Full color control and white emission from conjugated polymer nanofibers

The authors demonstrate full color tunability in the visible range, including white emission, by polymer nanofibers based on binary blends of conjugated materials. The nanofibers are realized by electrospinning and their emission is based on the dipole-dipole energy transfer from a blue-emitting donor and a red-emitting acceptor conjugated polymer. The fibers are characterized by scanning electron microscopy and time-resolved and cw photoluminescence. Light emission is tuned from blue to red, including bright white with color coordinates (0.38, 0.34) according to the standard of the Commission Internationale de l'Eclairage. Polymer nanofibers based on blends of conjugated compounds turn out to be a promising class of organic semiconductor building blocks for nanophotonics

Multilevel, room-temperature nanoimprint lithography for conjugated polymer-based photonics.

We demonstrate the multilevel patterning of organic light-emitting polymers by room-temperature nanoimprint lithography (RT-NIL), which is impossible to obtain by conventional hot embossing. In particular, we realize one- and two-dimensional photonic crystals with 500 nm periodic features and investigate the changes in the optical properties (luminescence and quantum yield) of the organic active layer. An increase of the quantum yield by 2.4% for the patterned film with respect to the untextured one and the enhancement of the output light emitted at a particular angle (ϑ = 69°) are observed for gratings whose Bragg periodicity matched the emission wavelength of the polymer. The employment of RT-NIL to pattern polymer semiconductors without degradation of their optical properties represents a strategic route for the realization of novel nanopatterned optoelectronic devices

Rapid soft lithography by bottom-up enhanced capillarity.

The growing demand for new solutions to pursue the trend of micro- and nanoelectronics predicted by Moore's law is stimulating the development of new high-resolution, low-cost lithographies. Here we demonstrate that several bottom-up approaches can be used to increase the throughput of soft lithography by exploiting the enhanced hydrophilicity, the low viscosity, and the fragility of the employed materials. In particular, the customized functionalization of the involved surfaces to improve the wettability to polymer fluids and the dramatic decrease of the viscosity of polymer compounds as the temperature is increased, together with the good thermal stability of the functionalized surfaces, allow a faster filling of elastomeric channels, up to almost an order of magnitude with respect to conventional microfluidics

Comparison of Shigella GMMA and glycoconjugate four-component formulations in animals

Shigellosis is leading bacterial cause of diarrhea with high prevalence in children younger than 5 years in low- and middle-income countries, and increasing number of reports of Shigella cases associated to anti-microbial resistance. No vaccines against Shigella are still licensed, but different candidates based on the O-antigen portion of lipopolysaccharides are in clinic. Generalized Modules for Membrane Antigens (GMMA) have been proposed as an alternative delivery system for the O-antigen, and a 4-component vaccine candidate (altSonflex1-2-3), containing GMMA from S. sonnei and S. flexneri 1b, 2a and 3a is being tested in a phase 1/2 clinical trial, with the aim to elicit broad protection against the most prevalent Shigella serotypes. Here, the 4-component GMMA vaccine candidate has been compared to a more traditional glycoconjugate formulation for the ability to induce functional antibodies in mice and rabbits. In mice, in the absence of Alhydrogel, GMMA induce higher IgG antibodies than glycoconjugates and stronger bactericidal titers against all Shigella serotypes. In the presence of Alhydrogel, GMMA induce O-antigen specific IgG levels similar to traditional glycoconjugates, but with a broader range of IgG subclasses, resulting in stronger bactericidal activity. In rabbits, GMMA elicit higher functional antibodies than glycoconjugates against S. sonnei, and similar responses to S. flexneri 1b, 2a and 3a, independently from the presence of Alhydrogel. Different O-antigen based vaccines against Shigella are now in clinical stage and it will be of particular interest to understand how the preclinical findings in the different animal models translate in humans

Polymer nanofibers by soft lithography

The fabrication of polymeric fibers by soft lithography is demonstrated. Polyurethane, patterned by capillarity-induced molding with high-resolution elastomeric templates, forms mm-long fibers with a diameter below 0.3 mu m. The Youngs modulus of the fabricated structures, evaluated by force-distance scanning probe spectroscopy, has a value of 0.8 MPa. This is an excellent example of nanostructures feasible by the combination of soft nanopatterning and high-resolution fabrication approaches for master templates, and particularly electron-beam lithography

Self-assembled extracellular matrix protein networks by microcontact printing.

Physiological patterns of the extracellular matrix protein, laminin-1, were obtained on glass substrates by physisorption-assisted microcontact printing. Besides the well-retained antigenicity confirmed by indirect immunofluorescence assays, we investigated the supramolecular organization of the proteins by atomic force microscopy. We found the characteristic protein self-assembling in polygonal networks with well-defined sub-100 nm quaternary structures of laminin. The formation of these physiological mesh-like protein matrices was obtained by means of one-step soft lithography without any preliminary functionalization of glass, which can be exploited for many possible applications for cell cultures and biomolecular devices

Adherence to Mediterranean Diet and its main determinants in a sample of Italian adults: results from the ARIANNA cross-sectional survey

Introduction: Over the last years, many Mediterranean countries, including Italy, have witnessed a shift away from the Mediterranean Diet, thus contributing to the high rates of overweight and obesity. The survey "Adherence to Mediterranean Diet in Italy (ARIANNA)" aimed to evaluate the Adherence to Mediterranean Diet (AMD) and its main determinants in the Italian population. Materials and methods: This study started on March 2023 and was addressed to adults aged >= 17 years, born and resident in Italy, proficient in Italian. Data are collected electronically through a voluntary, anonymous and self-administered questionnaire on the project website. Univariate and then multivariate logistic regressions were performed to evaluate associations between AMD and demographic characteristics, socio-economic status, health status, and lifestyle. Results: On a total of 3,732 completed questionnaires, the 87.70% of the respondents was female and the 71.28% was 17-40 years old. The 83.82% of the respondents had medium AMD, 11.33% low and only 4.85% high. The multivariate analysis revealed that being male (p 40 years (p < 0.05), workers (p <= 0.001), and unemployed (p < 0.05), determined the probability of having a lower AMD. Vegans and vegetarian's diets positively contributed to a higher AMD (p < 0.001). Discussion: These results highlighted a medium AMD in the Italian adult participants and suggested the necessity to implement tailored public health intervention strategies to improve food habits

Two dimensional patterning of fluorescent proteins in hydrogels.

This work describes the successful micropatterning of hybrid systems consisting of hydrogel-dispersed optically active and controllable proteins on solid surfaces without degradation of the photophysical properties of the light-emitting biomolecules. It demonstrates the preservation of the luminescence properties of proteins entrapped into isolated microstructures of poly(acrylamide) gel. This way we can exploit both the structural and function-preserving properties of the hydrogels and the functionality of light-emitting proteins. We believe that this approach can open the way to the realization of nanopatterned optical memories based on photochromic biomolecules

Effect of tungsten disulfide (WS_2) nanotubes on structural, morphological and mechanical properties of poly(L-lactide) (PLLA) films

Poly(L-lactide) (PLLA) is a semicrystalline, biocompatible and biodegradable polymer widely employed in many applications (food packaging, biomedical devices, drug delivery systems). This work deals with nanocomposites of PLLA and tungsten disulfide (WS_2) nanotubes (NTs) as a novel material to obtain thinner and stronger bioresorbable vascular scaffolds. We studied the influence of WS_2 NTs on the mechanical properties of PLLA-WS_2 films. Polarized optical microscopy reveals a high degree of orientation of the polymer molecules in stretched films that further increases with a post-stretching annealing treatment. At the same time, X-ray diffraction (XRD) and Raman spectroscopy confirm enhancement of the crystallinity induced by the WS_2 NTs

Imprinting strategies for 100 nm lithography on polyfluorene and poly(phenylenevinylene) derivatives and their blends

Abstract We report on the use of nanoimprint lithography at room temperature (RT-NIL) for the direct structuring of polyfluorene and poly(phenylenevinylene) derivatives and of their blends without the degradation of the emissive characteristics of the active molecules. We apply RT-NIL for the fabrication of periodic one- and two-dimensional gratings with feature width that varies from 100 to 500 nm. Moreover, we analysed the effects that a superimposed periodic corrugation induces on the emitted light in terms of spectral properties and luminescence efficiency, thus ruling out any degradation of the emission. In particular, the combination of nanopatterning and active blends opens new perspectives for the control of the emitted colour from conjugated polymer films