512 research outputs found
Monitoring the impact of fertilizers on soil leachates using sequential injection analysis for multiparametric determination
info:eu-repo/semantics/publishedVersio
Potential of mannan or dextrin nanogels as vaccine carrier/adjuvant systems
Polymeric nanogels have been sophisticatedly designed promising a new generation of vaccine delivery/adjuvant systems capable of boosting immune response, a strategic priority in vaccine design. Here, nanogels made of mannan or dextrin were evaluated for their potential as carriers/adjuvants in vaccine formulations. Since lymph nodes are preferential target organs for vaccine delivery systems, nanogels were biotin-labeled, injected in the footpad of rats, and their presence in draining lymph nodes was assessed by immunofluorescence. Nanogels were detected in the popliteal and inguinal lymph nodes by 24h upon subcutaneous administration, indicating entrapment in lymphatic organs. Moreover, the model antigen ovalbumin was physically encapsulated within nanogels and physicochemically characterized concerning size, zeta potential, ovalbumin loading, and entrapment efficiency. The immunogenicity of these formulations was assessed in mice intradermally immunized with ovalbuminmannan or ovalbumindextrin by determining ovalbumin-specific antibody serum titers. Intradermal vaccination using ovalbuminmannan elicited a humoral immune response in which ovalbumin-specific IgG1 levels were significantly higher than those obtained with ovalbumin alone, indicating a TH2-type response. In contrast, dextrin nanogel did not show adjuvant potential. Altogether, these results indicate that mannan nanogel is a material that should be explored as a future antigen delivery system.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work is supported by the Fundação para a Ciência e a Tecnologia (FCT) Portugal, post-doc grant SFRH/BPD/70524/2010 and the International Iberian Nanotechnology Laboratory (INL), PhD grant. The authors thank the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684). The authors also acknowledge the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462)
Bovine tuberculosis in the state of ParaÃba: retrospective survey
O objetivo do presente trabalho foi determinar a frequência de propriedades positivas (focos) e de animais positivos para a tuberculose bovina no Estado da ParaÃba. Foram utilizados dados da Agência de Defesa Agropecuária do Estado, coletados de suas 23 microrregiões, durante o perÃodo de janeiro de 2008 a julho de 2009. Durante esse perÃodo, foram examinadas 10.963 propriedades e 54.472 bovinos foram submetidos ao teste de tuberculinização. Para o diagnóstico foi utilizada, como prova de triagem, a tuberculinização cervical simples para gado de leite e a tuberculinização na prega caudal para gado de corte; como prova confirmatória foi utilizada a tuberculinização cervical comparativa. Uma propriedade foi considerada foco quando apresentou pelo menos um animal soropositivo. Das propriedades investigadas, 62 (0,57%) apresentaram pelo menos um animal positivo e dos animais analisados, 136 (0,25%) foram positivos. Houve diferença significativa (p<0,001) na proporção de fêmeas (0,32%) e machos (0,04%) positivos. A despeito da baixa freqüência de focos de brucelose e de animais soropositivos, é necessária a condução de medidas que incluem a conscientização dos produtores, fiscalização nas barreiras sanitárias e levantamentos periódicos da situação epidemiológica desta doença, principalmente nas microrregiões com maior frequência da infecção, com o objetivo de evitar, ou pelo menos minimizar, a disseminação do agente.The aim of this study was to determine the frequency of positive herds (foci) and positive animals for bovine tuberculosis in the state of ParaÃba, Northeast region of Brazil. Data from the Agency of Agricultural Protection in the state, collected from its 23 microregions, during the January 2008 to July 2009 period, were used. During this period, 10,963 herds were examined and 54,472 cattle were submitted to the tuberculin test. For diagnosis the cervical and caudal-fold tuberculin tests were used as screening tests in dairy and beef cattle, respectively; as confirmatory test, comparative cervical test was used. A herd was considered focus when presented at least one positive animal. Of the herds investigated, 62 (0.57%) had at least one positive animal, and of the animals examined, 136 (0.25%) were positive. There was significant difference (p<0.001) in the proportion of positivity for females (0.32%) and males (0.04%). Despite low frequency of foci of brucellosis and seropositive animals, it is necessary to conduct measures including awareness of producers, surveillance in sanitary barriers and periodic surveys of epidemiological situation of this disease especially in the regions with highest frequency of infection, aiming to avoid, or at least minimize, the spread of the agent
Molecular determinants of the SARS-CoV-2 fusion peptide activity
The COVID-19 pandemic, caused by the SARS-CoV-2 virus, emerged in late 2019 and quickly spread worldwide, resulting in over 125 million infections and 2.7 million deaths as of March 2021 accordingly to the World Health Organization. Despite the great advances achieved by the scientific community in providing crucial information about this virus, we are still far from completely understanding it.
SARS-CoV-2 is an enveloped virus, meaning that it is encapsulated by a lipid membrane, which needs to be fused to the host membrane to begin the infection process. Fusion between viral and host membrane is catalyzed by the spike (S) glycoprotein. The S-protein is composed of essential elements for the infection mechanism, namely the receptor-binding domain known to bind to angiotensin-converting enzyme 2 during the viral entry pathway. Another important region, known as the fusion peptide (FP), plays an essential part in the fusion mechanism, by inserting into and disturbing the host membrane. There is still not a consensus among scientists in terms of the fusion peptide location on the S-protein sequence, with two major candidate regions having been proposed.
We recently used a machine learning-based tool developed by us to identify viral FPs with accuracies over 85%. With this tool a putative FP, previously suggested in the literature, has been identified, as well as other proposals including the requirement of more than one FP. To further address this question, we are performing a systematic analysis of the SARS-CoV-2 putative FPs, using Molecular Dynamics (MD) simulations, which provide a detailed perspective of how these peptides insert and interact with the membrane. In parallel, we are characterizing these systems experimentally. Additionally we are exploring therapeutic strategies targeting these regions.
Given the major role of the FP in the virus infection process, this work provides relevant insights and contributes to the fight against COVID-19.info:eu-repo/semantics/publishedVersio
Green extraction techniques as advanced sample preparation approaches in biological, food, and environmental matrices: A review
Green extraction techniques (GreETs) emerged in the last decade as greener and sustainable alternatives to classical sample preparation procedures aiming to improve the selectivity and sensitivity of analytical methods, simultaneously reducing the deleterious side effects of classical extraction techniques (CETs) for both the operator and the environment. The implementation of improved processes that overcome the main constraints of classical methods in terms of efficiency and ability to minimize or eliminate the use and generation of harmful substances will promote more efficient use of energy and resources in close association with the principles supporting the concept of green chemistry. The current review aims to update the state of the art of some cutting-edge GreETs developed and implemented in recent years focusing on the improvement of the main analytical features, practical aspects, and relevant applications in the biological, food, and environmental fields. Approaches to improve and accelerate the extraction efficiency and to lower solvent consumption, including sorbent-based techniques, such as solid-phase microextraction (SPME) and fabric-phase sorbent extraction (FPSE), and solvent-based techniques (μQuEChERS; micro quick, easy, cheap, effective, rugged, and safe), ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE), in addition to supercritical fluid extraction (SFE) and pressurized solvent extraction (PSE), are highlighted.This research was funded by FCT (Fundação para a Ciência e a Tecnologia) through the
CQM Base Fund, UIDB/00674/2020, Programmatic Fund, UIDP/00674/2020, and CEB—Centre of
Biological Engineering, and by ARDITI (Agência Regional para o Desenvolvimento da Investigação
Tecnologia e Inovação) through the project M1420-01-0145-FEDER-000005, Centro de QuÃmica da
Madeira (CQM+; Madeira 14-20 Program). The authors also acknowledge FCT and the Madeira
14–20 Program to the Portuguese Mass Spectrometry Network (RNEM) through the PROEQUIPRAM
program, M14-20 M1420-01-0145-FEDER-000008). ARDITI is also acknowledged for the postdoctoral
fellowship granted to J.A.M.P. (Project M1420-09-5369-FSE-000001).info:eu-repo/semantics/publishedVersio
Cladosporium tenuissimum URM 7803: a promising new β-galactosidase producer
The Cladosporium genus, defined by Link in 1816, is one of the largest and most heterogeneous Hyphomycetes genus. It comprises more than 189 species still rarely explored biotechnologically. One of the most studied microbial enzymes, -galactosidase is a glycoside hydrolase enzyme that catalyzes the hydrolysis of -galactosides into monosaccharides through the breaking of a glycosidic bond. Recently, new studies comprising new microbial sources of -galactosidase, presenting biotechnologically interesting characteristics, have been encouraged. In this context, the present study evaluated the production of -galactosidase by a new isolate of Cladosporium tenuissimum. A C. tenuissimum inoculum was prepared adding 107 spore/mL in sterile saline solution 0.85% (w/v) NaCl containing 0.01% (w/v) Tween 80 and added to fermentation medium for enzyme production. The fermentation medium, composed of (% w/v): lactose (2), peptone (0.4), yeast extract (0.4) and salts (KH2PO4 (0.2), Na2HPO4.12H2O (0.8) and MgSO4.7H2O (0.025), pH 6.5, was maintained at 28° C and 180 rpm for 13 days. One sample (50 mL erlenmeyer) was removed every 24 hours and -galactosidase activity was evaluated using ONPG (ortho-Nitrophenyl--galactoside) method. The results showed maximum -galactosidase production by C. tenuissimum URM 7803 on thirteenth day, displayed enzymatic activity of 462.13 U/mL. The C. tenuissimum URM 7803 isolate proved to be a powerful new -galactosidase producer with potential application for food processing.info:eu-repo/semantics/publishedVersio
Grapevine bioclimatic indices in relation to climate change: a case study in the Portuguese Douro Demarcated Region
Climate change is of major relevance to wine production as most of the wine-growing regions of the world, in
particular the Douro region, are located within relatively narrow latitudinal bands with average growing season temperatures limited to 13-21ºC. This study focuses on the temporal variability of three grapevine bioclimatic indices, which are commonly used as part of the Geoviticulture Multicriteria Climatic Classification System (MCC) to classify the climate of wine producing regions worldwide. Dynamical downscaling of MPI-ESM-LR global data forced with RCP8.5 climatic scenario is performed with the Weather Research and Forecast (WRF) model to a regional scale including the Douro valley of Portugal for recent-past (1986-2005) and future periods (2046-2065; 2081-2100). Results indicate significant shifts towards warmer and dryer conditions during
the growing season and higher night temperatures during the grape ripening period. An assessment on the statistical significance of the differences between the recent-past and the future scenarios and the potential impact on wine production in the study area is performed. These results will provide evidence for future strategies aimed to preserve the high-quality wines in the region and their typicality in a sustainable way.The authors wish to thank the financial support of the
DOUROZONE project (PTDC/AAG-MAA/3335/2014; POCI-
01-0145-FEDER-016778) through the Project 3599 –
Promoting the scientific production and the technological
development, and thematic networks (3599-PPCDT) and
through FEDER, and the national funds from FCT – Science
and Technology Portuguese Foundation for the doc grant of C.
Silveira (SFRH/BD/112343/2015).info:eu-repo/semantics/publishedVersio
Analysis of climate change indices in relation to wine production: a case study in the Douro region (Portugal)
Climate change is of major relevance to wine production as most of the wine-growing regions of
the world, in particular the Douro region, are located within relatively narrow latitudinal bands with average
growing season temperatures limited to 13–21◦C. This study focuses on the incidence of climate variables and
indices that are relevant both for climate change detection and for grape production with particular emphasis
on extreme events (e.g. cold waves, storms, heat waves). Dynamical downscaling ofMPI-ESM-LR global data
forced with RCP8.5 climatic scenario is performed with the Weather Research and Forecast (WRF) model to
a regional scale including the Douro valley of Portugal for recent-past (1986–2005) and future periods (2046–
2065; 2081–2100). The number, duration and intensity of events are superimposed over critical phenological
phases of the vine (dormancy, bud burst, flowering, v´eraison, and maturity) in order to assess their positive
or negative implications on wine production in the region. An assessment on the statistical significance of
climatic indices, their differences between the recent-past and the future scenarios and the potential impact
on wine production is performed. Preliminary results indicate increased climatic stress on the Douro region
wine production and increased vulnerability of its vine varieties. These results will provide evidence for future
strategies aimed to preserve the high-quality wines in the region and their typicality in a sustainable way.The authors wish to thank the financial support of the DOUROZONE project (PTDC/AAG-MAA/3335/2014; POCI- 01-0145-FEDER-016778) through the Project 3599 – Promoting the scientific production and the technological development, and thematic networks (3599-PPCDT) and through FEDER.info:eu-repo/semantics/publishedVersio
Novel platinum(II) complexes of long chain aliphatic diamine ligands with oxalato as the leaving group: comparative cytotoxic activity relative to chloride precursors
Climate change impact on a wine-producing region using a dynamical downscaling approach: Climate parameters, bioclimatic indices and extreme indices
Climate change is of major relevance to wine production as most of the winegrowing
regions of the world are located within relatively narrow latitudinal bands
with average growing-season temperatures (GSTs) limited to 13–21 C. This study
focuses on the incidence of climate variables and indices that are relevant both for
climate change assessment and for grape production, with emphasis on grapevine
bioclimatic indices and extreme events (e.g., cold waves, storms, heatwaves).
Dynamical downscaling of European Reanalysis-Interim and Max Planck Institute
Earth System low-resolution global simulations forced with a Representative Concentration
Pathway 8.5 (RCP8.5) greenhouse gas emission scenario was performed
with the Weather Research and Forecast (WRF) model to a regional scale including
the Douro Valley of Portugal for recent-past (1986–2005) and future periods
(2046–2065, 2081–2100). The number, duration and intensity of events were superimposed
over critical phenological phases estimated by using a specific local
grapevine varietal phenological model in order to assess their positive or negative
implications for wine production in the region. An assessment of the relevance of
climate parameters and indices and their progression in recent-past and future climate
scenarios with regard to the potential impact on wine production was performed.
Results indicate a positive relation between higher growing-season heat
accumulations and greater vintage yields. A moderate incidence of very hot days
(daily maximum temperature above 35 C) and drought from pre-véraison phenological
conditions have a positive association with vintage ratings. However, the
mid- and long-term WRF-MPI RCP8.5 future climate scenarios reveal shifts to
warmer and drier conditions, with the mean GST not remaining within range for
quality wine production in the long-term future climate scenario. These results indicate
potential impacts that suggest a range of strategies to maintain wine production
and quality in the region.The authors wish to thank the DOUROZONE project
(PTDC/AAG-MAA/3335/2014; POCI-01-0145-FEDER-
016778) for financial support through Project 3599 – Promoting
the Scientific Production and the Technological
Development, and Thematic Networks (3599-PPCDT) – and
through FEDER, and the national funds from FCT-Science
and Technology Portuguese Foundation for the doctoral
grant of D. Blanco-Ward (SFRH/BD/139193/2018). Thanks
are also due for the financial support to CESAM
(UID/AMB/50017 - POCI-01-0145-FEDER-007638), to
FCT/MEC through national funds, and the co-funding by
FEDER within the PT2020 Partnership Agreement and
Compete 2020.info:eu-repo/semantics/publishedVersio
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