Synthesis of lignin nanoparticle­manganese dioxide complex and its adsorption of methyl orange.

Lignin nanoparticles (LNPs) were synthesized using an anti-solvent method and subsequently loaded with manganese dioxide (MnO2) via potassium permanganate treatment, resulting in the formation of MnO2@LNPs. An extensive investigation was conducted to elucidate the influence of MnO2@LNPs on the decolorization of methyl orange solution. The LNPs were successfully obtained by adjusting the preparation parameters, yielding particles exhibited average sizes ranging from 300 to 600 nm, and the synthesis process exhibited a high yield of up to 87.3% and excellent dispersion characteristics. Notably, LNPs size was reduced by decreasing initial concentration, increasing stirring rate, and adding water. In the acetone-water two-phase system, LNPs self-assembled into spherical particles driven by π-π interactions and hydrogen bond forces. Oxidation modification using potassium permanganate led to the formation of nanoscale MnO2, which effectively combined with LNPs. Remarkably, the resulting MnO2@LNPs demonstrated a two-fold increase in methyl orange adsorption capacity (227 mg/g) compared to unmodified LNPs. The process followed the Langmuir isotherm model and was exothermic.

Primary small cell neuroendocrine carcinoma of the oral cavity: A case report and review of the literature.

Small cell neuroendocrine carcinoma (SNEC) of the oral cavity is a rare and distinctive tumor with aggressive clinical behavior. Thus far, only a small number of cases have been reported and no definitive standard treatment strategy has been determined. The current study reports a case of oral SNEC arising in the lower gingiva in a 73-year-old male. Computed tomography displayed a relatively well-defined mass measuring 2.8×2×1.4 cm in size. The mass was located in the buccal side of the right mandibular posterior gingiva and exhibited no bony involvement. Histopathological examination revealed a proliferation of small cells with ovoid- to spindle-shaped nuclei, fine granular chromatin, inconspicuous nucleoli, scant cytoplasm and high mitotic activity. Immunohistochemically, the tumor cells were positive for cytokeratin AE1/AE3, chromogranin A, synaptophysin and neuron-specific enolase. Surgical resection and radical neck dissection were performed prior to the administration of adjuvant chemotherapy with a combination of cisplatin and etoposide. No evidence of local recurrence or metastasis was observed at 14 months post-surgery.