1,882 research outputs found
Hydrogen peroxide formation and iron ion oxidoreduction linked to NADH oxidation in radish plasmalemma vesicles
No full textPreviously, we showed the presence in radish (Raphanus sativus L.) plasmalemma vesicles of an NAD(P)H oxidase, active at pH 4.5–5.0, which elicits the formation of anion superoxide (Vianello and Macri (1989) Biochim. Biophys. Acta 980, 202–208). In this work, we studied the role of hydrogen peroxide and iron ions upon this oxidase activity NADH oxidation was stimulated by ferrous ions and, to a lesser extent, by ferric ions. Salicylate and benzoate, two known hydroxyl radical scavengers, inhibited both basal and iron-stimulated NADH oxidase activity. The iron chelators EDTA (ethylenediaminetetraacetic acid) and DFA (deferoxamine melysate) at high concentrations (2 mM) inhibited the NADH oxidation, whereas they were ineffective at lower concentrations (80 μM); the subsequent addition of ferrous ions caused a rapid and limited increase of oxygen consumption which later ceased. Hydrogen peroxide was not detected during NADH oxidation but, in the presence of salicylate, its formation was found in significant amounts. NADH oxidase activity was also associated to a Fe2+ oxidation which was only partialy inhibited by salicylate. Ferrous ion oxidation was partially inhibited by catalase and prevented by superoxide dismutase, while ferric ion reduction was abolished by catalase and unaffected by superoxide dismutase. These results show that during NADH oxidation iron ions undergo oxidoreduction and that hydrogen peroxide dismutase. These results show that during NADH oxidation iron this oxidation appears linked to the univalent oxidoreduction of iron ions by a reduced flavoprotein of radish plasmalemma which is then converted to a radical form. The latter, reacting with oxygen generates the superoxide anion which dismutates to H2O2. Hydrogen peroxide, through a Fenton's reaction, may react with Fe2+ to produce hydroxyl radicals, or with Fe3+ to generate the superoxide anion
Existence and regularity for solutions of quasilinear degenerate elliptic systems
No full textThe existence of a solution to a quasilinear system of degenerate equations is proved, assuming that the datum has an intermediate degree of summability and that the off -diagonal coefficients have a support contained in a crossed staircase set. The support required in this paper is larger than the one assumed in a previous work
Zearalenone-Induced uncoupling in plant mitochondria is sensitive to 6-ketocholestanol
No full textZearalenone (F-2) is a mycotoxin which acts as a protonophoric uncoupler in plant mitochondria [Macri, F. and Vianello, A., (1990) J. Plant Physiol. 136, 754-757]. In the present paper, the mechanism of F-2-induced uncoupling in pea mitochondria was studied. The uncoupling by F-2 was partially reversed by 6-
ketocholestanol (kCh) under conditions in which kCh completely reversed the FCCP-induced uncoupling and almost did not affect the palmitate-induced uncoupling. Recoupling effects of carboxyatractylate, ADP and cyclosporin A were small and could not essentially
decrease the kCh-insensitive part of F-2-induced uncoupling. It is suggested that a protein, mediating kCh-sensitive uncoupling, is involved in the F-2 effect in plant mitochondria
La religione della libertà. Riflessioni su C.A. Ciampi, "La libertà delle minoranze religiose" (a cura di F.P. Casavola, G. Long, F. Margiotta Broglio), Il Mulino, Bologna, 2009
No full textThe Fall of Hong Kong: The Condon Report
No full textDavid Macri recently defended his PhD thesis “Hong Kong in the Sino–Japanese War: The Logistics of Collective Security in South China, 1935–1941” at the University of Hong Kong. The thesis raises new and important questions about the strategic background to the events of late 1941. Dr. Macri is also interested in operational and tactical issues and this report from the US National Archives is of special interest to Canadians. The author, Major Reynolds Condon, was an American assistant military attaché in Hong Kong who witnessed the battle before being released back to the US. His report, while not always factually correct, helps shed some light on aspects of the battle for which he was an eyewitness
Brevi considerazioni in materia di governance delle pratiche di culto tra istanze egualitarie, soluzioni compiacenti e protocolli (quasi) “fotocopia”
No full textSOMMARIO: 1. Premessa - 2. I pezzi si muovono sulla scacchiera - 3. Azioni e reazioni (cenni) - 4. La libertà religiosa non è a rischio: il problema sta altrove - 5. “Predicare bene e razzolare male” - 6. Un protocollo ti salva la vita - 7. Un passo avanti … e due indietro - Appendice.
Short remarks on the governance of religious practices between egalitarian requests and complaisant solutions
ABSTRACT: In Italy, in the context of the Covid-19 emergency, issues concerning the governance of religious practices have emerged and have been faced by different religious groups. In this contribution political and legal distortions are analyzed in the context of the non-coherent (according to the author) reading of the constitutional framework by the Italian government
Differences in volume and surface of mandibular condyles in Caucasian adult subjects with low, normal or high mandibular plane angle
No full textObject: The aim of this study was to evaluate the condylar volumes in a group of patients aged between 15 and 50 years old. They were pre-orthodontic asymptomatic patients with different facial structure (low mandibular plane angle, normal angle, high angle). The evaluation of the volume of facial structures became recently important because the volumetric value of a solid can describe, in only one number, the data on the form and surface of the object, bearing in mind also the hollow structures (nasal cavity, sinus, oral cavity). The evaluation of the volume of facial structures is today possible through the segmentation of structures within the 3D reconstructions.
Materials and methods : We examined Cone Beam data of 60 young adult caucasian subjects with different facial structures (low angle, high angle, normal angle) before they were scheduled to undergo orthodontic treatment for dental problems of overcrowding. The criteria for inclusion of patients were the absence of TMD symptoms, of tooth agenesis, of previous Ortognathic surgery, of posterior occlusal stop, and extreme brachycephalic and dolichocephalic. The cephalometric analysis on Cone Beam data was performed with Dolphin 3D on DICOM files. The calculation of volume and condylar surface was done with the software Mimics, through the technique of segmentation.
Results: By dividing the sample into three groups (high angle, normal angle, low angle) we highlighted statistically significant differences in volumes and areas of right and left mandibular condyles within the types of facial divergence. The low angle subjects showed a significantly greater volume and condylar surface than the other two groups. In the three groups, the values of the areas showed a standard deviation and a range higher than the other 2 groups.
Discussion: The observed differences could be related to different muscle tone of the masticatory muscles. in another study F. Festa et al (2006) observed how the sEMG activity of the masseter, the anterior temporal, and of the upper trapezius and posterior cervical at mandibular rest position was higher in low angle subjects as compared to high angle and normal angle subjects. This higher sEMG activity may be responable for the volume of the condyle.
Conclusions: There is evidence of an association between volume and mandibular divergence. For all groups, values that indicate the condylar surface showed inter-individual variation higher than the values indicating the condylar volume and this result could be associated with the presence - on the condylar surface - of microscopic anfractuosity (small pits, furrows, various irregularities) that are able to influence the measurements of the condylar surface, but are not able to significantly influence the measurements of the condylar volum
Evaluation of Maxillary Dentoalveolar Expansion with Clear Aligners: A Retrospective CBCT Study
No full textBackground/Objectives: Currently, clear aligners are preferred to conventional appliances,
especially among adult patients. However, the use of aligners for treating maxillary
constriction is still debated in the literature. Therefore, the purpose of this study was
to assess maxillary dentoalveolar expansion following clear aligner therapy in adults
using CBCT scans. Methods: The study sample encompassed 50 non-growing patients
(27 females and 23 males) aged 20 to 42 undergoing clear aligner orthodontics without
dental extractions or auxiliaries. Transverse linear distances were measured on initial
and final CBCTs and, subsequently, analysed through paired t-test and ANOVA. We
considered alveolar bone measurements and interdental widths measured at the buccal
apices and cusps from canines to second molars. Results: The buccal alveolar ridge width
showed the greatest expansion (1.01 ± 0.38 mm), followed by the palatal alveolar ridge
and maxillary alveolar bone. Statistically significant improvements were observed for all
interdental measurements. The most considerable changes occurred in the interpremolar
cusp distances, while the least changes were seen in the intermolar apex distances. At
the cusp level, the average interpremolar widths increased by 3.44 ± 0.22 mm for the first
premolars and 3.14 ± 0.27 mm for the second ones. Conclusions: Clear aligner treatment
can effectively manage a constricted maxillary arch. We found significant changes in the
maxillary alveolar bone. Both inter-apex and inter-cusp widths increased in all teeth, with the highest values in the premolars. Moreover, the increases in interdental distances at both apex and cusp levels were related to tooth position
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