763 research outputs found

    Antifreeze protein mimetic metallohelices with potent ice recrystallization inhibition activity

    Get PDF
    Antifreeze proteins are produced by extremophile species to control ice formation and growth, and they have potential applications in many fields. There are few examples of synthetic materials which can reproduce their potent ice recrystallization inhibition property. We report that self-assembled enantiomerically pure, amphipathic metallohelicies inhibited ice growth at just 20 ÎĽM. Structure-property relationships and calculations support the hypothesis that amphipathicity is the key motif for activity. This opens up a new field of metallo-organic antifreeze protein mimetics and provides insight into the origins of ice-growth inhibition

    Chapter 9 THE NATURE AND ECOLOGICAL SIGNIFICANCE OF EPIFAUNAL COMMUNITIES WITHIN MARINE ECOSYSTEMS

    Get PDF
    oceanography, climate change, reefs, marine science, marine conservation, marine researc

    NMR-based assignment of isoleucine vs allo-isoleucine stereochemistry

    Get PDF
    A simple 1H and 13C NMR spectrometric analysis is demonstrated that permits differentiation of isoleucine and allo-isoleucine residues by inspection of the chemical shift and coupling constants of the signals associated with the proton and carbon at the α-stereocentre. This is applied to the estimation of epimerisation during metal-free N-arylation and peptide coupling reactions

    Methodology for reliable and reproducible cryopreservation of human cervical tissue

    Get PDF
    BACKGROUND: In order to conduct laboratory studies on donated cervical tissue at suitable times an effective and reliable cryopreservation protocol for cervical tissue is required. METHODS: An active freezing approach was devised utilising 10% dimethyl sulfoxide in foetal bovine serum as a cryoprotective agent with a cooling rate of 1 °C/min to -50 °C then 10 °C/min to -120 °C; a related thawing protocol was also optimised which would allow for the bio-banking of cervical tissue. Viability of freshly harvested cervical tissue was compared to frozen-thawed samples utilising colorimetric MTT assay. In parallel, fresh and freeze-thawed samples were cultured and tested on days 1, 7 and 14 to determine whether bio-banking had detrimental effects on tissue viability over time. RESULTS: Repeat testing revealed that tissue viability between fresh and freeze-thawed wasand freeze-thawed samples was comparable at all four time points (days 0, 1, 7 and 14) with no apparent reductions of viability, thus demonstrating this method of cryopreserving cervical tissue is reliable and reproducible, without detrimental effects on live tissue culture. We believe this methodology creates the opportunity for bio-banking donated cervical tissues, which aids improved experimental design and reduces time pressures and wastage

    Challenging the current hypothesis that thrombosis is responsible for the post-COVID-19 condition

    Get PDF
    People with the post-COVID-19 condition suffer symptoms that persist beyond 12 weeks following acute COVID-19 infection. Fatigue, shortness of breath, and cognitive dysfunction (“brain fog”) are common. Scientists, clinicians, and patients debate the pathophysiology. One pathophysiological hypothesis is that prothrombotic changes associated with acute COVID-19 persist, causing clots that lead to symptoms. This theory, arising from a research team in South Africa and supported by a paper in Nature Medicine, has been widely disseminated on social media and entered the public narrative as a cause of the post-COVID-19 condition.We describe the development of this theory, examine the findings of a Cochrane review that critically appraises the “microclot” beliefs, and critically appraise the influential study relating clotting biomarkers to cognitive deficits. We conclude the inferences for the hypothesis are not based on evidence, unlicensed use of antithrombotic medication is not justified, and apheresis should not be considered outside of a well-designed clinical trial

    A Gene Expression Fingerprint of C. Elegans Embryonic Motor Neurons

    Get PDF
    Differential gene expression specifies the highly diverse cell types that constitute the nervous system. With its sequenced genome and simple, well-defined neuroanatomy, the nematode C. elegans is a useful model system in which to correlate gene expression with neuron identity. The UNC-4 transcription factor is expressed in thirteen embryonic motor neurons where it specifies axonal morphology and synaptic function. These cells can be marked with an unc-4::GFP reporter transgene. Here we describe a powerful strategy, Micro-Array Profiling of C. elegans cells (MAPCeL), and confirm that this approach provides a comprehensive gene expression profile of unc-4::GFP motor neurons in vivo.

    "Post-GDM support would be really good for mothers": A qualitative interview study exploring how to support a healthy diet and physical activity after gestational diabetes.

    Get PDF
    BACKGROUND: Women with a history of gestational diabetes mellitus (GDM) are at high risk of developing type 2 diabetes mellitus (T2DM). They are therefore recommended to follow a healthy diet and be physically active in order to reduce that risk. However, achieving and maintaining these behaviours in the postpartum period is challenging. This study sought to explore women's views on suggested practical approaches to achieve and maintain a healthy diet and physical activity to reduce T2DM risk. METHODS: Semi-structured interviews with 20 participants in Cambridgeshire, UK were conducted at three to 48 months after GDM. The participants' current diet and physical activity, intentions for any changes, and views on potential interventions to help manage T2DM risk through these behaviours were discussed. Framework analysis was used to analyse the transcripts. The interview schedule, suggested interventions, and thematic framework were based on a recent systematic review. RESULTS: Most of the participants wanted to eat more healthily and be more active. A third of the participants considered that postpartum support for these behaviours would be transformative, a third thought it would be beneficial, and a third did not want additional support. The majority agreed that more information about the impact of diet and physical activity on diabetes risk, support to exercise with others, and advice about eating healthily, exercising with a busy schedule, monitoring progress and sustaining changes would facilitate a healthy diet and physical activity. Four other suggested interventions received mixed responses. It would be acceptable for this support to be delivered throughout pregnancy and postpartum through a range of formats. Clinicians were seen to have important roles in giving or signposting to support. CONCLUSIONS: Many women would appreciate more support to reduce their T2DM risk after GDM and believe that a variety of interventions to integrate changes into their daily lives would help them to sustain healthier lifestyles.RAD was funded by a PhD studentship from the National Institute for Health Research (NIHR) School for Primary Care Research (SPCR; SPCR-S-S102). This paper presents independent research funded by the NIHR SPCR. The views expressed are those of the author(s) and not necessarily those of the NIHR, the NHS or the Department of Health. JAUS was funded by a Cancer Research UK Cancer Prevention Fellowship (C55650/A21464). SJG is supported by the Medical Research Council (MC_UU_12015/4). The University of Cambridge has received salary support in respect of SJG from the NHS in the East of England through the Clinical Academic Reserve. CEA is supported by an Action Medical Research Grant (GN2778) and a Medical Research Council New Investigator Research Grant (MR/T016701/1). CLM is supported by the Diabetes UK Harry Keen Intermediate Clinical Fellowship (DUK-HKF 17/0005712) and the European Foundation for the Study of Diabetes – Novo Nordisk Foundation Future Leaders’ Award (NNF19SA058974). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Collective Sensemaking Around COVID-19: Experiences, Concerns, and Agendas for our Rapidly Changing Organizational Lives

    Get PDF
    Uncertainty is at the forefront of many crises, disasters, and emergencies, and the COVID-19 pandemic is no different in this regard. In this forum, we, as a group of organizational communication scholars currently living in North America, engage in sensemaking and sensegiving around this pandemic to help process and share some of the academic uncertainties and opportunities relevant to organizational scholars. We begin by reflexively making sense of our own experiences with adjusting to new ways of working during the onset of the pandemic, including uncomfortable realizations around privilege, positionality, race, and ethnicity. We then discuss key concerns about how organizations and organizing practices are responding to this extreme uncertainty. Finally, we offer thoughts on the future of work and organizing informed by COVID-19, along with a list of research practice considerations and potentially generative research questions. Thus, this forum invites you to reflect on your own experiences and suggests future directions for research amidst and after a cosmology event

    Scale-Up of the Carbon Dioxide Removal by Ionic Liquid Sorbent (CDRILS) System

    Get PDF
    The Carbon Dioxide Removal by Ionic Liquid Sorbent (CDRILS) system is designed for efficient, safe and reliable carbon dioxide (CO2) removal from cabin air on long-duration missions to the Moon, deep space, and Mars. CDRILS integrates an ionic liquid sorbent with hollow fiber membrane contactors for rapid CO2 removal and recovery. The liquid-based system provides continuous CO2 delivery, which avoids complicated valve networks to switch between absorbing and desorbing beds and enables simpler integration to the Sabatier without the need for the CO2 Management System (CMS). Ionic liquids are particularly desirable as liquid absorbents for space applications since they are non-volatile, non-odorous, and have high oxidative stability. The hollow fiber membrane contactors offer both high contact area and rigorous containment between the gas and liquid phases in a microgravity environment. Scale-up of the CDRILS technology has presented a series of fascinating challenges, since the interaction between hollow fiber properties, ionic liquid properties and performance is complex. Properties measured with lab-scale hollow fiber contactors are used to estimate the performance of contactors that are similar in scale to flight-scale demonstrations. To accomplish this, component and system models have been built to relate the key scrubber and stripper design and operating variables with performance, and experiments directed to validate the models have been performed. System size, weight and power are determined by component selection, arrangement, and operating conditions. Reliability will be extremely important for any long-range mission and depends on the stability of the ionic liquids and hollow fiber contactors. We report on our continuing long term stability experiments for the ionic liquid and contactor materials and our investigation of the physical properties of additional ionic liquids
    • …
    corecore