32151 research outputs found
Sort by
An operational distinction between quantum entanglement and classical non-separability
Get PDFFunding: Agencia Española de Inbestigación, Alexander von Humboldt-Stiftung, Scottish Universities Physics Alliance.Quantum entanglement describes superposition states in multi-dimensional systems—at least two partite—which cannot be factorized and are thus non-separable. Non-separable states also exist in classical theories involving vector spaces. In both cases, it is possible to violate a Bell-like inequality. This has led to controversial discussions, which we resolve by identifying an operational distinction between the classical and quantum cases.Peer reviewe
Functionalisation of the MOF-808 framework as a versatile catalyst for fine chemicals synthesis
Get PDFMOFs, particularly MOF-808 are potentially greener and more sustainable catalysts for synthetically useful reactions due to their chemical versatility. MOF-808 can be tuned into a bifunctional catalyst due to the ease with which its formate ligands can be exchanged with functionalised ones. With this in view, two MOF-808 materials were synthesised, in Zr and Hf forms: MOF-808(Zr/Hf) and MOF-808(Zr/Hf)-XL. MOF-808(Hf/Zr) has the ideal framework, while MOF-808(Zr/Hf)-XL is synthesised with a stoichiometric excess of benzenetricarboxylate linker, BTC. The MOFs were post-synthetically modified with three sulfonated ligands, 3-{(4-methoxyphenyl)thio}propane-1-sulfonate, 3-(di-tert-butylphosphino)propane-1-sulfonate and 2-(4-pyridyl)ethanesulfonate. After installing these ligands, they were metalated with Pd (II) or Ir(III) complexes.
Pd-MOF catalysts were successfully used to isomerise terminal alkenes. They were also tested in Suzuki-Miyaura coupling reactions where aryl bromides were coupled with different boronic acids or esters. Coupling of aryl chlorides with boronic acids using thioether-based MPTPS-MOF-808-Pd catalysts gave no conversion of the desired products. However, phosphine-based DTBPPS-MOF-808 catalysts gave products highlighting the need of a bulky, more electron donating ligand for this reaction. Testing Hf and Zr MOFs in the coupling of more challenging substrates resulted in low yields of the products when DTBPPS-MOF-808(Zr)-Pd was used. However, using DTBPPS-MOF-808(Hf)-Pd improved yields significantly.
MOF-808(Hf) was tested in borrowing hydrogen amine synthesis of N-alkylating anilines with secondary alcohols. In coupling 4-chloroaniline with a challenging alcohol, 1-(4-fluorophenyl)ethanol using both MOF-808(Hf) and MOF-808(Hf)-XL, MOF-808(Hf)-XL gives better selectivity and PESA was selected for the scope of the reaction, such that PESA-MOF-808(Hf)-XL-Ir was the catalyst of choice for alcohols with electron neutral to electron withdrawing groups. EXAFS indicates that the Ir remains in dispersed, rather than nanoparticle form. Reaction of electron-rich alcohols with anilines gave C–C coupled products as the main or only product when catalysed by PESA-MOF-808(Hf)-XL-Ir. Remarkably, MOF-808(Hf) and especially PESA-MOF-808(Hf)-Ir gave good yields of N-alkylated products via borrowing hydrogen."This work was supported by the Engineering and Physical Sciences Research Council (EPSRC) and GSK for an iCase studentship [grant number EP/T51746X/1]."--Fundin
Against victory : decolonising justice after war
Get PDFFunding: This research was funded by Colombia Científica, Pasaporte a la Ciencia 2018, Foco Sociedad ‘Construcción de una paz estable y duradera’.This article makes a case for a theoretical reorientation of post-war justice that moves away from the colonial imaginaries of military victory in just war theory. This intellectual tradition typically theorises a just peace from the perspective of ‘just victors’ interested in the definition of their rights and responsibilities in the aftermaths of a military confrontation against ‘unjust aggressors’ or ‘inherently aggressive and murderous regimes’. I argue that this approach finds its historical roots in the colonial imaginaries of the ethics of conquerors, which have been reformulated in the modern languages of rights and responsibilities. Coloniality explains such historical continuities and discontinuities in this intellectual tradition. The origins of this conception are not only of theoretical interest but also of practical relevance due to the entrenchment of colonial relations of punishment, protection and education rather than political relations of dialogue, compromise and mediation as the foundations of post-war justice.Peer reviewe
Contrasting two versions of the 4-cup 2-item disjunctive syllogism task in great apes
Get PDFFunding: This work was supported by the European Research Council under the European Union’s Seventh Framework Program (FP7/2007-2013)/ERC grant agreement no. 609819, SOMICS and Templeton World Charity Foundation, grant ID: TWCF0314. Twycross Zoo, East Midlands Zoological Society (Registered charity number: 501841) is supported by funding generated by its visitors, members and supporters. Edinburgh Zoo’s Budongo Research Unit is core supported by the Royal Zoological Society of Scotland (Registered charity number: SC004064) through funding generated by its visitors, members and supporters, and by the University of St Andrews (Registered charity number: SC013532) who core supports the maintenance and management costs of the research facility.Chimpanzees excel at inference tasks which require that they search for a single food item from partial information. Yet, when presented with 2-item tasks which test the same inference operation, chimpanzees show a consistent breakdown in performance. Here we test a diverse zoo-housed cohort (n = 24) comprising all 4 great ape species under the classic 4-cup 2-item task, previously administered to children and chimpanzees, and a modified task administered to baboons. The aim of this study is to delineate whether the divergent results reported from the literature are taxonomic differences or artefacts of their methodologies, while extending the literature to cover the remaining great ape species. We find that apes adaptively adjust their choice behaviour in both variants of the task, but that they perform better in trials where the information provided rules out a location rather than removes one of the food items. In a second experiment involving those subjects who passed the first, along with a group of naïve subjects, we test whether subjects were able to apply the logical operation selectively by including control trials where the correct response is reversed. Performance in standard trials breaks down with the addition of control trials, meaning that if apes did solve the first experiment logically, they are not capable of applying that logic flexibly. Considering this finding, we conclude that a 4-cup 2-item task may not be a suitable test of logical reasoning in great apes.Peer reviewe
High prevalence and non-suppression of HIV/AIDS in the East and Central African region heightens risk of severe outcomes for Clade I monkeypox virus infection, and may be a driver for subsequent adaptation
Get PDFFunding: The authors BK, BB, HKB, MW, WM, PK, JW are supported by EDCTP3-GH Horizon Europe grant # 101194676 — DECIPHER-MPOX and EDCTP3-GH Horizon grant # 101195146-PREGMPOX.In September 2023, a re-emergence of mpox was noted in the province of South Kivu, in DR Congo. So far, active transmission has been reported in 23 of the 26 provinces. Despite localisation within DRC, there are emerging concerns about possibility of cross-border transmission. In this perspective, we highlight the threat posed to HIV positive patients, particularly those with unsuppressed viral loads. We make several prepositions as part of the preparedness and response plans in the countries in the East and Central Africa region. The six prepositions include: 1) operationalize the Joint Africa Task Force for mpox consistent with Kinshasa declaration on mpox, 2) increased surveillance, 3) deployment of point of care diagnostics, 4) targeted reactive vaccination and enhanced antiretroviral therapy of HIV positive patients in areas of active transmission, 5) community engagement, 6) foster capacity building of national rapid response teams in East and Central Africa in mpox care and management through collaboration with DRC counterparts.Peer reviewe
Combined exsolution and electrodeposition strategy for enhancing electrocatalytic activity of Ti-based perovskite oxides in oxygen and hydrogen evolution reactions
Get PDFFunding: The authors acknowledge the support from the Engineering and Physical Sciences Research Council (EPSRC) Critical Mass grant EP/R023522/1, the Light element Analysis Facility Grant EP/T019298/1, the Strategic Equipment Resource grant EP/R023751/1, Innovate UK/EU Horizon EXSOTHyC 101137604 and China Scholarship Council (CSC).The significant interest in perovskite oxides stems from their compositional and structural flexibility, particularly in the field of electrochemistry. In this study, we have successfully devised the double E strategy (exsolution and electrodeposition strategies) for synthesizing perovskite-based bifunctional electrocatalysts, enabling simultaneous OER and HER applications with exceptional catalytic performance. Our synthesized R-LCTFe/Ni catalyst exhibits outstanding electrocatalytic activity, delivering low overpotentials of 349 mV and 309 mV at 10 mA cm−2 for OER and HER, respectively, indicating substantial improvements in the inherent electrocatalytic activity. Moreover, the impressive stability of R-LCTFe/Ni under alkaline conditions underscores its potential for practical water electrolysis applications. The superior bifunctional electrocatalytic performance can be attributed to the reduced charge transfer resistance and the synergistic cooperation between exsolved Fe nanoparticles and electrodeposited Ni compounds. The successful development of the R-LCTFe/Co catalyst further confirms the transferability of the double E strategy. Compared to R-LCTFe/Ni, the overpotential of R-LCTFe/Co is 58 mV higher for OER, yet 48 mV lower for HER at a current density of 10 mA cm−2. This study provides an efficient and promising approach for the fabrication of highly active perovskite-based electrocatalysts, contributing valuable insights into the design of bifunctional electrocatalysts for OER and HER.Peer reviewe
In gratitude for a lack of neglect : a second response to Kegan Chandler
Get PDFStephen Holmes, responding to Kegan Chandler, first points out that continuing academic conversation is beneficial, even if authors do not agree in every aspect of interpretation and conclusion. Holmes agrees that European anti-trinitarianism before 1700 was not rationalist, but biblicist. Matthew Caffyn (1628–1714) fits into this pattern, even if it is debatable to what extent he can be described as ‘anti-trinitarian’. However, the author enters into further discussion on a number of topics concerning whatit means to be (General) Baptist —in other words, what is the nature of a tradition —and he clarifies some interpretative claims in the light of understandingsof Christian orthodoxy. A section in this article is devoted to Caffyn’s theological views, especially his Christology. Holmes hopes that his reflections at least clarify where he and Chandler disagree, and why. Holmes concludes, ‘The fact that there are scholars who care enough about Caffyn and the General Baptists to dispute interpretations, andjournals that consider such disputes worth publishing, is a joy.Peer reviewe
EtIDip (EtIPr) – Synthesis, characterisation and reactivity of a robust, backbone-modified N-heterocyclic carbene and group 13 element complexes
Get PDFFunding: We are grateful to the China Scholarship Council (H.D.), the EPSRC DTG (EP/R513337/1) (C.B.), Erasmus+ (A.M.-S.), and the School of Chemistry at the University of St Andrews for support.We report the synthesis, characterisation and reactivity of the stable imidazol-2-ylidene EtIDip (EtIPr), {EtCN(Dip)}2C:, Dip = 2,6-iPr2C6H3, as a chemically robust alternative to IDip (IPr), {HCN(Dip)}2C:. The N-heterocyclic carbene EtIDip could be further converted to the oxidised species [EtIDipCl]Cl, EtIDipF2, EtIDipO, and EtIDipSe, and the group 13 element complexes EtIDipEX3, with E = B, X = Br; E = Al, X = I; E = Ga, X = I; E = Al, X = H. The properties of the EtIDip and IDip ligands are compared and the molecular structures of (DipNCEt)2, [EtIDipH]Cl, [EtIDipH]I, EtIDip, [EtIDipCl]Cl, EtIDipF2, EtIDipO, EtIDipBBr3, EtIDipAlI3, EtIDipGaI3, and EtIDipAlH3 have been determined.Peer reviewe
William Blundell and the authorship of A History of the Isle of Man (c.1648–1656)
Get PDFFunding: This research was part-funded by Culture Vannin and the Isle of Man Natural History and Antiquarian Society.Peer reviewe
Synthesis, x-ray structure, Hirshfeld analysis and antidiabetic assessment of a novel μ-oxalato Cu(II)-pyrazolone complex
Get PDFFunding: This work was supported by the Deanship of Scientific Research, Vice Presidency for Graduate Studies and Scientific Research, King Faisal University, Saudi Arabia (Project No. KFU242531).An unexpected dinuclear [(Cu(PP)(H2O))2-μ-ox]·3H2O complex; CuPPO, comprising a bridged oxa-late anion (ox2-) and 5-methyl-4-nitro-3-oxo-2-(pyridin-2-yl)-2,3-dihydropyrazol-1-ide (PP) as ligands was synthesized by reaction of 4-(2-(3-methyl-5-oxo-1-(pyridin-2-yl)- 1,5-dihydro-4H-pyrazol-4-ylidene)hydrazinyl) benzenesulfonamide (HPPS) and Cu(NO3)2·3H2O in presence of nitric acid and ethanol as solvent. An unexpected oxidation of ethanol to oxalate anion in addition to hydrolysis of HPPS with subsequent nitration occurred leading to formation of the PP ligand which acting as a bidentate NN-chelate. The new complex is characterized by elemental analy-sis, FTIR analysis, and single crystal X-ray diffraction. In this dinuclear complex, there are two crys-tallographically independent penta-coordinated Cu(II) centers with square pyramidal coordination geometry. The variety of intermolecular interactions affecting the molecular packing of the Cu(II) complex were decomposed by Hirshfeld analysis. The most significant interactions are O···H (33.4%) and C···H (10.7%). In addition, enrichment ratios greater than 1 for O···H, O···N, O···C, H···H, N···C, and C···C revealed high predisposition of each atom pair to interact. CuPPO was evaluated for its in vitro anti-diabetic activity against α-glucosidase, α-amylase and glucose uptake and the re-sults are compared with acarbose and berberine as reference anti-diabetic drugs. CuPPO showed ex-cellent inhibitory potential against α-glucosidase with IC50 values 6.52± 0.33 µM. Also, CuPPO showed higher glucose uptake compared to berberine with EC50 values of 19.03±0.12 µM.Peer reviewe
Access Repository Dashboard
Do you manage St Andrews Research Repository? Access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard!