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Titanyl Phosphate (titanyl + phosphate)

Distribution by Scientific Domains
Medical Sciences50%

Kinds of Titanyl Phosphate

  • potassium titanyl phosphate
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    Selected Abstracts

    Selective Vestibular Ablation by KTP Laser in Endolymphatic Hydrops,,

    THE LARYNGOSCOPE, Issue 6 2001
    Melanie Adamczyk MD
    Abstract Objectives and Hypothesis Vertigo, the cause of disability in many patients with Ménière's disease, may be the result of the effects of endolymphatic hydrops on the semicircular canals. We hypothesize that intractable vertigo may be controlled by destruction of the semicircular canal neuroepithelium using visible light lasers without the need for extensive fenestration of the bony labyrinth. This study was designed to assess the cochlear effects of potassium titanyl phosphate (KTP) laser-assisted triple semicircular canal ablation (TSCA) in endolymphatic hydrops. Study Design Randomized, prospective, and controlled. Methods Forty-one adult guinea pigs underwent either a unilateral endolymphatic duct occlusion to induce hydrops or a sham procedure. Ten weeks after induction of the hydrops, a KTP laser-assisted TSCA or a sham surgery was performed. Results Electrocochleographic thresholds to clicks and tone-bursts (2,20 kHz) did not change significantly up to 4 weeks after TSCA in hydropic ears. Cross-sectional histology confirmed the presence of hydrops and the ablation of the semicircular canals. Cochlear whole-mounts for hair cell counts showed no significant loss of outer or inner hair cells in hydropic ears treated with TSCA. Conclusion KTP laser-assisted TSCA can be performed in the guinea pig model of endolymphatic hydrops without significant loss of hearing. Evaluation of this technique may be warranted in patients with intractable Ménière's disease. [source]

    Cation movement and phase transitions in KTP isostructures; X-ray study of sodium-doped KTP at 10.5,K

    ACTA CRYSTALLOGRAPHICA SECTION B, Issue 3 2003
    Stefan T. Norberg
    An accurate structure model of sodium-doped potassium titanyl phosphate, (Na0.114K0.886)K(TiO)2(PO4)2, has been determined at 10.5,K by single-crystal X-ray diffraction. In addition to the low-temperature data, X-ray intensities have been collected at room temperature. When the temperature was decreased from room temperature to 10.5,K, both potassium cations moved 0.033,(2),Å along the c -axis, i.e. in the polar direction within the rigid Ti,O,P network. This alkaline metal ion displacement can be related to the Abrahams,Jamieson,Kurtz TC criteria for oxygen framework ferroelectrics. Potassium titanyl phosphate (KTP) is a well known material for second harmonic generation (SHG), and the influence of sodium dopant on the TiO6 octahedral geometry and SHG is discussed. The material studied crystallizes in the space group Pna21 with Z = 4, a = 12.7919,(5), b = 6.3798,(4), c = 10.5880,(7),Å, V = 864.08,(9),Å3, T = 10.5,(3),K and R = 0.023. [source]

    New phosphate langbeinites, K2MTi(PO4)3 (M = Er, Yb or Y), and an alternative description of the langbeinite framework

    ACTA CRYSTALLOGRAPHICA SECTION B, Issue 5 2002
    Stefan T. Norberg
    Three new potassium rare-earth/titanium phosphate structures, K2ErTi(PO4)3 (KErTP), K2YbTi(PO4)3 (KYbTP) and K2YTi(PO4)3 (KYTP), are presented, all of which are characterized by single-crystal X-ray diffraction studies. In addition, a fourth structure, K2CrTi(PO4)3 (KCrTP), has been reinvestigated. All structures are isostructural to the langbeinite-type structure and result from changes made to the growth constituents in high-temperature flux-growth experiments intended to give structurally modified potassium titanyl phosphate (KTP). The two crystallographically independent octahedra sites (site symmetry 3) have a mixed Ti/M (M = Er, Yb, Y or Cr) population, although the rare-earth metals favour one site while chromium favours the other. An alternative approach for the description of the channels and cation cages in langbeinite and related structures is given using [M5X6O39] units. The framework of langbeinite is compared with that of nasicon using these alternative building units. All of the investigated structures crystallize in space group P213 with Z,=,4; a,=,10.1053,(2),Å, R,=,0.023 (KErTP); a,=,10.0939,(8),Å, R,=,0.022 (KYbTP); a,=,10.1318,(6),Å, R,=,0.047 (KYTP); a,=,9.8001,(2),Å, R,=,0.016 (KCrTP). [source]

    Comparison of potassium titanyl phosphate vascular laser and hyfrecator in the treatment of vascular spiders and cherry angiomas

    CLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 6 2003
    G. Dawn
    Summary Patients with vascular spiders and angiomas, especially on exposed sites, demonstrate considerable psychological morbidity and therefore request treatment. Traditionally, electrosurgical modalities have been used to treat such lesions, but more recently lasers have been introduced. This open study assesses the efficacy of these two treatment modalities, scoring patients' preference and psychological morbidity before and after treatment. All patients had two vascular spiders or angiomas. One lesion was randomized for treatment with the hyfrecator, whilst the other lesion was treated with the potassium titanyl phosphate (KTP) vascular laser. The end-point of the study was either clearance of lesions or a maximum of three treatments at 2-month intervals. In this first comparative study, we demonstrate that both therapeutic modalities were effective in treating these lesions and in significantly reducing the post-treatment psychological morbidity score. However, on average, only one treatment with the KTP laser was required to achieve clearance compared with two treatments with the hyfrecator. This would result in less clinic visits. In addition, patients favoured the KTP laser because of the lack of side-effects. Both the KTP vascular laser and the hyfrecator were able to clear vascular spiders and angiomas, but the KTP laser was superior as fewer treatment episodes were required and patients preferred this treatment modality because of the lack of side-effects. [source]