91 research outputs found

    Modelling wax diffusion in crude oils: The cold finger device

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    Abstract In this paper we show how to obtain wax diffusivity and solubility values in crude oils from deposition measurements in the cold finger device with stirring. Providing a rather accurate knowledge of such quantities is of great importance in predicting the wax deposition rate in pipelines. We present a mathematical model in which the physical quantities are assumed to be space-independent in the bulk region of the device, because of agitation, so that mass transport occur in relatively thin boundary layers. As a consequence the deposition phenomenon is accelerated with respect to the static device (see [S. Correra, A. Fasano, L. Fusi, M. Primicerio, F. Rosso. Wax diffusivity under given thermal gradient: a mathematical model, to appear on ZAMM]), shortening the duration of experiments. Comparison with some available laboratory measurements shows a satisfactory agreement and the values obtained are in the range of those usually adopted by practitioners

    Missense mutations in the Fas gene resulting in autoimmune lymphoproliferative syndrome: a molecular and immunological analysis

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    Programmed cell death (or apoptosis) is a physiological process essential to the normal development and homeostatic maintenance of the immune system. The Fas/Apo-1 receptor plays a crucial role in the regulation of apoptosis, as demonstrated by lymphoproliferation in MRL-lpr/lpr mice and by the recently described autoimmune lymphoproliferative syndrome (ALPS) in humans, both of which are due to mutations in the Fas gene. We describe a novel family with ALPS in which three affected siblings carry two distinct missense mutations on both the Fas gene alleles and show lack of Fas-induced apoptosis. The children share common clinical features including splenomegaly and lymphadenopathy, but only one developed severe autoimmune manifestations. In all three siblings, we demonstrated the presence of anergic CD3+CD4-CD8- (double negative, [DN]) T cells; moreover, a chronic lymphocyte activation was found, as demonstrated by the presence of high levels of HLA-DR expression on peripheral CD3+ cells and by the presence of high levels of serum activation markers such as soluble interleukin-2 receptor (slL-2R) and soluble CD30 (sCD30)

    LLAMA Millimeter and Submillimeter Observatory. Update on its Science Opportunities

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    The Large Latin American Millimeter Array (LLAMA for short) is a joint scientific and technological undertaking of Argentina and Brazil whose goal is to install and to operate an observing facility capable of performing observations of the Universe at millimeter and sub-millimeter wavelengths. It will consist of a 12m ALMA-like antenna with the addition of two Nasmyth cabins. LLAMA is located at 4850m above sea level in the Puna Saltenia, in the northwest region of Argentina. When completed, LLAMA will be equipped with six ALMA receivers covering Bands 1, 2+3, 5, 6, 7, and 9, which will populate the two Nasmyth cabins. We summarize here the main ideas related with the Science that LLAMA could accomplish on different astronomical topics, gathered from the experience of a group of international experts on each field.Comment: 11 pages, contributed paper to the workshop "Prospects for low-frequency radio astronomy in South America", held in Buenos Aires, Nov 2022; to appear in the RevMexAA-S

    The Italian National Register of infants with congenital hypothyroidism: twenty years of surveillance and study of congenital hypothyroidism

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    All the Italian Centres in charge of screening, diagnosis, and follow-up of infants with congenital hypothyroidism participate in the Italian National Registry of affected infants, which performs the nationwide surveillance of the disease. It was established in 1987 as a program of the Health Ministry and is coordinated by the Istituto Superiore di SanitĂ . The early diagnosis performed by the nationwide newborn screening programme, the prompt treatment and the appropriate clinical management of the patients carried out by the Follow-up Centres, and the surveillance of the disease performed by the National Register of infants with congenital hypothyroidism are the components of an integrated approach to the disease which has been successfully established in our country

    Prevention of food and airway allergy : Consensus of the Italian Society of Preventive and Social Paediatrics, the Italian Society of Paediatric Allergy and Immunology, and Italian Society of Pediatrics

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    Background: Allergic sensitization in children and allergic diseases arising therefrom are increasing for decades. Several interventions, functional foods, pro- and prebiotics, vitamins are proposed for the prevention of allergies and they can't be uncritically adopted. Objective: This Consensus document was developed by the Italian Society of Preventive and Social Paediatrics and the Italian Society of Paediatric Allergy and Immunology. The aim is to provide updated recommendations regarding allergy prevention in children. Methods: The document has been issued by a multidisciplinary expert panel and it is intended to be mainly directed to primary care paediatricians. It includes 19 questions which have been preliminarily considered relevant by the panel. Relatively to each question, a literature search has been performed, according to the Italian National Guideline Program. Methodology, and a brief summary of the available literature data, has been provided. Many topics have been analyzed including the role of mother's diet restriction, use of breast/formula/hydrolyzed milk; timing of introduction of complementary foods, role (if any) of probiotics, prebiotics, vitamins, exposure to dust mites, animals and to tobacco smoke. Results: Some preventive interventions have a strong level of recommendation. (e.g., the dehumidifier to reduce exposure to mite allergens). With regard to other types of intervention, such as the use of partially and extensively hydrolyzed formulas, the document underlines the lack of evidence of effectiveness. No preventive effect of dietary supplementation with polyunsaturated fatty acids, vitamins or minerals has been demonstrated. There is no preventive effect of probiotics on asthma, rhinitis and allergic diseases. It has demonstrated a modest effect, but steady, in the prevention of atopic dermatitis. Conclusions: The recommendations of the Consensus are based on a careful analysis of the evidence available. The lack of evidence of efficacy does not necessarily imply that some interventions may not be effective, but currently they can't be recommended

    Riociguat treatment in patients with chronic thromboembolic pulmonary hypertension: Final safety data from the EXPERT registry

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    Objective: The soluble guanylate cyclase stimulator riociguat is approved for the treatment of adult patients with pulmonary arterial hypertension (PAH) and inoperable or persistent/recurrent chronic thromboembolic pulmonary hypertension (CTEPH) following Phase
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