943 resultados para Iron-deficiency anemia
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Immunoglobulin superfamily (IgSF) domains are conserved structures present in many proteins in eukaryotes and prokaryotes. These domains are well-capable of facilitating sequence variation, which is most clearly illustrated by the variable regions in immunoglobulins (Igs) and T cell receptors (TRs). We studied an antibody-deficient patient suffering from recurrent respiratory infections and with impaired antibody responses to vaccinations. Patient's B cells showed impaired Ca(2+) influx upon stimulation with anti-IgM and lacked detectable CD19 membrane expression. CD19 sequence analysis revealed a homozygous missense mutation resulting in a tryptophan to cystein (W52C) amino acid change. The affected tryptophan is CONSERVED-TRP 41 located on the C-strand of the first extracellular IgSF domain of CD19 and was found to be highly conserved, not only in mammalian CD19 proteins, but in nearly all characterized IgSF domains. Furthermore, the tryptophan is present in all variable domains in Ig and TR and was not mutated in 117 Ig class-switched transcripts of B cells from controls, despite an overall 10% amino acid change frequency. In vitro complementation studies and CD19 western blotting of patient's B cells demonstrated that the mutated protein remained immaturely glycosylated. This first missense mutation resulting in a CD19 deficiency demonstrates the crucial role of a highly conserved tryptophan in proper folding or stability of IgSF domains.
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Mycobacterium tilburgii rarely causes disseminated disease. We describe a case of M. tilburgii infection in an otherwise healthy 33-year-old woman, who was found to carry bi-allelic mutations of the gene encoding the β1 chain of the IL-12 receptor.
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info:eu-repo/semantics/nonPublished
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info:eu-repo/semantics/nonPublished
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info:eu-repo/semantics/nonPublished
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Interleukin-12 receptor β1 (IL-12Rβ1) deficiency is the most common form of Mendelian susceptibility to mycobacterial disease (MSMD). We undertook an international survey of 141 patients from 102 kindreds in 30 countries. Among 102 probands, the first infection occurred at a mean age of 2.4 years. In 78 patients, this infection was caused by Bacille Calmette-Guérin (BCG; n = 65), environmental mycobacteria (EM; also known as atypical or nontuberculous mycobacteria) (n = 9) or Mycobacterium tuberculosis (n = 4). Twenty-two of the remaining 24 probands initially presented with nontyphoidal, extraintestinal salmonellosis. Twenty of the 29 genetically affected sibs displayed clinical signs (69%); however 8 remained asymptomatic (27%). Nine nongenotyped sibs with symptoms died. Recurrent BCG infection was diagnosed in 15 cases, recurrent EM in 3 cases, recurrent salmonellosis in 22 patients. Ninety of the 132 symptomatic patients had infections with a single microorganism. Multiple infections were diagnosed in 40 cases, with combined mycobacteriosis and salmonellosis in 36 individuals. BCG disease strongly protected against subsequent EM disease (p = 0.00008). Various other infectious diseases occurred, albeit each rarely, yet candidiasis was reported in 33 of the patients (23%). Ninety-nine patients (70%) survived, with a mean age at last follow-up visit of 12.7 years ± 9.8 years (range, 0.5-46.4 yr). IL-12Rβ1 deficiency is characterized by childhood-onset mycobacteriosis and salmonellosis, rare recurrences of mycobacterial disease, and more frequent recurrence of salmonellosis. The condition has higher clinical penetrance, broader susceptibility to infections, and less favorable outcome than previously thought. © 2010 Lippincott Williams & Wilkins.
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Mathematical models of straight-grate pellet induration processes have been developed and carefully validated by a number of workers over the past two decades. However, the subsequent exploitation of these models in process optimization is less clear, but obviously requires a sound understanding of how the key factors control the operation. In this article, we show how a thermokinetic model of pellet induration, validated against operating data from one of the Iron Ore Company of Canada (IOCC) lines in Canada, can be exploited in process optimization from the perspective of fuel efficiency, production rate, and product quality. Most existing processes are restricted in the options available for process optimization. Here, we review the role of each of the drying (D), preheating (PH), firing (F), after-firing (AF), and cooling (C) phases of the induration process. We then use the induration process model to evaluate whether the first drying zone is best to use on the up- or down-draft gas-flow stream, and we optimize the on-gas temperature profile in the hood of the PH, F, and AF zones, to reduce the burner fuel by at least 10 pct over the long term. Finally, we consider how efficient and flexible the process could be if some of the structural constraints were removed (i.e., addressed at the design stage). The analysis suggests it should be possible to reduce the burner fuel lead by 35 pct, easily increase production by 5+ pct, and improve pellet quality.
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The micromagnetic structure and energy of 180° domain walls spanning laminar crystals of iron having (100) or (110) surfaces and ranging in thickness from 145 to 580 nm have been investigated by numerical integration of the Landau-Lifshitz-Gilbert equation. Stable equilibrium structures with two flux symmetries were obtained for both crystal orientations at all thicknesses studied.
Computational fluid dynamics: advancements in technology for modeling iron and steelmaking processes
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Computational fluid dynamics (CFD) software technology has formed the basis of many investigations into the behavior and optimization of primary iron and steelmaking processes for the last 25+ years. The objective of this contribution is to review the progress in CFD technologies over the last decade or so and how this can be brought to bear in advancing the process analysis capability of primary ferrous operations. In particular, progress on key challenges such as compute performance, fluid-structure transformation and interaction, and increasingly complex geometries are highlighted.
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A new series of iron(III) complexes [Fe(L(1))(HL(1))], [Fe(L(1)) Cl]; [H2L(1) = N'-(2-methoxythiobenzoyl)pyridine-2-carbohydrazide], [Fe(L(2))(acac)], [Fe(HL(2))2 Cl]; [H2L(2) = N'-(4-methoxythiobenzoyl)pyridine-2-carbohydrazide] and [Fe(L(3)) (acac)]; [H2L(3) = N'-(2-hydroxythiobenzoyl)pyridine-2-carbohydrazide] were prepared by stirring/refluxing/mixing the respective ligand with FeCl3/Fe(acac)3 in chloroform/methanol. All the compounds were characterized by elemental analyses, magnetic susceptibility, IR, UV and Mossbauer spectral data. The complexes high/low spin state and have tetrahedral/octahedral geometry.