Elucidating hepatic lipidosis in stray cats through serum biochemistry, liver histopathology and liver RNA expression of PPAR-δ and PPAR-γ

Early detection of feline hepatic lipidosis (FHL) with appropriate treatment can increase prognosis significantly. This study looks into the serum biochemistry and lipid composition of serum and liver samples in a group of stray cats (N=18) collected from pounds in Klang Valley, Malaysia. Alanine aminotransferase (ALT) in blood serum was used to detect for liver damage possibly due to FHL, confirmed through light microscopy, serum biochemistry (triglyceride, cholesterol, creatinine, and urea), liver triglyceride and cholesterol concentrations, and liver RNA expression of lipid droplet regulators peroxisome proliferator-activated receptors (PPARs). Differing severity of FHL in samples were divided and grouped using an adapted scoring method observing fatty change of liver (FCL) with trends between FCL groups investigated. Elevated serum ALT reflective of increasing FCL severity was observed with elevated concentrations of liver TAG and cholesterol levels. Serum TAG and cholesterol decreased with heightened FCL pointing to fatty acid oxidation and lipid restoration in the liver, supported by PPAR-γ expression which also propose macrophage activation for liver recovery alongside PPAR-δ for lipogenesis and inflammatory reactions. Elevated serum creatinine and urea levels with increasing FCL severity propose overall intact hepatic function in the stray cat samples

Multi-response analysis in the material characterisation of electrospun poly (lactic acid)/halloysite nanotube composite fibres based on Taguchi design of experiments: fibre diameter, non-intercalation and nucleation effects

Poly (lactic acid) (PLA)/halloysite nanotube (HNT) composite fibres were prepared by using a simple and versatile electrospinning technique. The systematic approach via Taguchi design of experiments (DoE) was implemented to investigate factorial effects of applied voltage, feed rate of solution, collector distance and HNT concentration on the fibre diameter, HNT non-intercalation and nucleation effects. The HNT intercalation level, composite fibre morphology, their associated fibre diameter and thermal properties were evaluated by means of X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), imaging analysis and differential scanning calorimetry (DSC), respectively. HNT non-intercalation phenomenon appears to be manifested as reflected by the minimal shift of XRD peaks for all electrospun PLA/HNT composite fibres. The smaller-fibre-diameter characteristic was found to be sequentially associated with the feed rate of solution, collector distance and applied voltage. The glass transition temperature (T g) and melting temperature (T m) are not highly affected by varying the material and electrospinning parameters. However, as the indicator of the nucleation effect, the crystallisation temperature (T c) of PLA/HNT composite fibres is predominantly impacted by HNT concentration and applied voltage. It is evident that HNT’s nucleating agent role is confirmed when embedded with HNTs to accelerate the cold crystallisation of composite fibres. Taguchi DoE method has been found to be an effective approach to statistically optimise critical parameters used in electrospinning in order to effectively tailor the resulting physical features and thermal properties of PLA/HNT composite fibres

Coalescence and break-up in dense bubbly flows

A combined experimental and computational study has been performed on the effect of coalescence and breakup in bubbly flows. A pseudo-2D bubble column with a special needle sparger has been constructed to obtain well-defined inlet conditions at the gas distributor. An advanced digital image analysis technique has been developed to determine the Bubble Size Distribution (BSD) as a function of position and superficial gas velocity. Most experimental studies of the size distribution have thus far concentrated on bubbly flow at relatively low void fractions. In the present study the column is operated in the regime of dense bubbly flow, where the individual bubble or a cluster of bubbles can be characterized, leading to the construction of the size distribution

Development of an image measurement technique for size distribution in dense bubbly flows

Present work describes the development of a non-intrusive image analysis technique to measure the bubble size distribution in bubbly flows. Generally image analysis methods for bubble characterization in bubbly flows are suitable at low void fractions. These methods depend mainly on the appropriate thresholding/conversion of the image into a binary image, dividing liquid and bubble objects. Clusters of overlapping bubbles are discarded using the criteria of a shape factor, thus leaving only solitary bubbles within an image. When the void fraction is low, the amount of discarded bubble data is very small compared with the obtained solitary bubble data. For bubbly flows with larger void fractions, the discarded data of overlapping/clustering bubbles is considerable. In this work the overlapping clusters are passed through a watershedding algorithm in order to segment the groups of bubble object areas into individual bubbles. The developed image algorithm is verified with synthetic bubble images and applied for an actual system involving bubbly flow in a pseudo-2D bubble column

DEM simulation on soil creep and associated evolution of pore characteristics

In this study, numerical simulations using the discrete element method (DEM) were performed to examine the evolution of pore characteristics in dense and loose samples subjected to a biaxial creep test. Sliding creep between particle contacts was incorporated in the DEM simulations, which displayed similar creep behavior found in experiments. The irregularly shaped pore geometry in the soil packing was quantified with a best-fitting ellipse with the aid of the region-based method. It has been found that the initial density of soils and the deviatoric stress values under which creep starts determine unique evolution of pore space. In addition, the weak pore structures, elongated along the horizontal direction (or perpendicular to the axial loading), collapse first and ultimately only those stable pore structures, elongated along the vertical direction (or parallel to the axial loading direction), survive and then dominate the entire soil structures as creep proceeds. The pore characteristics at last become more uniform and homogenized throughout the sample, and a more stable particle arching elongated along the loading direction is gradually produced during creep. © 2011 Elsevier Ltd