771 resultados para 1372


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A study of the interference of Zn2+ ions on phenol degradation by Fenton reaction (Fe2+/Fe3(+) + H2O2) is reported. One of the first intermediates formed in the reaction, catechol, can reduce Fe3+ to Fe2+ and, in the presence of H2O2 initiates an efficient catalytic redox cycle. In the initial stages of the reaction, this catechol-mediated cycle becomes the principal route of thermal degradation of phenol and its oxidation products. The Zn2+ ion addition enhances the persistence time of catechol, probably by stabilization of the corresponding semiquinone radical via complexation.

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A study of the interference of Zn2+ ions on phenol degradation by Fenton reaction (Fe2+/Fe3+ + H2O2) is reported. One of the first intermediates formed in the reaction, catechol, can reduce Fe3+ to Fe2+ and, in the presence of H2O2 initiates an efficient catalytic redox cycle. In the initial stages of the reaction, this catechol-mediated cycle becomes the principal route of thermal degradation of phenol and its oxidation products. The Zn2+ ion addition enhances the persistence time of catechol, probably by stabilization of the corresponding semiquinone radical via complexation.

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[EN] Several weeks of intense endurance training enhances mitochondrial biogenesis in humans. Whether a single bout of exercise alters skeletal muscle mitochondrial DNA (mtDNA) content remains unexplored. Double-stranded mtDNA, estimated by slot-blot hybridization and real time PCR and expressed as mtDNA-to-nuclear DNA ratio (mtDNA/nDNA) was obtained from the vastus lateralis muscle of healthy human subjects to investigate whether skeletal muscle mtDNA changes during fatiguing and nonfatiguing prolonged moderate intensity [2.0-2.5 h; approximately 60% maximal oxygen consumption (Vo(2 max))] and short repeated high-intensity exercise (5-8 min; approximately 110% Vo(2 max)). In control resting and light exercise (2 h; approximately 25% Vo(2 max)) studies, mtDNA/nDNA did not change. Conversely, mtDNA/nDNA declined after prolonged fatiguing exercise (0.863 +/- 0.061 vs. 1.101 +/- 0.067 at baseline; n = 14; P = 0.005), remained lower after 24 h of recovery, and was restored after 1 wk. After nonfatiguing prolonged exercise, mtDNA/nDNA tended to decline (n = 10; P = 0.083) but was reduced after three repeated high-intensity exercise bouts (0.900 +/- 0.049 vs. 1.067 +/- 0.071 at baseline; n = 7; P = 0.013). Our findings indicate that prolonged and short repeated intense exercise can lead to significant reductions in human skeletal muscle mtDNA content, which might function as a signal stimulating mitochondrial biogenesis with exercise training.

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For a long time, the work of a Franciscan Friar who had lived in Bologna and in Florence during the 13th and 14th centuries, Bartolomeo Della Pugliola, was thought to have been lost. Recent paleographic research, however, has affirmed that most of Della Pugliola’s work, although mixed into other authors, is contained in two manuscripts (1994 and 3843), currently kept at University Library in Bologna. Pugliola’s chronicle is central to Bolognese medieval literature, not only because it was the privileged source for the important work of Ramponis’ chronicle, but also because Bartolomeo della Pugliola’s sources are several significant works such as Jacopo Bianchetti’s lost writings and Pietro and Floriano Villolas’ chronicle (1163-1372). Ongoing historical studies and recent discoveries enabled me to reconstruct the historical chronology of Pugliola’s work as well as the Bolognese language between the 13th and 14th century The original purpose of my research was to add a linguistic commentary to the edition of the text in order to fill the gaps in medieval Bolognese language studies. In addition to being a reliable source, Pugliola’s chronicle was widely disseminated and became a sort of vulgate. The tradition of chronicle, through collation, allows the study of the language from a diachronic point of view. I therefore described all the linguistics phenomena related to phonetics, morphology and syntax in Pugliola’s text and I compared these results with variants in Villola’s and Ramponis’ chronicles. I also did likewise with another chronicle by a 16th century merchant, Friano Ubaldini, that I edited. This supplement helped to complete the Bolognese language outline from the 13th to the 16th century. In order to analize the data that I collected, I tried to approach them from a sociolinguistic point of view because each author represents a different variant of the language: closer to a scripta and the Florentine the language used by Pugliola, closer to the dialect spoken in Bologna the language used by Ubaldini. Differencies in handwriting especially show the models the authors try to reproduce or imitate. The glossary I added at the end of this study can help to understand these nuances with a number of examples.

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Leber’s hereditary optic neuropathy (LHON) is a mitochondrial disease characterized by a rapid loss of central vision and optic atrophy, due to the selective degeneration of retinal ganglion cells. The age of onset is around 20, and the degenerative process is fast and usually the second eye becomes affected in weeks or months. Even if this pathology is well known and has been well characterized, there are still open questions on its pathophysiology, such as the male prevalence, the incomplete penetrance and the tissue selectivity. This maternally inherited disease is caused by mutations in mitochondrial encoded genes of NADH ubiquinone oxidoreductase (complex I) of the respiratory chain. The 90% of LHON cases are caused by one of the three common mitochondrial DNA mutations (11778/ND4, 14484/ND6 and 3460/ND1) and the remaining 10% is caused by rare pathogenic mutations, reported in literature in one or few families. Moreover, there is also a small subset of patients reported with new putative pathogenic nucleotide changes, which awaits to be confirmed. We here clarify some molecular aspects of LHON, mainly the incomplete penetrance and the role of rare mtDNA mutations or variants on LHON expression, and attempt a possible therapeutic approach using the cybrids cell model. We generated novel structural models for mitochondrial encoded complex I subunits and a conservation analysis and pathogenicity prediction have been carried out for LHON reported mutations. This in-silico approach allowed us to locate LHON pathogenic mutations in defined and conserved protein domains and can be a useful tool in the analysis of novel mtDNA variants with unclear pathogenic/functional role. Four rare LHON pathogenic mutations have been identified, confirming that the ND1 and ND6 genes are mutational hot spots for LHON. All mutations were previously described at least once and we validated their pathogenic role, suggesting the need for their screening in LHON diagnostic protocols. Two novel mtDNA variants with a possible pathogenic role have been also identified in two independent branches of a large pedigree. Functional studies are necessary to define their contribution to LHON in this family. It also been demonstrated that the combination of mtDNA rare polymorphic variants is relevant in determining the maternal recurrence of myoclonus in unrelated LHON pedigrees. Thus, we suggest that particular mtDNA backgrounds and /or the presence of specific rare mutations may increase the pathogenic potential of the primary LHON mutations, thereby giving rise to the extraocular clinical features characteristic of the LHON “plus” phenotype. We identified the first molecular parameter that clearly discriminates LHON affected individuals from asymptomatic carriers, the mtDNA copy number. This provides a valuable mechanism for future investigations on variable penetrance in LHON. However, the increased mtDNA content in LHON individuals was not correlated to the functional polymorphism G1444A of PGC-1 alpha, the master regulator of mitochondrial biogenesis, but may be due to gene expression of genes involved in this signaling pathway, such as PGC-1 alpha/beta and Tfam. Future studies will be necessary to identify the biochemical effects of rare pathogenic mutations and to validate the novel candidate mutations here described, in terms of cellular bioenergetic characterization of these variants. Moreover, we were not able to induce mitochondrial biogenesis in cybrids cell lines using bezafibrate. However, other cell line models are available, such as fibroblasts harboring LHON mutations, or other approaches can be used to trigger the mitochondrial biogenesis.

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Nel trasporto di cose si registra l’intervento nella fase di riconsegna della merce di un soggetto diverso dall’originario contraente con il vettore: il destinatario. Tale contratto si caratterizza per uno sfasamento tra il momento della stipulazione del contratto tra mittente e vettore e quello della riconsegna delle merci, nel quale al destinatario viene riconosciuta facoltà di esercitare i diritti nascenti dal contratto di trasporto nei confronti del vettore; tale sfasamento temporale fra l’inizio e la fine della prestazione del vettore comporta una scissione in seno alla figura del creditore del trasporto nei confronti del vettore fra mittente e destinatario. Questo elemento crea una particolare situazione giuridica che è stata variamente inquadrata. Si verifica, infatti, un fenomeno di successione del destinatario al mittente nell’acquisto e nel conseguente esercizio dei diritti nascenti dal contratto di trasporto, ossia un trasferimento dei diritti dal mittente al destinatario, di portata apparentemente eversiva del principio della relatività degli effetti del contratto codificato dall’art. 1372 c.c. Si pone, dunque, il problema di individuare quali diritti nei confronti del vettore siano esercitabili dal destinatario, ossia quale sia il contenuto di tali diritti. In secondo luogo, si pone il problema di accertare con quali modalità temporali il destinatario acquisti tali diritti. Bisogna, poi, stabilire a quale titolo tale acquisto avvenga. Inoltre è necessario stabilire come si concili la legittimazione all’esercizio di tali diritti con i poteri di disposizione del carico e, in definitiva, di modifica del contratto del trasporto, riconosciuti al mittente e determinare a chi spetti la legittimazione ad esercitare le azioni derivanti dal contratto di trasporto verso il vettore. Questi quesiti toccano un problema di più ampia portata riguardante la configurazione giuridica della posizione negoziale assunta dal destinatario all’interno della complessa fattispecie contrattuale che vincola fra loro i tre soggetti e la determinazione del meccanismo giuridico che rende possibile il trasferimento dei diritti che nascono dal contratto di trasporto al destinatario, il quale si sostituisce al mittente nella titolarità degli stessi. La disciplina del trasporto non si presta ad una interpretazione univoca, ponendo problemi applicativi di non facile soluzione. Le esigenze di un’idonea configurazione giuridica del contratto di trasporto e dei rapporti intercorrenti fra i soggetti intorno ad esso interagiscono, quelle di un equo contemperamento degli interessi delle parti e quelle di una compiuta risposta ai problemi pratici connessi all’attuale realtà dei traffici non hanno trovato risposte condivise. La dottrina e la giurisprudenza hanno fornito diverse soluzioni, per lo più basate su un’interpretazione sistematica del contratto di trasporto, a margine del codice di commercio del 1882, prima, e del codice civile del 1942, poi. Si è dunque dato vita alla ricerca, all’interno delle norme generali in tema di obbligazioni e contratti, delle logiche e degli istituti ai quali può essere ricondotto l’acquisto da parte del destinatario del risultato della prestazione del vettore nella fase finale della riconsegna del carico. L’elaborato analizza tutte le teorie sviluppate dagli interpreti. In particolare viene esaminata la tesi accolta dalla dottrina e dalla giurisprudenza maggioritarie, volta a qualificare il trasporto come un contratto a favore a terzi, la tesi che qualifica tale contratto come un’ipotesi di indicazione o di delegazione di pagamento e la tesi che qualifica il trasporto come di cose come contratto naturalmente suscettibile di cessione al destinatario. Di tali teorie vengono indagate le conseguenze applicative, con particolare riferimento al contenuto dei diritti, delle azioni e delle eccezioni esercitabili dei soggetti che partecipano al contratto, per concludere che la teoria che fornisce il più ampio contemperamento degli interessi delle parti, alla luce dell’attuale realtà dei traffici, è quella che riconduce il trasferimento dei diritti inerenti al contratto di trasporto di cose all’istituto della cessione.

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The characteristics of aphasics’ speech in various languages have been the core of numerous studies, but Arabic in general, and Palestinian Arabic in particular, is still a virgin field in this respect. However, it is of vital importance to have a clear picture of the specific aspects of Palestinian Arabic that might be affected in the speech of aphasics in order to establish screening, diagnosis and therapy programs based on a clinical linguistic database. Hence the central questions of this study are what are the main neurolinguistic features of the Palestinian aphasics’ speech at the phonetic-acoustic level and to what extent are the results similar or not to those obtained from other languages. In general, this study is a survey of the most prominent features of Palestinian Broca’s aphasics’ speech. The main acoustic parameters of vowels and consonants are analysed such as vowel duration, formant frequency, Voice Onset Time (VOT), intensity and frication duration. The deviant patterns among the Broca’s aphasics are displayed and compared with those of normal speakers. The nature of deficit, whether phonetic or phonological, is also discussed. Moreover, the coarticulatory characteristics and some prosodic patterns of Broca’s aphasics are addressed. Samples were collected from six Broca’s aphasics from the same local region. The acoustic analysis conducted on a range of consonant and vowel parameters displayed differences between the speech patterns of Broca’s aphasics and normal speakers. For example, impairments in voicing contrast between the voiced and voiceless stops were found in Broca’s aphasics. This feature does not exist for the fricatives produced by the Palestinian Broca’s aphasics and hence deviates from data obtained for aphasics’ speech from other languages. The Palestinian Broca’s aphasics displayed particular problems with the emphatic sounds. They exhibited deviant coarticulation patterns, another feature that is inconsistent with data obtained from studies from other languages. However, several other findings are in accordance with those reported from various other languages such as impairments in the VOT. The results are in accordance with the suggestions that speech production deficits in Broca’s aphasics are not related to phoneme selection but rather to articulatory implementation and some speech output impairments are related to timing and planning deficits.

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N-acetylcysteine (NAC) is neuroprotective in animal models of acute brain injury such as caused by bacterial meningitis. However, the mechanism(s) by which NAC exerts neuroprotection is unclear. Gene expression of endothelin-1 (ET-1), which contributes to cerebral blood flow decline in acute brain injury, is partially regulated by reactive oxygen species, and thus a potential target of NAC. We therefore examined the effect of NAC on tumor necrosis factor (TNF)-alpha-induced ET-1 production in cerebrovascular endothelial cells. NAC dose dependently inhibited TNF-alpha-induced preproET-1 mRNA upregulation and ET-1 protein secretion, while upregulation of inducible nitric oxide synthase (iNOS) was unaffected. Intriguingly, NAC had no effect on the initial activation (i.e., IkappaB degradation, nuclear p65 translocation, and Ser536 phosphorylation) of NF-kappaB by TNF-alpha. However, transient inhibition of NF-kappaB DNA binding suggested that NAC may inhibit ET-1 upregulation by inhibiting (a) parallel pathway(s) necessary for full transcriptional activation of NF-kappaB-mediated ET-1 gene expression. Similar to NAC, the MEK1/2 inhibitor U0126, the p38 inhibitor SB203580, and the protein kinase inhibitor H-89 selectively inhibited ET-1 upregulation without affecting nuclear p65 translocation, suggesting that NAC inhibits ET-1 upregulation via inhibition of mitogen- and stress-activated protein kinase (MSK). Supporting this notion, cotreatment with NAC inhibited the TNF-alpha-induced rise in MSK1 and MSK2 kinase activity, while siRNA knock-down experiments showed that MSK2 is the predominant isoform involved in TNF-alpha-induced ET-1 upregulation.

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OBJECTIVE: The standard heart-lung machine is a major trigger of systemic inflammatory response and the morbidity attributed to conventional extracorporeal circulation (CECC) is still significant. Reduction of blood-artificial surface contact and reduction of priming volume are principal aims in minimized extracorporeal circulation (MECC) cardiopulmonary bypass systems. The aim of this paper is to give an overview of the literature and to present our experience with the MECC-smart suction system. METHODS AND RESULTS: At our institution, 1799 patients underwent isolated coronary artery bypass grafting (CABG) surgery, 1372 with a MECC-smart suction system and 427 with CECC. All in-hospital data were assessed and the results were compared between the 2 groups. Patient characteristics and the distribution of EuroSCORE risk profile in our collective were similar between both groups. Average age in the MECC collective was 67.5 +/- 11.4 years and average EuroSCORE was 5.0 +/- 1.5. Average number of distal anastomoses was similar to the average number encountered in patients undergoing CABG surgery with CECC (3.3 +/- 1.0 for MECC versus 3.2 +/- 1.1 for CECC; P = ns). Myocardial protection is superior in MECC patients with lower postoperative maximal cTnI values (11.0 +/- 10.8 micromol/L for MECC versus 24.7 +/- 25.3 micromol/L for CECC; P < .05). Postoperative recovery was faster in patients operated on with the MECC-smart suction system and discharge from the hospital was earlier than for CECC patients (7.4 +/- 1.9 days for MECC versus 8.8 +/- 3.8 days for CECC; P < .05). CONCLUSIONS: The MECC-smart suction system is a safe perfusion technique for CABG surgery. In patients operated on with this system, the clinical outcome seems to be better than in patients operated on with CECC. This promising and less damaging perfusion technology has the potential to replace CECC systems in CABG surgery.

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The numerical solution of the incompressible Navier-Stokes Equations offers an effective alternative to the experimental analysis of Fluid-Structure interaction i.e. dynamical coupling between a fluid and a solid which otherwise is very complex, time consuming and very expensive. To have a method which can accurately model these types of mechanical systems by numerical solutions becomes a great option, since these advantages are even more obvious when considering huge structures like bridges, high rise buildings, or even wind turbine blades with diameters as large as 200 meters. The modeling of such processes, however, involves complex multiphysics problems along with complex geometries. This thesis focuses on a novel vorticity-velocity formulation called the KLE to solve the incompressible Navier-stokes equations for such FSI problems. This scheme allows for the implementation of robust adaptive ODE time integration schemes and thus allows us to tackle the various multiphysics problems as separate modules. The current algorithm for KLE employs a structured or unstructured mesh for spatial discretization and it allows the use of a self-adaptive or fixed time step ODE solver while dealing with unsteady problems. This research deals with the analysis of the effects of the Courant-Friedrichs-Lewy (CFL) condition for KLE when applied to unsteady Stoke’s problem. The objective is to conduct a numerical analysis for stability and, hence, for convergence. Our results confirmthat the time step ∆t is constrained by the CFL-like condition ∆t ≤ const. hα, where h denotes the variable that represents spatial discretization.

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Previous research suggests that the personality of a relationship partner predicts not only the individual’s own satisfaction with the relationship but also the partner’s satisfaction. Based on the actor–partner interdependence model, the present research tested whether actor and partner effects of personality are biased when the same method (e.g., self-report) is used for the assessment of personality and relationship satisfaction and, consequently, shared method variance is not controlled for. Data came from 186 couples, of whom both partners provided self- and partner reports on the Big Five personality traits. Depending on the research design, actor effects were larger than partner effects (when using only self-reports), smaller than partner effects (when using only partner reports), or of about the same size as partner effects (when using self- and partner reports). The findings attest to the importance of controlling for shared method variance in dyadic data analysis.