Fabrication of an imprinted electrochemical sensor from l-tyrosine, 3-methyl-4-nitrophenol and gold nanoparticles for quinine determination.

This study employed a molecularly imprinted composite (MIC) to develop a selective and very sensitive sensor for the determination of quinine. To fabricate the MIC sensor, 3-methyl-4-nitrophenol (MNP) and L-tyrosine (Tyr) were simultaneously electrodeposited in acidic media containing HAuCl4 to entrap Au nanoparticles (AuNPs) into the formed composite network. The effect of Tyr on the sensitivity and selectivity of the sensor and its electrochemical performance were evaluated. The signal reduction of the Fe2+probe during differential pulse voltammetry (DPV) was used to determine the concentration of quinine. The signal was found to be linear over the quinine concentration range of 0.1 to 1000 pM with a detection limit of 0.05 pM. The sensor was used to determine the quinine content of several plasma and urine samples.

Very sensitive electrochemical determination of diuron on glassy carbon electrode modified with reduced graphene oxide-gold nanoparticle-Nafion composite film.

In this work, a very sensitive electrochemical sensor based on glassy carbon electrode (GCE) modified with reduced graphene oxide-gold nanoparticles/Nafion (rGO-AuNPs/Nafion) composite film was applied to determine diuron. Synthesized GO was characterized using X-ray diffraction (XRD) and UV-visible spectroscopy. The surface morphology of the rGO-AuNPs/Nafion film was also characterized using scanning electron microscopy and electrochemical impedance spectroscopy. Cyclic voltammetry (CV) and adsorptive differential pulse voltammetry (AdDPV) were applied to investigate the electrochemical response of the diuron on the modified electrode. The electrode showed a linear response at 1.0×10-9-1.0×10-7 M and a detection limit of 0.3nM under the optimized conditions. The effect of some other species on the determination of diuron was investigated and the sensor showed good selectivity for determination of diuron. The constructed sensor was applied to determine diuron in enriched samples of orange juice, mineral and tap water which statistical t-test showed accuracy of method. Also the sensor was applied to obtain diuron content in the tea sample. The reliability of the proposed sensor was confirmed after comparing the results with those obtained using high performance liquid chromatography (HPLC) as a comparative method.

A retrospective analysis of maxillofacial trauma in shiraz, iran: a 6-year- study of 768 patients (2004-2010).

STATEMENT OF PROBLEM: Information about the etiology and incidence of maxillofacial trauma is important for prevention and appropriate treatments of such injuries. PURPOSE: The purpose of this retrospective study was to conduct an analysis of maxillofacial injuries transferred and/or referred to the department of maxillofacial Surgery at Chamran emergency hospital, Shiraz, over a 6-year period with special reference to age, gender, occupation, date, type, site, etiology and clinical management. MATERIALS AND METHOD: The data for this study were collected and reviewed retrospectively from the records and radiographs of 768 patients who were treated for maxillofacial trauma in the department of maxillofacial surgery at the Shiraz Chamran Emergency Hospital, Iran, between 2004 and 2010. RESULTS: A total of 730 of the subjects were the patients with fractures of the facial skeleton. The mean age was 26.6± 12.6 years, ranging from 2 to 81 years. Traffic accident was the most frequent etiological factor of maxillofacial fractures irrespective of gender (69.9% for men and 54.2% for women), whereas the second most frequent cause of injuries was falling down (9.8% for men and 21.5% for women) .The other etiologies were assaults (5.2%), sport related injuries (1.3%) and firearm injuries (1%). Regarding the head injuries in patients with maxillofacial fractures, brain contusion was seen in 227(29.6%) patients and 13.5% of patients had lacerations in the facial soft tissue. The monthly distribution peaked in October, with 81 cases (10.5%), which would be for the reason that schools open in this month. The next highest incidence was in December, with 80 cases (10.4%), probably because of the changing weather's effect on road traffic. CONCLUSION: Isolated mandibular fracture due to the road traffic accident was the most common type of maxillofacial injuries in the city of Shiraz.

Effect of lullaby and classical music on physiologic stability of hospitalized preterm infants: a randomized trial.

BACKGROUND: Music is considered a subset of developmental supportive care. It may act as a suitable auditory stimulant in preterm infants. Also, it may reduce stress responses in autonomic, motor and state systems. OBJECTIVE: To assess and compare the influence of lullaby and classical music on physiologic parameters. METHOD: This is a randomized clinical trial with cross-over design. A total of 25 stable preterm infants with birth weight of 1000-2500 grams were studied for six consecutive days. Each infant was exposed to three phases: lullaby music, classical music, and no music (control) for two days each. The sequence of these phases was assigned randomly to each subject. Babies were continuously monitored for heart rate, respiratory rate, and oxygen saturation and changes between phases were analyzed. RESULT: Lullaby reduced heart rate (p < 0.001) and respiratory rate (p = 0.004). These effects extended in the period after the exposure (p < .001 and p = 0.001, respectively). Classical music reduced heart rate (p = 0.018). The effects of classical music disappeared once the music stopped. Oxygen saturation did not change during intervention. CONCLUSION: Music can affect vital signs of preterm infants; this effect can possibly be related to the reduction of stress during hospitalization. The implications of these findings on clinical and developmental outcomes need further study.

H-point standard addition method applied to simultaneous kinetic determination of antimony(III) and antimony(V) by adsorptive linear sweep voltammetry.

In this work, the applicability of H-point standard addition method (HPSAM) to the kinetic voltammetry data is verified. For this purpose, a procedure is described for the determination of Sb(III) and Sb(V) by adsorptive linear sweep voltammetry using pyrogallol as a complexing agent. The method is based on the differences between the rate of complexation of pyrogallol with Sb(V) and Sb(III) at pH 1.2. The results show that the H-point standard addition method is suitable for the speciation of antimony. Sb(III) and Sb(V) can be determined in the ranges of 0.003-0.120 and 0.010-0.240 microg mL(-1), respectively. Moreover, the solution is analyzed for any possible effects of foreign ions. The obtained results show that the HPSAM in combination to electroanalytical techniques is a powerful method with high sensitivity and selectivity. The procedure is successfully applied to the speciation of antimony in water samples.

Prediction of lambda(max) of 1,4-naphthoquinone derivatives using ant colony optimization.

Ant colony optimization (ACO) is a meta-heuristic algorithm, which is derived from the observation of real ants. In this paper, ACO algorithm is proposed to feature selection in quantitative structure property relationship (QSPR) modeling and to predict lambda(max) of 1,4-naphthoquinone derivatives. Feature selection is the most important step in classification and regression systems. The performance of the proposed algorithm (ACO) is compared with that of a stepwise regression, genetic algorithm and simulated annealing methods. The average absolute relative deviation in this QSPR study using ACO, stepwise regression, genetic algorithm and simulated annealing using multiple linear regression method for calibration and prediction sets were 5.0%, 3.4% and 6.8%, 6.1% and 5.1%, 8.6% and 6.0%, 5.7%, respectively. It has been demonstrated that the ACO is a useful tool for feature selection with nice performance.

Mean centering of ratio kinetic profiles for the simultaneous kinetic determination of binary mixtures in electroanalytical methods.

In this work, the applicability of mean centering (MC) of ratio kinetic profiles method to the kinetic voltammetry data is verified. For this purpose, a procedure is described for the determination of Sb(III) and Sb(V) by adsorptive linear sweep voltammetry using pyrogallol (py) as a complexing agent. The method is based on the differences between the rate of complexation of pyrogallol with Sb(V) and Sb(III) at pH 1.2. The results show that the mean centering of ratio kinetic profiles method is suitable for the speciation of antimony. Sb(III) and Sb(V) can be determined in the ranges of 3.0-120.0 and 10.0-240.0 ng mL(-1), respectively. Moreover, the solution is analyzed for any possible effects of foreign ions. The obtained results show that the method of MC in combination to electroanalytical techniques is a powerful method with high sensitivity and selectivity. The procedure is successfully applied to the speciation of antimony in pharmaceutical preparations.

Simultaneous spectrophotometric determination of iron, nickel and cobalt in micellar media by using direct orthogonal signal correction-partial least squares method.

A very simple and selective spectrophotometric method for simultaneous determination of iron(II), nickel(II) and cobalt(II) based on formation of their complexes with 1-(2-pyridylazo)-2-naphtol (PAN) in micellar media is described. Although the complexes of Fe(II), Ni(II) and Co(II) with reagent show a spectral overlap, they have been simultaneously determined by partial least squares (PLS) with and without preprocessing step using direct orthogonal signal correction (DOSC). The linear range was 0.30-4.50 microg ml(-1) for Co(II), 0.20-3.00 microg ml(-1) for Ni(II) and 0.30-5.00 microg ml(-1) for Fe(II). The results obtained by the PLS and DOSC-PLS were statistically compared. Interference effects of common anions and cations were studied and the proposed method was also applied satisfactorily to the determination of Fe(II), Ni(II) and Co(II) in synthetic samples.

Catalytic adsorptive stripping voltammetry determination of ultra trace amount of molybdenum using factorial design for optimization.

A highly sensitive procedure is presented for the determination of ultra-trace concentration of molybdenum by catalytic adsorptive stripping voltammetry. The method is based on adsorptive accumulation of the molybdenum (Mo)-pyrocatechol violet (PCV) complex on to a hanging mercury drop electrode, followed by reduction of the adsorbed species by voltammetric scan using differential pulse modulation. The reduction current is enhanced catalytically by chlorate. The influence of variables was completely studied by factorial design analysis. Optimum analytical conditions for the determination of molybdenum were established. Molybdenum can be determined in the range 1.0x10(-3)-100.0ngml(-1) with a limit of detection of 0.2pgml(-1). The influence of potential interfering ions on the determination of molybdenum was studied. The procedure was applied to the determination of molybdenum in mineral water and some analytical grade substances with satisfactory results.

Simultaneous determination of Fe(II) and Fe(III) in pharmaceutical formulations with chromogenic mixed reagent by using principal component artificial neural network and multivariate calibration.

The use of chemometric approaches for the simultaneous determination of Fe(II) and Fe(III) ions has been explored by means of a two component reagent. Mixed reagents of 1,10-phenanthroline and thiocyanate were used as a selective chromogenic system for speciation of Fe(II) and Fe(III). Although the complexes of Fe(II) and Fe(III) with mixed reagent show a spectral overlap, they have been simultaneously determined with chemometric approaches, such as principal component artificial neural network (PC-ANN), principal component regression (PCR) and partial least squares (PLS). A set of synthetic mixtures of Fe(II) and Fe(III) was evaluated and the results obtained by the applications of these chemometric approaches were discussed and compared. It was found that the PC-ANN and PLS methods afforded better precision relatively than its of PCR. PC-ANN and PLS methods were also applied satisfactorily in determination of Fe(II) and Fe(III) in pharmaceutical samples.

Simultaneous determination of trace amounts of cadmium, nickel and cobalt in water samples by adsorptive voltammetry using ammonium 2-amino-cyclopentene dithiocarboxylate as a chelating agent.

This paper reports the use of an adsorptive voltammetric technique for the simultaneous detection of Cd(II), Ni(II) and Co(II) using ammonium 2-amino-cyclopente dithiocarboxylate as a selective complexing agent. Scans containing three resolved peaks corresponding to these metals were obtained in synthetic and real samples. The reduction current peaks of the metals that were distinctly separated by 200 mV or more, allowing their determination over a wide range of concentrations. These metals can be quantified at concentrations above 1.33x10(-8) mol dm(-3) Cd(II), 8.51x10(-9) mol dm(-3) Ni(II) and 3.39x10(-10) mol dm(-3) Co(II). The influence of pH, ligand concentration, scan rate, accumulations time and applied potential was investigated. The R.S.D. at a concentration level of 1.78x10(-7) mol dm(-3) of Cd(II), 3.40x10(-7) mol dm(-3) and Ni(II) and 1.7x10(-9) mol dm(-3) of Co(II) was 2.5% for Cd(II), 2.7% for Ni(II) and 3.3% for Co(II). The method was applied to various water samples.