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Objective To study correlation between the deformation and displacement trend of the lumbosacral vertebra (L1-S1) for two typical scoliosis spine under vertical load, so as to provide the mechanical basis of treatment and prevention of scoliosis in clinic. Methods The X-ray computed tomography (CT) imaging of two typical scoliosis spine (Lenke-4AN type and Lenke- 5CN type) were converted into 3D models，and their finite element models were then established and verified. The internal stress distribution and displacement variation of the models were calculated by the finite element software; the correlation between the lumbosacral vertebral structure and displacement of the spine was analyzed. Results Under the same boundary conditions and load cases, the stress and displacement for two kinds of lumbosacral vertebral models showed different trends. Due to its left-leaning and forward convex bending deformation as well as relatively large lordosis angle(60°) and smaller left-leaning angle (17.37°), the Lenke-4AN type lumbosacral spine produced slightly small forward convex displacement(8.18 mm) and relatively large left-leaning displacement (0.97 mm). The Lenke- 5CN type lumbosacral spine showed left-leaning and forward convex bending deformation as well, with relatively large lordosis angle (59°) and left-leaning angle (26.97°), so it produced more severe left-leaning (20.65 mm) and forward deformation (9.22 mm). Conclusions The deformation trend of lumbosacral vertebra is closely related to its structural characteristics, and different scoliosis lumbosacral vertebral structures will cause corresponding deformation trend. The research findings are important for the prevention and treatment of scoliosis.
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Objective To study the correlation between the deformation and displacement trend of the lumbosacral vertebra (L1-S1) for two typical scoliosis spines under vertical loads,so as to provide the mechanical basis of treatment and prevention of scoliosis in clinic.Methods The X-ray computed tomography (CT) images of two typical scoliosis spines (Lenke-4AN type and Lenke-5CN type) were converted into 3D models,and their finite element models were then established and verified.The internal stress distribution and displacement variation of the models were calculated by the finite element software;the correlation between the lumbosacral vertebral structure and displacement of the spine was analyzed.Results Under the same boundary conditions and load cases,the stress and displacement for two kinds of lumbosacral vertebral models showed different trends.Due to its leftleaning and forward convex bending deformation as well as the relatively large lordosis angle (60°) and smaller left-leaning angle (17.37°),the Lenke-4AN type lumbosacral spine produced slightly small forward convex displacement (8.18 mm) and relatively large left-leaning displacement (0.97 mm).The Lenke-5CN type lumbosacral spine showed left-leaning and forward convex bending deformation as well,with relatively large lordosis angle(59°) and left-leaning angle (26.97°),so it produced more severe left-leaning displacement (20.65 mm) andforward convex displacement (9.22 mm).Conclusions The deformation trend of lumbosacral vertebra is closelyrelated to its structural characteristics,and different scoliosis lumbosacral vertebral structures will cause the corre-sponding deformation trend.The research findings are important for the prevention and treatment of scoliosis.
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Objective To study the correlation between the deformation and displacement trend of the lumbosacral vertebra (L1-S1) for two typical scoliosis spines under vertical loads,so as to provide the mechanical basis of treatment and prevention of scoliosis in clinic.Methods The X-ray computed tomography (CT) images of two typical scoliosis spines (Lenke-4AN type and Lenke-5CN type) were converted into 3D models,and their finite element models were then established and verified.The internal stress distribution and displacement variation of the models were calculated by the finite element software;the correlation between the lumbosacral vertebral structure and displacement of the spine was analyzed.Results Under the same boundary conditions and load cases,the stress and displacement for two kinds of lumbosacral vertebral models showed different trends.Due to its leftleaning and forward convex bending deformation as well as the relatively large lordosis angle (60°) and smaller left-leaning angle (17.37°),the Lenke-4AN type lumbosacral spine produced slightly small forward convex displacement (8.18 mm) and relatively large left-leaning displacement (0.97 mm).The Lenke-5CN type lumbosacral spine showed left-leaning and forward convex bending deformation as well,with relatively large lordosis angle(59°) and left-leaning angle (26.97°),so it produced more severe left-leaning displacement (20.65 mm) andforward convex displacement (9.22 mm).Conclusions The deformation trend of lumbosacral vertebra is closelyrelated to its structural characteristics,and different scoliosis lumbosacral vertebral structures will cause the corre-sponding deformation trend.The research findings are important for the prevention and treatment of scoliosis.
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<p><b>OBJECTIVE</b>To validate the value of age-adjusted D-dimer combined with clinical probability to confirm or exclude deep vein thrombosis (DVT) in elderly patients.</p><p><b>METHOD</b>Elderly patients ( ≥ 65 years) suspected with DVT were evaluated by Wells score and D-dimer test. All patients underwent ultrasonography examination except for patients with Wells score < 2 and negative D-dimer test results. Conventional cut-off value is 500 µg/L, while age-adjusted cut-off value is set as patient's age×10 µg/L. We compared the sensitivity and specificity using the 2 cut-off values in confirming or excluding the diagnoses of DVT.</p><p><b>RESULTS</b>The study population consisted of 624 patients [mean age(76.4 ± 19.3) years], DVT was confirmed in 192 (30.8%) patients. Using Wells score model, 326 patients (52.2%) were scored as unlikely DVT and DVT was confirmed by ultrasonography in 44 patients (13.5%), and 298 patients as likely DVT patients and DVT was confirmed in 148 patients (55.0%). The sensitivity, specificity, positive predictive value, and negative predictive value by conventional and age-adjusted D-dimer cut-off value for diagnosing DVT in low-risk patients evaluated by Wells score model were 95.5%, 40.4%, 20.0%, 98.3% and 95.5%, 61.0%, 27.6%, 87.1%, respectively, and which were 89.9%, 67.3%, 73.1%, 87.1% and 89.2%, 89.3%, 89.2%, 89.3%, respectively, in high-risk patients evaluated by Wells score model. Thus, specificity increased about 20% using age-adjusted D-dimer cut-off value compared with conventional D-dimer cut-off value.</p><p><b>CONCLUSION</b>The age-adjusted D-dimer cut-off value combined with clinical probability evaluation could increase diagnosing specificity of DVT in elderly patients.</p>
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Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Fibrin Fibrinogen Degradation Products , Predictive Value of Tests , Sensitivity and Specificity , Venous Thrombosis , DiagnosisABSTRACT
<p><b>OBJECTIVE</b>To investigate the expressions of telomerase reverse transcriptase (TRT) and vascular endothelial growth factor (VEGF) and their correlation in prostate cancer (PCa).</p><p><b>METHODS</b>TRT and VEGF expressions were assayed in 30 cases of PCa and 30 cases of benign prostatic hyperplasia (BPH) by means of immunohistochemistry (SP) combined with computer assisted image analysis.</p><p><b>RESULTS</b>The expression of TRT was detected in 19 of the 30 cases of PCa and 5 of 30 cases of BPH, and that of VEGF in 23 of the 30 PCa and 14 of the 30 BPH patients. TRT and VEGF expressions were significantly higher in cancer tissues than in BPH (P < 0.05). A significant correlation was observed between TRT and VEGF expressions (r = 0.8333, P < 0.05).</p><p><b>CONCLUSION</b>The expression of TRT or VEGF might be a malignant phenotype in PCa. The expression of TRT is significantly correlated with that of VEGF, but the mechanisms are yet to be further studied.</p>