pH-Responsive Fluorescent Metal-Organic Framework as a Functional Nanofiller for Smart Coatings.

A zirconium-based UiO-type UiO-66-(OH)2 metal-organic framework@carbon dot composite (Zr-MOF@CD) is synthesized through a facile solvent-free thermal method. The Zr-MOF@CD exhibits pH-responsive fluorescence behavior, which emits blue fluorescence for pH < 9 at an emission wavelength of 470 nm. At pH > 9, the fluorescence color turns from blue to yellow, with the emission behavior at 535 nm. Zr-MOF@CDs can serve as functional nanofillers in the epoxy coating for the fabrication of a smart coating, which can realize coating damage warning and metal corrosion reporting. The blue fluorescence can be observed in the area of coating damage with just a minor scratch. Once the scratch is severe enough to expose the metal substrate, the cathodic reaction of oxygen reduction in the corrosion galvanic cell causes an increased pH, where the emission of yellow fluorescence can be identified. The stable fluorescence response is free from the influence of concentration, time, temperature, and the interfering substance. Zr-MOF@CDs can also serve as nanocontainers for loading with the corrosion inhibitor and realizing the repairing of metal corrosion. The development of the smart coating with dual functions of autonomous reporting and repairing holds great potential to improve the lifetime of metals in various industrial applications.

Efficacy and Safety of Early Tracheotomy in Acute Cervical Spinal Cord Injury.

OBJECTIVE: To evaluate the clinical efficacy and safety of early tracheotomy versus delayed tracheotomy for patients with cervical spinal cord injury. STUDY DESIGN: A descriptive study. PLACE AND DURATION OF STUDY: Department of Orthopedic Surgery, The 80th Army Hospital of PLA, Weifang, Shandong, China, from January 2012 to June 2019. METHODOLOGY: Data of 45 patients with cervical spinal cord injury, who underwent tracheotomy and cervical spine internal fixation at the study place, were retrospectively analysed. Twenty-five patients underwent tracheotomy immediately after cervical spine internal fixation (early tracheotomy group) and 20 patients underwent tracheotomy 3-12 days after cervical spine internal fixation (delayed tracheotomy group). Clinical outcomes and tracheotomy complications were compared between the two groups. RESULTS: Compared with the delayed tracheotomy, the early tracheotomy significantly reduced the total duration of mechanical ventilation (p <0.01), duration of mechanical ventilation after tracheotomy (p <0.05), duration of indwelling tracheal tube (p <0.05), and hospital stay (p <0.01). There were no significant differences in pneumonia, mortality, and complications related to tracheotomy between the groups. No incision infection for tracheotomy and cervical spine internal fixation were found in all patients. CONCLUSION: Compared with delayed tracheotomy, early tracheotomy can significantly reduce the duration of mechanical ventilation, duration of indwelling tracheal tube, and hospital stay. Early tracheotomy did not increase the risk of infection of the cervical spine internal fixation. Therefore, early tracheotomy was beneficial and safe for patients. Key Words: Spinal cord injuries, Tracheotomy, Complications.

Progress and Applications of Polyphosphate in Bone and Cartilage Regeneration.

Patients with bone and cartilage defects due to infection, tumors, and trauma are quite common. Repairing bone and cartilage defects is thus a major problem for clinicians. Autologous and artificial bone transplantations are associated with many challenges, such as limited materials and immune rejection. Bone and cartilage regeneration has become a popular research topic. Inorganic polyphosphate (polyP) is a widely occurring biopolymer with high-energy phosphoanhydride bonds that exists in organisms from bacteria to mammals. Much data indicate that polyP acts as a regulator of gene expression in bone and cartilage tissues and exerts morphogenetic effects on cells involved in bone and cartilage formation. Exposure of these cells to polyP leads to the increase of cytokines that promote the differentiation of mesenchymal stem cells into osteoblasts, accelerates the osteoblast mineralization process, and inhibits the differentiation of osteoclast precursors to functionally active osteoclasts. PolyP-based materials have been widely reported in in vivo and in vitro studies. This paper reviews the current cellular mechanisms and material applications of polyP in bone and cartilage regeneration.

A Meta-Analysis of the Influencing Factors for Tracheostomy after Cervical Spinal Cord Injury.

BACKGROUND: Traumatic cervical spinal cord injury (CSCI) is a common disease that has high complication, disability, and mortality rates and a poor prognosis. Tracheostomy is an important supportive therapy for patients with CSCI. However, a consensus on the predictive factors for tracheostomy after CSCI has not been reached. OBJECTIVE: This meta-analysis study assessed the influencing factors for tracheostomy after CSCI. METHODS: We searched for relevant studies on the influencing factors for tracheostomy after CSCI. The extracted data were analyzed using RevMan 5.3 software. We calculated the odds ratio (OR) or mean difference (MD) and 95% confidence intervals (CIs). RESULTS: Sixteen eligible studies containing 9697 patients with CSCI were selected. The pooled OR (MD) and 95% CI of the influencing factors were as follows: age (mean ± SD): -0.98 (-4.00 to 2.03), advanced age: 1.93 (0.80 to 4.63), sex (male): 1.29 (1.12 to 1.49), American Spinal Injury Association Impairment Scale (AIS) A grade: 7.79 (5.28 to 11.50), AIS B grade: 1.15 (1.13 to 2.02), AIS C grade: 0.28 (0.20 to 0.41), AIS D grade: 0.04 (0.02 to 0.09), neurological level of injury (upper CSCI): 2.36 (1.51 to 3.68), injury severity score (ISS): 8.97 (8.11 to 9.82), Glasgow Coma Scale (GCS) score ≤8: 6.03 (2.19 to 16.61), thoracic injury: 1.78 (1.55 to 2.04), brain injury: 0.96 (0.55 to 1.69), respiratory complications: 5.97 (4.03 to 8.86), smoking history: 1.45 (0.99 to 2.13), traffic accident injury: 1.27 (0.92 to 1.74), and fall injury: 0.72 (0.52 to 1.01). CONCLUSIONS: The current evidence shows that male sex, AIS A grade, AIS B grade, neurological level of injury (upper CSCI), high ISS, GCS≤8, thoracic injury, and respiratory complications are risk factors for tracheostomy after CSCI, and AIS C grade and AIS D grade are protective factors. This study will allow us to use these factors for tracheostomy decisions and ultimately optimize airway management in patients with CSCI.