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Microbial manganese (Mn) oxidation plays a crucial role in shaping the fate of various elements, including arsenic (As). However, this process faces challenges in wastewater environments due to its inherent inefficiency and instability. In our initial research, a serendipitous discovery occurred: the addition of citrate to Fe(II)-containing wastewater stimulated the oxidation of Mn(II) by aerobic granular sludge (AGS). Subsequent experiments in four sequencing batch reactors (SBRs) over a 67-day period confirmed this stimulatory effect. The presence of Fe(II)-citrate led to a remarkable twofold increase in the oxidation of Mn(II) and As(III). The removal efficiency improved from 21±4 % to 87±7 % for Mn(II) and from 77.1 ± 1.8 % to 93.6 ± 0.2 % for As(III). The verification experiments demonstrated that the simultaneous addition of manganese-oxidizing bacteria (MnOB) and Fe(II)-citrate is an effective strategy for enhancing the oxidation and removal of Mn(II) and As(III) by AGS. Through a combination of genomic analysis, cell-free filtrate incubation, and bacterial batch cultivations (including monitoring the time-course changes of 17 substances and 2 free radicals), we elucidated a novel Mn(II) oxidation pathway in Pseudomonas, along with its stimulation method and mechanism. First, bacteria rapidly degrade citrate possibly via the citrate-Mg 2+ :H + symporter (CitMHS) and the tricarboxylic acid (TCA) cycle, resulting in the formation of colloidal Fe(II), colloidal Fe(III), and biogenic iron (hydr)oxides (FeOx). Then, colloidal Fe(II) and colloidal Fe(III) stimulated extracellular proteins to produce superoxide radicals (·O 2 ). These radicals were responsible for oxidizing Mn(II) into Mn(III), ultimately forming biogenic manganese oxides (MnOx). Finally, MnOx effectively oxidized As(III) to the less toxic As(V). This innovative approach for bacterial Mn(II) oxidation holds promise for treating Mn(II) and As(III) in water and wastewater. Furthermore, the mechanism by which colloidal iron stimulates extracellular proteins to produce ·O - ). These radicals were responsible for oxidizing Mn(II) into Mn(III), ultimately forming biogenic manganese oxides (MnOx). Finally, MnOx effectively oxidized As(III) to the less toxic As(V). This innovative approach for bacterial Mn(II) oxidation holds promise for treating Mn(II) and As(III) in water and wastewater. Furthermore, the mechanism by which colloidal iron stimulates extracellular proteins to produce ·O 2 - , thereby facilitating Mn(II) oxidation, may widely occur across various engineering and natural ecosystems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Basal cell carcinoma (BCC) is the most common keratinocyte carcinoma and the most prevalent skin cancer in humans, worldwide. BCC is histologically characterized by the proliferation of basaloid cells, arranged in globular masses of varying size, often separated from the surrounding stroma by optically empty spaces. Although attributed to tumor retraction during tissue processing for the preparation of pathology slides, these spaces are also seen on cryostat sections. The aim of this study is to in vivo characterize amyloid and mucin deposits in primary BCC lesions through RCM, followed by histopathological correlation. We included twenty-two consecutive subjects totaling thirty-one primary BCCs. Each lesion underwent the same evaluation protocol which included: clinical and dermoscopic images, RCM imaging, excisional biopsy under local anesthesia, and histopathological examination (colloidal iron and cytokeratin 34betaE12 stains). Hypo-reflective peritumoral clefts and hyper-reflective globules were measured on RCM images and compared to mucin and amyloid deposits seen on histology slides. The mean differences between RCM and histology measurements in both mucin and amyloid were not statistically significant. There were medium and strong correlations between RCM and histology regarding mucin and amyloid deposits, respectively.