Dataset Information

Hollow screw-like drill in plasma using an intense Laguerre-Gaussian laser.

ABSTRACT: With the development of ultra-intense laser technology, MeV ions can be obtained from laser-foil interactions in the laboratory. These energetic ion beams can be applied in fast ignition for inertial confinement fusion, medical therapy, and proton imaging. However, these ions are mainly accelerated in the laser propagation direction. Ion acceleration in an azimuthal orientation was scarcely studied. In this research, a doughnut Laguerre-Gaussian (LG) laser is used for the first time to examine laser-plasma interaction in the relativistic intensity regime in three-dimensional particle-in-cell simulations. Studies have shown that a novel rotation of the plasma is produced from the hollow screw-like drill of an mode laser. The angular momentum of particles in the longitudinal direction produced by the LG laser is enhanced compared with that produced by the usual laser pulses, such as linearly and circularly polarized Gaussian pulses. Moreover, the particles (including electrons and ions) can be trapped and uniformly compressed in the dark central minimum of the doughnut LG pulse. The hollow-structured LG laser has potential applications in the generation of x-rays with orbital angular momentum, plasma accelerators, fast ignition for inertial confinement fusion, and pulsars in the astrophysical environment.

SUBMITTER: Wang W

PROVIDER: S-EPMC4317693 | biostudies-other | 2015

REPOSITORIES: biostudies-other

ACCESS DATA

Similar Datasets

Project description:BackgroundWe introduced a new surgical method of percutaneous hollow perforated screw (HPS) fixation with concomitant bone-cement injection for the treatment of femoral neck metastasis and evaluated its efficacy for the palliative treatment of patients with advanced cancer.MethodsThe study included 87 patients (39 men and 48 women; mean age [and standard deviation], 64.2 ± 10.2 years; mean body mass index, 24.3 ± 3.2 kg/m2) who underwent percutaneous HPS fixation and cementoplasty (mean cement amount, 19.8 ± 8.3 mL) for the treatment of unilateral or bilateral femoral neck metastasis (total, 95 sites). Anesthesia type, operative time, operative blood loss, pain score changes (according to a visual analog scale [VAS]), walking status, and complications were assessed. The mean duration of follow-up was 10.1 ± 10.8 months (range, 2 to 43 months).ResultsThe majority of procedures were performed with local (3 patients) or spinal (72 patients) anesthesia (total, 75 patients; 86.2%). The mean operative time was 35.9 minutes, and the mean operative blood loss was 97.0 mL. The VAS score for pain improved significantly, from 6.8 ± 2.8 preoperatively to 2.8 ± 2.3 and 2.9 ± 2.8 at 1 and 6 weeks postoperatively (p < 0.001). At 6 weeks postoperatively, 63 (80.8%) of 78 patients were able to walk (with either normal or limping gait, a cane or crutch, or a walker). The prevalence of major local complications (cement leakage into the hip joint, fixation failure) was 10.5% (10 of 95), but major systemic complications (distant cement embolism) were not found.ConclusionsPercutaneous HPS fixation and cementoplasty for the treatment of femoral neck metastasis is a minimally invasive technique that provides effective pain relief and early stabilization. This technique seems to be useful for patients with advanced cancer for whom open surgery would be hazardous.Level of evidenceTherapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Dataset Information

Hollow screw-like drill in plasma using an intense Laguerre-Gaussian laser.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure