Growth, structure and defects of (La,Sr)(Al,Ta)O3 crystals for preparing BiFeO3 thin films.

A new (La,Sr)(Al,Ta)O3 (LSAT) crystal is focused on in this paper to be used as an ideal substrate for preparing perfect BiFeO3 thin films. The crystal structures are designed with a low lattice mismatch between LSAT and BiFeO3. LSAT crystals were grown by the Czochralski method. In order to get colourless crystals with high transmittance, density functional theory is used to simulate the crystals with different defects. From the results, it is found that the colour centre originates from the defect of VSr + VO or VSr + 2VO. Thus, it is necessary for the crystals to be annealed in O2 and then in N2. High-quality BiFeO3/LSAT thin films will have promising application prospects.

Is it Beneficial to Reuse the Balloon in Percutaneous Kyphoplasty for the Treatment of Non-Neoplastic Vertebral Compression Fractures?

BACKGROUND Percutaneous kyphoplasty (PKP) has been widely used to treat vertebral compression fractures (VCFs). Bilateral percutaneous punctures are always performed to access the fractured vertebrae. However, the procedure has expensive clinical costs, especially the cost for the device, which creates a heavy financial burden for patients. MATERIAL AND METHODS Data from 49 patients who have single-level non-neoplastic vertebral compression fracture (VCF) were collected for 12 months after treated by PKP, including 21 cases that used bilateral puncture with single balloon (S group) and 28 cases that used bilateral puncture with double balloon (D group). We assessed the clinical (visual analogue scale, VAS) and radiological (vertebral height and kyphotic angle, KA) outcomes. Cost data (gross medical cost, cost for the device and cost for drugs) were obtained from the medical bill of each patient. RESULTS Baseline patient variables were similar between the two groups except the compensation (S group