Publications by authors named "Debnath T"

The breaking of inversion symmetry combined with spin-orbit coupling, can give rise to intrigu- ing quantum phases and collective excitations. Here, we report systematic temperature dependent Raman scattering and theoretical calculations of phonon modes across the inversion symmetry- breaking structural transitions in a quasi-one-dimensional compound (TaSe4)3I. Our investigation revealed the emergence of three additional Raman-active modes in Raman spectra of the low- temperature (LT) non-centrosymmetric (NC) structure of the material.

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The mosquito fat body is the principal source of yolk protein precursors (YPP) during mosquito egg development in female . To better understand the metabolic and signaling pathways involved in mosquito reproduction, we investigated changes in the mosquito fat body phosphoproteome at multiple time points after a blood meal. Using LC/MS, we identified 3570 phosphorylated proteins containing 14,551 individual phosphorylation sites.

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Article Synopsis
  • - The study explores the stability and manipulation of 1D van der Waals materials, focusing on two specific examples: MoI and TaSeI, showing that individual atomic chains can be processed and stabilized.
  • - High-resolution imaging techniques confirm the existence of stable atomic chains of MoI at room temperature, while TaSeI allows for the creation of suspended chains using electron beams.
  • - The research includes ab initio calculations that validate the stability and cleavage energies of these 1D materials, demonstrating the feasibility of top-down processing methods at the atomic level.
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As reserves of non-renewable energy sources decline, the search for sustainable alternatives becomes increasingly critical. Next-generation energy materials play a key role in this quest by enabling the manipulation of properties for effective energy solutions and understanding interfaces to enhance energy yield. Studying these interfaces is essential for managing charge transport in optoelectronic devices, yet it presents significant challenges.

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Diamond is a semiconductor material with remarkable structural, thermal, and electronic properties that has garnered significant interest in the field of electronics. Although hydrogen (H) and oxygen (O) terminations are conventionally favored in transistor designs, alternative options, such as silicon (Si) and germanium (Ge), are being explored because of their resilience to harsh processing conditions during fabrication. Density-functional theory was used to examine the non-oxidized and oxidized group-IV (Si and Ge)-terminated diamond (100) surfaces.

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Inspired by biomineralization, the recent incorporation of organic molecules into inorganic lattices shows interesting optical properties and tunability. We functionalize all inorganic CsPbBr perovskite nanocrystals (PNCs) with amino acid (AA) cysteine using the water-hexane interfacial approach. Along with the AA cysteine, we added AuBr salt into the aqueous phase, leading to the formation of a Au-cysteine thiolate complex to activate the aqueous to nonaqueous phase transportation of the AA via a molecular shuttle, oleylamine.

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Taking advantage of the slow exciton-to-dopant energy transfer process, we dissociated the exciton in Mn-doped perovskite ultrafast electron shuttling to a surface adsorbed 4-nitro phenol molecule. The observed ultrafast electron transfer process is competitive to the ultrafast exciton scattering process (∼140 fs) to the continuum states optical phonons, but three-orders faster than the exciton-to-Mn energy transfer timescale.

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(TaSe_{4})_{2}I is a well-studied quasi-one-dimensional compound long-known to have a charge-density wave (CDW) transition around 263 K. We argue that the critical fluctuations of the pinned CDW order parameter near the transition can be inferred from the resistance noise on account of their coupling to the dissipative normal carriers. Remarkably, the critical fluctuations of the CDW order parameter are slow enough to survive the thermodynamic limit and dominate the low-frequency resistance noise.

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Considering the importance of physics and chemistry at material interfaces, we have explored the coupling of multinary chalcogenide semiconductor CuNiSnS nanoparticles (CNTS NPs) for the first time with the noble metal (Au) to form Au-CNTS nano-heterostructures (NHSs). The Au-CNTS NHSs is synthesized by a simple facile hot injection method. Synergistic experimental and theoretical approaches are employed to characterize the structural, optical, and electrical properties of the Au-CNTS NHSs.

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In recent years, machine learning (ML) and deep learning (DL) have been the leading approaches to solving various challenges, such as disease predictions, drug discovery, medical image analysis, etc., in intelligent healthcare applications. Further, given the current progress in the fields of ML and DL, there exists the promising potential for both to provide support in the realm of healthcare.

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Manganese doping has been demonstrated as a versatile tool to tune the emission of CsPbCl nanocrystals (NCs). Although this has been demonstrated in nanocubes and nanoplatelets, strategies for doping Mn in size-tunable, excitonic CsPbCl quantum dots (QDs) remain absent. In this work, we demonstrate the synthesis of size-tunable spheroidal CsPbCl:Mn QDs, which can be obtained by a water-hexane interfacial combined anion and cation exchange strategy starting from CsPbBr QDs.

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Lead halide perovskites suffer from water and moisture instability due to the highly ionic nature of the crystal structures, though a few groups took advantage of it for chemical transformation via water-assisted strategy. However, direct exposure of the perovskite to bulk water leads to uncontrolled chemical transformation. Here, we report a controlled chemical transformation of CsPbBr to CsPbBr triggered by nanoconfined water by placing CsPbBr in the nonpolar phase within a reverse micelle.

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Superalkalis are unusual species having ionization energies lower than that of the alkali metals. These species with various applications are of great importance in chemistry due to their low ionization energies and strong reducing property. A typical superalkali contains a central electronegative core decorated with excess metal ligands.

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Colon cancer affects people of all ages. However, its frequency, as well as the related morbidity and mortality, are high among older adults. The complex physiological changes in the aging gut substantially limit the development of cancer therapies.

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The uses and production of radionuclides in nuclear energy production and medical therapy are becoming more significant in today's world. While these applications have many benefits, they can produce harmful pollutants, such as radioactive iodine, that need to be sequestered. Effective capture and storage of radioactive iodine waste remains a major challenge for nuclear energy generation and nuclear medicine.

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Perovskite nanocrystals (NCs) are an emergent and game-changing entrant in semiconductor research, yet the research on the corresponding nanoheterostructures remains in its infancy. In this work, we fabricate a type II nanoarchitecture of CsPbX NCs (where X = Cl, Br, or I) and CuInS quantum dots to investigate the energy and charge transfer (ET and CT, respectively) processes. Optical measurements of CsPbX/CuInS show efficient photoluminescence (PL) quenching when X = Br or I, while the PL quenching efficiency of the X = Cl compound is 2 orders of magnitude lower.

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Optically excited electronic excitations are coupled to the soft and polar halide perovskite lattice, generating coherent phonons after subpicosecond interband laser-excitation. In Ag-based halide double perovskites, Ag-vacancies can bind free excitons, resulting in a pronounced bound exciton resonance. Here, we report the detection of three modulation frequencies corresponding to coherent phonons in Ag-based double perovskite nanocrystals at distinct spectral positions at the bound exciton resonance.

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Incorporation of artificial 3rd base pairs (unnatural base pairs, UBPs) has emerged as a fundamental technique in pursuit of expanding the genetic alphabet. 2,6-Dimethyl-2-isoquiniline-1-thione: D5SIC (DS) and 2-methoxy-3-methylnaphthalene: DNAM (DN), a potential unnatural base pair (UBP) developed by Romesberg and colleagues, has been shown to have remarkable capability for replication within DNA. Crystal structures of a polymerase/double-stranded DNA (ds-DNA) complex containing a DS-DN pair in the 3' terminus showed a parallelly stacked geometry for the pre-insertion, and an intercalated geometry for the post-insertion structure.

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DNA polymerases are fundamental enzymes that play a crucial role in processing DNA with high fidelity and accuracy ensuring the faithful transmission of genetic information. The recognition of unnatural base pairs (UBPs) by polymerases, enabling their replication, represents a significant and groundbreaking discovery with profound implications for genetic expansion. Romesberg examined the impact of DNA containing 2,6-dimethyl-2-isoquiniline-1-thione: D5SIC (DS) and 2-methoxy-3-methylnaphthalene: DNAM (DN) UBPs bound to DNA polymerase () through crystal structure analysis.

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Water-hexane interfacial preparation of photostable Au@CsPbBr (Au@CPB) hybrid nanocrystals (NCs) from pure CsPbBr (CPB) NCs is reported, with the coexistence of exciton and localized surface plasmon resonance with equal dominance. This enables strong exciton-plasmon coupling in these plasmonic perovskite NCs where not only the photoluminescence is quenched intrinsically due to ultrafast charge separation, but also the light absorption property increases significantly, covering the entire visible region. Using a controlled interfacial strategy, a reversible chemical transformation between CPB and Au@CPB NCs is shown, with the simultaneous eruption of larger-size ligand-free aqueous Au nanoparticles (NPs).

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Astaxanthin is a red-colored secondary metabolite with excellent antioxidant properties, typically finds application as foods, feed, cosmetics, nutraceuticals, and medications. Astaxanthin is usually produced synthetically using chemicals and costs less as compared to the natural astaxanthin obtained from fish, shrimps, and microorganisms. Over the decades, astaxanthin has been naturally synthesized from Haematococcus pluvialis in commercial scales and remains exceptional, attributed to its higher bioactive properties as compared to synthetic astaxanthin.

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Hot carriers rapidly lose kinetic energies on a subpicosecond time scale, posing significant limitations on semiconductors' photon-conversion efficiencies. To slow the hot carrier cooling, the phonon bottleneck effect is constructed prevalently in quantum-confined structures with discrete energy levels. However, the maximum energy separation (Δ) between the energy levels is in a range of several hundred meV, leading to unsatisfactory cooling time.

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Climate change poses a significant threat to the global ecosystem, prompting plants to use various adaptive mechanisms via molecular switches to combat biotic and abiotic stress factors. These switches activate stress-induced pathways by altering their configuration between stable states. In this review, we investigated the regulation of molecular switches in different plant species in response to stress, including the stress-regulated response of multiple switches in Arabidopsis thaliana.

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Colloidal multinary chalcogenides (MnCs) have emerged as excellent optoelectronic materials, where S- and Se-based MnCs show considerable progress; however, the Te counterpart suffers from detrimental surface oxidation. Moreover, Te-based I-III-VI MnCs (e.g.

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