Simplicial minisuperspace models in the presence of a massive scalar field with arbitrary scalar coupling

We extend previous simplicial minisuperspace models to account for arbitrary scalar coupling \eta R\phi^2.Comment: 24 pages and 9 figures. Accepted for publication by Classical and Quantum Gravit

Anisotropic simplicial minisuperspace model

The computation of the simplicial minisuperspace wavefunction in the case of anisotropic universes with a scalar matter field predicts the existence of a large classical Lorentzian universe like our own at late timesComment: 19 pages, Latex, 6 figure

Argonaute-2 protects the neurovascular unit from damage caused by systemic inflammation

Funding PPBI—Portuguese Platform of BioImaging, POCI-01-0145-FEDER-022122; FCT—Fundação para a Ciência e Tecnologia, UID/Multi/00709/2013, SFRH/ BD/137440/2018 (MMP), IF/00178/2015/CP1300/CT0001 (RF); FCT—L’Oréal— UNESCO Portugal for Women in Science (RF).Background: The brain vasculature plays a pivotal role in the inflammatory process by modulating the interaction between blood cells and the neurovascular unit. Argonaute-2 (Ago2) has been suggested as essential for endothelial survival but its role in the brain vasculature or in the endothelial–glial crosstalk has not been addressed. Thus, our aim was to clarify the significance of Ago2 in the inflammatory responses elicited by these cell types. Methods: Mouse primary cultures of brain endothelial cells, astrocytes and microglia were used to evaluate cellular responses to the modulation of Ago2. Exposure of microglia to endothelial cell-conditioned media was used to assess the potential for in vivo studies. Adult mice were injected intraperitoneally with lipopolysaccharide (LPS) (2 mg/kg) followed by three daily intraperitoneal injections of Ago2 (0.4 nM) to assess markers of endothelial disruption, glial reactivity and neuronal function. Results: Herein, we demonstrated that LPS activation disturbed the integrity of adherens junctions and downregulated Ago2 in primary brain endothelial cells. Exogenous treatment recovered intracellular Ago2 above control levels and recuperated vascular endothelial-cadherin expression, while downregulating LPS-induced nitric oxide release. Primary astrocytes did not show a significant change in Ago2 levels or response to the modulation of the Ago2 system, although endogenous Ago2 was shown to be critical in the maintenance of tumor necrosis factor-α basal levels. LPS-activated primary microglia overexpressed Ago2, and Ago2 silencing contained the inflammatory response to some extent, preventing interleukin-6 and nitric oxide release. Moreover, the secretome of Ago2-modulated brain endothelial cells had a protective effect over microglia. The intraperitoneal injection of LPS impaired blood–brain barrier and neuronal function, while triggering inflammation, and the subsequent systemic administration of Ago2 reduced or normalized endothelial, glial and neuronal markers of LPS damage. This outcome likely resulted from the direct action of Ago2 over the brain endothelium, which reestablished glial and neuronal function. Conclusions: Ago2 could be regarded as a putative therapeutic agent, or target, in the recuperation of the neurovascular unit in inflammatory conditions.publishersversionpublishe

Keratin-based peptide: biological evaluation and strengthening properties on relaxed hair

A peptide based on a fragment of hair keratin type II cuticular protein, keratin peptide (KP), was studied as a possible strengthening agent for weakened relaxed hair. The peptide was prepared both in aqueous water formulation (WF) and organic solvent formulations (OF), to determine the effect of organic solvents on peptide interaction with hair and the differences in hair recovery. Both peptide formulations were shown to improve mechanical and thermal properties of weakened hair with peptide in OF showing the stronger effect. As a potential new hair care product, and so would necessitate contact with skin, the cytotoxicity and genotoxicity of the peptide were also evaluated through different methodologies (Alamar Blue assay, 2′-7′-dichlorofluorescein probe, cell morphology and growth and evaluation of DNA damage by an alkaline version of the comet assay) in skin fibroblasts. These tests are indicators of the potential of peptide to cause irritation on skin or to be carcinogenic, respectively. The peptide in WF did not cause cytotoxicity or genotoxicity in any of the concentrations tested. The presence of OF, however, induced a 20% decrease in cell viability in all of the range of concentrations used after 72-h incubation. Moreover, OF inhibited cell growth and was considered genotoxic at first contact with cells. The peptide was therefore considered a promising strengthening agent for hair and was shown to be innocuous when applied in WF.The work was supported by a PhD Grant Fellowship (scholarship SFRH/BD/38363/2007) from FCT "Fundacao para a Ciencia e Tecnologia", Portugal. The authors have declared no conflict of interest

Estrogen protection in Parkinson´s disease – a GDNF role?

Estrogen protection in Parkinson´s disease – a GDNF role

Desalination in nuclear plants: a bibliometric study of research activity in scientific literature indexed by SCOPUS base

With the scarcity of fresh water, desalination is an important instrument to be considered for the production of non-salinized water through waste heat in the dual use of nuclear reactors. The gap that this study seeks to fill is related to the use of bibliometric method, based on information structure, about the scientific studies indexed on the evolution of the topic desalination in nuclear power plants. The objective of this work is to map the themes in the scientific literature between 1966 and the first semester of 2017. Data were collected from the research activities indexed by the SCOPUS database and analyzed with the support of bibliometric software VOSviewer. Among others, the results of the research led to the following conclusions: (1) the articles published in indexed journals represent the largest percentage of the type of instrument used for scientific dissemination, representing 64% of the documents; (2) it is estimated that between the years 2016 and 2025 the indexed research activities involving nuclear desalination continued to grow sharply

L-Asparaginase

L-Asparaginase (ASNase, EC 3.5.1.1) is a tetrameric aminohydrolase enzyme that catalyses the hydrolysis of the amino acid L-Asparagine into ammonia and L-aspartic acid. ASNase is present in different organisms such as bacteria, fungi, plant tissues and algae. ASNase is used in the pharmaceutical field as an anticancer drug for the treatment of acute lymphoblastic leukemia (ALL) and other malignant diseases such as Hodgkin’s disease. In the food sector, ASNase is used to prevent the formation of acrylamide, a toxic compound formed when starch-rich foods are cooked at temperatures above 100 °C. ASNase can also be used as a biosensor for the detection of L-asparagine levels.publishe

L-asparaginase-based biosensors

L-asparaginase (ASNase) is an aminohydrolase enzyme widely used in the pharmaceutical and food industries. Although currently its main applications are focused on the treatment of lymphoproliferative disorders such as acute lymphoblastic leukemia (ALL) and acrylamide reduction in starch-rich foods cooked at temperatures above 100 ºC, its use as a biosensor in the detection and monitoring of L-asparagine levels is of high relevance. ASNase-based biosensors are a promising and innovative technology, mostly based on colorimetric detection since the mechanism of action of ASNase is the catalysis of the L-asparagine hydrolysis, which releases L-aspartic acid and ammonium ions, promoting a medium pH value change followed by color variation. ASNase biosensing systems prove their potential for L-asparagine monitoring in ALL patients, along with L-asparagine concentration analysis in foods, due to their simplicity and fast response.publishe

Recent strategies and applications for l-asparaginase confinement

l-asparaginase (ASNase, EC 3.5.1.1) is an aminohydrolase enzyme with important uses in the therapeutic/pharmaceutical and food industries. Its main applications are as an anticancer drug, mostly for acute lymphoblastic leukaemia (ALL) treatment, and in acrylamide reduction when starch-rich foods are cooked at temperatures above 100 °C. Its use as a biosensor for asparagine in both industries has also been reported. However, there are certain challenges associated with ASNase applications. Depending on the ASNase source, the major challenges of its pharmaceutical application are the hypersensitivity reactions that it causes in ALL patients and its short half-life and fast plasma clearance in the blood system by native proteases. In addition, ASNase is generally unstable and it is a thermolabile enzyme, which also hinders its application in the food sector. These drawbacks have been overcome by the ASNase confinement in different (nano)materials through distinct techniques, such as physical adsorption, covalent attachment and entrapment. Overall, this review describes the most recent strategies reported for ASNase confinement in numerous (nano)materials, highlighting its improved properties, especially specificity, half-life enhancement and thermal and operational stability improvement, allowing its reuse, increased proteolysis resistance and immunogenicity elimination. The most recent applications of confined ASNase in nanomaterials are reviewed for the first time, simultaneously providing prospects in the described fields of application.publishe

Seroprevalence and Risk Factors Associated with Leishmania Infection in Dogs from Portugal

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