404 research outputs found

    Interpolation of bilinear operators between Banach function spaces

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    We study bilinear operators between couples of Banach function spaces with the second coordinate L∞L_\infty-space. We show an estimate in terms of the KK-functional. This is used to prove a result on interpolation of bilinear operators between considered couples

    Inverted and horizontal impacted third molars in an Early Modern skull from Wroclaw, Poland: a case report

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    Background: An impacted tooth is one of the most commonly occurring dental anomalies, although some types of impaction (i.e. inverted angulation) may be considered rare finding. There are many hypotheses regarding impaction aetiology. One of the most popular hypotheses suggested that this condition may result from insufficient space in retromolar space, other: improper angulation of tooth bud, malposition of the tooth germ or hereditary factors, insufficient interproximal attrition, ectopy or dysfunction of genes necessary for proper tooth eruption. This study aims to present the odontological and paleopathological assessment of the impacted molars observed within the skull excavated from an early modern cemetery in Wroclaw.  Materials and methods: The skull used in the study was complete and in a good state of preservation. It belonged to an adult individual whose body was buried at the former Salvator Cemetery (currently Czysty Square). The individual’s dentition was almost completely lost antemortem. Only second molars preserved within the maxillae (bilaterally) and the mandible was almost edentulous as well. The morphometric traits have been taken according to standards established by R. Martin. Macroscopic observations were supported by X-rays and computed tomography imaging.  Results: The age at death was estimated at 20–35 years. Comparison of the metric characteristics of skull with the reference material reveals that it is much smaller than the average female skull from this series. Morphometric indices calculated for both splanchocranium and neurocranium allow defining the skull and jaw as short, which could be an important factor involved in the teeth impaction.  Conclusions: Atypical impaction of the third molars could result from small size of skull and could have significantly deteriorated the quality of life of the individual.

    Hafnia-rich mixed oxide ceramics of the system HfO2-ZrO2-TiO2 for heaters and heat exchangers in electrothermal thrusters: The effects of titania on selected electrical and mechanical properties of Hafnia-rich mixed oxides in the system Hafnia-Zirconia-Titania, volume 1

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    A study of the effects of titania on selected properties of hafnia-rich mixed oxides in the system hafnia-zirconia-titania (HZT) was made in the region 5 to 20 mol percent titania. The studied properties included electrical conductivity, thermal expansion, and fracture strength and toughness. The effects of titania on the properties were studied for the reduced state as well as the oxidized state of the sintered mixed oxides. X-ray analysis showed that the materials were not always single phase. The oxidized compositions went from being monoclinic solid solutions at low titania additions to having three phases (two monoclinic and a titanate phase) at high additions of titania. The reduced compositions showed an increasing cubic phase presence mixed with the monoclinic phase as titania was added. The electrical conductivity increased with temperature at approximately 0.1 mhos/cm at 1700 C for all compositions. The thermal expansion coefficient decreased with increasing titania as did the monoclinic to tetragonal transformation temperature. The fracture strength of the oxidized bars tended to decrease with the addition of titania owing to the presence of the second phase titania. The fracture strength of the reduced bars exhibited a minimum corresponding to a two-phase region of monoclinic and cubic phases. When the second phases were suppressed, the titania tended to increase the fracture strength slightly in both the oxidized and reduced states. The fracture toughness followed similar trends

    Structural abnormalities of the optic nerve and retina in Huntington’s disease pre-clinical and clinical settings

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    Huntington’s disease (HD) is a fatal neurodegenerative disorder caused by a polyglutamine expansion in the huntingtin protein. HD-related pathological remodelling has been reported in HD mouse models and HD carriers. In this study, we studied structural abnormalities in the optic nerve by employing Spectral Domain Optical Coherence Tomography (SD-OCT) in pre-symptomatic HD carriers of Caucasian origin. Transmission Electron Microscopy (TEM) was used to investigate ultrastructural changes in the optic nerve of the well-established R6/2 mouse model at the symptomatic stage of the disease. We found that pre-symptomatic HD carriers displayed a significant reduction in the retinal nerve fibre layer (RNFL) thickness, including specific quadrants: superior, inferior and temporal, but not nasal. There were no other significant irregularities in the GCC layer, at the macula level and in the optic disc morphology. The ultrastructural analysis of the optic nerve in R6/2 mice revealed a significant thinning of the myelin sheaths, with a lamellar separation of the myelin, and a presence of myelonoid bodies. We also found a significant reduction in the thickness of myelin sheaths in peripheral nerves within the choroids area. Those ultrastructural abnormalities were also observed in HD photoreceptor cells that contained severely damaged membrane disks, with evident vacuolisation and swelling. Moreover, the outer segment of retinal layers showed a progressive disintegration. Our study explored structural changes of the optic nerve in pre- and clinical settings and opens new avenues for the potential development of biomarkers that would be of great interest in HD gene therapies

    The response surface methodology for optimization of tyrosinase immobilization onto electrospun polycaprolactone-chitosan fibers for use in bisphenol A removal.

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    Composite polycaprolactone-chitosan material was produced by an electrospinning method and used as a support for immobilization of tyrosinase by mixed ionic interactions and hydrogen bonds formation. The morphology of the fibers and enzyme deposition were confirmed by SEM images. Further, multivariate polynomial regression was used to model the experimental data and to determine optimal conditions for immobilization process, which were found to be pH 7, temperature 25 °C and 16 h process duration. Under these conditions, novel type of biocatalytic system was produced with immobilization yield of 93% and expressed activity of 95%. Furthermore, as prepared system was applied in batch experiments related to biodegradation of bisphenol A under various remediation conditions. It was found that over 80% of the pollutant was removed after 120 min of the process, in the temperature range 15-45 °C and pH 6-9, using solutions at concentration up to 3 mg/L. Experimental data collected proved that the stability and reusability of the tyrosinase were significantly improved upon immobilization: the immobilized biomolecule retained around 90% of its initial activity after 30 days of storage, and was still capable to remove over 80% of bisphenol A even after 10 repeated uses. By contrast, free enzyme was able to remove over 80% of bisphenol A at pH 7-8 and temperature range 15-35 °C, and retained less than 60% of its initial activity after 30 days of storage

    Estimate of size distribution of charged MSPs measured in situ in winter during the WADIS-2 sounding rocket campaign

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    We present results of in situ measurements of mesosphere-lower thermosphere dusty-plasma densities including electrons, positive ions and charged aerosols conducted during the WADIS-2 sounding rocket campaign. The neutral air density was also measured, allowing for robust derivation of turbulence energy dissipation rates. A unique feature of these measurements is that they were done in a true common volume and with high spatial resolution. This allows for a reliable derivation of mean sizes and a size distribution function for the charged meteor smoke particles (MSPs). The mean particle radius derived from Schmidt numbers obtained from electron density fluctuations was similar to 0.56 nm. We assumed a lognormal size distribution of the charged meteor smoke particles and derived the distribution width of 1.66 based on in situ-measured densities of different plasma constituents. We found that layers of enhanced meteor smoke particles' density measured by the particle detector coincide with enhanced Schmidt numbers obtained from the electron and neutral density fluctuations. Thus, we found that large particles with sizes >1 nm were stratified in layers of similar to 1 km thickness and lying some kilometers apart from each other
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