Design and Commissioning of the MOUETTE Hybrid Rocket Slab Burner

This paper illustrates the design and development process of the MOUETTE (Moteur OptiqUe pour ÉTudier et Tester Ergols hybrides) optical access slab burner for investigation of the combustion behaviour of hybrid rocket fuels. The system has been conceived to use gaseous oxygen as oxidizer with a mass flow rate of up to 100 g/s and a maximum combustion chamber pressure of 10 bar. The test chamber features two quartz glass windows to acquire high-speed imaging of the fuel grain during the combustion process, and a graphite nozzle to adjust the operative pressure. The ignition of the solid fuel grain is provided by a pyrotechnic igniter. The burner, together with its feed system and test bench, has been manufactured and integrated. Leaking and proofing tests have been carried out, followed by ignition sequence tests to define the operating procedure. A validation campaign with a paraffin-based fuel has been carried out to verify the functionality of the system.info:eu-repo/semantics/publishe

Unravelling the Structural and Molecular Basis Responsible for the Anti-Biofilm Activity of Zosteric Acid.

The natural compound zosteric acid, or p-(sulfoxy)cinnamic acid (ZA), is proposed as an alternative biocide-free agent suitable for preventive or integrative anti-biofilm approaches. Despite its potential, the lack of information concerning the structural and molecular mechanism of action involved in its anti-biofilm activity has limited efforts to generate more potent anti-biofilm strategies. In this study a 43-member library of small molecules based on ZA scaffold diversity was designed and screened against Escherichia coli to understand the structural requirements necessary for biofilm inhibition at sub-lethal concentrations. Considerations concerning the relationship between structure and anti-biofilm activity revealed that i) the para-sulfoxy ester group is not needed to exploit the anti-biofilm activity of the molecule, it is the cinnamic acid scaffold that is responsible for anti-biofilm performance; ii) the anti-biofilm activity of ZA derivatives depends on the presence of a carboxylate anion and, consequently, on its hydrogen-donating ability; iii) the conjugated aromatic system is instrumental to the anti-biofilm activities of ZA and its analogues. Using a protein pull-down approach, combined with mass spectrometry, the herein-defined active structure of ZA was matrix-immobilized, and was proved to interact with the E. coli NADH:quinone reductase, WrbA, suggesting a possible role of this protein in the biofilm formation process

Bone marrow and haemathological evaluation of 62 xenografted cynomolgus monkeys

Background: Non-human primates (NHP) are used in pre-clinical studies, such as pig-to-NHP xenotransplantation. In this context, the evaluation of clinical-pathological data is essential for monitoring the post-transplantation period. Cytological examination of bone marrow (BM) is a helpful adjunct for a complete interpretation of haematological data. The aim of this work is to evaluate the cytology of BM and haematological data in immunosuppressed (IS) xenotransplanted NHP. Methods: Sixty-two xenografted NHP were included: 36 recipients of porcine renal xenograft (RX group) and 17 recipients of neuronal precursors (NPX group). Both groups received a maintenance immunosuppression with cyclosporine A, sodium mycophenolate and steroids. RX group received an induction therapy consistent of cyclophosphamide and/or GAS914, or rituximab, or IVIG or anti-CD154; NPX received cyclosporine A and GAS914. A complete CBC and femoral BM smears collected at euthanasia were obtained. BM cytological evaluation and differential counts of erythroid, granulocytic, megakaryocytic, lymphocytic and plasmacytic series were performed. The myeloid-to-erythroid ratio (M:E), the erythroid (E-MI) and myeloid (M-MI) maturation indices were calculated. Results: Compare to the reference range, 44 NHP showed an increased M:E ratio (>1.85) due to myeloid hyperplasia and erythroid hypoplasia. In 16 cases the M:E ratio was severely increased (>5.45). Both E-MI and M-MI were raised in 61 and 57 cases, respectively. The highest values of M:E and M-MI were recorded in the RX group. The main haemathological alterations observed were anemia (54/62 NHP), leucopenia (15/62) and lymphopenia (25/62). Cytoplasmatic and nuclear vacuolization, dysplastic changes in granulocytic and erythroid lineages were the main morphological alterations in BM probably due to toxic effects of IS therapy. In spite of IS therapy, xenografted NHP showed a myeloid hyperplasia, mainly in RX group probably due to the marked inflammatory status during acute rejection. Conclusions: The BM evaluation in xenografted IS NHP may provide the basis for a complete interpretation of hematological profiles and represent an important tool for a better design of IS strategies

Morphological and oxidative alterations on sertoli cells cytoskeleton due to retinol-induced reactive oxygen species

Retinol (vitamin A) is involved in several cellular processes, like cell division, differentiation, transformation and apoptosis. Although it has been shown that retinol is a limitant factor for all these processes, the precise mechanisms by which retinol acts are still unknown. In the present study we hypothesised that alterations in the cytoskeleton of Sertoli cells induced by retinol supplementation could indicate an adaptive maintenance of its functions, since it plays an important role in the transformation process that we observed. Previous results demonstrated that Sertoli cells treated with retinol showed an oxidative imbalance, that leads the cell to two phenotypes: apoptosis or transformation. Our group has identified characteristics of Sertoli cells transformed by retinol which results in normal cell functions modification. In the present study the actin filament fluorescence assay and the deformation coefficient showed a modification in the morphology induced by retinol. We also observed an oxidative alteration in isolated cytoskeleton proteins and did not show alterations when these proteins are analyzed by electrophoreses. Our results showed an increase in mitochondria superoxide production and a decrease in nitric oxide levels. All results were partially or completely reverted by co-treatment of the antioxidant Trolox®. These findings suggest that the cytoskeleton components suffer individual alterations in different levels and that these alterations generate a global phenotype modification and that these processes are probably ROS dependent. We believe that the results from this study indicate an adaptation of the cytoskeleton to oxidative imbalance since there was not a loss of its function

Synthetic scheme of compounds 23, 24, 33, 34, 35, 38.

<p>Reagents and conditions: i) from <b>1</b> for <b>23</b>, from <b>5</b> for <b>24</b>, from <b>32</b> for <b>33</b>: H₂SO₄, MeOH, reflux, 1 h; ii) from <b>32</b>: Py · SO₃, DMF dry, 120°C, 25 min; iii) CH₃I, anhydrous K₂CO₃, dry DMF, reflux, 1.5 h; iv) 1N NaOH, EtOH.</p

A Service of zbw Forecasting with instabilities: An application to DSGE models with financial frictions Forecasting with Instabilities: an Application to DSGE Models with Financial Frictions Forecasting with Instabilities: an Application to DSGE Models wi

Standard-Nutzungsbedingungen: Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden. Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich machen, vertreiben oder anderweitig nutzen. Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, gelten abweichend von diesen Nutzungsbedingungen die in der dort genannten Lizenz gewährten Nutzungsrechte. Terms of use: Documents in EconStor may Abstract This paper examines whether the presence of parameter instabilities in dynamic stochastic general equilibrium (DSGE) models affects their forecasting performance. We apply this analysis to medium-scale DSGE models with and without financial frictions for the US economy. Over the forecast period 2001-2013, the models augmented with financial frictions lead to an improvement in forecasts for inflation and the short term interest rate, while for GDP growth rate the performance depends on the horizon/period. We interpret this finding taking into account parameters instabilities. Fluctuation test shows that models with financial frictions outperform in forecasting inflation but not the GDP growth rate

Can electrons travel through actin microfilaments and generate oxidative stress in retinol treated Sertoli cell?

In early reports our research group has demonstrated that 7 μM retinol (vitamin A) treatment leads to many changes in Sertoli cell metabolism, such as up-regulation of antioxidant enzyme activities, increase in damage to biomolecules, abnormal cellular division, pre-neoplasic transformation, and cytoskeleton conformational changes. These effects were observed to be dependent on the production of reactive oxygen species (ROS), suggesting extra-nuclear (non-genomic) effects of retinol metabolism. Besides 7 μM retinol treatment causing oxidative stress, we have demonstrated that changes observed in cytoskeleton of Sertoli cells under these conditions were protective, and seem to be an adaptive phenomenon against a pro-oxidant environment resulting from retinol treatment. We have hypothesized that the cytoskeleton can conduct electrons through actin microfilaments, which would be a natural process necessary for cell homeostasis. In the present study we demonstrate results correlating retinol metabolism, actin architecture, mitochondria physiology and ROS, in order to demonstrate that the electron conduction through actin microfilaments might explain our results. We believe that electrons produced by retinol metabolism are dislocated through actin microfilaments to mitochondria, and are transferred to electron transport chain to produce water. When mitochondria capacity to receive electrons is overloaded, superoxide radical production is increased and the oxidative stress process starts. Our results suggested that actin cytoskeleton is essential to oxidative stress production induced by retinol treatment, and electrons conduction through actin microfilaments can be the key of this correlation

Fluorescence analysis of matrix functionalization.

<p>A) Emission spectrum (λ_exc 380 nm) of 5 mM <i>p</i>-ACA in 0.4 M NaHCO₃, 1 M NaCl (pH 8,3). B) Emission spectra (λ_exc 350 nm) of suspensions of <i>p</i>-ACA/matrix (50 μl, drained volume; solid line) and EA/matrix (50 μl, drained volume; dashed line) in 2 mL of 0.4 M NaHCO₃, 1 M NaCl (pH 8,3). A. U., arbitrary units.</p

Global anti-biofilm performance of ZA-related compounds and structures with the most significant anti-biofilm performance.

<p>Global anti-biofilm performance value of each ZA-related compound calculated as (sum of cell adhesion codes of all concentrations)-(sum of planktonic growth codes of all concentrations). Values equal to 0 were considered without anti-biofilm performance, below 0 were considered globally able to exert an anti-biofilm activity, and above 0 were considered able to improve biofilm performance. Yellow: no anti-biofilm performance; Light orange: little anti-biofilm performance; Medium orange: moderate anti-biofilm performace; Dark orange: optimal anti-biofilm performance; Light green: little improvement of anti-biofilm performance; Medium green: moderate improvement of anti-biofilm performance; Dark green: optimal improvement of anti-biofilm performance.</p