Chemical characterization and anti-breast cancer effects of silver nanoparticles using Phoenix dactylifera seed ethanolic extract on 7,12-Dimethylbenz[a] anthracene-induced mammary gland carcinogenesis in Sprague Dawley male rats

The aim of the recent research was to investigate the anti-breast cancer effects of silver nanoparticles using Phoenix dactylifera seed ethanolic extract (AgNPs). After preparation of Phoenix dactylifera seed extract, GC/MS was performed to detect the compounds. The findings indicated that 9-Octadecenoic acid (Z)- methyl ester (40.95%) and Dodecanoic acid methyl ester (20%) were the most frequent constituents found in P. dactylifera. These nanoparticles were spherical with a size range of 17-19 nm and characterized using various analytical techniques including UV–Vis absorption spectroscopy to determine the presence of AgNPs in the solution. We studied functional groups of P. dactylifera extract in the reduction and capping process of AgNPs by FT-IR, crystallinity and FCC planes by X-ray diffraction (XRD) pattern and surface morphology, shapes, and size of AgNPs by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). DPPH free radical scavenging test was used to test the antioxidant properties of P. dactylifera and AgNPs, which revealed high antioxidant potential similar to butylated hydroxy toluene (BHT) as the positive control. The results of cytotoxicity analysis indicated that P. dactylifera and AgNPs were toxic for MCF-7 cells. In vivo design, induction of breast cancer was done by 7,12-Dimethylbenz[a] anthracene (DMBA) in 50 animals. After 10 days, the animals were randomly divided into six subgroups, including healthy control, untreated control, two groups receiving the P. dactylifera at 2 and 6 mg/kg and two groups receiving the AgNPs at 2 and 6 mg/kg concentrations. Both doses of P. dactylifera and AgNPs (especially AgNPs6) significantly (p ≤ 0.05) reduced the weight and volume of liver, mammary gland, kidney, spleen, ALP, AST, ALT, GGT, cholesterol, LDL, triglyceride, total and conjugated bilirubin, urea, creatinine, glucose, ferrous, ferritin, erythropoietin, GR, IL1, IL6, IL12, IL18, IFNY, and TNFα and increased HDL, total protein, albumin, WBC, lymphocyte, neutrophils, platelet, RBC, Hb, PCV, MCV, MCH, MCHC, SOD, CAT, GPx, IL4, IL5, IL10, IL13, and IFNα compared to the untreated group. Moreover, P. dactylifera and AgNPs (especially AgNPs6) significantly (p ≤ 0.05) treated breast cancer with reduction of organs free of metastasis compared to the untreated group. Seemingly, the AgNPs can be used for the treatment of breast cancer.     

Study of the effect of the ligand structure on the catalytic activity of Pd@ ligand decorated halloysite: Combination of experimental and computational studies

Taking advantage of computational chemistry, the best diamine for the synthesis of a multi‐dentate ligand from the reaction with 3‐(trimethoxysilyl) propylisocyanate (TEPI) was selected. Actually, predictive Density Functional Theory (DFT) calculations provided the right diamino chain, i.e. ethylenediamine, capable to sequester a palladium atom, together with the relatively polar solvent toluene, and then undergo the experiments as a selective catalytic agent. The ligand was then prepared and applied for the decoration of the halloysite (Hal) outer surface to furnish an efficient support for the immobilization of Pd nanoparticles. The resulting catalyst exhibited high catalytic activity for hydrogenation of nitroarenes. Moreover, it showed high selectivity towards nitro functional group. The study of the catalyst recyclability confirmed that the catalyst could be recycled for several reaction runs with only slight loss of the catalytic activity and Pd leaching. Hot filtration test also proved the heterogeneous nature of the catalysis.     

Kinetic spectrophotometric determination of sulfide, using in-cuvette mixing and titration techniques with computerized data acquisition

In-cuvette mixing and titration techniques have been used for the kinetic determination of sulfide based on its inhibition effect on the oxidation of indigo carmine with hexacyanoferrate(III) in the presence of silver. The reaction was monitored spectrophotometrically by measuring the decrease in absorbance of indigo carmine at 612 nm. Both initial rate and fixed-time methods were applied to the in-cuvette technique. Using in-cuvette mixing, sulfide up to 1800 ng was determined and detection limit and relative standard deviation for the determination of 120 ng of sulfide were calculated as 23.0 ng and 1.59%, respectively. On the basis of the titration technique, the upper limit of determination was 25 μg of sulfide and detection limit and average relative standard deviation for the determination of 1 μg of sulfide were 0.025 μg and 4.95%, respectively. The effect of foreign ions on the sulfide determination was studied. The proposed methods were applied to the determination of sulfide in water.     

Prussian Blue Modified Carbon Ionic Liquid Electrode: Electrochemical Characterization and Its Application for Hydrogen Peroxide and Glucose Measurements

Prussian blue modified carbon ionic liquid electrodes (PB‐CILEs) were fabricated using chemical and electrochemical procedures. Chemically fabricated PB‐CILE exhibited an excellent sensitivity (0.0866 μA μM^?1), low detection limit (0.01 μM) and two linear ranges (0.01–1 and 1–600 μM) toward hydrogen peroxide. Then, glucose oxidase (GOx) was immobilized on the surface of PB‐CILE to fabricate glucose biosensor using three different procedures involving cross linking with glutaraldehyde (GLU) and bovine serum albumin (BSA), entrapment into the Nafion matrix and covering with a sol‐gel layer. Glucose biosensor fabricated using cross linking procedure showed the best sensitivity (0.0019 μA μM^?1) and operational stability for glucose.     

Flow injection chemiluminescence analysis of phenolic compounds using the NCS-luminol system

A flow injection system coupled with two simple and sensitive chemiluminescence (CL) methods is described for the determination of some phenolic compounds. The methods are based on the inhibition effects of the investigated phenols on the CL signal intensities of N-chlorosuccinimide-KI-luminol (NCS-KI-luminol) and NCS-luminol systems. The influences of the chemical and hydrodynamic parameters on the decrease in CL signal intensities of NCS-KI-luminol and NCS-luminol systems for hydroquinone, catechol, and resorcinol, serving as the model compounds of analyte, were studied in the flow injection mode of analysis. Under the selected conditions, the proposed CL systems were used for the determination of some phenolic compound and analytical characteristics of the systems including calibration equation, correlation coefficient, linear dynamic range, limit of detection, and sample throughput. The limits of detection for hydroquinone, catechol, and resorcinol were 0.002, 0.01, and 0.3 μM using the NCS-KI-luminol system; for the NCS-luminol system these were 0.01, 0.17, and 1.6 μM, respectively. The relative standard deviation for 10 repeated measurements of 0.04, 0.06, and 1 μM of hydroquinone, catechol, and resorcinol were 1.9, 1.4, and 2.0%, respectively, with the NCS-KI-luminol system; for 0.2, 0.5, and 4 μM of hydroquinone, catechol, and resorcinol these were 2.6, 2.2, and 3.7%, respectively, using the NCS-luminol system. The method was applied to the determination of catechol in known environmental water samples with a relative error of less than 6%. A possible reaction mechanism of the proposed CL system is discussed briefly.      

Scale up and Application of Biosurfactant from <Emphasis Type="Italic">Bacillus subtilis</Emphasis> in Enhanced Oil Recovery

There is a lack of fundamental knowledge about the scale up of biosurfactant production. In order to develop suitable technology of commercialization, carrying out tests in shake flasks and bioreactors was essential. A reactor with integrated foam collector was designed for biosurfactant production using Bacillus subtilis isolated from agricultural soil. The yield of biosurfactant on biomass (Y _p/x), biosurfactant on sucrose (Y _p/s), and the volumetric production rate (Y) for shake flask were obtained about 0.45 g g⁻¹, 0.18 g g⁻¹, and 0.03 g l⁻¹ h⁻¹, respectively. The best condition for bioreactor was 300 rpm and 1.5 vvm, giving Y _x/s, Y _p/x, Y _p/s, and Y of 0.42 g g⁻¹, 0.595 g g⁻¹, 0.25 g g⁻¹, and 0.057 g l⁻¹ h⁻¹, respectively. The biosurfactant maximum production, 2.5 g l⁻¹, was reached in 44 h of growth, which was 28% better than the shake flask. The obtained volumetric oxygen transfer coefficient (K _L a) values at optimum conditions in the shake flask and the bioreactor were found to be around 0.01 and 0.0117 s⁻¹, respectively. Comparison of K _L a values at optimum conditions shows that biosurfactant production scaling up from shake flask to bioreactor can be done with K _L a as scale up criterion very accurately. Nearly 8% of original oil in place was recovered using this biosurfactant after water flooding in the sand pack.     

Sequential flow injection analysis of ammonium and nitrate using gas phase molecular absorption spectrometry

A flow injection method on the basis of gas phase molecular absorption is described for the sequential determination of ammonium and nitrate. Two hundred microliters of sample solution is injected into the flow line. For ammonium determination, the sample zone is directed to a line in which reacts with NaOH (13 M) and produces ammonia. But for nitrate determination, the sample zone is passed through the on-line copperized zinc (Zn/Cu) reduction column and produces ammonium ion and in the follows ammonia. The produced ammonia in both cases is purged into the stream of N₂ carrier gas. The gaseous phase is separated from the liquid phase using a gas-liquid separator and then is swept into a flow through cell, which has been positioned in the cell compartment of an UV-Vis spectrophotometer. The absorbance of the gaseous phase is measured at 194 nm. Under selected conditions for sequential analysis of ammonium and nitrate, linear relations were found between the peak heights of absorption signals and concentrations of ammonium (10-650 μg ml⁻¹) and nitrate (20-800 μg ml⁻¹). The limit of detections for ammonium and nitrate analysis were 8 and 10 μg ml⁻¹, respectively. The relative standard deviations of repeated measurements of 50 μg ml⁻¹ of ammonium and nitrate were 2.0, 2.9%, respectively. Maximum sampling rate was about 40 samples/h. The method was applied to the determination of ammonium in pharmaceutical products and the sequential determination of ammonium and nitrate in spiked water samples.     

Darstellung und Eigenschaften von tetragonalen α-Di(phthalocyaninato(1−))-praseodym(III)-polyhalogeniden; Kristallstruktur von α-[Pr(Pc−)2]Br1,5

Preparation and Properties of Tetragonal α-Di(phthalocyaninato(1?))praseodymium(III)-polyhalides; Crystal Structure of α-[Pr(Pc^?)₂]Br_1.5 Brown red di(phthalocyaninato(1?))-praseodym(III)-polyhalides [Pr(Pc^?)₂]X_y (X = Br, I) of variable composition (1 ≤ y ≤ 2.5) are formed by (electro)chemical oxidation of [Pr(Pc^2?)₂]^?. The thermical decomposition of these polyhalides at 250°C yields partially oxidized, green α-[PrPc^?Pc^2?]. Due to strong spin–spin coupling of the phthalocyanin-π-radicals only Pr^III contributes to the magnetic moment of ca. 3.0 B.M. for all complexes. Green metallic prisms of [Pr(Pc^?)₂]Br_1.5 crystallize in the tetragonal α-modification: space group P4/nnc with a = 19.634(5) Å, c = 6.485(2) Å; Z = 2. In the sandwich complex Pr^III is eightfold coordinated by the isoindoline N-atoms of the two staggered (41°), nearly planar Pc^?- ligands. The quasi-onedimensional character of the structure along [001] is due to the infinite columns of Pc^? ligands. The superperiod along [001] is a consequence of the distribution of the Pr atoms onto two incompletely filled crystallographic positions at a distance of c/2 and the disordered chains of the bromine atoms extending in the same direction. Powder diffractograms of Pr(Pc )₂Br2, [Pr(Pc^?)₂]I₂ und [PrPc Pc^2?] confirm the tetragonal α-modification of these complexes, too. The content of tribromide correlates with the population of the Pr(2)-site. In the UV-VIS-NTR absorption spectrum of a thin film of Pr(Pc )₂Br, the intense bands at 13.9 and 19.5 kK are assigned to the B and Q transition, respectively. The D band at 9. kK is characteristic for isolated dimeric Pc^?-π-radicals. Due to increasing electron delocalisation as a result of the growing columns the D band is shifted to lower energy appearing successively at 6.05 and 3.3 kK. The mir and resonance Raman (RR) spectra of α-[Pr(Pr^?)₂]X_y, (X = Br, I) show the well known diagnostic bands for Pc^?-π-radicals. Thc RR spectrum of the polyiodide is dominated by the overtone progression of the totally symmetric (I-I) stretching vibration of the triiodide at 108cm^?1. The FT-Raman spectra are also marked by the totally symmetric stretching vibration of the polyhalides (Br₃ : 145cm ¹; 1₃^?:105cm^?1; I₅^? 151 cm^?1).     

Carbon Ceramic Electrodes Modified with Laccase from Trametes hirsuta: Fabrication,Characterization and Their Use for Phenolic Compounds Detection

Fungal laccase (Lc) from the basidiomycete Trametes hirsuta was immobilized on top of a carbon ceramic electrode using physical absorption. Direct, unmediated heterogeneous electron transfer between Lc and the carbon ceramic electrode (CCE) under aerobic conditions was shown. The bioelectrocatalytic reduction of oxygen on Lc‐CCE started at about 430 mV vs. Ag|AgCl|KCl_sat at pH 3.5 and moved with about 57 mV in the cathodic region per pH unit. The Lc‐modified CCE was then used as a biosensing detection element in a single line flow injection system for the amperometric determination of a variety of phenolic substrates of the enzyme. The experimental conditions were studied and optimized for catechol serving as a model compound. Statistical aspects were applied and the sensor characteristics and Michaelis‐Menten constants of the investigated phenolic compounds were calculated and compared with those obtained for solid graphite electrodes modified with Trametes hirsuta laccase. The results showed that the CCE based biosensor in comparison with the solid graphite based biosensor offers a lower detection limit, a wider linear dynamic range, and excellent operational stability with no sensor passivation, indicating that the sol–gel lattice improves the electrochemical behavior of the biosensor.     

Characterization of graphite electrodes modified with laccase from Trametes versicolor and their use for bioelectrochemical monitoring of phenolic compounds in flow injection analysis

Spectrographic graphite electrodes were modified through adsorption with laccase from Trametes versicolor. The laccase-modified graphite electrode was used as the working electrode in an amperometric flow-through cell for monitoring phenolic compounds in a single line flow injection system. The experimental conditions for bioelectrochemical determination of catechol were studied and optimized. The relative standard deviation of the biosensor for catechol (10 μM, n=12) was 1.0% and the reproducibility for six laccase-modified graphite electrodes, prepared and used different days was about 11%. The optimal conditions for the biosensor operation were: 0.1 M citrate buffer solution ( at pH 5.0), flow rate of 0.51 ml min⁻¹ and a working potential of −50 mV versus Ag|AgCl. At these conditions the responses of the biosensor for various phenolic compounds were recorded and the sensor characteristics were calculated and compared with those known for biosensors based on laccase from Coriolus hirsutus, cellobiose dehydrogenase (CDH) from Phanerochaete chrysosporium and horseradish peroxidase (HRP).