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Objective: The mechanical high modulus structure of the proximal femur could guide clinical surgical treatment and instrument design of proximal femoral fractures. The purpose of this study is to analyze and verify the mechanical structure of the proximal femur. Methods: A total of 375 patients with intertrochanteric fractures were imaged using computed tomography (CT) scans. Patients were grouped according to age and sex. Cortical and medullary cavity parameters (cortical thickness [CTh], cortical mean density [CM], upper‐lower diameter length [ULL], and medial‐lateral diameter length [MLL]) were measured at eight planes. Six proximal femoral finite element models of different sexes and ages were constructed. To verify the measurement results, Abaqus was used to implement the force load to describe the von Mises stress distribution, and the maximum von Mises stress values of each wall of the proximal femur were compared. Results: The CTh values of the lower and upper walls were higher than those of the anterior and posterior walls of the femoral neck (p < 0.05). The CM values of the lower and upper walls were higher than those of the anterior and posterior walls of the subcephalic and middle femoral neck (p < 0.05). The ULL value gradually increased from the subcephalic region to the bottom (p < 0.05). The CTh and CM values of the medial and lateral walls were higher than those of the anterior and posterior walls in the femoral trochanteric region (p < 0.05). The MLL value decreased gradually from the plane 20 mm above the upper edge to that 20 mm below the vertex of the femoral lesser trochanter (p < 0.05). The von Mises stress was concentrated on the upper and lower walls of the femoral neck and on the medial and lateral walls of the femoral trochanteric region. The maximum von Mises stress values of the upper and lower walls were higher than those of the anterior and posterior walls of the femoral neck. The maximum von Mises stress values of the medial and lateral walls were higher than those of the anterior and posterior walls in the femoral trochanteric region, except for the plane 20 mm above the upper edge of the femoral lesser trochanter. Conclusion: The bone mass of the proximal femur presented a triangular high‐modulus distribution, which bore the main stress of the proximal femur. The triangular mechanical structure provides a guideline for the surgical strategy and instrument design of the proximal femur. [ABSTRACT FROM AUTHOR]

Glyoxal is considered to be the most likely substitute for formaldehyde to synthesize resin adhesives for wood bonding due to its reactivity, structural characteristics, being non-toxic, low volatility, and acceptable cost. Regrettably, the performance of the resin synthesized using glyoxal to directly replace all formaldehyde is not totally satisfactory, especially as it has almost no water resistance. This makes such a simple alternative fail to be suitable for industrial production. To prepare an environment-friendly glyoxal-based adhesive with good bonding performance, the work presented here relies first on reacting citric acid and hexamethylene diamine, producing a polyamide, with glyoxal, and then crosslinking it, thus synthesizing a thermosetting resin (namely CHG) adhesive and applying it for plywood bonding. The plywood prepared exhibits excellent dry and wet shear strength, which are better than GB/T9846-2015 standard requirements (≥0.7 MPa), and even after being soaked in hot water at 63 °C for 3 h, its strength is still as high as 1.35 MPa. The CHG resin is then potentially an adhesive for industrial application for replacing UF (urea-formaldehyde) and MUF (melamine-urea-formaldehyde) adhesives for wood composites. [ABSTRACT FROM AUTHOR]

Two types of urea–formaldehyde (UF) resin adhesives were synthesized with standard formaldehyde solution with 37% concentration and concentrated formaldehyde solution with 45% concentration. For 37% formaldehyde, 10% methanol was used as an inhibitor. For 45% formaldehyde, no more methanol was added. The chemical structure and changes during the resin preparation were analyzed. The performance of particleboards prepared with these resins was evaluated. The results indicated that the main difference between the concentrated formaldehyde and the standard formaldehyde was the higher content of methanol in the latter. Methanol affected the reaction during the preparation of UF resins and the final performance of the resins. Samples of the UF resin with standard formaldehyde taken at different stages during its preparation showed different contents of methylol groups, methylene ether bonds, uron structure, methylene bonds, and other groups compared to the resin prepared from concentrated formaldehyde. The performance concerning water resistance, mechanical performance, and formaldehyde emission of the particleboards prepared with the UF resin with concentrated formaldehyde was better than that with the resin with standard formaldehyde. [ABSTRACT FROM AUTHOR]

The utilization of air-supported fabric structures as formwork to construct concrete shells has attracted increasing attention in recent decades. An example of such an airform is the air-supported structure at Dahaize, which consists of a cylindrical part and a hemispherical part, and is 66 m in diameter and 65 m in height. The precise forming analysis of large-span air-supported structures requires the use of a reasonable material model that considers the biaxial stress condition and the creep behavior of the fabric. In this paper, a practical approach to modeling the biaxial time-dependent material behavior of composite fabrics is proposed based on the uniaxial linear viscoelastic theory and the plane stress orthotropic assumption. The multi-Kelvin physical model is developed to the two-dimensional form for the simulation of biaxial creep compliances. Biaxial tensile and biaxial creep tests are conducted on PVDF-coated polyester fabrics to calibrate the material parameters. The experimental stress conditions were determined according to the pre-estimated actual membrane stress distribution. The established material model is employed for the forming analysis of the Dahaize airform under conditions of varying creep times. The simulation results agree well with the on-site measured data, and this validates the accuracy and efficiency of the proposed material model. • A practical biaxial time-dependent material modeling of PVDF-coated polyester fabrics. • Biaxial tensile tests and 7-day biaxial creep tests on PVDF-coated polyester fabrics. • Forming analysis of air-supported fabric structures considering the creep of membrane. [ABSTRACT FROM AUTHOR]

As a biomass material, tannins are used in the preparation of wood adhesives, but their poor strength and water resistance has greatly limited their application. Therefore, it is necessary to prepare tannin-based wood adhesives with good water resistance. In the present study, tannin and hexanediamine were simply mixed at room temperature to prepare tannin-hexanediamine (TH) adhesive and then used to prepare plywood. Effects of mass ratio of hexanediamine to tannin and pH value of TH adhesive are studied. The results indicating the effects of mass ratio and pH value are apparent on shear strength. When the mass ratio is above 25 % and the pH value is above 9, the plywood shows good water resistance. Fourier transform-infrared (FTIR), X-ray photoelectron spectroscopy (XPS), liquid chromatography-mass spectrometry (LCMS) and X-ray diffraction (XRD) are used to determine the structures of TH adhesive, confirmed the reaction between tannin and hexanediamine to form macromolecules. Simultaneous thermal analyzer (TG–DSC) and Dynamic mechanical analysis (DMA) are used to analyze the thermal properties, indicate TH resin contains a good storage module and heat resistance. Therefore, with its good shear strength and water resistance, this newly developed tannin-based adhesive has the potential to application in wood-based panel industry, as an alternative of formaldehyde-based adhesive. [ABSTRACT FROM AUTHOR]

A thermoset polyamide resins were synthesized by citric acid and hexanediamine (CH), and was modified by oxidized glucose (OG). The effect of oxidation time and addition amount of oxidized glucose on shearing strength of plywood were characterized. Fourier transform-infrared (FT-IR) and liquid chromatography-mass spectrometry (LCMS) were used to determine the structures of the resins, the result shows that CH and OG reacted to form macromolecules. Differential Scanning Calorimeter (DSC), dynamic mechanical properties (DMA) were used to analyze its thermal properties, the results indicate that OG improved the storage module and the heat resistance. The CHOG resin exhibited a good bonding strength and water resistance, when the oxidation time is 0 min and the molar ratio of oxidized glucose to hexamethylene diamine is 1:1.6. Dry strength, 24 h wet strength and 63 °C hot water soaking wet strength of the plywood bonded with it are 1.36 MPa, 1.60 MPa, 1.49 MPa, respectively. Therefore, OG enhanced the shearing properties, and improve water resistance, which sheds new light on the preparation of bio-based wood adhesive for the manufacture of plywood. [Display omitted] • Branched synthetic polyamide obtained by polycondensation of citric acid and hexamethylenediamine. • Preparation of a green adhesive from polyamide resin and oxidized glucose without any formaldehyde was used. • The adhesive exhibits good bonding performance and water resistance. • The adhesive prepared in this work has good potential to be used in wood industry production. [ABSTRACT FROM AUTHOR]

• A nonlinear three-dimensional constitutive model of rigid polyurethane foam considering direction-dependence and tension–compression asymmetry. • Compressive and tensile tests of rigid polyurethane foam with DIC technique. • Implementation of nonlinear three-dimensional constitutive model of rigid polyurethane foam with Explicit Sub-stepping Method. Rigid polyurethane foam (RPUF) is characterized by direction-dependence and significant nonlinear performance. The direction-dependence shows the differences between foaming plane and foaming direction, while the nonlinear performance of RPUF not only shows the nonlinear relation between stress and strain, but also the tension–compression asymmetry. A new principal strain definition method of RPUF considering its foaming direction and foaming plane is hereby proposed for three-dimensional constitutive modeling. The constitutive model is established under the material principal strain coordinate system, along which the normal strains of two perpendicular directions in the foaming plane reach the maximum. The elastic moduli and Poisson's ratios vary with the sign and magnitude of the material principal strains. The nonlinear constitutive equation under the material principal strain coordinate system is derived in incremental form. The physical equation in the global coordinate system is obtained with coordinate transformation. With Digital Image Correlation (DIC) technique, compression and tensile tests along the foaming direction and perpendicular to the foaming direction were carried out to determine the constitutive model parameters. The proposed RPUF nonlinear constitutive model is applied to FEM analysis with the iterative algorithm of Explicit Sub-stepping Method. [ABSTRACT FROM AUTHOR]

Thin-walled structures have been widely used in vehicle components due to their lightweight characteristics. To design structural parameters that are more in line with actual requirements, it is often necessary to consider the influence of uncertainty in design parameters. An effective multi-objective design optimization method using hybrid search algorithms under interval uncertainty (MDOHSA) is proposed in this study. The MDOHSA mainly consists of the modified gray​ wolf optimization (mGWO) and the pattern search (PS) algorithms. The mGWO algorithm is applied to derive a new solution set and the PS algorithm is used to quickly search the lower and upper bounds of interval responses in MDOHSA. The non-dominated strategy considering uncertainty is designed by the possibility degree of interval value. The mGWO is designed by improving the initialization population and the updating mechanism. Some standard test functions are implemented to analyze the proposed method, and the result shows that the mGWO algorithm is superior to the other analogous algorithms. In this study, the car subframe, the hexagonal fractal structure, and the bracket of an intelligent sanitation vehicle are optimized by MDOHSA. The above results show that the optimization method proposed in this study is effective. The feasible solution of the multi-objective design optimization method can be selected according to the interval deviation degree of design variables and performance requirements. This study develops an effective multi-objective design optimization method for thin-walled structures under interval uncertainty and can continue to be used for the uncertain optimization of other engineering problems. • An effective multi-objective optimization method using hybrid search algorithms under interval uncertainty is proposed. • The modified grey wolf optimization is designed by improving the initialization population and the updating mechanism. • Thin-walled structures considering modal, dynamic crushing, and static loading are taken as optimization examples. [ABSTRACT FROM AUTHOR]

Purpose: To perform quantitative measurements of the anatomic morphology of the proximal ulna and establish the morphologic references based on Chinese for the surgical protocol and implant design. Methods: The computed tomography data of 156 upper extremities were involved in this study. The ulna model was reconstructed in Mimics. Ten distance and 6 angle parameters were measured by 4 independent investigators with a new quantitative measurement method. The intraclass correlation coefficient was used to evaluate the measuring reliability. Gender and side differences of measured parameters were evaluated. Results: Measurements showed a mean coronoid height of 15 mm, which was 42% of ulnar height with gender-specific differences (mean 16 mm in men and 14 mm in women, P < 0.001). A mean unsupported anteromedial facet width of 8 mm was 61% of the coronoid anteromedial facet. A larger opening angle correlates to a larger olecranon-diaphysis angle (P < 0.001) and larger coronoid height (P = 0.001). A mean proximal ulna dorsal angulation of 4.7° is present in 80% of models at an average of 52 mm distal to olecranon tip. The average proximal ulna varus angulation was 16° at a mean of 74 mm distal to the olecranon tip. Morphological features between the left and right sides were highly consistent. The ICC was between 0.789 and 0.978 for inter-observer and between 0.696 and 0.997 for intra-observer reliability. Conclusions: The proximal ulna features variable morphology but minor side differences among individuals. Over half of the anteromedial facet was not supported by the proximal ulnar diaphysis, making the coronoid vulnerable to elbow trauma. Preconditioning or customized design of the ulnar plate in the clinical setting with the help of contralateral morphology may be a good choice. [ABSTRACT FROM AUTHOR]

Abstract In this study, double-layer Zn-Al-Mg coatings were manufactured by the PVD process and heat treatment. The microstructure and initial corrosion behavior were investigated during the 20-‍day immersion experiment. And the influence of heat treatment at different temperatures was discussed. The double-layer Zn-Al-Mg coating showed the superior initial corrosion resistance compared to the Zn55Al coating. And the best corrosion resistance can be achieved after 300 °C heat treatment (ZAM3). According to EIS and fitting results, the resistance value of ZAM3 corrosion products layer decreased first from 1.5 × 108 to 3.8 × 106 Ω·cm2 and then increased to 7.8 × 109 Ω·cm2 during 20-day immersion. And this resistance value of Zn55Al coating decreased gradually from 3.3 × 103 to 5.6 × 102 Ω·cm2. The double-layer Zn-Al-Mg coating can provide two types of protection in different stages, the barrier protection of surface passive film from the beginning to the 8th day and the formation of double layer corrosion products from the 8th day to the 20th day. After 20-day immersion, the corrosion products of Zn 5 (OH) 8 Cl 2 ·H 2 O and Zn 6 Al 2 (OH) 16 CO 3 ·4H 2 O are easier to form on the surface of ZAM. And on the outermost surface of ZAM3 corrosion products, it tends to be covered by zinc carbonate hydroxide. This is different from the fact that the outermost surface of ZA corrosion products is often covered by zinc hydroxide. Graphical abstract Unlabelled Image Highlights • The corrosion resistance of ZnAl coating is improved by PVD-Mg and heat treatment. • The product layer resistance of ZAM3 is up to 7.8 × 109 Ω·cm2 after 20d immersion. • Barriers of passive film and double layer products are found in two diverse periods. • Mg2+ ions promote the formation of compact corrosion products. [ABSTRACT FROM AUTHOR]

A correction is presented to the article "Morphometric feature description of the proximal ulna based on quantitative measurement: a key consideration for implant design" which published internet portal on 12 December 2022 with Open Access under a Creative Commons Attribution.

• Built three fixation models: medial support pad (MSP)+LISS, antero-medial plate (AMP)+LISS, and medial plate (MP)+LISS. • Model of MSP+LISS showed better biomechanical performance than the double-plate model, testified by finite element analysis. • With finite element analysis, medial plate (MP)+LISS provided better biomechanical support than antero-medial plate (AMP)+LISS. In this study, we evaluated the biomechanical characteristics of different locations of medial fixation strategies in double-plate osteosynthesis for fixing AO/ASIF type 33-C2 femoral fractures by means of finite element analysis. We used 3-matic software and UG-NX software to construct AO/ASIF type 33-C2 Femoral fractures and lateral less invasive stabilization system (LISS) plates, medial plates (MPs), and medial support pads (MSPs), respectively. Then, the LISS, MP and MSP were assembled into the fracture model separately to form three fixation models: MSP+LISS, anteromedial plate (AMP+LISS), and MP+LISS. In the next procedure, we performed finite element analysis using ANSYS software after meshing the elements of the models in HyperMesh 11.0 software. Loading conditions including lateral-medial four-point bending, anterior-posterior four-point bending, axial loading, and torsional loading were applied to evaluate the biomechanical advantages among the three fixation types. We observed the peak Von Mises Stress (VMS) value, maximum displacement, bending angle in the coronal plane of the fracture, and torsional angle of the fracture to assess the degree of plate deformation and fixation stability. Our results showed that in both lateral-medial four-point bending and anterior-posterior four-point bending, the calculations of MP+LISS were marginally better than those of AMP+LISS. However, with the action of axial loading and torsional loading, the deformation of MP+LISS was distinctly smaller than that of AMP+LISS, and the fixation stability of MP+LISS was also prominently better. Under lateral-medial four-point bending, the VMS on the lateral plate of MSP+LISS (59.977 MPa) was approximately half of the two double-plate models. Under anterior and posterior four-point bending, the 38.209 MPa peak VMS of MSP+LISS was still superior to the other two double-plate models. Under torsional loading, the peak VMS (347.75 MPa), the maximum torsional angle of the femoral head (7.852 °), and the torsional angle of fracture (0.036 °) of MSP+LISS preceded those of the other two models. However, under axial loading, the peak VMS (76.376 MPa) and the maximum displacement (3.1798 mm) of MSP+LISS were slightly higher than those of MP+LISS. The MSP+LISS model showed better biomechanical performance than the double-plate models, which might be an effective solution for the treatment of comminuted distal femur fractures. [ABSTRACT FROM AUTHOR]

• The research compared the outcomes of intramedullary nailing with the computer-assisted system to those with traditional freehand method. • It was found that computer-assisted intramedullary nailing had a smaller tip-apex-distance than freehand implantation. • The better lag screws positions could be obtained in patients with computer-assisted intramedullary nailing. • The operative time and radiation use was not prolonged during the application of the computer-assisted system. Intramedullary nailing (IMN) is a general treatment for intertrochanteric hip fractures. The computer-assisted orthopaedics system (CAOS), ADAPT system (Stryker, NJ), has been developed to facilitate lag screw insertion. When compared to the conventional freehand method, the efficacy of CAOS has not been clearly clarified. Therefore, we conducted this systematic review and meta-analysis to answer: does the CAOS performed better than freehand method in IMN. Studies published up to January 2023 were searched in the PubMed, Embase, Web of Science and Cochrane Library databases with predetermined key words. Comparative clinical studies between CAOS (ADAPT system) and freehand method were included. The primary outcomes of interest were the tip-apex-distance (TAD) and positions of lag screw. Fluoroscopy use, operation duration and intraoperative/postoperative complications were also extracted. A meta-analysis was performed for pooled analysis. There were seven studies with 326 fractures in CAOS group and 325 fractures in Freehand group. All studies included presented high qualities. The CAOS group showed a statistically smaller TAD than Freehand group (weighted mean difference = -3.24 mm; 95% confidence interval [CI] -5.10 to -1.37 mm; p = 0.0007) and a better lag screw position (83/92 [90.2%] VS 64/92 [69.6%]; RR = 1.3; 95% CI 1.12 to 1.51; p = 0.0007). The operative time and radiation use revealed no difference between two groups. The current evidence indicated that ADAPT system could help to perform a more accurate lag screw than freehand manipulation while the operative time and radiation time was not reduced as expectations on such new technique. Long-term follow-up studies are appealed. [ABSTRACT FROM AUTHOR]

A cascaded H-bridge STATCOM requires large DC filter capacitors to suppress the low-frequency voltage fluctuation in each of the H-bridge cells. Keeping the voltage stress of power device unchanged, increasing the fluctuation of the DC-link voltage is a possible method to significantly reduce the required capacitance for a STATCOM. However, excessive voltage fluctuation greatly degrades the operating range of the inductive conditions. This paper proposes a universal capacitance design method that can significantly reduce the required capacitance when compared with the traditional design method. First, the inductance is constrained in the form normalized by the system impedance. Then a new analysis method between the DC-link capacitance and the operating range is introduced. Experiment results obtained on a low-power 5-level cascaded H-bridge STATCOM prototype are presented to validate the correctness of the proposed design method. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to compare the effectiveness of anatomic locking plate and reconstruction plate used in treating acetabular fractures. Methods: From January 2009 to January 2016, patients with acetabular fractures were included in this retrospective study. We grouped the patients into two groups based on the internal fixation: reconstruction plate group (RPG) and anatomic locking plate group (ALPG). The operation time, blood loss, intra-operative screw penetration, and plate breakage were compared between the two groups. The intra-operative fluoroscopic images were used to evaluate the fixation location. The quality of reduction and radiological grading were assessed according to the criteria developed by Matta. The clinical assessment was based on the Merle d'Aubigne-Postel score. Results: Eighty-three patients were included in this study and were followed up for an average of 35 months (range, 25 to 42 months). Thirty-five patients were treated with the anatomical locking plate, and 48 patients were treated with the reconstruction plate. The mean surgical time was significantly shorter (P < 0.0001) in ALPG patients than in RPG patients, and the intra-operative blood loss was significantly lower (P = 0.008). The rates of intra-operative screw penetration or plate breakage in the ALPG (0/35) are significantly lower than that in the RPG (7/48) (P = 0.018). Post-operative Matta score (P = 0.905), Merle d'Aubigne-Postel score (P = 0.957), and overall complication rates (P = 0.391) were not significantly different among the groups. Conclusion: Patients treated by anatomical locking plate had shorter operation time, less bleeding, and lower rate screw perforation compared to patients treated by reconstruction plate. Anatomical locking plate is a better choice for acetabulum fractures, especially complicated fractures. [ABSTRACT FROM AUTHOR]

Despite the widespread application prospect of soybean meal flour (SF) as a non-toxic and renewable wood adhesive, the practical application is limited by its poor mechanical properties and water resistance. In this work, a novel SF-based wood adhesive (CSP) was developed using citric acid (CA) as a modifier, which was further designated to produce plywood on a laboratory scale. Moreover, the effects of the mass ratio of CA/SF, hot-pressing temperature, and hot-pressing time on the bonding properties and water resistance of the resulting plywood were investigated in detail. As a result, under the optimal hot-pressing conditions (180 °C, 5 min), high-performance plywood bonded by CSP (CA/SF = 15/100) adhesive was fabricated, whose dry shear strength, cold-water wet shear strength (20 °C for 24 h), and hot-water wet shear strength (63 °C for 3 h) reached 1.65 MPa, 1.99 MPa, and 1.58 MPa, respectively. Due to the easy preparation process, sustainability, and favorable properties, the proposed fully bio-based CSP wood adhesive has great potential for the large-scale fabrication of eco-friendly wood panels in industry. A citric acid - soy protein wood adhesive was feasibly developed to fabricate formaldehyde-free plywood with high mechanical properties and water resistance. [Display omitted] [ABSTRACT FROM AUTHOR]

Despite the widespread application prospect of soybean meal flour (SF) as a non-toxic and renewable wood adhesive, the practical application is limited by its poor mechanical properties and water resistance. In this work, a novel SF-based wood adhesive (CSP) was developed using citric acid (CA) as a modifier, which was further designated to produce plywood on a laboratory scale. Moreover, the effects of the mass ratio of CA/SF, hot-pressing temperature, and hot-pressing time on the bonding properties and water resistance of the resulting plywood were investigated in detail. As a result, under the optimal hot-pressing conditions (180 °C, 5 min), high-performance plywood bonded by CSP (CA/SF = 15/100) adhesive was fabricated, whose dry shear strength, cold-water wet shear strength (20 °C for 24 h), and hot-water wet shear strength (63 °C for 3 h) reached 1.65 MPa, 1.99 MPa, and 1.58 MPa, respectively. Due to the easy preparation process, sustainability, and favorable properties, the proposed fully bio-based CSP wood adhesive has great potential for the large-scale fabrication of eco-friendly wood panels in industry. A citric acid - soy protein wood adhesive was feasibly developed to fabricate formaldehyde-free plywood with high mechanical properties and water resistance. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Anterior cortical impingement is a common phenomenon after intramedullary fixation in Asian patients with intertrochanteric fractures. It may cause thigh pain and even fracture of the femoral shaft, which may seriously affect postoperative rehabilitation and limb function of patients. However, little was known about risk factors for anterior cortical impingement in Chinese elderly after intramedullary nailing. Hence, the aim of this study was to certify the risk factors for anterior cortical impingement treated with intramedullary nails of intertrochanteric fracture, hoping to provide suggestions for surgical treatment.Patients and Methods: A retrospective consecutive series of 94 patients who had been diagnosed as intertrochanteric fracture at our institution was included from January 2019 to November 2019. All patients were treated with intramedullary fixation and followed up for at least 6 months. Demographic, surgical and anesthesiologic information, as well as radiographic data and complications were collected and reviewed.Results: The ratio of anterior cortical impingement is significantly higher in female patients than that of males (80.4% vs 18.6%, P=0.041). Higher incidence of anterior cortical impingement was found in the longer intramedullary nail group, especially in females. Gender (as a female patient) and length of nail were significant risk factors for anterior cortical impingement in intertrochanteric fracture patients treated with intramedullary nail (OR =2.662, 95% CI =1.010-7.018, P=0.447; OR =1.047, 95% CI =1.016-1.079, respectively). The length of nail was a risk factor for anterior cortical impingement in female intertrochanteric fracture patients treated with intramedullary nail (OR =1.051, 95% CI =1.015-1.089).Conclusion: Elderly female patients with intertrochanteric fractures treated with intramedullary nails had a higher incidence of anterior cortical impingement. The length of short intramedullary nail is a risk factor for anterior cortical impingement. Patients with anterior cortical impingement may suffer serious complications. [ABSTRACT FROM AUTHOR]

• The yttria-stabilized zirconia (YSZ) solid electrolyte oxygen sensor with LSCF (lanthanum strontium cobalt ferrite)/air reference electrode was investigated. • The performance of two LSCF/air reference electrode sensors was tested on a LBE dynamic loop. • This study demonstrates that the LSCF/air sensor can be used to monitor oxygen concentration in non-isothermal LBE systems. Oxygen sensors are the major part of the active oxygen control system (OCS) to be used in the liquid lead–bismuth eutectic (LBE) system. In this paper, the electromotive force (EMF) measured by yttria stabilized zirconia (YSZ) solid electrolyte sensor with LSCF (lanthanum strontium cobalt ferrite)/air reference electrode in static oxygen saturated LBE is used to obtain relationship between EMF and temperature. The EMF output by oxygen sensors is deterministic and predictable. At the same time, the performance of oxygen sensors in flow loop of liquid LBE were also studied. EMF output curves of oxygen sensors corresponding to the operation of consuming dissolved oxygen are given. It is proved that the LSCF/air sensor can be used to monitor oxygen concentration in non-isothermal LBE systems. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to develop a systematic three-dimensional (3D) classification of intertrochanteric fractures by clustering the morphological features of fracture lines using the Hausdorff distance-based K-means approach and assess the usefulness of it in the clinical setting.Methods: We retrospectively analyzed the data of 504 patients with intertrochanteric fractures who underwent closed reduction and intramedullary internal fixation. The morphological fracture lines of all patients extracted from computed tomography were transcribed freehand onto the template. All fracture lines were then clustered into five distinct types using the Hausdorff distance-based K-means clustering method. Five radiographic parameters and four functional parameters were used to evaluate the postoperative functional states and mobilization levels. Postoperative complications were also recorded.Results: Intertrochanteric fractures were classified into five types: type I (108/504, 21.4%), simple fracture with intact lateral femoral wall and greater trochanter fragment; type II (85/504, 16.9%), simple fracture with intact lateral femoral wall with/without lesser trochanter detachment; type III (147/504, 29.2%), fractures with intertrochanteric crest detachment involving the lesser trochanter and greater trochanter with an intact lateral femoral wall; type IV (113/504, 22.4%), fractures with large intertrochanteric crest detachment and large lesser trochanter and greater trochanter detachment partially involving the lateral femoral wall and less medial cortical support; type V (51/504, 10.1%), a combination of pertrochanteric and lateral fracture line involving the entire lateral femoral wall and lesser trochanter detachment. Parameters of femoral neck-shaft angle and sliding distance of the cephalic nail were significantly different among types. The complication rate generally increased from type I to type V (P = 0.035).Conclusions: The unsupervised clustering can achieve identification of the type of intertrochanteric fractures with clinical significance. The Tang classification can be used to describe fracture morphology, predict the possibility of achieving stable reduction and the risk of complications following intramedullary fixation. [ABSTRACT FROM AUTHOR]

Objectives: Using finite element analysis and biomechanical tests, the biomechanical behaviors of Medial Sustainable Nail (MSN) and Proximal Femoral Nail Antirotation (PFNA) were compared for the fixation of fracture type of AO/OTA 31-A2.3.Methods: Finite element software Abaqus 6.14 was used to conduct axial loading of 2100 N and we analyzed the von Mises stress distribution and the model displacement of two implant models. Biomechanical tests were separately conducted in the axial stiffness test and axial cyclical loading test on a mechanical testing machine.Results: The results indicate that von Mises stress of MSN was lower than that of PFNA, and the model displacement in the MSN group was lower than that in the PFNA group. In the axial stiffness tests, MSN group was stiffer than PFNA construct. With respect to the axial load to ultimate failure, the PFNA construct exhibited higher loads exceeding 4000 N while the MSN construct withstood 3313.8 ± 92.8 N. Specifically, F10mm was 2178.6 ± 133.2 N of the MSN group and 1822.6 ± 93.1 N of the PFNA group (P = 0.001). Additionally, X2100N was 9.8 ± 0.5 mm of the MSN group and 11.7 ± 0.7 mm of the PFNA group (P = 0.002). The MSN group exhibited superior performances in terms of the mean value of the vertical displacement, frontal rotation angle, and lateral rotation angle.Conclusions: The results indicated that the MSN construct might exhibit a better biomechanical performance when compared with that of the PFNA in reducing displacement and anti-varus in fracture type of AO/OTA 31-A2.3. [ABSTRACT FROM AUTHOR]

Objectives. We evaluated the biomechanical outcome of different plate fixation strategies (the single plate construct, 45° double-plate construct, 90° double-plate construct, 135° double-plate construct, and 180° double-plate construct) used for the fixation of the femoral shaft nonunion with no cortical support opposite the primary lateral plate. This may help surgeons choose the optimal therapy to the femoral shaft nonunion. Methods. The femoral shaft nonunion with no medial support and the models of lateral plate and medial plate was constructed in 3-matic software and UG-NX software, respectively. We then assembled the single plate and different double plates to the fracture model separately to form the fixation models. After meshing the models’ elements, we used the ABAQUS software to perform the finite element analysis. Values of the von Mises Stress (VMS) distribution of the implant, peak VMS, and model displacement and deformation were used to capture the mechanical factors in this study. Results. Our results indicated that the peak von Mises Stress (VMS) of the lateral plate was concentrated in middle surface of the lateral plate near the fragment of each group. The peak VMS was 5201.0 MPa (the single-plate construct), 3490.0 MPa (45° double-plate construct), 1754.0 MPa (90° double-plate construct), 1123.0 MPa (135° double-plate construct), and 816.5 MPa (180° double-plate construct). The additional short plate dispersed some stress leading to the decrease in the peak VMS of the lateral plate. As angle formed by the double plates increased, the dispersed function of the additional plate was becoming obvious. The bending angles of the lateral plate were 18° versus 12° versus 3° versus 2° versus 1° (the single-plate construct versus 45° double-plate construct versus 90° double-plate construct versus 135° double-plate construct versus 180° double-plate construct). Conclusions. Our study indicated that increasing the angle between the plates in a double-plate construct improves the stability of the construct over a single lateral plate when there is no cortical support opposite to the lateral plate. The strongest fixation occurred when the angle between the two plates was greater than ninety degrees. [ABSTRACT FROM AUTHOR]