Zinc: The Metal of Life

The importance of zinc was 1st reported for Aspergillus niger. It took over 75 y to realize that zinc is also an essential trace element for rats, and an additional 30 y went by before it was recognized that this was also true for humans. The adult body contains about 2 to 3 g of zinc. Zinc is found in organs, tissues, bones, fluids, and cells. It is essential for many physiological functions and plays a significant role in a number of enzyme actions in the living systems. Bioinformatics estimates report that 10% of the human proteome contains zinc‐binding sites. Based on its role in such a plethora of cellular components, zinc has diverse biological functions from enzymatic catalysis to playing a crucial role in cellular neuronal systems. Thus, based on the various published studies and reports, it is pertinent to state that zinc is one of the most important essential trace metals in human nutrition and lifestyle. Its deficiency may severely affect the homeostasis of a biological system. This review compiles the role of zinc in prophylaxis/therapeutics and provides current information about its effect on living beings.     

Ferromagnetism in Gd-doped CdS dilute magnetic semiconducting nanorods

Cd _x Gd_1?x S (x = 0–0.15) nanorods have been synthesized by solvothermal technique. X-ray diffraction study reveals that pure and Gd-doped CdS nanorods exhibits hexagonal wurtzite structure. Transmission electron microscopy reveals nanorods like morphology of synthesized CdS having 14 and 26 nm size of pure and 15 % doped CdS nanorods. UV–Visible absorption study confirms the blue shift in the energy band energy due to the quantum confinement effects. Photoluminescence spectra confirm the defect free nature of the synthesized nanorods with peaks emerging around 528 and 540 nm due to the green emission. The magnetic study shows that the pure and Gd-doped CdS nanorods exhibits ferromagnetic character and the magnetisation increased by five times from 0.074 to 0.422 emu/g upon Gd-doping.     

Influence of surface modification by 2-aminothiophenol on optoelectronics properties of ZnO nanoparticles

In this study, a precipitation method was used to synthesise ZnO nanoparticles using suitable precursors. An efficient surface modification method was proposed in order to reduce the agglomeration among synthesised small sized ZnO nanoparticles using 2-aminothiophenol as a capping agent. This article briefly investigated the effects of capping agent like 2-aminothiophenol on the optoelectronic properties of ZnO nanoparticles. The modified effectivity of 2-aminothiophenol has been examined on the nanosized ZnO nanoparticle for fluorescence and UV–visible (UV–vis) studies. The mechanism was studied for ZnO nanoparticles light emitting capability under different conditions. By facilitating the capping of ZnO with 2-aminothiophenol, fluorescence emission of the surface defects vanishes and ultraviolet (UV) emission increases. Surface capping by 2-aminothiophenol effectively covers most of the surface defects of ZnO and results in quenching of the visible region. The UV–vis absorption spectra of modified ZnO nanoparticles has been influenced by modified ZnO nanoparticles as a result of surface modification; where marked blue shift in absorption edge results. By surface modification of ZnO nanoparticles, change in optoelectronics properties has opened the new scope and possibilities to explore and fine tune the optical character of the modified ZnO for various optoelectronics applications such as UV laser.     

A novel robust logo watermarking scheme using fractional M-band wavelet transform

Digital watermarking, means of hiding/inserting a message, which can be an image, audio, video or text within the digital media. This hidden/inserting message can be later being extracted or detected for a variety of purposes. In this paper, a novel multi-resolution logo watermarking scheme using fractional M-band wavelet transform (Fr-M-band-WT) is proposed. The watermark is embedded in the multiresolution Fr-M-band-WT coefficients of low frequency bands of the host image using singular value decomposition (SVD). A multi-resolution nature of Fr-M-band-WT is exploited in the process of edge detection. Experimental results of the proposed logo watermarking scheme are compared with the previously available watermarking algorithms, fractional Fourier transform (FrFT), fractional wavelet transform (FrWT). Further, the proposed watermark extraction scheme is also tested on different attacks. The results after being investigated the proposed watermarking scheme shows a significant improvement as compared to other existing methods.     

Stimulation of acetylcholinesterase activity with nyctanthes arbor‐tristis leaves extract in the malathion‐treated immunosuppressed mice

The central nervous system's immune interaction appears to play a role in the psychosocial influence on immunologically resisted and mediated disease. Malathion is a known inhibitor of acetylcholinesterase activity. The accumulation of acetylcholine in nerve tissue affects organs with consequent symptoms that mimic the central nervous system action of acetylcholine. Subchronic and sublethal doses of malathion also suppressed the immune response. Nyctanthes arbor‐tristis has a immunopotentiative and pesticidal property. The effects of Nyctanthes arbor‐tristis on acetylcholinesterase (AchE) activity in the serum and brain was studied by treating the Swiss albino mice with an aqueous extract of N. arbor‐tristis [HL(aq)], as well as malathion‐immunosuppressed mice. The results revealed that the inhibition of AchE activity is reduced in malathion‐treated serum and brain tissue samples of mice, when they were given a HL(aq) extract treatment. Moreover, there was greater enhancement of AchE in serum than in brain tissue samples in HL(aq)‐treated mice. Thus the effect of malathion on AchE activity can be antagonised by HL(aq) treatment.     

Hybrid channel estimation for MIMO relay systems with Doppler offset influences

The design of the channel estimation method in a multiple‐input multiple‐output (MIMO) relay system plays a highly crucial role in deciding the overall system performance. For the realistic scenarios specifically, with fast time‐varying channel conditions due to highly mobile communicating nodes, the degree of accuracy to which the channel estimates are obtained for MIMO relay systems influences the communication system reliability significantly. However, most of the channel estimation approaches proposed in literature for MIMO relay systems assume that the Doppler offset contributed by highly mobile nodes is already known to the receiver, ignoring the resulting nonlinear system dynamics. Hence, a novel hybrid algorithm is proposed to address the issue of time‐varying channel estimation under fast‐fading channel condition with Doppler offset influences contributed by high‐mobility communicating nodes for a 1‐way 2‐hop MIMO amplify‐and‐forward relaying system. The problem is first formulated as a nonlinear state‐space model, and then an algorithm is developed to estimate the individual source‐to‐relay and relay‐to‐destination channels in the presence of the associated dynamic Doppler offset. In the proposed method, a set of superimposed orthogonal pilots is used for aiding in the updation of the channel gains, since Kalman filter–based updation may lead to accumulation of estimation and prediction error. A detailed computational complexity analysis of the proposed hybrid algorithm is presented, which shows that the algorithm has moderate computational complexity with a good performance in fast time‐varying channel conditions with high node mobility in a dual‐hop MIMO relay system.     

Deep Learning Based Analog Beamforming Design for Millimetre Wave Massive MIMO System

Software-defined networking (SDN) is a new approach that overcomes the obstacles which are faced by conventional networking architecture. The core idea of SDN is to separate the control plane from the data plane. This idea improves the network in many ways, such as efficient utilization of resources, better management of the network, reduced cost, innovation with new evolution, and many others. To manage all these changes, there is a great need for an efficient controller to improve the utilization of resources for the better performance of the network. The controller is also responsible for the analysis and monitoring of real-time data traffic. There is a great need for a high-performance controller in networking industries, data centres, academia, and research due to the tremendous growth of distributed processing-based real time applications. Therefore, it is crucial to investigate the performance of an open-source controller to provide efficient traffic routing, leading to improved utilization of resources for the enhanced performance metrics of the network. The paper presents an implementation of SDN architecture using an open-source RYU SDN controller for the network traffic analysis. The proposed work evaluates the performance of SDN architecture based custom network topology for a node to node performance parameters such as bandwidth, throughput and roundtrip time, etc. The simulation results exhibit an improved performance of the proposed work in comparison to the existing default network topology for SDN.

     

A Design of Planar Monopole Antenna for Wireless Applications

Wireless Personal Communications - This paper demonstrates the design of a planar monopole antenna with reduced size and high gain for wireless applications. In this design, a partial ground plane...     

Performance Analysis of CSS Over α–η–μ and α–κ–μ Fading Channel Using Clustering-Based Technique

Wireless Personal Communications - Cooperative spectrum sensing (CSS) is an efficient method, which is used to detect the presence/absence of primary user (PU) signal in the received spectrum at...