BACKGROUND: Wear particles factually serve as a medium carrying extensive information on the wear process involved in hip implants. Moreover, it has been demonstrated that wear particles contribute to the failure of Charnley total hip replacement.OBJECTIVE: To investigate the morphological characteristics of wear particles generated by couples of ultrahigh molecular weight polyethylene (UHMWPE) cups and Al2O3 femoral heads, mounted in a simulator in the presence of distilled water and explore the wear mechanism of UHMWPE cup.DESIGN: Wear tests were performed on a ball-in-socket hip simulator.SETTING: Department of Mechanical Engineering, Xuzhou Institute of Technology.MATERIALS: The molecular weight of UHMWPE selected as cup was 3 000 000. Its density was 0.935 g/cm3, hardness 30 HB, fracture strength 35 MPa, and water absorption < 0.01%. The experimental femoral head was made of alumina and zirconia (Al2O3: 87%, ZrO2: 13%). Its density was 4 g/cm3, hardness 90 HRA, tensile strength > 450 MPa, and tenacity 7 MPaM1/2.METHODS: The experiment was performed in the laboratory of tribology, China University of Mining and Technology from December 2003 to July 2005. Hip simulator was used to assess the tribological performance of Al2O3-UHMWPE at room temperature, 100 r/min, 784 N load for 1.5×106 cycles. Distilled water was used as the lubricant. Wear of UHMWPE acetabulum was measured every 3×105 cycles by taking out the acetabulum from simulator, cleaning in distilled water for 3 minutes in an ultrasonic bath, putting in an oven for 40 minutes at 80 ℃, and cooling off in a desiccator. A BT211D electronic balance (reciprocal sensibility, 0.01 mg) was used to measure the weight loss of UHMWPE acetabula according to the reference sample method to calculate the wear. A sample (20 mL) of distilled water lubricant used in test was obtained when the simulator was stopped for gravimetric analysis. Morphology of wear particles in samples and surface of worn UHMWPE acetabula were observed by using scanning electron microscope (SEM). The components of wear particles were determined by X-ray. Detailed measurements of the wear particles distribution were conducted by LS100(R) Laser Particle Size Analyzer (including LS SVM Plus).MAIN OUTCOME MEASURES: Morphology and size distribution of wear particles; Wear mechanism and wear rate of UHMWPE acetabula.RESULTS: The wear particles showed a wide range of particle sizes, varying from 0.3 to 180 μm, most of which ranged from 5 to 20 μm. More than 99% of wear particles were UHMWPE particles, which were classified into five groups in terms of their morphological characteristics: spherical particle, tearing particle, lamellar particle, fatigued flaking and rod-shaped particle. Lamellar or cube was the predominant form of Al2O3 ceramic particles with flat surface structure and upright edges. The worn surfaces of UHMWPE cup showed evidence of multidirectional scratching, adhesive and micro-contact fatigue wear, and plastic deformation.CONCLUSION: ①The dominant wear mechanisms acting in the UHMWPE cup are abrasive wear, adhesive wear, microcosmic fatigue wear and flaking associated with plastic deformation. ②The size of particles accumulating mostly is tiny among the particle groups.

BACKGROUND:Wear particles factually serve as a medium carrying extensive information on the wear process involved in hip implants.Moreover,it has been demonstrated that wear particles contribute to the failure of Charnley total hip replacement.OBJECTIVE:To investigate the morphological characteristics of wear particles generated by couples of ultrahigh molecular weight polyethylene(UHMWPE) cups and Al2O3 femoral heads,mounted in a simulator in the presence of distilled water and explore the wear mechanism of UHMWPE cup.DESIGN:Wear tests were performed on a ball-in-socket hip simulator.SETTING:Department of Mechanical Engineering,Xuzhou Institute of Technology.MATERIALS:The molecular weight of UHMWPE selected as cup was 3 000 000.Its density was 0.935 g/cm3,hardness 30 HB,fracture strength 35 MPa,and water absorption 450 MPa,and tenacity 7 MPaM1/2.METHODS:The experiment was performed in the laboratory of tribology,China University of Mining and Technology from December 2003 to July 2005.Hip simulator was used to assess the tribological performance of Al2O3-UHMWPE at room temperature,100 r/min,784 N load for 1.5?106 cycles.Distilled water was used as the lubricant.Wear of UHMWPE acetabulum was measured every 3?105 cycles by taking out the acetabulum from simulator,cleaning in distilled water for 3 minutes in an ultrasonic bath,putting in an oven for 40 minutes at 80 ℃,and cooling off in a desiccator.A BT211D electronic balance(reciprocal sensibility,0.01 mg) was used to measure the weight loss of UHMWPE acetabula according to the reference sample method to calculate the wear.A sample(20 mL) of distilled water lubricant used in test was obtained when the simulator was stopped for gravimetric analysis.Morphology of wear particles in samples and surface of worn UHMWPE acetabula were observed by using scanning electron microscope(SEM).The components of wear particles were determined by X-ray.Detailed measurements of the wear particles distribution were conducted by LS100(R) Laser Particle Size Analyzer(including LS SVM Plus).MAIN OUTCOME MEASURES:Morphology and size distribution of wear particles;Wear mechanism and wear rate of UHMWPE acetabula.RESULTS:The wear particles showed a wide range of particle sizes,varying from 0.3 to 180 ?m,most of which ranged from 5 to 20 ?m.More than 99% of wear particles were UHMWPE particles,which were classified into five groups in terms of their morphological characteristics:spherical particle,tearing particle,lamellar particle,fatigued flaking and rod-shaped particle.Lamellar or cube was the predominant form of Al2O3 ceramic particles with flat surface structure and upright edges.The worn surfaces of UHMWPE cup showed evidence of multidirectional scratching,adhesive and micro-contact fatigue wear,and plastic deformation.CONCLUSION:①The dominant wear mechanisms acting in the UHMWPE cup are abrasive wear,adhesive wear,microcosmic fatigue wear and flaking associated with plastic deformation.②The size of particles accumulating mostly is tiny among the particle groups.

Objective To evaluate the safety, feasibility and efficacy of CT-guided percutaneous hollow screw fixation in the treatment of patients with sacroiliac complex injury. Methods Forty-five patients (at age range of 15-58 years) with sacroiliac complex injuries including 20 males and 25 females were enrolled in this study. There were 28 traffic injuries and 17 fall injuries. Fourteen patients with sacral fractures ( 15 patients with Dennis type Ⅰ fractures and nine with Dennis type Ⅱ fractures), 12 with sacroiliac joint dislocation, six with sacral fracture combined with sacroiliac joint dislocation and nine with sacroiliac joint complex injury. All patients were treated by CT-guided percutaneous hollow screw fixation. The functional exercise was performed early after operation. Results Seventy-two hollow screws were installed in 45 patients, with the operation time for 21-68 minutes ( average 37 minutes) and the operative blood loss for 30-75 ml. Of all, 38 patients were followed up for 6-26 months. According to the Majeed functional criteria, the score of the patients was 72-96 points (average 90. 3 points ), which showed that the results were excellent in 33 patients and good in two, with excellence rate of 92%. No iatrogenic nerve injury, incision infection or screw fracture were detected. Conclusion CT-guided percutaneous hollow screw fixation takes advantages of precise direction, stable fixation and safe operation and hence is one of safe and effective methods for treatment of sacroiliac complex injury.

This article was aimed to study the latest research progress of Tripterygium hypoglaucum, in order to pro-vide references for further research on T. hypoglaucum. CNKI Chinese Journal Full-text Database was used as data source. Bibliometric analysis was conducted on T. hypoglaucum research articles issued from 1915~2013. Bibliometric method was used in the analysis on the change trend among years, research institutes, publication dates, research per-sonnels and research topics of the articles with the built-in analysis tools and network analysis tools. The results indi-cated that T. hypoglaucum research was still in the development stage. And there is still plenty of room for growth in aspects including resources, material basis, manufacturing pharmacy and so on.

OBJECTIVE To investigate and analyze the application of antibiotics in non-surgical departments in our hospital.METHODS To make a survey of the use of antimicrobials in non-surgical departments from a total of 548 randomly selected medical records during Jan-Mar 2007,the data of reasonable use of antibacterials were obtained after evaluation and analysis.RESULTS Of the 548 patients in our study,229(41.79%)used antimicrobials.The use of antimicrobials for infection prevention was in 46 cases(20.09%),for infection treatment was in 183 cases(79.91%).From them 95 cases(41.48%)used a combination of two and more antimicrobials.The most widely used antibacterials were penicillins,cephalosporins,and quinolones.CONCLUSIONS The use of antimicrobials is generally reasonable,and meets the safe,effective,and economical goal in our hospital.

Objective To study comparatively the clinical anaesthetic potency and adverse effects to children of 0.375% ropivacaine used for brachial plexus block in upper-limb paediatric surgery.Methods After undergoing basal anesthesia with ketamine,36 children scheduled for hand and forearm surgery were randomly allocated to receive brachial plexus block with 0.375% ropivacaine(group A) and to receive intravenous anesthesia with ketamine(group B).The effect of sensor block and motor block,the changes of vital sings,the occurrence of side effect(nausea and vomiting) and palinesthesia of children were observed.Results The patients in group A kept a steady vital signs,their blood pressure,cardiac and respiration rate were similar to the backgroud level before anesthesia,whereas in group B the blood pressure,cardiac and respiration rate of patients were increased and kept a rather higer level,fluctuated with the depth of anesthesia.Conclusion Ropivacaine used for brachial plexus block in upper-limb paediatric surgery is a simple,feasible,and safe method with anesthetized perfectly and less complication.

Objective:To construct the pleiotrophin (PTN )overexpression vector,and to explore the effect of PTN on the decidualization of uterine stromal cells in the mice.Methods:The specific primers containing restriction enzyme cutting sites were designed according to the PTN gene sequences published in GenBank for PCR amplification.The amplified fragment of PTN was recovered from the agarose gel and cloned into the pGEM-T vector.The pGEMT-PTN was cut by double enzyme digestion and ligated into pcDNA3.1 (+)to construct the PTN overexpression plasmid.After transfection with PTN overexpression plasmid,the expression levels of PTN mRNA in the uterine stromal cells and the expression levels of decidualization markers Prl8a2 and Prl3c1 were detected by qRT-PCR method.The uterine stromal cells transfected with pcDNA3.1 (+)empty vector were used as control group. Results:The results of identification by double enzyme digestion indicated that the bands of PTN overexpression plasmid were consistent with those of the target gene,and the clone sequencing results suggested that it had 100% homology with mouse PTN gene sequence published in GenBank.Compared with control group, the expression levels of PTN,Prl8a2 and Prl3c1 mRNA in mouse uterine stromal cells in PTN overexpression group were significantly increased (P < 0.05).Conclusion:PTN overexpression could increase the expression levels of decidualization markers in mouse uterine stromal cells,indicating that PTN might play an enhancement effect during uterine decidualization in the mice.

Artemisinin is the antidote to malaria, and has made hundreds of millions patients get rid of the disease since application in clinic. At present, the main accesses to artemisinin are directly extracted from Artemisia annua,chemical synthesis and biosynthesis. By comparing the differences of artemisinin production process between China and abroad, this research analyzes the reasons of the problem, and put forward their views and suggestions, so as to provide references for Artemisia annua further research.

OBJECTIVE To find out the situation of the application of anti-bacterial drugs in liver transplantation perioperative patients and to improve the quality of their usage.METHODS According to the criteria of DDD and DUI recommended by WHO,making a random sampling survey of the application of anti-bacterials in 206 liver transplantation perioperative patients who discharged hospital during Jan-Dec 2006,and then to analyze the rationality of their application.RESULTS Among the 206 patients,100.0% patients had received anti-bacterial drugs involving 13 kinds,137 patients in them used one,31.1% used two and 2.4% used three,and there were twelve in thirteen kinds of drugs whose DUI was no more than one.CONCLUSIONS The survey has proved that the liver transplantation perioperative patients have received rational therapy.

OBJECTIVE To understand the antibacterial usage among outpatients in our hospital and provide reference for their rational use in clinic treatment.METHODS Totally 18 232 prescriptions in 2007 were investigated and analyzed.RESULTS The rate of antibacterial usage was 21.9% which took up 6.25% of total cost.As for active treatment single drug consisted of 91.21%,two-drugs 9.09%,and three-drugs of 0.55%.CONCLUSIONS The antibiotic service is basically rational.