Development of a robust method for Cd(II) ions analysis using CeO2- and CeO2-Cu-BTC-based electrochemical sensors.

Simple and sensitive electrochemical sensors were fabricated from cerium oxide (CeO2) and copper-benzene tricarboxylic acid-modified cerium oxide (CeO2-Cu-BTC) materials for differential pulse voltammetric analysis of toxic cadmium (Cd) ions in aqueous solutions. The materials were prepared by hydrothermal method and structurally characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy with energy-dispersive X-ray (SEM-EDX), thermogravimetric analysis (TGA), and X-ray diffraction analysis (XRD). The CeO2-modified carbon paste electrode (CeCPE) and the CeO2-Cu-BTC-modified carbon paste electrode (CeBCPE) were electrochemically characterized by their cyclic voltammetry and electrochemical impedance study in standard K3[Fe(CN)6] single-electron redox process. Their electrochemical surface areas, electrode surface coverages, and charge transfer resistances were calculated to be 1.46 cm2, 2.338 × 10-5 mol∙cm-2, and 2790 Ω and 5.48 cm2, 2.476 × 10-5 mol∙cm-2, and 1254.65 Ω for CeCPE and CeBCPE, respectively. These fabricated electrodes were used as electrochemical sensors for cadmium ion estimation by optimizing the experimental parameters through differential pulse voltammetry. The optimized conditions included 10% modifier for CeCPE and 5% modifier for CeBCPE in 0.12 M HCl solution of pH 5 as supporting electrolyte at - 1.2 V deposition for 30 s in 0.01 to 10 mg L-1 linear cadmium solution range. Under these conditions, the limit of quantification (LOQ) of 0.368 mg L-1 and 0.005 mg L-1 was calculated for CeCPE and CeBCPE electrodes, respectively. The limit of detection (LOD) was calculated to be 0.121 mg L-1 and 0.002 mg L-1 for CeCPE and CeBCPE, respectively. All the experimental results indicated that electrodes fabricated from CeO2-Cu-BTC show better performance as compared to CeO2-based electrodes. Both these types of electrochemical sensors presented good repeatability and performance in the presence of interfering ions as well. From these findings, it can also be inferred that these electrochemical sensors can provide a simple and very sensitive method for approximation of toxic cadmium ions in aqueous solutions.

Performance Analysis and Optimization of a PBDB-T:ITIC Based Organic Solar Cell Using Graphene Oxide as the Hole Transport Layer.

The hole transport layer (HTL) in organic solar cells (OSCs) plays an imperative role in boosting the cell's performance. PEDOT:PSS is a conventional HTL used in OSCs owing to its high design cost and instability issues. It can be replaced with graphene oxide to increase the cell performance by overcoming instability issues. Graphene oxide (GO) has gained popularity in recent years for its practical use in solar energy due to its remarkable mechanical, electrical, thermal, and optical properties. This work uses SCAPS-1D to examine the results of graphene oxide (GO)-based organic solar cells by giving a comparison between the performance of absorber layers and a GO-based HTL to see which absorber material interacts more strongly with GO. The absorber layer PBDB-T:ITIC paired with GO as HTL outperforms the other absorber layers due to its better optical and electrical characteristics. Numerical simulations are performed within the SCAPS software at various absorber layer thicknesses, defect densities, and doping values to assess the influence on device performance and efficiency. After cell optimization, the best efficiency of an improved OSC is found to be 17.36%, and the outcomes of the simulated OSC are referenced to the results of the experimentally implemented OSC. These results provide a possible future direction for developing GO-based OSCs with higher efficiency.

Development of reduced graphene oxide-supported novel hybrid nanomaterials (Bi2WO6@rGO and Cu-WO4@rGO) for green and efficient oxidative desulfurization of model fuel oil for environmental depollution.

For the first time, two new kinds of inorganic-organic hybrid nanomaterials (Bi2WO6@rGO and Cu-WO4@rGO) were fabricated by simple hydrothermal treatment and employed for green and efficient oxidative desulfurization of real fuel. The characterization of newly synthesized nanocomposites was performed by SEM, EDX, P-XRD, FT-IR and TGA. SEM and XRD analyses revealed well decoration of dopants (Cu-WO4 and Bi-WO3) on the surface of rGO with a crystallite size of <50 nm. The catalytic activity of both nanocatalysts was examined for model (dibenzothiophene) and real fuel (kerosene and diesel) by oxidative desulfurization route. Experimental findings revealed a high efficiency of over 90% under optimal reaction conditions of 0.1 g catalyst, 1 mL of oxidant, and 100 mg/L after 120 min at 30 °C. The major factors affecting desulfurization efficiency (time, temperature, catalyst amount, dibenzothiophene (DBT) concentration and amount of oxidant) and kinetic studies were described. The DBT removal via oxidative desulfurization followed pseudo first-order kinetics with an activation energy of 14.57 and 16.91 kJ/mol for Cu-WO4@rGO and Bi2WO6@rGO, respectively. The prepared catalysts showed promising reusability for the ODS process up to 5 times with no significant decrease in efficiency. In conclusion, the findings confirm the robustness of newly prepared nanocomposite for efficient production of sulfur-free oil.

Hexokinase inhibition using D-Mannoheptulose enhances oncolytic newcastle disease virus-mediated killing of breast cancer cells.

BACKGROUND: Most cancer cells exhibit increased glycolysis and use this metabolic pathway cell growth and proliferation. Targeting cancer cells' metabolism is a promising strategy in inhibiting cancer cell progression. We used D-Mannoheptulose, a specific hexokinase inhibitor, to inhibit glycolysis to enhance the Newcastle disease virus anti-tumor effect. METHODS: Human breast cancer cells were treated by NDV and/or hexokinase inhibitor. The study included cell viability, apoptosis, and study levels of hexokinase enzyme, pyruvate, ATP, and acidity. The combination index was measured to determine the synergism of NDV and hexokinase inhibitor. RESULTS: The results showed synergistic cytotoxicity against breast cancer cells by combination therapy but no cytotoxic effect against normal cells. The effect was accompanied by apoptotic cell death and hexokinase downregulation and inhibition to glycolysis products, pyruvate, ATP, and acidity. CONCLUSIONS: The combination treatment showed safe significant tumor cell proliferation inhibition compared to monotherapies suggesting a novel strategy for anti-breast cancer therapy through glycolysis inhibition by hexokinase downregulation.

Newcastle disease virus suppress glycolysis pathway and induce breast cancer cells death.

Newcastle disease virus (NDV) can modulate cancer cell signaling pathway and induce apoptosis in cancer cells. Cancer cells increase their glycolysis rates to meet the energy demands for their survival and generate ATP as the primary energy source for cell growth and proliferation. Interfering the glycolysis pathway may be a valuable antitumor strategy. This study aimed to assess the effect of NDV on the glycolysis pathway in infected breast cancer cells. Oncolytic NDV attenuated AMHA1 strain was used in this study. AMJ13 and MCF7 breast cancer cell lines and a normal embryonic REF cell line were infected with NDV with different multiplicity of infections (moi) to determine the IC50 of NDV through MTT assay. Crystal violet staining was done to study the morphological changes. NDV apoptosis induction was assessed using AO/PI assay. NDV interference with the glycolysis pathway was examined through measuring hexokinase (HK) activity, pyruvate, and ATP concentrations, and pH levels in NDV infected and non-infected breast cancer cells and in normal embryonic cells. The results showed that NDV replicates efficiently in cancer cells and spare normal cells and induce morphological changes and apoptosis in breast cancer cells but not in normal cells. NDV infected cancer cells showed decreased in the HK activity, pyruvate and ATP concentrations, and acidity, which reflect a significant decrease in the glycolysis activity of the NDV infected tumor cells. No effects on the normal cells were observed. In conclusion, oncolytic NDV ability to reduce glycolysis pathway activity in cancer cells can be an exciting module to improve antitumor therapeutics.

Detection of human papillomavirus-16 e6-oncoprotein in epithelial ovarian tumors samples of iraqi patients.

BACKGROUND: Human papillomavirus (HPV) is the causal factor for cervical cancer. However, the role of HPV infection in ovarian cancer is unclear. OBJECTIVES: This study aimed to determine the presence of human papillomavirus-16 (HPV-16) in ovarian tumor tissues. PATIENTS AND METHODS: This was a retrospective study, which included 61 Archived human ovarian tumor tissues embedded in paraffin blocks. The ovarian tumor tissues were divided into four groups. The first group was the malignant ovarian epithelial tumor group; it included 31 cases with invasive surface epithelial ovarian tumors. The second group was the borderline epithelial ovarian tumor group: it included four cases with borderline intermediate malignancy. The third group was the benign epithelial ovarian tumors group: it included 18 cases with benign epithelial ovarian tumors. The fourth group had functional ovarian cystic lesions: it included eight cases with non-neoplastic functional ovarian cysts. Sections were made from each of the paraffin embedded blocks and examined using immunohistochemistry to detect HPV 16-E6-oncoprotein in ovarian tumor tissues. RESULTS: Out of the eight cases with functional cysts only one case (12.5%) expressed HPV. No HPV expression was seen in cases with benign and borderline tumors. Out of the 31 cases with one malignant surface epithelial ovarian tumor only three (9.67%) cases expressed HPV. There was no significant statistical difference in HPV expression among neoplastic and non-neoplastic ovarian tumors included in the present study (P= 0.476). CONCLUSIONS: HPV type 16 was detected in only 9.67% of malignant epithelial tumors. It appears that HPV infection plays a relatively minor role in the pathogenesis of ovarian carcinomas.

Possible role of nuclear factor kappaB detected by in situ hybridization in the pathogenesis of transitional cell carcinoma of the bladder.

OBJECTIVE: Transitional cell carcinoma (TCC) of the bladder remains a significant health problem worldwide. The molecular mechanisms of tumor development and progression are complicated but likely involve the interaction of tumor suppressor genes, oncogenes, cell cycle regulatory proteins and other factors. Hence, this study attempts to explore the role of nuclear factor-KB (NF-kappaB) in the TCC of the bladder in correlation with different clinicopathological criteria which are tumor grade, muscle invasion by the tumor, schistosomiasis and presentation whether primary or recurrent tumor. METHODS: Twenty patients with TCC of the bladder were included in the study from June 2003 to June 2004, and were diagnosed by histopathology. The expressions of the transcription factor NF-kappaB were studied by in situ hybridization technique (ISH). RESULTS: The results showed that there was a significant correlation (p < 0.05) with muscle invasion and schistosomiasis but not with other criteria. CONCLUSION: The current study showed the possible role of the transcription factor (NF-kappaB) in TCC of the bladder.