[A medium term analysis on of therapeutic effects of bio-lengthend stem hemiarthroplasty in the treatment of unstable osteoporotic intertrochanteric fractures in elderly patients].

Objective: To retrospectively study medium term follow up outcomes effects of effect of bio-lengthend stem hemiarthroplasty in the treatment of unstable osteoporotic intertrochanteric fractures in elderly patients.

Methods: Total of 32 elderly patients with the osteoporotic intertrochanteric fractures were treated with bio-lengthend stem hemiarthroplasty from Jan. 2016 to Jan.

[Estimation of biomechanical behavior in deep wedge-shaped defects restored by different methods under static and dynamic loads: a 3D finite analysis].

Purpose: To analyze the biomechanical properties of the right mandibular second premolar with deep wedge-shaped defects under static and dynamic loads by finite element method, so as to select appropriate repair method in clinic.

Methods: To establish the deep wedge-shaped defect model of the right mandibular second premolar, the unrepaired model after root canal treatment was used as the control group, and resin filling (group A), resin filling after post restoration (group B), crown restoration after resin filling (group C), post and crown restoration after resin filling (group D) were used as the experimental groups. According to different materials, group B and group D were further divided into fiber post (B1, D1) group and pure Ti post (B2, D2) group.

[Clinical application of lower cervical spinous process laminar screw technique in open door laminoplasty].

Objective: To investigate the clinical outcomes of lower cervical spinous process laminar screw technique in open door laminoplasty.

Methods: From February 2005 to June 2010,12 patients with cervical myelopathy were treated with open door laminoplasty by lower cervical spinous process laminar screw technique. There was intervertebral disc herniation with degenerative stenosis in 5 patients, ossification of posterior longitudinal ligament with osteophyte in 6 patients, cervical traumatic instability with spinal cord injuries in 1 patient.

[Anatomic study of lower cervical spinous process for laminar screw fixation].

Objective: To measure anatomic data of spinous process and vertebral plate and evaluate the possibility of fixation of spinous process and vertebral plate.

Methods: Twenty cadaveric cervibal spines of C3-C7 were dissected to expose vertebral plate and spinous process, and were measured by two methods, one was manual measured using digital caliper and the other was computed tomography scaning. Parameters were measured manually including vertebral plate height and width.

[Anatomic comparison between spinous process screws and pedicle screws techniques of the second cervical vertebar].

Objective: To compare anatomic difference between spinous process screws and pedicle screws techniques of the second cervical vertebra.

Methods: Ten human cadaveric of cervical spine (5 male, 5 female) were harvested and had no gross deformities such as scoliosis and/or kyphosis were found in the study. The average age of the subjects was 60.

[Biomechanical study on the posterior screw fixation in the lower cervical spine].

So far, the fixation in the lower cervical spine through posterior approach technology has commonly been used, besides the lateral screw and pedicle screw techniques, transarticular screw and laminar screw techniques have being paid more attention recently. This article introduced four screw fixation ways in the lower cervical spine through posterior approach and reviewed the recent biomechanics studies of four screw fixation techniques. The biomechanics study includes stabilization, pollout strength, insertion technique, and screw characteristic and so on.

[An anatomic study of posterior C(2) spinous process laminar screw fixation].

Objectives: To explore the feasibility and the technical parameters in posterior C2 spinous process laminar screw fixation, and discuss the clinic significance of C2 spinous process laminar screws.

Methods: Twenty cervical cadaveric spines of C2 were dissected, with care taken to expose the lamina and spinous process. After the entrance point of spinous process screw were determined, posterior C2 spinous process laminar screw implantation was performed under visual control.

[Indirect determination of trace mercury ion by flame AAS].

In this paper, the method of indirect analysis of trace Hg2+ has been researched. In the HAc-NaAc buffer solution (pH = 5.0), copper can enrich and displace Hg2+ in solution of sample.