Interplay between A-site and oxygen-vacancy ordering, and mixed electron/oxide-ion conductivity in = 1 Ruddlesden-Popper perovskite SrNdZnO.

Oxygen vacancies in Ruddlesden-Popper (RP) perovskites (PV) [AO][ABO] play a pivotal role in engineering functional properties and thus understanding the relationship between oxygen-vacancy distribution and physical properties can open up new strategies for fine manipulation of structure-driven functionalities. However, the structural origin of preferential distribution for oxygen vacancies in RP structures is not well understood, notably in the single-layer ( = 1) RP-structure. Herein, the = 1 RP phase SrNdZnO was rationally designed and structurally characterized by combining three-dimensional (3D) electron diffraction and neutron powder diffraction.

The role of adjuvants in overcoming antibacterial resistance due to enzymatic drug modification.

Antibacterial resistance is a prominent issue with monotherapy often leading to treatment failure in serious infections. Many mechanisms can lead to antibacterial resistance including deactivation of antibacterial agents by bacterial enzymes. Enzymatic drug modification confers resistance to β-lactams, aminoglycosides, chloramphenicol, macrolides, isoniazid, rifamycins, fosfomycin and lincosamides.

Carborane clusters increase the potency of bis-substituted cyclam derivatives against .

Bis-substituted cyclam derivatives have recently emerged as a promising new class of antibacterial agents, displaying excellent activity against drug-resistant () and efficacy in a zebrafish assay. Herein we report the synthesis and biological activity of new carborane derivatives within this class of antitubercular compounds. The resulting carborane-cyclam conjugates incorporating either hydrophobic -1,2-carborane or anionic, hydrophilic -7,8-carborane clusters display promising activity in an antibacterial assay employing the virulent strain H37Rv.

Carbon dots: a novel platform for biomedical applications.

Carbon dots (CDs) are a recently synthesised class of carbon-based nanostructures known as zero-dimensional (0D) nanomaterials, which have drawn a great deal of attention owing to their distinctive features, which encompass optical properties (., photoluminescence), ease of passivation, low cost, simple synthetic route, accessibility of precursors and other properties. These newly synthesised nano-sized materials can replace traditional semiconductor quantum dots, which exhibit significant toxicity drawbacks and higher cost.

GuLiM: A Hybrid Motion Mapping Technique for Teleoperation of Medical Assistive Robot in Combating the COVID-19 Pandemic.

Driven by the demand to largely mitigate nosocomial infection problems in combating the coronavirus disease 2019 (COVID-19) pandemic, the trend of developing technologies for teleoperation of medical assistive robots is emerging. However, traditional teleoperation of robots requires professional training and sophisticated manipulation, imposing a burden on healthcare workers, taking a long time to deploy, and conflicting the urgent demand for a timely and effective response to the pandemic. This paper presents a novel motion synchronization method enabled by the hybrid mapping technique of hand gesture and upper-limb motion (GuLiM).

Antiviral cyclic peptides targeting the main protease of SARS-CoV-2.

Antivirals that specifically target SARS-CoV-2 are needed to control the COVID-19 pandemic. The main protease (M) is essential for SARS-CoV-2 replication and is an attractive target for antiviral development. Here we report the use of the Random nonstandard Peptide Integrated Discovery (RaPID) mRNA display on a chemically cross-linked SARS-CoV-2 M dimer, which yielded several high-affinity thioether-linked cyclic peptide inhibitors of the protease.

AgMoO: an oxide solid-state Ag electrolyte.

AgMoO powders and micro-crystals were prepared at 400 °C for 24 h and 500 °C for 6 h using solid-state reactions. The AgMoO samples crystalized in a triclinic 1̄ space group with the cell parameters = 6.0972(1) Å, = 7.

Generation of oligonucleotide conjugates one-pot diselenide-selenoester ligation-deselenization/alkylation.

A breadth of strategies are needed to efficiently modify oligonucleotides with peptides or lipids to capitalize on their therapeutic and diagnostic potential, including the modulation of chemical stability and for applications in cell-targeting and cell-permeability. The chemical linkages typically used in peptide oligonucleotide conjugates (POCs) have limitations in terms of stability and/or ease of synthesis. Herein, we report an efficient method for POC synthesis using a diselenide-selenoester ligation (DSL)-deselenization strategy that rapidly generates a stable amide linkage between the two biomolecules.

Late-stage modification of peptides and proteins at cysteine with diaryliodonium salts.

The modification of peptides and proteins has emerged as a powerful means to efficiently prepare high value bioconjugates for a range of applications in chemical biology and for the development of next-generation therapeutics. Herein, we report a novel method for the chemoselective late-stage modification of peptides and proteins at cysteine in aqueous buffer with suitably functionalised diaryliodonium salts, furnishing stable thioether-linked synthetic conjugates. The power of this new platform is showcased through the late-stage modification of the affibody zEGFR and the histone protein H2A.

Synthesis and pharmacological evaluation of [F]PBR316: a novel PET ligand targeting the translocator protein 18 kDa (TSPO) with low binding sensitivity to human single nucleotide polymorphism rs6971.

Radiopharmaceuticals that target the translocator protein 18 kDa (TSPO) have been investigated with positron emission tomography (PET) to study neuroinflammation, neurodegeneration and cancer. We have developed the novel, achiral, 2-phenylimidazo[1,2-]pyridine, PBR316 that targets the translocator protein 18 kDa (TSPO) that addresses some of the limitations inherent in current TSPO ligands; namely specificity in binding, blood brain barrier permeability, metabolism and insensitivity to TSPO binding in subjects as a result of rs6971 polymorphism. PBR316 has high nanomolar affinity (4.

Rapid one-pot iterative diselenide-selenoester ligation using a novel coumarin-based photolabile protecting group.

The development of an iterative one-pot peptide ligation strategy is described that capitalises on the rapid and efficient nature of the diselenide-selenoester ligation reaction, together with photodeselenisation chemistry. This ligation strategy hinged on the development of a novel photolabile protecting group for the side chain of selenocysteine, namely the 7-diethylamino-3-methyl coumarin (DEAMC) moiety. Deprotection of this DEAMC group can be effected in a mild, reagent-free manner using visible light ( = 450 nm) without deleterious deselenisation of selenocysteine residues, thus enabling a subsequent ligation reaction without purification.

Synthesis and evaluation of pyridine-derived bedaquiline analogues containing modifications at the A-ring subunit.

Despite promising efficacy, the clinical use of the anti-tubercular therapeutic bedaquiline has been restricted due to safety concerns. To date, limited SAR studies have focused on the quinoline ring (A-ring), and as such, we set out to explore modifications within this region in an attempt to discover new bedaquiline variants with an improved safety profile. We herein report the development of unique synthetic strategies that facilitated access to novel bedaquiline analogues leading to the discovery that anti-tubercular activity could be retained following replacement of the quinoline motif with pyridine heterocycles.

Discovery of cryptic allosteric sites using reversed allosteric communication by a combined computational and experimental strategy.

Allostery, which is one of the most direct and efficient methods to fine-tune protein functions, has gained increasing recognition in drug discovery. However, there are several challenges associated with the identification of allosteric sites, which is the fundamental cornerstone of drug design. Previous studies on allosteric site predictions have focused on communication signals propagating from the allosteric sites to the orthosteric sites.

Classifying Multi-Level Stress Responses From Brain Cortical EEG in Nurses and Non-Health Professionals Using Machine Learning Auto Encoder.

Objective: Mental stress is a major problem in our society and has become an area of interest for many psychiatric researchers. One primary research focus area is the identification of bio-markers that not only identify stress but also predict the conditions (or tasks) that cause stress. Electroencephalograms (EEGs) have been used for a long time to study and identify bio-markers.

Aryl urea substituted fatty acids: a new class of protonophoric mitochondrial uncoupler that utilises a synthetic anion transporter.

Respiring mitochondria establish a proton gradient across the mitochondrial inner membrane (MIM) that is used to generate ATP. Protein-independent mitochondrial uncouplers collapse the proton gradient and disrupt ATP production by shuttling protons back across the MIM in a protonophoric cycle. Continued cycling relies on the formation of MIM-permeable anionic species that can return to the intermembrane space after deprotonation in the mitochondrial matrix.

A Hydrophobic-Interaction-Based Mechanism Triggers Docking between the SARS-CoV-2 Spike and Angiotensin-Converting Enzyme 2.

A recent experimental study found that the binding affinity between the cellular receptor human angiotensin-converting enzyme 2 (ACE2) and receptor-binding domain (RBD) in the spike (S) protein of novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is more than tenfold higher than that of the original severe acute respiratory syndrome coronavirus (SARS-CoV). However, main chain structures of the SARS-CoV-2 RBD are almost the same with that of the SARS-CoV RBD. Understanding the physical mechanism responsible for the outstanding affinity between the SARS-CoV-2 S and ACE2 is an "urgent challenge" for developing blockers, vaccines, and therapeutic antibodies against the coronavirus disease 2019 (COVID-19) pandemic.

Fully Exploited Oxygen Redox Reaction by the Inter-Diffused Cations in Co-Free Li-Rich Materials for High Performance Li-Ion Batteries.

To meet the growing demand for global electrical energy storage, high-energy-density electrode materials are required for Li-ion batteries. To overcome the limit of the theoretical energy density in conventional electrode materials based solely on the transition metal redox reaction, the oxygen redox reaction in electrode materials has become an essential component because it can further increase the energy density by providing additional available electrons. However, the increase in the contribution of the oxygen redox reaction in a material is still limited due to the lack of understanding its controlled parameters.

Longevity and the drift barrier: Bridging the gap between Medawar and Hamilton.

Most organisms have finite life spans. The maximum life span of mammals, for example, is at most some years, decades, or centuries. Why not thousands of years or more? Can we explain and predict maximum life spans theoretically, based on other traits of organisms and associated ecological constraints? Existing theory provides reasons for the prevalence of ageing, but making explicit quantitative predictions of life spans is difficult.

Solution-Processed Faraday Rotators Using Single Crystal Lead Halide Perovskites.

Lead halide perovskites (LHPs) have become a promising alternative for a wide range of optoelectronic devices, thanks to their solution-processability and impressive optical and electrical properties. More recently, LHPs have been investigated in magneto-optic studies and have exhibited spin-polarized emission, photoinduced magnetization, and long spin lifetimes. Here, the viability of methylammonium lead bromide (MAPbBr) single crystals as solution-processed Faraday rotators is demonstrated.

Acetic Acid Assisted Crystallization Strategy for High Efficiency and Long-Term Stable Perovskite Solar Cell.

Improving the quality of perovskite poly-crystalline film is essential for the performance of associated solar cells approaching their theoretical limit efficiency. Pinholes, unwanted defects, and nonperovskite phase can be easily generated during film formation, hampering device performance and stability. Here, a simple method is introduced to prepare perovskite film with excellent optoelectronic property by using acetic acid (Ac) as an antisolvent to control perovskite crystallization.

Dynamic pH responsivity of triazole-based self-immolative linkers.

Gating the release of chemical payloads in response to transient signals is an important feature of 'smart' delivery systems. Herein, we report a triazole-based self-immolative linker that can be reversibly paused or slowed and restarted throughout its elimination cascade in response to pH changes in both organic and organic-aqueous solvents. The linker is conveniently prepared using the alkyne-azide cycloaddition reaction, which introduces a 1,4-triazole ring that expresses a pH-sensitive intermediate during its elimination sequence.

Metasurfaces-based imaging and applications: from miniaturized optical components to functional imaging platforms.

This review focuses on the imaging applications of metasurfaces. These optical elements provide a unique platform to control light; not only do they have a reduced size and complexity compared to conventional imaging systems but they also enable novel imaging modalities, such as functional-imaging techniques. This review highlights the development of metalenses, from their basic principles, to the achievement of achromatic and tunable lenses, and metasurfaces implemented in functional optical imaging applications.