105 research outputs found

    Addressing single molecular spin with graphene based nano-architectures.

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    Finding reliable methods to exploit molecular degrees of freedom represents an intriguing problem involving the control of new mechanisms at the nano-scale and several technological challenges. Here we report a novel approach to address single molecular spin embedded in an electronic circuit. Our devices make use of molecules with well-defined magnetic anisotropy (TbPc2) embedded in nano-gapped electrodes obtained by electro-burning graphene layers. Such devices work as molecular spin transistors allowing the detection of the Tb spin flip during the sweep of an external magnetic field. The spin read out is made by the molecular quantum dot that, in turns, is driven by an auxiliary gate voltage. In the general context of (spin-)electronics, these results demonstrate that: 1) molecular quantum dots can be used as ultra-sensitive detectors for spin flip detection and 2) the use of graphene electrodes as platform to contact organo-metallic molecule is a viable route to design more complex nano-architectures

    Beyond cat scratch disease: a case report of bartonella infection mimicking vasculitic disorder

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    Cat scratch disease (CSD) is a bacterial disease caused by Bartonella henselae and it is mainly characterized by self-limiting lymphadenopathy in the draining site of a cat scratch or bite. We report a patient with history of fever, swelling lymph nodes, vasculitic-like skin lesions, and positivity of Bartonella serology initially considered as expression of a disimmune disease

    Evaluating the use of graphene electrodes in sub-micrometric, high-frequency n-type organic transistors

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    In this work we report on fully operational sub-micrometric low voltage OFETs by using graphene as the source-drain electrodes pair and a high-κ ultra-thin dielectric in a local gate architecture. The impact of the graphene electrodes on the miniaturization of the organic devices has been assessed, with particular attention to the influence of the contact resistances as well as the parasitic overlap gate capacitance on the device bandwidth. By the use of a modified Transmission-Line-Method, contact resistances have been analyzed as function of the applied voltages, revealing characteristic functional trends that follow the doping state of graphene electrodes. Through impedance spectroscopy of the electrodes, cut-off frequencies as high as 105 Hz have been estimated, highlighting the peculiar role of quantum capacitance of graphene in such architectures

    Tardive Dyskinesia, Oral Parafunction, and Implant-Supported Rehabilitation.

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    Oral movement disorders may lead to prosthesis and implant failure due to excessive loading. We report on an edentulous patient suffering from drug-induced tardive dyskinesia (TD) and oral parafunction (OP) rehabilitated with implant-supported screw-retained prostheses. The frequency and intensity of the movements were high, and no pharmacological intervention was possible. Moreover, the patient refused night-time splint therapy. A series of implant and prosthetic failures were experienced. Implant failures were all in the maxilla and stopped when a rigid titanium structure was placed to connect implants. Ad hoc designed studies are desirable to elucidate the mutual influence between oral movement disorders and implant-supported rehabilitation

    Testosterone Enanthate: An In Vitro Study of the Effects Triggered in MG-63 Cells

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    The aim of this study was to investigate the effects of the androgenic hormone testosterone enanthate (TE) on human MG-63 cells. MG-63 were cultured for 24 h in the presence of TE at increasing concentrations to assess its lethal dose. Therefore, the suitable concentration for a prolonged use of TE in vitro was assessed by viability assay over 9 days. Finally, MG-63 were exposed to TE for 14 days and assayed for differentiation by qPCR and Alizarin Red S staining. TE in the amount of 100 µM resulted as the maximum dose tolerated by MG-63 cells after 24 h. However, a prolonged exposure in culture TE in the amount of 100 µM showed a cytostatic effect on cell proliferation. On the contrary, TE 10 µM was tolerated by the cells and did not boost cell proliferation, but did enhance new bone formation, as revealed by COL1A1, ALPL, BGLAP, and IBSP gene expression after 3, 7, and 14 days, and calcium deposition by Alizarin Red S staining after 14 days. Based on the current study, 10 µM is the critical dose of TE that should be used in vitro to support bone differentiation of MG-63 cells

    Preparation of human primary macrophages to study the polarization from monocyte-derived macrophages to pro- or anti-inflammatory macrophages at biomaterial interface in vitro

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    Background/purpose: Testing of dental materials when in contact with innate immune cells has been so far hindered by the lack of proper in vitro models. Human primary monocyte-derived macrophages (MDMs) would be an excellent option to this aim. However, the inability to detach them from the tissue culture plates contrast the possibility to culture them on biomaterials. The goal of the present work is to present and validate an innovative protocol to obtain MDMs from peripheral blood monocytes, and to reseed them in contact with biomaterials without altering their viability and phenotype. Materials and methods: We differentiated MDMs on ultra-low attachment tissue culture plastics and recovered them with specific detachment solution in order to be reseeded on a secondary substrate. Therefore, using biological assays (RT-PCR, Western blot, and immunofluorescence) we compared their phenotype to MDMs differentiated on standard culture plates. Results: Transferred MDMs keep their differentiated M0 resting state, as well as the ability to be polarized into M1 (pro-inflammatory) or M2 (anti-inflammatory) macrophages. Conclusion: These data provide the dental material research community the unprecedented possibility to investigate the immunomodulatory properties of biomaterials for dental application

    Single-molecule devices with graphene electrodes

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    Several technological issues have to be faced to realize devices working at the single molecule level. One of the main challenges consists of defining methods to fabricate electrodes to make contact with single molecules. Here, we report the realization of novel spintronic devices made of a TbPc2 single molecule embedded between two nanometer-separated graphene electrodes, obtained by feedback-controlled electroburning. We demonstrate that this approach allows the realisation of devices working at low temperature. With these, we were able to characterize the magnetic exchange coupling between the electronic spin of the Tb3+ magnetic core and the current passing through the molecular system in the Coulomb blockade regime, thus showing that the use of graphene is a promising way forward in addressing single molecules

    THU0600 a case of systemic sclerosis complicated by renal crisis: potential etiopathogenetic role of cytomegalovirus and treatment

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    Background: Scleroderma renal crisis (SRC) is a rare complication of systemic sclerosis (SSc), which can be triggered by viruses, such as Cytomegalovirus (CMV). SRC presents as a new-onset accelerated-phase hypertension with/without rapidly progressive renal failure. Objectives: Here we describe the case of a patient developing SSc complicated by the appearance of SRC after a recent episode of acute Cytomegalovirus infection. Methods: A 66-year-old male was referred to our Scleroderma Unit in March 2019. He presented with widespread skin rash, exertional dyspnoea and peripheral oedemas. He reported a myocarditis due to CMV occurred in October 2018. Antibodies anti-CMV IgM were detected in his serum. The patient developed a progressive cutaneous involvement characterized by diffuse oedema, sclerosis and melanoderma. Subsequently, Raynaud’s phenomenon, puffy hands and pitting scars

    Correlation between density and resorption of fresh-frozen and autogenous bone grafts

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    Trial Design. This analysis compared the outcome of fresh-frozen versus autologous bone block grafts for horizontal ridge augmentation in patients with Cawood and Howell class IV atrophies. Methods. Seventeen patients received autologous grafts and 21 patients received fresh-frozen bone grafts. Patients underwent CT scans 1 week and 6 months after surgery for graft volume and density analysis. Results. Two autologous and 3 fresh-frozen grafts failed. Autologous and fresh-frozen grafts lost, respectively, 28% and 46% of their initial volume (P = 0.028). It is noteworthy that less dense fresh-frozen blocks lost more volume than denser grafts (61% versus 16%). Conclusions. According to these 6-month results, only denser fresh-frozen bone graft may be an acceptable alternative to autologous bone for horizontal ridge augmentation. Further studies are needed to investigate its behaviour at longer time points

    The importance of WNT pathways for bone metabolism and their regulation by implant topography

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    Endosseous implants are important tools to replace missing teeth or damaged tissue segments. Their clinical success depends on their integration in bone and, thus, on the response of bone cells to material and surface characteristics. Recent evidence has shown that surface topography and chemistry affect WNT signalling, a pivotal pathway for the commitment of mesenchymal progenitors to the osteoblast lineage and for bone homeostasis. WNT signalling comprises several cascades that, acting through different effectors, modulate several aspects of cell behaviour.It has been shown that cells growing on rough titanium surfaces display a different expression profile for WNT factors, and that surface features can alter the response of bone cells to WNT factors. Although the underlying mechanisms to this regulation are still poorly understood, the present review reports intriguing evidence that that cell cytoskeletal signalling is involved in activating WNT signalling in cells growing on rough implant surfaces
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