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Osteoma is a benign neoplasm composed of mature bone and is limited almost exclusively to the craniofacial bones. Osteoma of the coronoid process is very rare. We encountered a 35-year-old woman who noticed right cheek pain when opening her mouth. She was referred to our hospital in August 2021 for the further evaluation and treatment of radio-opacity of the right mandibular coronoid process. She had no relevant medical history, family history, or history of oral parafunction. Initial extra- and intraoral clinical examinations revealed no definite swelling and no limitation of joint motion. However, the maximum unassisted mouth opening was 37 mm, and she experienced pain in the medial mandibular ramus at mouth opening. After this discomfort she had been pain-free for 15 years. Panoramic radiography revealed mushroom-shaped radiopacity on the right-side mandibular coronoid process which had increased in size compared to 15 years earlier. Computed tomography showed a bone-like lesion on the right mandibular coronoid process measuring 28 × 18 × 15 mm, with lesion-shaped right skull base bone resorption. The clinical diagnosis was a benign osseous neoplasm of the coronoid process (right side). The lesion was excised intraorally under general anesthesia; the pathological diagnosis was compact bone osteoma. The postoperative course was uneventful. The patient was then able to open her mouth to 40 mm and her right cheek pain at mouth-opening had disappeared. There has been no recurrence as of 2 years post-surgery. [ABSTRACT FROM AUTHOR]

Metastasis of renal cell carcinoma (RCC) to the oral cavity is rare and usually indicates late-stage disease and has poor prognosis. In this report, we describe a case of metastatic RCC of the maxilla. The patient was an 81-year-old man who presented with swelling in the right maxillary gingiva, which interfered with the fit of his dentures, causing difficulty in oral intake. A pathology report from an oral biopsy indicated RCC metastasis to the gingiva. We performed tumor excision for oral ingestion. Six months after the surgery, the patient died due to multiple organ failure caused by systemic metastasis. However, recurrence in the oral cavity was not recognized, and oral intake was possible until his death. [ABSTRACT FROM AUTHOR]

Abstract: The polymer electrolyte fuel cell (PEFC) cathode is a performance-limiting component due to the slower oxygen reduction kinetics and mass transport limitations imposed by water generated in an electrochemical reaction. This water assists the performance of the PEFC by preventing drying of the polymer electrolyte. Conversely, the water hinders the transport of the reactant species by blocking the pores in the gas diffusion layer. Moreover, the effective electrode area is decreased, causing the cathode channel to become clogged with supersaturated water from the gas diffusion layer. This problem is overcome by separating the gas channel and the waste channel, and installing a water absorption layer (WAL). The new “WAL type” gas channel has an installed WAL in which the designed waste channel is compared with the gas flow characteristics of a conventional cathode gas channel by using the visualization technique. Gas flowing into the WAL type separator is barely blocked before the WAL absorbs water condensed in the cathode gas channel. Therefore, the WAL type separator effectively improves the PEFC performance. [Copyright &y& Elsevier]