Receptor-mediated endocytosis of IL-8: a fluorescent microscopic evidence and implication of the process in ligand-induced biological response in human neutrophils

Interleukin 8 (IL-8), a neurophil-activating and chemotactic cytokine, is known to play a key role in the pathogenesis of a large number of neutrophil-driven inflammatory diseases. Although the cytokine is rapidly internalized at 37 degrees C with its receptors, there was no direct evidence for the ligand-induced endocytosis of the receptor or that of the interaction of receptor ligand complex at 37 degrees C. As a result, our understanding about the regulation of Il-8 induced biological response is very limited. In the present study, using FITC-IL-8 conjugate as a probe, we have demonstrated the time- and temperature-dependent endocytosis of IL-8 under fluorescent microscope. We have also shown that the bright fluorescent light on the surface of neutrophils gradually disappears and it becomes almost dark after 120 min of incubation. Monodansyl cadaverine (MDC, 900 microM), however, was found to retain the fluorescent light of FITC coupled with Il-8 on the cells. MDC and ouabain (2.5 mM) can inhibit the ligand induced endocytosis by 76% and 96%, respectively, compared to control. With respect to control, IL-8 induced biological responses e.g. IL-8 directed migration, intracellular Ca2+ release and superoxide release are significantly reduced by 77%, 94% and 76%, respectively, in presence of MDC. The study presents a direct visual evidence of the time and temperature-dependent receptor-mediated endocytosis of IL-8 which is inhibited by MDC and ouabain. This information is useful for understanding the ligand receptor interaction at 37 degrees C and may be useful for developing anti-inflammatory agents against IL-8.     

Factor market distortions and backward incidence of pollution control

This paper analyzes the backward incidence of stronger pollution control into factors of production using a two-sector general equilibrium model in which the economy experiences perfect capital mobility but norigid factor price differential. In this context we conclude that higher levels of wage and capital rental differentials may act as an effective control over the pollution emission in the economy when factor price differentials directly depend on the pollution level.     

Appropriate bleaching technique for coconut fiber

Recipes for bleaching of coconut fiber at both ambient and elevated temperature were investigated using appropriate statistical design of experiments using hydrogen peroxide with essential bleaching assisting auxiliaries. The statistical tool is also being utilized to suggest optimized recipe for the treatments considering mainly whiteness index, yellowness index, and tenacity. Statistical computation affirmed need of higher amount of bleaching chemicals in elevated temperature than ambient bleaching. Both the bleaching treatments were resulting in small mass loss essentially of noncellulosic nature including lignin and thus result in improved mechanical properties. The change in whiteness and yellowness index of the bleached fiber under the shed storage condition for duration of 2 years was found to be negligible.     

Experimental investigation on the effect of MgO and TiO2 nanoparticles in stepped solar still

This work aims at augmenting the amount of potable water using MgO and TiO₂ in stepped solar still. Experiments were carried out for the climatic conditions of Chennai, India, with two different concentrations of nanofluids inside a stepped basin under three different cases. Results show that there is an improvement in yield of fresh water from stepped solar still by 33.18% and 41.05% using 0.1% and 0.2% volume concentration of TiO₂ nanofluid, respectively, whereas the freshwater yield from stepped still with MgO nanofluids improved by 51.7% and 61.89%. Furthermore, the economic analysis revealed that the cost of potable water from the modified solar still reduced from 0.029 to 0.016 $/kg. Similarly, the useful annual energy, yearly cost per kilogram, and annual cost per kilowatt hour are significantly profitable with the use of MgO nanofluid in the stepped basin and found as 512.46 kWh, 0.025 $/kg, and 0.026 $/kWh, respectively. It is also found that the cost of potable water from the modified still significantly increases as the amount of fresh water produced is decreased with increased fabrication cost of the solar still.     

Experimental exploration and theoretical certainty of thermal conductivity and viscosity of MgO-therminol 55 nanofluid

In this study, a combination of thermal conductivity, viscosity, and density characteristics are experimentally probed for attaining maximum heat transfer using MgO-Therminol 55 as nanofluid is reported. Recent studies proved that nanofluids have miserable properties that make them feasibly useful in many applications in heat transfer compared to base fluid.MgO-Therminol 55 nanofluid is synthesized by diffusion of MgO nanoparticles of size 160–190 nm in Therminol 55 at different concentrations (0.05%–0.3%). Thermal conductivity and viscosity are calculated at a temperature range of 30–60°C using kd₂ analyzer and Fenske viscometer. Data obtained from the experimental results reveals that when volume concentration is increased with respect to that thermal conductivity increases, viscosity decreases and density decreases at different temperatures. The proposed models were supportive to the experimental data.     

Fire retardant property of cotton fabric treated with herbal extract

Flame retardant functionality was imparted in cellulosic textile using spinach leaves juice (SJ), an eco-friendly natural product. The extracted juice was made alkaline and applied in fresh bleached and mercerized cotton fabrics. Flame retardant properties of the control and treated fabrics were analysed in terms of limiting oxygen index (LOI), horizontal and vertical flammability and radiant heat testing. The study showed that the treated fabrics had good flame retardant property compared to control fabrics. The LOI value was found to increase by 1.6 times after application of SJ. As a result of this, the fabric does not catch flame. In horizontal flammability, the treated fabric showed burning with afterglow (without presence of flame) with a propagation rate of 10 mm/min, which is almost nine times lower than the control fabric. The thermal degradation and pyrolysis was studied using thermogravimetric analysis. The chemical composition of the control and SJ-treated cellulosic fabric were analysed by FTIR, SEM and EDX. Durability of the flame retardant functionality to soap washing and weathering had also been studied. After application of SJ, cellulosic fabric sample produced natural green colour. There was no significant change in other physical properties.     

Effect of stabilizer on structural, optical and electrochemical properties of sol–gel derived spin coated TiO2 films

Thin films of TiO₂ were prepared using two different sol–gel routes. The two routes employed diethanolamine (DEA) and acetylacetone as stabilizing agents with titanium isopropoxide (Ti(OPrⁱ)₄) in ethanol as the deposition solution. The densification at 500 °C achieved the nanophase TiO₂ films, which were investigated by performing structural, optical and electrochemical studies. Ion storage capacity and transmission measurements showed superior response of the films derived from DEA. Between the films obtained from the two routes, the appearance of the rutile phase at lower temperature for the film synthesized using DEA was predicted on the basis of the thermal analysis of the corresponding xerogel. The nanocrystalline nature of the films was evident from the X-ray diffraction, atomic force microscopy, and scanning electron microscopy. The films deposited from both the stabilizers exhibited electrochromism in 1 M LiClO₄-propylene carbonate electrolyte on cathodic polarization.     

A comprehensive assessment on the durability of gas diffusion electrode materials in PEM fuel cell stack

Polymer electrolyte membrane (PEM) fuel cell is the most promising among the various types of fuel cells. Though it has found its applications in numerous fields, the cost and durability are key barriers impeding the commercialization of PEM fuel cell stack. The crucial and expensive component involved in it is the gas diffusion electrode (GDE) and its degradation, which limits the performance and life of the fuel cell stack. A critical analysis and comprehensive understanding of the structural and functional properties of various materials involved in the GDE can help us to address the related durability and cost issues. This paper reviews the key GDE components, and in specific, the root causes influencing the durability. It also envisages the role of novel materials and provides a critical recommendation to improve the GDE durability.