6,574 research outputs found

    Liquid-phase hydrogenation of bio-refined succinic acid to 1,4-butanediol using bimetallic catalysts

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    open access articleDevelopment of a Crotalaria juncea based biorefinery produce large quantity of waste glycerol after trans-esterification of the juncea seeds. This glycerol, after purification, is used as a substrate for producing succinic acid on a microbial route. Hydrogenation of this bio-refined succinic acid is carried out under high pressure in order to produce 1,4- butanediol (BDO) using a batch slurry reactor with cobalt supported ruthenium bimetallic catalysts, synthesized inhouse. It is demonstrated that, using small amounts of ruthenium to cobalt increases the overall hydrogenation activity for the production of 1,4-butanediol. Hydrogenation reactions are carried out at various operating temperatures and pressures along with changes in the mixing ratios of ruthenium chloride and cobalt chloride hexahydrate, which are used to synthesize the catalyst. The Ru-Co bimetallic catalysts are characterized by XRD, FE-SEM and TGA. Concentrations of the hydrogenation product are analyzed using Gas chromatography-Mass spectrometry (GC-MS). Statistical analysis of the overall hydrogenation process is performed using a Box-Behnken Design (BBD)

    Association between Transcription Factor AP-2B genotype, obesity, insulin resistance and dietary intake in a longitudinal birth cohort study Transcription Factor AP-2B associated with obesity

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    This is a post-peer-review, pre-copyedit version of an article published in International Journal of Obesity.The development of obesity has a large genetic component, and the gene encoding the transcription factor 2 beta (TFAP2B) has been identified as one of the responsible factors. We investigated the effect of TFAP2B intron 2 variable number tandem repeat (VNTR) genotype on obesity, insulin resistance and dietary intake from 15 to 33 years of age

    Quantifying Morphology and Diffusion Properties of Mesoporous Carbon from High-Fidelity 3D Reconstructions

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    A reliable quantitative analysis in electron tomography, which depends on the segmentation of the three-dimensional reconstruction, is challenging because of constraints during tilt-series acquisition (missing wedge) and reconstruction artifacts introduced by reconstruction algorithms such as the Simultaneous Iterative Reconstruction Technique (SIRT) and Discrete Algebraic Reconstruction Technique (DART). We have carefully evaluated the fidelity of segmented reconstructions analyzing a disordered mesoporous carbon used as support in catalysis. Using experimental scanning transmission electron microscopy (STEM) tomography data as well as realistic phantoms, we have quantitatively analyzed the effect on the morphological description as well as on diffusion properties (based on a random-walk particle-tracking simulation) to understand the role of porosity in catalysis. The morphological description of the pore structure can be obtained reliably both using SIRT and DART reconstructions even in the presence of a limited missing wedge. However, the measured pore volume is sensitive to the threshold settings, which are difficult to define globally for SIRT reconstructions. This leads to noticeable variations of the diffusion coefficients in the case of SIRT reconstructions, whereas DART reconstructions resulted in more reliable data. In addition, the anisotropy of the determined diffusion properties was evaluated, which was significant in the presence of a limited missing wedge for SIRT and strongly reduced for DART

    Management of childhood headache in the emergency department. Review of the literature

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    Headache is the third cause of visits to pediatric emergency departments (ED). According to a systematic review, headaches in children evaluated in the ED are primarily due to benign conditions that tend to be self-limiting or resolve with appropriate pharmacological treatment. The more frequent causes of non-traumatic headache in the ED include primitive headaches (21.8-66.3%) and benign secondary headaches (35.4-63.2%), whereas potentially life-threatening (LT) secondary headaches are less frequent (2-15.3%). Worrying conditions include brain tumors, central nervous system infections, dysfunction of ventriculo-peritoneal shunts, hydrocephalus, idiopathic intracranial hypertension, and intracranial hemorrhage. In the emergency setting, the main goal is to intercept potentially LT conditions that require immediate medical attention. The initial assessment begins with an in-depth, appropriate history followed by a complete, oriented physical and neurological examination. The literature describes the following red flags requiring further investigation (for example neuroimaging) for recognition of LT conditions: abnormal neurological examination; atypical presentation of headaches: subjective vertigo, intractable vomiting or headaches that wake the child from sleep; recent and progressive severe headache (< 6 months); age of the child < 6 years; no family history for migraine or primary headache; occipital headache; change of headache; new headache in an immunocompromised child; first or worst headache; symptoms and signs of systemic disease; headaches associated with changes in mental status or focal neurological disorders. In evaluating a child or adolescent who is being treated for headache, physicians should consider using appropriate diagnostic tests. Diagnostic tests are varied, and include routine laboratory analysis, cerebral spinal fluid examination, electroencephalography, and computerized tomography or magnetic resonance neuroimaging. The management of headache in the ED depends on the patient's general conditions and the presumable cause of the headache. There are few randomized, controlled trials on pharmacological treatment of headache in the pediatric population. Only ibuprofen and sumatriptan are significantly more effective than placebo in determining headache relief

    Ictal epileptic headache: When terminology is not a moot question

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    open7noThe relationship between headache and epilepsy is complex and despite the nature of this association is not yet clear. In the last few years, it has been progressively introduced the concept of the “ictal epileptic headache” that was included in the recently revised International Classification of Headaches Disorders 3rd edition (ICHD-3-revised). The diagnostic criteria for ictal epileptic headache (IEH) suggested in 2012 were quite restrictive thus leading to the underestimation of this phenomenon. However, these criteria have not yet been included into the ICHD-3 revision published in 2018, thus creating confusion among both, physicians and experts in this field. Here, we highlight the importance to strictly apply the original IEH criteria explaining the reasons through the analysis of the clinical, historical, epidemiological and pathophysiological characteristics of the IEH itself. In addition, we discuss the issues related to the neurophysiopathological link between headache and epilepsy as well as to the classification of these epileptic events as “autonomic seizure”.openParisi P.; Paolino M.C.; Raucci U.; Vecchia N.D.; Belcastro V.; Villa M.P.; Striano P.Parisi, P.; Paolino, M. C.; Raucci, U.; Vecchia, N. D.; Belcastro, V.; Villa, M. P.; Striano, P
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