Wearable piezoelectric mass sensor based on pH sensitive hydrogels for sweat pH monitoring.

Colorimetric and electrochemical (bio)sensors are commonly employed in wearable platforms for sweat monitoring; nevertheless, they suffer from low stability of the sensitive element. In contrast, mass-(bio)sensors are commonly used for analyte detection at laboratory level only, due to their rigidity. To overcome these limitations, a flexible mass-(bio)sensor for sweat pH sensing is proposed. The device exploits the flexibility of piezoelectric AlN membranes fabricated on a polyimide substrate combined to the sensitive properties of a pH responsive hydrogel based on PEG-DA/CEA molecules. A resonant frequency shift is recorded due to the hydrogel swelling/shrinking at several pH. Our device shows a responsivity of about 12 kHz/pH unit when measured in artificial sweat formulation in the pH range 3-8. To the best of our knowledge, this is the first time that hydrogel mass variations are sensed by a flexible resonator, fostering the development of a new class of compliant and wearable devices.

Soft and flexible piezoelectric smart patch for vascular graft monitoring based on Aluminum Nitride thin film.

Vascular grafts are artificial conduits properly designed to substitute a diseased blood vessel. However prosthetic fail can occur without premonitory symptoms. Continuous monitoring of the system can provide useful information not only to extend the graft's life but also to optimize the patient's therapy. In this respect, various techniques have been used, but all of them affect the mechanical properties of the artificial vessel. To overcome these drawbacks, an ultrathin and flexible smart patch based on piezoelectric Aluminum Nitride (AlN) integrated on the extraluminal surface of the prosthesis is presented. The sensor can be conformally wrapped around the external surface of the prosthesis. Its design, mechanical properties and dimensions are properly characterized and optimized in order to maximize performances and to avoid any interference with the graft structure during its activity. The sensorized graft is tested in vitro using a pulsatile recirculating flow system that mimics the physiological and pathological blood flow conditions. In this way, the ability of the device to measure real-time variations of the hemodynamics parameters has been tested. The obtained high sensitivity of 0.012 V Pa-1 m-2, joint to the inherent biocompatibility and non-toxicity of the used materials, demonstrates that the device can successfully monitor the prosthesis functioning under different conditions, opening new perspectives for real-time vascular graft surveillance.

Elucidating the effect of the lead iodide complexation degree behind the morphology and performance of perovskite solar cells.

The inclusion of iodide additives in hybrid perovskite precursor solutions has been successfully exploited to improve the solar cell efficiency but their impact on perovskite formation, morphology and photovoltaic performance is still not clear. Here an extensive analysis of the effect of iodide additives in the solution-phase and during the perovskite film formation, as well as their effect on device performance is provided. The results demonstrate that in the solution-phase the additives promote the formation of lead poly-iodide species resulting in the disaggregation of the inorganic lead iodide framework and in the formation of smaller nuclei inducing the growth of uniform and smooth perovskite films. Most importantly, the complexation capability of different iodide additives does not only directly affect film morphology but also influences the density of defect states by varying the stoichiometry of precursors. These findings demonstrate that the fine control of the interactions of the chemical species in the solution-phase is essential for the precise control of the morphology at the nanoscale and the growth of the perovskite films with a reduced density of defect states. Therefore, the in-depth understanding of all the processes involved in the solution-phase is the first step for the development of a facile and reproducible approach for the fabrication of hybrid perovskite solar cells with enhanced photovoltaic performance.

A bio-inspired real-time capable artificial lateral line system for freestream flow measurements.

To enhance today's artificial flow sensing capabilities in aerial and underwater robotics, future robots could be equipped with a large number of miniaturized sensors distributed over the surface to provide high resolution measurement of the surrounding fluid flow. In this work we show a linear array of closely separated bio-inspired micro-electro-mechanical flow sensors whose sensing mechanism is based on a piezoresistive strain-gauge along a stress-driven cantilever beam, mimicking the biological superficial neuromasts found in the lateral line organ of fishes. Aiming to improve state-of-the-art flow sensing capability in autonomously flying and swimming robots, our artificial lateral line system was designed and developed to feature multi-parameter freestream flow measurements which provide information about (1) local flow velocities as measured by the signal amplitudes from the individual cantilevers as well as (2) propagation velocity, (3) linear forward/backward direction along the cantilever beam orientation and (4) periodicity of pulses or pulse trains determined by cross-correlating sensor signals. A real-time capable cross-correlation procedure was developed which makes it possible to extract freestream flow direction and velocity information from flow fluctuations. The computed flow velocities deviate from a commercial system by 0.09 m s(-1) at 0.5 m s(-1) and 0.15 m s(-1) at 1.0 m s(-1) flow velocity for a sampling rate of 240 Hz and a sensor distance of 38 mm. Although experiments were performed in air, the presented flow sensing system can be applied to underwater vehicles as well, once the sensors are embedded in a waterproof micro-electro-mechanical systems package.

Spectrin Cosenza: a novel beta chain variant associated with Sp alphaI/74 hereditary elliptocytosis.

A Calabrian family (Southern Italy) with Sp alpha(I/74) hereditary elliptocytosis (HE) in the heterozygous state was studied. Sp alpha(I/74) HE is associated with asymptomatic elliptocytosis, a defect in spectrin dimer self association and an increase of the alpha(I/74) kD fragment from the alpha chain after partial tryptic digestion of spectrin. To identify the underlying molecular defect, we analysed exons V, W, X, Y, Z of the beta gene and exon 2 of the alpha gene by single-strand conformational polymorphism (SSCP) of the amplification products. Direct DNA sequencing of the mutant exon showed a C-->G substitution at position 6284 of the beta gene. The corresponding substitution at the protein level was Arg-->Pro in the 2064 position of the beta-spectrin chain.

Severe erythrocyte adenylate kinase deficiency due to homozygous A-->G substitution at codon 164 of human AK1 gene associated with chronic haemolytic anaemia.

A child of Italian origin with a congenital haemolytic anaemia had spectrophotometrically undetectable erythrocyte adenylate kinase (AK) activity. Her parents and brother had approximately 50% normal AK activity, and AK electrophoresis of red blood cell (RBC) crude extract on cellulose acetate strips showed the presence of the normal allele AK1-1. No AK band was detected in the AK electrophoresis of the proband, in whom the erythrocyte 2,3-diphosphoglycerate (2,3DPG) and glutathione (GSH) concentrations were normal whereas adenosine triphosphate (ATP) concentration, pyruvate kinase (PK) and glucose-6P-dehydrogenase (G6PD) activities were increased, reflecting the high reticulocyte count (6.9%). No other evident enzymatic defect was detected by standard procedures. Analysis of AK gene exons, based on polymerase chain reaction-single-strand conformational polymorphism (PCR-SSCP), clearly showed an abnormality in the fragment containing exon 6. The subsequent sequence analysis of this abnormal fragment revealed homozygous and heterozygous A-->G substitutions in the proband and in the parents and brother respectively at codon 164, corresponding to a tyrosine-->cysteine substitution in the AK protein.

SP alpha I/65 hereditary elliptocytosis in Calabria (southern Italy).

The alpha I/65 variant of spectrin has been described in black people, in North Africans and recently in two southern Italian families. This variant is associated in the heterozygous state with mild Hereditary Elliptocytosis (HE) and the molecular basis of the defect is invariably the duplication of TTG at codon 154 of the alpha spectrin gene. The present study reports the identification of five Calabrian families with SP alpha I/65 HE and their distribution in the population.

In vivo metabolic studies of glucose, ATP and 2,3-DPG in beta-thalassaemia intermedia, heterozygous beta-thalassaemic and normal erythrocytes: 13C and 31P MRS studies.

13C and 31P magnetic resonance spectroscopy was used to characterize the in vivo kinetics of glucose metabolism and intracellular ATP and 2,3-DPG concentrations in erythrocytes obtained from beta-thalassaemia intermedia, heterozygous beta-thalassaemic and normal individuals and maintained in suspension. Except for an upfield chemical shift in the 2P and 3P resonance of 2,3-DPG in the thalassaemia intermedia erythrocytes, the 31P spectra were comparable between all three blood types, showing similar concentrations of ATP (from 4.5 to 5.2 mumol/g Hb) and 2,3-DPG (from 17.2 to 19.7 mumol/g Hb). However, the profile of glucose metabolism was quite different in beta-thalassaemia intermedia erythrocytes, whereas glucose was consumed at a rate of 0.089 +/- 0.035 fmol/cell/h, significantly higher than that of normal (0.032 +/- 0.018 fmol/cell/h; P = 0.01) and heterozygous (0.025 +/- 0.004 fmol/cell/h; P = 0.01) erythrocytes. This near 3-fold faster rate of glucose metabolism in the thalassaemia intermedia erythrocytes could not be accounted for by any increase in glucose flux via the Embden-Meyerhof pathway, since no significant difference in 3-13C-lactate synthesis was observed among the three blood types (in units of fmol/cell/h, normal, 0.021 +/- 0.013; heterozygous, 0.021 +/- 0.006; beta-thalassaemia intermedia 0.045 +/- 0.025). These results reflect an accelerated rate of glucose metabolism in thalassaemia intermedia erythrocytes because the contribution of reticulocytes to this altered pattern of metabolism could be excluded. As the only other route of glucose metabolism in erythrocytes is the pentose phosphate pathway (PPP), these results indicate that the PPP is more active in beta-thalassaemia intermedia erythrocytes, perhaps as a consequence of their elevated intracellular oxidative state.

Osteoporosis in patients affected with thalassemia. Our experience.

The authors examine 72 patients affected with homozygous B-thalassemia; The study was conducted by clinical-hematological and radiologic examination. The Singh method is used to compare clinical data with the degree of osteoporosis. The results indicate that there is a high frequency of osteoporotic abnormalities in thalassemia. The authors postulate that osteoporotic lesions are principally caused by hyperplasia of the marrow, the overactive bone marrow widening the medullary space and the increased intramedullary pressure causing osteoporosis.

Genetic polymorphism at the phosphoglucomutase 1 (PGM1) locus in Cosenza Province (Calabria--southern Italy).

1315 school-boys of the Cosenza province (Calabria - southern Italy) were subtyped for the PGM1 locus. Three subsamples were examined, two from the Tyrrhenian and the Ionian coasts, respectively, and one from the internal part of this province. The PGM1*1S, PGM1*2S and PGM1*2F gene frequency estimates obtained for the population of the Ionian coast were significantly different from those of the tyrrhenian coast. Since the three subsamples were of similar size, estimates weighted also with the respective population sizes were calculated.

Hb F-Cosenza or G gamma 25(B7)Gly----Glu: a new fast-moving fetal hemoglobin variant.

A fast-moving gamma chain variant was discovered in the cord blood of a newborn during a screening program carried out in the northern region of Calabria, Southern Italy. The structural analysis showed a Gly----Glu substitution at position 25 of the G gamma chain indicating a new fetal hemoglobin variant that was named Hb F-Cosenza.