359 research outputs found

    Rapid Screening of Calcium Carbonate Precipitation in the Presence of Amino Acids: Kinetics, Structure, and Composition

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    Soluble additives are widely used to control crystallization, leading to a definition of properties including size, morphology, polymorph, and composition. However, because of the number of potential variables in these experiments, it is typically extremely difficult to identify reaction conditions—as defined by solution compositions, temperatures, and combinations of additives—that give the desired product. This article introduces a high-throughput methodology which addresses this challenge and enables the streamlined preparation and characterization of crystalline materials. Using calcium carbonate precipitated in the presence of selected amino acids as a model system, we use well plates as microvolume crystallizers, and an accurate liquid-handling pipetting workstation for sample preparation. Following changes in the solution turbidity using a plate reader delivers information about the reaction kinetics, while semiautomated scanning electron microscopy, powder X-ray diffraction, and Raman microscopy provide structural information about the library of crystalline products. Of particular interest for the CaCO3 system is the development of fluorescence-based protocols which rapidly evaluate the amounts of the additives occluded within the crystals. Together, these methods provide a strategy for efficiently screening a broad reaction space, where this can both accelerate the ability to generate crystalline materials with target properties and develop our understanding of additive-directed crystallization

    Calcite Kinetics for Spiral Growth and Two-Dimensional Nucleation

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    Calcite crystals grow by means of molecular steps that develop on {10.4} faces. These steps can arise stochastically via two-dimensional (2D) nucleation or emerge steadily from dislocations to form spiral hillocks. Here, we determine the kinetics of these two growth mechanisms as a function of supersaturation. We show that calcite crystals larger than ∼1 μm favor spiral growth over 2D nucleation, irrespective of the supersaturation. Spirals prevail beyond this length scale because slow boundary layer diffusion creates a low surface supersaturation that favors the spiral mechanism. Sub-micron crystals favor 2D nucleation at high supersaturations, although diffusion can still limit the growth of nanoscopic crystals. Additives can change the dominant mechanism by impeding spiral growth or by directly promoting 2D nucleation

    Inclusion of KI67 significantly improves performance of the PREDICT prognostication and prediction model for early breast cancer.

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    BACKGROUND: PREDICT (http://www.predict.nhs.uk) is a prognostication and treatment benefit tool for early breast cancer (EBC). The aim of this study was to incorporate the prognostic effect of KI67 status in a new version (v3), and compare performance with the Predict model that includes HER2 status (v2). METHODS: The validation study was based on 1,726 patients with EBC treated in Nottingham between 1989 and 1998. KI67 positivity for PREDICT is defined as >10% of tumour cells staining positive. ROC curves were constructed for Predict models with (v3) and without (v2) KI67 input. Comparison was made using the method of DeLong. RESULTS: In 1274 ER+ patients the predicted number of events at 10 years increased from 196 for v2 to 204 for v3 compared to 221 observed. The area under the ROC curve (AUC) improved from 0.7611 to 0.7676 (p=0.005) in ER+ patients and from 0.7546 to 0.7595 (p=0.0008) in all 1726 patients (ER+ and ER-). CONCLUSION: Addition of KI67 to PREDICT has led to a statistically significant improvement in the model performance for ER+ patients and will aid clinical decision making in these patients. Further studies should determine whether other markers including gene expression profiling provide additional prognostic information to that provided by PREDICT.SEARCH was funded through a programme grant from Cancer Research UK (C490/A10124) and this work is supported by the UK National Institute for Health Research Biomedical Research Centre at the University of Cambridge.This is the final version of the article. It first appeared from BioMed Central via http://dx.doi.org/10.1186/1471-2407-14-90

    How to harness and improve on video analysis for youth rugby player safety: A narrative review

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    Video analysis is a useful tool for injury surveillance in rugby union. There are few video analysis studies in the professional female game, with most studies published in the male elite/professional settings. Moreover, there is a sparsity of literature in youth rugby settings. The following narrative review outlines the strengths and limitations of the current video analysis literature for injury surveillance in youth rugby union, highlights the importance of video analysis for youth rugby player safety and welfare, and discusses recommendations for using video analysis to inform player safety in youth rugby

    How to harness and improve on video analysis for youth rugby player safety: A narrative review

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    Video analysis is a useful tool for injury surveillance in rugby union. There are few video analysis studies in the professional female game, with most studies published in the male elite/professional settings. Moreover, there is a sparsity of literature in youth rugby settings. The following narrative review outlines the strengths and limitations of the current video analysis literature for injury surveillance in youth rugby union, highlights the importance of video analysis for youth rugby player safety and welfare, and discusses recommendations for using video analysis to inform player safety in youth rugby

    Is late-life dependency increasing or not? A comparison of the Cognitive Function and Ageing Studies (CFAS)

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    Background: Little is known about how dependency levels have changed between generational cohorts of older people. We estimated years lived in different care states at age 65 in 1991 and 2011 and new projections of future demand for care. Methods: Two population-based studies of older people in defined geographical areas conducted two decades apart (the Cognitive Function and Ageing Studies) provided prevalence estimates of dependency in four states: high (24-hour care); medium (daily care); low (less than daily); independent. Years in each dependency state were calculated by Sullivan’s method. To project future demand, the proportions in each dependency state (by age group and sex) were applied to the 2014 England population projections. Findings: Between 1991 and 2011 there were significant increases in years lived from age 65 with low (men:1·7 years, 95%CI 1·0-2·4; women:2·4 years, 95%CI 1·8-3·1) and high dependency (men:0·9 years, 95%CI 0·2-1·7; women:1·3 years, 95%CI 0·5-2·1). The majority of men’s extra years of life were independent (36%) or with low dependency (36%) whilst for women the majority were spent with low dependency (58%), only 5% being independent. There were substantial reductions in the proportions with medium and high dependency who lived in care homes, although, if these dependency and care home proportions remain constant in the future, further population ageing will require an extra 71,000 care home places by 2025. Interpretation: On average older men now spend 2.4 years and women 3.0 years with substantial care needs (medium or high dependency), and most will live in the community. These findings have considerable implications for older people’s families who provide the majority of unpaid care, but the findings also supply valuable new information for governments and care providers planning the resources and funding required for the care of their future ageing populations

    Measuring psychological health in the perinatal period: workshop consensus statement, 19 March 2013

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    This consensus statement is the result of an invited workshop funded by the society for Reproductive and Infant Psychology on Measuring Psychological Health in the Perinatal Period which was held in Oxford on the 19th March 2013. The details of those who participated in the workshop can be found at the end of the consensus statement. The workshop evolved out of recognition that a major limitation to research and practice in the perinatal period is identifying valid, reliable and clinically relevant measures of psychological health

    Skin-Deep Surface Patterning of Calcite

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    The influence of soluble additives on the growth of calcite (CaCO3) is usually rationalized based on changes in crystal morphologies, where preferential association of the additives with either the acute or obtuse steps on the crystal surface gives rise to specific growth forms. In this work we investigate the influence of a highly acidic organic additive with calcite, cp20k from the barnacle Megabalanus rosa, and demonstrate that in addition to modifying the crystal morphology, additives can be used to generate calcite crystals with different surface architectures. These can potentially rise to interesting optical effects that may be important in applications such as in coatings and paints. These surface features form during dissolution/reprecipitation at the crystal surface during the incubation of crystals in solution, and confocal fluorescence microscopy confirmed they are limited to the surface of the crystal only. The surface patterning can also be tuned using alternative additives, mixtures of additives and by varying the solution conditions. Notably, we also show that surface structures can be used to determine the mode of interaction of additives with the microscopic surface steps under conditions where only minor changes in morphology have occurred

    A Randomised Controlled Trial of a Facilitated Home-Based Rehabilitation Intervention in Patients with Heart Failure with Preserved Ejection Fraction and their Caregivers:The REACH-HFpEF Pilot Study

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    Abstract Introduction Home-based cardiac rehabilitation may overcome suboptimal rates of participation. The overarching aim of this study was to assess the feasibility and acceptability of the novel Rehabilitation EnAblement in CHronic Hear Failure (REACH-HF) rehabilitation intervention for patients with heart failure with preserved ejection fraction (HFpEF) and their caregivers. Methods and results Patients were randomised 1:1 to REACH-HF intervention plus usual care (intervention group) or usual care alone (control group). REACH-HF is a home-based comprehensive self-management rehabilitation programme that comprises patient and carer manuals with supplementary tools, delivered by trained healthcare facilitators over a 12 week period. Patient outcomes were collected by blinded assessors at baseline, 3 months and 6 months postrandomisation and included health-related quality of life (primary) and psychological well-being, exercise capacity, physical activity and HF-related hospitalisation (secondary). Outcomes were also collected in caregivers. We enrolled 50 symptomatic patients with HF from Tayside, Scotland with a left ventricular ejection fraction ≥45% (mean age 73.9 years, 54% female, 100% white British) and 21 caregivers. Study retention (90%) and intervention uptake (92%) were excellent. At 6 months, data from 45 patients showed a potential direction of effect in favour of the intervention group, including the primary outcome of Minnesota Living with Heart Failure Questionnaire total score (between-group mean difference −11.5, 95% CI −22.8 to 0.3). A total of 11 (4 intervention, 7 control) patients experienced a hospital admission over the 6 months of follow-up with 4 (control patients) of these admissions being HF-related. Improvements were seen in a number intervention caregivers' mental health and burden compared with control. Conclusions Our findings support the feasibility and rationale for delivering the REACH-HF facilitated home-based rehabilitation intervention for patients with HFpEF and their caregivers and progression to a full multicentre randomised clinical trial to test its clinical effectiveness and cost-effectiveness
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