32 research outputs found

    Fatty tissue within the maxillary sinus: a rare finding.

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    BACKGROUND: We report a rare case of fatty tissue within the maxillary sinus in a 21-years-old woman, with a history of several previous punctures of the maxillary sinus. CASE PRESENTATION: Clinical data of the patient was analysed retrospectively. The patient presented with symptoms of left-sided chronic maxillary sinusitis and had undergone several punctures of the left maxillary sinus 18 months earlier. Subsequent to one of the procedures an acute pain in the left orbit lasting a couple of days was noted. Left endoscopic transnasal antrotomy was performed. The maxillary sinus was filled with polypous, chronically inflamed mucous membrane. Upon its removal, the maxillary roof was identified as drawn downwards and covered with normal mucous membrane. Upon dissection of the membrane, adipose tissue filling the zygomatic recess of the sinus was identified and subsequently removed. The maxillary roof was unchanged. Histopatologic examination confirmed the material to be adipose tissue. No short or long term sequelae occurred. CONCLUSION: Adipose tissue can be found in the maxillary sinus most commonly when penetrating from surrounding locations. It is our hypothesis that in the reported patient it penetrated from the orbit to the maxillary sinus following puncture. It seems that a hole in the maxillary sinus roof, about 1 mm in diameter, caused by the needle, may have been a portal of entry for the adipose tissue into the maxillary sinus. The discussed case suggests particular care be taken in performing puncture of the maxillary sinus

    Optical, Dielectric and Magnetic Properties of La1−xNdxFeO3 Powders and Ceramics

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    Nanocrystalline La1−xNdxFeO3 powders with different concentrations of Nd3+ have been synthesized using a modified Pechini method. Their structures were studied by X-ray powder diffraction (XRD). Furthermore, La1−xNdxFeO3 nanoceramics were prepared using a high pressure sintering technique. The luminescence spectra of the powders were investigated as a function of concentration of active dopant to check the possible energy transfers observed due to Nd3+ concentration changes. The electrical and magnetic properties of the powders and ceramics were investigated to determine the effect of Nd3+ doping on the dielectric permittivity and magnetization in the wide frequency range. © 2018 by the authors. Licensee MDPI, Basel, Switzerland.Funding: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 778070—TransFerr—H2020-MSCA-RISE-2017. Part of the work was developed within the scope of the project CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT Ref. UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement

    Impact of Alkali Ions Codoping on Magnetic Properties of La(0.9)A(0.1)Mn(0.9)Co(0.1)O(3) (A: Li, K, Na) Powders and Ceramics

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    The aim of the work was to check how the introduction of alkali and cobalt ions into a manganese structure can affect the structural disorder and, in consequence, lead to the changes (improvements) of magnetic properties. The high-pressure sintering technique was applied to check if the external factor can modify the magnetization of manganites. Nanocrystalline La0.9A0.1Mn0.9Co0.1O3 (where A is Li, K, Na) powders were synthesized by the combustion technique. The respective powders were used for nanoceramics preparation by the high-pressure sintering technique. The structure and morphology of the compounds were studied by X-ray powder diffraction, scanning electron microscopy and energy-dispersive X-ray spectroscopy. Magnetization studies for all compounds were performed in order to check the changes induced by either codoping or the sintering pressure. It was found that the type of the dopant ion and sintering pressure produced significant changes to the magnetic properties of the studied compounds. Alkali ions lead to the stabilization of Co ions in the +2 oxidation state and the formation of positive exchange interactions Mn3+–Mn4+ and Co2+–Mn4+ and the subsequent increase in remanent magnetization. High sintering pressure leads to a decrease in grain size and reduction of long-range ferromagnetic order and lower magnetization. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska‐Curie grant agreement No 778070–TransFerr–H2020‐MSCA‐RISE‐ 2017. Part of this work was developed within the scope of the project CICECO‐Aveiro Institute of Materials, UIDB/50011/2020 and UIDP/50011/2020, financed by national funds through the Portuguese Foundation for Science and Technology/MCTES. The equipment of the Ural Center for Shared Use “Modern nanotechnology” UrFU was used. The work has been supported in part by the Ministry of Science and Higher Education of the Russian Federation under Project № FEUZ‐2020‐0054

    Electron Absorption and Emission Spectra of Eu3+\text{}^{3+} in KEu(WO4\text{}_{4})2\text{}_{2}

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    Electron absorption and emission spectra of Eu3+\text{}^{3+} ion in stoichiometric KEu(WO4\text{}_{4})2\text{}_{2} were measured at the temperature range 15-300 K. The oscillator strengths of f-f transitions and the Judd-Ofelt parameters were evaluated. The assignment of vibronic transitions is given and mechanism of emission decay is discussed

    Comparative Studies of Vibronic Transitions in One- and Two-Photon Spectra of Gd3+\text{}^{3+} in Cs2\text{}_{2}NaGdCl6\text{}_{6}

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    Vibronic spectra of Gd3+\text{}^{3+} in Cs2\text{}_{2}NaGdCl6\text{}_{6} were measured under one- and two-photon excitations. Following the vibrational analysis of the Cs2\text{}_{2}NaGdCl6\text{}_{6} crystal an assignment of vibronic transitions was proposed. It was found that the vibronic transitions in one- and two-photon spectra are combined with the odd parity modes

    Absorptions and Emissions for the TmCl63\text{}_{6}^{3-} Ion in Cs2\text{}_{2}NaTmCl6\text{}_{6}

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    In this work we report both experimental and theoretical studies regarding the Cs2\text{}_{2}NaTmCl6\text{}_{6} elpasolite-type system, for which we have an updated database from linear and nonlinear optics. Both the absorption and the emission spectra for this system are rather complicated and a generalized vibronic crystal field-closure-ligand polarization calculation model has been employed to rationalize the observed spectral intensities. The calculation has been carried out by neglecting the interaction among the internal and the external vibrations and theoretical calculations have been performed with reference to both the emissions 3\text{}^{3}H4\text{}_{4}i\text{}_{i})>3\text{}^{3}F4\text{}_{4}j\text{}_{j}) and the absorptions 3\text{}^{3}H6\text{}_{6}(A1\text{}_{1})> 3\text{}^{3}F4\text{}_{4}i\text{}_{i}), 1\text{}^{1}G4\text{}_{4}i\text{}_{i}), 3\text{}^{3}H5\text{}_{5}l\text{}_{l}) withΓk\text{}_{k} (k=i,j)=A1\text{}_{1},E,T1\text{}_{1},T2\text{}_{2} andΓl\text{}_{l}=E, a\text{}^{a}T1\text{}_{1}, b\text{}^{b}T1\text{}_{1},T2\text{}_{2}. The advantages and disadvantages of our model calculation are discussed in the text, and despite the simplicity of the model it is shown that it has got some utility and flexibility to gain understanding in these complex phenomena

    Spectroscopic ProPerties of Eu3+\text{}^{3+} Ion in KEu(MoO4\text{}_{4})2\text{}_{2} Crystal

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    IR, Raman, electron absorption and emission spectra of KEu(MoO4\text{}_{4})2\text{}_{2} crystal were measured at the temperature range 8-300 K. The oscillator strengths of f-f transitions were evaluated

    Comparison of Optical Properties of Eu3+\text{}^{3+} Ions in the Silica Gel Glasses Obtained by Different Preparation Techniques

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    Silica sol-gel glasses doped with Eu3+\text{}^{3+} ions were obtained by different preparation techniques. The absorption, emission and excitation spectra of the obtained glasses were measured in the range of 77-300 K. The energy level diagrams of Eu3+\text{}^{3+} ions were derived. An intensity analysis of f-f transitions was performed. In particular, polymeric structure behaviour of europium compounds entrapped in silica gels glasses was temperature controlled during the preparation of glasses. Their optical properties were investigated

    Absorptions and Emissions for the TmCl 6

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    In this work we report both experimental and theoretical studies regarding the Cs2\text{}_{2}NaTmCl6\text{}_{6} elpasolite-type system, for which we have an updated database from linear and nonlinear optics. Both the absorption and the emission spectra for this system are rather complicated and a generalized vibronic crystal field-closure-ligand polarization calculation model has been employed to rationalize the observed spectral intensities. The calculation has been carried out by neglecting the interaction among the internal and the external vibrations and theoretical calculations have been performed with reference to both the emissions 3\text{}^{3}H4\text{}_{4}i\text{}_{i})>3\text{}^{3}F4\text{}_{4}j\text{}_{j}) and the absorptions 3\text{}^{3}H6\text{}_{6}(A1\text{}_{1})> 3\text{}^{3}F4\text{}_{4}i\text{}_{i}), 1\text{}^{1}G4\text{}_{4}i\text{}_{i}), 3\text{}^{3}H5\text{}_{5}l\text{}_{l}) withΓk\text{}_{k} (k=i,j)=A1\text{}_{1},E,T1\text{}_{1},T2\text{}_{2} andΓl\text{}_{l}=E, a\text{}^{a}T1\text{}_{1}, b\text{}^{b}T1\text{}_{1},T2\text{}_{2}. The advantages and disadvantages of our model calculation are discussed in the text, and despite the simplicity of the model it is shown that it has got some utility and flexibility to gain understanding in these complex phenomena
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