Intentional replantation for the treatment of a double-rooted maxillary lateral incisor with periodontal-endodontic lesions: a case report and literature review

Objective To investigate the clinical characteristics, diagnosis and treatment of severe combined periodontal-endodontic lesions in a double-rooted maxillary lateral incisor with a palatal radicular groove and to provide a reference for clinical diagnosis and treatment. Methods A patient with a double-rooted left maxillary lateral incisor with a palatal radicular groove and severe combined periodontal-endodontic lesions underwent complete root canal therapy and intentional replantation, and a retrospective analysis of the management of this type of patient was performed based on the literature. Results The 3-year follow-up examination revealed no discomfort, good healing of the upper left lateral incisor, no pathological loosening, and a palatal gingival sulcus was found at a depth of approximately 1 mm. Review of the literature showed that the prognosis of the affected tooth and the choice of treatment plan were correlated with the length and depth of extension of the lingual groove toward the root, the periodontal condition and the pulpal status of the affected tooth. For minor PRGs or for affected teeth with no loss of pulpal viability, flap surgery and odontoplasty can be used to avoid endodontic treatment or retreatment. For deep or long lingual grooves that result in significant loss of periodontal tissue, endodontic treatment, odontoplasty, or closure of the grooves and guided tissue regeneration are needed. In the case of PRGs with double root formation, the affected tooth can be preserved via root canal therapy, removal of the small root and filling with apical restorative material, and intentional replantation. Conclusion In cases of severe combined periodontal-endodontic lesions due to palatal radicular grooves occurring in double-rooted maxillary lateral incisors, clinical presentation and imaging can prevent missed diagnoses, and appropriate treatment should be based on the length and depth of lingual grooves extending toward the roots, periodontal conditions, and pulpal status of the affected teeth

Establishment of a genetic transformation system for cordycipitoid fungus Cordyceps chanhua

Cordyceps chanhua is a well-known edible and medicinal mushroom with a long history of use in China, and it contains a variety of secondary metabolites with interesting bioactive ingredients. However, recent researches have mainly focused on cultivation conditions, secondary metabolite compositions and pharmacological activities of C. chanhua, the lack of an efficient and stable genetic transformation system has largely limited further research on the relationship between secondary metabolites and biosynthetic gene clusters in C. chanhua. In this study, single-factor experiments were used to compare the effects of different osmotic stabilizers, enzyme concentrations and enzyme digestion times on protoplast yield, and we found that the highest yield of 5.53 × 108 protoplasts/mL was obtained with 0.7 M mannitol, 6 mg/mL snail enzyme and 4 h of enzyme digestion time, and the regeneration rate of protoplasts was up to approximately 30% using 0.7 M mannitol as an osmotic stabilizer. On this basis, a PEG-mediated genetic transformation system of C. chanhua was successfully established for the first time, which lays the foundation for further genetic transformation of C. chanhua

Application of automatic control system of hoist in main shaft of Wutongzhuang Coal Mine

In view of problems of low carrying capacity, low safe and reliable performance and low automation control degree existed in original electronic control system of hoist of Wutongzhuang Coal Mine, a reforming scheme of automatic control system of hoist was put forward, and key technical principles were introduced including frequency-conversion speed-regulation system of motor, communication system based on field bus and safety monitoring system. The application results show that average temperature of motor stator is about 10 ℃ lower than that of the original system, average temperature of rotor decreases by about 20 ℃, and temperature measuring element and water cooling unit in stator windings all contribute to reduction of failure rate of the motor; operating speed of the hoist is up to 10 m/s, single hook running time is about 135 s, and lifting load is 25 t which meets design requirements; Profibus and multi-level system architecture were adopted, functional modules, communication interfaces, system services and system monitoring belong to different levels to ensure reliability and scalability of the system

Deadlock-Free Multicast Wormhole Routing in Multicomputer Networks

Efficient routing of messages is the key to the performance of multicomputers. Multicast communication refers to the delivery of the same message from a source node to an arbitrary number of destination nodes. Wormhole routing is the most promising switching technique used in new generation multicomputers. In this paper, we present multicast wormhole routing methods for multicomputers adopting 2D-mesh and hypercube topologies. The dual-path routing algorithm requires less system resource, while the multi-path routing algorithm creates less traffic. More importantly, both routing algorithms are deadlock-free, which is essential to wormhole networks. Keywords: Multicomputers, Heuristic Algorithms, Hypercube Topology, 2D Mesh Topology, Multicast Communication, Wormhole Routing, NP-completeness, Grid Graphs. This work was supported in part by the NSF grants ECS-8814027 and MIP-8811815 ii 1 Introduction The performance of multicomputers is highly dependent on the underlying communicat..

Approximation Algorithms for Min-Max Cycle Cover Problems

As a fundamental optimization problem, the vehicle routing problem has wide application backgrounds and has been paid lots of attentions in past decades. In this paper we study its applications in data gathering and wireless energy charging for wireless sensor networks, by devising improved approximation algorithms for it and its variants. The key ingredients in the algorithm design include exploiting the combinatorial properties of the problems and making use of tree decomposition and minimum weighted maximum matching techniques. Specifically, given a metric complete graph G and an integer k > 0, we consider rootless, uncapacitated rooted, and capacitated rooted min-max cycle cover problems in G with an aim to find k rootless (or rooted) edge-disjoint cycles covering the vertices in V such that the maximum cycle weight among the k cycles is minimized. For each of the mentioned problems, we develop an improved approximate solution. That is, for the rootless min-max cycle cover problem, we develop a (5 1/3+ ε)-approximation algorithm; for the uncapacitated rooted min-max cycle cover problem, we devise a (6 1/3 + ε)-approximation algorithm; and for the capacitated rooted min-max cycle cover problem, we propose a (7+ε)-approximation algorithm. These algorithms improve the best existing approximation ratios of the corresponding problems 6+ε , 7+ε , and 13+ε , respectively, where ε is a constant with 0 < ε < 1. We finally evaluate the performance of the proposed algorithms through experimental simulations. Experimental results show that the actual approximation ratios delivered by the proposed algorithms are always no more than 2, much better than their analytical counterparts

Multicast Communication in Multicomputer Networks

Efficient routing of messages is the key to the performance of multicomputers. Multicast communication refers to the delivery of the same message from a source node to an arbitrary number of destination nodes. While multicast communication is highly demanded in many applications, it is not directly supported by all existing multicomputers; rather it is indirectly supported by multiple one-to-one or broadcast communications, which result in more network traffic and a waste of system resources. In this paper, we study routing evaluation criteria for multicast communication under different communication paradigms. Multicast communication in multicomputers is formulated as a graph theoretical problem. Depending on the evaluation criteria and communication mechanisms, we study three optimal multicast communication problems, which are equivalent to the finding of the following three subgraphs: optimal multicast path, optimal multicast cycle, and minimal Steiner tree, where the interconnectio..

The Message Flow Model for Routing in Wormhole-Routed Networks

The channel dependency graph (CDG) model was proposed for designing deterministic deadlock-free routing algorithms for wormhole-routed networks. A deterministic routing algorithm is deadlock-free if and only if its CDG is acyclic. Although the CDG model has been used to design several deadlock-free adaptive routing algorithms, it may limit their degree of adaptivity. In this paper, we introduce a new approach to deadlockfree routing in wormhole-routed networks called the message flow model. This method may be used to develop deterministic, partially-adaptive, and fully-adaptive routing algorithms for wormhole-routed networks with arbitrary topologies. We first establish the necessary and sufficient condition for deadlock-free routing based on the analysis of the message flow on each channel. We then show how to use the model to prove that a given adaptive routing algorithm is deadlock-free. Finally, we use the method to develop new, efficient adaptive routing algorithms for 2D meshes a..