Integration of cell phone imaging with microchip ELISA to detect ovarian cancer HE4 biomarker in urine at the point-of-care

Ovarian cancer is asymptomatic in the early stages and most patients present with advanced levels of disease. The lack of cost-effective methods that can achieve frequent, simple and non-invasive testing hinders early detection and causes high mortality in ovarian cancer patients. Here, we report a simple and inexpensive microchip ELISA-based detection module that employs a portable detection system, i.e., a cell phone/charge-coupled device (CCD) to quantify an ovarian cancer biomarker, HE4, in urine. Integration of a mobile application with a cell phone enabled immediate processing of microchip ELISA results, which eliminated the need for a bulky, expensive spectrophotometer. The HE4 level detected by a cell phone or a lensless CCD system was significantly elevated in urine samples from cancer patients (n = 19) than healthy controls (n = 20) (p < 0.001). Receiver operating characteristic (ROC) analyses showed that the microchip ELISA coupled with a cell phone running an automated analysis mobile application had a sensitivity of 89.5% at a specificity of 90%. Under the same specificity, the microchip ELISA coupled with a CCD had a sensitivity of 84.2%. In conclusion, integration of microchip ELISA with cell phone/CCD-based colorimetric measurement technology can be used to detect HE4 biomarker at the point-of-care (POC), paving the way to create bedside technologies for diagnostics and treatment monitoring.     

Viscometric and Morphological Properties of Novel Magnesium Electrolyte–Polyacrylamide Composite Polymers in Aqueous Solution

The viscometric properties of novel magnesium electrolyte–polyacrylamide composite polymers in aqueous solutions were investigated using response surface methodology. Independent factors such as concentration of the magnesium electrolyte (magnesium chloride and magnesium hydroxide), concentration of polyacrylamide, and the solution temperature were taken into account for viscometric modeling. Experiments were carried out according to central composite design, which includes factorial, central and axial points of the factors. Solution viscosity was taken as the response variable. A polynomial model for the viscometric properties was developed using ANOVA and non-linear regression analysis, and the R² values are 0.9995 and 0.9996 for aqueous solutions of magnesium chloride–polyacrylamide (MCPAM) and magnesium hydroxide–polyacrylamide (MHPAM) composite polymers, respectively. Two diagnostic plots have been constructed to validate the developed models for the natural logarithm of viscosity of aqueous solutions of the MCPAM and MHPAM composite polymers. The least-squares values show that the developed models are adequate for predictive purposes. TEM was used to investigate the morphological properties of MCPAM and MHPAM composite polymers. Magnesium chloride was impregnated into the polyacrylamide chain while magnesium hydroxide was just adsorbed on the surface of the polyacrylamide chain.     

Leaching of Triazine Pesticides in Loamy Soil and their Determination by Reversed Phase HPLC

Abstract

The separation and identification of triazine pesticides (ametryn, atrazine, cyanazine and simazine) was carried out on Nova Pak C₁₈ column (150 × 3.9mm). The mobile phase used was acetonitrile-water (65:35, v/v) adjusted to pH 4.5 with acetic acid. The flow rate of the mobile phase used was 1.0mL/min. The detection of the pesticides was carried out at 250 nm. The values of the separation factor (α) were in the range of 1.49–5.32 and the values of the resolution factors (R _s) were ranged from 1.18 to 2.99 for the separated pesticides. The developed HPLC method was used to determine the concentrations of the reported pesticides in the loamy soil samples. The recovery of the pesticides from soil samples was found to be about 50%. The relative standard deviation and limit of detection were in the range of 0.01–0.02 and 0.5–1.0 μg/mL respectively.     

QSAR and docking studies on chalcone derivatives for antitubercular activity against M. tuberculosis H37Rv

In our prior studies, we reported some known antitubercular drugs (rifampicin and streptomycin) and newly synthesized chalcone derivatives (16–26) tested in vitro against Mycobacterium tuberculosis H₃₇Rv strain. Most of the tested compounds were efficient antimycobacterial agents showing minimum inhibitory concentration values ranging from 3.5 to 30 µg mL⁻¹. In the present work, a quantitative structure–activity relationship (QSAR) study has been performed on these active chalcone derivatives to correlate their chemical structures with their observed inhibiting activity against M. tuberculosis. A QSAR model that is able to correlate well the antitubercular activity with the chemical structures of active chalcone derivatives 16, 24, 25a, 25c, and 26 has been developed, which is potentially helpful in the design of novel and more potent antitubercular agents. The r² and rCV² of a newly derived QSAR model were 0.89 and 0.84, respectively. The QSAR study indicates that chemical properties, viz. heat of formation (kcal mol⁻¹), lowest unoccupied molecular orbital energy (eV), and amine, hydroxyl, and methyl groups counts, correlate well with the activity. In silico screening results for oral bioavailability and absorption, distribution, metabolism, excretion, and toxicity compliance showed that compounds 25a, 25c, and 24 were found active similar to rifampicin and streptomycin. The docking study for the exploration of mechanism of action showed high binding affinity of active derivatives. Copyright © 2014 John Wiley & Sons, Ltd.     

Carbon nanotube-chitosan modified disposable pencil graphite electrode for vitamin B12 analysis

A single walled carbon nanotube-chitosan (SWCNT-chitosan) modified disposable pencil graphite electrode (PGE) was used in this study for the electrochemical detection of Vitamin B(12). Electrochemical behaviors of SWCNT-chitosan PGE and chitosan modified PGE were compared by using cyclic voltammetry (CV), square-wave voltammetry (SWV) and electrochemical impedance spectroscopy (EIS) techniques. SWCNT-chitosan modified electrode was also used for the quantification of Vitamin B(12) in pharmaceutical products. The results show that this electrode system is suitable for sensitive Vitamin B(12) analysis giving good recovery results. The surface morphologies of the SWCNT-chitosan PGE, chitosan modified PGE and unmodified PGE were characterized by using scanning electron microscopy (SEM).     

Comparison of urinary iodide determination in female thyroid patients by two techniques

Iodine deficiency affects a substantial portion of the world’s population, provoking severe health problems as well as important economic losses to the region in which this condition is found. In present study, evaluated the levels of urinary iodide (UI) and thyroid hormone status in female hypothyroid patients (HPs) and control subjects of same age group 16–30 years. The UI in HPs was measured by means of a Potentiometric method after microwave-assisted acid digestion, and compared the results with those obtained by the Sandell-Kolthoff method. The validity and accuracy was checked by using certified reference materials. The significantly lower concentration of iodide in the urine samples of the female goiter patients were observed as compared to control/referents subjects (p < 0.001). Serum thyroid status thyroid stimulating hormone, free triiodothyronine and free thyroxin were significantly lower in female patients as compared to control females (p < 0.003). The proposed method was relatively rapid, precise, accurate, efficient, as well as cost effective by using inexpensive equipment.     

Galerkin Finite Element Study on the Effects of Variable Thermal Conductivity and Variable Mass Diffusion Conductance on Heat and Mass Transfer

This article investigates the effects of variable thermal conductivity and variable mass diffusion coefficient on the transport of heat and mass in the flow of Casson fluid. Numerical simulations for two-dimensional flow induced by stretching surface are performed by using Galerkin finite element method (GFEM) with linear shape functions. After assembly process, nonlinear algebraic equations are linearized through Picard method and resulting linear system is solved iteratively using Gauss Seidal method with simulation tolerance 10^-8. Maximum value of independent variable η is searched through numerical experiments. Grid independent study was carried out and error analysis is performed. Simulated results are validated by comparing with already published results. Parametric study is carried out to explore the physics of the flow. The concentration increases when mass diffusion coefficient is increased. The concentration and thermal boundary layer thicknesses increase when ε₁ and ε are increased. The effect of generative chemical reaction on concentration is opposite to the effect of destructive chemical reaction on the concentration.     

Comments on “Design of fractional-order variants of complex LMS and NLMS algorithms for adaptive channel equalization”

This paper explores a nonlinear Cournot oligopoly with n firms displaying general isoelastic demand. The marginal profits-based gradient rule and the expectation rule Local Monopolistic Approximation were employed in two Cournot oligopoly games. Nash equilibrium stability analysis is carried out on each of the two games to throw light on the effects of demand elasticity and other parameters on the dynamics of the game. Our results show that the influence of demand elasticity on stability depends on firms’ expectation rules.     

A comparative study of HPLC and TLC separation of amino acids using Cu(II) ion

Separation of amino acids using Cu(II) by RP-HPLC and impregnated TLC is reported. For HPLC the sample mixture of amino acids containing copper (II) was injected into the column while for TLC the silica gel plates were impregnated with Cu(II). The mobile phase used in HPLC was acetate buffer (0.3 M , pH 6.0)-acetonitrile (9:1, v/v), and that in TLC was acetate buffer (0.3 M , pH 6.0):acetonitrile-n-butanol (12:5:10, by vol.). The results have been compared and discussed.     

Novel synthesis of nickel oxide-copper hexacyanoferrate binary hybrid nanocomposite for high-performance supercapacitor application

Journal of Solid State Electrochemistry - Nowadays, metal hexacyanoferrate/metal oxide composites have attracted intense interest as an electrode material for supercapacitor applications due to...