Target Tracking Systems on a Sphere With Topographic Information.

We consider the target tracking problem on a sphere with topographic structure. For a given moving target on the unit sphere, we suggest a double-integrator autonomous system of multiple agents that track the given target under the topographic influence. Through this dynamic system, we can obtain a control design for target tracking on the sphere and the adapted topographic data provides an efficient agent trajectory. The topographic information, described as a form of friction in the double-integrator system, affects the velocity and acceleration of the target and agents. The target information required by the tracking agents consists of position, velocity, and acceleration. We can obtain practical rendezvous results when agents utilize only target position and velocity information. If the acceleration data of the target is accessible, we can get the complete rendezvous result using an additional control term in the form of the Coriolis force. We provide mathematically rigorous proofs for these results and present numerical experiments that can be visually confirmed.

Secondary healing property using Neoveil®, a polyglycolic acid bioabsorbable sheet on the oral mucosal defects.

Neoveil® is a wound surface-covering agent composed of polyglycolic acid(PGA) effective for secondary healing. This study evaluated the secondary healing property of oral cavity mucosal defects using the PGA sheet. Thirty-four patients who underwent surgical excision of oral benign and malignant lesions, precancerous lesions, and tumors were evaluated. The PGA sheet was placed over the open wound to aid secondary healing. The defects were reviewed post-operatively for secondary healing, contracture, and secondary deformity. Male to female ratio was 20:14, and the mean age was 63.5 years. In all cases, the oral mucosal defect was present after the wide excision of the mucosal lesion. The PGA sheet was used as a surface covering agent which was found to be effective in secondary healing of the wound. Any side effects and adverse reactions which were caused by the PGA sheet was not evident. It can be used to avoid skin graft or free flap reconstruction or deformity from the direct closure in moderate size oral mucosal defect.

A deep learning model based on concatenation approach to predict the time to extract a mandibular third molar tooth.

BACKGROUND: Assessing the time required for tooth extraction is the most important factor to consider before surgeries. The purpose of this study was to create a practical predictive model for assessing the time to extract the mandibular third molar tooth using deep learning. The accuracy of the model was evaluated by comparing the extraction time predicted by deep learning with the actual time required for extraction. METHODS: A total of 724 panoramic X-ray images and clinical data were used for artificial intelligence (AI) prediction of extraction time. Clinical data such as age, sex, maximum mouth opening, body weight, height, the time from the start of incision to the start of suture, and surgeon's experience were recorded. Data augmentation and weight balancing were used to improve learning abilities of AI models. Extraction time predicted by the concatenated AI model was compared with the actual extraction time. RESULTS: The final combined model (CNN + MLP) model achieved an R value of 0.8315, an R-squared value of 0.6839, a p-value of less than 0.0001, and a mean absolute error (MAE) of 2.95 min with the test dataset. CONCLUSIONS: Our proposed model for predicting time to extract the mandibular third molar tooth performs well with a high accuracy in clinical practice.

Reconstruction of mandibular defects in osteoradionecrosis and medication-related osteonecrosis of the jaw using fibula free flap and management of postoperative wound infections.

BACKGROUND: Complications from osteoradionecrosis (ORN) and medication-related osteonecrosis of the jaw (MRONJ) include oro-cutaneous fistulas, necrotic bone exposure, soft-tissue defects, and pathologic fractures. The fibula free flap (FFF) is a common free flap method used to reconstruct the mandible in severe cases. Recently, we have used the FFF successfully for the reconstruction of ORN and MRONJ mandibular defects. We report this method as a recommended technique for the treatment of ORN and MRONJ and the management method of postoperative infections. METHODS: Four patients who were diagnosed with ORN of the mandible and 3 patients who were diagnosed with MRONJ of the mandible were included in the study. Among the 7 patients, 3 patients also had pathologic fractures. Partial mandibulectomy and FFF reconstruction were performed at the Department of Oral and Maxillofacial Surgery, Samsung Medical Center from April 2019 to March 2021. RESULTS: All 7 patients recovered following the reconstruction of the defect by FFF. Four patients experienced infections after surgery and pus cultures were performed. All were well healed without flap damage after changing the antibiotics by consultation with infectious medicine experts. CONCLUSION: FFF is a widely used method and can provide an extensive flap to reconstruct the mandible, especially those affected by ORN or MRONJ. If an infection occurs after surgery, appropriate antibiotic changes should be made through cooperation with the infectious medicine department. Therefore, FFF is a well-established and recommended method even in cases of challenging reconstruction.

Clinical validation of the 3-dimensional double-echo steady-state with water excitation sequence of MR neurography for preoperative facial and lingual nerve identification.

Purpose: This study aimed to evaluate the clinical usefulness of magnetic resonance (MR) neurography using the 3-dimensional double-echo steady-state with water excitation (3D-DESS-WE) sequence for the preoperative delineation of the facial and lingual nerves. Materials and Methods: Patients underwent MR neurography for a tumor in the parotid gland area or lingual neuropathy from January 2020 to December 2021 were reviewed. Preoperative MR neurography using the 3D-DESS-WE sequence was evaluated. The visibility of the facial nerve and lingual nerve was scored on a 5-point scale, with poor visibility as 1 point and excellent as 5 points. The facial nerve course relative to the tumor was identified as superficial, deep, or encased. This was compared to the actual nerve course identified during surgery. The operative findings in lingual nerve surgery were also described. Results: Ten patients with parotid tumors and 3 patients with lingual neuropathy were included. Among 10 parotid tumor patients, 8 were diagnosed with benign tumors and 2 with malignant tumors. The median facial nerve visibility score was 4.5 points. The distribution of scores was as follows: 5 points in 5 cases, 4 points in 1 case, 3 points in 2 cases, and 2 points in 2 cases. The lingual nerve continuity score in the affected area was lower than in the unaffected area in all 3 patients. The average visibility score of the lingual nerve was 2.67 on the affected side and 4 on the unaffected side. Conclusion: This study confirmed that the preoperative localization of the facial and lingual nerves using MR neurography with the 3D-DESS-WE sequence was feasible and contributed to surgical planning for the parotid area and lingual nerve.

An anesthetic management of head and neck cancer reconstructive surgery in a patient having hemophilia A: a case report.

Hemophilia A is a hemorrhagic disease caused by coagulation factor VIII deficiency. In head and neck cancer surgery, especially during a reconstructive one, complications can occur. These include hematomas due to bleeding which can then lead to flap ischemia, necrosis, and impaired wound healing. There are fewer cases of reconstructive surgery in patients with hemophilia A. Here in we report, a reconstructive surgery that involved mass resection, partial glossectomy (right), selective neck dissection (right, Levels I, II, III, IV), and reconstruction at the lateral arm free flap (left) in a 25-year-old man with hemophilia A. The surgery was successfully performed without any complications after pretreatment with Factor VIII concentrate, which has not been reported earlier.

Interference-Aware Adaptive Beam Alignment for Hyper-Dense IEEE 802.11ax Internet-of-Things Networks.

The increasing use of Internet of Things (IoT) devices in specific areas results in an interference among them and the quality of communications can be severely degraded. To deal with this interference issue, the IEEE 802.11ax standard has been established in hyper-dense wireless networking systems. The 802.11ax adopts a new candidate technology that is called multiple network allocation vector in order to mitigate the interference problem. In this paper, we point out a potential problem in multiple network allocation vector which can cause delays to communication among IoT devices in hyper-dense wireless networks. Furthermore, this paper introduces an adaptive beam alignment algorithm for interference resolution, and analyzes the potential delays of communications among IoT devices under interference conditions. Finally, we simulate our proposed algorithm in densely deployed environments and show that the interference can be mitigated and the IEEE 802.11ax-based IoT devices can utilize air interface more fairly compared to conventional IEEE 802.11 distributed coordination function.

Dispersal towards food: the singular limit of an Allen-Cahn equation.

The effect of dispersal under heterogeneous environment is studied in terms of the singular limit of an Allen-Cahn equation. Since biological organisms often slow down their dispersal if food is abundant, a food metric diffusion is taken to include such a phenomenon. The migration effect of the problem is approximated by a mean curvature flow after taking the singular limit which now includes an advection term produced by the spatial heterogeneity of food distribution. It is shown that the interface moves towards a local maximum of the food distribution. In other words, the dispersal taken in the paper is not a trivialization process anymore, but an aggregation one towards food.

Enterovirus inhibitory activity of C-8-tert-butyl substituted 4-aryl-6,7,8,9-tetrahydrobenzo[4,5]thieno[3,2-e][1,2,4]triazolo[4,3-a]pyrimidin-5(4H)-ones.

Members of a series of 4-aryl-6,7,8,9-tetrahydrobenzo[4,5]thieno[3,2-e][1,2,4]triazolo[4,3-a]pyrimidin-5(4H)-ones (1, Fig. 2) were prepared and tested against representative enteroviruses including Human Coxsackievirus B1 (Cox B1), Human Coxsackievirus B3 (Cox B3), human Poliovirus 3 (PV3), human Rhinovirus 14 (HRV14), human Rhinovirus 21 (HRV 21) and human Rhinovirus 71 (HRV 71). The C-8-tert-butyl group on the tetrahydrobenzene ring in these substances was found to be crucial for their enterovirus activity. One member of this group, 1e, showed single digit micromolar activities (1.6-8.85µM) against a spectrum of viruses screened, and the highest selectivity index (SI) values for Cox B1 (>11.2), for Cox B3 (>11.5), and for PV3 (>51.2), respectively. In contrast, 1p, was the most active analog against the selected HRVs (1.8-2.6µM), and showed the highest selectivity indices among the group of compounds tested. The SI values for 1p were 11.5 for HRV14, 8.4 for HRV21, and 12.1 for HRV71, respectively.

Immediate implant placement for schizophrenic patient with outpatient general anesthesia.

The difficult oral healthcare in intellectually disabled patients with poor behavioral control has led to debate over the cost-effectiveness and validity of implant treatment in these patients. The patient in the present report had schizophrenia that had led to poor oral care and severe dental caries in the full mouth. Tooth extraction and a removable prosthesis were planned, but the guardian wanted an implant procedure. Since the guardian showed strong will and cooperation with regard to the patient's oral healthcare, extraction followed by immediate implant placement was performed across two rounds of general anesthesia. Since the outcome appears successful, we present this case report. Immediate implant placement after tooth extraction requires fewer surgeries and rounds of general anesthesia, reduces horizontal bone resorption, and can achieve better esthetic results. Therefore, as long as a certain degree of oral care is possible, this can be a positive option for restoration of a partially edentulous mouth, even in intellectually disabled patients.