Multifunctional Mycobacterial Topoisomerases with Distinctive Features.

Tuberculosis (TB) continues to be a major cause of death worldwide despite having an effective combinatorial therapeutic regimen and vaccine. Being one of the most successful human pathogens, retains the ability to adapt to diverse intracellular and extracellular environments encountered by it during infection, persistence, and transmission. Designing and developing new therapeutic strategies to counter the emergence of multidrug-resistant and extensively drug-resistant TB remains a major task.

Impact of Pressure on Metavalent Bonding in BiTe influencing Electronic Topological Transitions.

BiTe, a member of the (Bi2)m(Bi2Te3)n homologous series, possesses natural van der Waals-like heterostructure with a Bi2 bilayer sandwiched between the two [Te-Bi-Te-Bi-Te] quintuple layers. BiTe exhibits both the quantum states of weak topological and topological crystalline insulators, making it a dual topological insulator and a suitable candidate for spintronics, quantum computing and thermoelectrics. Herein, we demonstrate that the chemical bonding in BiTe is to be metavalent, which plays a significant role in the pressure dependent change in the topology of the electronic structure Fermi surface.

Bactericidal Hemostatic Sponge: A Point of Care Solution to Combat Traumatic Injury.

Uncontrollable haemorrhage and associated microbial contamination in the battlefield and civilian injuries pose a tremendous threat to healthcare professionals. Such traumatic wounds often necessitate an effective point-of-care solution to prevent the consequent morbidity owing to blood loss or haemorrhage. However, developing superior hemostatic materials with anti-infective properties remains a challenge.

Decoding the Hume-Rothery Rule in a Bifunctional Tetra-metallic Alloy for Alkaline Water Electrolysis.

The 90-year-old Hume-Rothery rule was adapted to design an outstanding bifunctional tetra-metallic alloy electrocatalyst for water electrolysis. Following the radius mismatch principles, Fe (131 pm) and Ni (124 pm) are selectively incorporated at the Pd (139 pm) site of MoPd nanosheets. Analogously, Cu (132 pm) alloys with only Pd, while Ag (145 pm) alloys with both Pd and Mo (154 pm).

Coupling-Induced Dynamic Off-Centering of Cu Drives High Thermoelectric Performance in TlCuS.

Seeking new and efficient thermoelectric materials requires a detailed comprehension of chemical bonding and structure in solids at microscopic levels, which dictates their intriguing physical and chemical properties. Herein, we investigate the influence of local structural distortion on the thermoelectric properties of TlCuS, a layered metal sulfide featuring edge-shared Cu-S tetrahedra within CuS layers. While powder X-ray diffraction suggests average crystallographic symmetry with no distortion in CuS tetrahedra, the synchrotron X-ray pair distribution function experiment exposes concealed local symmetry breaking, with dynamic off-centering distortions of the CuS tetrahedra.

The dependence of shugoshin on Bub1-kinase activity is dispensable for the maintenance of spindle assembly checkpoint response in Cryptococcus neoformans.

During chromosome segregation, the spindle assembly checkpoint (SAC) detects errors in kinetochore-microtubule attachments. Timely activation and maintenance of the SAC until defects are corrected is essential for genome stability. Here, we show that shugoshin (Sgo1), a conserved tension-sensing protein, ensures the maintenance of SAC signals in response to unattached kinetochores during mitosis in a basidiomycete budding yeast Cryptococcus neoformans.

A Self-Formed Ag Nanostructure Based Neuromorphic Device Performing Arithmetic Computation and Area Integration: Influence of Presynaptic Pulsing Scheme on Mathematical Precision.

A material equivalent of a biosynapse is the key to neuromorphic architecture. Here we report a self-forming labyrinthine Ag nanostructure activated with a few pulses of 0.5 V, width and interval set at 50 ms, at current compliance () of 400 nA, serving as the active material for a highly stable device with programmable volatility.

Investigation of magnetic and transport properties of GdSbSe.

We report the detailed investigation of the magnetic, transport, and magnetocaloric effects (MCEs) of GdSbSe by magnetic susceptibilityχ(T), isothermal magnetization(), resistivityρ(T,H), and heat capacityCp(T)measurements, crystallizing in the ZrSiS-type tetragonal crystal system with space group P4/nmm. Temperature-dependent magnetic susceptibility measurements revealed long-range antiferromagnetic ordering with two additional magnetic anomalies below Néel temperature (TN≈8.6K), corroborated through magnetocaloric and specific heat studies.

Light-Triggered Reversible Assembly of Halide Perovskite Nanoplatelets.

Advancements in stimuli-driven nanoactuators necessitate the discovery of photo-switchable, self-contained semiconductor nanostructures capable of precise mechanical responses. The reversible assembly of 0D CsBiI halide perovskite nanoplatelets (NPLs) between stacked and scattered configurations are demonstrated under light and dark, respectively. This sunlight-triggered perpetual flipping of the NPLs, occurring in less than a minute, is associated with a color change between brown and red.

Computer simulations of entropic cohesion in reversibly crosslinked polymers.

Reversibly crosslinked polymer networks - polymer networks that can undergo bond association and dissociation reactions - rearrange their structures while maintaining their overall integrity, thus resulting in unique properties such as self-healing, reprocessability, shape memory and adaptability. Here, we show that the introduction of crosslinks, whether reversible or permanent, directly impacts the equilibrium polymer density and hence the material's surface tension. For a limiting case where the bonds are the same size as the polymer chain bonds, simulations, Flory hypotheses and thermodynamic calculations show that the crosslinks induce an increased entropic cohesion in the liquid.

In Situ Metal Vacancy Filling in Stable Pd-Sn Intermetallic Catalyst for Enhanced CC Bond Cleavage in Ethanol Oxidation.

A common challenge in electrochemical processes is developing high performance, stable catalysts for specific chemical reactions. In this work, a Pd-Sn intermetallic compound with   Pd site deficiency (PdSn) (x = 0.06) and trace amount of SnO was synthesised by controlled process.

Current fluctuations in the symmetric zero-range process below and at critical density.

Characterizing current fluctuations in a steady state is of fundamental interest and has attracted considerable attention in the recent past. However, the bulk of the studies are limited to systems that either do not exhibit a phase transition or are far from criticality. Here we consider a symmetric zero-range process on a ring that is known to show a phase transition in the steady state.

Charge noise in low Schottky barrier multilayer tellurium field-effect transistors.

Creating van der Waals (vdW) homojunction devices requires materials with narrow bandgaps and high carrier mobilities for bipolar transport, which are crucial for constructing fundamental building blocks like diodes and transistors in a 2D architecture. Following the recent discovery of elemental 2D tellurium, here, we systematically investigate the electrical transport and flicker noise of hydrothermally grown multilayer tellurium field effect transistors. While the devices exhibit a dominant p-type behavior with high hole mobilities up to ∼242 cm V s at room temperature and almost linear current-voltage characteristics down to 77 K, ambipolar behavior was observed in some cases.

An unusual activity of mycobacterial MutT1 Nudix hydrolase domain as a protein phosphatase regulates nucleoside diphosphate kinase function.

MutT proteins are Nudix hydrolases characterized by the presence of a Nudix box, GX5EX7REUXEEXGU, where U is a bulky hydrophobic residue and X is any residue. Major MutT proteins hydrolyze 8-oxo-(d)GTP (8-oxo-GTP or 8-oxo-dGTP) to the corresponding 8-oxo-(d)GMP, preventing their incorporation into nucleic acids. Mycobacterial MutT1 comprises an N-terminal domain (NTD) harboring the Nudix box motif, and a C-terminal domain (CTD) harboring the RHG histidine phosphatase motif.

Peptide-based nanomaterials and their diverse applications.

The supramolecular self-assembly of peptides offers a promising avenue for both materials science and biological applications. Peptides have garnered significant attention in molecular self-assembly, forming diverse nanostructures with α-helix, β-sheet, and random coil conformations. These self-assembly processes are primarily driven by the amphiphilic nature of peptides and stabilized by non-covalent interactions, leading to complex nanoarchitectures responsive to environmental stimuli.

The impact of ligand chain length on the HER performance of atomically precise Pt(SR) nanoclusters.

Atomically precise metal cluster-based electrocatalysts have been paid significant attention for an efficient hydrogen evolution reaction (HER). Herein, we have synthesized atomically precise Pt(SR) nanoclusters using 3-mercaptopropionic acid (MPA), 6-mercaptohexanoic acid (MHA), 8-mercaptooctanoic acid (MOA), and 11-mercaptoundecanoic acid (MUA) thiol ligands in aqueous media at room temperature to understand the impact of ligand chain length on the HER performance. The composition of Pt(SR) metal clusters was confirmed by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry.

Thermionic Emission in Artificially Structured Single-Crystalline Elemental Metal/Compound Semiconductor Superlattices.

Metal/semiconductor superlattices represent a fascinating frontier in materials science and nanotechnology, where alternating layers of metals and semiconductors are precisely engineered at the atomic and nano-scales. Traditionally, epitaxial metal/semiconductor superlattice growth requires constituent materials from the same family, exhibiting identical structural symmetry and low lattice mismatch. Here, beyond this conventional constraint, a novel class of epitaxial lattice-matched metal/semiconductor superlattices is introduced that utilizes refractory hexagonal elemental transition metals and wide-bandgap III-nitride semiconductors.

Integration of metal-organic frameworks and clay toward functional composite materials.

Metal-organic frameworks (MOFs) have become increasingly important as a class of porous crystalline materials because of their diverse applications. At the same time, significant progress has been achieved in the field of MOF-based composite materials toward novel applications based on the synergistic effect of two or more different components. Clay materials have been explored recently in MOF chemistry for the synthesis of MOF-clay composites, which are a new class of functional materials synthesized by a cooperative combination of MOFs with clay.

Electrically and magnetically readable memory with a graphene/1T-CrTe heterostructure: anomalous Hall transistor.

Using first-principles theoretical analysis, we demonstrate the spin-polarized anomalous Hall conductivity (AHC) response of a 2D vdW heterostructure of graphene and ferromagnetic CrTe that can be controlled with a perpendicular electric field . The origins of AHC and linear magnetoelectric responses are traced to (a) the transfer of electronic charge from graphene to ferromagnetic CrTe causing an out-of-plane electric polarization = 1.69 μC cm and (b) the crystal field and spin-split Dirac points of graphene.

Phase Transitions in a Vanthoffite-Type Compound, NaZn(SO): Insights from PXRD and Raman Spectroscopy.

The study of phase transitions in minerals or synthetic compounds analogous to mineral structures is of fundamental interest in different scientific disciplines, with applications ranging from understanding the Earth's geological history to advancing materials science and technology. They provide valuable data and insight into developing new functional materials with desired properties. In this context, we have investigated the structural phase transitions of NaZn(SO), a synthetic compound analogous to the Vanthoffite mineral NaMg(SO), which occurs abundantly in nature as oceanic salt deposits.

Bioinspired programmable coacervate droplets and self-assembled fibers through pH regulation of monomers.

Phase separation and phase transitions pervade the biological domain, where proteins and RNA engage in liquid-liquid phase separation (LLPS), forming liquid-like membraneless organelles. The misregulation or dysfunction of these proteins culminates in the formation of solid aggregates a liquid-to-solid transition, leading to pathogenic conditions. To decipher the underlying mechanisms, synthetic LLPS has been examined through complex coacervate formation from charged polymers.

Role of the initiation factor 3 in the fidelity of initiator tRNA selection on ribosome.

Initiation factors play critical roles in fine-tuning translation initiation, which is the first and the rate-limiting step in protein synthesis. In bacteria, initiation factors, IF1, IF2 and IF3 work in concert to accurately position the initiator tRNA (i-tRNA) in its formyl-aminoacyl form, and the mRNA start codon at the ribosomal P-site, setting the stage for accommodation of the aminoacyl-tRNA in response to the second codon, and formation of the first peptide bond. Among these, IF3 is particularly crucial in ensuring the fidelity of translation initiation as it is involved in the accuracy of the selection of i-tRNA and the start codon.