Nowadays, internet is becoming a suitable way of accessing the databases. Such data are exposed to various types of attack with the aim to confuse the ownership proofing or the content protection. In this paper, we propose a new approach based on fragile zero watermarking for the authentication of numeric relational data. Contrary to some previous databases watermarking techniques which cause some distortions in the original database and may not preserve the data usability constraints, our approach simply seeks to generate the watermark from the original database. First, the adopted method partitions the database relation into independent square matrix groups. Then, group-based watermarks are securely generated and registered in a trusted third party. The integrity verification is performed by computing the determinant and the diagonal’s minor for each group. As a result, tampering can be localized up to attribute group level. Theoretical and experimental results demonstrate that the proposed technique is resilient against tuples insertion, tuples deletion, and attributes values modification attacks. Furthermore, comparison with recent related effort shows that our scheme performs better in detecting multifaceted attacks.

Background: The morphology and classification of posterior malleolus (PM) fractures remain controversial. An increasing number of studies have found that merely focusing on the fragment size does not lead to a satisfactory prognosis. This study aimed to demonstrate the fracture line and comminution zones of PM fractures using computed tomography (CT), in order to provide insights into the injury mechanism of PM fractures. Methods: We retrospectively reviewed the data of 95 patients with PM fractures between 2013 and 2018 at a level 1 trauma center. The CT data of the PM of the patients were reconstructed using software. Images of all patients were superimposed together, and drawn as a heat map of the fragments and line distributions of PM fractures. Results: Our study included 66 type I, 19 type II, and 10 type III PM fractures according to the classification of Haraguchi. In the single-fragment fracture group, the fracture lines were mainly concentrated in the posterolateral tibial tubercle area (Volkmann’s tubercle) and a larger tubercle area involving the tibialis posterior groove. In the multifragment fracture group, there were 10 (43.5%) patients with a 2-fragment pattern and 13 (56.5%) patients with a compressive-fragment pattern. Conclusion: According to the fracture map and previous studies on the syndesmosis, our study provides a different understanding of the pathomechanisms of ankle injuries compared with previous classifications of PM fractures. Level of Evidence: Level III, retrospective study.

No abstract

Aims The morphology of medial malleolar fracture is highly variable and difficult to characterize without 3D reconstruction. There is also no universally accepeted classification system. Thus, we aimed to characterize fracture patterns of the medial malleolus and propose a classification scheme based on 3D CT reconstruction. Methods We retrospectively reviewed 537 consecutive cases of ankle fractures involving the medial malleolus treated in our institution. 3D fracture maps were produced by superimposing all the fracture lines onto a standard template. We sliced fracture fragments and the standard template based on selected sagittal and coronal planes to create 2D fracture maps, where angles α and β were measured. Angles α and β were defined as the acute angles formed by the fracture line and the horizontal line on the selected planes. Results A total of 121 ankle fractures were included. We revealed several important fracture features, such as a high correlation between posterior collicular fractures and posteromedial fragments. Moreover, we generalized the fracture geometry into three recurrent patterns on the coronal view of 3D maps (transverse, vertical, and irregular) and five recurrent patterns on the lateral view (transverse, oblique, vertical, Y-shaped, and irregular). According to the fracture geometry on the coronal and lateral view of 3D maps, we subsequently categorized medial malleolar fractures into six types based on the recurrent patterns: anterior collicular fracture (27 type I, 22.3%), posterior collicular fracture (12 type II, 9.9%), concurrent fracture of anterior and posterior colliculus (16 type III, 13.2%), and supra-intercollicular groove fracture (66 type IV, 54.5%). Therewere three variants of type IV fractures: transverse (type IVa), vertical (type IVb), and comminuted fracture (type IVc). The angles α and β varied accordingly. Conclusion Our findings yield insight into the characteristics and recurrent patterns of medial malleolar fractures. The proposed classification system is helpful in understanding injury mechanisms and guiding diagnosis, as well as surgical strategies. Cite this article: Bone Joint J 2021;103-B(5):931–938.

During the past decades, the utilization of Li-ion batteries offered the benefit of high energy and power density and can be used in a variety of applications, including the electrical...