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An effective force coarse-graining (EF-CG) method is presented in this paper that complements the more general multiscale coarse-graining (MS-CG) methodology. The EF-CG method determines effective pairwise forces between coarse-grained sites by averaging over the atomistic forces between the corresponding atomic groups in configurations sampled from equilibrium all-atom molecular dynamics simulations. The EF-CG method extracts the transferable part of the MS-CG force field at the cost of reduced accuracy in reproducing certain structural properties. Therefore, the EF-CG method provides an alternative to the MS-CG approach for determining CG force fields that give improved transferability but reduced structural accuracy. The EF-CG method is especially suitable for coarse-graining large molecules with high symmetry, such as bulky organic molecules, and for studying complex phenomena across a range of thermodynamic conditions. The connection between the EF-CG and MS-CG approaches as well as the limitations of the EF-CG method are also discussed. Numerical results for neopentane, methanol and ionic liquid systems illustrate the utility of the method. [ABSTRACT FROM AUTHOR]

Interactions between inorganic materials and biomolecules at the molecular level, although complex, are commonplace. Examples include biominerals, which are, in most cases, facilitated by and in contact with biomolecules; implantable biomaterials; and food and drug handling. The effectiveness of these functional materials is dependant on the interfacial properties i.e. the extent of molecular level ‘association’ with biomolecules. The goal of this overview is four-fold: to present biomolecule–inorganic materials interactions and our current understanding using selected examples; to elaborate on approaches that have been used to expose the mechanisms underpinning such interactions; to identify the ‘rules’ or ‘guiding principles’ that govern interactions that could be used to explain and hence predict behaviour; and finally to highlight the drawbacks of the present approaches and outline future challenges and opportunities. [ABSTRACT FROM AUTHOR]

Uranium is found in various types of rocks. HERFD-XRF imaging at the U M 4 edge is a novel non-destructive technique that visualizes the distribution of U(IV), (V), and (VI) oxidation states at concentration levels ranging from ppm to wt%, offering unprecedented insights into uranium habitat and valence.

Degradation or recycling of styrene-copolymers whose main chains are saturated carbon chains is very difficult under natural conditions. Here, we synthesized a new styrene-copolymer with degradable groups in the main chain using an emulsion polymerization process at room temperature by first synthesizing a functional monomer ( tert -butyl lipoate) with cyclic disulfide bonds.

Sequence-controlled copolymers can self-assemble into a wide assortment of complex architectures, with exciting applications in nanofabrication and personalized medicine. However, polymer synthesis is notoriously imprecise, and stochasticity in both chemical synthesis and self-assembly poses a significant challenge to tight control over these systems. While it is increasingly viable to design "protein-like" sequences, specifying each individual monomer in a chain, the effect of variability within those sequences has not been well studied. In this work, we performed nearly 15 000 molecular dynamics simulations of sequence-controlled copolymer aggregates with varying level of sequence stochasticity. We utilized unsupervised learning to characterize the resulting morphologies and found that sequence variation leads to relatively smooth and predictable changes in morphology compared to ensembles of identical chains. Furthermore, structural response to sequence variation was accurately modeled using supervised learning, revealing several interesting trends in how specific families of sequences break down as monomer sequences become more variable. Our work presents a way forward in understanding and controlling the effect of sequence variation in sequence-controlled copolymer systems, which can hopefully be used to design advanced copolymer systems for technological applications in the future.

Concentration gradients of simple salts in microfluidic channels control the transport of a common photoredox catalyst.

Antimicrobial stewardship plays an essential role in combating the global health threat posed by multidrug-resistant pathogens. Phenotypic antimicrobial susceptibility testing (AST) is the gold standard for analyzing bacterial responses to antimicrobials. However, current AST techniques, which rely on end-point bulk measurements of bacterial growth under antimicrobial treatment in a broth solution, have limitations in resembling the physiological working environment and resolving heterogeneity in response kinetics within the population. In this study, we investigate the responses of uropathogenic bacteria under antimicrobial treatment in individual urine. Our results demonstrate substantial heterogeneity in time-kill kinetics in response to antimicrobials in a host-dependent manner. We also establish a microfluidic gel encapsulation platform for single cell imaging to rapidly resolve heterogeneous subpopulations in response to antimicrobials. The platform captures both bacterial growth and killing within the gel and enables medium exchange to assess the ability of surviving cells to resume growth after antimicrobial removal. Our study lays the foundation for a new generation of precision single cell analysis for personalizing antimicrobial treatment.

Zeolite-formation mechanisms have long been the subject of intensive study, with most work concentrating on hydrothermal mechanisms. However, non-traditional zeolite syntheses that do not rely on hydrothermal crystallisation have provided a number of new routes to interesting and unexpected new materials, but their formation mechanisms remain poorly understood. Here, we show how simultaneous in situ liquid- and solid-state 29 Si NMR spectroscopy can reveal the mechanism of the formation of a zeolite from a layered silicate precursor. The study provides evidence for the species that are intercalated into the layered material and establishes those that are involved in building the inter-layer, zeolitic connections as a function of time during the zeolite formation process., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)

A goal of molecular electronics and spintronics is to create molecular devices that change their conductance in response to external stimuli. The Aharonov-Bohm (AB) effect implies that an electronic device formed from a quantum ring and metallic leads will exhibit such behavior under external magnetic fields. At first sight, it appears that unrealistically large fields would be required to significantly alter the conductance of a molecular ring. However, the sensitivity of a molecular AB interferometer to magnetic fields can be increased by weakening the coupling between the molecular ring and the metallic leads. An ideal molecular ring for an AB interferometer has a large radius (to encompass a larger fraction of the AB flux quantum), and a small effective mass (high electron mobility) to enhance its response to magnetic fields. Here, we use computational modelling to demonstrate that recently synthesized zinc porphyrin nanorings, with radii of 2-9 nm, could behave as molecular AB interferometers at achievable magnetic field strengths (5-10 T), if weak ring-lead coupling is used. Building on our recently developed semi-empirical approach, which incorporates the effects of finite magnetic fields on the electronic structure, we develop a transport computational platform that allows us to identify sharp Fano resonances in the transmittance probability of porphyrin nanorings that could be exploited to control the current with an applied magnetic field. These resonances are rationalized in terms of a magnetic field-induced delocalization of the molecular orbitals. Our findings indicate that molecular AB interferometry should be feasible with current experimental capabilities., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Molecular composites, such as bone and nacre, are everywhere in nature and play crucial roles, ranging from self-defense to carbon sequestration. Extensive research has been conducted on constructing inorganic layered materials at an atomic level inspired by natural composites. These layered materials exfoliated to 2D crystals are an emerging family of nanomaterials with extraordinary properties. These biocomposites are great for modulating electron, photon, and phonon transport in nanoelectronics and photonic devices but are challenging to translate into bulk materials. Combining 2D crystals with biomolecules enables various 2D nanocomposites with novel characteristics. This review has provided an overview of the latest biocomposites, including their structure, composition, and characterization. Layered biocomposites have the potential to improve the performance of many devices. For example, biocomposites use macromolecules to control the organization of 2D crystals, allowing for new capabilities such as flexible electronics and energy storage. Other applications of 2D biocomposites include biomedical imaging, tissue engineering, chemical and biological sensing, gas and liquid filtration, and soft robotics. However, some fundamental questions need to be answered, such as self-assembly and kinetically limited states of organic-inorganic phases in soft matter physics.

The molecular-beam epitaxial (MBE) growth of III-O and IV-O materials ( e.g. , Ga 2 O 3 , In 2 O 3 , and SnO 2 ) is known to be reaction-limited by complex 2-step kinetics and the desorption of volatile suboxides ( e.g. , Ga 2 O, In 2 O, SnO). We find that the different surface reactivities of suboxides and respective elements ( e.g. , Ga, In, Sn) with active oxygen define the film-growth-windows (FGWs) and suboxide-formation-windows (SFWs) of III-O and IV-O materials, respectively. To generalize, we provide elementary reaction pathways and respective Gibbs energies to form binary III-O, III-Se, IV-O, and IV-Se ground-states as well as their subcompounds during their MBE growth. We apply the 2-step kinetics model established for oxides to identify the subselenide-limited growth of Ga 2 Se 3 as the specific example for III-Se materials. Our kinetic and thermodynamic conclusions suggest subcompound-limited growth may be an inherent property for the growth of III-VI and IV-VI thin films by MBE and related epitaxial growth techniques.

Molten salts are important in a number of energy applications, but the fundamental mechanisms operating in ionic liquids are poorly understood, particularly at higher temperatures. This is despite their candidacy for deployment in solar cells, next-generation nuclear reactors, and nuclear pyroprocessing. We perform extensive molecular dynamics simulations over a variety of molten chloride salt compositions at varying temperature and pressures to calculate the thermodynamic and transport properties of these liquids. Using recent developments in the theory of liquid thermophysical properties, we interpret our results on the basis of collective atomistic dynamics (phonons). We find that the properties of ionic liquids are well explained by their collective dynamics, as in simple liquids. In particular, we relate the decrease of heat capacity, viscosity, and thermal conductivity to the loss of transverse phonons from the liquid spectrum. We observe the singular dependence of the isochoric heat capacity on the mean free path of phonons, and the obeyance of the Stokes-Einstein equation relating the viscosity to the mass diffusion. The transport properties of mixtures are more complicated compared to simple liquids, however viscosity and thermal conductivity are well guided by fundamental bounds proposed recently. The kinematic viscosity and thermal diffusivity lie very close to one another and obey the theoretical fundamental bounds determined solely by fundamental physical constants. Our results show that recent advances in the theoretical physics of liquids are applicable to molten salts mixtures, and therefore that the evolution and interplay of properties common to all liquids may act as a guide to a deeper understanding of these mixtures.

Atomic-scale changes can significantly impact heterogeneous catalysis, yet their atomic mechanisms are challenging to establish using conventional analysis methods. By using identical location scanning transmission electron microscopy (IL-STEM), which provides quantitative information at the single-particle level, we investigated the mechanisms of atomic evolution of Ru nanoclusters during the ammonia decomposition reaction. Nanometre-sized disordered nanoclusters transform into truncated nano-pyramids with stepped edges, leading to increased hydrogen production from ammonia. IL-STEM imaging demonstrated coalescence and Ostwald ripening as mechanisms of nanocluster pyramidalization during the activation stage, with coalescence becoming the primary mechanism under the reaction conditions. Single Ru atoms, a co-product of the catalyst activation, become absorbed by the nano-pyramids, improving their atomic ordering. Ru nano-pyramids with a 2-3 nm 2 footprint consisting of 3-5 atomic layers, ensure the maximum concentration of active sites necessary for the rate-determining step. Importantly, the growth of truncated pyramids typically does not exceed a footprint of approximately 4 nm 2 even after 12 hours of the reaction, indicating their high stability and explaining ruthenium's superior activity on nanotextured graphitic carbon compared to other support materials. The structural evolution of nanometer-sized metal clusters with a large fraction of surface atoms is qualitatively different from traditional several-nm nanoparticles, where surface atoms are a minority, and it offers a blueprint for the design of active and sustainable catalysts necessary for hydrogen production from ammonia, which is becoming one of the critical reactions for net-zero technologies., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Reactive oxygen species (ROS) play a critical role in regulating various physiological processes. To gain a comprehensive understanding of their distinct functions in different physiological events, it is imperative to detect binary ROS simultaneously. However, the development of the sensing method capable of binary ROS detection remains a significant challenge. In this study, we address this challenge by integrating chemically modified DNAzyme probes with a functionalized metal-organic framework (MOF) to create an efficient electrochemical sensing platform for the binary detection of ROS. ROS targets would activate the DNAzyme cleavage activity by removing the phenylboronate (BO) and phosphorothioate (PS) modifications, leading to the controlled release of doxorubicin (DOX) and methylene blue (MB) enclosed within MOF nanocomposites. This process generates two distinct voltammetric current peaks, with their potentials and intensities reflecting the identity and concentration of the ROS targets. The sensor demonstrates simultaneous detection of multiple ROS (H 2 O 2 and HClO) produced by cancer cells with high sensitivity across a broad linear range of 1 to 200 nM and a low detection limit in the sub-nanomolar range. The design strategies behind the developed ROS sensing system could also be exploited to create other biosensors with highly sensitive and binary detection to promote clinical research and revolutionize disease diagnostics., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Objectives : This study aimed to investigate short-term and long-term impact of avocado consumption without caloric restriction on the gut microbiota of free-living adults with abdominal obesity. Methods : The Habitual Diet and Avocado Trial (HAT) was a 26-week, multi-center, randomized, controlled trial involving 1008 individuals with abdominal obesity. Participants were randomly assigned to the Avocado Supplemented Diet Group (AVO), receiving one avocado per day, or the Habitual Diet group (HAB), maintaining their usual dietary habits. Fecal samples were collected at baseline, week 4 and week 26 from a subset of participants recruited at a University of California Los Angeles site ( n = 230). Fecal microbiota was assessed with shotgun metagenomics sequencing. Alpha diversity was assessed using the Chao1 and Shannon indices; beta diversity was assessed using Bray-Curtis dissimilarity with significance determined by repeated measures permutational multivariat analysis of variance. Potential association of intervention at week 4 and 26 with alpha diversity, species and metabolic pathways was examined using linear mixed effect models. Results : Compared to the HAB group, the AVO group had higher alpha diversity by 4 weeks, which persisted through the 26-week study period. Exploratory analysis based on healthy eating index-2015 (HEI-2015) indicated that participants with a low HEI score at baseline (≤52.7), had an increase in alpha diversity in the AVO group vs. HAB group. The AVO group had a significant change in beta diversity at week 26 compared to the HAB group. At the species level, the AVO group had significantly increased Faecalibacterium prausnitzii and Bacterium AF16_15 at week 26 compared to the HAB group. Functional analysis showed no significant difference in metabolic pathways between the HAB and AVO groups. Conclusions : Our findings document a potentially favorable effect of avocados on gut microbiota diversity. The prebiotic potential of avocados is more pronounced in individuals with a low diet quality score. This trial is registered at clinicaltrials.gov as NCT03528031 (https://clinicaltrials.gov/study/NCT03528031).

It is commonly stated that alkyl groups exert an inductive electron-releasing effect when compared to hydrogen. This information has been given in numerous organic chemistry textbooks over the last 75 years. The evidence for this position is weak, and does not withstand scrutiny, and there is some evidence for the contrary position. We provide a significant body of computational data that clearly show that alkyl groups exert an inductive electron-withdrawing (-I) effect when compared to hydrogen. This revised position is not in conflict with experimental data, since alkyl group inductive effects are small and are likely to be masked by hyperconjugation/polarizability effects (particularly in charged species), and also by solvent effects.

As a key building block of mammalian tissues, extracellular matrices (ECMs) stiffen under shear deformation and undergo cell-imparted healing after damage, features that regulate cell fate, communication, and survival. The shear-stiffening behavior is attributed to semi-flexible biopolymeric ECM networks. Inspired by the mechanical behavior of ECMs, we develop acellular nanocomposite living hydrogels (LivGels), comprising network-forming biopolymers and anisotropic hairy nanoparticle linkers that mimic the dynamic mechanical properties of living counterparts. We show that a bifunctional dynamic linker nanoparticle (nLinker), bearing semi-flexible aldehyde- and carboxylate-modified cellulose chains attached to rigid cellulose nanocrystals converts bulk hydrogels to ECM-like analogues via ionic and dynamic covalent hydrazone bonds. The nLinker not only enables the manipulation of nonlinear mechanics and stiffness within the biological window, but also imparts self-healing to the LivGels. This work is a step forward in designing living acellular soft materials with complex dynamic properties using bio-based nanotechnology.

Van der Waals (vdW) magnets offer unique opportunities for exploring magnetism in the 2D limit. Metal-organic magnets (MOM) are of particular interest as the functionalisation of organic ligands can control their physical properties. Here, we demonstrate tuning of mechanical and magnetic function of a noncollinear vdW ferromagnet, NiCl 2 (btd) (btd = 2,1,3-benzothiadiazole), through creating solid-solutions with the oxygen-substituted analogue ligand 2,1,3-benzoxadiazole (bod). We synthesise NiCl 2 (btd) 1- x (bod) x up to x = 0.33, above which we find mixtures primarily composed of 1D NiCl 2 (bod) 2 . Magnetometry reveals bod incorporation reduces the coercivity significantly (up to 60%), without altering the ordering temperatures. High pressure synchrotron diffraction measurements up to 0.4 GPa demonstrate that the stiffest axis is the b axis, through the Ni-N-(O/S)-N-Ni bonds, and the softest is the interlayer direction. Doping with bod fine-tunes this compressibility, softening the layers, but stiffening the interlayer axis. This demonstrates that substitution of organic ligands in vdW MOMs can be used to realise targeted magnetic and mechanical properties.

Gallium sulfide (GaS) stands out as a versatile nonlinear optical material for green-blue optoelectronic and photocatalytic nano-devices. In addition, the in-plane breaking strain and mechanical strength of layered GaS make it a promising candidate for next-generation flexible nanodevices. The fast and reliable assessment of the number of layers, without sample loss, is key for these applications. Here we unveil the influence of dimensionality in the structural, mechanical, and vibrational properties of GaS by applying density-functional theory-based quantum-simulations and group-theory analysis. We find its intralayer structure and interlayer distances are essentially independent of the number of layers, in agreement with the van der Waals forces as dominant interlayer interactions. The translational symmetry breaking along the stacking direction results in different structural symmetries for monolayers, N -odd layers, N -even layers, and bulk geometries. Its force constants against rigid-layer shear, K LSM = 1.35 × 10 19 N m -3 , and breathing, K LBM = 5.00 × 10 19 N m -3 , displacements remain the same from bulk to bilayer structures. The related stiffness coefficients in bulk are C 44 = 10.2 GPa and C 33 = 37.7 GPa, respectively. This insight into GaS interlayer interactions and elastic coefficients reveals it as a promising lubricant for nano-mechanic applications and it is easy to cleave for thickness engineering, even in comparison with layered graphite, MoS 2 and other transition metal dichalcogenides and group-IIIA metal monochalcogenides. We present the GaS Raman and infrared spectra dependence on the layer number as strategies for sample thickness characterization and derive formulas for distinguishing the number of layers in both high and low-frequency regimes. In addition, our analysis of their optical-activity selection rules and polarization dependencies is applicable to isostructural group-IIIA metal monochalcogenides with 2H-layer stacking, such as gallium/indium sulphide/selenide. These results contribute to rapid and non-destructive characterization of the material's structure, which is of paramount importance for the manufacturing of devices and the utilization of its diverse properties.

We have used spin-echo small-angle neutron scattering (SESANS) to probe the hierarchy of structures present in polymer-carbon nanocomposites, with length scales spanning over three orders of magnitude, from 10 nm to 16 μm. The data processing and reduction show a unified approach across two SESANS instruments (TU Delft and Larmor at the ISIS neutron source) and yield consistent data that are able to be modelled using well-established hierarchical models in freely available software such as SasView. Using this approach, we are able to extend the measured length scales by over an order of magnitude compared to traditional scattering methods. This yields information about the structure in the bulk that is inaccessible with conventional scattering techniques (SANS/SAXS) and points to a way for interrogating and investigating polymer nanocomposites routinely across multiple length scales.

Understanding the influence of counterion and backbone solvation on the conformational and thermodynamic properties of polyelectrolytes in solution is one of the main open challenges in polyelectrolyte science. To address this problem, we study the scattering from semidilute solutions of a semiflexible polyelectrolyte, carboxymethyl cellulose (CMC) with alkaline and tetra-alkyl-ammonium (TAA) counterions in aqueous media using small-angle neutron scattering (SANS), and small-angle X-ray scattering (SAXS), which allow us to probe concentration fluctuations of the polymer backbone and counterions. In SAXS, the calculated contrast arises primarily from the polymer backbone for both alkaline and TAA salts of CMC. In SANS, however, the contrast is dominated by the counterions for the TAA salts and the polymer backbone for the alkaline salts. Solutions are found to display a correlation peak in their scattering function, which at low concentrations is independent of counterion type. At moderate salt concentrations ( c ≳ 0.1 M), the peak positions obtained from SANS and SAXS for the CMC salts with the TAA counterions differ. This divergence suggests a decoupling in the lengthscale over which the couterions and the polymer fluctuate. Upturns in the scattering intensity in the low- q region signal the presence of long-ranged compositional inhomogeneities in the solutions. The strength of these decreases with increasing counterion-solvent interaction strength, as measured by the viscosity B coefficient, and are strongest for the corresponding sodium salt of CMC.

Electrostatic capacitors (ECs) are critical components in advanced electronics and electric power systems due to their rapid charge-discharge rate and high power density. While polymers are ideal for ECs due to their high voltage tolerance and mechanical flexibility, their low dielectric constants ( K ) and limited energy density remain significant limitations. Traditional polymer nanocomposites, which incorporate high- K ceramic fillers, have shown promise in enhancing dielectric properties but often at the cost of electric breakdown strength and scalability. In this perspective, we explore a pioneering approach that utilizes ultralow loadings of small-sized inorganic nanofillers to significantly improve dielectric constants without compromising other key properties. We delve into the unconventional effects observed in these polymer nanocomposites, including dielectric enhancements, charge trapping, mechanical reinforcements, and microstructural changes, and highlight the impressive energy storage performance achieved with minimal filler contents. We discuss innovative design strategies from viewpoints of polymer and filler structures and showcase recent advancements in nanoscale characterization and theoretical modelling for understanding the crucial role of polymer-filler interfaces. Finally, we stress fundamental challenges and prospects, providing insights into the transformative potential of these nanocomposites for next-generation energy storage applications., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The continuous mutational nature of SARS-CoV-2 and its inter-species' similarities emphasize the urgent need to design and develop more direct-acting antiviral agents against highly infectious variants. Herein, we report on the efficient discovery of potent non-covalent non-peptide-derived M pro inhibitors using miniaturized click chemistry and direct screening. Based on the privileged piperazine scaffold, 68 triazole-containing derivatives were assembled and screened. Notably, representative compound C1N46 (IC 50 = 1.87 μM, EC 50 = 6.99 μM, CC 50 > 100 μM) displayed potent inhibition activity against M pro and showed promising anti-SARS-CoV-2 properties in vitro . Additionally, C1N46 exhibited improved liver microsome stability compared to lead compound GC-14. Docking studies predicted a multi-site binding mode of the triazole-based compounds. In conclusion, our studies validate the efficacy and feasibility of click chemistry in rapidly discovering antiviral agents., Competing Interests: The authors declare no competing financial interest., (This journal is © The Royal Society of Chemistry.)

Developing improved zeolites is essential in novel sustainable processes such as the catalytic pyrolysis of plastic waste. This study used density functional theory to investigate how alkyl chain length, unsaturated bonds, and branching affect β-scission kinetics in four zeolite frameworks, a key reaction in hydrocarbon cracking. The activation enthalpy was evaluated for a wide variety of 23 hydrocarbons, with 6 to 12 carbon atoms, in FAU, MFI, MOR, and TON. The consideration of both branched and linear olefin and diolefin reactants for the β-scission indicates how the reactant structure influences the intrinsic cracking kinetics, which is especially relevant for the catalytic cracking of plastic waste feedstocks. Intrinsic chemical effects, such as resonance stabilization, the inductive effect, and pore stabilization were found to provide an essential contribution to the activation enthalpy. Additionally, a predictive group additive model incorporating a novel so-called "pore confinement descriptor" was developed for fast prediction of the β-scission activation barrier of a wide range of molecules in the four zeolites. The obtained model can serve as an input for detailed kinetic models in zeolite-catalyzed cracking reactions. The acquired fundamental insights in the cracking of hydrocarbons, relevant for renewable feedstocks, correspond well with experimental observations and will facilitate an improved rational zeolite design., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Coacervates represent models for membrane-free protocells and thus provide a simple route to synthetic cellular-like systems that provide selective encapsulation of solutes. Here, we demonstrate a simple and versatile post-coacervation crosslink method using the thiol-ene click reaction in aqueous media to prepare covalently crosslinked coacervates. The crosslinking of the coacervate enables stability at extreme pH where the uncrosslinked coacervate fully disassembles. The crosslinking also enhances the hydrophobicity within the coacervate environment to increase the encapsulation efficiency of bovine serum albumin (BSA), as compared to the uncrosslinked coacervate. Additionally, the crosslinked coacervate increases the stabilization of BSA at low pH. These crosslinked coacervates can act as carriers for enzymes. The enzymatic activity of alkaline phosphatase (ALP) is enhanced within the crosslinked coacervate compared to the ALP in aqueous solution. The post-coacervation crosslink approach allows the utilization of coacervates for encapsulation of biologicals under conditions where the coacervate would generally disassemble. We demonstrate that these crosslinked coacervates enable the protection of encapsulated protein against denaturation at extreme pH and enhance the enzymatic activity with encapsulation. This click approach to stabilization of coacervates should be broadly applicable to other systems for a variety of biologics and environmentally sensitive molecules.

The utilization of portable air cleaners (PACs) is a recommended supplemental approach to help remove airborne pathogens and mitigate disease transmission in learning environments. To improve PAC effectiveness, science-based information is needed to optimize their implementation strategies such as the deployment location, height, and number of PACs. In this study, we developed a Computational Fluid Dynamics (CFD) model to assess how PACs perform in occupied classrooms equipped with displacement and mixing ventilation systems. The results show that PACs with a flow rate of 2.6 h -1 reduce the mean aerosol intake of all students by up to 66%. A key benefit of using PACs is to facilitate air mixing and movement in indoor environments with inadequate ventilation, thereby effectively reducing high aerosol concentrations near the infector. Furthermore, our results highlight the impact of PAC location on its performance. PACs achieve the best effectiveness when placed closed to the infector (within a distance <3 m). In the absence of knowing who is infected, deploying a PAC at the center of the room is recommended. Moreover, adjusting PAC flow discharge height to the breathing height of occupants ( e.g. , 0.9-1.2 m for seated people) can enhance their effectiveness in spaces with poor air mixing.

A four-component Ugi reaction is described for the stereoselective synthesis of novel C-N atropisomeric peptide analogues. Using this approach, a combination of simple, readily available starting materials ( ortho -substituted anilines, aldehydes, carboxylic acids and isocyanides) could be combined to access complex products possessing both central and axial chirality in up to 92% yield and >95 : 5 d.r. Variation of the reaction temperature enabled the development of stereodivergent reactions capable of selectively targeting either diastereoisomer of a desired product from a single set of starting materials with high levels of stereocontrol. Detailed experimental and computational studies have been performed to probe the reaction mechanism and stereochemical outcome of these reactions. Preliminary studies show that novel atropisomeric scaffolds prepared using this method display inhibitory activity against M. tuberculosis with a significant difference in activity observed between different atropisomers., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Ion drift velocities in response to electric fields are a critical attribute of battery electrolytes. Accurately predicting species mobilities in such systems is an important challenge for atomistic simulations. In this work, we investigate two organic liquid electrolytes: LiPF 6 dissolved in (a) dimethyl carbonate (DMC) and (b) a mixture of DMC and ethylene carbonate (EC). We compare two approaches to measure mobilities: observing center of mass diffusion with no forces applied, and observing species drift in response to external forces. The two approaches are related by the fluctuation-dissipation theorem, but they are not equally efficient computationally. We argue that statistical errors of the two methods scale differently with system size and simulation run time. In a head-to-head test, we apply both methods to LiPF 6 in DMC in multiple simulations with the same size and run time. The drift method gives a much smaller variance in repeated measurements than the diffusion method, and should be preferred in practice., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Reactions between [(Tren TIPS )U VI N] (1, Tren TIPS = {N(CH 2 CH 2 NSiPr i 3 ) 3 } 3- ) and [M II (η 5 -C 5 R 5 ) 2 ] (M/R = Cr/H, Mn/H, Fe/H, Ni/H) were intractable, but M/R = Co/H or Co/Me afforded [(Tren TIPS )U V N-(η 1 :η 4 -C 5 H 5 )Co I (η 5 -C 5 H 5 )] (2) and [(Tren TIPS )U IV -NH 2 ] (3), respectively. For M/R = V/H [(Tren TIPS )U IV -NV IV (η 5 -C 5 H 5 ) 2 ] (4), was isolated. Complexes 2-4 evidence one-/two-electron uranium reductions, nucleophilic nitrides, and partial N-atom transfer.

Two bidentate ligands (L1 = 1-pentyl-2-(pyridin-2-yl)-1 H -benzimidazole and L2 = 1-heptyl-2-(pyridin-2-yl)-1 H -benzimidazole) were employed for the synthesis of five mononuclear Fe(II) coordination compounds 1-5 containing perchlorate, tetrafluoroborate and triflate counterions. Single-crystal X-ray diffraction analysis confirmed the expected molecular structures of all the reported compounds, revealing a moderately distorted octahedral geometry of {FeN 6 } coordination chromophores. All five compounds exhibit thermal spin crossover with T 1/2 temperatures allocated above 400 K. The theoretical calculations supported the experimental magnetic investigation and helped to explain the electronic structures of the reported complexes with respect to the occurrence of thermal spin state switching. In addition, compound 4 was employed for the preparation of Langmuir-Blodgett films and fabrication of molecular films using the method of spontaneous evaporation of the subphase. While the formation of Langmuir-Blodgett films was unsuccessful due to the instability of the compound at the water/air interface, the latter technique allowed the formation of molecular films of 4 with well-defined thickness and homogeneity.

Organofunctionalized borotungstate Keggin polyoxometalates, ( n Bu 4 N) 3 H[HBW 11 O 39 (P(O)Ph) 2 ] (PBW 11 ), ( n Bu 4 N) 3 H[HBW 11 O 39 (As(O)Ph) 2 ] (AsBW 11 ), and ( n Bu 4 N) 4 [HBW 11 O 39 (PhSiOSiPh)] (SiBW 11 ), were synthesized and structurally characterized. Cyclic voltammetry showed that the electronic properties of the clusters are dependent on the nature of the appended main group atoms (P, As, or Si). The first reduction potentials were found to shift positively with respect to that of the unmodified parent species ( n Bu 4 N) 5 [BW 12 O 40 ], with PBW 11 showing the largest shift at +100 mV. All clusters were evaluated as photocatalysts for the oxidative dimerization of amines where the organophosphonate hybrid PBW 11 was found to be the most active. This study demonstrates how organofunctionalization of polyoxometalates may be used to tune and improve their performance as photocatalysts for organic reactions., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Four novel Co(II) coordination compounds 1-4 of the general formula [Co(L n ) 2 ][Co(NCY) 4 ]· m CH 3 CN (where L n are tridentate ligands L1 = 2,6-bis(1-hexyl-1 H -benzimidazol-2-yl)pyridine for 1 and 2; L2 = 2,6-bis(1-octyl-1 H -benzimidazol-2-yl)pyridine for 3; L3 = 2,6-bis(1-dodecyl-1 H -benzimidazol-2-yl)pyridine for 4, Y = O for 1, 3, and 4 and Y = S for 2; m = 0 for 1 and 3, m = 0.5 for 2 and m = 2 for 4) were prepared and characterised. The molecular structures of all four compounds consist of the hexacoordinate complex cation [Co(L n ) 2 ] 2+ and tetracoordinate complex anion [Co(NCY) 4 ] 2- , with distorted octahedral and tetrahedral symmetry of coordination polyhedra, respectively. The electronic structures of all compounds feature an orbitally non-degenerate ground state well-separated from the lowest excited state, which allows the analysis of the magnetic anisotropy by the spin Hamiltonian model. ZFS parameters, derived from both CASSCF-NEVPT2 calculations and magnetic data analysis, indicate that tetrahedral anions [Co(NCY) 4 ] 2- exhibit small axial parameters | D | spanning the range of 2.2 to 7.7 cm -1 , while octahedral cations [Co(L n ) 2 ] 2+ display significantly larger | D | parameters in the range of 37 to 95 cm -1 . For 1-3, the Fourier-transform infrared magnetic spectroscopy (FIRMS) revealed a reasonable transmission with a magnetic absorption around the expected value for the ZFS accompanied by features allowing to identify phonon frequencies and simulate spin-phonon couplings. Dynamic magnetic investigations unveiled the field-induced slow relaxation of magnetisation, with maximal relaxation times ( τ ) of 92(2) μs for 2 at 2 K and B DC = 0.3 T. The temperature evolution of τ was analysed using a combination of Orbach, direct and Raman relaxations ( U eff = 8(1) K (5.6 cm -1 )) or Orbach, direct and spin-phonon induced relaxations ( U eff = 10.3(9) K (7.2 cm -1 )). The rest of the complexes, namely 1, 3, and 4 show field-induced slow relaxation of magnetisation with τ smaller than 16 μs.

Transition Metal Dichalcogenides (TMDs) are a unique class of materials that exhibit attractive electrical and optical properties which have generated significant interest for applications in microelectronics, optoelectronics, energy storage, and sensing. Considering the potential of these materials to impact such applications, it is crucial to develop a reliable and scalable synthesis process that is compatible with modern industrial manufacturing methods. Metal-organic chemical vapor deposition (MOCVD) offers an ideal solution to produce TMDs, due to its compatibility with large-scale production, precise layer control, and high material purity. Optimization of MOCVD protocols is necessary for effective TMD synthesis and integration into mainstream technologies. Additionally, improvements in metrology are necessary to measure the quality of the fabricated samples more accurately. In this work, we study MOCVD of wafer-scale molybdenum disulfide (MoS 2 ) utilizing two common chalcogen precursors, H 2 S and DTBS. We then develop a metrology platform for wafer scale samples quality assessment. For this, the coalesced films were characterized using Raman spectroscopy, atomic force microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and Kelvin probe force microscopy. We then correlate the structural analysis of these grown films with electrical performance by using aerosol jet printing to fabricate van der Pauw test structures and assess sheet resistance., Competing Interests: The authors declare no competing financial interests., (This journal is © The Royal Society of Chemistry.)

Owing to the considerable potential of photoelectrochemical (PEC) sensors, they have gained significant attention in the analysis of biological, environmental, and food markers. However, the limited charge mass transfer efficiency and rapid recombination of electron hole pairs have become obstacles in the development of PEC sensors. In this case, considering the unique advantages of carbon-based materials, they can be used as photosensitizers, supporting materials and conductive substrates and coupled with semiconductors to prepare composite materials, solving the above problems. In addition, there are many types of carbon materials, which can have semiconductor properties and form heterojunctions after coupling with semiconductors, effectively promoting the separation of electron hole pairs. Herein, we aimed to provide a comprehensive analysis of reports on carbon-based PEC sensors by introducing their research and application status and discussing future development trends in this field. In particular, the types and performance improvement strategies of carbon-based electrodes and the working principles of carbon-based PEC sensors are explained. Furthermore, the applications of carbon-based photoelectric sensors in environmental monitoring, biomedicine, and food detection are highlighted. Finally, the current limitations in the research on carbon-based PEC sensors are emphasized and the need to enhance the sensitivity and selectivity through material modification, structural design, improved device performance, and other strategies are emphasized.

Biocatalysis in ionic liquids enables novel routes for bioprocessing. Enzymes derived from extremophiles promise greater stability and activity under ionic liquid (IL) influence. Here, we probe the enzyme alcohol dehydrogenase 2 from the halophilic archaeon Haloferax volcanii in thirteen different ion combinations for relative activity and analyse the results against molecular dynamics (MD) simulations of the same IL systems. We probe the ionic liquid property space based on ion polarizability and molecular electrostatic potential. Using the radial distribution functions, survival probabilities and spatial distribution functions of ions, we show that cooperative ion-ion interactions determine ion-protein interactions, and specifically, strong ion-ion interactions equate to higher enzymatic activity if neither of the ions interact strongly with the protein surface. We further demonstrate a tendency for cations interacting with the protein surface to be least detrimental to enzymatic activity if they show a low polarizability when combined with small hydrophilic anions. We also find that the IL ion influence is not mitigated by the surplus of negatively charged residues of the halophilic enzyme. This is shown by free energy landscape analysis in root mean square deviation and distance variation plots of active site gating residues (Trp43 and His273) demonstrating no protection of specific structural elements relevant to preserving enzymatic activity. On the other hand, we observe a general effect across all IL systems that a tight binding of water at acidic residues is preferentially interrupted at these residues through the increased presence of potassium ions. Overall, this study demonstrates a co-ion interaction dependent influence on allosteric surface residues controlling the active/inactive conformation of halophilic alcohol dehydrogenase 2 and the necessity to engineer ionic liquid systems for enzymes that rely on the integrity of functional surface residues regardless of their halophilicity or thermophilicity for use in bioprocessing., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

This work presents a thorough characterization of Helaina recombinant human lactoferrin (rhLF, Effera™) expressed in a yeast system at an industrial scale for the first time. Proteomic analysis confirmed that its amino acid sequence is identical to that of native human LF. N-linked glycans were detected at three known glycosylation sites, namely, Asparagines-156, -497, and -642 and they were predominantly oligomannose structures having five to nine mannoses. Helaina rhLF's protein secondary structure was nearly identical to that of human milk lactoferrin (hmLF), as revealed by microfluidic modulation spectroscopy. Results of small-angle X-ray scattering (SAXS) and analytical ultracentrifugation analyses confirmed that, like hmLF, Helaina rhLF displayed well-folded globular structures in solution. Reconstructed solvent envelopes of Helaina rhLF, obtained through the SAXS analysis, demonstrated a remarkable fit with the reported crystalline structure of iron-bound native hmLF. Differential scanning calorimetry investigations into the thermal stability of Helaina rhLF revealed two distinct denaturation temperatures at 68.7 ± 0.9 °C and 91.9 ± 0.5 °C, consistently mirroring denaturation temperatures observed for apo- and holo-hmLF. Overall, Helaina rhLF differed from hmLF in the N-glycans they possessed; nevertheless, the characterization results affirmed that Helaina rhLF was of high purity and exhibited globular structures closely akin to that of hmLF.

Type I photodynamic therapy (PDT) is attracting increasing interest as an effective solution to the poor prognosis of patients with hypoxic tumors. The development of functional type I photosensitizers is limited by a lack of feasible strategies to systematically modulate electron transfer (ET) in photosensitization. Herein, we present an easily accessible approach for the preparation of nanophotosensitizers with self-assembly-integrated tumor-targeting and ET programming towards boosting tumor type I PDT. Specifically, a dual functional amphiphile PS-02 was designed with a ligand (6-NS) that had the ability to not only target tumor cell marker carbonic anhydrase IX (CAIX) but also regulate the ET process for type I PDT. The amphiphile PS-02 tended to self-assemble into PS-02 nanoparticles (NPs), which exhibited a local "ET-cage effect" due to the electron-deficient nature of 6-NS. It is noteworthy that when PS-02 NPs selectively targeted the tumor cells, the CAIX binding enabled the uncaging of the inhibited ET process owing to the electron-rich characteristic of CAIX. Therefore, PS-02 NPs integrated tumor targeting and CAIX activation towards boosting type I PDT. As a proof of concept, the improved PDT performance of PS-02 NPs was demonstrated with tumor cells under hypoxic conditions and solid tumor tissue in mouse in vivo experiments. This work provides a practical paradigm to develop versatile type I PDT nano-photosensitizers by simply manipulating ET and easy self-assembling., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

We report the magnetic structure and properties of a thiocyanate-based honeycomb magnet [Na(OH 2 ) 3 ]Mn(NCS) 3 which crystallises in the unusual low-symmetry trigonal space group P 3̄. Magnetic measurements on powder samples show this material is an antiferromagnet (ordering temperature T N,mag = 18.1(6) K) and can be described by nearest neighbour antiferromagnetic interactions J = -11.07(4) K. A method for growing neutron-diffraction sized single crystals (>10 mm 3 ) is demonstrated. Low temperature neutron single crystal diffraction shows that the compound adopts the collinear antiferromagnetic structure with T N,neut = 18.94(7) K, magnetic space group P 3̄'. Low temperature second-harmonic generation (SHG) measurements provide no evidence of breaking of the centre of symmetry.

The enantioselective de novo synthesis of pharmacologically important 14-hydroxy-6-oxomorphinans is described. 4,5-Desoxynaltrexone and 4,5-desoxynaloxone were prepared using this route and their biological activities against the opioid receptors were measured.

Chlorosomes, the photosynthetic antenna complexes of green sulfur bacteria, are paradigms for light-harvesting elements in artificial designs, owing to their efficient energy transfer without protein participation. We combined magic angle spinning (MAS) NMR, optical spectroscopy and cryogenic electron microscopy (cryo-EM) to characterize the structure of chlorosomes from a bchQ mutant of Chlorobaculum tepidum . The chlorosomes of this mutant have a more uniform composition of bacteriochlorophyll (BChl) with a predominant homolog, [8Ethyl, 12Ethyl] BChl c , compared to the wild type (WT). Nearly complete 13 C chemical shift assignments were obtained from well-resolved homonuclear 13 C- 13 C RFDR data. For proton assignments heteronuclear 13 C- 1 H (hCH) data sets were collected at 1.2 GHz spinning at 60 kHz. The CHHC experiments revealed intermolecular correlations between 13 2 /3 1 , 13 2 /3 2 , and 12 1 /3 1 , with distance constraints of less than 5 Å. These constraints indicate the syn - anti parallel stacking motif for the aggregates. Fourier transform cryo-EM data reveal an axial repeat of 1.49 nm for the helical tubular aggregates, perpendicular to the inter-tube separation of 2.1 nm. This axial repeat is different from WT and is in line with BChl syn - anti stacks running essentially parallel to the tube axis. Such a packing mode is in agreement with the signature of the Q y band in circular dichroism (CD). Combining the experimental data with computational insight suggests that the packing for the light-harvesting function is similar between WT and bchQ , while the chirality within the chlorosomes is modestly but detectably affected by the reduced compositional heterogeneity in bchQ .

Plastics have substantial societal benefits, but their widespread use has led to a critical waste management challenge. While mechanical recycling dominates the reuse of post-consumer plastics, it is limited in efficacy, especially for composites. To address this, we propose a direct reprocessing approach that enables the creation of hybrid, long-lasting, and durable composites from difficult-to-recycle plastics. This approach utilizes cold sintering, a process that consolidates inorganic powders through fractional dissolution and precipitation at temperatures far below conventional sintering; these temperatures are compatible with plastic processing. We show that this process can create inorganic-matrix composites with significant enhancements in tensile strength and toughness over pure gypsum, which is commonly found in construction waste. These composites can be recycled multiple times through direct reprocessing with the addition of only water as a processing promoter. This approach to recycling leads to composites with orders of magnitude lower energy demand, global warming potential, and water demand, when compared against common construction products. Altogether, we demonstrate the potential for cold sintering to integrate waste into high-performance recyclable composites.

The extension of conceptual density-functional theory (conceptual DFT) to include external electromagnetic fields in chemical systems is utilised to investigate the effects of strong magnetic fields on the electronic charge distribution and its consequences on the reactivity of π-systems. Formaldehyde, H 2 CO, is considered as a prototypical example and current-density-functional theory (current-DFT) calculations are used to evaluate the electric dipole moment together with two principal local conceptual DFT descriptors, the electron density and the Fukui functions, which provide insight into how H 2 CO behaves chemically in a magnetic field. In particular, the symmetry properties of these quantities are analysed on the basis of group, representation, and corepresentation theories using a recently developed automatic program for symbolic symmetry analysis, QSYM 2 . This allows us to leverage the simple symmetry constraints on the macroscopic electric dipole moment components to make profound predictions on the more nuanced symmetry transformation properties of the microscopic frontier molecular orbitals (MOs), electron densities, and Fukui functions. This is especially useful for complex-valued MOs in magnetic fields whose detailed symmetry analyses lead us to define the new concepts of modular and phasal symmetry breaking . Through these concepts, the deep connection between the vanishing constraints on the electric dipole moment components and the symmetry of electron densities and Fukui functions can be formalised, and the inability of the magnetic field in all three principal orientations considered to induce asymmetry with respect to the molecular plane of H 2 CO can be understood from a molecular perspective. Furthermore, the detailed forms of the Fukui functions reveal a remarkable reversal in the direction of the dipole moment along the CO bond in the presence of a parallel or perpendicular magnetic field, the origin of which can be attributed to the mixing between the frontier MOs due to their subduced symmetries in magnetic fields. The findings in this work are also discussed in the wider context of a long-standing debate on the possibility to create enantioselectivity by external fields.

Conjugated molecules and polymers are being designed as acceptor and donor materials for organic photovoltaic (OPV) cells. OPV performance depends on generation of free charge carriers through dissociation of excitons, which are electron-hole pairs created when a photon is absorbed. Here, we develop a tight-binding model to describe excitons on homo-oligomers, alternating co-oligomers, and a non-fullerene acceptor - IDTBR. We parameterize our model using density functional theory (DFT) energies of neutral, anion, cation, and excited states of constituent moieties. A symmetric molecule like IDTBR has two ends where an exciton can sit; but the product wavefunction approximation for the exciton breaks symmetry. So, we introduce a tight-binding model with full correlation between electron and hole, which allows the exciton to coherently explore both ends of the molecule. Our approach predicts optical singlet excitation energies for oligomers of varying length as well as IDTBR in good agreement with time-dependent DFT and spectroscopic results.

Here, an unusual MXene with a high ratio of oxygen functional groups was prepared by hydrothermal treatment of HF-etched MXene in aqueous KOH solution. The prepared MXene (H-220) exhibits ultrahigh specific capacitance (1030 F g -1 in a potential window of 0.85 V), and excellent rate and cycling performance simultaneously in a sulfuric acid electrolyte, and can act as an anode material of proton batteries.

Synthetic methods that enable the macrocyclisation of peptides facilitate the development of effective therapeutic and diagnostic tools. Herein we report a peptide cyclisation strategy based on intramolecular interception of visible-light-mediated cysteine desulfurisation. This method allows cyclisation of unprotected peptides in an aqueous solution via the installation of a hydrocarbon linkage. We explore the limits of this chemistry using a range of model peptides of increasing length and complexity, including peptides of biological/therapeutic relevance. The method is applied to replace the native disulfide of the peptide hormone, oxytocin, with a proteolytically/redox-stable hydrocarbon, and internal macrocyclisation of an MCL-1-binding peptide., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)