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991.
992.
Asif Jan Jisu Shin Junsung Ahn Sungeun Yang Kyung Joong Yoon Ji-Won Son Hyoungchul Kim Jong-Ho Lee Ho-Il Ji 《RSC advances》2019,9(46):27002
Low temperature CO oxidation reaction is known to be facilitated over platinum supported on a reducible cerium oxide. Pt species act as binding sites for reactant CO molecules, and oxygen vacancies on surface of cerium oxide atomically activate the reactant O2 molecules. However, the impacts of size of Pt species and concentration of oxygen vacancy at the surface of cerium oxide on the CO oxidation reaction have not been clearly distinguished, thereby various diverse approaches have been suggested to date. Here using the co-precipitation method we have prepared pure ceria support and infiltrated it with Pt solution to obtain 0.5 atomic% Pt supported on cerium oxide catalyst, and then systematically varied the size of Pt from single atom to ∼1.7 nm sized nanoparticles and oxygen vacancy concentration at surface of cerium oxide by controlling the heat-treatment conditions, which are temperature and oxygen partial pressure. It is found that Pt nanoparticles in range of 1–1.7 nm achieve 100% of CO oxidation reaction at ∼100 °C lower temperature compared to Pt single atom owing to the facile adsorption of CO but weaker binding strength between Pt and CO molecules, and the oxygen vacancy in the vicinity of Pt accelerates CO oxidation below 150 °C. Based on this understanding, we show that a simple hydrogen reduction at 550 °C for the single atom Pt supported on CeO2 catalyst induces the formation of highly dispersed Pt nanoparticles with size of 1.7 ± 0.2 nm and the higher concentration of surface oxygen vacancies simultaneously, enabling 100% conversion from CO to CO2 at 200 °C as well as 16% conversion even at 150 °C owing to the synergistic effects of Pt nanoparticles and oxygen vacancies.Understanding on effects of Pt size and oxygen vacancy at CeO2 surface in Pt/CeO2 catalyst for CO oxidation reaction enables to boost catalytic activity. 相似文献
993.
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996.
Jo Jae-Cheol Kim Seok Jin Lee Ho Sup Eom Hyeon-Seok Lee Soon Il Park Yong Lee Jeong-Ok Lee Yoojin Yhim Ho-Young Yang Deok-Hwan Byun Ja Min Kang Hye Jin Kim Hyo Jung Shin Ho-Jin Yoo Kwai Han Suh Cheolwon 《Annals of hematology》2020,99(2):223-228
Annals of Hematology - Limited-stage (Ann Arbor stage I or II) mantle cell lymphoma (MCL) is an extremely rare disease. Thus, there is little data on the clinical features and treatment outcomes of... 相似文献
997.
Cho Jae Ho Shin Cheol Min Han Kyung-Do Yoon Hyuk Park Young Soo Kim Nayoung Lee Dong Ho 《Journal of gastroenterology》2020,55(3):307-316
Journal of Gastroenterology - The relationship between overall obesity, as measured by body mass index (BMI) and risk of esophageal squamous cell carcinoma (ESCC) has been reported to show a... 相似文献
998.
Miey Park Han-Sung KimKyu Sung Shin Hyun Soo KimJi Young Park Wonkeun SongHyoun Chan Cho Kyu Man LeeJae-Seok Kim 《Vaccine》2014
Here, we examined the distribution of pneumococcal serotypes and the antibiotic susceptibility of Streptococcus pneumoniae in clinical blood isolates. The serotypes of 91 S. pneumoniae blood isolates, collected from January 2003 to March 2014, were identified by multiplex PCR and sequencing. The most common serotypes were 19F, 19A, 3, 4, and 14, accounting for 53.8% of the total. The serotype coverage rates of pneumococcal conjugated vaccine (PCV) 7, PCV10, and PCV13 were different during three test periods: 38.7%, 70.9%, and 93.5% in period I (2003–2005), 46.8%, 50.0%, and 75.0% in period II (2006–2008), and 28.5%, 32.1%, and 64.2% in period III (2009–2014), respectively. By contrast, the number of non-PCV13 serotypes increased from 6.4% in period I to 25% and 35.7% in periods II and III, respectively. The susceptibility of non-PCV13 serotypes to antimicrobial agents (penicillin, erythromycin, cefotaxime, and meropenem) was higher than that of PCV serotypes. In particular, non-PCV13 serotypes showed 100% and 95% susceptibility to penicillin and cefotaxime, respectively. Serotypes 19A and 19F showed high prevalence (79.1%) among 24 multi-drug resistant (MDR) isolates. Notably, all serotype 19A isolates were MDR. From January 2003 to March 2014, the proportion of non-PCV13 serotype pneumococci in blood isolates increased whereas the coverage rate of PCV13 decreased. Effective pneumococcal vaccines are required to protect against MDR serotype 19A isolates and the increasing number of non-PCV13 serotypes. 相似文献
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