Response to abatacept is associated with the inhibition of proteasome β1i expression in T cells of patients with rheumatoid arthritis

Objective: Abatacept is a biological disease-modifying antirheumatic drug (DMARD) used for the treatment of rheumatoid arthritis (RA) and modulates the costimulatory signal by cluster of differentiation (CD)28:CD80/CD86 interaction required for T cell activation. Since CD28-mediated signalling regulates many T cell functions including cytokine production of, for example, interferons (IFNs), it is of interest to clarify, whether response to abatacept has an effect on the IFN inducible immunoproteasome, as a central regulator of the immune response. Methods: Effects of abatacept on the proteasome were investigated in 39 patients with RA over a period of 24 weeks. Using real-time PCR, transcript levels of constitutive and corresponding immunoproteasome catalytic subunits were investigated at baseline (T0), week 16 (T16) and week 24 (T24) in sorted blood cells. Proteasomal activity and induction of apoptosis after proteasome inhibition were also evaluated. Results: Abatacept achieved remission or low disease activity in 55% of patients at T16 and in 70% of patients at T24. By two-way analysis of variance (ANOVA), a significant reduction of proteasome immunosubunit β1i was shown only in CD4+ and CD8+ T cells of sustained responders at both T16 and T24. One-way ANOVA analysis for each response group confirmed the results and showed a significant reduction at T24 in CD4+ and CD8+ T cells of the same group. Abatacept did not influence chymotrypsin-like activity of proteasome and had no effect on induction of apoptosis under exposure to a proteasome inhibitor in vitro. Conclusion: The reduction of proteasome immunosubunit β1i in T cells of patients with RA with sustained response to abatacept suggests association of the immunoproteasome of T cells with RA disease activity

Use of line spectral frequencies for emotion recognition from speech

We propose the use of the line spectral frequency (LSF) features for emotion recognition from speech, which have not been been previously employed for emotion recognition to the best of our knowledge. Spectral features such as mel-scaled cepstral coefficients have already been successfully used for the parameterization of speech signals for emotion recognition. The LSF features also offer a spectral representation for speech, moreover they carry intrinsic information on the formant structure as well, which are related to the emotional state of the speaker. We use the Gaussian mixture model (GMM) classifier architecture, that captures the static color of the spectral features. Experimental studies performed over the Berlin Emotional Speech Database and the FAU Aibo Emotion Corpus demonstrate that decision fusion configurations with LSF features bring a consistent improvement over the MFCC based emotion classification rates.TUBİTAK ; Bahçeşehir University Research Fun

Link between Organ-specific Antigen Processing by 20S Proteasomes and CD8+ T Cell–mediated Autoimmunity

Adoptive transfer of cross-reactive HSP60-specific CD8+ T cells into immunodeficient mice causes autoimmune intestinal pathology restricted to the small intestine. We wondered whether local immunopathology induced by CD8+ T cells can be explained by tissue-specific differences in proteasome-mediated processing of major histocompatibility complex class I T cell epitopes. Our experiments demonstrate that 20S proteasomes of different organs display a characteristic composition of α and β chain subunits and produce distinct peptide fragments with respect to both quality and quantity. Digests of HSP60 polypeptides by 20S proteasomes show most efficient generation of the pathology related CD8+ T cell epitope in the small intestine. Further, we demonstrate that the organ-specific potential to produce defined T cell epitopes reflects quantities that are relevant for cytotoxic T lymphocyte recognition. We propose tissue-specific antigen processing by 20S proteasomes as a potential mechanism to control organ-specific immune responses

Development of Receivers for the DSG Process

The direct steam generation (DSG) in parabolic trough collectors is a promising option for improving the mature SEGS type parabolic trough solar thermal power plant technology. The European DISS and INDITEP projects have proven the feasibility of the DSG process in parabolic trough collectors under real solar conditions at the life size DISS test facility at the Plataforma Solar de Almería (PSA). Because of this successful demonstration the erection of the first DSG demonstration plant is expected for the near future. So far no commercial parabolic trough receivers, also known as heat collecting elements (HCE), are available for the DSG process. These receivers would have to withstand a higher operation pressure since the operation pressure of the receivers is equal to the life steam pressure of the power cycle which can be 100 bar and more. Furthermore the thermal load of the receivers is higher since the heat transfer in the superheating section of a DSG collector loop is worse than that of SEGS type collector loops. To solve this problem SCHOTT Rohrglas has decided to adapt their receivers to the specific needs of the DSG process. In collaboration with the German Aerospace Center (DLR) necessary modifications were identified and integrated into the design of the SCHOTT receiver. Prototypes of the receivers have been manufactured. The paper presents the design of the DSG receivers for the first time

Heat Loss Measurements on Parabolic Trough Receivers

A measurement set-up to determine the heat losses of single parabolic trough receiver components at steady state conditions has been developed at Schott. This paper describes the functionality of the set-up and a comparative campaign with three Schott receivers of 7.0, 8.9 and 11.1% emittance (400°C) including test stands at German Aerospace Center (DLR) and U.S. National Renewable Energy Laboratory (NREL). This campaign showed generally good agreement with deviations <10%. Additionally, results are compared to heat loss predictions derived from optical measurements of the absorber coating via a one-dimensional simulation. The general trend suggests good accordance with a systematical deviation at lower emissivities. Overall, this non destructive measurement technique provides a good possibility to determine an important receiver specification, its heat loss

Hydrogen generation in CSP plants and maintenance of DPO/BP heat transfer fluids – A simulation approach

The ageing of diphenyl oxide/ biphenyl (DPO/BP) Heat Transfer Fluids (HTFs) implies challenging tasks for operators of parabolic trough power plants in order to find the economic optimum between plant performance and O&M costs. Focusing on the generation of hydrogen, which is effecting from the HTF ageing process, the balance of hydrogen pressure in the HTF is simulated for different operation scenarios. Accelerated build-up of hydrogen pressure in the HTF is causing increased permeation into the annular vacuum space of the installed receivers and must be avoided in order to maintain the performance of these components. Therefore, the effective hydrogen partial pressure in the HTF has to be controlled and limited according to the specified values so that the vacuum lifetime of the receivers and the overall plant performance can be ensured. In order to simulate and visualize the hydrogen balance of a typical parabolic trough plant, initially a simple model is used to calculate the balance of hydrogen in the system and this is described. As input data for the simulation, extrapolated hydrogen generation rates have been used, which were calculated from results of lab tests performed by DLR in Cologne, Germany. Hourly weather data, surface temperatures of the tubing system calculated by using the simulation tool from NREL, and hydrogen permeation rates for stainless steel and carbon steel grades taken from literature have been added to the model. In a first step the effect of HTF ageing, build-up of hydrogen pressure in the HTF and hydrogen loss rates through piping and receiver components have been modeled. In a second step a selective hydrogen removal process has been added to the model. The simulation results are confirming the need of active monitoring and controlling the effective hydrogen partial pressure in parabolic trough solar thermal power plants with DPO/BP HTF. Following the results of the simulation, the expected plant performance can only be achieved over lifetime, if the hydrogen partial pressure is actively controlled and limited