Fibroblasts prevent apoptosis of IL-2-deprived T cells without inducing proliferation: a selective effect on Bcl-XL expression

Tumour hypoxia is well recognised as a major factor contributing to radioresistance. This article examines the role of hypoxia in influencing the treatment outcome following radiotherapy (RT), and reviews the rationale and results of clinical trials that utilise hypoxic sensitizers or cytotoxins in the treatment of head and neck carcinoma. Histologic evidence for tumour hypoxia in human neoplasms was first reported in 1955. Since then, direct measurement by microelectrodes has revealed heterogeneity in intratumoural oxygen concentrations, and low oxygen concentrations are associated with poor local-regional control by RT. These findings coupled with the result of nuclear imaging studies employing radiolabelled imidazoles, provide strong evidence for the existence of tumour hypoxia which influences RT treatment outcome. Hyperbaric oxygen (HBO) trials for head and neck cancer, conducted in the early 1970s, demonstrated that HBO improved local control and survival rates in patients with head and neck cancer receiving radiotherapy (RT). Since the mid-1970s, clinical research in overcoming tumour hypoxia was mainly centred on the use of nitro-imidazoles as hypoxic cell sensitizers. However, the results from several major clinical trials remain inconclusive. Specifically, the Radiation Therapy Oncology Group (RTOG) misonidazole head and neck trial (298 patients) showed no benefit. The Danish misonidazole trial (626 patients) showed no overall benefit, however positive results were observed in a subgroup (304 pharyngeal cancer patients). Although the European Organisation for Research and Teaching of Cancer (EORTC) misonidazole trial with hyperfractionated RT showed no benefit, the Danish nimorazole trial demonstrated an overall benefit in survival as well as local control. The European etanidazole (ETA) trial (374 patients) showed no advantage of adding the drug to RT. The RTOG ETA trial (504 patients) showed no global benefit. However, positive results were observed in a subset of patients with early nodal disease (197 patients). In addition, a recent meta-analysis by Overgaard, utilising pooled results in the literature demonstrated that modification of tumour hypoxia significantly improved local-regional control in head and neck cancers with an odds ratio of 1.23 (95% confidence limits 1.09 to 1.37). Hypoxic cytotoxins, such as tirapazamine, represent a novel approach in overcoming radioresistant hypoxic cells. Tirapazamine is a bioreductive agent which, by undergoing one electron reduction in hypoxic conditions, forms cytotoxic free radicals that produce DNA strand breaks causing cell death. In vitro and in vivo laboratory studies demonstrate that tirapazamine is 40 to 150 times more toxic to cells under hypoxic conditions as compared to oxygenated conditions and that tirapazamine is superior to ETA in enhancing fractionated irradiation in mouse SCCVII and other tumour types with an enhancement ratio of 1.5 to 3.0. Phase I studies demonstrated that therapeutic doses of tirapazamine can be given safely. A multi-institutional phase II trial using tirapazamine with concurrent RT for head and neck cancer is now in progress.     

Chapatti sensory and textural quality in relation to whole meal flour and dough characteristics

Food Science and Biotechnology - Current study was designed to evaluate sensory and textural quality characteristics of chapatti, a commonly consumed flat bread in South-Asia in relation to flour...     

The effect of electrospinning parameters on the morphology of glass nanofibers

Abstract

Electrospinning of glass nanofibers, as one of the most important techniques for producing nanofibers, was the focus of the present research. This process was done using a carrying polymer in order to modify all important parameters of the process including the solution parameters, the electrospinning voltage, the electrospinning distance and feeding rate of the solution to achieve a desired nanofiber morphology. The produced nanofibers were pyrolyzed at a high temperature to remove the carrying polymer and the FTIR test approved that it was completely removed. The diameter of nanofibers and other details were investigated using SEM images and it was shown that the produced nanofibers have a finer diameter with an average of 228?nm and standard deviation of 46?nm in comparison to other works that reported 500?nm for these characteristics.     

Curcumin and Liver Disease: from Chemistry to Medicine

Curcumin, the natural yellow‐colored active principle, also called turmeric yellow, extracted from the perennial herb Curcuma longa L., has potent biological and pharmacological properties such as antioxidant, anti‐inflammatory, antifungal, antibacterial, anti‐ischemic, antitumor, and anticancer actions. The molecular mechanism of the hepatoprotective action of curcumin is due to its antioxidant properties and inhibitory activity against nuclear factor (NF)‐κB that regulates different proinflammatory and profibrotic cytokines. Overall, scientific reports demonstrate that curcumin has high therapeutic ability for treating hepatic disorders. Here is a systematic discussion of the hepatoprotective activity of curcumin and its possible mechanisms of actions.     

Performance analysis of LiAl0.5Co0.5O2 nanosheets for intermediate-temperature fuel cells

Exploring high conductive materials is still a challenge for high performance intermediate-temperature fuel cells. In this study, two-dimensional LiAl_0.5Co_0.5O₂ (LACO) nanosheets coated by a compatible amorphous LiAlO₂ (LAO) layer are evaluated as proton/Li⁺ conductor electrolyte. The fuel cell in which the LAO-LACO is used as electrolyte could deliver the maximum power output of 1120 mW cm^?2 at 550 °C. The LAO coating enhances not only the ionic conductivity by modifying the space-charge regions, but also improves the LACO's chemical stability and device performance. Kelvin probe force microscopy further detected a local electric field (LEF) built in the LAO-LACO coating confines protons at the interface to transport fast. Such heterostructure with the LEF accelerating mechanism presents a novel approach for developing high-performance intermediate-temperature fuel cells.     

An experimental study of forced convective heat transfer for fully developed Al2O3–water nanofluid in an annulus tube

Nanofluids have been known as practical materials to ameliorate heat transfer within diverse industrial systems. The current work presents an empirical study on forced convection effects of Al₂O₃–water nanofluid within an annulus tube. A laminar flow regime has been considered to perform the experiment in high Reynolds number range using several concentrations of nanofluid. Also, the boundary conditions include a constant uniform heat flux applied on the outer shell and an adiabatic condition to the inner tube. Nanofluid particle is visualized with transmission electron microscopy to figure out the nanofluid particles. Additionally, the pressure drop is obtained by measuring the inlet and outlet pressure with respect to the ambient condition. The experimental results showed that adding nanoparticles to the base fluid will increase the heat transfer coefficient (HTC) and average Nusselt number. In addition, by increasing viscosity effects at maximum Reynolds number of 1140 and increasing nanofluid concentration from 1% to 4% (maximum performance at 4%), HTC increases by 18%.     

3D MHD cross flow over an exponential stretching porous surface

The present study aims to investigate the effects of thermal‐diffusion and diffusion‐thermo onan magnetohydrodynamic convective flow of viscous fluids over an exponentially stretching sheet. Thermal radiation effects are also considered in the study. This analysis is carried out in three dimensions and a similarity transformation is adopted to get a set of ordinary differential equations from a set of partial differential equations. And the Fourth‐order Runge‐Kutta method and shooting technique along with the secant method are employed to find out an iterative solution. We also analyze here the influence of the variable magnetic field, nonuniform permeability and variable chemical reaction on the fluid flow. The impact of various pertinent parameters of interest has extensively been explored through graphs and tables. The major findings of the present study are that resistive Lorentz force diminishes the fluid velocity and uplifts the thermal as well as concentration fields. Inclusion of porous matrix improves the viscous drag force which in turn augments wall shear stresses and peters out the heat and mass transfer rates from the sheet. In addition, the thermal expansion coefficient has an inverse relation with temperature.     

Design of a cost-effective on-grid hybrid wind–hydrogen based CHP system using a modified heuristic approach

An economic model and optimization procedure is developed in this paper for grid-connected hybrid wind–hydrogen combined heat and power systems for residential applications in northeastern Iran. The model considers various significant factors: energy production cost, electrical trade with local grid, electrical power generation from the wind/hydrogen energy system, thermal recovery from the fuel cell, and maintenance. Also, various tariffs for purchasing and selling electrical energy from the local grid are considered for the hybrid system operation. The optimization objective is to minimize the system total cost subject to relevant constraints for residential applications. To achieve this aim, an efficient optimization method is proposed based on particle swarm optimization. The proposed algorithm performance is compared with that for the imperialist competition algorithm. The results show that the hybrid system is the most cost-effective for the residential load, and the results of the proposed algorithm are more promising than those for the alternative algorithm.     

Egg white proteins and β-cyclodextrin: effective cryoprotectant mixture against oxidative changes in the myofibrillar proteins of Culter alburnus

The effect of egg white protein (EWP) and β-cyclodextrin (β-CD) mixture was analysed on the myofibrillar proteins (MP) of Culter alburnus during a frozen storage at −18 °C for 60 days. Different proportions of EWP:β-CD mixture (0%, 2%, 4% and 6%) were added into MP to analyse their effect against oxidative changes. During the study, sulphydryl contents and Ca-ATPase activity (0.297 to 0.136 mmol g⁻¹) decreased. Moreover, protein denaturation also prompted the surface hydrophobicity (11.47 to 32.06 μg) and carbonyls (26.36 to 49 mg.28 nmol mg⁻¹) of control MP. A significant decline was observed in emulsifying properties. Besides, EWP:β-CD showed remarkable stability against oxidative changes, by significantly reducing the carbonyls (26.26 to 37.69 nmol mg⁻¹) and surface hydrophobicity (11.51 to 20.31 μg) and also the decline of Ca-ATPase activity (0.29 to 0.19 mmol g⁻¹). It can be concluded that EWP:β-CD (6%) is an efficient approach against oxidative changes in MP from Culter alburnus.     

Calorimetric and spectroscopic investigations of β-lactoglobulin upon interaction with copper ion

The effect of copper(II) ions (Cu(+2)) on the structure of β-lactoglobulin (β-lg) was investigated spectroscopically using UV-visible, fluorescence and circular dichroism (CD) and calorimetrically using isothermal titration calorimetry (ITC), at different temperatures. Results of the UV-visible studies showed that adding Cu(+2) to β-lg solution caused increasing turbidity, indicative of protein aggregation. It was noticeable that the rate of increasing turbidity was directly proportional to increasing temperature. The far-UV CD studies displayed that the Cu(+2) cannot induce any significant changes in the secondary structures of β-lg at different temperatures. Also, the ITC data indicated that the binding process of Cu(+2) to β-lg is mainly entropically driven. The results highlight that copper ions cause the tertiary structure of β-lg to change and induce a slightly open structure leading to the formation of supramolecular aggregates in β-lg which may result in the reduced allergenicity of β-lg and its increased use in industrial applications.