Characterization and catalytic performance of modified nano-scale ZSM-5 for the acetone-to-olefins reaction

In the acetone to olefins (ATO) reaction using ZSM-5 zeolites, isobutylene is initially produced via decomposition of an acetone dimer, followed by dimerization of the isobutylene and its cracking to form ethylene and propylene. Nano-scale ZSM-5 zeolite exhibited stable activity during the ATO reaction compared with that of macro-scale ZSM-5.1n order to further improve the catalytic stability of the nano-scale ZSM-5, control of the acidity of nano-scale ZSM-5 zeolites through SiO2 unit formation was examined using phenyl silane and triphenyl silane as new deactivators. This modification led to an increase in the olefins yield and an improvement in the catalyst lifetime. In particular, the regioselective deactivation of acid sites located on the external surface of the zeolite inhibits the formation of aromatics. Moreover, the acidity control within the pores significantly improved the catalyst lifetime. Notably, the modified nano-scale ZSM-5 zeolite exhibited a stable olefins yield above 55C-mol% for 180h

Pulmonary capillary hemangiomatosis-predominant vasculopathy in a patient with rheumatoid arthritis-associated interstitial lung disease : An autopsy report

Pulmonary capillary hemangiomatosis (PCH) is a rare cause of pulmonary hypertension (PH) associated with poor prognosis. Clinically, it is characterized by severe hypoxemia, centrilobular ground-glass opacities on computed tomography, and pulmonary congestion triggered by pulmonary vasodilating therapy. In some cases, PCH has been reported to develop with other disorders including connective tissue disease; however, to date, no reports have described PCH in a patient with rheumatoid arthritis. We report a case of a 59-year-old male PCH patient with rheumatoid arthritis and associated pulmonary fibrosis. He was initially diagnosed with severe group 3 PH and received sildenafil, which generated a favorable hemodynamic response. However, 5 years later, his pulmonary hemodynamics deteriorated, and he died at the age of 67. An autopsy was performed, and thickening of alveolar septa and capillary proliferation, pathological features of PCH, were extensively observed in both lungs. We discuss when PCH developed, how sildenafil improved his hemodynamics, and how PCH could be clinically detected by noninvasive evaluations