EFFECTS OF SUPPORT STRUCTURE DYNAMICS ON CENTRIFUGAL COMPRESSOR ROTOR RESPONSE

LectureAccurate modeling of complicated dynamic phenomena characterizing rotating machineries represents a critical aspect in the rotor dynamic field. A correct prediction of rotor behavior is fundamental to identify safe operating conditions avoiding unstable operating range that may lead to erroneous project solution or possible unwanted consequences for the plant. Considering generic rotating machineries as mainly partitioned in four components (rotors, bearings, stator and supporting structure), most research activities have been addressed so far with strong focus more on the single components rather than on the whole system assembly. The importance of a combined analysis of rotors and elastic supporting structure (Kruger 2013) arises with the continuous development of turbo machinery applications, in particular in the Oil & Gas field, where a wide variety of solutions, such as off-shore installations or modularized turbo compression and turbo generator trains, lead to the need of a more complete study not only limited to the rotor-bearing system

EFFECTS OF SUPPORT STRUCTURE DYNAMICS ON CENTRIFUGAL COMPRESSOR ROTOR RESPONSE

LectureAccurate modeling of complicated dynamic phenomena characterizing rotating machineries represents a critical aspect in the rotor dynamic field. A correct prediction of rotor behavior is fundamental to identify safe operating conditions avoiding unstable operating range that may lead to erroneous project solution or possible unwanted consequences for the plant. Considering generic rotating machineries as mainly partitioned in four components (rotors, bearings, stator and supporting structure), most research activities have been addressed so far with strong focus more on the single components rather than on the whole system assembly. The importance of a combined analysis of rotors and elastic supporting structure (Kruger 2013) arises with the continuous development of turbo machinery applications, in particular in the Oil & Gas field, where a wide variety of solutions, such as off-shore installations or modularized turbo compression and turbo generator trains, lead to the need of a more complete study not only limited to the rotor-bearing system

Heritage Machine

Heritage Machine is an architectural project based on the conceptual approach of building ephemeral placemaking that dissolves back into nature as ruins over time. The ideas of physical memory, and an original approach to sustainability and building life cycle are the ground themes of the project. Physically, the gradual transition from the exterior to the interior world through a series of thresholds, and the grand roof canopy of the common hub large enough to form its own microclimate, are low-tech architectural gestures that respond to local environmental constraints of the desert between Dubai and Abu Dhabi

Detection of mesenchymal stem cells senescence by prelamin A accumulation at the nuclear level

Background: Human mesenchymal stem cells (MSC), during in vitro expansion, undergo a progressive loss of proliferative potential that leads to the senescent state, associated with a reduction of their \u201cmedicinal\u201d properties. This may hampers their efficacy in the treatment of injured tissues. Quality controls on MSC-based cell therapy products should include an assessment of the senescent state. However, a reliable and specific marker is still missing. From studies on lamin-associated disorders, has emerged the correlation between defective lamin A maturation and cellular senescence. Findings: Primary cultured hMSC lines (n\ua0=\ua03), were analyzed by immunostaining at different life-span stages for the accumulation of prelamin A, along with other markers of cellular senescence. During culture, cells at the last stage of their life span displayed evident signs of senescence consistent with the positivity of SA-\u3b2-gal staining. We also observed a significant increase of prelamin A positive cells. Furthermore, we verified that the cells marked by prelamin A were also positive for p21Waf1 while negative for Ki67. Conclusions: Overall data support that the detection of prelamin A identifies senescent MSC, providing an easy and reliable tool to be use alone or in combination with known senescence markers to screen MSC before their use in clinical applications

Treatment of FANCA cells with resveratrol and N-acetylcysteine: a comparative study.

Fanconi anemia (FA) is a genetic disorder characterised by chromosome instability, cytokine ipersensibility, bone marrow failure and abnormal haematopoiesis associated with acute myelogenous leukemia. Recent reports are contributing to characterize the peculiar FA metabolism. Central to these considerations appears that cells from complementation group A (FANCA) display an altered red-ox metabolism. Consequently the possibility to improve FA phenotypical conditions with antioxidants is considered. We have characterized from the structural and biochemical point of view the response of FANCA lymphocytes to N-acetyl-cysteine (NAC) and resveratrol (RV). Surprisingly both NAC and RV failed to revert all the characteristic of FA phenotype and moreover their effects are not super imposable. Our data suggest that we must be aware of the biological effects coming from antioxidant treatment

Altered Mitochondrial Dynamic in Lymphoblasts and Fibroblasts Mutated for <i>FANCA-A</i> Gene: The Central Role of DRP1

Fanconi anemia (FA) is a rare genetic disorder characterized by bone marrow failure and aplastic anemia. So far, 23 genes are involved in this pathology, and their mutations lead to a defect in DNA repair. In recent years, it has been observed that FA cells also display mitochondrial metabolism defects, causing an accumulation of intracellular lipids and oxidative damage. However, the molecular mechanisms involved in the metabolic alterations have not yet been elucidated. In this work, by using lymphoblasts and fibroblasts mutated for the FANC-A gene, oxidative phosphorylation (OxPhos) and mitochondria dynamics markers expression was analyzed. Results show that the metabolic defect does not depend on an altered expression of the proteins involved in OxPhos. However, FA cells are characterized by increased uncoupling protein UCP2 expression. FANC-A mutation is also associated with DRP1 overexpression that causes an imbalance in the mitochondrial dynamic toward fission and lower expression of Parkin and Beclin1. Treatment with P110, a specific inhibitor of DRP1, shows a partial mitochondrial function recovery and the decrement of DRP1 and UCP2 expression, suggesting a pivotal role of the mitochondrial dynamics in the etiopathology of Fanconi anemia

Biochemical parameters in FANCA and wild-type (wt) cells untreated or treated with 500 µm nac or 10 µm rv for 5 days.

<p>A. Table reports values for oxygen consumption (µM O₂/min/mg) in FANCA and wild type (wt) primary fibroblasts treated NAC or RV after induction with pyruvate/malate (Complexes I, III and IV), or succinate (Complexes II+III+IV). B. Assay of the electron transfer from Complex I to Complex III on wt and FANCA samples. Electron transfer between Complex I and III was measured following the reduction of cytochrome c at 550 nm after the addition of 0.7 mM NADH, the substrate of Complex I. Data are reported as µmol reduced Cytochrome c/min/mg. C. Figure shows the ratio among ATP and AMP concentration in wt and FANCA samples. D. Histogram reports a comparison of the ATP-AMP phosphotransferase activity (AK1+AK2 white columns) and GTP-AMP phosphotransferase (AK3, black columns) activity on wt and FANCA samples. The activity is expressed as µmol of ADP produced/min/mg. Data are expressed as mean ± SD. Each panel is representative of at least five experiments.</p

Morphological changes of mitochondria in FANCA lymphocytes and healthy controls.

<p><b>A.</b> Representative transmission electron microscopy images of morphologically altered mitochondria from untreated (a,c,e,g) and treated FANCA (b,d,f,h,i) with different antioxidants. Mitochondria of untreated lymphocytes from FANCA patients 1, 2, 3 (a,c,e) appeared swollen (black arrows) with increased size, disrupted cristae (black asterisks) and rarefacted matrix (black arrowheads). On the contrary, mitochondria in untreated lymphocytes from FANCA4 patient were small, oval and round with dark matrix and swollen internal cristae (black stars). (b) Mitochondria of FA1 lymphocytes showed worsened alteration such as more enlarged shape (white arrow) after NAC treatment. (d) Mitochondria of FANCA2 lymphocytes appeared indistinguishable from untreated (b) in overall aspect, after NAC treatment (white arrowheads). (f) Mitochondria of FANCA3 and FANCA4 lymphocytes showed a striking rescue after NAC or RV treatments (white asterisks). (Scale bars, 1 µm) <b>B.</b> Representative micrographs of morphologically normal mitochondria (arrowheads) in control lymphocytes at day 1 and day 5 before and after NAC or RV treatments. (Scale bars 1µm).</p