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An explicit and novel structure,lattice dynamics,and photoemission of La-doped nanocrystalline SrZrO_(3) perovskite

Rare Metals 2021年第1期40卷 105-112页

作者： Kamilia Sedeek Nahed Makram Hanan Hantour taghreed zaghloul amer Shimaa Ali Said Nano-Materials Laboratory Physics DepartmentFaculty of ScienceAl-Azhar UniversityNasr CityCairo 11751Egypt Physics Department Faculty of ScienceAl-Azhar UniversityNasr CityCairo 11751Egypt

As no complete and comprehensive studies have been previously reported for La-doped nanocrystalline SrZrO_(3)(SZO),we researched herein a detailed investigation for pure and La-doped samples.A modified solid-state reaction process,including successive cycles of milling and sintering at high temperature,was followed to produce SZO and Sr_(0.9)La_(0.1)ZrO_(3)(SLZO)powdered *** analysis of X-ray diffractometer data predicts that the two samples exhibit orthorhombic structure with an increase in crystallite size by~25%for doped sample.A great reduction in Raman modes intensity(~60%)and an annihilation of several vibration modes were detected using Raman *** degree of ordering on the B-site was recorded to be higher in La-doped *** to ultraviolet-visible(UV-Vis)absorption,a decrease in the optical gap width(E_(g))from 4.40 eV to 4.21 eV was achieved by La incorporation due to the presence of additional defect states such as oxygen and Sr vacancies at the band *** process of electron-hole recombination was studied using photoluminescence(PL)*** of PL spectra yielded four emission bands:one green band,one blue band,and two violet *** intense violet emission atλ=393 nm approximately five times greater than that detected for pure SZO is realized as La^(3+)substitutes for Sr^(2+).Such property nominates SLZO for technological applications requiring highly intense violet emission,e.g.,light-emitting diodes.

关键词： Orthorhombic perovskite structure Lattice dynamics Diffused reflectance Photoluminescence Highly intense violet emission

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Sonographic gallbladder wall thickness measurement and the prediction of esophageal varices among cirrhotics

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World Journal of Hepatology 2023年第2期15卷 216-224页

作者： Mohamed H Emara Mariam zaghloul Ibrahim F amer Aya M Mahros Mohammed Hussien Ahmed Mahmoud A Elkerdawy Eslam Elshenawy Abdelrahman M Ahmed Rasheda Tarik I Zaher Mona Talaat Haseeb Emad Hassan Emara Hassan Elbatae Department of Hepatology Gastroenterology and Infectious DiseasesKafrelsheikh UniversityKafr-Elshikh 33516Egypt Department of Internal Medicine Gastroenterology UnitSecurity Forces HospitalRiyadh 11481Saudi Arabia Tropical Medicine Zagazig UniversityZagazig 44519Egypt Department of Diagnostic and Interventional Radiology Kafrelsheikh UniversityKafr-Elshikh 33516Egypt

Acute variceal bleeding in patients with liver cirrhosis and portal hypertension(PHT) is the most serious emergency complication among those patients and could have catastrophic outcomes if not timely managed. Early screening by esophago-gastro-duodenoscopy(EGD) for the presence of esophageal varices(EVs) is currently recommended by the practice guidelines for all cirrhotic patients. Meanwhile, EGD is not readily accepted or preferred by many patients. The literature is rich in studies to investigate and validate non-invasive markers of EVs prediction aiming at reducing the unneeded endoscopic procedures. Gallbladder(GB) wall thickness(GBWT) measurement has been found promising in many published research articles. We aim to highlight the validity of sonographic GBWT measurement in the prediction of EVs based on the available evidence. We searched databases including Cochrane library, Pub Med, Web of Science and many others for relevant articles. GBWT is associated with the presence of EVs in cirrhotic patients with PHT of different etiologies. The cut-off of GBWT that can predict the presence of EVs varied in the literature and ranges from 3.1 mm to 4.35 mm with variable sensitivities of 46%-90.9% and lower cutoffs in viral cirrhosis compared to non-viral, however GBWT > 4 mm in many studies is associated with acceptable sensitivity up to 90%. Furthermore, a relation was also noticed with the degree of varices and portal hypertensive *** cirrhotics, GBWT > 3.5 mm predicts the presence of advanced(grade Ⅲ-Ⅳ) EVs with a sensitivity of 45%, the sensitivity increased to 92% when a cut-off ≥ 3.95 mm was used in another cohort. Analysis of these results should carefully be revised in the context of ascites, hypoalbuminemia and other intrinsic GB diseases among cirrhotic patients. The sensitivity for prediction of EVs improved upon combining GBWT measurement with other non-invasive predictors, e.g., platelets/GBWT.

关键词： Sonographic Gallbladder wall thickness Prediction Esophageal varices Portal hypertension Esophago-gastro-duodenoscopy

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