The Brazilian TP53 mutation (R337H) and sarcomas Volc, Sahlua Miguel; Ramos, Cíntia Regina Niederauer; Galvão, Henrique de Campos Reis ...
PloS one,
01/2020, Volume:
15, Issue:
1
Journal Article
Peer reviewed
Open access
Sarcomas represent less than 1% of all solid neoplasms in adults and over 20% in children. Their etiology is unclear, but genetic susceptibility plays an important role in this scenario. Sarcoma is ...central in Li-Fraumeni Syndrome (LFS), a familial predisposition cancer syndrome. In Brazil, the high prevalence of p.Arg337His mutations in the TP53 gene brings about a unique condition: a cluster of LFS. In the present work, we studied 502 sarcoma patients not selected by age or family history in an attempt to assess the impact of the so-called "Brazilian germline TP53 mutation" (p.Arg337His) on this tumor type. We found that 8% of patients are carriers, with leiomyosarcoma being the main histologic type of sarcoma, corresponding to 52.5% of the patients with the mutated TP53 gene. These findings emphasize the importance of genetic counseling and can better guide the management of sarcoma patients.
Erythrina velutina
is a species of arboreal leguminous that occurs spontaneously in the northeastern states of Brazil. Leguminous seeds represent an abundant source of peptidase inhibitors, which ...play an important role in controlling peptidases involved in essential biological processes. The aim of this study was to purify and characterize a novel Kunitz-type peptidase inhibitor from
Erythrina velutina
seeds and evaluate its anti-proliferative effects against cancer cell lines. The Kunitz-type chymotrypsin inhibitor was purified from
Erythrina velutina
seeds (EvCI) by ammonium sulphate fractionation, trypsin– and chymotrypsin–sepharose affinity chromatographies and Resource Q anion-exchange column. The purified EvCI has a molecular mass of 18 kDa with homology to a Kunitz-type inhibitor. Inhibition assays revealed that EvCI is a competitive inhibitor of chymotrypsin (with
K
i
of 4 × 10
–8
M), with weak inhibitory activity against human elastase and without inhibition against trypsin, elastase, bromelain or papain. In addition, the inhibitory activity of EvCI was stable over a wide range of pH and temperature. Disulfide bridges are involved in stabilization of the reactive site in EvCI, since the reduction of disulfide bridges with DTT 100 mM abolished ~ 50% of its inhibitory activity. The inhibitor exhibited selective anti-proliferative properties against HeLa cells. The incubation of EvCI with HeLa cells triggered arrest in the cell cycle, suggesting that apoptosis is the mechanism of death induced by the inhibitor. EvCI constitutes an interesting anti-carcinogenic candidate for conventional cervical cancer treatments employed currently. The EvCI cytostatic effect on Hela cells indicates a promised compound to be used as anti-carcinogenic complement for conventional cervical treatments employed currently.
This article provides as contribution a systematic design procedure for robust current control of grid-tied inverters with LCL filters affected by inductor magnetic soft-saturation and also by ...uncertain grid impedances. The proposed design is based on the following: first, a polytopic time-varying model to describe the effect of the inductances variations; second, a set of linear matrix inequalities to design fixed (robust) state feedback gains, ensuring bounded settling times for the closed-loop transient responses. A less conservative set of linear matrix inequalities is used to certify the procedure. Experimental results from real-time simulations and from a real prototype with commercial powder core inductors show that the proposed procedure can provide superior results than conventional controllers designed not taking into account the soft-saturation. The results with the proposed controller comply with the IEEE 1547 Standard, leading to grid currents with low harmonic content, respecting limits prescribed by this standard even under distorted grid voltages.
This work reports the determination of mercury in fish samples purchased at a public market in Belem City, Brazil. The mercury quantification was performed using the DMA method, which allows limits ...of detection and quantification of 0.004 and 0.012 ng, respectively. Method accuracy was confirmed using a certified reference material of fish protein from (NRCC) National Research Council, Canada. The analyzed species were: Dourada (Brachyplatystoma rousseauxii), Filhote (Brachyplatystoma filamentosum), Pescada Branca (Cynoscion leiarchus), Piramutaba (Brachyplatystoma vaillanti). The mercury contents expressed as wet sample weight varied from 0.078 to 0.150 μg g-1. Afterward, the health risk assessment indices Estimated Weekly Intake (EWI), Target Hazard Quotient (THQ), and Maximum Safe Consuming Quantity (MSCQ) were applied to the analytical data, and the results obtained were exhaustively interpreted and discussed. All the indices demonstrated that the daily consumption of 25 g of these fishes does not pose a risk to the human health of the local population. However, these conclusions are preliminary and should not be used in public policy matters.
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•A brief review of the indices used to assess food contamination is presented.•Indices used to assess risks from heavy metals in food matrices are discussed.•The risk assessment of mercury in fish is presented and discussed in detail.•The leading indices employed to assess the human health risk in foods are presented.•DMA allows mercury determination in solid samples without any treatment.
Proportional-resonant controllers are largely used for grid-connected converters with LCL filters to ensure sinusoidal reference tracking and harmonic disturbance rejection. However, the design of ...such controllers becomes more difficult when it is necessary to ensure stability and suitable performance for converters operating under uncertain grid conditions, from stiff to weaker, and also when the number of resonants increases. In this more challenging scenario, available design procedures may lead to a poor tradeoff between transient and steady-state performances. To overcome this problem, this paper proposes an off-line automated control design procedure to obtain multiple robust optimized proportional-resonant controllers. The proposed procedure consists of two steps, where a particle swarm algorithm is used to obtain: i) the gains of an inner loop ensuring optimal active damping for the LCL filter resonance; ii) the gains of multiple proportional-resonant controllers by minimizing a tracking error index, taking into account uncertain grid impedance and control signal limits. The robust stability of the closed-loop system with the control gains tuned by the metaheuristics is certificated through a parameter-dependent Lyapunov function, constructed based on linear matrix inequalities. Several results from control Hardware-in-the-loop are presented for a case study, revealing that the proposal provides better performance in terms of reference tracking and disturbance rejection, when compared to similar control strategies from the literature. Experimental results from a prototype connected to the utility grid attest the practical feasibility of the proposed procedure.
This paper describes the development of a facile and environmentally friendly strategy for supporting palladium nanoparticles (Pd NPs) on multiwalled carbon nanotubes (MWCNTs) with ethanol as the ...solvent/reducing agent, potassium tetrachloropalladate(II) (K2PdCl4) as the Pd precursor, and polyvinylpyrrolidone (PVP) as the surface modifier. More specifically, our approach was based on the nonbonding interaction between MWCNTs and PVP, which is a cheap, nontoxic, and commercial polymer. As PVP can serve not only as a surface modifier but also as a stabilizing agent for Pd NPs, the utilization of additional functionalization steps, reducing agents, and stabilizers was not required to achieve uniform Pd deposition over the MWCNTs. Our results demonstrate that Pd NPs below 5 nm in diameter can be directly supported on MWCNTs by this route. Also, sequential Pd‐reduction steps can be employed to improve the coverage of Pd NPs at the MWCNT surfaces, although this can also lead to the formation of larger Pd particles or aggregates. The electrocatalytic activity for ethanol oxidation was investigated as a function of the composition and structure of the materials produced, in which MWCNTs decorated with Pd NPs of smaller sizes and lower coverages displayed the highest activities. The results described herein suggest that our approach may serve as a simple platform for the synthesis of MWCNTs decorated with metal NPs with well‐defined morphologies and uniform dispersion for electrochemical and catalytic applications.
The nonbonding interaction between polyvinylpyrrolidone (PVP) and multiwalled carbon nanotubes (MWCNTs) was employed to achieve deposition of palladium nanoparticles less than 5 nm in size over the surface of the MWCNTs; with ethanol as the solvent/reducing agent, potassium tetrachloropalladate(II) as the precursor, and PVP as the surface modifier.
In this work, we report copper oxide nanofibers (CuO – N) synthesized by Solution Blow Spinning (SBS) for oxygen evolution reaction (OER), and their comparison with a control sample based on a ...commercial powder (CuO – C). Both materials were characterized by various techniques, including X-ray diffraction (XRD), magnetometry, scanning electron microscopy (SEM), and spectroscopy (Fourier transform infrared (FT-IR), Raman and X-ray photoelectron (XPS)) to determine the purity, microstructural and surface chemical properties. Subsequently, the performance of copper oxide catalysts in a 1.0 M KOH solution was investigated. Copper oxide with nanofiber morphology (CuO – N) exhibited a small overpotential of 385 mV @ 10 mA cm−2 and a Tafel coefficient of only 76 mV dec−1, i.e., fast kinetics for water splitting, a result that is modulated by oxygen vacancies (O2/O1 = 0.83). The oxygen vacancies are due to the presence of Cu1+ in the lattice. The analyses of the magnetization measurements at 5 K suggest a larger amount of Cu1+ in sample CuO – N. Therefore, this work sheds light on how to design low-cost nanofibrous catalysts based on abundant transition metals in the earth's crust by SBS, an economical and scalable technique, which is promising for energy applications.
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Angina bullosa haemorrhagica (ABH) is characterized by the recurrent appearance of blood blisters on the oral mucosa, mainly in adults' soft palate. In general, the blisters rupture spontaneously, ...lacking the necessity for biopsy. We report the clinical features of 23 ABH cases, emphasizing the clinical behavior and the management of these conditions.
A retrospective descriptive cross-sectional study was performed. A total of 12,727 clinical records of oral and maxillofacial lesions from four dental services in Brazil were analyzed. Clinical data were collected from the clinical records and evaluated.
The series comprised 12 males (52.2%) and 11 females (47.8%), with a mean age of 56.8 ± 14.6 years (ranging: 24-82 years) and a 1.1:1 male-to-female ratio. Most of the lesions affected the soft palate (n = 15, 65.2%). Clinically, the lesions presented mainly as an asymptomatic (n = 17, 73.9%) blood-filled blister that ruptured after a few minutes or hours, leaving an erosion. The masticatory trauma was the most frequent triggering event. No patient had coagulation disorders. A biopsy was performed in only four cases (17.4%). Treatment was symptomatic with a favorable outcome.
ABH is still poorly documented in the literature, and its etiology remains uncertain. ABH mainly affects the soft palate of elderly adults and has a favorable evolution in a few days. The therapeutic approach is often focused only on the relief of symptoms. However, it can share some clinical features with more serious diseases. Therefore, clinicians must recognize these lesions to avoid misdiagnosis.
Invited for the cover of this issue is the group of Pedro Camargo at the University of São Paulo, Brazil, collaborating with the group of Sarah Haigh at the University of Manchester, UK. The cover ...image shows the deposition of palladium nanoparticles (Pd NPs) on the surface of carbon nanotubes (CNTs) by a simple strategy employing ethanol as the solvent/reducing agent, potassium tetrachloropalladate(II) (K2PdCl4) as the Pd precursor, and polyvinylpyrrolidone (PVP) as the surface modifier.
We are fascinated with the possibility of using simple chemistry to develop strategies that enable precise control over size, shape, structure, and even composition for multimetallic systems...
Read more about the story behind the cover in the Cover Profile and about the research itself on p. 1439 ff.
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