Interface Functionalities in Multilayer Stack Organic Light Emitting Transistors (OLETs)

Herein is described a multidisciplinary approach to understand the performance limitations of small molecule organic light emitting transistors (OLETs) based on a layered architecture, an innovative architecture potentially competitive with the state of the art and more flexible for spectral emission control. The processes of charge injection and field‐effect transport at metal/organic and organic/organic interfaces are analysed using microscopic and spectroscopic techniques in coordination. Atomic force microscopy and ultrasonic force microscopy are employed to characterize the interface morphology and the initial growth stages of organic films where charge transport actually occurs. X‐ray diffraction and near edge X‐ray dichroic absorption with linearly polarised light allow to determine the unit cell packing and the molecular orientation at the active organic interfaces, as well as the amount of non‐ordered domains. Moreover, chemical reactivity at the interfaces is measured by X‐ray photoelectron spectroscopy. It is found that a strong reaction occurs at the metal‐organic interfaces, with molecular fragmentation. Additionally, the transport properties strongly depend on the nature of the materials forming the organic stack. Specifically, amorphous conjugated films as bottom layers can promote an increased molecular disorder in the upper active layer, with a concomitant deterioration of the conduction properties.     

Method for rapid high-frequency seismogram calculation

We present a method for rapid, high-frequency seismogram calculation that makes use of an algorithm to automatically generate an exhaustive set of seismic phases with an appreciable amplitude on the seismogram. The method uses a hierarchical order of ray and seismic-phase generation, taking into account some existing constraints for ray paths and some physical constraints. To compute synthetic seismograms, the COMRAD code (from the Italian: “COdice Multifase per il RAy-tracing Dinamico”) uses as core a dynamic ray-tracing code. To validate the code, we have computed in a layered medium synthetic seismograms using both COMRAD and a code that computes the complete wave field by the discrete wave number method. The seismograms are compared according to a time–frequency misfit criteria based on the continuous wavelet transform of the signals. Although the number of phases is considerably reduced by the selection criteria, the results show that the loss in amplitude on the whole seismogram is negligible. Moreover, the time for the computing of the synthetics using the COMRAD code (truncating the ray series at the 10th generation) is 3–4-fold less than that needed for the AXITRA code (up to a frequency of 25 Hz).     

Longitudinally two-photon pumped leaky waveguide dye film laser

Longitudinally two-photon pumped (TPP) and frequency-upconverted cavity lasing is achieved in a planar leaky waveguide configuration which utilizes a dye-doped polymer film coating on the surface of an optical glass prism. The TPP lasing dye is 4-dimethylamino-N-methylstilbazolium tosylate (DAST) that has been extensively studied as a second order nonlinear optical material. The spectral, temporal, and spatial structures as well as the output-input characteristics of the TPP cavity lasing were measured using a ~170-μm-thick film with a ~2.4-mm pump depth. The leaky waveguide lasing was featured by a nearly single transverse-mode and five axial-modes structure. In our preliminary study, the net conversion efficiency from the absorbed 1064-nm pump pulse energy to the output ~607-nm upconverted cavity lasing energy was found to be ~0.65%. However, this efficiency can be considerably increased by further optimizing the system parameters     

Sourdough lactobacilli and celiac disease

Celiac disease (CD) is one of the most common food intolerance. The only effective treatment for CD is a strict adherence to a gluten-free diet throughout the patient's lifetime. Gluten-free products are not widely available and are usually more expensive than their gluten-containing counterparts. There is, therefore, an urgent need to develop safe and effective therapeutic alternatives, to develop high-quality gluten-free products and to investigate the potential of the bread making biotechnology following ancient protocols which include long-time fermentation by selected sourdough lactic acid bacteria. This review describes the most relevant results related to biotechnologies that use selected sourdough lactic acid bacteria and probiotics as starters for sourdough fermentation to investigate their potential to decrease the risk of gluten contamination in gluten-free products. As shown by studies in vitro on celiac intestinal tissue and in vivo on CD patients, the bacterial proteolytic activity is rather promising not only as currently demonstrated for eliminating traces of contaminant gluten but probably also in perspective for the manufacture of tolerated baked goods.     

Portevin–Le Chatelier Effects in a High-Mn Austenitic Steel

High-manganese austenitic steels were recently proposed to fabricate structural car body parts because of their very favorable combination of strength and ductility. They exhibit Portevin–Le Chatelier macroscopic plastic localization phenomena at the room temperature, as evidenced by the tensile curves first by the isolated stress peaks corresponding to the nucleation of deformation bands, which travel along the tensile axis, and then by serrations due to static deformation bands. The bands extend to the whole width of the specimen and cause a local temperature increase along with a slight surface relief. These plastic instabilities were studied during tensile tests at strain rates between 0.0004 and 0.04 s^?1, with optical video recording, infrared thermography and optical extensometry, the latter based on digital image correlation. Two types of bands, type A and type C, were observed and are described.     

Scanning Probe Microscopy on heterogeneous CaCu<Subscript>3</Subscript>Ti<Subscript>4</Subscript>O<Subscript>12</Subscript> thin films

The conductive atomic force microscopy provided a local characterization of the dielectric heterogeneities in CaCu₃Ti₄O₁₂ (CCTO) thin films deposited by MOCVD on IrO₂ bottom electrode. In particular, both techniques have been employed to clarify the role of the inter- and sub-granular features in terms of conductive and insulating regions. The microstructure and the dielectric properties of CCTO thin films have been studied and the evidence of internal barriers in CCTO thin films has been provided. The role of internal barriers and the possible explanation for the extrinsic origin of the giant dielectric response in CCTO has been evaluated.     

Facile production of up-converted quantum dot lasers

We report a facile production of an up-converted surface-emitting DFB laser, performed by exploiting the versatility of sol-gel chemistry, the intriguing properties of well designed graded CdSe-CdS-Cd(0.5)Zn(0.5)S-ZnS colloidal quantum dots, and the scalability of nanoimprinting. Our laser prototype operates in the visible region following efficient optical pumping by either direct one-photon excitation or through the up-conversion of near infrared (NIR) light. By achieving cavity mode Q-factors in excess of 650 and retaining high lasing stabilities in air, this work highlights the feasibility of creating integrated lasing devices through solution based methods.     

Dietary Supplementation with the Probiotic SF68 Reinforces Intestinal Epithelial Barrier in Obese Mice by Improving Butyrate Bioavailability

Scope

Modifications in intestinal microbiota and its metabolites, the short-chain fatty acids (SCFA) are main factors altering intestinal epithelial barrier integrity and eliciting the onset of a meta-inflammation observed in obesity. The present study is aimed at evaluating the efficacy of Enterococcus faecium (SF68) administration in counteracting the impairment of gut barrier and enteric inflammation in a model of diet-induced obesity, characterizing the molecular mechanisms underlying such beneficial effects.

Methods and Results

Male C57BL/6J mice, fed with standard diet (SD) or high-fat diet (HFD), are treated with SF68 (10⁸ CFU day⁻¹). After 8 weeks, plasma interleukin (IL)-1β and lipopolysaccharide binding protein (LBP) are measured, analysis of fecal microbiota composition and butyrate content as well as intestinal malondialdehyde, myeloperoxidase, mucins, tight junction protein, and butyrate transporter expression are investigated. After 8 weeks, SF68 administration counteracts the body weight gain in HFD mice, reducing plasma IL-1β and LBP. In parallel, SF68 treatment acts against the intestinal inflammation in HFD-fed animals and improves the intestinal barrier integrity and functionality in obese mice via the increase in tight junction protein and intestinal butyrate transporter (sodium-coupled monocarboxylate transporter 1 ) expression.

Conclusions

Supplementation with SF68 reduces intestinal inflammation and reinforces the enteric epithelial barrier in obese mice, improving the transport and utilization of butyrate.     

Effect of long term dietary supplementation with plant extract on carcass characteristics meat quality and oxidative stability in pork

The effects of dietary supplementation in pigs with plant extract (PE) from Lippia spp., titrated in verbascoside (5 mg/kg feed), from weaning to slaughter (166 days), on carcass characteristics, meat quality, collagen characteristics, oxidative stability and sensory attributes of Longissimus dorsi (LD) muscle were examined. Ten pigs per treatment were slaughter at a live weight of 109.5 ± 1.4 kg. No influence on carcass characteristics, LD meat quality parameters and collagen characteristics were observed. Dietary PE increased (P < 0.001) α-tocopherol levels in LD muscle. Raw LD of pig fed PE showed lower (P < 0.001) lipid oxidation levels than controls. A reduction (P = 0.05) of fat odor and rancid flavor intensity in cooked LD muscle stored at 4 °C for 24 h was observed in the treated group. This study shows that PE is an effective antioxidant in pork meat, enhancing oxidative status and sensory attributes, without affecting other meat quality parameters.