630 research outputs found
A contribution to the vibrational analysis of metal complexes with pyridine and related ligands
Air melting of Cu-Cr alloys
Method and apparatus for making a Cu-Cr melt involves melting Cu-bearing alloy component in a melting vessel disposed in ambient air atmosphere, retaining Cr-bearing alloy component in an inverted ceramic crucible held submerged in the melted Cu-bearing alloy component, introducing inert gas into the melted Cu-bearing alloy component, and flowing the melted Cu-bearing alloy component in the melting vessel through openings in the submerged crucible to contact the Cr-bearing alloy component
Collecting data for sexually transmitted infections (STI) surveillance: what do patients prefer in Flanders?
Mastication Dyspraxia: A Neurodevelopmental Disorder Reflecting Disruption of the Cerebellocerebral Network Involved in Planned Actions
This paper reports the longitudinal clinical, neurocognitive, and neuroradiological findings in an adolescent patient with nonprogressive motor and cognitive disturbances consistent with a diagnosis of developmental coordination disorder (DCD). In addition to prototypical DCD, the development of mastication was severely impaired, while no evidence of swallowing apraxia, dysphagia, sensorimotor disturbances, abnormal tone, or impaired general cognition was found. He suffered from bronchopulmonary dysplasia and was ventilated as a newborn for 1.5 months. At the age of 3 months, a ventriculoperitoneal shunt was surgically installed because of obstructive hydrocephalus secondary to perinatal intraventricular bleeding. At the age of 5 years, the patient’s attempts to masticate were characterized by rough, effortful, and laborious biting movements confined to the vertical plane. Solid food particles had a tendency to get struck in his mouth and there was constant spillage. As a substitute for mastication, he moved the unground food with his fingers in a lateral direction to the mandibular and maxillary vestibule to externally manipulate and squeeze the food between cheek and teeth with the palm of his hand. Once the food was sufficiently soft, the bolus was correctly transported by the tongue in posterior direction and normal deglutition took place. Repeat magnetic resonance imaging (MRI) during follow-up disclosed mild structural abnormalities as the sequelae of the perinatal intraventricular bleeding, but this could not explain impaired mastication behavior. Quantified Tc-99m-ethylcysteinate dimer single-photon emission computed tomography (Tc-99m-ECD SPECT), however, revealed decreased perfusion in the left cerebellar hemisphere, as well as in both inferior lateral frontal regions, both motor cortices, and the right anterior and lateral temporal areas. Anatomoclinical findings in this patient with DCD not only indicate that the functional integrity of the cerebellocerebral network is crucially important in the planning and execution of skilled actions, but also seem to show for the first time that mastication deficits may be of true apraxic origin. As a result, it is hypothesized that “mastication dyspraxia” may have to be considered as a distinct nosological entity within the group of the developmental dyspraxias following a disruption of the cerebellocerebral network involved in planned actions
An electro-responsive hydrogel for intravascular applications: an in vitro and in vivo evaluation
There is a growing interest in using hydrogels for biomedical applications, because of more favourable characteristics. Some of these hydrogels can be activated by using particular stimuli, for example electrical fields. These stimuli can change the hydrogel shape in a predefined way. It could make them capable of adaptation to patient-specific anatomy even post-implantation. This is the first paper aiming to describe in vivo studies of an electro-responsive, Pluronic F127 based hydrogel, for intravascular applications. Pluronic methacrylic acid hydrogel (PF127/MANa) was in vitro tested for its haemolytic and cytotoxic effects. Minimal invasive implantation in the carotid artery of sheep was used to evaluate its medium-term biological effects, through biochemical, macroscopic, radiographic, and microscopic evaluation. Indirect and direct testing of the material gave no indication of the haemolytic effects of the material. Determination of fibroblast viability after 24 h of incubation in an extract of the hydrogel showed no cytotoxic effects. Occlusion was obtained within 1 h following in vivo implantation. Evaluation at time of autopsy showed a persistent occlusion with no systemic effects, no signs of embolization and mild effects on the arterial wall. An important proof-of-concept was obtained showing biocompatibility and effectiveness of a pluronic based electro-responsive hydrogel for obtaining an arterial occlusion with limited biological impact. So the selected pluronic-methacrylic acid based hydrogel can be used as an endovascular occlusion device. More importantly it is the first step in further development of electro-active hydrogels for a broad range of intra-vascular applications (e.g. system to prevent endoleakage in aortic aneurysm treatment, intra-vascular drug delivery)
Critical role of metals in biochemical properties of xylose isomerase
Improving the activity of xylose isomerase (XI) is highly desired for achieving efficient fermentation of xylose in lignocellulosic biomass using XI-expressing S. cerevisiae. XI is a metalloenzyme which requires two bivalent metals for its catalytic activity. The enzyme from Piromyces sp. E2 (PirXI)[1],[2] is activated with various metal ions including Mg2+, Mn2+, Ca2+, Co2+, Zn2+ and Fe2+. The biochemical properties of PirXI are dependent on the types of its metal cofactors. Moreover, the enzyme shows different affinities towards these metals. Characterization of these properties is critical for understanding the enzyme behavior in vivo and to further adapt the enzyme to the cytosolic metal environment. Recently, we have shown that altered intracellular metal composition can improve anaerobic growth of a xylose-fermenting strain by enhancing the activity of PirXI[3]. Furthermore, our current study on PirXI and other studies on different XIs have shown that it is also possible to change the metal preferences of the enzyme[4]. A PirXI variant with a single amino acid substitution in the proximity of the metal binding residues showed significant changes in metal preference compared to the wild-type PirXI. Further exploration on metal specificity of PirXI is necessary to optimize the in vivo enzyme activity.
References:
1.Kuyper M, Harhangi HR, Stave AK, Winkler AA, Jetten MS, de Laat WT, den Ridder JJ, Op den Camp HJ, van Dijken JP, Pronk JT, FEMS Yeast Research 4 (2003) 69-78
2.van Maris AJ, Winkler AA, Kuyper M, de Laat WT, van Dijken JP, Pronk JT, Adv Biochem Engin/Biotechnol (2007) 108: 179–204
3.Verhoeven MD, Lee M, Kamoen L, van den Broek M, Janssen DB, Daran JG, van Maris AJA, Pronk JT, Sci. Rep (2017) 7, 46155
4.van Tilbeurgh H, Jenkins J, Chiadmi M, Janin J, Wodak SJ, Mrabet NT, Lambeir AM, Biochemistry (1992) 31: 5467-547
Van Afval Af
__Abstract__
Er is in de gemeentelijke afvalwereld consensus dat de toekomst ligt in gesloten materiaalkringlopen. Ook het Verpakkingenakkoord spreekt de ambitie uit dat in de komende tien jaar een versnelling nodig is richting grootschalig hergebruik, sluiten van kringlopen en de ontwikkeling van een goed functionerende circulaire grondstoffenmarkt. Vergelijkbare ambities zijn ook door veel gemeenten individueel en de Rijksoverheid in haar ‘afval is grondstof’ beleid uitgesproken. Die gemeentelijke ambitie – en dan specifiek op het gebied van verpakkingen - is de directe aanleiding voor deze transitie-studie. Het beoogt overzicht en suggesties te bieden aan gemeenten (en andere partijen) over hun rol in de circulaire economie vanuit hun positie in de afvalketen. Veel gemeenten hebben de beleidsvoorbereiding en/of uitvoering bij samenwerkingsverbanden of overheidsgedomineerde bedrijven gelegd. In dit document bedoelen we met gemeenten, tenzij anders vermeld, dus ook de lokale overheid inclusief deze partijen. Tijdens de interviews en sessies bleken de meningen soms verdeeld of het Verpakkingenakkoord op alle punten een stap in de goede richting is. In deze studie gaan we uit er vanuit dat het nu gesloten Verpakkingenakkoord een gegeven is, maar we besteden wel aandacht aan hoe gemeenten de invulling en uitvoering van het Verpakkingenakkoord (en de organisatie van afvalbeheer in het algemeen) de komende jaren kunnen vormgeven en strategisch positie kunnen kiezen
Clinical characteristics and outcomes of patients with hepatic angiomyolipoma:A literature review
First reported in 1976, hepatic angiomyolipoma (HAML) is a rare mesenchymal liver tumor occurring mostly in middle-aged women. Diagnosis of the liver mass is often incidental on abdominal imaging due to the frequent absence of specific symptoms. Nearly 10% of HAMLs are associated with tuberous sclerosis complex. HAML contains variable proportions of blood vessels, smooth muscle cells and adipose tissue, which renders radiological diagnosis hazardous. Cells express positivity for HMB-45 and actin, thus these tumors are integrated into the group of perivascular epithelioid cell tumors. Typically, a HAML appears on magnetic resonance imaging (or computed tomography scan) as a hypervascular solid tumor with fatty areas and with washout, and can easily be misdiagnosed as other liver tumors, particularly hepatocellular carcinoma. The therapeutic strategy is not clearly defined, but surgical resection is indicated for symptomatic patients, for tumors showing an aggressive pattern (i.e., changes in size on imaging or high proliferation activity and atypical epithelioid pattern on liver biopsy), for large (> 5 cm) biopsy-proven HAML, and if doubts remain on imaging or histology. Conservative management may be justified in other conditions, since most cases follow a benign clinical course. In summary, the correct diagnosis of HAML is challenging on imaging and relies mainly on pathological findings
Time-layered cultural map of Australia
Copyright © 2020 for this paper by its authors. Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0). This paper reports on an Australian project that is developing an online system to deliver researcher-driven national-scale infrastructure for the humanities, focused on mapping, time series, and data integration. Australian scholars and scholars of Australia worldwide are well served with digital resources and tools to deepen the understanding of Australia and its historical and cultural heritage. There are, however, significant barriers to use. The Time Layered Cultural Map of Australia (TLCMap) will provide an umbrella infrastructure related to time and space, helping to activate and draw together existing high-quality resources. TLCMap expands the use of Australian cultural and historical data for research through sharply defined and powerful discovery mechanisms. See https://tlcmap.newcastle.edu.au/
Three-Dimensional Geometric Analysis of Balloon-Expandable Covered Stents Improves Classification of Complications after Fenestrated Endovascular Aneurysm Repair
In balloon-expandable covered stent (BECS) associated complications after fenestrated endovascular aneurysm repair (FEVAR), geometric analysis may determine the cause of failure and influence reintervention strategies. This study retrospectively classifies BECS-associated complications based on computed tomographic angiography (CTA) applied geometric analysis. BECS-associated complications of FEVAR-patients treated in two large vascular centers between 2012 and 2021 were included. The post-FEVAR CTA scans of complicated Advanta V12 BECSs were analyzed geometrically and complications were classified according to its location in the BECS. BECS fractures were classified according to an existing classification system. In 279 FEVAR-patients, 34 out of the 683 included Advanta V12 BECS (5%) presented with a complication. Two Advanta V12 complications occurred during the FEVAR procedure and 32 occurred during follow-up of which five post-FEVAR CTA scans were missing or not suitable for analysis. In the remaining 27 BECSs complications were classified as (endoleaks (n = 8), stenoses (n = 4), occlusions (n = 6), fractures (n = 3), and a combination of complications (n = 6)). All BECSs associated complications after FEVAR with available follow up CTA scans could be classified. Geometric analysis of BECS failure post-FEVAR can help to plan the reintervention strategy
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