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In order to solve the problems of the difficulty of determining the principal stiffness directions of industrial robots due to asymmetric structures and mode coupling chatters occurred in robotic milling processes caused by poor rigidly, a stiffness orientation method was proposed. Moreover, the stability of milling processes was improved by controlling the robot functional redundancy and optimizing the posture. Firstly, the stiffness ellipsoid in Cartesian coordinate system at the end of industrial robots was calculated to determine robotic principal stiffness directions in the cutting planes. Then, the stability criterion of mode coupling chatters was obtained by establishing the dynamics model of the machining system. Further, based on the stiffness orientation method, a posture optimi-zation algorithm was proposed for robotic milling. Cutting experiments confirm that stability in robotic milling along the given trajectory may be guaranteed through the optimization of industrial robot configurations without changing other parameters. [ABSTRACT FROM AUTHOR]

In order to solve the problems of uneven fitting clearance between rib strip and skin on the composite reinforced siding plates, a rubber soft die should be pasted on the surface of rigid die. The rubber soft die should be polished to eliminate fitting clearance. However, if polishing parameters were not proper, the surface of rubber soft mold was easy to get hairy, and the roughness value was too large, which was easy to absorb polishing dusts. Aiming at the above problems, a set of robot-based polishing and dust removal system was built for end face polishing of rubber materials. The influences of polishing parameters, such as abrasive particle size, polishing rotation speed, polishing pressure and edging distance on the surface roughness were explored. A method was proposed to predict the surface roughness of rubber polishing by robot based on GRA-RSM, which might be used to establish the prediction model of roughness(Ra) of the rubber materials after polishing. The fitting coefficient R² value of the model is as 0.9878, which indicates that the model fits well. The root mean square error between the predicted value of Ra calculated by the model and the observed value is as 0.014 47, which verify the validity of the prediction model. Based on the prediction model, the parameter combination with the minimum roughness Ra value(3.3 µm) is obtained(polishing rataion speed 4158.9 r/min, polishing pressure 38.4 N, and edging distance 30 mm). [ABSTRACT FROM AUTHOR]

Objective: To investigate the role and mechanism of S100 calcium binding protein B (S100B) in osteoarthritis (OA) cartilage damage repair., Methods: Twenty New Zealand rabbits were randomly divided into control group and model group, with 10 rabbits in each group. Rabbits in the model group were injured by the right knee joint immobilization method to make the artilage injury model, while the control group did not deal with any injury. After 4 weeks, the levels of interleukin-1β (IL-1β) and tumor necrosis factor α (TNF-α) in synovial fluid were detected by ELISA method; the mRNA and protein expressions of S100B, fibroblast growth factor 2 (FGF-2), and FGF receptor 1 (FGFR1) in cartilage tissue were examined by real-time fluorescence quantitative PCR (qRT-PCR) and Western blot assay. Human synovial fibroblasts (SF) were isolated and cultured in vitro . The effects of S100B overexpression and knockdown on the levels of IL-1β and TNF-α (ELISA method) and the expressions of FGF-2 and FGFR1 gene (qRT-PCR) and protein (Western blot) were observed. Moreover, the effects of FGFR1 knockdown in above S100 overexpression system on the levels of IL-1β and TNF-α (ELISA method) and the expressions of FGF-2 and FGFR1 gene (qRT-PCR) and protein (Western blot) were observed., Results: ELISA detection showed that the expressions of IL-1β and TNF-α in the synovial fluid of the model group were significantly higher than those of the control group ( P <0.05); qRT-PCR and Western blot detection showed that the mRNA and protein expressions of S100B, FGF-2, and FGFR1 in cartilage tissue were significantly higher than those of the control group ( P <0.05). Overexpression and knockdown S100 could respectively significantly increase and decrease lipopolysaccharides (LPS) induced IL-1β and TNF-α levels elevation and the mRNA and protein expressions of FGF-2 and FGFR1 ( P <0.05); whereas FGFR1 knockdown could significantly decrease LPS induced IL-1β and TNF-α levels elevation and the mRNA and protein expressions of FGF-2 and FGFR1 ( P <0.05)., Conclusion: S100B protein can regulate the inflammatory response of SF and may affect the repair of cartilage damage in OA, and the mechanism may be related to the activation of FGF-2/FGFR1 signaling pathway.

Objective: To compare the effectiveness between micro-anchor repair and modified pull-out suture in the treatment of mallet fingers., Methods: Between June 2010 and March 2011, 33 patients with mallet fingers were treated by micro-anchor repair method (n = 18, group A) and by modified pull-out suture method in which the broken tendons were sutured with double metal needle Bunnell's suture and a knot was tied palmarly (n = 15, group B). There was no significant difference in age, gender, and disease duration between 2 groups (P > 0.05)., Results: The operation time was (62.5 +/- 3.1) minutes in group A and (65.0 +/- 4.6) minutes in group B, showing no significant difference (t = 1.85, P = 0.07). The treatment expense in group A [(8 566.2 +/- 135.0) yuan] was significantly higher than that in group B [(5 297.0 +/- 183.5) yuan] (t = 58.92, P = 0.00). Incision infection occurred in 2 cases of group A and 1 case of group B; the other patients obtained healing of incision by first intention. Relapsed mallet finger was observed in 1 case of group B. All patients in 2 groups were followed up 12-21 months. According to the Crawford functional assessment system, the results were excellent in 5 cases, good in 10 cases, fair in 2 cases, and poor in 1 case at the last follow-up with an excellent and good rate of 83.3% in group A; the results were excellent in 4 cases, good in 9 cases, fair in 1 case, and poor in 1 case with an excellent and good rate of 86.7% in group B. There was no significant difference in the excellent and good rate between 2 groups (chi 2 = 0.23, P = 0.97)., Conclusion: Both micro-anchor repair and modified pull-out suture are simple and effective methods in the treatment of mallet finger. But compared with micro-anchor repair, pull-out suture has lower expense.

Bacterial Growth Potential (BGP) method was used to investigate the limiting effect of phosphorus in the biological process for drinking water treatment in a water plant in Huai River basin. BGP was increased by 54% when 50 micrograms.L-1 KH2PO4-P was added to the raw water, while addition of other inorganic nutrients had no significant difference from the addition of phosphorus. The effect of addition of 20 mg.L-1 C6H12O6 to raw water was not so strong as that of 50 micrograms.L-1 KH2PO4-P. The CODMn removal rate of the biological filter was 7.5 percentiles higher than the control one and carbon was the main limiting nutrient in its effluent when phosphorus was added to the raw water, while phosphorus was the main limiting nutrient in the effluent of the control filter. These results suggest that phosphorus was a limiting nutrient and had a stronger limiting effect than carbon on the biological process in this plant thus the removal efficiency of the organic matters could be increased by adding phosphorus to the influent.