Publications by authors named "Mariana R Almeida"

Coffee is a widely popular beverage worldwide, known for its distinct sensory properties which are greatly affected by geographical origin. Herein, we performed an untargeted metabolomic evaluation of green coffee beans (n = 40) from four different regions in Brazil: Cerrado Mineiro, Sul de Minas, Caparaó, and Mogiana Paulista; by using UHPLC-HRMS (ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry). The most significant metabolites responsible for coffee characterization were theobromine, zeatin, phenylacetaldehyde, 2-acetyl-1-pyrroline, chlorogenic acids, ferulic acid, p-coumaric acid, abscisic acid, and jasmonic acid.

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While optical analysis spectroscopy offers operational ease and low cost, it suffers from limitations regarding sensitivity when it comes to analyzing analytes at low concentrations. On the other hand, surface-enhanced Raman spectroscopy (SERS) offers high sensitivity but low selectivity in complex matrices. In this study, we have effectively addressed these challenges by integrating multiphase electroextraction (MPEE) as a sample preparation technique with these two spectroscopic methods for determining methylene blue (MB) dye in tap water samples.

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Criminal practices in which an individual becomes vulnerable and prone to sexual assault after ingesting drinks spiked with doping substances have become a social concern globally. As forensic protocols require a multi-tiered strategy for chemical evidentiary analysis, the backlog of evidence has become a significant problem in the community. Herein, a fast, sensible, and complementary dual analytical methodology was developed using a single commercial paper substrate for surface-enhanced Raman spectroscopy (SERS) and paper spray mass spectrometry (PS-MS) analysis to identify psychotropic substances added to alcoholic beverages irrefutably.

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The potential use of carbon-based methodologies for drug delivery and reproductive biology in cows raises concerns about residues in milk and food safety. This study aimed to assess the potential of Fourier transform Raman spectroscopy and discriminant analysis using partial least squares (PLS-DA) to detect functionalized multiwalled carbon nanotubes (MWCNT) in bovine raw milk. Oxidized MWCNT were diluted in milk at different concentrations from 25.

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In this paper, we employed sandpaper as an efficient medium to analyze polishable solid samples. As proof of principle, the surfaces of coffee beans were sanded with pieces of sandpaper cut into a triangular shape. The triangle was placed in front of the mass spectrometer inlet, and methanol was dropped on its surface.

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Surface-enhanced Raman spectroscopy (SERS) has gained increasing attention because it provides rich chemical information and high sensitivity, being applicable in many scientific fields including medical diagnosis, forensic analysis, food control, and microbiology. Although SERS is often limited by the lack of selectivity in the analysis of samples with complex matrices, the use of multivariate statistics and mathematical tools has been demonstrated to be an efficient strategy to circumvent this issue. Importantly, since the rapid development of artificial intelligence has been promoting the implementation of a wide variety of advanced multivariate methods in SERS, a discussion about the extent of their synergy and possible standardization becomes necessary.

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Many developing countries have highly unequal health systems across their regions. The pandemic of COVID-19 brought an additional challenge, as hospital structures equipped with doctors, intensive care units and respirators are not available to a sufficient extent in all regions. Using Data Envelopment Analysis, we create a COVID Index to verify whether the hospital structures in 543 Brazilian microregions are adequate to deal with COVID-19 and to verify whether public policies were implemented in the right direction.

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The objective of this study was to evaluate the ability of Raman spectroscopy to identify the genotype of green coffee beans. Four genotypes of Arabic coffee: one Mundo Novo line (G1) and three Bourbon lines (G2, G3, and G4). The harvest was selected using a wet processing method.

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Raman spectroscopy was used to identify chemical changes associated sensory quality of coffee beans, for natural and pulped natural coffee stored in different packaging. The green beans of natural coffee and pulped natural coffee were stored in three types of packaging materials in a commercial warehouse. Sensory analyses were performed, and Raman spectra were collected after 0, 3, 6, 9, 12, and 18 storage months.

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This work developed an analytical method to differentiate conventional and omega-3 fat acids enriched eggs by Raman spectroscopy and multivariate supervised classification with Partial Least Squares Discriminant Analysis (PLS-DA). Forty samples of enriched eggs and forty samples of different types of common eggs from different batches were used to build the model. Firstly, gas chromatography was employed to analyze fatty acid profiles in egg samples.

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Thalidomide was indicated as a sedative and antiemetic and prescribed for pregnant women. Its tragic teratogenic effects culminated in withdrawal from the market. Since the discovery of its anti-angiogenic and anti-inflammatory actions, thalidomide has been used in the treatment of leprosy and multiple myeloma, which justify studies of its stability.

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Few reports describe the effect of lactose hydrolysis on the properties of milk powder during production and storage. Hence, the aim of this study was to evaluate the effects of five different levels of enzymatic lactose hydrolysis during the production and storage of milk powder. As the lactose hydrolysis rate increased, adhesion to the drying chamber also increased, due to higher levels of particle agglomeration.

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In this work, Raman hyperspectral imaging, in conjunction with independent component analysis, was employed as an analytical methodology to detect an ammonium nitrate fuel oil (ANFO) explosive in banknotes after an ATM explosion experiment. The proposed methodology allows for the identification of the ANFO explosive without sample preparation or destroying the sample, at quantities as small as 70μgcm. The explosive was identified following ICA data decomposition by the characteristic nitrate band at 1044cm.

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Article Synopsis
  • Schistosomiasis is a significant public health issue, particularly in Brazil, where the water rat (Nectomys squamipes) serves as a wild reservoir for the parasite Schistosoma mansoni.
  • The study identified that natural infection with S. mansoni in these rats leads to hepatic steatosis, characterized by increased lipid accumulation in liver cells, without harming liver function.
  • Researchers found higher levels of total cholesterol and triglycerides in infected rats and notable fatty acids changes, suggesting that lipid accumulation could be a protective response against the infection.
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Most eukaryotic cells contain varying amounts of cytosolic lipidic inclusions termed lipid bodies (LBs) or lipid droplets (LDs). In mammalian cells, such as macrophages, these lipid-rich organelles are formed in response to host-pathogen interaction during infectious diseases and are sites for biosynthesis of arachidonic acid (AA)-derived inflammatory mediators (eicosanoids). Less clear are the functions of LBs in pathogenic lower eukaryotes.

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Elucidating cardiac evolution has been frustrated by lack of fossils. One celebrated enigma in cardiac evolution involves the transition from a cardiac outflow tract dominated by a multi-valved conus arteriosus in basal actinopterygians, to an outflow tract commanded by the non-valved, elastic, bulbus arteriosus in higher actinopterygians. We demonstrate that cardiac preservation is possible in the extinct fish Rhacolepis buccalis from the Brazilian Cretaceous.

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In this work, FT-Raman spectroscopy was explored to evaluate spreadable cheese samples. A partial least squares discriminant analysis was employed to identify the spreadable cheese samples containing starch. To build the models, two types of samples were used: commercial samples and samples manufactured in local industries.

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The aim of this study was to develop a methodology using Raman hyperspectral imaging and chemometric methods for identification of pre- and post-blast explosive residues on banknote surfaces. The explosives studied were of military, commercial and propellant uses. After the acquisition of the hyperspectral imaging, independent component analysis (ICA) was applied to extract the pure spectra and the distribution of the corresponding image constituents.

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Frankfurters are widely consumed all over the world, and the production requires a wide range of meat and non-meat ingredients. Due to these characteristics, frankfurters are products that can be easily adulterated with lower value meats, and the presence of undeclared species. Adulterations are often still difficult to detect, due the fact that the adulterant components are usually very similar to the authentic product.

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The Amazon tree Aniba rosaeodora Ducke (rosewood) provides an essential oil valuable for the perfume industry, but after decades of predatory extraction it is at risk of extinction. The extraction of the essential oil from wood implies the cutting of the tree, and then the study of oil extracted from the leaves is important as a sustainable alternative. The goal of this study was to test the applicability of Raman spectroscopy and Partial Least Square Discriminant Analysis (PLS-DA) as means to classify the essential oil extracted from different parties (wood, leaves and branches) of the Brazilian tree A.

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Objective: To investigate elementary school teachers' baseline knowledge about ADHD and learning disorders (LD) and the impact of a strategy to increase awareness of these disorders.

Method: A total of 37 teachers were selected from four elementary schools in the catchment area of the University Hospital, in Porto Alegre, Brazil. To evaluate teachers' knowledge, two self-report questionnaires about ADHD and LD were applied before and after an awareness program on these disorders.

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Fourier transform Raman spectroscopy and chemometric tools have been used for exploratory analysis of pure corn and cassava starch samples and mixtures of both starches, as well as for the quantification of amylose content in corn and cassava starch samples. The exploratory analysis using principal component analysis shows that two natural groups of similar samples can be obtained, according to the amylose content, and consequently the botanical origins. The Raman band at 480 cm(-1), assigned to the ring vibration of starches, has the major contribution to the separation of the corn and cassava starch samples.

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Spectroscopic techniques, including Raman, IR, UV/vis, and NMR were used to characterize the samples of the azo dye Ponceau 4R (also known as E124, New Coccine; Cochineal Red; C.I. no.

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