High-Strength Amorphous Silicon Carbide for Nanomechanics.

For decades, mechanical resonators with high sensitivity have been realized using thin-film materials under high tensile loads. Although there are remarkable strides in achieving low-dissipation mechanical sensors by utilizing high tensile stress, the performance of even the best strategy is limited by the tensile fracture strength of the resonator materials. In this study, a wafer-scale amorphous thin film is uncovered, which has the highest ultimate tensile strength ever measured for a nanostructured amorphous material. This silicon carbide (SiC) material exhibits an ultimate tensile strength of over 10 GPa, reaching the regime reserved for strong crystalline materials and approaching levels experimentally shown in graphene nanoribbons. Amorphous SiC strings with high aspect ratios are fabricated, with mechanical modes exceeding quality factors 108 at room temperature, the highest value achieves among SiC resonators. These performances are demonstrated faithfully after characterizing the mechanical properties of the thin film using the resonance behaviors of free-standing resonators. This robust thin-film material has significant potential for applications in nanomechanical sensors, solar cells, biological applications, space exploration, and other areas requiring strength and stability in dynamic environments. The findings of this study open up new possibilities for the use of amorphous thin-film materials in high-performance applications.

Enhanced urinary stability of peptide hormones and growth factors by dried urine microsampling.

Volumetric absorptive microsampling (VAMS) and dried urine spot (DUS) strategies were applied for the collection of dried microsamples for anti-doping testing of low-stability peptide hormones and growth factors prohibited by the World Anti-Doping Agency (WADA). Drying, storage and transport conditions, as well as pretreatment steps, were optimised before liquid chromatography - tandem mass spectrometry (LC-MS/MS) analysis. The analytical method has been fully validated in terms of sensitivity (limits of quantitation 0.3-10 ng/mL), precision (RSD% < 6.6 %) and extraction yields (78-91 %). Dried microsample stability studies (90 days) have been performed and compared to fluid urine stability. Significantly higher losses have been observed in fluid urine stored at -20 °C (up to 55 %) and -80 °C (up to 29 %) than in dried urine microsamples stored at room temperature (< 19 %). The final microsampling and analysis protocols allow the collection of urine microvolumes, unlikely to be tampered, stably storable and shippable with no particular precautions for possible anti-doping testing of prohibited peptides and hormones.

VAMS and StAGE as innovative tools for the enantioselective determination of clenbuterol in urine by LC-MS/MS.

Clenbuterol is a chiral, selective ß2-adrenergic agonist. It is administered as a racemic mixture for therapeutic purposes (as a bronchodilator or prospective neuroprotective agent), but also for non-therapeutic uses (athletic performance enhancement, cattle growth promotion). Aim of the present study is to develop an original, enantioselective workflow for the analysis of clenbuterol enantiomers in urine microsamples. An innovative miniaturised sampling procedure by volumetric absorptive microsampling (VAMS) and a microsample pretreatment strategy based on stop-and-go extraction (StAGE) tips were developed and coupled to an original, chiral analytical method, exploiting liquid chromatography with triple quadrupole detection (LC-MS/MS). The method was validated, with satisfactory results: good linearity (r2 ≥ 0.9995) and LOQ values (0.3 ng/mL) were found over suitable concentration ranges. Extraction yield (>87 %), precision (RSD < 4.3 %) and matrix effect (85-90 %) were all within acceptable levels of confidence. After validation, the method was applied to the determination of clenbuterol in dried urine sampled by VAMS from patients taking the drug for therapeutic reasons. Analyte content ranged from 0.8 to 2.5 ng/mL per single enantiomer, with substantial retention of the original drug racemic composition. The VAMS-StAGE-LC-MS/MS workflow seems to be suitable for future application to anti-doping testing of clenbuterol in urine.

Solution-Based Fabrication of Polycrystalline Si Thin-Film Transistors from Recycled Polysilanes.

Currently, research has been focusing on printing and laser crystallization of cyclosilanes, bringing to life polycrystalline silicon (poly-Si) thin-film transistors (TFTs) with outstanding properties. However, the synthesis of these Si-based inks is generally complex and expensive. Here, we prove that a polysilane ink, obtained as a byproduct of silicon gases and derivatives, can be used successfully for the synthesis of poly-Si by laser annealing, at room temperature, and for n- and p-channel TFTs. The devices, fabricated according to CMOS compatible processes at 350 °C, showed field effect mobilities up to 8 and 2 cm2/(V s) for n- and p-type TFTs, respectively. The presented method combines a low-cost coating technique with the usage of recycled material, opening a route to a convenient and sustainable production of large-area, flexible, and even disposable/single-use electronics.