Evaluating the biomechanical performance of Ti6Al4V volar plates in patients with distal radius fractures

Purpose: This study aimed to investigate the biomechanical performance of three Ti6Al4V volar plates with the latest designs using a finite element model.Methods: An AO type 23-A3 distal radius fracture and the models of T plate (2.4 mm LCP Volar Distal Radius Plate), V plate (2.4 mm LCP Two-Column Volar Distal Radius Plate) and π Plate (2.4 mm Volar Rim Distal Radius Plate) (all from Depuy Synthes, West Chester, PA, USA, Ti6Al4V) were built in 3D-matic software. After assembling the internal fixation and fractures, we imported these models into the finite element analysis software (ABAQUS). An axial loading of 100 N was added to the distal end of each model. The displacements of total models and implants, the principal strains and the von Mises stresses in the plates were calculated and compared to capture the biomechanical features of the three plates.Results: The T plate, V plate and π plate represented a model displacement of 0.8414 mm, 1.134 mm and 1.936 mm, respectively. The T plate was with the implant displacement of 0.7576 mm, followed by the V plate (0.8802 mm) and the π plate (1.545 mm). The T plate had the smallest principal strain of 0.23%, the V plate showed an intermediate level of 0.28%, and the π plate had a value of 0.72%. The least peak von Mises stress was observed in the V plate with 263.6MPa, and this value was 435.6 MPa and 1050 MPa in the T plate and π plate, respectively.Conclusion: The biomechanical features of three Ti6Al4V volar locking plates in an AO type 23-A3 fracture were described in our analysis. The T plate and the V plate showed similar biomechanical performance while the π plate represented worse performance than the other two plates

Prediction of osteoporosis from proximal femoral cortical bone thickness and Hounsfield unit value with clinical significance

BackgroundUtilizing dual-energy x-ray absorptiometry (DXA) to assess bone mineral density (BMD) was not routine in many clinical scenarios, leading to missed diagnoses of osteoporosis. The objective of this study is to obtain effective parameters from hip computer tomography (CT) to screen patients with osteoporosis and predict their clinical outcomes.MethodsA total of 375 patients with hip CT scans for intertrochanteric fracture were included. Among them, 56 patients possessed the data of both hip CT scans and DXA and were settled as a training group. The cortical bone thickness (CTh) and Hounsfield unit (HU) values were abstracted from 31 regions of interest (ROIs) of the proximal femur. In the training group, the correlations between these parameters and BMD were investigated, and their diagnostic efficiency of osteoporosis was assessed. Finally, 375 patients were divided into osteoporotic and nonosteoporotic groups based on the optimal cut-off values, and the clinical difference between subgroups was evaluated.ResultsThe CTh value of ROI 21 and the HU value of ROI 14 were moderately correlated with the hip BMD [r = 0.475 and 0.445 (p < 0.001), respectively]. The best diagnostic effect could be obtained by defining osteoporosis as CTh value < 3.19 mm in ROI 21 or HU value < 424.97 HU in ROI 14, with accuracies of 0.821 and 0.883, sensitivities of 84% and 76%, and specificities of 71% and 87%, respectively. The clinical outcome of the nonosteoporotic group was better than that of the osteoporotic group regardless of the division criteria.ConclusionThe CTh and HU values of specific cortex sites in the proximal femur were positively correlated with BMD of DXA at the hip. Thresholds for osteoporosis based on CTh and HU values could be utilized to screen osteoporosis and predict clinical outcomes

Characterization of a DNA Aptamer for Ovarian Cancer Clinical Tissue Recognition and in Vivo Imaging

Backgrounds/Aims: Ovarian cancer is the most lethal gynaecologic malignancy and is difficult to detect early. The inefficient early diagnosis of ovarian cancer is the main contributor to its high mortality rate. Aptamers, as chemical antibodies, are single-stranded DNA or RNA oligonucleotides that target cells or molecules with high affinity. Methods: Binding ability of R13 was measured by flow cytometry analysis. Stability of R13 was tested in blood serum of an ovarian cancer patient. Internalization of R13 was verified by confocal microscope imaging. 80 cases ovarian cancer tissues, 10 cases normal ovary tissues in a microarray and 6 fallopian tube tissues were prepared for this study. R13’s target ability was further confirmed in vivo tumor models in NOD/SCID mice. Results: In this study, we found aptamer R13 bound to ovarian cancer cells with dissociation constants in the nanomolar range. Moreover, these results were further confirmed by tissue imaging. Next we demonstrated that the targets of R13 are membrane proteins and that its internalization occurs in a caveolae-mediated and clathrin-mediated manner. The target function of R13 was determined by imaging A2780 tumours in mouse models. Conclusion: These findings suggest that R13 is a promising novel tool to diagnose and deliver drugs to treat ovarian cancer

Multifunctional Superabsorbent Polymer under Residue Incorporation Increased Maize Productivity through Improving Sandy Soil Properties

Superabsorbent polymer (SAP) is a new water-retaining and nutrient-holding material with the potential to improve soil properties and promote crop growth in arid and semiarid areas. This study investigated the effects of multifunctional SAP on the sandy soil properties and maize productivity in Yanghuang irrigated area of Ningxia where residue incorporation was a common agricultural practice, we tested multifunctional SAP at different doses of 0, 30, 60, 90, and 120 kg ha–1 under the residue incorporation to the field. The soil bulk density in the 0–0.40 m layer was significantly lower by 6.2–8.2% under SAP at 60–120 kg ha–1 compared with no SAP, but the total soil porosity was improved significantly by 8.5–11.2%, where the SAP at 90 and 120 kg ha–1 had the greatest effects. The applications of SAP at 60 and 90 kg ha–1 significantly improved soil organic matter, and available P and K contents in the 0–0.40 m soil layer. The soil water storage (0–1.0 m) under SAP at 60–120 kg ha–1 was significantly increased by 17.1–18.7% compared with no SAP throughout the whole maize growing season. The SAP at 60–90 kg ha–1 significantly promoted crop growth and maize yield formation, and increased grain yield, whereas the net income were the highest with applying SAP at 30–60 kg ha–1. In combination with the soil physicochemical property, crop productivity and economic benefit comprehensive analysis of this two-year study, we recommended that the application of multifunctional SAP at 30–60 kg ha–1 under residue incorporation significantly improved the sandy soil properties, as well as increasing maize growth, crop productivity, and obtain the higher net income for farmers in Yanghuang irrigation area of Ningxia, China