scholarly journals Multiwall Carbon Nanotube-Induced Apoptosis and Antioxidant Gene Expression in the Gills, Liver, and Intestine ofOryzias latipes

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Jin Wuk Lee ◽  
Young Chul Choi ◽  
Rosa Kim ◽  
Sung Kyu Lee
Keyword(s):  
Gene Expression ◽  
Multiwall Carbon Nanotubes ◽  
Gene Induction ◽  
Multiwall Carbon Nanotube ◽  
Antioxidant Gene ◽  
Significant Gene ◽  
Antioxidant Gene Expression ◽  
And Gender ◽  
Induced Apoptosis ◽  
Multiwall Carbon

Multiwall carbon nanotubes (MWCNTs) have many attractive properties with potential applications in various fields. Despite their usefulness, however, the associated waste can be hazardous to the environment. To examine adverse effects in aquatic environments,Oryzias latipeswere exposed to MWCNTs dispersed in water for 14 days and apoptosis and antioxidant gene expression were observed. This work showed that in gills exposed to 100 mg/L MWCNTs for 4 days, there was significantp53,caspase-3 (Cas3),caspase-8 (Cas8), andcaspase-9 (Cas9)gene expression relative to the controls, whilecatalase (CAT)andglutathione-S-transferase (GST)expression were reduced. At 14 days,CAT,GST, andmetallothionein (MT)were induced significantly in the gills andCas3,Cas8, andCas9were induced in the liver. No significant gene induction was seen in intestine. Intracellular reactive oxygen species (ROS) were increased significantly only at 14 days. Histologically, no apoptosis was observed with exposure to 100 mg/L MWCNTs for 21 days. The gills were more sensitive to MWCNT toxicity than the other organs. Males had higher apoptosis gene induction than females. These results demonstrated that MWCNTs could cause apoptosis in a manner influenced by tissue and gender in aqueous environments.

Plain para-aramid/phenolic multiwall carbon nanotubes prepreg/multistiched preform composites: Experimental characterization of mode-I toughness

2018 ◽  
Vol 53 (13) ◽  
pp. 1847-1864 ◽  
Author(s):  
K Bilisik ◽  
E Sapanci
Keyword(s):  
Fracture Toughness ◽  
Multiwall Carbon Nanotubes ◽  
Beam Theory ◽  
Mode I ◽  
Multiwall Carbon Nanotube ◽  
Axial Filament ◽  
Pull Out ◽  
Fiber Bridging ◽  
Nanotube Composites ◽  
Multiwall Carbon

The fracture toughness (mode-I) properties of nanostitched para-aramid/phenolic multiwall carbon nanotube prepreg composites were investigated. The fracture toughness (GIC) of the stitching and nanostitched composites showed 42-fold and 41-fold (beam theory), 18-fold and 21-fold (modified beam theory) increase compared to the control, respectively. The prepreg para-aramid stitching yarn and nanostitched yarn were dominant parameters. The toughness resistance to arrest crack growth in the nanostitched composite was primarily due to nanostitching fiber bridging and pull-out, and was secondarily due to nanotubes and biaxial fiber bridging and pull-out. The failed surfaces of the nanostitched and stitching composites had tensile filament failures in the aramid stitching fibers where filament/matrix/nanotube debonding and axial filament fibrillar splitting were found. The results indicated that stitching yarn and the nanotubes arrested the crack propagation. Therefore, the nanostitched and stitched para-aramid/phenolic composites displayed a better damage resistance performance compared to those of the control or nanotube composites.

Electroless Coating of Silver on Multiwall Carbon Nanotubes

2012 ◽  
Vol 710 ◽  
pp. 774-779
Author(s):  
Niraj Nayan ◽  
S.V.S. Narayana Murty ◽  
S.C. Sharma ◽  
K. Sreekumar ◽  
Parameshwar Prasad Sinha
Keyword(s):  
Carbon Nanotubes ◽  
Surface Modification ◽  
Multiwall Carbon Nanotubes ◽  
Activation Process ◽  
Multiwall Carbon Nanotube ◽  
Effective Utilization ◽  
Electroless Coating ◽  
Silver Matrix ◽  
Electrical Brush ◽  
Multiwall Carbon

Silver reinforced with carbon nanotubes, instead of graphite, would increase both the electrical conductivity, hardness and wear resistance of the electrical brush materials. The effective utilization of carbon nanotubes in the Ag/CNT composite depends strongly on its uniform distribution and strong interfacial adhesion to the silver matrix and thus demands for its surface modification. In order to carry out the surface modification of carbon nanotubes, electroless coating was given to them after liquid phase oxidation, sensitization and activation process. The room-temperature chemical treatment results in a nominally complete coating over the entire outer surface of multiwall carbon nanotube. The surface morphology of the carbon nanotubes after each step has been studied using TGA, DSC, XRD, FTIR and SEM.

Effect of silicon in Pyropia yezoensis under temperature and irradiance stresses through antioxidant gene expression

2018 ◽  
Vol 31 (2) ◽  
pp. 1297-1302 ◽  
Author(s):  
Bao Le ◽  
Mawra Nadeem ◽  
Seung-Hwan Yang ◽  
Jong-Am Shin ◽  
Man-Gu Kang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Pyropia Yezoensis ◽  
Antioxidant Gene ◽  
Antioxidant Gene Expression

scholarly journals Highly Deformable Porous Electromagnetic Wave Absorber Based on Ethylene–Propylene–Diene Monomer/Multiwall Carbon Nanotube Nanocomposites

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 858 ◽  
Author(s):  
Hasti Bizhani ◽  
Ali Asghar Katbab ◽  
Emil Lopez-Hernandez ◽  
Jose Miguel Miranda ◽  
Raquel Verdejo
Keyword(s):  
Electromagnetic Interference ◽  
Multiwall Carbon Nanotubes ◽  
Multiwall Carbon Nanotube ◽  
Ethylene Propylene Diene Monomer ◽  
Ethylene Propylene ◽  
Electrical Percolation ◽  
Vulcanized Rubber ◽  
Electrical Percolation Threshold ◽  
High Flexibility ◽  
Multiwall Carbon

The need for electromagnetic interference (EMI) shields has risen over the years as the result of our digitally and highly connected lifestyle. This work reports on the development of one such shield based on vulcanized rubber foams. Nanocomposites of ethylene–propylene–diene monomer (EPDM) rubber and multiwall carbon nanotubes (MWCNTs) were prepared via hot compression molding using a chemical blowing agent as foaming agent. MWCNTs accelerated the cure and led to high shear-thinning behavior, indicative of the formation of a 3D interconnected physical network. Foamed nanocomposites exhibited lower electrical percolation threshold than their solid counterparts. Above percolation, foamed nanocomposites displayed EMI absorption values of 28–45 dB in the frequency range of the X-band. The total EMI shielding efficiency of the foams was insignificantly affected by repeated bending with high recovery behavior. Our results highlight the potential of cross-linked EPDM/MWCNT foams as a lightweight EM wave absorber with high flexibility and deformability.

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