17 research outputs found
Bacteriophages immobilized on electrospun cellulose microfibers by non-specific adsorption, protein–ligand binding, and electrostatic interactions
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Bacteriophages immobilized on electrospun cellulose microfibers by non-specific adsorption, protein–ligand binding, and electrostatic interactions
Phage therapy has significant potential in specifically targeting bacterial pathogens in food and medicine. There is a significant interest to combine phages with materials to enhance and broaden potential applications of phages. This study compares non-specific adsorption, protein–ligand binding, and electrostatic interactions on cellulose microfibers without any chemical or genetic modification of phages. Success in immobilization of phages on biomaterials without genetic and chemical modification can enable effective translation of naturally occurring phages and their cocktails for antimicrobial applications. The immobilization approaches were characterized by phage loading efficiency, phage distribution, and phage release from fibers. The results indicated that non-specific adsorption and protein–ligand binding had insignificant phage loading while electrostatic interactions yielded approximately 15–25% phage loading normalized to the initial titer of the phage loading solution. Confocal imaging of the electrostatically immobilized phage fibers revealed a random phage distribution on the fiber surface. Phage release from the electrostatically immobilized phage fibers indicated a slow release over a period of 24 h. Overall, the electrostatic immobilization approach bound more active phages than non-specific adsorption and protein–ligand binding and thus may be considered the optimal approach to immobilizing phages onto biomaterial surfaces
The action of local anesthetics on myelin structure and nerve conduction in toad sciatic nerve
The action of local anesthetics on myelin structure and nerve conduction in toad sciatic nerve.
X-ray scattering and electrophysiological experiments were performed on toad sciatic nerves in the presence of local anesthetics. In vitro experiments were performed on dissected nerves superfused with Ringer's solutions containing procaine, lidocaine, tetracaine, or dibucaine. In vivo experiments were performed on nerves dissected from animals anesthesized by targeted injections of tetracaine-containing solutions. In all cases the anesthetics were found to have the same effects on the x-ray scattering spectra: the intensity ratio of the even-order to the odd-order reflections increases and the lattice parameter increases. These changes are reversible upon removal of the anesthetic. The magnitude of the structural changes varies with the duration of the superfusion and with the nature and concentration of the anesthetic molecule. A striking quantitative correlation was observed between the structural effects and the potency of the anesthetic. Electron density profiles, which hardly showed any structural alteration of the unit membrane, clearly indicated that the anesthetics have the effect of moving the pairs of membranes apart by increasing the thickness of the cytoplasmic space. Electrophysiological measurements performed on the very samples used in the x-ray scattering experiments showed that the amplitude of the compound action potential is affected earlier than the structure of myelin (as revealed by the x-ray scattering experiments), whereas conduction velocity closely follows the structural alterations
A cognitive architecture for modular and self-reconfigurable robots
The field of reconfigurable swarms of modular robots has achieved a current status of performance that allows applications in diverse fields that are characterized by human support (e.g. exploratory and rescue tasks) or even in human-less environments. The main goal of the EC project REPLICATOR [1] is the development and deployment of a heterogeneous swarm of modular robots that are able to switch autonomously from a swarm of robots, into different organism forms, to reconfigure these forms, and finally to revert to the original swarm mode [2]. To achieve these goals three different types of robot modules have been developed and an extensive suite of embodied distributed cognition methods implemented [3]. Hereby the methodological key aspects address principles of self-organization. In order to tackle our ambitious approach a Grand Challenge has been proposed of autonomous operation of 100 robots for 100 days (100 days, 100 robots). Moreover, a framework coined the SOS-cycle (SOS: Swarm-Organism-Swarm) is developed. It controls the transitions between internal phases that enable the whole system to alternate between different modes mentioned above. This paper describes the vision of the Grand Challenge and the implementation and the results of the different phases of the SOS-cycle
Do Maternal Knowledge and Attitudes towards Childhood Immunizations in Rural Uganda Correlate with Complete Childhood Vaccination?
Improving childhood vaccination coverage and timeliness is a key health policy objective in many developing countries such as Uganda. Of the many factors known to influence uptake of childhood immunizations in under resourced settings, parents' understanding and perception of childhood immunizations has largely been overlooked. The aims of this study were to survey mothers' knowledge and attitudes towards childhood immunizations and then determine if these variables correlate with the timely vaccination coverage of their children. From September to December 2013, we conducted a cross-sectional survey of 1,000 parous women in rural Sheema district in southwest Uganda. The survey collected socio-demographic data and knowledge and attitudes towards childhood immunizations. For the women with at least one child between the age of one month and five years who also had a vaccination card available for the child (N = 302), the vaccination status of this child was assessed. 88% of these children received age-appropriate, on-time immunizations. 93.5% of the women were able to state that childhood immunizations protect children from diseases. The women not able to point this out were significantly more likely to have an under-vaccinated child (PR 1.354: 95% CI 1.018-1.802). When asked why vaccination rates may be low in their community, the two most common responses were "fearful of side effects" and "ignorance/disinterest/laziness" (44% each). The factors influencing caregivers' demand for childhood immunizations vary widely between, and also within, developing countries. Research that elucidates local knowledge and attitudes, like this study, allows for decisions and policy pertaining to vaccination programs to be more effective at improving child vaccination rates
Derivation of the sample of children and mothers.
<p>Derivation of the sample of children and mothers.</p
Frequency of specific vaccinations missed by children between the ages of one month and five years that had vaccination history documented but were not fully up to date.
<p>Frequency of specific vaccinations missed by children between the ages of one month and five years that had vaccination history documented but were not fully up to date.</p
Number of diseases identified correctly and incorrectly as vaccine preventable by women surveyed (N = 1000).
<p>Number of diseases identified correctly and incorrectly as vaccine preventable by women surveyed (N = 1000).</p
Knowledge of childhood immunizations and perceived probability that next child will receive required immunizations by all women in the study sample and those with a child between one month and 5 years age with a vaccination card (U5+Card).
<p>Knowledge of childhood immunizations and perceived probability that next child will receive required immunizations by all women in the study sample and those with a child between one month and 5 years age with a vaccination card (U5+Card).</p