1,528 research outputs found

    Automation for monitoring of the refractive index profile of vapor-phase-deposited soot preforms for optical fiber

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    The vapor-phase axial deposition process is currently one of the most advantageous methods to produce preforms for optical fibers, due to its high efficiency and reduced production cost. However, this method has great difficulty in determining the refractive index profile, since it is influenced by too many process parameters. In this work, an automation system to determine the refractive index profile by monitoring the preform deposition surface profile during the soot preform deposition stage is presented. Based on a previous study that showed a strong correlation between these two profiles, an automation system was developed in LABVIEW to monitor the deposition surface profile during the preform deposition stage in order to estimate the preform germanium doping profile and refractive index profile, as well as a theoretical study to develop this system in order to minimize the performance impairment. As a result, not only preforms with a predetermined index profile were produced but also a reduction in production cost was obtained by decreasing the number of preform rejects. (c) 2006 American Institute of Physics.77

    Uma década de neonaticídios na grande Lisboa: contributos da Psicologia e Psiquiatria

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    O neonaticĂ­dio corresponde ao homicĂ­dio de uma criança durante as primeiras 24 horas de vida. Neste trabalho procurou-se caracterizar casos de neonaticĂ­dio ocorridos na ĂĄrea da Grande Lisboa, atravĂ©s de um estudo retrospetivo de todos os processos investigados na Delegação do Sul do Instituto Nacional de Medicina Legal e CiĂȘncias Forenses, I.P. (INMLCF), entre 1 de janeiro de 2001 e 31 de dezembro de 2010. Identificaram-se cinco casos de neonaticĂ­dio (2.96 por 100000 nados-vivos), atribuĂ­veis a cinco mĂŁes com uma idade mĂ©dia de 25 anos, cuja principal motivação foi a gravidez indesejada. Em todos os casos, a gravidez foi ocultada, evoluiu sem cuidados mĂ©dicos prĂ©-natais e o parto ocorreu em casa, sem assistĂȘncia. NĂŁo foi identificada qualquer perturbação mental que verificasse os requisitos normativos de inimputabilidade para o crime. Embora raros, os casos de neonaticĂ­dio causam particular alarme social e levantam diversas questĂ”es jurĂ­dicas e mĂ©dico- legais. O facto de se encontrarem associados Ă  ocultação da gravidez e Ă  ausĂȘncia de perturbação mental evidente das suas autoras, dificulta a adoção de medidas preventivas, destacando-se a importĂąncia de um diagnĂłstico precoce de gravidez em mulheres em idade fĂ©rtil

    Five-year review of an international clinical research-training program

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    The exponential increase in clinical research has profoundly changed medical sciences. Evidence that has accumulated in the past three decades from clinical trials has led to the proposal that clinical care should not be based solely on clinical expertise and patient values, and should integrate robust data from systematic research. As a consequence, clinical research has become more complex and methods have become more rigorous, and evidence is usually not easily translated into clinical practice. Therefore, the instruction of clinical research methods for scientists and clinicians must adapt to this new reality. To address this challenge, a global distance-learning clinical research-training program was developed, based on collaborative learning, the pedagogical goal of which was to develop critical thinking skills in clinical research. We describe and analyze the challenges and possible solutions of this course after 5 years of experience (2008-2012) with this program. Through evaluation by students and faculty, we identified and reviewed the following challenges of our program: 1) student engagement and motivation, 2) impact of heterogeneous audience on learning, 3) learning in large groups, 4) enhancing group learning, 5) enhancing social presence, 6) dropouts, 7) quality control, and 8) course management. We discuss these issues and potential alternatives with regard to our research and background

    Absence of diabetic retinopathy in a patient who has had diabetes mellitus for 69 years, and inadequate glycemic control: case presentation

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    The main risk factors for the development and progression of diabetic retinopathy (DR) are chronic hyperglycemia, disease duration and systemic blood pressure. So far chronic hyperglycemia is the strongest evidence concerning the risk of developing DR. However there are some patients with poor metabolic control who never develop this diabetic complication. We present a case of a 73-year-old woman with type 1 diabetes mellitus, diagnosed 69 years ago. The patient is 73 years old, with no evidence of DR, despite poor glycemic control and several risk factors for DR. This case suggests the presence of a possible protection factor, which could be genetic

    Vitamin D in women with class II/III obesity: Findings from the DieTBra trial

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    Objective: To assess the prevalence of vitamin D deficiency and factors associated with serum vitamin D levels in adult women with class II/III obesity. Methods: We analysed baseline data from 128 adult women with class II/III obesity i.e. BMI ≄35 kg/m2 who participated in the DieTBra clinical trial. Sociodemographic, lifestyle, sun exposure, sunscreen, dietary intake of calcium and vitamin D, menopause, diseases, medication, and body composition data were analysed using multiple linear regression. Results: 128 women had mean BMI 45.53 ± 6.36, mean age 39.7 ± 8.75 kg/m2 and serum vitamin D 30.02 ng/ml ± 9.80. Vitamin D deficiency was 14.01%. There was no association between serum vitamin D levels and BMI, body fat percentage, total body fat and waist circumference. Age group (p = 0.004), sun exposure/day (p = 0.072), use of sunscreen (p = 0.168), inadequate calcium intake (p = 0.030), BMI (p = 0.192), menopause (p = 0.029) and lipid-lowering drugs (p = 0.150) were included in the multiple linear regression. The following remained associated with low serum vitamin D: being 40–49 years (p = 0.003); ≄50 years of age (p = 0.020) and inadequate calcium intake (p = 0.027). Conclusion: The prevalence of vitamin D deficiency was lower than expected. Lifestyle, sun exposure and body composition were not associated. Age over 40 years and inadequate calcium intake were significantly associated with low serum vitamin D levels

    Targeting BTK for the treatment of FLT3-ITD mutated acute myeloid leukemia

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    Approximately 20% of patients with acute myeloid leukaemia (AML) have a mutation in FMS-like-tyrosine-kinase-3 (FLT3). FLT3 is a trans-membrane receptor with a tyrosine kinase domain which, when activated, initiates a cascade of phosphorylated proteins including the SRC family of kinases. Recently our group and others have shown that pharmacologic inhibition and genetic knockdown of Bruton's tyrosine kinase (BTK) blocks AML blast proliferation, leukaemic cell adhesion to bone marrow stromal cells as well as migration of AML blasts. The anti-proliferative effects of BTK inhibition in human AML are mediated via inhibition of downstream NF-ÎșB pro-survival signalling however the upstream drivers of BTK activation in human AML have yet to be fully characterised. Here we place the FLT3-ITD upstream of BTK in AML and show that the BTK inhibitor ibrutinib inhibits the survival and proliferation of FLT3-ITD primary AML blasts and AML cell lines. Furthermore ibrutinib inhibits the activation of downstream kinases including MAPK, AKT and STAT5. In addition we show that BTK RNAi inhibits proliferation of FLT3-ITD AML cells. Finally we report that ibrutinib reverses the cyto-protective role of BMSC on FLT3-ITD AML survival. These results argue for the evaluation of ibrutinib in patients with FLT3-ITD mutated AML

    Toxicity and genotoxicity of wastewater from gasoline stations

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    The toxicity and genotoxicity of wastewater from eight gasoline stations in BrasĂ­lia, Brazil's capital city, was studied by assessing chromosomal aberrations, chromosomal malsegregation and the mitotic index in Alliumcepa root cells, and the occurrence of micronucleus and nuclear abnormalities in peripheral erythrocytes of tilapia fish (Oreochromis niloticus). The content of gasoline station effluents was also analyzed based on several physico-chemical parameters. None of the wastewater samples was genotoxic to A. cepa root cells, although cell proliferation was significantly inhibited, especially at the highest concentrations. Likewise, no micronuclei were observed in O. niloticus peripheral erythrocytes, even after exposure to high concentrations, but there was an increase in the number of nuclear abnormalities and fish mortality. These results show that although the effluent from gasoline stations is processed by an oil/water separation system before being discharged into the main sewage system, the wastewater still contains toxic compounds

    Five-year review of an international clinical research-training program

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    The exponential increase in clinical research has profoundly changed medical sciences. Evidence that has accumulated in the past three decades from clinical trials has led to the proposal that clinical care should not be based solely on clinical expertise and patient values, and should integrate robust data from systematic research. As a consequence, clinical research has become more complex and methods have become more rigorous, and evidence is usually not easily translated into clinical practice. Therefore, the instruction of clinical research methods for scientists and clinicians must adapt to this new reality. To address this challenge, a global distance-learning clinical research-training program was developed, based on collaborative learning, the pedagogical goal of which was to develop critical thinking skills in clinical research. We describe and analyze the challenges and possible solutions of this course after 5 years of experience (2008-2012) with this program. Through evaluation by students and faculty, we identified and reviewed the following challenges of our program: 1) student engagement and motivation, 2) impact of heterogeneous audience on learning, 3) learning in large groups, 4) enhancing group learning, 5) enhancing social presence, 6) dropouts, 7) quality control, and 8) course management. We discuss these issues and potential alternatives with regard to our research and background
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