Determination of Debye Temperatures and Lamb-Mössbauer Factors for LnFeO3 Orthoferrite Perovskites (Ln = La, Nd, Sm, Eu, Gd)

Lanthanide orthoferrites have wide-ranging industrial uses including solar, catalytic and electronic applications. Here a series of lanthanide orthoferrite perovskites, LnFeO3 (Ln = La; Nd; Sm; Eu; Gd), prepared through a standard stoichiometric wet ball milling route using oxide precursors, has been studied. Characterisation through X-ray diffraction and X-ray fluorescence confirmed the synthesis of phase-pure or near-pure LnFeO3 compounds. 57Fe Mössbauer spectroscopy was performed over a temperature range of 10 K to 293 K to observe hyperfine structure and to enable calculation of the recoil-free fraction and Debye temperature (θD) of each orthoferrite. Debye temperatures (Ln = La 474 K; Nd 459 K; Sm 457 K; Eu 452 K; Gd 473 K) and recoil-free fractions (Ln = La 0.827; Nd 0.817; Sm 0.816; Eu 0.812; Gd 0.826) were approximated through minimising the difference in the temperature dependent experimental Centre Shift (CS) and theoretical Isomer Shift (IS), by allowing the Debye temperature and Isomer Shift values to vary. This method of minimising the difference between theoretical and actual values yields Debye temperatures consistent with results from other studies determined through thermal analysis methods. This displays the ability of variable-temperature Mössbauer spectroscopy to approximate Debye temperatures and recoil-free fractions, whilst observing temperature induced transitions over the temperature range observed. X-ray diffraction and Rietveld refinement show an inverse relationship between FeO6 octahedral volume and approximated Debye temperatures. Raman spectroscopy show an increase in the band positions attributed to soft modes of Ag symmetry, Ag(3) and Ag(5) from La to GdFeO3 corresponding to octahedral rotations and tilts in the [010] and [101] planes respectively

POLYPOID CYSTITIS: A FINDING AND DIFFERENTIAL DIAGNOSIS

Background. Polypoid cystitis may simulate urothelial neoplasias cystoscopically and histologically. The frequency of polypoid cystitis is 0.38%; that among patients undergoing bladder catheterization is 6 %.Subjects and methods. The authors estimated the frequency of polypoid cystitis among chronic cystitis patients admitted to City Clinical Hospital Fifty, a base of the Clinic of Urology, Moscow State University of Medicine and Dentistry, in the period from February 2008 to February 2010. Out of 819 patients followed up, 3 who had diagnosed as having polypoid cystitis complained of pollakiuria, imperative micturate urges, and macrohematuria. They underwent ultrasonography, computed tomography, and cystoscopy; bladder masses measured 1.0, 7.0, and 11.5 cm, respectively; extensive growth was verified in 2 cases. Endoscopic studies identified procumbent rough-villous masses without well-defined outlines with the signs of bullous edema, decay, hemorrhages, and urinary salt encrustations. By taking into account the clinical picture and laboratory and instrumental findings, the authors suspected stage T3bNхMх bladder tumor in 2 patients and T1NхMх stage in 1. According to the European Association of Urology guidelines for management of bladder cancer, the patients underwent transurethral bladder resection. The patients were diagnosed as having polypoid cystitis on the basis of postmortem evidence.Results. In this study the frequency of polypoid cystitis was 37 %. Polypoid cystitis, a benign mass without a risk for malignancy, had signs of invasive transitional cell carcinoma.Conclusion. Such cases that rarely occur in practice are of clinical value and interest to urologists, pathologists, and oncologists.</p

ПОЛИПОИДНЫЙ ЦИСТИТ: НАХОДКА И ДИФФЕРЕНЦИАЛЬНЫЙ ДИАГНОЗ

Background. Polypoid cystitis may simulate urothelial neoplasias cystoscopically and histologically. The frequency of polypoid cystitis is 0.38%; that among patients undergoing bladder catheterization is 6 %.Subjects and methods. The authors estimated the frequency of polypoid cystitis among chronic cystitis patients admitted to City Clinical Hospital Fifty, a base of the Clinic of Urology, Moscow State University of Medicine and Dentistry, in the period from February 2008 to February 2010. Out of 819 patients followed up, 3 who had diagnosed as having polypoid cystitis complained of pollakiuria, imperative micturate urges, and macrohematuria. They underwent ultrasonography, computed tomography, and cystoscopy; bladder masses measured 1.0, 7.0, and 11.5 cm, respectively; extensive growth was verified in 2 cases. Endoscopic studies identified procumbent rough-villous masses without well-defined outlines with the signs of bullous edema, decay, hemorrhages, and urinary salt encrustations. By taking into account the clinical picture and laboratory and instrumental findings, the authors suspected stage T3bNхMх bladder tumor in 2 patients and T1NхMх stage in 1. According to the European Association of Urology guidelines for management of bladder cancer, the patients underwent transurethral bladder resection. The patients were diagnosed as having polypoid cystitis on the basis of postmortem evidence.Results. In this study the frequency of polypoid cystitis was 37 %. Polypoid cystitis, a benign mass without a risk for malignancy, had signs of invasive transitional cell carcinoma.Conclusion. Such cases that rarely occur in practice are of clinical value and interest to urologists, pathologists, and oncologists.Введение. Полипоидный цистит цистоскопически и гистологически может «симулировать» уротелиальные неоплазии. Частота встречаемости полипоидного цистита составляет 0,38 %; среди пациентов, перенесших катетеризацию мочевого пузыря (МП), – 6 %.Материалы и методы. Мы оценили частоту встречаемости полипоидного цистита среди пациентов с хроническим циститом, поступивших в клинику урологии МГМСУ на базе ГКБ № 50 за период с февраля 2008 по февраль 2010 г. Из наблюдавшихся 819 пациентов 3 больных с диагностированным полипоидным циститом предъявляли жалобы на учащенное мочеиспускание, императивные позывы и макрогематурию. Им были проведены ультразвуковое исследование, компьютерная томография и цистоскопия, размеры образования МП составили 1,0; 7,0 и 11,5 см соответственно, в 2 случаях подтвержден распространенный характер роста. При эндоскопическом исследовании определялись стелющиеся грубоворсинчатые образования без четких границ с явлениями буллезного отека, распада, кровоизлияний и инкрустацией мочевыми солями. С учетом клинической картины и данных лабораторно-инструментальных исследований у 2 пациентов предположили наличие опухоли МП стадии T3bNхMх, у 1 – стадии T1NхMх. Согласно рекомендациям руководства Европейской ассоциации урологов по лечению рака МП пациентам была выполнена трансуретральная резекция МП. На основании данных патоморфологического исследования у пациентов диагностирован полипоидный цистит.Результаты. Частота встречаемости полипоидного цистита в нашем исследовании составила 37 %. Полипоидный цистит, доброкачественное образование без риска развития злокачественного процесса, имел признаки инвазивного переходно-клеточного рака.Заключение. Подобные случаи, редко встречающиеся в практике, представляют клиническую ценность и интересны для урологов, патологов и онкологов