Optical Backplane Based on Ring-Resonators: Scalability and Performance Analysis for 10Gb/s OOK-NRZ

The use of architectures that implement optical switching without any need of optoelectronic conversion allows us to overcome the limits imposed by today’s electronic backplane, such as power consumption and dissipation, as well as power supply and footprint requirements. We propose a ring-resonator based optical backplane for router line-card interconnection. In particular we investigate how the scalability of the architecture is affected by the following parameters: number of line cards, switching-element round-trip losses, frequency drifting due to thermal variations, and waveguide-crossing effects. Moreover, to quantify the signal distortions introduced by filtering operations, the bit error rate for the different parameter conditions are shown in case of an on-off keying non-return-to-zero (OOK-NRZ) input signal at 10 Gb/s

Poly(Alkylene 2,5-thiophenedicarboxylate) polyesters: A new class of bio-based high-performance polymers for sustainable packaging

In the present study, 100% bio-based polyesters of 2,5-thiophenedicarboxylic acid were synthesized via two-stage melt polycondensation using glycols containing 3 to 6 methylene groups. The so-prepared samples were characterised from the molecular point of view and processed into free-standing thin films. Afterward, both the purified powders and the films were subjected to structural and thermal characterisation. In the case of thin films, mechanical response and barrier properties to O2 and CO2 were also evaluated. From the results obtained, it emerged that the length of glycolic sub-units is an effective tool to modulate the chain mobility and, in turn, the kind and amount of ordered phases developed in the samples. In addition to the usual amorphous and 3D crystalline phases, in all the samples investigated it was possible to evidence a further phase characterised by a lower degree of order (mesophase) than the crystalline one, whose amount is strictly related to the glycol sub-unit length. The relative fraction of all these phases is responsible for the different mechanical and barrier performances. Last, but not least, a comparison between thiophene-based homopolymers and their furan-based homologues was carried out

Fibrous hamartoma of Infancy: An Italian multi-istitutional experience.

Fibrous hamartoma of infancy: an Italian multi-institutional experience. Carretto E, Dall'Igna P, Alaggio R, Siracusa F, Granata C, Ferrari A, Cecchetto G. Source Division of Paediatric Surgery, Department of Paediatrics, University of Padua, Padua, Italy. Abstract BACKGROUND: Fibrous hamartoma (FH) of infancy is a benign mesenchymal tumor, occurring as a superficial mass. Complete excision is curative. OBJECTIVE AND METHODS: The clinical features and treatment results of 18 children with FH are described. RESULTS: Local excision was the most common procedure. Surgery was radical in 10 patients, with microscopic residual disease in 6; all of them are alive with no evidence of disease 2 to 49 months after diagnosis. One patient, treated with a local reexcision for macroscopic residual disease (and chemotherapy for a synchronous desmoid fibromatosis) is well 83 months after diagnosis; the last patient, with a lesion of the labia majora, only underwent biopsy and is doing well, awaiting plastic surgery. LIMITATIONS: The results did not reach statistical significance due to difficulties in collecting cases. CONCLUSIONS: FH should be treated by complete excision; in our experience a nonradical excision was also able to achieve the cure. An aggressive approach should be avoided, as the overall prognosis is excellent. PMID: 16635660 [PubMed - indexed for MEDLINE

Congenital hepatic mesenchymal hamartoma associated with mesenchymal stem villous hyperplasia of the placenta: case report

A newborn with an unusual association of hepatic mesenchymal hamartoma and mesenchymal stem villous hyperplasia of the placenta is presented. At birth, the large hepatic mass caused severe respiratory distress necessitating early surgical intervention. This report on the association of hepatic mesenchymal hamartoma and mesenchymal stem villous hyperplasia of the placenta strongly suggests a common pathogenetic origin of the 2 lesions

Il dosaggio del lattato in neonati con distensione addominale come fattore prognostico di sindrome da compartimento addominale

L'ipertensione intraaddominale (IAH) e la risultante sindrome da compartimento addominale (ACS), caratterizzata da incremento della pressione >20 mmHg e insufficienza d’organo o multiorgano, sono state descritte in neonati con patologie addominali chirurgiche. La gestione effettiva e preventiva dell'IAH è associata a minore morbidità. In uno studio retrospettivo abbiamo analizzato 20 neonati con distensione addominale persistente per individuare fattori predittivi di IAH ed ACS. Il Gold-Standard della misurazione dell'IAH è la misurazione pressoria intravescicale ancora non standardizzata c/o le UTIN. Per definire l'IAH abbiamo quindi utilizzato il monitoraggio della saturazione di ossigeno (SpO2) prossimale e distale rispetto all’addome e 2 segni di compromissione d’organo (oliguria, ipotensione, insufficienza respiratoria, acidosi metabolica). Abbiamo riscontrato un rischio tendenzialmente elevato di disfunzione multiorgano e decesso in neonati di età gestazionale maggiore (p=0,09) e con una causa congenita di ACS (p<0,05), e in neonati in correzione con bicarbonati (p=0,05). Alti valori di lattato già al ricovero correlano con un deficit di basi maggiore nelle fasi avanzate di ACS (p<0,05) e con una distensione tardiva (p<0,05) associata, a sua volta, a valori di lattato più elevati nelle fasi di distensione ed acidosi (p<0,05) rispetto alla distensione precoce. Il lattato alla distensione è tendenzialmente più alto in chi avrà eventi più gravi (p=0,06) pur non correlando con il decesso (p=0,2). Solo nella fase successiva di acidosi i valori di lattato sono predittivi di decesso (p<0,05). In nessuna fase sono state riscontrate correlazioni con l’insufficienza respiratoria. L’unico fattore predittivo per un decorso sfavorevole è l’insulto tissutale perfusionale precoce misurato tramite il lattato che tuttavia non correla con il decesso perché probabilmente neonati, soprattutto con difetti della parete addominale, possono sopportare pressioni intraaddominali più elevate senza andare incontro ad insufficienza multiorgano. Al contrario sembra che neonati con ACS secondaria o con età gestazionale maggiore tollerino meno l’IAH sviluppando ACS a pressioni più basse poichè gli spazi intraaddominali sono già definiti