Thyroid-specific transcription factors control Hex promoter activity

The homeobox-containing gene Hex is expressed in several cell types, including thyroid follicular cells, in which it regulates the transcription of tissue-specific genes. In this study the regulation of Hex promoter activity was investigated. Using co-transfection experiments, we demonstrated that the transcriptional activity of the Hex gene promoter in rat thyroid FRTL-5 cells is ∼10-fold greater than that observed in HeLa and NIH 3T3 cell lines (which do not normally express the Hex gene). To identify the molecular mechanisms underlying these differences, we evaluated the effect of the thyroid-specific transcription factor TTF-1 on the Hex promoter activity. TTF-1 produced 3-4-fold increases in the Hex promoter activity. Gel-retardation assays and mutagenesis experiments revealed the presence of functionally relevant TTF-1 binding sites in the Hex promoter region. These in vitro data may also have functional relevance in vivo, since a positive correlation between TTF-1 and Hex mRNAs was demonstrated in human thyroid tissues by means of RT-PCR analysis. The TTF-1 effect, however, is not sufficient to explain the difference in Hex promoter activity between FRTL-5 and cells that do not express the Hex gene. For this reason, we tested whether Hex protein is able to activate the Hex promoter. Indeed, co-transfection experiments indicate that Hex protein is able to increase the activity of its own promoter in HeLa cells ∼4-fold. TTF-1 and Hex effects are additive: when transfected together in HeLa cells, the Hex promoter activity is increased 6-7-fold. Thus, the contemporary presence of both TTF-1 and Hex could be sufficient to explain the higher transcriptional activity of the Hex promoter in thyroid cells with respect to cell lines that do not express the Hex gene. These findings demonstrate the existence of direct cross-regulation between thyroid-specific transcription factors

Effect of the Austempering Process on the Microstructure and Mechanical Properties of 27MnCrB5-2 Steel

AbstractThe effect of austempering parameters on the microstructure and mechanical properties of 27MnCrB5-2 steel has been investigated by means of: dilatometric, microstructural and fractographic analyses; tensile and Charpy V-notch (CVN) impact tests at room temperature and a low temperature.Microstructural analyses showed that upper bainite developed at a higher austempering temperature, while a mixed bainitic-martensitic microstructure formed at lower temperatures, with a different amount of bainite and martensite and a different size of bainite sheaf depending on the temperature. Tensile tests highlighted superior yield and tensile strengths (≈30%) for the mixed microstructure, with respect to both fully bainitic and Q&T microstructures, with only a low reduction in elongation to failure (≈10%). Impact tests confirmed that mixed microstructures have higher impact properties, at both room temperature and a low temperature

Holonomic quantum computation with neutral atoms

We propose an all-geometric implementation of quantum computation using neutral atoms in cavity QED. We show how to perform generic single- and two-qubit gates, the latter by encoding a two-atom state onto a single, many-level atom. We compare different strategies to overcome limitations due to cavity imperfections.Comment: 14 pages, 9 figure

Studio del processo di macinazione meccanica di un acciaio per lavorazioni a caldo

Gli acciai per lavorazioni a caldo sono caratterizzati da buona tenacità ed elevata durezza a caldo.La metallurgia delle polveri, grazie alla produzione di materiali con microstruttura più fine,consente di migliorare entrambe queste caratteristiche. In questo lavoro, una polvere di AISI H13atomizzata in gas è stata macinata meccanicamente in modo da ridurre sia la dimensione delleparticelle che la dimensione della grana cristallina. I risultati mostrano che dopo 1000 minuti dimacinazione in un mulino planetario a sfere la dimensione del grano può essere ridotta in modosignificativo fino a 15nm. L’elevato grado di deformazione introdotto nelle particelle attiva ilprocesso di sinterizzazione e di conseguenza la polvere può essere sinterizzata a temperature e pertempi inferiori. Per produrre campioni ad alta densità e per mantenere la dimensione della granafine (<1?m) la polvere è stata sinterizzata tramite Spark Plasma Sintering. La microstruttura e ladurezza dei campioni prodotti da polvere macinata sono state investigate e confrontate con quelle diun materiale prodotto con polvere atomizzata

Optical Holonomic Quantum Computer

In this paper the idea of holonomic quantum computation is realized within quantum optics. In a non-linear Kerr medium the degenerate states of laser beams are interpreted as qubits. Displacing devices, squeezing devices and interferometers provide the classical control parameter space where the adiabatic loops are performed. This results into logical gates acting on the states of the combined degenerate subspaces of the lasers, producing any one qubit rotations and interactions between any two qubits. Issues such as universality, complexity and scalability are addressed and several steps are taken towards the physical implementation of this model.Comment: 16 pages, 3 figures, REVTE

A theoretical scheme for generation of Gazeau-Klauder coherent states via intensity-dependent degenerate Raman interaction

A theoretical scheme is presented for generating Gazeau-Klauder coherent states(GKCSs) via the generalization of degenerate Raman interaction with coupling constant to intensity-dependent coupling. Firstly, we prove that in the intensity-dependent degenerate Raman interaction, under particular conditions, the modified efective Hamiltonian can be used instead of Hamiltonian in the interaction picture, for describing the atom-field interaction. We suppose that the cavity field is initially prepared in a nonlinear CS, which is not temporally stable. As we will observe, after the occurrence of the interaction between atom and field, the generated state involves a superposition of GKCSs which are temporally stable and initial nonlinear CS. Under specific conditions which may be prepared, the generated state just includes GKCS. So, in this way we produced the GKCS, successfully.Comment: 12 pages, 1 figures, Optics Communications, Article in Pres

The Bougainvillea mealybug Phenacoccus peruvianus, a rapid invader from South America to Europe

Τα κοκκοειδή έντομα εμφανίζονται συχνά ως εισβολείς σε νέες περιοχές. Το είδος Phenacoccus peruvianus Granara de Willink, 2007, γνωστό και ως ψευδόκοκκος της βουκαμβίλιας παρατηρήθηκε για πρώτη φορά στην Ευρώπη το 1999 στην Ισπανία (Αλμερία) και αργότερα το 2002 στην Ιταλία (Σικελία). Αρχικά το είδος είχε αναγνωριστεί ως Phenacoccus sp. Κατα- γραφές του είδους έγιναν συχνότερες και σε άλλες περιοχές της Ισπανίας (συμπεριλαμβανομέ- νων και των Βελεαρίδων νήσων), στη Μ. Βρετανία, τη Γαλλία (συμπεριλαμβανομένης και της Κορσικής), το Μονακό και την Πορτογαλία. Τα φυτά ξενιστές ήταν στις περισσότερες περι- πτώσεις του γένους Bougainvillea.Scale insects are frequent invaders of new territories. The Bougainvillea mealybug, Phenacoccus peruvianus Granara de Willink, 2007, was recorded in Europe for the first time in 1999 in Spain (Almeria) and later in 2002 in Italy (Sicily). Initially, this unknown species was identified provisionally as Phenacoccus sp. Records of this species became frequent later when it was found in other localities in Spain (including the Balearic Islands), Great Britain, France (including Corsica), Monaco, and Portugal. The host plants of this mealybug were in most cases species of Bougainvillea

Cavity QED with Diamond Nanocrystals and Silica Microspheres

Normal mode splitting is observed in a cavity QED system, in which nitrogen vacancy centers in diamond nanocrystals are coupled to whispering gallery modes in a silica microsphere. The composite nanocrystal-microsphere system takes advantage of the exceptional spin properties of nitrogen vacancy centers as well as the ultra high quality factor of silica microspheres. The observation of the normal mode splitting indicates that the dipole optical interaction between the relevant nitrogen vacancy center and whispering gallery mode has reached the strong coupling regime of cavity QED

Thermal fatigue properties of laser treated steels

This paper presents the thermal fatigue resistance of laser treated steels. The C40 and AISI H13 steels were machined into a geometry which allowed thermal gradients on the inner and outer surface during testing. A CO2 laser system was used with a focused spot size of 0.09 mm on the sample surface. The laser peak power and pulse repetition frequency (PRF) range were set to 760 and 1515 W, and 2900 to 3500 Hz respectively. The thermal fatigue machine used consists of Nabertherm model cylindrical high temperature furnace with digital control panel, controlled temperature quenching system, and pneumatics control sample movement mechanism. The thermal fatigue test involved immersion of samples into molten aluminium, and quenched in ionised water emulsion at 17°C temperature. The quenching system equipped with thermocouple to control the water temperature. Testing was done at a total of 1,750 number of cycles. Internal surface cooling was controlled by water inlet and outlet tubes. Samples were cleaned using NaOH solution after thermal fatigue testing to remove oxides on the surface. The solution temperature and magnetic stirrer speed were set to 100°C and 4.5 rpm respectively. Samples were characterised using scanning electron microscope (SEM), energy discharge x-ray spectroscopy (EDXS) and 2D stylus profilometer. Presence of different phases on the sample surface were analysed from back-scattered detector micrographs. Heat checks were observed on laser glazed surface at several regions. Carbides and oxides elements were detected on the sample surface after the thermal fatigue test. The relationship between surface roughness of laser treated surface and thermal fatigue behaviour was investigated