36,349 research outputs found
Paleotectonic and paleoceanographic controls on microbial-serpulids communities in the Norian-Rhaetian carbonates of Italy: a synthesis.
No full textIn Colacicchi R., Parisi G. & Zamparelli V. (eds.), Bioevents and Integrate Stratigraphy in the Triassic and Jurassic of Italy. Con il contributo di BERRA F., BONI M., CLAPS M., CLIMACO A., COZZI A., PODDA F., PONTON M. & TROMBETTA L
Vestibular and somatosensory afferents affect trigeminal motoneuron activity in guinea pigs
No full textSINTESI DI IDROGELI SELF-HEALING E SHAPE MEMORY OTTENUTI MEDIANTE POLIMERIZZAZIONE MICELLARE
No full textGli idrogeli sono reti polimeriche tridimensionali idrofiliche e reticolate in grado di assorbire grandi quantità di acqua. I punti di reticolazione possono essere chimici o fisici. Nel primo caso, la reticolazione si ottiene legando covalentemente le catene durante la polimerizzazione. Per ottenere idrogeli fisici, invece, si sfruttano fenomeni di interazione secondari.
In questo lavoro abbiamo realizzato idrogeli fisici mediante polimerizzazione micellare radicalica. In generale, questo tipo di polimerizzazione prevede l’utilizzo di un monomero idrofilico (acrilammide), uno idrofobico (ottadecilacrilato, C18A) che deve formare microblocchi idrofobici, un tensioattivo (SDS) e un sale (NaCl). L’ iniziatore, di tipo redox, è costituito da persolfato di ammonio e metabisolfito di sodio. Oltre ai monomeri indicati, è stato anche aggiunto un monomero multifunzionale, il divinilbenzene (DVB), con l'obiettivo di creare all’ interno dei microblocchi idrofobici, catene ramificate e valutarne l'effetto sulle caratteristiche del materiale.
Sono state preparate tre serie di campioni variando il rapporto tra acrilammide e ottadecilacrilato e la quantità di divinilbenzene. I campioni ottenuti sono stati caratterizzati mediante analisi di diffrazione dei raggi X e misure termo-reologiche. All’aumentare della concentrazione di C18A, diminuisce la quantità di acqua negli idrogeli, aumentano le entalpie di fusione e di cristallizzazione e aumenta il modulo meccanico G’. D’altra parte, all’aumentare della concentrazione di DVB diminuisce il contenuto d’acqua ed aumenta il modulo meccanico G’.
Il comportamento self-healing di questi materiali è stato studiato attraverso misure reologiche. La capacità self-healing diminuisce al diminuire del C18A ed all’aumentare del DVB
The Kidney from Prenatal to Adult Life: Perinatal Programming and Reduction of Number of Nephrons during Development
No full textModified embryonic-fetal development resulting in low birth weight may lead to a reduced nephron endowment, hypertension and renal diseases in adulthood. Regarding the involvement of genetic factors, several environmental conditions may also contribute towards reducing the number of nephrons in the fetus and infant, subsequently constituting a health burden in later life. To date no methods of investigation for the early detection of a reduced nephron reserve are available. However, more structured studies should be implemented to investigate the role of angiotensin-converting enzyme inhibitors in managing proteinurias and glomerulosclerosis in children with renal conditions characterized by reduce nephron number and glomerular hypertrophic changes. In view of the current lack of specific methods of investigation and management, close monitoring of children and young adults at risk of reduced renal reserve should be carried out to enhance the early detection of potential changes in renal function
Morphometric analysis of lunar sinuous rilles
No full textLunar rilles are any of the long, narrow depressions on the surface of the Moon. These structures have different characteristics, which are related to their origin. Here, a classification of the lunar rilles in different groups with similar morphometric features and likely the same formation mechanisms is proposed. The detection, classification and mapping of lunar rilles has been achieved in two quadrants of the northern hemisphere, which are located between -90°E to 90°E longitude and 0°N to 60°N latitude. For the detection and mapping of rilles, we used images from the Lunar Reconnaissance Orbiter Camera (LROC) [1] which have a resolution of 100 m/pixel and the DEM from Lunar Orbiter Laser Altimeter (LOLA) with a resolution of 6 m/pixel. This work is part of an international cooperation between Italy and China called “Moon Mapping project” for the collaboration between Italian and Chinese college students
Acute Diverticulitis in the Young: The Same Disease in a Different Patient
No full textBackground. Natural history and risk factors for diverticulitis in young patients are still debatable. This study aimed to assess whether difference exists in patients aged 50 and younger when compared to older patients and to identify risk factors for acute diverticulitis in the young. Patients and Methods. From January 2006 to December 2011, 80 patients were admitted to our department for acute diverticulitis. We carried out a cross-sectional study in 23 patients (28.7%) aged 50 and younger and 57 older patients (71.3%). Results. Acute diverticulitis in the young was not more aggressive than in the older patient. Diverticulitis at patient’s admission was similar with respect to Hinchey’s stage and prior history of diverticulitis. No significant difference was found for both medical and surgical treatment. The rate of recurrent diverticulitis in nonoperated patients was similar. Male gender, body mass index ≥25, and assumption of alcohol were independent risk factors for the occurrence of an acute diverticulitis in the young. Conclusions. The same disease seems to be affecting young patients such as overweight or obese male individual. Current policies to prevent diverticular disease and its related complications must include obesity control together with high-fiber diet and regular exercise
- …
