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21
result(s) for
"Castro, Sílvia V. F."
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Posttreatment of 3D‐printed surfaces for electrochemical applications: A critical review on proposed protocols
by
Munoz, Rodrigo A. A.
,
Richter, Eduardo M.
,
Castro, Sílvia V. F.
in
3-D printers
,
3D printed sensors
,
Analgesics
2022
This mini‐review presents an overview of recent trends for 3D printed sensors and biosensors (with a focus on Fused Deposition Modeling (FDM) based technology), along with their posttreatment surfaces to improve electrochemical applications. The protocols described in the literature and advances in this field were covered, bringing a critical discussion about the achievements and limitations to improve the electrical properties of conducting filaments, as well as their electroanalytical performance. In addition, the pros and cons of the processes used in surface posttreatment to improve the performance of electrodes constructed by FDM are presented, comparing the time consumed during chemical and electrochemical treatments or combining the two to improve the characteristics of the sensors. Finally, the discussion about the real necessity of surface treatments of electrodes constructed by FDM technology, the techniques used for this, and some ecological protocols are discussed (surface posttreatments with and without reagents) or whether the simple optimization of printing parameters could also significantly improve the electrochemical performance of sensors built with such technologies.
Journal Article
Rapid sequential determination of the explosives 2,4,6-trinitrotoluene and cyclotrimethylenetrinitramine in forensic samples employing a graphite sheet sensor and cyclic square-wave stripping voltammetry
by
Munoz, Rodrigo A. A.
,
Richter, Eduardo M.
,
Souza, Maria M. C.
in
2,4,6-Trinitrotoluene
,
Accumulation
,
Acids
2024
The development of a portable analytical procedure is described for rapid sequential detection and quantification of the explosives 2,4,6-trinitrotoluene (TNT) and cyclotrimethylenetrinitramine (RDX) in forensic samples using a graphite sheet (GS). A single GS platform works as a collector of explosive residues and detector after its assembly into a 3D-printed cell. The detection strategy is based on cyclic square-wave stripping voltammetry. The cathodic scan from + 0.1 to −1.0 V with accumulation at 0.0 V enables the TNT detection (three reduction peaks), and the anodic scan from + 0.2 to + 1.55 V with accumulation at −0.9 V provides the RDX detection (two oxidation processes). Low detection limit values (0.1 µmol L
−1
for TNT and 2.4 µmol L
−1
for RDX) and wide linear ranges (from 1 to 150 µmol L
−1
for TNT and from 20 to 300 µmol L
−1
for RDX) were obtained. The sensor did not respond to pentaerythritol tetranitrate (PETN), which was evaluated as a potential interferent, because plastic explosives contain mixtures of TNT, RDX, and PETN. The GS electrode was also evaluated as a collector of TNT and RDX residues spread on different surfaces to simulate forensic scenarios. After swiping over different surfaces (metal, granite, wood, cloths, hands, money bills, and cellphone), the GS electrode was assembled in the 3D-printed cell ready to measure both explosives by the proposed method. In all cases, the presence of TNT and RDX was confirmed, attesting the reliability of the proposed device to act as collector and sensor.
Graphical abstract
Journal Article
Permeability and in vivo distribution of poly(Ɛ-caprolactone) nanoparticles loaded with zidovudine
by
Milena C R S Magalhães
,
de Castro, Whocely V
,
Castro, Brenda F M
in
Acquired immune deficiency syndrome
,
AIDS
,
Antiretroviral drugs
2018
Zidovudine (AZT) is one of first choice drugs for the treatment of acquired immunodeficiency syndrome (AIDS). Despite its efficacy to control virus replication, the extent of adverse effects and the therapeutic regimen are directly related to patients’ non-compliance. In this work, we evaluated the permeability and in vivo distribution of AZT incorporated into poly(Ɛ-caprolactone), PCL, nanoparticles (AZT-NP) aiming to reduce the normally observed side effects and increase the drug bioavailability. AZT-NP were obtained by interfacial deposition of preformed polymer. The mean diameter of the nanoparticles was 283.4 nm ± 17.0 with a polydispersity index of 0.232 ± 0.073. The nanoparticles presented a zeta potential of − 32.4 mV ± 3.3, entrapment rate of 53.11% ± 9.25, and were stable for at least 7 days. The drug and the polymer showed no incompatibility in thermal analysis. The permeability of AZT across Caco-2 cells was 22-fold higher for AZT-NP compared to the drug solution. The nanoparticles were able to release AZT in vivo after oral administration in mice, and the plasma levels of labeled AZT-NP were higher and more constant when compared to free labeled AZT. Thus, AZT-NP demonstrated superior performance compared to the drug solution in vivo and in vitro, showing the potential of this system for the treatment of AIDS.
Journal Article
Effects of Free and Nanoencapsulated Benznidazole in Acute Trypanosoma cruzi Infection: Role of Cholinergic Pathway and Redox Status
by
Fracasso, Mateus
,
da Rocha, Maria Izabel U. M.
,
Morsch, Vera M.
in
AChE
,
benznidazole
,
Bioavailability
2024
Background/Objectives: The Trypanosoma cruzi infection promotes an intense inflammatory process that affects several tissues. The cholinergic system may exert a regulatory immune response and control the inflammatory process. This study aimed to evaluate the comparative effect of free and nanoencapsulated benznidazole in acute T. cruzi infection to assess hematological, biochemical, and oxidative status triggered by the cholinergic system. Methods: For this, fifty female Swiss mice were distributed in eight groups, i.e., uninfected and infected animals under four treatment protocols: untreated (control—CT); vehicle treatment (Eudragit L 100—EL-100); benznidazole treatment (BNZ); and nanoencapsulated benznidazole treatment (NBNZ). After eight treatment days, the animals were euthanized for sample collection. Results: The peak of parasitemia was at day 7 p.i., and the BNZ and NBNZ controlled and reduced the parasite rate but showed no efficacy in terms of total elimination of parasites analyzed by RT-PCR in both infected groups. The infection promotes significant anemia, leukopenia, and thrombocytopenia, which the BNZ improves. There was an increase in AChE activity during infection, leading to a pro-inflammatory response and an increase in M1 and M2 mACh receptors in the BNZ group, showing that the treatment interacted with the cholinergic pathway. In addition, a pro-oxidative response was characterized in the infection and mainly in the infected BNZ and NBNZ groups. The histopathological analysis showed significative splenomegaly and inflammatory infiltrate in the heart, liver, and spleen. Conclusions: The administration of the BNZ or NBNZ reverses hematological, hepatic, and renal alterations through cholinergic signaling and stimulates a pro-inflammatory response during acute T. cruzi infection.
Journal Article
Seasonal Temperature Fluctuations Differently Affect the Immune and Biochemical Parameters of Diploid and Triploid Oncorhynchus mykiss Cage-Cultured in Temperate Latitudes
by
Castro-Cunha, Manuela
,
Gravato, Carlos
,
Calheiros, José
in
Aquaculture
,
Biomarkers
,
Fish production
2020
In the coming decades, and despite advances in the selection of resistant strains and the production of triploid organisms, the temperature could seriously affect salmonid aquaculture. Lower environmental tolerance has been hinted at for triploids, but the physiological mechanisms leading to such differences, and whether they are translated to the individual level, are poorly understood. This study aimed to evaluate the effects of seasonal variations on the humoral and immune status in the blood (peripheral blood leukocytes) and plasma (antiprotease, lysozyme and peroxidase activities), the oxidative stress (catalase, glutathione-S-transferase, total glutathione and lipid peroxidation) balance in the liver, and the energy budget (sugars, lipids, proteins and energy production) in the liver and muscle of diploid and triploid Oncorhynchus mykiss. Leukocytes’ numbers changed with the water temperature and differed between fish ploidies. Peroxidase activity was increased in the summer, but lysozyme and antiprotease activities were increased in the winter. Concomitantly, antioxidant defenses were significantly altered seasonally, increasing oxidative damage at higher temperatures. Moreover, warmer waters induced a reduction in the energy production measured in the liver. Differences in feed efficiency, which have been previously reported, were confirmed by the low lipid and protein contents of the muscle of the triploids. In sum, the inherent trade-offs to deal with the seasonal changes culminated in the higher growth observed for diploid fish.
Journal Article
Spatial and temporal fluctuations in COVID-19 fatality rates in Brazilian hospitals
2022
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Gamma variant of concern has spread rapidly across Brazil since late 2020, causing substantial infection and death waves. Here we used individual-level patient records after hospitalization with suspected or confirmed coronavirus disease 2019 (COVID-19) between 20 January 2020 and 26 July 2021 to document temporary, sweeping shocks in hospital fatality rates that followed the spread of Gamma across 14 state capitals, during which typically more than half of hospitalized patients aged 70 years and older died. We show that such extensive shocks in COVID-19 in-hospital fatality rates also existed before the detection of Gamma. Using a Bayesian fatality rate model, we found that the geographic and temporal fluctuations in Brazil’s COVID-19 in-hospital fatality rates were primarily associated with geographic inequities and shortages in healthcare capacity. We estimate that approximately half of the COVID-19 deaths in hospitals in the 14 cities could have been avoided without pre-pandemic geographic inequities and without pandemic healthcare pressure. Our results suggest that investments in healthcare resources, healthcare optimization and pandemic preparedness are critical to minimize population-wide mortality and morbidity caused by highly transmissible and deadly pathogens such as SARS-CoV-2, especially in low- and middle-income countries.
Analysis of individual-level patient records from Brazil reveals that the extensive shocks in COVID-19 mortality rates are associated with pre-pandemic geographic inequities as well as shortages in healthcare capacity during the pandemic.
Journal Article
Penicillium chrysogenum as a fungal factory for feruloyl esterases
2023
Plant biomass is a promising substrate for biorefinery, as well as a source of bioactive compounds, platform chemicals, and precursors with multiple industrial applications. These applications depend on the hydrolysis of its recalcitrant structure. However, the effective biological degradation of plant cell walls requires several enzymatic groups acting synergistically, and novel enzymes are needed in order to achieve profitable industrial hydrolysis processes. In the present work, a feruloyl esterase (FAE) activity screening of Penicillium spp. strains revealed a promising candidate (Penicillium rubens Wisconsin 54–1255; previously Penicillium chrysogenum), where two FAE-ORFs were identified and subsequently overexpressed. Enzyme extracts were analyzed, confirming the presence of FAE activity in the respective gene products (PrFaeA and PrFaeB). PrFaeB-enriched enzyme extracts were used to determine the FAE activity optima (pH 5.0 and 50–55 °C) and perform proteome analysis by means of MALDI-TOF/TOF mass spectrometry. The studies were completed with the determination of other lignocellulolytic activities, an untargeted metabolite analysis, and upscaled FAE production in stirred tank reactors. The findings described in this work present P. rubens as a promising lignocellulolytic enzyme producer.Key points• Two Penicillium rubens ORFs were first confirmed to have feruloyl esterase activity.• Overexpression of the ORFs produced a novel P. rubens strain with improved activity.• The first in-depth proteomic study of a P. rubens lignocellulolytic extract is shown.
Journal Article
Carbon dioxide (CO2) emissions and adherence to Mediterranean diet in an adult population: the Mediterranean diet index as a pollution level index
2023
Background
Research related to sustainable diets is is highly relevant to provide better understanding of the impact of dietary intake on the health and the environment.
Aim
To assess the association between the adherence to an energy-restricted Mediterranean diet and the amount of CO
2
emitted in an older adult population.
Design and population
Using a cross-sectional design, the association between the adherence to an energy-reduced Mediterranean Diet (erMedDiet) score and dietary CO
2
emissions in 6646 participants was assessed.
Methods
Food intake and adherence to the erMedDiet was assessed using validated food frequency questionnaire and 17-item Mediterranean questionnaire. Sociodemographic characteristics were documented. Environmental impact was calculated through greenhouse gas emissions estimations, specifically CO
2
emissions of each participant diet per day, using a European database. Participants were distributed in quartiles according to their estimated CO
2
emissions expressed in kg/day: Q1 (≤2.01 kg CO
2
), Q2 (2.02-2.34 kg CO
2
), Q3 (2.35-2.79 kg CO
2
) and Q4 (≥2.80 kg CO
2
).
Results
More men than women induced higher dietary levels of CO
2
emissions. Participants reporting higher consumption of vegetables, fruits, legumes, nuts, whole cereals, preferring white meat, and having less consumption of red meat were mostly emitting less kg of CO
2
through diet. Participants with higher adherence to the Mediterranean Diet showed lower odds for dietary CO
2
emissions: Q2 (OR 0.87; 95%CI: 0.76-1.00), Q3 (OR 0.69; 95%CI: 0.69-0.79) and Q4 (OR 0.48; 95%CI: 0.42-0.55) vs Q1 (reference).
Conclusions
The Mediterranean diet can be environmentally protective since the higher the adherence to the Mediterranean diet, the lower total dietary CO
2
emissions. Mediterranean Diet index may be used as a pollution level index.
Journal Article
The impact of freezing of gait on functional dependency in Parkinson’s disease with regard to motor phenotype
2020
Background and objectiveFreezing of gait (FOG) is a disabling symptom more frequent in Parkinson’s disease (PD) patients with postural instability gait difficulty (PIGD) phenotype. The aim of this study was to determine the prevalence of self-reported FOG in a large group of PD patients as well as assess its relationship with functional dependency with regard to motor phenotype.MethodsThe data correspond to the baseline evaluation of the COPPADIS-2015 study. Patients with FOG were identified as those with a score of 1 or greater on item-3 of the freezing of gait questionnaire (FOG-Q). Functional dependency was defined as a Schwab and England (S&E) ADL scale score less than 80%. PIGD and non-PIGD (tremor dominant + indeterminate) groups were considered regarding to motor phenotype.ResultsAmong the 689 PD patients (62.6 ± 8.9 years old, 59.8% males), 240 reported FOG (34.8%), whereas 63 presented functional dependency (9.1%). A total of 22.1% of patients with FOG presented functional dependency vs. only 2.2% of those without FOG (p < 0.0001). FOG was related to functional dependency (OR = 3.470; 95%CI 1.411–8.530; p = 0.007) after adjustment to age, gender, disease duration, daily equivalent levodopa dose, comorbidity (number of non-antiparkinsonian drugs/day), motor status (UPDRS-III), PIGD phenotype, motor complications (UPDRS-IV), NMS burden (NMSS total score), cognition (PD-CRS), and mood (BDI-II). However, according to motor phenotype, FOG was related to functional dependency only in PIGD patients (OR = 7.163; 95%CI 1.206–42.564; p = 0.030).ConclusionsSelf-reported FOG is associated with functional dependency in PIGD but not in non-PIGD motor phenotype patients.
Journal Article
Candida albicans Germ-Tube Antibody: Evaluation of a New Automatic Assay for Diagnosing Invasive Candidiasis in ICU Patients
by
Martín-Mazuelos, Estrella
,
Parra-Sánchez, Manuel
,
García-Rey, Silvia
in
Antibodies, Fungal - blood
,
Antifungal agents
,
Automation
2017
Testing for
Candida albicans
germ-tube antibody IFA IgG assay (CAGTA) is used to detect invasive candidiasis infection. However, most suitable assays lack automation and rapid single-sample testing. The CAGTA assay was adapted in an automatic monotest system (invasive candidiasis [CAGTA] VirClia
®
IgG monotest (VirClia
®
), a chemiluminescence assay with ready-to-use reagents that provides a rapid objective result. CAGTA assay was compared with the monotest automatic VirClia
®
assay in order to establish the diagnostic reliability, accuracy, and usefulness of this method. A prospective study with 361 samples from 179 non-neutropenic critically ill adults patients was conducted, including 21 patients with candidemia, 18 with intra-abdominal candidiasis, 84 with
Candida
spp. colonization, and 56 with culture-negative samples, as well as samples from ten healthy subjects. Overall agreement between the two assays (CAGTA and VirCLIA) was 85.3%. These assays were compared with the gold-standard method to determine the sensitivity, specificity as well as positive and negative predictive values. In patients with candidemia, values for CAGTA and VirCLIA assays were 76.2 versus 85.7%, 80.3 versus 75.8%, 55.2 versus 52.9%, and 91.4 versus 94.3%, respectively. The corresponding values in patients with intra-abdominal candidiasis were 61.1 versus 66.7%, 80.3 versus 75.8%, 45.8 versus 42.9%, and 88.3 versus 89.3%, respectively. No differences were found according to the species of
Candida
isolated in culture, except for
Candida albicans
and
C. parapsilosis
, for which VirClia
®
was better than CAGTA. According to these results, the automated VirClia
®
assay was a reliable, rapid, and very easy to perform technique as tool for the diagnosis invasive candidiasis.
Journal Article