Design, Synthesis and Processing of Bio-Inspired Soft Materials: Toward New Optoelectronic Devices

The research work carried out during my PhD course has been focused on the following two main topics: 1) The design, synthesis and characterization of new nature-inspired organic electroluminescent emitters and their application in opto-electronic devices. This work will be discussed in the SECTION 1. 2) The design, synthesis and properties of eumelanin-based semiconductors and their applications in electronic devices. This work will be discussed in the SECTION 2. The research activity discussed in SECTION 1 will concern the design, the synthesis and the characterization of new nature-inspired organic electroluminescent emitters and their applications in opto-electronic devices. In details, the following points will be stressed: - the identification of suitable nature-inspired heterocyclic platforms that can be used to develop new electroluminescent materials for opto-electronic applications; - the design of structural modifications of natural compounds for a better match with organic electronics requirements by exploiting the theoretical approach; - the development of new rapid and convenient synthetic strategies for a gram scale production of the organic emitters; - the structural, photo-physical, electronic and thermal characterization of the synthesized compounds along with the investigation of the performances of the opto-electronic devices thereof. The research activity described in SECTION 2 has been devoted to the design, synthesis, processing and properties of eumelanin-based semiconductors and their applications in electronic devices, with the aim of throwing new light onto this controversial issue. In details, the following points will be stressed: - the identification of suitable approaches for a more easy processing of melanin thin films; - the investigation of the factors influencing the conductivity of melanin thin films; - the study of the possible role of melanin thin films as innovative bio-interface

Double-Framed Thin Elastomer Devices

Elastomers and, in particular, polydimethylsiloxane (PDMS) are widely adopted as biocompatible mechanically compliant substrates for soft and flexible micro-nanosystems in medicine, biology, and engineering. However, several applications require such low thicknesses (e.g., <100 μm) that make peeling-off critical because very thin elastomers become delicate and tend to exhibit strong adhesion with carriers. Moreover, microfabrication techniques such as photolithography use solvents which swell PDMS, introducing complexity and possible contamination, thus limiting industrial scalability and preventing many biomedical applications. Here, we combine low-adhesion and rectangular carrier substrates, adhesive Kapton frames, micromilling-defined shadow masks, and adhesive-neutralizing paper frames for enabling fast, easy, green, contaminant-free, and scalable manufacturing of thin elastomer devices, with both simplified peeling and handling. The accurate alignment between the frame and shadow masks can be further facilitated by micromilled marking lines on the back side of the low-adhesion carrier. As a proof of concept, we show epidermal sensors on a 50 μm-thick PDMS substrate for measuring strain, the skin bioimpedance and the heart rate. The proposed approach paves the way to a straightforward, green, and scalable fabrication of contaminant-free thin devices on elastomers for a wide variety of applications.Elastomers and, in particular, polydimethylsiloxane (PDMS) are widely adopted as biocompatible mechanically compliant substrates for soft and flexible micro-nanosystems in medicine, biology, and engineering. However, several applications require such low thicknesses (e.g., <100 μm) that make peeling-off critical because very thin elastomers become delicate and tend to exhibit strong adhesion with carriers. Moreover, microfabrication techniques such as photolithography use solvents which swell PDMS, introducing complexity and possible contamination, thus limiting industrial scalability and preventing many biomedical applications. Here, we combine low-adhesion and rectangular carrier substrates, adhesive Kapton frames, micromilling-defined shadow masks, and adhesive-neutralizing paper frames for enabling fast, easy, green, contaminant-free, and scalable manufacturing of thin elastomer devices, with both simplified peeling and handling. The accurate alignment between the frame and shadow masks can be further facilitated by micromilled marking lines on the back side of the low-adhesion carrier. As a proof of concept, we show epidermal sensors on a 50 μm-thick PDMS substrate for measuring strain, the skin bioimpedance and the heart rate. The proposed approach paves the way to a straightforward, green, and scalable fabrication of contaminant-free thin devices on elastomers for a wide variety of applications

Detection of low-level HCV variants in DAA treated patients: comparison amongst three different NGS data analysis protocols

Background: Notwithstanding the efforts of direct-acting antivirals (DAAs) for the treatment of chronically infected hepatitis C virus (HCV) patients, concerns exist regarding the emergence of resistance-associated substitutions (RAS) related to therapy failure. Sanger sequencing is still the reference technique used for the detection of RAS and it detects viral variants present up to 15%, meaning that minority variants are undetectable, using this technique. To date, many studies are focused on the analysis of the impact of HCV low variants using next-generation sequencing (NGS) techniques, but the importance of these minority variants is still debated, and importantly, a common data analysis method is still not defined. Methods: Serum samples from four patients failing DAAs therapy were collected at baseline and failure, and amplification of NS3, NS5A and NS5B genes was performed on each sample. The genes amplified were sequenced using Sanger and NGS Illumina sequencing and the data generated were analyzed with different approaches. Three different NGS data analysis methods, two homemade in silico pipeline and one commercially available certified user-friendly software, were used to detect low-level variants. Results: The NGS approach allowed to infer also very-low level virus variants. Moreover, data processing allowed to generate high accuracy data which results in reduction in the error rates for each single sequence polymorphism. The results improved the detection of low-level viral variants in the HCV quasispecies of the analyzed patients, and in one patient a low-level RAS related to treatment failure was identified. Importantly, the results obtained from only two out of the three data analysis strategies were in complete agreement in terms of both detection and frequency of RAS. Conclusions: These results highlight the need to find a robust NGS data analysis method to standardize NGS results for a better comprehension of the clinical role of low-level HCV variants. Based on the extreme importance of data analysis approaches for wet-data interpretation, a detailed description of the used pipelines and further standardization of the in silico analysis could allow increasing diagnostic laboratory networking to unleash true potentials of NGS

Regional myocardial perfusion imaging in predicting vessel-related outcome: interplay between the perfusion results and angiographic findings

Background: Despite myocardial perfusion imaging (MPI) by cadmium-zinc-telluride (CZT) single-photon emission computed tomography (SPECT) camera is largely used in the diagnosis and risk stratification of patients with suspected or known coronary artery disease (CAD), no data are available on the prognostic value of a regional MPI evaluation. We evaluated the prognostic value of regional MPI by the CZT camera in predicting clinical outcomes at the vessel level in patients with available angiographic data. Methods and results: Five hundred and forty-one subjects with suspected or known CAD referred to 99mTc-sestamibi gated CZT-SPECT cardiac imaging and with available angiographic data were studied. Both regional total perfusion deficit (TPD) and ischemic TPD (ITPD) were calculated separately for each vascular territory (left anterior descending, left circumflex, and right coronary artery). The outcome end points were cardiac death, target vessel-related myocardial infarction, or late coronary revascularization. The prevalence of CAD ≥ 50%, regional stress TPD, and regional ITPD was significantly higher in vessels with events as compared to those without (both P < 0.001). The receiver operating characteristics area under the curve for regional ITPD for the identification of vessel-related events was 0.81 (95% confidence interval 0.75–0.86). An ITPD value of 2.0% provided the best trade-off for identifying the vessel-related event. At multivariable analysis, both CAD ≥ 50% and ITPD ≥ 2.0% resulted in independent predictors of events. Conclusions: Regional myocardial perfusion assessed by the CZT camera demonstrated good reliability in predicting vessel-related events in patients with suspected or known CAD

La gestión institucional del currículum híbrido: Estudio de casos en educación media en Uruguay

La pandemia del COVID-19 afectó los procesos educativos habituales, a partir de la suspensión de las clases presenciales, en marzo del 2020. Si bien Uruguay contaba con una infraestructura tecnológica desarrollada en los últimos años por el Plan Ceibal, esto afectó a estudiantes, docentes, centros educativos y autoridades de la educación, y generó la necesidad de desarrollar alternativas viables que permitieran la continuidad educativa durante el tiempo de no presencialidad. La suspensión inesperada de las clases presenciales en marzo del 2020 generó un problema dado que, justamente, el habitus de los docentes no tenía información suficiente para hacerle frente a la emergencia que se presentaba. La exclusión del edificio escolar rompía la narración histórica acerca de la enseñanza y las respuestas de los diferentes actores fueron diversas. El primer aspecto a señalar fue la construcción de otro espacio para la enseñanza superpuesto al espacio doméstico. Lo público y lo privado perdieron la frontera y la irrupción de las formas de la vida profesional inundó el espacio doméstico. Eso influyó, por un lado, en la visibilización de diversas realidades habitacionales que quedaban expuestas en las pantallas. Pero también la irrupción de escenas domésticas ante personas con las que, previamente, sólo se tenía un contacto profesional. Las mascotas, los hijos, la entrega del supermercado, todo comenzó a mezclarse con la enseñanza de los contenidos escolares. El segundo aspecto fue la dilución del tiempo en el mismo sentido que la del espacio, es decir la yuxtaposición del tiempo laboral y el doméstico. Pero también hubo una ruptura en la concepción del tiempo como regulador propio de la enseñanza: los ritmos escolares que alternaban clases y recreos y organizaban las rutinas desaparecieron. De pronto la unidad hora de clase, día, semana perdieron su materialidad y requirieron nuevos acuerdos para poder desarrollarse. Con la reapertura paulatina y segmentada en grupos pequeños surgió lo que se llamó modalidad híbrida donde los espacios físicos y virtuales y los tiempos sincrónicos y asincrónicos fueron configurando nuevos escenarios institucionales. Los equipos de conducción tuvieron que tomar decisiones para organizar este nuevo tiempo y los y las docentes fueron implementando diversas estrategias de sostenimiento del vínculo pedagógico y de desarrollo de los aprendizajes de los estudiantes. El presente trabajo busca aportar datos sobre los aspectos vinculados al uso de la tecnología y la gestión institucional durante la no presencialidad, y en los períodos intermedios de retorno a las aulas, poniendo el foco en los centros educativos, relativas a la gestión de los espacios educativos presenciales y virtuales en sus múltiples formas de combinarse en las distintas etapas del proceso, así como a las dinámicas comunicacionales de los colectivos docentes, estudiantiles y de gestión, tanto a la interna como entre cada uno de ellos. El objetivo general de la investigación fue “Conocer las estrategias de gestión curricular tomadas por los equipos directivos de los centros de enseñanza media de Uruguay para llevar adelante la modalidad híbrida durante el período 2020- 2021”. Para el propósito de la investigación se diseñaron y aplicaron diversos instrumentos para recabar información que permitiera generar conocimiento sobre la gestión institucional del modelo híbrido desarrollado en estos períodos. El estudio se realiza desde una perspectiva narrativa, de corte cualitativo, a través de entrevistas en profundidad a directivos y docentes de cada uno de los centros educativos seleccionados. Asimismo, y de forma complementaria, se realizaron dos encuestas de carácter anónimo, una para directivos y otra para docentes, que además de aportar información sobre la temática, permitieron focalizar luego las entrevistas en función de los datos allí obtenidos.Agencia Nacional de Investigación e InnovaciónFundación Ceiba

Clinical-Genetic Features Influencing Disability in Spastic Paraplegia Type 4: A Cross-sectional Study by the Italian DAISY Network

Background and objectives: Hereditary spastic paraplegias (HSPs) are a group of inherited rare neurologic disorders characterized by length-dependent degeneration of the corticospinal tracts and dorsal columns, whose prominent clinical feature is represented by spastic gait. Spastic paraplegia type 4 (SPG4, SPAST-HSP) is the most common form. We present both clinical and molecular findings of a large cohort of patients, with the aim of (1) defining the clinical spectrum of SPAST-HSP in Italy; (2) describing their molecular features; and (3) assessing genotype-phenotype correlations to identify features associated with worse disability. Methods: A cross-sectional retrospective study with molecular and clinical data collected in an anonymized database was performed. Results: A total of 723 Italian patients with SPAST-HSP (58% men) from 316 families, with a median age at onset of 35 years, were included. Penetrance was 97.8%, with men showing higher Spastic Paraplegia Rating Scale (SPRS) scores (19.67 ± 12.58 vs 16.15 ± 12.61, p = 0.009). In 26.6% of patients with SPAST-HSP, we observed a complicated phenotype, mainly including intellectual disability (8%), polyneuropathy (6.7%), and cognitive decline (6.5%). Late-onset cases seemed to progress more rapidly, and patients with a longer disease course displayed a more severe neurologic disability, with higher SPATAX (3.61 ± 1.46 vs 2.71 ± 1.20, p &lt; 0.001) and SPRS scores (22.63 ± 11.81 vs 12.40 ± 8.83, p &lt; 0.001). Overall, 186 different variants in the SPAST gene were recorded, of which 48 were novel. Patients with SPAST-HSP harboring missense variants displayed intellectual disability (14.5% vs 4.4%, p &lt; 0.001) more frequently, whereas patients with truncating variants presented more commonly cognitive decline (9.7% vs 2.6%, p = 0.001), cerebral atrophy (11.2% vs 3.4%, p = 0.003), lower limb spasticity (61.5% vs 44.5%), urinary symptoms (50.0% vs 31.3%, p &lt; 0.001), and sensorimotor polyneuropathy (11.1% vs 1.1%, p &lt; 0.001). Increasing disease duration (DD) and abnormal motor evoked potentials (MEPs) were also associated with increased likelihood of worse disability (SPATAX score&gt;3). Discussion: The SPAST-HSP phenotypic spectrum in Italian patients confirms a predominantly pure form of HSP with mild-to-moderate disability in 75% of cases, and slight prevalence of men, who appeared more severely affected. Early-onset cases with intellectual disability were more frequent among patients carrying missense SPAST variants, whereas patients with truncating variants showed a more complicated disease. Both longer DD and altered MEPs are associated with worse disability

PTPA variants and impaired PP2A activity in early-onset parkinsonism with intellectual disability

The protein phosphatase 2A complex (PP2A), the major Ser/Thr phosphatase in the brain, is involved in a number of signalling pathways and functions, including the regulation of crucial proteins for neurodegeneration, such as alpha-synuclein, tau and LRRK2. Here, we report the identification of variants in the PTPA/PPP2R4 gene, encoding a major PP2A activator, in two families with early-onset parkinsonism and intellectual disability. We carried out clinical studies and genetic analyses, including genome-wide linkage analysis, whole-exome sequencing, and Sanger sequencing of candidate variants. We next performed functional studies on the disease-associated variants in cultured cells and knock-down of ptpa in Drosophila melanogaster. We first identified a homozygous PTPA variant, c.893T&gt;G (p.Met298Arg), in patients from a South African family with early-onset parkinsonism and intellectual disability. Screening of a large series of additional families yielded a second homozygous variant, c.512C&gt;A (p.Ala171Asp), in a Libyan family with a similar phenotype. Both variants co-segregate with disease in the respective families. The affected subjects display juvenile-onset parkinsonism and intellectual disability. The motor symptoms were responsive to treatment with levodopa and deep brain stimulation of the subthalamic nucleus. In overexpression studies, both the PTPA p.Ala171Asp and p.Met298Arg variants were associated with decreased PTPA RNA stability and decreased PTPA protein levels; the p.Ala171Asp variant additionally displayed decreased PTPA protein stability. Crucially, expression of both variants was associated with decreased PP2A complex levels and impaired PP2A phosphatase activation. PTPA orthologue knock-down in Drosophila neurons induced a significant impairment of locomotion in the climbing test. This defect was age-dependent and fully reversed by L-DOPA treatment. We conclude that bi-allelic missense PTPA variants associated with impaired activation of the PP2A phosphatase cause autosomal recessive early-onset parkinsonism with intellectual disability. Our findings might also provide new insights for understanding the role of the PP2A complex in the pathogenesis of more common forms of neurodegeneration.</p

Design, Synthesis and Processing of Bio-Inspired Soft Materials: Toward New Optoelectronic Devices

The research activity of my PhD course has been focused on two main topics: 1) The design, synthesis and characterization of new nature-inspired organic electroluminescent emitters and their application in opto-electronic devices. 2) The design, synthesis and properties of eumelanin-based semiconductors and their applications in electronic devices. The research activity has been carried out in the laboratories of Dr Manini, Dept. Chemical Sciences – University of Naples Federico II (DCS-UniNA), in the laboratories of Dr Maglione, Lab. Nanomaterials and Devices – ENEA C.R. Portici (ENEA) and in the Laboratories of Prof. Rolandi, Dept. Materials Science and Engineering – University of Washington Seattle (DMSE-UW) and Dept. Electrical Engineering – University of California Santa Cruz (DEE-UCSC). 1) Design, synthesis and characterization of new nature-inspired organic electroluminescent emitters and their application in opto-electronic devices. Within this context, the research activity has been focused on the synthesis of nature-inspired luminescent materials and their possible applications as organic emitters in Organic Light Emitting Devices (OLEDs). Main outcomes have been: a) Synthesis of eumelanin-inspired triazatruxenes as novel blue emitters; b) Synthesis of dopamine-inspired iridium(III) complexes as red emitters; c) Synthesis of pyridophenoxazinone-based iridium(III) complexes. 2) Design, synthesis and properties of eumelanin-based semiconductors and their applications in electronic devices. Within this context the research activity has been focused on two main aspects concerning the fabrication and functioning of eumelanin-based electronic devices, that is to improve the processing step for the deposition of homogeneous eumelanin thin films and to delineate the factors governing the electrical conduction of eumelanin-based devices. Main outcomes have been: a) Novel approaches to eumelanin thin film deposition; b) Electrical properties of eumelanin thin films; c) New melanin-based bio-interfaces