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Under the traditional control method, the dual three-phase permanent magnet synchronous motor (DTP-PMSM) has a harmonic plane with low impedance, and it can produce larger harmonic current. Model predictive control (MPC) has a simple control structure and a good dynamic performance. The MPC is usually used in a high-performance control system of multiphase motors. Aiming at the DTP-PMSM drive system, an improved MPC strategy based on the biplane virtual voltage vector is proposed in this paper. In the proposed biplane MPC scheme, the voltage vector of the α-β plane is virtual to 25 voltage vectors, while the voltage vector of the x-y plane is virtual to zero. At the same time, the voltage vector of the x-y plane is virtual to 25 voltage vectors, while the voltage vector of the α-β plane is virtual to zero. On this basis, the cost function of the biplane is evaluated. The operating time and reference voltage of each vector are calculated. The virtual voltage vector on the α-β plane is used for electromechanical energy conversion to generate the best electromagnetic torque and reduce torque ripple. The virtual voltage vector on the x-y plane is used to suppress the stator current harmonics and improve the efficiency of the DTP-PMSM. The simulation and experimental results demonstrate the superiority of the proposed biplane MPC. [ABSTRACT FROM AUTHOR]

Abstract Background Left ventricular (LV) volumes can be calculated from various linear, monoplane, and multiplane echocardiographic methods, and the same method can be applied to different imaging views. However, these methods and their variations have not been comprehensively evaluated against real‐time 3‐dimensional echocardiography (RT3D). Hypothesis/Objectives To identify the LV volumetric approaches that produce the least bias and the best agreement with RT3D, and to assess interoperator reproducibility between an experienced and an inexperienced operator. Animals Fifty‐nine client‐owned dogs with myxomatous mitral valve disease (38 Stage B1, 13 Stage B2, 8 Stages C/D) received echocardiograms, with a subset of 28 dogs (14 Stage B1, 10 Stage B2, 4 Stages C/D) imaged by 2 operators. Methods Prospective method comparison study. Body weight‐indexed end‐diastolic and end‐systolic LV volumes using linear methods in long‐ and short‐axis views (Teichholz, cube, modified cube), monoplane methods in right parasternal and left apical views (area‐length and Simpson's method of discs), biplane Simpson's method of discs, and real‐time triplane (RT3P) were compared against RT3D. Results The RT3P method exhibited no bias and demonstrated the highest agreement with RT3D. The linear methods showed significant bias and lower agreements for end‐diastolic volumes, end‐systolic volumes, or both. Volumes derived from different imaging views using the same method showed poor agreement. Both RT3P and RT3D methods demonstrated poor interoperator reproducibility. Conclusions and Clinical Importance Incorporating additional dimensions improves bias and agreement in LV volume quantification, but comprehensive clinical experience with RT3P and RT3D is needed to improve consistency across all operators.

Abstract Introduction Ultrasound is the current standard for central venous access due to its advantages in efficiency and safety. In-plane and out-of-plane visualization techniques are commonly used, but there is no clear evidence showing an advantage of one technique over the other. The objective of this study was to compare the success and time required for biplane visualization vs. in-plane and out-of-plane techniques in simulated models. Methodology Ten emergency medicine specialists participated in 60 simulated events, with randomization of the visualization technique for each event. Each event required intravenous cannulation of a simulated model for jugular venous access, with a maximum of three attempts allowed. The number of attempts required for each event, success of puncture and venous cannulation, frequency of redirection and puncture of the posterior wall, time required to obtain an optimal window, visualize the needle inside the vessel, and passage of the guidewire were recorded. The success ratios and times required for each visualization technique (biplane, in-plane, and out-of-plane) were compared. Results Cannulation success rate was 100% for all three techniques. Success on the first attempt was 95% for biplane visualization vs. 100% for in-plane and out-of-plane. The median total time for the procedure was higher for biplane visualization (29.9 s) compared to in-plane (25.2 s) and out-of-plane (29 s), but this difference was not statistically significant (p = 0.999). There were no significant differences in cannulation success, needle redirection, or posterior wall puncture frequency between biplane visualization and in-plane and out-of-plane techniques. Conclusions This study suggests that biplane visualization with the use of pocket ultrasound for internal jugular cannulation in simulated models did not demonstrate significant differences when compared with in-plane and out-of-plane visualization techniques. Further research with larger sample sizes may be needed to confirm these results.

Introduction: Ultrasound is the current standard for central venous access due to its advantages in efficiency and safety. In-plane and out-of-plane visualization techniques are commonly used, but there is no clear evidence showing an advantage of one technique over the other. The objective of this study was to compare the success and time required for biplane visualization vs. in-plane and out-of-plane techniques in simulated models. Methodology: Ten emergency medicine specialists participated in 60 simulated events, with randomization of the visualization technique for each event. Each event required intravenous cannulation of a simulated model for jugular venous access, with a maximum of three attempts allowed. The number of attempts required for each event, success of puncture and venous cannulation, frequency of redirection and puncture of the posterior wall, time required to obtain an optimal window, visualize the needle inside the vessel, and passage of the guidewire were recorded. The success ratios and times required for each visualization technique (biplane, in-plane, and out-of-plane) were compared. Results: Cannulation success rate was 100% for all three techniques. Success on the first attempt was 95% for biplane visualization vs. 100% for in-plane and out-of-plane. The median total time for the procedure was higher for biplane visualization (29.9 s) compared to in-plane (25.2 s) and out-of-plane (29 s), but this difference was not statistically significant (p = 0.999). There were no significant differences in cannulation success, needle redirection, or posterior wall puncture frequency between biplane visualization and in-plane and out-of-plane techniques. Conclusions: This study suggests that biplane visualization with the use of pocket ultrasound for internal jugular cannulation in simulated models did not demonstrate significant differences when compared with in-plane and out-of-plane visualization techniques. Further research with larger sample sizes may be needed to confirm these results. [ABSTRACT FROM AUTHOR]

Purpose: To compare the changes in posterior tibial slope (PTS) between retrotuberosity biplane open-wedge high tibial osteotomies (RT-OWHTOs) with and without additional anteromedial staple fixation. Methods: Seventy-nine and 77 cases of RT-OWHTOs without (Group N) and with (Group S) additional staple fixation, respectively, were retrospectively reviewed. All procedures were performed using a locking spacer plate. Demographics and preoperative knee condition were similar between the groups. Clinically, the Western Ontario and McMaster Universities Arthritis Index and range of motion were evaluated preoperatively and 2 years postoperatively. Radiographically, the mechanical axis (MA), medial proximal tibial angle (MPTA), and PTS were evaluated preoperatively and within 2 years postoperatively. Hinge fractures were investigated using computed tomography at 2 weeks postoperatively. PTS loss was defined as the difference between the corresponding values at 2 weeks and 2 years postoperatively. The incidence of PTS failure (PTS loss ≥ ± 3°) was also investigated. Results: The clinical results were not significantly different between groups N and S preoperatively and 2 years postoperatively. There were no significant differences in the MA, MPTA, and PTS between the groups preoperatively and 2 weeks postoperatively; changes in these variables did not differ significantly between the groups. The incidence of hinge fractures, all of which were categorized as Takeuchi type 1, did not differ significantly. PTS loss within 2 years postoperatively was significantly greater in group N than in group S (1.0° vs. 0.1°; p < 0.01). The incidence of the PTS failure was 16.5% (13/79) and 2.6% (2/77) in groups N and S, respectively (p < 0.01). Conclusion: Additional anteromedial staple fixation could prevent changes in the PTS in RT-OWHTO. It is a simple method for preventing an increase in the PTS after RT-OWHTO. Level of evidence: III. [ABSTRACT FROM AUTHOR]

The potential of the joined/box-wing aircraft as an environmentally friendly airliner that is capable of meeting current and future emission thresholds led to the investigation of this concept. This study reviews the evolution and current trends in the aerodynamic design of the box-wing aircraft with specific emphasis on box-wing theory, airfoil characteristics, and aerodynamic issues of the box-wing aircraft. The study was undertaken to highlight the distinct features of the box-wing configuration which make it very attractive for future airliners. The study reveals that the box-wing aircraft possesses a significant aerodynamic advantage over conventional aircraft. The boxwing aircraft configuration is also a less radical departure from the conventional concept. It thus could be developed with existing triedand- tested aircraft design technologies, methodologies, and processes. Hence this article is a commentary that highlights the enormous potential of the box-wing aircraft and the need for further studies in this research domain. [ABSTRACT FROM AUTHOR]

Thrombectomy is now the standard of care in the treatment of acute ischemic stroke caused by emergent large vessel occlusion. Therefore thrombectomy services have expanded from Comprehensive Stroke Centers to Thrombectomy-Capable Stroke Centers. Stroke interventions at these sites are performed in both biplane and monoplane angiography suites. It has been hypothesized that differences in these systems may affect time to successful reperfusion, with a potentially significant effect on neurologic outcomes. With an increase in TSCs, this study aims to evaluate the safety and efficacy of monoplane thrombectomy versus biplane thrombectomy. Patients who presented with isolated proximal middle cerebral artery M1 occlusions and underwent endovascular thrombectomy from March 2015 to August 2018 at 5 different centers within a single health system were included. Thrombectomy was performed by the same group of experienced neurointerventionalists. The primary endpoint was functional outcome as measured by the modified Rankin scale at 90 days. Secondary endpoints included recanalization grade as measured by the Thrombolysis in Cerebral Infarction score, time to final reperfusion, and incidence of hemorrhagic conversion. A total of 197 patients were included in this study. Of them, 80.7% underwent thrombectomy on biplane systems. Time to final reperfusion was 10.2 minutes longer in the monoplane group but was not statistically significant (P = 0.252). There was no significant difference in the rates of favorable reperfusion (P = 0.755), hemorrhagic conversion (P = 0.580), or functional outcome at 90 days (favorable modified Rankin Scale 0–2, P = 0.210; favorable modified Rankin Scale 0–3, P = 0.697). Despite perceived advantages of biplane systems in reducing procedural time, our study demonstrates no significant differences between systems. These data support the safety and efficacy of performing thrombectomy on monoplane systems and may also carry implications for reducing patient transfer times and potentially increasing thrombectomy access to areas of the world where biplane suites may not be available. The next step would be a prospective randomized trial comparing both systems in different settings. [ABSTRACT FROM AUTHOR]

In this paper, the low-speed aerodynamic characteristics of a basic wing-fuselage supersonic biplane incorporating trailing-edge flaps are assessed using both wake and balance measurements. The effects of the flap attachment location, flap deflection, and flap length are evaluated. These experiments employed a flow velocity of 20 m/s and a Reynolds number of 1.4×105, along with a model having a simple three-dimensional wing-fuselage supersonic biplane configuration; and wake data were obtained with a five-hole probe. Installing the flap near the wingtip was found to produce strong interactions between the wingtip and the flap vortices in the wake, leading to significant induced drag at the wingtip. The local lift increases not only at the flap attachment location but also over the entire wingspan. Positioning the flaps near the body is determined to be more effective, and it gives rise to higher lift and smaller drag than in the case of installing the flap near the wingtip, due to the effects of the tapered wing configuration. The effects of the flap length and flap deflection are also confirmed, with longer flaps and larger flap deflection giving higher lift and more drag. [ABSTRACT FROM AUTHOR]

ObjectiveWe aim to clarify the vascular and nerve anatomy of the breast and combine it with an ultrasound knife to use in transaxillary endoscopic biplane breast augmentation.MethodsThis study is a retrospective review of patients undergoing transaxillary endoscopic biplane breast augmentation between October and October 2021. Related variables were collected using a standardized data collection template. The detailed process of the transaxillary endoscopic biplane breast augmentation under anatomy instruction is carefully described in this study, and the postoperative effect was closely observed.ResultsSixty-three female patients underwent transaxillary endoscopic biplane breast augmentation. The average implants volume counted 242.46 ± 31.34 cc, and the average operation time was 155.92 ± 22.34 min. Patients were followed up for a mean of 13.67 months (range, 3–27 months), and most of the patients achieved good postoperative results and no severe complications and were satisfied with both appearance and function.ConclusionsThe application of anatomy combined with an ultrasound knife in transaxillary endoscopic biplane breast augmentation is a promising way to achieve good breast shapes with high patient satisfaction and is worthy of clinical promotion and application.

The Ansaldo A.1 "Balilla" biplane is of great historical interest, because it illustrates the level of development reached by the Italian aircraft industry during the last stages of World War I. To date, the airplane is kept in its original state, and it has never been restored. The aircraft is essentially made of wood and fabric. Wood in particular has been used in a very skilful way, making the airplane lightweight, yet elastic and resistant. In this work, the entire wooden structure of the aircraft was analysed, and the tree species were microscopically identified. Species belonging to six different genera have been identified. We found spruce in the frame, elm in the wing ribs, walnut in the propeller, alder in various plywood layers, rosewood in the outer layer of the decorative plywood, and pine in the tail rudder. The main structure of the aircraft was made of spruce, most likely a Sitka spruce, which was widely used for aircraft construction. The Ansaldo A.1 "Balilla" biplane is an excellent example of the wise use of wood before the revolution upon the boost in synthetic materials and represents an important historical and cultural heritage. [ABSTRACT FROM AUTHOR]

In this study, the basic aerodynamic characteristics of a Busemann biplane model in a low-speed wind tunnel were clarified by the wake survey technique. A low-speed wind tunnel of the blowdown type was used, and it had an exit nozzle size is in 1.5m x 1.5 m. A wake measurement system and six-component balance system were installed in the test section. A five-hole probe was used in the wake measurement system to measure the velocity distribution. The Busemann biplane model was designed to cruise at Mach 1.7. The total length of the model was 742 mm, and the width was 556 mm. The shape of the fuselage was 76mm square on a side, and the nose had a double-conical shape. The flow velocity was 20m/s, and the Reynolds number derived from the mean chord length was 1.4 © 105. The results of the study are summarized as follows. Based on the visualization of the wake flow, vortices were generated from the tips of the upper and lower wing elements of the biplane at an attack angle of α = 0°, but the vortices had an opposing rotation direction. Analysis of the wake data showed that locally induced drag was not generated at the wing tip. At α = 6° and 8°, the profile drag increased, probably due to the influence of the flow separation from the upper surface of the upper wing element. However, the total lift coefficient increased with an increasing angle of attack, even at α > 8°. Therefore, it can be concluded that the biplane lift is mainly generated by the lower wing elements. [ABSTRACT FROM AUTHOR]

Erdős and Lovász noticed that an r‐uniform intersecting hypergraph H with maximal covering number, that is, τ(H)=r, must have at least 83r−3 edges. There has been no improvement on this lower bound for 45 years. We try to understand the reason by studying some small cases to see whether the truth lies very close to this simple bound. Let q(r) denote the minimum number of edges in an intersecting r‐uniform hypergraph. It was known that q(3)=6 and q(4)=9. We obtain the following new results: The extremal example for uniformity 4 is unique. Somewhat surprisingly it is not symmetric by any means. For uniformity 5, q(5)=13, and we found three examples, none of them being some known graph. We use both theoretical arguments and computer searches. In the footsteps of Erdős and Lovász, we also consider the special case, when the hypergraph is part of a finite projective plane. We determine the exact answer for r∈{3,4,5,6}. For uniformity 6, there is a unique extremal example. In a related question, we try to find 2‐intersecting r‐uniform hypergraphs with maximal covering number, that is, τ(H)=r−1. An infinite family of examples is to take all possible r‐sets of a (2r−2)‐vertex set. There is also a geometric candidate: biplanes. These are symmetric 2‐designs with λ=2. We determined that only three biplanes of the 18 known examples are extremal. [ABSTRACT FROM AUTHOR]

In this paper, we first study biplanes D with parameters (v, k, 2), where the block size k ∈ { 13 , 16 } . These are the smallest parameter values for which a classification is not available. We show that if k = 13 , then either D is the Aschbacher biplane or its dual, or Aut (D) is a subgroup of the cyclic group of order 3. In the case where k = 16 , we prove that | Aut (D) | divides 2 7 · 3 2 · 5 · 7 · 11 · 13 . We also provide an example of a biplane with parameters (16, 6, 2) with a flag-transitive and point-primitive subgroup of automorphisms preserving a homogeneous cartesian decomposition. This motivated us to study biplanes with point-primitive automorphism groups preserving a cartesian decomposition. We prove that such an automorphism group is either of affine type (as in the example), or twisted wreath type. [ABSTRACT FROM AUTHOR]

The dual codes of the ternary linear codes of the residual designs of biplanes on 56 points are used to prove the nonexistence of quasisymmetric 2‐(56,12,9) and 2‐(57,12,11) designs with intersection numbers 0 and 3, and the nonexistence of a 2‐(267,57,12) quasi‐3 design. The nonexistence of a 2‐(149,37,9) quasi‐3 design is also proved. [ABSTRACT FROM AUTHOR]

This article presents the implementation of closed-loop simple adaptive control on fixed-wing micro air vehicle dynamics to improve flight performance characteristics. It is known that to retain the micro air vehicle system performance during the entire flight regime is difficult due to model uncertainties, large parameter variation and wind disturbances compared to flight velocity. An adaptive controller can adapt to the uncertainties but the complexity involved in their implementation is high due to unavailability of required sensor information and computational resources on a micro air vehicle platform. Lack of flight test results in the open literature incorporating adaptive control so far can be partially attributed to this complexity. In this case, adaptive control architecture is implemented in such a way that only the uncertainties in the system dynamics are taken care of by the adaptive control and desired nominal plant performance is achieved by the basic controller. The proposed adaptive controller architecture is implemented in real flight test, and improvement of tracking performance over a proportional–integral–derivative controller is demonstrated which illustrates superior performance to conventional architectures. The proposed design approach can be implemented easily to an existing system, and system performance can be enhanced in the presence of unmodelled and uncertain system dynamics. [ABSTRACT FROM AUTHOR]

Since its introduction >15 years ago, the use of spatial and temporal image correlation (STIC) technology has contributed substantially to fetal echocardiography. Moreover, significant advances have occurred in 3- and 4-dimensional (3D/4D) echocardiography over the past several years including the matrix probe along with advances in gray scale and color Doppler post processing, resulting in improved display of ultrasound images. In this article, we provide examples to show these recent developments including the use of color Doppler with STIC in the glass-body mode and the matrix probe thus enabling the demonstration of cardiac anomalies of the 4-chamber-view and great arteries. The use of the matrix probe allows the examination of cardiac structures in 2 orthogonal planes simultaneously, which can help in display of anatomy side by side (Biplane mode). In addition, the rapid image reconstruction of the matrix probe allows for the display of live 4D and the rapid acquisition of a STIC volume. The display of multiplanar images of the heart in 3D/4D has also been used to automate the display of ultrasound images, resulting in standardization of the image display and thus minimizing the operation dependency of the ultrasound examination. Future addition of image recognition software can also provide assistance in image review. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the agreements of both biplane and short-axis Simpson's (SAX) methods for left atrial ejection fraction (LAEF) calculation utilising cardiovascular magnetic resonance imaging (CMR) in heart failure with preserved ejection fraction (HFpEF) and evaluate their relation to clinical outcomes. One hundred and thirty six subjects (HFpEF n = 97, controls n = 39) underwent CMR, six-minute walk tests and blood sampling in our prospective, observational, single-centre study. Overall, LAEF (%) was lower in HFpEF patients compared to controls (SAX 34 ± 13 vs 47 ± 8, biplane 34 ± 16 vs 51 ± 11; p < 0.0001 for both). Atrial fibrillation (AF) was present in 24% of HFpEF and was associated with higher LA volumes and lower LAEF compared to sinus rhythm (p < 0.0001) with both methods. Biplane LAEF correlated strongly with SAX measurements (overall Pearson's r = 0.851, sinus rhythm r = 0.651, AF r = 0.882; p < 0.0001). Biplane LAEF did not differ significantly compared to SAX LAEF (overall 34 ± 16 vs 34 ± 13%; p = 0.307) except in AF subjects in whom biplane LAEF was lower (mean difference 2 ± 4%, p = 0.013). There were 44 composite events (25 deaths, 19 HF hospitalizations) in HFpEF during median follow-up of 1429 days. LAEF below the median was associated with increased risk of composite endpoints (Log-Rank biplane p < 0.0001; SAX p = 0.009). In multivariable Cox proportional hazards regression analysis, both biplane LAEF (hazard ratio [HR] 0.604; 95% confidence interval [CI] (0.406-0.900); p = 0.013) and SAX LAEF (HR 0.636; CI 0.441-0.918; p = 0.016) remained independent predictors along with indexed extracellular volume. CMR LAEF, derived from either the short-axis or biplane method is lower in HFpEF compared to healthy controls and remains a strong marker of prognosis. [ABSTRACT FROM AUTHOR]

Biplane wind turbine blades have been shown to have improved structural performance, aerodynamic performance, and reduced aerodynamic loads compared to conventional blade designs. Here, the impact of these factors on blade mass is quantified for the first time. The objectives of this work are to quantify the mass of biplane wind turbine blades which have been designed for realistic loads, and to understand the mass-driving constraints for such blades. A numerical optimization approach is used to design the internal structure of biplane wind turbine blades, minimizing blade mass subject to a number of design requirements which are imposed as constraints. The mass reductions are significant, showing that the optimal biplane blades are more than 45% lighter than a similarly-optimized monoplane blade. This is primarily due to the improved resistance to flapwise deflection when compared to the monoplane blades, which allows for considerably less spar cap material to be used in the biplanes. Biplane blades are also shown to have improved resistance to edgewise fatigue damage, requiring less trailing edge reinforcement. Given such large mass reductions, some criticality is required, and the limitations of the present approach are discussed. The results of the optimization present strong evidence that biplane wind turbine blades may be an enabling concept for the next generation of lighter, larger, and more cost-effective wind turbine blades. • It is shown through optimization that biplane blades can be built as much as 45% lighter than conventional monoplane blades. • Mass reductions are due primarily to the way biplane blades bear loads, reducing bending stresses. • A fast, robust framework for the generation and analysis of cross sections geometries was developed for this analysis. [ABSTRACT FROM AUTHOR]

This paper presents the analysis of propeller-induced flow effects on the dynamics of a fixed wing biplane micro air vehicle. The analysis is based on wind tunnel tests and mathematical modeling. This analysis plays a pivotal role because the propeller-induced flow has significant effects on the dynamics of fixed wing micro air vehicle due to submergence of a large portion of the wing in propeller slipstream. Although the effect of the propeller-induced flow on the various aerodynamic parameter is reported in the literature; however, its effects on overall forces, moments and vehicle dynamics are not quantified so far. In this paper, propeller-induced flow effects are modeled as a function of motor rotation speed and mathematical analysis is performed to quantify their effects. The wind tunnel test is conducted at different propeller speeds on a biplane micro air vehicle "Skylark", having wingspan and chord length of 150 mm and 140 mm, respectively. Analysis of results shows that the propeller slipstream increases the overall lift, drag, side force, range, and endurance significantly. Propeller flow also contributes to the rolling moment and the pitching moment, while it has negligible effects on the yawing moment. It is shown that the trim angle of attack is lower when the propeller flow is considered in computing the trim conditions. [ABSTRACT FROM AUTHOR]

• the curative outcomes of BDSF and CFIX methods were juxtaposed for the management of Pauwels III femoral neck fractures in young and middle-aged individuals. • Compared to the CFIX group, the BDSF group displayed a lower incidence of bone nonunion, internal fixation failure, and femoral head necrosis. • the BDSF approach presents a shorter healing duration and a diminished incidence of bone nonunion, internal fixation failure, femoral head necrosis, and femoral neck shortening. Traditional treatment methods have certain limitations. In recent years, the technique of internal fixation with double-plane double-supported screws based on X-ray images has been proposed to improve the therapeutic effect. The main objective of this research was to examine the effectiveness of the X-ray image-based bi-planar double-braced screw internal fixation technique. During surgery, the procedure was determined based on X-ray images, followed by an open reduction procedure at the fracture site, and finally internal fixation using bi-planar double-support screws. All patients were successfully treated with X-ray image-based bi-planar double support screw fixation. After surgery, X-ray images showed a good reduction of the fracture site without significant loosening or failure of the internal fixation. At the postoperative follow-up, the patient's pain symptoms were significantly relieved, and no significant complications occurred during recovery. [ABSTRACT FROM AUTHOR]

The first-approach techniques for analytical evaluation of the airfoil shape and calculation of the aerodynamic coefficients for a box-wing aircraft are suggested. The reliability of the calculation results was estimated using FLZ code (the vortex lattice method). The comparison showed satisfactory convergence of coefficients for the clean configuration and some discrepancy for the take-off and landing configuration. [ABSTRACT FROM AUTHOR]

Background: Three‐dimensional (3D) echocardiography is the most accurate echocardiographic method for ventricular chamber quantification. It is unclear how two‐dimensional (2D) techniques perform against 3D technology and whether 2D methods can be extrapolated to obtain 3D data. Methods: Retrospective review of transthoracic echocardiography was performed, with comparison of ejection fraction (EF), end‐diastolic volume (EDV), end‐systolic volume (ESV), and 2D strain‐derived global longitudinal strain (GLS) and synchrony index. Results: One‐hundred patients were identified. Using 3D echocardiography as reference standard, good correlation was noted with 2D strain‐derived EF (r = 0.89, P < 0.01) and with 2D standard biplane EF (r = 0.90, P < 0.01) and similarly for EDV (r = 0.84 and r = 0.81, respectively, both P < 0.01). Two‐dimensional strain‐derived EDV by 8% and 2D biplane‐derived EDV underestimated by 8% (P < 0.01). In relation to 3D EF, 2D strain underestimated by 2% and 2D standard biplane overestimated by 2% (P < 0.01). There was a negative correlation between GLS and 3D EF (r = 0.84, P = 0.001). On multivariate analysis, 3D EF could be derived from 2D strain [3D EF = 34.345 + (0.125 * EDV) + (−0.289 * ESV) + (−1.141 * GLS)]. Three‐dimensional echocardiography‐derived synchrony parameter (ie, standard deviation from mean time to minimum systolic volume from 16 subvolumes) did not correlate with 2D strain‐derived synchrony index (r = 0.171). Conclusions: Two‐dimensional standard biplane and 2D strain EF and EDV strongly correlate with 3D EF and EDV. Although 2D methods are predictive of 3D findings, over‐ and underestimations may occur. Three‐dimensional echocardiography should be used when available. [ABSTRACT FROM AUTHOR]

Objective To compare the efficacy of simultaneous implantation of biplanar silicone prosthesis combined with autologous fat transplantation versus simple silicone prosthesis implantation alone for breast augmentation. Methods From 2013 to 2017, 90 patients with macromastia were randomly divided into 2 groups, 45 patients in each group. Simple silicone prosthesis implantation for breast augmentation was performed in the control group. Simultaneous implantation of biplanar silicone prosthesis combined with autologous fat transplantation for breast augmentation was performed in the observation group. The amount of fat for transplantation was evaluated. The subaxillary or areola incision was chosen, and the prosthesis was placed under the biplane. The purified autologous fat was evenly injected into the subcutaneous adipose layer, the posterior mammary space, the medial margin of the breast, and the new submammary fold. The shape and symmetry of bilateral breasts in a semi-sitting position was observed and adjustments was made to the amount of fat transplanted according to the sizes of both breasts. Results All ninety patients were followed-up for 3 to 24 months. Both groups achieved satisfactory results. The symmetry, softness, tactile impression, and cleavage morphology of the breasts of the observation group were better than those of the control group. The difference was statistically significant (P＜0.05). Compared with the control group, there was no significant difference in breast shape and upper pole fullness (P＞0.05) in the observation group. One patient in the observation group found subcutaneous nodules in the right medial and inferior breast at 4 months postoperative. Conclusion The efficacy of simultaneous implantation of biplanar silicone prosthesis combined with autologous fat transplantation for composite augmentation mammoplasty was better than that of simple silicone prosthesis implantation alone. This method had fewer complications and the patients' satisfactory rate was high. [ABSTRACT FROM AUTHOR]

As an alternative to conventional wind turbines, this study considered kites with onboard wind turbines driven by a high airspeed due to crosswind flight ( “ drag power”). The hypothesis of this study was, that if the kite's lift coefficient is maximized, then the power, energy yield, allowed costs and profit margin are also maximized. This hypothesis was confirmed based on a kite power system model extended from Loyd's model. The performance of small-scale and utility-scale kites in monoplane and biplane configurations were examined for increasing lift coefficients. Moreover, several parameters of the utility-scale system were optimized with a genetic algorithm. With an optimal lift coefficient of 4.5, the biplane outperformed the monoplane. A 40 m wing span kite was expected to achieve a rated power of about 4.1 MW with a power density of about 52 kW/m 2 . A parameter sensitivity analysis of the optimized design was performed. Moreover, to demonstrate the feasibility of very high lift coefficients and the validity of a utilized simplified airfoil polar model, CFDs of a proposed high-lift multi-element airfoil were performed and the airfoil polars were recorded. Finally, a planform design of a biplane kite was proposed. [ABSTRACT FROM AUTHOR]

Background: High tibial osteotomy [HTO] is a surgical procedure for treatment of medial compartmental osteoarthritis combined with varus deformities of the knee in middle-aged patients. The goal of this procedure is to shift the weight-bearing axis from the medial compartment to the lateral compartment of the knee joint, resulting in a change of knee alignment from varus to valgus. Although changing the coronal plane is the main purpose of high tibial osteotomy, changes in axial rotation after the procedure has been documented in previous studies. Unintentional change in the axial plane following HTO has been proposed as one of the factors that influence overall gait mechanics and patellofemoral kinematics. Objective: This study aimed to measure changes in the degree of rotation in the axial plane resulting from biplane medial opening wedge high tibial osteotomy [MOWHTO]. Materials and Methods: Nine patients with medial compartmental osteoarthritis combined with varus deformity were enrolled in this study. Biplane MOWHTO with medial high tibia plate fixation was performed on all the patients by a single surgeon. The change in rotational profile of the tibia after surgery was determined by comparing the pre- and post-surgery angle between the proximal posterior tibial axis and the distal bimalleolar axis using CT scans. The data were analyzed using a paired t-test. Values of/><0.05 were considered statistically significant. Results: A change in rotational profile after biplane MOWHTO was found in all patients. Eight patients showed external rotation and one patient showed internal rotation. However, the change in the degree of axial rotation was not significant. Conclusion: Although not significant, minor changes in the degree of rotation were detected. Those changes suggest that an unintended rotation of the tibia could have occurred during biplane MOWHTO, especially changes in the external rotation patterns. Unintended rotation of the tibia is a factor that needs be considered during the opening of the osteotomy gap in high tibial osteotomy. [ABSTRACT FROM AUTHOR]

Let B be a biplane of order k − 2 represented by a canonical incidence matrix M . We prove that for the principal submatrix of order k − 2 starting at the ( k + 1 ) st row and column of M there are at most k − 2 values up to isomorphism. This result provides almost trivial classification of biplanes up to order 7 . [ABSTRACT FROM AUTHOR]

Introduction: Osteosynthesis of femoral neck fractures is related up to 46% rate of complications. The novel method of biplane double-supported screw fixation (BDSF; Filipov's method) offers better stability using three medially diverging cannulated screws with two of them buttressed on the calcar. Biomechanically, the most effective component is the distal screw placed at steeper angle and supported on a large area along the distal and posterior cortex of the femoral neck following its spiral anterior curve. Thereby, BDSF achieves the strongest possible distal-posterior cortical support for the fixation construct, which allows for immediate full weight-bearing. The aim of this study was to evaluate the outcomes from the first 5-year period of BDSF clinical application.Materials and Methods: Subject of this retrospective study were 207 patients with displaced Garden III-IV femoral neck fractures treated with BDSF. Three 7.3-mm cannulated screws were laid in two medially diverging oblique planes. The distal and the middle screws were supported on the calcar. The distal screw had additional support on the posterior neck cortex.Results: The outcomes in 207 patients were analysed in 29.6 ± 16.8 months follow-up. Bone union occurred in 96.6% of the cases (males 97.6%, females 96.4%, P = 0.99). Rate of nonunion was 3.4%, including fixation failure (2.4%), pseudoarthrosis (0.5%) and nonunion with AVN (0.5%). Rate of AVN was 12.1% (males 4.8%, females 13.9%, P = 0.12). Modified Harris hip score was 86.2 ± 18.9 (range 10-100), with no significant difference between genders, P = 0.07. Older patients were admitted with significantly more comorbidities (P = 0.001), and on follow-up they were significantly less mobile (P = 0.005) and had significantly more difficulties to put socks and shoes on (P < 0.001).Conclusions: By providing additional cortical support, the novel BDSF method enhances femoral neck fracture fixation strength. [ABSTRACT FROM AUTHOR]