Spinodal Curve for the System Water + 1-Pentanol + 1-Propanol at 25 °C

The liquid–liquid equilibrium data at 25 °C of the system water–1-pentanol–1-propanol, that present a I type solubility gap, have been used to calculate the spinodal curve of this system through the use of the Wheeler–Widom model. As in the case of the water–chloroform–acetic acid system, analyzed with the same model in the past, a local fitting method has been necessary. A procedure based on the experimental position of the plait point was used to obtain the single spinodal points. The relative positions of binodal and spinodal curves indicate the presence of a large metastable area in the alcoholic-rich region.     

Synthesis,characterization and controlled toxicity of a novel hybrid material based on cisplatin and docetaxel

This paper is focused on the synthesis and characterization of a novel hybrid material based on cisplatin and docetaxel-loaded functionalized simultanously carbon nanotubes able to be used in cancer therapy as drug delivery system with controlled toxicity. This material was physico-chemically investigated by determining the structure, as evidenced by Fourier transform infrared (FTIR) spectroscopy, transmission electronmicroscopy (TEM) and its stability was studied with the aid of thermogravimetric analysis (TGA). The amount of platinum ions released into the solution of simulated body fluid (SBF) was highlighted by coupled plasma mass spectrometry (ICP-MS). Toxicology experiments were performed with MDA-MB 231 breast cancer epithelial cells. The performance of the new drug delivery hybrid material was compared with functionalised carbon nanotubes with therapeutic agents functionalized with a single therapeutic agent.      

Electrochemical Peptide-Based Sensors for Foodborne Pathogens Detection

Food safety and quality control pose serious issues to food industry and public health domains, in general, with direct effects on consumers. Any physical, chemical, or biological unexpected or unidentified food constituent may exhibit harmful effects on people and animals from mild to severe reactions. According to the World Health Organization (WHO), unsafe foodstuffs are especially dangerous for infants, young children, elderly, and chronic patients. It is imperative to continuously develop new technologies to detect foodborne pathogens and contaminants in order to aid the strengthening of healthcare and economic systems. In recent years, peptide-based sensors gained much attention in the field of food research as an alternative to immuno-, apta-, or DNA-based sensors. This review presents an overview of the electrochemical biosensors using peptides as molecular bio-recognition elements published mainly in the last decade, highlighting their possible application for rapid, non-destructive, and in situ analysis of food samples. Comparison with peptide-based optical and piezoelectrical sensors in terms of analytical performance is presented. Methods of foodstuffs pretreatment are also discussed.     

Nanocomposites Based on Poly(Amide-Imide) Matrix with Na–Mg Triple Chain Hydrosilicate

Crystallography Reports - A new polymer-inorganic nanocomposite composed of fibrous Na–Mg triple chain hydrosilicate with a poly(amide-imide) matrix was developed. Its structure, morphology,...     

Influence of Phytochemical Reductive Capacity on Ultraviolet–visible Spectroscopic Behavior of Silver Nanoparticles

ABSTRACT

A widely used method for obtaining silver nanoparticles uses plant extracts for reduction because of the presence of phytochemicals such as terpenoids, tannins, and flavonoids. Extracts of Flores sambuci, Hypericum perforatum, Lavandula angustifolia, Origanum vulgare, Rosmarinus officinalis, and Salvia officinalis were used for generating silver nanoparticles. The ultraviolet–visible spectra of silver nanoparticle solutions were correlated with variations of phytochemical characteristics to evaluate the plant extracts. These parameters were the antioxidant activity, total flavonoids, total tannins, total terpenoids, and total phenolics. Correlations between measurements of extracts’ phytoreductive characteristics were explained using Pearson coefficients. The results showed medium linear positive correlations for total tannins with the spectra of silver nanoparticle solutions. The antioxidant activity and total terpenoids presented medium linear negative correlations. Pearson coefficients between total phenolics and relative areas from ultraviolet–visible spectra from 350 to 600?nm were close to zero indicating no linear correlation.     

Chemometric Optimization of Biologically Active Compounds Extraction from Grape Marc: Composition and Antimicrobial Activity

The article focuses on the optimization of the extraction process of biologically active compounds (BAC) from grape marc—a by-product of the wine industry. The influence of temperature, specifically 30 °C, 45 °C and 65 °C, and ethanol concentration in solutions, specifically 0–96% (v/v) on the extraction yield of polyphenols, flavonoids, tannins and anthocyanins, were investigated. The composition of individual polyphenols, anthocyanins and organic acids, antioxidant activity (DPPH and ABTS) and CIELab chromatic characteristics of the grape marc extracts (GME), were characterized. The microbiostatic and microbicidal effects in direct contact of GME with pathogenic microorganisms, Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, were determined in vitro. The influence of extraction parameters on the total polyphenol content (TPC), total flavonoid content (TFC), tannin content (TC), total anthocyanin content (TAC) and their interdependencies were studied using information analysis. A mathematical model was developed on cubic spline functions. The analysis of individual compounds showed the presence of a wide range of flavonoids (procyanidin B2, procyanidin B1, hyperoside and quercetin), flavones (catechin), hydroxybenzoic acid derivatives (gallic, protocatechuic, p-hydroxybenzoic acids, m-hydroxybenzoic acid, syringic acid), hydroxycinic acid derivatives and ferulic acid methyl ester. The malvidol-3-glucoside was the main anthocyanin identified in the extract. A high amount of tartaric acid was also found. GME showed significant antimicrobial activity against Gram-positive bacteria and lower activity against Gram-negative bacteria.     

The Geometry of Systems of Third Order Differential Equations Induced by Second Order Regular Lagrangians

A system of third order differential equations, whose coefficients do not depend explicitly on time, can be viewed as a third order vector field, which is called a semispray, and lives on the second order tangent bundle. We prove that a regular second order Lagrangian induces such a semispray, which is uniquely determined by two associated Poincaré-Cartan one-forms. To study the geometry of this semispray, we construct a horizontal distribution, which is a Lagrangian subbundle for an associated Poincaré-Cartan two-form. Using this semispray and the associated nonlinear connection we define dynamical covariant derivatives of first and second order. With respect to this, the second order dynamical derivative of the Lagrangian metric tensor vanishes.