Spectroscopic analyses of molecular packing in pentacene thin films

Pentacene thin films are studied with three different and not invasive techniques to assess their capability to identify the thin-film thickness (in this research from 50nm to 300 nm). Atomic Force Microscopy can detect the morphology of a surface and therefore the thickness at the edge of a scratch in the layer. X-ray spectroscopy can assess the presence of a bulk-phase and a thin-film phase related to the thickness of a pentacene layer. Finally the photocurrent spectroscopy, carried out on pentacene thin-film transistors, can measure the density of states distribution around the band edge and show the increase of the Davydov splitting related to a particular thickness. This information is extremely useful in the implementation of electronic devices like Organic Thin Film Transistors (OTFT), Organic LEDs and solar cells

A Methodology to Virtualize Technical Engineering Laboratories: MastrLAB-VR

Due to the importance given today to innovation, the education sector is evolving thanks digital technologies. Virtual Reality (VR) can be a potential teaching tool offering many advantages in the field of training and education, as it allows to acquire theoretical knowledge and practical skills using an immersive experience in less time than the traditional educational process. These assumptions allow to lay the foundations for a new educational environment, involving and stimulating for students. Starting from the objective of strengthening the innovative teaching offer and the learning processes, the case study of the research concerns the digitalization of MastrLAB, High Quality Laboratory (HQL) belonging to the Department of Structural, Building and Geotechnical Engineering (DISEG) of the Polytechnic of Turin, a center specialized in experimental mechanical tests on traditional and innovative building materials and on the structures made with them. The MastrLAB-VR has been developed, a revolutionary innovative training tool designed with the aim of educating the class in total safety on the techniques of use of machinery, thus reducing the dangers arising from the performance of potentially dangerous activities. The virtual laboratory, dedicated to the students of the Building and Civil Engineering Courses of the Polytechnic of Turin, has been projected to simulate in an absolutely realistic way the experimental approach to the structural tests foreseen in their courses of study: from the tensile tests to the relaxation tests, from the steel qualification tests to the resilience tests on elements at environmental conditions or at characterizing temperatures. The research work proposes a methodology for the virtualization of technical laboratories through the application of Building Information Modelling (BIM), starting from the creation of a digital model. The process includes the creation of an independent application, which with Oculus Rift technology will allow the user to explore the environment and interact with objects through the use of joypads. The application has been tested in prototype way on volunteers, obtaining results related to the acquisition of the educational notions exposed in the experience through a virtual quiz with multiple answers, achieving an overall evaluation report. The results have shown that MastrLAB-VR is suitable for both beginners and experts and will be adopted experimentally for other laboratories of the University departments

Turning an organic semiconductor into a low-resistance material by ion implantation

We report on the effects of low energy ion implantation on thin films of pentacene, carried out to investigate the efficacy of this process in the fabrication of organic electronic devices. Two different ions, Ne and N, have been implanted and compared, to assess the effects of different reactivity within the hydrocarbon matrix. Strong modification of the electrical conductivity, stable in time, is observed following ion implantation. This effect is significantly larger for N implants (up to six orders of magnitude), which are shown to introduce stable charged species within the hydrocarbon matrix, not only damage as is the case for Ne implants. Fully operational pentacene thin film transistors have also been implanted and we show how a controlled N ion implantation process can induce stable modifications in the threshold voltage, without affecting the device performanc

Nation States, Cities, and People: Alternative Ways to Measure Globalization

In the last decade, attempts to measure globalization have multiplied, and they have led to the devising of diverse globalisation indexes. Besides other important similarities, the main feature shared by the most notable of these indexes is the fact that they use the same unit of analysis: the nation-state. This is a paradoxical situation, if one considers that one of the most distinctive characteristics of globalization is that its dynamics extend beyond the state. Gives this premise, the aim of the article is, on the one hand, to justify in any case the use of instruments that seek to measure globalization on the basis of states, and, on the other, to propose alternative approaches to such measurement. The paper\u2019s underlying assumption is that different approaches to the measurement of globalization are not mutually exclusive. Rather, such a plurality of perspectives is opportune given the complexity and multidimensionality of the concept of globalization

Gut microbiome and blood glucose control in type 1 diabetes: a systematic review

ObjectiveThe risk of developing micro- and macrovascular complications is higher for individuals with type 1 diabetes (T1D). Numerous studies have indicated variations in gut microbial composition between healthy individuals and those with T1D. These changes in the gut ecosystem may lead to inflammation, modifications in intestinal permeability, and alterations in metabolites. Such effects can collectively impact the metabolic regulation system, thereby influencing blood glucose control. This review aims to explore the relationship between the gut microbiome, inflammation, and blood glucose parameters in patients with T1D.MethodsGoogle Scholar, PubMed, and Web of Science were systematically searched from 2003 to 2023 using the following keywords: “gut microbiota,” “gut microbiome,” “bacteria,” “T1D,” “type 1 diabetes,” “autoimmune diabetes,” “glycemic control,” “glucose control,” “HbA1c,” “inflammation,” “inflammatory,” and “cytokine.” The examination has shown 18,680 articles with relevant keywords. After the exclusion of irrelevant articles, seven observational papers showed a distinct gut microbial signature in T1D patients.ResultsThis review shows that, in T1D patients, HbA1c level was negatively correlated with abundance of Prevotella, Faecalibacterium, and Ruminococcaceae and positively correlated with abundance of Dorea formicigenerans, Bacteroidetes, Lactobacillales, and Bacteriodes. Instead, Bifidobacteria was negatively correlated with fasting blood glucose. In addition, there was a positive correlation between Clostridiaceae and time in range. Furthermore, a positive correlation between inflammatory parameters and gut dysbiosis was revealed in T1D patients.ConclusionWe draw the conclusion that the gut microbiome profiles of T1D patients and healthy controls differ. Patients with T1D may experience leaky gut, bacterial translocation, inflammation, and poor glucose management due to microbiome dysbiosis. Direct manipulation of the gut microbiome in humans and its effects on gut permeability and glycemic control, however, have not been thoroughly investigated. Future research should therefore thoroughly examine other potential pathophysiological mechanisms in larger studies

Benchmarking of graphene-based materials: real commercial products versus ideal graphene

There are tens of industrial producers claiming to sell graphene and related materials (GRM), mostly as solid powders. Recently the quality of commercial GRM has been questioned, and procedures for GRM quality control were suggested using Raman Spectroscopy or Atomic Force Microscopy. Such techniques require dissolving the sample in solvents, possibly introducing artefacts.A more pragmatic approach is needed, based on fast measurements and not requiring any assumption on GRM solubility. To this aim, we report here an overview of the properties of commercial GRM produced by selected companies in Europe, USA and Asia. We benchmark: (A) size, (B) exfoliation grade and (C) oxidation grade of each GRM versus the ones of ‘ideal’ graphene and, most importantly, versus what reported by the producer. In contrast to previous works, we report explicitly the names of the GRM producers and we do not re-dissolve the GRM in solvents, but only use techniques compatible with industrial powder metrology.A general common trend is observed: products having low defectivity (%sp2 bonds >95%) feature low surface area (<200 m2 g−1), while highly exfoliated GRM show a lower sp2 content, demonstrating that it is still challenging to exfoliate GRM at industrial level without adding defects

Biomimetic graphene for enhanced interaction with the external membrane of astrocytes

Graphene and graphene substrates display huge potential as material interfaces for devices and biomedical tools targeting the modulation or recovery of brain functionality. However, to be considered reliable neural interfaces, graphene-derived substrates should properly interact with astrocytes, favoring their growth and avoiding adverse gliotic reactions. Indeed, astrocytes are the most abundant cells in the human brain and they have a crucial physiological role to maintain its homeostasis and modulate synaptic transmission. In this work, we describe a new strategy based on the chemical modification of graphene oxide (GO) with a synthetic phospholipid (PL) to improve interaction of GO with brain astroglial cells. The PL moieties were grafted on GO sheets through polymeric brushes obtained by atom-transfer radical-polymerization (ATRP) between acryloyl-modified PL and GO nanosheets modified with a bromide initiator. The adhesion of primary rat cortical astrocytes on GO–PL substrates increased by about three times with respect to that on glass substrates coated with standard adhesion agents (i.e. poly-D-lysine, PDL) as well as with respect to that on non-functionalized GO. Moreover, we show that astrocytes seeded on GO–PL did not display significant gliotic reactivity, indicating that the material interface did not cause a detrimental inflammatory reaction when interacting with astroglial cells. Our results indicate that the reported biomimetic approach could be applied to neural prosthesis to improve cell colonization and avoid glial scar formation in brain implants. Additionally, improved adhesion could be extremely relevant in devices targeting neural cell sensing/modulation of physiological activity

Sustainable Electronics Based on Crop Plant Extracts and Graphene: A “Bioadvantaged” Approach

In today’s fast-paced and well-connected world, consumer electronics are evolving rapidly. As a result, the amount of discarded electronic devices is becoming a major health and environmental concern. The rapid expansion of flexible electronics has the potential to transform consumer electronic devices from rigid phones and tablets to robust wearable devices. This means increased use of plastics in consumer electronics and the potential to generate more persistent plastic waste for the environment. Hence, today, the need for flexible biodegradable electronics is at the forefront of minimizing the mounting pile of global electronic waste. A “bioadvantaged” approach to develop a biodegradable, flexible, and application-adaptable electronic components based on crop components and graphene is reported. More specifically, by combining zein, a corn-derived protein, and aleuritic acid, a major monomer of tomato cuticles and sheellac, along with graphene, biocomposite conductors having low electrical resistance (≈10 Ω sq−1) with exceptional mechanical and fatigue resilience are fabricated. Further, a number of high-performance electronic applications, such as THz electromagnetic shielding, flexible GHz antenna construction, and flexible solar cell electrode, are demonstrated. Excellent performance results are measured from each application comparable to conventional nondegrading counterparts, thus paving the way for the concept of “plant-e-tronics” towards sustainability

Teoria relazionale e azioni migratorie

Il saggio si propone di fornire una rapida presentazione critica dei paradigmi sociologici che si sono succeduti nel tentativo di comprendere l’azione migratoria. Vista l’effervescenza del fenomeno migratorio in epoca di globalizzazione ci è parso prudente cautelarci prendendo le mosse da un’epoca lontana, l’inizio del ‘900, periodo, per altro, che già presentava sia pure in forma iniziale non pochi dei caratteri strutturali di globalizzazione economica che oggi si ritengono tipici. Lo spunto concreto, usato quale metro di paragone, è rappresentato dall’azione migratoria vissuto dalla nostra nonna materna, Maria. Così, dopo un’essenziale descrizione delle sue vicende migratorie e uno schematico quadro delle principali tendenze presenti nelle due discipline, l’economia e la sociologia, che forse più sistematicamente di altre si sono occupate di mobilità umana nello spazio, presenteremo i diversi paradigmi dominanti nel XX secolo nella lettura delle scelte migratorie applicandoli a questo particolare caso concreto. In altre parole, con questa esercitazione tenteremo di descrivere ciò che sarebbe emerso osservando le scelte di mobilità di nonna Maria attraverso le lenti di ciascun paradigma, cercando contemporaneamente di mostrarne limiti e punti di forza

Mudanças da estruttura familiar em um contexto migratório

Il saggio presenta un’analisi comparata dei mutamenti nella struttura famigliare delle famiglie di origine italiana e tedesca dopo un secolo di permanenza negli Stati di Rio Grande do Sul e Santa Caterina in Brasile. La ricerca si basa su un questionario prestrutturato, somministrato ad un campione casuale e rappresentativo (stratificato per sesso, età e insediamento urbano o rurale) di 2.400 individui, dei quali due terzi discendenti di italiani e un terzo discendenti di tedeschi. Gli aspetti indagati e dei quali si esaminano i mutamenti riguardano: le tendenze demografiche, l’endogamia/esogamia etnica dei matrimoni, i modelli famigliari predominanti, la conoscenza e l’uso della lingua del paese d’origine e di quella del paese ospitante, il livello d’istruzione media conseguito, il settore e il livello ricoperto nell’attività lavorativa ed, infine, la mobilità sociale e geografica