4,083 research outputs found

    Marine-derived polymers in ionic liquids: architectures development and biomedical applications

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    Marine resources have considerable potential to develop high-value materials for applications in different fields, namely pharmaceutical, environmental, and biomedical. Despite that, the lack of solubility of marine-derived polymers in water and common organic solvents could restrict their applications. In the last years, ionic liquids (ILs) have emerged as platforms able to overcome those drawbacks, opening many routes to enlarge the use of marine-derived polymers as biomaterials, among other applications. From this perspective, ILs can be used as an efficient extraction media for polysaccharides from marine microalgae and wastes (e.g., crab shells, squid, and skeletons) or as solvents to process them in different shapes, such as films, hydrogels, nano/microparticles, and scaffolds. The resulting architectures can be applied in wound repair, bone regeneration, or gene and drug delivery systems. This review is focused on the recent research on the applications of ILs as processing platforms of biomaterials derived from marine polymers.FCT (JMG, PD/BD/135247/2017 and LCR, SFRH/BPD/93697/2013). This work was also financially supported by a PhD programme in Advanced Therapies for Health (PATH) (PD/00169/2013); FCT R&D&I projects with references PTDC/BII‐BIO/31570/2017, PTDC/CTM‐CTM/29813/2017 and PTDC/CTM‐BIO/4706/2014‐(POCI‐01‐0145‐ FEDER‐016716) and R&D&I Structured Projects with reference NORTE‐01‐0145‐FDER‐00002

    Tailoring natural-based oleogels combining ethylcellulose and virgin coconut oil

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    Oleogels are becoming an attractive research field, since they have recently been shown to be feasible for the food and pharmaceutical sectors and provided some insights into the biomedical area. In this work, edible oleogels were tailored through the combination of ethylcellulose (EC), a gelling agent, with virgin coconut oil (VCO), vegetable oil derived from coconut. The influence of the different EC and VCO ratios on the structural, physical, and thermal properties of the oleogels was studied. All EC/VCO-based oleogels presented a stable network with a viscoelastic nature, adequate structural stability, modulable stiffness, high oil-binding capability, antioxidant activity, and good thermal stability, evidencing the EC and VCOâ s good compatibility.The authors acknowledge financial support from the Portuguese FCT (SFRH/BPD/93697/2013, and CEECIND/01306/2018). This work is also financially supported by the FCT R&D&I projects with references POCI-01-0145-FEDER-029813 (PTDC/CTM-CTM/29813/2017), POCI-01-0145-FEDER-031570 (PTDC/BII-BIO/31570/2017), and TERM RES Hub, Ref Norte-01-0145-FEDER-02219015

    Fire behaviour in different periods and configurations of a landscape in Northeastern Portugal

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    Neste trabalho aborda-se a importância do planejamento do uso e ocupação do solo, e do manejo dos sistemas florestais na redução do perigo de incêndio, analisando-se o comportamento do fogo em relação às alterações na paisagem da Deilão, nordeste de Portugal. Foram utilizadas cadeias de Markov e modelos de autômatos celulares como metodologia para projetar a paisagem no futuro. FlamMap foi utilizado para simular o comportamento do fogo. De acordo com as métricas da paisagem obtidas no Fragstats, observou- se que os cenários e projeções em Deilão têm uma tendência à simplificação da paisagem, o que pode facilitar a ocorrência de incêndios maiores e mais graves. A análise dos resultados indicou uma tendência ao aumento do perigo de incêndios na região, em grande parte, ocasionado pela expansão de plantações contínuas de florestas. Para evitar tais impactos, o manejo florestal e ordenamento da paisagem devem ser modificados a fim de se reduzir o acúmulo de materiais combustíveis.In this study, we discuss the importance of land use, land cover planning and forest stand management in fire hazard reduction, through the analysis of fire behavior in relation to landscape changes in Deilão, northeastern Portugal. Markov chains and cellular automata model were used to project future landscapes whose structures were quantified by landscape metrics. The FlamMap model was used to simulate fire behavior. According to landscape metrics from Fragstats, we observed that scenarios and projections in Deilão have a trend towards landscape simplification, which may facilitate the occurrence of larger, more severe fires. The analyses indicate an increased fire hazard trend in the region, largely caused by the continuity of forest cover. To avoid such impacts, forest management and landscape plannig should be modified in order to reduce the accumulation of combustible materials.info:eu-repo/semantics/publishedVersio

    Results From the Epidemiology of Chronic Diseases Cohort Study 3

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    Introduction: The public health problem of food insecurity also affects the elderly population. This study aimed to estimate the prevalence of household food insecurity and its associations with chronic disease and health-related quality of life characteristics in individuals ≥65 years of age living in the community in Portugal. Methods: The data were collected from the Epidemiology of Chronic Diseases Cohort Study 3 (EpiDoC3)-Promoting Food Security Study (2015-2016), which was the third evaluation wave of the EpiDoC and represented the Portuguese adult population. Food insecurity was assessed using a psychometric scale adapted from the Brazilian Food Insecurity Scale. The data on sociodemographic variables, chronic disease, and management of chronic disease were self-reported. Health-related quality of life were assessed using the European Quality of Life Survey (version validated for the Portuguese population). Logistic regression models were used to determine crude and adjusted odds ratios (for age group, gender, region, and education). The dependent variable was the perceived level of food security. Results: Among older adults, 23% were living in a food-insecure household. The odds of living in a food-insecure household were higher for individuals in the 70-74 years age group (odds ratio (OR) = 1.405, 95% confidence interval (CI) 1.392-1.417), females (OR = 1.545, 95% CI 1.534-1.556), those with less education (OR = 3.355, 95% CI 3.306-3.404), low income (OR = 4,150, 95% CI 4.091-4.210), and those reporting it was very difficult to live with the current income (OR = 16.665, 95% CI 16.482-16.851). The odds of having a chronic disease were also greater among individuals living in food-insecure households: diabetes mellitus (OR = 1.832, 95% CI 1.818-1.846), pulmonary diseases (OR = 1.628, 95% CI 1.606-1.651), cardiac disease (OR = 1.329, 95% CI 1.319-1.340), obesity (OR = 1.493, 95% CI 1.477-1.508), those who reduced their frequency of medical visits (OR = 4.381, 95% CI 4.334-4.428), and who stopped taking medication due to economic difficulties (OR = 5.477, 95% CI 5.422-5.532). Older adults in food-insecure households had lower health-related quality of life (OR = 0.212, 95% CI 0.210-0.214). Conclusions: Our findings indicated that food insecurity was significantly associated with economic factors, higher values for prevalence of chronic diseases, poor management of chronic diseases, and decreased health-related quality of life in older adults living in the community.publishersversionpublishe

    Novel genipin cross-linked chitosan-silk fibroin sponges for cartilage engineering strategies

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    The positive interaction of materials with tissues is an important step in regenerative medicine strategies. Hydrogels that are obtained from polysaccharides and proteins are expected to mimic the natural cartilage environment and thus provide an optimum milleu for tissue growth and regeneration. In this work, novel hydrogels composed of blends of chitosan and Bombyx mori silk fibroin were cross-linked with genipin (G) and were freeze dried to obtain chitosan/silk (CSG) sponges. CSG sponges possess stable and ordered structures because of protein conformational changes from R-helix/random-coil to -sheet structure, distinct surface morphologies, and pH/ swelling dependence at pH 3, 7.4, and 9. We investigated the cytotoxicity of CSG sponge extracts by using L929 fibroblast-like cells. Furthermore, we cultured ATDC5 cells onto the sponges to evaluate the CSG sponges’ potential in cartilage repair strategies. These novel sponges promoted adhesion, proliferation, and matrix production of chondrocyte-like cells. Sponges’ intrinsic properties and biological results suggest that CSG sponges may be potential candidates for cartilage tissue engineering (TE) strategies.S.S.S. and M.T.R. thank the Portuguese Foundation for Science and Technology (FCT) for Ph.D. scholarships (SFRH/BD/8658/2002 and SFRH/BD/30745/2006, respectively). A.F.M.P. thanks the FCT and FEDER for a grant (POCI/FIS/61621/2004). This work was partially supported by the European-Union-funded STREP project HIPPOCRATES (NMP3-CT-2003-505758) and was carried out under the scope of the European NoE EXPERTISSUES (NMP3-CT-2004-500283). We also acknowledge Adriano Pedro for his contribution to the micro-CT analysis

    Loss of LAT1 sex-dependently delays recovery after caerulein-induced acute pancreatitis

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    Background: The expression of amino acid transporters is known to vary during acute pancreatitis (AP) except for LAT1 (slc7a5), the expression of which remains stable. LAT1 supports cell growth by importing leucine and thereby stimulates mammalian target of rapamycin (mTOR) activity, a phenomenon often observed in cancer cells. The mechanisms by which LAT1 influences physiological and pathophysiological processes and affects disease progression in the pancreas are not yet known. Aim: To evaluate the role of LAT1 in the development of and recovery from AP. Methods: AP was induced with caerulein (cae) injections in female and male mice expressing LAT1 or after its knockout (LAT1 Cre/LoxP). The development of the initial AP injury and its recovery were followed for seven days after cae injections by daily measuring body weight, assessing microscopical tissue architecture, mRNA and protein expression, protein synthesis, and enzyme activity levels, as well as by testing the recruitment of immune cells by FACS and ELISA. Results: The initial injury, evaluated by measurements of plasma amylase, lipase, and trypsin activity, as well as the gene expression of dedifferentiation markers, did not differ between the groups. However, early metabolic adaptations that support regeneration at later stages were blunted in LAT1 knockout mice. Especially in females, we observed less mTOR reactivation and dysfunctional autophagy. The later regeneration phase was clearly delayed in female LAT1 knockout mice, which did not regain normal expression of the pancreas-specific differentiation markers recombining binding protein suppressor of hairless-like protein (rbpjl) and basic helix-loop-helix family member A15 (mist1). Amylase mRNA and protein levels remained lower, and, strikingly, female LAT1 knockout mice presented signs of fibrosis lasting until day seven. In contrast, pancreas morphology had returned to normal in wild-type littermates. Conclusion: LAT1 supports the regeneration of acinar cells after AP. Female mice lacking LAT1 exhibited more pronounced alterations than male mice, indicating a sexual dimorphism of amino acid metabolism

    Is SAPS 3 better than APACHE II at predicting mortality in critically ill transplant patients?

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    OBJECTIVES: This study compared the accuracy of the Simplified Acute Physiology Score 3 with that of Acute Physiology and Chronic Health Evaluation II at predicting hospital mortality in patients from a transplant intensive care unit. METHOD: A total of 501 patients were enrolled in the study (152 liver transplants, 271 kidney transplants, 54 lung transplants, 24 kidney-pancreas transplants) between May 2006 and January 2007. The Simplified Acute Physiology Score 3 was calculated using the global equation (customized for South America) and the Acute Physiology and Chronic Health Evaluation II score; the scores were calculated within 24 hours of admission. A receiver-operating characteristic curve was generated, and the area under the receiver-operating characteristic curve was calculated to identify the patients at the greatest risk of death according to Simplified Acute Physiology Score 3 and Acute Physiology and Chronic Health Evaluation II scores. The Hosmer-Lemeshow goodness-of-fit test was used for statistically significant results and indicated a difference in performance over deciles. The standardized mortality ratio was used to estimate the overall model performance. RESULTS: The ability of both scores to predict hospital mortality was poor in the liver and renal transplant groups and average in the lung transplant group (area under the receiver-operating characteristic curve = 0.696 for Simplified Acute Physiology Score 3 and 0.670 for Acute Physiology and Chronic Health Evaluation II). The calibration of both scores was poor, even after customizing the Simplified Acute Physiology Score 3 score for South America. CONCLUSIONS: The low predictive accuracy of the Simplified Acute Physiology Score 3 and Acute Physiology and Chronic Health Evaluation II scores does not warrant the use of these scores in critically ill transplant patients

    Chemical composition and bioactivity of oilseed cake extracts obtained by subcritical and modified subcritical water

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    Recovery of bioactive compounds from biowaste is gaining more and more interest in circular economy models. The oilseed cakes are usually insufficiently exploited by most technologies since they represent valuable matrices abundant in proteins, minerals, and phytochemicals, but their use is mostly limited to feed ingredients, fertilizers or biofuel production. This study was thus focused on the exploration of new valorization pathways of oilseed cakes by subcritical water, representing a safe and economic alternative in the creation of value chains. Pumpkin, hemp, and flax seed cakes were treated with subcritical water in nitrogen and carbon-dioxide atmospheres, as well as in nitrogen atmosphere with the addition of acid catalyst. The degradation of carbohydrate fraction was studied by quantifying sugars and sugar degradation products in the obtained extracts. The extracts obtained under different conditions were further compared chemically with respect to total phenols and flavonoids, as well as to the content of individual phenolic compounds. Furthermore, the effects of subcritical water treatment conditions on antioxidant, antiradical and cytotoxic properties of thus obtained extracts were defined and discussed.This research was funded by the Italian Ministry of University (MIUR) call PRIN2017, project 2017LEPH3M “PANACEA: A technology PlAtform for the sustainable recovery and advanced use of NAnostructured CEllulose from Agro-food residues” and the Ministry of Science and Higher Education of the Russian Federation within the project MEGAgrant. This work was also funded by the Science Fund of the Republic of Serbia (Grant No. 7747845, In situ pollutants removal from waters by sustainable green nanotechnologies—CleanNanoCatalyze), the Portuguese Foundation for Science and Technology (project 5537 DRI, Sérvia 2020/21), are also acknowledged. The work was also supported by the FCT/MCTES through national funds, FEDER (through COMPETE funds) and Fundação para a Ciência e Tecnologia (project UIDB/50006/2020) and the Ministry of education, science and technological development of the Republic of Serbia (Grant No 451-03-68/2020–14/200134).info:eu-repo/semantics/publishedVersio

    Functional hybrid nanoemulsions for sumatriptan intranasal delivery

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    In recent years, advanced nanohybrid materials processed as pharmaceuticals have proved to be very advantageous. Triptans, such as the commercially available intranasal sumatriptan (SMT), are drugs employed in the treatment of painful migraine symptoms. However, SMT effectiveness by the intranasal route is limited by its high hydrophilicity and poor mucoadhesion. Therefore, we designed hybrid nanoemulsions (NE) composed of copaiba oil as the organic component plus biopolymers (xanthan, pectin, alginate) solubilized in the continuous aqueous phase, aiming at the intranasal release of SMT (2% w/v). Firstly, drug-biopolymer complexes were optimized in order to decrease the hydrophilicity of SMT. The resultant complexes were further encapsulated in copaiba oil-based nanoparticles, forming NE formulations. Characterization by FTIR-ATR, DSC, and TEM techniques exposed details of the molecular arrangement of the hybrid systems. Long-term stability of the hybrid NE at 25°C was confirmed over a year, regarding size (~ 120 nm), polydispersity (~ 0.2), zeta potential (~ −25 mV), and nanoparticle concentration (~ 2.1014 particles/mL). SMT encapsulation efficiency in the formulations ranged between 41–69%, extending the in vitro release time of SMT from 5 h (free drug) to more than 24 h. The alginate-based NE was selected as the most desirable system and its in vivo nanotoxicity was evaluated in a zebrafish model. Hybrid NE treatment did not affect spontaneous movement or induce morphological changes in zebrafish larvae, and there was no evidence of mortality or cardiotoxicity after 48 h of treatment. With these results, we propose alginate-based nanoemulsions as a potential treatment for migraine pain.Fil: Ribeiro, Lígia N. M.. Universidade Estadual de Campinas; BrasilFil: Rodrigues da Silva, Gustavo H.. Universidade Estadual de Campinas; BrasilFil: Couto, Verônica M.. Universidade Estadual de Campinas; BrasilFil: Castro, Simone R.. Universidade Estadual de Campinas; BrasilFil: Breitkreitz, Márcia C.. Universidade Estadual de Campinas; BrasilFil: Martinez, Carolina Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; Argentina. Universidad Nacional de Quilmes; ArgentinaFil: Igartúa, Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes; ArgentinaFil: Prieto, Maria Jimena. Universidad Nacional de Quilmes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: de Paula, Eneida. Universidade Estadual de Campinas; Brasi
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