3,173 research outputs found

    Nanotoxicology Of Metal Oxide Nanoparticles

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)This review discusses recent advances in the synthesis, characterization and toxicity of metal oxide nanoparticles obtained mainly through biogenic (green) processes. The in vitro and in vivo toxicities of these oxides are discussed including a consideration of the factors important for safe use of these nanomaterials. The toxicities of different metal oxide nanoparticles are compared. The importance of biogenic synthesized metal oxide nanoparticles has been increasing in recent years; however, more studies aimed at better characterizing the potent toxicity of these nanoparticles are still necessary for nanosafely considerations and environmental perspectives. In this context, this review aims to inspire new research in the design of green approaches to obtain metal oxide nanoparticles for biomedical and technological applications and to highlight the critical need to fully investigate the nanotoxicity of these particles.52934975Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)NanoBioss (MCTI)Brazilian Network on NanotoxicologyFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Tuberculosis national registries and data on diagnosis delay - Is there room for improvement?

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    Introduction and objectives Excessive delay in the diagnosis of Tuberculosis may have a negative impact on the epidemiological control and elimination of this disease. An accurate determination and analysis of delay times may help identify where and how to improve Tuberculosis diagnosis according to local needs. The Portuguese Tuberculosis Surveillance System – SVIG-TB – is the main source of data regarding diagnosis delay. However, to our knowledge, there has been no recent evaluation of its data. This study's primary aim was to conduct a thorough quantitative and qualitative evaluation of data obtained from the SVIG-TB registry concerning the delay in Tuberculosis diagnosis in Matosinhos, a Portuguese municipality. Methods All patients living in the Matosinhos municipality diagnosed with Tuberculosis between January 1st 2012 and December 31st 2019 were identified and individual SVIG-TB records retrieved. Patient-related, Healthcare-related and Total delay in Tuberculosis diagnosis were determined based on data obtained from this source and compared to data recovered from patient record review. Missing data, registering errors and differences in diagnosis delay between these two sources were analysed and compared. Subsequently, diagnosis delay data from a recent Portuguese nationwide SVIG-TB paper, covering years 2010 to 2014, was compared to local SVIG-TB and patient record review data. Results This study identified a significantly greater percentage of cases with missing data on delay in SVIG-TB records when compared to Patient Record Review (57.2% versus 1.11%). The median patient-related, healthcare-related and Total delay in Tuberculosis diagnosis were of 17, 30 and 68 days, respectively, in the SVIG-TB based data. A significant underestimation of healthcare-related and total Tuberculosis diagnosis delay was identified in SVIG-TB data when compared to Patient Record Review. There was no significant difference between Patient-related delays determined from these two sources. Compared to the national study results, missing values were more common in this data set (57.2 vs 44.6%), mainly due to the absence of patient-related delay data. Median Total and Healthcare-related delays were significantly greater in Matosinhos Municipality, regardless of the data source (SVIG-TB or Patient Record Review). The patient-related delay was, conversely, shorter. Conclusions SVIG-TB has been crucial in guiding National Public Health policies on the path towards Tuberculosis elimination in Portugal. However, there is still room for improvement. These results provide a basis for further reflection on the shortcomings and potential of SVIG-TB in guiding the national Tuberculosis program.This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors

    Mindfulness and other simple neuroscience-based proposals to promote the learning performance and mental health of students during the COVID-19 pandemic

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    The COVID-19 pandemic has had a negative impact on education. The restrictions imposed have undoubtedly led to impairment of the psychological well-being of both teachers and students, and of the way they experience interpersonal relationships. As reported previously in the literature, adverse effects such as loneliness, anxiety, and stress have resulted in a decrease in the cognitive performance of school and higher education students. Therefore, the objective of this work is to present a general overview of the reported adverse effects of the COVID-19 pandemic which may potentially influence the learning performance of students. Some neuroscientific findings related to memory and cognition, such as neuroplasticity and long-term potentiation, are also shown. We also discuss the positive effects of the practice of mindfulness, as well as other simple recommendations based on neuroscientific findings such as restful sleep, physical activity, and nutrition, which can act on memory and cognition. Finally, we propose some practical recommendations on how to achieve The COVID-19 pandemic has had a negative impact on education. The restrictions imposed have undoubtedly led to impairment of the psychological well-being of both teachers and students, and of the way they experience interpersonal relationships. As reported previously in the literature, adverse effects such as loneliness, anxiety, and stress have resulted in a decrease in the cognitive performance of school and higher education students. Therefore, the objective of this work is to present a general overview of the reported adverse effects of the COVID-19 pandemic which may potentially influence the learning performance of students. Some neuroscientific findings related to memory and cognition, such as neuroplasticity and long-term potentiation, are also shown. We also discuss the positive effects of the practice of mindfulness, as well as other simple recommendations based on neuroscientific findings such as restful sleep, physical activity, and nutrition, which can act on memory and cognition. Finally, we propose some practical recommendations on how to achieve more effective student learning in the context of the pandemic. The aim of this review is to provide some assistance in this changing and uncertain situation in which we all find ourselves, and we hope that some of the information could serve as a starting point for hypotheses to be tested in educational research and their association with neuroscience.This research was funded by the Dirección de Investigación-Universidad de La Frontera (DI20-1003) and Project Covid (73) Process number: 23006.002357/2020-20—Universidade Federal do ABC. In addition, this work was partially funded by FEDER funds through the Operational Competitiveness Program—COMPETE and by National Funds through Fundação para a Ciência e Tecnologia (FCT)—under the projects PTDC/CTM-TEX/28295/2017 and UID/CTM/00264/2019

    Confronting the 95 GeV excesses within the UN2HDM

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    We consider the small excesses around 95 GeV found in several searches for a new scalar in γγ\gamma \gamma, ττ\tau \tau and bbˉb \bar b final states. Instead of trying to accommodate them all, as is usually done in the literature, in the context of a given Standard Model~(SM) extension, we investigate whether it would be possible that one or two of these excesses correspond to an actual new scalar, while the remaining ones are merely statistical fluctuations. To this end, we use as benchmark model the UN2HDM, a SM extension with one scalar doublet, one scalar singlet, and an extra U(1)\text{U}(1)' symmetry, which has been previously studied in the context of multiboson cascade decays. We show that most of the possibilities where the excesses in one or two of these channels disappear in the future can be accommodated by type-I or type-III UN2HDMs.Comment: LaTeX 17 page

    A Systematic Review

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    Publisher Copyright: © 2023 by the authors.The recognition that the gut microbiota of obese children differs from lean children has grown, and some studies suggest that physical activity positively influences the gut microbiota. This systematic review explores the changes in the gut microbiota composition of obese and non-obese children and adolescents and provides an understanding of the effects of physical activity interventions in modulating their microbiota. The PRISMA protocol was used across PubMed, Scopus, and Web of Science. Overall, twenty-four research papers were included in accordance with the chosen inclusion and exclusion criteria, eighteen studies compared the gut microbiota of obese and normal-weight children and adolescents, and six studies explored the effect of physical activity interventions on the gut microbiota. The analysis indicated that obese gut microbiota is reduced in Bacteroidetes, Bifidobacterium and alpha diversity but enriched in Proteobacteria and Lactobacillus. Interventions with physical activity seem to improve the alpha diversity and beneficial bacteria linked to body weight loss in children and adolescents. The gut microbiota of obese children exhibited a remarkably individual variation. More interventions are needed to clearly and accurately explore the relationships between child obesity, gut microbiota, and physical activity and to develop approaches to decrease the incidence of paediatric obesity.publishersversionpublishe

    Evaluation of the effects of nitric oxide-releasing nanoparticles on plants

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    Nowadays, there are several commercially available products containing nanostructured materials. Meanwhile, despite the many benefits that can be obtained from nanotechnology, it is still necessary to understand the mechanisms in which nanomaterials interact with the environment, and to obtain information concerning their possible toxic effects. In agriculture, nanotechnology has been used in different applications, such as nanosensors to detect pathogens, nanoparticles as controlled release systems for pesticides, and biofilms to deliver nutrients to plants and to protect food products against degradation. Moreover, plants can be used as models to study the toxicity of nanoparticles. Indeed, phytotoxicity assays are required to identify possible negative effects of nanostructured systems, prior to their implementation in agriculture. Nitric oxide (NO) plays a key role in plant growth and defense, and recently, several papers described the beneficial effects due to application of exogenous NO donors in plants. The tripeptide glutathione (GSH) is an important anti-oxidant molecule and is the precursor of the NO donor, S-nitrosoglutathione (GSNO). In this context, the present work investigates the effects of different concentrations of alginate/chitosan nanoparticles, containing either GSH or GSNO, on the development of two test species (Zea mays and Glycine sp.). The results showed that the alginate/chitosan nanoparticles present a size average range from 300 to 550 nm with a polydispersity index of 0.35, and encapsulation efficiency of GSH between 45 - 56%. The NO release kinetics from the alginate/chitosan nanoparticles containing GSNO showed sustained and controlled NO release over several hours. Plant assays showed that at the concentrations tested (1, 5 and 10 mM of GSH or GSNO), polymeric nanoparticles showed no significant inhibitory effects on the development of the species Zea mays and Glycine sp., considering the variables shoot height, root length, and dry mass. Therefore, these nanoparticles seem to have promissing uses in agriculture, and might be potencially used as controlled release systems applied by the foliar route6174th International Conference on Safe Production and Use of Nanomaterials (Nanosafe

    Xanthone biosynthesis and accumulation in calli and suspended cells of Hypericum androsaemum

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    Calli and suspended cells of Hypericum androsaemum accumulated high levels of 1,3,5,6 and 1,3,6,7 oxygenated xanthones. The major compounds include simple oxygenated xanthones or derivatives with prenyl, pyran or methoxyl groups, four of them being new natural compounds. A hypothetical biosynthetic scheme is proposed based on the isolated compounds and statistical analysis. Xanthone accumulation was influenced greatly by medium factors, namely hormone supplementation. Calli grown with 4.5 mM a-naphtaleneacetic acid (NAA) 2.3 mM kinetin (KIN) had the highest specific xanthone production (1.3% biomass dry weight (DW)), whereas suspended cells grown in similar medium accumulated a lower amount (0.87% DW). Calli displayed a negative linear relationship between total xanthone accumulation and NAA concentration, in the range of 4.5–22.5 mM. However, in this range the xanthone 1,3,6,7:1,3,5,6 ratio and the biomass production showed a positive linear relationship with NAA concentration. Substitution of 4.5 mM of NAA by the same molar amount of 2,4-dichlorophenoxyacetic acid (2,4-D), in the presence of 2.3 mM of KIN, caused a decrease in xanthone accumulation in calli. The use of N6-benzyladenine (BA) instead of KIN reduced xanthone production, independently of the auxin used. This effect was attenuated when both hormones were present.Fundação para a Ciência e a Tecnologia (FCT

    The drinking of a Salvia officinalis infusion improves liver antioxidant status in mice and rats

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    In this study we evaluate the biosafety and bioactivity (antioxidant potential) of a traditional water infusion (tea) of common sage (Salvia officinalis L.) in vivo in mice and rats by quantification of plasma transaminase activities and liver GST and GR enzyme activities. The replacement of water by sage tea for 14 days in the diet of rodents did not affect the body weight and food consumption and did not induce liver toxicity. On the other hand, a significant increase of liver GST activity was observed in rats (24%) and mice (10%) of sage drinking groups. The antioxidant potential of sage tea drinking was also studied in vitro in a model using rat hepatocytes in primary culture. The replacement of drinking water with sage tea in the rats used as hepatocyte donors resulted in an improvement of the antioxidant status of rat hepatocytes in primary culture, namely a significant increase in GSH content and GST activity after 4 hours of culture. When these hepatocyte cultures were exposed to 0.75 or 1 mM of tert-butyl hydroperoxide for 1 hour, some protection against lipid peroxidation and GSH depletion was conferred by sage tea drinking. However, the cell death induced by t-BHP as shown by LDH leakage was not different from that observed in cultures from control animals. This study indicates that the compounds present in this sage preparation contain interesting bioactivities which improve the liver antioxidant potential.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/6942/2001, Programa Operacional “Ciência, Tecnologia, Inovação” (POCTI) - POCTI/AGR/43482/2001

    Synthesis, characterization and cytotoxicity of S-nitrosomercaptosuccinic acid-containing alginate/chitosan nanoparticles

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    Nitric oxide (NO) is an endogenous free radical, which plays key roles in several biological processes including vasodilation, neurotransmission, inhibition of platelet adhesion, cytotoxicity against pathogens, wound healing, and defense against cancer. Due to the relative instability of NO in vivo (half-life of ca. 0.5 seconds), there is an increasing interest in the development of low molecular weight NO donors, such as S-nitrosothiols (RSNOs), which are able to prolong and preserve the biological activities of NO in vivo. In order to enhance the sustained NO release in several biomedical applications, RSNOs have been successfully allied to nanomaterials. In this context, this work describes the synthesis and characterization of the NO donor S-nitroso-mercaptosuccinic acid (S-nitroso-MSA), which belongs to the class of RSNOs, and its incorporation in polymeric biodegradable nanoparticles composed by alginate/chitosan. First, chitosan nanoparticles were obtained by gelation process with sodium tripolyphosphate (TPP), followed by the addition of the alginate layer, to enhance the nanoparticle protection. The obtained nanoparticles presented a hydrodynamic diameter of 343 +/- 38 nm, polydispersity index (PDI) of 0.36 +/- 0.1, and zeta potential of -30.3 +/- 0.4 mV, indicating their thermal stability in aqueous suspension. The negative zeta potential value was assigned to the presence of alginate chains on the surface of chitosan/TPP nanoparticles. The encapsulation efficiency of the NO donor into the polymeric nanoparticles was found to be 98 +/- 0.2%. The high encapsulation efficiency value was attributed to the positive interactions between the NO donor and the polymeric content of the nanoparticles. Kinetics of NO release from the nanoparticles revealed a spontaneous and sustained release of therapeutic amounts of NO, for several hours under physiological temperature. The incubation of NO-releasing alginate/chitosan nanoparticles with human hepatocellular carcinoma (HepG2) cell line revealed a concentration-dependent toxicity. These results point to the promising uses of NO-releasing alginate/chitosan nanoparticles for anti-cancer chemotherapy.Brazilian Network on NanotoxicologyLaboratory of Nanostructure Synthesis and Biosystem Interactions-NANOBIOSS (MCTI)Newton Advanced Fellowship (The Royal Society)Univ Fed ABC, Ctr Nat & Human Sci, Av Estados 5001, BR-09210580 Santo Andre, SP, BrazilUniv Fed Sao Paulo, Exact & Earth Sci Dept, Rua Sao Nicolau 210, BR-09913030 Diadema, SP, BrazilUniv Fed Sao Paulo, Exact & Earth Sci Dept, Rua Sao Nicolau 210, BR-09913030 Diadema, SP, BrazilBrazilian Network on Nanotoxicology: 52120/2011-1Laboratory of Nanostructure Synthesis and Biosystem Interactions-NANOBIOSS (MCTI): 402280-2013Newton Advanced Fellowship (The Royal Society): NA140046Web of Scienc
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