Cardiovascular effects among workers exposed to multiwalled carbon nanotubes

2018 ◽  
Vol 75 (5) ◽  
pp. 351-358 ◽  
Author(s):  
Eelco Kuijpers ◽  
Anjoeka Pronk ◽  
Robert Kleemann ◽  
Jelle Vlaanderen ◽  
Qing Lan ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Phase I ◽  
Multiwalled Carbon Nanotubes ◽  
Phase Ii ◽  
Geometric Mean ◽  
Intercellular Adhesion Molecule ◽  
Intercellular Adhesion Molecule 1 ◽  
Multiwalled Carbon ◽  
Cross Sectional ◽  
High Exposure

ObjectivesThe increase in production of multiwalled carbon nanotubes (MWCNTs) has led to growing concerns about health risks. In this study, we assessed the association between occupational exposure to MWCNTs and cardiovascular biomarkers.MethodsA cross-sectional study was performed among 22 workers of a company commercially producing MWCNTs (subdivided into lab personnel with low or high exposure and operators), and a gender and age-matched unexposed population (n=42). Exposure to MWCNTs and 12 cardiovascular markers were measured in participants’ blood (phase I). In a subpopulation of 13 exposed workers and six unexposed workers, these measures were repeated after 5 months (phase II). We analysed associations between MWCNT exposure and biomarkers of cardiovascular risk, adjusted for age, body mass index, sex and smoking.ResultsWe observed an upward trend in the concentration of endothelial damage marker intercellular adhesion molecule-1 (ICAM-1), with increasing exposure to MWCNTs in both phases. The operator category showed significantly elevated ICAM-1 geometric mean ratios (GMRs) compared with the controls (phase I: GMR=1.40, P=1.30E-3; phase II: GMR=1.37, P=0.03). The trends were significant both across worker categories (phase I: P=1.50E-3; phase II: P=0.01) and across measured GM MWCNT concentrations (phase I: P=3.00E-3; phase II: P=0.01). No consistent significant associations were found for the other cardiovascular markers.ConclusionThe associations between MWCNT exposure and ICAM-1 indicate endothelial activation and an increased inflammatory state in workers with MWCNT exposure.

Electrical Conductivity and Electromagnetic Interference Shielding Effectiveness of Multiwalled Carbon Nanotubes Filled ABS Composites

2011 ◽  
Vol 194-196 ◽  
pp. 1554-1557 ◽  
Author(s):  
Hong Yin Shen ◽  
Qing Ze Jiao ◽  
Yun Zhao ◽  
Han Sheng Li ◽  
Zhe Sun
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Electromagnetic Interference ◽  
Volume Resistivity ◽  
Shielding Effectiveness ◽  
Multiwalled Carbon ◽  
Cross Sectional ◽  
Emi Shielding Effectiveness ◽  
Solution Blending ◽  
Combined Solution

Multiwalled carbon nanotubes filled ABS (ABS/MWCNTs) composites were prepared via a method combined solution-blending with hot-press forming. Fractured cross-sectional surfaces of the ABS/MWCNTs composites were analyzed by scanning electron microscopy showing that MWCNTs were dispersed homogeneously in the ABS matrix. The volume resistivity of these composites was also analyzed and the percolation threshold was obtained at low filler loadings about 1–3 wt%. The Electromagnetic interference (EMI) shielding effectiveness (SE) of ABS/MWCNTs composites was investigated in 100–1500 MHz. It was found that SE of the prepared composites strongly depended on MWCNT loading. The highest EMI SE reaching 36 dB was observed for ABS/MWCNT composites containing 15 wt% of MWCNTs at 760 MHz.

KALEIDOSCOPIC MODE CHANGE IN CROSS-SECTIONAL DEFORMATION OF REINFORCED CARBON NANOTUBES

2013 ◽  
Vol 27 (31) ◽  
pp. 1350179 ◽  
Author(s):  
SUNG-JIN PARK ◽  
HIROYUKI SHIMA ◽  
MOTOHIRO SATO
Keyword(s):  
Carbon Nanotubes ◽  
Elastic Medium ◽  
Multiwalled Carbon Nanotubes ◽  
Radial Pressure ◽  
Multiwalled Carbon ◽  
Cross Sectional ◽  
Mode Change ◽  
The Core ◽  
Elastic Approximation ◽  
Physical Consequences

Cross-sectional deformation of multiwalled carbon nanotubes under isotropic radial pressure is investigated in a realm of continuum elastic approximation. The nanotube we assumed is subjected to the embedment into an elastic medium and stiffener insertion into the core cavity. Combination of the two reinforcement manipulations is found to cause kaleidoscopic mode changes in the radial corrugation, in which the cylindrical walls exhibit wavy patterns along the circumferential direction. Physical consequences of the diverse corrugation patters are also discussed.

Effect of Multiwalled Carbon Nanotubes On Mechanical Properties of Concrete

2012 ◽  
Vol 2 (6) ◽  
pp. 166-168 ◽  
Author(s):  
Dr.T.Ch.Madhavi Dr.T.Ch.Madhavi ◽  
◽  
Pavithra.P Pavithra.P ◽  
Sushmita Baban Singh Sushmita Baban Singh ◽  
S.B.Vamsi Raj S.B.Vamsi Raj ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Multiwalled Carbon

Sorption of Bisphenol A in Aqueous Solutions on Irradiated and as-Grown Multiwalled Carbon Nanotubes

2018 ◽  
Vol 69 (5) ◽  
pp. 1233-1239
Author(s):  
Raluca Madalina Senin ◽  
Ion Ion ◽  
Ovidiu Oprea ◽  
Rusandica Stoica ◽  
Rodica Ganea ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Bisphenol A ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Multiwalled Carbon Nanotubes ◽  
Adsorption Process ◽  
Sorption Process ◽  
Multiwalled Carbon ◽  
Before And After ◽  
Kinetic Sorption

In this study, non-irradiated and weathered multiwalled carbon nanotubes (MWCNTs) obtained through irradiation, were studied as adsorbents for BPA, both nanomaterials being characterized before and after the adsorption process. The objectives of our investigation were to compare the characteristics of non-irradiated and irradiated MWCNTs, to evaluate the adsorption capacity of BPA by pristine and irradiated MWCNTs and to determine the variation of the kinetic, sorption and thermodynamic parameters during sorption process using both sorbents.

Molecularly Imprinted Sensor for Ascorbic Acid Based on Gold Nanoparticles and Multiwalled Carbon Nanotubes

2020 ◽  
Vol 16 (7) ◽  
pp. 905-913
Author(s):  
Youyuan Peng ◽  
Qingshan Miao
Keyword(s):  
Carbon Nanotubes ◽  
Gold Nanoparticles ◽  
Ascorbic Acid ◽  
Multiwalled Carbon Nanotubes ◽  
Ph Value ◽  
Biological Fluids ◽  
Water Soluble ◽  
Multiwalled Carbon ◽  
Experimental Conditions ◽  
Molecularly Imprinted

Background: L-Ascorbic acid (AA) is a kind of water soluble vitamin, which is mainly present in fruits, vegetables and biological fluids. As a low cost antioxidant and effective scavenger of free radicals, AA may help to prevent diseases such as cancer and Parkinson’s disease. Owing to its role in the biological metabolism, AA has also been utilized for the therapy of mental illness, common cold and for improving the immunity. Therefore, it is very necessary and urgent to develop a simple, rapid and selective strategy for the detection of AA in various samples. Methods: The molecularly imprinted poly(o-phenylenediamine) (PoPD) film was prepared for the analysis of L-ascorbic acid (AA) on gold nanoparticles (AuNPs) - multiwalled carbon nanotubes (MWCNTs) modified glass carbon electrode (GCE) by electropolymerization of o-phenylenediamine (oPD) and AA. Experimental parameters including pH value of running buffer and scan rates were optimized. Scanning electron microscope (SEM), fourier-transform infrared (FTIR) spectra, cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were utilized for the characterization of the imprinted polymer film. Results: Under the selected experimental conditions, the DPV peak currents of AA exhibit two distinct linear responses ranging from 0.01 to 2 μmol L-1 and 2 to 100 μmol L-1 towards the concentrations of AA, and the detection limit was 2 nmol L-1 (S/N=3). Conclusion: The proposed electrochemical sensor possesses excellent selectivity for AA, along with good reproducibility and stability. The results obtained from the analysis of AA in real samples demonstrated the applicability of the proposed sensor to practical analysis.

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