APPLICATION OF MODIFIED USP APPARATUS I AND IN SITU FIBER OPTIC ANALYSIS FOR DRUG RELEASE FROM IBUPROFEN NANOSPHERES

Objective: The main objective of this study was to ascertain the applicability of the modified USP Apparatus I and in situ fiber optic UV analysis for in vitro release testing of ibuprofen (model drug) nanospheres (IbNS).Methods: IbNSwere prepared by solvent displacement and utilizing an ultrasonicator at 20KHz for 15 minutes. Characterization of the prepared IbNSinvolved particle size and shape analysis. Drug excipient compatibility was checked through differential scanning calorimeter (DSC). The accuracy, precision,and IbNS release profile obtained with the modified USP apparatus I using in situ fiber optics were compared to the traditional method of sample analysis. Results: Results also showed the spherical shape of the IbNS(80% between 150-300 nm). DSC showed no interaction between the ingredients used in the formulation process. The fiber optics technique was accurate and precise. Percentage drug release obtained using fiber optics analysis was statistically significant (p=1.0232), and higher as compared to that obtained using the traditional siphoning method. This difference was attributed to loss of nanospheres during the pipetting (separation process)and manual errors in the traditional analysis method. Conclusion: Fiber optics dip probe technique along with the modified USP apparatus I could be a new and better way for analysis of nano-formulations.Â

The use of flat panel angioCT (DynaCT) for navigation through a deformed and fractured carotid stent

Navigation through a previously deployed and deformed stent is a difficult interventional task. Inadvertent navigation through the struts of a stent can potentially lead to incomplete secondary stent extension and vessel occlusion. Better visualisation of the pathway through the stent can reduce the risks of the procedural complications and reduce the reluctance of the interventionalist to navigate through a previously deployed stent. We describe a technique of visualisation of the pathway navigated by a guidewire through a previously deployed deformed and fractured carotid stent by the use of DynaCT. Three-dimensional reconstruction of the stent/microwire allows excellent visualisation of the correct pathway of the microwire within the sten

A novel mutation in HSD11B2 causes apparent mineralocorticoid excess in an Omani kindred

Apparent mineralocorticoid excess (AME) is a rare autosomal recessive genetic disorder causing severe hypertension in childhood due to a deficiency of 11β-hydroxysteroid dehydrogenase type 2 (11βHSD2), which is encoded by HSD11B2. Without treatment, chronic hypertension leads to early development of end-organ damage. Approximately 40 causative mutations in HSD11B2 have been identified in ∼100 AME patients worldwide. We have studied the clinical presentation, biochemical parameters, and molecular genetics in six patients from a consanguineous Omani family with AME. DNA sequence analysis of affected members of this family revealed homozygous c.799A>G mutations within exon 4 of HSD11B2, corresponding to a p.T267A mutation of 11βHSD2. The structural change and predicted consequences owing to the p.T267A mutation have been modeled in silico. We conclude that this novel mutation is responsible for AME in this family

Excess stroke in Mexican Americans compared with non-Hispanic Whites: the Brain Attack Surveillance in Corpus Christi Project.

Mexican Americans are the largest subgroup of Hispanics, the largest minority population in the United States. Stroke is the leading cause of disability and third leading cause of death. The authors compared stroke incidence among Mexican Americans and non-Hispanic Whites in a population-based study. Stroke cases were ascertained in Nueces County, Texas, utilizing concomitant active and passive surveillance. Cases were validated on the basis of source documentation by board-certified neurologists masked to subjects\u27 ethnicity. From January 2000 to December 2002, 2,350 cerebrovascular events occurred. Of the completed strokes, 53% were in Mexican Americans. The crude cumulative incidence was 168/10,000 in Mexican Americans and 136/10,000 in non-Hispanic Whites. Mexican Americans had a higher cumulative incidence for ischemic stroke (ages 45-59 years: risk ratio = 2.04, 95% confidence interval: 1.55, 2.69; ages 60-74 years: risk ratio = 1.58, 95% confidence interval: 1.31, 1.91; ages \u3eor=75 years: risk ratio = 1.12, 95% confidence interval: 0.94, 1.32). Intracerebral hemorrhage was more common in Mexican Americans (age-adjusted risk ratio = 1.63, 95% confidence interval: 1.24, 2.16). The subarachnoid hemorrhage age-adjusted risk ratio was 1.57 (95% confidence interval: 0.86, 2.89). Mexican Americans experience a substantially greater ischemic stroke and intracerebral hemorrhage incidence compared with non-Hispanic Whites. As the Mexican-American population grows and ages, measures to target this population for stroke prevention are critical

Clinical, genetic, and structural basis of apparent mineralocorticoid excess due to 11β-hydroxysteroid dehydrogenase type 2 deficiency

Mutations in 11β-hydroxysteroid dehydrogenase type 2 gene (HSD11B2) cause an extraordinarily rare autosomal recessive disorder, apparent mineralocorticoid excess (AME). AME is a form of low renin hypertension that is potentially fatal if untreated. Mutations in the HSD11B2 gene result either in severe AME or a milder phenotype (type 2 AME). To date, ∼40 causative mutations have been identified. As part of the International Consortium for Rare Steroid Disorders, we have diagnosed and followed the largest single worldwide cohort of 36 AME patients. Here, we present the genotype and clinical phenotype of these patients, prominently from consanguineous marriages in the Middle East, who display profound hypertension and hypokalemic alkalosis. To correlate mutations with phenotypic severity, we constructed a computational model of the HSD11B2 protein. Having used a similar strategy for the in silico evaluation of 150 mutations of CYP21A2, the disease-causing gene in congenital adrenal hyperplasia, we now provide a full structural explanation for the clinical severity of AME resulting from each known HSD11B2 missense mutation. We find that mutations that allow the formation of an inactive dimer, alter substrate/coenzyme binding, or impair structural stability of HSD11B2 yield severe AME. In contrast, mutations that cause an indirect disruption of substrate binding or mildly alter intramolecular interactions result in type 2 AME. A simple in silico evaluation of novel missense mutations could help predict the often-diverse phenotypes of an extremely rare monogenic disorder

Photovoltaic module and system fault analysis

Photovoltaic (PV) systems have a total installed capacity of 6 GW in Australia at the end of 2016 according to International Energy Agency (IEA). Despite this, there are PV systems and system components that are suboptimal. The weather and different climate zones affect the performance of PV solar system, and it could cause degradation and reduction in performance. Because of this, an online questionnaire called the Photovoltaic Module and System Fault Reporting Portal (PVFRP) was established. This project was funded by the Australian Renewable Energy Agency (ARENA) and coordinated by the School of Engineering and Information Technology at Murdoch University in cooperation with the Clean Energy Council (CEC), the Australian PV Institute (APVI), UNSW, and Ekistica (Project Participants). This portal covers five main sections: Module, Installation, Inverter, Other Equipment and General Issues. The PVFRP is aimed to gather data a section of a PV system that has a failure and further details about the defective components. Due to the issues found in the original version a revised version of PVFRP was developed. The revised version was approved by the Murdoch University Human Research Ethics Committee, and it has been in operation since October 2017. This thesis project intend to analyse the obtained data from PVFRP and summarise the recently published findings associated with operational failure in PV systems including their main driving factors. In general, the findings from both versions of the PVFRP are also recognised in the literature findings of similar area studies performed in nationally and/or internationally. The repoted failure types vary over the five sections. Some safety problems issues were also reported through PVFRP such as incorrect wiring of polarised DC circuit breakers, and exposed live conduct

Synthesis of ZnO-NPs Using a Convolvulus arvensis Leaf Extract and Proving Its Efficiency as an Inhibitor of Carbon Steel Corrosion

This paper studies the use of zinc oxide nanoparticles (ZnO-NPs) synthesized using an extract of Convolvulus arvensis leaf and expired ZnCl2, as efficient inhibitors of carbon steel corrosion in a 1 M HCl solution. The synthesized ZnO-NPs were characterized by Fourier-transform infrared (FTIR) and UV-Vis spectroscopy analysis. The corrosion inhibition of carbon steel in 1 M HCl was also investigated through potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and the determination of weight loss. The results show that the efficiency of the prevention increased when the concentration of ZnO-NPs was increased to 91%, and that the inhibition efficiency was still high (more than 89%) despite decreasing at high temperatures, acting as a mixed-type inhibitor. A sample of carbon steel with a protective layer of inhibitor on top was observed during immersion in 1 M HCl for 20 h; an increase in the charge transfer resistance (Rct) and stability of the inhibitor could be observed after 6 h. Adsorption isotherm models demonstrated that the inhibitor adsorption mechanism on the carbon steel surface followed Langmuir rather than Freundlich and Temkin behaviors. The thermodynamic parameters showed that the adsorption process is one of mixed, spontaneous, and exothermic adsorption. The results illustrate that the ZnO-NPs were a strong inhibitor of carbon steel corrosion in acid medium. The results of scanning electron microscopy (SEM) images showed that the ZnO-NPs formed a good protective film on the carbon steel surface