BACKGROUND:In clinic, monosegmental pedicle screw fixation via the fractured vertebrae is commonly used for the treatment of thoracolumbar fracture. Studies have confirmed that the spinal stability is strengthened through bilateral pedicle screw fixation via fractured vertebrae, but some studies suggest that monosegmental pedicle screw fixation via fractured vertebrae can increase the spinal stability, and the conclusion lacks of the supports of biomechanics.
OBJECTIVE:To evaluate the biomechanical properties of monosegmental pedicle screws fixation via fractured vertebrae for thoracolumbar fracture.
METHODS:Eight cadavers’ thoracolumbar specimens (T11-L3) were provided by the Department of Anatomy, Yangzhou University School of Medicine. Saw was used to transect 2/3 of the vertebrae in order to make complete experimental thoracolumbar specimens. Eight specimens were divided into two group;beyond-fractured vertebrae fixation group and monosegmental fixation via fracture vertebrae group. The specimens in the two groups were treated with adjacent vertebral four screw fixation beyond fractured vertebrae and adjacent vertebral four screw fixation+monosegmental pedicle screw fixation via fractured vertebrae respectively.
RESULTS AND CONCLUSION:After thoracolumbar fracture, the differences between beyond fractured vertebrae fixation and monosegmental pedicle screw fixation via fractured vertebrae were as fol ows:load-strain relationship 12%, load-displacement relationship 11%, strength 18%, axial rigidity 11%, torsional mechanical properties 11%and pul out test 1.8%, and there were no significant differences between two groups (P<0.05). The biomechanics performance of monosegmental pedicle screw fixation via fractured vertebrae was more superior to that of pedicle screw fixation beyond the fracture vertebra for thoracolumbar fracture.

Objective:To establish a rat model of diabetic microangiopathopathy and simulate the biochemical and pathological changes of diabetic retinal and renal microangiopathopathy.Methods:Forty healthy male Sprague-Dawley rats were randomly divided into blank group and model group (10 and 30 rats, respectively). After the rats in blank group and model group were fed ordinary diet and high-fat and high-sugar diet for 5 weeks, respectively, the rats in model group were injected with 1% streptozotocin (STZ) through the abdominal cavity at the dose of 35 mg/kg to establish a type 2 diabetes model. After modeling, the rats were continuously fed until the 10th week (4 weeks after modeling), the general conditions of the rats were observed, and samples were collected for follow-up experiments. Serum creatinine (CREA), triglyceride (TG), total cholesterol (TC), high density lipoprotein (HDL-C), low density lipoprotein (LDL-C), microalbuminuria, urinary creatinine (UCr) and urine sugar were detected. Calculate the kidney index and microalbumin/urinary creatinine ratio (UACR). Optical coherence tomography angiography (OCTA) was used to observe the vascular changes and non-perfusion area of retinal superficial capillary plexus. The morphological and structural changes of kidney and retina were observed by hematoxylin-eosin and periodate Scheff staining. The expression of nerve fibers and nucleus of Müller cells in rat retina was observed by immunofluorescence staining. Ultrastructural results of retina were observed by transmission electron microscope. Independent sample t test was used for comparison between groups. Results:Four weeks after modeling, compared with blank group, the body weight of rats in model group was significantly decreased, and random glucose was significantly increased, with statistical significance ( t=5.755, -51.291; P<0.05). Renal index, urinary glucose and UACR were significantly increased, while UCr was significantly decreased, with statistical significance ( t=10.878, 137.273, 3.482,-6.110; P<0.05). CREA decreased, TG, TC, HDL-C, LDL-C increased, and the differences were statistically significant ( t=-28.012, 33.018, 118.018, 13.585, 16.480; P<0.05). OCTA examination showed that there was no perfusion area of shallow retinal capillaries. The optical microscope showed that the inner boundary membrane of retina in model group was swollen and thickened, the surface was uneven, the inner and outer nuclear layer cells were disordered and the density decreased. Glomerular congestion was accompanied by cortical tubular epithelial swelling, widening of the mesangial area, and thickening of the basement membrane. The results of immunostaining showed that the inner and outer plexiform layers of the retina showed lamellar strong green fluorescence expression, and the inner and outer nuclear layers showed scattered dot green fluorescence expression. Transmission electron microscopy showed that the basal membrane of retinal microvessels in model group was slightly thickened, vascular endothelial cells edema, endothelial nucleus and perinucleus contraction, nuclear membrane contraction, mild mitochondrial swelling, vacuolation. Conclusion:High-glucose and high-fat feeding plus a single intraperitoneal injection of STZ 35 mg/kg can successfully establish a microangiopathic model of type 2 diabetes.

BACKGROUND: The contraction behaviors of cardiomyocytes (CMs), especially contraction synchrony, are crucial factors reflecting their maturity and response to drugs. A wider field of view helps to observe more pronounced synchrony differences, but the accompanied greater computational load, requiring more computing power or longer computational time. METHODS: We proposed a method that directly correlates variations in optical field brightness with cardiac tissue contraction status (CVB method), based on principles from physics and photometry, for rapid video analysis in wide field of view to obtain contraction parameters, such as period and contraction propagation direction and speed. RESULTS: Through video analysis of human induced pluripotent stem cell (hiPSC)-derived CMs labeled with green fluorescent protein (GFP) cultured on aligned and random nanofiber scaffolds, the CVB method was demonstrated to obtain contraction parameters and quantify the direction and speed of contraction within regions of interest (ROIs) in wide field of view. The CVB method required less computation time compared to one of the contour tracking methods, the LucasKanade (LK) optical flow method, and provided better stability and accuracy in the results. CONCLUSION This method has a smaller computational load, is less affected by motion blur and out-of-focus conditions, and provides a potential tool for accurate and rapid analysis of cardiac tissue contraction synchrony in wide field of view without the need for more powerful hardware.

BACKGROUND: The contraction behaviors of cardiomyocytes (CMs), especially contraction synchrony, are crucial factors reflecting their maturity and response to drugs. A wider field of view helps to observe more pronounced synchrony differences, but the accompanied greater computational load, requiring more computing power or longer computational time. METHODS: We proposed a method that directly correlates variations in optical field brightness with cardiac tissue contraction status (CVB method), based on principles from physics and photometry, for rapid video analysis in wide field of view to obtain contraction parameters, such as period and contraction propagation direction and speed. RESULTS: Through video analysis of human induced pluripotent stem cell (hiPSC)-derived CMs labeled with green fluorescent protein (GFP) cultured on aligned and random nanofiber scaffolds, the CVB method was demonstrated to obtain contraction parameters and quantify the direction and speed of contraction within regions of interest (ROIs) in wide field of view. The CVB method required less computation time compared to one of the contour tracking methods, the LucasKanade (LK) optical flow method, and provided better stability and accuracy in the results. CONCLUSION This method has a smaller computational load, is less affected by motion blur and out-of-focus conditions, and provides a potential tool for accurate and rapid analysis of cardiac tissue contraction synchrony in wide field of view without the need for more powerful hardware.

BACKGROUND: The contraction behaviors of cardiomyocytes (CMs), especially contraction synchrony, are crucial factors reflecting their maturity and response to drugs. A wider field of view helps to observe more pronounced synchrony differences, but the accompanied greater computational load, requiring more computing power or longer computational time. METHODS: We proposed a method that directly correlates variations in optical field brightness with cardiac tissue contraction status (CVB method), based on principles from physics and photometry, for rapid video analysis in wide field of view to obtain contraction parameters, such as period and contraction propagation direction and speed. RESULTS: Through video analysis of human induced pluripotent stem cell (hiPSC)-derived CMs labeled with green fluorescent protein (GFP) cultured on aligned and random nanofiber scaffolds, the CVB method was demonstrated to obtain contraction parameters and quantify the direction and speed of contraction within regions of interest (ROIs) in wide field of view. The CVB method required less computation time compared to one of the contour tracking methods, the LucasKanade (LK) optical flow method, and provided better stability and accuracy in the results. CONCLUSION This method has a smaller computational load, is less affected by motion blur and out-of-focus conditions, and provides a potential tool for accurate and rapid analysis of cardiac tissue contraction synchrony in wide field of view without the need for more powerful hardware.

BACKGROUND: The contraction behaviors of cardiomyocytes (CMs), especially contraction synchrony, are crucial factors reflecting their maturity and response to drugs. A wider field of view helps to observe more pronounced synchrony differences, but the accompanied greater computational load, requiring more computing power or longer computational time. METHODS: We proposed a method that directly correlates variations in optical field brightness with cardiac tissue contraction status (CVB method), based on principles from physics and photometry, for rapid video analysis in wide field of view to obtain contraction parameters, such as period and contraction propagation direction and speed. RESULTS: Through video analysis of human induced pluripotent stem cell (hiPSC)-derived CMs labeled with green fluorescent protein (GFP) cultured on aligned and random nanofiber scaffolds, the CVB method was demonstrated to obtain contraction parameters and quantify the direction and speed of contraction within regions of interest (ROIs) in wide field of view. The CVB method required less computation time compared to one of the contour tracking methods, the LucasKanade (LK) optical flow method, and provided better stability and accuracy in the results. CONCLUSION This method has a smaller computational load, is less affected by motion blur and out-of-focus conditions, and provides a potential tool for accurate and rapid analysis of cardiac tissue contraction synchrony in wide field of view without the need for more powerful hardware.

BACKGROUND: The contraction behaviors of cardiomyocytes (CMs), especially contraction synchrony, are crucial factors reflecting their maturity and response to drugs. A wider field of view helps to observe more pronounced synchrony differences, but the accompanied greater computational load, requiring more computing power or longer computational time. METHODS: We proposed a method that directly correlates variations in optical field brightness with cardiac tissue contraction status (CVB method), based on principles from physics and photometry, for rapid video analysis in wide field of view to obtain contraction parameters, such as period and contraction propagation direction and speed. RESULTS: Through video analysis of human induced pluripotent stem cell (hiPSC)-derived CMs labeled with green fluorescent protein (GFP) cultured on aligned and random nanofiber scaffolds, the CVB method was demonstrated to obtain contraction parameters and quantify the direction and speed of contraction within regions of interest (ROIs) in wide field of view. The CVB method required less computation time compared to one of the contour tracking methods, the LucasKanade (LK) optical flow method, and provided better stability and accuracy in the results. CONCLUSION This method has a smaller computational load, is less affected by motion blur and out-of-focus conditions, and provides a potential tool for accurate and rapid analysis of cardiac tissue contraction synchrony in wide field of view without the need for more powerful hardware.