Comparison of 20nm silver nanoparticles synthesized with and without a gold core: Structure, dissolution in cell culture media, and biological impact on macrophages

Widespread use of silver nanoparticles raises questions of environmental and biological impact. Many synthesis approaches are used to produce pure silver and silver-shell gold-core particles optimized for specific applications. Since both nanoparticles and silver dissolved from the particles may impact the biological response, it is important to understand the physicochemical characteristics along with the biological impact of nanoparticles produced by different processes. The authors have examined the structure, dissolution, and impact of particle exposure to macrophage cells of two 20 nm silver particles synthesized in different ways, which have different internal structures. The structures were examined by electron microscopy and dissolution measured in Rosewell Park Memorial Institute media with 10% fetal bovine serum. Cytotoxicity and oxidative stress were used to measure biological impact on RAW 264.7 macrophage cells. The particles were polycrystalline, but 20 nm particles grown on gold seed particles had smaller crystallite size with many high-energy grain boundaries and defects, and an apparent higher solubility than 20 nm pure silver particles. Greater oxidative stress and cytotoxicity were observed for 20 nm particles containing the Au core than for 20 nm pure silver particles. A simple dissolution model described the time variation of particle size and dissolved silver for particle loadings larger than 9 μg/ml for the 24-h period characteristic of many in-vitro studies

A Unique Presentation of Concomitant Hypo-Hyperdontia in Seven Year Old Child: A Rare Report

Numerical variations of teeth are common. Hypodontia considered being presence of less number of teeth in normal complement while extra teeth to normal dentition are considered as hyperdontia. Hypodontia and hyperdontia are two opposite numerical variations of human dentition and occurrence of these two conditions is called as concomitant hypo-hyperdontia. The occurrence of hypo-hyperdontia in a patient is common. This report describes a rare occurrence of conical shape supernumerary teeth in premolar region and agenesis of tooth 55 and 81 in primary dentition and teeth 15, 25 and 41 in permanent dentition.DOI: 10.14693/jdi.v22i3.97

Applicability of genetic algorithms to reconstruction of projected data from ultrasonic tomography

In this paper simulation studies of the ultrasound computerized tomography (CT) technique employing time of flight data is presented. An enhanced genetic algorithm based reconstruction technique is proposed that is capable of detecting multiple types of inclusions in the test specimen to be reconstructed. It is assumed that the physical properties of the inclusions are known a priori. The preliminary results of our algorithm for a simple configuration are found to be better than those reported with MART1. In addition to being able to identify inclusions of different materials, both the shape and location of the inclusions could be reconstructed using the proposed algorithm. The results are found to be consistent and satisfactory for a wide range of grid sizes and geometries of inclusion(s). Based on the regression analysis an empirical relation between the number of unknowns and the reconstruction time is found which enables one to predict the reconstruction time for higher resolutions

Pre-Interventional Cardiac and ECG Changes in Acute Organophosphate Poisoning Cases Admitted to a Tertiary Hospital in India

Background: Cardiac complications are the less common fatal effect of acute organophosphate poisoning. This study was undertaken to analyze the pre-interventional cardiac and Electrocardiographic (ECG) changes in acute organophosphate poisoning cases.Materials and Methods: Clinical records of acute organophosphate poisoning patients of age less than 50 years admitted to KLE’s Dr. Prabhakar Kore Hospital, Belgaum, Karnataka, from 01-01-2010 to 31-12-2010 were analyzed. Cases of organophosphate poisonings referred from other hospitals, poisoning with multiple agents, patients with history of previous cardiac diseases and coexisting medical conditions were excluded from the study. Poisoning Severity Score was calculated as per International Programme on Chemical Safety and patients were grouped into 3 grades.Results: In this study, 50 cases of acute organophosphate poisoning (male - 32; female - 18) were analyzed. Sinus tachycardia was present in 45 patients (90%), hypertension in 13 (26%) and hypotension in 12 (24%). Prolonged corrected QT interval was observed in 14 patients (28%), elevated ST segment in 2 (4%), inverted T wave in 13 (26%) and conduction defects in 1 (2%). Among 14 patients with prolonged corrected QT interval, 12 were in grade III and 2 in grade II severity; and, among 13 patients who had inverted T wave, 2 were in grade I, 4 in grade II and 7 in grade III severity. Acidosis, as assessed by blood pH and HCO3, was observed in 22 patients (44%).Conclusion: Fatal cardiac complications do occur in acute organophosphate poisoning, which are overlooked at times as the most common complications expected are respiratory complications. Higher incidence of ECG changes in Grade III cases suggests that if the cardiac complications develop, the patient should be immediately transferred to an intensive cardiac care unit

Multifocal Epithelial Hyperplasia of Oral Cavity Expressing HPV 16 Gene: A Rare Entity

Focal epithelial hyperplasia is a rare contagious disease caused by human papilloma virus. Usually HPV involves either cutaneous or mucosal surfaces, whereas concomitant mucocutaneous involvement is extremely rare. We report such a unique case of multifocal epithelial hyperplasia involving multiple sites of oral cavity along with skin lesions in a 65-year-old female. We also discuss the probable multifactorial etiology and variable clinical presentations of the lesions, including evidence of HPV 16 expression, as detected by polymerase chain reaction. The present report illustrates the need for careful examination and prompt diagnosis of the disease, as it might be associated with high risk genotypes such as HPV 16 and 18

In situ observation of defect growth beyond the irradiated region in yttria-stabilized zirconia induced by 400 keV xenon ion-beam at -90 and 30{degrees}C

Single crystals of yttria-stabilized zirconia were irradiated with 400 keV Xe ion-beam at room temperature and minus 90 degrees centigrade. Defect growth was monitored in situ with Rutherford Backscattering and ion channeling techniques using a 2 MeV He ion beam

Increased power generation in supercapacitive microbial fuel cell stack using Fe-N-C cathode catalyst

The anode and cathode electrodes of a microbial fuel cell (MFC) stack, composed of 28 single MFCs, were used as the negative and positive electrodes, respectively of an internal self-charged supercapacitor. Particularly, carbon veil was used as the negative electrode and activated carbon with a Fe-based catalyst as the positive electrode. The red-ox reactions on the anode and cathode, self-charged these electrodes creating an internal electrochemical double layer capacitor. Galvanostatic discharges were performed at different current and time pulses. Supercapacitive-MFC (SC-MFC) was also tested at four different solution conductivities. SC-MFC had an equivalent series resistance (ESR) decreasing from 6.00 Ω to 3.42 Ω in four solutions with conductivity between 2.5 mScm−1 and 40 mScm−1. The ohmic resistance of the positive electrode corresponded to 75–80% of the overall ESR. The highest performance was achieved with a solution conductivity of 40 mS cm−1 and this was due to the positive electrode potential enhancement for the utilization of Fe-based catalysts. Maximum power was 36.9mW (36.9Wm−3) that decreased with increasing pulse time. SC-MFC was subjected to 4520 cycles (8 days) with a pulse time of 5 s (ipulse 55 mA) and a self-recharging time of 150 s showing robust reproducibility