[Intraoperative ultrasound assisted circumferential decompression for multilevel ossification of the posterior longitudinal ligament in thoracic vertebrae].

OBJECTIVE: To analyze the effect of short-segment circumferential decompression and the nerve function improvement in 30 cases of multilevel thoracic OPLL assisted by intraoperative ultrasound. METHODS: A total of 30 patients with multilevel thoracic OPLL from January 2016 to January 2021 were enrolled, all of whom were located by intraoperative ultrasound and underwent circumferential decompression. There were 14 males and 16 females, with an average age of (49.3±11.4) years. The initial symptoms were mainly numbness and weakness of lower limbs (83.3%), and the mean duration of symptoms was (33.9±42.9) months (1-168 months). Neurological function was assessed by the Modified Japanese Orthopedic Association (mJOA) score (0-11) preoperative and at the last follow-up, in which the rate of neurological improvement was calculated by the Harabayashi method. The patients were divided into excellent improved group and poor improved group according to the improvement of neurological function. The age, body mass index (BMI), duration of symptoms, operation time, blood loss, mJOA score, surgical level, and cerebrospinal fluid leakage of the two groups were collected and analyzed for statistical differences. The factors influencing the improvement of neurological function were analyzed by univariate and multivariate Logisitic regression analysis. RESULTS: The mean operation time was 137.4±33.8 (56-190) min, and the mean blood loss was (653.7±534.2) mL (200－3 000 mL). The preoperative mJOA score was 6.0±2.1 (2－9), and the last follow-up mJOA score was 7.6±1.9 (4－11), which was significantly improved in all the patients (P < 0.001). The average improvement rate of neurological function was 38.1%±24.4% (14.3%－100%), including 75%－100% in 4 cases, 50%－74% in 3 cases, 25%－49% improved in 14 cases, and 0%－24% in 9 cases. There was significant difference in intraoperative blood loss between the excellent improved group and the poor improved group (P=0.047). Intraoperative blood loss was also an independent risk factor in regression analysis of neurological improvement. CONCLUSION: Thoracic circumferential decompression assisted with intraoperative ultrasound can significantly improve the neurological function of patients with multilevel OPLL and achieve good efficacy. The improvement rate of nerve function can be improved effectively by controlling intraoperative blood loss.

New Optical Manipulation of Relativistic Vortex Cutter.

A new relativistic vortex cutter driven by the Laguerre-Gaussian (LG) mode is carried out for the first time in three-dimensional particle-in-cell simulations. Studies show that the electric fields periodically concentrate and emanate within every laser wavelength for the reflected circularly polarized LG_{p}^{l} (p=0, l=1, σ_{z}=-1) laser, which works just like a vortex cutter, resulting in a relativistic ultrashort collimated electron cluster with a constant period in space. A single particle model is given and verifies that the cluster formation has a close relation with the parameters of orbital angular momentum (l) and spin angular momentum (σ_{z}). Such a relativistic vortex cutter potentially can be applied for the accelerator, generating high-flux particle and coherent radiation sources, and so on.

Collisionless Shock Acceleration of High-Flux Quasimonoenergetic Proton Beams Driven by Circularly Polarized Laser Pulses.

We present experimental studies on ion acceleration using an 800-nm circularly polarized laser pulse with a peak intensity of 6.9×10^{19} W/cm^{2} interacting with an overdense plasma that is produced by a laser prepulse ionizing an initially ultrathin plastic foil. The proton spectra exhibit spectral peaks at energies up to 9 MeV with energy spreads of 30% and fluxes as high as 3×10^{12} protons/MeV/sr. Two-dimensional particle-in-cell simulations reveal that collisionless shocks are efficiently launched by circularly polarized lasers in exploded plasmas, resulting in the acceleration of quasimonoenergetic proton beams. Furthermore, this scheme predicts the generation of quasimonoenergetic proton beams with peak energies of approximately 150 MeV using current laser technology, representing a significant step toward applications such as proton therapy.

[Analysis of deafness-related gene mutations in 23 nonsyndromic hearing impairment families in Guangxi Zhuang Autonomous Region].

Objective:To investigate the genetic characteristics of the mutations responsible for nonsyndromic hearing loss in Guangxi Zhuang Autonomous Region, and analyze the deafness-related gene mutations in nonsyndromic hearing impairment families in this region.Method:In 23 nonsyndromic hearing impairment families,66 patients or their families were enrolled as family history group and 167 patients or their families without family histiory as control group, respectively. Deafness gene mutations were determined with deafness-related gene mutations detection kits. The mutation rates among the deafness probands, the hearing impairment patients and their audibility relatives were analyzied. Whole length sequences of the deafness-related gene were detected if there was mutation by the kits, to explore Guangxi region-specific mutation-sites.Result:Common deafness-related gene mutation rate in family history group(31.82%) was higher than that in control group(11.38%), including those that in GJB2 homozygous(21.21%), SLC26A4 homozygous (9.09%), both were higher than the control group (GJB2 homozygous 5.99%, SLC26A4 homozygous 3.59%) . The rate of common deafness-related gene mutations in the deafness probands was 34.78%, in the hearing impairment patients was 30.56%, in their audibility relatives was 29.63%, all of which were higher than those in the control group. We found three rarely seen mutations, SLC26A4 IVS11+47T>C, 1548insC and GJB2 109 A>G, by detecting the whole-length sequences of the deafness-related gene.Conclusion:The results indicated that GJB2 and SLC26A4 were the most frequent mutant genes in Guangxi region. Analysis of the individual family were helpful to linkage the mutations and the deafness.