Improving accuracy and efficiency of the machined PEEK denture based on NSGA-II integrated GABP neural network.

Objectives: The polymer polyetheretherketone (PEEK) is gradually being used in dental restorations because of its excellent mechanical properties, chemical resistance, fatigue resistance, thermal stability, radiation translucency and good biocompatibility. To process PEEK dentures with lower surface roughness as quickly as possible, the non-dominated sorting genetic algorithm-II (NSGA-II) integrated genetic algorithm back propagation (GABP) neural network was proposed, which can adjust the combination of process parameters for milling PEEK dentures.

Methods: The PEEK machining was conducted using a four-axis dental milling machine at different process parameters.

A stable liquid-solid interface of a lithium metal anode enabled by micro-region meshing.

Although lithium metal is regarded as the most promising anode for high energy density lithium ion batteries, the unstable solid-liquid interface during cycling severely shortens the battery lifetime. The Li deposition behavior is greatly influenced by the current density distribution on the surface of the electrode, which is significantly associated with the electrode structure. A well-designed electrode structure plays a key role in stabilizing the solid-liquid interface of the Li metal anode.

An amorphous hierarchical MnO/acetylene black composite with boosted rate performance as an anode for lithium-ion batteries.

Amorphization is considered to be an effective way to enhance the electrochemical performances of electrode materials due to the existence of isotropy and numerous defects. Herein, an amorphous hierarchically structured MnO/acetylene black (a-MnO/AB) composite is successfully fabricated via a redox method and subsequent mechanical ball milling. The a-MnO/AB composite is composed of approximately 300 nm flower-like amorphous MnO submicron spheres and acetylene black particles with a diameter of about 50 nm.

Thermal Positioning Error Modeling of Servo Axis Based on Empirical Modeling Method.

In order to investigate the thermal effect of a servo axis' positioning error on the accuracy of machine tools, an empirical modeling method was proposed, which considers both the geometric and thermal positioning error. Through the analysis of the characteristics of the positioning error curves, the initial geometric positioning error was modeled with polynomial fitting, while the thermal positioning error was built with an empirical modeling method. Empirical modeling maps the relationship between the temperature points and thermal error directly, where the multi-collinearity among the temperature variables exists.

Petal-like metal-organic framework stabilized Si@C with long cycle life and excellent kinetics.

Poor electrochemical kinetics caused by the unstable structure for the dramatically volumetric expansion (>300%) hinders the application of silicon in rechargeable lithium ion batteries. Si@C-Ni-MOF composites with petal-like Ni-MOFs as the skeleton and Si@C nanoparticles as the active center were synthesized via facile solvothermal process. The resulting Ni-MOF-Si@C material maintains admirable stability on cycling, and its capacity remains 1545.

A study on autonomous suturing task assignment in robot-assisted minimally invasive surgery.

Background: Sutures are a set of standard actions which are accomplished by multi-instruments, researchers studied the robot autonomy of suturing, which was based on movement planning completed by a single instrument, but did not consider the assignment of suturing tasks to instruments.

Method: A method was proposed for the autonomous suturing task assignment to instruments, which built a comprehensive evaluation index under some constraint conditions to determine the optimal scheme of the suturing task assignment to instruments.

Results: An experiment of duodenal ulcer repair with a suturing operation was conducted under the guidance of a surgeon, and the results showed that the optimal scheme of the suturing task assignment was obtained by using the proposed method.

Ultra-Precision Machining of a Compound Sinusoidal Grid Surface Based on Slow Tool Servo.

Compound sinusoidal grid surface with nanometric finish plays a significant role in modern systems and precision calibrator, which can make the systems smaller, the system structure more simple, reduce the cost, and promote the performance of the systems, but it is difficult to design and fabricate by traditional methods. In this paper, a compound freeform surface constructed by a paraboloidal base surface and sinusoidal grid feature surface is designed and machined by slow tool servo (STS) assisted with single point diamond turning (SPDT). A novel combination of the constant angle and constant arc-length method is presented to optimize the cutting tool path.

Study about Mechanical Property and Machinability of Polyimide.

Polyimide (PI) is a kind of polymer material with properties of high heat-resistance and good mechanical strength. As a special engineering material, it has been widely used in the fields of aviation, nanotechnology, etc. PI has been regarded as one of the most promising engineering plastics in the future.

Can Computed Tomography Accurately Measure Acetabular Anterversion in Developmental Dysplasia of the Hip? Verification and Characterization Using 3D Printing Technology.

Background: One of the important pathologic changes in developmental dysplasia of the hip (DDH) is increased acetabular version angle (AA). Reasonable correction for excessive AA is an important step in the treatment of DDH, making accurate AA measurement very crucial. However, the results of different AA measurement methods vary.

Dynamic long leg casting fixation for treating 12- to 18-month-old infants with developmental dysplasia of the hip.

Objective To evaluate the effect of dynamic long leg casting in paediatric patients with developmental dysplasia of hip (DDH) diagnosed at 12-18 months. Methods The adductor tenotomy, closed reduction, and dynamic long leg casting method was adopted to treat paediatric patients with DDH. The hips were divided into four groups according to the Tonnis radiographic dislocation classification.

Comparison and Analysis on Mechanical Property and Machinability about Polyetheretherketone and Carbon-Fibers Reinforced Polyetheretherketone.

The aim of this paper is to compare the mechanical property and machinability of Polyetheretherketone (PEEK) and 30 wt% carbon-fibers reinforced Polyetheretherketone (PEEK CF 30). The method of nano-indentation is used to investigate the microscopic mechanical property. The evolution of load with displacement, Young's modulus curves and hardness curves are analyzed.

Evaluation of femoral head coverage following Chiari pelvic osteotomy in adolescents by three-dimensional computed tomography and conventional radiography.

Introduction: Currently, the cover of the femoral head was mainly assessed using conventional plain films after Chiari pelvic osteotomy in most studies. The purpose of the current study was to observe whether the femoral head coverage measured by three-dimensional computed tomography (3D-CT) was consistent with the radiographic findings.

Patients And Methods: A total of 24 patients (24 hips) with an average age of 11.

Evaluation of the modified Albee arthroplasty for femoral head loss secondary to septic arthritis in young children: surgical technique.

Background: Surgical treatment options for femoral head deficiency in infants secondary to septic arthritis of the hip are varied and associated with uncertain long-term outcomes. The modified Albee arthroplasty has been considered an acceptable procedure; however, the long-term outcomes of this procedure have not been reported, to our knowledge. We evaluated the long-term outcomes of the modified Albee arthroplasty in young patients with severe sequelae of septic arthritis of the hip.

Psoas abscess with associated septic arthritis of the hip in infants.

We describe psoas abscess with concomitant septic hip arthritis in 2 infants, 3 and 7 months old. The common clinical features were a palpable mass in the inguinal region, irritable hip, and delayed treatment. The diagnosis of septic hip was delayed in one child, and they both had residual hip deformity at follow-up.

[Evaluation of mid-term follow-up after Salter innominate osteotomy in developmental dysplasia of the hip].

Objectives: To evaluate the mid-term outcome after Salter innominate osteotomy in developmental dysplasia of the hip (DDH), and to observe the developmental characteristics of the hip after operation and the relationships between the mid-term outcome and radiographic parameters as well as age at operation.

Methods: : Forty-four patients with 61 treated hips were selected. The patients were treated with Salter innominate osteotomy and followed-up for at least three years with intact serial radiographs.

Evaluation of the modified Albee arthroplasty for femoral head loss secondary to septic arthritis in young children.

Background: Surgical treatment options for femoral head deficiency in infants secondary to septic arthritis of the hip are varied and associated with uncertain long-term outcomes. The modified Albee arthroplasty has been considered an acceptable procedure; however, the long-term outcomes of this procedure have not been reported, to our knowledge. We evaluated the long-term outcomes of the modified Albee arthroplasty in young patients with severe sequelae of septic arthritis of the hip.

The mechanism of acute elbow flexion contracture in children with congenital proximal radioulnar synostosis.

We have evaluated and treated 3 cases of acute onset elbow flexion contracture in children ranging in age from 6 to 13 years, with type-IV (Cleary and Omer) congenital proximal radioulnar synostosis. All were resolved by manipulative traction under general anesthesia during which an audible elbow "snap" was noted. Two of the cases required surgical treatment of a deformed radial head with good results after a 2 to 4-year follow-up.

The split-heel technique in the management of chronic calcaneal osteomyelitis in children.

The split-heel technique has distinct advantages over the conventional medial or lateral approach in the operative debridement of extensive and predominantly plantar chronic calcaneal osteomyelitis in children above 5 years of age. We report three cases (age 5.5-11 years old) of chronic calcaneal osteomyelitis in children treated using the split-heel approach with 3-10 years follow-up showing excellent functional and cosmetic results.

[Association study between mutations of transcription regulator sequences of COL1A1 gene and idiopathic con-genital talipes equinovarus].

RT-PCR was used to detect the expressions of COL1A1 mRNA in 20 patients with idiopathic congenital talipes equinovarus (ICTEV). The primers were designed by Primer 5 according to sequences of -1 031 bp~ +30 bp and the first intron of COL1A1. PCR-DGGE was used to screen the mutations in COL1A1 gene.

[Proteomic analysis of the ankle joint bone, ankle joint tissue and spinal cord of clubfoot-like deformity in rat fetuses].

Objective: To explore the etiology of idiopathic talipes equinovarus (ITEV) in all-trans retinoic acid (ATRA) induced clubfoot-like deformity in rat fetuses with two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS).

Methods: Clubfoot-like deformity model in rat fetuses was induced with ATRA (135 mg/kg) in gestation day (GD10) pregnant Wistar rats. 2-DE was applied to separate the total proteins of ankle joint tissue, ankle joint bone and spinal cord of the animal models.

[Association and mutation analysis of GLI3 gene in idiopathic congenital talipes equinovarus].

Objective: To explore the association and mutation of GLI3 gene in idiopathic congenital talipes equinovarus(ICTEV).

Methods: (1) Genotype of 2 single nucleotide polymorphism (SNP) in 84 idiopathic congenital talipes equinovarus nuclear pedigree were analyzed by restriction fragment length polymorphism. Association analysis was directed between single SNP locus and ICTEV through ETDT software, respectively.

Renal expression of epidermal growth factor and transforming growth factor-beta1 in children with congenital hydronephrosis.

Objectives: To study the potential role of pelviureteral junction obstruction (PUJO) in causing progressive renal damage in children through the renal expression of epidermal growth factor (EGF) and transforming growth factor-beta1 (TGF-beta1).

Methods: The expression of EGF and TGF-beta1 was evaluated in the renal tissues of 25 children with congenital hydronephrosis by immunohistochemistry, in situ hybridization, and reverse transcriptase polymerase chain reaction techniques.

Results: Children with PUJO had a significant increase in TGF-beta1 and a marked reduction in EGF expression compared with controls.

[Analysis of association between 5' HOXD gene and idiopathic congenital talipes equinovarus].

Objective: Four single nucleotide polymorphisms (SNP) in HOXD10, HOXD12 and HOXD13 genes were chosen to investigate SNP and haplotypes distribution in idiopathic congenital talipes equinovarus nuclear pedigrees.

Methods: Genotypes of 4 SNPs in 84 idiopathic congenital talipes equinovarus nuclear pedigrees were analyzed by restriction fragment length polymorphism and DNA sequencing. Analysis of association between SNP locus and idiopathic congenital talipes equinovarus was performed using ETDT software.

[Association analysis on the polymorphisms of PCOL2 and Sp1 binding sites of COL1A1 gene and the congenital dislocation of the hip in Chinese population].

Objective: To investigate the polymorphism distribution of the PCOL2 and Sp1 binding sites of the collagen type I alpha 1(COL1A1) gene in Chinese population and explore their relationship with congenital dislocation of the hip (CDH).

Methods: The PCOL2 polymorphism (-1997 G/T) in COL1A1 promoter and the Sp1 polymorphism (1546 G/T) in intron 1 were genotyped in 243 members from 81 CDH nuclear family trios by the technique of polymerase chain reaction-restriction fragment length polymorphism, and then transmission disequilibrium test was used to analyze the data of genotypes.

Results: No statistically significant association was observed between CDH and PCOL2 polymorphism.

[The primary observation of congenital clubfoot].

Objective: To explore the possible correlations between clinical and experimental pathological changes of congenital clubfoot and the pathodynamic developmental procedure.

Methods: Eighty-three female Wistar rats were administered with retinoic acid on the 10th day after pregnancy. And from February 2001 to February 2004, 48 patients were analyzed with electropysiological examination.