Objective To establish a rapid specific quantitative assay for Bacillus anthracis detection. Methods According to the principle of complex probe quantitative assay, the primers and quantitative probes targeted at chromatosome DNA rpoB were designed and applied to detect Bacillus anthracis. The influence factor of quantitative PCR were determined. Results The optimal system of this method was aquired: the length of quenching probe is 15mer,the ratio of fluorescent probe to quenching probe is 1/2 and the concentrtion of Mg 2+ is 3 mmol/L.The sensitivity of this assay for Bacillus anthracis is 10 3 copies. It can distinguish Bacillus anthracis from other closely related Bacillus. Conclusion The method can rapidly quantitatively detect the Bacillus anthracis with high sensitivity and specificity, it can be applied to clinical diagnosis.

Objective To establish the three-dimensional (3D) finite element model of unicompartmental knee arthroplasty (UKA) with 3° and 7° posterior tibial slope at different knee flexion angles, and to study biomechanical properties and prosthetic wear of the knee joints with two types of posterior tibia slope and their effects on knee function. Methods Combining CT and MRI images of human knee joints with the 3rd-generation Oxford prosthesis, the finite element UKA model with 3° and 7° posterior tibia slope were established. The 1 kN load was applied to center point of the medial and lateral condyles of the femur to simulate the standing load of human body. The maximum stresses and distributions of the prosthesis and articular cartilage at different knee flexion angles were analyzed. ResultsThe maximum stress of the meniscus liner with 3° posterior tibia slope at 0°, 30°, 60°, 90°, 120° knee flexion angles increased by 28.06%, 68.99%, 19.45%, 21.06% and 53.38%, the distribution area was concentrated from the side of the meniscus liner to the central area, and the stress concentration was obvious at 120° knee flexion. The maximum stress of prosthesis with 3° posterior tibia slope was greater than that with 7 ° posterior tibia slope. The expansion of stress concentration area would cause wear and loosening of the prosthesis, contact stress and concentration area of the articular cartilage would subsequently increase with posterior tibia slope increasing, and stress concentration would be more obvious at high knee flexion angles. Conclusions Tibial prosthesis has the higher stress and greater wear under the condition of 3° posterior tibia slope than 7° posterior tibia slope. The research findings provide theoretical basis for the UKA design in clinic.