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Although the prevalence of antibiotic resistance is increasing at an alarming rate, there are a dwindling number of effective antibiotics available. Thus, the development of novel antibacterial agents should be of utmost importance. Peptidoglycan biosynthesis has been and is still an attractive source for antibiotic targets; however, there are several components that remain underexploited. In this review, we examine the enzymes involved in the biosynthesis of one such component, UDP-N-acetylglucosamine, an essential building block and precursor of bacterial peptidoglycan. Furthermore, given the presence of a similar biosynthesis pathway in eukaryotes, we discuss the current knowledge on the differences and similarities between the bacterial and eukaryotic enzymes. Finally, this review also summarises the recent advances made in the development of inhibitors targeting the bacterial enzymes.

Directional or stabilising selection should drive the expression of a dominant movement phenotype within a population. Widespread persistence of multiple movement phenotypes within wild populations, however, suggests that individuals that move (movers) and those that do not (residents) can have commensurate performance. The costs and benefits of mover and resident phenotypes remain poorly understood. Here, we explored how the presence and timing of movements are correlated with annual somatic growth rates, a useful proxy for performance because it is easily measured and rapidly reflects environmental changes. We used otolith growth measurements and stable isotope analyses to recreate growth and among-reach movement histories of a partially migrating, long-lived freshwater fish, golden perch Macquaria ambigua. We compared the association between movement and growth at two temporal scales: (a) short-term (annual) differences in growth, in the years preceding, during or following movement; and (b) long-term (lifetime) differences in growth. Overall, 59% of individuals performed at least one among-reach movement, with these individuals subsequently more likely to move repeatedly throughout their lives. Movers grew faster than residents, with this difference most pronounced in the juvenile and early adult stages, when most movements occurred. Annual growth did not, however, change immediately prior to or following a specific movement event. Among-individual variation in growth was initially higher for residents than for movers but decreased with age, at a faster rate for residents than for movers, such that levels conformed after 5 years of age. Our results indicate that lifetime movement is linked to faster growth in the early years of a fish's life. These faster growing movers are likely to be larger at a given age, leading to numerous potential benefits. However, the persistence of resident phenotypes suggests that there is likely a cost-benefit trade-off to moving. The presence of multiple movement phenotypes may contribute to the resilience of populations by buffering against naturally and anthropogenically exacerbated environmental variability.

The UK government introduced a nationwide lockdown on the 23rd March 2020 to prevent the spread of COVID-19. All elective hospital and dental practice assessments and procedures were mandated to stop. Key hospital dental workers were required to work, and Guy’s and St Thomas’ NHS Foundation Trust became a designated Urgent Dental Care Centre (UDC) for the greater London area. The paediatric dental emergency walk-in service was suspended and replaced with a telephone triage system and evaluation of digital images sent by parents/carers when needed. The aim of this paper is to describe the emergency service provided by staff in the department of Paediatric Dentistry at St Thomas’ Hospital during the first lockdown. A prospective service evaluation of the modified paediatric dental emergency service was carried out between 25th March and 29th May 2020. Four-hundred and sixty-four patients accessed the paediatric dental emergency service via telephone during the service evaluation period. Of these, 192 (41%) had dental pain, 121 (26%) had pain and swelling of dental origin, and 89 (19%) had trauma. Remote telephone consultations and digital photographs were useful to screen emergency paediatric dental patients, but lack of face-to-face consultations with radiographic assessment and access to general anaesthetic services were major limiting factors.

The hydration of carbon–carbon triple bonds is an important and atom economic synthetic transformation. Herein, we report a mild and selective method for the catalytic Markovnikov hydration of (E)-aryl enynes to the corresponding enones, mediated through the bench-stable aminium salt, tris(4-bromophenyl)ammoniumyl hexachloroantimonate (TBPA). The chemoselective and diastereoselective method proceeds under neutral metal-free conditions, delivering excellent product yields from terminal and internal alkyne units. The synthesis of biologically important (E)-3-styrylisocoumarins, including a formal synthesis of the natural product achlisocoumarin III, demonstrates the utility of this novel transformation.

Herbicide resistance represents one of the biggest threats to our natural environment and agricultural sector. Thus, new herbicides are urgently needed to tackle the rise in herbicideresistant weeds. Here, we employed a novel strategy to repurpose a ‘failed’ antibiotic into a new and target-specific herbicidal compound. Specifically, we identified an inhibitor of bacterial dihydrodipicolinate reductase (DHDPR), an enzyme involved in lysine biosynthesis in plants and bacteria, that exhibited no antibacterial activity but severely attenuated germination of the plant Arabidopsis thaliana. We confirmed that the inhibitor targets plant DHDPR orthologues in vitro, and exhibits no toxic effects against human cell lines. A series of analogues were then synthesised with improved efficacy in germination assays and against soil-grown A. thaliana plants. We also showed that our lead compound is the first lysine biosynthesis inhibitor with herbicidal activity against a weed species, providing proof-of-concept that DHDPR inhibition may represent a much-needed new herbicide mode of action. Furthermore, this study exemplifies the untapped potential of repurposing ‘failed’ antibiotic scaffolds to fast-track the development of herbicide candidates targeting the respective plant enzymes to combat the global rise in herbicide-resistant weeds.

Diversity Oriented Clicking (DOC) is a unified click-approach for the modular synthesis of lead-like structures through application of the wide family of click transformations. DOC evolved from the concept of achieving "diversity with ease", by combining classic C-C π-bond click chemistry with recent developments in connective SuFEx-technologies. We showcase 2-Substituted-Alkynyl-1-Sulfonyl Fluorides (SASFs) as a new class of connective hub in concert with a diverse selection of click-cycloaddition processes. Through the selective DOC of SASFs with a range of dipoles and cyclic dienes, we report a diverse click-library of 173 unique functional molecules in minimal synthetic steps. The SuFExable library comprises 10 discrete heterocyclic core structures derived from 1,3- and 1,5-dipoles; while reaction with cyclic dienes yields several three-dimensional bicyclic Diels-Alder adducts. Growing the library to 278 discrete compounds through late-stage modification was made possible through SuFEx click derivatization of the pendant sulfonyl fluoride group in 96 well-plates-demonstrating the versatility of the DOC approach for the rapid synthesis of diverse functional structures. Screening for function against MRSA (USA300) revealed several lead hits with improved activity over methicillin.

SuFEx click chemistry is a powerful method designed for the selective, rapid and modular synthesis of functional molecules. Classical SuFEx reactions form stable S-O linkages upon exchange of S-F bonds with aryl silyl-ether substrates, and while near-perfect in their outcome, are sometimes disadvantaged by relatively high catalyst loadings and prolonged reaction times. We herein report the development of 'Accelerated SuFEx Click Chemistry' (ASCC), an improved SuFEx method for the efficient and catalytic coupling of aryl and alkyl alcohols with a range of SuFExable hubs. We demonstrate Barton's hindered guanidine base (2- tert -butyl-1,1,3,3-tetramethylguanidine; BTMG) as a superb SuFEx catalyst that, when used in synergy with silicon additive hexamethyldisilazane (HMDS), yields stable S-O bond linkages in a single step; often within minutes. The powerful combination of BTMG and HMDS reagents allows for catalyst loadings as low as 1.0 mol% and, in congruence with click-principles, provides a scalable method that is safe, efficient, and practical for modular synthesis. ASSC expands the number of accessible SuFEx products and will find significant application in organic synthesis, medicinal chemistry, chemical biology, and materials science .

The hydration of carbon-carbon triple bonds is an important and atom economic synthetic transformation. Herein, we report a mild and selective method for the catalytic Markovnikov hydration of (E)-aryl enynes to the corresponding enones, mediated through the bench-stable aminium salt, tris(4-bromophenyl)ammoniumyl hexachloroantimonate (TBPA). The chemoselective and diastereoselective method proceeds under neutral metal-free conditions, delivering excellent product yields from terminal and internal alkyne units. The synthesis of biologically important (E)-3-styrylisocoumarins, including a formal synthesis of the natural product achlisocoumarin III, demonstrates the utility of this novel transformation.

SuFEx (Sulfur Fluoride Exchange) is a modular, next generation family of click reactions, geared towards the rapid and reliable assembly of functional molecules. This review discusses the growing number of applications of SuFEx, which can be found in nearly all areas of modern chemistry; from drug discovery to materials science.

Introduction: Minimising spread of the COVID-19 infection through reducing face-to-face consults is essential. In doing so, alternative assessment and communication methods for management of patients with oral conditions should be considered. Material and methods: Patients on the waiting list for the joint oral medicine-paediatric dental clinic between March and June 2020 were prioritised based on a criteria including relevant medical history, diagnosis and clinical need and current management − monitoring, topical therapy or systemic therapy. A telephone consult method was chosen to assess and follow up patients and a parental satisfaction questionnaire was conducted following telephone consult. Results: Recurrent aphthous stomatitis (RAS) was the most common diagnosis of patients reviewed on the telephone clinic. Overall, the patient satisfaction questionnaire revealed that 100% of respondents would prefer a telephone consult during COVID-19 rather than face-to-face appointments. 74% opted for a video consult in preference to a telephone consult. Conclusion: This service evaluation has found telephone consults to be a valuable alternative to face-to-face consults in the management of patients with chronic oral mucosal diseases. Telephone consultations have high parental satisfaction and are an effective, convenient method to assess and follow up patients whilst maintaining their safety during the COVID-19 pandemic.

The UK government introduced a nationwide lockdown on the 23rd March 2020 to prevent the spread of COVID-19. All elective hospital and dental practice assessments and procedures were mandated to stop. Key hospital dental workers were required to work, and Guy's and St Thomas' NHS Foundation Trust became a designated Urgent Dental Care Centre (UDC) for the greater London area. The paediatric dental emergency walk-in service was suspended and replaced with a telephone triage system and evaluation of digital images sent by parents/carers when needed. The aim of this paper is to describe the emergency service provided by staff in the department of Paediatric Dentistry at St Thomas' Hospital during the first lockdown.A prospective service evaluation of the modified paediatric dental emergency service was carried out between 25th March and 29th May 2020.Four-hundred and sixty-four patients accessed the paediatric dental emergency service via telephone during the service evaluation period. Of these, 192 (41%) had dental pain, 121 (26%) had pain and swelling of dental origin, and 89 (19%) had trauma.Remote telephone consultations and digital photographs were useful to screen emergency paediatric dental patients, but lack of face-to-face consultations with radiographic assessment and access to general anaesthetic services were major limiting factors.

Escaping Lyman continuum photons from galaxies likely reionized the intergalactic medium at redshifts $z\gtrsim6$. However, the Lyman continuum is not directly observable at these redshifts and secondary indicators of Lyman continuum escape must be used to estimate the budget of ionizing photons. Observationally, at redshifts $z\sim2-3$ where the Lyman continuum is observationally accessible, surveys have established that many objects that show appreciable Lyman continuum escape fractions $f_{esc}$ also show enhanced [OIII]/[OII] (O$_{32}$) emission line ratios. Here, we use radiative transfer analyses of cosmological zoom-in simulations of galaxy formation to study the physical connection between $f_{esc}$ and O$_{32}$. Like the observations, we find that the largest $f_{esc}$ values occur at elevated O$_{32}\sim3-10$ and that the combination of high $f_{esc}$ and low O$_{32}$ is extremely rare. While high $f_{esc}$ and O$_{32}$ often are observable concurrently, the timescales of the physical origin for the processes are very different. Large O$_{32}$ values fluctuate on short ($\sim$1 Myr) timescales during the Wolf-Rayet-powered phase after the formation of star clusters, while channels of low absorption are established over tens of megayears by collections of supernovae. We find that while there is no direct causal relation between $f_{esc}$ and O$_{32}$, high $f_{esc}$ most often occurs after continuous input from star formation-related feedback events that have corresponding excursions to large O$_{32}$ emission. These calculations are in agreement with interpretations of observations that large $f_{esc}$ tends to occur when O$_{32}$ is large, but large O$_{32}$ does not necessarily imply efficient Lyman continuum escape., Comment: 12 pages, 5 figures, submitted to ApJL on September 15, 2020

Space telescope observations of massive black holes during their formation may be key to understanding the origin of supermassive black holes and high-redshift quasars. To create diagnostics for their detection and confirmation, we study a simulation of a nascent massive, so-called direct-collapse, black hole that induces a wave of nearby massive metal-free star formation, unique to this seeding scenario and to very high redshifts. Here we describe a series of distinct colors and emission line strengths, dependent on the relative strength of star formation and black hole accretion. We predict that the forthcoming James Webb Space Telescope might be able to detect and distinguish a young galaxy that hosts a direct-collapse black hole in this configuration at redshift 15 with as little as a 20,000-second total exposure time across four filters, critical for constraining supermassive black hole seeding mechanisms and early growth rates. We also find that a massive seed black hole produces strong, H$_2$-dissociating Lyman-Werner radiation., Comment: As submitted on May 30th, 2018. Published in Nature Astronomy on September 10th, 2018

Dynamic nuclear polarization (DNP) gives large (>100-fold) signal enhancements in solid-state NMR spectra via the transfer of spin polarization from unpaired electrons from radicals implanted in the sample. This means that the detailed information about local molecular environment available for bulk samples from solid-state NMR spectroscopy can now be obtained for dilute species, such as sites on the surfaces of catalysts and catalyst supports. In this paper we describe a DNP-enhanced solid-state NMR study of the widely used catalyst gamma-alumina which is often modified at the surface by the incorporation of alkaline earth oxides in order to control the availability of catalytically active penta-coordinate surface Al sites. DNP-enhanced 27Al solid-state NMR allows surface sites in gamma-alumina to be observed and their 27Al NMR parameters measured. In addition changes in the availability of different surface sites can be detected after incorporation of BaO.

The understanding of location and accessibility of zeolite acid sites is a key issue in heterogeneous catalysis. This paper provides a brief overview of Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR) characterisation of acidity in zeolites based on the application of test molecules with a diverse range of basicity and kinetic diameters. Many zeolites, including ZSM-5 and BEA, have been characterised by monitoring the interaction between the zeolite acid sites and test molecules, such as 1,3,5-triisopropylbenzene, pyridine and alkylpyridines, to probe the location, accessibility and strength of the Bronsted acid sites. 1,3,5-triisopropylbenzene can be used to distinguish Bronsted acid sites located on the external and internal surface in most medium and large pore channel zeolites. Bronsted acid sites on the external surface of medium pore zeolites can also be quantified using 2,6-di-tert-butyl-pyridine and 2,4,6-trimethylpyridine. It is concluded that using a combination of probe molecules, including co-adsorption experiments, affords differentiation between acid sites located in channels and cavities of different sizes and on the external and internal surfaces of various zeolitic structures.

The direct formation of a massive black hole is a potential seeding mechanism of the earliest observed supermassive black holes. We investigate how the existence of a massive black hole seed impacts the ionization and thermal state of its pre-galactic host halo and subsequent star formation. We show that its X-ray radiation ionizes and heats the medium, enhancing $\rm{H}_2$ formation in shielded regions, within the nuclear region in the span of a million years. The enhanced molecular cooling triggers the formation of a $\sim 10^4~{\rm M}_\odot$ metal-free stellar cluster at a star formation efficiency of $\sim 0.1\%$ in a single event. Star formation occurs near the edges of the H II region that is partially ionized by X-rays, thus the initial size depends on the black hole properties and surrounding environment. The simulated metal-free galaxy has an initial half-light radius of $\sim 10$ pc but expands to $\sim 50$ pc after 10 million years because of the outward velocities of their birth clouds. Supernova feedback then quenches any further star formation for tens of millions of years, allowing the massive black hole to dominate the spectrum once the massive metal-free stars die., Accepted for publication in ApJ Letters, 7 pages, 5 figures

Human-driven climate change and habitat modification are negatively impacting coastal ecosystems and the species that reside within them. Uncovering how individuals of key species respond to environmental influences is crucial for effective and responsive coastal resource and fisheries management. Here, using an otolith based analysis, we recreated the growth history of rock flathead Platycephalus laevigatus from Corner Inlet, Victoria, Australia, over a 32 yr timeframe and related growth variation to changes in key environmental variables. Growth increased with higher temperatures during the fish growing season (December-May) and also increased with higher freshwater flow during the period important for seagrass growth (July- February). We hypothesise that fish are responding to enhanced productivity in the seagrass food web, driven by increased nutrient input from freshwater flows. Fish also appear to be responding to higher temperatures via a direct physiological pathway. We then predicted fish growth under 3 plausible climate change scenarios. Growth is predicted to increase across all our projections, because any predicted decrease in river flow will likely be offset by rapid predicted increases in temperature. Our results highlight the value of understanding the drivers of long-term growth variation in harvested fishes as this allows for the prediction of future productivity under a range of environmental and management scenarios.

© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. Mapping the interaction sites between membrane-spanning proteins is a key challenge in structural biology. In this study a carbene-footprinting approach was developed and applied to identify the interfacial sites of a trimeric, integral membrane protein, OmpF, solubilised in micelles. The diazirine-based footprinting probe is effectively sequestered by, and incorporated into, the micelles, thus leading to efficient labelling of the membrane-spanning regions of the protein upon irradiation at 349 nm. Areas associated with protein–protein interactions between the trimer subunits remained unlabelled, thus revealing their location.

A recent federal district court decision found that the New York City Police Department engaged in unconstitutional policing. Officers stopped millions of minority young men over the span of several years. Most of those stopped were innocent of any wrongdoing. This article uses qualitative and quantitative research methods to investigate these inequities, examining the views of both the police and those who were stopped. The authors find that pressure on officers emanating from headquarters was responsible for much of the illegal behavior by lower-level officers. Additionally, youth in minority neighborhoods felt mistreated by the police; this led to distrust in the police. The authors suggest solutions to ameliorate this painful episode in police practice. The article concludes with specific recommendations such as reducing management pressure on officers and police developing community partnerships.

Background In 2017, the Royal College of Radiologists (RCR) published updated guidance on the radiological investigation of suspected physical abuse in children. New recommendations include CT head in all children under one year and that siblings or household contacts under two should also undergo radiological investigation. The latest guidance also recommends that all skeletal surveys are reported by two independent paediatric radiologists. Aims To audit current practice and assess the impact of introducing the RCR (2017) guidance in terms additional imaging needing to be performed. To assess the impact on workload of introducing double reporting for skeletal surveys. Methods Children under two who had suspected physical abuse were identified from the child protection team’s referral log. A retrospective analysis was performed of skeletal surveys from December 2014 to December 2016 using an audit proforma devised from the RCR guidelines (2017). IT systems were used to check for siblings aged ≤2 years. PACS was used to assess views obtained, time of final report and if surveys were double reported. Results 18 skeletal surveys were performed in the study period, all of which were deemed necessary. Results showed that compliance with the RCR guidance (2008) needed improvement: two skeletal surveys had missing views, only 20% of children who had an abnormal CT head had a follow-up MRI, 72% of skeletal surveys were reported within 72 hours and just 17% of children had follow-up imaging. If the RCR 2017 guidance were to be introduced, an additional three CT head scans would be required per year and two skeletal surveys would be required for siblings or household contacts. Double reporting would be required for 9 skeletal surveys per year. Conclusion New recommendations have implications for radiation dose but from the results, it would not increase the workload to an unmanageable degree. Based on results, we have chosen to introduce the latest RCR guidelines with the use of a proforma to improve compliance with standards.

Selenate-loaded selenium water remediation materials based on polymer fibres have been investigated by dynamic nuclear polarization (DNP) enhanced solid-state NMR. For carbon-13 a significant reduction in experiment time is obtained with DNP even when compared with conventional carbon-13 NMR spectra recorded using larger samples. For the selenium remediation materials studied here this reduction allows efficient acquisition of {1H}-77Se heteronuclear correlation spectra which give information about the nature of the binding of the remediated selenate ions with the grafted side chains which provide the required ion exchange functionality.

We study the cosmological evolution of the field equations in the context of Einstein–Aether cosmology by including a scalar field in a spatially flat Friedmann–Lemaître–Robertson–Walker spacetime. Our analysis is separated into two separate where a pressureless fluid source is included or absent. In particular, we determine the critical points of the field equations and we study the stability of the specific solutions. The limit of general relativity is fully recovered, while the dynamical system admits de Sitter solutions which can describe the past inflationary era and the future late-time attractor. Results for generic scalar field potentials are presented while some numerical behaviours are given for specific potential forms. © 2019, The Author(s).

Stock enhancement is an important tool used to rebuild depleted fish populations or enhance recreational fishing. Hatchery-reared individuals can express trait differences, such as growth, which may affect later survival. However, there is little understanding of how early life growth variation affects stocking success. We examined early life growth of golden perch Macquaria ambigua and assessed how growth within hatcheries affects the survival of stocked fish. We measured daily otolith increment widths at 10, 20 and 30 days after hatching, but before stocking into lakes in south-eastern Australia. Mean growth decreased with age, but variation in growth increased. We then compared the early life growth of these individuals to those recaptured after 2 years at liberty (age-2+). Faster individual growth between 20 and 30 days was positively correlated with increased length at stocking. Mean growth between 20 and 30 days of age-2+ fish was higher than that of young-of-year fish, but among-individual variation in growth did not differ between the two groups. These results suggest that individuals with fast hatchery growth have increased survival to 2 years. We propose that enhancing growth within hatcheries may increase the survival of stocked fish, and thus the cost-effectiveness of fish stocking.

A protocol for the efficient conversion of sulfonyl fluorides into sulfonyl azides through Lewis base activation is described. The in situ generated sulfonyl azides are efficient diazo-transfer agents, affording diazo compounds and primary azides in excellent yields.

High-surface area γ-alumina is industrially used as a catalyst support. Catalytically active elements are doped onto the support, where they can bind to AlO4, AlO5 or AlO6 sites on the surface. Pretreating the surface with alkaline earth oxides can alter the availability of these surface sites, hence affecting the catalytic activity. The surface binding sites of strontium oxide (SrO) on γ-alumina were previously unknown. Direct 27Al magic angle spinning nuclear magnetic resonance (MAS NMR) could not detect AlO5 sites at 9.4 T, so 1H‐27Al cross-polarisation (CP) MAS NMR was used to preferentially select the surface environment signals. We directly observed the three surface environments on dehydrated γ-alumina as a function of SrO impregnation up to 4 wt% SrO. We found that Sr2+ preferentially binds to AlO5 and AlO6 surface sites. 1H MAS NMR revealed SrO impregnation causes a reduction in the terminal (−0.3 ppm) and bridging (2.2 ppm) hydroxyl environments, as well as the promotion of a new peak in between these sites, at 0.5 ppm. By using 1H‐27Al CP/MAS NMR the relative proportions of surface sites on γ-alumina can be determined, allowing an optimal level of SrO doping that can saturate all the AlO5 sites. Importantly, this provides a method of subsequently depositing catalytically active elements on just the AlO4 or AlO6 sites, which can provide a different catalytic activity or stability compared to the AlO5 binding site.

We present a selection of elegant and diverse biomimetic syntheses of complex natural product dimers. The dimerisation pathways discussed encompass the most prevalent strategies, including: Diels-Alder, Aldol, Mannich, conjugate addition, oxidative, radical and photochemical approaches; each underpinned through rational biosynthetic speculation.

Technologies that enable surface modification are in high demand and are critical for the implementation of new functional materials and devices. Here, we describe the first modification of a carbon surface (in this case carbon fiber) using the sulfur-fluoride exchange (SuFEx) reaction. The parent sulfur (VI) fluoride moiety can be installed directly to the surface via electrochemical deposition of the fluorosulfate phenyldiazonium tetrafluoroborate salt, or by 'SuFExing' a phenol on the carbon surface followed by treatment of the material with SO2 F2 ; similar to a 'graft to' or 'graft from' functionalization approach. We demonstrate that these SuFEx-able surfaces readily undergo exchange with aryl silyl ethers, and that the subsequent sulfate linkages are themselves stable under electrochemical redox conditions. Finally, we showcase the utility of the SuFEx chemistry by installing a pendant amino group to the fiber surface resulting in interfacial shear strength improvements of up to 130 % in epoxy resin.

The jerantinine family of Aspidosperma indole alkaloids from Tabernaemontana corymbosa are potent microtubule-targeting agents with broad spectrum anticancer activity. The natural supply of these precious metabolites has been significantly disrupted due to the inclusion of T. corymbosa on the endangered list of threatened species by the International Union for Conservation of Nature. This report describes the asymmetric syntheses of (−)-jerantinines A and E from sustainably sourced (−)-tabersonine, using a straight-forward and robust biomimetic approach. Biological investigations of synthetic (−)-jerantinine A, along with molecular modelling and X-ray crystallography studies of the tubulin—(−)-jerantinine B acetate complex, advocate an anticancer mode of action of the jerantinines operating via microtubule disruption resulting from binding at the colchicine site. This work lays the foundation for accessing useful quantities of enantiomerically pure jerantinine alkaloids for future development.

We demonstrate 1,2-dibromoethane-1-sulfonyl fluoride (DESF) as a bench-stable and readily accessible precursor to the robust SuFEx connector, 1-bromoethene-1-sulfonyl fluoride (BESF). The in situ generation of BESF from DESF opens up several new reaction profiles, including application in the syntheses of unprecedented 3-substituted isoxazole-5-sulfonyl fluorides, 1-substituted-1H-1,2,3-triazole-4-sulfonyl fluorides, 2-amino-1-bromoethane-1-sulfonyl fluorides and 4-bromo-β-sultams in good to excellent yields. These new modules comprise a pendant sulfonyl fluoride handle, which further undergoes facile and selective SuFEx reactions with a selection of aryl silyl ethers to generate stable and useful sulfonate connections.

Low levels of transition metal oxides in alkali borosilicate glass systems can drastically influence crystallisation and phase separation properties. We investigated the non-monotonic effect of manganese doping on suppressing crystallisation, and the influence on optical properties by iron oxide doping, in terms of local atomic structure. Structural models based on empirical potential structure refinement were generated from neutron and X-ray scattering data, and compared against multinuclear solid-state NMR. This revealed that a 2.5% manganese doping had a disruptive effect on the entire glass network, supressing crystallisation of an undesired bismuth silicate phase, and that iron species preferentially locate near borate tetrahedra. Preventing phase separation and controlling crystallisation behaviour of glass are critical to the ultimate properties of automotive glass enamels.

Despite considerable research efforts, finding a chemically stable electrolyte mixture in the presence of reduced oxygen species remains a great challenge. Previously, dimethyl sulfoxide (DMSO) and sulfolane-based electrolytes were reported to be stable for Li-O2 battery applications. Recently LiOH-based chemistries have demonstrated to involve supressed side reactions in water-added ether- and DMSO-based electrolytes. Herein, we investigate the impact of dimethyl sulfoxide-based electrolyte and sulfolane co-solvent on the cell chemistry in the presence of water. We found that DMSO-based electrolyte leads to formation of a peroxide-hydroxide mixture as discharge products and the removal of both LiOH and Li2O2 on charging from 3.2 -3.6 V (vs. Li+/Li) is observed. In the presence of sulfolane as co-solvent, a mixture of Li2O2 and LiOH is formed as major discharge products with slightly more dominant LiOH formation than in the absence of sulfolane. The presence of sulfolane has also significant effects in the charging behaviour, exhibiting a clearer 3 e-/O2 oxygen evolution reaction profile during the entire charging process. This work provides insights into understanding the effects of the primary solvent on promoting LiOH formation and decomposition in LiI mediated non-aqueous Li-O2 batteries.

In the context of f(R) gravity with a spatially flat FLRW metric containing an ideal fluid, we use the method of invariant transformations to specify families of models which are integrable. We find three families of f(R) theories for which new analytical solutions are given and closed-form solutions are provided. © 2018 American Physical Society.

The 1H and 13C NMR spectra in methylammonium lead halide perovskites, CH3NH3PbX3 (X = I, Br and Cl) show that the CH3NH3+ units undergo dynamic reorientation, as the organic component tumbles in the perovskite cage. In addition, the differences in the anomalously long relaxation times of the protons associated with the CH3 and not the NH3 groups indicate that only the amine end of the CH3NH3+ group is interacting with the inorganic network. Using this information, we have refined some single crystal X-ray and neutron diffraction data to probe their unusual structures in more detail. Furthermore, impedance spectroscopy has been used to monitor the high-temperature phase transition of CH3NH3PbI3, which confirms a significant increase in conductivity, when it is in its high temperature and higher symmetry structural regime. The optical band-gaps of each halide perovskite were determined using UV-visible spectroscopy and are consistent with previous reports. NRF (Natl Research Foundation, S’pore) Accepted version

With the challenges faced by operations in a continuing low oil price environment and the continuing high failure rate of offshore moorings, the value derived from traditional mooring inspection strategies needs to be reassessed. This paper outlines a significantly improved approach to mooring and riser system inspection based on the acquisition of quantitative condition data using low cost/low risk inspection techniques. Specifically, this paper addresses the ability to perform specific, detailed, quantitative inspections using standard inspection tools mobilized to and launched from an offshore facility. By modifying inspection strategies to target specific areas of high risk and known degradation mechanisms, a much-improved understanding of the current condition of the system is gained and appropriate integrity management strategies developed based on the observed and measured rate of component degradation. In addition, the ability to respond rapidly to event-based forms of degradation is significantly improved. This approach will be demonstrated by a case study of the inspection of a known area of risk that is traditionally difficult to inspect and interpret - mooring chain links within a hawse pipe. High definition imagery of elements within the hawse pipe of an FPSO turret mooring system were acquired and then post processed into highly accurate (±1 mm) 3D chain link data, following which detailed numerical analysis of the remaining link capacity for worn links was performed. Previously acquired diver measured data is compared against 3D scan data and the improvements in the accuracy of the estimate of the remaining strength on the worn links is demonstrated. Based on the understanding of the remaining capacity and rate of degradation, future inspection intervals can be set on an informed basis, such that the rate of volumetric loss can be verified by measurement, thereby confirming the rate of degradation in link capacity. A cost-benefit analysis highlights the improvements in overall lifecycle costs that these quantitative, facility-based, inspection techniques can provide. This paper provides a demonstration of the ability to perform detailed quantitative surveys and utilize the acquired information to assess both current and future condition of safety critical elements. The paper demonstrates improvements in inspection strategy that are consistent with the new approaches to mooring system integrity management that are currently being finalized (e.g. the new API-RP-2MIM).

Amide bond formation is one of the most executed reactions in chemistry and biology. This is largely due to the ubiquity of the amide functional group in biological molecules, natural products and pharmaceutically important drugs. We report here the development of "SuFExAmide": a new sulfur-fluoride exchange (SuFEx) click chemistry based protocol for the efficient amidation of carboxylic acids via acyl fluoride intermediates. We have developed benzene-1,3-disulfonyl fluoride as a cost effective, powerful and versatile coupling agent, which delivers challenging secondary and tertiary amides in excellent yields from sterically hindered and electron-deficient amines. The straightforward method offers significant benefits over existing protocols in terms of substrate scope, efficiency and ease of operation and is demonstrated by the synthesis of 44 amides, including GNF6702, an antiprotozoal drug candidate. In the majority of cases, the amide products are obtained in high yield without the need for excess reagents or chromatographic purification.

We produce synthetic spectra and observations for metal-free stellar populations and high mass X-ray binaries in the Renaissance Simulations at a redshift of 15. We extend our methodology from the first paper in the series by modelling the production and extinction of emission lines throughout a dusty and metal-enriched interstellar and circum-galactic media extracted from the simulation, using a Monte Carlo calculation. To capture the impact of high-energy photons, we include all frequencies from hard X-ray to far infrared with enough frequency resolution to discern line emission and absorption profiles. The most common lines in our sample in order of their rate of occurrence are Ly$\alpha$, the C IV $\lambda\lambda1548,1551$ doublet, H-$\alpha$, and the Ca II $\lambda\lambda\lambda8498,8542,8662$ triplet. The best scenario for a direct observation of a metal-free stellar population is a merger between two Population III galaxies. In mergers between metal-enriched and metal-free stellar populations, some characteristics may be inferred indirectly. Single Population III galaxies are too dim to be observed photometrically at $z = 15$. Ly$\alpha$ emission is discernible by $JWST$ as an increase in $\rm{J_{200w} - J_{277w}}$ colour off the intrinsic stellar tracks. Observations of metal-free stars will be difficult, though not impossible, with the next generation of space telescopes., Comment: 19 pages, 14 figures, 1 table, submitted to MNRAS September 11, 2017, Published November 17, 2017