Structural, Optical and Electrical Properties of Cu0.6CoxZn0.4-xFe2O4 (x = 0.0, 0.1, 0.2, 0.3, 0.4) Soft Ferrites.

A series of cobalt-inserted copper zinc ferrites, Cu0.6CoxZn0.4-xFe2O4 (x = 0.0, 0.1, 0.2, 0.3, 0.4) having cubic spinel structure were prepared by the coprecipitation method. Various characterization techniques, including XRD, FTIR, UV-vis and I-V were used to investigate structural optical and electrical properties, respectively. The lattice constant was observed to be decreased as smaller ionic radii Co2+ (0.74 Å) replaced the higher ionic radii Zn2+ (0.82 Å). The presence of tetrahedral and octahedral bands was confirmed by FTIR spectra. Optical bandgap energy was determined in the range of 4.44-2.05 eV for x = 0.0 to 0.4 nanoferrites, respectively. DC electrical resistivity was measured and showed an increasing trend (5.42 × 108 to 6.48 × 108 Ω·cm) with the addition of cobalt contents as cobalt is more conductive than zinc. The range of DC electrical resistivity (108 ohm-cm) makes these nanomaterials potential candidates for telecommunication devices.

Synthesis, DNA binding and biological evaluation of benzimidazole Schiff base ligands and their metal(ii) complexes.

Two novel benzimidazole ligands (E)-2-((4-(1H-benzo[d]imidazole-2-yl)phenylimino)methyl)-6-bromo-4-chlorophenol (L1) and (E)-1-((4-(1H-benzo[d]imidazole-2-yl)phenylimino)methyl)naphthalene-2-ol (L2) with their corresponding Cu(ii), Ni(ii), Pd(ii) and Zn(ii) complexes were designed and synthesized. The compounds were characterized by elemental, IR, and NMR (1H & 13C) spectral analyses. Molecular masses were determined by ESI-mass spectrometry, and the structure of ligand L1 was confirmed by single crystal X-ray diffraction analysis. Molecular docking was carried out for the theoretical investigation of DNA binding interactions. The results obtained were verified experimentally by UV/Visible absorption spectroscopy in conjunction with DNA thermal denaturation studies. It was observed that ligands (L1 and L2) and complexes (1-8) were moderate to strong DNA binders, as evident from the binding constants (K b). The value was found to be highest for complex 2 (3.27 × 105 M-1) and lowest for 5 (6.40 × 103 M-1). A cell line study revealed that breast cancer cells were less viable to the synthesized compounds compared to that of standard drugs, cisplatin and doxorubicin, at the same concentration. The compounds were also screened for in vitro antibacterial activity for which complex 2 showed a promising broad-spectrum effect against all tested strains of bacteria, almost in the proximity of the reference drug kanamycin, while the rest of the compounds displayed activity against selected strains.

Carbon Nanotube Fiber-Based Flexible Microelectrode for Electrochemical Glucose Sensors.

Electrochemical sensors are gaining significant demand for real-time monitoring of health-related parameters such as temperature, heart rate, and blood glucose level. A fiber-like microelectrode composed of copper oxide-modified carbon nanotubes (CuO@CNTFs) has been developed as a flexible and wearable glucose sensor with remarkable catalytic activity. The unidimensional structure of CNT fibers displayed efficient conductivity with enhanced mechanical strength, which makes these fibers far superior as compared to other fibrous-like materials. Copper oxide (CuO) nanoparticles were deposited over the surface of CNT fibers by a binder-free facile electrodeposition approach followed by thermal treatment that enhanced the performance of non-enzymatic glucose sensors. Scanning electron microscopy and energy-dispersive X-ray analysis confirmed the successful deposition of CuO nanoparticles over the fiber surface. Amperometric and voltammetric studies of fiber-based microelectrodes (CuO@CNTFs) toward glucose sensing showed an excellent sensitivity of ∼3000 µA/mM cm2, a low detection limit of 1.4 µM, and a wide linear range of up to 13 mM. The superior performance of the microelectrode is attributed to the synergistic effect of the electrocatalytic activity of CuO nanoparticles and the excellent conductivity of CNT fibers. A lower charge transfer resistance value obtained via electrochemical impedance spectroscopy (EIS) also demonstrated the superior electrode performance. This work demonstrates a facile approach for developing CNT fiber-based microelectrodes as a promising solution for flexible and disposable non-enzymatic glucose sensors.

Assessment of essential and toxic elemental concentrations in tumor and non-tumor tissues with risk of colorectal carcinoma in Pakistan.

BACKGROUND: Colorectal tumor is a major cause of cancer morbidity and mortality both in USA and around the globe. Exposure to environmental toxicants such as toxic trace elements has been implicated in colorectal malignancy. However, data linking them to this cancer are generally lacking. METHODS: Accordingly, the current study was to investigate the distribution, correlation and chemometric evaluation of 20 elements (Ca, Na, Mg, K, Zn, Fe, Ag, Co, Pb, Sn, Ni, Cr, Sr, Mn, Li, Se, Cd, Cu, Hg and As) in the tumor tissues (n = 147) and adjacent non tumor tissues (n = 147) of same colorectal patients which were analyzed by flame atomic absorption spectrophometry employing nitric acid-perchloric acid based wet digestion method. RESULTS: On the average, Zn (p < 0.05), Ag (p < 0.001), Pb (p < 0.001), Ni (p < 0.01), Cr (p < 0.005) and Cd (p < 0.001) showed significantly higher levels in the tumor tissues compared with the non tumor tissues of patients, whereas mean levels of Ca (p < 0.01), Na (p < 0.05), Mg (p < 0.001), Fe (p < 0.001), Sn (p < 0.05) and Se (p < 0.01), were significantly elevated in the non tumor tissues than the tissues of tumor patients. Most of the elements revealed markedly disparities in their elemental levels based on food (vegetarian/nonvegetarian) habits and smoking (smoker/nonsmoker) habits of donor groups. The correlation study and multivariate statistical analyses demonstrated some significantly divergent associations and apportionment of the elements in the tumor tissues and non tumor tissues of donors. Noticeably, variations in the elemental levels were also noted for colorectal tumor types (lymphoma, carcinoids tumor and adenocarcinoma) and stages (I, II, III, & IV) in patients. CONCLUSION: Overall, the study revealed that disproportions in essential and toxic elemental concentrations in the tissues are involved in pathogenesis of the malignancy. These findings provide the data base that helps to oncologist for diagnosis and prognosis of colorectal malignant patients.

Synthesis, characterization and biological evaluation of novel benzimidazole derivatives.

In search of achieving less toxic and more potent chemotherapeutics, three novel heterocyclic benzimidazole derivatives: 2-(1H-benzo[d]imidazol-2-yl)-4-chlorophenol (BM1), 4-chloro-2-(6-methyl-1H-benzo[d]imidazol-2-yl)phenol (BM2) and 4-chloro-2-(6-nitro-1H-benzo[d]imidazol-2-yl)phenol (BM3) with DNA-targeting properties, were synthesized and fully characterized by important physicochemical techniques. The DNA binding properties of the compounds were investigated by UV-Visible absorption titrations and thermal denaturation experiments. These molecules exhibited a good binding propensity to fish sperm DNA (FS-DNA), as evident from the high binding constants (Kb) values: 1.9 × 105, 1.39 × 105 and 1.8 × 104 M‒1 for BM1, BM2 and BM3, respectively. Thermal melting studies of DNA further validated the absorption titration results and best interaction was manifested by BM1 with ΔTm = 4.96 °C. The experimental DNA binding results were further validated theoretically by molecular docking study. It was confirmed that the molecules (BM1-BM3) bind to DNA via an intercalative and groove binding mode. The investigations showed a correlation between binding constants and energies obtained experimentally and through molecular docking, indicating a binding preference of benzimidazole derivatives with the minor groove of DNA. BM1 was the preferential candidate for DNA binding because of its flat structure, π-π interactions and less steric hindrance. To complement the DNA interaction, antimicrobial assays (antibacterial & antifungal) were performed. It was observed that compound BM2 showed promising activity against all bacterial strains (Micrococcus luteus, Staphylococcus aureus, Enterobacter aerogenes and Escherichia coli) and fungi (Aspergillus flavus, Aspergillus fumigatus and Fusarium solani), while rest of the compounds were active against selective strains. The MIC values of BM2 were found to be in the range of 12.5 ± 2.2-25 ± 1.5 µg/mL. Thus, the compound BM2 was found to be the effective DNA binding antimicrobial agent. Furthermore, the preliminary cytotoxic properties of synthesized compounds were evaluated by brine shrimps lethality assay to check their nontoxic nature towards healthy normal cells.Communicated by Ramaswamy H. Sarma.