2,591 research outputs found

    Extraction and purification of phycobiliproteins from algae and their applications

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    Microalgae, macroalgae and cyanobacteria are photosynthetic microorganisms, prokaryotic or eukaryotic, living in saline or freshwater environments. These have been recognized as valuable carbon sources, able to be used for food, feed, chemicals, and biopharmaceuticals. From the range of valuable compounds produced by these cells, some of the most interesting are the pigments, including chlorophylls, carotenoids, and phycobiliproteins. Phycobiliproteins are photosynthetic light-harvesting and water-soluble proteins. In this work, the downstream processes being applied to recover fluorescent proteins from marine and freshwater biomass are reviewed. The various types of biomasses, namely macroalgae, microalgae, and cyanobacteria, are highlighted and the solvents and techniques applied in the extraction and purification of the fluorescent proteins, as well as their main applications while being fluorescent/luminescent are discussed. In the end, a critical perspective on how the phycobiliproteins business may benefit from the development of cost-effective downstream processes and their integration with the final application demands, namely regarding their stability, will be provided.publishe

    Hyperglycemia and nocturnal systolic blood pressure are associatedwith left ventricular hypertrophy and diastolic dysfunction in hypertensive diabetic patients

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    BACKGROUND: The aim of this study was to determine if hypertensive type 2 diabetic patients, when compared to patients with essential hypertension have an increased left ventricular mass index (LVMI) and a worse diastolic function, and if this fact would be related to 24-h pressoric levels changes. METHODS: Ninety-one hypertensive patients with type 2 diabetes mellitus (DM) (group-1 [G1]), 59 essential hypertensive patients (group-2 [G2]) and 26 healthy controls (group-3 [G3]) were submitted to 24-h Ambulatory Blood Pressure Monitoring (ABPM) and echocardiography (ECHO) with Doppler. We calculated an average of fasting blood glucose (AFBG) values of G1 from the previous 4.2 years and a glycemic control index (GCI) (percentual of FBG above 200 mg/dl). RESULTS: G1 and G2 did not differ on average of diurnal systolic and diastolic BP. However, G1 presented worse diastolic function and a higher average of nocturnal systolic BP (NSBP) and LVMI (NSBP = 132 ± 18 vs 124 ± 14 mmHg; P < 0.05 and LVMI = 103 ± 27 vs 89 ± 17 g/m(2); P < 0.05, respectively). In G1, LVMI correlated with NSBP (r = 0.37; P < 0.001) and GCI (r = 0.29; P < 0.05) while NSBP correlated with GCI (r = 0.27; P < 0.05) and AFBG (r = 0.30; P < 0.01). When G1 was divided in tertiles according to NSBP, the subgroup with NSBP≄140 mmHg showed a higher risk of LVH. Diabetics with NSBP≄140 mmHg and AFBG>165 mg/dl showed an additional risk of LVH (P < 0.05; odds ratio = 11). In multivariate regression, both GCI and NSBP were independent predictors of LVMI in G1. CONCLUSION: This study suggests that hyperglycemia and higher NSBP levels should be responsible for an increased prevalence of LVH in hypertensive patients with Type 2 DM

    CONCENTRATION OF SALIVARY CORTISOL AND TESTOSTERONE IN ELITE WOMEN FOOTBALL PLAYERS: ANALYSIS OF PERFORMANCE IN OFFICIAL MATCHES

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    This study aims to evaluate the relation between salivary concentrations of cortisol (C), testosterone (T), the ratio T:C and the individual performance of top-level female soccer athletes during official matches. Eighteen female athletes from a national soccer team (age 23.06 ± 4.33 years) participated in the study. Four official matches were analysed and the on-field time of each player as well as the index of individual effectiveness were calculated. Players were classified in two clusters according to their individual performance (cluster 1 – poor individual performance; cluster 2 – good individual performance) using K-means and their hormonal variables were compared. The players of cluster 2 generally revealed higher values (p˂.05) in both the positive actions and individual effectiveness, when compared with the players of cluster 1. The players of both clusters presented identical values of C, T and T:C at the four evaluated matches. The athletes of cluster 2 showed a significant increase in C (p˂.05) and a significant decrease in T and T:C before the games lost (M2 and M5). However, there was no linear relation between the variation of both hormones during the matches and the individual performance of players. Performance in competition revealed significant differences between players, though with no apparent relation to the hormonal kinetics of C and T before and after the matches

    An insight into the sialotranscriptome of the brown dog tick, Rhipicephalus sanguineus

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    <p>Abstract</p> <p>Background</p> <p><it>Rhipicephalus sanguineus</it>, known as the brown dog tick, is a common ectoparasite of domestic dogs and can be found worldwide. <it>R.</it><it>sanguineus </it>is recognized as the primary vector of the etiological agent of canine monocytic ehrlichiosis and canine babesiosis. Here we present the first description of a <it>R. sanguineus </it>salivary gland transcriptome by the production and analysis of 2,034 expressed sequence tags (EST) from two cDNA libraries, one consctructed using mRNA from dissected salivary glands from female ticks fed for 3-5 days (early to mid library, RsSGL1) and the another from ticks fed for 5 days (mid library, RsSGL2), identifying 1,024 clusters of related sequences.</p> <p>Results</p> <p>Based on sequence similarities to nine different databases, we identified transcripts of genes that were further categorized according to function. The category of putative housekeeping genes contained ~56% of the sequences and had on average 2.49 ESTs per cluster, the secreted protein category contained 26.6% of the ESTs and had 2.47 EST's/clusters, while 15.3% of the ESTs, mostly singletons, were not classifiable, and were annotated as "unknown function". The secreted category included genes that coded for lipocalins, proteases inhibitors, disintegrins, metalloproteases, immunomodulatory and antiinflammatory proteins, as Evasins and Da-p36, as well as basic-tail and 18.3 kDa proteins, cement proteins, mucins, defensins and antimicrobial peptides. Comparison of the abundance of ESTs from similar contigs of the two salivary gland cDNA libraries allowed the identification of differentially expressed genes, such as genes coding for Evasins and a thrombin inhibitor, which were over expressed in the RsSGL1 (early to mid library) versus RsSGL2 (mid library), indicating their role in inhibition of inflammation at the tick feeding site from the very beginning of the blood meal. Conversely, sequences related to cement (64P), which function has been correlated with tick attachment, was largely expressed in the mid library.</p> <p>Conclusions</p> <p>Our survey provided an insight into the <it>R. sanguineus </it>sialotranscriptome, which can assist the discovery of new targets for anti-tick vaccines, as well as help to identify pharmacologically active proteins.</p

    Morphological and conductivity studies of di-ureasil xerogels containing lithium triflate

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    Sol–gel derived poly(oxyethylene)/siloxane hybrids doped with lithium triflate, LiCF3SO3, have been investigated. The host hybrid matrix of these materials, named di-ureasil and represented by U(600), is composed by a siliceous framework to which polyether chains containing 8.5 oxyethylene repeat units are covalently bonded through urea linkages. Xerogel samples U(600)nLiCF3SO3 with n (where n is the molar ratio of oxyethylene moieties per Li+ ion) between ∞ and 0.1 have been examined. X-ray diffraction and differential scanning calorimetry have provided conclusive evidence that the xerogels analyzed are entirely amorphous. The salt-rich material with n=1 exhibits the highest conductivity over the whole range of temperature analyzed (e.g. 4.3×10−6 and 2.0×10−4 Ω−1 cm−1, respectively, at 25 and 94 °C).Fundação para a CiĂȘncia e a Tecnologia (FCT

    Uncovering the Use of Fucoxanthin and Phycobiliproteins into Solid Matrices to Increase Their Emission Quantum Yield and Photostability

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    In the search for a better and brighter future, the use of natural luminescent renewable materials as substitutes for synthetic ones in the energy field is of prime importance. The incorporation of natural pigments (e.g., xanthophylls and phycobiliproteins) is a fundamental step in a broad spectrum of applications that are presently marred by their limited stability. The incorporation of bio-based luminescent molecules into solid matrices allows the fabrication of thin films, which may dramatically increase the range of applications, including sustainable photovoltaic systems, such as luminescent solar concentrators or downshifting layers. In this work, we incorporated R-phycoerythrin (R-PE), C-phycocyanin (C-PC), and fucoxanthin (FX) into poly(vinyl alcohol) (PVA) and studied their optical properties. It was found that the emission and excitation spectra of the phycobiliproteins and FX were not modified by incorporation into the PVA matrix. Moreover, in the case of FX, the emission quantum yield (η) values also remained unaltered after incorporation, showing the suitability of the PVA as a host matrix. A preliminary photostability study was performed by exposing the solid samples to continuous AM1.5G solar radiation, which evidenced the potential of these materials for future photovoltaics.publishe

    Bio-based solar energy harvesting for onsite mobile optical temperature sensing in Smart Cities

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    The Internet of Things (IoT) fosters the development of smart city systems for sustainable living and increases comfort for people. One of the current challenges for sustainable buildings is the optimization of energy management. Temperature monitoring in buildings is of prime importance, as heating account for a great part of the total energy consumption. Here, a solar optical temperature sensor is presented with a thermal sensitivity of up to 1.23% °C-1 based on sustainable aqueous solutions of enhanced green fluorescent protein and C-phycocyanin from biological feedstocks. These photonic sensors are presented under the configuration of luminescent solar concentrators widely proposed as a solution to integrate energy-generating devices in buildings, as windows or façades. The developed mobile sensor is inserted in IoT context through the development of a self-powered system able to measure, record, and send data to a user-friendly website.publishe

    Different protocols of physical exercise produce different effects on synaptic and structural proteins in motor areas of the rat brain

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    The plastic brain responses generated by the training with acrobatic exercise (AE) and with treadmill exercise (TE) may be different. We evaluated the protein expression of synapsin I (SYS), synaptophysin (SYP), microtubule-associated protein 2 (MAP2) and neurofilaments (NF) by immunohistochemistry and Western blotting in the motor cortex, striatum and cerebellum of rats subjected to TE and AE. Young adult male Wistar rats were divided into 3 groups: sedentary (Sed) (n=15), TE (n=20) and AE (n=20). The rats were trained 3 days/week for 4 weeks on a treadmill at 0.6 km/h, 40 min/day (TE), or moved through a circuit of obstacles 5 times/day (AE). The rats from the TE group exhibited a significant increase of SYS and SYP in the motor cortex, of NF68, SYS and SYP in the striatum, and of MAP2, NF and SYS in the cerebellum, whereas NF was decreased in the motor cortex and the molecular layer of the cerebellar cortex. On the other hand, the rats from the AE group showed a significant increase of MAP2 and SYP in the motor cortex, of all four proteins in the striatum, and of SYS in the cerebellum. In conclusion, AE induced changes in the expression of synaptic and structural proteins mainly in the motor cortex and striatum, which may underlie part of the learning of complex motor tasks. TE, on the other hand, promoted more robust changes of structural proteins in all three regions, especially in the cerebellum, which is involved in learned and automatic tasks. (C) 2012 Elsevier B.V. All rights reserved.FAPESPFAPESPCNPqCNP

    Solar spectral management with electrochromic devices including PMMA films doped with biluminescent ionosilicas

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    The technological potential of poly(methyl methacrylate) (PMMA)-based composite films doped with lanthanide-doped sol–gel derived ionosilicas (IS-Ln) previously proposed for luminescent down-shifting (LDS) and luminescent solar concentrator (LSC) layers connected to photovoltaic (PV) cells is extended here to electrochromic devices (ECDs), targeting the fabrication of single energy harvesting/conversion/management LSC-LDS/PV/ECD systems. These integrated devices have foreseen application in the windows of future zero-energy buildings of smart cities. The proof-of-concept is given with the report of the electro-optical performance of an ECD comprising an optimized electrolyte film composed of PMMA, IS-Nd, and IS-Eu, and the 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid. This amorphous electrolyte is stable below 160 °C, exhibits high ionic conductivity (2.13 × 10−4 and 8.76 × 10−4 S cm−1 at room temperature and 44 °C, respectively), and emits in the visible (red color) and near-infrared (NIR) spectral regions. The device demonstrated fast switching speed (50 s) and high transparency in the visible-to-NIR spectral regions (transmittance (T) = 79/96/89/77% at 555/1000/1500/1650 nm in the as-prepared state, respectively). Upon application of ±2.5 V for 200 cycles, at the same wavelengths, the Tbleached/Tcolored values were 44/28, 46/26, 39/20, and 27/9%, respectively, and the coloration efficiency (CE) values CEin/CEout values were −302/+181, −381/+228, −446/+267 and −734/+440 cm2 C−1, respectively.publishe
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