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BACKGROUND: The Global Evidence, Local Adaptation (GELA) project aims to maximise the impact of research on poverty-related diseases by increasing researchers' and decision-makers' capacity to use global research to develop locally relevant guidelines for newborn and child health in Malawi, Nigeria and South Africa. To facilitate ongoing collaboration with stakeholders, we adopted an Integrated Knowledge Translation (IKT) approach within GELA. Given limited research on IKT in African settings, we documented our team's IKT capacity and skills, and process and experiences with developing and implementing IKT in these countries. METHODS: Six IKT champions and a coordinator formed the GELA IKT Working Group. We gathered data on our baseline IKT competencies and processes within GELA, and opportunities, challenges and lessons learned, from April 2022 to March 2023 (Year 1). Data was collected from five two-hour Working Group meetings (notes, presentation slides and video recordings); [2] process documents (flowcharts and templates); and [3] an open-ended questionnaire. Data was analysed using a thematic analysis approach. RESULTS: Three overarching themes were identified: [1] IKT approach applied within GELA [2], the capacity and motivations of IKT champions, and [3] the experiences with applying the GELA IKT approach in the three countries. IKT champions and country teams adopted an iterative approach to carry out a comprehensive mapping of stakeholders, determine stakeholders' level of interest in and influence on GELA using the Power-Interest Matrix, and identify realistic indicators for monitoring the country-specific strategies. IKT champions displayed varying capacities, strong motivation, and they engaged in skills development activities. Country teams leveraged existing relationships with their National Ministries of Health to drive responses and participation by other stakeholders, and adopted variable communication modes (e.g. email, phone calls, social media) for optimal engagement. Flexibility in managing competing interests and priorities ensured optimal participation by stakeholders, although the time and resources required by IKT champions were frequently underestimated. CONCLUSIONS: The intentional, systematic, and contextualized IKT approach carried out in the three African countries within GELA, provides important insights for enhancing the implementation, feasibility and effectiveness of other IKT initiatives in Africa and similar low- and middle-income country (LMIC) settings.
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Pesquisa Translacional Biomédica , Humanos , África do Sul , Malaui , Nigéria , Pesquisa Translacional Biomédica/organização & administração , Recém-Nascido , Fortalecimento InstitucionalRESUMO
BACKGROUND: Almost no research has been published reporting on evaluations of the effectiveness of psychological interventions for people with severe to profound intellectual disabilities and depression. This paper describes the development and initial feasibility testing of an adapted Behavioural Activation therapy (BeatIt2) for this population. METHOD: Phase 1 of the study examined participant recruitment and willingness to be randomised in the context of a planned Randomised Controlled Trial (RCT). Phase 2 examined the feasibility of delivering the intervention. RESULTS: Twenty adults with a severe or profound intellectual disability and clinically significant depression were recruited to Phase 1 of the study. In Phase 2, there was 100% participant retention for those recruited to the study at 6-month follow-up. The BeatIt2 therapy was reported to be acceptable for participants. CONCLUSION: COVID disruption meant that it was not possible to complete the planned feasibility RCT. The positive findings suggest that additional evaluation of BeatIt2 is warranted.
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Depressão , Deficiência Intelectual , Adulto , Humanos , Depressão/terapia , Deficiência Intelectual/psicologia , Estudos de Viabilidade , Terapia ComportamentalRESUMO
In nature and synthetic chemistry, stereoselective [2 + 1] cyclopropanation is the most prevalent strategy for the synthesis of chiral cyclopropanes, a class of key pharmacophores in pharmaceuticals and bioactive natural products. One of the most extensively studied reactions in the organic chemist's arsenal, stereoselective [2 + 1] cyclopropanation, largely relies on the use of stereodefined olefins, which can require elaborate laboratory synthesis or tedious separation to ensure high stereoselectivity. Here, we report engineered hemoproteins derived from a bacterial cytochrome P450 that catalyze the synthesis of chiral 1,2,3-polysubstituted cyclopropanes, regardless of the stereopurity of the olefin substrates used. Cytochrome P450BM3 variant P411-INC-5185 exclusively converts (Z)-enol acetates to enantio- and diastereoenriched cyclopropanes and in the model reaction delivers a leftover (E)-enol acetate with 98% stereopurity, using whole Escherichia coli cells. P411-INC-5185 was further engineered with a single mutation to enable the biotransformation of (E)-enol acetates to α-branched ketones with high levels of enantioselectivity while simultaneously catalyzing the cyclopropanation of (Z)-enol acetates with excellent activities and selectivities. We conducted docking studies and molecular dynamics simulations to understand how active-site residues distinguish between the substrate isomers and enable the enzyme to perform these distinct transformations with such high selectivities. Computational studies suggest the observed enantio- and diastereoselectivities are achieved through a stepwise pathway. These biotransformations streamline the synthesis of chiral 1,2,3-polysubstituted cyclopropanes from readily available mixtures of (Z/E)-olefins, adding a new dimension to classical cyclopropanation methods.
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Ciclopropanos , Sistema Enzimático do Citocromo P-450 , Ciclopropanos/química , Estereoisomerismo , Sistema Enzimático do Citocromo P-450/metabolismo , Álcoois , Acetatos , Alcenos/químicaRESUMO
Tandem Diels-Alder reactions are frequently used in the construction of polycyclic ring systems in complex organic compounds. Unlike the many Diels-Alderases (DAases) that catalyse a single cycloaddition, enzymes for multiple Diels-Alder reactions are rare. Here we demonstrate that two calcium-ion-dependent glycosylated enzymes, EupfF and PycR1, independently catalyse sequential, intermolecular Diels-Alder reactions in the biosynthesis of bistropolone-sesquiterpenes. We elucidate the origins of catalysis and stereoselectivity within these DAases through analysis of enzyme co-crystal structures, together with computational and mutational studies. These enzymes are secreted as glycoproteins with diverse N-glycans. The N-glycan at N211 in PycR1 significantly increases the affinity to the calcium ion, which in turn regulates the active cavity, making it specifically interact with substrates to accelerate the tandem [4 + 2] cycloaddition. The synergistic effect of the calcium ion and N-glycan on the catalytic centre of enzymes involved in secondary metabolism, especially for complex tandem reactions, can extend our understanding of protein evolution and improve the artificial design of biocatalysts.
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Produtos Biológicos , Sesquiterpenos , Reação de Cicloadição , Produtos Biológicos/química , Cálcio , CatáliseRESUMO
BACKGROUND: No previous studies have reported predictors and moderators of outcome of psychological therapies for depression experienced by adults with intellectual disabilities (IDs). We investigated baseline variables as outcome predictors and moderators based on a randomised controlled trial where behavioural activation was compared with guided self-help. METHODS: This study was an exploratory secondary data analysis of data collected during a randomised clinical trial. Participants (n = 161) were randomised to behavioural activation or guided self-help and followed up for 12 months. Pre-treatment variables were included if they have previously been shown to be associated with an increased risk of having depression in adults with IDs or have been reported as a potential predictor or moderator of outcome of treatment for depression with psychological therapies. The primary outcome measure, the Glasgow Depression Scale for Adults with Learning Disabilities (GDS-LD), was used as the dependant variable in mixed effects regression analyses testing for predictors and moderators of outcome, with baseline GDS-LD, treatment group, study centre and antidepressant use as fixed effects, and therapist as a random effect. RESULTS: Higher baseline anxiety (mean difference in outcome associated with a 1 point increase in anxiety 0.164, 95% confidence interval [CI] 0.031, 0.297; P = 0.016), lower performance intelligence quotient (IQ) (mean difference in outcome associated with a 1 point increase in IQ 0.145, 95% CI 0.009, 0.280; P = 0.037) and hearing impairment (mean difference 3.449, 95% CI 0.466, 6.432; P = 0.024) were predictors of poorer outcomes, whilst greater severity of depressive symptoms at baseline (mean difference in outcome associated with 1 point increase in depression -0.160, 95% CI -0.806, -0.414; P < 0.001), higher expectation of change (mean difference in outcome associated with a 1 point increase in expectation of change -1.013, 95% CI -1.711, -0.314; p 0.005) and greater percentage of therapy sessions attended (mean difference in outcome with 1 point increase in percentage of sessions attended -0.058, 95% CI -0.099, -0.016; P = 0.007) were predictors of more positive outcomes for treatment after adjusting for randomised group allocation. The final model included severity of depressive and anxiety symptoms, lower WASI performance IQ subscale, hearing impairment, higher expectation of change and percentage of therapy sessions attended and explained 35.3% of the variance in the total GDS-LD score at 12 months (R2 = 0.353, F4, 128 = 17.24, P < 0.001). There is no evidence that baseline variables had a moderating effect on outcome for treatment with behavioural activation or guided self-help. CONCLUSIONS: Our results suggest that baseline variables may be useful predictors of outcomes of psychological therapies for adults with IDs. Further research is required to examine the value of these potential predictors. However, our findings suggest that therapists consider how baseline variables may enable them to tailor their therapeutic approach when using psychological therapies to treat depression experienced by adults with IDs.
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Depressão , Deficiência Intelectual , Adulto , Humanos , Depressão/terapia , Deficiência Intelectual/terapia , Deficiência Intelectual/psicologia , Terapia Comportamental/métodos , Ansiedade , Comportamentos Relacionados com a SaúdeRESUMO
We report biosynthetic pathways that can synthesize and transform conjugated octaenes and nonaenes to complex natural products. The biosynthesis of (-)-PF1018 involves an enzyme PfB that can control the regio-, stereo-, and periselectivity of multiple reactions starting from a conjugated octaene. Using PfB as a lead, we discovered a homologous enzyme, BruB, that facilitates diene isomerization, tandem 8π-6π-electrocyclization, and a 1,2-divinylcyclobutane Cope rearrangement to generate a new-to-nature compound.
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Produtos Biológicos , Produtos Biológicos/metabolismo , Isomerismo , Polienos , CiclizaçãoRESUMO
Control noise is a limiting factor in the low-frequency performance of the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO). In this paper, we model the effects of using new sensors called Homodyne Quadrature Interferometers (HoQIs) to control the suspension resonances. We show that if we were to use HoQIs, instead of the standard shadow sensors, we could suppress resonance peaks up to tenfold more while simultaneously reducing the noise injected by the damping system. Through a cascade of effects, this will reduce the resonant cross-coupling of the suspensions, allow for improved stability for feed-forward control, and result in improved sensitivity of the detectors in the 10-20 Hz band. This analysis shows that improved local sensors, such as HoQIs, should be used in current and future detectors to improve low-frequency performance.
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In nature and synthetic chemistry, stereoselective [2+1] cyclopropanation is the most prevalent strategy for the synthesis of chiral cyclopropanes, a class of key pharmacophores in pharmaceuticals and bioactive natural products. One of the most extensively studied reactions in the organic chemist's arsenal, stereoselective [2+1] cyclopropanation, largely relies on the use of stereodefined olefins, which require elaborate laboratory synthesis or tedious separation to ensure high stereoselectivity. Here we report engineered hemoproteins derived from a bacterial cytochrome P450 that catalyze the synthesis of chiral 1,2,3-polysubstituted cyclopropanes, regardless of the stereopurity of the olefin substrates used. Cytochrome P450 BM3 variant IC-G3 exclusively converts ( Z )-enol acetates to enantio- and diastereoenriched cyclopropanes and in our model reaction delivers a leftover ( E )-enol acetate with 98% stereopurity, using whole Escherichia coli cells. IC-G3 was further engineered with a single mutation to enable the biotransformation of ( E )-enol acetates to α -branched ketones with high levels of enantioselectivity while simultaneously catalyzing the cyclopropanation of ( Z )-enol acetates with excellent activities and selectivities. We conducted docking studies and molecular dynamics simulations to understand how active-site residues distinguish between the substrate isomers and enable the enzyme to perform these distinct transformations with such high selectivities. Computational studies suggest the observed enantio- and diastereoselectivities are achieved through a stepwise pathway. These biotransformations streamline the synthesis of chiral 1,2,3-polysubstituted cyclopropanes from readily available mixtures of ( Z/E )-olefins, adding a new dimension to classical cyclopropanation methods.
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An ambimodal transition state (TS) that leads to formation of four different pericyclic reaction products ([4 + 6]-, [2 + 8]-, [8 + 2]-, and [6 + 4]-cycloadducts) without any intervening minima has been designed and explored with DFT computations and quasiclassical molecular dynamics. Direct dynamics simulations propagated from the ambimodal TS show the evolution of trajectories to give the four cycloadducts. The topography of the PES is a key factor in product selectivity. A good correlation is observed between geometrical resemblance of the products to the ambimodal TS (measured by the RMSD) and the ratio of products formed in the dynamics simulations.
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Advanced Laser Interferometer Gravitational-wave Observatory (LIGO A+) is a major upgrade to LIGO-the Laser Interferometer Gravitational-wave Observatory. For the A+ project, we have developed, produced, and characterized sensors and electronics to interrogate new optical suspensions designed to isolate optics from vibrations. The central element is a displacement sensor with an integrated electromagnetic actuator known as a BOSEM (Birmingham Optical Sensor and ElectroMagnetic actuator) and its readout and drive electronics required to integrate them into LIGO's control and data system. In this paper, we report on the improvements to the sensors and the testing procedures undertaken to meet the enhanced performance requirements set out by the A+ upgrade to the detectors. The best devices reach a noise level of 4.5 ×10-11m/Hz at a measurement frequency of 1 Hz, an improvement of 6.7 times over standard devices.
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Stereoselective synthesis of cis-decalin structures using [4 + 2] cycloaddition is challenging. We explored the biosynthetic pathway of the fungal natural product fischerin (1) to identify a new pericyclase FinI that can catalyze such a reaction. The cocrystal structure of FinI, a predicted O-methyltransferase, with the product and SAM provides insight into cis-decalin formation in nature.
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Produtos Biológicos , Biocatálise , Metiltransferases , CatáliseRESUMO
During torpor in a 13-lined ground squirrel heart rate and blood flow decrease, increasing the risk of blood clot formation. In response, cells involved in clotting called platelets are sequestered in the liver, stored in the cold for months, and released back into circulation upon arousal. This is in contrast to non-hibernating mammals, including humans, in which chilled platelets undergo cold storage lesions and phagocytosis, leading to rapid clearance from circulation post-transfusion. Because of this, human platelets must be stored at room temperature, limiting their shelf life to 7 days due to the increased risk of microbial contamination at warmer temperatures. Human and ground squirrel platelets were stored at room temperature or 4 °C before being analyzed for cold storage lesions. Human platelets stored at 4 °C displayed progressive increases in phosphatidylserine surface exposure and caspase activation, while ground squirrel platelets showed minimal change. Following cold storage, sialic acid residues on human platelets were cleaved, leading to increased phagocytosis of human platelets by HepG2 cells. Ground squirrel platelets stored in the cold showed no changes in desialylation and phagocytosis, with Taxol-treated ground squirrel platelets showing the lowest phagocytosis rates between both species and all treatments. These results suggest that ground squirrel platelets may be resistant to cold storage lesions seen in human platelets. Although these experiments were done in vitro, they suggest a mechanism by which ground squirrel platelets are adapted to be stored during hibernation and remain functional following arousal. Other hibernating species may employ similar adaptations to retain functional platelets following torpor.
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Hibernação , Torpor , Humanos , Animais , Plaquetas/fisiologia , Torpor/fisiologia , Temperatura , Hibernação/fisiologia , Temperatura Baixa , Sciuridae/fisiologiaRESUMO
We summarise a Cochrane review of qualitative evidence that explored parents' views and practices around routine childhood vaccination, and provide implications for research and practice that are relevant to the South African (SA) context. Many public health interventions to encourage vaccination are informed by an assumption that vaccine hesitancy is due to a lack of knowledge or irrational forms of thinking. The findings from this review suggest that childhood vaccination views and practices are complex social processes that are shaped by multiple factors and carry a variety of meanings. As such, we suggest that biomedical approaches must be supplemented by more nuanced and sociopolitically informed strategies for enhancing and sustaining childhood vaccination practices in SA.
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Cuidadores , Pais , Humanos , África do Sul , Vacinação , Saúde Pública , Conhecimentos, Atitudes e Prática em Saúde , Aceitação pelo Paciente de Cuidados de SaúdeRESUMO
In crystallization from solution, a ubiquitous process in both industry and the natural world, nucleation is usually the rate-determining step, followed by faster crystal growth. Consequently, crystals typically exist in the nm-size range for such limited times that their investigation and manipulation is hindered. Here, we show that, owing to a degree of restricted diffusion, crystallization in structured ternary fluids (STFs) can proceed via higher nucleation rate and slower crystal growth pathways. This enables STFs to act as nanocrystal incubators, with the nanocrystals existing for extended times. We demonstrate that this generates enhanced crystallization control, with the three ambient pressure polymorphs of glycine, the α-, γ- and ß-forms, all crystallizing from the octanol/ethanol/water STF, despite the well-known difficulty in crystallizing the slow growing γ-form and the instability of the ß-form. The ability of STFs to produce notoriously hard to crystallize polymorphs should make them a versatile tool, ideal for polymorph discovery. This may enable a step change in the current, scatter-gun approach to polymorph screening. Furthermore, we show that aliquots of the nanocrystal-containing fluids can successfully seed metastable solutions. Hence, STFs may ultimately help provide a generic methodology for producing crystals and seed suspensions of any desired polymorph to supersede current targeted crystallization and seeding strategies.
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INTRODUCTION: Serological methods provide useful metrics to estimate age-specific period prevalence in settings of low malaria transmission; however, evidence on the use of seropositivity as an endpoint remains scarce in studies to evaluate combinations of malaria control measures, especially in children. This study aims to evaluate the immediate effects of a targeted mass drug administration campaign (tMDA) in Haiti by using serological markers. METHODS: The tMDA was implemented in September-October 2018 using sulfadoxine-pyrimethamine and single low-dose primaquine. A natural quasi-experimental study was designed, using a pretest and posttest in a cohort of 754 randomly selected school children, among which 23% reported having received tMDA. Five antigens were selected as outcomes (MSP1-19, AMA-1, Etramp5 antigen 1, HSP40, and GLURP-R0). Posttest was conducted 2-6 weeks after the intervention. RESULTS: At baseline, there was no statistical difference in seroprevalence between the groups of children that were or were not exposed during the posttest. A lower seroprevalence was observed for markers informative of recent exposure (Etramp5 antigen 1, HSP40, and GLURP-R0). Exposure to tMDA was significantly associated with a 50% reduction in the odds of seropositivity for Etramp5 antigen 1 and a 21% reduction in the odds of seropositivity for MSP119. CONCLUSION: Serological markers can be used to evaluate the effects of interventions against malaria on the risk of infection in settings of low transmission. Antibody responses against Etramp5 antigen 1 in Haitian children were reduced in the 2-6 weeks following a tMDA campaign, confirming its usefulness as a short-term marker in child populations.
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Malária Falciparum , Malária , Anticorpos Antiprotozoários , Criança , Combinação de Medicamentos , Haiti/epidemiologia , Humanos , Malária/tratamento farmacológico , Malária/epidemiologia , Malária/prevenção & controle , Malária Falciparum/tratamento farmacológico , Malária Falciparum/epidemiologia , Malária Falciparum/prevenção & controle , Preparações Farmacêuticas , Plasmodium falciparum , Estudos SoroepidemiológicosRESUMO
Pericyclases, enzymes that catalyze pericyclic reactions, form an expanding family of enzymes that have biocatalytic utility. Despite the increasing number of pericyclases discovered, the Diels-Alder cyclization between a cyclopentadiene and an olefinic dienophile to form norbornene, which is among the best-studied cycloadditions in synthetic chemistry, has surprisingly no enzymatic counterpart to date. Here we report the discovery of a pathway featuring a norbornene synthase SdnG for the biosynthesis of sordaricin-the terpene precursor of antifungal natural product sordarin. Full reconstitution of sordaricin biosynthesis reveals a concise oxidative strategy used by Nature to transform an entirely hydrocarbon precursor into the highly functionalized substrate of SdnG for intramolecular Diels-Alder cycloaddition. SdnG generates the norbornene core of sordaricin and accelerates this reaction to suppress host-mediated redox modifications of the activated dienophile. Findings from this work expand the scopes of pericyclase-catalyzed reactions and P450-mediated terpene maturation.