2,590 research outputs found
Occurrence of tet(O/M/O) mosaic gene in tetracycline-resistant Campylobacter
Campylobacter is one of the most important microorganisms responsible for foodborne diseases in the EU. In this study, we investigated resistance to tetracycline in 139 Campylobacter jejuni and Campylobacter coli samples isolated from human clinical cases. From these, 110 were resistant to tetracycline, with MIC (minimal inhibitory concentration) varying in a range of 1 to >512 ug/mL, and 109 (78.4%) carried tet(O), a gene that confers resistance to tetracycline through the expression of a protein that confers protection to the ribosome. Amongst the tetracycline-resistant isolates, one C. jejuni (HCC30) was the only tet(O)-negative sample, presenting an MIC of 256 ug/mL. Instead, the mosaic gene tet(O/M/O) was found in HCC30 and, as far as we know, this is the first description of this chimeric gene originating from homologous recombination between tet(O) and tet(M). The previously described mosaic gene tet(O/32/O), also found in Campylobacter, presents a
chimeric structure very similar to that of tet(O/M/O), affecting domains II and III of encoded proteins distantly related to the elongation factor G (EF-G). The tet(O/M/O) mosaic gene has been found in nucleotide databases in several genomes of Campylobacter isolated from different origins, indicating its frequent acquisition, even though it can be undetected through screening by PCR with specific tet(O) primers. In this work, we address the improvement of classical PCR to effciently diagnose the most prevalent tetracycline resistance determinants in Campylobacter, including tet(O/M/O), which should be taken into account in the optimization of campylobacteriosis treatments.info:eu-repo/semantics/publishedVersio
Optimal filter approximation by means of a phase-only filter with quantization
Approximate filters based on a phase-only filter for reliable recognition of objects are proposed. Good light efficiency and discrimination capability close to that of the optimal filter can be obtained. Computer simulation results are presented and discussed
Drp1-mediated mitochondrial fission regulates calcium and F-actin dynamics during wound healing
This work was supported by national funds through FCT - Fundação para a Ciência e a Tecnologia, I.P., in the context of a program contract to L. Carvalho (4, 5 and 6 of article 23.º of D.L. no. 57/2016 of 29 August, as amended by Law no. 57/2017 of 19 July), PD/BD/106058/2015 to S. Ponte and PTDC/BIA-BID/29709/2017; the European Research Council (2007-StG-208631) and CONGENTO LISBOA-01-0145-FEDER-022170.Mitochondria adapt to cellular needs by changes in morphology through fusion and fission events, referred to as mitochondrial dynamics. Mitochondrial function and morphology are intimately connected and the dysregulation of mitochondrial dynamics is linked to several human diseases. In this work, we investigated the role of mitochondrial dynamics in wound healing in the Drosophila embryonic epidermis. Mutants for mitochondrial fusion and fission proteins fail to close their wounds, indicating that the regulation of mitochondrial dynamics is required for wound healing. By live-imaging, we found that loss of function of the mitochondrial fission protein Dynamin-related protein 1 (Drp1) compromises the increase of cytosolic and mitochondrial calcium upon wounding and leads to reduced ROS production and F-actin defects at the wound edge, culminating in wound healing impairment. Our results highlight a new role for mitochondrial dynamics in the regulation of calcium, ROS and F-actin during epithelial repair.publishersversionpublishe
Pineapple by-products integrated valorisation towards functional foods
This work was financially supported by CBQF under the FCT – Fundação para a Ciência e a
Tecnologia through project Multibiorefinery – Multi-purpose strategies for the valorisation of a wide range of
agroforestry by-products and fisheries: A step forward in the creation of an integrated biorefinery, (POCI-01-0145-
FEDER-0066) and the project UID/Multi/50016/2019 and by PhD grant SFRH/BD/104074/2014 to Débora Campos.info:eu-repo/semantics/publishedVersio
ICTs in remote assessment
This work describes an experience carried out using Information and Communication Technologies (ICTs) in the assessment of the individual project in the final graduation year. This challenge involved two institutions of higher education: Minho and Porto Universities
Ies we can: web-based gamified learning for social entrepreneurship and innovation
In the Social Entrepreneurship and Innovation course of the Occupational Therapy degree (School of Health, Polytechnic University of Porto) a gamification method was employed to complement the teaching-learning process.info:eu-repo/semantics/publishedVersio
Integral valorization of pineapple (Ananas comosus l.) by-products through a green chemistry approach towards added value ingredients
We would like to thank the scientific collaboration of Escola Superior de Biotecnologia of
Universidade Católica Portuguesa through CBQF under FCT–Fundação para a Ciência e a Tecnologia, to accept
Débora Campos through a Ph.D. grant SFRH/BD/104074/2014.Industrial by-products are produced every day through fruit processing industries. Pineapple is not an exception; when processed, around 60% (w/w) of its weight are peels, stem, trimmings, and crown, the only used fruit part for human consumption. Due to high concerns of sustainability in the food system and negative high impact of human practice in the environment, a strategy has to be developed. Therefore, a green chemistry approach was applied to pineapple by-products to make an integrated valorization by the extraction of bioactive molecules. Two pineapple by-products (peels and stems) were studied, applying a green chemistry approach, which means the non-use of organic solvents or extreme methodologies. A subdivision of each by-product was done by the application of a juice machine. The peels and stems in the fresh state were ground separately, creating two fractions for each by-product—a juice and a wet pulp (press cake). The press cake was characterized, dried, and ground to create a fine powder flour. To the juice, a precipitation methodology with polysaccharides was applied, which allowed the bromelain separation (developing of an enzymatic fraction) from the fruit juice. The enzymatic extract was freeze-dried, and the juice was spray-dried, developing two more fine powders. Thus, three new ingredients were produced from each by-product, creating a total of six new ingredients. Overall, the enzymatic fractions represented around 0.26% (w/w) of pineapple weight. Pineapple stem juice represented 4.8% (w/w), and peel juice represented 17.3% (w/w). Pineapple stem flour represented 3.1% (w/w), and peel flour represented 11.4% (w/w) of the total pineapple weight. To valorize the by-products juices, a full characterization was performed of bioactive molecules and biological activities. When comparing the two juices, the peel juice showed lower content of total phenolic compounds, lower antioxidant capacity, and lower content of vitamin C. The different phenolic compounds were identified by HPLC analysis in the two pineapple by-products juices. However, the same compounds in both juices were quantified (chlorogenic, caffeic, and ferulic acids). On the other hand, the by-products flours had a high content of insoluble dietary fiber (IDF), mainly cellulose and hemicellulose. Therefore, the approach applied in this work opens the door to the production of green products, as a result of by-products valorization. This could be applied not only in the food industry but also in the nutraceutical and cosmetic industries.This research was funded by BiValBi–Biotechnologies to Valorize the regional Biodiversity in Latin
America, in the funding project FP/-PEOPLE-2013-IRSES PEOPLE Marie Curie Program through project
reference PIRSES-GA-2013-611493 and by FCT through project Multibiorefinery–Multi-purpose strategies for
the creation of an integrated biorefinery (POCI-01-0145-FEDER-0066) and the project UID/Multi/50016/2019.info:eu-repo/semantics/publishedVersio
Insights into the restoration of tributyltin contaminated environments using marine bacteria from Portuguese fishing ports
Tributyltin (TBT) is an organotin chemical mainly used as biocide in marine antifouling paints. Despite the restrictions and prohibitions on its use, TBT is still an environmental problem due to its extensive application and subsequent release into the environment, being regarded as one of the most toxic chemicals released into the marine ecosystems. Microorganisms inhabiting impacted sites are crucial for their restoration since they have developed mechanisms to tolerate and break down pollutants. Nonetheless, transformation products resulting from the degradation process may still be toxic or, sometimes, even more toxic than the parent compound. The determination of the parent and degradation products by analytical methods, although necessary, may not be ecologically relevant since no information is provided regarding their ecotoxicity. In this study, marine bacteria collected from seven Portuguese fishing ports were isolated and grown in the presence of TBT. Bacteria that exhibited higher growth were used to bioremediate TBT-contaminated waters. The potential of these bacteria as bioremediation agents was evaluated through ecotoxicological assays using the sea snail Gibbula umbilicalis as model organism. Data suggested that some TBT-tolerant bacteria, such as Pseudomonas putida, can reduce the toxicity of TBT contaminated environments. This work contributes to the knowledge of TBT-degrading bacteria.info:eu-repo/semantics/publishedVersio
Thrombophilic risk factors for retinal vein occlusion
The aim is to study risk factors for retinal vein occlusion (RVO), such as thrombophilic and cardiovascular risk factors (CRF). A retrospective consecutive case series of 60 patients with RVO was made, tested for CRF, hyperhomocysteinemia, lupic anticoagulant, antiphospholipid antibody and 5 gene variants: factor V (FV) Leiden (G1691A), factor II (PT G20210A), 5,1-methylenetetra-hydrofolate reductase (MTHFR; 677 C > T and 1298 A > C), plasminogen activator inhibitor 1 (PAI-1; 4 G/5 G). More than 1 CRF were present in 36 patients (60%), which had a significantly higher mean age at diagnosis (66.7 ± 12.9 versus 59.5 ± 13.7 with ≤1 CRF, [t(57) = -2.05, p = 0.045, d = 0.54). Patients with thermolabile MTHFR forms with decreased enzyme activity (T677T or C677T/A1298C) had a significant lower mean age [57.6 ± 15.1; t (58) = 3.32; p = 0.002; d = 0.846] than patients with normal MTHFR enzyme activity (68.5 ± 10.2). Regarding CRF and thermolabile forms of MTHFR, the mean age at diagnosis could be significantly predicted [F(2,56) = 7.18; p = 0.002] by the equation: 64.8 - 10.3 × (thermolabile MTHFR) - 5.31 × ( ≤ 1CRF). Screening of MTHFR polymorphisms may be useful in younger RVO patients, particularly when multiple CRF are absent.info:eu-repo/semantics/publishedVersio
Pushing the Limits for Thiol−Ene and CuAAC Reactions: Synthesis of a 6th Generation Dendrimer in a Single Day
Dendrimer synthesis should not be tedious and time-consuming. By utilizing an AB2−CD2 approach and having orthogonal, “clickable” groups on each monomer, the time for dendrimer assembly can be drastically reduced. This was shown by preparation of a sixth generation dendrimer from starting monomer units in a single day
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