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This paper deals with the electrochemically induced charge injection in the conductive polymer (CP), exemplified by well examined archetypal CP—poly(3-hexylthiophene-2,5-diyl). The polar solvent of acetonitrile with salt tetrabutylammonium hexafluorophosphate was used to transport electrons in the electrolyte. The decisive mechanism is the recombination current at the electrolyte/CP interface taking place at the Fermi energy of CP, whose energy position is determined by the externally applied voltage. The corresponding mechanism of the charge carrier transport in the polymer bulk is the space-charge limited current (SCLC) by holes or electrons (or more precisely positive and negative polarons) at the respective transport paths of HOMO and LUMO bands. The charge transport mechanisms and the occupation statistics are the basis of the energy-resolved electrochemical impedance spectroscopy for the mapping of the density of electronic states of conductive organic semiconductors [F. Schauer, V. Nádaždy, and K. Gmucová, J. Appl. Phys. 123, 161590 (2018)]. From the application point of view, the major message of the paper is that it is possible to pass high current densities of the order of 0.1 A cm−2 via electrochemical systems with the CP, induced by means of doping processes of both CP surface and its bulk, leading to the charge injection and SCLC in CP. [ABSTRACT FROM AUTHOR]

There is potential in applying conjugated polymers in novel organic optoelectronic devices, where a comprehensive understanding of the fundamental processes and energetics involved during transport and recombination is still lacking, limiting further device optimization. The electronic transport modeling and its optimization need the energy distribution of transport and defect states, expressed by the energy distribution of the Density of States (DOS) function, as input/comparative parameters. We present the Energy Resolved-Electrochemical Impedance Spectroscopy (ER-EIS) method for the study of transport and defect electronic states in organic materials. The method allows mapping over unprecedentedly wide energy and DOS ranges. The ER-EIS spectroscopic method is based on the small signal interaction between the surface of the organic film and the liquid electrolyte containing reduction-oxidation (redox) species, which is similar to the extraction of an electron by an acceptor and capture of an electron by a donor at a semiconductor surface. The desired DOS of electronic transport and defect states can be derived directly from the measured redox response signal to the small voltage perturbation at the instantaneous position of the Fermi energy, given by the externally applied voltage. The theory of the ER-EIS method and conditions for its validity for solid polymers are presented in detail. We choose four case studies on poly(3-hexylthiophene-2,5-diyl) and poly[methyl(phenyl)silane] to show the possibilities of the method to investigate the electronic structure expressed by DOS of polymers with a high resolution of about 6 orders of magnitude and in a wide energy range of 6 eV. [ABSTRACT FROM AUTHOR]

Background: Bullous pemphigoid (BP), the by far most frequent autoimmune blistering skin disease (AIBD), is immunopathologically characterized by autoantibodies against the two hemidesmosomal proteins BP180 (collagen type XVII) and BP230 (BPAG1 or dystonin). Several comorbidities and potentially disease‐inducing medication have been described in BP, yet a systematic analysis of these clinically relevant findings and autoantibody reactivities has not been performed. Objective: To determine associations of autoantibody reactivities with comorbidities and concomitant medication. Methods: In this prospective multicenter study, 499 patients diagnosed with BP in 16 European referral centers were included. The relation between anti‐BP180 NC16A and anti‐BP230 IgG ELISA values at the time of diagnosis as well as comorbidities and concomitant medication collected by a standardized form were analysed. Results: An association between higher serum anti‐BP180 reactivity and neuropsychiatric but not atopic and metabolic disorders was observed as well as with the use of insulin or antipsychotics but not with dipeptidyl peptidase‐4 (DPP4) inhibitors, inhibitors of platelet aggregation and L‐thyroxine. The use of DPP4 inhibitors was associated with less anti‐BP180 and anti‐BP230 reactivity compared with BP patients without these drugs. This finding was even more pronounced when compared with diabetic BP patients without DPP4 inhibitors. Associations between anti‐BP180 and anti‐BP230 reactivities were also found in patients using insulin and antipsychotics, respectively, compared with patients without this medication, but not for the use of inhibitors of platelet aggregation, and L‐thyroxine. Conclusion: Taken together, these data imply a relation between autoantibody reactivities at the time of diagnosis and both neuropsychiatric comorbidities as well as distinct concomitant medication suggesting a link between the pathological immune mechanisms and clinical conditions that precede the clinically overt AIBD. [ABSTRACT FROM AUTHOR]

Summary: Background: Impaired growth and anaemia are major extracutaneous complications of epidermolysis bullosa (EB), but data on their development are lacking. Objectives: To determine the clinical course of growth and anaemia in children with EB and clarify the impact of nutritional compromise, inflammation and genetic factors. Methods: A retrospective study was conducted of 200 children, 157 with recessive dystrophic EB (RDEB) and 43 with junctional EB (JEB)‐generalized intermediate, followed at the main referral centre in Germany. Growth charts were calculated using the modified LMS method and were correlated with parameters of anaemia, nutrition, inflammation and the molecular defect in a linear model. Results: In our cohort of patients with RDEB, weight impairment started at 12–18 months old; by the age of 10 years, 50% showed wasting. The predicted median weight at age 20 years was 35·2 kg for men and 40·1 kg for women. In JEB, growth resembled that of healthy children. Anaemia was present from the second year of life onwards in RDEB and JEB. Low levels of haemoglobin, iron, vitamin D, zinc and albumin, high levels of C‐reactive protein, and absence of collagen VII correlated significantly with low weight in RDEB. No correlation was observed in JEB. Conclusions: The results highlight that nutritional compromise occurs early in children with RDEB and therefore may require interventions as of the first year or two of life. What's already known about this topic? Children with epidermolysis bullosa (EB) suffer from failure to thrive and anaemia as major extracutaneous complications.The course of growth and the development of anaemia in EB are poorly characterized. What does this study add? A molecularly well characterized cohort of 200 children with EB was followed with regard to anthropometrics, anaemia and inflammation.We demonstrate early onset of growth failure and anaemia, most pronounced in the subset of recessive dystrophic EB.Awareness of early growth delay and nutritional deficiencies will improve EB care in daily practice. Linked Comment:Laimer. Br J Dermatol 2020; 182: 1327–1328. Plain language summary available online Respond to this article [ABSTRACT FROM AUTHOR]

Presents information on a study which modeled a thin field-effect transistor based on amorphous semiconductors using an iterative scheme. Modeling of the field-effect transistor; Conclusions.

Studies the criteria for space-charge-limited currents applied as spectroscopical method for localized electron states elucidation. Density of states; Energy position; Temperature.

Low stability and degradability of polymers by ambient air, UV irradiation or charge transport are major problems of molecular electronics devices. Recent research tentatively suggests that the presence of a crystalline phase may increase polymer stability due to an intensive energy trapping in the ordered phase. Using the UV degradability, we demonstrate this effect on an archetypal model σ bonded polymer - poly[methyl(phenyl)silane] (PMPSi) - with partially crystalline and amorphous-like layers. UV degradation with 345 nm, derived from the branching state generation rate, was inversely proportional to the crystalline phase content, changing from 4.8x1011 s-1 (partially crystalline phase) to 1.8x1013 s-1 (amorphous-like phase). A model is proposed where crystallites formed by molecular packing act as effective ecitation energy traps with a suppressed nonradiative recombination improving thus PMPSi film stability. The molecular packing and higher crystalline phase proportion may be a general approach for stability and degradability improvement of polymers in molecular electronics. [ABSTRACT FROM AUTHOR]

The superconducting stellarator Wendelstein 7-X is currently being commissioned. First plasmas are expected for the second half of 2015. W7-X is designed to overcome the main drawbacks of the stellarator concept and simultaneously demonstrate its intrinsic advantages relative to the tokamak—i.e., steady-state operation without the requirement of current drive or stability control. An elaborate optimization procedure was used to avoid excessive neoclassical transport losses at high plasma temperature, while simultaneously achieving satisfactory equilibrium and stability properties at high $\beta $ in combination with a viable divertor concept. In addition, fast-ion confinement must be consistent with the requirements of alpha-heating in a power plant. Plasma operation of Wendelstein 7-X follows a staged approach following the successive completion of the in-vessel components. The main objective of Wendelstein 7-X is the demonstration of steady-state plasma at fusion relevant plasma parameters. Wendelstein 7-X will address major questions for the extrapolation of the concept to a power plant. These include divertor operation at high densities, plasma fueling at high central temperatures, avoiding impurity accumulation, and an assessment of the effect of neoclassical optimization on turbulent transport and fast-ion confinement. A power plant concept based on an extrapolation from Wendelstein 7-X, the helical advanced stellarator, has been developed. [ABSTRACT FROM AUTHOR]

System codes are commonly employed for the analysis and conceptual design of fusion reactors. For the helical-axis advanced stellarator (HELIAS) line, a new set of system code models have been developed to account for the stellarator-specific 3-D aspects. The models have recently been implemented in the systems code PROCESS and verified with respect to different test cases. After having established confidence in the stellarator models, system studies were carried out for the five-field-period HELIAS case to define the accessible reactor design window. In the multidimensional physics and engineering parameter space, sensitivity studies are carried out for the reactor regime to ascertain tradeoffs between different parameters and costs. Exemplary design points are analyzed in more detail using the plasma operation contour approach, which, for example, can be used to determine the optimum start-up path to ignition. Finally, with a common set of nondevice-specific models, the PROCESS framework allows a direct comparison of tokamaks and stellarators. Although the five-period HELIAS is a larger machine in terms of major radius, the required mass for both concepts is comparable leading to similar construction costs. [ABSTRACT FROM AUTHOR]

Rotating detonation engines have the potential to achieve the high propulsive efficiencies of detonation cycles in a simple and effective annular geometry. A two-dimensional Euler simulation is modified to include mixing factors to simulate the imperfect mixing of injected reactant streams. Contrary to expectations, mixing is shown to have a minimal impact on performance. Oblique detonation waves are shown to increase local stream thermal efficiency, which compensates for other losses in the flow stream. The degree of reactant mixing is, however, a factor in controlling the stability and existence of rotating detonations. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 54-year-old female with oral mucosa, progressive microstomia and jaw pain. It is noted that she was diagnosed with recessive dystrophic epidermolysis bullosa. The article adds that Epidermolysis bullosa results from mutations in genes encoding proteins involved in cell-cell and cell-matrix adhesion in the epidermis and use of mmunofluorescence mapping for assessment of the efficacy of experimental therapeutic approaches.

We introduce an energy resolved electrochemical impedance spectroscopy method to map the electronic density of states (DOS) in organic semiconductor materials. The method consists in measurement of the charge transfer resistance of a semiconductor/electrolyte interface at a frequency where the redox reactions determine the real component of the impedance. The charge transfer resistance value provides direct information about the electronic DOS at the energy given by the electrochemical potential of the electrolyte, which can be adjusted using an external voltage. A simple theory for experimental data evaluation is proposed, along with an explanation of the corresponding experimental conditions. The method allows mapping over unprecedentedly wide energy and DOS ranges. Also, important DOS parameters can be determined directly from the raw experimental data without the lengthy analysis required in other techniques. The potential of the proposed method is illustrated by tracing weak bond defect states induced by ultraviolet treatment above the highest occupied molecular orbital in a prototypical r-conjugated polymer, poly[methyl(phenyl)silylene]. The results agree well with those of our previous DOS reconstruction by post-transient space-charge-limited-current spectroscopy, which was, however, limited to a narrow energy range. In addition, good agreement of the DOS values measured on two common p-conjugated organic polymer semiconductors, polyphenylene vinylene and poly(3-hexylthiophene), with the rather rare previously published data demonstrate the accuracy of the proposed method. [ABSTRACT FROM AUTHOR]

The conventional Zel'dovich-von Neumann-Döring (ZND) detonation theory is modified with two-dimensional velocity vectors to account for the performance and steady-state flow features of a rotating detonation engine. The developed analytical model explains many of the steady-state features of the rotating detonation and its thermodynamics. The generation of swirl is shown to be the primary mechanism of energy transfer. [ABSTRACT FROM AUTHOR]

Electron-positron plasmas are unique in their behavior due to the mass symmetry. Strongly magnetized electron-positron, or pair, plasmas are present in a number of astrophysical settings, such as astrophysical jets, but they have not yet been created in the laboratory. Plans for the creation and diagnosis of pair plasmas in a stellarator are presented, based on extrapolation of the results from the Columbia Non-neutral Torus stellarator, as well as recent developments in positron sources. The particular challenges of positronium injection and pair plasma diagnostics are addressed. [ABSTRACT FROM AUTHOR]

The performance of a novel microwave ignition source was experimentally tested against a standard multi-spark ignition system. Comparison of the combustion and detonation performance was measured. The growth of combustion kernels and the discharge pattern of the igniters were recorded using high-speed video cameras for visual comparison. The results showed that the transition of deflagration to detonation transition was comparable between the two ignition systems. Significant improvement in ignition of lean mixtures of ethylene and ethane were observed for the microwave ignition system over the baseline multi-spark ignition and thus should be considered for application as a lean ignition source. [ABSTRACT FROM AUTHOR]

Aim: To complete our study on tannin degradation via gallic acid by the biotechnologically interesting yeast Arxula adeninivorans as well as to characterize new degradation pathways of hydroxylated aromatic acids. Methods and Results: With glucose-grown cells of A. adeninivorans, transformation experiments with hydroxylated derivatives of benzoic acid were carried out. The 12 metabolites were analysed and identified by high performance liquid chromatography and GC/MS. The yeast is able to transform the derivatives by oxidative and nonoxidative decarboxylation as well as by methoxylation. The products of nonoxidative decarboxylation of protocatechuate and gallic acid are substrates for further ring fission. Conclusion: Whereas other organisms use only one route of transformation, A. adeninivorans is able to carry out three different pathways (oxidative, nonoxidative decarboxylation and methoxylation) on one hydroxylated aromatic acid. The determination of the KM-values for protocatechuate and gallic acid in crude extracts of cells of A. adeninivorans cultivated with protocatechuate and gallic acid, respectively, suggests that the decarboxylation of protocatechuate and gallic acid may be catalysed by the same enzyme. Significance and Impact of the Study: This transformation pathway of protocatechuate and gallic acid via nonoxidative decarboxylation up to ring fission is novel and has not been described so far. This is also the first report of nonoxidative decarboxylation of gallic acid by a eukaryotic micro-organism. [ABSTRACT FROM AUTHOR]

A laccase from the aquatic ascomycete Phoma sp. UHH 5-1-03 (DSM 22425) was purified upon hydrophobic interaction and size exclusion chromatography (SEC). Mass spectrometric analysis of the laccase monomer yielded a molecular mass of 75.6 kDa. The enzyme possesses an unusual alkaline isoelectric point above 8.3. The Phoma sp. laccase undergoes pH-dependent dimerisation, with the dimer (∼150 kDa, as assessed by SEC) predominating in a pH range of 5.0 to 8.0. The enzyme oxidises common laccase substrates still at pH 7.0 and 8.0 and is remarkably stable at these pH values. The laccase is active at high concentrations of various organic solvents, all together indicating a considerable biotechnological potential. One laccase gene ( lac1) identified at the genomic DNA level and transcribed in laccase-producing cultures was completely sequenced. The deduced molecular mass of the hypothetical protein and the predicted isoelectric point of 8.1 well agree with experimentally determined data. Tryptic peptides of electrophoretically separated laccase bands were analysed by nano-liquid chromatography–tandem mass spectrometry. By using the nucleotide sequence of lac1 as a template, eight different peptides were identified and yielded an overall sequence coverage of about 18%, thus confirming the link between lac1 and the expressed laccase protein. [ABSTRACT FROM AUTHOR]

Photoexcitation, photodegradation and metastability of electronic states of poly[methyl(phenyl)silylene] on air and in vacuo are discussed. UV radiation causes the formation of excitons, ion-pairs, free radicals, delocalized positive polarons and scission of Si&sbnd;Si bonds. Due to the chain deformation during the exciton and polaron formation metastable electronic states 0.45 eV deep originate in vacuo. These states make the conjugation length shorter and can be thermally annealed. On air polysiloxane structures arise. [ABSTRACT FROM AUTHOR]

j. wesche, e. hammer, d. becher, g. burchhardt and f. schauer. 2004.Biphenyl-degrading bacteria are able to metabolize dibenzofuran via lateral dioxygenation andmeta-cleavage of the dihydroxylated dibenzofuran produced. This degradation was considered to be incomplete because accumulation of a yellow-orange ring-cleavage product was observed. In this study, we want to characterize the 1,2-dihydroxydibenzofuran cleaving enzyme which is involved in dibenzofuran degradation in the bacteriumRalstoniasp. SBUG 290.In this strain, complete degradation of dibenzofuran was observed after cultivation on biphenyl. The enzyme shows a wide substrate utilization spectrum, including 1,2-dihydroxydibenzofuran, 2,3-dihydroxybiphenyl, 1,2-dihydroxynaphthalene, 3- and 4-methylcatechol and catechol. MALDI-TOF analysis of the protein revealed a strong homology to thebphCgene products. We therefore cloned a 3·2 kb DNA fragment containing thebphCgene ofRalstoniasp. SBUG 290. The deduced amino acid sequence ofbphCis identical to that of the corresponding gene inPseudomonassp. KKS102. ThebphCgene was expressed inEscherichia coliand themeta-fission activity was detected using either 2,3-dihydroxybiphenyl or 1,2-dihydroxydibenzofuran as substrate.These results demonstrate that complete degradation of dibenzofuran by biphenyl degraders can occur after initial oxidation steps catalysed by gene products encoded by thebph-operon. The ring fission of 1,2-dihydroxydibenzofuran is catalysed by BphC. Differences found in the metabolism of the ring fission product of dibenzofuran among biphenyl degrading bacteria are assumed to be caused by different substrate specificities of BphD.This study shows for the first time that the gene products of thebph-operon are involved in the mineralization of dibenzofuran in biphenyl degrading bacteria. [ABSTRACT FROM AUTHOR]

Investigations of the unicellular marine cyanobacterium Synechococcus PCC 7002 revealed its ability to metabolize phenol under non-photosynthetic conditions up to 100 mg L−1. Under continuous light, photoautotrophic growth was reduced only slightly in the presence of this phenol concentration, but no transformation was observed. However neither under photoautotrophic nor heterotrophic conditions were the cells able to use phenol for growth. During the degradation of phenol in the dark cis,cis-muconic acid was produced as the major product, which was identified by gas chromatography/mass spectrometry. This result was confirmed by an identical absorption spectrum and an identical retention time in high performance liquid chromatographic analysis with authentic muconic acid as standard. This provides the first record for an ortho-fission of a phenolic substance by cyanobacteria. Further investigations of the breakdown mechanism of phenol have shown that the transformation is an extracellular process inhibited by heat, proteases and metal ions and is probably catalyzed by a protein. [ABSTRACT FROM AUTHOR]

Substrate oxidation of aromatic substances by the enzyme laccase followed by a heteromolecular coupling with a co-substrate is a promising possibility for the synthesis of new compounds. To find a suitable reactor for the effective production of new compounds, the laccase-catalysed coupling of 3-(3,4-dihydroxyphenyl)propionic acid with 4-aminobenzoic acid was investigated as a model system. Based on the kinetic parameters, a mathematical model was used to predict the reaction yield and oxygen demand in a discontinuously stirred tank reactor and a continuously operated stirred tank reactor. Membrane processes were used for bubble-free aeration of the system and to recover the soluble enzyme. [ABSTRACT FROM AUTHOR]

Thirty-five strains of soil bacteria were grown with biphenyl (BP) and tested for their capacity to cooxidize dibenzofuran (DBF). During metabolism of DBF, the culture medium of 17 strains changed from colorless to orange, indicating a meta-cleavage pathway of DBF degradation. The ring cleavage product of these isolates was shown to be 2-hydroxy-4-(3′-oxo-3′H-benzofuran-2′-yliden)but-2-enoic acid (HOBB). The strain SBUG 271, studied in detail and identified as Rhodococcus erythropolis, degraded DBF via 1,2-dihydroxydibenzofuran. The ensuing meta-cleavage yielded HOBB and salicylic acid. In addition, the four monohydroxylated monomers of DBF and two metabolites, which were not further characterized, were detected. Thus, our results demonstrate that the metabolic mechanism involves lateral dioxygenation of DBF followed by meta-cleavage and occurs in Gram-negative as well as in Gram-positive BP-degrading bacteria. [ABSTRACT FROM AUTHOR]

Under-resolved passive-scalar measurements in liquid and gaseous shear layers have been known to over-predict mixed-fluid quantities as a result of sub-resolution stirring. In recent studies, simultaneous cold-chemistry (nitric oxide) and passive-scalar (acetone) planar laser-induced fluorescence have been employed for the measurement of sub-resolution molecular mixing. In the current work, the theory and experimental approach of this technique are reviewed, and new analyses of quenching corrections, differential diffusion errors, and imaging resolution are presented. Results from both experimental work and direct numerical simulations indicate that this technique provides a successful means of quantifying macro- and micro-scale turbulent molecular mixing in gaseous shear flows. [ABSTRACT FROM AUTHOR]

Examines the thermohydraulic properties of superconducting magnets of the stellarator fusion experiment WENDELSTEIN 7-X. Quench propagation; Eddy current heating of the coil housings; Helium relief system.

Penicillium canescens oxidises dibenzofuran (DBF) to produce monohydroxylated derivatives and other more hydrophilic metabolites. These substances are water-soluble but unstable in organic solvents such as ethyl acetate, acetone or dichloromethane. Both extraction with ethyl acetate and enzymatic treatment of the aqueous culture filtrate with β-glucuronidase led to decay of the hydrophilic metabolites and indicated these products to be glycoside conjugates. The glycosyl residue was identified as glucose both by liquid chromatography and by the use of glucose oxidase. The conjugate pattern formed was the same in type and amount, independent of the carbon source used for cultivation of the fungus. Clearly, DBF transformation in P. canescens occurred in two phases: first the conversion to 2-, 3-, and 4-hydroxydibenzofuran (phase I), followed by the formation of the corresponding glucosyl conjugates (phase II). In contrast, 2,3-dihydroxydibenzofuran added to the cultures was transformed by ring cleavage producing a muconic acid-like dead-end product. [ABSTRACT FROM AUTHOR]

Space-charge-limited (SCL) photoconductivity in transient regime and its modification, T-SCLC (transient space-charge-limited currents), are readily observed in high resistivity materials with mobile carriers and thus may be with advantage used as a tool for the study of the density of localized states (DOS) in organic molecular semiconductors. The only prerequisite for the experimental observation of SCL photoconductivity is a reasonably long Maxwell relaxation time. This paper presents the new possibilities of the T-SCLC method for elucidation of the DOS in organic molecular solids with practical examples of modeling, reconstruction of post-transit data and its application for a typical polymer — poly(methylphenylsilyene). [ABSTRACT FROM AUTHOR]

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