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Cycloadditions as a sweet route to ‘double C-glycosylation’
Get PDFFunding: This research was funded by the European Union’s Seventh Framework Programme (FP7/2007–2013/ERC grant agreement no. 614779 GenoChemetics to R.J.M.G.), the European Union’s Horizon 2020 research and innovation programme under grant agreement No 654008 and the BBSRC Follow on Fund BB/Y513738/1, BB/T017058/1 and the EU Interreg IV Trans Manche/Channel cross-border projects IS:CE chem (ref 4061) and AIcc (ref 4196).Pharmaceuticals, such as the antibiotic erythromycin, and sodium-dependent glucose transporter (SGLT1 & SGTL2) inhibitors such as Bexagliflozin (diabetes) and Sotagliflozin (heart disease), are often sugar-decorated (glycosylated). Glycosylation is a key component of the binding motif in SGLT inhibitors and in natural products, glycosylation often confers improved bioactivity and bioavailability. Whilst a single C-glycoside link between a sugar moiety and its aglycone core is a common feature in natural products isolated to date, only a small number, including the antibiotics granaticin and sarubicin, are covalently bonded twice to a single sugar moiety. The way in which this “double C-glycosylation” is naturally mediated is not yet known, yet speculated. Here we report the exploration and development of a potentially biomimetic procedure that utilises intermolecular cycloaddition chemistry to access new “double C-glycosylated” products and enables the creation of bridged polycyclic ethers from a common maltol derived oxidopyrylium salt precursor.Peer reviewe
Hydrogenation of carbamates, ureas and polyurethanes using heterogeneous catalysts
Get PDFFunding: This research is funded by a UKRI Future Leaders Fellowship (MR/W007460/1) and the EaSI-CAT centre for Doctoral Training (JSK)..We report here the hydrogenation of carbamates, ureas, and polyurethanes using heterogeneous catalysts. Under our catalytic conditions, carbamates and urea derivatives can be selectively hydrogenated to formamides and alcohols and amines, whereas polyurethanes were hydrogenatively depolymerized to make diamines and polyols. Recycling of catalysts for the hydrogenative depolymerization of a polyurethane has also been demonstrated 10 times.Peer reviewe
Performance evaluation of alternative bacteriological measures of response to MDR/RR-TB therapy during the initial 16 weeks of treatment
Get PDFFunding: The European & Developing Countries Clinical Trials Partnership (EDCTP) funded this study through grant number TMA2018CDF-2351. Additional funding to Willy Ssengooba as a NURTURE fellow through NIH grant D43TW010132.Background Monitoring response to Multi-Drug-Resistant Tuberculosis (MDR-TB) treatment is burdensome to TB programmes and may benefit from alternative effective tools. We evaluated the concordance of alternative bacteriological measures of response to therapy (AMRT) with sputum culture during the initial sixteen weeks of MDR-TB treatment. Methods In a prospective study of MDR/RR-TB among smear positive adults, aged 18-years and above. Pooled early morning and spot sputa were obtained before treatment initiation (95% on Bdq, Lzd, Lfx, Cfz, Cs regimen) and at weeks 2, 4, 6, 8, 12, and 16 during treatment between 14/02/2020 and 09/02/2024. Samples were tested using Concentrated Fluorescent Microscopy (CFM), Fluorescein-di-acetate (FDA)-Acid Fast Bacilli (AFB) vital smear microscopy, the Tuberculosis-Molecular bacterial load assay (TB-MBLA), and Middle brook 7H11 selective (MB7H11S) colony-forming units as the AMRT. Concordance of the AMRT for sputum conversion determination was compared to Mycobacterial Growth Indicator Tube (MGIT) culture conversion at weeks 12 and 16 of treatment. Results A total of 101 MDR/RR-TB patients were screened of which 42 were smear negative. Fifty-nine participants were enrolled, of whom 58 (98%) provided baseline sputa and these were included in the analysis. The concordance, n/N (%) of each AMRT test with MGIT culture conversion at week 12 were: 31/35(88.6%) for CFM, 32/33 (97.0%) for FDA, and 25/26 (96.2%) for TB-MBLA, and 11/11 (100%) for MB7H11S. At week 16, concordance of each AMRT were: 39/40 (97.5%) for CFM, 35/36 (97.2%) for FDA, 32/32 (100%) for TB-MBLA, and 15/15 (100%) for MB7H11S. Among people living with HIV, the concordances of AMRT with MGIT culture conversion varied at week 8 but was 100% for all tests at weeks 12 and 16. Baseline clinical and/or bacteriological factors did not influence the concordance of AMRT to MGIT culture conversion at weeks 12, and 16. Conclusion Our data show that concentrated Fluorescent smear, Fluorescein-di-acetate smear microscopy, and TB-MBLA are suitable alternative measures of response to TB therapy compared to MGIT culture among MDR-TB participants. Use of these alternative rapid methods may allow timely decision making as well as rapid evaluation of alternative MDR-TB treatment regimens.Peer reviewe
Impact of sudden stratospheric warmings on United Kingdom mortality
Get PDFFunding: A. J. C. P. and W. T. K. H. were part funded by the UK Climate Resilience programme is supported by the UKRI Strategic Priorities Fund. The programme is co-delivered by the Met Office and NERC on behalf of UKRI partners AHRC, EPSRC, ESRC. S. H. L. was funded by NERC via the SCENARIO Doctoral Training Partnership (NE/L002566/1).Sudden stratospheric warmings (SSWs) during boreal winter are one of the main drivers of sub-seasonal climate variability in the Northern Hemisphere. Although the impact of SSW events on surface climate and climate extremes has been clearly demonstrated, the impact of the resulting climate anomalies on society has not been so widely considered. In the United Kingdom (UK), SSWs are associated with cold weather, which is linked to significant increases in mortality. This study demonstrates, for the first time, that SSWs are linked to increases in mortality in the UK. A distributed lag nonlinear model and standard parameter settings from the literature is used to construct a daily time series of UK deaths attributable to cold weather between 1991 and 2018. Weekly mortality associated with SSWs is diagnosed using a superposed epoch analysis of attributed mortality for the 15 SSW events in this period. SSW associated mortality peaks between 3 and 5 weeks after SSW central date and leads to, on average, 620 additional deaths in the same period. Given that the impacts of SSWs can be skilfully predicted on sub-seasonal timescales, this suggests that health and social care systems could derive substantial benefit from sub-seasonal forecasts during SSWs.Peer reviewe
Structural controls on lithium mineralization in shear-zone hosted granitic pegmatites of the Zulu pegmatite field, Zimbabwe – implications for exploration
Get PDFFunding: LK acknowledges funding from the SEG Hugh McKinstry fund and the Geological Society of London for fieldwork and analytical support. LK was supported by a National Environmental Research Council PhD studentship (Grant no. NE/S007474/1).Granitic pegmatites are a significant source of critical metals including tin, tantalum, and most notably lithium. To meet future demand, a comprehensive exploration model is required to assist in the discovery of new hard rock deposits. Whereas recent work has largely focused on understanding the source and mineralization processes of pegmatites, the structural controls on the distribution and size of individual deposits remains poorly understood and understudied. In this contribution, we present a structural study on the Zulu pegmatite field in Zimbabwe, which provides a good example of the influence of shear zones, host rock rheology, and lithological competency contrasts on the orientation, size, and distribution of pegmatite bodies within a pegmatite field. At Zulu, we observe both structural and petrographic evidence for two types of pegmatite emplacement within an active shear zone during D2 strike-slip dominated deformation. An early generation (Type 1) was emplaced syn-kinematic to D2 within dilational jogs subparallel to the shear fabric, and continued ductile shearing also drove significant recrystallization which affected the primary magmatic phases and therefore influenced the preserved mineralogy. A later generation (Type 2) was emplaced syn-to-late-kinematic to D2 along tension gashes and subordinate fracture sets oblique to the shear fabric, which served to truncate the cooling history and preserve a primarily magmatic mineralogy within this pegmatite group. By comparing Zulu to other large pegmatite deposits, we conclude that geologic structures are critical to source-to-sink connectivity in lithium pegmatite systems, and affect the mineralization potential of individual deposits by driving recrystallization. Assessing the structural history and relative timing of emplacement within a pegmatite field, in conjunction with detailed (micro)textural observations from within pegmatite bodies, is essential to understanding pegmatite emplacement geometries. A more systematic approach in constraining these relationships will therefore aid in generating new exploration targets in both greenfield and brownfield settings.Peer reviewe
Global overview of short-term alcohol policies : need for global exchange of experience and impact measurement
Get PDFAlcohol use disorder is a global public health concern and national policies are often implemented to help control alcohol consumption and related consequences. Increasingly, many countries are resorting to transient (short-term) alcohol policies which are implemented for a restricted period of time as an action plan for particular events or health-related issues. The COVID-19 pandemic emphasised the need for rapid decision-making and short-term fast-acting policies. This paper discusses contexts in which these transient policies are used and highlights the need for impact measurement and global exchange of experiences. This is particularly important to avoid gaps that the global alcohol industry could utilise to expand its influence and market.Peer reviewe
The East and the origins of "the West"Drawing boundaries between Russia and Europe in the 19th century
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exoALMA. I. Science goals, project design, and data products
Get PDFFunding: J.B. acknowledges support from NASA XRP grant No. 80NSSC23K1312. M.B., D.F., and J.S. have received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (PROTOPLANETS, grant agreement No. 101002188). P.C. and L.T. acknowledge support by the Italian Ministero dell’Istruzione, Università e Ricerca through the grant Progetti Premiali 2012—iALMA (CUP C52I13000140001) and by the ANID BASAL project FB210003. N.C. has received funding from the European Research Council (ERC) under the European Union Horizon Europe research and innovation program (grant agreement No. 101042275, project Stellar-MADE). S.F. is funded by the European Union (ERC, UNVEIL, 101076613), and acknowledges financial contribution from PRIN-MUR 2022YP5ACE. M.F. is supported by a Grant-in-Aid from the Japan Society for the Promotion of Science (KAKENHI: No. JP22H01274). C.H. acknowledges support from NSF AAG grant No. 2407679. I.H., C.H., and T.H. are supported by an Australian Government Research Training Program (RTP) Scholarship. J.D.I. acknowledges support from an STFC Ernest Rutherford Fellowship (ST/W004119/1) and a University Academic Fellowship from the University of Leeds. Support for AFI was provided by NASA through the NASA Hubble Fellowship grant No. HST-HF2-51532.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. G.L. has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No. 823823 (DUSTBUSTERS). C.L. has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No. 823823 (DUSTBUSTERS) and by the UK Science and Technology research Council (STFC) via the consolidated grant ST/W000997/1. C.P. acknowledges Australian Research Council funding via FT170100040, DP18010423, DP220103767, and DP240103290. D.P. acknowledges Australian Research Council funding via DP18010423, DP220103767, and DP240103290. G.R. acknowledges funding from the Fondazione Cariplo, grant No. 2022-1217, and the European Research Council (ERC) under the European Union’s Horizon Europe Research & Innovation Programme under grant agreement No. 101039651 (DiscEvol). H.-W.Y. acknowledges support from National Science and Technology Council (NSTC) in Taiwan through grant NSTC 113-2112-M-001-035- and from the Academia Sinica Career Development Award (AS-CDA-111-M03). G.W.F. acknowledges support from the European Research Council (ERC) under the European Union Horizon 2020 research and innovation program (grant agreement No. 815559 (MHDiscs)). G.W.F. was granted access to the HPC resources of IDRIS under the allocation A0120402231 made by GENCI. T.C.Y. acknowledges support by Grant-in-Aid for JSPS Fellows JP23KJ1008. Support for B.Z. was provided by The Brinson Foundation. This work was partly supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)—Ref No. 325594231 FOR 2634/2 TE 1024/2-1, and by the DFG Cluster of Excellence Origins (https://www.origins-cluster.de/). This project has received funding from the European Research Council (ERC) via the ERC Synergy Grant ECOGAL (grant 855130).Planet formation is a hugely dynamic process requiring the transport, concentration, and assimilation of gas and dust to form the first planetesimals and cores. With access to observations with extremely high spatial and spectral resolution at unprecedented sensitivities, it is now possible to probe the planet-forming environment in detail. To this end, the exoALMA Large Program targeted 15 large protoplanetary disks, ranging between ∼1″ and ∼7″ in radius, and mapped the gas and dust distributions. 12CO J = 3–2, 13CO J = 3–2, and CS J = 7–6 molecular emission was imaged at high angular (∼0.″15) and spectral (∼100 m s−1) resolution, achieving a surface brightness temperature sensitivity of ∼1.5 K over a single channel, while the 330 GHz continuum emission was imaged at 90 mas resolution and achieved a point source sensitivity of ∼40 μJy beam−1. These observations constitute some of the deepest observations of protoplanetary disks to date. Extensive substructure was found in all but one disk, traced by both dust continuum and molecular line emission. In addition, the molecular emission allowed for the velocity structure of the disks to be mapped with excellent precision (uncertainties of the order of 10 m s−1), revealing a variety of kinematic perturbations across all sources. From this sample it is clear that, when observed in detail, all disks appear to exhibit physical and dynamical substructure indicative of ongoing dynamical processing due to young, embedded planets, large-scale (magneto)hydrodynamical instabilities or winds.Peer reviewe
Perspectives on parametric oscillators : theoretical, historical, experimental and inventive
Get PDFWhen Henry Ford promised his customers "Any colour you like....", there was an accompanying caveat emptor, ".....so long as it’s black.".
In the early days of lasers, it seemed that the prospective laser scientist would also have Hobson's choice of output wavelength. Significant laser power was only available at fixed wavelengths, almost all in the near- and mid-infra-red. The idea of variable wavelength laser output was unrealistic.
It was soon suggested that the high electric fields associated with laser energy might induce curious effects in some materials - the atoms in these materials might no longer display perfectly linear optical properties. This was demonstrated experimentally in 1961, and led to the further suggestion that it might be possible to use these nonlinear effects to generate tuneable laser- -quality light. In 1965 this idea was realized and parametric optics was created.
The optical parametric oscillator (OPO) and its derivatives stand at the very edge of modern optical technology. They have attracted considerable commercial interest and their ability to deliver laser-quality variable-output light makes them desirable for spectroscopists and surgeons alike.
This thesis gives different perspectives on the OPO: the theory of its operation, its history, a brief analysis of the most recent developments in its field, and discussion of innovative uses of OPOs to explore 20th Century physics' greatest achievements - relativity and quantum theory. It also gives details of experimental work conducted in this laboratory showing the tuneable properties of an LBO OPO, for both Type I and Type II phase matching geometries. Four appendices review essential background knowledge of crystals and resonators.
It is hoped that it will be of use to those who are new to the field of optical parametric oscillators, and will allow them to gain a broad view of this important technology
The legend of gesture : a link to our past
No full textIn the search for human uniqueness, language stands out due to its seemingly infinite flexibility that underpins our ability for complex social interactions and large-scale cooperation. Yet, if language is such an adaptive trait, why is it unique to our species? One prominent theory suggests that it is less unique than we may think, and that language evolved from a gestural communication system inherited from our great ape ancestors. Each ape species uses approximately 80 distinct gestures flexibly and intentionally in daily social interactions. Many of these gestures are used similarly across species, with a positive correlation between repertoire overlap and phylogenetic relatedness, suggesting a common ancestral origin. However, human access to this ‘ape-typical’ gestural repertoire remains largely under-studied. My PhD addresses this gap by examining how humans use and understand ape-typical gestures, employing comparative methods borrowed from primatologists. Through an observational study, I analysed the gestures used by 0.5–6.5-year-old children across eight countries using the GesturalOrigins coding system and found that children used the majority of the ape gestural repertoire (68 out of 85 actions; 80%). Children as young as six-months used 24 of these gestures, with an additional 24 emerging before 1.5 years—highlighting the importance of gestures before and during language acquisition. Importantly, they continued to use them into their 7th year, well after language was in place. I also conducted an online study where language-proficient adults interpreted ape-typical gestures exchanged between human adults. Adults agreed on the meaning of 9 out of 10 gestures, with 6 matching their original use in chimpanzees. These findings suggest that the ability to understand ape-typical gestures persists into adulthood. Together, my findings support a phylogenetic origin for an ape-typical gestural system that emerges early in human development and continues to provide an important cognitive scaffold for language use
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