A Case of Squamous Metaplasia of the Stomach

Fx1 Highlights: • Thin alumina barrier coating can enhance photo-activity of bismuth vanadate photoanode materials • There are two distinct potential domains with different enhancement characteristics and mechanisms • The thickness of alumina films can be controlled with a sol-gel coating to provide optimized performance Abstract Nanostructured semiconductor photoanodes play an important role in solar fuel generation, and the design of the semiconductor -aqueous electrolyte interface can be crucial in enhancing the energy conversion efficiency. We have investigated the effects on photoelectrochemical oxygen evolution for monoclinic nanostructured BiVO4 films uncoated and coated with microporous sol-gel Al2O3 "over-layers". Variation of the thickness of the Al2O3 coating (formed by surface sol-gel deposition and annealing at 435 o C) led to a reduction of pseudo-capacitance and allowed optimization of the quantum efficiency. Exploration of the photocurrent enhancement as a function of applied potential reveals two distinct potential domains/mechanisms: (i) a low bias region enhancement effect (assigned to a lowering of the rate of external recombination of electrons with oxygen) and (ii) a high bias region of enhancement (assigned to higher charge carrier mobility due to less trapping in surface states).

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“…Photocurrents have been optimised to reach 2.4 mA cm -2 at 1.23 V vs. RHE and under one sun (AM1.5 or ca. 100 mWcm -2 ) illumination [37].…”

Section: Introductionmentioning

confidence: 99%

Enhancing activity in a nanostructured BiVO4 photoanode with a coating of microporous Al2O3

Gromboni

Coelho

Mascaro

et al. 2017

Applied Catalysis B: Environmental

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“…10 Squamous metaplasia has been described in healing gastric ulcers and a variety of conditions associated with long-standing chronic inflammation. 11 An island of squamous epithelium has been known to occur near the cardia. 4 The pathogenesis of gastric squamous papilloma is deduced from esophageal squamous papilloma.…”

Section: Discussionmentioning

confidence: 99%

Gastric Squamous Papilloma in a 52-Year-Old Female Patient

Jang

Kim

et al. 2014

Clin Endosc

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A papilloma is a benign epithelial lesion characterized by finger-like projections of tissue lined by an overgrowth of squamous cells and a core of connective tissue. We report a case of squamous papilloma on the cardia in a 52-year-old asymptomatic female. Endoscopy showed a 1-cm sized is polyp with hyperemic change originating from the cardia adjacent to the esophagogastric junction, the biopsy of which suggested a diagnosis of squamous papilloma. Endoscopic mucosal resection was performed to obtain a definite diagnosis and the polyp was completely removed. The histological result was compatible with squamous papilloma, and its surrounding tissues showed foveolar epithelium, which suggested a stomach origin. This is the first report of endoscopic resection of a gastric squamous papilloma. Squamous papilloma should be considered in the differential diagnosis of a gastric polyp, especially one in the cardia. As the prognostic value of a squamous papilloma is not well known, we recommend endoscopic resection to treat a gastric squamous papilloma, when possible.

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“…SM is much rarer than the well-known chronic gastritis-associated intestinal metaplasia (IM) and pyloric metaplasia. 3,4 Its pathogenesis is not clear. It has been reported with IM, atrophic mucosa, chronic gastritis, and in normal gastric mucosa.…”

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confidence: 99%

“…4 The reported cases showed foveolar and surface epithelium replaced by nonkeratinizing stratified squamous epithelium covered by attenuated glandular epithelium. 3,4 Endoscopically, it appears as a gray-white to whitish mucosal lesion. 3,4…”

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confidence: 99%

“…Some authors suggest an origin from SM or ectopic squamous epithelium, while others propose that squamous tumor cells arise from stem cells in the IM of gastric mucosa. 3,5 Other authors suggest that ductal structures and squamous epithelia are inconstant, but not unusual observations in gastric mucosa. 6 We have observed foci of immature SM and ductal structures in 3 different types of gastric polyps (Figure 2).…”

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confidence: 99%

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Squamous Lesions of the Stomach

AbdullGaffar

Quraishi

2019

Int J Surg Pathol

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Squamous lesions of the stomach are rare and of controversial origin. They include squamous cell carcinoma (SCC) and squamous metaplasia (SM). Gastric SCC comprises 0.2% to 1.4% of gastric carcinomas. 1,2 Because its clinical, radiologic, and endoscopic features are nonspecific, diagnosis relies on microscopic examination of gastric biopsy. 1,2 It is a diagnosis of exclusion. Invasion from adjacent organs and metastasis from distant sites should be ruled out by endoscopy and radiology, which should demonstrate a primary gastric mass or ulcer. Histologically, absent malignant glandular elements, negative mucin stains, negative glandular immunomarkers such as CK7, CK20, MUC2, and MUC5A with positive squamous immunomarkers such as P63 and CK5/6 should rule out gastric adenosquamous carcinoma or poorly differentiated adenocarcinoma (Figure 1). SM is much rarer than the well-known chronic

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A Case of Squamous Metaplasia of the Stomach

Cited by 6 publications

References 7 publications

Enhancing activity in a nanostructured BiVO4 photoanode with a coating of microporous Al2O3

Enhancing activity in a nanostructured BiVO4 photoanode with a coating of microporous Al2O3

Gastric Squamous Papilloma in a 52-Year-Old Female Patient

Squamous Lesions of the Stomach

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