[Treatment of cervical ossification of posterior longitudinal ligament with titanium alloy trabecular bone three-dimensional printed artificial vertebral body].

Objective: To evaluate the effectiveness of using titanium alloy trabecular bone three-dimensional (3D) printed artificial vertebral body in treating cervical ossification of the posterior longitudinal ligament (OPLL). Methods: A retrospective analysis was conducted on clinical data from 45 patients with cervical OPLL admitted between September 2019 and August 2021 and meeting the selection criteria. All patients underwent anterior cervical corpectomy and decompression, interbody bone graft fusion, and titanium plate internal fixation. During operation, 21 patients in the study group received titanium alloy trabecular bone 3D printed artificial vertebral bodies, while 24 patients in the control group received titanium cages. There was no significant difference in baseline data such as gender, age, disease duration, affected segments, or preoperative pain visual analogue scale (VAS) score, Japanese Orthopaedic Association (JOA) score, Neck Disability Index (NDI), vertebral height, and C 2-7Cobb angle ( P>0.05). Operation time, intraoperative blood loss, and occurrence of complications were recorded for both groups. Preoperatively and at 3 and 12 months postoperatively, the functionality and symptom relief were assessed using JOA scores, VAS scores, and NDI evaluations. The vertebral height and C 2-7 Cobb angle were detected by imaging examinations and the implant subsidence and intervertebral fusion were observed. Results: The operation time and incidence of complications were significantly lower in the study group than in the control group ( P<0.05), while the difference in intraoperative blood loss between the two groups was not significant ( P>0.05). All patients were followed up 12-18 months, with the follow-up time of (14.28±4.34) months in the study group and (15.23±3.54) months in the control group, showing no significant difference ( t=0.809, P=0.423). The JOA score, VAS score, and NDI of the two groups improved after operation, and further improved at 12 months compared to 3 months, with significant differences ( P<0.05). At each time point, the study group exhibited significantly higher JOA scores and improvement rate compared to the control group ( P<0.05); but there was no significantly difference in VAS score and NDI between the two groups ( P>0.05). Imaging re-examination showed that the vertebral height and C 2-7Cobb angle of the two groups significantly increased at 3 and 12 months after operation ( P<0.05), and there was no significant difference between 3 and 12 months after operation ( P>0.05). At each time point, the vertebral height and C 2-7Cobb angle of the study group were significantly higher than those of the control group ( P<0.05), and the implant subsidence rate was significantly lower than that of the control group ( P<0.05). However, there was no significant difference in intervertebral fusion rate between the two groups ( P>0.05). Conclusion: Compared to traditional titanium cages, the use of titanium alloy trabecular bone 3D-printed artificial vertebral bodies for treating cervical OPLL results in shorter operative time, fewer postoperative complications, and lower implant subsidence rates, making it superior in vertebral reconstruction.

A novel two-dimensional Janus TiSiGeN4 monolayer with N vacancies for efficient photocatalytic nitrogen reduction.

The photocatalytic nitrogen reduction reaction (pNRR) is a clean technology that converts H2O and N2 into NH3 under environmental conditions using inexhaustible sunlight. Herein, we designed a novel two-dimensional (2D) Janus TiSiGeN4 structure and evaluated the pNRR performance of the structure with the presence of nitrogen vacancies at different positions using density functional theory (DFT) calculations. The intrinsic dipoles in the Janus TiSiGeN4 structure generate a built-in electric field, which promotes the migration of photogenerated electrons and holes towards the (001) and (00-1) surfaces, respectively, to achieve efficient charge separation. For the pNRR, the Si atoms exposed after the formation of top N vacancies can realize the efficient activation of N2 through the "acceptance-donation" mechanism, while the presence of middle N vacancies not only suppresses the hydrogen evolution reaction, a competition reaction, but also lowers the reaction barrier for the protonation of N atoms. The limiting potential of TiSiGeN4 with the coexistence of both top and middle N vacancies (TiSiGeN4-VN-mt) is as low as -0.44 V. In addition, the introduction of N vacancies generates defect levels, narrowing the band gap and improving the light response. This work provides theoretical guidance for the design of efficient pNRR photocatalysts under mild conditions.

Alleviating Severe Cytoskeletal Destruction of Spinal Motor Neurons: Another Effect of Docosahexaenoic Acid in Spinal Cord Injury.

Spinal cord injury (SCI) treatment remains a major challenge. Spinal motor neurons (MNs) are seriously injured in the early stage after SCI, but this has not received sufficient attention. Oxidative stress is known to play a crucial role in SCI pathology. Our studies demonstrated that oxidative stress can cause severe damage to the cytoskeleton of spinal MNs. Docosahexaenoic acid (DHA) has been shown to have beneficial effects on SCI, but the mechanism remains unclear, and no study has investigated the effect of DHA on oxidative stress-induced spinal MN injury. Here, we investigated the effect of DHA on spinal MN injury through in vivo and in vitro experiments, focusing on the cytoskeleton. We found that DHA not only promoted spinal MN survival but, more importantly, alleviated the severe cytoskeletal destruction of these neurons induced by oxidative stress in vitro and in mice with SCI in vivo. In addition, the mechanisms involved were investigated and elucidated. These results not only suggested a beneficial role of DHA in spinal MN cytoskeletal destruction caused by oxidative stress and SCI but also indicated the important role of the spinal MN cytoskeleton in the recovery of motor function after SCI. Our study provides new insights for the formulation of SCI treatment.

Oxidative stress disrupts the cytoskeleton of spinal motor neurons.

BACKGROUND AND AIM: Traumatic spinal cord injury (SCI) is a common and devastating central nervous disease, the treatment of which faces many challenges to the medical community and society as a whole. Treatment measures based on oxidative stress of spinal motor neurons during SCI are expected to help restore biological functions of neurons under injury conditions. However, to date, there are no systematic reports regarding oxidative stress on spinal motor neuron injury. Our aim is to better understand and explain the influences and mechanisms of oxidative stress on spinal motor neurons during SCI. METHODS: We first exposed VSC4.1 motor neurons to hydrogen peroxide (H2 O2 ) and evaluated the effects on cell viability, morphology, cycling, and apoptosis, with an emphasis on the changes to the cytoskeleton and the effect of N-acetyl-l-cysteine (NAC) on these changes. Then, we investigated the effects of NAC on these cytoskeletal changes in vitro and in vivo. RESULTS: We found that H2 O2 caused severe damage to the normal cytoskeleton, leading to a reduction in neurite length and number, rearrangement of the actin cytoskeleton, and disorder of the microtubules and neurofilaments in VSC4.1. Importantly, NAC attenuated the oxidative damage of spinal motor neurons in vitro and in vivo, promoting the recovery of hindlimb motor ability in mice with SCI at the early stage of injury. CONCLUSION: This study shows that oxidative stress plays an important role in the cytoskeleton destruction of spinal motor neurons in SCI, and treatment of SCI on this basis is a promising strategy. These findings will help to elucidate the role of oxidative stress in spinal motor neuron injury in SCI and provide references for further research into the study of the pathology and underlying mechanism of SCI.

A Model Study on Raw Material Chemical Composition to Predict Sinter Quality Based on GA-RNN.

The quality control process for sintered ore is cumbersome and time- and money-consuming. When the assay results come out and the ratios are found to be faulty, the ratios cannot be changed in time, which will produce sintered ore of substandard quality, resulting in a waste of resources and environmental pollution. For the problem of lagging sinter detection results, Long Short-Term Memory and Genetic Algorithm-Recurrent Neural Networks prediction algorithms were used for comparative analysis, and the article used GA-RNN quality prediction model for prediction. Through correlation analysis, the chemical composition of the sintered raw material was determined as the input parameter and the physical and metallurgical properties of the sintered ore were determined as the output parameters, thus successfully establishing a GA-RNN-based sinter quality prediction model. Based on 150 sets of original data, 105 sets of data were selected as the training sample set and 45 sets of data were selected as the test sample set. The results obtained were compared to the real value with an average prediction error of 1.24% for the drum index, 0.92% for the low-temperature reduction chalking index (RDI), 0.95% for the reduction index (RI), 0.40% for the load softening temperature T10%, and 0.43% for the load softening temperature T40%, with all within the running time thresholds. The study of this model enables the prediction of the quality of sintered ore prior to sintering, thus improving the yield of sintered ore, increasing corporate efficiency, saving energy, and reducing environmental pollution.

[Posterior debridement, interbody fusion, internal fixation for treatment of lumbar discitis].

OBJECTIVE: To evaluate the clinical effects of posterior debridement, interbody fusion with internal fixation in the treatment of lumbar discitis. METHODS: The clinical data of 13 patients with lumbar discitis treated from January 2005 to June 2012 was retrospectively analyzed. There were 9 males and 4 females, aged from 31 to 68 years old with an average of 56 years old. There were 2 cases on L3, 4, 4 cases on L4, 5, and 7 cases on L5S1. Two cases complicated with diabetes, 4 cases with hypertension, and 1 case with obsolete pulmonary tuberculosis. ESR level of 13 cases was 12-89 mm/h with an average of 42 mm/h; and C reactive protein fluctuations level was level 8-114 ng/L with an average of 47 ng/L. All the patients denied history of operation or injection, and the main symptom was severe pain and limitation of motion in lumbar, with no efficacy for conservative methods. Preoperative VAS was from 5 to 10 points with an average of 7.8 points. All patients were treated with posterior debridement, interbody fusion, and internal fixation. RESULTS: All the patients left hospital after wound healing, and the effective antibiotics were continuously used for 4 weeks intravenously and 2 weeks for orally. All patients were followed up from 7 to 24 months with an average of 18 months. VAS decreased for 0-1 point. No internal fixation breakage, and recurrence were found. Bone graft got fusion, and postoperative pathology showed phlogistic changes. CONCLUSIONS: One-stage posterior debridement, interbody fusion with internal fixation was an effective method in treating lumbar discitis, and it lead to quicker relived pain relief and earlier mobilization.

[Distribution of phosphorus fractions and bio-available phosphorus forms and their relationships in sewage sludge].

To investigate the potential bioavailability and mobility of phosphorus (P) in sewage sludge, the Standards, Measurements and Testing (SMT) programme was employed to characterize the distribution of P in sewage sludge from different treatment stage of Jiangxinzhou WWTP. The results showed that the inorganic phosphorus (IP), accounting for 61%, was the predominant fraction of total phosphorus (TP), while the organic phosphorus (OP) in TP was only 15% to 35%. And the IP mainly distributed in the non-apatite inorganic phosphorus (NAIP) fraction, accounting for more than 60%. It suggested the high potential bioavailability and mobility of P in sewage sludge. The significant positive correlations between the contents of TP and the NAIP + OP indicated that the determination of TP could be used to estimate the potential bioavailability of P in sewage sludge. The correlations between the P fractions and the physical-chemical characteristics suggested that the LOI and pH would influence significantly on the potential mobility of P in sewage sludge.