Application of high-frequency ultrasound in the diagnosis of gastrointestinal magnet ingestion in children.

Background: The incidence of magnet ingestion by children has recently increased in China. Magnet ingestion is associated with an extremely high risk of gastrointestinal damage because loops of bowel can become trapped and squeezed between multiple magnets in different locations. However, the lack of imaging sensitivity makes clinical decision-making difficult. Objective: This study was conducted to investigate the performance of ultrasound in diagnosing gastrointestinal magnet ingestion in children. Methods: From April 2017 to February 2021, all children with a history of magnet ingestion or a diagnosis of gastrointestinal magnet as shown by x-ray or ultrasound in our hospital were included as study candidates. Patients who were lost to follow-up or had known malformations of the gastrointestinal tract were excluded. Eligible patients were those with surgical or endoscopic confirmation of gastrointestinal magnet, those who passed the magnet out of the alimentary tract without assistance, and those with confirmed absence of the magnet on abdominal x-ray examination after 1 month of conservative treatment. All eligible patients' ultrasound and x-ray examination data were evaluated. The sensitivity, specificity, and area under the curve (AUC) of ultrasound was calculated for diagnosing magnet ingestion, locating the magnet (stomach, small intestine, or colon), and confirming the phenomenon of wall entrapment. Results: Of 112 patients, 107 had a magnetic foreign body and 5 did not. Magnets were correctly detected by ultrasound in 97 patients, with an observed sensitivity of 90.65% and specificity of 100%. Satisfactory sensitivity was obtained for ultrasound localization of gastric magnets (96.30%) and small intestinal magnets (100.00%), but sensitivity for ultrasound localization of colonic magnets was relatively poor (73.33%). The discrimination of wall entrapment by ultrasound was good (AUC = 0.93), with an observed sensitivity and specificity of 92.00% and 93.62%, respectively. Conclusions: Ultrasound can be used to locate gastrointestinal magnets (in the stomach, small intestine, or colon) with good clinical efficacy in identifying wall entrapment.

[Spectral analysis of some brass coins excavsted from Ezhou of Hubei province].

XRD and XRF were used to identify several brass coins of Qing dynasty collected in the Ezhou Museum and excavated from Ezhou of Hubei province. The reality of the coins contains 36.53%-37.75% of Zn, 54.12%-59.04% of Cu and 3.51%-7.56% of Pb, and the ration of the alloy is steady and scientific, indicating that the technic of the alloy of brass was quite perfect in the mid to late of Qing dynasty. Zn3Cu2 (OH)6 (CO3)2 was found in the corrosion for the first time, and CuO, ZnO, Fe2O3 and CuCl were found too. The high content of Cl-, around the local condition (including the polluted environment), may be the main reason for those brass coins to be eroded seriously. These findings provide some reference for collecting and protecting coins.

Unexpected solvent-free cycloadditions of 1,3-cyclohexanediones to 1-(pyridin-2-yl)-enones mediated by manganese(III) acetate in a ball mill.

Under solvent-free ball-milling conditions, manganese(III) acetate dihydrate-mediated cycloadditions of 5,5-dimethyl-1,3-cyclohexanedione and 1,3-cyclohexanedione to various 1-(pyridin-2-yl)-enones proceeded efficiently to afford trans-2-acyl-3-aryl/alkyl-2,3,6,7-tetrahydro-4(5H)-benzofuranone derivatives. The cyclization reactions exhibited good to excellent yields, as well as extremely high diastereoselectivity and unexpected regioselectivity. Manganese(III) acetate behaved both as an oxidant and as a Lewis acid.

Solid-state radical reactions of 1,3-cyclohexanediones with in situ generated imines mediated by manganese(III) acetate under mechanical milling conditions.

Under solid-state conditions, manganese(iii) acetate-mediated radical reactions of 1,3-cyclohexanedione and 5,5-dimethyl-1,3-cyclohexanedione with in situ generated imines proceeded efficiently by mechanical milling at room temperature and good to excellent yields were achieved.