The Dynamic Emission Zone in Sandwich Polymer Light‐Emitting Electrochemical Cells

In light‐emitting electrochemical cells (LECs), the position of the emission zone (EZ) is not predefined via a multilayer architecture design, but governed by a complex motion of electrical and ionic charges. As a result of the evolution of doped charge transport layers that enclose a dynamic intrinsic region until steady state is reached, the EZ is often dynamic during turn‐on. For thick sandwich polymer LECs, a continuous change of the emission color provides a direct visual indication of a moving EZ. Results from an optical and electrical analysis indicate that the intrinsic zone is narrow at early times, but starts to widen during operation, notably well before the electrical device optimum is reached. Results from numerical simulations demonstrate that the only precondition for this event to occur is that the mobilities of anions (μ_a) and cations (μ_c) are not equal, and the direction of the EZ shift dictates μ_c > μ_a. Quantitative ion profiles reveal that the displacement of ions stops when the intrinsic zone stabilizes, confirming the relation between ion movement and EZ shift. Finally, simulations indicate that the experimental current peak for constant‐voltage operation is intrinsic and the subsequent decay does not result from degradation, as commonly stated.     

Soft Nanopatterning on Light‐Emitting Inorganic–Organic Composites

In this work we demonstrate the nanopatterning of nanocomposites made by luminescent zinc oxide nanoparticles and light‐emitting conjugated polymers by means of soft molding lithography. Vertical nanofluidics is exploited to overcome the polymer transport difficulties intrinsic in materials incorporating nanocrystals, and the rheology, fluorescence, absolute quantum yield, and emission directionality of the nanostructured composites are investigated. We study the effect of patterned gratings on the directionality of light emitted from the nanocomposites, finding evidence of the enhancement of forward emitted light, due to the printed wavelength‐scale periodicity. These results open new possibilities for the realization of nanopatterned devices based on hybrid organic‐inorganic systems.     

Biocompatible Electromechanical Actuators Composed of Silk‐Conducting Polymer Composites

Single‐component, metal‐free, biocompatible, electromechanical actuator devices are fabricated using a composite material composed of silk fibroin and poly(pyrrole) (PPy). Chemical modification techniques are developed to produce free‐standing films with a bilayer‐type structure, with unmodified silk on one side and an interpenetrating network (IPN) of silk and PPy on the other. The IPN formed between the silk and PPy prohibits delamination, resulting in a durable and fully biocompatible device. The electrochemical stability of these materials is investigated through cyclic voltammetry, and redox sensitivity to the presence of different anions is noted. Free‐end bending actuation performance and force generation within silk‐PPy composite films during oxidation and reduction in a biologically relevant environment are investigated in detail. These silk–PPy composites are stable to repeated actuation, and are able to generate forces comparable with natural muscle (>0.1 MPa), making them ideal candidates for interfacing with biological tissues.     

Magnetization Reversal in CsNiIICrIII(CN)6 Coordination Nanoparticles: Unravelling Surface Anisotropy and Dipolar Interaction Effects

CsNiCr(CN)₆ coordination nanoparticles with sizes ranging from 6 to 30 nm are highly diluted in an organic polymer matrix. Their static and dynamic magnetic behaviour allows unravelling of surface anisotropy and interparticle dipolar interaction effects. The single magnetic domain critical size is thus evaluated to be around 22 nm with a blocking temperature of 21 K (at ν = 1 Hz) and an effective energy barrier for the reversal of the magnetization of 426 K.     

On the stability preserving property of the double bilinear transformation on a class of 2-D transfer functions

This paper addresses the BIBO (bounded-input bounded-output) stability of a class of discrete 2-D quarter-plane filters in the presence of nonessential singularities of the second kind (NSSK's) on the unit bidisk. Conditions under which the double bilinear transformation (DBT) preserves stability are derived. The results presented here also extend the class of systems whose stability can be predicted. Use of the inverse DBT to produce a continuous equivalent of the discrete 2-D transfer function allows easy application of a continuous-domain equivalent of a criterion developed by Dautov. The necessary and sufficient condition for stability derived in this work provides a simple check for the class of systems under consideration. From this class of systems, it is also possible to construct stable pairs of mutually inverse transfer functions.     

Multiphoton Lithography as a Promising Tool for Biomedical Applications

Multiphoton lithography (MPL) is a powerful and useful structuring tool capable of generating 2D and 3D arbitrary micro- and nanometer features of various materials with high spatial resolution down to nm-scale. This technology has received tremendous interest in tissue engineering and medical device manufacturing, due to its ability to print sophisticated structures, which is difficult to achieve through traditional printing methods. Thorough consideration of two-photon photoinitiators (PIs) and photoreactive biomaterials is key to the fabrication of such complex 3D micro- and nanostructures. In the current review, different types of two-photon PIs are discussed for their use in biomedical applications. Next, an overview of biomaterials (both natural and synthetic polymers) along with their crosslinking mechanisms is provided. Finally, biomedical applications exploiting MPL are presented, including photocleaving and photopatterning strategies, biomedical devices, tissue engineering, organoids, organ-on-chip, and photodynamic therapy. This review offers a helicopter view on the use of MPL technology in the biomedical field and defines the necessary considerations toward selection or design of PIs and photoreactive biomaterials to serve a multitude of biomedical applications.     

Ultrastructural alterations during embryonic rats' lung development caused by ozone

Ozone (O3) is an oxidizing agent that acts on phospholipids, proteins and sugars of cellular membranes producing free radicals, which cause oxidative damages. The O3 exposure has been used as a model to study oxidative stress, in which the respiratory airways represent the entrance to the organism. In this study, ultrastructural alterations were identified at the bronchiolar level during the intra-uterine lung development, using an O3 exposure model in pregnant rats during 18, 20 and 21 days of gestation. Twelve pregnant Wistar rats, six controls and six exposed to 1 ppm O3 inhalation during 12 h per day, were used. The rats were sacrificed at gestational days 18, 20 and 21; the fetuses were obtained and their lungs dissected. The ultrastructural analysis evidenced swollen mitochondria, cytoplasmic vacuolization of the epithelial cells and structural disorder caused by the oxidative stress. At gestation day 20, flake-off epithelial cells and laminar bodies in the bronchiolar lumen were observed. In the 21-gestation-day group, the mitochondria were edematous and their cristae were disrupted by the damage caused in mitochondrial membranes.     

UNICORE 6 — Recent and Future Advancements

UNICORE is a European Grid Technology with more than 10 years of history. Originating from the Supercomputing domain, the latest version UNICORE 6 has turned into a general-purpose Grid technology that follows established standards and offers a rich set of features to its users. The paper starts with an architectural insight into UNICORE 6, highlighting the workflow features, standards and the different clients. Next, the current state of advancement is presented by describing recent developments. The paper closes with an outlook on future planned developments.     

Organizational Media Affordances: Operationalization and Associations with Media Use

The concept of affordances has been increasingly applied to the study of information and communication technologies (ICTs) in organizational contexts. However, almost no research operationalizes affordances, limiting comparisons and programmatic research. This article briefly reviews conceptualizations and possibilities of affordances in general and for media, then introduces the concept of organizational media affordances as organizational resources. Analysis of survey data from a large Nordic media organization identified six reliable and valid organizational media affordances: pervasiveness, editability, self-presentation, searchability, visibility, and awareness. Eight media scales based on frequency of use of 10 media within each of three organization levels were differentially associated with these affordances. The conceptualization, measurement approach, and results from this study provide the foundation for considerable future organizational communication and ICT research.