Perspectives on a Few Puzzles in Phase Transformations: When Should the Farthest Reach the Earliest?

We briefly review the facts concerning two important aspects of phase transitions, namely, critical and coarsening phenomena. A discussion of the universal features, highlighting the current challenges, is provided. Following this, we elaborate on a topic of much recent interest, viz.

Confining charge-transfer complex in a metal-organic framework for photocatalytic CO reduction in water.

In the quest for renewable fuel production, the selective conversion of CO to CH under visible light in water is a leading-edge challenge considering the involvement of kinetically sluggish multiple elementary steps. Herein, 1-pyrenebutyric acid is post-synthetically grafted in a defect-engineered Zr-based metal organic framework by replacing exchangeable formate. Then, methyl viologen is incorporated in the confined space of post-modified MOF to achieve donor-acceptor complex, which acts as an antenna to harvest visible light, and regulates electron transfer to the catalytic center (Zr-oxo cluster) to enable visible-light-driven CO reduction reaction.

Delivery of chemotherapeutic drug targeting folate receptor to oral cancer cells using functionalized carbon nanospheres.

Folate receptor (FR) () has long been the subject of active interest as regards its potential to serve as a target for cancer therapy. FR has been found to be overexpressed in several cancers, including clinical samples of different stages from OSCC (oral squamous cell carcinoma) patients. However, no clear correlation or conclusive finding has been obtained so far which might indicate the efficacy of FR as a credible target for the treatment of OSCC.

Ordered and disordered microstructures of nanoconfined conducting polymers.

We probe the microstructural differences of conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) derivatives under geometrical nanoconfinement using a high-resolution electron microscopy (HRTEM) technique. Highly ordered domains of poly(3,4-ethylenedioxythiophene):tosylate PEDOT:Tos, which is polymerized within alumina nanochannels, are observed. These features are in contrast to those of the polymer blend poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate) PEDOT:PSS inserted into the nanopores.

2D nanosheets of layered double perovskites: synthesis, photostable bright orange emission and photoluminescence blinking.

Lead (Pb)-free layered double perovskites (LDPs) with exciting optical properties and environmental stability have sparked attention in optoelectronics, but their high photoluminescence (PL) quantum yield and understanding of the PL blinking phenomenon at the single particle level are still elusive. Herein, we not only demonstrate a hot-injection route for the synthesis of two-dimensional (2D) ∼2-3 layer thick nanosheets (NSs) of LDP, CsCdBiCl (pristine), and its partially Mn-substituted analogue [, CsCdMnBiCl (Mn-substituted)], but also present a solvent-free mechanochemical synthesis of these samples as bulk powders. Bright and intense orange emission has been perceived for partially Mn-substituted 2D NSs with a relatively high PL quantum yield (PLQY) of ∼21%.

Crystal structures of non-uracil ring fragments in complex with Mycobacterium tuberculosis uracil DNA glycosylase (MtUng) as a starting point for novel inhibitor design: A case study with the barbituric acid fragment.

Uracil DNA glycosylase (UDG or Ung) is a key enzyme involved in uracil excision from the DNA as a repair mechanism. Designing Ung inhibitors is thus a promising strategy to treat different cancers and infectious diseases. The uracil ring and its derivatives have been shown to inhibit Mycobacterium tuberculosis Ung (MtUng), resulting from specific and strong binding with the uracil-binding pocket (UBP).

Not teaching evolution is an injustice.

Since April, India has been roiled by controversy around the excision of several topics, including evolution and the periodic table, from school textbooks (up to grade 10) by the National Council for Educational Research and Training (NCERT). This was projected as an exercise in "rationalization" of content aimed at reducing the study load on students. The move was opposed by large numbers of academics and worried citizens.

High-pressure synthesis and magnetic properties of tetragonal BaCuO ( = Sm and Eu).

We report the experimental discovery of a new structural phase of well-known orthorhombic BaCuO ( = Sm and Eu), exhibiting a tetragonal crystal structure with space group . The high-pressure tetragonal phase is isostructural with the brown phase BaCuO ( = La, Pr, and Nd). In this structure, the Cu ions form an isolated square planar environment, contrary to the orthorhombic phase, where the Cu ions are located in a distorted square pyramid.

Evolution of YacG to safeguard DNA gyrase from external perturbation.

Cells have evolved strategies to safeguard their genome integrity. We describe a mechanism to counter double strand breaks in the chromosome that involves the protection of an essential housekeeping enzyme from external agents. YacG is a DNA gyrase inhibitory protein from Escherichia coli that protects the bacterium from the cytotoxic effects of catalytic inhibitors as well as cleavage-complex stabilizers of DNA gyrase.

Analysis of Structural Change across the Liquid-Liquid Transition and the Widom Line in Supercooled Stillinger-Weber Silicon.

We consider the changes in the structure of supercooled Stillinger-Weber silicon at pressures at which the studied range of temperatures traverses the liquid-liquid transition or the "Widom line" (at which the isothermal compressibility or the specific heat exhibits a maximum). In addition to the conventional characterizations in terms of the pair-correlation function and bond orientational order, we analyze the statistics of rings in the bond network as well as the statistics of clusters of low density liquid (LDL)- and high density liquid (HDL)-like atoms. We investigate the nature of the change in these structural characterizations when the liquid-liquid transition line or the Widom line is crossed.

Engineering Photo-Crosslinked Antimicrobial Coating to Tackle Catheter-Associated Infections In Vivo.

Microbial colonization on urinary and intravascular catheter surfaces results in steeply rising cases of catheter-associated infections as well as blood stream infections. Currently marketed efforts include impregnation and loading of antimicrobials and antiseptics that leach out into the local environment and inactivate microbes. However, they suffer from uncontrolled release, induction of resistance, and undesired toxicity.

Elusive Double Perovskite Iodides: Structural, Optical, and Magnetic Properties.

Halide double perovskites [A M M X ] are an important class of materials that have garnered substantial interest as non-toxic alternatives to conventional lead iodide perovskites for optoelectronic applications. While numerous studies have examined chloride and bromide double perovskites, reports of iodide double perovskites are rare, and their definitive structural characterization has not been reported. Predictive models have aided us here in the synthesis and characterization of five iodide double perovskites of general formula Cs NaLnI (Ln=Ce, Nd, Gd, Tb, Dy).

Correction: Molybdenum chloride double perovskites: dimensionality control of optical and magnetic properties.

[This corrects the article DOI: 10.1039/D3SC00132F.].

Mutational and structural analyses of UdgX: insights into the active site pocket architecture and its evolution.

UdgX excises uracil from uracil-containing DNA to concurrently form a covalent bond with the resulting AP-DNA. Structurally, UdgX is highly similar to family-4 UDGs (F4-UDGs). However, UdgX is unique in possessing a flexible R-loop (105KRRIH109).

Confining Molecular Photosensitizer and Catalyst in MOF toward Artificial Photosynthesis: Validating Electron Transfer by DRIFT Study.

Exploration of different chemical systems for photocatalytic CO reduction by using sunlight en route to the achievement of artificial photosynthesis stems from global warming and the energy crisis. In this work, we have covalently grafted the molecular photosensitizer (PS) [Ru(MBA)(bpy)]Cl (bpy: 2,2'-bipyridine) and the catalyst [Mn(MBA)(CO)Br] inside the Zr-MOF-808 () nanopore postmodified with 2-(5'-methyl-[2,2'-bipyridine]-5-yl)acetic acid (H-MBA) and developed a single integrated system named for the CO reduction reaction (CORR). is found to be active toward CO-to-CO conversion, with a maximum production of 1027 μmol g after 26 h of reaction having >99% selectivity in the aqueous medium without any additional hole scavenger.

Restoration of Sleep and Circadian Behavior by Autophagy Modulation in Huntington's Disease.

Circadian and sleep defects are well documented in Huntington's disease (HD). Modulation of the autophagy pathway has been shown to mitigate toxic effects of mutant Huntingtin (HTT) protein. However, it is not clear whether autophagy induction can also rescue circadian and sleep defects.

NiCo@NiCoO/NCNT as Trifunctional ORR, OER, and HER Electrocatalysts and its Application in a Zn-Air Battery.

The efficient electrochemical conversion and storage devices can be boosted by the development of cost-effective and durable electrocatalysts. However, simultaneous in-depth understanding of the reaction mechanism is also required. Herein, we report the preparation, characterization, and electrochemical activities of bimetallic NiCo NPs and core-shell NiCo@NiCoO NPs stabilized on N-doped carbon nanotubes (NCNTs).

Boosting photo-assisted efficient electrochemical CO reduction reaction on transition metal single-atom catalysts supported on the CN nanosheet.

CO reduction to value-added chemicals turns out to be a promising and efficient approach to resolve the increasing energy crisis and global warming. However, the catalytic efficiency of CO reduction reaction (CORR) to form C products (CO, HCOOH, CHOH, CH) needs to be quite efficient. Herein with the help of density functional theory, CORR towards C products was investigated on a transition metal (TM = Fe, Co, Ni) embedded CN framework.

High-Flux lamellar MoSe membranes for efficient dye/salt separation.

Membrane-based technology is emerging as an efficient technique for wastewater treatment in recent years. Membranes made up of two-dimensional materials provide high selectivity and water flux compared to conventional polymeric membranes. Herein, we report the synthesis and use of MoSe membrane for dye and drug separation in wastewater, mainly from textile and pharmaceutical industries.

Structurally Induced Chirality of an Achiral Chromophore on Self-Assembled Nanofibers: A Twist Makes It Chiral.

The surface domains of self-assembled amphiphiles are well-organized and can perform many physical, chemical, and biological functions. Here, we present the significance of chiral surface domains of these self-assemblies in transferring chirality to achiral chromophores. These aspects are probed using l- and d-isomers of alkyl alanine amphiphiles which self-assemble in water as nanofibers, possessing a negative surface charge.

Hydrodynamic effects in kinetics of phase separation in binary fluids: Critical versus off-critical compositions.

Via hydrodynamics-preserving molecular dynamics simulations we study growth phenomena in a phase-separating symmetric binary mixture model. We quench high-temperature homogeneous configurations to state points inside the miscibility gap, for various mixture compositions. For compositions at the symmetric or critical value we capture the rapid linear viscous hydrodynamic growth due to advective transport of material through tubelike interconnected domains.

Probing the tightly bound layer in poly(vinyl alcohol) thin films using swelling measurements.

A strongly adsorbed, tightly bound polymer layer can exist at the polymer/substrate interface in polymer thin films and polymer nanocomposites. The characteristics of the tightly bound layer have long been of interest because of its effect on physical properties. However, direct investigations are challenging as the layer is buried deep within the sample.

Distinct subunit architecture and assembly pattern of DNA gyrase from mycobacteria.

DNA gyrase, the sole negative supercoiling type II topoisomerase, is composed of two subunits, GyrA and GyrB, encoded by the gyrA and gyrB genes, respectively, that form a quaternary complex of A B . In this study, we have investigated the assembly of mycobacterial DNA gyrase from its individual subunits, a step prerequisite for its activity. Using analytical size-exclusion chromatography, we show that GyrA from Mycobacterium tuberculosis and Mycobacterium smegmatis forms tetramers (A ) in solution unlike in Escherichia coli and other bacteria where GyrA exists as a dimer.

Isoamphipathic antibacterial molecules regulating activity and toxicity through positional isomerism.

Peptidomimetic antimicrobials exhibit a selective interaction with bacterial cells over mammalian cells once they have achieved an optimum amphiphilic balance (hydrophobicity/hydrophilicity) in the molecular architecture. To date, hydrophobicity and cationic charge have been considered the crucial parameters to attain such amphiphilic balance. However, optimization of these properties is not enough to circumvent unwanted toxicity towards mammalian cells.