233 research outputs found

    Investigation of the composition of the Luna 16 lunar sample

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    The concentrations of aluminum, manganese, sodium, chromium, iron, cobalt, and 12 rare earth elements were determined by neutron activation analysis using slow neutrons. Oxygen and silicon were determined using a fast neutron generator. Mossbauer spectroscopy was used to investigate iron compounds in Luna 16 regolith samples from the upper part of the core

    Magnetic resonance-guided focused ultrasound treatment of facet joint pain: summary of preclinical phase

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    STUDY DESIGN: A phantom experiment, two thermocouple experiments, three in vivo pig experiments, and a simulated treatment on a healthy human volunteer were conducted to test the feasibility, safety, and efficacy of magnetic resonance-guided focused ultrasound (MRgFUS) for treating facet joint pain. OBJECTIVE: The goal of the current study was to develop a novel method for accurate and safe noninvasive facet joint ablation using MRgFUS. SUMMARY OF BACKGROUND DATA: Facet joints are a common source of chronic back pain. Direct facet joint interventions include medial branch nerve ablation and intra-articular injections, which are widely used, but limited in the short and long term. MRgFUS is a breakthrough technology that enables accurate delivery of high-intensity focused ultrasound energy to create a localized temperature rise for tissue ablation, using MR guidance for treatment planning and real-time feedback. METHODS: We validated the feasibility, safety, and efficacy of MRgFUS for facet joint ablation using the ExAblate 2000® System (InSightec Ltd., Tirat Carmel, Israel) and confirmed the system's ability to ablate the edge of the facet joint and all terminal nerves innervating the joint. A phantom experiment, two thermocouple experiments, three in vivo pig experiments, and a simulated treatment on a healthy human volunteer were conducted. RESULTS: The experiments showed that targeting the facet joint with energies of 150–450 J provides controlled and accurate heating at the facet joint edge without penetration to the vertebral body, spinal canal, or root foramina. Treating with reduced diameter of the acoustic beam is recommended since a narrower beam improves access to the targeted areas. CONCLUSIONS: MRgFUS can safely and effectively target and ablate the facet joint. These results are highly significant, given that this is the first study to demonstrate the potential of MRgFUS to treat facet joint pain

    Calcium phosphate coating formed on titanium scaffold by plasma electrolytic oxidation

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    The article provides the results of the preparation of calcium phosphate coatings by plasma electrolytic oxidation. Calcium phosphate coatings are formed on titanium scaffolds with a porous structure. Titanium scaffolds are products of additive manufacturing equipment by selective laser melting. The morphology of the obtained coating, phase and elemental composition are described, the Ca/P ratio of the coating is dete rmined. The surface of the scaffold is porous due to the baking of powder particles during production. XRD analysis shows the presence of calcium phosphate and oxide compounds. The resulting oxide coating is evenly distributed over the porous surface of the scaffold. Titanium, aluminum and vanadium are located in the areas of the coating free of calcium phosphate particles. The average Ca/P ratio for the resulting coating was 2.48. This value is close to the Ca/P ratio in human bone. It is concluded that the use of the PEO method is promising for the manufacture of scaffolds with a porous structure with calcium phosphate coatings for use in traumatology and orthopedics. The use of titanium scaffolds with a porous structure with calcium phosphate coatings will improve the osseointegration of implants and exclude the possibility of implant failure
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