End-of-life tire (ELT) rubber has been widely researched to replace fine or coarse aggregates in cementitious composites. While most studies paid attention to its effect on the engineering ...properties, very few considered chemical reactions with pore solution and the potential for environmental leachate. Recently the authors developed a methodology to remove zinc from the ELT rubber, since zinc can be toxic if it is leached into the environment. In this study, the authors utilized ELT rubber before and after the zinc extraction process to partially replace fine aggregate in a mortar. Flowability, compressive strength, flexural strength, and ultrasonic pulse velocity were measured for the engineering properties of rubberized mortars. Simultaneously, isothermal calorimetry was also employed to investigate the effects of ELT rubber on the hydration process of the rubberized mortars. In addition, the pore solution and leaching solutions were taken at different curing ages and then analyzed for elemental and total organic carbon (TOC) contents. The results showed a remarkable loss in engineering properties of rubberized mortar when ELT rubber was utilized, and the decrease in performance was more pronounced in the samples with zinc-extracted ELT rubber. The pore solution was found to contain significant quantities of zinc and TOC. However, the authors also found that using silica fume to partially replace cement could effectively recover the loss in strength and could reduce the leachability of zinc and TOC.
•A metallurgical processing technique is implemented to leach zinc from end-of-life tire rubber.•The fate of zinc and organic carbon leached from end-of-life tire rubber is studied.•Cement-based materials are proven effective to immobilize zinc and organic carbon leached from tire rubber.
Abstract
Curing temperature is widely known for its effects on the strength of various cementitious-based civil engineering materials, including in stabilized soils. Curing materials at different ...temperatures can cause negative or positive impacts on the mechanical properties of these materials due to the effect of temperature on hydration behavior, hydration rate, and ion exchange. This paper aims to better understand these factors in geoengineering applications. In particular, the discussion focuses on the effects of curing temperatures ranging from below freezing to 50 °C on the hydration process of cement paste (
i.e.
, hydration rate, mineral dissolution, compressive strength) and the hydration process and strengthening mechanism of cement-stabilized soils. Finally, an informative table listing the advantages and disadvantages of the influences of each temperature level on these materials is provided as a summary of the findings from the literature.
Treatment of elbow bone defects is still a huge challenge in orthopaedic in order to restore the shape and function of the elbow joint. Bone defect reconstruction is very difficult due to ...biomechanical complexity of the elbow joint and the poor coverage tissue of this area, so mega-prothesis can be considered the most optimal solution in these cases.
We present two clinical cases of megaprosthesis elbow replacement for treatment of bone defects caused by sequelae of trauma. There is one case of 3 cm bone defect at proximal ulna and one case of 3 cm bone defect at distal humerus. In the 1st case, the elbow joint is fusioned and the second case, the elbow joint is degenerated totally after 3 previous surgery. We performed total elbow replacement with a customized megaprosthesis for them. The Mayo elbow function assessment scale 1 pre-surgery was poor at 50 points. The average age is 35 years old. The mean post-operative follow-up time was 14 months. Range of elbow flexed motion was 135 degrees, both patients were maximally extension, the forearm pronation and supination were 90 and 75 degrees, respectively. The Mayo score is very good with 97,5 points. Both patients were completely satisfied with the postoperative results.
Our results show that megaprosthesis elbow replacement is a very effective option for cases large elbow bone defects due to trauma sequelae. However, careful preoperative preparation is required for the best outcome.
•Megaprosthesis replacement is more popular for bone tumor around elbow•Massive bone defect sequelae around elbow after trauma is really challenged to treat successfully. It will be more difficult if there is a problem with elbow joint: stiffness, degeneration, or fusion. In the past, functional arthrodesis of elbow was the main indication to resolve this problem.•With the development of 3D technology and biomaterial science, megaprosthesis is the best solution for limb preservation after bone tumor wide resection.•Application of megaprosthesis was not only limited for bone tumor, but we can also use it in some rare non-oncologic case, especially around elbow.•We introduced 2 cases with posttraumatic massive bone loss of distal humerus and proximal ulnar which are treated by. megaprosthesis successfully.
Recently, a regional model for assessing the risk of multi-ship collision has been developed to reduce the risk of ship collision in territorial sea areas such as trade ports and entry waterways and ...improve the safety and efficiency of ship traffic. The focus is on marine traffic in the visualized waters with the risk of ship collision. However, due to the lack of information from experts with sufficient knowledge and experience in a given area, they also have some limitations in adequately and comprehensively representing the risk of collision, especially in busy waterways where encounters of more than two ships often appear. In addition, they could not visualize the location of the proximity collision and the exact risk value in real time. Therefore, to overcome the limitations of previous studies, this paper proposes a new regional collision risk visualization system, which combines density-based spatial clustering of applications with noise (DBSCAN) and analysis and knowledge-based ship domains and uses AIS data to intuitively and accurately map the dynamic collision risk of water areas at successive moments, predict areas where collisions can happen by dynamic risk index and warn the ships. Identifying high-risk collision areas between multi-ships can be enhanced using the developed system, which allows for reliable and accurate analysis to help implement safety measures.
Snapping shoulder syndrome could be effectively treated with scapulothoracic arthroscopy. The excision of the scapular superomedial corner is assumed to help lower the recurrence rate. However, the ...amount of resection is still controversial. Furthermore, we lack a technique to measure if the resected amount was adequate based only on arthroscopy evaluation.
We describe a 47-year-old man who suffered from severe snapping shoulder syndrome as a consequence of a deformity of the left superomedial scapular corner. The patient had endoscopic bursectomy and superomedial corner resection. Intraoperative three-dimensional CT scans (3D-CT) were used to evaluate the amount of resection. The patient recovered without incident and resumed his usual activities within 30 days following surgery. At the six-month follow-up, there were no recurrent symptoms.
Intraoperative 3D imaging significantly enhances the safety and efficacy of scapulothoracic arthroscopy. This is a novel technique that, to our knowledge, has not been reported previously in the literature.
•The scapular superomedial corner excision may help reduce recurrence rates of treatment for snapping shoulder syndrome.•The lack of anatomical landmarks makes estimating the resected volume by arthroscopic vision challenging.•This is the first report of the application of intra-operative 3D imaging for scapulothoracic arthroscopy.•Intraoperative 3D imaging significantly enhances the safety and effectiveness of scapulothoracic arthroscopy.•Intraoperative 3D imaging help in the precise identification of anatomical landmarks in small or complex regions.
and importance: Pelvic osteosarcoma is quite rare and is a challenging task for orthopedic surgeons. This aim of this study is to present the first case report using customized 3D-printed prosthesis ...in Vietnam.
57-year-old male was diagnosed with pelvic osteosarcoma. After neoadjuvant chemotherapy, we did limb-salvage surgery after partial pelvic resection. He had to undergo another surgery due to an infection complication that exposed part of the prosthesis. At 6 months follow-up, the patient's overall status was stable. VAS score when moving is 2/10. He can walk with one crutch. Patient is still being followed up and treated.
Management of pelvic osteosarcoma remains a challenging task for orthopedic surgeons. Advancements in customized 3D-printed prosthesis have been applied in treatment of pelvic osteosarcoma. Despite the complications, the results are promising. We believe that this is a new and innovative route in surgery of pelvic osteosarcoma.
Using customized 3D-printed prosthesis is a good way for management of pelvic osteosarcoma.
•Osteosarcoma of pelvis is not common, account for 4–10% of all bone cancer.•Pelvis connect the lower limb with body by hip joint and support the intraabdominal organ.•It is very difficult to preserve the pelvis after wide resection.•Custom made 3D printed implant give us a chance to restore the pelvis anatomically and functionally.
Tenosynovial giant cell tumor (TSGCT) is a slow-growing soft tissue tumor that develops from the synovial tissue of tendon sheaths, joints, or bursae. In the knee, this type of tumor is uncommon. ...Giant cell tumors of the cruciate ligaments' tendon sheath are far more infrequent. Only 16 localized TSGCTs of the cruciate ligaments have been recorded in the literature to our knowledge, with 9 involving the anterior cruciate ligament (ACL) and 7 involving the posterior cruciate ligament (PCL).
We present a rare case of localized TSGCT arising from the PCL's femoral insertion in a 44-year-old male, as well as a literature review on localized TSGCT of cruciate ligaments in the knee. The diagnosis of tumor's presence was made using MRI while the definitive diagnosis was obtained through intraoperative evaluation and postoperative pathology.
Arthroscopic tumor resection was an effective and safe treatment option based on the available data.
•Giant cell tumors of the cruciate ligaments are extremely uncommon.•The most typical clinical presentations are pain and decreased range of motion of the knee without a history of trauma.•MRI helps confirm the presence of a tumor but not its original location or type.•Based on available data, arthroscopic tumor removal is an effective and safe treatment option.
The purpose of this research is to evaluate the results of arthroscopic suture fixation with fiber wires used as treatment for ACL avulsion fracture, and to determine how effective such a technique ...is when it comes to restoring of knee function.
This prospective study involves 28 patients, who underwent arthroscopic fixation of displaced ACL avulsion fractures at Saint Paul Hospital (Hanoi) from January 2014 to March 2018.
The first three weeks were not marked with any abnormalities associated with post-operative sutures and hematomas, infectious complications were not detected either. Post-operative displacement of fracture fragments did not take place among the patients involved in the study. At the 3-month follow-up, the average IKDC score was 90.7 (range: 76–100), and the average Lysholm score was 93.6 (range 82–100). The percentage of excellent scores was 42.9% (12 patients), good scores accounted for 50% (14 patients), while fair/poor scores accounted for 3.6% each (1 patient on each score). The percentage of excellent/good scores was 92.9% in total.
This study shows that ACL avulsion fracture can be treated effectively by arthroscopic suture fixation with fiber wires. In fact, this technique may restore knee function and stability.
•Evaluating the results of arthoscopic suture fixation with fiber wires used as treatment for ACL avulsion fracture.•The study involves 28 patients.•The ACL avulsion fracture can be treated effectively by arthoscopic suture fixation with fiber wires. It may restore knee function and stabiity.
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