467 research outputs found

    Ectopic eruption of the first permanent molar in the maxilla: Cephalometric features of 13 pediatric patients

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    Ectopic eruption of the first permanent molar in the maxilla, generally characterized by the wrong axial positioning during eruption, is reported to occur in about 2–6% of children. Its incidence is surely under-estimated as it frequently remains undiagnosed and, additionally, becomes irreversible, resulting in posterior crowding in such cases. This retrospective study aims to investigate the cephalometric features of patients affected by ectopic eruption of the maxillary first molar in comparison to a control group of patients. From a total of 1935 subjects, 13 patients were enrolled in the study group, while 26 patients were randomly selected as a control group. Lateral cephalometric teleradiographs obtained at the time of diagnosis were used to measure cephalometric values between study patients and controls. The prevalence of ectopic eruption of the first maxillary permanent molar in our patients was 1.14%. The mandibular angle (SN-GoMe) was found to be significantly greater in the study group than in control. The same statistical trend was observed for the inter-maxillary angle (SnaSnp-GoMe); also, the distance Sna-Me was greater in the study group. Differences between groups were statistically significant for the following distances: Snp-Sna, Ba-S and SOR-Sna, which were found to be, overall, greater in the study group. Ectopic eruption of the first permanent molar in the maxilla seems to be associated with morphogenetic characteristics of patients, mainly with a dolichocephalic pattern

    Combustion and performance characteristics of air-fuel mixtures ignited by means of photo-thermal ignition of Nano-Energetic Materials

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    Abstract This work presents an experimental investigation to determine the performance and characteristics of the combustion process triggered by a new ignition system based on photo-thermal effect, observed when nano-Energetic Materials are exposed to a flash light. The resulting combustion process has been compared with the one obtained using the spark-plug traditionally used in spark ignition engines. Results showed that the photo-thermal ignition determines higher combustion pressure gradient, peak pressure, total heat released, fuel combustion efficiency, and a shorter ignition delay and combustion duration compared with the spark ignition, for all the tested fuels and air-fuel ratios

    Early mandibular canine-lateral incisor transposition: case report

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    Purpose. The main aim of the present study is to present a case of mandibular transposition between lateral incisor and canine in a paediatric patient. Materials and methods. A fixed multibracket orthodontic treatment was performed by means of a modified welded arch as to correct the transposition and obtaining a class I functional and symmetrical occlusion, also thanks to the early diagnosis of the eruption anomaly. Results. Our case report shows that a satisfactory treatment of mandibular transpositions is obtained when detected at an early stage of the tooth development. Conclusions. The main treatment options to be taken into consideration in case of a mandibular transposition are two: correcting the transposition or aligning it leaving the dental elements in their transposed order; in both cases, the followups show a stable condition, maintained without relapses. Several factors, such as age of the patient, occlusion, aesthetics, patient’s collaboration, periodontal support and duration of treatment have to be considered as to prevent potential damage to dental elements and support appliances. The choice between the two treatment approaches for mandibular lateral incisor/canine transpositions mainly depends on the time the anomaly is detected

    On the vanishing viscosity limit in a disk

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    We say that the solution u to the Navier-Stokes equations converges to a solution v to the Euler equations in the vanishing viscosity limit if u converges to v in the energy norm uniformly over a finite time interval. Working specifically in the unit disk, we show that a necessary and sufficient condition for the vanishing viscosity limit to hold is the vanishing with the viscosity of the time-space average of the energy of u in a boundary layer of width proportional to the viscosity due to modes (eigenfunctions of the Stokes operator) whose frequencies in the radial or the tangential direction lie between L and M. Here, L must be of order less than 1/(viscosity) and M must be of order greater than 1/(viscosity)

    Hepatic arterial infusion of chemotherapy for advanced hepatobiliary cancers: State of the art

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    Liver functional failure is one of the leading causes of cancer-related death. Primary liver tumors grow up mainly in the liver, and thus happens for liver metastases deriving from other organs having a lower burden of disease at the primary site. Systemic chemotherapy usually offers a modest benefit in terms of disease control rate, progression-free survival, and overall survival at the cost of a significant percentage of adverse events. Liver malignancies are mostly perfused by the hepatic artery while the normal liver parenchyma by the portal vein network. On these bases, the therapeutic strategy consisting of hepatic arterial infusion (HAI) of chemotherapy takes place. In literature, HAI chemotherapy was applied for the treatment of advanced hepatobiliary cancers with encouraging results. Different chemotherapeutic agents were used such as Oxaliplatin, Cisplatin, Gemcitabine, Floxuridine, 5-Fluorouracil, Epirubicin, individually or in combination. However, the efficacy of this treatment strategy remains controversial. Therefore, this review aims to summarize the current knowledge on this approach from different points of view, such as techniques, drugs pharmacology and pharmacokinetics, and clinical outcomes for advanced hepatobiliary cancers

    Air/methane mixture ignition with Multi-Walled Carbon Nanotubes (MWCNTs) and comparison with spark ignition

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    The possibility to ignite the single wall carbon nanotubes (SWCNTs) containing impurities of iron in atmosphere once exposed to the radiation of a flash camera was observed for the first time in 2002. Afterwards, it was proposed to exploit this property in order to use nanostructured materials as ignition agents for fuel mixtures. Finally, in 2011 it was shown that SWCNTs can be effectively used as ignition source for an air/ethylene mixture filling a constant volume combustion chamber; the observed combustion presented the characteristics of a homogeneous-like combustion. In this paper a system for the ignition of an air/methane mixture is proposed, based on the exposition of multi wall carbon nanotubes (MWCNTs) to a low consumption flash camera. Namely, several experiments have been run in which 20 mg of MWCNTs, containing 75% in weight of ferrocene, have been added to an air/methane fuel mixture inside a constant volume combustion chamber. The mixture has been heated up to 373 K and the onset pressure was set equal to 3 bar. The experiments have been run varying the equivalence ratio in the range 1–2. The combustion process so realized has been compared to that obtained igniting the mixture with a traditional spark as in spark ignition engines. The comparison has been based on chamber pressure measurement as well as combustion process images, both sampled at a frequency equal to 2,5 kHz for an overall duration of 1.8 s. Results confirm that the ignition triggered with MWCNTs leads to a homogeneous-like combustion, without observing a well-defined flame front propagation. The contrary is observed, as expected, with the spark assisted ignition. Moreover, dynamic pressure measurements show that, compared to spark assisted ignition, the MWCNTs photo-ignition determines a more rapid pressure gradient and a higher peak pressure which corresponds to a higher energy release rate

    Vegetarian and vegan weaning of the infant: How common and how evidence-based? a population-based survey and narrative review

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    Background: Vegetarian and vegan weaning have increasing popularity among parents and families. However, if not correctly managed, they may lead to wrong feeding regimens, causing severe nutritional deficiencies requiring specific nutritional support or even the need for hospitalization. Aim: To assess the prevalence of vegetarian and vegan weaning among Italian families and to provide an up-to-date narrative review of supporting evidence. Materials and methods: We investigated 360 Italian families using a 40-item questionnaire. The narrative review was conducted searching scientific databases for articles reporting on vegetarian and vegan weaning. Results: 8.6% of mothers follow an alternative feeding regimen and 9.2% of infants were weaned according to a vegetarian or vegan diet. The breastfeeding duration was longer in vegetarian/vegan infants (15.8 vs. 9.7 months; p < 0.0001). Almost half of parents (45.2%) claim that their pediatrician was unable to provide sufficient information and adequate indications regarding unconventional weaning and 77.4% of parents reported the pediatrician’s resistance towards alternative weaning methods. Nine studies were suitable for the review process. The vast majority of authors agree on the fact that vegetarian and vegan weaning may cause severe nutritional deficiencies, whose detrimental effects are particularly significant in the early stages of life. Discussion and conclusion: Our results show that alternative weaning methods are followed by a significant number of families; in half of the cases, the family pediatrician was not perceived as an appropriate guide in this delicate process. To date, consistent findings to support both the safety and feasibility of alternative weaning methods are still lacking. Since the risk of nutritional deficiencies in the early stages of life is high, pediatricians have a pivotal role in guiding parents and advising them on the most appropriate and complete diet regimen during childhood. Efforts should be made to enhance nutritional understanding among pediatricians as an unsupervised vegetarian or vegan diet can cause severe nutritional deficiencies with possible detrimental long-term effects

    Parp inhibitors and epithelial ovarian cancer: Molecular mechanisms, clinical development and future prospective (Review)

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    Epithelial ovarian cancer (EOC) has a poor prog- nosis. Since the introduction of paclitaxel as antineoplastic agent >20 years ago, only a few phase III randomized trials have shown challenging data regarding different therapeutic options for facing its aggressive clinical course and granting active therapies to patients. Different studies have shown the utility of poly(ADP-ribose) polymerase (PARP) inhibitors in women with EOC with or without BRCA mutations, both germ- line and somatic. Three PARP inhibitors, olaparib, rucaparib and niraparib, have been recently approved by the Food and Drug Administration for clinical use in EOC patients, though with different clinical indications and profiles of toxicity, while two other molecules, veliparib and talazoparib, are still under clinical investigation. The aim of the present paper is to evaluate the current status of PARP inhibitors in terms of molecular activity, pharmacodynamic properties and clinical applications

    Molecular and Functional Characterization of Three Different Postzygotic Mutations in PIK3CA-Related Overgrowth Spectrum (PROS) Patients: Effects on PI3K/AKT/mTOR Signaling and Sensitivity to PIK3 Inhibitors

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    BACKGROUND PIK3CA-related overgrowth spectrum (PROS) include a group of disorders that affect only the terminal portion of a limb, such as type I macrodactyly, and conditions like fibroadipose overgrowth (FAO), megalencephaly-capillary malformation (MCAP) syndrome, congenital lipomatous asymmetric overgrowth of the trunk, lymphatic, capillary, venous, and combined-type vascular malformations, epidermal nevi, skeletal and spinal anomalies (CLOVES) syndrome and Hemihyperplasia Multiple Lipomatosis (HHML). Heterozygous postzygotic PIK3CA mutations are frequently identified in these syndromes, while timing and tissue specificity of the mutational event are likely responsible for the extreme phenotypic variability observed. METHODS: We carried out a combination of Sanger sequencing and targeted deep sequencing of genes involved in the PI3K/AKT/mTOR pathway in three patients (1 MCAP and 2 FAO) to identify causative mutations, and performed immunoblot analyses to assay the phosphorylation status of AKT and P70S6K in affected dermal fibroblasts. In addition, we evaluated their ability to grow in the absence of serum and their response to the PI3K inhibitors wortmannin and LY294002 in vitro. RESULTS AND CONCLUSION: Our data indicate that patients' cells showed constitutive activation of the PI3K/Akt pathway. Of note, PI3K pharmacological blockade resulted in a significant reduction of the proliferation rate in culture, suggesting that inhibition of PI3K might prove beneficial in future therapies for PROS patients

    Bovine Lactoferrin Prevents Invasive Fungal Infections in Very Low Birth Weight Infants: A Randomized Controlled Trial.

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    BACKGROUND: Lactoferrin is a mammalian milk glycoprotein involved in innate immunity. Recent data show that bovine lactoferrin (bLF) prevents late-onset sepsis in preterm very low birth weight (VLBW) neonates. METHODS: This is a secondary analysis of data from a multicenter randomized controlled trial where preterm VLBW neonates randomly received bLF (100 mg/day; group A1), bLF + Lactobacillus rhamnosus GG (10(6) colony-forming units per day; group A2), or placebo (group B) for 6 weeks. Here we analyze the incidence rates of fungal colonization, invasive fungal infection (IFI), and rate of progression from colonization to infection in all groups. RESULTS: This study included 472 neonates whose clinical, nutritional, and demographical characteristics were similar. Overall, the incidence of fungal colonization was comparable (17.6%, 16.6%, and 18.5% in A1, A2, and B, respectively; P = .89 [A1] and .77 [A2]). In contrast, IFIs were significantly decreased in A1 and A2 (0.7% and 2.0%, respectively) compared with B (7.7%; P = .002 [A1] and .02 [A2]), and this was significantly true both in <1000 g (0.9% [A1] and 5.6% [A2], vs 15.0%) and in 1001 to 1500 g infants (0% and 0% vs 3.7%). The progression rate colonization-infection was significantly lower in the bLF groups: 3.7% (A1) and 12% (A2), vs 41.9%; P < .001 (A1) and P = .02 (A2). No IFI-attributable deaths occurred in the treatment groups, versus 2 in placebo. No adverse effects or intolerances occurred. CONCLUSIONS: Prophylactic oral administration of bLF reduces the incidence of IFI in preterm VLBW neonates. No effect is seen on colonization. The protective effect on IFI is likely due to limitation of ability of fungal colonies to progress toward invasion and systemic disease in colonized infants
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