54 research outputs found

    What is the best approach to goiter for euthyroid patients?

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    A detailed history and exam, confirmation of euthyroid status, and imaging when appropriate is the best approach to euthyroid patients with thyroid enlargement in regions where goiters are not endemic. Ultrasound imaging is recommended in any case of diagnostic uncertainty. Evaluate dominant or suspicious nodules further, while diffuse goiters without symptoms require no further evaluation and can be followed clinically (strength of recommendation [SOR]: C, expert opinion)

    Recyclable NHC catalyst for the development of a generalized approach to continuous Buchwald-Hartwig reaction and work-up

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    A generalized approach to the optimization and implementation of Buchwald-Hartwig reactions in flow is reported, through the combination of three key factors: a highly active palladium catalyst; a universal approach for continuous work-up and purification, and a methodology for catalyst recycling and reuse. The palladium N-heterocyclic carbene (NHC) pre-catalyst [Pd(IPr*)(cin)Cl] 4 (IPr* = 1,3-bis(2,6-bis(diphenylmethyl)-4-methylphenyl)imidazol-2-ylidene; cin = η3-cinnamyl) is an excellent choice for continuous Buchwald-Hartwig reactions, due to its inherent high activity and stability. In preparation for running this reaction in flow (published concurrently), a detailed study has been carried out into its water stability, ultimately allowing the recycling of the catalyst in the organic phase up to 3 times in batch mode. A “right-first-time” work-up methodology has also been developed, resulting in a universal protocol that allows the selective extraction of the Buchwald-Hartwig product into the aqueous stream as a salt, while retaining the aryl bromide starting material in the organic stream with the catalyst, thus negating the requirement for further purification. It is therefore envisaged that this approach will particularly amenable to exploitation in the Pharmaceutical industry. An optimized, scalable synthesis of [Pd(IPr*)(cin)Cl] is also reported on multi-hundred gram scale

    The Changing Face of Winter: Lessons and Questions From the Laurentian Great Lakes

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    Among its many impacts, climate warming is leading to increasing winter air temperatures, decreasing ice cover extent, and changing winter precipitation patterns over the Laurentian Great Lakes and their watershed. Understanding and predicting the consequences of these changes is impeded by a shortage of winter-period studies on most aspects of Great Lake limnology. In this review, we summarize what is known about the Great Lakes during their 3–6 months of winter and identify key open questions about the physics, chemistry, and biology of the Laurentian Great Lakes and other large, seasonally frozen lakes. Existing studies show that winter conditions have important effects on physical, biogeochemical, and biological processes, not only during winter but in subsequent seasons as well. Ice cover, the extent of which fluctuates dramatically among years and the five lakes, emerges as a key variable that controls many aspects of the functioning of the Great Lakes ecosystem. Studies on the properties and formation of Great Lakes ice, its effect on vertical and horizontal mixing, light conditions, and biota, along with winter measurements of fundamental state and rate parameters in the lakes and their watersheds are needed to close the winter knowledge gap. Overcoming the formidable logistical challenges of winter research on these large and dynamic ecosystems may require investment in new, specialized research infrastructure. Perhaps more importantly, it will demand broader recognition of the value of such work and collaboration between physicists, geochemists, and biologists working on the world\u27s seasonally freezing lakes and seas

    "If we use the strength of diversity among researchers we can only improve the quality and impact of our research": Issues of equality, diversity, inclusion, and transparency in the process of applying for research funding

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    This paper sets out the recommendations that have emerged from a six-month-long exploration and discussion of the processes that take place before research is submitted for funding: the ‘pre-award’ environment. Our work concentrated on how this environment is experienced by researchers at all career stages and from a variety of backgrounds, demographics, and disciplines, as well as by research managers and research support professionals. In the later stages of our exploration, representatives from research funders were also involved in the discussions. The primary component of this project was an analysis of pre-award activities and processes at UK universities, using information collated from workshops with researchers and research management and support staff. The findings of this analysis were presented as a workflow diagram, which was then used to surface issues relating to equality, diversity, inclusion, and transparency in context. The workflow diagram and the issues highlighted by it were used to structure discussions at a symposium for a range of research stakeholders, held in Bristol, UK, in January 2023. The recommendations set out in this paper are drawn from discussions that took place at that event. This paper is not an exhaustive landscape analysis, nor a review of existing research and practice in the area of pre-award processes or of recent thinking on the topics of equality, diversity, and inclusion (EDI). Instead, it aims to summarise and encapsulate the suggestions put forward by the stakeholders during the symposium. These recommendations, from experienced professionals working in the field, are based on their encounters with the issues raised in the project. They do not solely relate to those working on pre-award processes, but may also apply to funders, policymakers, university leaders, and professional associations, since many of the challenges flagged in our research are systemic and cultural, and reach far beyond the research office

    Evaluating the Effects of SARS-CoV-2 Spike Mutation D614G on Transmissibility and Pathogenicity.

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    Global dispersal and increasing frequency of the SARS-CoV-2 spike protein variant D614G are suggestive of a selective advantage but may also be due to a random founder effect. We investigate the hypothesis for positive selection of spike D614G in the United Kingdom using more than 25,000 whole genome SARS-CoV-2 sequences. Despite the availability of a large dataset, well represented by both spike 614 variants, not all approaches showed a conclusive signal of positive selection. Population genetic analysis indicates that 614G increases in frequency relative to 614D in a manner consistent with a selective advantage. We do not find any indication that patients infected with the spike 614G variant have higher COVID-19 mortality or clinical severity, but 614G is associated with higher viral load and younger age of patients. Significant differences in growth and size of 614G phylogenetic clusters indicate a need for continued study of this variant

    SARS-CoV-2 B.1.617.2 Delta variant replication and immune evasion

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    Abstract: The B.1.617.2 (Delta) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first identified in the state of Maharashtra in late 2020 and spread throughout India, outcompeting pre-existing lineages including B.1.617.1 (Kappa) and B.1.1.7 (Alpha)1. In vitro, B.1.617.2 is sixfold less sensitive to serum neutralizing antibodies from recovered individuals, and eightfold less sensitive to vaccine-elicited antibodies, compared with wild-type Wuhan-1 bearing D614G. Serum neutralizing titres against B.1.617.2 were lower in ChAdOx1 vaccinees than in BNT162b2 vaccinees. B.1.617.2 spike pseudotyped viruses exhibited compromised sensitivity to monoclonal antibodies to the receptor-binding domain and the amino-terminal domain. B.1.617.2 demonstrated higher replication efficiency than B.1.1.7 in both airway organoid and human airway epithelial systems, associated with B.1.617.2 spike being in a predominantly cleaved state compared with B.1.1.7 spike. The B.1.617.2 spike protein was able to mediate highly efficient syncytium formation that was less sensitive to inhibition by neutralizing antibody, compared with that of wild-type spike. We also observed that B.1.617.2 had higher replication and spike-mediated entry than B.1.617.1, potentially explaining the B.1.617.2 dominance. In an analysis of more than 130 SARS-CoV-2-infected health care workers across three centres in India during a period of mixed lineage circulation, we observed reduced ChAdOx1 vaccine effectiveness against B.1.617.2 relative to non-B.1.617.2, with the caveat of possible residual confounding. Compromised vaccine efficacy against the highly fit and immune-evasive B.1.617.2 Delta variant warrants continued infection control measures in the post-vaccination era
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