Study and suppression of the microstructural anisotropy generated during the consolidation of a carbonyl iron powder by field-assisted hot pressing

Published OnlineA spherical carbonyl iron powder was consolidated by the field-assisted hot pressing technique using graphite tools at two different temperatures, both above the austenitizing temperature. The microstructures obtained exhibited a compositional gradient in carbon along the consolidated material. Thus, the outer rim of the cylindrical samples was composed of cementite and pearlite that gradually turned to pearlite, leading to a fully ferritic microstructure at the core of the sample. The increase in the temperature has led to a higher introduction of carbon within the sample. The interposition of a thin tungsten foil between the graphite die/punches and the powders has significantly reduced the diffusion of the carbon through the iron matrix and has suppressed the microstructural anisotropy.Publicad

Analytical Validation of a New Enzymatic and Automatable Method for d-Xylose Measurement in Human Urine Samples

Hypolactasia, or intestinal lactase deficiency, affects more than half of the world population. Currently, xylose quantification in urine after gaxilose oral administration for the noninvasive diagnosis of hypolactasia is performed with the hand-operated nonautomatable phloroglucinol reaction. This work demonstrates that a new enzymatic xylose quantification method, based on the activity of xylose dehydrogenase from Caulobacter crescentus, represents an excellent alternative to the manual phloroglucinol reaction. The new method is automatable and facilitates the use of the gaxilose test for hypolactasia diagnosis in the clinical practice. The analytical validation of the new technique was performed in three different autoanalyzers, using buffer or urine samples spiked with different xylose concentrations. For the comparison between the phloroglucinol and the enzymatic assays, 224 urine samples of patients to whom the gaxilose test had been prescribed were assayed by both methods. A mean bias of -16.08 mg of xylose was observed when comparing the results obtained by both techniques. After adjusting the cut-off of the enzymatic method to 19.18 mg of xylose, the Kappa coefficient was found to be 0.9531, indicating an excellent level of agreement between both analytical procedures. This new assay represents the first automatable enzymatic technique validated for xylose quantification in urine.The authors thank IgorMart´ın for his support with statistical analysis, Jos´e Claros and Ricardo Jara from Immunostep for their work in the kit development, and Guillermo Corrales for his technical assistance. The work presented in this manuscript was funded by Venter Pharma S.L., Madrid, Spain.Peer Reviewe

Management of Traumatic Dacryocystitis and Failed Dacryocystorhinostomy Using Silicone Lacrimal Intubation Set

The aim of this work is to study the management and success rate of traumatic dacryocystitis and failed dacryocystorhinostomy (DCR) using Silicone lacrimal intubation set. A prospective study was conducted at a tertiary eye care hospital, India from February 2006 to January 2008. This study material comprised 50 patients of traumatic dacryocystitis and failed dacryocystorhinostomy. Anterior single flap external dacryocystorhinostomy with Silicon intubation was performed in all the patients. The patients were followed up at weekly intervals for 1 month and thereafter every 2 months for 1 year post operatively. Criteria determining success were based on resolution of epiphora and patency on syringing. In traumatic dacryocystitis, 21(91.3%) cases fulfilled these criteria while 23(85.2%) cases of failed DCR were successful. The overall success rate (88%) was determined with an average follow-up of 1 year. Globally, the technique was effective in 85% of cases. The results were comparable with other similar studies. This study concludes that performing a DCR in traumatic dacryocystitis and failed DCR taking into consideration the complications and chances of failure is a challenge for the surgeon. We opine that External dacryocystorhinostomy with Silicon Intubation is one of the most effective modality in dealing with such cases

Tandem and Sequential Multi-Enzymatic Syntheses

Summary This chapter contains sections titled: •Production of Isorhamnetin 3-O-Glucoside in Escherichia coli Using Engineered Glycosyltransferase •Multienzymatic Preparation of (−)-3-(Oxiran-2-yl)Benzoic Acid •Enzymatic Synthesis of Carbohydrates from Dihydroxyacetone and Aldehydes by a One Pot Enzyme Cascade Reaction •Aldolase Based Multi-Enzyme System for Carbon[BOND]Carbon Bond Formation •Tandem Biocatalytic Process for the Kinetic Resolution of β-Phenylalanine and its Analogs •A Chemoenzymatic Synthesis of a Deoxy Sugar Ester of N-Boc-Protected L-Tyrosine •Electrochemical Systems for the Recovery of Succinic Acid from FermentationsPeer reviewe

Cholinergic Potentiation and Audiovisual Repetition-Imitation Therapy Improve Speech Production and Communication Deficits in a Person with Crossed Aphasia by Inducing Structural Plasticity in White Matter Tracts

Donepezil (DP), a cognitive-enhancing drug targeting the cholinergic system, combined with massed sentence repetition training augmented and speeded up recovery of speech production deficits in patients with chronic conduction aphasia and extensive left hemisphere infarctions (Berthier et al., 2014). Nevertheless, a still unsettled question is whether such improvements correlate with restorative structural changes in gray matter and white matter pathways mediating speech production. In the present study, we used pharmacological magnetic resonance imaging to study treatment-induced brain changes in gray matter and white matter tracts in a right-handed male with chronic conduction aphasia and a right subcortical lesion (crossed aphasia). A single-patient, open-label multiple-baseline design incorporating two different treatments and two post-treatment evaluations was used. The patient received an initial dose of DP (5 mg/day) which was maintained during 4 weeks and then titrated up to 10 mg/day and administered alone (without aphasia therapy) during 8 weeks (Endpoint 1). Thereafter, the drug was combined with an audiovisual repetition-imitation therapy (Look-Listen-Repeat, LLR) during 3 months (Endpoint 2). Language evaluations, diffusion weighted imaging (DWI), and voxel-based morphometry (VBM) were performed at baseline and at both endpoints in JAM and once in 21 healthy control males. Treatment with DP alone and combined with LLR therapy induced marked improvement in aphasia and communication deficits as well as in selected measures of connected speech production, and phrase repetition. The obtained gains in speech production remained well-above baseline scores even 4 months after ending combined therapy. Longitudinal DWI showed structural plasticity in the right frontal aslant tract and direct segment of the arcuate fasciculus with both interventions. VBM revealed no structural changes in other white matter tracts nor in cortical areas linked by these tracts. In conclusion, cholinergic potentiation alone and combined with a model-based aphasia therapy improved language deficits by promoting structural plastic changes in right white matter tracts