The high percentage of N 2 in the air can provide an abundant nitrogen source for ammonia industry.

Surgical treatment to restore full range of motion and full weight bearing after extensive femoral bone resection in patients with primary or metastatic femoral tumours is individually challenging. Especially when the remaining distal or proximal bone is very short, a rigid fixation of an implant is difficult to achieve due to the reverse funnel shape of the metaphysis. Herein, we present a nov...

The aim of this review paper is to define the fixation of the cemented stem. Polymethyl methacrylate, otherwise known as "bone cement", has been used in the fixation of hip implants since the early 1960s. Sir John Charnley, the pioneer of modern hip replacement, incorporated the use of cement in the development of low frictional torque hip arthroplasty. In this paper, the concepts of femoral st...

We report two cases where a proximal humeral locking plate was used for the fixation of an extremely distal, type III peri-prosthetic femoral fractures in relation to a total knee replacement (TKR). In each case there was concern regarding the fixation that could be achieved using the available anatomic distal femoral plates due to the size and bone quality of distal fragment. The design of the...

Two experiments examined possible negative transfer in nonexperts from the use of pictorial examples in a laboratory design problem-solving situation. In Experiment 1, 89 participants were instructed to "think aloud" and were assigned to 1 of 3 conditions: (a) control (standard instructions), (b) fixation (inclusion of a problematic example, describing its problematic elements), or (c) defixati...

STUDY DESIGN A biomechanical comparison of fixation constructs in an experimental fracture model. OBJECTIVE To determine the relative postoperative stability of anterior graft and plating with that of posterior or combined fixation constructs in an unstable thoracolumbar burst fracture model. SUMMARY OF BACKGROUND DATA Several treatment modalities have been proposed for unstable thoracolumb...

OBJECTIVE This study evaluated the mechanical characteristics and stress distribution of the hybrid technique fixation of the sagittal split ramus osteotomy. STUDY DESIGN In the mechanical test, 10 polyurethane replicas of human hemimandibles of each group were submitted to linear loading test. For the photoelastic evaluation, 3 hemimandible replicas of photoelastic resin were subjected to ph...

Utilizing the measured corneal birefringence from a data set of 150 eyes of 75 human subjects, an algorithm and related computer program, based on Müller-Stokes matrix calculus, were developed in MATLAB for assessing the influence of corneal birefringence on retinal birefringence scanning (RBS) and for converging upon an optical/mechanical design using wave plates ("wave-plate-enhanced RBS") th...

rotavirus is the most important pathogen responsible for acute diarrhea in infants and young children. the incidence of rotavirus infection was studied in 156 children less than six years of age who were suffering from acute gastroenteritis, between february 22, 2006 and february 21, 2007 in mashhad. rotavirus antigen was detected by latex agglutination test (rotascreen) in 28.8% of the stool s...