Mixed POT-BM Approach for Modeling Unhealthy Air Pollution Events

This article proposes a novel data selection technique called the mixed peak-over-threshold–block-maxima (POT-BM) approach for modeling unhealthy air pollution events. The POT technique is employed to obtain a group of blocks containing data points satisfying extreme-event criteria that are greater than a particular threshold u. The selected groups are defined as POT blocks. In parallel with that, a declustering technique is used to overcome the problem of dependency behaviors that occurs among adjacent POT blocks. Finally, the BM concept is integrated to determine the maximum data points for each POT block. Results show that the extreme data points determined by the mixed POT-BM approach satisfy the independent properties of extreme events, with satisfactory fitted model precision results. Overall, this study concludes that the mixed POT-BM approach provides a balanced tradeoff between bias and variance in the statistical modeling of extreme-value events. A case study was conducted by modeling an extreme event based on unhealthy air pollution events with a threshold u > 100 in Klang, Malaysia.

Graphene-Silver Nanocomposite: Synthesis, and Adsorption Study of Cibacron Blue Dye from Their Aqueous Solution

Graphene and graphene-silver nanocomposites have been prepared by the Hummers modified method and chemical reduction process in a simple one-pot technique. The electronic microscopes (scanning and transmutation), have been used to diagnose morphology and topography of nanocomposites, and X-ray diffraction is used to characterize the structure of the nanocomposites. The results reveal that the silver nanoparticles were effectively composited onto the nanosheets of the graphene within the diameter of silver particles, ranging from 10 to 22 nanometers. In present study, the synthesized nanocomposites are used as an adsorbent for Cibacron Blue P-6B dye from its aqueous solutions through diverse temperatures (15, 25, 35, 45, and 55 ◦C). Additionally, the thermodynamic parameters (ΔS, ΔH, ΔG) and the order of the adsorption process were calculated.

The management of laryngeal lipoid proteinosis

BackgroundLipoid proteinosis is a rare autosomal recessive disorder caused by mutations in the extracellular matrix protein 1 gene. It is characterised by deposition of hyaline material in the skin and mucous membranes. This paper describes the management of two cases with laryngopharyngeal disease.MethodsTwo patients with a biopsy diagnosis of lipoid proteinosis were identified from the surgical pathology archive covering the period 2004–2016. Their notes were reviewed.ResultsAn adult male and an adult female were identified. Both had dysphonia and laryngopharyngeal lesions. The patients underwent interval laser microlaryngoscopy to debulk disease but minimise mucosal injury and scarring, using a ‘pepper pot’ technique. Both had adequate symptom control.ConclusionLipoid proteinosis is a rare genetic condition, which typically presents in infancy with dysphonia and subsequent skin involvement. Two cases are presented to demonstrate that laryngotracheal symptoms can be controlled with interval laser debulking and the ‘pepper pot’ technique without causing stenosis.

New fast “One-pot” Technique for the Production of Glycyrrhetinic Acid from the Roots of licorice (Glycyrrhiza glabra)

The aim of this work was to develop and study a fast “one-pot” procedure for the production of glycyrrhetinic acid (GLA) from the roots of licorice ( Glycyrrhiza glabra L.) using subcritical water (SBW). Technique requires no use expensive and toxic organic solvents. For the first time the new method was used for the production of glycyrrhetinic acid (aglycone of glycyrrhizic acid) by “one-pot” technique. HPLC was used to determine the quantitative compositions of the obtained products. It has been shown that variation of only one parameter of the process (temperature) allows alteration of composition of the products obtained by new “one-pot” technique. The “one-pot” procedure developed for the production of GLA in SBW is faster (12 folds) than conventional methods that use expensive and toxic organic solvents. The proposed procedure has the excellent potential for the future development of the fast and low cost technologies for the production of GLA and its derivatives in the pharmaceutical, food and cosmetic industries.