SYNTHESIS OF COPPER OXIDE NANOPARTICLES BY CHEMICAL PRECIPITATION METHOD FOR THE DETERMINATION OF ANTIBACTERIAL EFFICACY AGAINST STREPTOCOCCUS SP. AND STAPHYLOCOCCUS SP.

Objective: To determine antimicrobial efficacy of copper oxide nanoparticles (CuO NPs) against Streptococcus sp. and Staphylococcus sp. Methods: CuO NPs were synthesized using chemical precipitation method. The reducing agent, 0.1 M NaOH, was used along with 100 mM CuSO4 precursor for the synthesis of CuO NPs. The characterization of CuO NPs was done by ultraviolet-visible spectroscopy and scanning electron microscopy (SEM) to study optical and morphological characteristics, correspondingly. The identification of bacterial cultures was done through microscopic and biochemical studies. Antibacterial efficacy of CuO NPs was determined against Streptococcus sp. and Staphylococcus sp. by qualitative and quantitative methods through anti-well diffusion assay and broth dilution method, respectively. Results: The absorption spectrum and band gap were found to be at 260 nm and 4.77 eV, respectively. The SEM image of CuO NPs shows cluster of nanostructures having width of individual clusters in the range of 100 nm–500 nm. CuO NPs showed inhibition at a concentration ranging from 60 μg/mL to 1000 μg/mL. Conclusion: Finally, CuO NPs can be used as effective antibacterial agent against Streptococcus sp. and Staphylococcus sp. and may have applications in medical microbiology

Resistive switching and synaptic properties modifications in gallium-doped zinc oxide memristive devices

The massively parallel computing capabilities of the human brain can be mimicked with the help of neuromorphic computing approach and this can be achieved by developing the electronic synaptic device. In the present work, we have synthesized gallium-doped ZnO thin films using a cost-effective hydrothermal method and characterized the thin films using field-emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. Furthermore, gallium-doped ZnO memristive devices were developed using standard procedure and electrically characterized for the neuromorphic application. In particular, resistive switching and synaptic properties of gallium-doped ZnO thin films were investigated. The bipolar resistive switching with an analog memory like behavior was observed in the developed memristive devices. In the present case, good synaptic properties, endurance, and retention characteristics were observed for 0.5% Ga doped memristive device. Our results suggested that the synaptic weight, potentiation-depression, and symmetric Hebbian learning can be tuned with properly engineering the ZnO memristive device with appropriate gallium doping. The detailed analysis of I-V results suggested that resistive switching is occurred due to Ohmic and Schottky conduction mechanisms. Keywords: Memristive device, Resistive switching, Gallium doped ZnO, Electronic synapse, Potentiation and depression, Hebbian learnin

Development and validation of a multigene variant profiling assay to guide targeted and immuno therapy selection in solid tumors.

We present data on analytical validation of the multigene variant profiling assay (CellDx) to provide actionable indications for selection of targeted and immune checkpoint inhibitor (ICI) therapy in solid tumors. CellDx includes Next Generation Sequencing (NGS) profiling of gene variants in a targeted 452-gene panel as well as status of total Tumor Mutation Burden (TMB), Microsatellite instability (MSI), Mismatch Repair (MMR) and Programmed Cell Death-Ligand 1 (PD-L1) respectively. Validation parameters included accuracy, sensitivity, specificity and reproducibility for detection of Single Nucleotide Alterations (SNAs), Copy Number Alterations (CNAs), Insertions and Deletions (Indels), Gene fusions, MSI and PDL1. Cumulative analytical sensitivity and specificity of the assay were 99.03 (95% CI: 96.54-99.88) and 99.23% (95% CI: 98.54% - 99.65%) respectively with 99.20% overall Accuracy (95% CI: 98.57% - 99.60%) and 99.7% Precision based on evaluation of 116 reference samples. The clinical performance of CellDx was evaluated in a subsequent analysis of 299 clinical samples where 861 unique mutations were detected of which 791 were oncogenic and 47 were actionable. Indications in MMR, MSI and TMB for selection of ICI therapies were also detected in the clinical samples. The high specificity, sensitivity, accuracy and reproducibility of the CellDx assay is suitable for clinical application for guiding selection of targeted and immunotherapy agents in patients with solid organ tumors