Pituitary hyperplasia mimicking macroadenoma associated with primary hypothyroidism in a patient with selective L-thyroxine malabsorption

We present the case of a 29-year-old woman who developed a severe hypothyroidism induced by a thyroxine malabsorption and a secondary pituitary hyperplasia. We performed thyroxine absorption tests to diagnose the malabsorption and to evaluate the best therapeutic intervention. Once assessed a correct therapy lowering TSH, we observed the regression of pituitary mass confirming our diagnosis of secondary pituitary hyperplasia. We suggest to evaluate any possible reason for thyroxine malabsorption and to consider the hypothesis of pituitary hyperplasia in the presence of pituitary mass together with overt hypothyroidism

Pituitary hyperplasia mimicking macroadenoma associated with primary hypothyroidism in a patient with selective L-thyroxine malabsorption

We present the case of a 29-year-old woman who developed a severe hypothyroidism induced by a thyroxine malabsorption and a secondary pituitary hyperplasia. We performed thyroxine absorption tests to diagnose the malabsorption and to evaluate the best therapeutic intervention. Once assessed a correct therapy lowering TSH, we observed the regression of pituitary mass confirming our diagnosis of secondary pituitary hyperplasia. We suggest to evaluate any possible reason for thyroxine malabsorption and to consider the hypothesis of pituitary hyperplasia in the presence of pituitary mass together with overt hypothyroidism

Development Of A High Pressure Rotordynamic Test Rig For Centrifugal Compressors Internal Seals Characterization

Lecturepg. 46-59The current centrifugal compressor design for the Oil & Gas market is more and more challenging since the cost requirements and the presence of many competitors is pushing towards casing size reduction and rotational speed increase. The first requirement basically leads to increase the number of wheels per rotor and the second to cross more critical speeds requiring the proper degree of damping. The two consequences together lead also to increase the rotor flexibility ratio (defined as the ratio between the Maximum Continuous Speed and the first critical speed as per the Fulton diagram and API617 7th ed. [1-2]) and finally the rotordynamic stability is very much challenged. The centrifugal compressors rotordynamic stability is then strictly related to the internal seals’ dynamic behaviour and for this reason the authors’ Company decided several years ago to develop internally a High Pressure Seal Test Rig to measure seals’ stiffness and damping. The rig is now in operation. This paper aims to describe the main test rig capabilities, the applied identification procedures and the preliminary test results on a long labyrinth seal (smooth rotor - straight toothed stator). Due to the pressure level (500bar design pressure), the test rig plant appears like a high-pressure industrial plant equipped with the testing cell (a 1:1 scale high pressure compressor) and all the relevant auxiliaries: a 400 kW electric motor (driven by a VFD), a speed increaser gear box, a high pressure reservoir (6 m 3 ) with a volumetric compressor to fill it, high pressure pipes and valves. The testing cell is composed of a high-pressure compressor casing with stator parts capable to regulate the seal inlet swirl and a rotor running on Active Magnetic Bearings (AMBs), which serve as exciters (5kN MAX Force over a 0-330 Hz frequency range per axis) and displacement transducers. Special instrumentation is installed into the testing cell in order to measure the main test parameters: seal upstream/downstream gas pressure, upstream temperature and swirl and mass flow. Industrial high-pressure instrumentation is installed on the plant for regulation and monitoring purpose. Maximum test pressure is 350bar and maximum rotational speed is 15000rpm. Test gas is nitrogen. The AMBs control-system capabilities have been tuned to define several alternative excitation patterns and the relevant state of the art identification techniques have been applied. The first seal tested is a long labyrinth seal to simulate a centrifugal compressor balance piston seal. Test results and comparison with a commercial bulk flow code predictions will be fully described. Finally, the future test program will be showed

Sviluppo e validazione sperimentale del sistema di identificazione dei coefficienti dinamici delle tenute interne per compressori centrifughi

Il lavoro di tesi è stato sviluppato nell’ambito di un tirocinio svoltosi presso il Nuovo Pignone S.p.A. di Firenze, azienda facente parte del gruppo General Electric (GE), leader mondiale nella progettazione, costruzione ed installazione di turbomacchine per il business Oil&Gas. L’attività è stata svolta nel reparto di ricerca e sviluppo AT/OGTL (Advanced Technology, Oil&Gas Tecnology Laboratory) della GE Oil&Gas. Oggetto di questa tesi è l’identificazione sperimentale dei coefficienti dinamici di tenute a labirinto utilizzando il banco prova sviluppato internamente da GE Oil & Gas, denominato “Ultra High Pressure Seal Test Rig”, per misurare la rigidezza e lo smorzamento delle tenute interne di compressori centrifughi ad alte prestazioni. L’attività di ricerca si è quindi così articolata: •Studio dei criteri di progettazione per compressori centrifughi, con particolare riferimento alla gestione dei fenomeni di instabilità originati dalla presenza di sistemi di tenuta. •Studio dei sistemi, delle attrezzature, delle metodologie di misura e delle macchine utilizzate per l'esecuzione delle verifiche sperimentali volte a validare i modelli di calcolo teorici. •Sviluppo, implementazione e validazione di una metodologia di identificazione dei coefficienti dinamici con implementazione di metodi per lo studio della propagazione dell’errore al fine di stimare le incertezze. •Pianificazione ed esecuzione delle prove sperimentali. •Analisi dei risultati sperimentali e confronto con risultati ottenuti tramite software di design. •Studio di sensibilità dei dati sperimentali alle diverse condizioni di test e verifica delle ipotesi del modello teorico. •Conclusioni e sviluppi futuri

Conservation and pastoral value of former arable lands in the agro-pastoral system of the Alta Murgia National Park (Southern Italy)

Grasslands are an important element of European landscapes and environment. In the last decades, several causes have contributed to their decline, among which the intensification of agriculture activities. The National Park of Alta Murgia represents a typical agro-pastoral karst system where the conversion to arable lands caused a drastic decline of semi-natural rocky grasslands of high naturalistic value that traditionally were used for sheep grazing. This change of land use created much concern about the lack of biodiversity and soil degradation. Thus, the Park Authority promotes reconversions of arable lands into grasslands to safeguard biodiversity, increase pastoralism and enhance the multi-functionality of farms. This study evaluates the conservation and pastoral value of plant communities in former arable lands derived from grasslands conversion (by crushing the rocky substrate) and subsequently abandoned. We selected seven sites of these abandoned arable lands, no longer ploughed or sown for three to five or twelve to fifteen years. In order to have a comparison with situations of low anthropic pressures, other five sites were selected in nearby natural rocky grasslands, without evidence of soil disturbance. Further two sites were selected in lands manually cleared from stones and taken out of crop production for more than fifty years. Vegetation samples were carried out according to the standard phytosociological method. Shannon and Richness indexes, ecological and phytogeographical quality and pastoral value were calculated. The ecological quality was calculated through the ratio between cover of diagnostic taxa of the higher syntaxonomic units characterising the undisturbed pastures and total cover. The phytogeographical value was evaluated considering the cover of endemic, sub-endemic and rare taxa out of the total cover value of each plant sample. For the calculation of pastoral value we considered the palatability of taxa on a scale ranging from 0 to 5 according to data found in scientific literature. From a conservation perspective, sites originated from the conversion of rocky pastures by crushing of the rocky surface showed marked differences from undisturbed grasslands, even after 15 years from abandonment. Lands manually cleared and abandoned for more than fifty years did not show appreciable differences from semi-natural grasslands, conserving many taxa of high conservation value. On the other hand, fields originated from grasslands conversion showed higher pastoral value. This paper emphasises the need for safeguarding the rocky substrates and their remnant typical grassland communities, even in the so-called quote. Results are useful for the sustainable management of the agro-pastoral system of Alta Murgia, taking into account the ecological and economic role of those lands whose rocky substrate had been crushed

<i>Camelina sativa</i> (L. Crantz) Fresh Forage Productive Performance and Quality at Different Vegetative Stages: Effects of Dietary Supplementation in Ionica Goats on Milk Quality

The research meant to study the productive performances of Camelina sativa and the effects of feeding Camelina fresh forage harvested during five phenological stages (I: main stem elongation; II: maximum stem elongation: III: inflorescence appearance; IV: flowering; V: fruit set visible) on the yield, chemical composition and fatty acid profile of milk from autochthonous Ionica goats. Goats were randomly assigned to two groups (n = 15) that received a traditional forage mixture (Control) or Camelina forage harvested at different stages (CAM). The field experiment was conducted in two years; no significant differences between years were recorded for any of the Camelina production traits. The total biomass increased (p Camelina sativa is a multi-purpose crop that may be successfully cultivated in Southern Italy regions and used as fresh forage for goat feeding. Milk obtained from Camelina fed goats showed satisfactory chemical and fatty acid composition, with potential benefits for human health

Characterisation of lipid fraction of marine macroalgae by means of chromatography techniques coupled to mass spectrometry

In this work the characterisation of the lipid fraction of several species of marine macro algae gathered along the eastern coast of Sicily is reported. Two species of green marine algae (Chloropyceae), two species of red marine algae (Rhodophyceae) and four species of brown marine algae (Pheophyceae) were evaluated in terms of fatty acids, triacylglycerols, pigments and phospholipids profile. Advanced analytical techniques were employed to fully characterise the lipid profile of these Mediterranean seaweeds, such as GC-MS coupled to a novel mass spectra database supported by the simultaneous use of linear retention index (LRI) for the identification of fatty acid profile; LC-MS was employed for the identification of triacylglycerols (TAGs), carotenoids and phospholipids; the determination of accurate mass was carried out on carotenoids and phospholipids. Quantitative data are reported on fatty acids and triacylglycerols as relative percentage of total fraction. © 2013 Elsevier Ltd. All rights reserved