Sapthagiri College of Engineering, Bangalore

Realizing highly independent, controllable wide and narrow multi-band response is one of the main design challenges of multiband filters. In this article, we present a novel design strategy based on a metacell to cope with this issue. As an example, a compact, multiband filter with highly independent, controlled broad and narrow dual-band responses centered at 3.3 and 5.8 GHz, respectively is designed utilizing only two resonator structures: an symmetric step impedance resonator (A-SIR) and a split ring resonator (SRR). The broad and narrow band responses are independent and are controlled independently by the impedance ratio (R) and number of rings in the metacell structure. Based on the quasistatic circuit model of the metacell, an independently controlled narrowband response is analyzed with analytical models. To estimate and verify the proposed filter structure design, two filter hardware models are developed and tested. A good concordance is observed between the simulated and measured results.

The key challenges in the design of multi-band filters are realizing highly independent, controlled asymmetric-wide and narrow dual-band response. To address these challenges this paper proposes the design and development of a dual-band band-pass filter (BPF) with highly independent, controlled wide and narrow band responses. The proposed filter is constructed using only two resonator structures, asymmetric step impedance resonator (A-SIR) and metacell. The wide and narrow band responses are independent and are controlled independently by impedance ratio (R) and the number of cells (N) in metacell structure, respectively. Additionally quasistatic circuit model of the metacell is used to analyze independently controlled narrow passband response. The prototype of the filter is fabricated, and the simulation results are validated through experimental measurements.

Based on a multitarget-directed drug design technique, a series of new quinoxalinone-based pyrazole derivatives (4a-h) were designed and synthesized. The potency of newly synthesized molecules to inhibit the anti -proliferation of the human cancer cell lines MCF-7 (breast), HCT-116 (colon), and A549 (lung) was examined. The most effective compounds against the examined cancer cell lines were 4e, 4f, 4 g, and 4 h. Among these, compounds 4e and 4 h had a strong anticancer activity that was equivalent to sorafenib. The capacity of the potent compounds (4e, 4f, 4 g, and 4 h) to inhibit the in vitro activity of the thymidylate synthase (TS) enzyme, BRaf, and EGFR kinases was also tested. With IC50 values for the TS enzyme, BRaf kinase, and EGFR kinase ranging from 1.16 to 2.97 mu M, 1.28 to 3.69 mu M, and 1.93 to 4.28 mu M, respectively, all the investigated compounds showed a noticeable inhibitory action. Among the synthesized hybrids, compound 4 h showed IC50 value of 2.04, 2.69 and 1.93 mu M against MCF-7, HCT-116, and A549 cell line, respectively, and 1.16, 1.28 and 1.93 nM against TS, BRaf and EGFR kinase enzyme, respectively. All of the synthesized hybrids adhered to Lipinski's guidelines, which suggested that they would have favorable oral drug-like qualities. To determine the probable interaction between the potent compounds and the TS active site, molecular docking study was conducted.

The impressive growth in present‐day wireless communication systems demands compact, low‐power, cost‐effective, planar multiband microwave devices to increase the speed of communication and reduce hardware requirements, which subsequently reduce the power requirement of the system. Accordingly, this article aims to design a multiband microstrip bandpass filter with asymmetric dual‐band response based on metacell. The proposed filter is designed for wide and narrow dual‐band responses with fractional bandwidths of 72% and 2.6%, respectively. For the first time in this article, a new application of metacell in the design of dual‐band filters is discussed. A folded asymmetric step‐impedance resonator and a novel metacell structure—Dual loop split ring resonators are used to obtain wideband and dual‐band responses, respectively. The proposed work discusses the design methodology, and analysis of metacell structure based on a quasistatic model and compares simulation results with experimental results. The proposed dual‐band filter presents an insertion loss (S21) of less than 1 dB and input reflection coefficient (S11) greater than 10 dB in both passbands centered at 3.3 and 5.7 GHz. The designed filter is suitable for wireless communication applications—Wireless Access in the Vehicular Environment.

In this study, nickel oxide nanoparticles (NiONPs) were produced by the co-precipitation method and characterized by scanning electron microscopy, X-ray diffraction (XRD), Fourier transform-infrared and Ultraviolet-visible spectroscopy. XRD analysis showed an average crystal size of 6 nm, while SEM analysis exemplified the oblong form with a particle size of 12 nm. As-prepared NiONPs were combined with multiwalled carbon nanotubes (MWCNTs) and graphite powder to prepare NiONPs-MWCNTs modified carbon paste electrode (MCPE). The fabricated NiONPs-MWCNTsMCPE sensor was used to analyze Gemfibrozil (GEM) in pharmaceutical formulations. Electrochemical methods such as cyclic voltammetry, differential pulse voltammetry, and electrochemical impedance spectroscopy employed in sensor characterization and electroanalysis of GEM. The sensor exhibited excellent electrochemical behavior towards GEM. It showed a lower limit of detection (LOD, 2.7x10-8 M), the limit of quantification (LOQ, 9.07x10-8 M), higher sensitivity, higher linear range, and long-term stability compared to the reported methods. The NiONPs-MWCNTsMCPE sensor was evaluated for practical application by performing spiking tests in pharmaceutical formulations and human urine samples, demonstrating significant recovery, high effectiveness, and accuracy. Further, nanoparticles manifested promising antibacterial action against Staphylococcus aureus, E. coli, Klebsiella aerogenes, Pseudomonas aeruginosa, and Klebsiella aerogenes. A schematic illustration of the fabrication of a NiONPs-MWCNTsMCPE electrochemical sensor for assessment of Gemfibrozil in pharmaceutical formulations and human urine samples and the antibacterial characteristics of NiONPs against selected microbesimage