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Divalent lanthanide (Ln) compounds are excellent reducing agents with unique reactivity profiles. These reagents are typically used in superstoichiometric amounts, often in combina-tion with harmful additives. Reactions catalytic in Ln(II) reagents that retain the reactivity and selectivity of the stoichiometric transformations are currently lacking due to the absence of effective and selective methods to form reactive Ln(II) species from stable precursors. Here, active Ln(II) is generated from a Ln(III) precursor through reduction by a photoexcited coumarin or carbostyril chromophore, which, in turn, is regenerated by a sacrificial reductant. The reductant can be metallic (Zn) or organic (amines) and can be used in strictly stoichiometric amounts. A broad range of reactions, including C-halogen, C=C, C=X (X = O, N), P=O, and N=N reductions, as well as C-C, C-X (X = N, S, P), and N-N couplings were readily carried out in yields and selectivities comparable to or better than those afforded by the analogous stoichiometric transformations. The reaction outcomes could be altered by changing the ligand or the lanthanide or through the addition of environmentally benign additives (e.g., water). EPR spectroscopy supported the formation of both Ln(II) and oxidized chromophore intermediates. Taken together, these results establish photochemical Ln(II) generation as a powerful strategy for rendering Ln(II)-mediated reactions catalytic.

CO2 conversion to value-added chemicals is a crucial technology towards carbon-neutral fuels.1 Photocatalysisusing sunlight is an energy-efficient alternative to electrochemical and thermal CO2 reduction.1Photocatalysts usually yield either CO or HCO2H with varying degrees of selectivity.1 Herein, a lanthanide-based photocatalytic platform producing CO, HCO2H, CH4 or CH3OH is reported. The catalyst consistsof a pendant amine for CO2 capture and a light-harvesting sensitiser that generates the reactive divalentlanthanide centre. CO2 reduction to CO or formate was possible with >99% selectivity and with thehighest turnover number reported for a photocatalyst by virtue of a distinct mechanistic pathway. Attractive(bi)carbonate CO2 feedstocks were efficiently converted to CO, and CO could be reduced to thesecondary products methane and methanol, demonstrating the wide utility of the platform.

Yb(III) complexes based on ligands with a 1,4,7-triazacyclononane (tacn) macrocyclic core were synthesised. The complexes carry a 4-methoxymethyl-substituted carbostyril chromophore that serves as a light-harvesting antenna. The ligands supply 5 nitrogen and 3 oxygen donors via 1 methylenecarboxamide and 2 picolinate donors, creating +1 charged complexes with an octadentate binding environment. The electronic properties of the picolinates are modulated by varying the substitution at the 4 position with OMe, H, Cl, or CF₃. Cyclic voltammetry indicated that the tacn-based Yb(III) complexes were easier to reduce than the analogous cyclen complexes. The first reductive event is likely picolinate-centred, followed by the formation of further reduced species. Antenna excitation yielded Yb(III) luminescence in the near-infrared (NIR) region in all cases. The antenna photophysical properties were consistent with intraligand photoinduced electron transfer from the excited carbostyril to the picolinate groups. The relative quantum yields of Yb(III) luminescence were determined. The lowest value was obtained for the complex with the most efficient antenna-to-picolinate photoinduced electron transfer. Despite intraligand electron transfer quenching of the antenna, the tacn-based Yb complexes were more emissive than their cyclen analogues, highlighting the influence of the ligand structure on the luminescence properties of NIR emissive lanthanide(III) ions.

Yb(III) complexes of macrocyclic ligands based on1,4,7,10-tetraazacyclododecane were synthesized. The ligands carried a carbostyril chromophore for Yb(III) sensitization, and carboxylate or carbamide donors for metal binding, forming complexes of 0, +1, +2, or +3 overall charge. The coordination geometry was little affected by the replacement of carboxylates with amides, as shown by paramagnetic 1H NMR spectroscopy. The Yb(III)/Yb(II) reduction potentials were dependent on the nature of the metal binding site, and the more positively charged complexes were easier to reduce. Carbostyril excitation resulted in Yb(III) luminescence in every complex. The residual carbostyril fluorescence quantum yields were smaller in complexes containing more reducible Yb(III) centers decreasing from 5.9% for uncharged complexes to 3.1−4.4% in +3 charged species, suggesting photoinduced electron transfer (PeT) from the antenna to the Yb(III). The relative Yb(III) luminescence quantum yields were identical within the experimental error, except for the +3 charged complex with fully methylated coordinating amides, which was the most intense Yb(III) emitter of the series in water. Quenching of the Yb(III) excited state by NH vibrations proved to limit Yb(III) emission. No clear improvement of the Yb(III) sensitization efficiency was shown upon faster PeT. This result can be explained by the concomitant sensitization of Yb(III) by phonon-assisted energy transfer (PAEnT) from the antenna triplet excited state, which was completely quenched in all of the Yb complexes. Depopulation of the triplet by PeT quenching of the donor singlet excited state would be compensated by the sensitizing nature of the PeT pathway, thus resulting in a constant overall sensitization efficiency across the series.

The exploration of chemical systems occurs on complex energy landscapes. Comprehensively sampling rugged energy landscapes with many local minima is a common problem for molecular dynamics simulations. These multiple local minima trap the dynamic system, preventing efficient sampling. This is a particular challenge for large biochemical systems with many degrees of freedom. Replica exchange molecular dynamics (REMD) is an approach that accelerates the exploration of the conformational space of a system, and thus can be used to enhance the sampling of complex biomolecular processes. In parallel, the empirical valence bond (EVB) approach is a powerful approach for modeling chemical reactivity in biomolecular systems. Here, we present an open-source Python-based tool that interfaces with the Q simulation package, and increases the sampling efficiency of the EVB free energy perturbation/umbrella sampling approach by means of REMD. This approach, Q-RepEx, both decreases the computational cost of the associated REMD-EVB simulations, and opens the door to more efficient studies of biochemical reactivity in systems with significant conformational fluctuations along the chemical reaction coordinate.

Recent years have seen an explosion of interest in understanding the physicochemical parameters that shape enzyme evolution, as well as substantial advances in computational enzyme design. This review discusses three areas where evolutionary information can be used as part of the design process: (i) using ancestral sequence reconstruction (ASR) to generate new starting points for enzyme design efforts; (ii) learning from how nature uses conformational dynamics in enzyme evolution to mimic this process in silico; and (iii) modular design of enzymes from smaller fragments, again mimicking the process by which nature appears to create new protein folds. Using showcase examples, we highlight the importance of incorporating evolutionary information to continue to push forward the boundaries of enzyme design studies.

The “ethylene carbonate (EC)–propylene carbonate (PC) mystery” has puzzled electrochemists for decades. Surprisingly, the minor structural difference between PC and EC, a methyl vis-à-vis a proton, prevents PC unlike EC to form a stable solid electrolyte interphase (SEI) on carbon (C), which along with the popularity of PC has impeded the development of Li-ion batteries with many years. Despite several hypotheses, the fundamental reason remains debated largely due to the lack of sufficient experimental evidence. Herein, SEI formed as a result of EC and PC reductions are analyzed by two state-of-the-art operando techniques, online electrochemical mass spectrometry and electrochemical quartz crystal microbalance with dissipation monitoring. Although both EC- and PC-based electrolytes appear to have virtually identical reaction pathways, PC is reduced much more extensively than EC and forms a much thicker SEI. However, while the SEI derived from EC remains on the electrode, PC reduction products redissolve in the electrolyte leaving the bare C electrode behind. The presented study illustrates the complex scheme of competing electro-/chemical reactions behind SEI formation and provides further scientific details needed to eventually form a consensus of the processes governing electrode/electrolyte interphases in Li-ion batteries.

The solid electrolyte interphase (SEI) is arguably one of the most critical components of the Li-ion cell. Despite decades of studies of the SEI, its intrinsic complexity and the lack of suitable characterization tools still prevent a real consensus on the governing mechanisms to be reached. Herein, operando Raman spectroscopy supported by complimentary online electrochemical mass spectrometry is employed to study the SEI formation on Au in a model electrolyte based on LiClO₄ in ethylene carbonate (EC). Both the electrolyte itself and cell contaminants, such as O₂, CO₂, and H₂O, contribute in stepwise electro-/chemical processes to the build-up of the SEI. Effects associated with electrode/electrolyte double-layer charging, electrode adsorbate polarization (stark effect), and SEI dissolution are discerned. Lithium carbonate and lithium oxide are identified as major products formed already ≈2 V versus Li⁺/Li. Although Raman spectroscopy provides deeper insights into the underlying mechanisms, complementary techniques are necessary to support spectral interpretations. Classical challenges in the field of surface science, such as contaminations, have to be systematically addressed if the puzzle of the SEI ever will be completed.

Electrolyte additives are indispensable to enhance the performance of Li-ion batteries. Lithium bis(oxalato)borate (LiBOB) has been explored for many years, as it improves both cathode and anode performance. No consensus regarding its reaction mechanisms has, however, been established. A model operando study combining attenuated total reflection infrared spectroscopy (ATR-FTIR), electrochemical quartz crystal microbalance (EQCM), and online electrochemical mass spectrometry (OEMS) is herein presented to elucidate LiBOB reduction and electrode/electrolyte interphases thus formed. Reduction of the BOB^– ion sets in at ∼1.8 V with solid lithium oxalate and soluble oxalatoborates as the main products. The reduced BOB^– ion also reacts with itself and its environment to evolve CO₂, which in turn impacts the interphase formed on the negative electrode. This study provides further insights into the reduction pathways of LiBOB and how they contribute to the interphase formation.

Introduction Trust of women and families toward health institutions has led to increased use of their services for childbirth. Whilst unpleasant experience of care during childbirth will halt this achievement and have adverse consequences. We examined the experience of women regarding the care received during childbirth in health institutions in Nepal. Method A prospective cohort study conducted in 11 hospitals in Nepal for a period of 18 months. Using a semi-structured questionnaire based on the typology of mistreatment during childbirth, information on childbirth experience was gathered from women (n = 62,926) at the time of discharge. Using those variables, principal component analysis was conducted to create a single mistreatment index. Bivariate and multivariate linear regression analyses were conducted to assess the association of the mistreatment index with sociodemographic, obstetric and newborn characteristics. Result A total of 62,926 women were consented and enrolled in the study. Of those women, 84.3% had no opportunity to discuss any concerns, 80.4% were not adequately informed before providing care, and 1.5% of them were refused for care due to inability to pay. According to multivariate regression analysis, women 35 years or older (beta, - 0.3587; p-value, 0.000) or 30-34 years old (beta,- 0.38013; p-value, 0.000) were less likely to be mistreated compared to women aged 18 years or younger. Women from a relatively disadvantaged (Dalit) ethnic group were more likely to be mistreated (beta, 0.29596; p-value, 0.000) compared to a relatively advantaged (Chettri) ethnic group. Newborns who were born preterm (beta, - 0.05988; p-value, 0.000) were less likely to be mistreated than those born at term. Conclusion The study reports high rate of some categories of mistreatment of women during childbirth. Women from disadvantaged ethnic group, young women, and term newborns are at higher risk of mistreatment. Strengthening health system and improving health workers' readiness and response will be key in experience respectful care during childbirth.

Background: Postpartum depression is associated with low socioeconomic status, adverse birthing processes, and life stress. Increasing evidence of mistreatment during childbirth, negative birth experiences, and poor quality of maternal care is of global concern.

Objective: To assess the risk of experiencing depressive symptoms among postpartum women exposed to mistreatment during institutional birthing in Nepal.

Method: We conducted a prospective cohort study from 29 March to 19 August 2022. Of 1629 women who gave birth in a hospital in Nepal, 1222 were assessed for mistreatment during childbirth and depressive symptoms using the Edinburgh Postnatal Depression Scale. We used binomial generalized linear mixed model to examine the risk ratio of postpartum depressive symptoms in women exposed to mistreatment during childbirth.

Results: The prevalence of postpartum depressive symptoms was 4.4%. Women exposed to mistreatment during childbirth were almost fifty percent more likely to have postpartum depressive symptoms (cRR 1.47; 95% CI 1.14, 1.89; p = 0.003) compared with the unexposed group. Furthermore, adolescent mothers exposed to mistreatment during childbirth had a seventy percent increased risk of depressive symptoms (aRR 1.72; 95% CI 1.23, 2.41; p = 0.002). Similarly, women who gave birth to female infants were thirty percent more likely to experience postpartum depressive symptoms (aRR 1.32; 95% CI 1.01–1.74; p = 0.039).

Conclusion: We observed an association between postpartum depressive symptoms and mistreatment during institutional births in Nepal. The implementation of appropriate respectful maternity care during childbirth and also routine screening for depressive symptoms is critical to improving perinatal mental health and well-being.

Mistreatment during institutional childbirth can be multifactorial and may have a detrimental effect on women’s health and their future utilization of care. Understanding drivers of mistreatment during childbirth is key to promoting respectful maternity care. This study aimed to understand mistreatment during childbirth from a subjective perspective and to explore the underlying factors causing it. A qualitative study of sixteen in-depth interviews was conducted with postnatal women between 5 to 16 weeks postpartum in a health facility in Nepal. Purposing sampling was used to select a heterogenous group. Data were analyzed using Nvivo12, applying Braun and Clarke’s thematic analysis approach. Four themes were identified: (1) mistreatment, (2) undignified care, (3) power and territorial display, and (4) adverse hospital culture. Mistreatment took the form of verbal and physical abuse. Undignified care during childbirth included neglect, solitary birth, poor communication and poor clinical practices such as the use of fundal pressure. Power and territoriality were experienced through restricted birth companionship, creating a fearful environment for women. Unfavorable hospital culture was characterized by participants’ descriptions of a stressful and hostile hospital environment. Institutional policy changes, such as companion of choice and improved quality of care, can ensure safe and respectful care during childbirth. 

Background

Mistreatment in facility-based births is a multi-faceted problem that requires a variety of interventions at both community and facility levels. Quality improvement interventions are usually policy driven and developed at a higher level with little involvement of the target population and users. The increasing evidence of mistreatment during childbirth in Nepal, despite the enforcement of laws to protect safe reproductive rights, raises concerns about the ongoing human rights violations and the development of a negative hospital culture with destructive institutional norms of mistreatment. We aim to co-design effective interventions with midwives working in a tertiary hospital in Nepal, putting women at the centre of care to improve respectful maternity care.

Methods:

The co-design process was based on Hasso Platnner’s human centred design thinking process using five steps: empathise, define, ideate, prototype and test. We engaged 18 nurses and midwives in a collaborative two-day workshop. Participants identified problems through brainstorming sessions, informed by their experiences and supported by qualitative data on women’s perceptions of mistreatment during childbirth. Thoughtful ideas were generated to mitigate different areas of challenges to problem solving. Based on the ideas, several prototypes were developed and priortized for testing to refine the solutions. 

Results

The workshop was well attended and the positive group dynamics created a comfortable environment for open discussion during the workshop. Participants disagreed on perceived discrimination in care, but agreed on limited birth companionship, verbal abuse, ineffective communication and poor standards of care. The most important issues identified were lack of in-service training, nurse burnout and lack of public awareness. Bottom-up communication in the system, communication skills training for health workers and community-based antenatal counselling were brought forward as possible solutions. 

Conclusion

The involvement of midwives ensures that the perspectives and insights of those directly affected by the problem are at central to its identification and resolution. This participatory and context-specific approach has the potential to improve 

Purpose – The main purpose of this paper is to contribute to a better, empirically grounded and theoretically informed understanding of DA (data analytics) use and non-use in accounting for decision making. To that end, it explores the links between accounting logic, commercial logic, and DA use in financial due diligence (FDD).

Design/methodology/approach – The paper reports the findings of a case study of DA use in the FDD practice of a Big Four accounting firm in Sweden (Pseudonym: DealCo). The primary data comprises semi-structured interviews, observations, and additional meetings. Institutional logics is mobilized as method theory.

Findings – First, accounting logic and commercial logic both drove and hindered DA use in DealCo’s FDD practice in different ways. Second, conflicting prescriptions for DA use existed mostly within commercial logic rather than between accounting logic and commercial logic. Third, accounting logic and commercial logic, as perceptual and conceptual filters, seemed to shape DealCo’s advisors’ understanding of DA and give rise to an efficiency-centric DA logic. This logic in turn, as a high-level model of how to employ DA in the context of FDD, governed DA use broadly.

Originality/value – The paper draws attention to direct and indirect links between accounting logic and commercial logic, on the one hand, and DA conceptions and use, on the other hand. It, thereby, advances prior theorization of DA use in accounting for decision making.

Purpose – New digital technologies are reshaping the business landscape and accounting work. This paper investigates how incorporating more data and new data analytics (DA) tools impacts the role and use of judgment in financial due diligence (FDD). 

Design/methodology/approach – The paper reports findings from a field study at a Big Four accounting firm in Sweden (“DealCo”). The primary data includes semi-structured interviews, observations, and other meetings. Theoretically, it draws on Dewey’s The Logic of Judgments of Practise and Logic: The Theory of Inquiry and distinguishes between theoretical (what is probably true) and practical judgment (what to do).

Findings – In DealCo’s FDD practice, using more data and new DA tools meant that the realm of possibility had expanded significantly. To manage the newfound abundance, and to use DA effectively, DealCo’s advisors invoked practical and theoretical judgments in different stages and areas of the data-driven FDD. The paper identifies four critical uses of judgment: Setting priorities and exercising restraint (practical judgment) and forming hypotheses and doing sense checks (theoretical judgment). In these capacities, practical judgment and theoretical judgment were essential in transforming raw data into actionable insights and, in effect, an indeterminate situation into a determinate one. 

Originality/value – The study foregrounds the practical dimension of knowledge production for decision making and contributes to a better understanding of the role, use, and importance of accounting professionals’ judgment in a data-driven world.

Today, the value of data analytics and data-driven insights is widely recognized in the business world. It is, therefore, surprising if not worrying that many areas of accounting have remained Excel strongholds. Connecting to the debate around “Excel-clinging” in accounting, this paper explores accounting professionals’ reasons for holding on to spreadsheet technology. Drawing on empirical insights from qualitative case studies of data analytics (non-)use in two Big Four financial due diligence practices in Sweden, and theoretical ideas from general systems theory and around situated functionality, it conceptualizes Excel as an embedded system: an IT system that combines hard functionality and soft functionality and is part of a larger system of actors, interactions and artifacts. The case studies highlight that, in relation to soft functionality (e.g., learning, sharing, safeguarding and control), Excel still offers several advantages over more powerful data analytics tools. Furthermore, they foreground sub- and especially suprasystem-related dependencies that make fully letting go of Excel difficult, if not impossible. The paper makes two timely contributions. First, it extends prior theorizing of Excel-clinging by drawing attention to (i) soft functionality-related switching costs and (ii) suprasystem-related switching difficulties. Second, it adds to the understanding of and the literature on technology resistance in accounting more broadly by (i) offering new insights into the cost-benefit side of technology resistance and the prevalence of normative pressures and (ii) illustrating how these aspects can be considered concurrently within a system approach.

Digital technologies offer an opportunity to rethink what accounting can be and to redraw the boundaries of the domain. In light of this, this paper explores how data analytics (DA) adoption is implicated in the re-formation of accounting. Methodologically, the paper follows a twofold approach. First, informed by Miller’s thinking around alterations at the margins of accounting, it develops a 2x2 matrix model that (i) distinguishes between two dimensions of DA adoption, operational efficiency and insight generation, and (ii) suggests that the transformation of both creates opportunities for accounting professionals to enter new areas of practice and redraw the boundaries of the accounting domain. Second, the model is illustrated by means of a case study of DA adoption in financial due diligence (FDD). The case draws attention to central shifts in practices (e.g., new ways of doing FDD) and cognitions (e.g., new understandings of DA). In relation to that, it furthermore shows how the (DA-induced) hygienization of traditional FDD work and the commoditization of once-new DA-based analyses result in domain extension in the form of a new offering – business due diligence – in which financial and commercial due diligence aspects are becoming increasingly blended. The paper sheds new light on the significance of DA adoption in accounting and contributes to a better understanding of how and when the adoption of digital technologies makes accounting’s boundaries more permeable. Moreover, it adds to the understanding of the cognitive-cultural aspect of DA adoption in accounting.

Using forests as burial and ceremonial places is a long-standing cultural practice in Mozambique. However, this information is still not translated into land-cover and land-use maps. Thus the locations of these forests and their descriptions remain unknown. To address this gap in the knowledge, this paper presents the results of mapping 52 local heritage sites in Inhambane, and analysing land-cover changes of two locally protected forest patches. Results from spatiotemporal change analysis show that these patches experienced fewer disturbances in comparison to other areas of vegetation.

In this paper, I explore negotiations of heritage in heritage forests from three case studies in southern Mozambique using oral history, field walking, video documentation and conversations. I argue that at local level there are processes of negotiation, authorisation, and legitimacy of heritage in forests. Such local forms of heritage negotiation and heritage discourse are authoritative and need to be recognised in both the planning of heritage conservation, and also in nature conservation. This recognition can strengthen local custodians to safeguard forest patches as locally protected areas, and opening room for heritage practitioners to be engaged by local people in the process of cultural heritage management.

This study presents the vegetation composition of two forests, Chitanga and Mafai in Inhambane Province, Mozambique, which are protected by local communities. Plant diversity, forest structure and the existence of threatened plant species are assessed. This is the first biological study carried out in locally protected forests in Inhambane Province. Plant species were recorded in twelve 20 m x 20 m plots. A total of 952 plants from 151 species, 166 genera and 30 families were identified. 50 plant species occurred in both forests; 64 were only recorded in Chitanga; and 37 were unique to Mafai. In both forests, plant communities were dominated by the Fabaceae and Malvaceae families. Statistical analysis on the number of plants, genera, stand density, stand basal area, species richness, Shannon diversity, Inverse Simpson, and Pielou evenness indices shows that on average Chitanga is similar to Mafai. Both forests host near endemic and red listed plant species (Cissampelos hirta, Dolichandrone alba, Diospyros inhacaesis, Hyperacanthus microphyllus, Paropsia braunii, Synaptolepis oliveriana, and Vepris myrei). The study is significant in demonstrating the biological richness of locally protected forests. It illustrates how locally organised protection through customary laws plays an important role in the biodiversity and conservation status of non-formally protected areas. Inventories of other heritage forests in Inhambane province and Mozambique are recommended for the future firstly, as a means of providing botanical data and, secondly, as a means of supporting the formal adoption of heritage forest as conservation areas in a manner that does not alienate the communities safeguarding the forests. (c) 2024 The Author(s). Published by Elsevier B.V. on behalf of SAAB. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

Mozambique has undocumented forest patches that are cultural landscapes and locally protected as heritage sites. Using the case of Inhambane Province, in this paper, we present the status and purposes of forest patches protected by local communities and discuss threats working against local protection. Findings point out that these heritage forests are reservoirs for biodiversity conservation and the local system of conservation is effective, but there are challenges local custodians face to safeguard heritage forests, ranging from illegal logging, misrecognition of customary protection and lack of legislation enforcement. We argue that the existence of heritage forests requires collaboration between entities dealing with forests, heritage and conservation. We suggest strategies to increase protection in the Inhambane Province and the Mozambique context. This will support local institutions in the protection of heritage forests, as biodiversity reservoirs and in keeping heritage practices and the customary protection of heritage forests alive.

Background: Oxycodone active uptake across the blood-brain barrier (BBB) is associated with the putative proton-coupled organic cation (H⁺/OC) antiporter system. Yet, the activity of this system at the blood-cerebrospinal fluid barrier (BCSFB) is not fully understood. Additionally, sex differences in systemic pharmacokinetics and pharmacodynamics of oxycodone has been reported, but whether the previous observations involve sex differences in the function of the H⁺/OC antiporter system remain unknown. The objective of this study was, therefore, to investigate the extent of oxycodone transport across the BBB and the BCSFB in female and male Sprague-Dawley rats using microdialysis.

Methods: Microdialysis probes were implanted in the blood and two of the following brain locations: striatum and lateral ventricle or cisterna magna. Oxycodone was administered as an intravenous infusion, and dialysate, blood and brain were collected. Unbound partition coefficients (K_p,_uu) were calculated to understand the extent of oxycodone transport across the blood-brain barriers. Non-compartmental analysis was conducted using Phoenix 64 WinNonlin. GraphPad Prism version 9.0.0 was used to perform t-tests, one-way and two-way analysis of variance followed by Tukey's or Sidak's multiple comparison tests. Differences were considered significant at p < 0.05.

Results: The extent of transport at the BBB measured in striatum was 4.44 ± 1.02 (K_p,_uu,_STR), in the lateral ventricle 3.41 ± 0.74 (K-p,K-uu,K-LV) and in cisterna magna 2.68 ± 1.01 (K_p,K_uu,K_CM). These K_p,_uu values indicate that the extent of oxycodone transport is significantly lower at the BCSFB compared with that at the BBB, but still confirm the presence of active uptake at both blood-brain interfaces. No significant sex differences were observed in neither the extent of oxycodone delivery to the brain, nor in the systemic pharmacokinetics of oxycodone.

Conclusions: The findings clearly show that active uptake is present at both the BCSFB and the BBB. Despite some underestimation of the extent of oxycodone delivery to the brain, CSF may be an acceptable surrogate of brain ISF for oxycodone, and potentially also other drugs actively transported into the brain via the H⁺/OC antiporter system.

Background: Oxycodone, a widely used opioid analgesic, has an unbound brain-to-plasma concentration ratio (Kp,uu) greater than unity, indicating active uptake across brain barriers associated with the putative proton-coupled organic cation (H+/OC) antiporter system. With this study, we aimed to elucidate oxycodone's CNS disposition during lipopolysaccharide (LPS)-induced systemic inflammation in Sprague-Dawley rats.

Methods: Using brain microdialysis, we dynamically and simultaneously monitored unbound oxycodone concentrations in blood, striatum, lateral ventricle, and cisterna magna following intravenous administration of oxycodone post-LPS challenge.

Results: Our results indicated a reduced, sex-independent brain net uptake of oxycodone across the blood-brain barrier (BBB) measured in the striatum. Notably, the LPS challenge has significantly altered the systemic pharmacokinetics (PK) of oxycodone, in a sex-specific manner, leading to lower clearance and higher blood concentrations in females compared to LPS-treated males and healthy rats of both sexes. Proteomic analysis using Olink Target 96 Mouse Exploratory assay confirmed the induction of systemic inflammation and neuroinflammation. The inflammation led to an increased paracellular transport, measured using 4 kDa dextran, while preserving net active uptake of oxycodone across both BBB and the blood-cerebrospinal fluid barrier (BCSFB), with Kp,uu values of 2.7 and 2.5, respectively. The extent of uptake was 1.6-fold lower (p < 0.0001) at the BBB and unchanged at the BCSFB after the LPS challenge compared to that in healthy rats. However, the mean exposure of unbound oxycodone in the brain following LPS was similar to that in healthy rats, primarily due to the LPS-induced changes in systemic exposure.

Conclusions: These findings highlight the dissimilar responses at blood-brain interfaces during LPS-induced inflammation. Advancing the knowledge of neuropharmacokinetic mechanisms, specifically those involving the H+/OC antiporter system, will enable the development of more effective therapeutic strategies during inflammation conditions.

Background: The primary objective of this study was to advance our understanding of active drug uptake at brain barriers in higher species than rodents, by examining oxycodone brain concentrations in pigs.

Methods: This was investigated by a microdialysis study in healthy and endotoxemic conditions to increase the understanding of inter-species translation of putative proton-coupled organic cation (H+/OC) antiporter-mediated central nervous system (CNS) drug delivery in health and pathology, and facilitate the extrapolation to humans for improved CNS drug treatment in patients. Additionally, we sought to evaluate the efficacy of lumbar cerebrospinal fluid (CSF) exposure readout as a proxy for brain unbound interstitial fluid (ISF) concentrations. By simultaneously monitoring unbound concentrations in blood, the frontal cortical area, the lateral ventricle (LV), and the lumbar intrathecal space in healthy and lipopolysaccharide (LPS)-induced inflammation states within the same animal, we achieved exceptional spatiotemporal resolution in mapping oxycodone transport across CNS barriers.

Results: Our findings provide novel evidence of higher unbound oxycodone concentrations in brain ISF compared to blood, yielding an unbound brain-to-plasma concentration ratio (Kp,uu,brain) of 2.5. This supports the hypothesis of the presence of the H+/OC antiporter system at the blood-brain barrier (BBB) in pigs. Despite significant physiological changes, reflected in pSOFA scores, oxycodone blood concentrations and its active net uptake across the BBB remained nearly unchanged during three hours of i.v. infusion of 4 µg/kg/h LPS from Escherichia coli (O111:B4). Mean Kp,uu,LV values indicated active uptake also at the blood-CSF barrier in healthy and endotoxemic pigs. Lumbar CSF concentrations showed minimal inter-individual variability during the experiment, with a mean Kp,uu,lumbarCSF of 1.5. LPS challenge caused a slight decrease in Kp,uu,LV , while Kp,uu,LumbarCSF remained unaffected.

Conclusions: This study enhances our understanding of oxycodone pharmacokinetics and CNS drug delivery in both healthy and inflamed conditions, providing crucial insights for translating these findings to clinical settings.

The development of neurotherapeutic drugs that utilize H⁺/OC antiporter-mediated active uptake across the blood-brain barrier (BBB) and brain cell membranes requires a thorough understanding of cellular pharmacokinetics and identification of reliable experimental readouts. This study aimed to evaluate the uptake of H⁺/OC antiporter substrates, oxycodone and pyrilamine, across and into brain endothelial and parenchymal cells in vitro at clinically relevant concentrations. We explored whether BBB cell models of different origins have the potential to serve as tools for investigation of drug active uptake. Transport studies across primary rat brain endothelial cells (BECs), uptake studies in immortalized human cerebral microvascular endothelial cells (hCMEC/D3) and brain slices were combined with non-specific drug binding estimations obtained by equilibrium dialysis for comparisons of uptake across these models. Given that drugs are often administered during disease states, we also assessed uptake of oxycodone in hCMEC/D3 cells in the presence of interleukin 6 (IL-6), to evaluate its impact on the uptake. To compare the performance of different models, and the uptake across cell types, we used the unbound intra-to-extracellular concentration ratio (K_p,uu,cell) as a key parameter. Our findings showed a preserved uptake of antiporter substrates into and across hCMEC/D3 and primary rat BECs. The rate of uptake into hCMEC/D3 cells, measured as flux, was time- and concentration-dependent, while the extent of uptake, measured as K_p,uu,cell, was independent of both. IL-6 did not affect the uptake rate of oxycodone but significantly increased its extent, independent of IL-6 concentration. The extent of uptake into parenchymal cells was also concentration-independent and similar to the one measured in endothelial cells, with K_p,uu,cell values around 1.8. Our study offers valuable insights into how antiporter substrates are distributed in the brain across multiple barriers. The findings highlight the importance of assessing both the rate and extent of drug transport, as well as emphasizing the utility of K_p,uu,cell as a key metric for comparing drug transport across different experimental models. At the present stage, hCMEC/D3 and primary rat BEC models have the potential to identify active uptake via the antiporter system and could be used for verification of uptake mechanisms.

The pyrilamine-sensitive proton-coupled organic cation (H⁺/OC) antiporter system facilitates the active net uptake of several marketed organic cationic drugs across the blood-brain barrier (BBB). This rare phenomenon has garnered interest in the H⁺/OC antiporter system as a potential target for CNS drug delivery. However, analysis of pharmacovigilance data has uncovered a significant association between substrates of the H⁺/OC antiporter and neurotoxicity, particularly drug-induced seizures (DIS) and mood- and cognitive-related adverse events (MCAEs). This preclinical study aimed to elucidate the CNS regional disposition of H⁺/OC antiporter substrates at therapeutically relevant plasma concentrations to uncover potential pharmacokinetic mechanisms underlying DIS and MCAEs. Here, we investigated the neuropharmacokinetics of pyrilamine, diphenhydramine, bupropion, tramadol, oxycodone, and memantine. Using the Combinatory Mapping Approach for Regions of Interest (CMA-ROI), we characterized the transport of unbound drugs across the BBB in specific CNS regions, as well as the blood-spinal cord barrier (BSCB) and the blood-cerebrospinal fluid barrier (BCSFB). Our findings demonstrated active net uptake across the BBB and BSCB, with unbound ROI-to-plasma concentration ratio, K_p,uu,ROI, values consistently exceeding unity in all assessed regions. Despite minor regional differences, no significant distinctions were found when comparing the whole brain to investigated regions of interest, indicating region-independent active transport. Furthermore, we observed intracellular accumulation via lysosomal trapping for all studied drugs. These results provide new insights into the CNS regional neuropharmacokinetics of these drugs, suggesting that while the brain uptake is region-independent, the active transport mechanism enables high extracellular and intracellular drug concentrations, potentially contributing to neurotoxicity. This finding emphasizes the necessity of thorough neuropharmacokinetic evaluation and neurotoxicity profiling in the development of drugs that utilize this transport pathway.

BACKGROUND BK virus (BKV) infection after kidney transplantation leads to BKV-associated nephropathy (BKVAN) in up to 10% of recipients, and is associated with an increased risk of allograft dysfunction or loss. The objective of this study was to estimate the incidence of BKVAN and to analyze whether enhanced induction is associated with an increased risk of BKVAN, possibly justifying more intensive surveillance.

MATERIAL AND METHODS This was a single-center retrospective cohort study. All patients who underwent kidney transplantation or simultaneous pancreas and kidney transplantation at the Uppsala University Hospital in Sweden between 2005 and 2014 were included, a period when BKV screening was not yet implemented. The effect of enhanced induction, defined as treatment with thymoglobulin, rituximab, and/or eculizumab, often in combination with IVIg and glycosorb, immunoadsorption and/or plasmapheresis/apheresis, was analyzed in a multivariable Cox proportional hazards model together with sex, age, cytomegalovirus mismatch (donor+/recipient-) and rejection treatment as co-predictors. Further, the effects of BKVAN on graft survival was analyzed in a univariable Cox proportional hazards model.

RESULTS In total 44 of 928 (4.7%) patients developed a biopsy-verified BKVAN 4.8 (1.5-34.2) months after transplantation. Male sex was identified as a risk factor (HR 2.02, P=0.04) but not enhanced induction. Patients with BKVAN experienced a significantly higher risk of graft loss (HR 4.37, P<0.001).

CONCLUSIONS Male sex, but not enhanced induction, was found to be a risk factor for BKVAN development after kidney transplantation. BKVAN is associated with an increased risk of graft loss.

Background: BK polyomavirus (BKPyV) infection after kidney transplantation can lead to serious complications such as BKPyV-associated nephropathy (BKPyVAN) and graft loss. The aim of this study was to investigate the incidence of BKPyVAN after implementing a BKPyV screening program, to map the distribution of BKPyV genotypes and subtypes in the Uppsala-orebro region and to identify host and viral risk factors for clinically significant events.

Methods This single-center prospective cohort study included kidney transplant patients aged >= 18 years at the Uppsala University Hospital in Sweden between 2016 and 2018. BKPyV DNA was analyzed in plasma and urine every 3 months until 18 months after transplantation. Also genotype and subtype were determined. A logistic regression model was used to analyze selected risk factors including recipient sex and age, AB0 incompatibility and rejection treatment prior to BKPyVAN or high-level BKPyV DNAemia.

Results: In total, 205 patients were included. Of these, 151 (73.7%) followed the screening protocol with 6 plasma samples, while184 (89.8%) were sampled at least 5 times. Ten (4.9%) patients developed biopsy confirmed BKPyVAN and 33 (16.1%) patients met criteria for high-level BKPyV DNAemia. Male sex (OR 2.85, p = 0.025) and age (OR 1.03 per year, p = 0.020) were identified as significant risk factors for developing BKPyVAN or high-level BKPyV DNAemia. BKPyVAN was associated with increased viral load at 3 months post transplantation (82,000 vs. < 400 copies/mL; p = 0.0029) and with transient, high-level DNAemia (n = 7 (27%); p < 0.0001). The most common genotypes were subtype Ib2 (n = 50 (65.8%)) and IVc2 (n = 20 (26.3%)).

Conclusions: Male sex and increasing age are related to an increased risk of BKPyVAN or high-level BKPyV DNAemia. BKPyVAN is associated with transient, high-level DNAemia but no differences related to viral genotype were detected.

Objective: The aim of this study was to examine the psychometric properties and diagnostic accuracy of the Swedish version of the Wender Utah Rating Scale (WURS) in psychiatric patients with similar symptoms but diagnosed with either attention deficit hyperactivity disorder (ADHD), bipolar disorder (BP), and/or borderline personality disorder (BPD).

Methods: A total of 121 patients from an outpatient psychiatric clinic for young adults (18–25 years) were diagnosed using the Structured Clinical Interview for DSM Axis I and Axis II (SCID-I and SCID-II), and ADHD was diagnosed using the Schedule for Affective Disorders and Schizophrenia for School-Age Children (K-SADS). WURS were filled in by the participants and compared with a diagnosis of ADHD according to K-SADS.

Results: Internal consistency of the WURS was 0.94. The principal component analysis resulted in a three-factor solution that accounted for 61.3% of the variance. The ADHD group had significantly higher mean scores compared to all other groups. The diagnostic accuracy of the WURS was examined using AUC and ROC analysis, and the optimal cut-off score was 39, with a sensitivity of 0.88 and specificity of 0.70, with AUC 0.87, 95% CI 0.80–0.94, PPV 0.59, and NPV 0.92.

Conclusion: The psychometric properties of the Swedish WURS were good. For assessment of adult ADHD, in patients with symptoms of emotional instability, impulsivity, and attention problems but of different origins, a somewhat higher cut-off score than the originally suggested was preferable for identification of ADHD.

BackgroundThe aim of this study was to investigate if temperament and experience of childhood trauma differed between young psychiatric patients with borderline personality disorder (BPD), bipolar disorder (BD) and attention-deficit/hyperactivity disorder (ADHD).MethodsDiagnoses were based on the Structured Clinical Interview for DSM Axis I and Axis II. Temperament was assessed by the Temperament and Character Inventory (TCI) and childhood trauma by the Early Trauma Inventory-Self Report-Short Form (ETI-SR-SF). Temperament and childhood trauma were compared between the BPD group (n = 19) and the non-BPD group (BD/ADHD) (n = 95). Interactions between trauma and temperament were evaluated using a logistic regression model with a BPD diagnosis as outcome variable.ResultsParticipants in the BPD group showed higher novelty seeking (NS) and harm avoidance (HA). Traumatic experiences in childhood were common but the BPD group differed very little from the others in this regard. The interaction between temperament and trauma had low explanatory power for a BPD diagnosis in this sample.ConclusionTemperament might be useful to distinguish BPD when symptoms of impulsivity and affective instability are evaluated in psychiatric patients. The results from the interaction analysis support the multifactorial background to BPD.

Background

Insecure adult attachment has been associated with psychiatric disorders characterized by emotional dysregulation, such as borderline personality disorder (BPD), bipolar disorder (BD) and attention deficit/hyperactivity disorder (ADHD). However, little is known about the differences in attachment patterns between these diagnostic groups. The aim of this study was to identify clusters of adult attachment style in a cross-diagnostic group of patients with BDP and/or BD and/or ADHD and explore the characteristics of these clusters based on temperament profile, childhood trauma and psychiatric diagnoses.

Methods

K-means cluster analysis was used to identify subgroups, based on the Attachment Style Questionnaire Short Form dimensions, in a clinical cohort of 150 young adults (113 women and 37 men, mean age ± SD = 23.3 ± 2.1) diagnosed with BPD, and/or BD, and/or ADHD.

Results

Three distinct clusters were identified: a secure, an insecure/avoidant-anxious and an insecure/avoidant cluster. These three clusters differed in temperament profile and related psychiatric diagnoses.

Conclusions

The three clusters of attachment in individuals with BPD, BD and/or ADHD could support differentiation between the disorders as well provide information usable for planning of treatment.

Background: Differences in adverse cardiac remodeling between patients who have bicuspid (BAV) and tricuspid aortic valve (TAV) with severe isolated aortic stenosis (AS) and its prognostic impact after surgical aortic valve replacement remains unclear. We sought to investigate differences in preoperative diastolic and systolic function in patients with BAV and TAV who have severe isolated AS and the incidence of postoperative heart failure hospitalization and mortality. Methods: Two hundred seventy-one patients with BAV (n=152) or TAV (n=119) and severe isolated AS without coronary artery disease or other valvular heart disease, scheduled for surgical aortic valve replacement, were prospectively included. Comprehensive preoperative echocardiographic assessment of left ventricular (LV) diastolic and systolic function was performed. The heart failure events were registered during a mean prospective follow-up of 1260 days versus 1441 days for patients with BAV or TAV, respectively. Results: Patients with BAV had a more pronounced LV hypertrophy with significantly higher indexed LV mass ([LVMi] 134 g/m(2) versus 104 g/m(2), P<0.001), higher prevalence of LV diastolic dysfunction (72% versus 44%, P<0.001), reduced LV ejection fraction (55% versus 60%, P<0.001), significantly impaired global longitudinal strain (P<0.001), significantly higher NT-proBNP (N-terminal pro-brain natriuretic peptide) levels (P=0.007), and a higher prevalence of preoperative levosimendan treatment (P<0.001) than patients with TAV. LVMi was associated with diastolic dysfunction in both patients with BAV and TAV. There was a significant interaction between aortic valve morphology and LVMi on LV ejection fraction, which indicated a pronounced association between LVMi and LV ejection fraction for patients with BAV and lack of association between LVMi and LV ejection fraction for patients with TAV. Postoperatively, the patients with BAV required significantly more inotropic support (P<0.001). The patients with BAV had a higher cumulative incidence of postoperative heart failure admissions compared with patients with TAV (28.2% versus 10.6% at 6 years after aortic valve replacement, log-rank P=0.004). Survival was not different between patients with BAV and TAV (log-rank P=0.165). Conclusions: Although they were significantly younger, patients with BAV who had isolated severe AS had worse preoperative LV function and an increased risk of postoperative heart failure hospitalization compared with patients who had TAV. Our findings suggest that patients who have BAV with AS might benefit from closer surveillance and possibly earlier intervention.

AIMS: To investigate (i) the association between pre-operative left atrial (LA) reservoir strain and post-operative atrial fibrillation (AF) and (ii) the incidence of post-operative ischaemic stroke events separately in bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV) patients after surgical aortic valve replacement for isolated severe aortic stenosis (AS).

METHODS AND RESULTS: We prospectively enrolled 227 patients (n = 133 BAV and n = 94 TAV) with isolated severe AS scheduled for aortic valve replacement. A comprehensive intra- and inter-observer validated pre-operative echocardiogram with an analysis of LA reservoir strain was performed. Post-operative AF was defined as a sustained (>30 s) episode of AF or atrial flutter. The timing of neurological events was defined in accordance with the Valve Academic Research Consortium-3 criteria for stroke. Post-operative AF occurred in 114 of 227 patients (50.2%), with no difference between BAV and TAV patients (48.1 vs. 53.1%, P = 0.452). Persisting post-operative AF at discharge was more frequent in BAV patients (29.7 vs. 8.0%, P = 0.005). Pre-operative LA reservoir strain was independently associated with post-operative AF (odds ratio = 1.064, 95% confidence interval 1.032-1.095, P < 0.001), with a significant interaction between LA reservoir strain and aortic valve morphology (P_interaction = 0.002). The cumulative transient ischemic attack (TIA)/stroke incidence during follow-up was significantly higher in BAV patients (19.1 vs. 5.8% at 5 years).

CONCLUSION: Pre-operative LA function was associated with post-operative AF after aortic valve replacement in BAV AS patients, while post-operative AF in TAV AS patients likely depends on transient post-operative alterations and traditional cardiovascular risk factors. TIA/stroke during follow-up was more common in BAV AS patients.

BACKGROUND: This study aimed to compare the incidence and prognostic implications of new-onset conduction disturbances after surgical aortic valve replacement (SAVR) in patients with bicuspid aortic valve (BAV) aortic stenosis (AS) versus patients with tricuspid aortic valve (TAV) AS (ie, BAV-AS and TAV-AS, respectively). Additionally, the study included stratification of BAV patients according to subtype.

METHODS: In this cohort study, the incidence of postoperative third-degree atrioventricular (AV) block with subsequent permanent pacemaker requirement and new-onset left bundle-branch block (LBBB) was investigated in 1147 consecutive patients without preoperative conduction disorder who underwent isolated SAVR (with or without ascending aortic surgery) between January 1, 2005, and December 31, 2022. The groups were stratified by aortic valve morphology (BAV, n=589; TAV, n=558). The outcomes of interests were new-onset third-degree AV block or new-onset LBBB during the index hospitalization. The impact of new-onset postoperative conduction disturbances on survival was investigated in BAV-AS and TAV-AS patients during a median follow-up of 8.2 years. BAV morphology was further categorized according to the Sievers and Schmidtke classification system (possible in 307 BAV-AS patients) to explore association between BAV subtypes and new-onset conduction disturbances after SAVR.

RESULTS: The overall incidence of third-degree AV block and new-onset LBBB after SAVR was 4.5% and 7.8%, respectively. BAV-AS patients had a higher incidence of both new-onset third-degree AV block (6.5% versus 2.5%; P=0.001) and new-onset LBBB (9.7% versus 5.7%; P=0.013) compared with TAV-AS patients. New-onset LBBB was associated with an increased all-cause mortality during follow-up (adjusted hazard ratio, 1.60 [95% CI, 1.12-2.30]; P=0.011), whereas new-onset third-degree AV block was not associated with worse prognosis. Subgroup analysis of the BAV cohort revealed that BAV-AS patients with fusion of the right- and non-coronary cusps had the highest risk of new-onset third-degree AV block (adjusted odds ratio [aOR], 8.33 [95% CI, 3.31-20.97]; P<0.001, with TAV as reference group) and new-onset LBBB (aOR, 4.03 [95% CI, 1.84-8.82]; P<0.001, with TAV as reference group), whereas no significant association was observed for the other BAV subtypes.

CONCLUSIONS: New-onset LBBB after SAVR is associated with increased all-cause mortality during follow-up, and is more frequent complication in BAV AS patients compared with TAV-AS patients. BAV-AS patients with fusion of the right- and non-coronary cusps have an increased risk for conduction disturbances after SAVR. This should be taken into consideration when managing these patients.

Aortic valve degeneration (AVD) is a life-threatening condition that has no medical treatment and lacks individual therapies. Although extensively studied with standard approaches, aetiologies behind AVD are unclear. We compared abundances of extracellular matrix (ECM) proteins from excised valve tissues of 88 patients with isolated AVD of normal tricuspid (TAV) and congenital bicuspid aortic valves (BAV), quantified more than 1400 proteins per ECM sample by mass spectrometry, and demonstrated that local ECM preserves molecular cues of the pathophysiological processes. The BAV ECM showed enrichment with fibrosis markers, namely Tenascin C, Osteoprotegerin, and Thrombospondin-2. The abnormal physical stress on BAV may cause a mechanical injury leading to a continuous Tenascin C-driven presence of myofibroblasts and persistent fibrosis. The TAV ECM exhibited enrichment with Annexin A3 (p = 1.1 x 10(-16) and the fold change 6.5) and a significant deficit in proteins involved in high-density lipid metabolism. These results were validated by orthogonal methods. The difference in the ECM landscape suggests distinct aetiologies between AVD of BAV and TAV; warrants different treatments of the patients with BAV and TAV; elucidates the molecular basis of AVD; and implies possible new therapeutic approaches. Our publicly available database (human_avd_ecm.surgsci. uu.se) is a rich source for medical doctors and researchers who are interested in AVD or heart ECM in general. Systematic proteomic analysis of local ECM using the methods described here may facilitate future studies of various tissues and organs in development and disease.

The effect of Eu doping in the Tsai quasicrystal (QC) GdCd_7.88 and its periodic 1/1 approximant crystal (AC) GdCd₆ are investigated. This represents the first synthesis of Eu-containing stable QC samples, where three samples with the final composition Gd_1-xEu_xCd_7.6±α at Eu doping concentrations x = 0.06, 0.13, and 0.19 are obtained (α ∼ 0.2). They are compared to two 1/1 ACs with compositions Gd_1-xEu_xCd₆ (x = 0.12, 0.16). In addition, a new type of 1/1 AC, differing only by the inclusion of extra Cd sites unique to the Eu₄Cd₂₅ 1/1 AC, has been discovered and synthesized for the concentrations Gd_1-xEu_xCd_6+δ (x = 0.25, 0.33, 0.45, 0.69, 0.73, and 0 < δ ≤ 0.085). Due to the preferred cube morphology of its single grains, we refer to them as c-type 1/1 ACs and to the conventional standard ones as s-type. In both QCs and s-type ACs, the Eu content appears to saturate at a concentration of similar to 20%. On the other hand, any Gd| Eu ratio is allowed in the c-type ACs, varying continuously between GdCd₆ and Eu₄Cd₂₅. We describe and contrast the changes in composition, atomic structure, specific heat, and magnetic properties induced by Eu doping in the quasicrystalline phase and the s-type and c-type 1/1 ACs. By comparing our results to the literature data, we propose that the occupancy of the extra Cd sites can be used to predict the stability of Tsai-type quasicrystalline phases.

We report the effect of magnetic dilution on the physical properties of (Gd_1−xY_x)Cd₆ approximant crystals (ACs), close siblings of their corresponding quasicrystal (QC). Compared to the pure system GdCd₆, we observe remarkable changes in the thermodynamic and magnetic bulk properties near and below the static-ordering temperatures from diluting the magnetic Gd atoms with nonmagnetic Y atoms by only 1–3% (x=0.01–0.03). On the other hand, the corresponding QC system exhibits a monotonic change in its spin-glass behavior upon the magnetic dilution. We discuss the origin of the magnetic-dilution behavior in the present AC system in terms of possible magnetic frustration and short-range magnetic correlation that can be linked to its peculiar structure.

Gd14AuxAl86-x Tsai-type 1/1 quasicrystal approximants (ACs) exhibit three magnetic orders that can be finely tuned by the valence electron concentration (e/a ratio). This parameter has been considered to be crucial for controlling the long-range magnetic order in quasicrystals (QCs) and ACs. However, the nonlinear trend of the lattice parameter as a function of Au concentration suggests that Gd14AuxAl86-x 1/1 ACs are not following a conventional solid solution behavior. We investigated Gd14AuxAl86-x samples with x values of 52, 53, 56, 61, 66, and 73 by single-crystal X-ray diffraction. Our analysis reveals that increasing Au/Al ordering with increasing x leads to distortions in the icosahedral shell built of the Gd atoms and that trends observed in the interatomic Gd-Gd distances closely correlate with the magnetic property changes across different x values. Our results demonstrate that the e/a ratio alone may be an oversimplified concept for investigating the long-range magnetic order in 1/1 ACs and QCs and that the mixing behavior of the nonmagnetic elements Au and Al plays a significant role in influencing the magnetic behavior of the Gd1(4)Au(x)Al(86-x) 1/1 AC system. These findings will contribute to improved understanding towards tailoring magnetic properties in emerging materials.

A single-crystal neutron diffraction study was conducted on a Ho13.6Au61.1Al25.3 Tsai-type quasicrystal approximant synthesised by the self-flux method. The magnetisation measurements reveal a ferrimagnetic behaviour with a transition below 6 K. In agreement with the magnetometry data, a non-coplanar whirling spin order in the icosahedral clusters around the crystallographic [1 1 1] direction with a ferrimagnetic arrangement was observed from single-crystal neutron diffraction measurements below 5.5 K. The magnetic structure of Ho13.6Au61.1Al25.3 is compared to the previously published magnetic structures of related RE-Au-SM (RE = Tb and Ho; SM = Al, Si and Ga) systems.