Publications by authors named "Carlos Abreu"

In the parameter spaces of nonlinear dynamical systems, we investigate the boundaries between periodicity and chaos and unveil the existence of fractal sets characterized by a singular fractal dimension that deviates greatly from the fractal sets in their vicinity. This extreme fractal dimension stands out from the typical value previously considered universal for these parameter boundaries. We show that such singular fractal sets dwell along parameter curves, called extreme curves, that intersect periodicity cascades at their centers of stability across all scales of parameter spaces.

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Dye-sensitized solar cells (DSSCs) have recently entered the market for indoor photovoltaics. Fast electron injection from dye to titania, the lifetime of the excited dye, and the suppression of back electron recombination at the photoanode/electrolyte interface are crucial for a high photocurrent conversion efficiency (PCE). This study presents block copolymers of poly(4-vinylpyridine) and poly(styrene)-P4VP--PSt as efficient accelerators of electron injection from dye to titania with extended lifetime excited states and long-lasting back electron recombination suppression.

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Diabetes mellitus is a prevalent chronic autoimmune disease with a high impact on global health, affecting millions of adults and resulting in significant morbidity and mortality. Achieving optimal blood glucose levels is crucial for diabetes management to prevent acute and long-term complications. Carbohydrate counting (CC) is widely used by patients with type 1 diabetes to adjust prandial insulin bolus doses based on estimated carbohydrate content, contributing to better glycemic control and improved quality of life.

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For patients with Type 1 diabetes mellitus (T1DM), accurate carbohydrate counting (CC) is essential for successful blood glucose regulation. Unfortunately, mistakes are common and may lead to an incorrect dosage of prandial insulin. In this work, we aim to demonstrate that each person has their own limits for CC errors, which can be computed using patient-specific data.

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Agaricus subrufescens, also known as the "sun mushroom," has significant nutritional and medicinal value. However, its short shelf life due to the browning process results in post-harvest losses unless it's quickly dehydrated. This restricts its availability to consumers in the form of capsules.

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Background: Stereotactic body radiotherapy (SBRT) is a treatment option for early-stage inoperable primary lung cancer. Here we report a thorough description of the prognostic value of pre-SBRT SUVmax for predicting the efficacy of SBRT in early-stage lung adenocarcinoma.

Methods: This is a retrospective study of consecutive cases of early-stage inoperable lung adenocarcinoma, staged with PET-CT, treated with SBRT between 2007 and 17.

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Ships that transport oil or derivatives on the Lower Amazon River waterway are at a considerably high risk of suffering spills, with severe environmental and socioeconomic consequences. The present study is aimed at modeling and simulating the oil dispersion and magnitude of these accidents in terms of the vulnerability of biological resources, considering two oil types most often transported by medium-sized tankers in the region (S500 and S10). The study method was as follows: (a) secondary data were collected from local species, and the coastal sensitivity index (CSI) was calculated, obtained from Brazil's Letters of Environmental Sensitivity to Oil Spill (Cartas de Sensibilidade Ambiental ao Derramamento de Óleo (SAO)); (b) ship traffic information was obtained from Brazil's Statistical Yearbook of Waterway (Anuário Estatístico Aquaviário (ANTAQ)); (c) modeling and numerical simulation of oil spills in water were performed, in order to investigate dispersion scenarios (SisBaHia); (d) three numerical scenarios of oil plume dispersion (in May and November) were integrated to assess species vulnerability in three zones of environmental interest (I, II, and III).

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Background: This study aims to assess the clinical outcomes of patients with spine metastases who underwent stereotactic ablative radiation therapy (SABR) as part of their treatment. SABR has arisen as a contemporary treatment option for spinal metastasis patients with good prognoses.

Materials And Methods: Between November 2010 and September 2018, Spinal SABR was performed in patients with metastatic disease in different settings: radical (SABR only), postoperative (after decompression and/or fixation surgery), and reirradiation.

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Large ships are efficient in transporting oil and its derivatives. However, they can cause spills in the event of accidents. The aim of the study is to simulate oil dispersion processes in scenarios of likely accidents with ships traveling on sea routes interconnected with Amazonian ports and with the Atlantic Ocean.

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Objective: The aim of this study was to evaluate what data exists in the literature about the fate of SCE.

Methods: This is an integrative review of papers published in the last ten years, in the Medline and PubMed databases on the subject.

Results: the studies included in this review demonstrate that the difficulties in defining the fate of surplus cryopreserved embryos are mainly due to the absence of specific legislation in most countries.

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After mushroom production, the substrate plus the cultivated mycelium represents a byproduct, the so-called "spent mushroom substrate" (SMS). We evaluated different SMS types in fresh form, recently taken from the cultivation rooms, for the production of lettuce and arugula in the open field, greenhouse and greenhouse in pot. Three kinds of SMS were used (i - SMS of ABL (Agaricus subrufescens), ii - SMS of POS (Pleurotus ostreatus) and iii - 50% SMS of ABL + 50% SMS of POS) at three doses (1, 2 and 4 kg m).

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Synthesis of block copolymers (BCPs) by catalytic halogen exchange (cHE) is reported, using supplemental activator and reducing agent Atom Transfer Radical Polymerization (SARA ATRP). The cHE mechanism is based on the use of a small amount of a copper catalyst in the presence of a suitable excess of halide ions, for the synthesis of block copolymers from macroinitiators with monomers of mismatching reactivity. cHE overcomes the problem of inefficient initiation in block copolymerizations in which the second monomer provides dormant species that are more reactive than the initiator.

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Purpose: To evaluate the interobserver agreement of chest computed tomography (CT) findings in the diagnosis of expected changes and local recurrence after stereotactic body radiation therapy (SBRT) in patients with early-stage lung cancer or a single pulmonary metastasis.

Materials And Methods: A total of 54 patients with early-stage lung cancer or pulmonary metastasis who were treated with SBRT from 2007 to 2015 were included. The exclusion criteria were patients who presented with pulmonary infection during follow-up and patients who underwent a single CT during follow-up.

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Thiourea dioxide, a green and inexpensive compound used at industrial scale, was employed as reducing agent for the controlled polymerization of a wide range of monomer families, namely, acrylates (methyl acrylate, 2-hydroxyethyl acrylate, butyl acrylate, methacrylates (2-(dimethylamino)ethyl methacrylate, 2-aminoethyl methacrylate hydrochloride, and methyl methacrylate), styrene, acrylonitrile, and vinyl chloride (nonactivated monomer) by ATRP. Mechanistic studies confirmed that the polymerizations are ruled by the activators regenerated by electron transfer (ARGET) mechanism. It is worth noting that vinyl chloride has never been polymerized by ARGET ATRP.

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Purpose Stereotactic body radiation therapy (SBRT) has emerged as a treatment option for patients with non-small-cell lung cancer (NSCLC). We report the clinical outcomes and toxicity for patients with inoperable primary NSCLC treated with SBRT. Methods Between 2007 and 2015, 102 consecutive lung lesions were treated with SBRT at our center, of which 59 primary NSCLC lesions (from 54 patients with inoperable disease) were retrospectively reviewed (43 lesions were excluded because of metastases or because there was no biopsy specimen).

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The mechanism of atom transfer radical polymerization (ATRP) mediated by sodium dithionite (NaSO), with CuBr/MeTREN as catalyst (MeTREN: tris[2-(dimethylamino)ethyl]amine)) in ethanol/water mixtures, was investigated experimentally and by kinetic simulations. A kinetic model was proposed and the rate coefficients of the relevant reactions were measured. The kinetic model was validated by the agreement between experimental and simulated results.

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Aqueous supplemental activator and reducing agent atom transfer radical polymerization (SARA ATRP) using inorganic sulfites was successfully carried out for the first time. Under optimized conditions, a well-controlled poly[oligo(ethylene oxide) methyl ether acrylate] (POEOA) was obtained with <30 ppm of soluble copper catalyst using tris(2-pyridylmethyl)amine (TPMA) ligand in the presence of an excess of halide salts (e.g.

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Objective:: To provide a quantitative profile of the indications and use of stereotactic body radiotherapy (SBRT) in a developing country oncology-based institution. In addition, to describe the patients' and treatment characteristics, and to provide a temporal analysis.

Method:: SBRT patients treated from 2007 to 2015 were retrospectively evaluated by two independently investigators.

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Natural flowering can cause serious scheduling problems in the pineapple (Ananas comosus) industry and increase harvest costs. Pineapple flowering is thought to be triggered by increased ethylene levels and artificial forcing of pineapple flowering is a common practice to promote flowering synchronisation. However, little is known about the early hormonal and molecular changes of pineapple flowering induction and development.

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Objectives: To examine the association between trial sponsorship and conflicts of interest (COI) with clinical trial conclusions for prostate cancer trials related to radiotherapy.

Materials And Methods: The MEDLINE database was searched for all prostate cancer clinical trials published between 2004 and 2013 and identified 1396 studies. Two investigators independently identified trials published in the English language of ≥30 patients, and extracted relevant data.

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For early-stage lung cancer, the treatment of choice is surgery. In patients who are not surgical candidates or are unwilling to undergo surgery, radiotherapy is the principal treatment option. Here, we review stereotactic body radiotherapy, a technique that has produced quite promising results in such patients and should be the treatment of choice, if available.

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There are many available options for prostate cancer treatment, including active surveillance, surgery, brachytherapy and external beam radiotherapy. Based on a radiobiological rationale, which considers the prostate tumor as a low α/β tumor, the use of higher and fewer fractions to prostate cancer external beam radiotherapy treatment has been proposed. Instead of the traditional fractions of 1.

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A very fast and controlled atom transfer radical (co)polymerization (ATRP) of acrylates, methacrylates, styrene, and vinyl chloride is reported in a single dipolar aprotic solvent, sulfolane, with the use of ppm amount of the copper catalyst. The observed rates of polymerization () of the monomers studied are similar to those reported using dimethyl sulfoxide (DMSO) and other polar solvents typically employed in single electron transfer (SET)-mediated atom transfer radical polymerization (ATRP) processes. As proof-of-concept, ABA type block copolymers of polystyrene--poly(vinyl chloride)--polystyrene and poly(methyl acrylate)--poly(vinyl chloride)--poly(methyl acrylate) were prepared for the first time using a reversible deactivation radical polymerization (RDRP) method in a single solvent.

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An unusual synergistic effect between 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF) and dimethyl sulfoxide (DMSO) mixtures is reported for the supplemental activator and reducing agent atom transfer radical polymerization (SARA ATRP) of methyl acrylate (MA) using a catalytic system composed by sodium dithionate (NaSO) and CuBr/MeTREN (MeTREN: tris[2-(dimethylamino)ethyl]amine) at room temperature. To the best of our knowledge, the use of ionic liquids (IL) has never been reported for the SARA ATRP. The kinetic data obtained for a broad range of target molecular weights revealed very fast polymerization rates, low dispersity values ( < 1.

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Biomedical wireless sensor networks are a key technology to support the development of new applications and services targeting patient monitoring, in particular, regarding data collection for medical diagnosis and continuous health assessment. However, due to the critical nature of medical applications, such networks have to satisfy demanding quality of service requirements, while guaranteeing high levels of confidence and reliability. Such goals are influenced by several factors, where the network topology, the limited throughput, and the characteristics and dynamics of the surrounding environment are of major importance.

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