Conformable AlN Piezoelectric Sensors as a Non-invasive Approach for Swallowing Disorder Assessment.

Deglutition disorders (dysphagia) are common symptoms of a large number of diseases and can lead to severe deterioration of the patient's quality of life. The clinical evaluation of this problem involves an invasive screening, whose results are subjective and do not provide a precise and quantitative assessment. To overcome these issues, alternative possibilities based on wearable technologies have been proposed. We explore the use of ultrathin, compliant, and flexible piezoelectric patches that are able to convert the laryngeal movement into a well-defined electrical signal, with extremely low anatomical obstruction and high strain resolution. The sensor is based on an aluminum nitride thin film, grown on a soft Kapton substrate, integrated with an electrical charge amplifier and low-power, wireless connection to a smartphone. An ad-hoc designed laryngeal motion simulator (LMS), which is able to mimic the motions of the laryngeal prominence, was used to evaluate its performances. The physiological deglutition waveforms were then extrapolated on a healthy volunteer and compared with the sEMG (surface electromyography) of the submental muscles. Finally, different tests were conducted to assess the ability of the sensor to provide clinically relevant information. The reliability of these features permits an unbiased evaluation of the swallowing ability, paving the way to the creation of a system that is able to provide a point-of-care automatic, unobtrusive, and real-time extrapolation of the patient's swallowing quality even during normal behavior.

Secondary Metabolite Production from Industrially Relevant Bacteria is Enhanced by Organic Nanofibers.

Streptomycetes are exploited for the production of a wide range of secondary metabolites, including antibiotics. Therefore, both academic and industrial research efforts are focused on enhancing production of these precious metabolites. So far, this has been mostly achieved by classical or recombinant genetic techniques, in association with process optimization for either submerged or solid state fermentation. New cultivation approaches addressing the natural mycelial growth and life cycle would allow the biosynthetic potential of filamentous strains to be much better exploited. We developed a cultivation system for antibiotic-producing microorganisms which involves electrospun organic nanofibers deposited onto agar plates or immersed in liquid media. Dense filamentous networks of branched hyphae formed by bacterial colonies were found to wrapped around the fibers. We analyzed the effects of fibers on growth and antibiotic production in Streptomyces lividans, and found that the actinorhodin, undecylprodigiosin and calcium dependent antibiotic productions were positively modulated, with a two- to sixfold enhancement compared to standard culture conditions. Highlighting the secondary metabolism-promoting role of nanofibers in bacterial cultures, these results open a route to the design of improved culture systems for microorganisms based on organic nanostructures.