A finite element analysis of the supportive effect of a new type of rotary support plate on lateral tibial plateau fractures.

Background: Tibial plateau fractures (TPFs) are a challenging type of fracture in orthopedic traumatology. We previously designed a plate (Patent Number: CN201520195596.5) for posterolateral TPF combined with posterior lateral collapse.. In this study, finite element analysis was used to compare the biomechanical characteristics of two internal fixation methods for posterolateral TPF. We investigated the support effect of the new steel plate on lateral TPFs combined with posterior TPFs. Methods: Two models of complex TPF were established. Model A was fixed with the new type of plate, and model B was fixed without the plate. Three axial loads of 500, 1,000, and 1,500 N were applied using FEA on the two fracture models (A and B) to analyze the data. Results: In model A, the maximum displacement at 500, 1,000, and 1,500 N was 0.085797, 0.17043, and 0.25465 mm, respectively; the maximum stress of the bone block was 11.285, 20.648, and 29.227 MPa, respectively; and the maximum strain of the bone block was 0.0012474, 0.007435, and 0.0035769 mm, respectively. The maximum displacement of the internal fixation was 0.096932, 0.18682, and 0.27655 mm, respectively; the maximum stress was 69.54, 112.1, and 155.71 MPa, respectively; and the maximum strain was 0.00066228, 0.0010676, and 0.0014829 mm, respectively. In model B, the maximum displacement of fractures at 500, 1,000, and 1,500 N was 0.15675, 0.29868, and 0.44017 mm, respectively; the maximum stress of the bone block was 6.5519, 12.575, and 18.842 MPa, respectively; and the maximum strain of the bone block was 0.0032554, 0.0074357, and 0.012146 mm, respectively. The maximum displacement of the screw was 0.14177, 0.27109, and 0.39849 mm, respectively; the maximum stress was 48.916, 92.251, and 135.27 MPa, respectively; and the maximum strain was 0.00046608, 0.00087893, and 0.0012887 mm, respectively. Conclusions: The fixation method using this type of plates and screws can replace other methods using two plates to fix complex TPF.

38-year-old woman with nasal congestion: A rare case of septum-originated benign fibrous histiocytoma.

INTRODUCTION: Benign fibrous histiocytoma (BFH) is a mesenchymal tumor composed of fibroblasts and histiocytes, which normally occurs in the bone tissue and/or the skin of the limbs. BFH of the nasal septum is rare worldwide. PATIENT CONCERNS: A 38-year-old female patient attended our clinic with congestion in her right nasal cavity. DIAGNOSES: Endoscopic examination revealed a mass within the right nasal passage. Immunohistochemical staining demonstrated cells labeled with VIM (+), CD68PGM1 (+), CD34 (-), Actin (-), PCK (-), EMA (-), Desmin (-), SMA (-), S-100 (-), P63 (-), ALK-1 (-), beta-catenia (+), and KI67 (+). Clinical and histopathological examinations showed that the mass was a septum-originated BFH. INTERVENTIONS: For the treatment of BFH of the nasal septum, the mass was removed endoscopically using a transnasal approach. OUTCOMES: No recurrence was observed over 30 months of follow-up. CONCLUSION: To prevent the recurrence wide local resection with histological clear margin and long-term follow-up with an endoscope are necessary.

Subwavelength focusing of light in the planar anisotropic metamaterials with zone plates.

We present here a structure with just a single slit covering the planar anisotropic metamaterial. The metamaterial has hyperbolic dispersion and can be realized using metal-dielectric multilayers. The structure combines the focusing performance of the zone plates and subwavelength resolution of the anisotropic metamaterials so that subwavelength focal spots can be obtained at the focal plane. The relationship between the focal spot size and slit width has been investigated, and a resolution of 36 nm about 1/10 of 365 nm incident wavelength is obtained with a 100 nm wide single slit.

[Study on preparation of a wound healing agent: fibronectin].

In search of the optimal preparation method for large-scale purification of human plasma fibronectin, we adopted affinity chromatography with gelatin and the Sepharose 4B activated with cyanogen bromide to purify fibronectin from type "C" plasma of healthy males, and scanned the best method under the conditions of different amount of plasma loading and different residence time in column. In a given column volume of gelatin, the absorbent was related with the plasma residence time in column and the total amount of plasma loaded. As a result, the optimal loading amount of plasma is 150 ml, and the residence time is 20 minutes. The preparation method, herein, has been proved to require small amount of plasma and yield large amount of fibronectin.