Leveraging QSPR-guided ZIF selection for MWCNTs/ZIF-8 platforms for electrochemical immunosensing of lactoferrin
Electrochemical immunosensor; Lactoferrin; QSPR; Zeolitic imidazolate frameworks
This study presents a data-driven workflow integrating quantitative structureproperty relationship (QSPR) modelling with Monte Carlo (MC) adsorption simulations to guide zeolitic imidazolate framework (ZIF) selection for lactoferrin (LF) immunosensing.MC simulations calculated adsorption energies (Eads) of LF across 27 ZIFs, represented using MOFid/MOFkey-encoded SMILES notation, enabling construction of a predictive QSPR model (top-performing model: PLS, R2=0.891, Q2=0.888). The model successfully ranked ZIFs according to predicted LF affinity, with ZIF-8 emerging as the optimal candidate based on computational predictions, structural robustness, and synthetic accessibility. Following computational validation through molecular docking, ZIF-8 was integrated with multiwalled carbon nanotubes (MWCNTs) on a glassy carbon electrode (GCE), enabling noncovalent immobilization of anti-LF antibodies. Electrochemical measurements performed using square-wave voltammetry (SWV) with a ferri/ferrocyanide [Fe(CN)6] 3?/4- redox probe demonstrated a linear response over 1060ng/mL LF (R2=0.994), a limit of detection (LOD) of 4.78ng/mL, and recoveries of 95105% in spiked milk samples with reproducibility ?8% RSD (n=3). Shelf-life studies showed 74% signal retention after four weeks of storage at 4C. Electrochemical analysis revealed a synergistic enhancement of charge transfer (Rct) in the MWCNTs/ZIF-8 composite (0.572k? vs. 12.79k? for bare GCE). This work demonstrates a transferable, computationally driven framework for screening framework materials in MOF/ZIF-based biosensors, bridging predictive materials design with experimental device fabrication for broad applications in clinical diagnostics and food quality monitoring. 2026 Published by Elsevier B.V.
Harilal, Calvin Carl; Lephalala, Matshidiso; Shahbaaz, Mohd; Gupta, Anjali; Kanchi, Suvardhan; Uwaya, Gloria Ebube; Bisetty, Krishna
Journal of Electroanalytical Chemistry;Volume;1014;Issue;;Article No.;120173;
Restricted Access; Hardcopy may be available in the library
https://doi.org/10.1016/j.jelechem.2026.120173 https://www.scopus.com/pages/publications/105037063819?origin=resultslist
Harilal C.C., Department of Chemistry, Faculty of Applied Sciences, Durban University of Technology, P. O Box 1334, Durban, 4000, South Africa; Lephalala M., Department of Chemistry, Faculty of Applied Sciences, Durban University of Technology, P. O Box 1334, Durban, 4000, South Africa; Shahbaaz M., Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1A, Aachen, 52074, Germany; Gupta A., Department of Chemistry and Sustainability, School of Basic Sciences, Galgotias University, Uttar Pradesh, Greater Noida, 201306, India; Kanchi S., Department of Chemistry, CHRIST University, Bengaluru, 560029, India, Centre for Renewable Energy and Environmental Sustainability, CHRIST University, Bengaluru, 560 029, India; Uwaya G.E., Department of Chemistry, Faculty of Applied Sciences, Durban University of Technology, P. O Box 1334, Durban, 4000, South Africa; Bisetty K., Department of Chemistry, Faculty of Applied Sciences, Durban University of Technology, P. O Box 1334, Durban, 4000, South Africa
Surveilling bodies, governing morality: Biopower and the contagious diseases acts in colonial India
Biopower; Colonial India; Contagious diseases acts; Devadasis; Identities; Resistance; Sexuality
This article explores the Contagious Diseases Acts (CD Acts) in colonial India using Michel Foucault's theory of biopower, focusing on their impact on devadasis. The Acts subjected women's bodies to medical and legal scrutiny, pathologizing female sexuality while reinforcing patriarchal and caste hierarchies. Devadasis, historically associated with temple practices, were recast as vectors of disease and moral disorder, aligning with the colonial administration's broader project of governance through regulation and surveillance. This study examines how the CD Acts functioned as a technology of power, reshaping devadasis identities and controlling their bodies to sustain social and political order. It also investigates how these mechanisms were challenged by resistance, demonstrating the adaptive and contested nature of colonial power. By situating the devadasis within the framework of biopower, this analysis illuminates the intersection of health policies, sexuality, and governance in shaping colonial hierarchies and marginalizing vulnerable communities. 2025 Elsevier Masson SAS
Ethics, Medicine and Public Health;Volume;33;Issue;;Article No.;101088;
https://doi.org/10.1016/j.jemep.2025.101088 https://www.scopus.com/pages/publications/105001244830?origin=resultslist
Thomas J.A., Research Scholar, Department of International Studies, Political Science and History, Christ (Deemed to be University), Bengaluru, India; Vagishwari S.P., and Head of Department, Department of International Studies, Political Science and History, Christ (Deemed to be University), Bengaluru, India
Climate change and health risk perception in India: A replication of the climate change risk perception model
CCRPM; Climate change; Climate change risk perception; India; Perceived health risk; Replication
Behavioral science insights into attitudinal antecedents of climate change risk perception in India are limited. Addressing the lack of nationally diverse samples in environmental psychology research, this study replicates the climate change risk perception model (CCRPM, van der Linden, 2015) in the Indian context. In a nationally comparable sample (N = 749), participants were measured on sociodemographic, cognitive, experiential, and socio-cultural factors associated with climate risk perception. Results of hierarchical regression analyses found that the CCRPM explained 32.85 % of climate change risk perception. Confirmatory factor analysis outcomes empirically support a two-factor structure of risk perception, personal, and societal/generalized in the Indian context. Moreover, the CCRPM explains limited (19.5 %) variance in perceptions of health risks associated with climate change. Experiential factors (such as affect, and personal experience) and prescriptive norms were strongly associated with climate change and health risk perception in India. Highlighting the vulnerabilities associated with health and climate change may prove essential to communicating climate change risks in India. 2025 Elsevier Ltd
Journal of Environmental Psychology;Volume;104;Issue;;Article No.;102626;
https://doi.org/10.1016/j.jenvp.2025.102626 https://www.scopus.com/pages/publications/105006628368?origin=resultslist
Iyer A., Department of Psychology, School of Psychological Sciences, Christ University, Bangalore, India; Alphonsa Jose K., Department of Psychology, School of Psychological Sciences, Christ University, Bangalore, India
A novel image compression method using wavelet coefficients and Huffman coding
Bits per pixel; Compression ratio; Integer wavelet transform; Medical imaging; Visual quality
Compressing medical images to reduce their size while maintaining their clinical and diagnostic information is crucial. Because medical images can be large and demand a lot of storage and transmission capacity, effective compression methods aid medical institutions in better storing and transmitting medical images, reducing costs, speeding up data transfer, and simplifying managing image databases. However, it is essential to note that image compression in medical imaging can also introduce drawbacks, such as loss of information and poor output image quality. Therefore, a suitable compression algorithm and parameter must be chosen to balance file size and visual fidelity. This paper suggests an effective image compression method employing the Discrete Wavelet Transform (DWT), followed by a reduction operation and Huffman coding to produce a mere lossless encoding to transmit the images over a channel. The extracted DWT coefficients are mapped to the nearest integral value. All four sub-bands of DWT are joined, and then a window of 3 3 is selected for reduction operation by choosing the origin as the pivot element. The Huffman coding algorithm is used to compress the processed image. The pivot origin element is used in the reversible reduction while uncompressing the image. When sending compressed data across an unreliable route, the window size and pivot element selection keep the compressed data secure. Standard measures such as bits per pixel (BPP) and compression ratio (CR) are used to assess the suggested approach. The efficiency of the suggested course of action is supported by the research's findings, which use a peak signal-to-noise ratio (PSNR) of 54.66 dB. 2023 The Authors
Thomas, Shiju; Krishna, Addapalli; Govind, Sabeen; Sahu, Aditya Kumar
Journal of Engineering Research (Kuwait);Volume;13;Issue;1;pp.361-370
https://doi.org/10.1016/j.jer.2023.08.015 https://www.scopus.com/pages/publications/105001062458?origin=resultslist
Thomas S., Department of Computer Science and Engineering, School of Engineering and Technology, Christ University, Karnataka, Bangalore, India, Department of Computer Science, Rajagiri College of Social Sciences (Autonomous), Kerala, Kalamassery, India; Krishna A., Department of Computer Science and Engineering, School of Engineering and Technology, Christ University, Karnataka, Bangalore, India; Govind S., Department of Computer Science, Rajagiri College of Social Sciences (Autonomous), Kerala, Kalamassery, India; Sahu A.K., Amrita School of Computing, Amrita Vishwa Vidyapeetham, Andhra Pradesh, Amaravati, India
Paraquat associated stomatitis: A forensic marker of exposure intent and prognosis
Forensic toxicology; Oral mucositis; Paraquat; Poisoning; Stomatitis
Introduction: Paraquat-associated stomatitis (PAS) is a hallmark of paraquat poisoning but its potential as an intent-specific or prognostic marker remains unexplored. This study investigated whether PAS patterns differ between accidental and suicidal exposures. Methods: A pooled, individual case analysis of 170 paraquat poisoning cases from 122 publications was conducted following PRISMA guidelines. Data on demographics, exposure intent, and detailed oral lesion characteristics (morphology, pattern, severity) were extracted. Statistical analyses identified predictors of intent and prognosis. Results: Oral lesions were present in 78.8% of cases. While the overall prevalence of PAS did not differ between accidental (85.1%) and suicidal (83.9%) intents, lesion morphology was a key differentiator. Widespread ulcers were strongly associated with suicidal ingestion (aOR=6.37; 95% CI 1.9520.78; P=0.002), independent of lesion severity or WHO grade. Conversely, focal but objectively more severe ulcers characterized accidental exposures. Lesion morphology, not severity, distinguishes intent. Other independent predictors of suicidal intent included female sex (aOR=3.40; P=0.031), oliguria (aOR=4.21; P=0.006), and delayed treatment (aOR=8.39; P=0.023). Paradoxically, accidental exposures were associated with significantly higher mortality (68.9%) compared to suicidal cases (39.8%) (P=0.001). The absence of PAS reliably indicated a non-oral exposure route (P<0.001). Discussion: This work introduces the novel concept of intent-specific PAS morphology, establishing ulcer pattern as a forensic marker. It is demonstrated, for the first time, that widespread lesions objectively indicate suicide, while focal, severe ulcers signify accidental exposurea finding linked to a paradoxical mortality risk. This intent-specific signature could provide clinicians with a rapid, objective tool for stratification. For medicolegal investigations, it qualifies PAS as crucial physical evidence to clarify disputed histories, advocating for its systematic documentation in clinical and autopsy practice as a new standard in forensic toxicology. 2026 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Mohandoss, Anusa Arunachalam; Thavarajah, Rooban
Journal of Forensic and Legal Medicine;Volume;119;Issue;;Article No.;103113;
https://doi.org/10.1016/j.jflm.2026.103113 https://www.scopus.com/pages/publications/105035119169?origin=resultslist
Mohandoss A.A., Department of Psychiatry, Shri Sathya Sai Medical College and Research Institute, Affiliated to Sri Balaji Vidyapeeth, Deemed to be University, SBV Nagar, Chennai Campus, Tamil Nadu, 603108, India; Thavarajah R., Marundeeswara Oral Pathology Services and Analytics, B-1, Mistral Apartments, Wipro Street (Off Rajiv Gandhi IT Highway), Shollinganallur, Chennai, 600119, India, Department of Oral and Maxillofacial Pathology, Ragas Dental College & Hospital, (Affiliated to the Tamil Nadu Dr. MGR Medical University, Chennai) 2/102 East Coast Road, Uthandi, Chennai, 600119, India
Physicochemical characterization of fluoride solid electrolyte PbSnF4 synthesized via sonochemical reaction
Fluoride ion conductor; Ionic conductivity; Ionic transference number; Solid electrolyte; Sonochemical technique
Demand for batteries with enhanced energy density and improved thermal safety is a key focus for researchers striving to build a sustainable environment. As fluoride ion batteries (FIB) are expected to exhibit high energy density and exceptional thermal stability, research activities are focused on identifying fluoride ion-conducting electrolytes. Among the various fluoride ion conductors, PbSnF4, renowned for its superior ionic conductivity, is typically synthesized via mechanochemical reaction. In the present work, PbSnF4 was synthesized via an acoustic cavitation-driven sonochemical reaction. This novel synthesis route has reduced the duration of the synthesis process to a few minutes compared with several hours for the mechanochemical reaction. The structural, morphological, and ionic transport properties are investigated. The ionic conductivity of the resulting orthorhombic PbSnF4 is evaluated to be 4.5 10?4 S/cm at RT. The contribution of fluoride ions to the total ionic conductivity is estimated via the DC polarization technique as 0.92. The electrochemical stability window (ESW) is measured through cyclic voltammetry (CV) as 0.7 V with PbF2/PbSnF4/SS cell configuration. 2025
M, Meena; Money, Benson K; Bhide, Amrtha
Journal of Fluorine Chemistry;Volume;285-286;Issue;;Article No.;110450;
https://doi.org/10.1016/j.jfluchem.2025.110450 https://www.scopus.com/pages/publications/105009295702?origin=resultslist
M M., Department of Physics, National Institute of Technology Puducherry, Karaikal, 609609, India; Money B.K., School of Engineering and Technology, Christ (Deemed to be University), Bangalore, 560074, India; Bhide A., Department of Physics, National Institute of Technology Puducherry, Karaikal, 609609, India
An efficient reconfigurable band tuning filter design for channelizer in transponder satellite system
Channelizer; Cosine modulation; Exponential modulation; FIR filters; Interpolated FIR (IFIR)
For improved performance in a variety of applications, the transponder in satellite systems must be very flexible. The channelizer-dependent transponder system significantly boosts the operation of a satellite system. When channelizing wideband input signals, a digital filter bank is typically used to extract several small sub-bands. In this research, a reconfigurable band tuning (RBT) design for the channelizer in the satellite transponder system is designed and implemented. Cosine modulation, exponential modulation and IFIR filter are the techniques behind the RBT design. The RBT design facilitates the generation of many channels enabling channelization with non-uniform narrow transition width. A number of examples are presented to illustrate how well the RBT design performs. Findings indicate that there are fewer filter coefficients in the RBT design than there are in the current approaches Effective implementation of a properly designed RBT design lowers power consumption and simplifies the hardware. 2024 The Franklin Institute
Varghese, Rinu C.; Amir, A.; Inbanila, K.
Journal of the Franklin Institute;Volume;362;Issue;2;Article No.;107474;
https://doi.org/10.1016/j.jfranklin.2024.107474 https://www.scopus.com/pages/publications/85213205183?origin=resultslist
Varghese R.C., CHRIST (Deemed to be University), Karnataka, Bangalore, India; Amir A., CHRIST (Deemed to be University), Karnataka, Bangalore, India; Inbanila K., CHRIST (Deemed to be University), Karnataka, Bangalore, India
Comprehensive spectro-temporal studies of GX 17+2 using AstroSat observations
Accretion, accretion discs; Stars: neutron; X-rays: binaries: GX 17+2
We performed a comprehensive spectro-temporal study of the Z-type neutron star low-mass X-ray binary GX 17+2 using long term data from the AstroSat/Soft X-ray Telescope (SXT) and Large Area X-ray Proportional Counter (LAXPC). The hardnessintensity diagrams (HIDs) of the source revealed a positive correlation between the hardness and intensity, characteristic of soft spectral state. Additionally, the LAXPC-20 HID showed the presence of secular shifts in both hardness and intensity. Time-averaged spectral modelling in the 0.7 ? 30.0 keV energy range indicated that the spectra could be well fitted with the model combination: constant edge edge tbabs thcomp bbodyrad. This analysis yielded a blackbody radius (Rbb) of ?59 km, photon index (?) of ?2.84 and electron temperature (kTe) of ?4.84 keV. Time-averaged temporal analysis revealed normal branch oscillations (NBOs) at ? 7 Hz in Observations 1 and 3, flaring branch oscillation (FBO) at ?15 Hz in Observation 2, and horizontal branch oscillation (HBO) at ?36 Hz in Observation 5. Flux resolved spectro-temporal analysis indicated that the source remained in the soft spectral state throughout all observations. A positive correlation was observed between kTbb, Fbb and Fbol, whereas an anti-correlation was noted between kTe and Fbol. The constant frequency of NBOs with an increase in Fbol suggests that their origin lies in a region strongly influenced by the corona, as explained by the radiation-hydrodynamic model. The origin of FBOs may be attributed to the damped radiation-hydrodynamic mode of radial flow, while the origin of HBOs is supported by the beat-frequency model. 2024 Elsevier B.V.
Thomas, Neal Titus; Lavanya, S.; Gudennavar, S.B.; Bubbly, S.G.
Journal of High Energy Astrophysics;Volume;45;pp.250-261
https://doi.org/10.1016/j.jheap.2024.12.007 https://www.scopus.com/pages/publications/85213209972?origin=resultslist
Thomas N.T., Department of Physics and Electronics, CHRIST University, Karnataka, Bangalore, 560029, India; Lavanya S., Department of Physics and Electronics, CHRIST University, Karnataka, Bangalore, 560029, India; Gudennavar S.B., Department of Physics and Electronics, CHRIST University, Karnataka, Bangalore, 560029, India; Bubbly S.G., Department of Physics and Electronics, CHRIST University, Karnataka, Bangalore, 560029, India
Modelling the energy dependent X-ray variability of Mrk 335
Galaxies:individual:Mrk 335; Galaxies:seyfert; Methods:numerical; X-rays:galaxies
We present a technique which predicts the energy dependent fractional r.m.s. for linear correlated variations of a pair of spectral parameters and apply it to an XMM-Newton observation of Mrk 335. The broadband X-ray spectrum can be interpreted as a patchy absorber partially covering the primary emission, a warm and hot coronal emission or a relativistically blurred reflection along with the primary emission. The fractional r.m.s. has a non-monotonic behaviour with energy for segments of lengths 3 and 6 ksecs. For each spectral model, we consider every pair of spectral parameters and fit the predicted r.m.s. with the observed ones, to get the pair which provides the best fit. We find that a variation in at least two parameters is required for all spectral interpretations. For both time segments, variations in the covering fraction of the absorber and the primary power law index gives the best result for the partial covering model, while a variation in the normalization and spectral index of the warm component gives the best fit in the two corona interpretation. For the reflection model, the best fit parameters are different for the two time segment lengths, and the results suggests that more than two parameters are required to explain the data. This, combined with the extreme values of emissivity index and reflection fraction parameters obtained from the spectral analysis, indicates that the blurred reflection model might not be a suitable explanation for the Mrk 335 spectrum. We discuss the results as well as the potential of the technique to be applied to other data sets of different AGN. 2025 Elsevier B.V.
Akhila, K.; Misra, Ranjeev; Sarma, Rathin; Ezhikode, Savithri H.; Jeena, K.
Journal of High Energy Astrophysics;Volume;45;pp.418-427
https://doi.org/10.1016/j.jheap.2025.01.014 https://www.scopus.com/pages/publications/85215425989?origin=resultslist
Akhila K., Department of Physics, Providence Women's College (Autonomous), University of Calicut, Kerala, 673009, India; Misra R., Inter-University Centre for Astronomy and Astrophysics (IUCAA), PB No. 4, Ganeshkhind, Pune, 411007, India; Sarma R., Department of Physics, Rabindranath Tagore University, Assam, Hojai, 782435, India; Ezhikode S.H., St. Francis de Sales College (Autonomous), Electronics City, Bengaluru, 560100, India, Department of Physics and Electronics, CHRIST (Deemed to be University), Bangalore, 560029, India; Jeena K., Department of Physics, Providence Women's College (Autonomous), University of Calicut, Kerala, 673009, India
Spectral and type I X-ray burst studies of M15 X-2 using NICER observations
Accretion; Accretion discs; Stars: neutron; X-rays: binaries; X-rays: bursts, burst oscillation; X-rays: individual: M15 X-2
In this work, we present spectral and burst analyses of three thermonuclear type I X-ray bursts (B1, B2, and B3) detected from the ultracompact neutron star low-mass X-ray binary M15 X-2, using data from the Neutron Star Interior Composition Explorer (NICER). Time-averaged spectral fitting with the model tbabsthcompiskbb) suggests that the source was in a soft or soft-intermediate spectral state, characterized by a photon power law index of ??2 and an average mass accretion rate of ?0.09 m?Edd. The type I X-ray bursts exhibited rapid rise times of 1.25?2.75 s, followed by longer decay phases lasting 14.50?23.25 s, with characteristic burst timescales (?) of ?11 s, which are consistent with pure helium burning. Notably, burst B3 displayed a double-peaked profile indicative of a photospheric radius expansion event, from which we inferred the neutron star radius to be 10.8+2.4?2.2 km. Based on the peak flux of the burst, we estimated the source distance to be 10.54+1.43?1.26 kpc under the assumption of isotropic emission, and 14.06+1.90?1.68 kpc for anisotropic emission geometry. A strong ?420 Hz burst oscillation candidate was detected in the cooling tail of burst B1. 2025 Elsevier B.V.
Varun, M.; Thomas, Neal Titus; Giridharan, L.; Gudennavar, S.B.; Bubbly, S.G.
Journal of High Energy Astrophysics;Volume;49;Issue;;Article No.;100461;
https://doi.org/10.1016/j.jheap.2025.100461 https://www.scopus.com/pages/publications/105015778948?origin=resultslist
Varun M., Department of Physics and Electronics, CHRIST University, Karnataka, Bangalore, 560029, India; Thomas N.T., Department of Physics and Electronics, CHRIST University, Karnataka, Bangalore, 560029, India; Giridharan L., Department of Physics and Electronics, CHRIST University, Karnataka, Bangalore, 560029, India; Gudennavar S.B., Department of Physics and Electronics, CHRIST University, Karnataka, Bangalore, 560029, India; Bubbly S.G., Department of Physics and Electronics, CHRIST University, Karnataka, Bangalore, 560029, India
Clues on the X-ray emission mechanism of blazars PKS 2155?304 and 3C 454.3 through polarization studies
BL Lacertae objects: individual: PKS 2155-304; Galaxies: active; Quasars: individual 3C 454.3; Techniques: polarization; X-rays: galaxies
X-ray polarization measurable with the imaging X-ray Polarimetry Explorer (IXPE) could constrain the long debated leptonic versus hadronic origin for the high energy component in the broad band spectral energy distribution (SED) of blazars. We report here the results from IXPE and SED modeling of PKS 2155?304 and 3C 454.3, a high and low synchrotron peaked blazar. For PKS 2155?304, from model-independent analysis, we found polarization angle ?X = (130 2.5) deg and polarization degree ?X = (20.9 1.8)% in the 2?8 keV band in agreement with spectro-polarimetric analysis. We found ?X to vary with time and indications of it to vary between energies, suggesting that the emission regions are stratified. For 3C 454.3, we did not detect X-ray polarization in the June 2023 observation, analyzed here for the first time. The detection of X-ray polarization in PKS 2155?304 and its non-detection in 3C 454.3 is in accordance with the X-ray emission from synchrotron and inverse Compton process, respectively, operating in these sources. Further, our division of the dataset into finer time bins allows a more granular view of polarization variability. Additionally, we modeled the broadband SEDs of both the sources using data acquired quasi-simultaneously with IXPE, in the optical, UV and X-rays from Swift, AstroSat and ?-rays from Fermi. In PKS 2155?304, the observed X-ray is found to lie in the high energy tail of the synchrotron component of the SED, while in 3C 454.3 the observed X-ray lies in the rising part of the inverse Compton component of the SED. Our SED modeling along with X-ray polarization observations favor a leptonic scenario for the observed X-ray emission in PKS 2155?304. The SED modeling for these specific IXPE epochs has not been presented before, allowing us to place additional constraints on the physical conditions in the jet. These results strengthen the case for a structured jet model where X-ray emission originates from a compact acceleration zone near the shock front, while lower-energy optical emission is produced in a broader, more turbulent region. 2025 Elsevier B.V.
Bharathan, Athira M.; Stalin, C.S.; Sahayanathan, Sunder; Mathew, Blesson
Journal of High Energy Astrophysics;Volume;50;Issue;;Article No.;100472;
https://doi.org/10.1016/j.jheap.2025.100472 https://www.scopus.com/pages/publications/105017445317?origin=resultslist
Bharathan A.M., Department of Physics and Electronics, CHRIST (Deemed to be University), Karnataka, Bangalore, 560029, India; Stalin C.S., Indian Institute of Astrophysics, Block II, Koramangala, Karnataka, Bangalore, 560029, India; Sahayanathan S., Astrophysical Sciences Division, Bhabha Atomic Research Centre, Maharashtra, Mumbai, 400085, India, Homi Bhabha National Institute, Maharashtra, Mumbai, 400094, India; Mathew B., Department of Physics and Electronics, CHRIST (Deemed to be University), Karnataka, Bangalore, 560029, India
AstroSat's view of kHz quasi-periodic oscillations from 4U 1820?30
Accretion, accretion discs; Stars: neutron; X-rays: binaries; X-rays: individual: 4U 1820?30
This study presents the spectro-temporal analysis of the neutron star low mass X-ray binary 4U 1820?30, using data from three observations conducted by AstroSat 's Soft X-ray Telescope and Large Array X-ray Proportional Counter. Spectral analysis revealed that the source spectra could be modelled using an absorbed blackbody and a multi-temperature disk model along with a Comptonization model with ?=1.24 ? 1.89 and the inner accretion disk located at an distance of ?17 km from the neutron star. This showed the source to be in the hard spectral state. Temporal analysis revealed the presence of kHz quasi-periodic oscillations (QPOs) with frequencies in the 640 ? 1090 Hz range with root mean squared (RMS) amplitudes between 6 ? 10 per cent and quality factors between 8 ? 42. The RMS amplitude?energy and time lag?energy spectra of the upper and lower kHz QPOs hint them to be caused by modulations of photons having a common radiative mechanism. Moreover, the maximum RMS amplitude and time lag exhibited an anti-correlation with mass accretion rate. Using an analytical relation based on the relativistic precession model, the mass of the neutron star in the system was estimated to be 1.8 M?. The emission radius of one of the detected kHz QPOs was estimated to be ? 17 km. 2025 Elsevier B.V.
Giridharan, L.; Thomas, Neal Titus; Gudennavar, S.B.; Bubbly, S.G.
Journal of High Energy Astrophysics;Volume;50;Issue;;Article No.;100494;
https://doi.org/10.1016/j.jheap.2025.100494 https://www.scopus.com/pages/publications/105022186237?origin=resultslist
Giridharan L., Department of Physics and Electronics, CHRIST University, Karnataka, Bangalore, 560029, India; Thomas N.T., Department of Physics and Electronics, CHRIST University, Karnataka, Bangalore, 560029, India; Gudennavar S.B., Department of Physics and Electronics, CHRIST University, Karnataka, Bangalore, 560029, India; Bubbly S.G., Department of Physics and Electronics, CHRIST University, Karnataka, Bangalore, 560029, India
Effects of coronal mass ejection on PSR J1022+1001 and possible mode change of PSR J2145 - 0750 in the InPTA DR2
Gravitational wave background; Mode change; Pulsar; Sun
The Indian Pulsar Timing Array (InPTA) has recently published its second data release (DR2), comprising the timing analysis of seven years of data on 27 millisecond pulsars (MSPs), observed simultaneously in the 300 - 500 MHz (band 3) and 1260 - 1460 MHz (band 5), using the upgraded Giant Metrewave Radio Telescope (uGMRT). The low-frequency data, particularly in band 3, is highly sensitive to propagation effects such as dispersion measure (DM) fluctuations, which can be imprints of some astrophysical phenomena (scientific outliers). Here, we analyze the two outliers of possible astrophysical origin coming from the band 3 DM time series of two pulsars: PSR J1022+1001, with an ecliptic latitude of ?0.06?, and PSR J2145 - 0750, one of the brightest MSPs, with multi-component profile morphology. Our study reveals compelling evidence for a coronal mass ejection (CME) event traced in the data of PSR J1022+1001, and reports evidence for a potential mode-changing event in PSR J2145 - 0750. By contrasting these two cases, we show that DM fluctuations due to CME interacions and intrinsic mode-changing events produce distinct observational signatures, enabling a physically informed classification of scientific outliers in PTA datasets. Extending the analyses presented here to the full sample of InPTA-DR2 pulsars is expected to reveal additional CME events, and possible mode-changing events. Such detections will not only improve our understanding of solar and pulsar magnetospheric plasma interactions but will also enable more accurate modelling of DM variations, leading to improved pulsar timing solutions, which are crucial for high-precision Pulsar Timing Array (PTA) science. 2026 Elsevier B.V.
Chowdhury, Shaswata; Krishnakumar, M.A.; Bagchi, Manjari; Joshi, Bhal Chandra; Nobleson, K.; Jose, Jibin; Desai, Shantanu; Singh, Manpreet; Vyasraj, Vaishnavi; Meena, Kuldeep; Amarnath; Chakraborty, Manoneeta; Kala, Shubham; Deb, Debabrata; Zuraiq, Zenia; Pandian B, Arul; Dhanda Batra, Neelam; Dwivedi, Churchil; Mondal, Sushovan; Paladi, Avinash Kumar; Rai, Kaustubh; Susobhanan, Abhimanyu; Shukla, Adya; Srivastava, Aman; Surnis, Mayuresh; Tahbildar, Hemanga; Takahashi, Keitaro; Tarafdar, Pratik; Thiagaraj, Prabu; Vara, Kunjal
Journal of High Energy Astrophysics;Volume;51;Issue;;Article No.;100547;
https://doi.org/10.1016/j.jheap.2025.100547 https://www.scopus.com/pages/publications/105028031010?origin=resultslist
Chowdhury S., The Institute of Mathematical Sciences, C. I. T. Campus, Taramani, Chennai, 600113, India; Krishnakumar M.A., Radio Astronomy Centre, National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, Udhagamandalam, 643001, India; Bagchi M., The Institute of Mathematical Sciences, C. I. T. Campus, Taramani, Chennai, 600113, India, Training School Complex, Homi Bhabha National Institute, Anushakti Nagar, Mumbai, 400094, India; Joshi B.C., National Centre for Radio Astrophysics, SP Pune University Campus, Maharashtra, Pune, 411007, India, Department of Physics, Indian Institute of Technology Roorkee, Uttarakhand, Roorkee, 247667, India; Nobleson K., Faculty of Advanced Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto, 860-8555, Japan; Jose J., Department of Astronomy, Astrophysics, and Space Engineering, Indian Institute of Technology Indore, Indore, 453552, India; Desai S., Department of Physics, IIT Hyderabad, Telangana, Kandi, 502284, India; Singh M., Department of Physical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, SAS Nagar, Punjab, Mohali, 140306, India; Vyasraj V., Department of Physics, IIT Hyderabad, Telangana, Kandi, 502284, India; Meena K., UM-DAE Centre for Excellence in Basic Sciences, University of Mumbai, Vidyanagari Mumbai, 400098, India; Amarnath, Raman Research Institute, Karnataka, Bengaluru, 560080, India; Chakraborty M., Department of Astronomy, Astrophysics, and Space Engineering, Indian Institute of Technology Indore, Indore, 453552, India; Kala S., The Institute of Mathematical Sciences, C. I. T. Campus, Taramani, Chennai, 600113, India; Deb D., Centre for Space Research, North-West University, Private Bag X6001, Potchefstroom, 2520, South Africa; Zuraiq Z., Department of Physics, Indian Institute of Science, C. V. Raman Avenue, Bengaluru, 560012, India; Pandian B A., Raman Research Institute, Karnataka, Bengaluru, 560080, India, Department of Physics and Electronics, The Christ (Deemed to be University), Bangalore, India; Dhanda Batra N., Department of Physics, Indian Institute of Technology, Hauz Khas, Delhi New Delhi, 110016; Dwivedi C., Astronomy and Astrophysics Division, Physical Research Laboratory, Thaltej Campus, Gujarat, Ahmedabad, 380059, India; Mondal S., The Institute of Mathematical Sciences, C. I. T. Campus, Taramani, Chennai, 600113, India, Training School Complex, Homi Bhabha National Institute, Anushakti Nagar, Mumbai, 400094, India; Paladi A.K., Department of Physics, Indian Institute of Science, C. V. Raman Avenue, Bengaluru, 560012, India; Rai K., Department of Physics, IISER Bhopal, Bhauri Bypass Road, Bhopal, 462066, India; Susobhanan A., Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Callinstra 38, Hannover, D-30167, Germany; Shukla A., Department of Physics, Indian Institute of Technology Roorkee, Uttarakhand, Roorkee, 247667, India; Srivastava A., Department of Physics, IIT Hyderabad, Telangana, Kandi, 502284, India, Department of Physics, GLA University, Mathura, 281406, India; Surnis M., Department of Physics, IISER Bhopal, Bhauri Bypass Road, Bhopal, 462066, India; Tahbildar H., Department of Physics, IISER Bhopal, Bhauri Bypass Road, Bhopal, 462066, India; Takahashi K., Faculty of Advanced Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto, 860-8555, Japan; Tarafdar P., INAF - Osservatorio Astronomico di Cagliari, via della Scienza 5, Selargius (CA), 09047, Italy; Thiagaraj P., Raman Research Institute, Karnataka, Bengaluru, 560080, India; Vara K., Department of Physics, IISER Bhopal, Bhauri Bypass Road, Bhopal, 462066, India
Detection of time delay between UV and X-ray variability in Mrk 1044 using AstroSat observations
Active - galaxies; Galaxies; Galaxies - X-rays; Individual; Mrk 1044 - ultraviolet
Active galactic nuclei are known to exhibit flux variations across the entire electromagnetic spectrum. Among these, correlations between UV/optical and X-ray flux variations serve as a key diagnostics for understanding the physical connection between the accretion disk and the corona. In this work, we present the results of analysis of ultraviolet (UV) and X-ray flux variations in the narrow line Seyfert 1 galaxy Mrk 1044. Simultaneous observations in the far-UV band (FUV: 1300 - 1800 and the X-ray band (0.5 - 7 keV) obtained during 31 August - 8 September 2018 with the Ultraviolet Imaging Telescope and the Soft X-ray Telescope onboard AstroSat were used for this study. Significant flux variability was detected in both FUV and X-ray bands. The fractional root mean square variability amplitude ( F var) was found to be 0.036 0.001 in the FUV band and 0.384 0.004 in the X-ray band. To explore potential time lag between the two bands, cross-correlation analysis was performed using both the interpolated cross-correlation function (ICCF) and just another vehicle for estimating lags in nuclei (JAVELIN) methods. Results from both approaches are consistent within 2 ? uncertainty, indicating that X-ray variations lead the FUV variations, with measured lags of 2.25 0.05 days (ICCF) and 2.35?0.01+0.02 days (JAVELIN). This is the first detection of a time delay between UV and X-ray variations in Mrk 1044. The observed UV lag supports the disk reprocessing scenario, wherein X-ray emission from the corona irradiates the accretion disk, driving the observed UV variability. 2026 Elsevier B.V.
Reshma, M.; Stalin, C.S.; Mandal, Amit Kumar; Kayal, Abhijit; Gudennavar, S.B.; Joseph, Prajwel
Journal of High Energy Astrophysics;Volume;51;Issue;;Article No.;100552;
https://doi.org/10.1016/j.jheap.2026.100552 https://www.scopus.com/pages/publications/105027550161?origin=resultslist
Reshma M., Department of Physics and Electronics, CHRIST University, Karnataka, Bangalore, 560029, India; Stalin C.S., Indian Institute of Astrophysics, Block II, Koramangala, Karnataka, Bangalore, 560034, India; Mandal A.K., Center for Theoretical Physics of the Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland; Kayal A., Indian Institute of Astrophysics, Block II, Koramangala, Karnataka, Bangalore, 560034, India; Gudennavar S.B., Department of Physics and Electronics, CHRIST University, Karnataka, Bangalore, 560029, India; Joseph P., Indian Institute of Astrophysics, Block II, Koramangala, Karnataka, Bangalore, 560034, India
The indian pulsar timing array data release 2: II. Customised single-pulsar noise analysis and noise budget
Gravitational waves; Neutron stars; Pulsar timing arrays; Pulsars
We present the results of customised single-pulsar noise analysis of 27 millisecond pulsars from the second data release of the Indian Pulsar Timing Array (InPTA-DR2). We model various stochastic noise sources present in the dataset using stationary Gaussian processes and estimate the noise budget of the InPTA-DR2 using Bayesian inference, involving model selection, Fourier harmonics selection, and parameter estimation for each pulsar. We check the efficacy of our noise characterisation by performing the Anderson-Darling test for Gaussianity on the noise-subtracted residuals. We find that all 11 pulsars with time baseline ? 2.5 yr show Gaussian residuals and do not have evidence for any red noise process in the optimal model, except for PSR J1944 + 0907, which shows presence of DM noise. PSRs J0437 - 4715, J1909 - 3744 and J1939 + 2134 show preference for the most complicated noise model, having achromatic and chromatic red noise processes. Only 4 out of 15 pulsars with time baseline ? 2.5 yr show significant non-Gaussianity in noise-subtracted residuals. We suspect that this may require more advanced methods to model noise processes properly. A comparative study of six pulsars with data removed near solar conjunctions showed deviations from the parameter estimates obtained with the original dataset, indicating potential bias in red noise processes due to unmodeled solar-wind effects. The results presented in this work remain broadly consistent with the InPTA-DR1 noise budget, with better constraints obtained on noise processes for several pulsars and support for achromatic red noise in PSR J1012 + 5307 due to the extended time baseline. 2026 The Author(s).
Nobleson, K.; Dwivedi, Churchil; Desai, Shantanu; Joshi, Bhal Chandra; Grover, Himanshu; Deb, Debabrata; Vyasraj, Vaishnavi; Vara, Kunjal; Tahbildar, Hemanga; Susobhanan, Abhimanyu; Surnis, Mayuresh; Srivastava, Aman; Sardana, Shubhit; Takahashi, Keitaro; Amarnath; Arumugam, P.; Bagchi, Manjari; Batra, Neelam Dhanda; Chakraborty, Manoneeta; Chowdhury, Shaswata; Jacob, Shebin Jose; Jose, Jibin; Kala, Shubham; Kato, Ryo; Krishnakumar, M.A.; Meena, Kuldeep; Paladi, Avinash Kumar; Pandian, Arul; Rai, Kaustubh; Rana, Prerna; Singh, Manpreet; Singha, Jaikhomba; Shukla, Adya; Tarafdar, Pratik; Thiagraj, Prabu; Zuraiq, Zenia
Journal of High Energy Astrophysics;Volume;53;Issue;;Article No.;100594;
https://doi.org/10.1016/j.jheap.2026.100594 https://www.scopus.com/pages/publications/105033285648?origin=resultslist
Nobleson K., International Research Organization for Advanced Science and Technology, Faculty of Advanced Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto, Kumamoto City, 860-8555, Japan; Dwivedi C., Astronomy and Astrophysics Division, Physical Research Laboratory, Thaltej Campus, Thaltej, Gujarat, Ahmedabad, 380059, India; Desai S., Department of Physics, IIT Hyderabad, Telangana, Kandi, 502284, India; Joshi B.C., National Centre for Radio Astrophysics, SP Pune University Campus, Maharashtra, Pune, 411007, India, Department of Physics, Indian Institute of Technology Roorkee, Uttarakhand, Roorkee, 247667, India; Grover H., Department of Physics, Indian Institute of Technology Roorkee, Uttarakhand, Roorkee, 247667, India; Deb D., Centre for Space Research, North-West University, Private Bag X6001, Potchefstroom, 2520, South Africa; Vyasraj V., Department of Physics, IIT Hyderabad, Telangana, Kandi, 502284, India; Vara K., Department of Physics, Indian Institute of Science Education and Research, Bhauri Bypass Road, Madhya Pradesh, Bhopal, 462066, India; Tahbildar H., Department of Physics, Indian Institute of Science Education and Research, Bhauri Bypass Road, Madhya Pradesh, Bhopal, 462066, India; Susobhanan A., School of Physics, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala PO, Kerala, Thiruvananthapuram, 695551, India; Surnis M., Department of Physics, Indian Institute of Science Education and Research, Bhauri Bypass Road, Madhya Pradesh, Bhopal, 462066, India; Srivastava A., Department of Physics, IIT Hyderabad, Telangana, Kandi, 502284, India, Department of Physics, GLA University, Uttar Pradesh, Mathura, 281406, India; Sardana S., Department of Physics, Indian Institute of Science Education and Research, Bhauri Bypass Road, Madhya Pradesh, Bhopal, 462066, India; Takahashi K., International Research Organization for Advanced Science and Technology, Faculty of Advanced Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto, Kumamoto City, 860-8555, Japan; Amarnath, Raman Research Institute, Karnataka, Bengaluru, 560080, India; Arumugam P., Department of Physics, Indian Institute of Technology Roorkee, Uttarakhand, Roorkee, 247667, India; Bagchi M., The Institute of Mathematical Sciences, C.I.T. Campus, Taramani, Tamilnadu, Chennai, 600113, India, Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Maharashtra, Mumbai, 400094, India; Batra N.D., Indian Institute of Technology, Delhi, Hauz Khas, New Delhi, 110016, India; Chakraborty M., Department of Astronomy, Astrophysics, and Space Engineering, Indian Institute of Technology Indore, Madhya Pradesh, Indore, 453552, India; Chowdhury S., The Institute of Mathematical Sciences, C.I.T. Campus, Taramani, Tamilnadu, Chennai, 600113, India; Jacob S.J., Department of Physics, Government Brennen College Thalassery Kannur University, Kerala, Kannur, 670106, India; Jose J., Department of Astronomy, Astrophysics, and Space Engineering, Indian Institute of Technology Indore, Madhya Pradesh, Indore, 453552, India; Kala S., The Institute of Mathematical Sciences, C.I.T. Campus, Taramani, Tamilnadu, Chennai, 600113, India; Kato R., Mizusawa VLBI Observatory, National Astronomical Observatory of Japan, 2-21-1 Osawa, Tokyo, Mitaka, 181-8588, Japan; Krishnakumar M.A., Radio Astronomy Centre National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, Tamilnadu, Udhagamandalam, 643001, India; Meena K., UM-DAE Centre for Excellence in Basic Sciences, University of Mumbai Vidyanagari, Maharashtra, Mumbai, 400098, India; Paladi A.K., Joint Astronomy Programme, Department of Physics, Indian Institute of Science, Karnataka, Bengaluru, 560012, India; Pandian A., Raman Research Institute, Karnataka, Bengaluru, 560080, India, Department of Physics and Electronics, CHRIST (Deemed to be University), Karnataka, Bengaluru, 560029, India; Rai K., Department of Physics, Indian Institute of Science Education and Research, Bhauri Bypass Road, Madhya Pradesh, Bhopal, 462066, India; Rana P., Department of Astronomy, University of Cape Town, Cape Town, 7700, South Africa, High Energy Physics, Cosmology & Astrophysics Theory (HEPCAT) Group, Department of Mathematics and Applied Mathematics, University of Cape Town, Cape Town, 7700, South Africa; Singh M., Department of Physical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, SAS Nagar, Punjab, Mohali, 140306, India; Singha J., High Energy Physics, Cosmology & Astrophysics Theory (HEPCAT) Group, Department of Mathematics and Applied Mathematics, University of Cape Town, Cape Town, 7700, South Africa; Shukla A., Department of Physics, Indian Institute of Technology Roorkee, Uttarakhand, Roorkee, 247667, India; Tarafdar P., INAF - Osservatorio Astronomico di Cagliari, via della Scienza 5, Selargius (CA), 09047, Italy; Thiagraj P., Raman Research Institute, Karnataka, Bengaluru, 560080, India; Zuraiq Z., Department of Physics, Indian Institute of Science, Karnataka, Bengaluru, 560012, India
Ultraviolet variability in radio-loud active galactic nuclei observed by UVIT onboard AstroSat
Active galactic nuclei; BL lacertae objects; Blazars; Flat spectrum radio quasars; Narrow-line Seyfert 1 galaxy; Ultraviolet variability
Radio-loud active galactic nuclei (AGN) are among the most luminous objects in the Universe, emitting radiation from low-energy radio waves to high energy ? -rays. They are well known to exhibit flux variations at nearly all accessible wavelengths. However, their variability properties in the ultraviolet (UV) band remain relatively less explored compared to other wavebands. Here, we present the results of a systematic investigation of the UV flux and spectral variability characteristics of 24 radio-loud AGN spanning the redshift range 0.018 ? z ? 2.218. The sample comprises 17 BL Lac objects, 6 flat spectrum radio quasars (FSRQs) and one radio-loud narrow line Seyfert 1 galaxy. We used observations obtained with the Ultra-Violet Imaging Telescope (UVIT) onboard AstroSat during its first ten years of operation, covering both the far-UV (FUV; 1300 - 1800 and near-UV (NUV; 2000 - 3000 bands. Of the 24 sources analysed, 18 showed significant UV variability on hour timescales. We found a bluer when brighter (BWB) spectral trend in two sources: the FSRQ CTA 102 and the BL Lac PKS 0447 - 439. The observed UV variability in our sample of radio-loud AGN, together with the BWB trend detected in these two sources, supports a scenario in which the hour timescale UV variations are driven by intrinsic processes within their relativistic jets. 2026 Elsevier B.V.
Reshma, M.; Stalin, C.S.; Kumar Mandal, Amit; Gudennavar, S.B.; Benedict, Senorita; Joseph, Prajwel
Journal of High Energy Astrophysics;Volume;53;Issue;;Article No.;100601;
https://doi.org/10.1016/j.jheap.2026.100601 https://www.scopus.com/pages/publications/105034549515?origin=resultslist
Reshma M., Department of Physics and Electronics, CHRIST University, Karnataka, Bengaluru, 560029, India; Stalin C.S., Indian Institute of Astrophysics, Block II, Koramangala, Karnataka, Bengaluru, 560034, India; Kumar Mandal A., Center for Theoretical Physics of the Polish Academy of Sciences, Al. Lotnikow 32/46, Warsaw, 02-668, Poland; Gudennavar S.B., Department of Physics and Electronics, CHRIST University, Karnataka, Bengaluru, 560029, India; Benedict S., St. Josephs University, 36, Lal Bagh Main Road, Langford Gardens, Bengaluru, 560 027, India; Joseph P., Indian Institute of Astrophysics, Block II, Koramangala, Karnataka, Bengaluru, 560034, India
Cosmic acceleration from topological fluctuations of quantum spacetime
Accelerated expansion; CMB; DESI BAO; Euclidean quantum gravity; Topological dark energy
The observed late-time acceleration of the Universe challenges our understanding of gravity and the quantum vacuum. We investigate the framework of Topological Dark Energy, where cosmic acceleration emerges not from a fundamental cosmological constant or exotic fields, but from the topological structure of quantum spacetime. In this picture, the vacuum is a dynamic spacetime foam in which gravitational instantons-non-perturbative configurations in Euclidean quantum gravity-nucleate and alter global topology. The cumulative effect of these processes, coupled to macroscopic gravity through the Gauss-Bonnet invariant, yields a dynamical effective cosmological constant, ?eff. Its sign and magnitude are determined by the statistical ensemble of instantons, allowing the dark energy equation of state to evolve across the phantom divide. By embedding the Topological Dark Energy in a FriedmannLemareRobertsonWalker background, we derive its background and linear perturbative cosmological dynamics and confront the model with DESI DR2 BAO, Union3 supernova, and Planck CMB data. The results show that Topological Dark Energy is observationally viable, reproducing key features of the expansion history while offering a theoretically motivated alternative to ?CDM. 2026 Elsevier B.V.
Kavya, N.S.; Mishra, Sai Swagat; Sahoo, P.K.; Capozziello, Salvatore
Journal of High Energy Astrophysics;Volume;53;Issue;;Article No.;100621;
https://doi.org/10.1016/j.jheap.2026.100621 https://www.scopus.com/pages/publications/105036332356?origin=resultslist
Kavya N.S., Center for Mathematical Needs, Department of Mathematics, CHRIST (Deemed to be University), Bengaluru 560029, India; Mishra S.S., Department of Mathematics, School of CS & AI, SR University, Telangana, Warangal, 506371, India; Sahoo P.K., Department of Mathematics, Birla Institute of Technology and Science, Pilani, Hyderabad Campus, Jawahar Nagar, Kapra Mandal, Medchal District, Telangana, 500078, India; Capozziello S., Dipartimento di Fisica E Pancini, Universitdegli Studi di Napoli Federico II, Complesso Universitario di Monte S. Angelo, Via Cinthia Edificio 6, Napoli, I-80126, Italy, Scuola Superiore Meridionale, Via Mezzocannone 4, Napoli, I-80134, Italy, Istituto Nazionale di Fisica Nucleare Sezione di Napoli, Via Cinthia, Napoli, I-80126, Italy
New constraints on f(T) gravity from DESI DR2 and dark energy survey supernovae
Cosmological parameters; Distance scale; Methods: Statistical; Observations
We present new observational constraints on three viable f (T) gravity parametrizationsthe Power Law (f 1CDM), Linder (f 2CDM), and Exponential (f 3CDM) modelsusing the latest Baryon Acoustic Oscillations (BAO) measurements from the Dark Energy Spectroscopic Instrument (DESI) Data Release 2 (DR2). We combine the spectroscopic DESI-DR2 data with Cosmic Chronometer (CC) measurements, the Type Ia Supernovae sample from the Dark Energy Survey (DES) Year 5, and early-universe CMB distance priors to break parameter degeneracies. Our Bayesian MCMC analysis reveals that while late-time data alone suggests a statistical preference for a non-zero deviation from GR at the 1 ? 2 ? level, the inclusion of CMB priors pulls the models significantly closer to the standard ?CDM limit. Specifically, we constrain the joint dataset distortion parameters to p1=?0.002?0.041+0.047, 1/p2=0.156?0.057+0.10, and 1/p3=0.144?0.023+0.071. Across all three models, the addition of early-universe data anchors the inferred Hubble constant to sub-percent precision, clustering around H0?67.3?67.7kms?1Mpc?1, showing excellent agreement with Planck 2018 results but remaining in tension with local SH0ES calibrations. Statistical model comparison demonstrates that while late-time data favors the f (T) extensions (?AIC'?2), the comprehensive joint analysis renders them statistically indistinguishable from ?CDM based on the Akaike Information Criterion (?AIC ? 2). Furthermore, the Bayesian Information Criterion (BIC) finds moderate to strong evidence against the extensions (4 ' ?BIC ? 7.5) due to the penalty on model complexity. We conclude that while current precision data accommodate late-time torsional modifications to gravity, the standard ?CDM model remains a statistically sufficient and more parsimonious description of the cosmic expansion when considering the full evolutionary history. 2026 Elsevier B.V.
Journal of High Energy Astrophysics;Volume;53;Issue;;Article No.;100631;
https://doi.org/10.1016/j.jheap.2026.100631 https://www.scopus.com/pages/publications/105038897276?origin=resultslist
Naik D.M., Department of Mathematics, Government First Grade College Shikaripura, Kuvempu University, Shivamogga-577 427, Karnataka, India; Kavya N.S., Department of Mathematics, Centre for Mathematical Needs, CHRIST (Deemed to be University), Bengaluru, 560029, India
Surface modified CaO nanoparticles with CMC/D-carvone for enhanced anticancer, antimicrobial and antioxidant activities
Anti-cancer; Antimicrobial; Antioxidant; CaO nanoparticles; CMC; D-carvone
The rising prevalence of antimicrobial resistance and the continued challenge to cancer therapy are in desperate need of developing innovative therapeutic strategies. In this regard, the present research work focuses on the development of CaO NPs and CaO-CMC-Dcar nanocomposites for enhanced antimicrobial and anti-cancer activities. CaO nanoparticles were synthesized by facile one pot chemical approach and eventually functionalized with CMC and D-carvone biomolecules. XRD analysis revealed that the crystallite size for CaO and CaO-CMC-Dcar nanoparticles was found to be 21.18 nm and 17.02 nm respectively. The band gap values obtained for CaO and CaO-CMC-Dcar nanoparticles were 4.44 eV, and 4.25 eV respectively. The CaO-CMC-Dcar nanoparticles show absorption maxima at 292 nm, slightly red-shifted from bare CaO nanoparticles. HRTEM and SEM analysis revealed that the prepared samples were roughly spherical and agglomerated in nature. Antimicrobial activity was evaluated against methicillin-resistant Staphylococcus aureus (MRSA) and Candida albicans. The zone of inhibition (ZOI) for CaO-CMC-Dcar nanoparticles against MRSA and C. albicans was 20.1 0.3 mm and 21.1 0.2 mm, respectively, significantly higher than that of pure CaO nanoparticles (14.1 0.2 mm and 13.2 0.1 mm) and comparable to standard anti-bacterial streptomycin and antifungal fluconazole discs. Anticancer activity was assessed via MTT assay against MOLT-4 blood cancer cells, where the IC50 values for CaO and CaO-CMC-Dcar nanoparticles were 22.6 ?g/mL and 21.54 ?g/mL, respectively. Additionally, CaO-CMC-Dcar nanoparticles exhibited enhanced antioxidant activity (80 %) compared to CaO (70 %) at 20 ?g/mL, with performance comparable to that of Vitamin C. Experimental results revealed that the CaO-CMC-Dcar nanoparticles exhibited superior biological activity compared to pure CaO nanoparticles. 2025 Indian Chemical Society
Suresh, Mickymaray; Alothaim, Abdulaziz S.; Alfaleh, Faleh A.; Alsowayeh, Noorah; Suresh, Kaviya; Thangavelu, Indumathi; Arulselvan, Palanisamy
Journal of the Indian Chemical Society;Volume;102;Issue;2;Article No.;101586;
https://doi.org/10.1016/j.jics.2025.101586 https://www.scopus.com/pages/publications/85216075049?origin=resultslist
Suresh M., Department of Biology, College of Science- Al-Zulfi, Majmaah University, Riyadh Region, Majmaah, 11952, Saudi Arabia; Alothaim A.S., Department of Biology, College of Science- Al-Zulfi, Majmaah University, Riyadh Region, Majmaah, 11952, Saudi Arabia; Alfaleh F.A., Department of Biology, College of Science- Al-Zulfi, Majmaah University, Riyadh Region, Majmaah, 11952, Saudi Arabia; Alsowayeh N., Department of Biology, College of Science- Al-Zulfi, Majmaah University, Riyadh Region, Majmaah, 11952, Saudi Arabia; Suresh K., Department of Pharmaceutics, Sri Ramachandra Faculty of Pharmacy, Sri Ramachandra Institute of Higher Education and Research (DU), Porur, Chennai, 600 116, India; Thangavelu I., Department of Chemistry, CHRIST (Deemed to be University), Karnataka, Bangalore, (560029), India; Arulselvan P., Department of Chemistry, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences (SIMATS), Saveetha University, Chennai, 602105, India
Development and characterization of Fe2O3 nanoparticles coated with chitosan and folic acid for biomedical applications
Antibacterial activity; Anticancer activity; DPPH; Fe2O3 -CS-FA NPs; Marigold flowers
Polymeric inorganic nanoparticles have emerged as promising nanomedicines due to their unique properties, offering enhanced antibacterial and anticancer effects. Thus, the study focus on the synthesis of Fe2O3 and Fe2O3 coated with chitosan and folic acid nanoparticles (Fe2O3-CS-FA NPs) mediated by Tagetes erecta (T. erecta) extract and assess their biological effects. The synthesized NPs are analysed by various characterisation techniques. FTIR spectroscopy of Fe2O3 and Fe2O3 -CS-FA NPs revealed characteristic peaks corresponding to Fe2O3, chitosan, and folic acid molecules. The XRD pattern confirmed the successful synthesis of Fe2O3 NPs and Fe2O3 -CS-FA NPs, indicating a rhombohedral structure. FESEM demonstrated spherical structures for both Fe2O3 and Fe2O3 -CS-FA NPs. Antimicrobial activity was assessed against various pathogens using the disk diffusion method, showing that Fe2O3-CS-FA NPs demonstrated superior antibacterial activity compared to Fe2O3 NPs. In terms of antioxidant activity, Fe2O3 -CS-FA NPs showed the highest scavenging activity against DPPH, outperforming Fe2O3 NPs. The anticancer activity of both Fe2O3 NPs and Fe2O3 -CS-FA NPs was tested against the HCT-116 human colon cancer cell line, where Fe2O3 -CS-FA NPs demonstrated greater anticancer activity with an IC50 value of 10.2 ?g/mL compared to Fe2O3 at 13.8 ?g/mL. Based on the findings of this research, there is a strong indication that Fe2O3 -CS-FA NPs hold significant potential as a nanomaterial well-suited for advanced biomedical applications in the industry. 2025 Indian Chemical Society
Kushwaha, Ravi Kant; Shah, Uzma Noor; Sandhwar, Vishal; Pandey, Sakshi; Thangavelu, Indumathi; AlGhamdi, AbdulAziz A.; Tadepalli, Srinivas
Journal of the Indian Chemical Society;Volume;102;Issue;9;Article No.;101909;
https://doi.org/10.1016/j.jics.2025.101909 https://www.scopus.com/pages/publications/105010904673?origin=resultslist
Kushwaha R.K., Maharishi School of Pharmaceutical Sciences, Maharishi University of Information Technology, Uttar Pradesh, Lucknow, India; Shah U.N., Department of Genetics, School of Sciences, JAIN (Deemed-to-be University), Karnataka, India; Sandhwar V., Department of Chemical Engineering, PIT, Parul University, Gujarat, Vadodara, India; Pandey S., Centre of Research Impact and Outcome, Chitkara University, Punjab, Rajpura, 140417, India; Thangavelu I., Department of Chemistry, CHRIST (Deemed to be University), Bangalore, 560029, India; AlGhamdi A.A., Department of Chemical Engineering, College of Engineering, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh, 11432, Saudi Arabia; Tadepalli S., Department of Chemical Engineering, College of Engineering, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh, 11432, Saudi Arabia