A method to address beam cross coupling errors in phased array Doppler sonar.

Performance of Doppler sonar is degraded by beam cross coupling errors. This performance degradation presents itself as the loss of precision and bias of velocity estimates output by the system. A model is proposed here to reveal the physical essence of the beam cross coupling. Specifically, the model can analyze the effects of environmental conditions and vehicle attitude on the coupling bias. Based on this model, a phase assignment method is also proposed to reduce the beam cross coupling bias. The results obtained for various settings validate the efficacy of the proposed method.

Heterogeneous VLC/RF multi-hop cluster V2V channel allocation algorithm based on equivalent SINR.

To address low communication quality and limited transmission rate between vehicle nodes in the vehicularad hoc network (VANET), this paper builds a heterogeneous visible light communication (VLC) and radio frequency (RF) communication multi-hop communication model based on vehicle node clustering, and then a heterogeneous VLC/RF multi-hop cluster vehicle-to-vehicle (V2V) channel allocation algorithm based on equivalent signal to interference plus noise ratio (SINR) (NCAABES) is presented. This algorithm is based on the clustering of vehicle nodes, which introduces the concept of equivalent SINR. The equivalent SINR of the VLC channel between the cluster head (CH) and cluster member (CM) is used as the condition for channel allocation. When the channel between CH and CM is blocked or low quality, the neighboring vehicle between two vehicles is used as a relay node to communicate in a multi-hop way, and the channel with the best SINR is chosen as the current CH-CM or CM-CM communication method. The simulation results show that the SINR of NCAABES in this paper increases by 21.73%, 30.23%, and 70.96% compared to the novel multi-hop clustering scheme based on the weighted virtual distance detection (MCSVDD), the VLC network (VLCnet), and the RF network (RFnet), respectively. And the NCAABES's bit error rate (BER) is always the lowest compared to MCSVDD, VLCnet, and RFnet, even when the number of vehicles and transmission power change. This algorithm can improve the quality of communication between vehicle nodes, make VANET more efficient, and get a higher transmission rate.

Comparison of the histopathological characteristics of diffuse sclerosing osteomyelitis of the mandible, chronic suppurative osteomyelitis, and craniofacial fibrous dysplasia.

BACKGROUND: There are relatively few reports on the histopathological characteristics of diffuse sclerosing osteomyelitis of the mandible (DSOM), which is difficult to distinguish from chronic suppurative osteomyelitis (CSO) and craniofacial fibrous dysplasia (CFD). This study aimed to summarize and compare the histopathological characteristics of DSOM, CFD, and CSO. MATERIALS AND METHODS: In this study, hematoxylin and eosin-stained sections of patients with DSOM, CSO, and CFD at the Peking University Hospital of Stomatology from 2015 to 2020 were retrieved. The histopathological characteristics were summarized, including new bone formation, inflammatory cell infiltration, bone trabecular morphology, osteoclasts, sequestrum, bacterial mass, and calcified spherules, similar to cementicles. The histopathological characteristics of DSOM, CSO, and CFD were compared, and the results were statistically analyzed. RESULTS: In total, 50, 13, and 10 patients with DSOM, CSO, and CFD were included in this study, respectively. In terms of new bone formation, both DSOM and CSO showed reactive bone formation (p = 1), whereas CFD mainly showed fiber osteogenesis (p < 0.001). The inflammatory cells of DSOM were mainly lymphocytes and plasma cells, whereas those of CSO were mainly lymphocytes and neutrophils (p < 0.001), and there was usually no inflammatory cell infiltration in the CFD specimens (p < 0.001). DSOM, CSO, and CFD showed irregular bone trabeculae (p = 0.045, p = 0.703) and active osteoclasts (p1 = 0.189, p2 = 0.256). DSOM showed a small amount of bacterial mass but no sequestrum; neither of which was found in CFD (p = 1, p = 1), but it was common in CSO (p = 0.011 and p = 0.025). DSOM and CSO showed smooth and regular basophilic lines (p = 0.308), whereas CFD showed a rough and irregular basophilic line (p < 0.001). CONCLUSIONS: The histopathological characteristics of the three diseases were partly similar, but there were evident differences. The main differences are the type of new bone formation, types and distribution of inflammatory cells, and presence of sequestrum and bacterial masses. These differences will help clinicians diagnose DSOM.

GNAS mutation analysis assists in differentiating chronic diffuse sclerosing osteomyelitis from fibrous dysplasia in the jaw.

Chronic diffuse sclerosing osteomyelitis of the mandible (DSOM) and fibrous dysplasia (FD) are distinct lesions with overlapping clinicopathological features that complicate their diagnosis. This study aimed to evaluate the efficacy of GNAS mutation analysis in differentiating between these two conditions. DNA samples from patients with DSOM (n = 35) and FD (n = 29) were collected to analyze the presence of GNAS mutations in exons 8 and 9, the two previously reported hotspot regions, using polymerase chain reaction and direct sequencing. Twenty-four of 29 patients (83%) with FD showed missense mutations in codon 201 in exon 8, whereas no mutation was detected in exon 9. No mutations were found in any of the 35 cases with DSOM. We also identified one case with an uncertain diagnosis due to overlapping clinicopathological features of DSOM and FD. A Q227H mutation was detected in this case, that confirmed the diagnosis of FD. Taken together, the findings indicate that mutational analysis of the GNAS is a reliable approach to differentiate between DSOM and FD of the jaw.

Is Operative Management Effective for Non-Bacterial Diffuse Sclerosing Osteomyelitis of the Mandible?

PURPOSE: Operative management has been reported to show varying degrees of therapeutic effects for non-bacterial diffuse sclerosing osteomyelitis of the mandible (DSOM). The purpose of this study was to retrospectively analyze and summarize the operative outcomes for non-bacterial DSOM. METHODS: In this retrospective cohort study, patients with non-bacterial DSOM who received operative treatment were enrolled at the Peking University Hospital of Stomatology between 2012 and 2019. The primary predictor variables were the type of operative treatment and number of operations. The outcome variables were operative outcomes (symptom relief or ineffective) and time to recurrent symptoms after operations. Other study variables were demographics, including sex, age, and non-bacterial DSOM onset time. The χ2 test and Kaplan-Meier model were used to evaluate differences. RESULTS: The sample was composed of 72 patients with a mean age at onset of 26.1 ± 17.8 years and showed a female predilection. Decortication was performed for 68 patients with non-bacterial DSOM, and 4 patients underwent segmental mandibulectomy. Symptom relief was achieved in 37 (54.4%) patients after the first decortication, and the median time to symptom recurrence was 2.0 months. Furthermore, the longest time to symptom recurrence was not more than 6 months in all patients. Among the 4 patients who underwent segmental mandibulectomy, 2 who received fibula repair experienced recurrence of symptoms at 4 and 5 months after the operations, respectively, and their normal mandible and the transplanted fibula also presented with imaging manifestations of osteomyelitis. CONCLUSIONS: Decortication and segmental mandibulectomy were not effective for non-bacterial DSOM. This finding is consistent with the results of other reports, and this condition may be best managed non-operatively by rheumatologists.

Comparing Clinical and Radiographic Characteristics of Chronic Diffuse Sclerosing Osteomyelitis and Craniofacial Fibrous Dysplasia in the Mandible.

PURPOSE: Differential diagnosis of chronic diffuse sclerosing osteomyelitis of the mandible (DSOM) and craniofacial fibrous dysplasia (CFD) involving the mandible is challenging. The purpose of this study was to explore the differences of the clinical and radiographic characteristics between these 2 conditions. PATIENTS AND METHODS: In this retrospective cross-sectional, blinded, comparative study, clinical and imaging data of patients with DSOM and CFD at the Peking University Hospital of Stomatology from 2012 to 2018 were retrieved. Clinical characteristics, mainly pain, swelling, and trismus, and radiographic findings, including sclerosis, lysis, and subperiosteal bone formation, were evaluated. The t test, χ2 test, and Fisher-Freeman-Halton test were used to determine differences. RESULTS: Thirty-seven patients with DSOM and 32 patients with CFD were included (mean ages, 24.2 and 28.4 years, respectively); both groups showed a female predilection. DSOM (91.9%) and CFD (84.4%) were mainly unilateral. Patients with DSOM mainly presented with pain (94.6%), soft-tissue swelling (100.0%), and trismus (54.1%), whereas those with CFD did not experience pain (90.6%) and showed bone enlargement (87.5%) without trismus (6.3%). Panoramic radiographs and computed tomography scans of patients with DSOM showed subperiosteal bone formation, cortex lysis, and poorly demarcated cortex, whereas those patients with CFD mainly showed moderate-to-severe bone expansion, well-demarcated cortex, and tooth and mandibular canal displacement. CONCLUSIONS: These findings emphasize the importance of clinical and radiographic features in differentiating between DSOM and CFD. Pain, soft-tissue or bone-tissue swelling, subperiosteal bone formation, clarity of the boundary of the cortex and medulla, and continuity of the cortical bone are key points facilitating differentiation.

Application of pamidronate disodium for the treatment of diffuse sclerosing osteomyelitis of the mandible: A clinical study.

OBJECTIVE: This study aimed to assess the clinical effectiveness of using pamidronate disodium to treat patients with diffuse sclerosing osteomyelitis of the mandible (DSOM ). STUDY DESIGN: Patients with DSOM who were hospitalized in the Department of Oral and Maxillofacial Surgery, Peking University Hospital of Stomatology (Beijing, China), between March 2018 and March 2019 were included. All patients were treated with intravenous administration of pamidronate disodium for 3 days. Pain intensity, mouth opening, blood workup findings, imaging examination findings, and incidence of complications before and after treatment and during the follow-up period, were recorded and compared. RESULTS: Forty-three patients were treated with pamidronate disodium. Adverse reactions, including fever, hypocalcemia, hypokalemia, and diarrhea, were observed during treatment. Fourteen patients had moderate to severe pain before treatment, and the pain was markedly alleviated after days 2 and 3 of treatment. Pain and swelling were found to have disappeared at the 6-month follow-up in 39 patients (90.7%). Mean mouth opening increased from 28.5 mm to 38.1 mm. Imaging examinations showed that the bone mass in the affected area had markedly improved in 32 patients (74.4%). CONCLUSIONS: Pamidronate disodium alleviated pain and swelling and improved mouth opening in patients with DSOM. Follow-up after 6 to 18 months demonstrated stable treatment effectiveness.

L-Lysine-grafted graphene oxide as an effective adsorbent for the removal of methylene blue and metal ions.

In this paper, novel L-lysine-modified graphene oxide (Lys-GO) was synthesized through amidation. The morphological and structural properties of Lys-GO were characterized using infrared spectrometry, scanning electronic microscopy and X-ray photoelectron spectroscopy. The as-prepared Lys-GO material was systematically investigated in a series of batch adsorption experiments for the removal of methylene blue (MB) and copper ions (Cu2+) from wastewater. These results showed that Lys-GO is a bifunctional adsorbent for the removal of dyes and metal ions, and excellent adsorption efficiency was obtained. The maximum adsorption capacities for MB dye and Cu2+ were 1679.1 mg/g and 186.9 mg/g at 35 °C, respectively. The kinetics of adsorption followed well the linear pseudo-second-kinetic model. The isotherm results indicated that MB adsorption can be described with the Langmuir isotherm model, while the adsorption of Cu2+ can be described with the Freundlich model. The excellent adsorption capacity indicated that the Lys-GO may be a promising adsorption material for the removal of environmental pollutants.