28 research outputs found

    Structural, thermal and dissolution properties of MgO- and CaO-containing borophosphate glasses: effect of Fe2O3 addition

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    This paper investigated manufacture of high-durability phosphate glass fibres for biomedical applications. Five different borophosphate glass formulations in the systems of 45P2O5–5B2O3–5Na2O–(29 − x)CaO–16MgO–(x)Fe2O3 and 45P2O5–5B2O3–5Na2O–24CaO–(21 − x)MgO–(x)Fe2O3 where x = 5, 8 and 11 mol% were produced via melt quenching. The compositions and amorphous nature of the glasses were confirmed by ICP-MS and XRD, respectively. FTIR results indicated depolymerisation of the phosphate chains with a decrease in Q2 units with increasing Fe2O3 content. DSC analyses showed an increase in Tg by ~5 °C with an increment of 3 mol% in Fe2O3 content. The thermal properties were also used to calculate processing window (i.e. Tc,ons—Tg) and another parameter, Kgl, to determine the suitability for fibre drawing directly from melt, which equals (Tc,ons—Tg)/(Tl—Tc,ons). The degradation study conducted in PBS solution at 37 °C showed a decrease of 25–47% in degradation rate with increasing Fe2O3 content. This confirmed that the chemical durability of the glasses had increased, which was suggested to be due to Fe2O3 addition. Furthermore, the density measured via Archimedes method revealed a linear increase with increasing Fe2O3 content

    The PtdIns 3-Kinase/Akt Pathway Regulates Macrophage-Mediated ADCC against B Cell Lymphoma

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    Macrophages are important effectors in the clearance of antibody-coated tumor cells. However, the signaling pathways that regulate macrophage-induced ADCC are poorly defined. To understand the regulation of macrophage-mediated ADCC, we used human B cell lymphoma coated with Rituximab as the tumor target and murine macrophages primed with IFNγ as the effectors. Our data demonstrate that the PtdIns 3-kinase/Akt pathway is activated during macrophage-induced ADCC and that the inhibition of PtdIns 3-kinase results in the inhibition of macrophage-mediated cytotoxicity. Interestingly, downstream of PtdIns 3-kinase, expression of constitutively active Akt (Myr-Akt) in macrophages significantly enhanced their ability to mediate ADCC. Further analysis revealed that in this model, macrophage-mediated ADCC is dependent upon the release of nitric oxide (NO). However, the PtdIns 3-kinase/Akt pathway does not appear to regulate NO production. An examination of the role of the PtdIns 3-kinase/Akt pathway in regulating conjugate formation indicated that macrophages treated with an inhibitor of PtdIns 3-kinase fail to polarize the cytoskeleton at the synapse and show a significant reduction in the number of conjugates formed with tumor targets. Further, inhibition of PtdIns 3-kinase also reduced macrophage spreading on Rituximab-coated surfaces. On the other hand, Myr-Akt expressing macrophages displayed a significantly greater ability to form conjugates with tumor cells. Taken together, these findings illustrate that the PtdIns 3-kinase/Akt pathway plays a critical role in macrophage ADCC through its influence on conjugate formation between macrophages and antibody-coated tumor cells

    SARS-CoV-2 Omicron-B.1.1.529 leads to widespread escape from neutralizing antibody responses

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    On 24th November 2021, the sequence of a new SARS-CoV-2 viral isolate Omicron-B.1.1.529 was announced, containing far more mutations in Spike (S) than previously reported variants. Neutralization titers of Omicron by sera from vaccinees and convalescent subjects infected with early pandemic Alpha, Beta, Gamma, or Delta are substantially reduced, or the sera failed to neutralize. Titers against Omicron are boosted by third vaccine doses and are high in both vaccinated individuals and those infected by Delta. Mutations in Omicron knock out or substantially reduce neutralization by most of the large panel of potent monoclonal antibodies and antibodies under commercial development. Omicron S has structural changes from earlier viruses and uses mutations that confer tight binding to ACE2 to unleash evolution driven by immune escape. This leads to a large number of mutations in the ACE2 binding site and rebalances receptor affinity to that of earlier pandemic viruses

    Exercise order affects the total training volume and the ratings of perceived exertion in response to a super-set resistance training session

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    Sandor Balsamo1–3, Ramires Alsamir Tibana1,2,4, Dahan da Cunha Nascimento1,2, Gleyverton Landim de Farias1,2, Zeno Petruccelli1,2, Frederico dos Santos de Santana1,2, Otávio Vanni Martins1,2, Fernando de Aguiar1,2, Guilherme Borges Pereira4, Jéssica Cardoso de Souza4, Jonato Prestes41Department of Physical Education, Centro Universitário UNIEURO, Brasília, 2GEPEEFS (Resistance training and Health Research Group), Brasília/DF, 3Graduate Program in Medical Sciences, School of Medicine, Universidade de Brasília (UnB), Brasília, 4Graduation Program in Physical Education, Catholic University of Brasilia (UCB), Brasília/DF, BrazilAbstract: The super-set is a widely used resistance training method consisting of exercises for agonist and antagonist muscles with limited or no rest interval between them – for example, bench press followed by bent-over rows. In this sense, the aim of the present study was to compare the effects of different super-set exercise sequences on the total training volume. A secondary aim was to evaluate the ratings of perceived exertion and fatigue index in response to different exercise order. On separate testing days, twelve resistance-trained men, aged 23.0 ± 4.3 years, height 174.8 ± 6.75 cm, body mass 77.8 ± 13.27 kg, body fat 12.0% ± 4.7%, were submitted to a super-set method by using two different exercise orders: quadriceps (leg extension) + hamstrings (leg curl) (QH) or hamstrings (leg curl) + quadriceps (leg extension) (HQ). Sessions consisted of three sets with a ten-repetition maximum load with 90 seconds rest between sets. Results revealed that the total training volume was higher for the HQ exercise order (P = 0.02) with lower perceived exertion than the inverse order (P = 0.04). These results suggest that HQ exercise order involving lower limbs may benefit practitioners interested in reaching a higher total training volume with lower ratings of perceived exertion compared with the leg extension plus leg curl order.Keywords: resistance training, super-set method, ratings of perceived exertion, total training volum

    Desigualdades no acesso e utilização dos serviços de saúde na Região Metropolitana de São Paulo Health care services utilization and access inequalities in the Sao Paulo Metropolitan Region

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    Este artigo relata achados dos estudos de casos realizados em cinco municípios da Região Metropolitana de São Paulo (RMSP): São Paulo, Guarulhos, Santo André, Osasco e Franco da Rocha. As desigualdades no acesso aos serviços e sua utilização foram descritas a partir de tabulações avançadas da Pesquisa de Condições de Vida-PCV de 1998 do Seade. Analisamos informações a partir das variáveis posse ou não de planos de saúde, quintil de renda e faixa etária. Os atributos estudados foram: utilização dos serviços, tipo de cobertura do plano, procura pelos serviços e tempo médio de espera no atendimento. A comparação com estudos de outras regiões metropolitanas do Brasil, a partir da PNAD 98 do IBGE, permite afirmar que existem disparidades intra-regionais somente detectadas em estudos de menor escala espacial - os municípios. Apesar da RMSP possuir a maior cobertura de planos de saúde no Brasil, nota-se grande heterogeneidade interna. As desigualdades na posse de planos, no acesso, tempo de espera, tipo de cobertura se manifestam claramente na análise segundo quintil de renda e faixa etária. Conforme os resultados, sugerimos o aumento da capacidade de regulação do Estado, permitindo que os princípios da universalidade e eqüidade se estabeleçam no SUS, efetivando o direito à saúde.<br>This paper presents case study findings in five municipalities in the São Paulo Metropolitan Region. Inequalities in access to health care services and their utilization were described through advanced tabulation data from the 1998 SEADE Life Conditions Survey. The variables analyzed were: owning or not owning private health care insurance, income and age brackets. The health care service attributes studied were: health care services coverage by a health insurance plan, health services demands and average waiting time to receive health care. Compared with other studies, using the 1998 IBGE PNAD, the results allowed us to confirm interregional imbalances which can only be detected in shorter special scale studies: the municipalities. Despite showing the high private health insurances coverage the São Paulo Metropolitan Region has a great inner heterogeneity. The inequalities in private health care insurance, access, waiting time, and type of insurance coverage were observed through income quintiles and age classes analyses. Findings suggest that an expansion of the State's regulation capacity is necessary in order to empower the Brazilian Health Care System principles of universality and equity to be qualified to offer Brazilians the right to access health care services
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