Tunable Contacts of Bi2 O2 Se Nanosheets MSM Photodetectors by Metal-Assisted Transfer Approach for Self-Powered Near-Infrared Photodetection.

Owing to the Fermi pinning effect arose in the metal electrodes deposition process, metal-semiconductor contact is always independent on the work function, which challenges the next-generation optoelectronic devices. In this work, a metal-assisted transfer approach is developed to transfer Bi2 O2 Se nanosheets onto the pre-deposited metal electrodes, benefiting to the tunable metal-semiconductor contact. The success in Bi2 O2 Se nanosheets transfer is contributed to the stronger van der Waals adhesion of metal electrodes than that of growth substrates. With the pre-deposited asymmetric electrodes, the self-powered near-infrared photodetectors are realized, demonstrating low dark current of 0.04 pA, high Ilight /Idark ratio of 380, fast rise and decay times of 4 and 6 ms, respectively, under the illumination of 1310 nm laser. By pre-depositing the metal electrodes on polyimide and glass, high-performance flexible and omnidirectional self-powered near-infrared photodetectors are achieved successfully. This study opens up new opportunities for low-dimensional semiconductors in next-generation high-performance optoelectronic devices.

Time trends and endoscopic management of foreign body ingestion in the upper GI tract: a retrospective analysis of 1152 cases in China

Objectives: foreign body ingestions are encountered in the clinical practice and sometimes require endoscopic management. However, time trends and epidemiology of these cases have not been fully clarified. Whether seasons and festivals have an effect on the occurrence has been poorly described. Method: from 2009 to 2020, 1,152 consecutive foreign body ingestion cases were enrolled in our endoscopic center. Case records were reviewed for demographic data, foreign body type and location, outpatient or hospitalization, adverse events and dates. Annual time trends and seasonal variation were analyzed as well as the influence of Chinese legal festivals on the incidence. The impact of SARS-CoV-2 pandemic on the potential delay for clinical consultation of these cases was preliminarily explored. Clinical features of these cases were demonstrated. Results: the overall success rate was 99.7 % and the adverse events rate was 2.4 %. There was an uptrend in the annual frequency of food foreign body ingestion endoscopic extraction from 0.65 in 2009 to 8.86 in 2020 per 1,000 esophagogastroduodenoscopy patients (r = 0.902, p < 0.001). Furthermore, the frequency of endoscopic extraction significantly increased in winter (p < 0.001) and during Chinese New Year celebratory season (p = 0.003). The duration of hospitalization may be longer in the pandemic period (p = 0.0049). Conclusion: considering the uptrend of the annual frequency of food related foreign body endoscopic extraction, the publicity about the danger of foreign body ingestion should be enhanced. Arrangement of endoscopic physicians and assistants during the high-incidence season should be emphasized. (AU)

Time trends and endoscopic management of foreign body ingestion in the upper GI tract: a retrospective analysis of 1,152 cases in China.

OBJECTIVES: foreign body ingestions are encountered in the clinical practice and sometimes require endoscopic management. However, time trends and epidemiology of these cases have not been fully clarified. Whether seasons and festivals have an effect on the occurrence has been poorly described. METHOD: from 2009 to 2020, 1,152 consecutive foreign body ingestion cases were enrolled in our endoscopic center. Case records were reviewed for demographic data, foreign body type and location, outpatient or hospitalization, adverse events and dates. Annual time trends and seasonal variation were analyzed as well as the influence of Chinese legal festivals on the incidence. The impact of SARS-CoV-2 pandemic on the potential delay for clinical consultation of these cases was preliminarily explored. Clinical features of these cases were demonstrated. RESULTS: the overall success rate was 99.7 % and the adverse events rate was 2.4 %. There was an uptrend in the annual frequency of food foreign body ingestion endoscopic extraction from 0.65 in 2009 to 8.86 in 2020 per 1,000 esophagogastroduodenoscopy patients (r = 0.902, p < 0.001). Furthermore, the frequency of endoscopic extraction significantly increased in winter (p < 0.001) and during Chinese New Year celebratory season (p = 0.003). The duration of hospitalization may be longer in the pandemic period (p = 0.0049). CONCLUSION: considering the uptrend of the annual frequency of food related foreign body endoscopic extraction, the publicity about the danger of foreign body ingestion should be enhanced. Arrangement of endoscopic physicians and assistants during the high-incidence season should be emphasized.