196,060 research outputs found
The morphology of seminiferous tubules of human testicular biopsies. Analysis of the data obtained with two different techniques
No full textTesticular biopsies of fertile men and of azoospermic patients for vas deferens agenesis were processed with two different techniques, i.e. routine histological procedure and semithin sections of electron microscopy preparations. Tubular morphology, testicular biopsy score count and tubular diameter were analyzed in comparison. The two techniques give rise to a different qualitative and quantitative evaluation of all tubular parameters considered. Otherwise they confirm the real existence of the so-called 'tubular blockage' situation with central tubular cellular mass and cell degeneration
Studio immunocitochimico di componenti la matrice extracellulare della parete dei tubuli seminiferi in biopsie testicolari umane
No full textAnalisi immunocitochimica di componenti extracellulari nella parete del tubulo seminifero umano.
No full textLocalizzazione immunocitochimica di alcuni componenti la matrice extracellulare nella parete del tubulo seminifero umano
No full textI canti popolari in Sicilia: una riflessione a margine di un incontro a Milena
No full textA partire da un corpus di canti popolari registrati a Milena (CL), si offre un quadro della dialettica tra oralità e scrittura, fra letteratura dialettale e poesia popolare, che caratterizza, in generale, i repertori etno-musicali dell’Isola. Talora la formalizzazione blocca questo percorso di continua rigenerazione testuale, ma altre volte è possibile confrontare varianti che hanno autori individuabili o contesti socio-economici ricostruibili
M&As and determinants of financial multiples in shipping: the European ro-pax and ferry market
No full textThe paper investigates the determinants of M&As in the shipping industry by applying an original methodology paved on strategic management and financial perspectives. Despite the magnitude of the figures related to the financial deals and the potentially dramatic effects of M&As on the shipping industry, a literature gap persists in this business. No prior studies have theoretically and empirically addressed the determinants affecting the valuation process of target shipping companies. Therefore, financial multiples constitute a valuable method to address this topic. Given the relevance and size of the ro-pax and ferry market for the European maritime transport system as well as the increasing number of transactions, the paper investigates the determinants of the financial multiples in this market. The paper grounds on an original conceptual model that includes endogenous, exogenous, and transaction-related variables and proposes nine research hypotheses on endogenous variables. The hypotheses are empirically tested through ordinary least squares regression analysis on 85 M&As carried out in the 2005–2021 timeframe. The findings demonstrate differences between asset-side and equity-side multiples suggesting asset-side multiples are more suitable for pricing shipping companies. The paper adds extant academic literature by unveiling the principal endogenous variables that affect the due diligence of target ro-pax and ferry companies
Type I collagen CNBr peptides: species and behavior in solution
No full textThe properties of type I collagen CNBr peptides in solution were studied to investigate the molecular species formed, their conformation, and factors influencing equilibria between peptide species. Peptides formed homologous trimers, even though the native parent protein is heterotrimeric, [alpha 1(I)]2 alpha 2-(I). Their triple-helical content was found to be high (> 75% for most peptides). Full helical content was not reached mainly because of the presence of monomer species; chain misalignment, if present, and trimer unraveling at terminal ends appeared to play a minor role in reducing helicity. Circular dichroism spectra and resistance to trypsin digestion at 4 and 20 degrees C demonstrated that the conformation of trimers was very similar to the collagen triple-helical conformation. Rotary shadowing of peptide alpha 1(I) CB7 supported this finding. Analytical gel filtration in nondenaturing conditions showed that the trimers of some peptides have the ability to autoaggregate. In the case of peptides alpha 1(I) CB8 and alpha 2(I) CB4, most of the intermolecular interactions between trimeric molecules were disrupted by 0.5 M NaCl, demonstrating that their ionic character is important. Changes in ionic strength also altered the hydrodynamic size of single- and triple-stranded molecules. The different molecular species are in equilibrium. The kinetics of the conversion of trimer to monomer species was determined in a time course experiment using trypsin digestion and found to be a relatively slow process (trimer half-life is a few days at 4 degrees C, about one order of magnitude lower at 20 degrees C) with an activation energy of roughly 4-9 kcal/mol. The circular dichroism profile at increasing temperatures showed that the melting temperature for triple-helical peptides is about 6-10 degrees C lower than that of the parent native type I collagen. The folding of peptides is a spontaneous process (exothermic but with unfavourable entropy change), and the triple-helical conformation originates solely as the result of the collagen sequence because it forms from heat-denatured samples
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