4,606 research outputs found

    Drug Release from Viscoelastic Swelling Polymeric Platforms

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    We consider a polymeric spherical platform containing a solid dispersed drug that is in contact with a solvent fluid. While swelling, a non-Fickian sorption of the solvent molecules occurs induced by the effect of the viscoelastic properties of the polymer. The solid drug in contact with the solvent fluid dissolves and a Fickian release of dissolved drug takes place. The fluid entrance, the drug dissolution, and the drug release to an external environment are described by a system of PDEs complemented with an equation for the swelling front, initial, and boundary conditions. The model includes the two major factors that govern a swelling process of a polymeric platform within a release medium: the cross-link density and the concentration of the external medium. Energy estimates for the mass of solvent fluid and of undissolved and dissolved drug in the polymeric platform are established. Numerical simulations that illustrate the theoretical results are also included

    G-genotyping of rotaviruses in stool samples in Salento, Italy

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    Rotaviruses are the most common agents of diarrhoeal illnessin infants and young children. Gastroenteritis caused byrotaviruses is also more likely to be associated with severe dehydration compared to other viral gastroenteritis.We determined the G-genotype of rotaviruses circulating in theSalento. During 2004, 144 stool samples were collected fromsubjects with a positive screening test and stored at -20 °C untilconfirmation could take place using molecular biology techniques. A reverse transcription-polymerase chain reaction (RTPCR) assay for the amplification of gene VP7 of rotavirus wasdeveloped and used; G-genotype was determined by sequencing and phylogenetic analysis. A total of 101 stool samples were detected positive by RT-PCRand 35 were sequence analyzed and classified into G1, G2, G4,G9 and G12 type. The overall relative incidence of G-types inSalento is different to that of other developed countries. Themost prevalent genotype was G2 while genotype G1 was present at low levels. It is also interesting to note the presence ofG9 rotavirus, which is now recognized as the fifth globallyimportant rotavirus genotype.In this study, therefore, we demonstrate the usefulness of a simple method for correctly determining the G genotypes circulating in a geographic region

    Evidence-Based Dentistry: What's New?

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    The importance of evidence for every branch of medicine in teaching in order to orient the practitioners among the great amount of most actual scientific information's, and to support clinical decisions, is well established in health care, including dentistry

    Acute respiratory muscle unloading improves time-to-exhaustion during moderate- and heavy-intensity cycling in obese adolescent males

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    Obesity significantly impairs breathing during exercise. The aim was to determine, in male obese adolescents (OB), the effects of acute respiratory muscle unloading, obtained by switching the inspired gas from ambient air (AIR) to a normoxic helium + oxygen gas mixture (HeO2) (AIR \u2192 HeO2) during moderate [below gas exchange threshold (GET)] and heavy [above GET] constant work rate cycling. Ten OB [age 16.0 \ub1 2.0\ua0years (mean \ub1 SD); body mass index (BMI) 38.9 \ub1 6.1\ua0kg/m2] and ten normal-weight age-matched controls (CTRL) inspired AIR for the entire exercise task, or underwent AIR \u2192 HeO2 when they were approaching volitional exhaustion. In OB time to exhaustion (TTE) significantly increased in AIR \u2192 HeO2 vs. AIR during moderate [1524 \ub1 480\ua0s vs. 1308 \ub1 408 (P = 0.024)] and during heavy [570 \ub1 306\ua0s vs. 408 \ub1 150 (P = 0.0154)] exercise. During moderate exercise all CTRL completed the 40-min task. During heavy exercise no significant differences were observed in CTRL for TTE (582 \ub1 348\ua0s [AIR \u2192 HeO2] vs. 588 \ub1 252 [AIR]). In OB, but not in CTRL, acute unloading of respiratory muscles increased TTE during both moderate- and heavy-exercise. In OB, but not in CTRL, respiratory factors limit exercise tolerance during both moderate and heavy exercise

    The effect of an optimized diet as an adjunct to non-surgical periodontal therapy in subjects with periodontitis: a prospective study

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    Diet and nutrition are generally categorized as modifiable lifestyle risk factors for the development of periodontal disease because diet may influence a person’s inflammatory status. This study aimed to evaluate the efficacy of the application of a diet plan focused on reducing inflammation and oxidative stress in treating periodontitis. Subjects suffering from periodontitis were divided into two groups. Both groups underwent non-surgical periodontal therapy, and in the optimized diet (OD) group, this treatment was associated with a diet plan. The sample consisted of 60 subjects; 32 (53%) were treated in the non-optimized diet group (ND group) and 28 (47%) in the OD group. In both groups, the periodontal treatment significantly improved the recorded periodontal outcomes between T0 and T1 (FMPS, FMBS, CAL, PPD). Inter-group differences were not statistically significant (p < 0.05). The linear regression models showed that the optimized diet was associated with a higher reduction in PPD and FMBS after the treatment, while patients who had higher LDL levels (over 100 mg/mL) had a less favorable improvement of PPD. The application of an improved diet plan can increase the reduction in PPD and FMBS after non-surgical periodontal therapy when compared with periodontal treatment alone

    Reduction of High Cholesterol Levels by a Preferably Fixed-Combination Strategy as the First Step in the Treatment of Hypertensive Patients with Hypercholesterolemia and High/Very High Cardiovascular Risk: A Consensus Document by the Italian Society of Hypertension

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    The primary and secondary prevention strategies of atherosclerotic cardiovascular disease (ASCVD) largely rely on the management of arterial hypertension and hypercholesterolemia, two major risk factors possibly linked in pathophysiological terms by the renin-angiotensin system activation and that often coexist in the same patient synergistically increasing cardiovascular risk. The classic pharmacologic armamentarium to reduce hypercholesterolemia has been based in the last two decades on statins, ezetimibe, and bile acid sequestrants. More recently numerous novel, additive resources targeting different pathways in LDL cholesterol metabolism have emerged. They include drugs targeting the proprotein convertase subtilisin/kexin type 9 (PCSK9) (inhibitory antibodies; small-interfering RNAs), the angiopoietin-like protein 3 (inhibitory antibodies), and the ATP-citrate lyase (the inhibitory oral prodrug, bempedoic acid), with PCSK9 inhibitors and bempedoic acid already approved for clinical use. With the potential of at least halving LDL cholesterol levels faster and more effectively with the addition of ezetimibe than with high-intensity statin alone, and even more with the addition of the novel available drugs, this document endorsed by the Italian Society of Hypertension proposes a novel paradigm for the treatment of the hypertensive patient with hypercholesterolemia at high and very high ASCVD risk. Our proposal is based on the use as a first-line of a preferably fixed combination of lipid-lowering drugs, under the motto “Our goal: achieve control. No setback: combine and check”

    Super D-branes from BRST Symmetry

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    Recently a new formalism has been developed for the covariant quantization of superstrings. We study properties of Dp-branes and p-branes in this new framework, focusing on two different topics: effective actions and boundary states for Dp-branes. We present a derivation of the Wess-Zumino terms for super (D)p-branes using BRST symmetry. To achieve this we derive the BRST symmetry for superbranes, starting from the approach with/without pure spinors, and completely characterize the WZ terms as elements of the BRST cohomology. We also develope the boundary state description of Dp-branes by analyzing the boundary conditions for open strings in the completely covariant (i.e., without pure spinors) BRST formulation.Comment: 31 pp; journal version, expended discussion of D-brane pure spinor constraints in Section 2.

    Geological, seismological and geodetic evidence of active thrustingand folding south of Mt. Etna (eastern Sicily): Revaluation of “seismicefficiency” of the Sicilian Basal Thrust

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    tGeological studies and morphological analysis, compared with seismological and geodetic data, suggestthat a compressive regime currently occurs at crustal depth in the western sector of Mt. Etna, accommo-dated by shallow thrusting and folding at the front of the chain, south of the volcanic edifice. In particular,a large WSW-ENE trending anticline, interpreted as detachment fold, is growing west and north of Cata-nia city (the Catania anticline). Geological data suggest that during the last 6000 years the frontal foldhas been characterized by uplift rates of ∌6 mm/yr along the hinge, consistent with the interferometricdata (10 mm/yr) recorded in the last 20 years. Moreover, a NNW-SSE oriented axis of compression hasbeen obtained by seismological data, consistent with GPS measurements over the last 20 years whichhave revealed a shortening rate of ∌5 mm/yr along the same direction. Besides the activity related to thevolcanic feeding system, the seismic pattern under the Mt. Etna edifice can be certainly related to theregional tectonics. The compressive stress is converted into elastic accumulation and then in earthquakesalong the ramps beneath the chain, whereas on the frontal area it is accommodated by aseismic defor-mation along an incipient detachment within the clayish foredeep deposits. The high rate of shorteningat the aseismic front of the chain, suggests a greater “seismic efficiency” in correspondence of ramps atthe rear.Published32-412T. Tettonica attivaJCR Journalrestricte

    New Geological, seismological and geodetic evidence of active thrusting and folding south of Mt. Etna (eastern Sicily): revaluation of “seismic efficiency” of the Sicilian Basal Thrust

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    New geological, seismological and geodetic data indicate that a NNW-SSE compressive regime occurs in the southern and western sector of Mt. Etna, accommodated by aseismic folding at the front of the chain. In particular, a large WSW-ENE trending anticline (the Catania anticline) is growing west and north of Catania within a middle-late Pleistocene fold system. For its location, geometry and growth rate, it is consistent with detachment fold models. We exclude that this structure have developed in response to volcanic spreading, as proposed by previous authors. Looking at the earthquakes distribution , an interesting finding is a clear trend of the seismic events deepening from very shallow hypocenters, in the area south of Etna, down to a depth of about 35 km, towards the NNW. Moreover, most of the events are clustered. We computed the focal mechanisms for the major and best recorded earthquakes occurring in the area. One cluster located at few kilometers north-west of the summit craters shows fault mechanisms of the deeper events with nearly horizontal P-axes striking NNW-SSE. A segment of the Sicilian Basal Thrust, located at crustal depth under the northwestern sector of the volcano, could be the seismic source. We propose the occurrence of detachment folding at the chain front, as response of a surface frontal propagation of this regional structure, migrating within the clayish middle-late Pleistocene foredeep deposits or at the top of the buried Hyblean foreland sequence. Geological and morphometric analyses suggest a maximum up warp deformation along the anticline axis of 40 m in the last 6000-7000 yrs, with a vertical slip-rate of 5 - 7 mm/yr. These values are consistent with the growth rate of 9 - 10 mm/yr estimated by interferometric data and the horizontal shortening of 5 mm/yr obtained by GPS measurements. Our analysis confirms that, besides the activity related to the volcanic feeding system, the seismic pattern under Mt. Etna edifice can be certainly related to the regional dynamics. The compressive stress is converted into elastic accumulation and then in earthquakes along the ramps to the rear of the chain, whereas along the frontal detachment it is accommodated by aseismic ductile deformation. In fact, despite the high rates of convergence, the seismicity is moderate at the front of the chain and the “seismic efficiency" of the Sicilian Basal Thrust is greater in correspondence of ramps at the rear, where strong earthquakes can occur.Publishedhttp://www.geoscienze2014.it/1T. Geodinamica e interno della Terraope
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