Mechanical Properties and Microstructure of Polypropylene-Glass-Fiber-Reinforced Desert Sand Concrete.

In order to improve the performance of desert sand concrete, polypropylene fiber (PF) and glass fiber (GF) were used to prepare desert sand concrete (DSC) with different fiber and volume content, and the basic mechanical properties, such as cube compressive, tensile and flexural strengths, were tested and studied. Based on the mercury injection method (MIP) and scanning electron microscopy (SEM), the evolution of pore structure and interface structure was analyzed. The mechanism of fiber toughening was revealed at the microscopic level. The results show that the slump of DSC decreases with the increase in fiber content. The slump of glass-fiber-reinforced DSC (GFRDSC) is smaller than that of polypropylene-fiber-reinforced DSC (PFRDSC). The strength enhancement of DSC by fibers is in the order of flexural strength > split tensile strength > compressive strength. The flexural strength of hybrid-fiber-reinforced DSC (HyFRDSC) (0.1% PF + 0.1% GF) is increased by 40.7%. Meanwhile, fibers can improve the toughness of DSC. The MIP results show that the porosity of HyFRDSC decreased by 50.01%, and the addition of fiber can effectively refine the large pore size. The SEM results show that the incorporation of PF and GF causes the formation of a uniform and dense structure between the fibers, cement and aggregate. The two can give full play to the crack-resisting and toughening effect in different loading stages, thus improving the macromechanical properties of DSC.

Clinical Analysis of Minimally Invasive Percutaneous Treatment of Severe Lumbar Disc Herniation with UBE Two-Channel Endoscopy and Foraminal Single-Channel Endoscopy Technique.

For surgical treatment, herniation of traditional open surgery is the traditional approach and the representative operation for lamina windowing excision of nucleus pulposus. In recent years, the unilateral dual channel spine endoscopic technology (UBE/BESS) has caused extensive concern of spine surgery performer. This research compared the results of minimally invasive percutaneous treatment of severe lumbar disc herniation with foraminal single-channel endoscopy and unilateral biportal endoscopy (UBE). A retrospective study was conducted on 50 patients with severe disc herniation treated with minimally invasive percutaneous treatment in MinDong Hospital affiliated to Fujian Medical University from September 2019 to September 2021. According to different surgical methods, they were divided into two groups: foraminal single-channel endoscopic group and UBE dual-channel endoscopic group. There were 22 cases in the UBE surgery group and 28 cases in the interforaminal endoscopic group. The comparison included operation time, postoperative hospital stays, preoperative and postoperative pain scale (VAS), and postoperative MRI to observe the residual condition of prolapsed nucleus pulposus and the occurrence of complications. There were no significant differences between the UBE group and the interforaminal endoscopic group in incision length, operation time, postoperative hospital stays, and improvement of VAS score before and after surgery. In terms of postoperative nucleus pulposus residual rate and postoperative recurrence rate, the two-channel UBE group was significantly better than the single-channel interforaminal endoscopic group. The incidence of postoperative anemia in the interforaminal endoscopic group was significantly lower than that in the UBE group. In the treatment of severe disc herniation, UBE two-channel endoscopy has the advantages of lower recurrence rate, lower nucleus pulposus residual rate, shorter learning curve, and better field of vision than foraminal single-channel endoscopy, which is worth promoting in primary hospitals.

Reconstructing Nanohydroxyapatite Prosthesis Based on CT-Scanning Data and Its Application in Spinal Injury.

This study investigated the nanohydroxyapatite (nHA) prosthesis application effect based on CT-scanning data in spinal injury. This study chose 26 spinal injury patients treated in our hospital from September 2017 to September 2018, who were randomly divided into two groups. nHA prosthesis based on CT-scanning data was implanted in the nHA group, whereas titanium mesh was implanted in the titanium mesh group. Consequently, osteoblasts were cultured to test the biological activity of nHA and titanium alloy. In cell tests, we found osteoblasts could better adhere to nHA, and proliferation and activity were higher when planted on nHA material. After surgical treatment, all patients' spinal symptoms (VAS score, JOA score, and Cobb angle) had improved and did not cause obvious inflammatory foreign body reactions. During a two-year follow-up, the fusion time and support settlement in the nHA group was lower, and the vertebral fusion rate and ASIA score were higher than those in the titanium mesh group. Thus, CT-scanning data could further improve the vertebral fusion rate in the nHA group. Consequentially, nHA prosthesis based on CT-scanning data is a better choice for spinal injury therapy.