Interferometric Biosensor for High Sensitive Label-Free Recording of HiPS Cardiomyocytes Contraction in Vitro.

Heart disease remains a leading cause of global mortality, underscoring the need for advanced technologies to study cardiovascular diseases and develop effective treatments. We introduce an innovative interferometric biosensor for high-sensitivity and label-free recording of human induced pluripotent stem cell (hiPSC) cardiomyocyte contraction in vitro. Using an optical cavity, our device captures interference patterns caused by the contraction-induced displacement of a thin flexible membrane. First, we demonstrate the capability to quantify spontaneous contractions and discriminate between contraction and relaxation phases. We calculate a contraction-induced vertical membrane displacement close to 40 nm, which implies a traction stress of 34 ± 4 mN/mm2. Finally, we investigate the effects of a drug compound on contractility amplitude, revealing a significant reduction in contractile forces. The label-free and high-throughput nature of our biosensor may enhance drug screening processes and drug development for cardiac treatments. Our interferometric biosensor offers a novel approach for noninvasive and real-time assessment of cardiomyocyte contraction.

Anomalous diffusion of acoustic waves in 2D periodic media: Radiative transport and renormalization analysis.

This work investigates the occurrence of anomalous transport of acoustic waves propagating in two-dimensional (2D) perfectly periodic media and presents dedicated analysis tools to explore and understand the properties of the medium controlling the transitions between different transport regimes. By leveraging a two-fold approach that combines both radiative transport and renormalization theory, the propagation properties of the inhomogeneous medium can be characterized both near and at the transition from normal to anomalous diffusion. The proposed approach builds upon the classical radiative transfer theory of bulk materials, and it is specifically designed to study 2D systems. The ability to simulate and interpret the field quantities that describe such transport mechanisms can play a significant role in the development of wave-based imaging technology for highly inhomogeneous and scattering media.

Ultrasound generation in water via quasi-periodically snapping polymeric core-shell micro-bead excited with radiowaves.

This work reports the results of a theoretical and numerical study showing the occurrence of stochastically resonating bistable dynamic in polymeric micro-bead of sub-micrometric size with stiff core and soft shell. The system, submerged in water, is excited with a pulsed laser working in the Mega-Hertz frequency range and tuned to match both an optical and acoustic resonance of the system. The laser interacts with the carbon nanotubes embedded in the shell of the polymeric micro-bead generating heat. The concurrent action of the generated heat with the standing acoustic oscillations, gives rise to a stochastically resonating bistable system. The system in fact is forced to switch between two states (identifiable with the creation and organized disruption of a quasi-hexagonal tessellation) via a snap-through-buckling mechanism. This phenomenon results in the unprecedented generation of pressure oscillations. These results open the way to develop a new type of core-shell micro-transducers for radioacoustic imaging applications able to work in the Mega-Hertz frequency range. From a more general thermodynamic perspective, the reported mechanism shows a remarkable periodicity and energy conversion efficiency.

Stochastic scattering model of anomalous diffusion in arrays of steady vortices.

We investigate the occurrence of anomalous transport phenomena associated with tracer particles propagating through arrays of steady vortices. The mechanism responsible for the occurrence of anomalous transport is identified in the particle dynamic, which is characterized by long collision-less trajectories (Lévy flights) interrupted by chaotic interactions with vortices. The process is studied via stochastic molecular models that are able to capture the underlying non-local nature of the transport mechanism. These models, however, are not well suited for problems where computational efficiency is an enabling factor. We show that fractional-order continuum models provide an excellent alternative that is able to capture the non-local nature of anomalous transport processes in turbulent environments. The equivalence between stochastic molecular and fractional continuum models is demonstrated both theoretically and numerically. In particular, the onset and the temporal evolution of heavy-tailed diffused fields are shown to be accurately captured, from a macroscopic perspective, by a fractional diffusion equation. The resulting anomalous transport mechanism, for the selected ranges of density of the vortices, shows a superdiffusive nature.

Changing epidemiology of acute liver failure in Italy: a single-center experience over 25 years.

BACKGROUND: Acute liver failure (ALF) is a rare but often lethal syndrome. In Italy, recent data on its incidence and causes are lacking. We report here the epidemiological analysis of ALF cases observed in Campania, a Southern Italian region, over the last 25 years. METHODS: Medical records of ALF cases hospitalized from 1992 to 2018 were retrospectively analyzed. RESULTS: Two hundred ten ALF cases occurred during 1992-2018: 103 (49%) hepatitis B virus (HBV)-related (including 5 cases also infected with Delta virus), 39 (19%) from undetermined cause, 36 (17%) drug-induced, 11 (5%) Wilson's disease-associated, 8 (4%) hepatitis A virus (HAV)-related and 12 (6%) from other causes. Separate time-periods analysis of data showed a significant progressive decrease in ALF incidence mainly attributable to a decline of HBV and other viruses etiology. Already before 2010, HAV or Delta virus-related cases have no longer been observed. No hepatitis C or E virus-related ALF was detected through the study period. A progressive decrease in frequency of ALF due to undetermined causes or drug was also evident. CONCLUSIONS: A decrease in ALF incidence and a changing in its etiology were observed in Campania during 1992-2018. Both results were likely mainly due to 1991 introduction of HBV universal vaccination and may be considered generalizable nationwide.