously by P. falciparum is active as an antioxidant, probably protecting the parasite from the radicals generated by drugs.
•Theoretical study of the semiclassical lattice Boltzmann method.•Expansion of Fermi-Dirac and Bose-Einstein distributions up to fourth order.•Hydrodynamic equations for semiclassical ...fluids.•Development and test of an isothermal model for electrons in metals in 2D and 3D.
We determine properties of the lattice Boltzmann method for semiclassical fluids, which is based on the Boltzmann equation and on an equilibrium distribution function given either by the Bose–Einstein or the Fermi–Dirac distributions. New D-dimensional polynomials, that generalize the Hermite ones, are introduced and we find that the weight that renders the polynomials orthonormal has to be approximately equal, or equal, to the equilibrium distribution function itself for an efficient numerical implementation of the lattice Boltzmann method. In light of the new polynomials we discuss the convergence of the series expansion of the equilibrium distribution function and the obtainment of the hydrodynamic equations. A discrete quadrature is proposed and some discrete lattices in one, two and three dimensions associated to weight functions other than the Hermite weight are obtained. We derive the forcing term for the LBM, given by the Lorentz force, which dependents on the microscopic velocity, since the bosonic and fermionic particles can be charged. Motivated by the recent experimental observations of the hydrodynamic regime of electrons in graphene, we build an isothermal lattice Boltzmann method for electrons in metals in two and three dimensions. This model is validated by means of the Riemann problem and of the Poiseuille flow. As expected for electron in metals, the Ohm’s law is recovered for a system analogous to a porous medium.
Effects on strength performance and muscle activation in the contralateral limb have been observed after training with the ipsilateral limb (IL). Cross fatigue effects in the contralateral limb (CL) ...can occur at intervals of up to 48 h after a training session performed with the ipsilateral limb. The objective of this study was to verify the effect of a training session in the ipsilateral limb, on the strength and activation of the muscles in the contralateral limb also submitted to the training protocol.
10 untrained men (mean ± SD: age = 23.7 ± 4.9 years) performed unilateral knee extension with both limbs in equated protocols, in two conditions with different intervals between limbs – 20 min and 24 h.
There were no differences in the comparison of the force produced between the pre x post interventions with the CL limb, as well as in the activation of the quadriceps during its performance. These results were similar for the two different intervals between the protocols.
It was concluded that when the CL member performs the protocol after the IL, the responses in the CL depend mainly on the requirement imposed on the protocol performed by this member, without influence of the training protocol performed previously with the IL member.
We propose a blind adaptive reduced-rank widely linear beamforming algorithm using the generalized sidelobe canceller structure for interference suppression. A structured Krylov-subspace-based ...approach is devised to construct the dimensionality reducing transformation matrix, and a recursive least-squares algorithm is developed according to the widely linear constrained constant modulus criterion to update the reduced-rank filter. We analyze the convergence and complexity of the proposed algorithm and validate its performance gains through simulations.
Different cellular mechanisms have been described as being potentially involved in the progression of neurodegeneration in Parkinson's disease, although their role is still unclear. The present study ...aimed to identify in detail, through differentially expressed genes analysis by bioinformatics approaches, the molecular mechanisms triggered after a systemic insult in parkinsonian mice. To address this objective, we combined a dextran sodium sulfate (DSS)-induced ulcerative colitis experimental mice model with an acute 1-methyl-4-phenyl-1,2,3,6-tetradropyridine (MPTP) intoxication. The animals were divided into four experimental groups based on the different treatments: (i) control, (ii) DSS, (iii) MPTP and (iv) MPTP + DSS. The data obtained by microarray and functional enrichment analysis point out the implication of different molecular mechanisms depending on the experimental condition. We see, in the striatum of animals intoxicated only with DSS, dysfunction processes related to the blood. On the other hand, oxidative stress processes are more prominent at the MPTP intoxicated mice. Finally, differentially expressed genes within the MPTP + DSS show functional enrichment in inflammation and programmed cell death. Interestingly, we identify a significant synergistic negative effect of both toxins since the expression of differentially expressed genes (DEGs) related to balanced cellular homeostasis was not enough to prevent processes associated with cell death. This work provides detailed insights into the involvement of systemic inflammation, triggered after an insult in the colon, in the progression of the degeneration in Parkinsonism. In this way, we will be able to identify promising therapeutic targets that prevent the contribution of inflammatory processes in the progression of Parkinson's disease.
Titanium and its alloys have been routinely used to replace bone and teeth. This success is mainly due to their remarkable clinical response, mechanical properties, chemical stability and appropriate ...biocompatibility associated to a titanium dioxide (TiO2) layer. Chemically, the TiO2 surface is mostly terminated by OH groups. An increased amount of reactive OH groups can be obtained by UV radiation treatment on TiO2 surface, which can be readily functionalized with bifunctional organic molecules. Among the several types of organic molecules available for reaction with OH groups, bisphosphonates (BP) have been associated with a positive effect on new bone formation. In this way, the present contribution aims at giving an overview study from the physicochemical properties of two distinct BP (alendronate and risedronate), immobilized on the titanium surface containing hydroxylated TiO2 film by UV radiation. Surface properties such as contact angle, surface free energy and topography/roughness were evaluated. In addition, biocompatibility and mineralization tests performed with osteoblastic-like cells are presented to evaluate the potential of these functional materials to be applied in the dentistry and orthopedics fields. The results suggest that the UV treatment increased the surface wettability and allowed an oriented immobilization of BP. In addition, the BP functionalized surfaces exhibited high viability and mineralization of pre-osteoblast cells. Therefore, these compounds emerge as a potential treatment on implants surfaces.
•UV treatment increased the surface wettability.•UV treatment allowed an oriented immobilization of BP.•BP functionalized surfaces exhibited high viability and mineralization of pre-osteoblast cells.
Among various compounds used in research and clinic for degenerative bone diseases, low level laser therapy (LLLT), comprising low level lasers (LLL) and light emitting diodes (LEDs), has been ...investigated regarding its effects on bone metabolism. They have specific wavelengths but in general act as a cellular biomodulator, and as a therapeutic agent, rebalancing and normalizing their activity. However, they are not standardized yet, since their parameters of use are relevant for the effects and mechanisms of action. Therefore, the aim of this study was to compare the influence of two spectrums of LLL and LED phototherapy, at the same energy densities (10 and 50J/cm2), on human osteoblasts proliferation and differentiation. The involvement of ERK signaling on proliferation was also investigated by evaluating its activation during proliferation under different phototherapies by western blotting and CFSE-based osteoblast proliferation was measured in a presence or absence of the ERK-specific inhibitor. Osteogenic differentiation was evaluated through in vitro mineralization and gene expression of type I collagen (COL1A1) and osteonectin (SPARC) by Real Time- PCR. Increases in viable cells and proliferation were obtained after irradiation, regardless of LLLT type. However, only red at 10J/cm2 and infrared at both doses, but not LED, induced ERK1/2 activation. In the presence of ERK inhibitor, the LLL-induced proliferation was prevented. In addition, while COL1A1 gene expression was upregulated by red laser, SPARC does so by infrared stimulation. However, LED, at both doses, increased both COL1A1 and SPARC expression. All LLLT increased mineralization, dependent on the dose and time. Thus, LLL and LED differently modulated the metabolism of human osteoblasts, increasing proliferation by mechanism dependent or not of ERK signaling activation and osteogenic differentiation markers.
•COL1A1 gene expression is upregulated by red laser.•LED increases COL1A1 and SPARC expression.•LLL and LED increase proliferation by mechanism dependent or not of ERK signaling.
To characterize the adherence of bone conduction hearing devices (BCHDs) for hearing management in children with unilateral congenital aural atresia (UCAA) in relation to the age of offer and ...fitting. BCHD Soft Bands help predict amplification benefits before surgery can be performed beginning around five years when both hearing and parental compliance reach stability. We hypothesized device compliance might decrease with age of fitting from lack of early acclimatization.
Retrospective case series of patients less than five years old at a tertiary pediatric center's microtia clinic database, born between 2014 and 2018 with UCAA. Adherence was assessed through electronic health record note documentation at less than 1 year, 1–2 years, and greater than 2 years from fitting. The ages at offer and fitting, along with the time from offer to fitting, were recorded.
One hundred and eight patients with UCAA were identified, including 46 patients fit with a BCHD used for further analysis. Adherence rates at 1 year, 1–2 years, and greater than 2 years were 47.8%, 30%, and 43.5%, respectively. However, there was no significant association between age offered, age fit, or time from offer to fit and adherence at all time points. Also, there was no significant difference between ages at the time of BCHD offer for those who chose not to proceed with fitting (20.9 months) compared to the age of offer in patients that were subsequently fit (13.9 months).
BCHD adherence in patients less than five years old may not be affected by the age offered or fit. The time between offer and fitting was also not associated with usage. BCHDs should be offered to UCAA patients regardless of age. Further investigation in this younger age group would help expand these findings.
The effect of ohmic heating processing (10, 100, 1000 Hz - 25 V;45, 60, 80 V - 60 Hz until 65 °C-30 min) on physical (color, rheology, particle size diameter), thermal (differential scanning ...calorimetry, DSC), physicochemical (time domain nuclear magnetic resonance, TD-NMR) and microstructural (optical microscopy) properties of raspberry-flavored whey drink was investigated. The samples were submitted to an ohmic system and conventional pasteurization (65 °C-30 min). Both processing led to increases in the color parameters (C*, h* and ∆E*) in the first 30 min. For the treatments, 10 Hz-25 V and 1000 Hz-25 V, more viscous, and consequently increased D4,3 and D3,2 values were observed, and similar results were obtained for the DSC behavior. The microstructure confirmed aggregation of cell structure in those configurations (10 Hz and 1000 Hz-25 V). OH, parameters for both ohmic configurations have an impact in all the evaluated parameters for raspberry-flavored whey drink, which can be interesting for the dairy industry.
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•Whey-raspberry flavored beverage submitted to Ohmic Heating.•Increased viscosity and D4,3 and D3,2 values and color parameters.•Aggregation of cell structure.•Frequency and voltage proportionated different thermal behavior.
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