184 research outputs found
On the generalized spinor classification: Beyond the Lounesto's Classification
In this paper we advance into a generalized spinor classification, based on
the so-called Lounesto's classification. The program developed here is based on
an existing freedom on the spinorial dual structures definition, which, in a
certain simple physical and mathematical limit, allows us to recover the usual
Lounesto's classification. The protocol to be accomplished here gives full
consideration in the understanding of the underlying mathematical structure, in
order to satisfy the quadratic algebraic relations known as Fierz-Pauli-Kofink
identities, and also to provide physical observables. As we will see, such
identities impose a given restriction on the number of possible spinorial
classes allowed in the classification. We also expose a mathematical device
known as \emph{Clifford's algebra deformation}, which ensures real spinorial
densities and holds the Fierz-Pauli-Kofink quadratic relations.Comment: 9 pages, 0 figure
Sustainable Triazine-Based Dehydro-Condensation Agents for Amide Synthesis
Conventional methods employed today for the synthesis of amides often lack of economic and environmental sustainability. Triazine-derived quaternary ammonium salts, e.g., 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM(Cl)), emerged as promising dehydro-condensation agents for amide synthesis, although suffering of limited stability and high costs. In the present work, a simple protocol for the synthesis of amides mediated by 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT) and a tert-amine has been described and data are compared to DMTMM(Cl) and other CDMT-derived quaternary ammonium salts (DMT-Ams(X), X: Cl- or ClO4-). Different tert-amines (Ams) were tested for the synthesis of various DMT-Ams(Cl), but only DMTMM(Cl) could be isolated and employed for dehydro-condensation reactions, while all CDMT/tert-amine systems tested were efficient as dehydro-condensation agents. Interestingly, in best reaction conditions, CDMT and 1,4-dimethylpiperazine gave N-phenethyl benzamide in 93% yield in 15 min, with up to half the amount of tert-amine consumption. The efficiency of CDMT/tert-amine was further compared to more stable triazine quaternary ammonium salts having a perchlorate counter anion (DMT-Ams(ClO4)). Overall CDMT/tert-amine systems appear to be a viable and more economical alternative to most dehydro-condensation agents employed today
Reshaping Curriculum to Enhance the Relevance of Literary Competence in Children's Education06
Twenty-first century learners face a multi-literacy landscape as they strive to acquire the cognitive skills needed for independent learning, apply linguistic skills to other knowledge base, and become computer literate. This article envisions a combination of skill sets and knowledge bases as the foundation of a literary competence-based curriculum. Such a curriculum would have the goal of enhancing young learners"critical thinking abilities; this would also help them take charge of the cognitive,linguistic, and sociocultural dimensions of written and spoken language in order to make learning transferable and applicable to the real world
Evaluating immunological and inflammatory changes of treatment-experienced people living with HIV switching from first-line triple cART regimens to DTG/3TC vs. B/F/TAF: the DEBATE trial
Background: The aim of this randomized clinical trial (RCT) was to compare immunological changes in virally suppressed people living with HIV (PLWH) switching from a three-drug regimen (3DR) to a two-drug regimen (2DR).Methods: An open-label, prospective RCT enrolling PLWH receiving a 3DR who switched to bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) or dolutegravir/lamivudine (DTG/3TC) was performed. Blood was taken at baseline and months 6 and 12. The primary outcome was the change in CD4+ or CD8+ T-cell counts and CD4/CD8 ratio over time points. The secondary outcomes were the changes in immunological and inflammatory parameters. Parametric mixed-linear models with random intercepts and slopes were fitted separately for each marker after controlling for potential confounders.Results: Between the two arms (33 PLWH each), there was no difference in CD4+ or CD8+ T cells, CD4/CD8 ratio, and IL-6 trajectories. PLWH switching to DTG/3TC had increased levels of both transitional memory and terminally differentiated CD4+ T cells (arm-time interaction p-value = 0.02) and to a lesser extent for the corresponding CD8+ T-cell subsets (p = 0.09). Significantly lower levels of non-classical monocytes were detected in the B/F/TAF arm at T6 (diff = -6.7 cells/mm(3); 95% CI; -16, +2.6; p-value for interaction between arm and time = 0.03). All differences were attenuated at T12.Conclusion: No evidence for a difference in absolute CD4+ and CD8+ T-cell counts, CD4/CD8 ratio, and IL-6 trajectories by study arm over 12 months was found. PLWH on DTG/3TC showed higher levels of terminally differentiated and exhausted CD4+ and CD8+ T lymphocytes and non-classical monocytes at T6. Further studies are warranted to better understand the clinical impact of our results
Evaluating immunological and inflammatory changes of treatment-experienced people living with HIV switching from first-line triple cART regimens to DTG/3TC vs. B/F/TAF: the DEBATE trial
Background: The aim of this randomized clinical trial (RCT) was to compare immunological changes in virally suppressed people living with HIV (PLWH) switching from a three-drug regimen (3DR) to a two-drug regimen (2DR). Methods: An open-label, prospective RCT enrolling PLWH receiving a 3DR who switched to bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) or dolutegravir/lamivudine (DTG/3TC) was performed. Blood was taken at baseline and months 6 and 12. The primary outcome was the change in CD4+ or CD8+ T-cell counts and CD4/CD8 ratio over time points. The secondary outcomes were the changes in immunological and inflammatory parameters. Parametric mixed-linear models with random intercepts and slopes were fitted separately for each marker after controlling for potential confounders. Results: Between the two arms (33 PLWH each), there was no difference in CD4+ or CD8+ T cells, CD4/CD8 ratio, and IL-6 trajectories. PLWH switching to DTG/3TC had increased levels of both transitional memory and terminally differentiated CD4+ T cells (arm–time interaction p-value = 0.02) and to a lesser extent for the corresponding CD8+ T-cell subsets (p = 0.09). Significantly lower levels of non-classical monocytes were detected in the B/F/TAF arm at T6 (diff = −6.7 cells/mm3; 95% CI; −16, +2.6; p-value for interaction between arm and time = 0.03). All differences were attenuated at T12. Conclusion: No evidence for a difference in absolute CD4+ and CD8+ T-cell counts, CD4/CD8 ratio, and IL-6 trajectories by study arm over 12 months was found. PLWH on DTG/3TC showed higher levels of terminally differentiated and exhausted CD4+ and CD8+ T lymphocytes and non-classical monocytes at T6. Further studies are warranted to better understand the clinical impact of our results. Clinical Trial Registration: https://clinicaltrials.gov, identifier NCT04054089
Vaccines against toxoplasma gondii : challenges and opportunities
Development of vaccines against Toxoplasma gondii infection in humans is of high priority, given the high burden of disease in some areas of the world like South America, and the lack of effective drugs with few adverse effects. Rodent models have been used in research on vaccines against T. gondii over the past decades. However, regardless of the vaccine construct, the vaccines have not been able to induce protective immunity when the organism is challenged with T. gondii, either directly or via a vector. Only a few live, attenuated T. gondii strains used for immunization have been able to confer protective immunity, which is measured by a lack of tissue cysts after challenge. Furthermore, challenge with low virulence strains, especially strains with genotype II, will probably be insufficient to provide protection against the more virulent T. gondii strains, such as those with genotypes I or II, or those genotypes from South America not belonging to genotype I, II or III. Future studies should use animal models besides rodents, and challenges should be performed with at least one genotype II T. gondii and one of the more virulent genotypes. Endpoints like maternal-foetal transmission and prevention of eye disease are important in addition to the traditional endpoint of survival or reduction in numbers of brain cysts after challenge
Pregnancy outcomes and cytomegalovirus DNAaemia in HIV infected pregnant women with CMV
no disponibil
Rate , correlates and outcomes of repeat pregnancy in HIV-infected women
Objectives: The aim of the study was to assess the rate, determinants, and outcomes of repeat pregnancies in women with HIV infection. Methods: Data from a national study of pregnant women with HIV infection were used. Main outcomes were preterm delivery, low birth weight, CD4 cell count and HIV plasma viral load. Results: The rate of repeat pregnancy among 3007 women was 16.2%. Women with a repeat pregnancy were on average younger than those with a single pregnancy (median age 30 vs. 33 years, respectively), more recently diagnosed with HIV infection (median time since diagnosis 25 vs. 51 months, respectively), and more frequently of foreign origin [odds ratio (OR) 1.36; 95% confidence interval (CI) 1.10–1.68], diagnosed with HIV infection in the current pregnancy (OR: 1.69; 95% CI: 1.35–2.11), and at their first pregnancy (OR: 1.33; 95% CI: 1.06–1.66). In women with sequential pregnancies, compared with the first pregnancy, several outcomes showed a significant improvement in the second pregnancy, with a higher rate of antiretroviral treatment at conception (39.0 vs. 65.4%, respectively), better median maternal weight at the start of pregnancy (60 vs. 61 kg, respectively), a higher rate of end-of-pregnancy undetectable HIV RNA (60.7 vs. 71.6%, respectively), a higher median birth weight (2815 vs. 2885 g, respectively), lower rates of preterm delivery (23.0 vs. 17.7%, respectively) and of low birth weight (23.4 vs. 15.4%, respectively), and a higher median CD4 cell count (+47 cells/μL), with almost no clinical progression to Centers for Disease Control and Prevention stage C (CDC-C) HIV disease (0.3%). The second pregnancy was significantly more likely to end in voluntary termination than the first pregnancy (11.4 vs. 6.1%, respectively). Conclusions: Younger and foreign women were more likely to have a repeat pregnancy; in women with sequential pregnancies, the second pregnancy was characterized by a significant improvement in several outcomes, suggesting that women with HIV infection who desire multiple children may proceed safely and confidently with subsequent pregnancies
Programa de intervención en representaciones de creatividad y motivación académica de adolescentes
Creativity and its promotion are widespread concerns in education. However, few efforts have been made to implement
intervention programs designed to promote creativity and other related aspects (e.g., academic motivation). The Future Problem Solving
Program International (FPSPI), aimed for training creativity representations and creative problem solving skills in young people, has
been one of the most implemented programs. This intervention’s materials and activities were adapted for Portuguese students, and
a longitudinal study was conducted. The program was implemented during four months, in weekly sessions, by thirteen teachers.
Teachers received previous training for the program and during the program’s implementation. Intervention participants included
77 Basic and Secondary Education students, and control participants included 78 equivalent students. Pretest-posttest measures of
academic motivation and creativity representations were collected. Results suggest a significant increase, in the intervention group,
in motivation and the appropriate representations of creativity. Practical implications and future research perspectives are presented.A criatividade e sua promoção geram grande preocupação em educação. Contudo, poucos esforços têm existido para
implementar programas destinados a sua promoção e de outros aspetos relacionados (e.g., motivação acadêmica). O Future Problem
Solving Program International (FPSPI), criado para melhorar as representações de criatividade e a resolução criativa de problemas
em jovens, tem sido um dos mais implementados. Os seus materiais e atividades foram adaptados para estudantes portugueses,
efetuando-se um estudo longitudinal. O programa foi implementado durante quatro meses, semanalmente, por treze professores, que
receberam formação antes e durante a implementação. O grupo experimental incluiu 77 estudantes do Ensino Básico e Secundário,
apresentando o grupo de controlo 78 estudantes com caracterÃsticas equivalentes. Os dados sobre a motivação e criatividade foram
recolhidos num pré e pós-teste. Os resultados sugerem um aumento significativo na motivação e crenças apropriadas de criatividade
no grupo experimental. Implicações práticas e perspectivas para investigações futuras são apresentadas.La creatividad y su promoción generan gran preocupación en educación. Sin embargo, han sido llevados a cabo pocos
esfuerzos para implementar programas de promoción de la creatividad y otros aspectos (e.g., motivación académica). El Future
Problem Solving Program International (FPSPI), creado para mejorar las representaciones de creatividad y la solución creativa de
problemas en jóvenes, ha sido bastante implementado. Se adaptaron sus materiales y actividades para estudiantes portugueses, y
se desarrolló un estudio longitudinal. El programa se implementó semanalmente durante cuatro meses por trece profesores, que
recibieron formación antes y durante la implementación. El grupo experimental incluyó 77 estudiantes de Educación Primaria y
Secundaria y el grupo de control incluyó 78 estudiantes con caracterÃsticas semejantes. Los datos de motivación y creatividad fueron
recogidos en un pre y post-test, sugiriendo un aumento significativo de motivación y creencias apropiadas sobre la creatividad en el
grupo experimental. Se presentan implicaciones prácticas y perspectivas para futuras investigaciones.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BPD/80825/201
- …