An all-solid-state biocompatible ion-to-electron transducer for bioelectronics

Reported here is an all-solid-state organic electrochemical transistor based on the biopolymer melanin. The underlying mechanism is demonstrated using a unique hydration dependence protocol and explained using an adapted double capacitor model. The demonstration of an all-solid-state bioelectronic prototype is critical for the development of miniaturised bioelectronic logic

Patients' and public views and attitudes towards the sharing of health data for research: a narrative review of the empirical evidence.

INTRODUCTION: International sharing of health data opens the door to the study of the so-called 'Big Data', which holds great promise for improving patient-centred care. Failure of recent data sharing initiatives indicates an urgent need to invest in societal trust in researchers and institutions. Key to an informed understanding of such a 'social license' is identifying the views patients and the public may hold with regard to data sharing for health research. METHODS: We performed a narrative review of the empirical evidence addressing patients' and public views and attitudes towards the use of health data for research purposes. The literature databases PubMed (MEDLINE), Embase, Scopus and Google Scholar were searched in April 2019 to identify relevant publications. Patients' and public attitudes were extracted from selected references and thematically categorised. RESULTS: Twenty-seven papers were included for review, including both qualitative and quantitative studies and systematic reviews. Results suggest widespread-though conditional-support among patients and the public for data sharing for health research. Despite the fact that participants recognise actual or potential benefits of data research, they expressed concerns about breaches of confidentiality and potential abuses of the data. Studies showed agreement on the following conditions: value, privacy, risk minimisation, data security, transparency, control, information, trust, responsibility and accountability. CONCLUSIONS: Our results indicate that a social license for data-intensive health research cannot simply be presumed. To strengthen the social license, identified conditions ought to be operationalised in a governance framework that incorporates the diverse patient and public values, needs and interests

Intracrystalline site preference of oxygen isotopes in goethite: A single-mineral paleothermometer

The crystal structure of goethite, FeO(OH), has two distinct oxygen sites, one with exclusively Fe-O bonds, the other with bonds to both iron and hydrogen. We developed a method to assess the oxygen isotope contrast between these sites by measuring both the bulk goethite and the oxygen released in the conversion of goethite to hematite. The method involves collecting the water released by dehydroxylation, fluorinating that population of extracted atoms, and measuring the resulting oxygen isotope composition (extracted δO¹⁸). Then, on a separate aliquot, all structural oxygen is fluorinated and measured (bulk δO¹⁸). Using synthetic goethite precipitates grown under controlled environmental conditions, we found significant temperature-dependent fractionation, ε_(bulk-extracted)=(5.51±0.26)×(10⁶/T²)−(44.5±2.8); T in Kelvin). This intracrystalline fractionation forms the basis of a single-phase paleothermometer with an estimated uncertainty of ∼2-3°C. The temperature dependence appears to be independent of the isotopic composition of the parent fluid from which the goethite formed and the pH of that fluid. This intracrystalline thermometer can be used to simultaneously determine the formation temperature of a goethite and the isotopic composition of the water from which it formed. Natural goethites analyzed with this technique yield geologically reasonable formation temperatures of between 15 and 41°C

Venous bicarbonate and creatine kinase as diagnostic and prognostic tools in the setting of acute traumatic rhabdomyolysis

Background. Myorenal or crush syndrome often develops following soft-tissue traumatic injury. It is a spectrum of disease that may result in severe renal dysfunction and kidney injury requiring renal replacement therapy.Objectives. To review a large cohort of patients with so-called myorenal or crush syndrome and assess the biochemical markers of venous bicarbonate and creatine kinase as predictors for the development of acute kidney injury (AKI).Methods. All patients with myorenal syndrome who presented to Khayelitsha District Hospital, Cape Town, South Africa (SA), and Ngwelezana Hospital, Empangeni, KwaZulu-Natal, SA, between January and December 2017 were identified and reviewed.Results. A total of 212 patients were included in the study. At both hospitals, 94% of the patients were male. Using the Pearson correlation coefficient, we compared creatinine kinase (CK) against serum creatinine. The mean CK level was 5 311.8 U/L and the mean creatinine level 133.457 μmol/L. The r-value was 0.2533. Although this is a technically positive correlation, the relationship between the variables is weak. Using the Pearson R Calculator, we inserted the r-value to calculate the p-value. The p-value was 0.000208. When comparing venous bicarbonate (HCO3) against creatinine, the mean HCO3 level was 22.296 mmol/L and the mean creatinine level 162.053 μmol/L. The r-value was –0.3468. Although this is a technically negative correlation, the relationship between the variables is weak. Using the Pearson R Calculator, we inserted the r-value to calculate the p-value. The p-value was 0.000013. The inverse ratio shown with HCO3 v. creatinine, although still a weak correlation, is significantly better in predicting an increase in creatinine compared with the weak positive correlation of CK v. creatinine.Conclusions. Although both venous HCO3 and CK showed a weak correlation with creatinine, the former performed significantly better in predicting AKI. In a resource-constrained system, we recommend that HCO3 be measured to assess patients with crush injury and that CK be regarded as a complementary modality

Regularity of Cauchy horizons in S2xS1 Gowdy spacetimes

We study general S2xS1 Gowdy models with a regular past Cauchy horizon and prove that a second (future) Cauchy horizon exists, provided that a particular conserved quantity $J$ is not zero. We derive an explicit expression for the metric form on the future Cauchy horizon in terms of the initial data on the past horizon and conclude the universal relation A\p A\f=(8\pi J)^2 where A\p and A\f are the areas of past and future Cauchy horizon respectively.Comment: 17 pages, 1 figur

Rayleigh-Taylor and Richtmyer-Meshkov instabilities: A journey through scales

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordHydrodynamic instabilities such as Rayleigh-Taylor (RT) and Richtmyer-Meshkov (RM) instabilities usually appear in conjunction with the Kelvin-Helmholtz (KH) instability and are found in many natural phenomenon and engineering applications. They frequently result in turbulent mixing, which has a major impact on the overall flow development and other effective material properties. This can either be a desired outcome, an unwelcome side effect, or just an unavoidable consequence, but must in all cases be characterized in any model. The RT instability occurs at an interface between different fluids, when the light fluid is accelerated into the heavy. The RM instability may be considered a special case of the RT instability, when the acceleration provided is impulsive in nature such as that resulting from a shock wave. In this pedagogical review, we provide an extensive survey of the applications and examples where such instabilities play a central role. First, fundamental aspects of the instabilities are reviewed including the underlying flow physics at different stages of development, followed by an overview of analytical models describing the linear, nonlinear and fully turbulent stages. RT and RM instabilities pose special challenges to numerical modeling, due to the requirement that the sharp interface separating the fluids be captured with fidelity. These challenges are discussed at length here, followed by a summary of the significant progress in recent years in addressing them. Examples of the pivotal roles played by the instabilities in applications are given in the context of solar prominences, ionospheric flows in space, supernovae, inertial fusion and pulsed-power experiments, pulsed detonation engines and scramjets. Progress in our understanding of special cases of RT/RM instabilities is reviewed, including the effects of material strength, chemical reactions, magnetic fields, as well as the roles the instabilities play in ejecta formation and transport, and explosively expanding flows. The article is addressed to a broad audience, but with particular attention to graduate students and researchers that are interested in the state-of-the-art in our understanding of the instabilities and the unique issues they present in the applications in which they are prominent.Science and Technology Facilities CouncilScience and Technology Facilities Counci

Disturbed corpus callosum microstructure in the presence of normal volume characterizes patients with adult ADHD

Background: Microstructural changes and volume reductions in the corpus callosum (CC) are implicated in childhood ADHD. There are however indications that, in adulthood ADHD, reduced white matter integrity is persistent whereas CC volume normalizes. Our goal was to investigate this in a relatively large adult ADHD sample. In addition to commonly used fractional anisotropy (FA) and mean diffusivity (MD), we calculated parallel (axial diffusion; AD) and perpendicular (radial diffusion; RD) diffusivities to white matter tracts which may offer additional information regarding tissue microstructure. Methods: White matter integrity and volume of the CC were investigated in 87 adult ADHD patients and 98 matched controls. We used diffusion tensor imaging in conjunction with tract-based spatial statistics to examine FA, MD, AD and RD within the genu, body and splenium of the CC. Volumetrics of the CC and its subdivisions were determined using FreeSurfer software. Results: The body of the CC showed lower FA (p = .005) and higher MD (p = .019) and RD (p = .008) values in ADHD patients, compared to controls. Volume of the CC did not differ between the groups (p = .633). Conclusions: Our findings show that callosal volume becomes normal while disturbed white matter integrity of the CC is persistent in adult ADHD. Abnormalities in the body of the CC, the subdivision that contains the commissural fibers connecting the somatosensory, auditory and motor areas may play an important role in the pathophysiology of ADHD

Water Managers' Boundary Judgments and Adaptive Water Governance. An Analysis of the Dutch Haringvliet Sluices Case

__Abstract__ In this paper, we explore how managing actors' boundary judgments influence the adaptability of water governance. We approach this question by examining the relationship between the way water managers frame, and act in, complex water issues on the one hand and develop adaptive water governance strategies on the other. We define four categories of boundary judgments made by water managers in order to deal with the complexities in water governance issues. An in-depth case study analysis of an attempt to adjust the management of the water regime in the south-west Delta of the Netherlands is provided in order to reconstruct the water managers' boundary judgments and their impact upon governance strategies used. We found that, most of the time, the water managers involved predominantly made tight boundary judgments. These tight boundary judgments seemed to hamper the mutual learning process among a variety of stakeholders that is needed to realize adaptive water governance. We argue that wide boundary judgments enhance the chance of realizing adaptive practices and build upon exploration, learning, and connection