George Hospital is a secondary level hospital in the Garden Route district of the Western Cape. Its theatre complex consists of five theatres and an endoscopy suite. The main stakeholders in the ...theatre complex are the surgical disciplines, the nursing staff and anaesthesiology. The thread that connects all stakeholders of theatre is the documentation requirements of every case that passes through the complex. This process has historically been associated with two specific frustrations: the legibility of notes and the duplication of information evident in creating the necessary documents for the surgeon, anaesthetist and nursing staff. The information recorded was often illegible, uncoded and incomplete. This resulted in concerns about inappropriate patient care as a result of misinterpretation of notes, insufficient data surrounding pending medico-legal cases or for morbidity and mortality review, and the inability to review individual and theatre complex performance. These issues were not unique to our hospital but when I arrived in 2010, the frustration they engendered was enough for me to try and create a solution – an automated documentation and information system. The clinicians needed a tool to make their work easier, and management needed an operational tool that would provide them with clinician-created data reflecting the efficiency of the theatre environment. The ultimate aim was to create a user-friendly digital platform for clinicians to engage with in theatre to assist in patient care.
In this paper, a summary of published techniques for power conditioning within energy harvesting systems is presented. The focus is on low-power systems, e.g, <;10 mW, for kinetic energy harvesting. ...Published concepts are grouped according to functionality and results contrasted. The various techniques described are considered in terms of complexity, efficiency, quiescent power consumption, startup behavior, and utilization of the harvester compared to an optimum load. This paper concludes with an overview of power management techniques that aim to maximize the extracted power and the utilization of the energy harvester.
Turbine types suit specific ranges of head, flow rate and shaft speed and are usually categorised by specific speed. In the pico range, under 5 kW, the requirements are often different to that of ...larger scale turbines and qualitative requirements become more influential in selection. Pico hydro turbines can be applied beyond these conventional application domains, for example at reduced heads, by using non-traditional components such as low speed generators. This paper describes a method to select which turbine architecture is most appropriate for a low-head pico hydro specification using quantitative and qualitative analyses of 13 turbine system architectures found in the literature. Quantitative and qualitative selection criteria are determined from the particular requirements of the end user. The individual scores from this analysis are weighted based on the perceived relative importance of each of the criteria against the original specification and selects a turbine variant based on the total weighted score. This methodology is applied to an example of a remote site, low head and variable flow requirement, leading to the selection of a propeller turbine variant or single-jet Turgo turbine for this specification.
► Limitations with specific speed selection methodology at pico hydro level discussed. ► Method to select a pico hydro turbine for a low head site is presented. ► Quantitative and qualitative criteria developed from the specification. ► These criteria are used to give tangible evidence for the design choice of turbine. ► Propeller or single-jet Turgo design shown suitable for low head pico specification.
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A micron-sized droplet of bromine water immersed in a surfactant-laden oil phase can swim (S. Thutupalli, R. Seemann, S. Herminghaus, New J. Phys.
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073021 (2011). The bromine reacts with the ...surfactant at the droplet interface and generates a surfactant mixture. It can spontaneously phase-separate due to solutocapillary Marangoni flow, which propels the droplet. We model the system by a diffusion-advection-reaction equation for the mixture order parameter at the interface including thermal noise and couple it to fluid flow. Going beyond previous work, we illustrate the coarsening dynamics of the surfactant mixture towards phase separation in the axisymmetric swimming state. Coarsening proceeds in two steps: an initially slow growth of domain size followed by a nearly ballistic regime. On larger time scales thermal fluctuations in the local surfactant composition initiates random changes in the swimming direction and the droplet performs a persistent random walk, as observed in experiments. Numerical solutions show that the rotational correlation time scales with the square of the inverse noise strength. We confirm this scaling by a perturbation theory for the fluctuations in the mixture order parameter and thereby identify the active emulsion droplet as an active Brownian particle.
Graphical abstract
Summary
Background
Autosomal recessive congenital ichthyoses (ARCIs) are keratinization disorders caused by impaired skin barrier function. Mutations in the genes encoding the lipoxygenases 12R‐LOX ...and eLOX‐3 are the second most common cause of ARCIs. In recent years, human skin equivalents recapitulating the ARCI phenotype have been established.
Objectives
To develop a murine organotypic tissue culture model for ARCI.
Methods
Epidermal keratinocytes were isolated from newborn 12R‐LOX‐deficient mice and cocultivated with mouse dermal fibroblasts embedded in a scaffold of native collagen type I.
Results
With this experimental set‐up the keratinocytes formed a well‐organized multilayered stratified epithelium resembling skin architecture in vivo. All epidermal layers were present and the keratinocytes within showed the characteristic morphological features. Markers for differentiation and maturation indicated regular epidermal morphogenesis. The major components of epidermal structures were expressed, and were obviously processed and assembled properly. In contrast to their wild‐type counterparts, 12R‐LOX‐deficient skin equivalents showed abnormal vesicular structures in the upper epidermal layers correlating with altered lipid composition and increased transepidermal water loss, comparable with 12R‐LOX‐deficient mice.
Conclusions
The mouse skin equivalents faithfully recapitulate the 12R‐LOX‐deficient phenotype observed in vivo, classifying them as appropriate in vitro models to study molecular mechanisms involved in the development of ARCI and to evaluate novel therapeutic agents. In contrast to existing human three‐dimensional skin models, the generation of these murine models is not constrained by a limited supply of material and does not depend on in vitro expansion and/or genetic manipulations that could result in inadvertent genotypic and phenotypic alterations.
What's already known about this topic?
Several human skin equivalents recapitulating the pathological phenotype of ichthyoses have been established.
What does this study add?
This is the first murine tissue culture model for autosomal recessive congenital ichthyosis generated with neonatal, noncultivated keratinocytes.
In contrast to existing human models, this mouse model is not constrained by limited supply of the required material and does not depend on in vitro expansion and/or genetic manipulations that could result in inadvertent genotypic and phenotypic alterations.
Since its initial identification in 1986, Lyme disease has been clinically diagnosed in 29 provinces in China; however, national incidence data are lacking. To summarize Lyme disease seropositivity ...data among persons across China, we conducted a systematic literature review of Chinese- and English-language journal articles published during 2005‒2020. According to 72 estimates that measured IgG by using a diagnostic enzyme-linked assay (EIA) alone, the seropositivity point prevalence with a fixed-effects model was 9.1%. A more conservative 2-tier testing approach of EIA plus a confirmatory Western immunoblot (16 estimates) yielded seropositivity 1.8%. Seropositivity by EIA for high-risk exposure populations was 10.0% and for low-risk exposure populations was 4.5%; seropositivity was highest in the northeastern and western provinces. Our analysis confirms Lyme disease prevalence, measured by seropositivity, in many Chinese provinces and populations at risk. This information can be used to focus prevention measures in provinces where seropositivity is high.
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