Browsing by Author "Pandey, Prem C."
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Publication A whole cell fluorescence quenching-based approach for the investigation of polyethyleneimine functionalized silver nanoparticles interaction with Candida albicans(Frontiers Media S.A., 2023) Tiwari, Atul Kumar; Gupta, Munesh Kumar; Narayan, Roger J.; Pandey, Prem C.The antimicrobial activity of metal nanoparticles can be considered a two-step process. In the first step, nanoparticles interact with the cell surface; the second step involves the implementation of the microbicidal processes. Silver nanoparticles have been widely explored for their antimicrobial activity against many pathogens. The interaction dynamics of functionalized silver nanoparticles at the biological interface must be better understood to develop surface-tuned biocompatible nanomaterial-containing formulations with selective antimicrobial activity. Herein, this study used the intrinsic fluorescence of whole C. albicans cells as a molecular probe to understand the cell surface interaction dynamics of polyethyleneimine-functionalized silver nanoparticles and antifungal mechanism of the same. The results demonstrated that synthesized PEI-f-Ag-NPs were ~ 5.6 � 1.2 nm in size and exhibited a crystalline structure. Furthermore, the recorded zeta potential (+18.2 mV) was associated with the stability of NPS and shown a strong electrostatic interaction tendency between the negatively charged cell surface. Thus, rapid killing kinetics was observed, with a remarkably low MIC value of 5 ?g/mL. PEI-f-Ag-NPs quenched the intrinsic fluorescence of C. albicans cells with increasing incubation time and concentration and have shown saturation effect within 120 min. The calculated binding constant (Kb = 1 � 105 M?1, n = 1.01) indicated strong binding tendency of PEI-f-Ag-NPs with C. albicans surface. It should also be noted that the silver nanoparticles interacted more selectively with the tyrosine-rich proteins in the fungal cell. However, calcofluor white fluorescence quenching showed non-specific binding on the cell surface. Thus, the antifungal mechanisms of PEI-f-Ag-NPs were observed as reactive oxygen species (ROS) overproduction and cell wall pit formation. This study demonstrated the utility of fluorescence spectroscopy for qualitative analysis of polyethyleneimine-functionalized silver nanoparticle interaction/binding with C. albicans cell surface biomolecules. Although, a quantitative approach is needed to better understand the interaction dynamics in order to formulate selective surface tuned nanoparticle for selective antifungal activity. Copyright � 2023 Tiwari, Gupta, Narayan and Pandey.Publication Amine-Functionalized Silver Nanoparticles: A Potential Antiviral-Coating Material with Trap and Kill Efficiency to Combat Viral Dissemination (COVID-19)(Springer Nature, 2023) Tiwari, Atul Kumar; Gupta, Munesh Kumar; Pandey, Govind; Pandey, Shivangi; Pandey, Prem C.The outbreak of COVID-19 has drastically affected the daily lifestyles of people globally where specific Coronavirus-2 transmits primarily by respiratory droplets. Structurally, the SARS-CoV-2 virus is made up of four types of proteins in which S-protein is indispensable among them, as it causes rapid replication in the host body. Therefore, the glycine and alanine composed of HR1 of S-protein is the ideal target for antiviral action. Different forms of surface-active PPEs can efficiently prevent this transmission in this circumstance. However, the virus can survive on the conventional PPEs for a long time. Hence, the nanotechnological approaches based on engineered nanomaterials coating on medical equipments can potentially prevent the dissemination of infections in public. Silver nanoparticles with tuneable physicochemical properties and versatile chemical functionalization provide an excellent platform to combat the disease. The coating of amine-functionalized silver nanoparticle (especially amine linked to aliphatic chain and trialkoxysilane) in its nanostructured form enables cloths trap and kill efficient. PPEs are a primary and reliable preventive measure, although they are not 100% effective against viral infections. So, developing and commercializing surface-active PPEs with trap and kill efficacy is highly needed to cope with current and future viral infections. This review article discusses the COVID-19 morphology, antiviral mechanism of Ag-NPs against SARS-CoV-2 virus, surface factors that influence viral persistence on fomites, the necessity of antiviral PPEs, and the potential application of amine-functionalized silver nanoparticles as a coating material for the development of trap and kill-efficient face masks and PPE kits. � The Author(s), under exclusive licence to Springer Science+Business Media, LLC 2022. Springer Nature or its licensor holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.Publication Assessing the niche of Rhododendron arboreum using entropy and machine learning algorithms: role of atmospheric, ecological, and hydrological variables(SPIE, 2022) Anand, Akash; Srivastava, Prashant K.; Pandey, Prem C.; Khan, Mohammed L.; Behera, Mukund D.Species distribution models (SDMs) have been used extensively in the field of landscape ecology and conservation biology since its origin in the late 1980s. But there is still a void for a universal modeling approach for SDMs. With recent advancements in satellite data and machine learning algorithms, the prediction of species occurrence is more accurate and realistic. Presently, four machine learning and regression-based algorithms, namely, generalized linear model, maximum entropy, boosted regression tree, and random forest (RF) are used to model the geographical distribution of Rhododendron arboreum, which is economically and medicinally important species found in the fragile ecosystem of Himalayas. To establish complex relation between the occurrence data and regional climatic and land use parameters, several satellite products, namely, MODIS, Sentinel-5p, GPM, ECOSTRESS, and shuttle radar topography mission (SRTM), are acquired and used as predictor variables to the different SDM algorithms. The performance evaluation has been conducted using the area under curve (AUC), which showed the best result for Maxent (AUC = 0.871) and poor result was observed for RF (AUC = 0.755) among all. The overall prediction confirmed the distribution of Rhododendron arboreum in the mid to high altitudes of central and southern parts of the Garhwal Division. We provide crucial evidence that combining multisatellite products using machine learning algorithms can provide a much better understanding of species distribution that can eventually help the researchers and policymakers to take the necessary step toward its conservation. � 2022 Society of Photo-Optical Instrumentation Engineers (SPIE).Publication Challenges and future possibilities toward himalayan forest monitoring(wiley, 2022) Gupta, Ayushi; Srivastava, Prashant K.; Satish, K.V.; Chauhan, Aashri; Pandey, Prem C.The Himalayan region is one of the most sensitive of the Earth's biodiversity hotspots. This chapter explores the environmental, cultural, and socio-economic importance of the Himalayan forest ecosystem, which is prone to rapidly increasing ecological deteriorations due to deforestation, forest fire, soil erosion, climate change, and various anthropogenic disturbances and challenges to monitoring these consequences for better management of the Himalayan forest. Satellite monitoring helps to identify and collect spatial data on land-use changes, emissions, and productions from forests as well other natural resources. Species distribution models are of paramount importance in the conservation and management of biodiversity, and are considered one of the spatially quantifiable essential biodiversity variables. Forest surveys in mountainous areas are particularly difficult due to variable topography and weather patterns. Seasonal taxonomic and floristic surveys are significantly more difficult and entirely dependent on nature's grace. � 2023 John Wiley & Sons Ltd. Published 2023 by John Wiley & Sons Ltd.Publication Earth observation applications for urban mapping and monitoring: research prospects, opportunities and challenges(Elsevier, 2023) Chauhan, Aashri; Wasim, Md.; Mohanty, Smrutisikha; Pandey, Prem C.; Pandey, Manish; Maurya, Neeraj K.; Rankavat, Shalini; Dubey, Surya BhushanThe significant loss of urban green spaces led to increasing Urban Heat Island (UHI) effects, environmental pollution, and other factors that have made it more difficult for societies to create healthier living conditions. The first-generation Earth Observation (EO) data like MODIS500 and GlobCover300 had less to moderate spectral and spatial resolution having limitations in the precise mapping of urban environmental variables. Monitoring and evaluating the urban environment have improved with the advancement of EO like GlobeCover30 and the Global Human Settlement Layer, which are connected to a multisensor approach, Unmanned Aerial Vehicles (UAVs) - LIDAR for 3D mapping, as well as microwave SAR applications. The present chapter offers an overview of interesting facets of urban area research that uses EO datasets directly or indirectly to address the complexity present in the urban environment for mapping and monitoring. It also offers potential future directions for creating a sustainable urban environment. It also included some case studies that demonstrate the potential of EO in mapping and monitoring urban areas, land use/land cover changes, air pollution, site suitability, road safety, urban flood monitoring, and UHI effects. � 2024 Elsevier Ltd. All rights reserved.Publication Earth observations for urban policies and future pathways for urban environmental research(Elsevier, 2023) Ekka, Pawan; Upreti, Manjari; Shilky; Saikia, Purabi; Kumar, Amit; Pandey, Prem C.; Srivastava, Prashant K.Urban research is now evolving, and there are several challenges that need to be addressed in the near future, which has led to pathways for further development. The scientific community must consider a multitude of options for urban monitoring, evaluation, planning, and management. In this chapter, we have provided a brief overview of different models for urban studies and research based on Earth observation datasets. This chapter discusses a variety of potential research areas, including satellite-based monitoring of urban areas, IoT and cloud computing in urban management, and the use of machine learning in urban environmental research. In addition to digitization, the availability of big data sets, machine learning (ML), and artificial intelligence (AI) will revolutionize the way urban areas are analyzed and planned, opening up new possibilities for sustainable urban challenges. The chapter outlines qualitative and quantitative methods utilizing predictive models and scenario analysis for identifying and implementing urban environmental policies. The recommendations provided in this chapter can be used for further urban studies, research, and the development of smart and resilient cities. � 2024 Elsevier Ltd. All rights reserved.Publication Nanotechnology: A Potential Weapon to Fight against COVID-19(John Wiley and Sons Inc, 2022) Tiwari, Atul K.; Mishra, Anupa; Pandey, Govind; Gupta, Munesh K.; Pandey, Prem C.The COVID-19 infections have posed an unprecedented global health emergency, with nearly three million deaths to date, and have caused substantial economic loss globally. Hence, an urgent exploration of effective and safe diagnostic/therapeutic approaches for minimizing the threat of this highly pathogenic coronavirus infection is needed. As an alternative to conventional diagnosis and antiviral agents, nanomaterials have a great potential to cope with the current or even future health emergency situation with a wide range of applications. Fundamentally, nanomaterials are physically and chemically tunable and can be employed for the next generation nanomaterial-based detection of viral antigens and host antibodies in body fluids as antiviral agents, nanovaccine, suppressant of cytokine storm, nanocarrier for efficient delivery of antiviral drugs at infection site or inside the host cells, and can also be a significant tool for better understanding of the gut microbiome and SARS-CoV-2 interaction. The applicability of nanomaterial-based therapeutic options to cope with the current and possible future pandemic is discussed here. � 2021 Wiley-VCH GmbHPublication Size and Zeta Potential Clicked Germination Attenuation and Anti-Sporangiospores Activity of PEI-Functionalized Silver Nanoparticles against COVID-19 Associated Mucorales (Rhizopus arrhizus)(MDPI, 2022) Tiwari, Atul Kumar; Gupta, Munesh Kumar; Pandey, Govind; Tilak, Ragini; Narayan, Roger J.; Pandey, Prem C.The SARS-CoV-2 infections in Indian people have been associated with a mucormycotic fungal infection caused by the filamentous fungi Rhizopus arrhizus. The sporangiospores of R. arrhizus are omnipresent in the environment and cause infection through inhalation or ingestion of contaminated air and foods. Therefore, the anti-sporangiospore activity of polyethyleneimine functionalized silver nanoparticles (PEI-f-Ag-NPs) with variable size and surface charge as a function of the molecular weight of PEI was explored. The results showed that both PEI-f-AgNP-1 and PEI-f-AgNP-2, potentially, attenuated the germination and reduced the viability of sporangiospores. Furthermore, the results showed that the minimum inhibitory concentration (MIC) values of both PEIf-AgNP-1 and PEI-f-AgNP-2 (1.65 and 6.50 ?g/mL, respectively) were dependent on the nanoparticle size and surface ? potentials. Similarly, the sporangiospore germination inhibition at MIC values was recorded, showing 97.33% and 94% germination inhibition, respectively, by PEI-f-AgNP-1 and 2 within 24 h, respectively. The confocal laser scanning microscopy, SEM-EDS, and confocal Raman spectroscopy investigation of PEI-f-Ag-NPs treated sporangiospores confirmed size and surface charge-dependent killing dynamics in sporangiospores. To the best of our knowledge, this is the first investigation of the polyethyleneimine functionalized silver nanoparticle-mediated size and surface charge-dependent anti-sporangiospore activity against R. arrhizus, along with a possible antifungal mechanism. � 2022 by the authors. Licensee MDPI, Basel, Switzerland.Publication Synthesis of vancomycin functionalized fluorescent gold nanoparticles and selective sensing of mercury (II)(Frontiers Media SA, 2023) Tiwari, Atul Kumar; Yadav, Hari Prakash; Gupta, Munesh Kumar; Narayan, Roger J.; Pandey, Prem C.Mercury ions (Hg2+) are widely found in the environment; it is considered a major pollutant. Therefore, the rapid and reliable detection of Hg2+ is of great technical interest. In this study, a highly fluorescent, sensitive, and selective fluorometric assay for detecting Hg2+ ions was developed using vancomycin functionalized and polyethyleneimine stabilized gold nanoparticles (PEI-f-AuNPs@Van). The as-made gold nanoparticles were highly fluorescent, with excitation and emission maxima occurring at 320 and 418�nm, respectively. The size of nanoparticles was ~7�nm; a zeta potential of ~38.8�mV was determined. The XRD analysis confirmed that the nanoparticles possessed crystalline structure with face centerd cubic symmetry. Using the PEI-f-AuNP@Van probe, the detection limit of Hg2+ ion was achieved up to 0.988�nM (within a linear range) by calculating the KSV. However, the detection limit in a natural environmental sample was shown to be 12.5�nM. Furthermore, the selectivity tests confirmed that the designed probe was highly selective to mercury (II) cations among tested other divalent cations. Owing to its sensitivity and selectivity, this approach for Hg2+ ions detection can be utilized for the analysis of real water samples. Copyright � 2023 Tiwari, Yadav, Gupta, Narayan and Pandey.
