Browsing by Author "Anamika"

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A New Series of Heteroleptic Cd(II) Diimine-Ferrocenyl Dithiocarbamate Complexes which Successfully Co-Sensitizes TiO2 Photoanode with Ru N719 Dye in DSSC
(Wiley-Blackwell, 2017) Krishna K. Manar; Neetu; Anamika; Pankaj Srivastava; Michael G. B. Drew; Nanhai Singh
New heteroleptic complexes of the form [Cd(diimine)(Fcdtc)2] (diimine= 1,10-phenanthroline (phen), Fcdtc=N-ferrocenyl-N-pyridin-3-ylmethyl dithiocarbamate (KL1) Cd1; 2,2’-bipyridyl (bpy), N-ferrocenyl-N-pyridin-4-ylmethyl dithiocarbamate (KL2) Cd2; bpy, (KL1) Cd3 and phen, (KL2) Cd4) have been synthesised and characterized by elemental analyses, spectroscopy (IR, UV-Vis., 1H and 13C {1H} NMR) and their structures have been revealed by X-ray crystallography. These complexes have been explored as co-sensitizers with N719 over TiO2 for application as dye sensitized solar cells (DSSC) photoanodes. The use of these complexes as co-sensitizers resulted in extended UV-Visible spectral response, greater dye loading, enhanced electron life time, reduced charge recombination and thermodynamically more facile charge transfer in the DSSC. Among all the co-sensitized cells (Cd1/N719, Cd2/N719, Cd3/N719 and Cd4/N719), the Cd1-based cell demonstrated not only the highest incident photon to current efficiency (IPCE) 47% but the obtained current conversion efficiency 3.84%, was much higher than that of the N719 based cell (2.70%) under the same illumination condition. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Development of Dactylaria eudermata Drechsler a predaceous fungi in meloidogyne incognita
(2011) Anamika; R.K. Singh
Dactylaria eudermata Drechsler is one of the important predaceous fungi occurring widely in different soils. The fungus produces hyphal bails and network compound in which nematodes are entangled. This hyphal nets as trapping structure which may be single dimensional to two or three dimensional and are formed through repeated hyphal anastomosis, which capture nematodes either through the adhesive material present on the surface of hyphal nets or due to physical entanglement. In the experiment it was observed that inflation of hyphal bails takes 30 to 50 minutes and capturing and killing the nematode by a single conidia in water takes 35-55 hours, were as time required for inflation of hyphal bails and real trapping and killing of a nematode in maize meal (MMA: water (1:10) medium) takes one minute and 30-50 hours respectively. © 2011 Taylor & Francis.
Distribution of root-knot nematode on major field crops in Uttar Pradesh (India)
(2011) Anamika; Sobita Simon; K.P. Singh; G. Ghosh
An extensive survey was conducted (2007-2009) to assess the incidence and intensity of root-knot disease on field crops especially rice and vegetable crops in 21 districts, representing the major production centre in Uttar Pradesh (India). Based on incidence, population density and associated damage on affected crops, Meloidogyne species were considered to be the most important parasites of the crops under local condition. The increasing occurrence and damage of this nematode to tomato, rice, brinjal, okra, cowpea, cucurbits, onion, pumpkin and bitter gourd grown in northern India was recently documented. Heavy galling was caused in many crops including rice, tomato, okra, cowpea, onion, pumpkin, brinjal and bitter gourd; also root decay or reduced root system was common among these crops. Attacked plants had yellowish foliage, unthrifty growth and small slow growing fruits and poor yields. The extent of crop losses depends on the initial nematode population, susceptibility of the crop, cropping sequence, age of the plants, soil fertility and involvement of secondary pathogens. © 2011 Taylor & Francis.
Effect of Substituents on the Crystal Structures, Optical Properties, and Catalytic Activity of Homoleptic Zn(II) and Cd(II) β-oxodithioester Complexes
(American Chemical Society, 2020) Chote Lal Yadav; Anamika; Gunjan Rajput; Kamlesh Kumar; Michael G. B. Drew; Nanhai Singh
Five novel zinc(II) and cadmium(II) β-oxodithioester complexes, [Zn(L1)2] (1), [Zn(L2)2]n (2), [Zn(L3)2]n (3) [Cd(L1)2]n (4), [Cd(L2)2]n (5), with β-oxodithioester ligands, where L1 = 3-(methylthio)-1-(thiophen-2-yl)-3-thioxoprop-1-en-1-olate, L2 = 3-(methylthio)-1-(pyridin-3-yl)-3-thioxoprop-1-en-1-olate, and L3 = 3-(methylthio)-1-(pyridin-4-yl)-3-thioxoprop-1-en-1-olate, were synthesized and characterized by elemental analysis, IR, UV-vis, and NMR spectroscopy (1H and 13C{1H}). The solid-state structures of all complexes were ascertained by single-crystal X-ray crystallography. The β-oxodithioester ligands are bonded to Zn(II)/Cd(II) metal ions in an OΓS and N chelating/chelating-bridging fashion leading to the formation of 1D (in 2-4) and 2D (in 5) coordination polymeric structures, but complex 1 was obtained as a discrete tetrahedral molecule. Complex 4 crystallizes in the C2 chiral space group and has been studied using circular dichroism (CD) spectroscopy. The multidimensional assemblies in these complexes are stabilized by many important noncovalent C-H···π(ZnOSC3, chelate), π···π, C-H···π, and H···H interactions. The catalytic activities of 1-5 in reactions involving C-C and C-O bond formation have been studied, and the results indicated that complex 3 can be efficiently utilized as a heterogeneous bifunctional catalyst for the Knoevenagel condensation and multicomponent reactions to develop biologically important organic molecules. The luminescent properties of complexes were also studied. Interestingly, zinc complexes 1-3 showed strong lumniscent emission in the solid state, whereas cadmium complexes 4 and 5 exhibited bright luminescent emission in the solution phase. The semiconducting behavior of the complexes was studied by solid-state diffuse reflectance spectra (DRS), which showed optical band gaps in the range of 2.49-2.62 eV. © 2020 American Chemical Society.
Efficient Photoinduced Charge Transfer between Linear Conjugated Polymer and Polymer Network for Light Harvesting Application
(American Chemical Society, 2025) Neelam Gupta; Anamika; Arpita Maurya; Sobhan Hazra; Bhola Nath Pal; Biplab Kumar Kuila
The development of light-harvesting systems based on a donor-acceptor heterostructure for efficient conversion of light to renewable energy is an emerging area of research. Here, we have demonstrated an efficient donor-acceptor heterostructure by hybridizing a high-band gap conjugated polymer network (CPN) with a linear conjugated polymer P3HT to boost charge separation and the light-harvesting property. Steady-state and time-resolved spectroscopic studies show efficient photoinduced electron transfer from P3HT to CPN and simultaneous hole transfer from CPN to P3HT due to the proper alignment of the band gap. The light-harvesting property of the hybrid materials was demonstrated by employing the hybrids as active layers for the fabrication of all polymer photodiodes which show photodetectivity from ultraviolet A to the entire visible region with high responsivity (0.85 A/W) and detectivity of 2.41 × 1011 Jones at 620 nm and −5 V in a CPN/P3HT blend of 1:1. The repetitive on-off switching of a photodetector at zero bias clearly indicates its ability to operate in self-biased mode. This result will open up more possibilities for designing a light-harvesting system based on a high-band gap conjugated polymer network that can utilize UV and visible regions of solar light. © 2025 American Chemical Society.
Engaging a highly fluorescent conjugated polymer network for probing endogenous hypochlorite in macrophage cells: improved sensitivity via signal amplification
(Royal Society of Chemistry, 2025) Rikitha S. Fernandes; Neelam Gupta; Ch Sanjay; Anamika; Ambati Himaja; Balaram Ghosh; Biplab Kumar Kuila; Nilanjan Dey
We have employed a triazine-based conjugated polymer network (CPN) for the selective detection of hypochlorite in a semi-aqueous environment. CPNs have been widely employed in gas capture, separation, and adsorption, but the fluorescent properties of CPNs possessing extensive p-conjugated systems tend to be unexplored. Herein, we report the photophysical properties of the CPN and investigate its sensing capability towards hypochlorite. Spectroscopic investigations reveal that the CPN forms p-stacked aggregates in aqueous medium, while loose aggregates were observed to be formed in hydrophobic solvents. The fluorogenic CPN demonstrates remarkable selectivity via fluorescence quenching and a blueshift response towards hypochlorite in a semi-aqueous medium, accompanied by a color change under UV light. Such a turn-off fluorescence response, along with the blue shift upon hypochlorite sensing, was attributed to the oxidation of the sulfur atom of the thiophene functionality of the CPN, consequently resulting in suppression of Intramolecular Charge Transfer (ICT) in the corresponding oxidized adduct. The fluorescence intensity of the CPN exhibits a linear response to hypochlorite concentration, achieving a low detection limit of 1.2 nM. Furthermore, the practical applicability was demonstrated by the detection of hypochlorite in water samples and fluorescent test-paper strips. Additionally, the present system is utilized for bio-imaging of endogenous hypochlorite in RAW 264.7 cells. © 2025 The Author(s)
Epigenetic role of sirtuins in neurodegenerative brain disorders
(Elsevier, 2021) Archita Khanna; Anamika; Surendra Kumar Trigun
Sirtuins, a family of NAD+-dependent class III histone deacetylases (HDACs), are known to deacetylate some histone and nonhistone proteins including various transcription and cell signaling factors, thereby helping to regulate expression of many genes under a variety of stress challenges, and therefore they are referred to as important epigenetic regulators of the cell functions. This is in line with the classical Zn2+-dependent class I and class II HDACs, first recognized as protein level epigenetic regulators, which by modulating chromatin dynamics could affect DNA functions. All together, seven cell organelle-specific mammalian sirtuin homologues are known with distinct metabolic roles. SIRT 1, 6, and 7 are predominantly localized in the nucleus; SIRT 3, 4, and 5 are mitochondrial; while SIRT2 is found in the cytoplasm. The research during the past decade could characterize a good number of protein targets like histone H3 (H3K9), PGC1α, FOX03a, p53, and NF-κB type transcription factors for SIRT1 and SOD2, IDH2, LCAD, AceCS2, FOX03a etc. for mitochondrial SIRT3, which are now argued to be critically associated with the cell survival versus cell death mechanisms. As dysregulation of gene expression and mitochondrial dysfunction constitutes the base line of pathogenesis of many neurodegenerative brain disorders, like Alzheimer’s disease, Parkinson’s disease, Huntington’s, stroke etc., it is argued that SIRT1 and SIRT3 are likely to be the logical hot spots for exploring pathogenesis and therapeutic options against these brain disorders. Indeed some findings describe that SIRT1 and/or SIRT3 overexpression/activation could impart neuroprotection, whereas their inactivation/suppression could correlate with the neuronal derangements associated with aging and excitotoxic brain disorders. Thus sirtuin biochemistry seems to be an evolving concept in discerning the neuropathology of brain disorders. © 2021 Elsevier Inc. All rights reserved.
Ferrocene-Functionalized Dithiocarbamate Zinc(II) Complexes as Efficient Bifunctional Catalysts for the One-Pot Synthesis of Chromene and Imidazopyrimidine Derivatives via Knoevenagel Condensation Reaction
(American Chemical Society, 2021) Anamika; Chote Lal Yadav; Michael G. B. Drew; Kamlesh Kumar; Nanhai Singh
Four new mononuclear/coordination polymeric (CP) zinc(II) complexes (1-4) of ferrocenyl/pyridyl-functionalized dithiocarbamate ligands, N-ferrocenylmethyl-N-butyl dithiocarbamate (L1), N-ferrocenylmethyl-N-ethylmorpholine dithiocarbamate (L2), N-ferrocenylmethyl-N-2-(diethylamino)ethylamine dithiocarbamate (L3), and N-4-methoxybenzyl-N-3-methylpyridyl dithiocarbamate (L4), have been synthesized and characterized by elemental analyses, IR, UV-vis, and 1H and 13C{1H} NMR spectroscopic techniques. The solid-state structures of complexes 1, 3, and 4 have been determined by single-crystal X-ray crystallography as well as powder X-ray diffraction. Single-crystal X-ray crystallography revealed a monomeric structure for complex 1 but 1D polymeric structures for complexes 3 and 4. In all complexes, dithiocarbamate ligands are bonded to the Zn(II) metal ion in a S^S chelating mode, and in the CPs, N atoms on the 2-(diethylamino)ethylamine and 3-pyridyl functionalities in the ligands on the neighboring molecules are also bonded to metal centers, leading to the formation of either a discrete tetrahedral molecule in 1 or 1D CP structures in 3 and 4. The Zn(II) metal centers in the polymeric structures exhibited either square-pyramidal or octahedral geometries. The supramolecular structures in these complexes are sustained via C-H···π(ZnCS2, chelate; 3 and 4), C-H···π, and H···H interactions. The catalytic performances of complexes have also been assessed in the Knoevenagel condensation and one-pot multicomponent reactions. Catalysis results showed that the CP 3 acts as a heterogeneous bifunctional catalyst with excellent transformation efficiency at low catalyst loading. ©
Highly efficient structurally characterised novel precatalysts: Di- and mononuclear heteroleptic Cu(i) dixanthate/xanthate-phosphine complexes for azide-alkyne cycloadditions
(Royal Society of Chemistry, 2019) Anamika; Anand K. Agrahari; Krishna K. Manar; Chote Lal Yadav; Vinod K. Tiwari; Michael G. B. Drew; Nanhai Singh
Novel heteroleptic dinuclear [Cu2(L)(PPh3)4] (L = 2,6-pyridinedimethyldixanthate L1 1, 1,4-benznedimethyldixanthate L2 2, 1,4-cyclohexanedixanthate L3 3) and mononuclear [Cu(L4)(PPh3)2] 4 (L4 = piperonylxanthate) and [Cu(L5)(dppf)] 5 (L5 = methylxanthate, dppf = 1,1′-bis(diphenylphosphino)ferrocene) complexes have been synthesised and characterised by elemental (C, H, and N) analysis, high resolution mass spectrometry, and IR, UV-vis, 1H, 13C{1H} and 31P{1H} NMR spectroscopy. Single crystal X-ray diffraction revealed S,S-bifunctional coordination of the dixanthate group in dinuclear complexes 1-3 while 4 and 5 are mononuclear. Complexes 1-5 adopt tetrahedral coordination geometry about the copper atom. These precatalysts having two and one copper(i) centres in a single molecule have been applied in copper catalysed azide-alkyne cycloaddition (CuAAC) reactions for the synthesis of a variety of glycoconjugate triazoles using the Click approach. Particularly the dinuclear catalyst 1, formed on the pyridyl linker based dixanthate ligand, displayed outstanding and reusable catalytic activity for this reaction. Full optimization of the reaction conditions demonstrated a noteworthy Click catalytic system with low catalyst loading under mild reaction conditions. © 2019 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
Hippocampus mitochondrial MnSOD activation by a SIRT3 activator, honokiol, correlates with its deacetylation and upregulation of FoxO3a and PGC1α in a rat model of ammonia neurotoxicity
(John Wiley and Sons Inc, 2023) Anamika; Anima Roy; Surendra K. Trigun
We have recently reported that honokiol (HKL), by activating mitochondrial SIRT3, normalizes reactive oxygen species level and mitochondrial integrity in hippocampus of the moderate grade hepatic encephalopathy (MoHE) rat model of ammonia neurotoxicity. To delineate the mechanism by which HKL does so, the present study describes activity versus level of the deacetylated mitochondrial Mn-superoxide dismutase (MnSOD) and expression of MnSOD versus levels of its main transcription regulators, FoxO3a and PGC1α, in the hippocampus of the MoHE rats. MoHE in rat was developed by administration of 100 mg/kg bw thioacetamide i.p. for 10 days. The study parameters were compared between the control, the MoHE rats and the MoHE rats treated with HKL (10 mg/Kg b.w.) for 7 days. As compared to control, the hippocampus mitochondria from MoHE rats showed a significantly declined activity of MnSOD vs enhanced lipid peroxidation coinciding with the increased level of its acetylated form. The HKL treatment could, however, normalize all these parameters in those MoHE rats. Also, a significantly reduced expression of MnSOD in the hippocampus of the MoHE rats coincided with a similar decline in transcript level of Foxo3a and Pgc1α. This was consistent with the reduced level of immuno-stained Foxo3a and Pgc1α proteins in hippocampus DG, CA1 and CA3 regions of those MoHE rats. However, all these factors were observed to be restored back to their normal levels due to the treatment with HKL. As HKL is a specific activator of mitochondrial SIRT3, these findings suggest involvement of Sirt3 activation led deacetylation of MnSOD and upregulation of its transcription activators, FoxO3a and PGC1α, in restoring mitochondrial MnSOD level in the hippocampus of the MoHE rat model of ammonia neurotoxicity. © 2023 Wiley Periodicals LLC.
Impact of substituents on the crystal structures and anti-leishmanial activity of new homoleptic Bi(iii) dithiocarbamates
(Royal Society of Chemistry, 2019) Anamika; Rajan Singh; Krishna K. Manar; Chote Lal Yadav; Akhilesh Kumar; Rakesh K. Singh; Michael. G. B. Drew; Nanhai Singh
Six new functionalised homoleptic Bi(iii) dithiocarbamate complexes, [Bi(L1-L6)3] (L1 = (N-4-nitrobenzyl-N-furfuryl)dithiocarbamate 1, L2 = (N-4-chlorobenzyl-N-3-methylpyridyl)dithiocarbamate 2, L3 = (N-4-bromobenzyl-N-3-methylpyridyl)dithiocarbamate 3, L4 = (N-4-dimethylaminobenzyl-N-3-methylpyridyl)dithiocarbamate 4, L5 = (1-(2-pyridyl)piperazine)dithiocarbamate 5 and L6 = (N-4-methoxybenzyl-N-benzyl)dithiocarbamate 6), have been prepared and characterised by elemental analyses, powder X-ray diffraction (PXRD) and (IR, UV-Vis, 1H and 13C{1H} NMR) spectroscopy. The structures of the six complexes have been revealed in the solid state by X-ray crystallography and assessed by DFT calculations. Complexes 1 and (2, 5 and 6) are similarly dimeric in which the three dithiocarbamate ligands are bound to the seven and eight-coordinate Bi(iii) centre, respectively, in asymmetric S,S-bidentate and μ2,κ2 S,S-chelating/chelating-bridging modes. By contrast, complex 4 is monomeric with a six-co-ordinate metal atom while complex 3 forms a polymeric structure with the metal in a seven-coordinate environment. The specific geometries of all compounds are distorted by the stereochemical lone pair. In these complexes, supramolecular structures have been sustained by non-covalent C-H⋯N, C-H⋯O, C-H⋯Cl, C-H⋯Br, C-H⋯π, C-H⋯π (BiCS2, chelate) and H⋯H interactions. The anti-leishmanial activities of the complexes have been tested; 5 and 6 showed potential anti-promastigote activity with IC50 values of 7.16 and 7.44 μM, and anti-amastigote activity with IC50 values of 8.40 and 9.70 μM, respectively. Cytotoxicity assays for complexes 1-6 showed toxicity on promastigotes but lower toxicity against the RAW 264.7 cell line at different concentrations. © 2019 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
Influence of functionalities over polymer, trimer, dimer formation and optical properties of cadmium dithiocarbamates
(Elsevier Ltd, 2016) Krishna K. Manar; Manoj K. Yadav; Anamika; Michael G.B. Drew; Nanhai Singh
Homoleptic cadmium(II) bis(dithiocarbamate) complexes having polymeric [Cd(L)2]∞(L = C7H5O2CH2NCS2CH2C6H5(L1), 1; C6H4NO2CH2NCS2CH2C4H3O (L2), 2; C6H4FCH2NCS2CH2C4H3O (L3), 3), trinuclear [Cd(L4)2]3(L4 = 4-ClC6H4CH2NCS2CH2C4H3O, 4) and dinuclear [Cd(L5)2]2, (L5 = 3-ClC6H4CH2NCS2CH2C6H5, 5) structures have been synthesized and characterized by elemental analyses, spectroscopy (IR,1H and13C {1H} NMR and UV–Vis.) and their structures have been revealed by X-ray crystallography. In 1–3 the dithiocarbamate ligands are uniquely bonded to the Cd atoms in a μ2,κ2S,S-chelating-bridging fashion, portraying 1D coordination polymeric structures in which the cadmium(II) ions adopt six coordinate distorted octahedral structures. In 4 the six dithiocarbamate ligands are spectacularly arranged about the Cd atoms resulting in a centrosymmetric trinuclear complex in which the central metal adopts an octahedral geometry and the terminal Cd atoms are in square pyramidal environments. Complex 5 has the well-established centrosymmetric dimeric structure in which the metal atoms have a five-coordinate trigonal bipyramidal geometry. Complexes 1–4 are rare examples of polymeric and trinuclear cadmium dithiocarbamate complexes. 1–5 show luminescent characteristics in solution and in the solid state arising from the metal perturbed intra-ligand charge transfer (ILCT) states. Their TG analyses show a single step decomposition with the formation of CdS nanoparticles, which have been examined by PXRD and HRTEM. © 2016 Elsevier Ltd
Mitochondrial SIRT3 and neurodegenerative brain disorders
(Elsevier B.V., 2019) Anamika; Archita Khanna; Papia Acharjee; Arup Acharjee; Surendra Kumar Trigun
Sirtuins are highly conserved NAD+ dependent class III histone deacetylases and catalyze deacetylation and ADP ribosylation of a number of non-histone proteins. Since, they require NAD+ for their activity, the cellular level of Sirtuins represents redox status of the cells and thereby serves as bona fide metabolic stress sensors. Out of seven homologues of Sirtuins identified in mammals, SIRT3, 4 & 5 have been found to be localized and active in mitochondria. During recent past, clusters of protein substrates for SIRT3 have been identified in mitochondria and thereby advocating SIRT3 as the main mitochondrial Sirtuin which could be involved in protecting stress induced mitochondrial integrity and energy metabolism. As mitochondrial dysfunction underlies the pathogenesis of almost all neurodegenerative diseases, a role of SIRT3 becomes an arguable speculation in such brain disorders. Some recent findings demonstrate that SIRT3 over expression could prevent neuronal derangements in certain in vivo and in vitro models of aging and neurodegenerative brain disorders like; Alzheimer's disease, Huntington's disease, stroke etc. Similarly, loss of SIRT3 has been found to accelerate neurodegeneration in the brain challenged with excitotoxicity. Therefore, it is argued that SIRT3 could be a relevant target to understand pathogenesis of neurodegenerative brain disorders. This review is an attempt to summarize recent findings on (1) the implication of SIRT3 in neurodegenerative brain disorders and (2) whether SIRT3 modulation could ameliorate neuropathologies in relevant models. © 2017 Elsevier B.V.
New heteroleptic [Ni(ii) 1,1-dithiolate-phosphine] complexes: Synthesis, characterization and electrocatalytic oxygen evolution studies
(Royal Society of Chemistry, 2020) Anamika; Dharmendra Kumar Yadav; Krishna K. Manar; Chote Lal Yadav; Kamlesh Kumar; Vellaichamy Ganesan; Michael G. B. Drew; Nanhai Singh
Four new heteroleptic Ni(ii) complexes with general formula [Ni(ii)(LL′)] (L = 2-(methylene-1,1′-dithiolato)-5-phenylcyclohexane-1,3-dione (L1) and 2-(methylene-1,1′-dithiolato)-5,5′-dimethylcyclohexane-1,3-dione (L2); L′ = 1,2-bis(diphenylphosphino)ethane (dppe) and bis(diphenylphosphino)monosulphide methane (dppms) have been synthesized and characterized by elemental analysis and spectroscopy (IR, UV-Vis, 1H, 13C{1H} and 31P{1H} NMR). All complexes 1-4 have also been characterized by PXRD and single crystal X-ray crystallography. The solid state molecular structures revealed distorted square planar geometry about the four-coordinate Ni(ii) metal centre together with rare Ni⋯H-C intra/intermolecular anagostic interactions in axial positions. In these complexes supramolecular structures have been sustained by non-covalent C-H⋯O, C-O⋯H-O, C-H⋯π, C-H⋯π (NiCS2, chelate), π⋯π and H⋯H interactions. Their electrocatalytic properties have been investigated for oxygen evolution reaction (OER) in which complex 2 showed the highest activity with 10 mA cm-2 at the potential of 1.58 V vs. RHE. In addition, complex 2 also exhibits an OER onset potential at 1.52 V vs. RHE. This journal is © The Royal Society of Chemistry.
Nitrogen- and Sulfur-Enriched Conjugated Polymer Network as an Electrocatalyst for the Oxygen Reduction Reaction and as a Cathode Material for Zinc–Air Batteries
(American Chemical Society, 2025) Arpita Maurya; Neelam Gupta; Priti Singh; Nitika Bhutani; Anamika; Rik Rani Koner; Mudit Dixit; Biplab Kumar Kuila
Over the past decade, heteroatom-doped metal-free carbon materials (MFCMs) have been recognized as effective oxygen reduction reaction (ORR) catalysts. However, the active centers for the ORR in MFCMs are difficult to precisely confirm and controllably synthesize using conventional methods such as high-temperature pyrolysis or heteroatom doping. To elucidate the active center precisely and the structure–property relationship, we demonstrated a conjugated polymer network (CPN), TTB, comprising triazine, thiophene, and benzothiadiazole for ORR and as a cathode catalyst for a zinc–air battery. Density functional theory calculations revealed that the benzothiadiazole building block acts as an active center, leading to ORR catalytic activity. TTB was thoroughly characterized through different characterization techniques like FTIR, XPS, XRD, FESEM, HRTEM, and BET surface area and pore size analysis. The onset potential of 0.81 V vs reversible hydrogen electrode (RHE), diffusion-limiting current density of 3.0 mA/cm2, and E1/2of 0.68 V vs RHE with good electrochemical stability are comparable to the benchmark ORR catalyst (10% Pt/C). TTB was further used as the cathode electrocatalyst for a zinc–air battery, resulting in an open-circuit potential of 1.46 V and a specific capacity of 613 mAh g–1. A rechargeable zinc–air battery was also fabricated with TTB and RuO2as the cathode electrocatalysts, showing a voltage gap of 0.9 V and good cyclic stability. These findings show that the rational design and precise synthesis of conjugated polymer networks can facilitate the development of new ORR catalysts useful as cathode materials for zinc–air batteries. © 2025 American Chemical Society
Occurrence of root-knot disease in green onion in Allahabad
(2011) Anamika; Sobita Simon; R.K. Singh
Onion is an important indispensable item in every kitchen as condiment and vegetable, hence commands an extensive internal market. The green leaves and immature and mature bulbs are eaten raw or used in preparation of vegetables. Among the various pests and diseases associated with onion, the root knot nematode (Meloidogyne incognita) had proved itself as an important limiting factor for successful cultivation of this crop. Recently root-knot nematode was observed to cause serious losses to green onion crop grown mostly in the field located near the Jamuna & Ganga river belt of Allahabad and the surrounding area in U.P. Differential host test was done to confirm the root knot disease in onion. The specific identity of the nematode was determined by cutting perineal pattern of the females and was confirmed as Meloidogyne incognita. © 2011 Taylor & Francis.
Oxidative stress and aging
(Elsevier, 2025) Vineeta Singh; Anamika; Nidhi Chandra; Vartika Gupta; Priyanka Gautam; Shivani Rath; Arshdeep Kaur Sethi; Rameshwar Nath Chaurasi; Vijay Nath Mishra
Oxidative stress results from an imbalance between reactive oxygen species and reactive nitrogen species production and the body’s antioxidant defense mechanisms. Excessive accumulation of these reactive molecules damages lipids, proteins, and DNA, contributing to cellular dysfunction and aging. The Free Radical Theory of Aging, proposed by Denham Harman, suggests that oxidative stress accelerates molecular deterioration, leading to age-related functional decline. However, modern research highlights a nuanced perspective where oxidative stress plays both detrimental and adaptive roles, influencing cellular signaling and stress responses. Emerging evidence underscores the interplay of genetic and environmental factors in oxidative homeostasis, offering insights into potential therapeutic interventions for aging-related disorders. Understanding oxidative stress as a dynamic and regulated process rather than a purely degenerative force opens avenues for targeted strategies to modulate aging and extend healthspan. © 2026 Elsevier Inc. All rights reserved..
Preparation, Characterization and Photosensitizing Activities of Homoleptic Cu(II) Dithiocarbamates in TiO2-Based DSSC
(Wiley-Blackwell, 2019) Krishna K. Manar; Neetu; Kavita Kumari; Anamika; Chote L. Yadav; Pankaj Srivastava; Michael G. B. Drew; Nanhai Singh
New homoleptic copper(II) dithiocarbamate complexes, [Cu(L1-L5)2] (L1=N-benzyl-N-4-bromobenzyl dithiocarbamate− Cu1; L2=N-benzyl-N-4-methoxybenzyl dithiocarbamate− Cu2; L3=4-N,N-diethylbenzyl-N-methyl dithiocarbamate− Cu3; L4=N-methyl-N-4-isopropylbenzyl dithiocarbamate− Cu4 and L5=N-3-pyridyl-N-4-bromobenzyl dithiocarbamate− Cu5) have been synthesized and characterized by elemental analysis, HRMS, IR and UV-Vis. spectroscopy, PXRD and cyclic voltammetry. The monomeric (1−3) and dimeric (4) structures have been elucidated by X-ray crystallography. In all four structures the copper atom has square planar geometry. In 3 and 4 existence of rare C−H⋅⋅⋅Cu intermolecular anagostic interactions have been detected in the solid state. All complexes were exploited as sensitizers for TiO2 photoanode based dye-sensitized solar cells (DSSC). When TiO2 anchored with these complexes was used as DSSC photoanode, significant light harvesting properties were observed with an exceptionally high light-to-electrical energy conversion efficiency (3.62%) shown by Cu3 complex. The extent of interfacial charge-recombination and electron lifetime was evaluated from the electrochemical impedance spectroscopy (EIS) studies. The better performance of Cu3 compared to other complexes was attributed to its structural features. All the complexes with σrt, 10−6-10−9 S cm−1 are weakly conducting but show semiconducting behaviour in the 303–383 K temperature range with Ea values of 0.20−0.90 eV. © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Protein misfolding and aggregation and its role in dementia with Lewy bodies
(Elsevier, 2025) Vineeta Singh; Anamika; Nidhi Chandra; Vartika Gupta; Priyanka Gautam; Bhargawi Mishra; Arshdeep Kaur Sethi; Shivani Rath; Vijay Nath Mishra
Dementia with Lewy bodies (DLB) is a progressive neurodegenerative disorder characterized by the accumulation of misfolded α-synuclein within Lewy bodies, leading to widespread neuronal dysfunction. Protein misfolding and aggregation serve as key pathological mechanisms, influenced by genetic mutations, as well as environmental triggers like toxins and infections. The interplay between α-synuclein and other neurodegenerative pathways, particularly tau and amyloid-β, exacerbates disease progression. Advances in biomarker research, including neuroimaging and fluid-based assays, are enhancing early detection, while emerging therapeutic strategies focus on molecular chaperones, autophagy enhancement, and gene-editing approaches. Understanding the mechanisms of protein misfolding in DLB not only improves diagnostic accuracy but also provides potential avenues for disease-modifying therapies. Ongoing research offers promising prospects for targeted interventions, bridging the gap between pathophysiological insights and clinical applications in neurodegenerative disorders. © 2026 Elsevier Inc. All rights reserved..
SIRT1 activation by resveratrol reverses atrophy of apical dendrites of hippocampal CA1 pyramidal neurons and neurobehavioral impairments in moderate grade hepatic encephalopathy rats
(Elsevier B.V., 2020) Archita Khanna; Anamika; Suwarna Chakraborty; Sunil Jamuna Tripathi; Arup Acharjee; Shankaranarayana Rao BS; Surendra K. Trigun
A preliminary observation about resveratrol (RSV) dependent normalization of inflammatory and apoptotic factors in the cortex of hyperammonemic rat model of moderate grade hepatic encephalopathy (MoHE) led us to evaluate whether RSV is ultimately able to confer neuroprotection against MoHE pathogenesis and that it does so by activating its bonafide molecular target SIRT1. The present study compared the profile of relevant neurobehavioral pattern vs neuromorphometry of hippocampal CA1 neurons and SIRT1 activity in the hippocampus of the chronic liver failure (CLF) model of moderate grade HE (MoHE) rats induced by administration of 100 mg/kg body weight of thioacetamide i.p. for 10 days and in the CLF/MoHE rats treated with 10 mg/kg body weight RSV i.p. for 7 days. As compared to the control group rats, the MoHE rats showed significantly deranged pattern of memory and motor functions on MWM and rota rod tests, respectively. These behavioural deficits were associated with a significant reduction in apical dendrite length and number of branching points in the CA1 pyramidal neurons. Interestingly, all these parameters were found to be recovered back to their normal levels in the MoHE rats treated with RSV. Concordantly, MoHE associated declined SIRT1 activity in the hippocampus could be normalized back due to RSV treatment to those MoHE rats. Our findings suggest that RSV is able to normalize MoHE associated memory impairments and motor deficits vis a vis reversal of CA1 dendritic atrophy via SIRT1 activation. © 2020 Elsevier B.V.