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1.
Chem Commun (Camb) ; 59(19): 2791-2794, 2023 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-36789540

RESUMO

A novel route is described to obtain 2-aminoimidazole azo dyes with a unique substituent pattern in the heteroaryl unit that provides halochromic properties, exhibiting vibrant colours that change from magenta to deep blue. Potent antimicrobial properties against infectious yeasts were demonstrated. No cytotoxicity was detected for concentrations lower than 16 µg mL-1.


Assuntos
Compostos Azo , Corantes , Imidazóis , Concentração de Íons de Hidrogênio
2.
Nanomaterials (Basel) ; 12(6)2022 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-35335819

RESUMO

Nanotechnology is a powerful tool for engineering functional materials that has the potential to transform textiles into high-performance, value-added products. In recent years, there has been considerable interest in the development of functional textiles using metal nanoparticles (MNPs). The incorporation of MNPs in textiles allows for the obtention of multifunctional properties, such as ultraviolet (UV) protection, self-cleaning, and electrical conductivity, as well as antimicrobial, antistatic, antiwrinkle, and flame retardant properties, without compromising the inherent characteristics of the textile. Environmental sustainability is also one of the main motivations in development and innovation in the textile industry. Thus, the synthesis of MNPs using ecofriendly sources, such as polysaccharides, is of high importance. The main functions of polysaccharides in these processes are the reduction and stabilization of MNPs, as well as the adhesion of MNPs onto fabrics. This review covers the major research attempts to obtain textiles with different functional properties using polysaccharides and MNPs. The main polysaccharides reported include chitosan, alginate, starch, cyclodextrins, and cellulose, with silver, zinc, copper, and titanium being the most explored MNPs. The potential applications of these functionalized textiles are also reported, and they include healthcare (wound dressing, drug release), protection (antimicrobial activity, UV protection, flame retardant), and environmental remediation (catalysts).

3.
Antibiotics (Basel) ; 9(6)2020 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-32526972

RESUMO

The increased resistance of bacteria against conventional pharmaceutical solutions, the antibiotics, has raised serious health concerns. This has stimulated interest in the development of bio-based therapeutics with limited resistance, namely, essential oils (EOs) or antimicrobial peptides (AMPs). This study envisaged the evaluation of the antimicrobial efficacy of selected biomolecules, namely LL37, pexiganan, tea tree oil (TTO), cinnamon leaf oil (CLO) and niaouli oil (NO), against four bacteria commonly associated to nosocomial infections: Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and Pseudomonas aeruginosa. The antibiotic vancomycin and silver nanoparticles (AgNPs) were used as control compounds for comparison purposes. The biomolecules were initially screened for their antibacterial efficacy using the agar-diffusion test, followed by the determination of minimal inhibitory concentrations (MICs), kill-time kinetics and the evaluation of the cell morphology upon 24 h exposure. All agents were effective against the selected bacteria. Interestingly, the AgNPs required a higher concentration (4000-1250 µg/mL) to induce the same effects as the AMPs (500-7.8 µg/mL) or EOs (365.2-19.7 µg/mL). Pexiganan and CLO were the most effective biomolecules, requiring lower concentrations to kill both Gram-positive and Gram-negative bacteria (62.5-7.8 µg/mL and 39.3-19.7 µg/mL, respectively), within a short period of time (averaging 2 h 15 min for all bacteria). Most biomolecules apparently disrupted the bacteria membrane stability due to the observed cell morphology deformation and by effecting on the intracellular space. AMPs were observed to induce morphological deformations and cellular content release, while EOs were seen to split and completely envelope bacteria. Data unraveled more of the potential of these new biomolecules as replacements for the conventional antibiotics and allowed us to take a step forward in the understanding of their mechanisms of action against infection-related bacteria.

4.
Nanomaterials (Basel) ; 10(4)2020 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-32224934

RESUMO

Polyvinylpyrrolidone-coated silver nanoparticles (PVP-AgNPs) dispersed in ethanol, water and water/alginate were used to functionalize untreated and dielectric barrier discharge (DBD) plasma-treated polyamide 6,6 fabric (PA66). The PVP-AgNPs dispersions were deposited onto PA66 by spray and exhaustion methods. The exhaustion method showed a higher amount of deposited AgNPs. Water and water-alginate dispersions presented similar results. Ethanol amphiphilic character showed more affinity to AgNPs and PA66 fabric, allowing better uniform surface distribution of nanoparticles. Antimicrobial effect in E. coli showed good results in all the samples obtained by exhaustion method but using spray method only the DBD plasma treated samples displayed antimicrobial activity (log reduction of 5). Despite the better distribution achieved using ethanol as a solvent, water dispersion samples with DBD plasma treatment displayed better antimicrobial activity against S. aureus bacteria in both exhaustion (log reduction of 1.9) and spray (methods log reduction of 1.6) due to the different oxidation states of PA66 surface interacting with PVP-AgNPs, as demonstrated by X-Ray Photoelectron Spectroscopy (XPS) analysis. Spray method using the water-suspended PVP-AgNPs onto DBD plasma-treated samples is much faster, less agglomerating and uses 10 times less PVP-AgNPs dispersion than the exhaustion method to obtain an antimicrobial effect in both S. aureus and E. coli.

5.
BMJ Open ; 8(1): e018934, 2018 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-29301762

RESUMO

OBJECTIVES: To estimate cardiac rehabilitation (CR) referral and participation rates among patients with acute coronary syndrome (ACS) and to identify their determinants, in two Portuguese regions. DESIGN: Prospective cohort study. SETTING: Patients consecutively admitted to the cardiology department of two hospitals, one in the district of Porto and one in the north-east region (NER) of Portugal, were enrolled in the EPIHeart cohort and then followed up for 6 months. PARTICIPANTS: Between August 2013 and December 2014, 939 patients were included in the cohort, and 853 were re-evaluated at 6-month follow-up. OUTCOME MEASURES: Referral rate was defined as the proportion of eligible patients who were referred to a CR programme, whereas participation rate was defined as the proportion of eligible patients who completed a CR programme, as was recommended by their physicians. RESULTS: Patients referred were 32.3% and 10.7% of those eligible in Porto and NER, respectively. In both regions, referral to CR decreased with age and with longer travel times to CR centres and increased with education or social class. At follow-up, 128 patients from Porto (26.2% of those eligible and 81.0% of those referred) and 26 from NER (7.1% of those eligible and 66.7% of those referred) reported actually participating in a CR programme. In Porto, the main barriers to participation were the long time until a programme was available and lack of perceived benefit. Patients in NER identified distance to CR and costs as the main barriers. CONCLUSIONS: CR remains clearly underused in Portugal, with major inequalities in access between regions. Achieving equitable and greater use of CR requires a multilevel approach addressing barriers related to healthcare system, providers and patients in order to improve provision, referral and participation.


Assuntos
Síndrome Coronariana Aguda/reabilitação , Reabilitação Cardíaca , Acessibilidade aos Serviços de Saúde , Participação do Paciente/estatística & dados numéricos , Encaminhamento e Consulta/estatística & dados numéricos , Fatores Socioeconômicos , Idoso , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Portugal , Estudos Prospectivos , Centros de Reabilitação
6.
Front Psychol ; 8: 2319, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29375437

RESUMO

Background: About 2/3 of the Europeans reside in cities. Thus, we must expand our knowledge on how city characteristics affect health and well-being. Perceptions about cities' resources and functioning might be related with health, as they capture subjective experiences of the residents. We characterized the health status of 74 European cities, using all-cause mortality as indicator, and investigated the association of mortality with residents' dissatisfaction with key domains of urban living. Methods: We considered 74 European cities from 29 countries. Aggregated data on residents' dissatisfaction was obtained from the Flash Eurobarometer, Quality of life in European cities (2004-2015). For each city a global dissatisfaction score and a dissatisfaction score by domain (environment, social, economic, healthcare, and infrastructures/services) were calculated. Data on mortality and population was obtained from the Eurostat. Standardized Mortality Ratios, SMR, and 95% Confidence Intervals (95% CI) were calculated. The association between dissatisfaction scores and SMR was estimated using Generalized Linear Models. Results: SMR varied markedly (range: 73.2-146.5), being highest in Eastern Europe and lowest in the South and Western European cities. Residents' dissatisfaction levels also varied greatly. We found a significant association between city SMR and residents' dissatisfaction with healthcare (ß = 0.334; IC 95% 0.030-0.639) and social environment (ß = 0.239; IC 95% 0.015-0.464). No significant association was found with the dissatisfaction scores related with the physical and economic environment and the infrastructures/services. Conclusions: We found a significant association between city levels of mortality and residents' dissatisfaction with certain urban features, suggesting subjective assessments can be also used to comprehend urban health.

7.
Bioorg Med Chem Lett ; 24(19): 4699-4702, 2014 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-25193230

RESUMO

A mild and simple method was developed to prepare a series of fifteen 5-aminoimidazole 4-carboxamidrazones, starting from the easily accessible 5-amino-4-cyanoformimidoyl imidazoles. The antimicrobial activity of these novel amidrazones was screened against Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli, Pseudomonas aeruginosa) bacteria and Candida sp. (Candida albicans, Candida krusei, Candida parapsilosis). Only a subset of compounds displayed fair-moderate activity against S. aureus and E. coli but all exhibited activity against Candida sp. The three most potent antifungal compounds were further tested against Cryptococcus neoformans, Aspergillus fumigatus and three dermatophytes (Trichophyton rubrum, Trichophyton mentagrophytes, Microsporum gypseum). These three hit compounds strongly inhibited C. krusei and C. neoformans growth, although their activity on filamentous fungi was very weak when compared to the activity on yeasts.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Hidrazonas/farmacologia , Imidazóis/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Antifúngicos/síntese química , Antifúngicos/química , Candida/crescimento & desenvolvimento , Relação Dose-Resposta a Droga , Bactérias Gram-Negativas/crescimento & desenvolvimento , Bactérias Gram-Positivas/crescimento & desenvolvimento , Hidrazonas/síntese química , Hidrazonas/química , Imidazóis/síntese química , Imidazóis/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Estrutura-Atividade
8.
BMC Genomics ; 15: 371, 2014 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-24885229

RESUMO

BACKGROUND: Cork oak (Quercus suber) is one of the rare trees with the ability to produce cork, a material widely used to make wine bottle stoppers, flooring and insulation materials, among many other uses. The molecular mechanisms of cork formation are still poorly understood, in great part due to the difficulty in studying a species with a long life-cycle and for which there is scarce molecular/genomic information. Cork oak forests are of great ecological importance and represent a major economic and social resource in Southern Europe and Northern Africa. However, global warming is threatening the cork oak forests by imposing thermal, hydric and many types of novel biotic stresses. Despite the economic and social value of the Q. suber species, few genomic resources have been developed, useful for biotechnological applications and improved forest management. RESULTS: We generated in excess of 7 million sequence reads, by pyrosequencing 21 normalized cDNA libraries derived from multiple Q. suber tissues and organs, developmental stages and physiological conditions. We deployed a stringent sequence processing and assembly pipeline that resulted in the identification of ~159,000 unigenes. These were annotated according to their similarity to known plant genes, to known Interpro domains, GO classes and E.C. numbers. The phylogenetic extent of this ESTs set was investigated, and we found that cork oak revealed a significant new gene space that is not covered by other model species or EST sequencing projects. The raw data, as well as the full annotated assembly, are now available to the community in a dedicated web portal at http://www.corkoakdb.org. CONCLUSIONS: This genomic resource represents the first trancriptome study in a cork producing species. It can be explored to develop new tools and approaches to understand stress responses and developmental processes in forest trees, as well as the molecular cascades underlying cork differentiation and disease response.


Assuntos
Etiquetas de Sequências Expressas , Quercus/genética , Transcriptoma , DNA de Plantas/análise , Biblioteca Gênica , Filogenia , Quercus/crescimento & desenvolvimento , Análise de Sequência de DNA
9.
Carbon Balance Manag ; 8(1): 11, 2013 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-24209606

RESUMO

BACKGROUND: The United Nation's Program for Reducing Emissions from Deforestation and Forest Degradation (REDD+) aims to reduce the 20% contribution to global emissions of greenhouse gases from the forest sector, offering a financial value of the carbon stored in forests as an incentive for local communities. The pre-requisite for the setup of a participatory REDD + Program is the monitoring, reporting and verification (MRV) of baseline carbon stocks and their changes over time. In this study, we investigated miombo woodland's dynamics in terms of composition, structure and biomass over a 4-year period (2005-2009), and the Carbon Stock Density (CSD) for the year 2009. The study was conducted in the Niassa National Reserve (NNR) in northern Mozambique, which is the 14th largest protected area in the world. RESULTS: Mean tree density distributed across 79 species increased slightly between 2005 and 2009, respectively, from 548 to 587 trees ha-1. Julbernardia globiflora (Benth.) was the most important species in this area [importance value index (IVI2005= 61 and IVI2009 = 54)]. The woodlands presented an inverted J-shaped diametric curve, with 69% of the individuals representing the young cohort. Woody biomass had a net increase of 3 Mg ha-1 with the highest growth observed in Dyplorhynchus condilocarpon (Müll.Arg.) Pichon (0.54 Mg ha-1). J. globiflora had a net decrease in biomass of 0.09 Mg ha-1. Total CSD density was estimated at ca. 67 MgC ha-1 ± 24.85 with soils (average 34.72 ± 17.93 MgC ha-1) and woody vegetation (average 29.8 MgC ha-1 ± 13.07) representing the major carbon pools. The results point to a relatively stable ecosystem, but they call for the need to refocus management activities. CONCLUSIONS: The miombo woodlands in NNR are representative of the woodlands in the eco-region in terms of vegetation structure and composition. They experienced net increase in woody biomass, a considerable recruitment level and low mortality. According to our results, NNR may present good potential for carbon sequestration especially in soils and woody biomass, representing an important potential carbon sink. However, further investigations are needed in order to address the contribution of this area to MRV REDD + initiatives.

10.
Acta Odontol Latinoam ; 24(3): 252-7, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22550818

RESUMO

The aim of this study was to evaluate the influence of time of application of antioxidant agents on the bond strength to bovine enamel after bleaching by light emitting diode. Twenty two bovine incisors were used, on which the vestibular surfaces were flattened and divided into four experimental groups (n = 15) according to each antioxidant agent, with two groups each, varying the application time of 1 or 10 minutes, all submitted to the same whitening agent (Lase Peroxide) and the control group was only restored. The other groups were treated with antioxidant agents before the restorative procedure using the adhesive system All Bond 3 and resin Filtek Z-350. To obtain the dental fragments, teeth were placed in a precision cutter (Elquip), obtaining 0.8 mm 2 with sticks that were submitted to micro tensile testing at a test speed of 0.5 mm/min. The results, statistically analyzed by ANOVA and Tukey test (p < 0.05), indicated an increase in the value of bond strength of bleached groups treated with ascorbic acid, and a reduction when combined with sodium thiosulfate. No improvement in bond strength was found in the others.


Assuntos
Antioxidantes/farmacologia , Colagem Dentária , Clareamento Dental , Animais , Bovinos , Análise do Estresse Dentário
12.
J Plant Physiol ; 167(5): 333-42, 2010 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-19939498

RESUMO

Low positive temperature (chilling) is frequently linked to the promotion of oxidative stress conditions, and is of particular importance in the coffee plant due to its severe impact on growth, development, photosynthesis and production. Nevertheless, some acclimation ability has been reported within the Coffea genus, and is possibly related to oxidative stress control. Using an integrated biochemical and molecular approach, the characterization of the antioxidative system of genotypes with different cold acclimation abilities was performed. Experiments were carried out using 1.5-year-old coffee seedlings of Coffea canephora cv. Apoatã, C. arabica cv. Catuaí, C. dewevrei and 2 hybrids, Icatu (C. arabicaxC. canephora) and Piatã (C. dewevreixC. arabica) subjected to a gradual cold treatment and a recovery period. Icatu showed the greatest ability to control oxidative stress, as reflected by the enhancement of several antioxidative components (Cu,Zn-SOD and APX activities; ascorbate, alpha-tocopherol and chlorogenic acids (CGAs) contents) and lower reactive oxygen species contents (H(2)O(2) and OH). Gene expression studies show that GRed, DHAR and class III and IV chitinases might also be involved in the cold acclimation ability of Icatu. Catuaí showed intermediate acclimation ability through the reinforcement of some antioxidative molecules, usually to a lesser extent than that observed in Icatu. On the other hand, C. dewevrei showed the poorest response in terms of antioxidant accumulation, and also showed the greatest increase in OH values. The difference in the triggering of antioxidative traits supports the hypothesis of its importance to cold (and photoinhibition) tolerance in Coffea sp. and could provide a useful probe to identify tolerant genotypes.


Assuntos
Antioxidantes/metabolismo , Coffea/fisiologia , Aclimatação/genética , Aclimatação/fisiologia , Antioxidantes/fisiologia , Ascorbato Peroxidases , Ácido Ascórbico/metabolismo , Ácidos Cafeicos/metabolismo , Catalase/genética , Catalase/metabolismo , Coffea/genética , Coffea/metabolismo , Temperatura Baixa , Genótipo , Estresse Oxidativo/genética , Estresse Oxidativo/fisiologia , Peroxidases/genética , Peroxidases/metabolismo , Reação em Cadeia da Polimerase , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , alfa-Tocoferol/metabolismo
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