A label-free electrochemical biosensor based on 3D cubic Eu3+/Cu2O nanostructures with clover-like faces for the determination of anticancer drug cytarabine

The present research utilized a simplified procedure for developing a novel electro-chemical DNA biosensor based on a carbon paste electrode (CPE) modified with three-dimensional (3D) cubic Eu³⁺/Cu₂O nanostructures with clover-like faces (Eu³⁺/Cu₂O CLFNs). The modified electrode was applied to monitor electro-chemical interactions between dsDNA and cytarabine for the first time. Then, the decreased oxidation signal of guanine following the interactions between cytarabine and dsDNA was utilized as an indicator for selectively determining cytarabine using differential pulse voltammetry (DPV). According to the findings, the oxidation peak current of guanine was linearly proportionate with the cytarabine concentration in the range between 0.01 and 90 μM. Additionally, the limit of quantification (LOQ) and the limit of detection (LOD) respectively equaled 9.4 nM and 2.8 nM. In addition, the repeatability, applicability and reproducibility of this analysis to drug dosage forms and human serum samples were investigated. Furthermore, UV-vis spectroscopy, DPV, docking and viscosity measurements were applied to elucidate the interaction mechanism of dsDNA with cytarabine. It was found that this DNA biosensor may be utilized to sensitively, accurately and rapidly determine cytarabine.

Electrochemical biosensor based on three-dimensional (3D) cubic of Eu³⁺/Cu₂O with clover-like face nano-structures and ds-DNA modified carbon paste electrode for detecting cytarabine was fabricated.     

Tetrazol-Cu(i) immobilized on nickel ferrite catalyzed green synthesis of indenopyridopyrimidine derivatives in aqueous media

After the initial study of different protocols in the synthesis of indeno[2′,1′:5,6]pyrido[2,3-d]pyrimidines, herein, a new method is presented using cheaper and more accessible starting materials to produce high-efficiency products. In this protocol, the novel nanocatalyst is very effective in the progression of the reaction and increasing the efficiency. This green approach in aqueous media has several advantages as compared with other methods, such as easier work-up, very mild reaction conditions, reusability of the catalyst, and eco-friendliness. The products of this four-component condensation were evaluated using IR, ¹H NMR, ¹³C NMR spectra, and C. H. N. analyses, and the catalyst structure was confirmed by FT-IR, XRD, SEM, EDX, TGA and VSM techniques.

In this protocol, a novel nanocatalyst was very effective in progression of the reaction and increasing efficiency. This green approach in aqueous media has several advantages compared with the reported methods.     

CHA2DS2‐VASc and PESI scores are associated with right ventricular dysfunction on computed tomography pulmonary angiography in patients with acute pulmonary thromboembolism

BackgroundAccurate risk stratification is the most important step in the management of patients with acute pulmonary thromboembolism (PTE). Pulmonary embolism severity index (PESI) is a clinical tool for PTE risk stratification. CHA₂DS₂‐VASc score, a risk assessment tool in patients with atrial fibrillation, is recently considered for acute PTE. The presence of right ventricular (RV) dysfunction in imaging is more efficient in acute PTE risk evaluation.HypothesisThis study aims to evaluate the association between CHA₂DS₂‐VASc and PESI score and each of them with RV dysfunction on computed tomography pulmonary angiography (CTPA).MethodsOne hundred eighteen patients with a definite diagnosis of PTE were entered. The CHA₂DS₂‐VASc and PESI scores were calculated for all of them. RV dysfunction including an increase in RV to left ventricular diameter ratio, interventricular septal bowing, and reflux of contrast medium into the inferior vena cava was examined by CTPA.ResultsPESI and CHA₂DS₂‐VASc scores were significantly associated with RV dysfunction. In addition, different classes of PESI scores were correlated with RV dysfunction. Moreover, this study showed that the CHA₂DS₂‐VASc score and PESI score had a positive correlation. The area under the curve value for the CHA₂DS₂‐VASc score was 0.625 with 61.54% sensitivity and 60.0% specificity for predicting RV dysfunction while for PESI score was 0.635 with 66.7% sensitivity and 60.0% specificity.ConclusionThis study showed that not only CHA₂DS₂‐VASc and PESI scores are positively correlated, but they are both associated with RV dysfunction diagnosed by CTPA. CHA₂DS₂‐VASc and PESI scores are able to predict RV dysfunction.     

Effect of Thermomechanical Treatment of Al-Zn-Mg-Cu with Minor Amount of Sc and Zr on the Mechanical Properties

In this study, the mechanical and microstructural properties of Al-Zn-Mg-Cu-Zr cast alloy with 0.1% Sc under homogeneous, dissolution, and T6 and thermomechanical treatments with the aim of increasing the volume fraction of MgZn₂. Al₃(Sc,Zr) reinforcing precipitates were examined by hardness, microscopic examinations, tensile tests and software analysis. The results showed that, firstly, the hardness results are well proportional to the results of the tensile properties of alloys and, secondly, the strength of the alloy with thermomechanical treatments compared to T6 treatments increased from 492 MPa to 620 MPa and the elongation increased from 8% to 17% and was 100% upgraded. Microstructural and fracture cross section investigations showed that Al₃(Sc,Zr) nanosize dispersoids were evenly distributed among MgZn₂ dispersoids and the alloy fracture was of semi-ductile type and nanosize dispersoids less than 10 nm were observed at the end of the dimples in the fracture section. The volume fraction of nanosize dispersoids in the whole microstructure of thermomechanical treatment samples was also much higher than that of T6 heat treated samples, so that the percentage of Al₃(Sc,Zr) precipitates arrived from less than 1% in T6 operation to 8.28% in the quench-controlled thermomechanical operation (with 50% deformation). The quality index (QI) in thermomechanical treatment samples is 19% higher than T6 samples, so that this index has increased from 641 in T6 operation to 760 in samples under thermomechanical treatment due to precipitate morphology, volume fraction of precipitates, their uniform distribution in the matrix, and nano sized precipitates in samples under thermomechanical treatment.