241 research outputs found
On the Anatomy of Health-related Actions for Which People Could Reasonably be Held Responsible: A Framework
Should we let personal responsibility for health-related behavior influence the allocation of healthcare resources? In this paper, we clarify what it means to be responsible for an action. We rely on a crucial conceptual distinction between being responsible and holding someone responsible, and show that even though we might be considered responsible and blameworthy for our health-related actions, there could still be well-justified reasons for not considering it reasonable to hold us responsible by giving us lower priority. We transform these philosophical considerations into analytical use first by assessing the general features of health-related actions and the corresponding healthcare needs. Then, we identify clusters of structural features that even adversely affected people cannot reasonably deny constitute actions for which they should be held responsible. We summarize the results in an analytical framework that can be used by decision-makers when considering personal responsibility for health as a criterion for setting priorities.publishedVersio
Conformational Dynamics of hSGLT1 during Na+/Glucose Cotransport
This study examines the conformations of the Na+/glucose cotransporter (SGLT1) during sugar transport using charge and fluorescence measurements on the human SGLT1 mutant G507C expressed in Xenopus oocytes. The mutant exhibited similar steady-state and presteady-state kinetics as wild-type SGLT1, and labeling of Cys507 by tetramethylrhodamine-6-maleimide had no effect on kinetics. Our strategy was to record changes in charge and fluorescence in response to rapid jumps in membrane potential in the presence and absence of sugar or the competitive inhibitor phlorizin. In Na+ buffer, step jumps in membrane voltage elicited presteady-state currents (charge movements) that decay to the steady state with time constants Ďmed (3â20 ms, medium) and Ďslow (15â70 ms, slow). Concurrently, SGLT1 rhodamine fluorescence intensity increased with depolarizing and decreased with hyperpolarizing voltages (ÎF). The charge vs. voltage (Q-V) and fluorescence vs. voltage (ÎF-V) relations (for medium and slow components) obeyed Boltzmann relations with similar parameters: zδ (apparent valence of voltage sensor) â 1; and V0.5 (midpoint voltage) between â15 and â40 mV. Sugar induced an inward current (Na+/glucose cotransport), and reduced maximal charge (Qmax) and fluorescence (ÎFmax) with half-maximal concentrations (K0.5) of 1 mM. Increasing [ÎąMDG]o also shifted the V0.5 for Q and ÎF to more positive values, with K0.5's â 1 mM. The major difference between Q and ÎF was that at saturating [ÎąMDG]o, the presteady-state current (and Qmax) was totally abolished, whereas ÎFmax was only reduced 50%. Phlorizin reduced both Qmax and ÎFmax (Ki â 0.4 ÎźM), with no changes in V0.5's or relaxation time constants. Simulations using an eight-state kinetic model indicate that external sugar increases the occupancy probability of inward-facing conformations at the expense of outward-facing conformations. The simulations predict, and we have observed experimentally, that presteady-state currents are blocked by saturating sugar, but not the changes in fluorescence. Thus we have isolated an electroneutral conformational change that has not been previously described. This rate-limiting step at maximal inward Na+/sugar cotransport (saturating voltage and external Na+ and sugar concentrations) is the slow release of Na+ from the internal surface of SGLT1. The high affinity blocker phlorizin locks the cotransporter in an inactive conformation
Implementing Silicon Nanoribbon Field-Effect Transistors as Arrays for Multiple Ion Detection
Ionic gradients play a crucial role in the physiology of the human body, ranging from metabolism in cells to muscle contractions or brain activities. To monitor these ions, inexpensive, label-free chemical sensing devices are needed. Field-effect transistors (FETs) based on silicon (Si) nanowires or nanoribbons (NRs) have a great potential as future biochemical sensors as they allow for the integration in microscopic devices at low production costs. Integrating NRs in dense arrays on a single chip expands the field of applications to implantable electrodes or multifunctional chemical sensing platforms. Ideally, such a platform is capable of detecting numerous species in a complex analyte. Here, we demonstrate the basis for simultaneous sodium and fluoride ion detection with a single sensor chip consisting of arrays of gold-coated SiNR FETs. A microfluidic system with individual channels allows modifying the NR surfaces with self-assembled monolayers of two types of ion receptors sensitive to sodium and fluoride ions. The functionalization procedure results in a differential setup having active fluoride-and sodium-sensitive NRs together with bare gold control NRs on the same chip. Comparing functionalized NRs with control NRs allows the compensation of non-specific contributions from changes in the background electrolyte concentration and reveals the response to the targeted species
WHOOPING CRANE STAY LENGTH IN RELATION TO STOPOVER SITE CHARACTERISTICS
Whooping crane (Grus americana) migratory stopovers can vary in length from hours to more than a month. Stopover sites provide food resources and safety essential for the completion of migration. Factors such as weather, climate, demographics of migrating groups, and physiological condition of migrants influence migratory movements of cranes (Gruidae) to varying degrees. However, little research has examined the relationship between habitat characteristics and stopover stay length in cranes. Site quality may relate to stay length with longer stays that allow individuals to improve body condition, or with shorter stays because of increased foraging efficiency. We examined this question by using habitat data collected at 605 use locations from 449 stopover sites throughout the United States Great Plains visited by 58 whooping cranes from the AransasâWood Buffalo Population tracked with platform transmitting terminals. Research staff compiled land cover (e.g., hectares of corn; landscape level) and habitat metric (e.g., maximum water depth; site level) data for day use and evening roost locations via site visits and geospatial mapping. We used Random Forest regression analyses to estimate importance of covariates for predicting stopover stay length. Site-level variables explained 9% of variation in stay length, whereas landscape-level variables explained 43%. Stay length increased with latitude and the proportion of land cover as open-water slough with emergent vegetation as well as alfalfa, whereas stay length decreased as open-water lacustrine wetland land cover increased. At the site level, stopover duration increased with wetted width at riverine sites but decreased with wetted width at palustrine and lacustrine wetland sites. Stopover duration increased with mean distance to visual obstruction as well as where management had reduced the height of vegetation through natural (e.g., grazing) or mechanical (e.g., harvesting) means and decreased with maximum water depth. Our results suggest that stopover length increases with the availability of preferred land cover types for foraging. High quality stopover sites with abundant forage resources may help whooping cranes maintain fat reserves important to their annual life cycle
Competing surface reactions limiting the performance of ion-sensitive field-effect transistors
Š 2015 Elsevier B.V. All rights reserved.Ion-sensitive field-effect transistors based on silicon nanowires are promising candidates for the detection of chemical and biochemical species. These devices have been established as pH sensors thanks to the large number of surface hydroxyl groups at the gate dielectrics which makes them intrinsically sensitive to protons. To specifically detect species other than protons, the sensor surface needs to be modified. However, the remaining hydroxyl groups after functionalization may still limit the sensor response to the targeted species. Here, we describe the influence of competing reactions on the measured response using a general site-binding model. We investigate the key features of the model with a real sensing example based on gold-coated nanoribbons functionalized with a self-assembled monolayer of calcium-sensitive molecules. We identify the residual pH response as the key parameter limiting the sensor response. The competing effect of pH or any other relevant reaction at the sensor surface has therefore to be included to quantitatively understand the sensor response and prevent misleading interpretations
NDM-5 and OXA-181 Beta-Lactamases, a Significant Threat Continues To Spread in the Americas
ABSTRACT Among Gram-negative bacteria, carbapenem-resistant infections pose a serious and life-threatening challenge. Here, the CRACKLE network reports a sentinel detection and characterization of a carbapenem-resistant Klebsiella pneumoniae ST147 isolate harboring bla NDM-5 and bla OXA-181 from a young man who underwent abdominal surgery in India. bla NDM-5 was located on an IncFII plasmid of â90 kb, whereas bla OXA-181 was chromosomally encoded. Resistome and genome analysis demonstrated multiple copies of the transposable element IS 26 and a âhot-spot regionâ in the IncFII plasmid
The current understanding of precision medicine and personalised medicine in selected research disciplines:study protocol of a systematic concept analysis
INTRODUCTION: The terms âprecision medicineâ and âpersonalised medicineâ have become key terms in health-related research and in science-related public communication. However, the application of these two concepts and their interpretation in various disciplines are heterogeneous, which also affects research translation and public awareness. This leads to confusion regarding the use and distinction of the two concepts. Our aim is to provide a snapshot of the current understanding of these concepts. METHODS AND ANALYSIS: Our study will use Rodgersâ evolutionary concept analysis to systematically examine the current understanding of the concepts âprecision medicineâ and âpersonalised medicineâ in clinical medicine, biomedicine (incorporating genomics and bioinformatics), health services research, physics, chemistry, engineering, machine learning and artificial intelligence, and to identify their respective attributes (clusters of characteristics) and surrogate and related terms. A systematic search of the literature will be conducted for 2016â2022 using databases relevant to each of these disciplines: ACM Digital Library, CINAHL, Cochrane Library, F1000Research, IEEE Xplore, PubMed/Medline, Science Direct, Scopus and Web of Science. These are among the most representative databases for the included disciplines. We will examine similarities and differences in definitions of âprecision medicineâ and âpersonalised medicineâ in the respective disciplines and across (sub)disciplines, including attributes of each term. This will enable us to determine how these two concepts are distinguished. ETHICS AND DISSEMINATION: Following ethical and research standards, we will comprehensively report the methodology for a systematic analysis following Rodgersâ concept analysis method. Our systematic concept analysis will contribute to the clarification of the two concepts and distinction in their application in given settings and circumstances. Such a broad concept analysis will contribute to non-systematic syntheses of the concepts, or occasional systematic reviews on one of the concepts that have been published in specific disciplines, in order to facilitate interdisciplinary communication, translational medical research and implementation science
Experiences of young people and their caregivers of using technology to manage type 1 diabetes mellitus: Systematic literature review and narrative synthesis
Background:Â In the last decade, diabetes management has begun to transition to technology-based care, with young people being the focus of many technological advances. Yet, detailed insights into the experiences of young people and their caregivers of using technology to manage type 1 diabetes mellitus are lacking.Objective:Â The objective of our study was to describe the breadth of experiences and perspectives on diabetes technology use among children and adolescents with type 1 diabetes mellitus and their caregivers.Methods: This systematic literature review used integrated thematic analysis to guide a narrative synthesis of the included studies. We analyzed the perspectives and experiences of young people with type 1 diabetes mellitus and their caregivers reported in qualitative studies, quantitative descriptive studies, and studies with a mixed methods design.Results:Seventeen articles met the inclusion criteria, and they included studies on insulin pump, glucose sensors, and remote monitoring systems. The following eight themes were derived from the analysis: (1) expectations of the technology prior to use, (2) perceived impact on sleep and overnight experiences, (3) experiences with alarms, (4) impact on independence and relationships, (5) perceived usage impact on blood glucose control, (6) device design and features, (7) financial cost, and (8) user satisfaction. While many advantages of using diabetes technology were reported, several challenges for its use were also reported, such as cost, the size and visibility of devices, and the intrusiveness of alarms, which drew attention to the fact that the user had type 1 diabetes mellitus. Continued use of diabetes technology was underpinned by its benefits outweighing its challenges, especially among younger people.Conclusions:Â Diabetes technologies have improved the quality of life of many young people with type 1 diabetes mellitus and their caregivers. Future design needs to consider the impact of these technologies on relationships between young people and their caregivers, and the impact of device features and characteristics such as size, ease of use, and cost.</p
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