Programmable Entropy-Driven Circuit-Cascaded Self-Feedback DNAzyme Network for Ultra-Sensitive Fluorescence and Photoelectrochemical Dual-Mode Biosensing.

Inspired by natural DNA networks, programmable artificial DNA networks have become an attractive tool for developing high-performance biosensors. However, there is still a lot of room for expansion in terms of sensitivity, atom economy, and result self-validation for current microRNA sensors. In this protocol, miRNA-122 as a target model, an ultrasensitive fluorescence (FL) and photoelectrochemical (PEC) dual-mode biosensing platform is developed using a programmable entropy-driven circuit (EDC) cascaded self-feedback DNAzyme network. The well-designed EDC realizes full utilization of the DNA strands and improves the atomic economy of the signal amplification system. The unique and rational design of the double-CdSe quantum-dot-released EDC substrate and the cascaded self-feedback DNAzyme amplification network significantly avoids high background signals and enhances sensitivity and specificity. Also, the enzyme-free, programmable EDC cascaded DNAzyme network effectively avoids the risk of signal leakage and enhances the accuracy of the sensor. Moreover, the introduction of superparamagnetic Fe3O4@SiO2-cDNA accelerates the rapid extraction of E2-CdSe QDs and E3-CdSe QDs, which greatly improves the timeliness of sensor signal reading. In addition to the strengths of linear range (6 orders of magnitude) and stability, the biosensor design with dual signal reading makes the test results self-confirming.

The need for thoracic magnetic resonance imaging before vertebral augmentation surgery in patients with lumbar vertebral fractures.

BACKGROUND: Osteoporotic vertebral compression fractures (OVCFs) of the lumbar region may be accompanied by thoracic fractures. Treating only the lumbar fractures can lead to worsening of the thoracic fractures or unresolved postoperative symptoms. This study aims to investigate the need to perform thoracic MRI before vertebral augmentation (including percutaneous vertebroplasty and percutaneous kyphoplasty) in patients with lumbar OVCF. METHODS: This study retrospectively analyzed patients with lumbar OVCF who were scheduled for surgical treatment. All patients underwent thoracic and lumbar MRI before surgery. We evaluated the proportion of thoracic fractures accompanying lumbar fractures at each segment and identified the common locations of these accompanying fractures. Univariate and multivariate analyses were conducted to determine the risk factors and optimal thresholds for predicting accompanying thoracic fractures. RESULTS: The study recruited 700 patients, of whom 96 (13.71%) had new thoracic fractures along with lumbar fractures. The most common thoracic segments affected were T10 (22.50%), T9 (19.17%), T8 (26.67%), and T7 (20.83%). Univariate analysis showed significant differences in age and cause of injury between the thoracic fracture group and the control group. The bone density of the thoracic fracture group was significantly lower than that of the control group. Multivariate logistic regression analysis indicated that lifting heavy objects, sprains, and low bone density are risk factors for thoracic fractures in patients with lumbar OVCF. CONCLUSION: It is crucial to perform thoracic MRI before surgery in patients with lumbar OVCF. This helps to avoid missing thoracic fractures, prevent the worsening of injuries, and ensure better postoperative outcomes.