Functional Characterization of Antithrombin Mutations by Monitoring of Thrombin Inhibition Kinetics

Inactivation of thrombin by the endogenous inhibitor antithrombin (AT) is a central mechanism in the regulation of hemostasis. This makes hereditary AT deficiency, which is caused by SERPINC1 gene mutations, a major thrombophilic risk factor. Aim of this study was to assess to what extent AT mutations impair thrombin inhibition kinetics. The study population included 36 thrombophilic patients with 19 different mutations and mean AT levels of 65% in a thrombin-based functional assay, and 26 healthy controls. To assess thrombin inhibition kinetics, thrombin (3.94 mU/mL final concentration) was added to citrated plasma. Subsequently, endogenous thrombin inhibition was stopped by addition of the reversible thrombin inhibitor argatroban and the amount of argatroban-complexed thrombin quantified using an oligonucleotide-based enzyme capture assay. The plasma half-life of human thrombin was significantly longer in patients with AT mutations than in the controls (119.9 versus 55.9 s). Moreover, it was disproportionately prolonged when compared with preparations of wild type AT in plasma, in whom a comparable thrombin half-life of 120.8 s was reached at a distinctly lower AT level of 20%. These findings may help to better understand the increased thrombotic risk of SERPINC1 mutations with near normal AT plasma levels in functional assays.     

Ergebnisbericht der Task Force EHEC zur Aufkl?rung des EHEC O104:H4 Krankheitsausbruchs in Deutschland

This is a report on the results of the work of the German EHEC Task Force on the food safety side of the EHEC O104:H4 disease outbreak investigation in Germany. During the first phase of the outbreak investigation the main goal was to identify the contaminated food. To achieve this, two different strategies were followed in parallel. One approach was a detailed trace back analysis for all salad ingredients and raw vegetables that have been served to customers at five outbreak clusters in order to identify common food sources and delivery chains. The second approach was a trace forward analysis of the supply chains of a sprout producer in order to find out if he had delivered any outbreak clusters. Both approaches revealed that contaminated sprouts from a producer in Lower Saxony highly likely had caused the outbreak. Aim of the second investigation phase was to find and stop the source of the EHEC O104:H4 bacteria. The Task Force gave recommendations on source elimination measures and collected and analysed epidemiological information in order to find out when the source was active. Next to that, a detailed trace back for batches of suspicious seeds that had been used by the sprout producer was initiated. The results from this activity formed the basis for the tracing of seeds coordinated by the European Food Safety Authority, which revealed that fenugreek seeds imported from Egypt were the most likely common link between the EHEC O104:H4 outbreaks in Germany and France. In conclusion, the newly developed outbreak investigation strategy of the task Force EHEC with close collaboration between German federal and federal state authorities and between food safety authorities, health authorities and scientists was a recipe of success and can be a model for future food-borne outbreak investigations.     

Multicomponent gas diffusion in hardened cement paste at temperatures up to 350 °C

Diffusional gas transport of a H₂/CO₂ mixture versus N₂ in the pore system of hardened cement pastes was studied at four temperatures up to 350 °C in a Wicke-Kallenbach cell. The pastes possessed separation factors α_H2,CO2 from 1.42 to 3.43, i.e. the diffusion of hydrogen took place considerably faster than the diffusion of carbon dioxide. The separation factors depended on the threshold radii of the pastes, smaller threshold radii leading to higher separation factors. The Knudsen numbers of the controlling constrictions of the pore system and the temperature dependence of the effective diffusion coefficients of the gases show that gas transport in these constrictions takes place in the transient regime between Knudsen diffusion and bulk diffusion, smaller constriction widths leading to predominating Knudsen diffusion. It is therefore possible to use cement paste membranes to separate gas components of low molecular weight from higher weight components.     

Crystallinity,thermal diffusivity,and electrical conductivity of carbon black filled polyamide 46

Polyamide 46 (PA 46) with carbon black (CB) has been subjected to a heat treatment. Crystallinity, specific heat capacity, crystalline melting peak temperature, thermal diffusivity, and electrical conductivity were measured. The crystallinity increases with duration of thermal treatment. The maximum value is dependent on the filler fraction. A lower CB content leads to a higher crystallinity at maximum tempering time. The crystalline melting peak temperature increases with decreasing filler fraction and duration of thermal treatment due to different crystal types and/or diverging geometric forms of the crystals. Thermal diffusivity and electrical conductivity act positively proportional to each other and increase with CB content and tempering time. The thermal diffusivity decreases with increasing temperature. The volume resistance of PA 46 is lowered by heat treatment. By CB addition in combination with a tempering process, the PA 46 can be transferred into a conductor. CB is moved by PA 46 crystals into amorphous regions forming conductive pathways. © 2019 The Authors. Journal of Applied Polymer Science published by Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48882.     

Optimal parameters in variable‐velocity scanning luminescence lifetime microscopy

We determine the optimal parameters (scan velocities) for measuring the luminescence lifetime on the microsecond scale using the recently introduced method based on scanning the excitation beam across the sample. Using simulations, we evaluate the standard deviation and bias of the luminescence decay rate determined by scanning with two different velocities. The analysis is performed for Poisson‐ and normal‐distributed signals, representing different types of detection techniques. We also show that a weak uncorrected background induces a bias in the obtained decay rate, and take this effect into account when choosing optimal measurement parameters. For comparison, the analysis is additionally performed for two conventional gating schemes for lifetime measurement. The variable‐velocity scanning method is found to be more robust to the effect of the background signal than the gating schemes.     

Affective and deliberative processes in risky choice: Age differences in risk taking in the Columbia Card Task.

The authors investigated risk taking and underlying information use in 13- to 16- and 17- to 19-year-old adolescents and in adults in 4 experiments, using a novel dynamic risk-taking task, the Columbia Card Task (CCT). The authors investigated risk taking under differential involvement of affective versus deliberative processes with 2 versions of the CCT, constituting the most direct test of a dual-system explanation of adolescent risk taking in the literature so far. The “hot” CCT was designed to trigger more affective decision making, whereas the “cold” CCT was designed to trigger more deliberative decision making. Differential involvement of affective versus deliberative processes in the 2 CCT versions was established by self-reports and assessment of electrodermal activity. Increased adolescent risk taking, coupled with simplified information use, was found in the hot but not the cold condition. Need-for-arousal predicted risk taking only in the hot condition, whereas executive functions predicted information use in the cold condition. Results are consistent with recent dual-system explanations of risk taking as the result of competition between affective processes and deliberative cognitive-control processes, with adolescents’ affective system tending to override the deliberative system in states of heightened emotional arousal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Focus groups and critical social IS research: how the choice of method can promote emancipation of respondents and researchers

Critical social research in information systems has been gaining prominence for some time and is increasingly viewed as a valid research approach. One problem with the critical tradition is a lack of empirical research. A contributing factor to this gap in the literature is the lack of agreement on what constitutes appropriate methodologies for critical research. The present paper contributes to this debate by exploring the role that focus group research can play in the critical approach. This paper outlines the main characteristics of critical research with an emphasis on its emancipatory faculties. It then reviews the focus group method from the perspective of critical approach and provides a critical account of two research projects that used focus groups as a method of data collection. The paper presents the argument that focus groups, if designed and executed in light of a critical approach, can contribute to the emancipation of researchers and respondents. This argument is built upon the critical theories of the two most influential theorists in critical social information systems research, namely Jürgen Habermas and Michel Foucault. Critically oriented focus groups have the potential to improve communication and move real discourses closer to Habermas's ideal speech situation. At the same time, they can contribute to challenging the prevailing orthodoxy and thereby overcome established regimes of truth in the Foucauldian tradition. The paper ends by developing a set of guiding questions that provide a means for researchers to ensure that the emancipatory potential of focus group research can be achieved.     

Microstructure, cytotoxicity and corrosion of powder-metallurgical iron alloys for biodegradable bone replacement materials

Up to now biodegradable bone implants with the ability of bearing high loads for the temporary replacement of bones or as osteosynthesis material are not available. Iron and iron based alloys have been identified as appropriate materials, since they combine high strength at medium corrosion rates. Thus, the aim of the present study is the development of a degradable iron based alloy with the perspective of using them as matrix material of cellular structures with biomechanical tailored properties. A powder metallurgical approach has been used to manufacture Fe-C, Fe-0.6P, Fe-1.6P, Fe-B and Fe-Ag samples, which have been tested with respect to their microstructure, their cytotoxicity, and their degradation rate. In order to determine the cytotoxicity of the material a monolayer culture of fibroblast and a perfusion chamber system has been chosen, which was recommended by the ISO 10993-5:1999 for biological testing of medical devices. It has been found, that in particular phosphorus features beneficial properties, since density and thus the strength of the material are increased. No corrosion inhibiting effects of phosphorus on the degradation rate have been found.     

Conversion of individual natural gas to district heating: Geographical studies of supply costs and consequences for the Danish energy system

Replacing individual natural gas heating with district heating based to increasing shares of renewable energy sources may further reduce CO₂-emissions in the Danish Building mass, while increasing flexibility of the energy system to accommodate significantly larger amounts of variable renewable energy production. The present paper describes a geographical study of the potential to expand district heating into areas supplied with natural gas. The study uses a highly detailed spatial database of the built environment, its current and potential future energy demand, its supply technologies and its location relative to energy infrastructure. First, using a spatially explicit economic model, the study calculates the potentials and costs of connection to expanded district heating networks by supply technology. Then a comprehensive energy systems analysis is carried out to model how the new district heat can be supplied from an energy system with higher shares of renewable energy. It can be concluded on the basis of these analyses that the methods used proved highly useful to address issues of geographically dependent energy supply; however the spatio-economic model still is rather crude. The analyses suggest to expand district heating from present 46% to somewhere in between 50% and 70%. The most attractive potential is located around towns and cities. The study also suggests that CO₂-emissions, fuel consumption and socio-economic costs can be reduced by expanding district heating, while at the same time investing in energy savings in the building mass as well as increased district heating network efficiency.