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The region surrounding the excitonic insulator phase is a three-component plasma composed of electrons, holes, and excitons. Due to the extended nature of the excitons, their presence influences the surrounding electrons and holes. We analyze this correlation. To this end, we calculate the density of bound electrons, the density of electrons in the correlated state, the momentum-resolved exciton density, and the momentum-resolved density of electron-hole pairs that are correlated but unbound. We find qualitative differences in the electron-hole correlations between the weak-coupling and the strong-coupling regime.
Abstract
The presented experimental system is a barrier discharge system with plane parallel electrodes. The lateral surface charge distribution being deposited on the dielectric layer during each breakdown is observed optically using the well known electro-optic effect (Pockels effect). The temporal resolution of the surface charge measurement has been increased to 200 ns, and so for the first time it is possible to resolve the charge transfer to the dielectric surface in a single breakdown. In the present measurements, a patterned glow-like barrier discharge is investigated. It is found that the charge reversal in a single discharge spot (microdischarge) starts in the centre and then grows outwards. These experimental findings verify previously unconfirmed predictions from earlier numerical calculations and thereby contribute to a better understanding of the interaction between the plasma and the electrical charge on the electrodes.
Inflammation is part of the body's immune response in order to remove harmful stimuli—like pathogens, irritants or damaged cells—and start the healing process. Recurrent or chronic inflammation on the other side seems a predisposing factor for carcinogenesis and has been found associated with cancer development. In chronic pancreatitis mutations of the cationic trypsinogen (PRSS1) gene have been identified as risk factors of the disease. Hereditary pancreatitis (HP) is a rare cause of chronic pancreatic inflammation with an early onset, mostly during childhood. HP often starts with recurrent episodes of acute pancreatitis and the clinical phenotype is not very much different from other etiologies of the disease. The long-lasting inflammation however generates a tumor promoting environment and represents a major risk factor for tumor development This review will reflect our knowledge concerning the specific risk of HP patients to develop pancreatic cancer.
Purines of exogenous and endogenous sources are degraded to uric acid in human beings. Concentrations >6.8 mg uric acid/dl serum cause hyperuricemia and its symptoms. Pharmaceuticals and the reduction of the intake of purine-rich food are used to control uric acid levels. A novel approach to the latter proposition is the enzymatic reduction of the purine content of food by purine-degrading enzymes. Here we describe the production of recombinant guanine deaminase by the yeast Arxula adeninivorans LS3 and its application in food. In media supplemented with nitrogen sources hypoxanthine or adenine, guanine deaminase (AGDA) gene expression is induced and intracellular accumulation of guanine deaminase (Agdap) protein occurs. The characteristics of the guanine deaminase isolated from wild-type strain LS3 and a transgenic strain expressing the AGDA gene under control of the strong constitutive TEF1 promoter were determined and compared. Both enzymes were dimeric and had temperature optima of 55°C with high substrate specificity for guanine and localisation in both the cytoplasm and vacuole of yeast. The enzyme was demonstrated to reduce levels of guanine in food. A mixture of guanine deaminase and other purine degradation enzymes will allow the reduction of purines in purine-rich foods.
Staphylococcus aureus is a human pathogen that can cause a wide range of diseases. Although formerly regarded as extracellular pathogen, it has been shown that S. aureus can also be internalized by host cells and persist within these cells. In the present study, we comparatively analyzed survival and physiological adaptation of S. aureus HG001 after internalization by two human lung epithelial cell lines (S9 and A549), and human embryonic kidney cells (HEK 293). Combining enrichment of bacteria from host-pathogen assays by cell sorting and quantitation of the pathogen's proteome by mass spectrometry we characterized S. aureus adaptation during the initial phase between 2.5 h and 6.5 h post-infection. Starting with about 2 × 106 bacteria, roughly 1450 S. aureus proteins, including virulence factors and metabolic enzymes were identified by spectral comparison and classical database searches. Most of the bacterial adaptation reactions, such as decreased levels of ribosomal proteins and metabolic enzymes or increased amounts of proteins involved in arginine and lysine biosynthesis, enzymes coding for terminal oxidases and stress responsive proteins or activation of the sigma factor SigB were observed after internalization into any of the three cell lines studied. However, differences were noted in central carbon metabolism including regulation of fermentation and threonine degradation. Since these differences coincided with different intracellular growth behavior, complementary profiling of the metabolome of the different non-infected host cell types was performed. This revealed similar levels of intracellular glucose but host cell specific differences in the amounts of amino acids such as glycine, threonine or glutamate. With this comparative study we provide an impression of the common and specific features of the adaptation of S. aureus HG001 to specific host cell environments as a starting point for follow-up studies with different strain isolates and regulatory mutants.
Background: Alcohol dependence is among the most severely stigmatized mental disorders. We examine whether negative stereotypes and illness beliefs related to alcohol dependence have changed between 1990 and 2011. Methods: We used data from two population surveys with identical methodology that were conducted among German citizens aged ≥18 years, living in the ‘old' German states. They were conducted in 1990 and 2011, respectively. In random subsamples (1990: n = 1,022, and 2011: n = 1,167), identical questions elicited agreement with statements regarding alcohol dependence, particularly with regard to the illness definition of alcohol dependence and blame. Results: Overall, agreement with negative stereotypes did not change in the course of 2 decades. About 55% of the respondents agreed that alcohol dependence is an illness like any other, >40% stated that it was a weakness of character and 30% endorsed that those affected are themselves to blame for their problems. Conclusions: It is apparent that promoting an illness concept of alcohol dependence has not been an easy solution to the problem of stigma. We discuss how the normative functions of alcohol dependence stigma might have prevented a reduction of negative stereotypes.
People smile in various emotional contexts, for example, when they are amused or angry or simply being polite. We investigated whether younger and older adults differ in how well they are able to identify the emotional experiences accompanying smile expressions, and whether the age of the smiling person plays a role in this respect. With this aim, we produced 80 video episodes of three types of smile expressions: positive-affect smiles had been spontaneously displayed by target persons as they were watching amusing film clips and cartoons. Negative-affect smiles had been displayed spontaneously by target persons during an interaction in which they were being unfairly accused. Affectively neutral smiles were posed upon request. Differences in the accompanying emotional experiences were validated by target persons' self-reports. These smile videos served as experimental stimuli in two studies with younger and older adult participants. In Study 1, older participants were less likely to attribute positive emotions to smiles, and more likely to assume that a smile was posed. Furthermore, younger participants were more accurate than older adults at identifying emotional experiences accompanying smiles. In Study 2, both younger and older participants attributed positive emotions more frequently to smiles shown by older as compared to younger target persons, but older participants did so less frequently than younger participants. Again, younger participants were more accurate than older participants in identifying emotional experiences accompanying smiles, but this effect was attenuated for older target persons. Older participants could better identify the emotional state accompanying smiles shown by older than by younger target persons. Taken together, these findings indicate that there is an age-related decline in the ability to decipher the emotional meaning of smiles presented without context, which, however, is attenuated when the smiling person is also an older adult.
Abstract
Experimental studies on dusty plasmas containing systems of (super-)paramagnetic dust particles are presented. In our experiments, external (homogeneous as well as inhomogeneous) magnetic fields in the mT range are applied to study the effect on single particles or few-particle systems that are trapped inside the sheath region. The behavior of the paramagnetic dust particles is considerably different than that of dielectric plastic particles, which are widely used in dusty plasmas. It is revealed that especially non-magnetic contributions play an important role in the interaction between superparamagnetic particles.