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Oriented by requirement of trust management in multiple cloud environment, this paper presents T-broker, a trustaware service brokering scheme for efficient matching cloud services (or resources) to satisfy various user requests. First, a trusted third party-based service brokering architecture is proposed for multiple cloud environment, in which the T-broker acts as a middleware for cloud trust management and service matching. Then, T-broker uses a hybrid and adaptive trust model to compute the overall trust degree of service resources, in which trust is defined as a fusion evaluation result from adaptively combining the direct monitored evidence with the social feedback of the service resources. More importantly, T-broker uses the maximizing deviation method to compute the direct experience based on multiple key trusted attributes of service resources, which can overcome the limitations of traditional trust schemes, in which the trusted attributes are weighted manually or subjectively. Finally, T-broker uses a lightweight feedback mechanism, which can effectively reduce networking risk and improve system efficiency. The experimental results show that, compared with the existing approaches, our T-broker yields very good results in many typical cases, and the proposed system is robust to deal with various numbers of dynamic service behavior from multiple cloud sites.

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To investigate the clinical efficacy of pre-operative simulation using a three-dimensional (3D) printing model for surgical treatment of old and complex tibial plateau fractures. Forty-two patients with old and complex tibial plateau fractures were retrospectively reviewed from January 2014 to January 2018, which were divided into a conventional planning group (n = 22) and a planning with 3D printing group (n = 20). In the planning with 3D printing group, preoperative equal-ratio fracture models prepared using the 3D printing technique were used to perform pre-operative simulation and guide the real surgical operation. In the conventional planning group, the operation was performed based on pre-operative computed tomography (CT) images. Surgery duration, blood loss and the number of fluoroscopy during operations were recorded. During follow-up, the quality of fracture reduction and complications were also recorded. Knee functions were evaluated using the hospital for special surgery (HSS) scoring system. The operation time, blood loss and the number of fluoroscopy during operation in the planning with 3D printing group were less than that in the conventional planning group (P < 0.01). All patients were followed up for mean of 24.38 ± 7.62 months. The rate of excellent fracture reduction in the planning with 3D printing group and conventional planning group was 75% and 45.45%, respectively (P = 0.05). The complication rate was 15% in the planning with 3D printing group and 31.82% in the conventional planning group. At the final follow-up evaluation, the mean HSS score was 86.05 ± 7.67 in the planning with 3D printing group and 79.09 ± 6.75 in the conventional planning group (P = 0.003). The rate of excellent results in the planning with 3D printing group was 70% and in the conventional planning group was 45.45% (P = 0.083). In conclusion, pre-operative simulation using a 3D printing model may be helpful for the treatment of old and complex tibial plateau fractures, which may be conducive to the pre-operative planning and to making the surgical procedure accurate and personalized. However, its clinical effectiveness need to be further assessed by a prospective randomized-controlled study. Complex tibial plateau fractures are mostly caused by high-energy injuries and are often accompanied with the collapse of the tibial plateau surface, displacement of the comminuted fragments and knee joint dislocation. If this type of fracture is not treated properly, complications such as postoperative wound infection, skin necrosis, joint deformity and traumatic arthritis are very likely to occur 1. If complex tibial plateau fractures develop into old fractures, they become more challenging for orthopedic surgeons to optimize the surgical procedures to improve the operation efficiency and to reduce postoperative complications 2. In general, for complex tibial plateau fractures, the surgical planning is mainly based on pre-operative X-ray and CT images. Although three-dimensional (3D)-CT can display the spatial position relations...

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