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Magnetite (Fe3O4) nanoparticles have been successfully prepared by a novel one-step and surfactant-free approach utilizing ferrous ion, as a single iron source. In this manner, the reaction occurs between two aqueous solutions via the spontaneous transfer of ammonia gas from one to another in room temperature. No ferric source or oxidizing specie, oxidation controlling and capping agents are needed and the method is suited for large-scale preparation. The effects of reaction conditions on the formation of Fe3O4 were investigated using powder X-ray diffraction (XRD), Fourier transformation infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) techniques. The results have demonstrated that the pure and single phase magnetite nanoparticles were synthesized at the final pH values higher than 8. Accordingly, the formation mechanism of these nanostructures is proposed. Moreover, the vibrating sample magnetometry (VSM) measurements of the as-synthesized nanoparticles show their room temperature superparamagnetic characteristic with a typical saturation magnetization of 51 emug−1.

Abstract  A new salicylate-selective electrode based on the complex (2,3;6,7;10,11;14,15-tetraphenyl-4,9,13,16-tetraoxo-1,5,8,12-tetraazacyclohexadecane) copper(II) [CuL] as the membrane carrier was developed. The electrode exhibits a good Nernstian slope of −60.9 ± 1.0 mV/decade and a linear range from 1.0 × 10−6 to 1.0 × 10−1 M for salicylate. The detection limit is 5.0 × 10−7 M. The electrode has a fast response time (5–15 s) and can be used for more than three months. The selective coefficients were determined by the fixed interference method (FIM) and separate solution method (SSM). The salicylate-selective electrode could be used in the pH range 3.5–10.5. It was employed as an indicator electrode for direct determination of salicylate in pharmaceutical samples. [ABSTRACT FROM AUTHOR]

A fluorescence probe was designed using a nitrogen-contained mesoporous hyper-cross-linked polymer precursor (NH 2 -HCP) in order to selectively detect silver (Ag + ) ions. NH 2 -HCP exhibits fluorescence intensity, but upon the addition of Ag + , a significant enhancement in fluorescence signal is observed. The relationship between fluorescence intensity enhancement and Ag + concentration shows a linear and monotonic trend. The probe's response to various other cations such as Al 3+ , Fe 3+ , Cd 2+ , Ni 2+ , Cu 2+ , Fe 2+ , Hg 2+ , Mg 2+ , Zn 2+ , Pb 2+ , Mn 2+ , Co 2+ , Ca 2+ , Na + , and K + , as well as halogen anions like F - , Cl - , Br - , and I - was also investigated. Under optimal conditions, the probe demonstrated a linear range of 0.1-3 μM and a detection limit of 0.01 μM., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The meta-phenylenediamine polymer, when hyper-cross-linked, exhibits a minimal fluorescence intensity. However, the introduction of silver ions induces a significant increase in intensity, attributed to the plasmonic effect. This heightened intensity is selectively increased more upon the addition of thiosulfate ions. Capitalizing on this property, a fluorescence probe was developed. The correlation between fluorescence intensity reduction and S 2 O 3 2- concentration follows a linear and consistent pattern. The precursor's response to diverse anions such as SO 4 2- , CO 3 2- , HPO 4 2- , Cr 2 O 7 2- , F - , Cl - , Br - , I - , H 2 PO 4 - , CH 3 COO - , NO 3 - , ClO - , and HCO 3 - was also examined. Under optimal conditions, the probe exhibited a linear range of 0.5-3 µM with a detection limit of 0.01 µM. Its effectiveness was demonstrated in measuring thiosulfate concentrations in aqueous media., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Zinc oxide nanosheets (ZnONSs) were successfully synthesized using Zn(NO3)2·4H2O as the starting reagent in ammonia atmosphere at room temperature by a novel gas-solution precipitation method. XRD and EDS patterns indicated that pure ZnONSs were produced only in 15min reaction time. Besides, investigating the optical properties of the as-prepared ZnO nanosheets using UV-Vis diffused reflectance spectroscopy (DRS) exhibited their semiconducting property by revealing one optical band gap in 3.3eV. Moreover, rhodamine B and methylene blue degradation were used as a probe reaction to test the as-synthesized ZnONSs photoactivity. Furthermore, a possible reaction mechanism for ZnONSs formation was discussed. On the other hand, operation of ZnONSs in Dye-sensitized solar cell (DSSC) was investigated by current density-voltage (Jsc-Voc) curve. Finally, a pencil graphite electrode was decorated using ZnONSs and pure MWCNT to provide an electrochemical device for Pb(+2) ions sensing. This modified electrode showed agreeable responses to trace amounts of Pb(+2) in NaOAC/HOAC buffer solutions. The limit of detection was found to be 0.112nmolL(-1) for Pb(+2)., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Background: There is a great amount of literature concerning the effect of racial segregation on health outcomes but few papers have discussed the effect of segregation on the basis of social, demographic and economic characteristics on health. We estimated the independent effect of segregation of determinants of socioeconomic status on infant mortality in Iranian population., Methods: For measuring segregation, we used generalized dissimilarity index for two group and multi group nominal variables and ordinal information theory index for ordinal variables. Sample data was obtained from Iranian latest national census and multilevel modeling with individual variables at level one and segregation indices measured at province level for socioeconomic status variables at level two were used to assess the effect of segregation on infant mortality., Results: Among individual factors, mother activity was a risk factor for infant mortality. Segregated provinces in regard to size of the house, ownership of a house and motorcycle, number of literate individual in the family and use of natural gas for cooking and heating had higher infant mortality. Segregation indices measured for education level, migration history, activity, marital status and existence of bathroom were negatively associated with infant mortality., Conclusion: Segregation of different contextual characteristics of neighborhood had different effects on health outcomes. Studying segregation of social, economic, and demographic factors, especially in communities, which are racially homogenous, might reveal new insights into dissimilarities in health.

A new sulfate-selective electrode based on the complex N,N'-bis(2-amino-1-oxo-phenelenyl)phenylenediamine copper(II) (CuL) as the membrane carrier was developed. The electrode exhibited a good Nernstian slope of -29.5 +/- 0.5 mV/decade and a linear range of 1.0 x 10(-7) - 1.0 x 10(-1) M for sulfate. The limit of detection was 1.0 x 10(-8) M. It has a fast response time of 10 s and can be used for more than three months. The selective coefficients were determined by the fixed interference method (FIM). The electrode could be used in the pH range 3.5 - 8.0. It was employed as an indicator electrode for direct determination of sulfate in pharmacy and cement samples.