Design, Synthesis, and Structure-Activity Relationships of 3,4,5-Trisubstituted 4,5-Dihydro-1,2,4-oxadiazoles as TGR5 Agonists

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EDITORIAL

<p>To make comparisons among the different modes for each strain gauge, each strain was normalized with respect to the average among the fixation modes. The average and standard deviation of the seven specimens are plotted.</p

Differential Histopathological and Behavioral Outcomes Eight Weeks after Rat Spinal Cord Injury by Contusion, Dislocation, and Distraction Mechanisms

The objective of this study was to compare the long-term histological and behavioral outcomes after spinal cord injury (SCI) induced by one of three distinct biomechanical mechanisms: dislocation, contusion, and distraction. Thirty male Sprague-Dawley rats were randomized to incur a traumatic cervical SCI by one of these three clinically relevant mechanisms. The injured cervical spines were surgically stabilized, and motor function was assessed for the following 8 weeks. The spinal cords were then harvested for histologic analysis. Quantification of white matter sparing using Luxol fast blue staining revealed that dislocation injury caused the greatest overall loss of white matter, both laterally and along the rostrocaudal axis of the injured cord. Distraction caused enlarged extracellular spaces and structural alteration in the white matter but spared the most myelinated axons overall. Contusion caused the most severe loss of myelinated axons in the dorsal white matter. Immunohistochemistry for the neuronal marker NeuN combined with Fluoro Nissl revealed that the dislocation mechanism resulted in the greatest neuronal cell losses in both the ventral and dorsal horns. After the distraction injury mechanism, animals displayed no recovery of grip strength over time, in contrast to the animals subjected to contusion or dislocation injuries. After the dislocation injury mechanism, animals displayed no improvement in the grooming test, in contrast to the animals subjected to contusion or distraction injuries. These data indicate that different SCI mechanisms result in distinct patterns of histopathology and behavioral recovery. Understanding this heterogeneity may be important for the future development of therapeutic interventions that target specific neuropathology after SCI

Research on Gold Demand Prediciton Based on GM-GPR Model

The prediction system of gold demands in China is faced with issues such as uncertain factors, limited historical data, and nonlinearity. In order to have a more accurate prediction of gold demands, a prediction method based on the integration of grey prediction and Gaussian process regression is proposed. Specifically, equal weights are assigned to each model and a grey prediction is adopted to reflect the uncertain and changing relationship of gold demands, with Gaussian process regression indicating the nonlinear impacts of factors on gold demands. Moreover, modified particle swarm optimization plays a role in optimizing the hyper-parameters of Gaussian process regression, which solves the issue that conjugate gradient algorithms depend on initial value setting and are susceptible to be confined by locally optimal solutions. According to the study, the proposal of the paper is superior to a separate Gaussian process regression or grey prediction in terms of better predicting gold demands

Posteroanterior stiffness predicts sagittal plane midthoracic range of motion and three-dimensional flexibility in cadaveric spine segments

Background. Spinal joint mobilization is a mainstay of clinical assessment of individuals with back pain. The clinician manually assesses stiffness and joint motion relative to segments above and below. Although clinical theory suggests that manually performed techniques can predict or detect intervertebral motion, this hypothesis remains untested. Methods. Using a precision opto-electronic camera system and a custom spine testing machine, we measured intervertebral range of motion, neutral zone motion and three-dimensional flexibility in eight T5–T8 cadaveric specimens (mean age = 81 years). We then measured stiffness when a cyclic posteroanterior load was applied at the spinous process of T6 using a servohydraulic material testing machine (Instron 8874), simulating the posteroanterior spinal mobilization technique. Findings. There was a strong significant inverse relationship between stiffness during cyclic posteroanterior loading of T6 and flexion or extension range of motion of T6 relative to T7 (r = −0.88, P < 0.01, extension; r = −0.81, P = 0.01, flexion), and T6–T7 flexibility in all six directions. Interpretation. Stiffness during simulated central cyclic posteroanterior mobilization in the cadaveric midthoracic spine is inversely correlated with flexion and extension range of motion and three-dimensional flexibility at the level at which the technique is applied. These findings provide biomechanical support for the inclusion of specific joint mobilization in the assessment of older adults with back pain

An empirical analysis on whether China’s infrastructure lending is a debt trap for Africa

Since the first interest-free loans in 1960, China’s lending has played a significant role in African development. However, whether China’s debt is raising the African countries’ sovereign default risk ？This study uses the panel data of China’s lending to Africa to conduct quantitative research to answer this question. While empirical evidence shows that generally in both scenarios (with and without lag effect), China’s debt (represented by debt to GDP) is not relevant to African countries’ sovereign default risk (represented by CRP) for the whole African continent, the debtor countries’ region is also not relevant to the countries’ sovereign default risk. This study reveals that the change in China’s lending is not the only factor affecting the total debt. Sovereign default risk also depends on the GDP growth because if it grows faster than the debt, theoretically debt burden (and the default risk) may decrease rather than increase with debt

Anterior Transarticular Crossing Screw Fixation for Atlantoaxial Joint Instability: A Biomechanical Study

Objective To evaluate the biomechanical stability of anterior transarticular crossing screw (ATCS) and compare it with anterior transarticular screw (ATS) which may provide basic evidence for clinical application. Methods Eight human fresh cadaveric specimens (occiput-C4) were tested with 5 conditions including the intact status, the injury status (type II odontoid fracture), the injury+ATS fixation status (traditional bilateral ATS fixation); the injury+unilateral ATCS fixation status; and the injury+bilateral ATCS fixation status. Specimens were applied to a pure moment of 1.5 Nm in flexion-extension, lateral bending, and axial rotation, respectively. The range of motions (ROMs) and the neutral zones (NZs) of C1 to C2 segment were calculated and compared between 5 status. Results ATS and ATCS fixations significantly reduced the motions in all directions when compared with the intact and injury statues (p 0.05). Three fixations resulted in similar NZs in all directions (p > 0.05). Conclusion ATCS is a biomechanically effective alternative or supplemental method for atlantoaxial instability

Feasibility of Anterior Fixation with Single Screw for Odontoid Fractures in Pediatrics: A Computed Tomographic Study

Objective Although it is an effective fixation technique for an unstable odontoid, anterior fixation remains challenging in pediatric populations. Our study measures the anatomical parameters of the odontoid to identify the feasibility of anterior fixation with a single screw for children. Methods We retrospectively collected data from 112 normal male and female children (aged between 2 and 18) in our institute from January 1, 2022 to December 31, 2022. Subjects were divided into a youth group (2–6 years old), a juvenile group (7–12 years old), and an adolescent group (13–18 years old). Sagittal and coronal computed tomography images of the upper cervical spine were used to measure the screw length, angle, and inner and outer diameters of the odontoid. One‐way analysis of variance with the Tukey test was used to analyze the parameters among the groups, while the t‐test was used to analyze gender differences. Correlations between parameters and age were assessed using Pearson's test. Results There were significant differences between male and female subjects in screw length and inner and outer diameters (of both sagittal and coronal views) but not in screw angle. The narrowest diameter of the odontoid was 4.0 ± 1.5 mm in the youth group, 5.5 ± 1.5 mm in the juvenile group, and 5.6 ± 1.1 mm in the adolescent group, respectively. There were significant differences among the three groups in screw length (p 4 mm. Screw length and inner and outer diameters in lateral view were positively correlated with age, and screw angle was negatively correlated with age. Conclusion It is feasible to insert a standard single screw (Φ 3.5 mm) into the odontoid of children aged 7–18 years old but not those aged 2–6 years old. How the anatomical parameters of the odontoid change with age, especially the narrowest diameters, is worthy of attention

Failure Characteristics of the Thoracic Spine with a Posteroanterior Load: Investigating the Safety of Spinal Mobilization

Study Design. In vitro biomechanical study of human cadaveric thoracic spine segments and one intact cadaver and applied load measurements in human volunteers. Objectives. To quantify failure load and pattern of midthoracic vertebrae under a posteroanterior load and to compare failure load in vitro with applied load in vivo. Summary of Background Data. Osteoporosis and back pain are common alone and in combination among older adults. Spinal mobilization techniques have been shown to relieve back pain and improve function in various clinical settings. However, whether controlled spinal mobilization can cause vertebral fracture in individuals with osteoporosis is not known. Methods. Twelve T5-T8 cadaveric specimens (mean age, 77 years) were scanned using bone densitometry, radiographed, and measured for bone size. The authors measured failure load, failure site, and intervertebral motion (using a precision optoelectronic camera system) when a posteroanterior load was applied at the spinous process of T6 using a servohydraulic material testing machine. Post-test radiography and CT scan were used to verify failure site. These tests were repeated in an intact cadaver using a Tekscan I-Scan sensor to measure applied loads. The authors also quantified in vivo applied loads during posteroanterior mobilization during seven trials by two experienced physiotherapists. Results. Mean (SD) in vitro failure load of 479 N (162 N) was significantly higher than the mean (SD) in vivo applied load of 145 N (38 N) (P = 0.0004). Macroscopic observation revealed a fracture at the T6 spinous process in 11 specimens and one at the T7 spinous process. These fractures were detected by plain radiography in three of 12 cases and by CT scan in six of 12 case