Reactivity of Gypsum-Based Materials Subjected to Thermal Load: Investigation of Reaction Mechanisms

The thermal stability of gypsum-based materials, and in this context, especially their long-term behavior, is the background of our current research activities. A comprehensive investigation program was compiled in which detailed examinations of various model materials exposed to thermal loads were carried out. The understanding of the partly not entirely consistent state of knowledge shall be sharpened especially by in situ observations of the thermally induced conversion reaction of gypsum into hemihydrate. The temporal course of the reaction was investigated non-destructively by in situ investigations in a high-resolution X-ray computed tomography setup, and the experiment was accompanied by detailed characterizations of the microstructure and composition. In this contribution, selected results of experiments with a high-purity natural gypsum rock as the model substance are presented. Studying the influence of temperature on the reaction showed that, even under supposedly dry conditions, the reaction could take place at much lower temperatures than usually reported in the literature. It was demonstrated that the transformation of gypsum into hemihydrate could take place at a temperature of already 50 °C. The results indicated that even under “classical” heating conditions in a conventional oven, the dissolution and crystallization processes in water films on the mineral surfaces could be suggested to be a driving force for the reaction. A corresponding reaction model, which took these aspects into account, was proposed in this work

Temsirolimus Is Highly Effective as Third-Line Treatment in Chromophobe Renal Cell Cancer

We report unexpectedly high efficacy of temsirolimus as third-line treatment in a patient with metastatic chromophobe renal cell carcinoma. After failure of two sequentially administered tyrosine kinase inhibitors, treatment with temsirolimus resulted in a prolonged partial remission of 14 months, and the response is still continuing. Up to now, no data from randomized clinical studies have been published addressing the question of efficacy of temsirolimus as third-line treatment after failure of tyrosine kinase inhibitors. The case presented here implies that temsirolimus could be a viable option for patients with metastatic chromophobe renal cell carcinoma

Talking Different Languages: The Role of Plant-Plant Communication When an Invader Beats up a Strange Neighborhood

Communication through airborne volatile organic compounds (VOCs) and root exudates plays a vital role in the multifarious interactions of plants. Common ragweed (Ambrosia artemesiifolia L.) is one of the most troublesome invasive alien species in agriculture. Below- and aboveground chemical interactions of ragweed with crops might be an important factor in the invasive species' success in agriculture. In laboratory experiments, we investigated the contribution of intra- and interspecific airborne VOCs and root exudates of ragweed to its competitiveness. Wheat, soybean, and maize were exposed to VOCs emitted from ragweed and vice versa, and the adaptation response was measured through plant morphological and physiological traits. We observed significant changes in plant traits of crops in response to ragweed VOCs, characterized by lower biomass production, lower specific leaf area, or higher chlorophyll contents. After exposure to ragweed VOCs, soybean and wheat produced significantly less aboveground dry mass, whereas maize did not. Ragweed remained unaffected when exposed to VOCs from the crops or a conspecific. All crops and ragweed significantly avoided root growth toward the root exudates of ragweed. The study shows that the plant response to either above- or belowground chemical cues is highly dependent on the identity of the neighbor, pointing out the complexity of plant-plant communication in plant communities

Reduction of the Superfluid Density in the Vortex-Liquid Phase of Bi2Sr2CaCu2Oy

In-plane complex surface impedance of a Bi2Sr2CaCu2Oy single crystal was measured in the mixed state at 40.8 GHz.The surface reactance, which is proportional to the real part of the effective penetration depth, increased rapidly just above the first-order vortex-lattice melting transition field and the second magnetization peak field.This increase is ascribed to the decrease in the superfluid density rather than the loss of pinning.This result indicates that the vortex melting transition changes the electronic structure as well as the vortex structure.Comment: 4 pages, 4 figures, accepted for publication in Phys. Rev. Let

Bitter Taste Disrupts Spatial Discrimination of Piperine-Evoked Burning Sensations: A Pilot Study

Simple Summary The chemical senses smell, taste, and trigeminal sense enable us to interact with the environment and play an essential role in protecting us from hazardous events. It is theorized that capsaicin and piperine not only elicit burning, but also bitter sensations through bitter taste-responding gustatory receptor cells that possess special channels. Similar psychophysiological responses to capsaicin and piperine suggest that bitter taste might also disrupt the spatial discrimination to piperine-induced burning sensations. Results showed that bitter taste disrupted the spatial discrimination of piperine-evoked burning sensations, providing further evidence for a qualitative similarity between burning and bitter sensations and the usefulness of chemical irritants in spatial discrimination tasks. Abstract This study aimed to investigate the perceptual similarity between piperine-induced burning sensations and bitter taste using piperine-impregnated taste strips (PTS). This pilot study included 42 healthy participants. PTS of six ascending concentrations (1 mg, 5 mg, 10 mg, 15 mg, 20 mg, and 25 mg piperine/dL 96% ethanol) were presented at the anterior tongue, and participants rated perceived intensity and duration. Then, participants performed a spatial discrimination task in which they had to report which of the two strips presented to the anterior tongue contained an irritating stimulus when one strip was always a PTS while the other strip was impregnated with either a single taste quality (sweet or bitter) or a blank strip. Repeated measures one-way ANOVA revealed that burning sensations of higher concentrated PTS were perceived more intense and more prolonged compared to lower concentrated PTS. McNemar’s test showed that PTS were identified correctly significantly less often when presented with bitter strips compared to when presented with blank (p = 0.002) or sweet strips (p = 0.017). Our results showed that bitter taste disrupts the spatial discrimination of piperine-evoked burning sensations. PTS might serve as a basis for further studies on disease-specific patterns in chemosensory disorders

Spatial references with gaze and pointing in shared space of humans and robots

Renner P, Pfeiffer T, Wachsmuth I. Spatial references with gaze and pointing in shared space of humans and robots. In: Freksa C, Nebel B, Hegarty M, Barkowsky T, eds. Spatial Cognition IX. Lecture Notes in Computer Science. Vol 8684. Berlin [u.a.]: Springer; 2014: 121-136.For solving tasks cooperatively in close interaction with humans, robots need to have timely updated spatial representations. However, perceptual information about the current position of interaction partners is often late. If robots could anticipate the targets of upcoming manual actions, such as pointing gestures, they would have more time to physically react to human movements and could consider prospective space allocations in their planning. Many findings support a close eye-hand coordination in humans which could be used to predict gestures by observing eye gaze. However, effects vary strongly with the context of the interaction. We collect evidence of eye-hand coordination in a natural route planning scenario in which two agents interact over a map on a table. In particular, we are interested if fixations can predict pointing targets and how target distances affect the interlocutor's pointing behavior. We present an automatic method combining marker tracking and 3D modeling that provides eye and gesture measurements in real-time

Hereditäre Netzhautdystrophien

Der Begriff „hereditäre Netzhautdystrophien“ fasst eine genetisch und phänotypisch sehr heterogene Gruppe erblicher Netzhauterkrankungen zusammen, deren gemeinsames Charakteristikum eine fortschreitende Verschlechterung der Sehfunktionen ist. Klinisch werden etwa 100 zum Teil extrem seltene Krankheitsbilder unterschieden. Die hohe phänotypische Variabilität und die insbesondere in frühen Krankheitsstadien oft unspezifischen Netzhautveränderungen und subjektiven Symptome erschweren dem Augenarzt die Diagnosestellung. Umgekehrt ist jedoch für den Patienten eine frühzeitige Diagnosestellung von immenser Bedeutung für die weitere Lebensplanung. Diese Fortbildung fokussiert daher vorwiegend auf eine praxisorientierte Strategie zur adäquaten Diagnostik hereditärer Netzhautdystrophien, jedoch nicht auf die detaillierte Differenzialdiagnose der Netzhautdystrophien. Für den Patienten ist die Einbeziehung hereditärer Netzhautdystrophien in die Differenzialdiagnose einer unklaren Sehstörung von großer Relevanz

Evidenzbasierte Diagnostik hereditärer Netzhautdystrophien 2009 = Evidence-Based Diagnostic Approach to Inherited Retinal Dystrophies 2009

Hintergrund: Hereditäre Netzhautdystrophien bilden eine heterogene Gruppe erblicher Erkrankungen mit einem sehr variablen klinischen Erscheinungsbild und multiplen assoziierten Genen. Diagnostik und Differenzialdiagnostik sind daher schwierig. Ziel dieser Arbeit ist es, Leitlinien für eine effektive Diagnostik zu geben. Methoden: Literaturrecherche und Auswertung eigener Erfahrungen mit klinischer (n = 3200) und molekulargenetischer (n = 4050) Diagnostik von Patienten mit Netzhautdystrophien. Ergebnisse: Für eine frühzeitige Diagnosestellung von Netzhautdystrophien ist deren Einbeziehung in die Differenzialdiagnose unklarer Sehstörungen von wesentlicher Bedeutung. Wichtigster diagnostischer Test ist das Ganzfeld-Elektroretinogramm (ERG), mit welchem generalisierte Netzhautdystrophien nachgewiesen werden können. Bei einem normalen ERG-Befund ist ein multifokales ERG zur Abklärung von Makuladystrophien indiziert. Fundusautofluoreszenz, Nah-Infrarot-Autofluoreszenz und hochauflösende optische Kohärenztomografie verbessern die Frühdiagnose, da morphologische Veränderungen bereits vor ophthalmoskopisch sichtbaren Veränderungen nachweisbar sein können. Darüber hinaus stellen diese nichtinvasiven bildgebenden Verfahren neue Phänomene dar, die für die Differenzialdiagnose, Verlaufskontrolle und das Verständnis der Pathogenese von Netzhautdystrophien wesentlich sind. Für eine zunehmende Anzahl hereditärer Netzhauterkrankungen besteht heute die Möglichkeit einer routinemäßigen molekulargenetischen Diagnostik. Eine möglichst genaue klinische Diagnosestellung ist hierbei unentbehrlich, um gezielt nach Mutationen in ausgewählten Genen suchen zu können. Ist eine genetische Untersuchung indiziert, empfiehlt sich die Kontaktaufnahme zu einem Humangenetiker vor Ort, um eine genetische Beratung der Familie einzuleiten sowie den konkreten Untersuchungsablauf und die Voraussetzungen für eine Kostenübernahme der Krankenkassen zu besprechen. Im Rahmen der humangenetischen Beratung wird in der Regel auch die molekulargenetische Diagnostik veranlasst und gegebenenfalls die Untersuchung weiterer Familienmitglieder koordiniert. Schlussfolgerungen: Die Kombination von elektrophysiologischer Diagnostik, bildgebenden Verfahren und molekulargenetischer Analyse erlaubt eine differenzierte Diagnose von Netzhautdystrophien und eine adäquate Beratung der Patienten. Bei Verdacht auf eine Netzhautdystrophie ist eine Überweisung des Patienten an ein Schwerpunktzentrum für Netzhautdystrophien zu empfehlen

The MHC2TA -168A>G gene polymorphism is not associated with rheumatoid arthritis in Austrian patients

An association between susceptibility to rheumatoid arthritis (RA) and a common -168A>G polymorphism in the MHC2TA gene with differential major histocompatibility complex (MHC) II molecule expression was recently reported in a Swedish population. The objective of the present study was to replicate this finding by examining the -168A>G polymorphism in an Austrian case–control study. Three hundred and sixty-two unrelated RA cases and 351 sex-matched and age-matched controls as well as 1,709 Austrian healthy individuals were genotyped. All participants were from the same ethnic background. Genotyping was performed using 5' allelic discrimination assays. The association between susceptibility to RA and the -168A>G single nucleotide polymorphism was examined by chi-square test. Comparison was made assuming a dominant effect (AG + GG genotypes versus AA genotype). In contrast to the primary report, the frequency of MHC2TA -168G allele carriers was not significantly different between patients and controls in the Austrian cohort. The homozygous MHC2TA -168 GG genotype was more frequent in matched controls than in Austrian RA patients. There was no association between the presence of RA-specific autoantibodies and the MHC2TA -168 GG genotype. In this cohort of Austrian patients, no association between the MHC2TA polymorphism and RA was found

Effect of a Normal-State Pseudogap on Optical Conductivity in Underdoped Cuprate Superconductors

We calculate the c-axis infrared conductivity $\sigma_c(\omega)$ in underdoped cuprate superconductors for spinfluctuation exchange scattering within the CuO$_2$-planes including a phenomenological d-wave pseudogap of amplitude $E_g$. For temperatures decreasing below a temperature $T^* \sim E_g/2$, a gap for $\omega < 2E_g$ develops in $\sigma_c(\omega)$ in the incoherent (diffuse) transmission limit. The resistivity shows 'semiconducting' behavior, i.e. it increases for low temperatures above the constant behavior for $E_g=0$. We find that the pseudogap structure in the in-plane optical conductivity is about twice as big as in the interplane conductivity $\sigma_c(\omega)$, in qualitative agreement with experiment. This is a consequence of the fact that the spinfluctuation exchange interaction is suppressed at low frequencies as a result of the opening of the pseudogap. While the c-axis conductivity in the underdoped regime is described best by incoherent transmission, in the overdoped regime coherent conductance gives a better description.Comment: to be published in Phys. Rev. B (November 1, 1999