Plasmonic nanostructures for optical biosensing

In the last few decades, an increasing interest for nanotechnologies is spanning more and more fields of application thanks to the unique properties exhibited by metal nanomaterials if stimulated by external electromagnetic radiations. Indeed, a new research field called plasmonics is emerging and fast growing as a result of the recent technological progress and a deeper understanding of such phenomena. Recently, several types of plasmonic nanostructures are being conceived aiming at improving the performance of plasmon-based devices. For instance, sharp nanostructures exhibit higher field enhancement than smooth surfaces thereby representing a remarkable advantage in applications relying on signal amplification such as surface-enhanced Raman spectroscopy and plasmon-enhanced fluorescence. In addition, when nanostructures are ordered in periodic arrays, collective modes can arise as a result of the field coupling among the surface plasmons so as to promote the occurrence of impressive effects such as lattice resonances. Therefore, the possibility to tune the optical response of a nanostructure by tailoring the nanomaterial shape and size, as well as the structure arrangement, is spurring the researchers to explore new approaches, in terms of both nanofabrication and nano applications, in order to go beyond the current limits of many techniques. The aim of this work is to provide an understanding of this growing field of research and to convey the main features in biosensing applications. To date, several biosensor-based approaches including colorimetric and fluorescence analysis have been explored to effectively work alongside – or even replace – the gold standard methods in a wide variety of applications including environmental pollution monitoring and medical diagnostics. In this regard, optical biosensors offer a rapid, affordable, and practical approach in many fields of applications paving the way for point of care tests and high-throughput analysis. Fluorescence-based techniques are of growing interest since their potential high-throughput analysis, point of care applications, and improvable sensitivity through plasmon-enhanced fluorescence effect. On the other hand, when quickness, practicality, and easiness of use are preferred rather than extremely high sensitivity and accuracy, colorimetric biosensors relying on gold nanoparticles are the ideal candidates since their capability to produce a qualitative response in a few minutes visible by naked eye (a portable and handheld spectrophotometer can be employed if a quantitative measurement is required). The performance of colorimetric biosensors have been tested for detecting small molecules, such as 17β-estradiol in tap water down to picomolar level, and SARS-CoV-2 virions in naso-oropharyngeal swabs from hospital patients, whereas two-dimensional patterns of honeycomb-arranged and randomly positioned gold nanoparticles have been implemented in fluorescence-based malaria apta-immunoassays to effectively amplify the signal intensity through plasmon-enhanced fluorescence effect thereby attaining an ultrasensitive limit of detection at femtomolar level for detecting proteins in human whole blood

Analysis of the optical response of a SARS-CoV-2-directed colorimetric immunosensor

The optical response of different configurations of functionalized gold nanoparticles (f-AuNPs) and SARS-CoV-2 virions is simulated in order to explore the behavior of a colloidal solution containing 105–1013 virions/ml. The analysis herein reported is carried out for three concentration regimes: (i) low (≲108 virions/ml), (ii) intermediate (∼109–1010 virions/ml), and (iii) high (≳1011 virions/ml). Given the high binding effectiveness of f-AuNPs to virions, three different configurations are expected to arise: (i) virions completely surrounded by f-AuNPs, (ii) aggregates (dimers or trimers) of virions linked by f-AuNPs, and (iii) single f-AuNP surrounded by virions. It is demonstrated that 20 nm diameter gold nanoparticles functionalized against all three kinds of SARS-CoV-2 proteins (membrane, envelope, and spike) allow one to reach a limit of detection (LOD) of ∼106 virions/ml, whereas the use of only one kind of f-AuNP entails a ten-fold worsening of the LOD. It is also shown that the close proximity (∼5 nm) of the f-AuNP to the virions assumed throughout this analysis is essential to avoid the hook effect, thereby pointing out the importance of realizing an apt functionalization procedure that keeps thin the dielectric layer (e.g., proteins or aptamers) surrounding the gold nanoparticles

Therapeutic and prognostic predictive value of the Control Volume severity grade on proximal humerus fractures due to bone fragility

Background The treatment of proximal humerus fracture complicated by bone fragility is still controversial. The aim of this study is to compare the Neer classification and the Control Volume severity grade for the accuracy in the selection of the type of treatment and for prognostic evaluation. Materials and methods We retrospectively collected the records of all patients admitted at the Emergency Department of our Institute, from 2013 to 2020, for a closed displaced proximal humerus fracture further investigated with a CT scan before treatment decision. We selected all patients with a minimum age of 65 years. The included fractures were retrospectively classified according to Neer, and Control Volume severity grade. The included patients were evaluated with Simple Shoulder Test (SST). A statistical analysis was performed to correlate the type of treatment and the clinical results to the Neer classification and the Control Volume severity grade. Results Sixty-four patients (80%), were available for the telephonically interview at a mean follow up of 4 years and were included. According to the Control Volume model, we identified fracture with a low, medium and high severity grade, in 23 (36%), 13 (20%), and, 28 (44%) cases, respectively. Fifteen patients (23,5%) were conservatively treated, whether fourty-nine patients (76,5%) were operated. We find a statistical correlation between control volume severity grade and type of treatment. No Therapeutic correlation was detected for the Neer classification. A statistical correlation between the severity grade and clinical outcome could be observed only for patients with the same type of treatment. Conclusions The use of Control Volume severity grade is associated with better therapeutic and prognostic informations in confront to the Neer classification

Escalating CO2 degassing at the Pisciarelli fumarolic system, and implications for the ongoing Campi Flegrei unrest

This short communication aims at providing an updated report on degassing activity and ground deformation variations observed during the ongoing (2012–2019) Campi Flegrei caldera unrest, with a particular focus on Pisciarelli, currently its most active fumarolic field.We show that the CO2 flux fromthe main Pisciarelli fumarolic vent (referred as “Soffione”) has increased by a factor N 3 since 2012, reaching in 2018–2019 levels (N600 tons/ day) that are comparable to those typical of a medium-sized erupting arc volcano. A substantial widening ofthe degassing vents and bubbling pools, and a further increase in CO2 concentrations in ambient air (up to 6000 ppm), have also been detected since mid-2018. We interpret this escalating CO2 degassing activity using a multidisciplinary dataset that includes thermodynamically estimated pressures for the source hydrothermal system, seismic and ground deformation data. From this analysis, we show that degassing, deformation and seis- micity have all reached in 2018–2019 levels never observed since the onset ofthe unrest in 2005, with an overall uplift of~57 cmand ~448 seismic events in the last year. The calculated pressure ofthe Campi Flegrei hydrother- mal system has reached ~44 bar and is rapidly increasing. Our results raise concern on the possible evolution of the Campi Flegrei unrest and reinforce the need for careful monitoring of the degassing activity at Pisciarelli, hopefully with the deployment of additional permanent gas monitoring units.Published151-1574V. Processi pre-eruttiviJCR Journa

HDAC class I inhibitor domatinostat sensitizes pancreatic cancer to chemotherapy by targeting cancer stem cell compartment via FOXM1 modulation

Pancreatic ductal adenocarcinoma (PDAC) represents an unmet clinical need due to the very poor prognosis and the lack of effective therapy. Here we investigated the potential of domatinostat (4SC-202), a new class I histone deacetylase (HDAC) inhibitor, currently in clinical development, to sensitize PDAC to first line standard gemcitabine (G)/taxol (T) doublet chemotherapy treatment. Methods: Synergistic anti-tumor effect of the combined treatment was assessed in PANC1, ASPC1 and PANC28 PDAC cell lines in vitro as well as on tumor spheroids and microtissues, by evaluating combination index (CI), apoptosis, clonogenic capability. The data were confirmed in vivo xenograft models of PANC28 and PANC1 cells in athymic mice. Cancer stem cells (CSC) targeting was studied by mRNA and protein expression of CSC markers, by limiting dilution assay, and by flow cytometric and immunofluorescent evaluation of CSC mitochondrial and cellular oxidative stress. Mechanistic role of forkhead box M1 (FOXM1) and downstream targets was evaluated in FOXM1-overexpressing PDAC cells. Results: We showed that domatinostat sensitized in vitro and in vivo models of PDAC to chemotherapeutics commonly used in PDAC patients management and particularly to GT doublet, by targeting CSC compartment through the induction of mitochondrial and cellular oxidative stress. Mechanistically, we showed that domatinostat hampers the expression and function of FOXM1, a transcription factor playing a crucial role in stemness, oxidative stress modulation and DNA repair. Domatinostat reduced FOXM1 protein levels by downregulating mRNA expression and inducing proteasome-mediated protein degradation thus preventing nuclear translocation correlated with a reduction of FOXM1 target genes. Furthermore, by overexpressing FOXM1 in PDAC cells we significantly reduced domatinostatinducing oxidative mitochondrial and cellular stress and abolished GT sensitization, both in adherent and spheroid cells, confirming FOXM1 crucial role in the mechanisms described. Finally, we found a correlation of FOXM1 expression with poor progression free survival in PDAC chemotherapy-treated patients

CBCT/ExoCT reconstruction software

Reconstruction algorithm for cone beam CT with conventional and oscillating scanning orbit Disclaimer This software was developed in Matlab environment (MathWorks Inc) by Antonio Minopoli and Antonio Sarno as part of the PRIN project Q-CT funded by the Italian Ministry of University and Research (CUP E53D23012420006). The activity of Antonio Sarno was also part of the Prof-of-Concept project QE-CBCT funded by the Italian Ministry of the Economic Development (MISE) through the Italian Institute of Nuclear Physics (CUP C18H23000670002). Permission of use is hereby granted, free of charge, to any person obtaining a copy of the Software, to deal in the software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, or sell copies of the Software or derivatives. Developers assume no responsibilities whatsoever for the use by other parties of the software and make no guarantees, expressed or implied, about its quality, reliability, or any other characteristics. Although this software can be redistributed and/or modified freely. Software features The developed software permits analytical FDK reconstruction in CBCT, either by using CPU or GPU architecture. It permits sinogram input either for conventional circular scanning geometry or for oscillating geometry as described in the quoted paper. Instruction for the use This MATLAB project implements the Feldkamp-Davis-Kress (FDK) reconstruction algorithm specifically adapted for cone beam computed tomography (CBCT) with an oscillating scanning orbit. The algorithm is designed to handle the source overlapping introduced by the oscillating orbit, providing accurate 3D reconstructions from cone beam data. It was developed and tested on Matlab R2024a and Windows OS List additional toolboxes required Image Processing Toolbox Parallel Computing Toolbox Instructions Download the folder containing the main code (ExoCT_code.m), the parameter setting with two example settings (User_setting_ex1.m and User_setting_ex2.m), the folder ‘/Functions’ containing the supporting functions (FDK.p, Filtering.p, Geometry_initialization.p, Stack_saving.p), and two sinograms contained in the folder ‘/Sinograms’ to be used with the user setting examples (PP1_sino.tif and PP3_sino.tif). Define parameters in User_setting_*.m, in detail: param.sinogram: filename or full path in case the folder containing the sinogram is different from “Sinogram” folder provided param.horizontal: “true” if the angle of projections varies along the horizontal axis, “false” if along the vertical axis param.log: “true” if the sinogram pixel values are expressed as logarithm, “false” otherwise param.gpu: “1” to enable the use of GPU, “0” to disable it param.px_size: pixel size in millimeters param.DSD: source-detector distance in millimeters param.DSO: source-object distance in millimeters param.tot_angle: total scanning angle param.dir: “-1” if the gantry rotates counterclockwise, “1” if the gantry rotates clockwise param.PP: number of projections per oscillation period param.amplitude: full amplitude oscillation in millimeters param.vx: voxel size along x axis in millimeters param.vy: voxel size along y axis in millimeters param.vz: voxel size along z axis in millimeters param.filter: the available filters are “ram-lak”, “shepp-logan”, “cosine”, “hamming”, “hann” param.save: “true” to save the reconstructed volume, “false” otherwise. Run ExoCT_code.m The output volume will be saved in the dedicated subdirectory Reconstructed_volume. Each of the reconstructed axial slice will be saved as a separate 32-bit ASCII file

Opto-fluidically multiplexed assembly and micro-robotics

Abstract Techniques for high-definition micromanipulations, such as optical tweezers, hold substantial interest across a wide range of disciplines. However, their applicability remains constrained by material properties and laser exposure. And while microfluidic manipulations have been suggested as an alternative, their inherent capabilities are limited and further hindered by practical challenges of implementation and control. Here we show that the iterative application of laser-induced, localized flow fields can be used for the relative positioning of multiple micro-particles, irrespectively of their material properties. Compared to the standing theoretical proposal, our method keeps particles mobile, and we show that their precision manipulation is non-linearly accelerated via the multiplexing of temperature stimuli below the heat diffusion limit. The resulting flow fields are topologically rich and mathematically predictable. They represent unprecedented microfluidic control capabilities that are illustrated by the actuation of humanoid micro-robots with up to 30 degrees of freedom, whose motions are sufficiently well-defined to reliably communicate personal characteristics such as gender, happiness and nervousness. Our results constitute high-definition micro-fluidic manipulations with transformative potential for assembly, micro-manufacturing, the life sciences, robotics and opto-hydraulically actuated micro-factories