1,720,967 research outputs found
Short-term effects of two feedback systems on the self-correction movement in patients with idiopathic scoliosis. A study design.
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Surface Engineering of Magnesium Alloys for the Next Generation of Biodegradable Device
No full textAlthough the biocompatibility and good mechanical properties make the magnesium and its alloys excellent candidates for biomedical applications, the high corrosion rate, involving hydrogen release and the alkalization of the physiological environment, limit their clinical use. However, this constrain could be exploited for the realization of biodegradable devices. In this regard, it is necessary to ensure a degradation rate comparable to the rate of growth of the hosting tissues, avoiding side effects, premature failures, and adverse reactions. The surface engineering approaches which involve the use of a coating made of single or multiple layers represent a possible method to tailor the deterioration rate. The poor adhesion strength between layers could be an important drawback of this approach. In the present research, a multilayer coating composed of an oxide layer, a bio-inspired polydopamine (PDA)-based one and a biodegradable polymer film, made of polylactic acid (PLA) has been realized on magnesium alloys substrates. The first layer was obtained by a plasma electrolytic oxidation (PEO) treatment to increase the corrosion resistance. Then, the polydopamine layer has been applied by the dip-coating method to improve the adhesion between the oxide layer and the polylactic acid film. Each layer and their combinations were characterized by using morphological examinations, and electrochemical test by means of potentiodynamic polarization (PD) and electrochemical impedance spectroscopy (EIS) methods. The use of a multilayer coating has demonstrated to be a promising strategy to control the degradation rate of the magnesium alloys to produce biodegradable device
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Lower-Limb Exoskeletons for Gait Training in Parkinson’s Disease: The State of the Art and Future Perspectives
Get PDFGait dysfunction (GD) is a common impairment of Parkinson's disease (PD), which negatively impacts patients' quality of life. Among the most recent rehabilitation technologies, a lower-limb powered exoskeleton (LLEXO) arises as a useful instrument for gait training in several neurological conditions, including PD. However, some questions relating to methods of use, achievable results, and usefulness compared to traditional rehabilitation methodologies still require clear answers. Therefore, in this review, we aim to summarise and analyse all the studies that have applied an LLEXO to train gait in PD patients. Literature research on PubMed and Scopus retrieved five articles, comprising 46 PD participants stable on medications (age: 71.7 +/- 3.7 years, 24 males, Hoehn and Yahr: 2.1 +/- 0.6). Compared to traditional rehabilitation, low-profile lower-limb exoskeleton (lp-LLEXO) training brought major improvements towards walking capacity and gait speed, while there are no clear major benefits regarding the dual-task gait cost index and freezing of gait symptoms. Importantly, the results suggest that lp-LLEXO training is more beneficial for patients with an intermediate-to-severe level of disease severity (Hoehn and Yahr > 2.5). This review could provide a novel framework for implementing LLEXO in clinical practise, highlighting its benefits and limitations towards gait training
Designing the Surface of Medical Devices
No full textThe most important properties of metal medical devices are i) biocompatibility, ii) mechanical strength and, in some cases, iii) reliable osseointegration. The surface of biodevices can be designed and then modified to improve these properties. After a brief review of the technologies used to modify the surface of metallic biodevices, some examples of surface treatments used to improve their properties are given. The effect of acid etching on the surface shape of the metal material to improve implant osseointegration, to produce a surface with more ‘valleys’ than ‘peaks’, a requirement for improved osseointegration, is shown. It is demonstrated that the “shape” of the surface can be easily and quantitatively measured by using appropriate roughness parameters. In addition, to reduce the risk of implant rejection, nanoscale reservoirs for controlled drug delivery can be formed on the previously acid-etched implant surface. To this end, the methods used to grow titania nanotube dental screws from commercially pure titania are presented. The shape and length of the nanotubes can be varied to increase or decrease the duration of drug delivery as required
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