Preparation, Properties and Cytotoxicity Assessment of Nanosized Pt-Rh Composite Catalyst for the Decomposition of Gaseous Ammonia

2010 ◽  
Vol 160-162 ◽  
pp. 1285-1290
Author(s):  
Chang Mao Hung

The behavior of the ammonia (NH3) oxidation was by selective catalytic oxidation (SCO) over a nanosized Pt-Rh composite catalyst in a tubular fixed-bed flow quartz reactor (TFBR) at temperatures between 423 and 673 K. The catalysts surface properties were characterized using UV-Vis and TEM. The experimental results show high activities for NH3 removal was achieved during catalytic oxidation over the Pt-Rh catalyst at 673 K with an oxygen content of 4%. N2 was the main product in the NH3-SCO process over the nanosized Pt-Rh composite catalyst. These results also verify that the Pt-Rh metals on catalyst surfaces, resulting in the formation of the remarkable catalytically active sites at the metal-support interface in the reduction of NH3 in this process. In addition, the nanosized Pt-Rh composite-induced cytotoxicity testing was mainly applied to the human lung MRC-5 cell line and the percentage of cell survival was determined by MTS analysis in vitro. For nanosized Pt-Rh composite, only minor cytotoxicity was observed when human lung cells were exposed.

2011 ◽  
Vol 214 ◽  
pp. 21-25 ◽  
Author(s):  
Chang Mao Hung

The behavior of the ammonia (NH3) oxidation was by selective catalytic oxidation (SCO) over a honeycomb supported Pt-Pd-Rh composite catalyst in a tubular fixed-bed flow quartz reactor (TFBR) at 673 K. A honeycomb Pt-Pd-Rh composite catalyst was prepared by incipient wetness impregnation with aqueous solutions of H2PtCl6, Pd(NO3)3 and Rh(NO3)3 that were coated on cordierite cellular ceramic materials. The catalysts surface properties were characterized using OM. The experimental results show that contaminants crystal aggregation phases and washcoat loss from high initial concentration of NH3 may be responsible for the deactivation of the catalysts. In addition, the catalytic redox behavior was determined by cyclic voltammetric (CV), which showed that the catalytic behavior is related to the metal oxide properties of the catalyst.


Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 750
Author(s):  
Werner E. G. Müller ◽  
Meik Neufurth ◽  
Shunfeng Wang ◽  
Heinz C. Schröder ◽  
Xiaohong Wang

The anti-cancer antitumor antibiotic bleomycin(s) (BLM) induces athyminic sites in DNA after its activation, a process that results in strand splitting. Here, using A549 human lung cells or BEAS-2B cells lunc cells, we show that the cell toxicity of BLM can be suppressed by addition of inorganic polyphosphate (polyP), a physiological polymer that accumulates and is released from platelets. BLM at a concentration of 20 µg ml−1 causes a decrease in cell viability (by ~70%), accompanied by an increased DNA damage and chromatin expansion (by amazingly 6-fold). Importantly, the BLM-caused effects on cell growth and DNA integrity are substantially suppressed by polyP. In parallel, the enlargement of the nuclei/chromatin in BLM-treated cells (diameter, 20–25 µm) is normalized to ~12 µm after co-incubation of the cells with BLM and polyP. A sequential application of the drugs (BLM for 3 days, followed by an exposure to polyP) does not cause this normalization. During co-incubation of BLM with polyP the gene for the BLM hydrolase is upregulated. It is concluded that by upregulating this enzyme polyP prevents the toxic side effects of BLM. These data might also contribute to an application of BLM in COVID-19 patients, since polyP inhibits binding of SARS-CoV-2 to cellular ACE2.


1989 ◽  
pp. 103-117
Author(s):  
C. C. Harris ◽  
J. C. Willey ◽  
N. Matsukura ◽  
J. F. Lechner ◽  
M. Miyashita ◽  
...  

2017 ◽  
Vol 280 ◽  
pp. S212
Author(s):  
Hang Nguyen ◽  
Kenneth Sexton ◽  
Lisa Smeester ◽  
Kjersti Marie Aagaard ◽  
Cynthia Do Shope ◽  
...  

2006 ◽  
Vol 291 (5) ◽  
pp. L887-L895 ◽  
Author(s):  
Xiaopeng Li ◽  
Maria Molina-Molina ◽  
Amal Abdul-Hafez ◽  
Jose Ramirez ◽  
Anna Serrano-Mollar ◽  
...  

Previous work from this laboratory demonstrated de novo synthesis of angiotensin (ANG) peptides by apoptotic pulmonary alveolar epithelial cells (AEC) and by lung myofibroblasts in vitro and in bleomycin-treated rats. To determine whether these same cell types also synthesize ANG peptides de novo within the fibrotic human lung in situ, we subjected paraffin sections of normal and fibrotic (idiopathic pulmonary fibrosis, IPF) human lung to immunohistochemistry (IHC) and in situ hybridization to detect ANG peptides and angiotensinogen (AGT) mRNA. These were analyzed both alone and in combination with cell-specific markers of AEC [monoclonal antibody (MAb) MNF-116] and myofibroblasts [α-smooth muscle actin (α-SMA) MAb] and an in situ DNA end labeling (ISEL) method to detect apoptosis. In normal human lung, IHC detected AGT protein in smooth muscle underlying normal bronchi and vessels, but not elsewhere. Real-time RT-PCR and Western blotting revealed that AGT mRNA and protein were 21-fold and 3.6-fold more abundant, respectively, in IPF lung biopsies relative to biopsies of normal human lung (both P < 0.05). In IPF lung, both AGT protein and mRNA were detected in AEC that double-labeled with MAb MNF-116 and with ISEL, suggesting AGT expression by apoptotic epithelia in situ. AGT protein and mRNA also colocalized to myofibroblast foci detected by α-SMA MAb, but AGT mRNA was not detected in smooth muscle. These data are consistent with earlier data from isolated human lung cells in vitro and bleomycin-induced rat lung fibrosis models, and they suggest that apoptotic AEC and myofibroblasts constitute key sources of locally derived ANG peptides in the IPF lung.


CHEST Journal ◽  
1983 ◽  
Vol 83 (5) ◽  
pp. 81S-82 ◽  
Author(s):  
A. G. Leitch ◽  
R. A. Lewis ◽  
E. J. Corey ◽  
K. F. Austen

RSC Advances ◽  
2020 ◽  
Vol 10 (72) ◽  
pp. 43950-43959
Author(s):  
Ozge Kose ◽  
Marion Stalet ◽  
Lara Leclerc ◽  
Valérie Forest

Characterization of the formation of the protein corona of TiO2 nanoparticles as a function of the main nanoparticle properties and investigation of potential relationship with the cytotoxicity nanoparticles induce in vitro in human lung cells.


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