Osteoporotic vertebral compression fractures (OVCFs) affect the elderly population, especially postmenopausal women. Percutaneous kyphoplasty is designed to treat painful vertebral compression fractures for which conservative therapy has been unsuccessful. ...

(1) Background: The choice of surgical access for 4-level degenerative cervical myelopathy (DCM) remains controversial, and the clinical and radiological outcomes of anterior surgery using a low-profile cage (Low-P) versus posterior surgery using cervical pedicle screw fixation (CPS) have not been compared. (2) Methods: This is a retrospective controlled study conducted between January 2019 and June 2021 of 72 patients with 4-level DCM who underwent ACDF using a low-profile cage (n = 39) or laminectomy and instrument fusion using CPS (n = 33). The minimum follow-up time was 12 months. The outcomes were C2–7Cobb angle, C2–7sagittal vertical axis (SVA) fusion rate, the Japanese Orthopedic Association (JOA) score, pain visual analog scale (VAS), neck disability index (NDI), and complications. (3) Results: Both anterior and posterior procedures significantly improved the patients’ quality-of-life parameters. Anterior cervical convexity and SVA significantly increased in both groups, but the SVA was greater in the posterior group than in the anterior group (p < 0.001). The C2–7 Cobb angle significantly improved in both groups postoperatively, and at the final follow-up, there was a slight but nonsignificant reduction in cervical lordosis in both groups (p = 0.567). There was a longer operative time, less intraoperative blood loss, and reduced mean hospital stay in the anterior group compared to the posterior group, with two cases of postoperative hematoma requiring a second operation, two cases of axial pain (AP), five cases of dysphagia, two cases of c5 palsy in the anterior group, and four cases of axial pain, and three cases of c5 palsy in the posterior group. According to Bridwell fusion grade, anterior fusion reached grade I in 28 cases (71.8%) and grade II in 10 cases (25.6%) in the anterior group, and posterior fusion reached grade I in 25 cases (75.8%) and grade II in 8 cases (24.2%) in the posterior group. (4) Conclusions: There was no difference between the anterior and posterior surgical approaches for MDCM in terms of improvement in neurological function. Posterior surgery using CPS achieved similar recovery of cervical anterior convexity as anterior surgery with a shorter operative time but was more invasive and had a greater increase in SVA. The use of Low-P in anterior surgery reduced the incidence of dysphagia and cage subsidence and was less invasive, but with a longer operative time.

The secondary electron spectrum (SES) contains complex surface information and is widely used in surface analysis technology. A theoretical model of the SES for metals was proposed to reveal the effect of the surface potential barrier on the SES. In our model, an improved inner secondary electron energy distribution was established according to the free electron gas model. The transmission coefficient of inner secondary electrons was determined by solving the density of electronic states. Finally, the model was verified by our experiments, and the effects of the coverage fraction and potential barrier height, width, and form on the SES were comprehensively analyzed. The results show that H2O adsorption lowers the barrier height and enhances the tunneling effect, resulting in the most probable energy shifting toward the low-energy end and full width at half maximum narrowing. In addition, increasing or broadening the barrier can weaken the secondary electron tunneling effect, reduce the secondary electron number, and increase the most probable energy and the full width at half maximum. The model in this paper provides a reliable analysis method for studying the SES under different surface barriers for metals. Relevant results have significant value for the analysis of scanning electron microscopy images and optimization of secondary electron detection systems.

Cold atmospheric plasma (CAP) is considered to be a highly promising cancer treatment method, due to its “selective” anti-cancer effect. However, the physical theoretical explanation about this effect and the microscopic interactive mechanisms between CAP and tumors are still lacking. In this work, the CAP-induced electric field-caused electroporation (EP) processes of the cell membrane are modeled based on molecular dynamics. Additionally, the umbrella sampling method is utilized to compute the free energy profile of the intracellular permeation processes of the reactive oxygen species (ROS) through EP-formed pore-like structures at different EP stages. Comparative results are shown as follows. 1) Cancer cell membranes with lower cholesterol components show lower EP-generation threshold and faster EP-formation, and 2) lower free-energy barrier and earlier occurrence of free-energy barrier reduction are shown in all EP stages in cancer cell membrane. The above results explain the difference between cancer cells and normal cells when affected by CAP. Our work delves into the formation of CAP-induced EP and the transport of ROS through EP-formed pore-like structures, which contributes to a better understanding of the microscopic mechanisms of the “selective” anti-cancer effect of CAP, and provides important references for developing CAP-based cancer treatment methods, and devices, thereby facilitating the translation of CAP into clinical applications.