668 research outputs found
High resolution medium energy ion scattering (MEIS) analysis for the quantitative depth profiling of ultra thin high-k layers
No full textUltrathin high-k layers such as hafnium oxide (HfO2) in combination with a subnanometer SiO2 or Hf silicate have emerged as Si compatible gate dielectric materials. Medium energy ion scattering (MEIS) analysis has been carried out on a range of such metal oxide chemical vapor deposition grown HfO2/SiO2 and HfSiOx(60%Hf)/SiO2 gate oxide films of thickness between 1 and 2 nm on Si(100), before and after decoupled plasma nitridation (DPN). The ability of MEIS in combination with energy spectrum simulation to provide quantitative layer information with subnanometer resolution is illustrated and the effect of the DPN process is shown. Excellent agreement on the deduced layer structures and atomic composition with the as grown layer parameters, as well as with those obtained from cross section electron microscopy and other studies, is demonstrated. MEIS analysis of a high-k, metal gate TiN/Al2O3/HfO2/SiO2/Si stack shows the interdiffusion, after thermal treatment, of Hf and Al from the caplayer, inserted to modify the metal gate workfunction
High Resolution Depth Profile Analysis of Ultra Thin High-κ Hf Based Films Using MEIS Compared with XTEM, XRF, SE and XPS
No full textNanometre thin high-k hafnium oxide (HfO2) layers combined with a sub-nm SiO2 layers or Hf silicate have become Si compatible gate dielectrics. Medium energy ion scattering (MEIS) analysis has been applied to a range of such MOCVD grown HfO2/SiO2 and HfSiOx(60%Hf)/SiO2 gate oxide films of thickness between 1 and 2 nm on top of Si(100), before and after decoupled plasma nitridation (DPN). MEIS in combination with energy spectrum simulation provides quantitative layer information with sub-nm resolution on these layer structures and their atomic composition that is in excellent agreement with a) the as grown layer parameters and b) results obtained from techniques, such as SE, XPS, XRF and XTEM. MEIS analysis of a metal gate, high-k TiN/Al2O3/HfO2/SiO2/Si stack shows the interdiffusion, after thermal treatment, of Hf and Al from the caplayer, which was inserted to modify the metal gate work function
Non licet stare caelestibus. Studies on Astronomy and Its History Offered to Salvo De Meis
No full textThe present volume collects a series of studies presented to Salvatore De Meis as an homage in his honour by an international Group of distinguished scholars
Modulation of a CA2+-dependent K+ current by intracellular cAMP in rat thalamocortical relay neurons.
No full textVoltage-activated calcium channels in thalamic neurons are considered important elements in the generation of thalamocortical burst firing during periods of electroencephalographic synchronization. A potent counterpart of calcium-mediated depolarization may reside in the activation of calcium-dependent potassium conductances. In the present study, thalamocortical relay cells that were acutely disso-ciated from the rat ventrobasal thalamic complex (VB) were studied using whole-cell patch-clamp techniques. The calcium-dependent potassium-current (IK(Ca)) was evident as a slowly activating component of outward current sensitive to the calcium ions (Ca2+)-channel blocker methoxyverapamil (10 μM) and to substitution of external calcium by manganese. The IK(Ca) was blocked by tetraethylam-monium chloride (1 mM) and iberiotoxin (100 nM), but not apamin (1 μM). In addition, isolated VB neurons were immunopositive to anti-α(913–926) antibody, a sequence-directed antibody to the a-subunit of “big” Ca2+-dependent K+-channel (BKCa) channels. Activators of the adenylyl cyclase cyclic adenosine monophosphate (cAMP) system, such as forskolin (20 μM), dibutyryl-cAMP (10 mM) and 3-isobutyl-1 -methylxanthine (500 μM), selectively and reversibly suppressed IK(Ca). These results suggest that a rise in intracellular cAMP level leads to a decrease in a calcium-dependent potassium conductance presumably mediated via BKCa type channels, thereby providing an additional mechanism by which neurotransmitter systems are able to control electrogenic activity in thalamocortical neurons and circuits during various states of electroencephalographic synchronization and de-synchronization
Axial skeleton anterior-posterior patterning is regulated through feedback regulation between Meis transcription factors and retinoic acid.
No full textVertebrate axial skeletal patterning is controlled by co-linear expression of Hox genes and axial level-dependent activity of HOX protein combinations. MEIS transcription factors act as co-factors of HOX proteins and profusely bind to Hox complex DNA; however, their roles in mammalian axial patterning remain unknown. Retinoic acid (RA) is known to regulate axial skeletal element identity through the transcriptional activity of its receptors; however, whether this role is related to MEIS/HOX activity remains unknown. Here, we study the role of Meis in axial skeleton formation and its relationship to the RA pathway in mice. Meis elimination in the paraxial mesoderm produces anterior homeotic transformations and rib mis-patterning associated to alterations of the hypaxial myotome. Although Raldh2 and Meis positively regulate each other, Raldh2 elimination largely recapitulates the defects associated with Meis deficiency, and Meis overexpression rescues the axial skeletal defects in Raldh2 mutants. We propose a Meis-RA-positive feedback loop, the output of which is Meis levels, that is essential to establish anterior-posterior identities and patterning of the vertebrate axial skeleton.This research was supported by the Ministerio de Ciencia, Innovación y Universidades (PGC2018-096486-B-I00), the Instituto de Salud Carlos III (RD16/ 0011/0019) and by the Comunidad de Madrid (S2017/BMD3875). The Centro Nacional de Investigaciones Cardiovasculares Carlos III is supported by the Ministerio de Ciencia, Innovación y Universidades and the Pro Centro Nacional de Investigaciones Cardiovasculares Carlos III Foundation, and is a Severo Ochoa Center of Excellence (SEV-2015-0505). A.C.L.-D. was the recipient of a Formación Personal Investigador fellowship from the Ministerio de Economı́a y Competitividad (BES-2013-064374).S
Ceramic Membranes for the Separation of Plasma Enhancement Gases
No full textLow and medium Z impurity seeding gases, or plasma enhancement gases (PEGs) will be injected into the plasma of a Tokamak to convert the plasma thermal energy to ultraviolet and soft X-ray radiation. Possible PEGs are nitrogen, neon, argon, xenon and other inert gases. for the exhaust processing system of the demonstration fusion reactor (DEMO), the use of inorganic membranes was recently taken into consideration. Two commercial ceramic membranes (produced by Atech Innovations GmbH, Germany) were tested at a permeation apparatus built at ENEA Casaccia laboratories. Single gas permeances for H2, He, Ar and N2 were measured with a pressure drop across the membranes between 10 Pa up to 130 kPa at room temperature. For both membranes the permeance order follows the Knudsen regime. The Knudsen permeance measured for the two membranes are on the order of 10−7–10−8. The selectivities found are low (similar to ideal Knudsen). © 2018, Springer Fachmedien Wiesbaden GmbH, part of Springer Nature
Artes de viver :: recriando e reinventando espaços - memórias das famílias da Vila Operária mineira Próspera Criciúma (1945/1961) /
No full textDissertação (Mestrado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas
To Salvo
No full textThe present volume collects a series of studies presented to Salvatore De Meis as an homage in his honour by an international Group of distinguished scholars. Presentation of the Volume and of the scientific activity of Salvo De Meis
MEIS and PBX homeobox proteins in ovarian cancer
No full textThree amino-acid loop extension (TALE) homeobox proteins MEIS and PBX are cofactors for HOX-class homeobox proteins, which control growth and differentiation during embryogenesis and homeostasis. We showed that MEIS and PBX expression are related to cisplatin resistance in ovarian cancer cell lines. Therefore, MEIS1, MEIS2 and PBX expression were investigated immunohistochemically in a tissue microarray (N=232) of ovarian cancers and ovarian surface epithelium (N=15). Results were related to clinicopathologic characteristics and survival. All cancers expressed MEIS1, MEIS2 and PBX in nucleus and cytoplasm. MEIS1 and 2 only stained nuclear in surface epithelium. Nuclear MEIS2 was negatively related to stage, grade and overall survival in univariate analyses. Additionally, MEIS and PBX RNA expression in ovarian surface epithelium and other normal tissues and ovarian cancer versus other tumour types using public array data sets were studied. In ovarian cancer, MEIS1 is highly expressed compared to other cancer types. In conclusion, MEIS and PBX are extensively expressed in ovarian carcinomas and may play a role in ovarian carcinogenesis
I Pronostici di Domenico Maria da Novara
No full textNegli approfonditi studi che si sono susseguiti nel corso dei secoli sull’opera di Copernico e nelle ampie discussioni che questi studi hanno sollevato, molti si sono occupati di colui che fu il suo professore di astronomia nello Studium universitario di Bologna, il Magister Dominicus Maria Ferrariensis de Novaria, Doctor in almo ac inclyto Studio Bononiesi, come egli stesso usava firmarsi.
Gli unici scritti noti del Novara sono i Pronostici astronomico-astrologici che egli redigeva ogni anno, come gli imponeva il suo contratto da professore di astronomia con lo Studio bolognese. Del totale di una quarantina di Pronostici che egli avrebbe dovuto redigere, per ognuno degli anni del suo insegnamento, in volgare e in latino, alla metà degli anni Cinquanta del Novecento se ne conoscevano appena nove e già alla fine del XVI secolo Giovanni Antonio Magini, anch’egli professore di astronomia a Bologna, lamentava la difficoltà di reperirli.
Una ricerca avviata alcuni anni or sono ci ha consentito di ritrovare trentadue Pronostici del Novara, distribuiti in varie biblioteche in Europa e negli Stati Uniti, che coprono il periodo dal 1484, primo anno del suo insegnamento a Bologna, al 1504, anno della sua morte.
Questo lavoro ha lo scopo di rendere disponibile per la prima volta alla comunità degli studiosi un’analisi sistematica dei Pronostici sinora conosciuti.
Fabrizio Bònoli presenta la figura del Novara e dell’ambiente nel quale visse.
Giuseppe Bezza ha eseguito un’analisi del contenuto astrologico dei Pronostici, nel quadro delle conoscenze del tempo.
Salvo De Meis ha analizzato i fenomeni astronomici menzionati dal Novara, in particolare per la loro precisione, comparata a quella degli astronomi suoi contemporanei
Cinzia Colavita e Fabrizio Bònoli hanno redatto la trascrizione dei testi originali dei Pronostici.
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In the in-depth studies conducted over the centuries on the work of Copernicus and the far-reaching discussions these studies have generated, many scholars have investigated his astronomy professor at the Studium of Bologna, Magister Dominicus Maria Ferrariensis de Novaria, Doctor in almo ac inclyto Studio Bononiesi, as he would customarily sign his name.
Novara’s only known writings are the astronomical-astrological Pronostici he drew up every year, as stipulated by his contract as professor of astronomy at the university. Although he must have written about forty Pronostici – one for each year he taught there – in the vernacular and in Latin, in the mid-1950s only nine of them were known and, indeed, as far back as the late sixteenth century Giovanni Antonio Magini, likewise professor of astronomy in Bologna, reported how difficult it was to find them.
The research we undertook several years ago has allowed us to trace thirty-two of Novara’s Pronostici, distributed in various libraries in Europe and the United States; they span the period between 1484, the first year he taught in Bologna, and 1504, the year he died.
The aim of this work is to provide the academic community with a systematic analysis of the known Pronostici for the very first time.
Fabrizio Bònoli presents Novara and the milieu in which he lived.
Giuseppe Bezza analyses the astrological contents of the Pronostici in the context of the knowledge of the era.
Salvo De Meis examines the astronomical phenomena mentioned by Novara, particularly because of his accuracy with respect to coeval astronomers.
Cinzia Colavita and Fabrizio Bònoli have transcribed the original texts of the Pronostici
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