Journals
2025 EN
Sahu Anupam · Kumar Dharmendra · Tripathi Tanya
+5 more
Abstract This paper introduces the design of a high‐performance Surface Plasmon Resonance (SPR) sensor using a SnSe 2 /Si/PbTiO 3 heterostructure for detecting malaria, targeting the different stages of the plasmodium parasite lifecycle. The Tin di‐selenide (SnSe 2 ) with high refractive index (RI) and excellent absorption property in visible and infrared regions allows efficient interaction with the evanescent field, thereby increasing sensitivity for small RI changes near the surface. The strategic integration of lead titanate (PbTiO 3 ), known for its high RI and tunable bandgap, with SnSe 2 and Silicon (Si) layers, the proposed sensor design (FK51A‐prism/Ag/SnSe 2 /Si/PbTiO 3 /Sensing‐Medium) significantly improves sensitivity to 390.41°/RIU for the ring stage of malaria. The Kretschmann configuration, in conjunction with the Transfer Matrix Method (TMM) and angular interrogation, has been utilized to optimize the performance of the proposed SPR sensor. The proposed design achieves an optimal Quality Factor (QF) of 130.92 RIU⁻¹, enabling the detection of small changes in RI. With a Detection Accuracy (DA) of 0.33 deg −1 for the ring stage, the proposed SPR sensor demonstrates its potential for early and accurate malaria diagnosis. Also, the enhanced DA and QF in later stages (trophozoite and schizont stages) offers broad detection range of the proposed SPR design. The design offers a promising application across different biomedical applications.
Journals
2025 EN
Das Chayan · Saikia Dibyajyoti · Gandi Appala Naidu
+1 more
Abstract This study explores the thermoelectric and optoelectronic properties of HfSi₂N₄ and HfGe₂N₄ monolayers (ML) through first‐principles calculations. Both materials exhibit excellent structural stability, as confirmed by phonon dispersion and ab initio molecular dynamics simulations. HfSi₂N₄ demonstrates superior power factors and higher thermal conductivity, while HfGe₂N₄ achieves a remarkable thermoelectric figure of merit ( Z T $ZT$ ) of 0.92 at 900 K under p‐type doping, surpassing many 2D materials. The inclusion of spin‐orbit coupling further enhances the thermoelectric performance, especially for HfGe₂N₄. The electronic properties reveal indirect bandgaps of 2.89 eV for HfSi₂N₄ and 2.75 eV for HfGe₂N₄, with strong optical absorption peaks in the visible range, making them suitable for optoelectronic applications. The materials exhibit high carrier mobility, with HfSi₂N₄ reaching 582 cm 2 V⁻¹s⁻¹ and HfGe₂N₄ achieving an impressive 1870 cm 2 V⁻¹s⁻¹ for holes. Thermal conductivity analysis reveals that HfGe₂N₄ has significantly lower values than HfSi₂N₄, favoring thermoelectric efficiency. The synergy of high Seebeck coefficients ( S ), tunable thermal conductivity, and optical properties makes these monolayers promising candidates for advanced thermoelectric devices and visible‐light optoelectronics. This study provides a comprehensive comparison, offering valuable insights into their applicability in next‐generation energy conversion and optoelectronic technologies.
Journals
2025 EN
Singh Satyam · Sharma Manju
Abstract Additives, such as hydrate promoters or inhibitors, play a crucial role in hydrate growth by altering the thermodynamics or kinetics during the formation of hydrates. Ethylenediaminetetracetic acid (EDTA) bisamide can act as methane hydrate promoter or inhibitor based on length of alkyl side group due to shorter or longer alkyl chains, respectively. Molecular dynamics simulations effect of EDTA bisamide are reported with longer alkyl (n‐heptyl) side group on selective sequestration of carbon dioxide during CH 4 ‐CO 2 exchange in natural gas hydrates in a ternary‐gas system with different third gas species (N 2 , H 2 S, Ar, Kr, and Xe). The results show there is formation of gas cluster in bulk liquid region due to hydrophobic tails of EDTA bisamide. The lifetime of Xe and CH 4 clusters is the longest among the reported systems due to favorable interactions between Xe and CH 4 . The carbon dioxide sequestration in the newly formed sI‐hydrate cages is the highest for Xe(3:1) system, followed by N 2 (2:2), and is the poorest in Ar(2.5:1.5) and H 2 S(2:2) systems. Xe and Ar show reverse trends in sequestration of carbon dioxide in presence of EDTA bisamide as compared to the earlier reported simulations in a ternary‐gas system in the absence of additives (PCCP, 2023, 25 , 30211–3022).
Journals
2025 EN
Paul Debjoty · Yadav Shivesh · Gupta Shikhar
+9 more
Abstract Topological chiral antiferromagnets, such as Mn 3 Sn, are emerging as promising materials for next‐generation spintronic devices due to their intrinsic transport properties linked to exotic magnetic configurations. Here, it is demonstrated that anisotropic strain in Mn 3 Sn thin films offers a novel approach to manipulate the magnetic ground state, unlocking new functionalities in this material. Anisotropic strain reduces the point group symmetry of the manganese (Mn) Kagome triangles from C 3 v to C 1 , significantly altering the energy landscape of the magnetic states in Mn 3 Sn. This symmetry reduction enables even a tiny in‐plane Dzyaloshinskii‐Moriya (DM) interaction to induce canting of the Mn spins out of the Kagome plane. The modified magnetic ground state introduces a finite scalar spin chirality and results in a significant Berry phase in momentum space. Consequently, a large anomalous Hall effect emerges in the Kagome plane at room temperature ‐ an effect that is absent in the bulk material. Moreover, this twofold degenerate magnetic state enables the creation of multiple‐stable, non‐volatile anomalous Hall resistance (AHR) memory states. These states are field‐stable and can be controlled by thermal‐assisted current‐induced magnetization switching, requiring modest current densities and small bias fields, thereby offering a compelling new functionality in Mn 3 Sn for spintronic applications.
Journals
2025 EN
Chung Peter Hayoung · Ryu Jiyeon · Seo Daejae
+4 more
Abstract Artificial synapse devices are essential elements for highly energy‐efficient neuromorphic computing. They are implemented as crossbar array architecture, where highly selective synaptic weight updates for training and sneak leakage‐free inference operations are required. In this study, self‐selective bipolar artificial synapse device is proposed with n‐ZnO/p‐NiO x /n‐ZnO heterojunction, and its analog synapse operation with high selectivity is demonstrated in 32 × 32 crossbar array architecture without the aid of selector devices. The built‐in potential barrier at p‐NiO x /n‐ZnO junction and the Zener tunneling effect provided nonlinear current–voltage characteristics at both voltage polarities for self‐selecting function for synaptic potentiation and depression operations. Voltage‐driven redistribution of oxygen ions inside n–p–n oxide structure, evidenced by x‐ray photoelectron spectroscopy, modulated the distribution of oxygen vacancies in the layers and consequent conductance in an analog manner for the synaptic weight update operation. It demonstrates that the proposed n–p–n oxide device is a promising artificial synapse device implementing self‐selectivity and analog synaptic weight update in a crossbar array architecture for neuromorphic computing.
Journals
2025 EN
Barman Sayantika · Sahu Monalisha · Chakraborty Arup
+1 more
Abstract Background The construction industry in India heavily relies on unorganized workers, who often lack adequate access to safety measures, placing them at significant risk of accidents and injuries. The objective was to determine risk perceptions of construction workers, and explore their safety practices, facilitators, and barriers. Methods A mixed‐methods approach with a convergent parallel design (QUAN + qual) was undertaken. Quantitative strand included face‐to‐face interviews with 203 randomly selected building construction workers from 10 construction sites in five selected municipal wards in Kolkata. Questions pertained to socio‐demographics, occupational characteristics, risk perception, and safety practices. The qualitative arm involved key informant interviews to unravel the facilitators and barriers affecting safety practices and nonparticipant observation. Results The perceived risk for respiratory problems due to dust, pain from carrying loads, slips, trips or falls, and heat‐related illnesses was in the medium‐ to high category for 64.0%, 58.6%, 39.9%, and 36.5% of the study participants, respectively. However, the safety practices for these respective domains were in the good practice category for 6.9%, 4.9%, 54.2%, and 34.5% of the workers. From the qualitative arm, it was evident that availability of PPE, a conducive environment, and availability of worker‐friendly technology could be important predictors of safety practices. Barriers such as time constraints and feasibility due to discomfort and expenditure were also identified. Conclusion Despite high‐risk perception, safety practices were not consistently good among construction workers. Further research is crucial to enhance the health and safety of unorganized workers in India.
Journals
2025 EN
Chauhan Satyam · Dahir Ikran · Kumari Veena
+4 more
Abstract Background Sleep‐related disturbances are commonly reported in approximately 50% of older adults and have been associated with various psychiatric (e.g., psychosis) and neurodegenerative disorders (e.g., dementia). While the overlapping relationships between psychosis and sleep‐related disturbances in cognitive impairment have been recognised for decades, the mediating role of subjective cognitive impairment (SCI) in the relationship between MBI‐psychosis and sleep‐related disturbance is poorly understood. This study, therefore, aimed to investigate the magnitude of MBI‐psychosis on various sleep facets (i.e., sleep fragmentation, duration, inertia, quality, maintenance, satisfaction, daytime napping, deep sleep) while accounting for SCI in healthy UK‐based 14,846 older adults (74.3% females; mean age: 63.15±7.44). Method All participants were recruited from the general population and completed a range of online self‐report measures on sleep, MBI‐psychosis, SCI. Linear regression was used to analyse the relationship between MBI‐psychosis and sleep; mediation analysis examined the effects of SCI on this relationship. Result The findings demonstrated significant yet small‐sized correlations between MBI‐psychosis, SCI, and all sleep facets ( p < 0.001). While MBI‐psychosis had a direct significant effect on all sleep facets; SCI also partially mediated the psychosis‐sleep relationship ( p < 0.001). However, after controlling for depression, anxiety, and sex, the direct effect of psychosis on sleep was limited to sleep duration, daytime napping, and sleep onset. At the same time, SCI was found to fully mediate the relationship of psychosis with deep sleep, sleep fragmentation, inertia, quality, satisfaction and maintenance; SCI also partially mediated the relationship of psychosis with sleep onset and duration (all β<0.2) . Conclusion These findings highlight the importance of early identification of sleep‐related disturbances and associated comorbid disorders, including depression and anxiety, in middle‐aged and older adults as a preventative strategy for cognitive decline and the onset of dementia.
Journals
2025 EN
Sahu Nihar · Guchhait Chandrakanta · Mohanta Indrajit
+2 more
Abstract Certain proteins and synthetic covalent polymers experience aqueous phase transitions, driving functional self‐assembly. Herein, we unveil the ability of supramolecular polymers (SPs) formed by G 4 .Cu + to undergo heating‐induced unexpected aqueous phase transitions. For the first time, guided by Cu + , guanosine (G) formed a highly stable G‐quartet (G 4 .Cu + )/G‐quadruplex as a non‐canonical DNA secondary structure with temperature tolerance, distinct from the well‐known G 4 .K + . The G 4 .Cu + self‐assembled in water through π‐π stacking, metallophilic and hydrophobic interactions, forming thermally robust SPs. This enhanced stability is attributed to the stronger coordination of Cu + to four carbonyl oxygens of G‐quartet and the presence of Cu + ‐ ‐ ‐Cu + attractive metallophilic interactions in Cu + ‐induced G‐quadruplex, exhibiting a significantly higher interaction energy than K + as determined computationally. Remarkably, the aqueous SP solution exhibited heating‐induced phase transitions—forming a hydrogel through dehydration‐driven crosslinking of SPs below cloud temperature ( T cp ) and a hydrophobic collapse‐induced solid precipitate above T cp , showcasing a lower critical solution temperature (LCST) behavior. Notably, this LCST behavior of G 4 .Cu + SP originates from biomolecular functionality rather than commonly exploited thermo‐responsive oligoethylene glycols with supramolecular assemblies. Furthermore, exploiting the redox reversibility of Cu + /Cu 2+ , we demonstrated control over the assembly and disassembly of G‐quartets/G‐quadruplex and gelation reversibly.
Journals
2025 EN
Das Sujit · Jain Amul · Ahamed Subuhan
+9 more
Abstract Two unprecedented redox‐active, low‐spin Fe(III)‐triradical complexes, [Fe(III)(SS‐NHC═S •− ) 3 ]·NHC═S ( 1 ·NHC═S; E═S) and [Fe(III)(SS‐NHC═Se •− ) 3 ] ( 2 ; E═Se) have been synthesized and structurally characterized by SCXRD. They were further characterized spectroscopically using IR, Raman, EPR, and UV–vis‐NIR spectroscopy. The low‐spin electronic configuration of the central Fe(III) ion ( 1 ) and the nature of the magnetic interaction between the Fe(III) center and the three unpaired electrons in 1 have been investigated by magnetic measurements. In addition, the bonding stability and electron density distribution in 1 were studied by quantum chemical calculations and correlated with experimental results. Finally, a series of well‐defined functional homopolymers were synthesized via catalytic polymerization reactions using [Fe(III)(SS‐NHC═S •− ) 3 ] ( 1 ) as a catalyst at ambient temperature. These reactions yielded poly( N , N ‐dimethylacrylamide) (PDMA), poly( N ‐isopropyl acrylamide) (PNIPAM), poly(dimethyl amino ethyl methacrylate) (PDMAEMA), and poly(benzyl methacrylate) (PBzMA) with low dispersities ranging from 1.2 to 1.22. The successful synthesis of various diblock copolymers confirmed excellent chain‐end fidelity of the synthesized homopolymers. These homopolymers and diblock copolymers highlight the versatile catalytic polymerization reactions of these Fe‐radical complexes. Herein, we present a report on the polymerization of various acrylamides and methacrylates using a redox‐active Fe‐dithiolene complex for the first time.
Journals
2025 EN
Sahu Bhanendra · Paul Sudipta · Sinha Priyank
+1 more
Abstract Sulfur‐dots (S‐dots) serve as a cost‐effective and non‐toxic alternative to traditional photocatalysts or transition metals typically required in photoinduced reversible deactivation radical polymerization (photoRDRP). Herein, we report a facile and efficient method for synthesizing well‐defined multi‐arm star polymers through S‐dots mediated photoRDRP under ambient conditions. This approach enables precise control over polymer growth with excellent spatiotemporal control over polymerization, as evidenced by the ability to pause and resume polymerization with UVA light (“ON/OFF” switching). This methodology was successfully applied to produce a variety of polymer architectures, including multi‐arm star homopolymers and dual‐responsive diblock and triblock copolymers. Among these, the synthesized 4‐arm star [poly(N,N‐dimethyl acrylamide)‐ block ‐poly(dimethyl amino ethyl methacrylate)‐ block ‐poly(butyl acrylate)] 4 ‐Br [4‐arm star (PDMA‐ b ‐PDMAEMA‐ b ‐PBA) 4 ‐Br] triblock copolymer was used to assess pH and temperature responsiveness. This work introduces a sustainable, metal‐free route for the development of next‐generation smart polymers suitable for biomedical and environmental applications and highlights the versatility of S‐dots as a catalyst.