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High-speed imaging of non-photochemical laser-induced nucleation in aqueous cesium chloride
Get PDFA study of non-photochemical laser-induced nucleation (NPLIN) of cesium chloride in aqueous supersaturated solutions is presented. Single, unfocused laser pulses (duration 5 ns, peak power density 180 MW cm−2) of 532 nm laser light were used to induce crystal nucleation, and the resulting dynamics were studied using imaging at frame rates up to 250 000 frames per second (4 μs per frame). Thermocavitation events were observed in a surrounding index-matching fluid, both in the bulk and at the exterior walls of vials. These events were attributed to heating of solid particles by the laser light. The cavities were observed to oscillate in size, with the initial expansion and collapse lasting approximately 50 μs. In some cases, a small persistent gas bubble (lifetime >1 s) was observed after the cavitation event. Within the supersaturated salt solutions, new objects were observed in the image frame of the laser pulse, which faded within 20 μs. These objects were attributed to cavitation: this is the first time that thermocavitation has been observed during NPLIN using an unfocused laser pulse. Crystals were observed to grow at the locations of cavitation events, and the growth was faster at higher supersaturations. Crystals were sometimes observed to form in the location of particles that were observed before the laser pulse, which we consider to be impurity particles that trigger NPLIN. The results provide direct evidence for the nanoparticle-heating mechanism for NPLIN, which begins with thermocavitation. The possible role of stable gas bubbles in NPLIN of crystals is discussed.</p
Denudation rates and Holocene sediment storage dynamics inferred from in situ 14C concentrations in the Feshie basin, Scotland
Get PDFScotland's Highlands are tectonically quiescent but have experienced high rates of isostatic uplift in response to deglaciation. To understand the effects of both deglaciation and regional uplift on landscape evolution, we measured the concentration of cosmogenic in situ 14C in river sands collected in Glen Feshie (Cairngorms). Like other terrestrial cosmogenic radionuclides, in situ 14C can be used to calculate basin-wide denudation rates over millennial timescales. 14C has a short half-life relative to other in situ cosmogenic radionuclides, giving it an advantage in post-glacial landscapes: Very little 14C will be inherited from exposure before glaciation of the landscape, meaning that concentrations will reflect sediment production and transport dominantly in the Holocene. When we calculate denudation rates based on the common assumption of basin-wide homogeneity of erosion, we find no correlation between topographic metrics such as the normalised channel steepness index and inferred denudation rates, which range between 0.175 and 1.356 mm/year. Based on field and remote sensing observations, we suggest that 14C becomes diluted downstream due to sediment supply from paraglacial terrace material, and develop a mixing model to test this hypothesis. We identify the terraces that are likely to contribute sediment to the channels through flood modelling, geomorphic mapping and remote sensing observations. Our mixing model indicates that the observed distribution of 14C concentrations can be explained if terrace escarpments have basin-averaged migration distances of 8 to 30 cm during large flood events. This interpretation is consistent with remotely sensed images of channel activity and terrace bank retreat within the catchment. Our results show that paraglacial sediment stores contribute to sediment fluxes in the late Holocene and highlight the on-going glacial legacy on landscape evolution
What is the patient re-identification risk from using de-identified clinical free text data for health research?
Get PDFImportant clinical information is recorded in free text in patients’ records, notes, letters and reports in healthcare settings. This information is currently under-used for health research and innovation. Free text requires more processing for analysis than structured data, but processing natural language at scale has recently advanced, using large language models. However, data controllers are often concerned about patient privacy risks if clinical text is allowed to be used in research. Text can be de-identified, yet it is challenging to quantify the residual risk of patient re-identification. This paper presents a comprehensive review and discussion of elements for consideration when evaluating the risk of patient re-identification from free text. We consider (1) the reasons researchers want access to free text; (2) the accuracy of automated de-identification processes, identifying best practice; (3) methods previously used for re-identifying health data and their success; (4) additional protections put in place around health data, particularly focussing on the UK where “Five Safes” secure data environments are used; (5) risks of harm to patients from potential re-identification and (6) public views on free text being used for research. We present a model to conceptualise and evaluate risk of re-identification, accompanied by case studies of successful governance of free text for research in the UK. When de-identified and stored in secure data environments, the risk of patient re-identification from clinical free text is very low. More health research should be enabled by routinely storing and giving access to de-identified clinical text data
The effects of renewable electricity supply when renewables dominate:Evidence from Uruguay
Get PDFThe benefits of expanding wind and solar electricity generation depend on their effect on the electricity production mix. Using hourly production data, I study the electricity transition to renewables in Uruguay, a country that currently has 94% of its grid green. First, I quantify how an increase in wind and solar production substitutes hydro, biomass, and fossil fuel electricity production. Second, I analyze how this transition reduces CO2 emissions in the context of large hydropower production. Third, I analyze how this affects spot prices. I find that the increase in wind and solar production has the following effects: (i) a displacement of hydro and fossil fuel production, especially in winter, with no effect on biomass; (ii) a reduction in CO2 emissions; (iii) a decrease in spot prices caused by the shutting off of the most (marginally) costly plants; and (iv) a spillover effect to the region due to an increase in exports to Argentina and Brazil. I find, however, that the increase in wind and solar production is insufficient to eradicate fossil fuels. These results show the effect of increasing renewables, how they interact with each other - particularly in hydro-dependent countries -, and their effect on emissions and spot prices
Visible Light Driven Heterogeneous Cu‐Ti‐gCN Photoredox Catalyzed Synthesis of Diverse N‐Heterocyclic Derivatives via ODH and CDC Reactions
Get PDFVisible light-mediated oxidative dehydrogenation (ODH) of partially saturated heterocycles and different cross dehydrogenative coupling (CDC) reactions using heterogeneous photoredox catalyst is described in this paper. A systematic study led to an ODH of partially saturated heterocycles and different CDC reactions in very good-to-excellent yields. Oxygen is used as a clean oxidant in both ODH and CDC reactions. The methodology is atom economic and exhibits excellent tolerance toward various functional groups, and broad substrate scopes. This methodology was found to be suitable for scale-up and reusability.</p
Solvent Selection, Sustainability Analysis & Technoeconomic Evaluation and Optimisation of Batch Cooling Crystallisation Processes for Flurbiprofen Production
Get PDFSelecting suitable solvents for the crystallisation of pharmaceuticals can be a challenging task, given the vast number of solvents that we can choose from. To simplify this problem, we can use principles from solid-liquid equilibria (SLE) alongside established thermodynamic models to identify promising candidates prior to conducting experiments. This study addresses the batch cooling crystallisation of flurbiprofen – a non-steroidal anti-inflammatory drug (NSAID) used to treat arthritis – using a simple model framework implemented within MATLAB. The Apelblat equation is employed to describe the thermophysical behaviour of flurbiprofen over a wide temperature range (283.15–323.15 K) in twelve (12) solvents: three alkanes (n-hexane, n-heptane, n-octane); two (isopropyl, methyl-tert-butyl) ethers; five alcohols (n-propanol, isopropanol, n-butanol, isobutanol, isopentanol); an ester (isopropyl acetate); and a nitrile (acetonitrile). Moreover, we have used green metrics (E-factor, Scope 1 and 2 carbon emissions) with established process economics models to determine the most promising solvent (n-propanol) for an environmentally friendly and economical manufacturing process.</p
Commentary:Time to abandon the 'clinical high risk state for psychosis' (CHR-P) concept in adolescence? Commentary on Frearson et al. 'Efficacy of preventative interventions for children and adolescents at clinical high risk of psychosis: A systematic review and meta-analysis of intervention studies'
Get PDFThere has been much academic interest in 'the clinical high risk for psychosis' (CHR-P) concept. Indeed, as two child and adolescent psychiatrists interested in psychosis prediction and prevention, we enthusiastically embraced the paradigm in our clinical and academic work. However, despite more than two decades of research, there is no definition of CHR-P in adolescence that has proven to be able to usefully predict transition to psychosis. Indeed, research suggests that much, if not all, of the risk associated with CHR diagnoses in adolescents is captured by being help-seeking for mental health problems, rather than being associated with a CHR diagnosis itself. In this commentary, we critique the systematic review by Frearson et al. (2025). In particular, we challenge the conceptualisation around the CHR-P concept, as applied to under 18 s, and the assumptions underpinning it. We also highlight issues with the terminology used when describing the experiences of young people categorised as being at CHR-P. Rather, we make the case for understanding and supporting help-seeking young people with distressing perceptual and ideational disturbance employing a needs-based, person-centred approach.</p
The Estonian Biobank’s journey from biobanking to personalized medicine
Get PDFLarge biobanks have set a new standard for research and innovation in human genomics and implementation of personalized medicine. The Estonian Biobank was founded a quarter of a century ago, and its biological specimens, clinical, health, omics, and lifestyle data have been included in over 800 publications to date. What makes the biobank unique internationally is its translational focus, with active efforts to conduct clinical studies based on genetic findings, and to explore the effects of return of results on participants. In this review, we provide an overview of the Estonian Biobank, highlight its strengths for studying the effects of genetic variation and quantitative phenotypes on health-related traits, development of methods and frameworks for bringing genomics into the clinic, and its role as a driving force for implementing personalized medicine on a national level and beyond
Familial similarity and heritability of personality traits and life satisfaction are higher than shown in typical single-method studies
Get PDFPersonality trait similarity among ordinary relatives is surprisingly low, with parent–offspring and sibling–sibling correlations usually r ≤ .15. We explain why these correlations are biased in typical single-method studies and argue that this problem can only be addressed with multimethod designs. We also explain why ordinary relative comparisons can provide a more generalizable way of estimating (additive, narrow-sense) heritability than the better known twin comparisons. In a sample of parent–offspring (Npairs = 522), sibling–sibling (Npairs = 388), and second-degree relative pairs (Npairs = 476), who rated their Big Five personality traits and life satisfaction and were each rated by an independent informant (Nparticipants = 2,258 + informants), we found that parent–offspring and sibling correlations were about one third higher than typically shown (r ≈ .20). Based on the ordinary relative comparisons, the heritability of personality traits and life satisfaction was about 40%, compared with about 26% typical to self-report studies. Life satisfaction was as heritable as personality traits, sharing about 80% of its genetic variance with neuroticism, extraversion, and conscientiousness. About half of life satisfaction’s phenotypic correlations with neuroticism and extraversion and its entire correlation with conscientiousness were explained by shared genetic factors. Using data from a larger sample of relatives with only self-reports (Nparticipants = 32,004; Npairs = 24,118), we provide further evidence that growing up together does not make people more similar. The results were consistent for both aggregate traits and individual items. Only multimethod designs can accurately reveal traits’ similarity among relatives and their genetic and environmental transmission
Rampant Reticulation in a Rapid Radiation of Tropical Trees - Insights from Inga (Fabaceae)
Get PDFEvolutionary radiations underlie much of the species diversity of life on Earth, particularly within the world’s most species-rich tree flora – that of the Amazon rainforest. Hybridisation occurs in many radiations, with effects ranging from homogenisation of divergent species to the generation of genetic and phenotypic novelty that fuels speciation. However, the influence of hybridisation on Amazonian tree radiations has been little studied. We address this using the ubiquitous, species-rich, neotropical tree genus Inga, which typifies rapid radiations of rainforest trees. We assess patterns of gene tree incongruence to ascertain whether hybridisation was associated with rapid radiation in Inga. Given the importance of insect herbivory in structuring rainforest tree communities (and hence the potential for hybridisation to promote adaptation through admixture of defence traits), we also test whether introgression of loci underlying chemical defences against herbivory occurred during the radiation of Inga. Our phylogenomic analyses of 189/288 Inga species using >1300 target capture loci showed widespread introgression in Inga. Specifically, we found widespread phylogenetic incongruence explained by introgression, with phylogenetic networks recovering multiple introgression events across Inga and up to 20% of shared, likely introgressed, genetic variation between some species. In addition, most defence chemistry loci showed evidence of positive selection and marginally higher levels of introgression. Overall, our results suggest that introgression has occurred widely over the course of Inga’s history, possibly in a syngameon scenario, likely facilitated by extensive dispersal across Amazonia. Furthermore, in some cases introgression of chemical defence loci may influence adaptation in Inga
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