45 research outputs found

    Mechanical and tribological characterization of nanostructured HfB2 flms deposited from compound target

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    Fabrication and development of HfB2-based nanostructured coatings was investigated. All flms were deposited on stainless-steel substrates by RF magnetron sputtering from stochiometric HfB2 target in argon atmosphere. The aim of this work is to evaluate the efects of the bias potential on the microstructure, mechanical and tribological properties. These parameters strongly depend on the experimental conditions. X-ray difraction analysis indicated the diference in microstructure: from dense hexagonal structure with (0001) preferred orientation of nanocrystallites to quasi-amorphous with blurred HfB2 phase peaks. All coatings were measured using nanoindentation (using Berkovich tip), tribology (ballon-disk) and nano-scratch (friction). Coatings with a thickness of 1–2 µm had a signifcant dependence of properties on the microstructure: hardness drastically increased from 8 to 45 GPa, H/E ratio and elastic recovery changed respectively: 0.04–0.15 and 0.26–0.72

    Natural killer cells as a therapeutic tool for infectious diseases - current status and future perspectives

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    Natural Killer (NK) cells are involved in the host immune response against infections due to viral, bacterial and fungal pathogens, all of which are a significant cause of morbidity and mortality in immunocompromised patients. Since the recovery of the immune system has a major impact on the outcome of an infectious complication, there is major interest in strengthening the host response in immunocompromised patients, either by using cytokines or growth factors or by adoptive cellular therapies transfusing immune cells such as granulocytes or pathogen-specific T-cells. To date, relatively little is known about the potential of adoptively transferring NK cells in immunocompromised patients with infectious complications, although the anti-cancer property of NK cells is already being investigated in the clinical setting. This review will focus on the antimicrobial properties of NK cells and the current standing and future perspectives of generating and using NK cells as immunotherapy in patients with infectious complications, an approach which is promising and might have an important clinical impact in the future

    The Trace Kynurenine, Cinnabarinic Acid, Displays Potent Antipsychotic-Like Activity in Mice and Its Levels Are Reduced in the Prefrontal Cortex of Individuals Affected by Schizophrenia

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    Cinnabarinic acid (CA) is a kynurenine metabolite that activates mGlu4 metabotropic glutamate receptors. Using a highly sensitive ultra-performance liquid chromatography/tandem mass spectrometry (UPLC/MS-MS) method, we found that CA is present in trace amounts in human brain tissue. CA levels were largely reduced in the prefrontal cortex (PFC) of individuals affected by schizophrenia. This reduction did not correlate with age, sex, duration of the disease, and duration and type of antipsychotic medication and might, therefore, represent a trait of schizophrenia. Interestingly, systemic treatment with low doses of CA (<1 mg/kg, i.p.) showed robust efficacy in several behavioral tests useful to study antipsychotic-like activity in mice and rats and attenuated MK-801-evoked glutamate release. CA failed to display antipsychotic-like activity and inhibit excitatory synaptic transmission in mice lacking mGlu4 receptors. These findings suggest that CA is a potent endogenous antipsychotic-like molecule and reduced CA levels in the PFC might contribute to the pathophysiology of schizophrenia
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