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BACKGROUND: Inadequate scaffolding performance hinders the clinical application of the biodegradable zinc alloy stents. OBJECTIVE: In this study we propose a novel stent with the tenon-and-mortise structure to improve its scaffolding performance. METHODS: 3D models of stents were established in Pro/E. Based on the biodegradable zinc alloy material and two numerical simulation experiments were performed in ABAQUS. Firstly, the novel stent could be compressed to a small-closed ring by a crimp shell and can form a tenon-and-mortise structure after expanded by a balloon. Finally, 0.35 MPa was applied to the crimp shell to test the scaffolding performance of the novel stent and meanwhile compare it with an ordinary stent. RESULTS: Results showed that the novel stent decreased the recoiling ratio by 70.7% compared with the ordinary stent, indicating the novel structure improved the scaffolding performance of the biodegradable zinc alloy stent. CONCLUSION: This study proposes a novel design that is expected to improve the scaffolding performance of biodegradable stents.

In aero-engines, mortise-tenon joint structures are often used to connect the blades to the turbine disk. The disadvantages associated with conventional manufacturing techniques mean that a low-cost, high-efficiency, and high-quality nickel-based mortise–tenon joint structure is an urgent requirement in the field of aviation engineering. Electrochemical cutting is a potential machining method for manufacturing these parts, as there is no tool degradation in the cutting process and high-quality surfaces can be obtained. To realize the electrochemical cutting of a mortise-tenon joint structure, a method using a tube electrode with helically distributed jet-flow holes on the side-wall is proposed. During feeding, the tube electrode rotates along its central axis. Flow field simulations show that the rotational speed of the tube electrode determines the direct spraying time of the high-speed electrolyte ejected from the jet-flow holes to the machining area, while the electrolyte pressure determines the flow rate of the electrolyte and the velocity of the electrolyte ejected from the jet-flow holes. The machining results using the proposed method are verified experimentally, and the machining parameters are optimized. Finally, mortise and tenon samples are successfully machined using 20 mm thick Inconel 718 alloy with a feeding rate of 5 μm/s.

OBJECTIVE To evaluate the accuracy and reliability of a novel fluoroscopic technique for assessing tibial rotation and compare it to a previously described fluoroscopic method. METHODS A multiplanar circular ring external fixator was secured to the tibial diaphysis of five cadaveric lower extremity specimens. Using deformity correction software, the frame and tibia were programmed to randomly rotate 5, 10, 15, 20, 25, and 30 degrees of internal and external rotation. Following each rotation, two blinded, independent observers measured the degree of tibial rotation using two different fluoroscopic methods: the previously described "mortise" method and the novel "intermalleolar" method. A total of 65 measurements were made by each observer. Accuracy and inter-observer reliability were calculated. RESULTS Both intermalleolar and mortise methods had a mean absolute rotational difference from the true torsion of 3 degrees (SE 1, range 0-10 degrees intermalleolar versus 0-18 degrees mortise). We found that 98.5% (128/130) of measurements using the intermalleolar method were less than 10 degrees from the true rotation, compared to 93.8% (122/130) using the mortise method. Both the intermalleolar and mortise methods had excellent inter-observer reliability (ICC 0.99 and 0.96, respectively). CONCLUSION Measuring tibial rotation fluoroscopically using the intermalleolar method is both accurate and reliable. Compared to the previously described mortise method, it has similar accuracy and provides a value that approximates the true tibial rotation. Also, it can be employed reliably and effectively intraoperatively to identify tibial malrotation and assist in intraoperative rotational corrections.

Background: Syndesmosis is an important soft-tissue component supporting ankle stability. It is commonly injured along with ankle fractures. Accurate reduction and fixation of syndesmosis is essential to obtain better functional results. Therefore, we aimed to find a practical method using the mortise view of the ankle to determine the optimal syndesmosis fixation angle intraoperatively. Methods: We randomly selected 200 adults (100 women and 100 men) aged 18 to 60 years. Three-dimensional anatomical models of the tibia and fibula were created. We created a best-fit plane on the articular surface of the medial malleolus and a 90° vertical plane to the medial malleolus plane. We determined two splines on the cortical borders of the tibia and fibula distant from the most superior point of the ankle joint in horizontal view. We created two spheres that fit to the predefined splines. The optimal syndesmosis fixation angle was determined measuring the angle between the line connecting the center points of the spheres and the 90° vertical plane to the medial malleolus plane. Results: We observed no statistically significant difference in optimal syndesmosis fixation angles between sex groups. The participant mean ± SD age was 47.1 ± 10.5 years. The optimal syndesmosis fixation angle in the mortise view was found to be 21° ± 4.3°. Conclusions: We determined the optimal syndesmosis fixation angle to be 21° ± 4.3° using the mortise view of the ankle. The surgeon could evaluate the whole articular surface of the ankle joint with the medial and lateral syndesmotic spaces in mortise view accurately, and at the same position syndesmosis fixation could be performed at a mean ± SD angle of 21° ± 4.3°.

An assembled rectangular tunnel has the advantages of high space utilization rate and strong urban applicability. This solution has been widely used in urban underground traffic construction. During their construction and operation, the joints are the weakest parts of the structure. The mechanical behavior of joints is closely related to the safety of the tunnel; thus, it is important to use a joint with good mechanical behavior. This study presents a new type of joints for shallow buried assembled rectangular tunnels. To evaluate the effect of design parameters (tenon depth and tenon angle) on the behavior of joints, the finite element method was used. At the same time, the mechanical behavior of rectangular tunnel joint was analyzed and compared with that of a traditional straight joint under the same loading conditions, showing better results. The performance-based engineering (PBE) concept was implemented to evaluate the robustness of rectangular tunnel joints. The results show that if the bolt is placed on the tensile side of the structure, it provides a strong restraining effect on the deformation of the joint. When the tenon depth and angle are 0.8 m and 3.6°, respectively, the overall behavior of the rectangular tunnel joint was improved. The new type of assembled rectangular tunnel joint designed in this study has a good application prospect in a shallow stratum and provides new ideas for the design and construction of such tunnels.

Purpose To evaluate the ultrastructural features of collagen fibrils, matrix metalloproteinase (MMP) and alpha-smooth muscle actin (α-SMA) expression in the Tenon's capsule of buphthalmic eyes. Methods A prospective comparative case series study was conducted on 35 buphthalmic eyes vs 25 control eyes. Children with congenital glaucoma (CG) who underwent a combined trabeculectomy-trabeculotomy procedure with mitomycin C (CTTM); the Tenon's capsule was obtained during the surgical procedure. The control group included children with strabismus, the Tenon's capsule was obtained in the course of strabismus surgery. Both H&E and Masson's trichrome staining were done. The Metalloprotenease-2 (MMP-2), alpha smooth muscle actin (α-SMA) immunohistochemical staining was performed. Results Mean collagen percentage area by Masson trichrome stain in Tenons capsule was significantly higher in buphthalmic eyes (54.76% ± 0.32 vs 33.71% ± 1.4; P Conclusions Tenon capsule of buphthalmic eyes have their own histopathological features and properties making them more liable for fibrosis with high rate of failure following antiglaucoma surgeries. Such detailed information has not been published before which may aid in the identification of new antifibrotic therapies in management of glaucoma.

This article presents the bending strength and flexural properties of the glued T-type spruce loose tenon construction joints with and without reinforced plastic clamp fitting. Construction joints are designed according to Eurocode 5. The samples are made from European spruce (Picea abies Karst.) C24 class construction material with relative wood moisture 18% and relative wood density 410 kg/m3. Samples are assembled with water/high temperature resistant polyurethane adhesive and polyvinyl acetate dispersion adhesive. The total number of samples is 48. The sample width is 95mm and thickness is 45mm. Samples were subjected to moisture, weight controls and 48h stored in the climate chamber before practical bending load test. T-type loose tenon joint construction samples with reinforced plastic clamp fittings glued with polyurethane adhesive under bending load are 2.6% stronger and 13.8% less flexural then without reinforced plastic clamp fittings. T-type loose tenon joint construction samples with reinforced plastic clamp fittings glued with polyvinyl acetate dispersion adhesive under bending load are 9.7% weaker and 20% less flexural then without reinforced plastic clamp fittings. The accuracy of the developed bending strength, deformability and elasticity modulus of the examined construction joints was verified positively by experimental studies.

The performances of timber frames with loose connections under lateral load is studied in this paper with an analytical friction-slip-contact model of the mortise-tenon (MT) connection with gaps where different contact states between the mortise and tenon are described. The nonlinear contact behavior within the joint is modelled via an analytically formulated hybrid finite element with a MT connection or a column foot (CF) connection. The mechanical behavior of the connection with different horizontal and vertical gaps is further studied. The load–displacement curves at the top of the frame model with hybrid finite elements are compared with those from the solid element model in ABAQUS. They are matching each other very well. Parametric study with different height and length of tenon on the lateral resistance of the frame is also conducted. The gap in the MT connection is found to be the major source of weakness in the lateral resistance of the frame. Results obtained may serve as reference for the maintenance of heritage timber structures in China.

Trabeculectomy is the gold standard procedure performed in glaucoma when topical medication and laser intervention failed. In a trabeculectomy, number of clinical trials have shown the efficacy of ranibizumab in minimizing extracellular matrix accumulation at the filtering site. Ranibizumab (LucentisTM) is a drug that targets vascular endothelial growth factor (VEGF). However, to date the actual mechanisms of this anti-VEGF in trabeculectomy is still not well understood. Hence, in here we aimed to elucidate the effects of ranibizumab on human Tenon’s fibroblast (HTF) isolated from patients undergoing trabeculectomy. In our previous study, we had reported that ranibizumab reduces the level of spermidine metabolite whereby spermidine is an important polyamine for cell proliferation. For this current study, cultured HTFs were divided into untreated, control IgG, ranibizumab only, difluoromethylornithine (DFMO; inhibitor of spermidine) only and ranibizumab with DFMO. All cells were extracted for PCR array (expression of CDKN1A, CDK2, and CDK4) and protein expression of p53, p21, CDK2, and CDK4 by Western Blot. In here, our result demonstrated that cells treated with ranibizumab or DFMO and cells treated with ranibizumab-DFMO have similar effects as both show increased in p53 and p21. Meanwhile, no significant differences in expression of CDKN1A, CDK2 and CDK4 were observed in all groups. In essence, our findings suggest that ranibizumab action is mediated by p21 and p53.

In the furniture industry, some traditional Chinese mortise and tenon joints are not suitable for the current requirements for carbon reduction and environmental protection of furniture products. This article aims to explore new ideas and new methods of modern mortise and tenon structure design. The reduction principle in the green design concept is introduced for the furniture modern mortise and tenon structure design. Based on modern furniture, a systematic analysis of the modern mortise and tenon structure design is carried out. Additionally, this review discusses the method of applying the reduction principle in modern tenon and tenon structure design in the context of green design. The development status and trend of modern mortise and tenon structure design is summarized and an innovative design practice of modern mortise and tenon structure is carried out. The combination of green design and furniture design has important practical significance in a modern context.

In the past decades, more and more precast piers have been used in actual engineering, which brings convenience in construction and standardization of production. However, precast piers still have some shortcomings, such as shear slip between segments and poor energy dissipation. Thus, a self-centering mortise-tenon segmental bridge pier was proposed in this paper. To research the seismic performance of the self-centering mortise-tenon segment piers, three scaled model piers with their scale ratio as 1:3 were designed and prefabricated, namely as a cast-in-place model pier (CP) and 2 self-centering mortise-tenon segment model piers (designated as MTSP1 and MTSP2) with the initial pretension of 1302 MPa and 1488 MPa, respectively. The cyclic pseudo-static tests of the three piers were carried out. The comparison analysis was made respecting to the test results including the damage form, hysteretic characteristics, skeleton curve, energy dissipation capacity, residual displacement and equivalent stiffness of the three specimens. It was shown that MTSP specimens had higher horizontal bearing capacity. While the yield load, ultimate load, displacement ductility coefficient and initial stiffness of MTSP1 and MTSP2 were higher than those of CP. The MTSP had better performance considering the above aspects. The mean value of the residual displacement of MTSP2 was lower than that of CP 21.14 % and 29. 72 % respectively, as the drift ratio reaching 5 %. The MTSP specimens had better self-centering capacity due to the increased pretension stress which reducing the residual displacement greatly. The energy dissipation reinforcements improved the energy dissipation capacity of the segmental assembled piers. Based on the ABAQUS model, the numerical simulation was carried out and compared with the experimental data. MTSP had great energy dissipation capacity and self-centering capacity. It was suggested that MTSP should be used to make up for the deficiency of segmental assembled pier and improve the seismic performance of segmental assembled pier.

Composite lattice cores sandwich structures have shown obvious advantages in specific mechanical property and potential multifunctional integration. 3D-Kagome lattice core is regarded as a classic core configuration with relative optimal theoretical performance. However, it is still unavailable due to preparation problem of the overlap joint-node of composite cores. In this paper, a self-locking mortise-tenon joint method is presented to sucessfully fabricate the integrated 3D-Kagome cores with the expected mechanical properties. The out-of-plane compressive behaviour and energy absorption characteristics are experimentally studied. For the composite structures with various relative densities, three kinds of compressive curves are observed, following by different failure modes. An obvious bearing reinforcement emerges for the lattice cores with high relative density. As the length-to-thickness ratio of the core-rods increases, the initial peak strength and modulus of structures both decrease with a slowing rate. Though the mortises weaken the load-bearing capacity of core-rods, the active constraint of mortise-tenon joint suppresses an obvious degradation. The dominated failure more depends on the core-height than rod-thickness. The composite 3D-Kagome cores show more excellent mechanical properties than other similar structures, especially for the elastic strain before the initial peak stress. The semi-rigid power-wasting mortise-tenon joint and load-bearing characteristics of Kagome core together provide a large deformation tolerance at a relatively high stress level. All suggest that the presented 3D-Kagome lattice cores could be considered as a potential energy absorbing material.

We present a computational framework for modeling and optimizing complex assemblies using cone joints. Cone joints are integral joints that generalize traditional single-direction joints such as mortise and tenon joints to support a general cone of directions for assembly. This additional motion flexibility not just reduces the risk of deadlocking for complex joint arrangements, but also simplifies the assembly process, in particular for automatic assembly by robots. On the other hand, compared to planar contacts, cone joints restrict relative part movement for improved structural stability. Cone joints can be realized in the form of curved contacts between associated parts, which have demonstrated good mechanical properties such as reduced stress concentration. To find the best trade-off between assemblability and stability, we propose an optimization approach that first determines the optimal motion cone for each part contact and subsequently derives a geometric realization of each joint to match this motion cone. We demonstrate that our approach can optimize cone joints for assemblies with a variety of geometric forms, and highlight several application examples.

To closely examine the mechanical properties of mortise and tenon woodworking joinery in outdoor environments, it is essential to obtain fundamental data regarding the influence of moisture content...

BACKGROUND This study reports a case of autologous tenon capsule packing to treat the posterior exit wound of penetrating injury. CASE SUMMARY To treat a 58-year-old male patient with penetrating eyeball injury caused by an iron sheet, we used autologous tenon capsule packing. Two months after removal of the silicone oil, the corrected visual acuity was 0.3, the retina was flat, the tenon capsule graft was in place, the posterior wound closed well, and the intraocular pressure was 15.8 mmHg. CONCLUSION Autologous tenon capsule packing to treat the posterior exit wound of penetrating injury is safe and effective.

Shear experiments on mortise and tenon joints with top and bottom notches in the beam end were conducted with the length of the tenon as a variable. In addition, material experiments were performed to investigate the structural performance of the fracture modes of the joint. The experimental results show that when the lower notch at the beam end experiences splitting, the shear forces were identical for different tenon lengths and did not decrease. In addition, the deformation performance of the joint up to yielding was largely due to the compressive deformation perpendicular to the grain of the wood on the sides of the tenon. Based on the theory of the calculation method of the splitting strength of a notched beam, a formula for the splitting strength when the end of the beam is moment-resisting was proposed. It was confirmed that the proposed formula could estimate the shear force that caused the splitting fracture of the lower notch. In addition, the increase in shear force after the lower notch experienced splitting fracture was due to the increase in clamping force of the beam end due to rotational deformation.

Mortise-and-tenon joints have been widely used for thousands of years in wooden architectures in virtue of their artistic and functional performance. However, imitation of similar structural and mechanical design philosophy to construct mechanically adaptive materials at the molecular level is a challenge. Herein, we report a mortise-and-tenon joint inspired mechanically interlocked network (MIN), in which the [2]rotaxane crosslink not only mimics the joint in structure, but also reproduces its function in modifying mechanical properties of the MIN. Benefiting from the hierarchical energy dissipative ability along with the controllable intramolecular movement of the mechanically interlocked crosslink, the resultant MIN simultaneously exhibits notable mechanical adaptivity and structural stability in a single system, as manifested by decent stiffness, strength, toughness, and deformation recovery capacity.

Background: To determine the optimal direction of the syndesmotic screw and introduce a consistent landmark for practical application by analyzing three-dimensional (3D) modeling and virtual implantation.Methods: A total of 102 cadaveric lower legs (50 males and 55 females, average height of 160.6 ± 7.1cm) were used to reconstruct a 3D model by using the Mimics® software and the joint morphology was evaluated. Syndesmotic cylinders (Ø3.5 mm/Length 100 mm) were transversely placed in the proximal end of the incisura fibularis for simulating screw fixation. The tibial proximal cylinder, which was tangent to the posterior tibial condyles, was traced and the angle between the two cylinders was measured as the tibial torsion angle (TTA). After rotating the syndesmotic cylinder parallel to the ground, the overlapping degree between the proximal fibula and tibia were assessed as a radiologic indicator. Results: Concerning tibial torsion, the TTA was an average of 36.7° (range, 17.2°–54.4°, SD 8.78) When the syndesmotic cylinder was rotated to be parallel to the ground, the proximal fibula had non- or linear overlap with the lateral border of the tibia, regardless of the joint morphology. In this nonoverlapping view, compared to the mortise view, the three criteria for normal fibular length could be better visualized. Conclusion: The syndesmotic cylinder in the proximal end of the incisura fibularis could be consistently placed parallel to the ground by internally rotating the tibia until there was a non- or linear overlap between the proximal fibula and the tibia, regardless of the joint morphology.

The deformation failure of a shield segment joint can lead to serious leakage, and the joint must therefore be reinforced in advance to control its deformation. The combination of a bolt and positioning tenon, as a new type of reinforcement, can quickly control the deformation of shield segment joints. Numerical simulation is conducted to analyze the variation characteristics of bolt stress, bolt groove stress, and deformation of segment displacement under the vertical load of a preloading bolt. Results indicate that the most important factor in resisting the deformation of segment displacement under a vertical external force is bolt preloading. Greater bolt preloading leads to greater friction resistance between segments and stronger resistance against segment displacement deformation. The positioning tenon can effectively reduce the displacement between shield segments, and the average displacement can be reduced to approximately 60%. The control of the deformation mechanical behavior of shield segment joints by a bolt and tenon provides a theoretical reference for practical engineering.

A restoring force model of through-tenon and half-tenon joints was studied with a certain level of universality. To address the differences among data collected under different test conditions, test data collected via through-tenon and half-tenon joints were counted and fitted, and their similarities were then generalized. To better simulate the gap and stiffness degradation between the through-tenon and half-tenon joints, the skeleton curves frameworks were simplified into four phases, namely sliding, elastic, yielding, and failure. The normalized control parameters collected through the characteristics of the framework of through-tenon and half-tenon joints, as well as the different coefficients of strength degradation and stiffness degradation were calculated. The hysteretic rules of the restoring force model of through-tenon and half-tenon joints were developed. Through case study, the results show that the MAPE (mean absolute percentage error) and R2 (coefficient of determination) of experimental data in the references and simulated data of through-tenon are respectively 12.570% and 0.735, while those of half-tenon are respectively 11.763% and 0.772; and the restoring force model of through-tenon and half-tenon joints being constructed had a certain level of universality. The results demonstrated that the construction of refined finite element analysis model of Chinese ancient timber architectures can be simplified to a certain extent to meet the pressing time for seismic performance analysis of many ancient timber architectures. It provides researchers with an innovative pathway to enhance the efficiency of seismic performance analysis of ancient timber architectures.

Ankle drawer and varus-valgus stress tests have evolved to examine for excessive joint displacement in the sagittal and coronal planes which may correlate to ligament instability. However, there appear to be no formal manual test(s) assessing for axial plane (longitudinal) instability of the mortise joint. In keeping with Cartesian and Cyriax principles, The TOAST (Traction On Ankle Stress Test) was developed to dynamically assess for 3rd vector axial strain pain generation and long-axis mortise joint gapping. The test is easy to learn as longitudinal manual traction of the mortise joint and applied counterforce hand positions are similar to emergent ankle fracture dislocation reduction technique. The TOAST may also be performed under dynamic ultrasound control.

This study aimed to estimate the design value for mortise and tenon joints. In this respect, the design value for static load tests was determined using lower tolerance limit methods. A lower tolerance limit value at 0.99/0.99 confidence/proportional level was chosen as a design value (199.05 N.m) to secure higher joint reliability in a furniture frame. A side frame of a simple wooden chair was theoretically analyzed to obtain internal forces acting on joints, whereas the load of 1000 N was applied in the vertical direction on the top of the front leg. A full-frame chair with mortise and tenon joints would not be overstressed when a chair is under static load while not exceeding 2000 N. By applying this method, all chairs should survive static load up to 2000 N. While performing cyclic front-to-back load test, all tested chairs met the American Library Association requirements for light-duty service load, specified for household chairs. This study demonstrates that a joint failure could be prevented under expected loads specified by the standard if the joint design value is known.

In order to study the lateral resistance of reinforced traditional Chinese timber frames with mortise-tenon connections, three cyclic tests were conducted on one-bay mortise-tenon jointed traditional timber frames. Three reinforcement methods, i.e., steel angle strengthening, wood brace, and Timu, were studied. Seismic performances were evaluated according to the experimental phenomena and the test results. The failure mode, hysteresis curves, skeleton curves, curves of stiffness degradation, and energy dissipation capacity of the three specimens were analyzed based on the tests. The test results showed that the wood frames had good deformability. The stiffness degradation of the timber frame was severe at the initial loading stage; however, the degradation rate tended to decrease after the initial stage. In addition, the energy dissipation increased as the lateral displacement increased. The wooden frames with mortise tenon joints strengthened by steel angle, wood brace, and Timu can achieve good aseismic results. The study can provide a theoretical basis for seismic design and reinforcing methods of traditional timber structures.

This article aims to investigate the contact characteristics of mortise and tenon (M&T) joints in the traditional timber structures. In particular, the normal embedded compressive contact between contact surfaces of M&T joint was investigated. Based on basic contact theory and contact characteristics between mortise and tenon, a normal elasto-plastic contact model, which can reflect the real normal contact behavior of M&T joints in traditional wooden structures, was proposed. Coulomb friction contact was utilized to describe the tangential slipping characteristics of the contact surfaces. Micro-morphology scanning tests of wood samples with different roughness were carried out to determine the parameters involved in the normal contact model. The normal contact model subroutine of M&T joint was compiled by FORTRAN language, implemented into ABAQUS through user-defined interface (UINTER). Then the proposed model was verified by shear tests of wood contact surfaces considering different normal pressures. Finally, a finite element model (FEM) of straight tenon joint subjected to cyclic reversed loading, based on the proposed normal elasto-plastic contact model, was developed, and a FEM considering normal “hard contact” between the contact surfaces, was also performed. The simulation results were validated by the experimental results. Results showed that the user-defined normal elasto-plastic contact FEM was more in line with the actual force state and mechanical behavior of M&T joints, which can more accurately predict the failure modes and simulate the hysteretic behavior of M&T joints, compared to the FEM considering normal “hard contact” of the contact surfaces.

The grouted mortise-tenon joint, invented as the connection between the large prefabricated elements, is the most important component in the prefabricated underground structures. This paper conducts analysis of load-carrying capacity performance and failure mode with 1 : 1 prototype test in key working direction of different double mortise-tenon joint types for the prefabricated metro station. The resistance moment is developed and used to analyze the bending bearing characteristic curve, and the corresponding test results of each stage of the characteristic curve are described in detail. In addition, the bending bearing performance of different types of double-tenon joints under different load conditions is compared. The test results clarify the ultimate failure mode of double-tenon joint and the variable bearing capacity characteristics of the joint with the increase in axial load and explain the bearing performance of each stage. It is also found the auxiliary pretightening device is helpful to delay the appearance of cracks and improve the bearing capacity, especially when it is set on the tension side. The research results have important application value for the joint design of prefabricated metro station structures.

Low stiffness of the near-net-shaped blade machining fixture of aero-engine creates challenges for the CNC machining accuracy and efficiency of near-net-shaped blade. This study aims to optimize the fixture’s material and structure to improve the stiffness of the blade-fixture system. First, the main influencing factors of the near-net-shaped blade tenon root CNC machining process were analyzed, and the influences of the positioning and clamping component materials and structures on the stiffness of the machining fixture were analyzed based on finite element analysis (FEA). Second, the mechanical properties of the positioning and clamping components of different materials and structures were analyzed based on cross-scale analysis from microscopic and macroscopic perspectives. Finally, the positioning and clamping components of the machining fixture were designed based on material selection and structure optimization, and the optimized machining fixture with new material and structural was verified by CNC machining process. The results showed that the material and structure of the positioning and clamping components were the main influencing factors of the machining fixture stiffness. The positioning and clamping components of the PEEK-GF30 material of the new splicing structure could effectively improve the blade-fixture stiffness.

The aim of this paper is to study the nonlinear dynamics of the tenon and mortise of aero-engine compressor blades, based on lumped parameter model of tenon and mortise of blade disk system, considering the influence of gap and friction, The nonlinear vibration characteristics of mistuned bladed disk with different mistuning parameters are studied. The effects of tenon and mortise gap, dry friction, blade damping mistuning and tenon damping mistuning on the vibration characteristics of the mistuned bladed disk under strong coupling and weak coupling are obtained respectively. The results show that the gap and friction has little effect on the vibration response of the weakly coupled bladed disk, but the gap and friction has a great influence on the strongly coupled bladed disk, the larger the gap, the more complex the nonlinear dynamic characteristics of tenon. Under the same gap and coupling strength, the mistuning parameters have a certain influence on the vibration amplitude of the bladed disk.

To compare and assess silicone membrane-based sub-Tenon’s block (STB) simulator and animal eye model (goat’s eye) for practicing STB in terms of anatomical similarity and feel of texture of eye layers. The study included 34 participants (26 learners and 8 consultants) from tertiary ophthalmic centres. The participants were divided into groups A and B. Group A performed STB on the goat’s eyes before using the silicone membrane simulator. Group B performed STB on the simulator and further proceeded to the goat’s eye. Participants had to rate the anatomical similarity and feel of the texture for the simulator model on a scale of 0–10 and share their preference between the two models. In group A, the scores given to the simulator model and the feel of texture of layers were 8.05 ± 0.88 and 7.97 ± 1.07, respectively, and the scores given to the animal model and the feel of texture of layers were 8.11 ± 0.97 and 8.21 ± 0.88, respectively. Group B participants scored the simulator model and feel of texture of layers with 8.13 ± 0.95 and 8.25 ± 0.99, respectively. Overall, 89% participants preferred the simulator; the reasons included ease of usage, helpful warning system, absence of biological waste, and facility for repeatable training. The study validated anatomical accuracy, preference, and ability of usage of the STB simulator. For broader usage, further study involving higher number of participants is recommended.

Sub-tenon ophthalmic blocks are gaining popularity for ophthalmic anesthesia but have no suitable systems available for training. In this article, the design and development of the first mannequin-based system to train and evaluate an ophthalmic anesthesiologist to perform the sub-tenon block correctly is presented. The system has integrated sensors with new sensing schemes for needle tip tracking and detection of errors incurred by the trainee. An integrated, conductive silicone-based eye model sensor is presented in this article. The model replicates the human ocular anatomy, and the embedded sensors within the eye model help to classify, assess, and evaluate the performed procedure. The developed system was also validated in a pilot clinical study for naturality and usage in a clinical setting with 37 ophthalmic anesthetists. The system recorded 98.3 % accuracy assessing the performed procedure during the clinical study, and the participants rated the naturality of the system with a score of 8.0 ± 0.63 (on a scale of 10) ( ${p} ). 89 % of the participants and experienced sub tenon block instructors who previously used provisional animal eye-based models for training preferred the training system for its usage of anatomically accurate models and effective warning systems that evaluate the performed procedure.

We present a case of an 84-year-old patient with acquired bilateral superotemporal orbital fat prolapse. The disease occurs when there is dehiscence in Tenon’s capsule, allowing fat to herniate forward spontaneously. This can happen when there is a discontinuity of Tenon’s capsule. We discussed visual symptoms at presentation, surgical technique, and visual and aesthetic outcomes.

Custom 3D printed total talus implants have been used successfully as a functional alternative to arthrodesis or amputation in cases of severe talar destruction or loss. However, the ideal material and construct still remains to be elucidated. Current models have been made from aluminum ceramic, cobalt chrome, stainless steel, titanium, or metal combinations. The implants may be constrained (subtalar arthrodesis) or unconstrained (press fit within mortise). They may also be combined with a tibial prosthesis or used in isolation. The majority of currently published case studies examine unconstrained and isolated implants. This case study presents satisfactory 1-y outcomes in 3 cobalt chrome constrained total talar implants used in combination with a tibial prosthesis, and a literature review of total talus replacements.