Browsing by Author "Shashank Shekhar Mishra"

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An experimental and theoretical investigation on structure-property correlation of Cu2Mn1Al1−xGax full-Heusler alloy
(Elsevier Ltd, 2022) Shashank Shekhar Mishra; Anurag Bajpai; Thakur Prasad Yadav; Ram Manohar Yadav; Anand B. Puthirath; Liangzi Deng; Moein Adnani; Ching-Wu Chu; Robert Vajtai; Pulickel M. Ajayan; Krishanu Biswas; Nilay Krishna Mukhopadhyay
The present study reports the evolution of microstructure and magnetic properties of Cu2MnAl1−xGax Heusler alloys. The L21 phase, which remained stable up to a Ga substitution of x = 0.3, transformed into mixed phases, i.e., hexagonal close packed (HCP) and complex cubic structure (CCS) on further addition of Ga. The non-monotonic increase in the lattice constant indicates that some amount of Ga retains its monovalent state. The magnetic phase showed a transition from ferromagnetic to paramagnetic state with increasing Ga concentration. The re-entrant temperature (TR) decreased from 8.2 K to 5.2 K as Ga content increased from 5 at% to 10 at%. The strength of magnetic exchange-coupling also reduced with an increase in Ga content. Gaussian process regression (GPR) was used to estimate the lattice parameter using the ionic radii and Pauling electronegativity of the constituents. The modeling approach showed high accuracy and stability, providing new insights into future alloy development. © 2021 Elsevier B.V.
Gene Therapy, OMICS Approaches, and Translational Neurodegenerative Models: Recent Advancements and Future Perspectives
(CRC Press, 2024) Aakriti Sharma; Shashank Shekhar Mishra; Sandeep Singh
Gene therapy, OMICS approaches, and translational neurodegenerative models collectively represent a cutting-edge triumvirate at the forefront of addressing neurodegenerative diseases. Gene therapy, through gene replacement, silencing, and editing, aims to correct genetic defects at their source, offering hope for conditions like Alzheimer’s and Parkinson’s. OMICS technologies-including genomics, transcriptomics, proteomics, and metabolomics-provide a comprehensive view of the molecular intricacies of these diseases, identifying genetic variants, gene expression changes, and protein profiles critical for understanding and developing targeted interventions. Translational neurodegenerative models bridge the gap between bench research and clinical applications, utilising in vitro cell cultures, induced pluripotent stem cells, and organoids to replicate disease complexities observed in humans. These models enhance the reliability and relevance of patient-specific studies, paving the way for personalised treatments. Understanding the molecular basis of neurodegeneration is imperative for advancing therapeutic interventions, offering insights into genetic mutations, abnormal protein aggregations, and disrupted signaling pathways. This knowledge facilitates the development of precise diagnostics, biomarkers, and targeted therapies, potentially halting or reversing disease progression. Gene therapy’s evolution, marked by key milestones such as the first clinical trial for Parkinson’s disease and the FDA approval for spinal muscular atrophy treatment, underscores its transformative potential. Techniques like CRISPR-Cas9 have further revolutionised the field, enabling precise genetic modifications. This integrated approach, combining gene therapy, OMICS, and translational models, holds promise for innovative and personalised medical interventions, aiming to improve outcomes and quality of life for individuals with neurodegenerative diseases. © 2025 selection and editorial matter, Sachchida Nand Rai, Sandeep Singh, Santosh Kumar Singh.
In vivo toxicity study of ethanolic extracts of evolvulus alsinoides & centella asiatica in swiss albino mice
(Open Access Macedonian Journal of Medical Sciences, 2019) Mukesh Kumar Yadav; Santosh Kumar Singh; Manish Singh; Shashank Shekhar Mishra; Anurag Kumar Singh; Jyoti Shankar Tripathi; Yamini Bhusan Tripathi
AIM: We aimed to investigate several parameters after the in vivo acute and sub-acute administration of ethanolic extracts from E. alsinoides & C. asiatica. METHODS: Malignant Ovarian Germ Cell Tumors for in vivo toxicity study guidelines 423 and 407 of Organization for Economic Co-operation and Development (OECD) were followed for acute and sub-acute toxicity assays respectively. For LD50 evaluation, a single dose of ethanolic extracts of Evolvulus alsinoides L. (EEA) and ethanolic extracts of Centella asiatica (ECA) was orally administered to mice at doses of 200, 400, 800, 1600 and 2000 mg/kg. Then the animals were observed for 72 hours. For acute toxicity evaluation, a single dose of both extracts was orally administered to mice at doses of 300, 600, 1200 and 2000 mg/kg and the animals were observed for 14 days. In the sub-acute study, the extracts were orally administered to mice for 28 days at doses of 300, 600, 1200 and 2000 mg/kg. To assess the toxicological effects, animals were closely observed on general behaviour, clinical signs of toxicity, body weight, food and water intake. At the end of the study, it was performed biochemical and hematological evaluations, as well as histopathological analysis from the following organs: brain, heart, liver, and kidney. RESULTS: The oral administration of E. alsinoides and C. asiatica ethanolic extracts, i.e. EEA 300, EEA 600, EEA 1200, EEA 2000, ECA 300, ECA 600, ECA 1200 & ECA 2000 mg/kg doses showed no moral toxicity effect in LD50, acute and sub-acute toxicity parameters. CONCLUSION: In this study, we had found that E. alsinoides & C. asiatica extract at different doses cause no mortality in acute and sub-acute toxicity study. Also, histopathology of kidney, liver, heart, and brain showed no alterations in tissues morphology. © 2019 Mukesh Kumar Yadav, Santosh Kumar Singh, Manish Singh, Shashank Shekhar Mishra, Anurag Kumar Singh, Jyoti Shankar Tripathi, Yamini Bhusan Tripathi.
Intellectual Property Rights in Neuroprotective Biomaterials
(Springer Nature, 2025) Chandrabhan Prajapati; Prabhash Nath Tripathi; Saloni Sood; Sachchida Nand Rai; Shashank Shekhar Mishra; Santosh Kumar Singh; Amit K. Tiwari
Intellectual property rights, or IPRs, are essential for promoting creativity and protecting medical research findings, such as neuroprotective biomaterials. Intellectual property rights remain associated with Article 27 regarding the UDHR (Universal Declaration of Human Rights) which mentions safeguarding the “material and moral interests” of creators, promoting their innovation and creative output, and striking a balance between their rights and the public’s access to advances in cultural and scientific research. The development, defence, along with the commercialization of neuroprotective biomaterials—which show promise in treating neurodegenerative illnesses and nervous system injuries— depend heavily on intellectual property rights (IPRs). However, IPRs have benefits like encouraging innovation, rewarding investment, and guaranteeing surveillance of quality, these rights also have major limitations that affect innovation, accessibility, cost, ethical issues, and global inequities. These restrictions obstruct the prompt availability and fair transportation of neuroprotective biomaterials, which interferes with the struggle against neurodegenerative disorders and promotes health outcomes worldwide. The difficulties in obtaining IPRs, possible patent disputes, exorbitant expenses, and regulatory barriers, however, provide challenging obstructions. Working together, academics, business, and legal professionals may help overcome these obstacles and make it easier to integrate modern innovations into healthcare applications. This chapter discusses the need for recent developments in neuroprotective biomaterials and highlights the intellectual property rights (also called IPRs) crucial role in protecting these advancements and ensuring ethical and legal observance in various nations as well. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.
Multifaceted investigation into the impact of Ga substitution for Al in V2MnAl inverse Heusler alloys
(Elsevier B.V., 2024) Shashank Shekhar Mishra; Thakur Prasad Yadav; Upendra Kumar; Bincy Babu Raj; Hyunseok Ko
This study investigates the impact of Ga substitution for Al in V2MnAl inverse Heusler alloys, focusing on lattice parameter variations. Despite similar valence electrons, Ga's distinct size and surface energy prompt questions about its role in alloy characteristics. Experimental synthesis of V2Mn1Al1−xGax alloys (x = 0 to 0.60) reveals crystal parameter changes. Theoretical exploration using density functional theory (DFT) probes how Ga doping at the Al site influences the density of states, altering the half-metallic properties of V2MnAl. Additionally, machine learning, with a dataset of 391 entries, predicts lattice constants based on atomic properties, enhancing our ability to maneuver material characteristics. This multifaceted approach aims to deepen our understanding of Ga's impact on Heusler alloys, bridging experimental and theoretical realms for comprehensive insights into materials design and behavior. © 2024 Elsevier B.V.
Natural Sources of Drugs for Neurodegenerative Diseases
(CRC Press, 2024) Chandrabhan Prajapati; Sachchida Nand Rai; Shashank Shekhar Mishra; Santosh Kumar Singh; Anurag Kumar Singh
Neurodegenerative diseases involve gradual breakdown and eventually death of nerve cells. Neurodegenerative disorders lack an effective therapy because the central nervous system’s neurons have a limited capacity for regeneration. There are many different causes of neurological illnesses, such as congenital anomalies, genetic disorders, autoimmune diseases, infections, and environmental or lifestyle-related health issues. Endophytes are a group of microorganisms that thrive within host plants without apparently harming them. Both plant-based bioactives and fungal endophyte-based bioactives exhibit neuroprotective activities. Antioxidant activity, anti-amyloid aggregation, anti-inflammatory, monoamine modification, and inhibition of acetylcholinesterase are some of the mechanisms by which plant-based bioactives exhibit neuroprotective activities. Ongoing research focuses on the neuroblastic cell regeneration approach to treat neurodegenerative disorders. Peptides, cytokines, and polyphenolic antioxidants have regenerative capacity and thus can be used to treat neurodegenerative diseases. Over 60 million people suffer from these incurable diseases worldwide as a result of the rapidly aging society. As a result, finding novel medications and therapeutic approaches has become a crucial study area. This chapter focuses on the efficacy of natural compounds derived from plants and associated microbes towards neurodegenerative disorders. © 2025 selection and editorial matter, Sachchida Nand Rai, Sandeep Singh, Santosh Kumar Singh.
Neuroprotective activity of evolvulus alsinoides & centella asiatica ethanolic extracts in scopolamine-induced amnesia in swiss albino mice
(Open Access Macedonian Journal of Medical Sciences, 2019) Mukesh Kumar Yadav; Santosh Kumar Singh; Manish Singh; Shashank Shekhar Mishra; Anurag Kumar Singh; Jyoti Shankar Tripathi; Yamini Bhusan Tripathi
AIM: To carry out the comparative nootropic, neuroprotective potentials of two medicinal plant species. MATERIAL AND METHODS: For neuroprotective activity; behavior models (elevated plus maze & morris water maze), in vivo antioxidant (superoxide dismutase, catalase, lipid peroxidation & reduced glutathione), inflammatory markers (IL-1β, IL-6 & TNF-α) and acetylcholine esterase (AChE) assessment procedures followed at different dosages i.e. 250 & 500 mg/kg of Evolvulus alsinoides and Centella asiatica ethanolic extracts. At the end of the study, it was performed histopathological analysis of the following organs: brain, heart, liver, and kidney. RESULTS: In oral administration of different doses of ethanolic extracts of both medicinal plants i.e. Sco + EEA 250 = 2.49 ± 0.29, Sco + EEA 500 = 2.67 ± 0.36, Sco + ECA 250 = 2.33 ± 0.17, Sco + ECA 500 = 2.77 ± 0.21, Sco + EEA + ECA 250 = 2.61 ± 0.32 and Sco + EEA + ECA 500 = 2.79 ± 0.16 U/mg of protein respectively against the scopolamine induced group Sco (control) = 5.51 ± 0.35 U/mg of protein extracts shows neuroprotective and nootropic activity with reducing AChE level in the brain homogenate of swiss albino mice. CONCLUSION: Since the E. alsinoides & C. asiatica are already used in traditional Indian medicine as the neuroprotective agent and also found promising effects over inflammatory diseases, wound healing, and immunomodulatory activity. The neuroprotective effect of both plants extracts attributed to inhibition of AChE activity and improve the spatial memory formation. © 2019 Mukesh Kumar Yadav, Santosh Kumar Singh, Manish Singh, Shashank Shekhar Mishra, Anurag Kumar Singh, Jyoti Shankar Tripathi, Yamini Bhusan Tripathi.
Phase stability and phase transformations in Al-Pd-Mn quasicrystalline alloys with low-Ga content
(Elsevier B.V., 2022) Shashank Shekhar Mishra; Thakur Prasad Yadav; Nilay Krishna Mukhopadhyay
Gallium having low surface energy (∼ 600 mJ/m2) and low melting temperature (29.76 °C), was utilized to substitute Al in Al-Pd-Mn quasicrystalline alloys, which may be considered for future development of a quaternary QC alloy with low surface energy. The influence of Ga up to 5 at% in decagonal Al70-XGaXPd10Mn20 (x = 0, 2.5, 5.0) alloys on the stability of decagonal phase was investigated systematically. The surface morphology and phase stability were studied in as-cast (slow cooling from liquid) and also in annealed condition (i.e., annealing at temperature 800 °C for 24 h). It is observed that Ga influences the stability of decagonal phase and the evolution of microstructure. The phase transformation from the mixed icosahedral and decagonal quasicrystal phases coexisting in as-cast Al70-XGaXPd10Mn20 (x = 0, 2.5, 5.0) alloys to a single decagonal quasicrystalline phase was observed on annealing, implying relative phase stability of quaternary decagonal phase around these compositions. © 2021
Rapidly quenched Ni45Fe5Mn40Sn10 Heusler alloys
(Universidade Federal de Sao Carlos, 2015) Shashank Shekhar Mishra; Thakur Prasad Yadava; Semanti Mukhopadhyay; Ram Manohar Yadav; Vajapeyajula Srinivasa Subrahmanyam; Nilay Krishna Mukhopadhyay; Onkar Nath Srivastava
The present work describes the synthesis and characterization of Ni45Fe5Mn40Sn10 Heusler alloys. The constituent pure metals were melted in radio frequency induction furnace to form the alloy and then cooled it quickly. The as-cast alloy was annealed at 850 °C for 24 h in vacuum and cooled in two different conditions i.e. self-cooling at room temperature in air and sudden cooling at liquid nitrogen temperature (quenched). The X-ray diffraction, scanning and transmission electron microscopic techniques have been used for structural/microstructural characterization as well as chemical analysis of the material. The effect of annealing and subsequent cooling in two different conditions has been described and discussed in the context of evolution of B2 and orthorhombic martensite with lattice parameter a= 0.65 nm, b=0.59 nm and c=0.56 nm.
Superior catalytic action of high-entropy alloy on hydrogen sorption properties of MgH2
(Elsevier Ltd, 2024) Satish Kumar Verma; Shashank Shekhar Mishra; Nilay Krishna Mukhopadhyay; Thakur Prasad Yadav
Magnesium hydride (MgH2) is the mostly used material for solid-state hydrogen storage. However, their slow kinetics and highly unfavorable thermodynamics make them unsuitable for the practical applications. The current study describes the unusual catalytic action of a new class of catalyst, a high-entropy alloy (HEA) of Al20Cr16Mn16Fe16Co16Ni16 and its leached version, on the de/re-hydrogenation properties of MgH2. The onset desorption temperature of MgH2 was reduced significantly from 360 °C (for ball-milled MgH2) to 338 °C when it was catalyzed with a leached HEA-based catalyst. On the other hand, a fast de/re-hydrogenation kinetics of MgH2 was observed during the addition of leached HEA-based catalyst. It absorbed ∼6.1 wt% of hydrogen in just 2 min at a temperature of 300 °C under 10 atm hydrogen pressure and desorbed ∼5.4 wt% within 40 min. At moderate temperatures and low pressure, the HEA-based catalyst reduced desorption temperatures and improved re-hydrogenation kinetics. Even after 25 cycles of de/re-hydrogenation, the storage capacity of MgH2 catalyzed with the leached version of HEA degrades negligibly. © 2023 Hydrogen Energy Publications LLC
Synthesis and characterization of hexanary Ti-Zr-V-Cr-Ni-Fe high-entropy Laves phase
(Cambridge University Press, 2019) Shashank Shekhar Mishra; Semanti Mukhopadhyay; Thakur Prasad Yadav; Nilay Krishna Mukhopadhyay; Onkar Nath Srivastava
Three different high entropy-alloys consisting of six elements (Ti, Zr, V, Cr, Ni, and Fe) with varying Fe content were synthesized by using the RF induction melting technique. All the as-cast, slow-cooled, and rapidly quenched alloys exhibit C14 Laves phase, and it is found to be stable at high temperature. A lattice contraction has been observed with the addition of Fe. To the best of our knowledge, this is the first report on the synthesis of a single-phase high-entropy complex intermetallic compound in the hexanary alloy system. It has been shown that the thermodynamic calculations following Miedema's approach and the parametric approach utilizing several descriptors comprising configurational entropy, mixing enthalpy, atomic size mismatch, electronegativity, and valence electron concentration favor the stability of the high-entropy multicomponent Laves phase. Copyright © Materials Research Society 2019.
Wound healing potential of Apamarga Ksharodaka (herbal alkaline water made from Achyranthus aspera Linn.) in excision rodent wound model
(Rzeszow University Press, 2025) Ayush Kumar Garg; Sachchida Nand Rai; Chandrabhan Prajapati; Shashank Shekhar Mishra; Santosh Kumar Singh; Binay Sen
Introduction and aim. Wound healing is a biological process that aims to restore tissue integrity and function. Despite medical advances, wound management remains challenging. Traditional medicinal preparations, like Apamarga ksharodaka (AK), offer promising therapeutic potential due to their phytochemical richness. This study evaluated wound healing and antimicrobial activity of AK. This study aimed to validate the traditional claim of AK’s wound healing potential using an excision wound model. Material and methods. An excision wound model was created using 24 male Wistar rats. A positive control group applied 5% w/w povidone-iodine (PI) ointment. Wound contraction (WC), epithelialization period (ET), wound closure day, and histopathology were assessed. Antibacterial activity was evaluated against Escherichia coli, Streptococcus aureus, Pseudomonas aeruginosa, and Acinetobacter baumannii. Results. AK showed slightly better wound healing than PI ointment, with significant results in WC rate, wound closure, and ET. Histopathology revealed normal skin and organ architecture. The minimum MIC was 6.25 mg/ml against Pseudomonas aeruginosa with a maximum inhibition zone of 15 mm. Conclusion. AK is safe and effective for wound healing. © 2025 Publishing Office of the University of Rzeszow. All rights reserved.