Browsing by Author "Rupesh Kumar"

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A novel nanocomposite of HAp-TiC-Ag with enhanced mechanical and biological properties for bone regrowth and anticancer applications
(Royal Society of Chemistry, 2025) Sarvesh Kumar Avinashi; Shweta; Rajat Kumar Mishra; Saurabh Kumar; Amreen Shamsad; Shama Parveen; Surajita Sahu; Savita Kumari; Zaireen Fatima; Vijay Pratap; Rupesh Kumar; Monisha Banerjee; Monalisa Mishra; Horesh Kumar; Rakesh Kumar C. Gautam; Chandkiram Gautam
Hydroxyapatite (HAp)-based composites are extensively used in various applications, including bone regeneration, bone implants, catalysis, drug delivery, and cancer treatment, owing to their unique properties such as osteogenesis, osteoconduction, and osteoinduction, as well as their ability to inhibit tumor cell growth. In this study, pure HAp and silver (Ag) nanoparticles were synthesized using microwave irradiation and green synthesis methods, while a solid-state reaction route was employed for the fabrication of HAp-TiC-Ag composites aimed at enhancing their mechanical and biological properties. A range of characterization techniques, including XRD, FTIR, Raman, XPS, DLS, SEM, TEM, and in vitro assays, were used to assess the structural, morphological, mechanical, and biological properties of the composites. The composite HTA6 exhibited excellent mechanical properties, including a high compressive strength (185 MPa), elevated fracture toughness (10.88 MPa m1/2), a moderate Young's modulus (1.08 GPa), and a Vickers hardness (339.65 HV). The cell viability tests demonstrated that HTA6 treatment did not significantly reduce osteoblast cell growth, while significantly inhibiting the proliferation of cancer cells. Additionally, the composite showed good biocompatibility, displaying non-cytotoxicity in D. melanogaster and strong antibacterial activities against the tested bacteria. These findings suggest that HTA6 is a promising candidate for applications in bone regeneration and cancer treatment. © 2025 The Royal Society of Chemistry.
Design, development and bio-evaluation of a novel radio-ligand 99mTc-THQ-DTPA as a sigma 2 receptor specific breast tumor imaging agent
(Elsevier Ltd, 2024) Vishakha Chaudhary; Shubhra Chaturvedi; Anju Wadhwa; Ritika Chaudhary; Divya Gautam; Deepika Sharma; Rupesh Kumar; A.K. Mishra
Over-expression of sigma-2 receptor in cancer cells provides an opportunity to develop molecular probes for diagnosis, even for non-receptor specific malignancies like triple negative breast cancers. In this work, a novel sigma-2 receptor ligand [THQ-DTPA] has been synthesized and characterized using 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline (THQ) and diethylenetriaminepentaacetic acid (DTPA). The ligand is further chelated with 99mTc for application as metal based radiotracer [99mTc-THQ-DTPA]. Radiolabelling with 99mTc was achieved in an excellent yield of 98.0 ± 0.5% using stannous chloride as a reducing agent. The radioligand was found to be stable in human serum up-to 24 h, bio-compatible with less than 4% hemolysis, and exhibited high binding with sigma receptors isolated from rat liver membrane (Kd of 16.32 ± 4.93 nM and Bmax of 0.5232 ± 0.06 pmol/mg). Bio-distribution studies in triple-negative breast tumor bearing nude mice showed high tumor uptake after 30 min of injection with tumor/muscle (T/M) ratio of 3.58 ± 0.09. At 240 min, the T/M ratio (2.84 ± 0.20) decreased by 35% when administered in sigma blocked tumor bearing mice (1.81 ± 0.16) suggesting the selectivity of the ligand. Tumor imaging in gamma camera indicated a contrast of 3.56 at 30 min p.i. The above findings indicate that the ligand 99mTc-THQ-DTPA binds to sigma-2 receptors with high affinity and has potential for triple-negative breast tumor imaging. © 2023 Elsevier Ltd
Development of Ti-10Nb alloy by powder metallurgy processing route for dental application
(John Wiley and Sons Inc, 2024) Rupesh Kumar; R.K. Gautam
Titanium and its alloys are used to make dental implants because of its low density, high strength, and corrosion resistance. This paper describes the development of a potential biomaterial Ti-10Nb by powder metallurgy utilizing four different compaction pressures and analyses its microstructural, physical, mechanical, electrochemical, biological, and tribological behavior under various situations. The alloys were fabricated using four different compaction pressures, that is, 600, 650, 700, and 750 MPa, and sintered in a vacuum atmosphere at 1000°C for 1.5 h. The density of the samples was measured using Archimedes principle. X-ray diffraction and scanning electron microscopy equipped with energy dispersive spectroscopy were used to investigate the phase composition and microstructure, and a profilometer was used to examine the surface roughness of various samples. Vickers hardness tester was used to evaluate hardness, and a universal testing machine was used for compression testing. Corrosion and wear behavior were examined using a potentiostat and a Bio-Tribometer, respectively. This Ti-10Nb alloys consist of α + β phase, and have 16% highest porosity in sample compacted at 600 MPa. The samples compacted at 750 MPa achieved highest hardness, yield strength, compressive strength, and elastic modulus of 450 ± 29.72 HV, 718.22 ± 16.37 MPa, 1543.59 ± 24.37 MPa, and 41.27 ± 3.29 GPa, respectively. In addition, it also possesses highest corrosion and wear resistance with lowest icorr of 0.3954 ± 0.008 μA/cm2 and wear volume of (31.25 ± 0.206) × 10−3 mm3. These results indicate that the developed alloys have a variety of desirable properties, including high hardness, adequate compressive strength, good corrosion and wear resistance, apatite-forming capability, and a low elastic modulus, which is advantageous for avoiding stress shielding. Therefore, it may be recommended to use it as a dental implant material. © 2023 Wiley Periodicals LLC.
Exploring the dynamic microbial tapestry of South Asian rivers: insights from the Ganges and Yamuna ecosystems
(John Wiley and Sons Ltd, 2024) Sadashiv Chaturvedi; Biswameet Chakraborty; Liu Min; Amit Kumar; Bikram Pathak; Rupesh Kumar; Zhi-Guo Yu
This review meticulously examines the dynamics of river microbiomes, with an emphasis on the Ganges and Yamuna rivers of South Asia. These rivers are vital for both ecological and cultural landscapes and offer to understand the interaction between ecological and anthropogenic factors and their impact on microbial communities and activities. Ecological and hydrological factors such as seasonal changes, water flow and physico-chemical properties of rivers influence microbial diversity and abundance. The effect of heavy metals from industrial and agricultural sources on the river microbiome and how these pollutants modify microbial community structures and ecosystem health are not understood well yet. This underscores the need for sustainable water treatment and remediations for practical engineering solutions. The study reveals how these interactions, whether symbiotic or competitive, affect the composition and functionality of riverine microbial communities. An innovative aspect of our research is the potential of river microbiomes as indicators of urban sewage contamination. We demonstrate how microbial patterns can signal pollution levels, proving valuable for environmental monitoring, management and mitigation. A special attention to the role of microbes in river ecosystems' biogeochemical cycles has been paid to how these microbes contribute to nutrient recycling, organic matter decomposition and overall ecosystem productivity, underlining their crucial role in maintaining the aesthetic value of the river. Additionally, study evaluates the latest methodologies for analysing microbiome metagenomic data, including functional annotation and microbial community analysis techniques. Findings highlight the key importance of understanding river microbiomes for hydrology, ecology and microbiology researchers. © 2024 John Wiley & Sons Ltd.
Fabrication, structural, and enhanced mechanical behavior of MgO substituted PMMA composites for dental applications
(Nature Research, 2024) Savita Kumari; Rajat Kumar Mishra; Shama Parveen; Sarvesh Kumar Avinashi; Ajaz Hussain; Saurabh Kumar; Monisha Banerjee; Jitendra Rao; Rupesh Kumar; Rakesh Kumar Gautam; Chandkiram Gautam
The most common denture material used for dentistry is poly-methyl-methacrylate (PMMA). Usually, the polymeric PMMA material has numerous biological, mechanical and cost-effective shortcomings. Hence, to resolve such types of drawbacks, attempts have been made to investigate fillers of the PMMA like alumina (Al2O3), silica (SiO2), zirconia (ZrO2) etc. For the enhancement of the PMMA properties a suitable additive is required for its orthopedic applications. Herein, the main motive of this study was to synthesize a magnesium oxide (MgO) reinforced polymer-based hybrid nano-composites by using heat cure method with superior optical, biological and mechanical characteristics. For the structural and vibrational studies of the composites, XRD and FT-IR were carried out. Herein, the percentage of crystallinity for all the fabricated composites were also calculated and found to be 14.79–30.31. Various physical and optical parameters such as density, band gap, Urbach energy, cutoff energy, cutoff wavelength, steepness parameter, electron–phonon interaction, refractive index, and optical dielectric constant were also studied and their values are found to be in the range of 1.21–1.394 g/cm3, 5.44–5.48 eV, 0.167–0.027 eV, 5.68 eV, 218 nm, 0.156–0.962, 4.273–0.693, 1.937–1.932, and 3.752–3.731 respectively. To evaluate the mechanical properties like compressive strength, flexural strength, and fracture toughness of the composites a Universal Testing Machine (UTM) was used and their values were 60.3 and 101 MPa, 78 and 40.3 MPa, 5.85 and 9.8 MPa-m1/2 respectively. Tribological tests of the composites were also carried out. In order to check the toxicity, MTT assay was also carried out for the PM0 and PM15 [(x)MgO + (100 − x) (C5O2H8)n] (x = 0 and 15) composites. This study provides a comprehensive insight into the structural, physical, optical, and biological features of the fabricated PMMA-MgO composites, highlighting the potential of the PM15 composite with its enhanced density, mechanical strength, and excellent biocompatibility for denture applications. © 2024, The Author(s).
High-resolution analysis and prediction of heavy precipitation-induced GLOF events in North Sikkim Himalayas using the WRF model
(Elsevier Ltd, 2025) Peeyush Gupta; Manorama Sudhanshu Shekhar; Gyan Prakash Singh; Dev Sen Gupta; Amreek Singh; Amit Kumar; Rupesh Kumar; Dharmendra Singh Tomar
The northern Sikkim Himalaya hosts numerous high-altitude glacial lakes, many of which exhibit rapid expansion, rendering them highly susceptible to Glacial Lake Outburst Floods (GLOFs). These events release substantial volumes of water downstream, posing significant hydrometeorological hazards. The downstream regions of Sikkim, particularly the lower Teesta basin, experience flood hazards due to both direct precipitation and enhanced discharge from upstream glacial lakes. Among these, South Lhonak Lake (SLL), one of the largest lakes in the Teesta basin, has undergone rapid volumetric expansion, making it a critical hotspot for GLOF hazards. The study explores the application of the WRF model for GLOF-related research, offering a novel approach to understanding and predicting such events. This study used Weather Research and Forecasting (WRF) model to simulate and analyze heavy precipitation events across Sikkim, with a specific focus on the GLOF-triggering precipitation event of October 3–4, 2023, over the SLL region. The results suggest that intense precipitation, coupled with ice mass instability and lateral moraine failure, acted as the primary triggers for the catastrophic GLOF. Model simulations were conducted using high-resolution precipitation data acquired from the newly deployed X-band Doppler Weather Radar (DWR) installed by DGRE-DRDO at NIT Sikkim. The resulting outburst flood caused extensive damage to settlements, infrastructure, and hydropower projects along its course, extending several tens of kilometers downstream. The findings underscore the urgent need for an integrated monitoring framework combining high-resolution numerical weather prediction, satellite-based glacial lake surveillance, and real-time radar observations. This study represents the first application of the WRF model for GLOF-related precipitation forecasting in Sikkim, demonstrating its potential for enhancing early warning capabilities and risk mitigation strategies in the region. © 2025 Elsevier Ltd
Homology modeling, molecular docking and MD simulations study of 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline derivatives as sigma-2 receptor ligands
(Taylor and Francis Ltd., 2025) Vishakha Chaudhary; Shubhra Chaturvedi; Anju Wadhwa; Presenjit Verma; Divya Gautam; D. R. Sharma; Aastha Garg; Vishal Singh; Rupesh Kumar; Anil Kumar Mishra
The sigma-2 receptor has gathered attention as a promising target for cancer diagnosis and therapy since biochemical studies have evidenced the presence of the receptor in highly proliferating tumor cells. Computational drug design can help create targeted ligands against sigma-2, but a three-dimensional receptor structure is required as input. This study aims to develop a homology model of the human sigma-2 receptor. The template protein bovine sigma-2 (7m93) was aligned with the query sequence (Q5BJF2) to generate five models. These models were screened using potential energy parameters and molecular dynamics, with the model having the lowest energy and maximum stability being validated using stereo chemical parameters. The accepted model had 95.9% residues in allowed regions of the Ramachandran plot and an overall quality factor of 87.2611%. The model was tested using correlation analysis (R2= 0.744) of docking score and literature values of pKi. In addition, the model is used to understand the binding pattern of emerging selective 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline scaffold-based derivatives for designing ligands. The molecular dynamics studies of the model and ligand-bound model were performed for 100 ns to study the stability of the complexes, and the interactions compared with the known antagonist of sigma 2. © 2025 DRDO, India (previous affiliation). Published by Informa UK Limited, trading as Taylor & Francis Group.
Influence of TiO2as a filler into PMMA-ZrO2composites on structural, mechanical and biological properties for denture fabrication
(Elsevier Ltd, 2025) Akhileshwar Gupta; Savita Kumari; Sarvesh Kumar Avinashi; Rajat Kumar Mishra; Rupesh Kumar; Priyatama Behera; Monalisa Mishra; Rakesh Kumar C. Gautam; Saurabh Kumar; Shama Parveen; Jitendra Rao; Monisha Banerjee; Chandkiram Gautam
Polymethyl-methacrylate (PMMA) is widely being used in dentistry, while it has limited mechanical strength. Herein, PMMA composites were fabricated using heat cure technique within a system [(95-x) PMMA + 5 ZrO2 + x TiO2] (x = 8, 6, 4 and 2 wt%) and thoroughly characterized using density measurements, XRD, FTIR, SEM, EDAX, compression tests, 3-point bending, tribological, and hardness tests respectively. Moreover density, crystallite size, percentage of crystallinity, compressive strength, Young's modulus, flexural strength, flexural modulus, modulus of resilience, modulus of toughness, and brittleness coefficient were determined. Composite contains 5 wt% ZrO2and 2 wt% TiO2referred as ZPT2 exhibited the maximum compressive strength. Additionally, flexural strength and flexural modulus were found to be highest for ZPT2. The friction coefficient and hardness were found to be the lowest for ZPT2. In MTT (3-[4, 5-dimethylthiazol-2-yl]-2, 5- diphenyl tetrazolium bromide) assay, MG-63 osteoblast cells were exposed to various concentrations (5–30 μg/ml) of the compounds for 24 h. The results indicated that no significant cytotoxicity was observed for ZPT2. According to the results of the dye exclusion experiment, DAPI (4, 6-diamidino-2-phenylindole), and DCFH-DA (2, 7-dichlorodihydrofluorescein diacetate) staining, ZPT2 did not exhibit cellular damage, genotoxicity and reduced ROS (reactive oxygen species) production at lower concentrations. The combined biological results suggest that oral administration of the ZPT2 sample does not exhibit cytotoxicity and genotoxicity that makes it valuable for dentistry. © 2025 Elsevier Ltd and Techna Group S.r.l. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Insights Into Earthworms and Fungi: Pioneering Roles in Mitigating Global Food Scarcity and Combatting Land Degradation
(John Wiley and Sons Ltd, 2025) Sadashiv Chaturvedi; Amit Kumar; Min Liu; Khushi Mohan; Nikhilesh Singh; Rupesh Kumar
Climate change significantly impacts terrestrial ecosystems by altering soil moisture, temperature regimes, rainfall patterns, and frequency of extreme weather events. These disruptions lead to shifts in soil community structures, accelerates land degradation processes, which in turn exacerbate the global food crisis. This review explores the roles of earthworms and fungi in improving soil health and mitigating food insecurity through their contributions to nutrient cycling, soil fertility, and plant growth. Earthworms and fungi recognized as key biological agents in nutrient cycling, soil structures enhancement, and carbon sequestration. They play crucial roles in heavy metal remediation, soil quality, fostering sustainable agricultural practices such as organic farming. The review emphasizes the influence of earthworms on nutrient dynamics, particularly in response to organic residues management, soil characteristics, and field conditions. Earthworm activity positively affects soil microbial communities, which in turn impacts plant growth, even under stress factors like soil contamination and temperature extremes. Review identifies key research gaps in the understanding of earthworm and fungi distribution, performance, and their capacity for soil remediation in varied agro-ecological contexts. In addition to biotic factors, present review also examines alternative food habits and superfoods as strategies to address zero hunger, aligning with the United Nations Sustainable Development Goals (SDGs) for zero hunger, poverty eradication, improved health, and overall well-being. By incorporating earthworms and fungi into agricultural systems and addressing critical research needs, there is significant potential to mitigate land degradation and contribute to the alleviation of global food crises. © 2025 John Wiley & Sons Ltd.
Integrated Assessment of the Hydrogeochemical and Human Risks of Fluoride and Nitrate in Groundwater Using the RS-GIS Tool: Case Study of the Marginal Ganga Alluvial Plain, India
(Multidisciplinary Digital Publishing Institute (MDPI), 2024) Dev Sen Gupta; Ashwani Raju; Abhinav Patel; Surendra Kumar Chandniha; Vaishnavi Sahu; Ankit Kumar; Amit Kumar; Rupesh Kumar; Samyah Salem Refadah
Groundwater contamination with sub-lethal dissolved contaminants poses significant health risks globally, especially in rural India, where access to safe drinking water remains a critical challenge. This study explores the hydrogeochemical characterization and associated health risks of groundwater from shallow aquifers in the Marginal Ganga Alluvial Plain (MGAP) of northern India. The groundwater chemistry is dominated by Ca-Mg-CO3 and Ca-Mg-Cl types, where there is dominance of silicate weathering and the ion-exchange processes are responsible for this solute composition in the groundwater. All the ionic species are within the permissible limits of the World Health Organization, except fluoride (F−) and nitrate (NO3−). Geochemical analysis using bivariate relationships and saturation plots attributes the occurrence of F− to geogenic sources, primarily the chemical weathering of granite-granodiorite, while NO3− contaminants are linked to anthropogenic inputs, such as nitrogen-rich fertilizers, in the absence of a large-scale urban environment. Multivariate statistical analyses, including hierarchical cluster analysis and factor analysis, confirm the predominance of geogenic controls, with NO3−-enriched samples derived from anthropogenic factors. The spatial distribution and probability predictions of F− and NO3− were generated using a non-parametric co-kriging technique approach, aiding in the delineation of contamination hotspots. The integration of the USEPA human health risk assessment methodology with the urbanization index has revealed critical findings, identifying approximately 23% of the study area as being at high risk. This comprehensive approach, which synergizes geospatial analysis and statistical methods, proves to be highly effective in delineating priority zones for health intervention. The results highlight the pressing need for targeted mitigation measures and the implementation of sustainable groundwater management practices at regional, national, and global levels. © 2024 by the authors.
Recent Advancement in Organic Aerosol Understanding: a Review of Their Sources, Formation, and Health Impacts
(Institute for Ionics, 2023) Sadashiv Chaturvedi; Amit Kumar; Varsha Singh; Biswameet Chakraborty; Rupesh Kumar; Liu Min
Understanding the sources, mechanisms, and potential health impacts of volatile organic compounds (VOC) and secondary organic aerosols (SOA) is crucial for safeguarding human health, promoting sustainable industry and infrastructure practices, and addressing climatic challenges. These compounds originating from both anthropogenic and natural activities play a pivotal role in shaping air quality, climate dynamics, and public well-being. A comprehensive comprehension of their processes, interactions, and influence on atmospheric chemistry is imperative for devising effective strategies to mitigate associated health risks. This review comprehensively addresses the formation of biogenic and anthropogenic SOA, elucidates the intricate chemistry governing SOA generation, and expounds upon their far-reaching impacts. By encompassing diverse aspects such as tropospheric ozone, indoor and outdoor VOC and SOA formation, and the dynamic processes occurring during day and night cycles, this study facilitates a holistic understanding of the intricate interplay between VOC, SOA, and environmental dynamics, additionally underscores the importance of polycyclic aromatic hydrocarbons (PAHs) in this context. A deeper grasp of VOC and SOA sources, their transformation mechanisms, and the resulting implications will foster innovative solutions aimed at minimizing health risks, advancing sustainable industry practices, and driving climate action. This review delves into the multifaceted realm of VOC and SOA, highlighting their significance in achieving sustainable development goals (SDGs), particularly SGD-3 (Good Health and Well-being), 9 (Industry, Innovation, and Infrastructure), and 13 (Climate Action). © 2023, The Author(s), under exclusive licence to Springer Nature Switzerland AG.