Clot microatructure (dt) as a blomarker and measurement of thrombogenlcity in Acute Exacerbation of Chronic Obstructive Pulmonary Disease (AECOPD)

Introduction: Chronic obstructive pulmonary disease is an inflammatory condition of the lungs characterised by irreversible airway obstruction and impairment of gas exchange. Acute exacerbation is associated with an increased incidence of venous thromboembolism. The main aim of the study was to investigate whether patients with acute exacerbation were thrombogenic utilising the functional biomarker of clot microstructure, the fractal dimension (df). Methodology: The study recruited 30 stable patients from the chest clinic and 85 patients with acute exacerbation from the Emergency Department of a tertiary teaching hospital. One sample of blood was taken from stable group. Acute exacerbation group had four sampling points at 0 hours, 4-6 hours, 24 hours and 3-7 days. Results: The biomarker, df was significantly elevated in patients presenting with acute exacerbation when compared to stable group (1.71 ± 0.06 vs 1.69 ± 0.05, p=0.03). There was no significant increase in df across the four time points (p=0.28) in the acute exacerbation group. All inflammatory markers and fibrinolytic markers such as D-dimer were significantly higher in acute exacerbation group. Those who died during admission in the acute exacerbation group had significantly elevated df when compared to those who survived (1.76 ± 0.03 vs 1.71 ± 0.06, p=0.02) and binary regression analysis showed that df was a significant predictor of mortality (p=0.024). Conclusions: Patients with chronic obstructive pulmonary disease during exacerbation had denser and tighter clot microstructure as demonstrated by significantly elevated df when compared to stable group indicating that they were thrombogenic. This was due to profound inflammatory response and increased fibrin production. However, with appropriate treatments and prophylactic anticoagulation, there was no further increase in df which might explain low incidence of venous thromboembolism during admissions. Therefore, df is a useful biomarker that measures thrombogenicity, effect of treatment and predicts mortality in patients with acute exacerbation

Preparation of (Pb,Ba)TiO3 powders and highly oriented thin films by a sol-gel process

Solid solution Pb1-xBaxTiO3, with particular emphasis on Pb0.5Ba0.5TiO3, was prepared using a sol-gel process incorporating lead acetate trihydrate, barium acetate, and titanium isopropoxide as precursors, acetylacetone (2,4 pentanedione) as a chelating agent, and ethylene glycol as a solvent. The synthesis procedure was optimized by systematically varying acetylacetone: Ti and H2O:Ti molar ratios and calcination temperature. The resulting effects on sol and powder properties were studied using thermogravimetric analysis/differential scanning calorimetry, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller analysis, and x-ray diffraction (XRD). Crystallization of the perovskite structure occurred at a temperature as low as 450 °C. Thin films were prepared by spin coating on (100) MgO. Pyrolysis temperature and heating rate were varied, and the resultant film properties investigated using field-emission scanning electron microscopy, atomic force microscopy, and XRD. Under optimized conditions, highly oriented films were obtained at a crystallization temperature of 600 °C

Self-Cleaning Applications of TiO2 by Photo-Induced Hydrophilicity and Photocatalysis

Self-cleaning materials have gained considerable attention for both their unique properties and practical applications in energy and environmental areas. Recent examples of many TiO2-derived materials have been illustrated to understand the fundamental principles of self-cleaning hydrophilic and hydrophobic surfaces. Various models including those proposed by Wenzel, Cassie-Baxter and Miwa-Hashimoto are discussed to explain the mechanism of self-cleaning. Examples of semiconductor surfaces exhibiting the simultaneous occurrence of superhydrophilic and superhydrophobic domains on the same surface are illustrated, which can have various advanced applications in microfluidics, printing, photovoltaic, biomedical devices, anti-bacterial surfaces and water purification. Several strategies to improve the efficiency of photocatalytic self-cleaning property have been discussed including doping with metals and non-metals, formation of hetero-junctions between TiO2 and other low bandgap semiconductors, and fabrication of graphene based semiconductor nano-composites. Different mechanisms such as band-gap narrowing, formation of localized energy levels within the bandgap and formation of intrinsic defects such as oxygen vacancies have been suggested to account for the improved activity of doped TiO2 photocatalysts. Various preparation routes for developing efficient superhydrophilic–superhydrophobic patterns have been reviewed. In addition, reversible photocontrolled surfaces with tuneable hydrophilic/hydrophobic properties and its technological applications are discussed. Examples of antireflective surfaces exhibiting self-cleaning properties for the applications in solar cells and flat panel displays have also been provided. Discussion is provided on TiO2 based selfcleaning materials exhibiting hydrophilic and underwater superoleophobic properties and their utilities in water management, antifouling applications and separation of oil in water emulsions are discussed. In addition, ISO testing methods (ISO 27448: 2009, ISO 10678: 2010 and ISO 27447: 2009) for analysing self-cleaning activity and antibacterial action have also been discussed. Rapid photocatalytic self-cleaning testing methods using various photocatalytic activity indicator inks such as resazurin (Rz), basic blue 66 (BB66) and acid violet 7(AV7) for a broad range of materials such as commercial paints, tiles and glasses are also described. Various commercial products such as glass, tiles, fabrics, cement and paint materials developed based on the principle of photo-induced hydrophilic conversion of TiO2 surfaces have also been provided. The wide ranges of practical applications of self-cleaning photocatalytic materials suggest further development to improve their efficiency and utilities. It was concluded that a rational fabrication of multifunctional photocatalytic materials by integrating biological inspired structures with tunable wettability would be favorable to address a number of existing environmental concerns

A Highly Efficient Ag-ZnO Photocatalyst: Synthesis, Properties, and Mechanism

Highly photocatalytically active silver-modified ZnO has been prepared and the effect of silver modification was studied. The structural and optical properties were characterized by X-ray diffraction, Fourier transform IR, differential scanning calorimetry, BET surface area, Raman, UV-vis, and photoluminescence spectroscopy. The photocatalytic activity of these materials was studied by analyzing the degradation of an organic dye, rhodamine 6G (R6G), and it is found that 3 mol % silver-modified ZnO at 400°C shows approximately four times higher rate of degradation than that of unmodified ZnO and a three times higher rate than that of commercial TiO 2 photocatalyst Degussa P-25. It was also noted that the photocatalytic activity for the modified ZnO sample was five times higher than the unmodified sample using sunlight. The effect of silver in enhancing the photocatalytic activity has been studied by analyzing the emission properties of both ZnO and silvermodified ZnO in the presence (emission increases) and absence (emission decreases) of R6G. We attribute these observations to the extent of valence band hole production and the role of silver in trapping the conduction band (CB) electrons in the absence of R6G. In the presence of R6G, the dye preserves the CB electron population in the metal oxide, thus preserving and enhancing emission intensity. The sensitizing property of the dye and electron scavenging ability of silver together constitute to the interfacial charge transfer process in such a way to utilize the photoexcited electrons

Sigma Chromatic Number of Some Graphs

The Sigma coloring  of a graph G with n vertices is an injection from V(G) to {1,2,3...,n}  such that the color sums (adding  the colors of the neighbouring vertices) of any two neighbouring vertices are different. The smallest number  of  colours  needed  to color a graph G  is represented by its Sigma Chromatic number. In this article  we obtain the sigma -coloring of some graphs such as Barbell Graph, Twig graph, Shell graph,Tadpole, Lollipop, Fusing all the vertices of cycle and duplication of every edge by a vertex in cycle

The Effect of the Rate of Precursor Production on the Purity and Aggregation

The synthesis of zinc oxide through the decomposition of a solid oxalate precursor was investigated. It was found that the rate of preparation of the precursor had a quantitative effect on the morphology and extent of surface ligation of particles produced; contrary to our expectations,it was found that the slow combination of reagents led to a less pure product. It has been determined that this time dependence mimics the variation of reactant ratios. Zinc oxide particles were produced from a number of reactant ratios, and were characterised by TEM, XRD, FT-IR and DSC. It was found that the size of the crystallites produced was not affected, but that the nature of their surface ligation did rely upon these parameters