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Thymol has antioxidant, apoptotic, anti-cancer and, anti-inflammatory properties. In this study iron oxide nanoparticles were synthetized by chemical co-precipitation method, then coated with albumin and finally loaded with thymol. The properties and characteristics of these composites were investigated by x-ray diffraction (XRD), TEM, FTIR, FE-SEM, DLS, zeta potential techniques and, vibrating-sample magnetometry (VSM). Finally, the release and encapsulation behavior of these compounds was calculated. The anti-cancer effect of thymol loaded albumin-coated Fe3O4 nanoparticles were investigated by the MTT method. The rate of apoptosis was assessed by Flow Cytometry test, while BAX and BCL2 were assessed by ELISA test. Expression of the MAP1LC3A gene was also examined by the real-time PCR technique. The results of MTT, ELISA, Flow Cytometry, and, real-time PCR techniques showed that thymol loaded albumin-coated Fe3O4 nanoparticles at concentration of 150 μg/mL for 72-hour treatment most significantly affected cytotoxicity, apoptosis and, autophagy. Hence, this compound probably exhibited anti-cancer effect on the MDA-MB-231 cell line by activating the autophagy and apoptosis pathways. [ABSTRACT FROM AUTHOR]

The Chromazurol s has been electropolymerized on the glassy carbon electrode and the Poly- Chromazurol s modified glassy carbon electrode (PCSMGCE) has shown excellent electrocatalytic activity toward the oxidation of ascorbic acid in phosphate buffer solution (pH=3). It was used for the simultaneous determination of ascorbic acid (AA), dopamine (DA), and uric acid (UA). Analytical parameters were optimized and electrochemical behavior of modified electrode was studied. The calibration curves were obtained over the range of 3.0-2200.0 µmol Lâ1 AA, 0.09-980.0 µmol Lâ1 DA, and 0.05-900.0 µmol Lâ1 UA. Detection limits of 1.7 µmol Lâ1 AA, 0.05 µmol Lâ1 DA, and 0.03 µmol Lâ1 UA were obtained at pH 3.0. Prepared modified electrode had satisfactory results for determination of DA, AA and UA in dopamine injection solution, vitamin C tablets and human urine samples.

A sensitive and selective procedure is presented for voltammetric determination of cobalt. The procedure involves an adsorptive accumulation of cobalt pyrogallol red (PGR) complex on stationary mercury drop electrode, followed by cathodic stripping voltammetry measurement of reduction current of adsorbed complex at -1.17 V (vs. Ag/AgCl). The optimum conditions for determination of cobalt include pH 11.0, 35 μM pyrogallol red, an accumulation potential of -0.9 V (vs. Ag/AgCl) and scan rate 80 mVs-1. The peak current is proportional to the concentration of cobalt over the concentration range of 5.0 to 280 ng mL-1 with a detection limit of 1 ng mL-1 with an accumulation time of 140 s. The method was applied for the determination of cobalt in analytical grade NaCl and water samples.

A carbon paste electrode modified with multiwall carbon nanotubes (MWCNTPE) was prepared to study the electrocatalytic activity of dopamine (DP) in the presence of homocysteine (HCy) and it was used for determination of HCy. The diffusion coefficient of HCy (D = 6.79×10−6 cm2 s−1), and the kinetic parameters of its oxidation such as electron transfer coefficient (α = 0.46), and rate constant (kh = 7.44×102 dm3 mol-1 s-1) were also determined using electrochemical approaches. Under the optimum pH of 5.0, the peak current of oxidation of HCy at MWCNTPE in the presence of DP occurs at a potential about 530 mV and the results showed that the oxidation peak current of HCy at the modified carbon nanotubes electrode was higher than on unmodified electrode. The peak current of differential pulse voltammograms of HCy solutions increased linearly in the range of 3.0-600.0 μM HCy with the detection limit of 2.08 μM HCy. This method was also examined for determination of HCy in physiological serum and urine samples.

A color changeable optode for thallium(III) ions in aqueous solutions was prepared by physical inclusion of 4-(2-pyridylazo)-resorcinol into a plasticized PVC film. The increase in the absorbance of the optode at 524 nm is proportional to thallium(III) concentration. Different parameters effecting the sensitivity such as sample parameters and composition of the membrane were optimized. The response times of the prepared test-system are found to be 230, 210, and 180 s for 4.8 x [10.sup.-6], 4.8 x [10.sup.-5], and 4.8 x [10.sup.- 4] M Tl(III), respectively. The analytical performance of the optode was evaluated, obtaining a linear concentration range of two decades of concentration, 3.1 x [10.sup.-6] - 4.7 x [10.sup.-4] M Tl(III), with a limit of detection of 1.8 x [10.sup.-6] M Tl(III). Selectivity of the optode is also studied. Application of the optode to the determination of Tl(III) in some aqueous samples yields good results. Keywords: optical test-system, thallium determination, resorcinol derivative, spectrphotometry DOI: 10.1134/S1061934814020026, Recent decades have shown an increase in the development of optical chemical sensors as viable alternatives to other types of sensors. Such optical chemical sensors being termed 'optodes' or 'optrodes.' [...]

Immobilization of microbial cells on insoluble matrix has led to the stable performance of microorganisms in the petroleum industry. A novel floating polymer with very high potential was synthesized in the factory for cell life promotion and oil degradation. The entrapped cells of the novel and indigenous crude oil degrading bacterium, Klebsiella variicola strain SKV2 were analyzed by scanning electron microscope and the gas chromatography-mass spectrometry (GC-MS) analyses for crude oil degradation. The results showed that the efficiency of the biodegradation of crude oil on the one hand and the durability and microbial stability on the other hand were different in the two types of substrates used for fixation. GC-MS analysis showed that the maximum bioremediation efficiency of crude oil by the novel and indigenous K. variicola strain SKV2 free cells was 93.3% for 3 weeks. The biodegradation of crude oil was carried out completely and unprecedentedly, and thus 71.87% of crude oil components were completely deleted in the new method including microcapsules of agar and paraffin. The bioremediation of crude oil was 44.31% for scaffolds made of polyurethane polymer, while the cells were alive for more than 6 months in these scaffolds. [ABSTRACT FROM AUTHOR]

Mg-Al-LDH@MgFe2O4 nanocomposite was synthesized and was applied to enhance efficiency of gold micron-dendrites/glassy carbon electrode (Mg-Al-LDH@MgFe2O4/AuNDs/GCE) for oxidation of ethanol. Based on the results, Mg-Al-LDH@MgFe2O4/AuNDs showed a current density of 29.4 mA cm − 2 , which was 1.6 times higher than that on the surface of AuNDs/GCE. Also, long-term stability of the studied electrode showed that the nanocomposite improves CO-poisoning tolerance of the AuNDs. Accordingly, the Mg-Al-LDH@MgFe2O4/AuNDs catalyst exhibits an excellent potential for application in alkaline ethanol fuel cells. In this work, the Mg-Al-LDH@MgFe2O4 was synthesized and deposited on the glassy carbon electrode which modified with Au nanoparticles. Electrocatalytic effect of modified electrode for the oxidation of ethanol was investigated. The obtained current density on the modified electrode increased about 1.6 times. [ABSTRACT FROM AUTHOR]

Abstract: A new optical sensor for mercury(II) ions is developed based on immobilization of 4-(2-pyridylazo)-resorcinol (PAR) on a triacetylcellulose membrane. Chemical binding of Hg2+ ions in solution with a PAR immobilized on the triacetylcellulose surface could be monitored spectrophotometrically at 525nm. The optode shows excellent response over a wide concentration range of 5–3360μM Hg(II) with a limit of detection of 1.5μM Hg(II). The influence of factors responsible for the improved sensitivity of the sensor were studied and identified. The response time of the optode was 20min for a stable solution, and was 15min for a stirrer solution. The influence of potential interfering ions on the determination of 5×10−5 M Hg(II) was studied. The sensor was applied for determination of Hg(II) in water samples. [Copyright &y& Elsevier]