228 research outputs found

    The Latest Trends in Electric Vehicles Batteries

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    Global energy demand is rapidly increasing due to population and economic growth, especially in large emerging countries, which will account for 90% of energy demand growth to 2035. Electric vehicles (EVs) play a paramount role in the electrification revolution towards the reduction of the carbon footprint. Here, we review all the major trends in Li-ion batteries technologies used in EVs. We conclude that only five types of cathodes are used and that most of the EV companies use Nickel Manganese Cobalt oxide (NMC). Most of the Li-ion batteries anodes are graphite-based. Positive and negative electrodes are reviewed in detail as well as future trends such as the effort to reduce the Cobalt content. The electrolyte is a liquid/gel flammable solvent usually containing a LiFeP6 salt. The electrolyte makes the battery and battery pack unsafe, which drives the research and development to replace the flammable liquid by a solid electrolyte

    Bioactive macro/micro porous silk fibroin/Nano-sized calcium phosphate scaffolds with potential for bone tissue engineering applications

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    Aim: The development of novel silk/nano-sized calcium phosphate (silk/nano-CaP) scaffolds with highly dispersed CaP nanoparticles in the silk fibroin (SF) matrix for bone tissue engineering. Materials & methods: Nano-CaP was incorporated in a concentrated aqueous SF solution (16 wt.%) by using an in situ synthesis method. The silk/nano-CaP scaffolds were then prepared through a combination of salt-leaching/ lyophilization approaches. Results: The CaP particles presented good affinity to SF and their size was inferior to 200 nm when theoretical CaP/silk ratios were between 4 and 16 wt.%, as determined by scanning electron microscopy. The CaP particles displayed a uniform distribution in the scaffolds at both microscopic and macroscopic scales as observed by backscattered scanning electron microscopy and micro-computed tomography, respectively. The prepared scaffolds presented self-mineralization capability and no cytotoxicity confirmed by in vitro bioactivity tests and cell viability assays, respectively. Conclusion: These results indicated that the produced silk/nano-CaP scaffolds could be suitable candidates for bone-tissueengineering applications.This study was funded by the Portuguese Foundation for Science and Technology (FCT) through the projects Tissue2Tissue (PTDC/CTM/105703/2008) and Osteo Cart (PTDC/CTM-BPC/115977/2009). The funding from Foundation Luso-Americana is greatly acknowledged. L-P Yan gives thanks for his PhD scholarship from FCT (SFRHIBD/64717/2009). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or potions, expert testimony, grants or patents received or pending, or royalties

    Unraveling the insights into phage endolysin association

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    In view of the abundacy of phages (1), even rare phage-induced events are frequent at the global level. They have a staggering ecological impact on the bacterial population and in the evolution of bacterial genomic structure upon virus-host interactions, acting as agents in the recycling of organic matter and presenting a valuable tool in molecular biology and epidemiology. Th focus on genomic research have revealed information on open reading frames of proteins of interest (2). Increasing interest has been given to phage (endo )lysins in molecular biology, biotechnology and medicine. Lysins are phage lytic enzymes that break down the peptidoglycan of the bacterial cell wall at the terminal stage of the phage reproduction cycle, to release the phage progeny with the consequent death of the bacterial cells (3). Despite the increasing number of genomes in Genbank:, no effort has been made so far to understand the relation between lysins and their phage family and host species, presenting challenges in their annotation, comparative analysis, and representation. The almost 700 complete phage genomes deposited in the NCBI database were searched for the presence of lysins by making use of the pfam ( 4) identified domains and BLAST comparison of putative/unidentified complete genome against known lysins. In approximately 5% of the phage genomes it was not possible to identify any lysin. The identified enzymes were used to construct a phylogenetic tree with Phylip (5), using Neighbor-Joining, Maximum Likelihood and Parsimony algorithms (6). From the resulting tree, we were able to present a phage-lysin characterization network analysis taking into account the lysin aa sequence and the different phage classes (Family/Genus) and host species to study their evolutionary stories. Regarding the phage families, muramidases, amidases and peptidases are the largest type of lysins in Myoviridae, Podoviridae and Siphoviridae phages respectively. Grouped data will also be used to identify conserved domains among lysins of different phages which will play an important role in the annotation of the unidentified lytic cassette of sequenced phages

    Insights into phage endolysins

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    (Bacterio)phages are viruses that specifically infect bacteria, and thus are harmless to humans, animals, and plants. They are the most abundant microorganisms on the planet (estimated to be 1031 on Earth) in a ratio of 10 times more than bacteria (1). Consequently, even rare phage-induced events are frequent at the global level. Therefore, they have a staggering ecological impact on the bacterial population and in the evolution of bacterial genomic structure upon virus-host interactions, acting as agents in the recycling of organic matter and presenting a valuable tool in molecular biology and epidemiology. Regarding the diversity of phages, they can have different types of replication mechanisms, morphologies, nucleic acid composition and genome sizes. Over the last decade improvements on phages genome sequencing and progresses in genomic research have revealed information on open reading frames of proteins of interest (2). Increasing interest has been given to phage (endo)lysins in molecular biology, biotechnology and medicine. Lysins are phage lytic enzymes that break down the peptidoglycan of the bacterial cell wall at the terminal stage of the phage reproduction cycle, in order to release the phage progeny with the consequent death of the bacterial cells (3). The number of phage genomes deposited in GenBank has been increasing exponentially in the last years. However, no effort has been made so far to understand the relation between lysins and their phage family and host species, presenting challenges in their annotation, comparative analysis, and representation. The almost 700 complete phage genomes deposited in the NCBI database were searched for the presence of lysins by making use of the Pfam (4) identified domains and BLAST comparison of putative or unidentified complete genome against known lysins. In approximately 5% of the phage genomes it was not possible to identify any lysin. The identified enzymes were used to construct a phylogenetic tree with Phylip (5), using Neighbor-Joining, Maximum Likelihood and Parsimony algorithms (6). From the resulting tree, we were able to present a phage-lysin characterization network analysis taking into account the lysin aminoacid sequence and the different phage classes (Family/Genus) and host species to study their evolutionary stories. Regarding the phage families, muramidases, amidases and peptidases are the largest type of lysins in Myoviridae, Podoviridae and Siphoviridae phages respectively. Grouped data will also be used to identify conserved domains among lysins of different phages which will play an important role in the annotation of the still unidentified lytic cassette of phages with sequenced genomes

    Molecular aspects and comparative genomics of bacteriophage endolysins

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    Phages are recognized as the most abundant and diverse entities on the planet. Their diversity is predominantly determined by their dynamic adaptation capacities, when confronted with different selective pressures in an endless cycle of co-evolution with a widespread group of bacterial hosts. At the end of the infection cycle, progeny virions are confronted with a rigid cell wall that hinders their release into the environment and the opportunity to start a new infection cycle. Consequently, phages encode hydrolytic enzymes, called endolysins, to digest the peptidoglycan. In this work, we bring to light all phage endolysins found in completely sequenced double stranded nucleic acid phage genomes and uncover clues that explain the phage-endolysin-host ecology that led phages to recruit unique and specialized endolysins.This work was supported by a grant from the Portuguese Foundation for Science and Technology in the scope of the projects PTDC/AGR-ALI/100492/2008 and PTDC/AGR-ALI/121057/2010. Hugo Oliveira, Luis D. R. Melo, and Silvio B. Santos acknowledge the FCT grants SFRH/BD/63734/2009, SFRH/BD/66166/2009, and SFRH/BPD/75311/2010, respectively

    Injectable and tunable hyaluronic acid hydrogels releasing chemotactic and angiogenic growth factors for endodontic regeneration

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    Bioengineered soft tissues on any meaningful scale or complexity must incorporate aspects of the functional tissue, namely a vasculature, providing cells oxygen and nutrients critical for their survival. However, the ability of tissue engineering strategies to promote a fast revascularization is critically limited. Particularly in endodontic regenerative therapies, the complicated anatomy of the root canal system, and the narrow apical access limit the supply of new blood vessels and pulp tissue ingrowth. Here we characterize the viscoelastic and microstructural properties of a class of injectable hyaluronic acid (HA) hydrogels formed in situ, reinforced with cellulose nanocrystals (CNCs) and enriched with platelet lysate (PL), and test its ability to promote cells recruitment and proangiogenic activity in vitro. The incorporation of CNCs enhanced the stability of the materials against hydrolytic and enzymatic degradation. Moreover, the release of the chemotactic and pro-angiogenic growth factors (GFs) (PDGF and VEGF) from the PL-laden hydrogels showed an improved sustained profile proportional to the amount of incorporated CNCs. The PL-laden hydrogels exhibited preferential supportive properties of encapsulated human dental pulp cells (hDPCs) in in vitro culture conditions. Finally, PL-laden hydrogels stimulated chemotactic and pro-angiogenic activity by promoting hDPCs recruitment and cell sprouting in hDPCs/human umbilical vein endothelial cell co-cultures in vitro, and in an ex vivo model. These results support the use of the combined system as a scaffold for GFs delivery and cells recruitment, thereby exhibiting great clinical potential in treating injuries in vascularized tissues.RECOGNIZE project (UTAP-ICDT/CTM-BIO/0023/2014), project NORTE-01-0145-FEDER-000021. R.M.A. Domingues acknowledges FCT for SFRH/BPD/112459/2015. P.S. Babo acknowledges the project FOOD4CELLS (PTDC/CTM-BIO/4706/2014-POCI-01-0145-FEDER 016716) for his post-doc grantinfo:eu-repo/semantics/publishedVersio

    Specificity and sensitivity comparative study between phage PVP-S1 and monoclonal antibody as receptor in polydiacetylene vesicles for Salmonella colorimetric detection

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    Polydiacetylene polymer (PDA) has been intensively studied because of its properties as colour change from blue to red and change from non-fluorescent to fluorescent form due to an external stimulus that lead to a reorientation of the PDA within the organized structure. External stimulus could be temperature, pH, solvent influence, bacteria presence, mechanical stresses and others (Oliveira et al., 2012). Pires et al. (2010) support the hypothesis that such phenomena occurred due to conformational changes associated with the functional group rotation around the simple carbon-carbon bond present in PDA chains. When the backbones of PDA conjugated polymer chains are perturbed, the delocalized π-network induces changes in electronic absorption and emission properties (Huo et al., 1999). For a particular colour change, it is possible to incorporate a compound in the polydiacetylene carboxyl groups that will work as a specific receptor for the bacteria detection. This technology can be used for the detection of pathogens and thus is important to avoid food contamination once the standard technology demands long time and people trained. The selection of the receptor used in the PDA is the first critical step to develop a biosensor with improved selectivity, selectivity and stability. For this reason, the aim of this study was to make a comparative study between two recognition molecules: phage PVP-S1 (Santos et al., 2011) and a monoclonal antibody in the PDA sensor for the detection of Salmonella. Antibodies lack specificity, poor separation efficiency and sensitivity. Phages are extremely specific, withstand harsh environments, are economically and easily produced, show high stability during storage and thus present potential for bacterial detection. Overall the selection of the recognition molecule that show the best features is important to develop a simple and rapid sensor for the industry and consumer’s life. The specificity of the sensor was proven by using Staphylococus aures and Escherichia coli as gram-positive and gram-negative controls, respectively

    SMC-Last Extracted Photometry

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    We present point-source photometry from the Spitzer Space Telescope's final survey of the Small Magellanic Cloud (SMC). We mapped nearly 30 deg2 in two epochs in 2017, with the second extending to early 2018 at 3.6 and 4.5 μm using the Infrared Array Camera. This survey duplicates the footprint from the SAGE-SMC program in 2008. Together, these surveys cover a nearly 10 yr temporal baseline in the SMC. We performed aperture photometry on the mosaicked maps produced from the new data. We did not use any prior catalogs as inputs for the extractor in order to be sensitive to any moving objects (e.g., foreground brown dwarfs) and other transient phenomena (e.g., cataclysmic variables or FU Ori–type eruptions). We produced a point-source catalog with high-confidence sources for each epoch as well as a combined-epoch catalog. For each epoch and the combined-epoch data, we also produced a more complete archive with lower-confidence sources. All of these data products will be made available to the community at the Infrared Science Archive

    E-Cadherin Destabilization Accounts for the Pathogenicity of Missense Mutations in Hereditary Diffuse Gastric Cancer

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    E-cadherin is critical for the maintenance of tissue architecture due to its role in cell-cell adhesion. E-cadherin mutations are the genetic cause of Hereditary Diffuse Gastric Cancer (HDGC) and missense mutations represent a clinical burden, due to the uncertainty of their pathogenic role. In vitro and in vivo, most mutations lead to loss-of-function, although the causal factor is unknown for the majority. We hypothesized that destabilization could account for the pathogenicity of E-cadherin missense mutations in HDGC, and tested our hypothesis using in silico and in vitro tools. FoldX algorithm was used to calculate the impact of each mutation in E-cadherin native-state stability, and the analysis was complemented with evolutionary conservation, by SIFT. Interestingly, HDGC patients harbouring germline E-cadherin destabilizing mutants present a younger age at diagnosis or death, suggesting that the loss of native-state stability of E-cadherin accounts for the disease phenotype. To elucidate the biological relevance of E-cadherin destabilization in HDGC, we investigated a group of newly identified HDGC-associated mutations (E185V, S232C and L583R), of which L583R is predicted to be destabilizing. We show that this mutation is not functional in vitro, exhibits shorter half-life and is unable to mature, due to premature proteasome-dependent degradation, a phenotype reverted by stabilization with the artificial mutation L583I (structurally tolerated). Herein we report E-cadherin structural models suitable to predict the impact of the majority of cancer-associated missense mutations and we show that E-cadherin destabilization leads to loss-of-function in vitro and increased pathogenicity in vivo
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