Search

Poly-lactic acid based biocomposite strengthened with magnesium alloy wires (Mg wires/PLA composite) is prepared for bone fixation implantation. The influence of wire content and load mode on the degradation performances of the composite and its components is studied. The result suggests the degradation of Mg wires could slow down the pH decrease originated from the degradation of PLA, while a relatively high wire content contributes to descend the degradation rate of Mg wire in the composite. Dynamic load significantly promotes the mechanical loss of the specimens. After 30 days immersion, the Sb retention is about 65%, 52% and 55%, respectively for pure PLA, the composite at 10 vol% and 20 vol% under dynamic load, comparing to 75%, 70% and 72% under no load. Moreover, dynamic load could further mitigate the degradation of Mg wires by increasing convective transport of acidic products out of the composite.

OBJECTIVE: To compare the effectiveness of anterior subcutaneous pelvic internal fixator (INFIX) and plate internal fixation in treatment of unstable anterior pelvic ring fractures. METHODS: The clinical data of 48 patients with unstable anterior pelvic ring fractures who met the selection criteria between June 2014 and December 2019 were retrospectively analyzed. Among them, 21 cases were treated with INFIX (INFIX group), and 27 cases were treated with plate (plate group). There was no significant difference in gender, age, body mass index, cause of injury, time from injury to operation, Injury Severity Score (ISS), and fracture type between the two groups (P>0.05). The operation time, intraoperative blood loss, fracture healing time, partial weight-bearing time, and complete weight-bearing time were recorded and compared between the two groups. Matta standard was used to evaluate the quality of fracture reduction, and Majeed score system was used to evaluate the functional recovery of pelvic fracture after operation. RESULTS: The patients in both groups were followed up for an average of 12.5 months (range, 6-16 months). The operation time and intraoperative blood loss in INFIX group were significantly lower than those in plate group (t=−11.965,P=0.000; t=−20.105,P=0.000). There was no significant difference in the quality of fracture reduction, fracture healing time, partial weight-bearing time, and complete weight-bearing time between the two groups (P>0.05). At 14 weeks after operation, there was no significant difference in the scores of pain, working, standing and walking, and total scores between INFIX group and plate group (P>0.05), but there were significant differences in sitting and sexual intercourse scores (t=−4.250,P=0.003; t=−6.135,P=0.006). The incidences of lateral femoral cutaneous nerve injury, femoral nerve injury, and heterotopic ossification were significantly higher in INFIX group than in plate group (P

OBJECTIVE: To investigate the value of integrin α(v)β(3) targeted microPET/CT imaging with (68)Ga-NODAGA-RGD(2) as radiotracer for the detection of osteosarcoma and theranostics of osteosarcoma lung metastasis. METHODS: The (68)Ga-NODAGA-RGD(2) and (177)Lu-NODAGA-RGD(2) were prepared via one-step method and their stability and integrin α(v)β(3) binding specificity were investigated in vitro. Forty-one nude mice were injected with human MG63 osteosarcoma to established the animal model bearing subcutaneous osteosarcoma (n=21), osteosarcoma in tibia (n=5), and osteosarcoma pulmonary metastatic (n=15). The microPET-CT imaging was carried out in 3 animal models at 1 hour after tail vein injection of (68)Ga-NODAGA-RGD(2). Biodistribution study of (68)Ga-NODAGA-RGD(2) was performed in animal model bearing subcutaneous osteosarcoma at 10, 60, and 120 minutes. The animal model bearing pulmonary metastatic osteosarcoma was injected with (177)Lu-NODAGA-RGD(2) at 7 weeks after model establishment to observe the therapeutic effect of pulmonary metastatic osteosarcoma. Histological and immunohistochemistry examinations were also done to confirm the establishment of animal model and integrin β(3) expression in animal models bearing subcutaneous osteosarcoma and bearing pulmonary metastatic osteosarcoma. RESULTS: (68)Ga-NODAGA-RGD(2) and (177)Lu-NODAGA-RGD(2) had good stability in vitro with the 50% inhibitory concentration value of (5.0±1.1) and (6.5±0.8) nmol/L, respectively. The radiochemical purity of (68)Ga-NODAGA-RGD(2) at 1, 4, and 8 hours was 98.5%±0.3%, 98.3%±0.5%, and 97.9%±0.4%; while the radiochemical purity of (177)Lu-NODAGA-RGD(2) at 1, 7, and 14 days was 99.3%±0.7%, 98.7%±1.2%, and 96.0%±2.8%. (68)Ga-NODAGA-RGD(2) microPET-CT showed that the accumulation of (68)Ga-NODAGA-RGD(2) in animal models bearing subcutaneous osteosarcoma and osteosarcoma in tibia and in lung metastasis as small as 1-2 mm in diameter of animal model bearing pulmonary metastatic osteosarcoma. Biodistribution study of (68)Ga-NODAGA-RGD(2) in animal model bearing subcutaneous osteosarcoma revealed rapid clearance from blood with tumor peak uptake of (3.85±0.84) %ID/g at 120 minutes. The distribution of (177)Lu-NODAGA-RGD(2) in lung metastasis was similar with (68)Ga-NODAGA-RGD(2). The number and size of osteosarcoma metastasis decreased at 2 weeks after (177)Lu-NODAGA-RGD(2) administration and integrin targeting specificity was confirmed by pathology examination. CONCLUSION: (68)Ga-NODAGA-RGD(2) was potential for positive imaging and early detection of osteosarcoma and metastasis. Targeted radiotherapy with (177)Lu-NODAGA-RGD(2) was one potential alternative for osteosarcoma lung metastasis.

Background Although percutaneous kyphoplasty (PKP) is performed to restore the vertebral body height and kyphosis in osteoporotic vertebral compression fractures (OVCFs), the regained height may be lost on balloon deflation. This study compares PKP with modified percutaneous kyphoplasty (MPKP) in terms of the clinical outcomes in treating OVCFs. Methods Between May 2014 and March 2016, 76 patients with OVCFs were randomly assigned to 2 groups according to the procedure chosen: the PKP group (n = 36) and MPKP group (n = 40). Perioperative parameters, radiologic data, and other clinical parameters were compared between the groups. Results Of the 76 patients, 68 were followed-up for an average of 16 months. Both groups showed similar degrees of postoperative improvement on the visual analog scale, without any significant intergroup difference. However, the MPKP group showed greater improvement in vertebral body height and recovery of the Cobb angle compared with the PKP group. Additionally, the volume of bone cement and operative time were significantly higher in the MPKP group than in the PKP group, whereas the Oswestry Disability Index at the last follow-up was significantly lower in the MPKP group than in the PKP group. The cement leakage ratio and incidence of recurrent vertebral fractures did not differ significantly between the groups. Conclusions MPKP prevents the loss of vertebral height observed with PKP during balloon deflation in addition to providing greater height, Cobb angle recovery, and quality of life compared with PKP in cases of OVCF.

The automatic meter reading system has been increasingly and widely used for its efficient, convenient and intelligent management. However, the results of practical application of the previous meter reading systems are not always ideal because of poor conditions of low-voltage domestic grid. In view of these, one meter reading system based on power frequency communication and GPRS is proposed in this paper after analyzing the principle and realization of formal low-voltage meter reading system. The system overcomes the shortcomings of the original meter reading system while saving installment cost and also ensuring the stable and reliable of data transmission in the power line.

Along with the popularity of the optical fiber communication, virtual instrument based online monitoring real-time detecting and automatic diagnosis management system on multi-fiber is proposed in this paper. To manage fiber lines and landmarks, simplified landmark map are presented based on the landmark list. Multi-fiber lines are online monitored, which may have the different or same parameters. When the optical power of any monitored line exceeds the set threshold, the subsystem gives a low power alarm, detecting subsystem will be started automatically to detect alarmed line. After data processing and analysis of detection results, then draws the result curve in the virtual instrument panel. User can locate plot of the curve, and zoom in event curve based on the event list. It utilizes detection results, event list, landmark list and simplified landmarks map synthetically, and presents comprehensive diagnosis conclusion of detection based on the map. To avoid fault, the system predicts fault in future through the analysis of a period of the historical detection result. This system has the advantages of excellent stability, powerful analysis, friendly interface, and convenient operation.

Mobile communications is an important professional course for telecommunication engineering, so a practical system of mobile communication experiment is essential. Comparing with the traditional experimental teaching, Mobile Communication Soft Laboratory (MCSL) takes advantages of real-time and flexibility. Especially in lack of funds laboratory, MCSL can help learners to understand the principle. MCSL is programmed with VC and MATLAB. This paper is introduced three implemental means of experiments: confirmatory experiment, design experiment and comprehensive experiment. It is effective for students to be applied in experimental teaching