No abstract

Due to the unique functional properties of shape memory alloys (SMAs) and current scientific interest in Cu-containing biomaterials, a continuously cast Cu-Al-Ni alloy in the form of rods has been investigated as a potential candidate for biomedical application. Additionally, the fact that Cu- complexes have an antitumour effect served as a cornerstone to develop more efficient drugs based on trace element complexes. In line with that, our study aimed to analyse the basic properties of the Cu-Al-Ni alloy, along with its anticancer properties. The detailed chemical analysis of the Cu-Al-Ni alloy was performed using XRF and SEM/EDX analyses. Furthermore, a microstructural and structure investigation was carried out, combined with hardness measurements using the static Vickers method. Observations have shown that the Cu-Al-Ni microstructure is homogeneous, with the presence of typical martensitic laths. XRD analysis confirmed the presence of two phases, β′ (monoclinic) and γ′ (orthorhombic). The viability of osteosarcoma cells in contact with the Cu-Al-Ni alloy was evaluated using epifluorescence microscopy, while their morphology and attachment pattern were observed and analysed using a high-resolution SEM microscope. Biocompatibility testing showed that the Cu-Al-Ni alloy exerted a considerable antineoplastic effect.

Hypokinetic dysarthria is characterized by a speech that gradually becomes monotonous, poorly modulated, quiet and ultimately unintelligible. The goal of this research is to determine the acoustic characteristics of voice and speech in adults with hypokinetic dysarthria and the impact of the altered voice on the quality of communication. The sample consisted of 30 elderly respondents of both genders with Parkinson’s disease and hypokinetic dysarthria. In order to conduct a spectral analysis, the voice of patients was recorded while they were reading phonetically balanced text. The respondents conducted a self-assessment of the degree of their own handicap caused by voice disorder and impact of the voice handicap by completing the Voice Handicap Index (VHI). Statistically significant differences were determined in the position of some formants in respondents compared to the values of formants in typical speakers for the following vowels: F1 of the vowel /I/ and F2 of the vowels /E/, /I/, /O/ and /U/. By examining the relation between the score achieved on the VHI instrument and the value of formants, the only statistically significant correlation was achieved between the formant F1 of the vowel /A/ and functional and emotional subscale. By regression analysis used to determine the predictor of the quality of communication, it was confirmed that F1 of the vowel /A/ has a statistically significant contribution to the explanation of the score achieved on functional and emotional subscale, by explaining 15% of the functional subscale (Beta=−0,393 (11,30 – 47,37)) and 10% of the emotional subscale (Beta=−0,363 (−0,052 – 0,000)).

Cu-Al-Nishape memory alloys (SMAs) are widely known for their better properties in comparison to other SMAs (lower production costs, increased ductility, enhanced machinability, reduced liquidus temperature, and decreased hysteresis), but there is still controversy in terms of the biological properties of these materials. The aim of this study was to evaluate biofunctional performances of Cu-Al-Ni alloy produced by continuous casting. The micro-chemical analysis was investigated by SEM/EDX. Immersion tests performed for seven days were used to estimate the quantity of Cu, Al, and Ni ions released in neutral pH and slightly acidic artificial saliva. To assess the biocompatibility of the Cu-Al-Ni alloy samples, MTT assay on fibroblasts and dental pulp cells was performed in indirect and direct contact with samples after 1,3, and 7 days.The study revealed that continuous casting enables the primary fabrication of Cu-Al-Ni rods with a shape memory effect. Samples immersed in artificial saliva with 6.5 pH value showed no significant amounts of released ions, despite the high concentration of copper in the alloy. However, in the acidic environment, the suppression of Cu was 0.14 µg/cm2, Al 1.9 µg/cm2, and Ni 0.73 µg/cm2, and as expected, it was confirmed that Cu-Al-Ni alloy is not corrosion resistant in an acidic environment. In conclusion, this study showed that biocompatibility concerns are related only to materials with a high Cu content in acidic environments. Oppositely, small doses of Cu ions promote cell proliferation, which might be useful in further attempts to enrich different biomedical materials with copper.