Browsing by Author "Rajendra K. Singh"

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A novel hybrid sodium ion capacitor based on Na [Ni0.60Mn0.35Co0.05] O2 battery type cathode and presodiated D-Ti3C2Tx pseudocapacitive anode
(Elsevier Ltd, 2024) Vikas Yadav; Anupam Patel; Anurag Tiwari; Samriddhi; Shitanshu Pratap Singh; Raghvendra Mishra; Rajendra K. Singh
The combination of the high-power density of supercapacitors and the high energy density of batteries makes hybrid sodium-ion capacitors (HSICs) a promising device. HSICs can provide better performance characteristics by harnessing both ion adsorption/desorption in the capacitor-type electrode and sodium-ion intercalation in the battery-type electrode. Here, the synthesis of MXene (Ti3C2Tx), a two-dimensional (2D) carbide and nitride is reported. Delaminated MXene (D-Ti3C2Tx) is a promising candidate for anode material in HSIC due to its large surface area (∼ 42 m2/g) and good electronic conductivity. Electrochemical study indicates that D-Ti3C2Tx anode exhibits a high discharge capacity of ∼213 mAh/g at a current rate of 20 mA/g. Further the presodiated D-Ti3C2Tx anode is paired with Na [Ni0.60Mn0.35Co0.05] O2 (P2-NMC) cathode to obtain the configuration of HSIC. The HSIC exhibits good specific capacitance of ∼187 F/g and specific discharge capacity of ∼110 mAh/g at a current density of 10 mA/g, according to the electrochemical analysis. A notable improvement in specific energy density (∼ 256 Wh/kg) and specific power density (∼579 W/kg) is also demonstrated by the HSIC. With P2-NMC being used as the cathode material rather than traditional activated carbon, there has been a rise in specific energy density. © 2024 Elsevier B.V.
A twofold approach for prolonging the lifespan of cobalt-free Na[Ni0.55Mn0.35Fe0.1]O2 cathode via Bi5+-doping and Bi2O3 coating in sodium ion batteries
(Elsevier Ltd, 2024) Raghvendra Mishra; Rupesh K. Tiwari; Anupam Patel; Anurag Tiwari; Rajendra K. Singh
A cobalt-free biphasic (P2/O3) layered Na[Ni0.55Mn0.35Fe0.1]O2 (NFM) cathode material has been synthesized and dual surface and structural modifications have been performed. Bi5+ is doped into pure NFM in order to tune the P2/O3 phase, whereas, a thin layer of Bi2O3 is coated on surface of the Bi5+-doped NFM (BNFM) for surface modification. The structure, morphology, and electrochemical performance of prepared samples are analyzed and compared by various characterization techniques. The pristine NFM cathode exhibits the specific discharge capacity of 170 mAh g−1, while Bi-doped cathode exhibits 181 mAh g−1, and Bi2O3 coated cathode renders 180 mAh g−1. It is observed that, pristine NFM cathode suffers rapid capacity degradation and nearly ~80 % capacity loss within first 250 cycles. After 1000 cycles, BNFM shows 47 % capacity retention, while, Bi2O3 coated BNFM (BNMF@Bi2O3) shows 73 % capacity retention of initial capacity. This improvement in the rate capability is obtained due to the effect of Bi-doping and Bi2O3 coating, where, former enlarges interlayer spacing and latter provides the ionic conducting channel as well as protects the particle from the contact of the electrolyte. The combined effect of Bi-doping and Bi2O3 coating facilitates fast diffusion of Na-ions within the transition metal layers resulting in superior rate capability. © 2023 Elsevier Ltd
Absorption and velocity of acoustical waves in binary solutions of poly(ethylene glycol) and water
(2008) Rajendra K. Singh; Manish P. Singh; Rishi P. Singh
The velocity and absorption of ultrasonic waves have been measured in aqueous solutions of poly (ethylene glycol). The velocity of ultrasonic waves has been obtained in the frequency range 1MHz-12MHz over a wide range of temperature. The concentration (by weight) ranged from 1% to 10% of poly (ethylene glycol) in water. The shear viscosity has also been measured. Measurements were carried out in the temperature range 35 °C to 65 °C. It has been observed that the velocity of ultrasonic waves increases with temperature at a given concentration, while as concentration is increased at a given temperature, velocity is found to increase. The shear viscosity and density also decrease with temperature. © 2008 Acoustical Society of America.
Boosting sodium hybrid-ion capacitor performance via exfoliated Ti3C2TX (O/OH/F) anode and bio-derived activated hard carbon cathode
(Elsevier Ltd, 2025) Vikas G. Yadav; Anupam Patel; Anurag Tiwari; Samriddhi; Shitanshu Pratap Singh; Tanya Jaiswal; Rajendra K. Singh
The exfoliated MXene (eTCT) was synthesized from its parent MAX phase using a hydrofluoric acid-free etching system (HCl/LiF). The resulting eTCT sample exhibits a specific surface area of 51 m2 g−1 The fabricated eTCT electrode demonstrates remarkable electrochemical performance, delivering a high gravimetric specific discharge capacity of ∼280 mAh g−1 and an impressive specific capacitance of ∼385 F g−1, along with excellent rate capability. Cyclic voltammetry measurements reveal maximum specific capacitances of ∼730 F g−1 and ∼ 418 F g−1 at scan rates of 0.1 mV/s and 0.5 mV/s, respectively. After 150 cycles, the eTCT cell retains approximately 70 % of its initial discharge capacity, corresponding to a capacity fade rate of only 0.2 % per cycle. For energy storage applications. Further MXene's potential is explored by fabricating a sodium hybrid-ion capacitor (SHIC). Based on the total active mass of both electrodes, the SHIC achieves a gravimetric specific capacitance of 79 Fg−1. The eTCT//AMHC system demonstrates outstanding power and energy densities reaching ∼4.1 kW k g−1 and 156 Wh k g−1, respectively. These values surpass many lithium-based capacitors, highlighting the superior performance of MXene-based devices. The Wien2k calculations reveal that LiF-etched MXene exhibits enhanced electronic conductivity. Notably, MXene ([sbnd]F, -OH, [sbnd]O) show higher density of states (DOS) near the Fermi level compared to MAX phase, suggesting the enhancement in metallic character of MXene. Furthermore, the strong Na[sbnd]O interaction in Ti3C2O2 makes it particularly promising for sodium-ion storage applications. © 2025
Cation-Cation, Cation-Anion, and Anion-Anion Translation Diffusion in Ionic Liquids─Insight from NMR Relaxometry
(American Chemical Society, 2025) Elzbieta Masiewicz; Roksana Markiewicz; Rajendra K. Singh; Sujeet Kumar Chaurasia; Danuta Kruk
1H and 19F spin-lattice relaxation experiments have been performed for a series of ionic liquids: [HMIM][TFSI], [OMIM][TFSI], and [DMIM][TFSI] including the same anion and cations with progressively longer alkyl chains. The experiments were performed in a wide frequency range from 10 kHz to 10 MHz (referring to the 1H resonance frequency) versus temperature. This extensive data set has been analyzed in terms of a theoretical model including all relevant homonuclear (1H-1H and 19F-19F) and heteronuclear (1H-19F) relaxation pathways and linking the relaxation features to the relative translational diffusion between the ion pairs (cation-cation, cation-anion, and anion-anion). In addition to the comprehensive theoretical approach, closed-form expressions have been provided and applied to determine the diffusion coefficients from the slopes of the linear dependences of the relaxation rates on the square root of the resonance frequency. The combined experimental and theoretical studies have led to the determination of the complete set of diffusion coefficients, forming a consistent picture of the dynamical scenario. In addition to revealing the dynamical properties of the liquids and the influence of the subtle changes in the cation structure on the movement of both cations and anions, the theoretical means for exploiting Nuclear Magnetic Resonance relaxometry for ionic liquids have been provided. © 2024 American Chemical Society.
“Characterizing metabolic changes in rice roots induced by Meloidogyne graminicola and modulated by Arthrobotrys oligospora: A pathway-based approach”
(Academic Press, 2025) Vedant Gautam; Vibhootee Garg; Ravi Nagar; Nitesh K. Meena; Sunidhi Kumari; Hivre Anand Dashrath; Shreyashi Singh; Shubham Patel; Mukesh; Himanshu Singh; Prahlad Masurkar; Rajendra K. Singh
Root-knot nematodes (Meloidogyne graminicola) are significant agricultural pests that adversely affect rice yield and quality. Understanding the metabolic responses of rice to these pathogens, and the potential modulation by beneficial microorganisms like nematophagous fungi, is crucial for developing effective disease management strategies. This study explores the metabolic responses of rice roots to Meloidogyne graminicola infection and its modulation by the nematophagous fungus Arthrobotrys oligospora. Utilizing NMR-MS in negative ion mode, we identified 172 metabolite features, with 81 showing significant differences (p ≤ 0.1) between pathogen-challenged and non-challenged conditions. Among these, 47 metabolites were upregulated and 34 were downregulated. Principal Component Analysis (PCA) and Partial Least Squares Discriminant Analysis (PLS-DA) effectively differentiated between treatment groups, revealing key biomarkers such as tryptophan, 4-hydroxyphenylacetate, isopropanol, and glucuronate. Notably, acetone and ribose were upregulated, suggesting their role in stress responses and metabolic adaptation. Conversely, downregulated metabolites included N-isovaleroylglycine and 2-hydroxy-3-methylvalerate, reflecting reduced levels in pathogen-challenged roots. Pathway enrichment analysis highlighted significant metabolic pathways involved in plant defense, including glutathione metabolism, phenylalanine, tyrosine, and tryptophan biosynthesis, and amino sugar metabolism. These findings enhance our understanding of the metabolic adjustments in rice roots during pathogen attack and underscore potential biomarkers and pathways for improving crop resistance. The results provide a foundation for future research aimed at developing effective disease management strategies and enhancing plant resilience through targeted metabolic interventions. © 2024 Elsevier Ltd
Conducting Carbon Rich Graphitic Carbon Nitride Nanosheets with Attached Nano Sulfur Copolymer as High Capacity Cathode for Long-Lifespan Lithium-Sulfur Battery
(John Wiley and Sons Inc, 2022) Rupesh K. Tiwari; Shishir K. Singh; Nitin Srivastava; Raghvendra Mishra; Dipika Meghnani; Anupam Patel; Anurag Tiwari; Vimal K. Tiwari; Rajendra K. Singh
A mesoporous, conducting, high specific surface area, carbon-rich graphitic carbon nitride (GCN) nanosheets host covered by nano sulfur copolymer has been reported as a cathode material that shows high capacity along with long cyclability for rechargeable lithium-sulfur batteries (LiSBs). The thermal pyrolysis technique has been used for carbon-rich GCN sheets synthesis, and the chemical deposition approach has been used to attach surface nanoparticles to the sheets. Further, to improve the binding of nano sulfur with host material, copolymerization of nano sulfur is carried out with help of 1,3-diethynylbenzene (DEB) monomer through the solution route. The sulfur nanoparticles are loaded on conducting carbon-rich GCN framework for fast electro kinematics and further copolymerization of sulfur nanoparticles is done to prevent the dissolution of the active material (sulfur) into the electrolyte during the charging/discharging for high capacity and long cycle life rechargeable LiSBs cathode preparation. The synthesized composite with high sulfur loading (∼76 wt.% of composite cathode material) as cathode shows an initial discharge capacity of ∼1380 mAh g−1 at 0.1 C and a good discharge capacity of ∼700 mAh g−1 after 1000 cycles at 1 C with ultra-low-capacity fading ∼0.016 % of the initial capacity in each cycle. © 2022 Wiley-VCH GmbH.
Development of gel polymer electrolyte based on LiTFSI and EMIMFSI for application in rechargeable lithium metal battery with GO-LFP and NCA cathodes
(Springer New York LLC, 2019) Liton Balo; Himani Gupta; Shishir K. Singh; Varun K. Singh; Alok K. Tripathi; Nitin Srivastava; Rupesh K. Tiwari; Raghvendra Mishra; Dipika Meghnani; Rajendra K. Singh
In this paper, we report the effect of ionic liquid 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (EMIMFSI) on polymer poly(ethylene oxide) (PEO) and salt lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) electrolyte system. The glass transition temperature and degree of crystallinity decreased with an increasing amount of EMIMFSI resulting in an increase in the ionic conductivity. The highest room temperature ionic conductivity and Li+ transference number are observed for PEO + 20 wt% LiTFSI + 10 wt% EMIMFSI. These prepared gel polymer electrolytes (GPEs) are thermally and electrochemically stable enough for battery application. Two different cells with graphene oxide-doped lithium iron phosphate, LiFePO4 (GO-LFP) and lithium nickel cobalt aluminum oxide, LiNi0.80Co0.15Al0.05O2 (NCA) cathodes were tested with prepared GPEs. GO-LFP showed more predictable and consistent nature of capacity fading and good discharge capacity. However, NCA showed higher discharge capacity, better cyclic performance, lower capacity fading, and better performance at high C rates. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.
Dielectric relaxation and conductivity studies on (PEO:LiClO4) polymer electrolyte with added ionic liquid [BMIM][PF6]: Evidence of ion-ion interaction
(2011) Sujeet K. Chaurasia; Rajendra K. Singh; S. Chandra
Polymer electrolytes, (PEO:LiClO4)+x IL (1-Buty-3- methylimidazolium hexafluorophosphate) with varying concentration of IL; x = 0,5,10,15,20 wt % have been prepared by solution cast technique and characterized by X-Ray diffraction, differential scanning calorimetery, FTIR, conductivity and dielectric relaxation measurements in the frequency range of 100 Hz-5 MHz. Temperature dependence of relaxation frequency and conductivity were found to be typical of thermally activated process both at T > T m and T < Tm. Composition dependence of conductivity, dielectric relaxation, and degree of crystallinity has also been studied. On addition of IL, the degree of crystallinity after a decrease at 5 wt % IL increases slightly at 10 wt % and then finally decreasing. Variation of conductivity and relaxation frequency with composition could only be partly explained on the basis of variation of degree of crystallinity. An additional feature of ion-ion interaction (contact ion pair formation between IL or salt cations and their associated anions) has been invoked which was supported by FTIR studies. © 2010 Wiley Periodicals, Inc.
Diffusion mechanism in a sodium superionic sulfide-based solid electrolyte: Na11Sn2AsS12
(Institute of Physics, 2022) Anurag Tiwari; Shishir K. Singh; Nitin Srivastava; Dipika Meghnani; Raghvendra Mishra; Rupesh K. Tiwari; Anupam Patel; Himani Gupta; Vimal K. Tiwari; Rajendra K. Singh
Recently, in all solid-state batteries, sulfide-based solid electrolytes have received increased attention due to their high ionic conductivity, good mechanical features, and better chemical stability. Therefore, in the present study, we have synthesized a novel sodium superionic conducting sulfide-based inorganic solid electrolyte (Na11Sn2AsS12) using a solid-state reaction method. The prepared solid electrolyte (Na11Sn2AsS12) is characterized by different techniques such as x-ray diffractometry (XRD), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy, thermogravimetric analysis (TGA), electrochemical impedance spectroscopy, and linear sweep voltammetry to study its various properties such as structure, surface morphology, thermal stability, dielectric properties, ionic conductivity, and electrochemical stability window for sodium ion battery (SIB) applications. The XRD analysis confirms two coexisting phases - tetragonal and cubic, with phase fractions of 0.69 and 0.31, respectively. The SEM study reveals the irregular shape and dense morphology of the solid electrolyte. On the other hand, TGA shows that the prepared solid electrolyte is suitable for high temperature battery applications. The ionic and transport studies confirm that the synthesized Na11Sn2AsS12 is purely ionic in nature, with ionic conductivity found to be 1.14×10-4 S cm-1 and negligible electronic conductivity 1/4 1.43×10-10 S cm-1 at room temperature. Furthermore, the detailed ionic conduction mechanism is studied using temperature and frequency-dependent AC impedance analysis. In addition, the synthesized solid electrolyte Na11Sn2AsS12 exhibits a wide electrochemical window ( 1/47.0 V) and a high diffusion coefficient ( 1.3×10-7 cm2 s-1) showing suitable electrolyte properties for solid-state SIB applications. © 2022 IOP Publishing Ltd.
Electrochemical investigation of double layer surface-functionalized Li-NMC cathode with nano-composite gel polymer electrolyte for Li-battery applications
(Elsevier Ltd, 2022) Shishir K. Singh; Dimple P. Dutta; Himani Gupta; Nitin Srivastava; Raghvendra Mishra; Dipika Meghnani; Rupesh K. Tiwari; Anupam Patel; Anurag Tiwari; Rajendra K. Singh
A long cycle-stability and safety is key requirement for the large-scale application of rechargeable Li-batteries. In this study, a thin double-layer (reduce graphene oxide and Li2MoO4) coated Li-NMC111 cathode is successfully synthesized which delivers improved electrochemical performance such as higher specific energy density and better rate capability, as compared to the pristine Li-NMC111. Furthermore, a freestanding/flexible nano-composite gel polymer electrolyte (NGPEs) is successfully prepared by solution cast technique and found suitable for high-temperature Li-battery applications. The developed 5 wt.% MCM-41 containing NGPE (NGPE#1) not only facilitates enhanced Li-ion conductivity of ∼4.4 ✗ 10−3 S cm−1 at 30 °C but also prevents uncontrolled lithium dendrite growth. The RGO-wrapped Li2MoO4@Li-NMC111 cathode with optimized NGPE#1 delivers high specific discharge capacity (∼211 mAh g − 1 at 0.2C and ∼157 mAh g − 1 at 0.5C) and specific energy density (∼728 mWh g − 1 at 0.2C and ∼520 mWh g − 1 at 0.5C) as compared to pristine Li-NMC111 cathode. Moreover, after 100 cycles, the discharge capacity of RGO-wrapped Li2MoO4@Li-NMC111 with optimized NGPE#1 is obtained ∼150 mAh g − 1 at 0.5C, with 75% capacity retention of the maximum capacity. In addition, at 70 °C, the specific discharge capacity of Li/RGO-wrapped Li2MoO4@Li-NMC111 cell with optimized NGPE#1 is obtained ∼186 mAh g − 1 at 0.5C. © 2022 Elsevier Ltd
Enhanced Cyclic Stability of LiNi0.815Co0.15Al0.035O2 Cathodes by Surface Modification with BiPO4 for Applications in Rechargeable Lithium Polymer Batteries
(John Wiley and Sons Inc, 2021) Dipika Meghnani; Himani Gupta; Shishir K. Singh; Nitin Srivastava; Raghvendra Mishra; Rupesh K. Tiwari; Anupam Patel; Anurag Tiwari; Rajendra K. Singh
The effect of incorporating the ionic liquid (IL) N-methyl-N-propyl piperidinium bis(fluorosulfonyl)imide (PP13FSI) to a polymer electrolyte (PE) based on the polymer poly(ethylene oxide) (PEO)- lithium bis(fluorosulfonyl)imide (LiFSI) [PEO+20 wt.% LiFSI] is investigated. The concentration of PP13FSI IL is varied from 10 to 40 wt.% in the PEO+20 wt.% LiFSI system and the influences of the ionic conductivity, thermal stability, diffusion coefficient, and electrochemical stability are studied. The 40 wt.% IL containing PE shows good thermal stability ∼210 °C and high ionic conductivity, (Formula presented.), at 40 °C with a wide electrochemical stability window ∼4.7 V vs. Li/Li+ and high (Formula presented.) at 30 °C. Furthermore, the electronic conducting BiPO4 is coated on the LiNi0.815Co0.15Al0.035O2 (BiPO4@NCA) cathode by the liquid precipitation method. To investigate the structural and electrochemical properties of the pristine and BiPO4@NCA cathodes, XRD, SEM, TEM, and DSC as well as the electrochemical method are employed. The XRD results reveal a hexagonal layered structure without any impurity phase in BiPO4@NCA. The TEM investigations show that the BiPO4 layer (∼10 nm) is homogeneously coated on the NCA particles. The electrochemical testing showed an improvement in the cyclic performance of BiPO4@NCA with a capacity retention 94.64 % after 150 cycles, which is 8 % greater than that of the pristine NCA. © 2021 Wiley-VCH GmbH
Evaluation of Resistance in Indian Rice to Root-Knot Nematode (Meloidogyne graminicola): Insights from Field and Histopathological Studies
(Springer, 2025) Vedant Gautam; Vibhootee Garg; Hivre Anand Dashrath; Nitesh K. Meena; Nikhil Kumar Singh; Ashish Kumar; Nethi Somasekhar; Rajendra K. Singh
Rice (Oryza sativa L.) is a staple crop for over half of the global population, yet its cultivation faces significant threats from biotic stresses, particularly root-knot nematodes (Meloidogyne spp.). Among these, M. graminicola poses a major challenge in rice-growing regions, leading to substantial yield losses. This study evaluated the resistance of 348 rice varieties to M. graminicola through controlled pot and field experiments over two years (2023 and 2024). Varieties were classified based on gall index, revealing a spectrum of susceptibility from highly susceptible to highly resistant. Notably, varieties such as JR-1124 and JR-403 exhibited high gall index, while others like RP-5219-9-7-3-2-1-1, NPT-10, MTU 1390 (IR17M1172), Kushiari, RP 6750-RMS-2-23-67-91, Sonkharchi, Sugandha-3, HRT-183, and HR-12 demonstrated significant resistance. Resistant rice genotypes exhibited significantly higher PAL, POX, and total phenolic content at all intervals, indicating a strong biochemical defense response against Meloidogyne graminicola. Advanced techniques, including confocal microscopy, revealed distinct histopathological responses to M. graminicola infection, with susceptible rice varieties exhibiting extensive giant cell formation and root tissue degradation, while a resistant variety displayed restricted giant cell development, enhanced callose deposition, and maintained vascular integrity—highlighting robust defense mechanisms against nematode invasion. The findings underscore the potential for breeding programs to enhance resistance traits in rice, contributing to sustainable agricultural practices and improved food security. As nematode populations evolve, ongoing research is essential to adapt breeding strategies and maintain effective management of this significant pest in rice production systems. © The Author(s) 2025.
Exploring Ustilaginoidea virens, the causal agent of false smut of rice disease: A comprehensive study of infection dynamics, effectors, and genetic structure
(Academic Press, 2025) Prahlad Masurkar; Jhumishree Meher; Sukram Thapa; Rajendra K. Singh; Manas Kumar Bag; Vedant Gautam; Shivam Maurya
Villosiclava virens (Anamorph: Ustilaginoidea virens) is an important and enigmatic pathogen that causes rice false smut. Some similarities between Claviceps and Ustilaginoidea genera have been found, but according to recent genomic sequence comparison research, they have different sequences. U. virens secretes mycotoxins, which make the infected grains unfavorable for human consumption. The transcriptomic analysis and genome sequencing of U. virens showed 52,554,142 clean reads assembled into 36,496 transcripts, representing 18,534 unigenes. U. virens also contains the UvNLP protein as an NLP-specific NPP1 domain that belongs to a MAMPs class protein that acts as an elicitor for defence responses in resistant plants. Unique proteins, UvCGBP1, UvPRO1, and UvBI-1, are associated with the virulence, growth, and sporulation of U. virens. Several host QTLs-qFsr1, qFsr2, qFsr4, qFsr8, qFsr10, qFsr11 and qFsr12 have been validated in diverse background (IR28, Tequing NILs, MR183-2), and are crucial for resistance breeding. The genetic diversity of U. virens was measured using molecular markers, including RAPD, AFLP, SSR, ISSR, and, more recently, SNPs. The genetic diversity of U. virens isolates was higher among the isolates than in the geographical population. This review integrates advances in molecular biology, genomics, and host-pathogen interactions to inform sustainable management strategies. Further research is needed in early detection, chlamydospore germination, targeted fungicides, and resistant hybrid rice development. © 2025 Elsevier Ltd
Foot-and-mouth disease virus alters MUC genes expression and function of goblet cells in the intestines of naturally infected cattle calves
(Academic Press, 2025) Monalisa Sahoo; Rajendra K. Singh; Sagar M. Patel; Susen Kumar Panda; A. P. Acharya; Ritun C. Patra; Saminathan M; Vinay Kumar Sd; Rajesh Kumar Vandre; Jigyasa Rana; Mamata Pasayat; Jagannath Prasad Tripathy; N. R. Sahoo; Jitendra Kumar Biswal; Rabindra Prasad Singh
Foot-and-mouth disease (FMD), the “Risk Group 4” animal pathogen, causes devastating economic losses world over. The mechanism of the disease process is still not fully explored despite extensive research work going on. The present work highlights the intestinal pathology with mucin gene expression in 41 calves died from FMD virus infection in two separate outbreaks. A total of 41 intestinal (both small and large intestines) and mesenteric lymph node tissue were collected from these cases and tested for the presence of the FMD virus/antigen and various host cell responses using patho-molecular techniques. For the comparison, intestine and mesenteric lymph nodes from 2 apparently healthy calves were collected. Grossly, the small and large intestines showed marked congestion, thickening of the mucosa and the presence of catarrhal exudates within the lumen. The mesenteric lymph nodes (MLNs) were swollen and congested (21 cases). Microscopically, the intestine showed villous atrophy, crypt elongation, crypt cell proliferation, reduced number of goblet cells, necrosed villi, and lymphocytic infiltration in the lamina propria and sub-mucosa. The MLNs showed depleted cortical follicles and apoptotic bodies (19 cases). The lesions were predominant in the small intestine as compared to the large intestine. The affected intestine showed higher apoptosis cell counts, increased levels of proinflammatory cytokine genes (TNF-α, IL-1β), and reduced number of goblet cells containing sulphated mucins. In multiplex-PCR, the viral genome was detected in the intestine, and lymph nodes of 32 and 21 cases, respectively. Immunohistochemically, abundant cytoplasmic immunoreactivity was noticed mostly in the crypt epithelium of the affected intestine suggesting the association of the virus with intestinal pathology. The MLNs showed moderate immunoreactivity for viral antigen with higher apoptosis counts in 9 cases, suggesting the association of the virus with lymphocytolysis. The reduced expression of MUC1, MUC2, MUC4 mRNAs, while increased. expression of MUC5AC and MUC20 mRNAs was observed in the affected intestine. However, no significant difference in the expression level of MUC15 mRNA was observed. A similar distribution of MUC1, MUC2, and MUC5AC antigens was observed in the paraffin embedded tissue sections of the intestine of FMDV infected calves. The histopathological lesions, immunodetection of viral antigens, increased levels of pro-inflammatory cytokines, reduced goblet cell numbers with altered mucin gene expression likely lead to a defective absorptive function of the intestinal epithelium, which contributes to FMDV pathogenesis. © 2025
Fungal-derived ZnO nanoparticles functionalized with riboflavin and UDP-GlcNAc exhibit potent nematicidal activity against M. incognita
(Nature Research, 2025) Vedant Gautam; Vibhootee Garg; Nitesh K. Meena; Hivre Anand Dashrath; Kaminee Singh; A. Kumar; Ashish Ashwin Kumar; Rajendra K. Singh
This study reports the green synthesis of zinc oxide nanoparticles (ZnO NPs) using the nematophagous fungus Arthrobotrys oligospora and their evaluation as nematicidal agents against Meloidogyne incognita. The ZnO NPs were synthesized from fungal culture filtrate and characterized by UV–Vis, FTIR, XRD, Raman spectroscopy, SEM, TEM and EDAX confirming nanoscale particles (29.45–71.30 nm) with hexagonal wurtzite crystallinity. ^1H NMR-based metabolomics revealed functionalization of the nanoparticle surface with fungal metabolites, notably riboflavin and UDP-N-acetylglucosamine. In vitro bioassays demonstrated strong, dose-dependent nematicidal activity, achieving 94.8% juvenile mortality at 200 µg/mL after 72 h, significantly higher than the fungal extract alone (p < 0.05). Molecular docking showed that ZnO–riboflavin bound effectively to acetylcholinesterase and ZnO–UDP-GlcNAc to chitin synthase, suggesting dual disruption of neural signaling and cuticle biosynthesis. Collectively, these findings establish A. oligospora-mediated ZnO NPs as a metabolite-enriched nano-biocomposite with enhanced nematicidal efficacy, offering a novel and eco-friendly strategy for sustainable crop protection. © The Author(s) 2025.
Harnessing NMR technology for enhancing field crop improvement: applications, challenges, and future perspectives
(Springer, 2025) Vedant Gautam; Vibhootee Garg; Nitesh K. Meena; Sunidhi Kumari; Shubham Patel; Mukesh; Himanshu Singh; Shreyashi Singh; Rajendra K. Singh
Introduction: Nuclear Magnetic Resonance (NMR) spectroscopy has emerged as a transformative technology in agricultural research, offering powerful analytical capabilities for field crop improvement. With global challenges such as food security and climate change intensifying, there is an urgent need for innovative methodologies to enhance our understanding of plant health, metabolic pathways, and crop-environment interactions. NMR’s ability to provide nondestructive, real-time analysis of plant metabolites and soil chemistry positions it as a critical tool for addressing these pressing concerns. Objective: This review aims to elucidate the potential of NMR spectroscopy in advancing field crop improvement by highlighting its applications, challenges, and future perspectives in agricultural methodologies. The focus is on the evolution and application of NMR in agricultural research, particularly in metabolomics, phenotyping, and quality assessment. Method: A comprehensive literature review was conducted to analyze recent advancements in NMR applications in agriculture. Particular emphasis was given to high-resolution magic angle spinning (HR-MAS) and time-domain NMR techniques, which have been instrumental in elucidating plant metabolites and soil chemistry. Studies showcasing the integration of NMR with complementary technologies for enhanced metabolic profiling and genetic marker identification were reviewed. Results: Findings indicate that NMR spectroscopy is an indispensable tool in agriculture due to its ability to identify biomarkers indicative of crop resilience, monitor soil composition, and contribute to food safety and quality assessments. The integration of NMR with other technologies has accelerated metabolic profiling, aiding in the breeding of high-yielding and stress-resistant crop varieties. However, challenges such as sensitivity limitations and the need for standardization remain. Conclusion: NMR spectroscopy holds immense potential for revolutionizing agricultural research and crop improvement. Overcoming existing challenges, such as sensitivity and standardization, is crucial for its broader application in practical agricultural settings. Collaborative efforts among researchers, agronomists, and policymakers will be essential for leveraging NMR technology to address global food security challenges and promote sustainable agricultural practices. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2025.
Ion-polymer and ion-ion interaction in PEO-based polymer electrolytes having complexing salt LiClO4 and/or ionic liquid, [BMIM][PF 6]
(John Wiley and Sons Ltd, 2011) Sujeet K. Chaurasia; Rajendra K. Singh; S. Chandra
Ion-polymer and ion-ion association in polymer electrolyte films of PEO complexed with salt LiClO4, ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate, BMIMPF6) and (LiClO4 + BMIMPF 6) have been studied by laser Raman spectroscopy. The cations (Li+ and/or BMIM+) of the dopant salt/IL are shown to complex with the ether oxygen of the polymer backbone (i.e. C-O-C bond of PEO). The polymer-cation complexation results in the appearance of an additional peak at ∼1131 cm-1 apart from the C-O-C stretching vibrations of PEO at ∼1062 and 1141 cm-1. This peak due to polymer-cation complexation is relatively strong for LiClO4 than BMIMPF6, indicating stronger interaction for the former. In the PEO:LiClO4 and PEO:BMIMPF6 spectra, Raman peaks at 937 and 747 cm-1, respectively related to Li+· ClO and BMIM+· PF 'contact ion pairs', have also been observed as a result of ion-ion association. In the polymer electrolyte PEO:LiClO4 + BMIMPF 6 which contained two different anions, viz. ClO and PF, an interesting observation of the formation of 'cross contact ion pairs' viz. Li+· PF and BMIM+· ClO is also reported. Copyright © 2011 John Wiley & Sons, Ltd.
Liquid metal batteries for large-scale energy storage
(CRC Press, 2025) Vikas Yadav; Rajendra K. Singh
[No abstract available]
Mitigating the Capacity Degradation by Ion-Electron-Conducting Dual-Layer Coating on a Layered Oxide Cathode Material for Sodium Ion Batteries
(American Chemical Society, 2023) Raghvendra Mishra; Shishir K. Singh; Nitin Srivastava; Rupesh K. Tiwari; Dipika Meghnani; Anupam Patel; Anurag Tiwari; Vimal K. Tiwari; Rajendra K. Singh
A high-capacity and long-life layered P2-Na0.7[Ni0.35Mn0.60Co0.05]O2 (NMC) cathode material, dually coated with Na-ion-conducting Na2SiO3 and electron-conducting RGO, has been successfully synthesized and tested for half-cell as well as full-cell applications. The first coating layer of Na2SiO3 provides a three-dimensional (3D) diffusion channel for Na-ion migration, while the second coating layer of RGO offers the electron-conducting pathways to enhance the charge transfer. Moreover, Si4+ migration in the NMC lattice during Na2SiO3 coating causes the enhancement in the interlayer spacing, which significantly increases the Na+-diffusion rate. The structural, morphological, electronic, and electrochemical analyses of the prepared cathode materials have been performed. The synergic effect of dual-layer modification and Si4+ doping not only protects the cathode particles but also improves the Na-ion kinetics as well as charge transfer rate, resulting in superior electrochemical performance. The dually surface-modified cathode shows a maximum discharge capacity of 171 mAh g-1 at ∼13 mA g-1 and 62 mAh g-1 at ∼1300 mA g-1 with 76% capacity retention and ∼98% coulombic efficiency over 500 cycles at 1C rate (260 mA g-1) for the half cell, while for the full cell, it delivers an initial discharge capacity of ∼91 mAh g-1 and 66% capacity retention over 1000 cycles at 1C rate. © 2023 American Chemical Society.