300 research outputs found

    Quest and Probe Related to Erosion in the Wrap-Around of an Embankment

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    CESP\u27s divers team found several basalt blocks scattered on the stilling basin of a power plant. Water flowing through bottom outlets was initially supposed to cause erosion in the upstream rip-rap of the wrap-around. Events chronologically reported are: Underwater inspection; removal of materials; monitoring devices behavior; hydraulic tests. Hinder analyses led to recognition of misunderstanding on anomalous mechanism and misconception on the actual sources for the hauled rubbish

    Si-atoms substitutions effects on the electronic and optical properties of coronene and ovalene

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    We report a computational comparative study of the ground and excited states properties of graphene nanoribbons, analyzing the case of coronene (C24H12) and ovalene (C32H14) and their silicon-atoms substituted counterparts with single, double and triple atomic insertions. We used density functional theory (DFT) and time-dependent DFT to quantify the effects on the electronic and optical properties as a result of the chemical modifications. In particular, we compared ground-state total energies, electron affinities, ionization energies, fundamental gaps and optical absorption spectra, between the original systems and each substituted one. For both the molecules, we observed a general reduction of the fundamental gap after chemical modification. Concerning the optical properties, therefore, we observed a redshift of the optical onset in all the cases; in particular, we have found that, in one ovalene and coronene trimer-substituted configuration, the absorption edge takes place in the IR

    Transcutol® p containing slns for improving 8-methoxypsoralen skin delivery

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    Topical psoralens plus ultraviolet A radiation (PUVA) therapy consists in the topical application of 8-methoxypsoralen (8-MOP) followed by the skin irradiation with ultraviolet A radiation. The employment of classical 8-MOP vehicles in topical PUVA therapy is associated with poor skin deposition and weak skin permeability of psoralens, thus requiring frequent drug administration. The aim of the present work was to formulate solid lipid nanoparticles (SLNs) able to increase the skin permeation of 8-MOP. For this purpose, the penetration enhancer Transcutol® P (TRC) was added to the SLN formulation. SLNs were characterized with respect to size, polydispersity index, zeta potential, entrapment efficiency, morphology, stability, and biocompatibility. Finally, 8-MOP skin diffusion and distribution within the skin layers was investigated using Franz cells and newborn pig skin. Freshly prepared nanoparticles showed spherical shape, mean diameters ranging between 120 and 133 nm, a fairly narrow size distribution, highly negative ζ potential values, and high entrapment efficiency. Empty and loaded formulations were almost stable over 30 days. In vitro penetration and permeation studies demonstrated a greater 8-MOP accumulation in each skin layer after SLN TRC 2% and TRC 4% application than that after SLN TRC 0% application. Finally, the results of experiments on 3T3 fibroblasts showed that the incorporation of TRC into SLNs could enhance the cellular uptake of nanoparticles, but it did not increase their cytotoxicity

    Trimethyl chitosan hydrogel nanoparticles for progesterone delivery in neurodegenerative disorders

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    Progesterone is a sex hormone which shows neuroprotective effects in different neurodegenerative disorders, including Parkinson’s disease, stroke, and Alzheimer’s disease. However, the pharmacokinetic limitations associated with the peripheral administration of this molecule highlight the need for more efficient delivery approaches to increase brain progesterone levels. Since the nose-to-brain administration of mucoadhesive hydrogel nanoparticles is a non-invasive and convenient strategy for the delivery of therapeutics to the central nervous system, in this work, progesterone-loaded hydrogel nanoparticle formulations have been prepared, characterized, and tested in vivo. Nanoparticles, loaded with different progesterone concentrations, have been obtained by polyelectrolyte complex formation between trimethyl chitosan and sodium alginate, followed by ionotropic gelation with sodium tripolyphosphate as a cross-linking agent. All formulations showed a mean diameter ranging from 200 nm to 236 nm, a polydispersity index smaller than 0.23, and a high progesterone encapsulation efficiency (83–95%). The zeta potential values were all positive and greater than 28 mV, thus ensuring nanoparticles stability against aggregation phenomena as well as interaction with negative sialic residues of the nasal mucosa. Finally, in vivo studies on Sprague–Dawley male rats demonstrated a 5-fold increase in brain progesterone concentrations compared to basal progesterone level after 30 min of hydrogel nanoparticle inhalation

    Uterine artery pseudoaneurysm requiring embolization in pregnancy: a case report and review of the literature.

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    Background: Uterine Artery Pseudoaneurysm is a rare cause of pelvic pain and haemorrhage in pregnancy. It should be considered in the differential diagnosis of pregnant women presenting with abdominal pain and is readily diagnosed by colour Doppler ultrasound. If left untreated, they may bleed into the peritoneum causing severe pain and haemorrhagic shock and may progress to maternal and fetal death. Case presentation: We describe a case of a woman presenting with severe right iliac fossa pain at 26 weeks gestation attributed to a right uterine artery pseudoaneurysm diagnosed on duplex ultrasound which was successfully treated by uterine artery embolization at 28 weeks gestation without complication to the fetus. Conclusion: Uterine artery embolization appears to be a safe and effective method to treat pseudoaneurysm during pregnancy without compromising uteroplacental perfusion
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