Conductive plastic film electrodes for Pulsed Electric Field (PEF) treatment—A proof of principle

Nowadays Pulsed Electric Field (PEF) treatment of food needs to be performed prior to packaging, either hygienic or aseptic packaging is necessary. New techniques for PEF treatment after packaging can be considered when plastic conductive (film) electrodes can be integrated within the package, so that the package and the product can be treated as a whole. This paper describes a newly developed treatment chamber, which can be used to test the ability of any arbitrary plastic packaging film to be used as electrodes for PEF treatment. Tests with a flexible commercially available electrically conductive copolymer film showed that reduction of Lactobacillus plantarum by PEF was possible. This heat sealable film obeys the mechanical properties of a polymer; however it has an electrical conductivity of 0.75 S m^? 1 and approximately 2.3% of the surface area is electrically conductive. The maximum obtained inactivation was 2.1 log₁₀ with a specific energy of 17 J ml^? 1. The microbial experiments gave a consistent outcome compared with finite element simulations and with models from literature. Further research to reach real pasteurisation levels is needed as well as issues concerning utilisation of these film electrodes.Industrial relevanceStainless steel electrodes, which are widely used as electrode material for Pulsed Electric Field (PEF) treatment systems, have as main disadvantage that they exhibit certain wear. This article showed that polymer composites can be considered as electrode material for newly to be developed PEF treatment concepts. With extensive research on food grade composite films the integration of cheap disposable plastic electrodes in food packages comes within reach.     

omega-Hydrazino linear polyethylenimine: a monoconjugation building block for nucleic acid delivery

Nonviral gene therapy requires efficient vectors that are able to deliver nucleic acids inside the targeted cell nucleus. Developing new tools for the synthesis of supramolecular vectors with improved transfection efficiency and better biodistribution is therefore a crucial issue. Here we describe the synthesis of a 140-mer linear polyethylenimine (L-PEI) terminated at one end by a highly nucleophilic hydrazine residue. This cationic polymer, whose backbone is well known for its remarkable gene-delivery efficiency, constitutes a building block for omega-regioselective conjugation to molecules through the formation of stable linkages such as the hydrazone bonds. To demonstrate the potential of the omega-hydrazino linear polyethylenimine, human serum transferrin, a ligand that is well know to improve gene-delivery systems, was used as a model of sensitive material. The blood protein was oxidized to generate an aldehyde function and was subsequently conjugated to hydrazino PEI. The new polyethylenimine-transferrin (PEI-Tf) vector was purified and was shown to condense plasmid DNA into compact superstructures compatible with cellular uptake. Finally, the cellular-binding and gene-delivery properties of PEI/DNA polyplexes incorporating different quantities of transferrin were evaluated by FACS analysis and luciferase assay.     

Synthesis and characterization of polymeric V2O5/AlO(OH) with nanopores on alumina support

Polymeric vanadium pentoxide gel was formed via the reaction of V2O5 powder with hydrogen peroxide. The polymeric vanadium pentoxide gel was then dispersed in alumina gel. Different vanadium loading composites were coated on alumina support and calcined at 500 degrees C for 1 hr. These composite layers were characterized using TGA, FT-IR, XRD, SEM, and Autosorb. It was found that the lamellar structure of polymerized vanadium pentoxide was retained in the inorganic matrix. Crystalline alumina in gamma phase was formed after calcinations. However, the vanadium-alumina mixed oxides are lack of the well defined PXRD peaks for polycrystalline V2O5. This is possibly because the vanadia species are highly dispersed in the alumina matrix or the vanadia species are dispersed as crystalline which is smaller than 4 nm. In addition, the imbedded polymeric vanadium oxide improved the specific area and average pore diameter of the composite layer.     

Towards the derivation of verbal content relations from patent claims using deep syntactic structures

Research on the extraction of content relations from text corpora is a high-priority topic in natural language processing. This is not surprising since content relations form the backbone of any ontology, and ontologies are increasingly made use of in knowledge-based applications. However, so far most of the works focus on the detection of a restricted number of prominent verbal relations, including in particular is-a, has-part and cause. Our application, which aims to provide comprehensive, easy-to-understand content representations of complex functional objects described in patent claims, faces the need to derive a large number of content relations that cannot be limited a priori. To cope with this problem, we take advantage of the fact that deep syntactic dependency structures of sentences capture all relevant content relations—although without any abstraction. We implement thus a three-step strategy. First, we parse the claims to retrieve the deep syntactic dependency structures from which we then derive the content relations. Second, we generalize the obtained relations by clustering them according to semantic criteria, with the goal to unite all sufficiently similar relations. Finally, we identify a suitable name for each generalized relation. To keep the scope of the article within reasonable limits and to allow for a comparison with state-of-the-art techniques, we focus on verbal relations.     

Hydrofluoroethers as heat-transfer fluids for OLEDs: Operational range, stability, and efficiency improvement

In this work we introduce a simple yet very efficient method of heat dissipation by immersing OLED device into hydrofluoroether (HFE) fluids. It is shown that due to highly fluorous nature of this class of fluids, HFE do not damage organic semiconductors which are comprised in the OLED stack and therefore can be used as encapsulation media. HFE also have high thermal conductivity, low viscosity and can efficiently dissipate the heat by means of natural convection with laminar flow. By employing HFE we were able to significantly improve the OLED operating dynamic range. Lifetimes of OLEDs operating in HFE at high currents can be improved by about a factor of 8. Furthermore, HFE fluid significantly improves the light outcoupling by a factor of 70% due to higher than air refractive index (n = 1.3).     

Highly conductive silver nanowire networks by organic matrix assisted low-temperature fusing

In silver nanowire (AgNW) percolation network electrodes, the junction resistance at the wire-to-wire contact is crucial for the electrode performance. We introduce an organic sublayer between the substrate and the AgNW electrode to improve the sheet resistance and avoid the frequently applied high-temperature post-annealing process. Upon introduction of such a sublayer, a strong reduction of the sheet resistance (R_S) in the same order as it would be expected from a post-annealing process (e.g. 90 min@210 °C) is observed. This effect is investigated in-depth by using different sublayer material classes such as polyelectrolytes, tensides or differently charged polymers. Independent of charge and material class, especially those materials with hydrophobic and hydrophilic parts, dramatically reduce the sheet resistance. Consequently, hydrophobic interaction between substrate and nanowires and capillary forces during drying can be attributed as driving force. Using polyvinylpyrrolidone (PVP), also used as stabilizer for the AgNWs, leads to the largest reduction in sheet resistance of the investigated materials resulting in AgNW electrodes exhibiting R_S = 10.8 Ω/□ at 80.4% transparency (including substrate) without additional post-annealing at high temperatures.     

Long bone panoramas from fluoroscopic X-ray images

This paper presents a new method for creating a single panoramic image of a long bone from several individual fluoroscopic X-ray images. Panoramic images are useful preoperatively for diagnosis, and intraoperatively for long bone fragment alignment, for making anatomical measurements, and for documenting surgical outcomes. Our method composes individual overlapping images into an undistorted panoramic view that is the equivalent of a single X-ray image with a wide field of view. The correlations between the images are established from the graduations of a radiolucent ruler imaged alongside the long bone. Unlike existing methods, ours uses readily available hardware, requires a simple image acquisition protocol with minimal user input, and works with existing fluoroscopic C-arm units without modifications. It is robust and accurate, producing panoramas whose quality and spatial resolution is comparable to that of the individual images. The method has been successfully tested on in vitro and clinical cases.     

Fiducial optimization for minimal target registration error in image-guided neurosurgery

This paper presents new methods for the optimal selection of anatomical landmarks and optimal placement of fiducial markers in image-guided neurosurgery. These methods allow the surgeon to optimally plan fiducial marker locations on routine diagnostic images before preoperative imaging and to intraoperatively select the set of fiducial markers and anatomical landmarks that minimize the expected target registration error (TRE). The optimization relies on a novel empirical simulation-based TRE estimation method built on actual fiducial localization error (FLE) data. Our methods take the guesswork out of the registration process and can reduce localization error without additional imaging and hardware. Our clinical experiments on five patients who underwent brain surgery with a navigation system show that optimizing one marker location and the anatomical landmarks configuration reduced the TRE. The average TRE values using the usual fiducials setup and using the suggested method were 4.7 mm and 3.2 mm, respectively. We observed a maximum improvement of 4 mm. Reducing the target registration error has the potential to support safer and more accurate minimally invasive neurosurgical procedures.     

Morphological Stability of Diffusion Couples Under Electric Current

We consider the growth and morphological stability of an intermediate phase growing in a binary diffusion couple under electromigration conditions. The growth rate of the intermediate phase depends primarily on the direction of the electromigration current. Current flow that drives the diffusing species enhances growth of the intermediate phase, while current flow in the opposite direction slows growth. The morphological stability of the interfaces between the intermediate phase and the terminal phases depends on the current direction, the relative conductivities of the phases, and the thickness of the intermediate phase. We find that, when the intermediate phase has a higher conductivity than the terminal phases, the current direction that enhances growth of the intermediate phase can also cause an instability. Alternatively, when the conductivity of the intermediate phase is lower than the surrounding phases, the current direction that slows growth can cause an instability. Instability also requires that the thickness of the intermediate phase be larger than some critical value.