Fuel bioadditive production by chitosan/sulfosuccinic acid catalytic membrane

Global warming is one of the biggest environmental problems of late. The use of renewable raw material resources as biomass and its conversion into alternative energy resources have attracted considerable attention during the recent years. Ethyl levulinate (EL) is a kind of fuel bioadditive for use in diesel and biodiesel engines, which is produced by the esterification of ethanol and levulinic acid. In the present study, sulfosuccinic acid (SSA) catalysts supported on chitosan catalytic membrane is used for the synthesis of EL. The effects of temperature, catalyst amount, and molar feed ratio were studied.     

Palmitic Acid-Induced Neuron Cell Cycle G2/M Arrest and Endoplasmic Reticular Stress through Protein Palmitoylation in SH-SY5Y Human Neuroblastoma Cells

Obesity-related neurodegenerative diseases are associated with elevated saturated fatty acids (SFAs) in the brain. An increase in SFAs, especially palmitic acid (PA), triggers neuron cell apoptosis, causing cognitive function to deteriorate. In the present study, we focused on the specific mechanism by which PA triggers SH-SY5Y neuron cell apoptosis. We found that PA induces significant neuron cell cycle arrest in the G₂/M phase in SH-SY5Y cells. Our data further showed that G₂/M arrest is involved in elevation of endoplasmic reticular (ER) stress according to an increase in p-eukaryotic translation inhibition factor 2α, an ER stress marker. Chronic exposure to PA also accelerates beta-amyloid accumulation, a pathological characteristic of Alzheimer’s disease. Interestingly, SFA-induced ER stress, G₂/M arrest and cell apoptosis were reversed by treatment with 2-bromopalmitate, a protein palmitoylation inhibitor. These findings suggest that protein palmitoylation plays a crucial role in SFA-induced neuron cell cycle G₂/M arrest, ER stress and apoptosis; this provides a novel strategy for preventing SFA-induced neuron cell dysfunction.     

Energy management optimization of a hybrid power production unit based renewable energies

Hybrid power production units seem to be an interesting alternative for supplying isolated sites. This study proposes a new supervision strategy in order to ensure an optimized energy management of the hybrid system. The considered hybrid unit includes a wind generator (WG), a fuel cell (FC), an electrolyzer (EL) and a supercapacitor (SC). An overall power supervision approach was designed to guarantee the power flow management between the energy sources and the storage elements. The aim of the control system is to provide a permanent supply to the isolated site by adapting production to consumption according to the storage level. A mathematical analysis of the hybrid system using models implemented in Matlab/Simulink software was developed. Simulation results illustrate the performance of the control strategy for an optimal management of the hybrid power production unit under different scenarios of power generation and load demand.     

Water‐soluble ionic polythiophenes for biological and analytical applications

Ionic polythiophenes are important conjugated polymers because of their excellent optical properties and water solubility. They are classified as cationic, anionic and zwitterionic conjugated polyelectrolytes. This review article describes concisely their biological and analytical applications. The specific detection of different negatively charged biomolecules such as DNA and adenosine triphosphate, anions like halides and toxic pseudo‐halide (CN ^?) and environmental pollutants, e.g. surfactants, is discussed. The conformational changes of cationic polythiophenes (CPTs ) induced by various analytes due to formation of ionic conjugates and the cooperative responses of all segments cause dominant signal amplification even in the presence of a small perturbation. In addition, reactive oxygen scavenging, antimicrobial photosensitizing and cell imaging applications of CPTs are documented. Use of anionic polythiophenes for sensing of protamine and cations like Cu²⁺ and Ca²⁺ is also discussed. Finally, sensing of DNA , peptides and surfactants by zwitterionic polythiophenes is included. The concluding part discusses future prospects. © 2016 Society of Chemical Industry     

The role of mechanical forces in the planar-to-bulk transition in growing Escherichia coli microcolonies

Mechanical forces are obviously important in the assembly of three-dimensional multicellular structures, but their detailed role is often unclear. We have used growing microcolonies of the bacterium Escherichia coli to investigate the role of mechanical forces in the transition from two-dimensional growth (on the interface between a hard surface and a soft agarose pad) to three-dimensional growth (invasion of the agarose). We measure the position within the colony where the invasion transition happens, the cell density within the colony and the colony size at the transition as functions of the concentration of the agarose. We use a phenomenological theory, combined with individual-based computer simulations, to show how mechanical forces acting between the bacterial cells, and between the bacteria and the surrounding matrix, lead to the complex phenomena observed in our experiments—in particular the observation that agarose concentration non-trivially affects the colony size at transition. Matching these approaches leads to a prediction for how the friction between the bacteria and the agarose should vary with agarose concentration. Our experimental conditions mimic numerous clinical and environmental scenarios in which bacteria invade soft matrices, as well as shedding more general light on the transition between two- and three-dimensional growth in multicellular assemblies.     

一种防作弊加油机微处理器设计与应用

加油机作弊是石油石化行业的一大痼疾,本文结合加油机功能及结构原理,提出了一种加油机特定微处理器的设计及应用方案,可以有效实现预防加油机作弊的目标。     

Large-area TiO2 nanotube dye-sensitized solar cells using thermal-sprayed Ti layers on stainless steel

This work presents large-scale dye-sensitized solar cells and methods for their manufacture. A dye-sensitized solar cell device contains a photosensitive dye adsorbed on a large surface of the anode, and a transparent conductive cathode disposed opposite the anode, wherein platinum nano-catalytic particles adhere to its surface, and an electrolytic solution is sealed between the anode and the transparent conductive cathode. A titania nanotube film was fabricated by thermo-spraying titanium film on 304 stainless-steel substrate. The photo-current conversion efficiency was tested under an AM 1.5 solar simulator. The dye-sensitized solar cell device has a short current density of 8.22 mA cm^–2, open voltage of 0.71 V, fill factor of 0.59, and conversion efficiency of 3.4%. The internal impedance of the dye-sensitized solar cell was detected and simulated using an electrical impedance spectra technique with inductance, resistance, and capacitance characteristics. The stainless-steel/titania, titania/electrolyte, electrolyte, and electrolyte/(platinum/indium tin oxide) interfaces were simulated using an resistor–capacitor parallel circuit, and bulk materials such as stainless steel, tin doped indium oxide, and conducting wire were simulated by using a series of resistors and inductance.     

Analyses of Power Excursion Event in Chernobyl Accident with RETRAN Code

Nickel ferrite is one of the important corrosion products of PHWR's where Monel and carbon steel are used as the constructional materials in the primary heat transport system. The dissolution of synthetically prepared nickel ferrite was studied in low concentrations (<10 mmol/l) of HEDTA, DTPA, NTA and HIDA. The dependence of the dissolution rate on the ligand concentration was found to be langmuirian in all these cases. The effect of the addition of low concentrations of citric acid, oxalic acid, ascorbic acid and Fe(II)-ligand complex, individually, to each of the above chelating agents was also studied. The effect of pH and temperature on the dissolution rate was determined.     

The influence of lateral forces on the cell stiffness measurement by optical tweezers vertical indentation

We studied the lateral forces arising during the vertical indentation of the cell membrane by an optically trapped microbead, using back focal plane interferometry to determine force components in all directions. We analyzed the cell-microbead interaction and showed that indeed the force had also lateral components. Using the Hertz model, we calculated and compared the elastic moduli resulting from the total and vertical forces, showing that the differences are important and the total force should be considered. To confirm our results we analyzed cells from two breast cancer cell lines: MDA-MB-231 and HBL-100, known to have different cancer aggressiveness and hence stiffness.