Cell biomechanics and its applications in human disease diagnosis

Certain diseases are known to cause changes in the physical and biomechanical properties of cells.These include cancer,malaria,and sickle cell anemia among others.Typically,such physical property changes can result in several fold increases or decreases in cell stiffness,which are significant and can result in severe pathology and eventual catastrophic breakdown of the bodily functions.While there are developed biochemical and biological assays to detect the onset or presence of diseases,there is always a need to develop more rapid,precise,and sensitive methods to detect and diagnose diseases.Biomechanical property changes can play a significant role in this regard.As such,research into disease biomechanics can not only give us an in-depth knowledge of the mechanisms underlying disease progression,but can also serve as a powerful tool for detection and diagnosis.This article provides some insights into opportunities for how significant changes in cellular mechanical properties during onset or progression of a disease can be utilized as useful means for detection and diagnosis.We will also showcase several technologies that have already been developed to perform such detection and diagnosis.     

Flow and performance characteristics of twin-entry radial turbine under full and extreme partial admission conditions

This paper presents numerical and experimental investigation of the performance and internal flow field characteristics of twin-entry radial inflow turbines at full and extreme partial admission conditions. The turbine is tested on a turbocharger test facility, which was developed for small and medium size turbochargers. Experimental results show that the lowest efficiency corresponds to extreme conditions. Therefore, flow field analyzing is employed to consider these conditions. The flow pattern in the volute and impeller of a twin-entry turbine is analyzed using an in-house fully three-dimensional viscous flow solver. The computational performance results are compared with the experimental results and good agreement is found. The flow field at the outlet of the turbine is investigated using a five-hole pressure probe; the numerical results are also compared with experimental measurements at the outlet of the rotor. For the volute, results show that lowest entropy gain factor corresponds to the extreme conditions, particularly when shroud side entry is fully closed. At the inlet of the rotor for equal admission conditions, the incidence angle is mostly in the optimum values. However, large variation in the incidence angle is seen in the extreme conditions, which lead to larger incidence losses and consequently a lower efficiency. In addition, entropy distribution contours corresponding to the exit plane are considered. For full admission, the location of low entropy gain factor at this plane occupies a region near the shroud side of suction surface as well as near the hub side of the pressure surface that corresponds to a region of high absolute flow angle. However, for the extreme cases, the low entropy gain factor occupies a relatively larger region near the shroud side than full admission. So, higher loss generation is noted at the extreme cases. Moreover, this entropy gain factor region is increased when shroud side entry is fully closed.     

Nano‐WO3‐SO3H as a New Photocatalyst Insight Through Covalently Grafted Brønsted Acid: Highly Efficient Selective Oxidation of Benzyl Alcohols to Aldehydes

Modification of nano‐WO₃ with ?SO₃H groups as a covalently grafted solid acid reduced its band‐gap energy from 2.8 to 2.4 eV and made it an ideal nominee for photocatalytic reaction under visible light irradiation. This nano‐photocatalyst has been successfully used for the selective oxidation of different benzyl alcohols to corresponding aldehydes under blue LED irradiation. The reaction became approximately two times faster with excellent yields. It has shown that the nitrobenzene as an available industrial oxidant is applicable for photocatalytic oxidation of benzyl alcohol; remarkably high yield and selectivity have been observed.     

Spectrophotometric study of acidity constants of Alizarine Red S in various water-organic solvent

The acidity constants of Alizarine Red S were determined spectrophotometrically at 25 degrees C and at constant ionic strength 0.1 M (KNO3) in pure water as well as in aqueous media containing variable mole percentages (5-70%) of organic solvents. The organic solvents used were methanol, ethanol, N,N-dimethyl formamide (DMF), dimethyl sulfoxide (DMSO), acetonitrile and dioxan. The acidity constants of all related equilibria are estimated using the whole spectral fitting of the collected data to an established factor analysis model. DATAN program was applied for determining of acidity constants and pure spectra of different form of Alizarine Red S. The obtained results indicated that acidity constants decrease as the content of an organic solvent in the medium increases. There are linear relationship between acidity constants and the mole fraction of various organic solvents in the solvent mixtures. Effect of various solvents on acidity constants and pure spectrum of each component are also discussed.     

Immobilized Vanadium Histidine and Tryptophan Schiff Base Complexes on Modified Magnetite Nanoparticles as Epoxidation Catalyst

In this study, magnetically recoverable vanadium complexs designated as VO(Sal-Tryp)/AmpSCMNPs and VO(Sal-His)/AmpSCMNPs were prepared through immobilization of Schiff bases of histidine or tryptophan with salicylaldehyde on the surface of modified silica coated iron oxide magnetite nanoparticles with (3-aminopropyl) trimethoxysilane as aminopropyl (Amp) spacer followed by complexation with VOSO₄. Characterization was carried out by chemical analysis, Fourier transform infrared spectroscopy, XRD, scanning electron microscopy and vibrating sample magnetometry techniques. VO(Sal-Tryp)/AmpSCMNPs and VO(Sal-His)/AmpSCMNP were found to catalyze the epoxidation of allyl alcohols and olefins with tert-butyl hydroperoxide with excellent conversions and selectivities. Investigation of the stability and reusability revealed the heterogeneity character of the catalyst with no desorption during the course of epoxidation reactions. High yields, clean reactions, easily catalyst separation and recyclability of the solid catalyst are some advantages of this method.     

Lipid bilayers covalently anchored to carbon nanotubes

The unique physical and electrical properties of carbon nanotubes make them an exciting material for applications in various fields such as bioelectronics and biosensing. Due to the poor water solubility of carbon nanotubes, functionalization for such applications has been a challenge. Of particular need are functionalization methods for integrating carbon nanotubes with biomolecules and constructing novel hybrid nanostructures for bionanoelectronic applications. We present a novel method for the fabrication of dispersible, biocompatible carbon nanotube-based materials. Multiwalled carbon nanotubes (MWCNTs) are covalently modified with primary amine-bearing phospholipids in a carbodiimide-activated reaction. These modified carbon nanotubes have good dispersibility in nonpolar solvents. Fourier transform infrared (FTIR) spectroscopy shows peaks attributable to the formation of amide bonds between lipids and the nanotube surface. Simple sonication of lipid-modified nanotubes with other lipid molecules leads to the formation of a uniform lipid bilayer coating the nanotubes. These bilayer-coated nanotubes are highly dispersible and stable in aqueous solution. Confocal fluorescence microscopy shows labeled lipids on the surface of bilayer-modified nanotubes. Transmission electron microscopy (TEM) shows the morphology of dispersed bilayer-coated MWCNTs. Fluorescence quenching of lipid-coated MWCNTs confirms the bilayer configuration of the lipids on the nanotube surface, and fluorescence anisotropy measurements show that the bilayer is fluid above the gel-to-liquid transition temperature. The membrane protein α-hemolysin spontaneously inserts into the MWCNT-supported bilayer, confirming the biomimetic membrane structure. These biomimetic nanostructures are a promising platform for the integration of carbon nanotube-based materials with biomolecules.     

Preparation of Iodide Selective Carbon Paste Electrode with Modified Carbon Nanotubes by Potentiometric Method and Effect of CuS‐NPs on Its Response

In this research, multiwalled carbon nanotubes (MWCNTs) was oxidized and chemically modified through reaction with 3‐(trimethoxysilyl)propan‐1‐amine (TMSPA) and their subsequent reaction with 2‐hydroxy‐3‐methoxy benzaldehyde. Subsequently, this material was metalized by reaction with copper acetate that lead to formation and impergeation of 2‐methoxy‐6‐((3‐(trimethoxysilyl)propylimino)methyl)phenol MMSPIMP? MWCNT‐Cu. This novel material was identified with different techniques such as SEM and FT‐IR analysis. In this work, the reported material are exhibited high accurate and repeatable monitoring of iodide due to its high surface area with various reactive centre. It exhibited selectivity for iodide over the wide linear dynamic range between 1.8×10^?6 and 1.15×10^?1 M, with a Nernstian slope of ?59.12±0.7 mV per decade of activity and detection limit of 1.8×10^?6 M. Copper sulfide nanoparticles were prepared and their effect on the electrode response was investigated. The results were improved in the presence of nanoparticles with fast and stable response, good reproducibility, long‐term stability, high selectivity over the presence of common organic and inorganic anions, high detection limit and dynamic range. The proposed sensor has been applied as potentiometric determination of some iodine species over a pH range of 2.5–10.