172 research outputs found
Developments in nanoparticles for use in biosensors to assess food safety and quality
The following will provide an overview on how advances in nanoparticle technology have contributed towards developing biosensors to screen for safety and quality markers associated with foods. The novel properties of nanoparticles will be described and how such characteristics have been exploited in sensor design will be provided. All the biosensor formats were initially developed for the health care sector to meet the demand for point-of-care diagnostics. As a consequence, research has been directed towards miniaturization thereby reducing the sample volume to nanolitres. However, the needs of the food sector are very different which may ultimately limit commercial application of nanoparticle based nanosensors. © 2014 Elsevier Ltd
Listeria monocytogenes in Milk Products
peer-reviewedMilk and milk products are frequently identified as vectors for transmission of Listeria monocytogenes. Milk can be contaminated at farm level either by indirect external contamination from the farm environment or less frequently by direct contamination of the milk from infection in the animal. Pasteurisation of milk will kill L. monocytogenes, but post-pasteurisation contamination, consumption of unpasteurised milk and manufacture of unpasteurised milk products can lead to milk being the cause of outbreaks of listeriosis. Therefore, there is a concern that L. monocytogenes in milk could lead to a public health risk. To protect against this risk, there is a need for awareness surrounding the issues, hygienic practices to reduce the risk and adequate sampling and analysis to verify that the risk is controlled. This review will highlight the issues surrounding L. monocytogenes in milk and milk products, including possible control measures. It will therefore create awareness about L. monocytogenes, contributing to protection of public health
On a visualization of the convergence of the boundary of generalized Mandelbrot set to (n-1)-sphere
In this article we analyze the generalized Mandelbrot set in higher-order hypercomplex number spaces following both the Cayley-Dickson construction algebraic spaces and the spaces defined by Clifford algebras. The particular case of the generalized 3D quasi-Mandelbrot set was also considered. In particular, we investigated the increase of power of the iterated variable and proved that when this power tends to infinity, the Mandelbrot set is convergent to the unit circle. The same is true for the generalized Mandelbrot sets in higher-dimensional hypercomplex number spaces, i.e. when the power of iterated variable tends to infinity, the generalized Mandelbrot set is convergent to the unit (n-1)- sphere. The results of our investigation were visualized for the generalized Mandelbrot set in a complex number space and the generalized quasi-Mandelbrot set in a 3D Euclidean space
Proposal of design and experimental research of dynamics of chaotic double pendulum
W artykule opisano istotę działania chaotycznego wahadła dwuczłonowego, przedstawiono jego model matematyczny oraz wyniki numeryczne otrzymane na podstawie tego modelu. Do celów badawczych wykonano stanowisko pozwalające na obserwację i rejestrację oscylacji chaotycznych. Stanowisko pozwala na badanie oscylacji chaotycznych dla szerokiego zakresu parametrów początkowych: kątów wychylenia obu ramion oraz zmiennego obciążenia masowego na końcach każdego z ramion. Metoda pomiaru polega na wykorzystaniu metod analizy obrazu, tj. identyfikacji kolorów markerów, umiejscowionych na końcach ramion wahadła, a następnie wyznaczenia trajektorii ruchu poszczególnych punktów pomiarowych. Przedstawiono sposób przeprowadzenia badań oraz przykładowe wyniki.The paper describes the operation principle of the chaotic double pendulum, the mathematical model and numerical results obtained based on this model were presented. For the research purposes the test rig was developed, which allows for the monitoring and registration of chaotic oscillations. The test rig allows for monitoring of chaotic oscillations in the wide range of initial parameters: angles of deviation of both pendulum arms and variable mass loading at the ends of each arm. The method of measurements is based on using of the methods of image processing, i.e. identification of colors of the markers placed at the ends of pendulum arms and then the determination of the motion trajectories of particular measurement points. The experimental process as well as exemplary results was described
Muscarinic agonist therapy of Alzheimer's disease. A clinical trial of RS-86.
Cholinergic projections to the cerebral cortex from certain basal forebrain nuclei degenerate in Alzheimer's disease. Nevertheless, attempts to alleviate this disorder through the administration of drugs that increase the availability of acetylcholine to postsynaptic receptor sites have generally yielded disappointing results. In an attempt to evaluate the therapeutic efficacy of cholinomimetics that act independently of the presynaptic cholinergic terminals, a double-blind, placebo-controlled trial of the muscarinic agonist RS-86 (2-ethyl-8 methyl-2,8 diazospiro [4.5]-decane-1,3-dione hydrobromide) was undertaken. Eight patients with Alzheimer's disease with mild to moderately advanced dementia received RS-86 orally at maximum individually tolerated dose levels for eight days. Although some verbal and visuospatial tests showed slight alterations, no consistent overall change in cognitive performance could be discerned. These results lend further support to the view that short-term administration of cholinomimetic monotherapies may fail in the symptomatic treatment of Alzheimer's dementia
Cognitive concomitants of dopamine system stimulation in parkinsonian patients.
Verbal, visuospatial and motor functions were studied in eight Parkinsonian patients both during levodopa stimulated and unstimulated state and in eight matched, untreated, healthy controls. Profound changes in patients' motor status were accompanied by relatively selective effects on delayed verbal memory, a function which was also most impaired compared with controls. With dopaminomimetic therapy, tests of delayed verbal memory consistently improved, but did not reach control performance levels. These results could indicate a functional impairment in the mesocortical dopamine system, which can be attenuated, but not entirely corrected, by dopaminomimetic therapy
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