Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
1.
Sci Total Environ ; 874: 162310, 2023 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-36828068

RESUMO

A pilot annual monitoring survey (April 2018-March 2019) was conducted to investigate the presence of pesticides in superficial water and fish in Laguna del Cisne, one of the most critical drinking water sources in Uruguay. A total of 25 pesticide residues were detected in superficial water (89.3 % of the samples). Pesticide's temporal distribution was associated with crops and livestock practices, with higher occurrences in spring and summer than in autumn and winter. The most frequent compounds in superficial water were the insecticide chlorantraniliprole, and the herbicides glyphosate (including its metabolite AMPA) and metolachlor. The levels of Organochlorine pesticide, p,p'-DDT, was in some cases two order of magnitude above the international water quality guidelines for Ambient Water Criteria. In fishes, eight different pesticides were detected, at concentrations from 1000 to 453,000 ng·kg-1. The most frequent pesticides found were propiconazole, chlorpyrifos, and p,p'-DDE. The widespread occurrence of pesticides in fish suggests potential exposure effects on fish populations and the aquatic ecosystem. The sampling approach of this work allowed monitoring the continuous concentrations of several pesticides in surface waters and fishes to establish the influence from past and current agriculture practices in Laguna del Cisne basin. For safety measures, continuous monitoring programs must be performed in this system to prevent toxicity impacts on aquatic organisms and human health.


Assuntos
Água Potável , Hidrocarbonetos Clorados , Praguicidas , Poluentes Químicos da Água , Animais , Humanos , Praguicidas/análise , Lagos , Uruguai , Ecossistema , Poluentes Químicos da Água/análise , Hidrocarbonetos Clorados/análise , DDT , Diclorodifenil Dicloroetileno , Monitoramento Ambiental
2.
Toxins (Basel) ; 15(2)2023 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-36828400

RESUMO

The development of simple, reliable, and cost-effective methods is critically important to study the spatial and temporal variation of microcystins (MCs) in the food chain. Nanobodies (Nbs), antigen binding fragments from camelid antibodies, present valuable features for analytical applications. Their small antigen binding site offers a focused recognition of small analytes, reducing spurious cross-reactivity and matrix effects. A high affinity and broad cross-reactivity anti-MCs-Nb, from a llama antibody library, was validated in enzyme linked immunosorbent assay (ELISA), and bound to magnetic particles with an internal standard for pre-concentration in quantitative-matrix-assisted laser desorption ionization-time of flight mass spectrometry (Nb-QMALDI MS). Both methods are easy and fast; ELISA provides a global result, while Nb-QMALDI MS allows for the quantification of individual congeners and showed excellent performance in the fish muscle extracts. The ELISA assay range was 1.8-29 ng/g and for Nb-QMALDI, it was 0.29-29 ng/g fish ww. Fifty-five fish from a MC-containing dam were analyzed by both methods. The correlation ELISA/sum of the MC congeners by Nb-QMALDI-MS was very high (r Spearman = 0.9645, p < 0.0001). Using ROC curves, ELISA cut-off limits were defined to accurately predict the sum of MCs by Nb-QMALDI-MS (100% sensitivity; ≥89% specificity). Both methods were shown to be simple and efficient for screening MCs in fish muscle to prioritize samples for confirmatory methods.


Assuntos
Microcistinas , Anticorpos de Domínio Único , Animais , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Microcistinas/análise , Ensaio de Imunoadsorção Enzimática
3.
Microbiome ; 10(1): 208, 2022 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-36457116

RESUMO

BACKGROUND: The microbial community composition of urban environments is primarily determined by human activity. The use of metagenomics to explore how microbial communities are shaped in a city provides a novel input that can improve decisions on public health measures, architectural design, and urban resilience. Of note, the sewage system in a city acts as a complex reservoir of bacteria, pharmaceuticals, and antimicrobial resistant (AMR) genes that can be an important source of epidemiological information. Hospital effluents are rich in patient-derived bacteria and can thus readily become a birthplace and hotspot reservoir for antibiotic resistant pathogens which are eventually incorporated into the environment. Yet, the scope to which nosocomial outbreaks impact the urban environment is still poorly understood. RESULTS: In this work, we extensively show that different urban waters from creeks, beaches, sewage spillways and collector pipes enclose discrete microbial communities that are characterized by a differential degree of contamination and admixture with human-derived bacteria. The abundance of human bacteria correlates with the abundance of AMR genes in the environment, with beta-lactamases being the top-contributing class to distinguish low vs. highly-impacted urban environments. Indeed, the abundance of beta-lactamase resistance and carbapenem resistance determinants in the urban environment significantly increased in a 1-year period. This was in line with a pronounced increase of nosocomial carbapenem-resistant infections reported during the same period that was mainly driven by an outbreak-causing, carbapenemase-producing Klebsiella pneumoniae (KPC) ST-11 strain. Genome-resolved metagenomics of urban waters before and after this outbreak, coupled with high-resolution whole-genome sequencing, confirmed the dissemination of the ST-11 strain and a novel KPC megaplasmid from the hospital to the urban environment. City-wide analysis showed that geospatial dissemination of the KPC megaplasmid in the urban environment inversely depended on the sewage system infrastructure. CONCLUSIONS: We show how urban metagenomics and outbreak genomic surveillance can be coupled to generate relevant information for infection control, antibiotic stewardship, and pathogen epidemiology. Our results highlight the need to better characterize and understand how human-derived bacteria and antimicrobial resistance disseminate in the urban environment to incorporate this information in the development of effluent treatment infrastructure and public health policies. Video Abstract.


Assuntos
Infecção Hospitalar , Microbiota , Humanos , Antibacterianos/farmacologia , Esgotos , Farmacorresistência Bacteriana/genética , Microbiota/genética , Hospitais , Carbapenêmicos
4.
MethodsX ; 9: 101730, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35664042

RESUMO

The herbicide glyphosate (GLY) and its metabolite aminophosphonic acid (AMPA) are troublesome compounds for analysis in the environment. Here we report a reliable technique for GLY and AMPA determination in freshwater and soils by means of derivatization with 9-fluorenylmethoxycarbonyl chloride (FMOC-Cl) and further liquid chromatography with fluorescence detection (FLD) and tandem mass spectrometry (MS/MS) analysis. Selected experiments were carried out to evaluate selectivity, sensitivity, repeatability, linearity and quantification performance in both matrices.

5.
Sci Total Environ ; 838(Pt 2): 156077, 2022 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-35597351

RESUMO

Plastics pose a major threat to aquatic ecosystems especially in smaller size fractions. Salt marshes play a crucial role in maintaining the coastal zone and aquatic food web, yet their contamination, including by plastic materials, is still poorly investigated. This work investigated meso- (MEP, 5-25 mm) and microplastic (MIP, 1 µm-5 mm) contamination of a salt marsh, which reached average levels of 279.63 ± 410.12 items kg-1, 366.92 ± 975.18 items kg-1, and 8.89 ± 8.75 items L-1 in surface sediment, sediment cores and water, respectively. Photomicrographs revealed a complex fouling community on plastics surface for both different salt marsh zones and plastic formats. Abundance of plastics in sediment was higher in the dryer, vegetated zones compared to flooded, unvegetated zones. This is consistent with the role of vegetation as a trap for solid litter and final fate of plastic deposition, but also with local hydrodynamics influencing deposition pattern. Plastics were detected up to 66 cm-depth, presenting higher levels at surface sediments. It was also possible to identify the main groups of microorganisms (1638 bacterial cells, 318 microalgae cells, and 20049.93 µm2 of filamentous fungi) composing the Plastisphere communities on all plastic items recorded in the different zones. These results are a pioneer contribution, highlighting that regional salt marshes participate in sequestration and longstanding accumulation of plastic particles in estuarine environments, before exportation to the ocean.


Assuntos
Microplásticos , Poluentes Químicos da Água , Brasil , Ecossistema , Monitoramento Ambiental , Sedimentos Geológicos , Plásticos , Poluentes Químicos da Água/análise , Áreas Alagadas
6.
Environ Sci Pollut Res Int ; 29(2): 2311-2324, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34365604

RESUMO

Detection, identification, and quantification of microplastics have become increasingly relevant for determining their contribution and role in environmental pollution. Thermal analysis is positioned as one of the alternative techniques employed to quantify microplastics. However, a deeper investigation that explores its capabilities is required, since in techniques such as difference scanning calorimetry (DSC), the result of the melting curve is potentially affected by the size of the micro particles. Therefore, to use this technique in the field of quantitative analysis of microplastics, it is necessary to make an evaluation of how the micro particle size affects the signal obtained. We use spherical polyethylene (PE) particles of different sizes (75-710 µm) as a microplastic model to study the effect of particle size and the mixtures of different particle sizes on the melting curve. The effect of possible interferences on the DSC signal was studied and real microplastics isolated from wastewater were tested. It was found that the DSC signal (both melting temperature and peak shape) is affected by the size of the particles, even in the case of mixtures of particles of different sizes. However, through an appropriate sample preparation, it is possible to identify the signals corresponding to microplastics of different sizes and thus quantify their contribution to the mass of the sample. It was evidenced that factors such as the presence of inorganic materials tend to modify the melting temperature. Also, removal of interferences of organic origin is feasible. In addition, the presence of PP, HDPE and LDPE was evidenced in wastewater samples. Our results represent an important advance in the use of the DSC technique in the field of microplastics, since the existence of particles of different sizes can be evidenced in the same sample allowing for an estimation of the number of microplastic particles. Finally, we show the applicability of DSC study on microplastics in environmental matrices.


Assuntos
Microplásticos , Poluentes Químicos da Água , Varredura Diferencial de Calorimetria , Monitoramento Ambiental , Plásticos , Polietileno/análise , Poluentes Químicos da Água/análise
7.
Syst Biol ; 70(6): 1090-1100, 2021 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-33787920

RESUMO

Sigmodontine rodents (Cricetidae, Sigmodontinae) represent the second largest muroid subfamily and the most species-rich group of New World mammals, encompassing above 410 living species and ca. 87 genera. Even with advances on the clarification of sigmodontine phylogenetic relationships that have been made recently, the phylogenetic relationships among the 12 main groups of genera (i.e., tribes) remain poorly resolved, in particular among those forming the large clade Oryzomyalia. This pattern has been interpreted as consequence of a rapid radiation upon the group entrance into South America. Here, we attempted to resolve phylogenetic relationships within Sigmodontinae using target capture and high-throughput sequencing of ultraconserved elements (UCEs). We enriched and sequenced UCEs for 56 individuals and collected data from four already available genomes. Analyses of distinct data sets, based on the capture of 4634 loci, resulted in a highly resolved phylogeny consistent across different methods. Coalescent species-tree-based approaches, concatenated matrices, and Bayesian analyses recovered similar topologies that were congruent at the resolution of difficult nodes. We recovered good support for the intertribal relationships within Oryzomyalia; for instance, the tribe Oryzomyini appears as the sister taxa of the remaining oryzomyalid tribes. The estimates of divergence times agree with the results of previous studies. We inferred the crown age of the sigmodontine rodents at the end of the Middle Miocene, while the main lineages of Oryzomyalia appear to have radiated in a short interval during the Late Miocene. Thus, the collection of a genomic-scale data set with a wide taxonomic sampling provided resolution for the first time of the relationships among the main lineages of Sigmodontinae. We expect the phylogeny presented here will become the backbone for future systematic and evolutionary studies of the group.[Coalescent; Muroidea; Oryzomyalia; phylogenomics; polytomy; Rodentia; Sigmodontalia; species tree; UCEs.].


Assuntos
Roedores , Sigmodontinae , Animais , Arvicolinae , Teorema de Bayes , Filogenia , Sigmodontinae/genética
8.
Environ Sci Pollut Res Int ; 28(14): 18234-18245, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33410051

RESUMO

Semiconductor nanoparticle-mediated photocatalysis is an attractive option for water decontamination, being the semiconductors as SnS2 with a bandgap in the visible region, the most promising materials. In the present work, we evaluated the influence of important parameters in the photocatalytic application of SnS2 nanoparticles. Our results show that the presence of citric acid (used as a capping agent) restricts the formation of hexagonal nanoparticles. We also demonstrated that using thioacetamide as a sulfur source results in smaller nanoparticles than thiourea, 24.0 nm and 616 nm respectively. Moreover, small hexagonal nanoparticles play a key role in the photocatalytic activity of SnS2 nanoparticles. Compared with TiO2 performance, SnS2 nanoparticles exhibited faster kinetics for methyl orange (MO) degradation, Kapp = 0.0102 min-1, and 0.029 min-1, respectively. We proved that SnS2 is capable of breaking the azo bond of methyl orange by direct reduction. Furthermore, our analyses indicate that SnS2 nanoparticles do not degrade atrazine and imazapic, but the photocatalytic route of metribuzin competed with photolysis, resulting in a particular transformation product that was not obtained with light irradiation only. We demonstrated that SnS2 nanoparticles have high bond selectivity for azo breaking. Furthermore, they represent an advance for the development of designed materials (such as heterostructures), where the properties of SnS2 can be tuned.


Assuntos
Nanopartículas , Poluentes Químicos da Água , Compostos Azo , Catálise , Ácido Cítrico , Fotólise , Enxofre , Titânio
9.
Environ Sci Pollut Res Int ; 27(7): 7409-7419, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31884541

RESUMO

Many reports state the potential hazards of microplastics (MPs) and their implications to wildlife and human health. The presence of MP in the aquatic environment is related to several origins but particularly associated to their occurrence in wastewater effluents. The determination of MP in these complex samples is a challenge. Current analytical procedures for MP monitoring are based on separation and counting by visual observation or mediated with some type of microscopy with further identification by techniques such as Raman or Fourier-transform infrared (FTIR) spectroscopy. In this work, a simple alternative for the separation, counting and identification of MP in wastewater samples is reported. The presented sample preparation technique with further polarized light optical microscopy (PLOM) observation positively identified the vast majority of MP particles occurring in wastewater samples of Montevideo, Uruguay, in the 70-600 µm range. MPs with different shapes and chemical composition were identified by PLOM and confirmed by confocal Raman microscopy. Rapid identification of polyethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET) were evidenced. A major limitation was found in the identification of MP from non-birefringent polymers such as PVC (polyvinylchloride). The proposed procedure for MP analysis in wastewater is easy to be implemented at any analytical laboratory. A pilot monitoring of Montevideo WWTP effluents was carried out over 3-month period identifying MP from different chemical identities in the range 5.3-8.2 × 103 MP items/m3.


Assuntos
Microplásticos/análise , Águas Residuárias , Poluentes Químicos da Água , Monitoramento Ambiental , Microplásticos/química , Microscopia , Águas Residuárias/análise , Águas Residuárias/química
10.
Sci Total Environ ; 697: 134058, 2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31487597

RESUMO

Emerging contaminants (ECs) such as pharmaceuticals, personal care products, drugs of abuse and polar pesticides are under particular attention due to their high consumption, frequent detection in the environment and reported ecotoxicological risk. This study investigates the occurrence and distribution of multiclass of ECs in surface waters at basin scale of two Atlantic coastal lagoons of Uruguay, South America. For this purpose, a target screening approach covering up to 362 compounds was employed using nanoflow liquid chromatography - high resolution mass spectrometry (nanoLC/HRMS). 56 compounds were identified including five banned pesticides in the European Union: atrazine, carbendazim, chlorpyrifos ethyl, diazinon, and ethion. Pharmaceuticals, hormones and drugs of abuse showed maximum detection frequencies and concentrations downstream cities. The highest occurrence of pesticides was found in lagoons and streams with neighboring agricultural activity. ECs were also found in coastal sea. Environmental risk assessment revealed that the hormones 17α-ethinylestradiol and 17-ß-estradiol showed the highest risk to aquatic organisms in these basins. This study represents the first basin- scale monitoring of ECs in superficial waters encompassing streams, lagoons, and coastal seas in Uruguay, South America.

11.
Rev. bras. farmacogn ; 29(4): 500-503, July-Aug. 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1042273

RESUMO

Abstract Workflows based on gas and liquid chromatography coupled to mass spectrometry for the identification of toxic pyrrolizidine alkaloids present in plants were developed and applied to Echium plantagineum L., Boraginaceae, extracts. GC-MS based determinations need reduction and derivatization steps prior to MS analysis, which is performed using a Full Scan and Single Ion Monitoring sequence for screening, identification and quantification purposes. The LC-(ESI)-MS/MS determination was performed directly from the extract without derivatization. Acetyl lycopsamine, echimidine, echimidine N-oxide, echiumine, echiumine N-oxide, lycopsamine, lycopsamine N-oxide, 7,9-ditigloylretronecine N-oxide and a not reported PA of m/z 466, were identified and quantified in E. plantagineum extracts, through three operating modes of LC-QTRAP: precursor ion scan, enhanced product ion scan and multiple reaction monitoring. Precursor ion scan detects all the ions that give rise to a daughter ion at m/z 120, the presence of the parent pyrrolizidine alkaloid is confirmed through its MS2 spectrum (enhanced product ion) and quantified by multiple reaction monitoring. These workflows are general approaches to study chemical families using GC/LC-MS. For extracts suspicious of containing pyrrolizidine alkaloids, they are suitable tools for the quality and safety control of food, feed as well as phytotherapeutics.

12.
MethodsX ; 6: 929-937, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31080757

RESUMO

With the aim of monitoring multiclass semi-polar pesticide residues in freshwater fatty fish, two QuEChERS approaches (so-called acetate buffered and unbuffered versions) were evaluated for the determination of 77 pesticide residues. Compounds were selected according to the dominant rainfed agriculture activities in South America. Unbuffered QuEChERS was finally chosen for validation purposes owing that it provided the best results in terms of recovery yields. Method performance was evaluated in two instrumental systems, liquid chromatography - tandem mass spectrometry (LC-MS/MS) in Scheduled MRM™ algorithm available on hybrid quadrupole - linear ion trap (QLIT) instrument, and gas chromatography - mass spectrometry (GC-MS) under selected ion monitoring (SIM) mode. Spiking experiments were carried out to determine the trueness, precision, linearity, limit of quantification of the method as well as matrix effect. The Unbuffered QuECHERS method described here: •Was validated for the analysis of 67 pesticide residues in fish muscle tissue.•Presented quantification limits in the range 1-15 µg kg-1 for the vast majority of the studied compounds.•Enable environmental monitoring of pesticide residues in fish due to their low LOQs.

13.
Appl Environ Microbiol ; 85(1)2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30366992

RESUMO

Hanseniaspora is the main genus of the apiculate yeast group that represents approximately 70% of the grape-associated microflora. Hanseniaspora vineae is emerging as a promising species for quality wine production compared to other non-Saccharomyces species. Wines produced by H. vineae with Saccharomyces cerevisiae consistently exhibit more intense fruity flavors and complexity than wines produced by S. cerevisiae alone. In this work, genome sequencing, assembling, and phylogenetic analysis of two strains of H. vineae showed that it is a member of the Saccharomyces complex and it diverged before the whole-genome duplication (WGD) event from this clade. Specific flavor gene duplications and absences were identified in the H. vineae genome compared to 14 fully sequenced industrial S. cerevisiae genomes. The increased formation of 2-phenylethyl acetate and phenylpropanoids such as 2-phenylethyl and benzyl alcohols might be explained by gene duplications of H. vineae aromatic amino acid aminotransferases (ARO8 and ARO9) and phenylpyruvate decarboxylases (ARO10). Transcriptome and aroma profiles under fermentation conditions confirmed these genes were highly expressed at the beginning of stationary phase coupled to the production of their related compounds. The extremely high level of acetate esters produced by H. vineae compared to that by S. cerevisiae is consistent with the identification of six novel proteins with alcohol acetyltransferase (AATase) domains. The absence of the branched-chain amino acid transaminases (BAT2) and acyl coenzyme A (acyl-CoA)/ethanol O-acyltransferases (EEB1) genes correlates with H. vineae's reduced production of branched-chain higher alcohols, fatty acids, and ethyl esters, respectively. Our study provides sustenance for understanding and potentially utilizing genes that determine fermentation aromas.IMPORTANCE The huge diversity of non-Saccharomyces yeasts in grapes is dominated by the apiculate genus Hanseniaspora Two native strains of Hanseniaspora vineae applied to winemaking because of their high oenological potential in aroma and fermentation performance were selected to obtain high-quality genomes. Here, we present a phylogenetic analysis and the complete transcriptome and aroma metabolome of H. vineae during three fermentation steps. This species produced significantly richer flavor compound diversity than Saccharomyces, including benzenoids, phenylpropanoids, and acetate-derived compounds. The identification of six proteins, different from S. cerevisiae ATF, with diverse acetyltransferase domains in H. vineae offers a relevant source of native genetic variants for this enzymatic activity. The discovery of benzenoid synthesis capacity in H. vineae provides a new eukaryotic model to dilucidate an alternative pathway to that catalyzed by plants' phenylalanine lyases.


Assuntos
Genoma Fúngico , Hanseniaspora/genética , Paladar , Transcriptoma , Vinho/análise , Fermentação , Hanseniaspora/metabolismo
14.
PeerJ ; 6: e5856, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30402351

RESUMO

The glassfrog Centrolene buckleyi has been recognized as a species complex. Herein, using coalescence-based species delimitation methods, we evaluate the specific diversity within this taxon. Four coalescence approaches (generalized mixed Yule coalescents, Bayesian general mixed Yule-coalescent, Poisson tree processes, and Bayesian Poisson tree processes) were consistent with the delimitation results, identifying four lineages within what is currently recognized as C. buckleyi. We propose three new candidate species that should be tested with nuclear markers, morphological, and behavioral data. In the meantime, for conservation purposes, candidate species should be considered evolutionary significant units, in light of observed population crashes in the C. buckleyi species complex. Finally, our results support the validity of C. venezuelense, formerly considered as a subspecies of C. buckleyi.

15.
Environ Sci Pollut Res Int ; 25(17): 16767-16775, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29611128

RESUMO

There are several techniques used to analyze microplastics. These are often based on a combination of visual and spectroscopic techniques. Here we introduce an alternative workflow for identification and mass quantitation through a combination of optical microscopy with image analysis (IA) and differential scanning calorimetry (DSC). We studied four synthetic polymers with environmental concern: low and high density polyethylene (LDPE and HDPE, respectively), polypropylene (PP), and polyethylene terephthalate (PET). Selected experiments were conducted to investigate (i) particle characterization and counting procedures based on image analysis with open-source software, (ii) chemical identification of microplastics based on DSC signal processing, (iii) dependence of particle size on DSC signal, and (iv) quantitation of microplastics mass based on DSC signal. We describe the potential and limitations of these techniques to increase reliability for microplastic analysis. Particle size demonstrated to have particular incidence in the qualitative and quantitative performance of DSC signals. Both, identification (based on characteristic onset temperature) and mass quantitation (based on heat flow) showed to be affected by particle size. As a result, a proper sample treatment which includes sieving of suspended particles is particularly required for this analytical approach.


Assuntos
Plásticos/análise , Polietileno/análise , Polímeros/análise , Polipropilenos/análise , Varredura Diferencial de Calorimetria , Tamanho da Partícula , Plásticos/química , Polietileno/química , Polímeros/química , Polipropilenos/química , Reprodutibilidade dos Testes
16.
Sci Total Environ ; 631-632: 169-179, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29524894

RESUMO

Environmental sustainability of South American rainfed agroecosystems is of current concern. In this work, we evaluate the occurrence of multiple pesticide residues in muscle tissue of wild fish species from two large rivers in South America (Uruguay and Negro Rivers). Two sampling campaigns (representing summer and winter crops) were performed during 2015 targeting a wide biodiversity of fish species used for human consumption (ranging from migratory to non-migratory and from detritivorous to top-predators). Three different localities associated to rainfed agriculture were assessed, two of them enclosed to a RAMSAR site (National Park "Esteros de Farrapos e Islas del Rio Uruguay"). Pesticide residues occurred in muscle tissue of 143 from 149 sampled fishes (96%). Thirty different pesticides were detected at concentrations from <1 to 194µgkg-1. Incidence of pesticides in fish were tightly related to: i) features of the contaminant: (Kow, environmental persistence and mobility) and ii) intensity of use of particular pesticides and land dedicated to rainfed agriculture. Trifloxystrobin, metolachlor and pyraclostrobin showed the highest rates of occurrence. Of great concern is that strobirulins have highest toxicity to fish from those detected compounds. From the pattern of pesticides occurring for non-migratory fish species it was possible to trend important spatial differences related to the intensity of rainfed agriculture. Results suggest a regular exposition of aquatic wild biota to sublethal concentrations of multiple semi-polar pesticides.


Assuntos
Monitoramento Ambiental , Peixes/metabolismo , Resíduos de Praguicidas/metabolismo , Poluentes Químicos da Água/análise , Agricultura , Animais , Ecossistema , Resíduos de Praguicidas/análise , Praguicidas/análise , Praguicidas/metabolismo , Chuva , Rios/química , América do Sul , Poluentes Químicos da Água/metabolismo
17.
Rev Med Chil ; 144(2): 152-61, 2016 Feb.
Artigo em Espanhol | MEDLINE | ID: mdl-27092668

RESUMO

BACKGROUND: Exercise training could interact with the pharmacological therapy of hypertension, increasing the effects of these medications. AIM: To assess the effects of 12 weeks of physical training on blood pressure of hypertensive or diabetic patients, already receiving pharmacological therapy. MATERIAL AND METHODS: Twelve participants with diabetes and hypertension, 16 participants with hypertension and 18 healthy participants were studied. During six weeks no intervention was carried out, except the treatment for their underlying conditions. During the ensuing six weeks, participants were subjected 12 sessions of physical training. Blood pressure was measured at baseline and after six and twelve weeks of intervention. RESULTS: During the period without physical training, no changes in blood pressure were observed. After the physical training intervention systolic blood pressure decreased by 16, 17 and 20 mm Hg in participants with diabetes and hypertension, participants with hypertension and healthy participants, respectively. Diastolic blood pressure decreased by 9 and 6 mmHg in participants with diabetes and hypertension and hypertension alone, respectively. CONCLUSIONS: There is a decrease in blood pressure among hypertensive participants receiving pharmacological therapy, after a period of physical training.


Assuntos
Anti-Hipertensivos/uso terapêutico , Diabetes Mellitus Tipo 2/terapia , Terapia por Exercício/métodos , Hipertensão/terapia , Adulto , Estudos de Casos e Controles , Terapia Combinada/métodos , Estudos Transversais , Humanos , Hipertensão/fisiopatologia , Hipoglicemiantes/uso terapêutico , Metformina/uso terapêutico , Pessoa de Meia-Idade , Resultado do Tratamento
18.
Rev. méd. Chile ; 144(2): 152-161, feb. 2016. ilus, tab
Artigo em Espanhol | LILACS | ID: lil-779481

RESUMO

Background: Exercise training could interact with the pharmacological therapy of hypertension, increasing the effects of these medications. Aim: To assess the effects of 12 weeks of physical training on blood pressure of hypertensive or diabetic patients, already receiving pharmacological therapy. Material and methods: Twelve participants with diabetes and hypertension, 16 participants with hypertension and 18 healthy participants were studied. During six weeks no intervention was carried out, except the treatment for their underlying conditions. During the ensuing six weeks, participants were subjected 12 sessions of physical training. Blood pressure was measured at baseline and after six and twelve weeks of intervention. Results: During the period without physical training, no changes in blood pressure were observed. After the physical training intervention systolic blood pressure decreased by 16, 17 and 20 mm Hg in participants with diabetes and hypertension, participants with hypertension and healthy participants, respectively. Diastolic blood pressure decreased by 9 and 6 mmHg in participants with diabetes and hypertension and hypertension alone, respectively. Conclusions: There is a decrease in blood pressure among hypertensive participants receiving pharmacological therapy, after a period of physical training.


Assuntos
Humanos , Adulto , Pessoa de Meia-Idade , Diabetes Mellitus Tipo 2/terapia , Terapia por Exercício/métodos , Hipertensão/terapia , Anti-Hipertensivos/uso terapêutico , Estudos de Casos e Controles , Estudos Transversais , Resultado do Tratamento , Terapia Combinada/métodos , Hipertensão/fisiopatologia , Hipoglicemiantes/uso terapêutico , Metformina/uso terapêutico
19.
Food Chem ; 194: 1132-7, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26471663

RESUMO

The degradation of the postharvest fungicides imazalil, orthophenylphenol, and pyrimethanil was studied on Clementine mandarins during packinghouse storage for a 28day period at 4°C. Fruits to which orthophenylphenol was applied, were treated with imazalil and pyrimethanil at doses of 1000 and 2000mgL(-1), using cascade application for the later and cascade and wax for the former. The decay of the three fungicides was evaluated using an in-house validated analytical procedure that includes the extraction and dispersive clean up of the samples followed by the GC-MS determination of the pesticide residues. The impact of fruit storage time on pesticide residues concentration was assessed. The residues found for the different application technologies were always below the established Maximum Residue Limits by the Codex Alimentarius and the European Union (5mgkg(-1) for imazalil, 7 and 8mgkg(-1) for pyrimethanil, and 10mgkg(-1) and 5mgkg(-1) for orthophenylphenol). The fungicides dissipated differentially. Pyrimethanil showed little degradation, if any, at both tested concentrations, but the half-life of imazalil on the fruit was 15-18days, independent of the application technology. Orthophenylphenol dissipated with a half-life of 15days. The initial imazalil residue found after cascade treatment was not significantly different between the doses studied (p<0.5), whereas when the fungicide was included in wax as an emulsifiable concentrate the initial and final imazalil residues were significantly different. Final residue levels after 28days of storage were 0.12-0.24mgkg(-1) for imazalil, 0.68mgkg(-1) for 2-phenylphenol and 0.56mgkg(-1) for pyrimethanil for all the evaluated treatments.


Assuntos
Compostos de Bifenilo/química , Citrus/química , Frutas/química , Imidazóis/química , Pirimidinas/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...