252 research outputs found

    Delayed eruption of permanent dentition and maxillary contraction in patients with cleidocranial dysplasia: review and report of a family

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    Introduction. Cleidocranial dysplasia (CCD) is an inherited disease caused by mutations in the RUNX2 gene on chromosome 6p21. This pathology, autosomal dominant or caused by a spontaneous genetic mutation, is present in one in one million individuals, with complete penetrance and widely variable expressivity. Aim. To identify the incidence of these clinical findings in the report of the literature by means of PubMed interface from 2002 to 2015, with the related keywords. The report of local patients presents a clinical example, related to the therapeutic approach. Results and Discussions. The PubMed research resulted in 122 articles. All the typical signs were reported in all presented cases. The maxilla was hypoplastic in 94% of the patients. Missing of permanent teeth was found in two cases: one case presented a class II jaw relationship, instead of class III malocclusion. Similar findings were present in our cohort. Conclusion. CCD is challenging for both the dental team and the patient. The treatment requires a multidisciplinary approach. Further studies are required to better understand the cause of this disease. According to this review, a multistep approach enhances the possibilities to achieve the recovery of the most possible number of teeth, as such to obtain a good occlusion and a better aesthetic

    Beneficial effects of Trichoderma harzianum T-22 in tomato seedlings infected by Cucumber mosaic virus (CMV)

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    The study of the biochemical and molecular mechanisms deriving from the host-pathogen-antagonist interaction is essential to understand the dynamics of infectious processes and can be useful for the development of new strategies to control phytopathogens, particularly viruses, against which chemical treatments have no effect. In this work, we demonstrate the ability of the rhizospheric fungus Trichoderma harzianum strain T-22 (T22) to induce defense responses in tomato (Solanum lycopersicum var. cerasiforme) against Cucumber mosaic virus (CMV, family Bromoviridae, genus Cucumovirus) strain Fny. A granule formulation containing T22 was used for treating the plants before, simultaneously or after the CMV inoculation, in order to study the molecular and biochemical aspects of the interaction between T22 and tomato against the virus. Reactive oxygen species (ROS) and the genes encoding for ROS scavenging enzymes were investigated. Histochemical analysis revealed a different increase in the superoxide anion (O2 ) and hydrogen peroxide (H2O2) content in plants infected by CMV alone or in the presence of T22, confirming the involvement of ROS in plant defense responses. Gene expression analysis suggested a definite improvement in oxidative stress when plants were treated with T22 after inoculation with CMV. In conclusion, our data indicate that Trichoderma harzianum T-22 stimulates the induction of tomato defense responses against CMV, an action that implies the involvement of ROS, pointing towards its use as a treatment rather than as a preventive measure

    Towards understanding the thermal history of microstructural surface deformation when cutting a next generation powder metallurgy nickel-base superalloy

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    Despite the ongoing progress in metallurgical characterisation of machined surfaces, knowledge of the thermal conditions under which they originate during the workpiece-flank interaction is still lacking. When cutting advanced superalloys, little is known about temperature evolution in the machined part volume, where workpiece material interacts with the tool flank. In this work, the characteristics of the thermal field and the resulting surface metallurgy induced in a next generation nickel-base superalloy have been studied for cutting scenarios involving different combinations of thermo-mechanical boundary conditions. Analysis of the thermal field evolution in the workpiece subsurface has allowed the heating and cooling rates induced by cutting to be revealed, allowing description of two distinct types of thermal cycle, with a Heating-Peaking-Cooling (H–P–C) and a Heating-Quasi-isothermal Deformation-Cooling (HQC) structure depending on the process aggressiveness. Subsurface thermal history has been found to relate with the severity of the cutting-induced deformation, as it combines information on thermal field magnitude and on the process rates. Furthermore, thermal balance equations have been applied to study the rate of the heat generation in the machined subsurface due to its own plastic deformation while interacting with the tool flank. This has revealed that the highest rate of heat generation induced by plastic deformation occurred in thin surface layers at the beginning of the workpiece-flank contact, which has been associated to the conditions under which white layers (WLs) are generated. Energy balance analysis has furthermore indicated the development of a less severe and less impulsive deformation process at higher subsurface depths, which has been linked to the formation mechanism of material drag (MD) layers. In this way, the thermal history of machined surfaces has been related to their resulting metallurgical integrity, allowing in-depth understanding of the physical conditions developing when cutting next-generation superalloys

    Can higher cutting speeds and temperatures improve the microstructural surface integrity of advanced Ni-base superalloys?

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    Future Ni-base superalloys are designed to deliver outstanding mechanical behaviour at high temperatures, which may translate in significant machining challenges. In this work, a paradigm is presented by which is proven how machining of these materials could benefit from increased cutting speeds and temperatures provided that they are able to promote shear localisation and thermal softening in the chip deformation zones, whilst retaining high-temperature strength within the machined surface. In this way, thermal control of chip formation leads to both lower cutting forces and energies, as well as enhanced surface integrity with lower levels of microstructural reconfiguration

    Temperature-dependent shear localisation and microstructural evolution in machining of nickel-base superalloys

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    Understanding the microstructural evolution mechanisms in machining of advanced materials is essential to achieve excellent surface integrity levels within the manufacture of safety–critical components. However, as thermal and mechanical effects are coupled in conventional cutting operations, it is difficult to attribute their individual role on microstructural evolution and integrity. To investigate the temperature-dependency of microstructural evolution in cutting, a new experimental set-up has been developed to perform machining experiments under controlled temperatures. Results show that an onset in chip shear localisation with nanocrystalline grain refinement can be induced uniquely by an increase in cutting temperature under fixed cutting parameters, which microstructurally controls the transition from continuous to serrated chip formation. Increase in mechanical effects at HT leads to the formation of a continuous chip grain refinement layer, associated to a change in energy partition at the tool-workpiece interface. These small-scale behaviours are found to control the reduction in cutting forces and energy at higher temperatures, with a decrease of ∼ 25–30%. Nevertheless, despite the lower deformation energy, HT cutting induced larger amounts of microstructural deformation because of thermal softening effects, further disclosing the role of thermal effects on the interplay between shear localisation, microstructural evolution and surface integrity

    Understanding the Reactivity of a Thin Li1.5Al0.5Ge1.5(PO4)3 Solid-State Electrolyte toward Metallic Lithium Anode

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    The thickness of solid-state electrolytes (SSEs) significantly affects the energy density and safety performance of all-solid-state lithium batteries. However, a sufficient understanding of the reactivity toward lithium metal of ultrathin SSEs (<100 Âµm) based on NASICON remains lacking. Herein, for the first time, a self-standing and ultrathin (70 Âµm) NASICON-type Li1.5Al0.5Ge1.5(PO4)3 (LAGP) electrolyte via a scalable solution process is developed, and X-ray photoelectron spectroscopy reveals that changes in LAGP at the metastable Li–LAGP interface during battery operation is temperature dependent. Severe germanium reduction and decrease in LAGP particle size are detected at the Li–LAGP interface at elevated temperature. Oriented plating of lithium metal on its preferred (110) face occurs during in situ X-ray diffraction cycling

    First IXPE Observations of the Accreting X-ray Pulsar Her X-1

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    Theoretical models for the X-ray emission of accretion-powered pulsars predict a high degree and a strong spin-phase dependence of the X-ray polarization. Using observations of the Imaging X-ray Polarimetry Explorer of the accreting pulsar Her X-1, we were able to test these predictions for the first time ever

    CATANA protontherapy facility: The state of art of clinical and dosimetric experience

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    After nine years of activity, about 220 patients have been treated at the CATANA Eye Protontherapy facility. A 62MeV proton beam produced by a Superconducting Cyclotron is dedicated to radiotherapy of eye lesions, as uveal melanomas. Research and development work has been done to test different dosimetry devices to be used for reference and relative dosimetry, in order to achieve dose delivering accuracy. The follow-up results demonstrated the efficacy of proton beams and encouraged us in our activity in the fight against cancer
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