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This commentary introduces a new clinical trial construct, the Master Observational Trial (MOT), which hybridizes the power of molecularly based master interventional protocols with the breadth of real-world data. The MOT provides a clinical venue to allow molecular medicine to rapidly advance, answers questions that traditional interventional trials generally do not address, and seamlessly integrates with interventional trials in both diagnostic and therapeutic arenas. The result is a more comprehensive data collection ecosystem in precision medicine.
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Estudos Observacionais como Assunto/métodos , Medicina de Precisão/métodos , Projetos de Pesquisa/normas , Big Data , Protocolos de Ensaio Clínico como Assunto , Humanos , Terapia de Alvo Molecular/métodos , Terapia de Alvo Molecular/tendências , Estudos Observacionais como Assunto/normasRESUMO
Solar ultraviolet-B (UV-B) radiation has played a crucial role in the evolution of life on Earth, and potential changes in its levels could affect the health and functionality of humans and the ecosystems. UV exposure presents both risks and benefits to humans. However, optimal UV-B radiation exposure depends on several environmental and physiological factors and cannot be easily determined. The present document provides a review of the current state of knowledge relative to the effects of UV-B radiation on human health. A brief description of the physical mechanisms that control the levels of solar UV-B radiation at the Earth's surface is provided, with special emphasis on the role of ozone and the importance of the Montreal Protocol. A comprehensive review of studies reporting current trends in levels of surface solar UV-B radiation and projections of future levels reveals the dominant role of climatic changes in the long-term variability of UV-B radiation and its impact on the development of melanomas as well as eye disorders. The review provides strong evidence that despite the success of the Montreal Protocol and the expected ozone recovery, the future evolution of the levels of solar UV-B radiation at the Earth's surface is not certain.
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Ecossistema , Ozônio , Humanos , Raios Ultravioleta/efeitos adversos , Doses de RadiaçãoRESUMO
The ethical standards for the responsible conduct of human research have come a long way; however, concerns surrounding equity remain in human genetics and genomics research. Addressing these concerns will help society realize the full potential of human genomics research. One outstanding concern is the fair and equitable sharing of benefits from research on human participants. Several international bodies have recognized that benefit-sharing can be an effective tool for ethical research conduct, but international laws, including the Convention on Biological Diversity and its Nagoya Protocol on Access and Benefit-Sharing, explicitly exclude human genetic and genomic resources. These agreements face significant challenges that must be considered and anticipated if similar principles are applied in human genomics research. We propose that benefit-sharing from human genomics research can be a bottom-up effort and embedded into the existing research process. We propose the development of a "benefit-sharing by design" framework to address concerns of fairness and equity in the use of human genomic resources and samples and to learn from the aspirations and decade of implementation of the Nagoya Protocol.
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Genômica , Humanos , Genômica/ética , Genômica/métodos , Genoma Humano , Pesquisa em Genética/ética , Pesquisa em Genética/legislação & jurisprudênciaRESUMO
Atmospheric formic acid is severely underpredicted by models. A recent study proposed that this discrepancy can be resolved by abundant formic acid production from the reaction (1) between hydroxyl radical and methanediol derived from in-cloud formaldehyde processing and provided a chamber-experiment-derived rate constant, k1 = 7.5 × 10-12 cm3 s-1. High-level accuracy coupled cluster calculations in combination with E,J-resolved two-dimensional master equation analyses yield k1 = (2.4 ± 0.5) × 10-12 cm3 s-1 for relevant atmospheric conditions (T = 260-310 K and P = 0-1 atm). We attribute this significant discrepancy to HCOOH formation from other molecules in the chamber experiments. More importantly, we show that reversible aqueous processes result indirectly in the equilibration on a 10 min. time scale of the gas-phase reaction [Formula: see text] (2) with a HOCH2OH to HCHO ratio of only ca. 2%. Although HOCH2OH outgassing upon cloud evaporation typically increases this ratio by a factor of 1.5-5, as determined by numerical simulations, its in-cloud reprocessing is shown using a global model to strongly limit the gas-phase sink and the resulting production of formic acid. Based on the combined findings in this work, we derive a range of 1.2-8.5 Tg/y for the global HCOOH production from cloud-derived HOCH2OH reacting with OH. The best estimate, 3.3 Tg/y, is about 30 times less than recently reported. The theoretical equilibrium constant Keq (2) determined in this work also allows us to estimate the Henry's law constant of methanediol (8.1 × 105 M atm-1 at 280 K).
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The rapid melting of Arctic sea ice is the largest and clearest signal of anthropogenic climate change. Current projections indicate that the first ice-free Arctic summer will likely occur by mid-century, owing to increasing carbon dioxide concentrations in the atmosphere. However, other powerful greenhouse gases have also contributed to Arctic sea ice loss, notably ozone-depleting substances (ODSs). In the late 1980s, ODSs became strictly regulated by the Montreal Protocol, and their atmospheric concentrations have been declining since the mid-1990s. Here, analyzing new climate model simulations, we demonstrate that the Montreal Protocol, designed to protect the ozone layer, is delaying the first appearance of an ice-free Arctic summer, by up to 15 y, depending on future emissions. We also show that this important climate mitigation stems entirely from the reduced greenhouse gas warming from the regulated ODSs, with the avoided stratospheric ozone losses playing no role. Finally, we estimate that each Gg of averted ODS emissions results in approximately 7 km2 of avoided Arctic sea ice loss.
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Plant genetic resources (PGR), including collections held in national and international gene banks, provide access to a wide array of genetic diversity and are critical to genomics research, conservation efforts, and applied breeding. Yet, there is a general lack of awareness in the research community about the rules and treaties that govern the use of PGR, about access and benefit sharing obligations contained in international treaties and/or national laws, and about how best to comply with potentially applicable requirements. This article provides a brief history and overview of three key international agreements, namely the Convention on Biological Diversity, the Nagoya Protocol, and the International Treaty on Plant Genetic Resources for Food and Agriculture, which collectively address responsibilities and obligations related to the use of much of the world's PGR. By highlighting the coverage and key considerations of each agreement, the article provides a guide for those who use PGR in plant genetics research to better understand when and how international agreements apply, and-where the rules are unclear-to suggest best practices for compliance with existing agreements.
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Melhoramento Vegetal , Plantas , Plantas/genética , Cooperação Internacional , Alimentos , BiodiversidadeRESUMO
Increasing evidence suggests that human microbiota plays a crucial role in many diseases. Alpha diversity, a commonly used summary statistic that captures the richness and/or evenness of the microbial community, has been associated with many clinical conditions. However, individual studies that assess the association between alpha diversity and clinical conditions often provide inconsistent results due to insufficient sample size, heterogeneous study populations and technical variability. In practice, meta-analysis tools have been applied to integrate data from multiple studies. However, these methods do not consider the heterogeneity caused by sequencing protocols, and the contribution of each study to the final model depends mainly on its sample size (or variance estimate). To combine studies with distinct sequencing protocols, a robust statistical framework for integrative analysis of microbiome datasets is needed. Here, we propose a mixed-effect kernel machine regression model to assess the association of alpha diversity with a phenotype of interest. Our approach readily incorporates the study-specific characteristics (including sequencing protocols) to allow for flexible modeling of microbiome effect via a kernel similarity matrix. Within the proposed framework, we provide three hypothesis testing approaches to answer different questions that are of interest to researchers. We evaluate the model performance through extensive simulations based on two distinct data generation mechanisms. We also apply our framework to data from HIV reanalysis consortium to investigate gut dysbiosis in HIV infection.
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microRNA-210 (miRNA), a well-documented miRNA, has been implicated in a myriad of biological processes, including responses to hypoxia, angiogenesis, cell proliferation, and male infertility in humans. However, a comprehensive understanding of its functions in fish requires further investigation. This study pursued to elucidate the downstream effect of dre-miR-210-5p on primary ovarian cell culture in zebrafish (Danio rerio), an animal model. A protocol was settled down by incubations with either an miR-210 mimic or a scrambled miRNA in the isolated ovaries. RNA-sequencing analysis identified â¼6000 differentially expressed target genes revealing that downregulated genes were associated with reproduction-related pathways while immune-related pathways displayed an upregulated pattern. To identify molecular markers, predicted target genes were classified into reproduction and immune cell types. These findings underscore the existence of a profound interplay between the reproductive and immune systems, with miR-210 emerging as a pivotal player in orchestrating transcriptomic alterations within fish ovaries.
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MicroRNAs , Ovário , Humanos , Animais , Feminino , Masculino , Ovário/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Peixe-Zebra/genética , Oócitos/metabolismo , MeioseRESUMO
INTRODUCTION: The equity-focused ILANA study evaluated feasibility, acceptability, appropriateness of delivering on-label two-monthly cabotegravir and rilpivirine (CAB+RPV) injections for HIV-1 therapy in clinics and community settings. METHODS: The study, which mandated inclusive recruitment, was conducted May-December 2022 at six UK sites. Injections were delivered in clinic (months 1-6), and in clinic or community setting according to patient choice (months 6-12). Surveys were completed at baseline, M4 and M12 using validated measures for feasibility (FIM), acceptability (AIM), and appropriateness (IAM). Primary endpoint: proportion of participants agreeing that the injection and community setting were feasible (FIM>4) at M12. Fourteen participants completed interviews at baseline and M12. RESULTS: Community settings offered by sites included: home visits (n=3), HIV support organisations (n=2), community clinic (n=1). Of 114 participants,54% were female, 70% racially minoritised and 40% aged >50. 27/114 chose to receive injections in community settings. FIM/AIM/IAM scores at M12 were high for the injection (79.0-87.4%) and lower for the community setting (44.2-47.4%) overall. Subgroup analyses indicated differences in scores by gender and ethnicity. Among those who attended the community, FIM/AIM/IAM scores for the community setting at M12 were high (73.1-80.8%). Concerns about stigma, inconvenience, and losing access to trusted clinicians negatively influenced perceptions of receiving injections at community settings, amongst other factors. CONCLUSION: CAB+RPV injections were considered highly feasible, acceptable, and appropriate, however few chose community delivery. Those that chose community delivery found it highly acceptable and feasible. Further exploration of CAB+RPV delivery in alternative community sites not offered (e.g. primary care or pharmacies) is warranted.
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International consensus supports the development of standardized protocols for measured glomerular filtration rate (mGFR) to facilitate the integration of mGFR testing in both clinical and research settings. To this end, the European Kidney Function Consortium convened an international group of experts with relevant experience in mGFR. The working group performed an extensive literature search to inform the development of recommendations for mGFR determination using 1-compartment plasma clearance models and iohexol as the exogenous filtration marker. Iohexol was selected as it is non-radio labeled, inexpensive, and safe, can be assayed at a central laboratory, and the other commonly used non-radio-labeled tracers have been (inulin) or are soon to be (iothalamate) discontinued. A plasma clearance model was selected over urine clearance as it requires no urine collection. A 1 compartment was preferred to 2 compartments as it requires fewer samples. The recommendations are based on published evidence complemented by expert opinion. The consensus paper covers practical advice for patients and health professionals, preparation, administration, and safety aspects of iohexol, laboratory analysis, blood sample collection and sampling times using both multiple and single-sample protocols, description of the mGFR mathematical calculations, as well as implementation strategies. Supplementary materials include patient and provider information sheets, standard operating procedures, a study protocol template, and support for mGFR calculation.
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Consenso , Meios de Contraste , Taxa de Filtração Glomerular , Iohexol , Rim , Adulto , Humanos , Meios de Contraste/efeitos adversos , Meios de Contraste/farmacocinética , Meios de Contraste/administração & dosagem , Europa (Continente) , Iohexol/farmacocinética , Iohexol/análise , Taxa de Depuração Metabólica , Modelos BiológicosRESUMO
BACKGROUND: The care of adolescents and young adults (AYAs) with bone sarcomas involves unique challenges. The objectives of this study were to identify challenges and evaluate long-term outcomes of these patients from India who received treatment with novel protocols. METHODS: This prospective cohort study included AYA patients (aged 15-39 years) with osteosarcoma and Ewing sarcoma (ES), who were treated uniformly at the authors' institute using unique protocols (OGS-12 and EFT-2001) from 2011 to 2021 and from 2013 to 2018, respectively. RESULTS: The cohorts included 688 of 748 (91.9%) treatment-naive AYA patients with osteosarcoma and 126 of 142 (88.7%) treatment-naive AYA patients with ES. Among 481 of 561 patients (85.7%) who had nonmetastatic osteosarcoma treated according to protocol, at a median follow-up of 59.7 months, the 5-year event-free survival (5-EFS) rate was 58.6% (95% confidence interval, 54.1%-63.5%) and for 142 patients (20.6%) who had metastatic osteosarcoma, the 5-EFS rate was 18.7%. The 5-EFS rate was 66.4% and 21.9% for 104 patients (73%) with nonmetastatic ES and 38 patients (27%) with metastatic ES, respectively. Treatment-naive patients had better outcomes, similar to compliance in the form of protocol completion (hazard ratio, 1.93 [p = .0043] and 2.66 [p < .0001], respectively. Only 230 of 377 (61.0%) male patients and 10 of 134 (7.4%) female patients reached out to fertility specialists. In addition, 17 of 161 (10.6%) eligible male survivors and 14 of 61 (22.9%) eligible female survivors got married posttreatment. Furthermore, 14 of 17 (82.4%) males and 14 of 14 (100%) females conceived. Among 311 patients who were working or attending school during diagnosis, greater than 90% had interruptions. CONCLUSIONS: Homogenous treatment with the OGS-12 and EFT-2001 protocols resulted in internationally comparable long-term outcomes in the cohorts with nonmetastatic and metastatic AYA bone sarcomas. Treatment compliance, timely referral to sarcoma reference centers (avoiding prior inadvertent treatment), and streamlining fertility-preservation practices constitute unmet needs that demand prioritization.
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BACKGROUND: Immune checkpoint inhibitor (ICI) therapy has led to significant improvement in outcomes for patients with nononcogene-driven advanced non-small cell lung cancer (NSCLC). The rate of crossover and receipt of postprotocol ICI in frontline trials for advanced NSCLC has not been systematically evaluated. METHODS: ClinicalTrials.gov was used to identify phase 3 studies evaluating the use of immunotherapy or combination chemoimmunotherapy against chemotherapy alone in the frontline management of advanced NSCLC. Data on outcomes, rate of crossover and/or subsequent post-protocol receipt of immunotherapy, and the start dates of these clinical trials were then extracted. RESULTS: Twenty-three frontline trials in nononcogene-driven advanced NSCLC were identified. Six trials with ICI monotherapy/dual ICI therapy and 17 trials evaluating chemotherapy/ICI in first-line advanced NSCLC were included in the analysis. The crossover rate ranged 0% to 54% in ICI monotherapy/dual ICI trials and 0% to 52% in chemotherapy/ICI trials. Nineteen of 23 trials provided information on subsequent postprotocol therapies. Among the trials not allowing crossover, postprotocol ICI was administered to 17% to 45.8% of patients. Information regarding the eventual receipt of ICI therapy was available for 22 of 23 trials. Of 6631 patients, 2507 (37.8%) randomized to the control arm eventually received ICI therapy. CONCLUSION: The rate of crossover and postprotocol ICI use was low in frontline trials for first-line NSCLC incorporating ICI. Given the proven improved overall survival of ICI in a broad population, there is a need to ensure availability of this life-prolonging therapy in future trials, either by crossover treatment or postprotocol administration.
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Carcinoma Pulmonar de Células não Pequenas , Estudos Cross-Over , Inibidores de Checkpoint Imunológico , Imunoterapia , Neoplasias Pulmonares , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/terapia , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/imunologia , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/terapia , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/mortalidade , Imunoterapia/métodos , Inibidores de Checkpoint Imunológico/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Ensaios Clínicos Fase III como AssuntoRESUMO
The rapid increase in strength following strength-training involves neural adaptations, however, their specific localisation remains elusive. Prior focus on corticospinal responses prompts this study to explore the understudied cortical/subcortical adaptations, particularly cortico-reticulospinal tract responses, comparing healthy strength-trained adults to untrained peers. Fifteen chronically strength-trained individuals (≥2 years of training, mean age: 24 ± 7 years) were compared with 11 age-matched untrained participants (mean age: 26 ± 8 years). Assessments included maximal voluntary force (MVF), corticospinal excitability using transcranial magnetic stimulation (TMS), spinal excitability (cervicomedullary stimulation), voluntary activation (VA) and reticulospinal tract (RST) excitability, utilizing StartReact responses and ipsilateral motor-evoked potentials (iMEPs) for the flexor carpi radialis muscle. Trained participants had higher normalized MVF (6.4 ± 1.1 N/kg) than the untrained participants (4.8 ± 1.3 N/kg) (p = .003). Intracortical facilitation was higher in the strength-trained group (156 ± 49%) (p = .02), along with greater VA (98 ± 3.2%) (p = .002). The strength-trained group displayed reduced short-interval-intracortical inhibition (88 ± 8.0%) compared with the untrained group (69 ± 17.5%) (p < .001). Strength-trained individuals exhibited a greater normalized rate of force development (38.8 ± 10.1 N·s-1/kg) (p < .009), greater reticulospinal gain (2.5 ± 1.4) (p = .02) and higher ipsilateral-to-contralateral MEP ratios compared with the untrained group (p = .03). Strength-trained individuals displayed greater excitability within the intrinsic connections of the primary motor cortex and the RST. These results suggest greater synaptic input from the descending cortico-reticulospinal tract to α-motoneurons in strength-trained individuals, thereby contributing to the observed increase in VA and MVF.
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Potencial Evocado Motor , Músculo Esquelético , Tratos Piramidais , Treinamento Resistido , Estimulação Magnética Transcraniana , Humanos , Adulto , Masculino , Potencial Evocado Motor/fisiologia , Feminino , Estimulação Magnética Transcraniana/métodos , Tratos Piramidais/fisiologia , Treinamento Resistido/métodos , Músculo Esquelético/fisiologia , Adulto Jovem , Córtex Motor/fisiologia , Força Muscular/fisiologia , Adaptação Fisiológica/fisiologia , EletromiografiaRESUMO
In this proof-of-concept study, spatial transcriptomics combined with public single-cell ribonucleic acid-sequencing data were used to explore the potential of this technology to study kidney allograft rejection. We aimed to map gene expression patterns within diverse pathologic states by examining biopsies classified across nonrejection, T cell-mediated acute rejection, interstitial fibrosis, and tubular atrophy. Our results revealed distinct immune cell signatures, including those of T and B lymphocytes, monocytes, mast cells, and plasma cells, and their spatial organization within the renal interstitium. We also mapped chemokine receptors and ligands to study immune cell migration and recruitment. Finally, our analysis demonstrated differential spatial enrichment of transcription signatures associated with kidney allograft rejection across various biopsy regions. Interstitium regions displayed higher enrichment scores for rejection-associated gene expression patterns than tubular areas, which had negative scores. This implies that these signatures are primarily driven by processes unfolding in the renal interstitium. Overall, this study highlights the value of spatial transcriptomics for revealing cellular heterogeneity and immune signatures in renal transplant biopsies and demonstrates its potential for studying the molecular and cellular mechanisms associated with rejection. However, certain limitations must be borne in mind regarding the development and future applications of this technology.
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Rejeição de Enxerto , Transplante de Rim , Estudo de Prova de Conceito , Transcriptoma , Rejeição de Enxerto/patologia , Rejeição de Enxerto/genética , Rejeição de Enxerto/etiologia , Transplante de Rim/efeitos adversos , Humanos , Perfilação da Expressão Gênica , Prognóstico , Sobrevivência de Enxerto/imunologia , Biomarcadores/metabolismo , AloenxertosRESUMO
The Banff Working Group on Liver Allograft Pathology met in September 2022. Participants included hepatologists, surgeons, pathologists, immunologists, and histocompatibility specialists. Presentations and discussions focused on the evaluation of long-term allograft health, including noninvasive and tissue monitoring, immunosuppression optimization, and long-term structural changes. Potential revision of the rejection classification scheme to better accommodate and communicate late T cell-mediated rejection patterns and related structural changes, such as nodular regenerative hyperplasia, were discussed. Improved stratification of long-term maintenance immunosuppression to match the heterogeneity of patient settings will be central to improving long-term patient survival. Such personalized therapeutics are in turn contingent on a better understanding and monitoring of allograft status within a rational decision-making approach, likely to be facilitated in implementation with emerging decision-support tools. Proposed revisions to rejection classification emerging from the meeting include the incorporation of interface hepatitis and fibrosis staging. These will be opened to online testing, modified accordingly, and subject to consensus discussion leading up to the next Banff conference.
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Rejeição de Enxerto , Transplante de Fígado , Humanos , Rejeição de Enxerto/etiologia , Rejeição de Enxerto/patologia , Sobrevivência de Enxerto , AloenxertosRESUMO
Phage therapy has (re)emerged as a serious possibility for combating multidrug-resistant bacterial infections, including those caused by vancomycin-resistant Enterococcus faecium strains. These opportunistic pathogens belong to a specific clonal complex 17, against which relatively few phages have been screened. We isolated a collection of 21 virulent phages growing on these vancomycin-resistant isolates. Each of these phages harbored a typical narrow plaquing host range, lysing at most 5 strains and covering together 10 strains of our panel of 14 clinical isolates. To enlarge the host spectrum of our phages, the Appelmans protocol was used. We mixed four out of our most complementary phages in a cocktail that we iteratively grew on eight naive strains from our panel, of which six were initially refractory to at least three of the combined phages. Fifteen successive passages permitted to significantly improve the lytic activity of the cocktail, from which phages with extended host ranges within the E. faecium species could be isolated. A single evolved phage able to kill up to 10 of the 14 initial E. faecium strains was obtained, and it barely infected nearby species. All evolved phages had acquired point mutations or a recombination event in the tail fiber genetic region, suggesting these genes might have driven phage evolution by contributing to their extended host spectra.
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Bacteriófagos , Enterococcus faecium , Especificidade de Hospedeiro , Enterococos Resistentes à Vancomicina , Enterococcus faecium/efeitos dos fármacos , Bacteriófagos/genética , Enterococos Resistentes à Vancomicina/efeitos dos fármacos , Terapia por Fagos/métodos , Infecções por Bactérias Gram-Positivas/microbiologia , Resistência a Vancomicina , Vancomicina/farmacologia , Humanos , Antibacterianos/farmacologiaRESUMO
Basket trials are increasingly used for the simultaneous evaluation of a new treatment in various patient subgroups under one overarching protocol. We propose a Bayesian approach to sample size determination in basket trials that permit borrowing of information between commensurate subsets. Specifically, we consider a randomized basket trial design where patients are randomly assigned to the new treatment or control within each trial subset ("subtrial" for short). Closed-form sample size formulae are derived to ensure that each subtrial has a specified chance of correctly deciding whether the new treatment is superior to or not better than the control by some clinically relevant difference. Given prespecified levels of pairwise (in)commensurability, the subtrial sample sizes are solved simultaneously. The proposed Bayesian approach resembles the frequentist formulation of the problem in yielding comparable sample sizes for circumstances of no borrowing. When borrowing is enabled between commensurate subtrials, a considerably smaller trial sample size is required compared to the widely implemented approach of no borrowing. We illustrate the use of our sample size formulae with two examples based on real basket trials. A comprehensive simulation study further shows that the proposed methodology can maintain the true positive and false positive rates at desired levels.
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Projetos de Pesquisa , Humanos , Tamanho da Amostra , Teorema de Bayes , Simulação por ComputadorRESUMO
In this work, the reactions of quadricyclane with dimethyl azodicarboxylate (DMAD) and of quadricyclane with diethyl azodicarboxylate (DEAD) in gas phase and in water environments were studied by a first-principles investigation within the framework of auxiliary density functional theory (ADFT). For these type of organic reactions is known that water is required to accelerate them. Since the reason of why this occur is still unknown, this work aims to gain insight into this reaction mechanism. For this investigation, the generalized gradient approximation as well as a hybrid functional were employed. The obtained optimized structures for the reactants, of the products and of the transition states are reported, together with the corresponding frequency analysis results and the reaction profiles. Along the proposed concerted reaction mechanism, a critical points search of the electron density and a charge analysis were performed. The calculated potential energy barriers of these reactions in gas phase and in water environments are compared. In agreement with experiment, the obtained results indicate that both reactions occur faster in water than in gas phase. This study shows that there is a change in the polarity of the two most important carbon atoms of the formed compounds along the reactions and that the decrease of the activation energy barrier which occurs in liquid phase in these reactions is because the structures of the main transition states are stabilized by the water environment. Therefore, the here obtained results demonstrate the important role played by the water-molecule framework into the activation energy barrier and structures of the molecules that participate in the DMAD and DEAD cycloaddition reactions.
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Solvent effects on 31P-NMR parameters for triphenylphosphine oxide and triphenylphosphine in chloroform have been extensively investigated by testing different solvation models. The solvent is described implicitly, mixed implicitly/explicitly, and using full explicit models. Polarizable continuum model (PCM), molecular dynamic (MD) simulations, and hybrid quantum mechanics/molecular mechanics (QM/MM) calculations are used to disclose the effects of solute/solvent interactions and, more generally, the role of the embedding in NMR simulations. The results show the beneficial effect of carrying out QM/MM optimizations on top of geometries directly extracted from classical MD simulations, used to ensure representative conformational sampling. The nuclear shielding convergence has been tested against a different number of snapshots and with the inclusion of solvent shells into the QM region. An automated MD//QM/MM//GIAO protocol, implemented in the COBRAMM package, is here proposed and tested on trimethyl phosphite showing that our approach boosts the convergence of nuclear shielding satisfactorily. The present work aims to be a stepping-stone to assess proper QM/MM computational strategies in simulating chemical shifts in non-homogeneous systems like supramolecular and biological systems.
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Researchers in the biological and behavioural sciences are increasingly conducting collaborative, multi-sited projects to address how phenomena vary across ecologies. These types of projects, however, pose additional workflow challenges beyond those typically encountered in single-sited projects. Through specific attention to cross-cultural research projects, we highlight four key aspects of multi-sited projects that must be considered during the design phase to ensure success: (1) project and team management; (2) protocol and instrument development; (3) data management and documentation; and (4) equitable and collaborative practices. Our recommendations are supported by examples from our experiences collaborating on the Evolutionary Demography of Religion project, a mixed-methods project collecting data across five countries in collaboration with research partners in each host country. To existing discourse, we contribute new recommendations around team and project management, introduce practical recommendations for exploring the validity of instruments through qualitative techniques during piloting, highlight the importance of good documentation at all steps of the project, and demonstrate how data management workflows can be strengthened through open science practices. While this project was rooted in cross-cultural human behavioural ecology and evolutionary anthropology, lessons learned from this project are applicable to multi-sited research across the biological and behavioural sciences.