Bimodal structural tuning of pyrrole-2-carboxamide-based transmembrane ion transport systems.

The pyrrole-2-carboxamide moiety is well known for its presence in various natural products and its use in anion receptor systems. Here we assess the transmembrane anion transport activity of a series of substituted pyrrole-2-carboxamides and show them to be highly tuneable, versatile systems for anion transport by simple variations of pyrrole ring and amide substituents.

Heterocyclic Diaryliodonium-Based Inhibitors of Carbapenem-Resistant Acinetobacter baumannii.

Finding new therapeutic strategies against Gram-negative pathogens such as Acinetobacter baumannii is challenging. Starting from diphenyleneiodonium (dPI) salts, which are moderate Gram-positive antibacterials, we synthesized a focused heterocyclic library and found a potent inhibitor of patient-derived multidrug-resistant Acinetobacter baumannii strains that significantly reduced bacterial burden in an animal model of infection caused by carbapenem-resistant Acinetobacter baumannii (CRAB), listed as a priority 1 critical pathogen by the World Health Organization. Next, using advanced chemoproteomics platforms and activity-based protein profiling (ABPP), we identified and biochemically validated betaine aldehyde dehydrogenase (BetB), an enzyme that is involved in the metabolism and maintenance of osmolarity, as a potential target for this compound.

Self-assembled anion channel formation by bis(1,3-propanediol)-linked -dipropynylbenzene-based small molecules.

Two self-assembled barrel-rosette ion channels have been developed using bis(1,3-propanediol)-linked -dipropynylbenzene-based molecules. The system with an additional amide arm acted as a better channel compared to that having an ester arm. The amide-linked channel displayed substantial channel activity and excellent chloride selectivity in the lipid bilayer membranes.

A modular scaffold for triggerable and tunable nitroxyl (HNO) generation with a fluorescence reporter.

Nitroxyl (HNO) is a short-lived mediator of cell signalling and can enhance the sulfane sulfur pool, a cellular antioxidant reservoir, by reacting with hydrogen sulfide (HS). Here, we report esterase-activated HNO-generators that are suitable for tunable HNO release and the design of these donors allows for real-time monitoring of HNO release. These tools will help gain a better understanding of the cross-talk among short-lived gaseous signalling molecules that have emerged as major players in health and disease.

Risk measures and portfolio analysis in the paradigm of climate finance: a review.

Climate change brings with it new risks for the finance sector, which in turn provides new opportunities to mitigate this risk, emanating from climate change. To invest sustainably and move away from firms that have disproportionately high carbon footprints, investors need suitable risk measures and appropriate portfolio management approaches. In this paper, we conduct a review of the mathematical models used to measure carbon risk.

Inconsistent illusory motion in predictive coding deep neural networks.

Why do we perceive illusory motion in some static images? Several accounts point to eye movements, response latencies to different image elements, or interactions between image patterns and motion energy detectors. Recently PredNet, a recurrent deep neural network (DNN) based on predictive coding principles, was reported to reproduce the "Rotating Snakes" illusion, suggesting a role for predictive coding. We begin by replicating this finding, then use a series of "in silico" psychophysics and electrophysiology experiments to examine whether PredNet behaves consistently with human observers and non-human primate neural data.

Elucidating N-acyl amino acids as a model protoamphiphilic system.

Protoamphiphiles are prebiotically-plausible moieties that would have constituted protocell membranes on early Earth. Although prebiotic soup would have contained a diverse set of amphiphiles capable of generating protocell membranes, earlier studies were mainly limited to fatty acid-based systems. Herein, we characterize N-acyl amino acids (NAAs) as a model protoamphiphilic system.

Progress and prospects toward supramolecular bioactive ion transporters.

The majority of cellular physiological processes depend on natural ion channels, which are pore-forming membrane-embedded proteins that let ions flow across the cell membranes selectively. This selective movement of ions across the membranes balances the osmolality within and outside the cell. However, mutations in the genes that encode essential membrane transport proteins or structural reorganisation of these proteins can cause life-threatening diseases like cystic fibrosis.

Single event transition risk: A measure for long term carbon exposure.

Although there is a growing consensus that a low-carbon transition will be necessary to mitigate accelerated climate change, the magnitude of transition risk for investors is difficult to measure exactly. Investors are therefore constrained by the unavailability of suitable measures to quantify the magnitude of the risk and are forced to use the likes of absolute emissions data or ESG scores in order to manage their portfolios. In this article, we define the Single Event Transition Risk (SETR) and illustrate how it can be used to approximate the magnitude of the total exposure of the price of a share to the low-carbon transition.

S-H···O Hydrogen Bond Can Win over O-H···S Hydrogen Bond: Gas-Phase Spectroscopy of 2-Fluorothiophenol···HO Complex.

Study of sulfur (S) centered hydrogen bonding (SCHB) interactions in the literature is mostly limited to the molecular systems where S acts as a hydrogen-bond acceptor. It has been found that this unconventional SCHB is similar in strength to any conventional hydrogen bonding interaction involving electronegative atoms. However, SCHB involving S as a hydrogen-bond donor is not explored much in the literature.

Post collision analyzer to study charge-exchange processes in ion-molecule collisions.

We have designed an electrostatic charge state analyzer for ion beams having energies in the range of 5-20 keV/q. It is primarily built to investigate the different ionization processes involved in the slow (v < 1 a.u.

Nontoxic Artificial Chloride Channel Formation in Epithelial Cells by Isophthalic Acid-Based Small Molecules.

Artificial channels capable of facilitating the transport of Cl ions across cell membranes while being nontoxic to the cells are rare. Such synthetic ion channels can mimic the functions of membrane transport proteins and, therefore, have the potential to treat channelopathies by replacing defective ion channels. Here we report isophthalic acid-based structurally simple molecules 1 a and 2 a, which self-assemble to render supramolecular nanochannels that allow selective transport of Cl ions.

A multi-chromic supercapacitor of high coloration efficiency integrating a MOF-derived VO electrode.

Modern technological trends in smart electronic devices demand more intelligent automation. Simultaneous integration of energy storage and multicolor electrochromism in a single device improves user-device interfacing based on a salient human-readable output. In this work, primarily metal-organic framework (MOF) derived VO was synthesized which, as an electrochromic material, shows high optical modulation of 35% at 485 nm, with very fast switching speeds (2.

A bis-NHC-CAAC dimer derived dicationic diradical.

The isolation of carbon-centered diradicals is always challenging due to synthetic difficulties and their limited stability. Herein we report the synthesis of a -1,4-cyclohexylene bridged bis-NHC-CAAC dimer derived thermally stable dicationic diradical. The diradical character of this compound was confirmed by EPR spectroscopy.

HS contributed from CSE during cellular senescence suppresses inflammation and nitrosative stress.

Aging involves the time-dependent deterioration of physiological functions attributed to various intracellular and extracellular factors. Cellular senescence is akin to aging and involves alteration in redox homeostasis. This is primarily marked by increased reactive oxygen/nitrogen species (ROS/RNS), inflammatory gene expression, and senescence-associated beta-galactosidase activity, all hallmarks of aging.

Ordered Macro/Microporous Ionic Organic Framework for Efficient Separation of Toxic Pollutants from Water.

In case of pollutant segregation, fast mass diffusion is a fundamental criterion in order to achieve improved performance. The rapid mass transport through porous materials can be achieved by availing large open pores followed by easy and complete accessibility of functional sites. Inducing macroporosity into such materials could serve as ideal solution providing access to large macropores that offer unhindered transport of analyte and full exposure to interactive sites.

Formation of supramolecular channels by reversible unwinding-rewinding of bis(indole) double helix via ion coordination.

Stimulus-responsive reversible transformation between two structural conformers is an essential process in many biological systems. An example of such a process is the conversion of amyloid-β peptide into β-sheet-rich oligomers, which leads to the accumulation of insoluble amyloid in the brain, in Alzheimer's disease. To reverse this unique structural shift and prevent amyloid accumulation, β-sheet breakers are used.

Vigilance, arousal, and acetylcholine: Optimal control of attention in a simple detection task.

Paying attention to particular aspects of the world or being more vigilant in general can be interpreted as forms of 'internal' action. Such arousal-related choices come with the benefit of increasing the quality and situational appropriateness of information acquisition and processing, but incur potentially expensive energetic and opportunity costs. One implementational route for these choices is widespread ascending neuromodulation, including by acetylcholine (ACh).

Aza-PNA: Engineering E-Rotamer Selectivity Directed by Intramolecular H-bonding.

The replacement of α(CH) by NH in monomers of standard PNA and its homologue β- PNA leads to respective -PNA monomers ( and ) in which the NH can form either an 8-membered H-bonded ring with folding of the backbone (DMSO and water) or a 5-membered NH─αCO (water) to stabilize -type rotamers. Such -PNA oligomers with exclusive rotamers and intraresidue backbone H-bonding can modulate its DNA/RNA binding and assembling properties.

Selective and rapid water transportation across a self-assembled peptide-diol channel the formation of a dual water array.

Achieving superfast water transport by using synthetically designed molecular artifacts, which exclude salts and protons, is a challenging task in separation science today, as it requires the concomitant presence of a proper water-binding site and necessary selectivity filter for transporting water. Here, we demonstrate the water channel behavior of two configurationally different peptide diol isomers that mimic the natural water channel system, , aquaporins. The solid-state morphology studies showed the formation of a self-assembled aggregated structure, and X-ray crystal structure analysis confirmed the formation of a nanotubular assembly that comprises two distinct water channels.

Donor free stibenium cation as an efficient cyanosilylation catalyst.

The synthesis of novel stibenium cations and their catalytic application in cyanosilylation of carbonyl compounds have been described. Treatment of chlorostibine LSbCl [L = 1,2-CH{N(CHBu)}] (2) with 1 equiv. of AgOTf and AgSbF resulted in the formation of donor free LSbOTf () and [LSb][SbF] (), respectively.

Microhydration of Phenyl Formate: Gas-Phase Laser Spectroscopy, Microwave Spectroscopy, and Quantum Chemistry Calculations.

Herein, we have investigated the structure of phenyl formate⋅⋅⋅water (PhOF⋅⋅⋅H O) dimer and various non-covalent interactions present there using gas-phase laser spectroscopy and microwave spectroscopy combined with quantum chemistry calculations. Two conformers of PhOF⋅⋅⋅H O (C1 and T1), built on the two cis/trans conformers of the bare molecule, have been observed in the experiment. In cis-PhOF, there is an n → interaction between the lone-pair orbital of the carbonyl oxygen atom and the π* orbital of the phenyl ring, which persists in the monohydrated C1 conformer of PhOF⋅⋅⋅H O according to the NBO and NCI analyses.

First-Row Transition Metal Complexes of a Phosphine-Silylene-Based Hybrid Ligand.

We have prepared two new silylene-phosphine-based hybrid ligands Si{N(R)CH(PPh)}{PhC(NBu)} [R = TMS {trimethylsilyl} () and TBDMS {-butyldimethylsilyl} ()], which possess two donor sites. Furthermore, the treatment of the bidentate ligand with base metal halides {FeBr, CoBr, NiCl·dme [nickel chloride(II) ethylene glycol dimethyl ether]} and with NiBr·dme [nickel bromide(II) ethylene glycol dimethyl ether] afforded four-coordinate six-membered metal complexes , respectively, which feature coordination from both Si(II) and P(III) sites. Subsequently, complexes [(FeBr)Si{N(SiMe)CH(PPh)}{PhC(NBu)}], [(CoBr)Si{N(SiMe)CH(PPh)}{PhC(NBu)}], [(NiCl)Si{N(SiMe)CH(PPh)}{PhC(NBu)}], and [(NiBr)Si{N(SiBuMe)CH(PPh)}{PhC(NBu)}] are studied for their redox and magnetic properties with the help of UV-vis spectroscopy, cyclic voltammetry, SQUID magnetometry, and theoretical calculations.

Amyloid pathology disrupts gliotransmitter release in astrocytes.

Accumulation of amyloid-beta (Aβ) is associated with synaptic dysfunction and destabilization of astrocytic calcium homeostasis. A growing body of evidence support astrocytes as active modulators of synaptic transmission via calcium-mediated gliotransmission. However, the details of mechanisms linking Aβ signaling, astrocytic calcium dynamics, and gliotransmission are not known.

Genetic architecture of dispersal and local adaptation drives accelerating range expansions.

Contemporary evolution has the potential to significantly alter biotic responses to global change, including range expansion dynamics and biological invasions. Models predicting range dynamics often make highly simplifying assumptions about the genetic architecture underlying relevant traits. However, genetic architecture defines evolvability and higher-order evolutionary processes, which determine whether evolution will be able to keep up with environmental change or not.