Solid-state synthesis of NASICON (Na3Zr2Si2PO12) using nanoparticle precursors for optimisation of ionic conductivity

In this work, the effect of varying the size of the precursor raw materials SiO2 and ZrO2 in the solid-state synthesis of NASICON in the form Na3Zr2Si2PO12 was studied. Nanoscale and macro-scale precursor materials were selected for comparison purposes, and a range of sintering times were examined (10, 24 and 40 h) at a temperature of 1230 °C. Na3Zr2Si2PO12 pellets produced from nanopowder precursors were found to produce substantially higher ionic conductivities, with improved morphology and higher density than those produced from larger micron-scaled precursors. The nanoparticle precursors were shown to give a maximum ionic conductivity of 1.16 × 10−3 S cm−1 when sintered at 1230 °C for 40 h, in the higher range of published solid-state Na3Zr2Si2PO12 conductivities. The macro-precursors gave lower ionic conductivity of 0.62 × 10−3 S cm−1 under the same processing conditions. Most current authors do not quote or consider the precursor particle size for solid-state synthesis of Na3Zr2Si2PO12. This study shows the importance of precursor powder particle size in the microstructure and performance of Na3Zr2Si2PO12 during solid-state synthesis and offers a route to improved predictability and consistency of the manufacturing process

Survey of Effect Peppermint on Pyloric Spasm in Children During Endoscopy

Introduction: Gastrointestinal Endoscopy is  as a diagnosis and treatment of gastrointestinal diseases in children. Due to severe response and spastic in  the muscles of the digestive tract is created during endoscopy,endoscopy is often face with difficult. The aim of this study is to evaluate peppermint impact in pyloric spasm in children undergo endoscopy.   Material and Methods: In this clinical trial study, 120 children (under 14 years old) in Ghaem hospital that Pyloric spasm during endoscopy were randomly divided into two groups, peppermint (n=60) and control (n=60) respectively. Case group recieve peppermint and control group receive placebo. Data were analyzed using SPSS version 11.5 and descriptive and analytical tests    (T-test, Corraletion, Mann-Whitney).   Results:  Pyloric sphincter stayed open in 48.3% of peppermint   group patients and 5% of controlgroup (

Diagnostic Accuracy of Polyclonal Stool Antigen for Detection of Helicobacter Pylori Infection in Children

Introduction: Helicobacter pylori infection has various clinical features. One of the most common presentations of this infection is upper abdominal pain. Complications such as gastritis, gastric ulcer, gastric carcinoma and MALT lymphoma mandate early diagnosis of H.P infection by a low cost and non invasive manner. The aim of this study was to evaluate the diagnostic role of H.P stool antigen detection as a simple and non invasive method for diagnosis of this infection.   Materials and Methods: Upper endoscopy with gastric biopsy was done on all patients between 6 months to 18 years old with upper abdominal pain. Stool test was done by polyclonal anti-h.p antibody. Results of stool Test were compared with results of RUT and histologic examination   Results: Overall 110 patients (57 boys,53 girls) were studied, 32 patients were Helicobacter pylori positive and 78 patients were Helicobacter pylori negative based on RUT and histologic examination. Stool antigen testing was positive for 39 patients. Sensitivity and specificity of stool Ag were 100% and 91% respectively.   Conclusion: Stool Ag test has high sensitivity and negatity predictive value for diagnosis of Helicobacter pylori infection.   Keywords: Helicobacter pylori, Sensitivity, Stool antigen test, Specificity

Congenital Rickets: Report of Four Cases

Introduction: Vitamin D deficiency and rickets continue to be health problems in developing countries and most of the infants with congenital rickets may present with hypocalcemic seizure.   Case Report: In this article, the report on four infants who presented with hypocalcemic seizures but subsequently were found to have congenital rickets is presented. All of them had hypocalcaemia and low level of serum 25- hydroxy vitamin D. Their mothers had not received vitamin D supplementation during pregnancy and so evidence of vitamin D deficiency was presented.   Conclusion: Although current vitamin D supplementation guidelines for infants was effective in prevention of rickets in Iranian children, it is necessary to evaluate women before pregnancy to prevent this entity. Also infants without vitamin D supplementation therapy who present with seizures during the first 6 months of age should undergo biochemical and other investigations for rickets.   Keywords:Congenital rickets, Vitamin D deficiency, Hypocalcemia, Seizure