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The current pandemic, novel corona virus 19 disease (COVID-19), has created havoc across the world. Now a third wave is possible, and we have already crossed two waves. The current review article presents recent reports about the COVID-19, the ways of treatments, and prevention. In view of the potential threats of a pandemic, various scientists have been trying to understand the pathophysiology of this disease to uncover possible treatment regimens and discover effective therapeutic agents and vaccines. To add further information to support the ongoing current research and development against SARS-CoV-2, the authors have provided the basics of pathophysiology, possible targets, and current treatment strategy for corona viruses. The current review highlights the antiviral strategies involving small molecules and different biological targets involved in corona virus infection and replication. The information included in this article provides a strong intellectual foundation for the ongoing development of therapeutic agents and vaccines.

Japanese encephalitis (JE) is a mosquito-borne flavivirus infection named Japanese Encephalitis Virus (JEV), prevalent in Asia-pacific countries, requires an accurate and rapid diagnosis to contain the outbreak of the disease. In cases of low viral load in early-stage infections, this task becomes difficult. Therefore, we have developed a surface-enhanced Raman spectroscopy (SERS) based biosensor for rapid, sensitive, and early-stage detection of JE antigen. In this work, silver nanoparticles were deposited over a glass coverslip and used as a substrate for designing the sensing platform. Silver Nanoparticles have good metallic properties and plasmon activity. Therefore, it amplifies the Raman signals and provides a suitable surface for the SERS substrate. The developed platform has been used for the detection of the Japanese encephalitis virus (JEV). The fabricated sensor shows a linear response from 5 ng/mL to 80 ng/mL with a limit of detection (LoD) of ∼7.6 ng/mL. Therefore, this method could be a significant addition to the diagnostic modalities for early, sensitive, and specific diagnoses of JE antigen even at the nanogram level.

Three-dimensional (3D) bioprinting is an emerging technology for fabricating cells, biomaterials and extracellular matrix (ECM) into customized shapes and patterns. Here, we report additive manufacturing to create a customized 3D bioactive constructs for regenerative medicine. We have attempted to emphasize the use of agarose and graphene oxide as a promising material for the conceptualization of bioink unpaid to its unique physicochemical properties. The 3D printed structure is able to regenerating bone tissues and regulates the cellular differentiation without any significant morphological changes. The presence of graphene oxide enhances the osteoinductive behavior of the developed scaffolds, which is further supplemented by encapsulating human mesenchymal stem cells (hMSCs) on the 3D printed scaffolds.A significant enhanced expression of early osteogenic markers like morphogenetic protein (BMP), Runx-2, collagen-1, osteopontin, osteocalcin as well as mineralized ECM are observed on agarose-hydroxyapatite and graphene oxide 3D printed scaffolds compared to agarose-hydroxyapatite 3D printed scaffolds. Thus, the outcomes of the developed 3D bioprinted scaffolds provide a promising strategy for development of personalized bone grafts for tissue regeneration.

Wastewater produced by the textile industry contains various dyes and organic compounds that directly or indirectly affect surface water or groundwater pollution. Visible-light-driven semiconductor photocatalysis is the leading pathway for the degradation of environmental pollutants. Herein we report the bottom-up hydrothermal growth of 2D tin disulfide nanostructures (SnS2 NSs) for the efficient photodegradation of organic pollutants such as Rhodamine B (Rh.B) and Methyl Violet (M.V) in an aqueous medium under visible light (λ > 400 nm) irradiation. The as-synthesized SnS2 NSs were characterized by various structural, morphological, and optical techniques such as XRD, RAMAN, TEM, UV–Vis, Brunauer–Emmett–Teller, etc. Furthermore, the low bandgap (∼1.6 eV), the high surface area (56 m2/g), and the anionic nature of SnS2 NSs attribute to it as an efficient photocatalyst for photocatalytic applications. The photocatalytic properties of SnS2 NSs showed good degradation efficiency of 94 and 99.6% for Rh. B and M.V, respectively, in 25 min. The kinetic rate constant of these dyes was estimated by using the Langmuir–Hinshelwood model. Here we also performed the recyclability test of the photocatalyst and discussed the plausible mechanism for the photocatalytic degradation of organic pollutants. The XPS spectra of SnS2 NSs were studied before and after the photodegradation of Rh.B and M.V, indicating the high stability of the photocatalyst. Moreover, in vitro cytotoxicity was also evaluated against human cervical cancer cell lines (HeLa cells) with different concentrations (0–1,000 μg/ml) of as-synthesized SnS2 NSs. This intended work provides a possible treatment for the degradation of organic pollutants under visible light to balance the aquatic ecosystems.

The advances in the arena of biomedical engineering enable us to fabricate novel biomaterials that provide a suitable platform for rapid bone regeneration. Herein, we have investigated the in vitro and in vivo osteogenic differentiation, proliferation, and bone regeneration capability of molybdenum disulfide nanosheets (MoS2NSs) reinforced HAP nanocomposite scaffolds. The MG-63 cells were incubated with HAP and HAP/MoS2NSs nanocomposite and followed for various cellular activities. The cells incubated with HAP@2 shows higher cell adhesion, cell proliferation, and alkaline phosphatase activity (ALP) in contrast to HAP. The in vivo and in vitro results of the increased ALP level confirm that HAP@2 promotes osteogenic differentiation. This improved osteogenesis was validated with upregulation of osteogenic marker viz. transcription factor, RUNX-2 (∼34 fold), collagen-1 (∼15 fold), osteopontin (∼11 fold), osteocalcin (∼20 fold), and bone morphogenetic protein-2 (∼12 fold) after 12 week postimplantation in comparison to drilled. The X-ray imaging demonstrates that HAP@2 implants promote rapid osteogenesis and bioresorbability than HAP and drilled. The outcomes of the present study provide a promising tool for the regeneration of bone deformities, without using any external growth factor.

Carbon quantum dots (CQDs) and their derivatives have potential applications in the field of biomedical imaging. Toxicity is one of the critical parameters that can hamper their success in biological applications. In this context, our goal was to systematically investigate both in vivo and in vitro toxicity of nitrogen doped carbon quantum dots (NCQDs). In vivo toxic effects were evaluated for 30 days in Swiss albino mice at two different concentrations (5.0 mg per kg body weight (BW) and 10.0 mg per kg BW) of NCQDs. Results of haematological, serum biochemical, antioxidant and histopathological parameters showed no noteworthy defects at both of these concentrations. An in vitro assessment was performed against the human cervical cancer cell line (HeLa cells) at the concentration of 0-400 μg ml-1. The LDH profile, DNA fragmentation, apoptosis, and growth cycle of cells showed no apparent toxicity of NCQDs. The overall study offers highly biocompatible N-doped carbon quantum dots, which may be considered as an attractive material for future biomedical applications.

The Molybdenum disulfide nanosheets (MoS2-NSs) thin films has received increasing attention recently due to their versatile multi functionality including catalytic properties, photoluminescence and flexibility, which suggests their future, uses for biomedical applications. However, there are no studies in detail related with biocompatibility of MoS2 thin sheets. Here, weevaluated the dose-dependent effects of MoS2-NSs on cell viability (MTT assay) and release of lactate dehydrogenase (LDH) into culture media using MG-63 cells, as well as haemolysis, hematological, serum biochemical, antioxidants and histopathological parameters in Swiss albino mice. The MoS2-NSs was synthesized via facile hydrothermal method and characterized using XRD, Raman, SEM, TEM and HRTEM. The in vitro study results suggest that at lower concentration MoS2-NSs does not causes any toxicity. The lethal dose (LD50) was evaluated by intraperitoneal administration with different concentrations and estimated as ~1.0 mg kg-1. The higher dose (1.5 mg kg-1) of MoS2-NSs showed significant alteration in hematological markers and serum biochemical enzymes, as compared to control. Lipid peroxidation also shows significant alteration with respect to the control. Histopathological, hematological and biochemical examination, revealed no remarkable changes at lower concentration (less than 1.0 mg kg-1), however, higher concentration (1.5 mg kg-1) causes significant histopathological, antioxidants and biochemical alterations in tissues and serum, respectively. The results suggest that the lower concentration of MoS2-NSs can be used in future biomedical applications.

The adverse effect of power swing (PS) led to blackout situation in Indian power network during July 30 and 31, 2012. During PS, the decision-making property of distance relay is greatly affected. To avoid this, modern distance relay is equipped with a PSB element that is used to prevent the false tripping imposed by PS. But in case of occurrence of fault followed to PS condition, the fault remains undetected due to PSB element. Therefore a reliable decision-making algorithm is required to overcome such type of problem. Furthermore, in case of a fault during PS in a double-circuit transmission line (DCTL), transient disturbances are also imposed in the voltage and current signals of similar phases of the healthy circuit due to the effect of mutual coupling between the two circuits. To resolve such protection challenges, this chapter proposes an intelligent technique based on bagged decision tree (BDT) algorithm for fault during PS detection and classification in a DCTL using wavelet packet energy (WPE) of voltage and current signals. All type of shunt faults are simulated and preprocessed to design an input data set to erudite the proposed intelligent scheme and concurrently tested with new faulty cases. Moreover, immunity of the proposed scheme has been analyzed for capacitor coupling voltage transformer transients as well as the current transformer saturation condition. The main advantage of the proposed scheme is that it is independent of the threshold setting, zero sequence mutual compensation factor, and remote-end data. It is also not influenced by variation in different fault parameters and power system operating parameters such as power flow angle and source impedance ratio. The proposed scheme is validated on an existing 400 kV, 50 Hz, double-circuit line of Chhattisgarh state power transmission network using MATLAB/Simulink software. Further, to validate the proposed scheme in real time, the experimental studies are carried out using the real-time digital simulator setup.

The current study reports a facile, single step microwave assisted synthesis of nitrogen, oxygen-doped carbon quantum dots (NCQDs) with high quantum yield (~36%). The synthesized NCQDs with an average size of 4 nm demonstrate many fold increase in the intensity of photoluminescence (PL) over the undoped carbon quantum dots (CQDs). UV–Vis absorption peak exhibits a red shift of 26 nm for NCQDs with respect to pristine CQDs. The spectral shift was further confirmed by density functional theory based calculations. X-ray photoelectron spectroscopy measurements reveal the graphitic nature and significantly high nitrogen doping of NCQDs (38.2%). The NCQDs exhibited excitation dependent PL behaviour in the visible region with maximum emission peak recorded at 415 nm with optimum excitation wavelength of 340 nm. The remarkably enhanced PL properties of NCQDs have been employed as fluorescent probe for sensitive and selective sensing of Cu2+ ions. The Cu2+ quenches the fluorescence intensity of NCQDs due to its high binding affinity towards N and O containing functional groups in quantum dots. The NCQDs render a simple, reliable and sensitive detection of Cu2+ ions with limit of detection as low as 1.8 µM.

Carbon quantum dots (CQDs) and their derivatives have potential applications in the field of biomedical imaging. Toxicity is one of the critical parameters that can hamper their success in biological applications. In this context, our goal was to systematically investigate both in vivo and in vitro toxicity of nitrogen doped carbon quantum dots (NCQDs). In vivo toxic effects were evaluated for 30 days in Swiss albino mice at two different concentrations (5.0 mg per kg body weight (BW) and 10.0 mg per kg BW) of NCQDs. Results of haematological, serum biochemical, antioxidant and histopathological parameters showed no noteworthy defects at both of these concentrations. An in vitro assessment was performed against the human cervical cancer cell line (HeLa cells) at the concentration of 0–400 μg ml(–1). The LDH profile, DNA fragmentation, apoptosis, and growth cycle of cells showed no apparent toxicity of NCQDs. The overall study offers highly biocompatible N-doped carbon quantum dots, which may be considered as an attractive material for future biomedical applications.

The tandem operation of draglines is in use in some of the major Indian opencast coalmines owing to the favourable geo-mining conditions, technical suitability, efficiency and economic viability. In view of the importance of tandem operation, the present study has been undertaken in a large Indian opencast coalmine in order to critically investigate the horizontal and vertical tandem operation of draglines on moderately strong and high sandstone benches (35–42 m), overlying a 15–18 m thick coal seam. The study has revealed that although the preparation of balancing diagram for planning of dragline operations is the first and the most important step, its actual implementation is equally important. Marked discrepancies in the productivity parameters as envisaged by the balancing diagram and as observed in the field studies, have been investigated and reported. The study also propounds the importance of appraisal of dragline productivity parameters, such as, cycle time, swing angle, seating position, availability, utilization, etc., in the field scale. Irrespective of the mode of operation (horizontal or vertical tandem), the study moots the concept of computation of the weighted cycle time and overall cycle time vis-a-vis swing angle variation for the draglines operating in field. The results drawn from the case study have been discussed in terms of cycle time computations, annual output computation and evaluation of earthmoving efficiency for the horizontal and vertical tandem modes of operation.

The present work proposes partially reduced graphene oxide-gold nanorods supported by chitosan (CH-prGO-AuNRs) as a potential bioelectrode material for enhanced glucose sensing. Developed on ITO substrate by immobilizing glucose oxidase on CH-prGO-AuNRs composite, these CH-prGO-AuNRs/ITO bioelectrodes demonstrate high sensitivity of 3.2 µA/(mg/dL)/cm(2) and linear range of 25-200 mg/dL with an ability to detect as low as 14.5 mg/dL. Further, these CH-prGO-AuNRs/ITO based electrodes attest synergistiacally enhanced sensing properties when compared to simple graphene oxide based CH-GO/ITO electrode. This is evident from one order higher electron transfer rate constant (Ks) value in case of CH-prGO-AuNRs modified electrode (12.4×10(-2) cm/s), in contrast to CH-GO/ITO electrode (6×10(-3) cm/s). Additionally, very low Km value [15.4 mg/dL(0.85 mM)] ensures better binding affinity of enzyme to substrate which is desirable for good biosensor stability and resistance to environmental interferences. Hence, with better loading capacity, kinetics and stability, the proposed CH-prGO-AuNRs composite shows tremendous potential to detect several bio-analytes in the coming future.