scholarly journals Characteristics of the response of the microalga (Dunaliella viridis) to cerium compounds in culture

2019 ◽  
Vol 27 (2) ◽  
pp. 142-147
Author(s):  
E. M. Klimova ◽  
A. I. Bozhkov ◽  
E. A. Bychenko ◽  
E. V. Lavinskaya ◽  
N. M. Zholobak ◽  
...  
Keyword(s):  
Biological Effect ◽  
Cell Shape ◽  
Cerium Dioxide ◽  
Test System ◽  
Ceo2 Nanoparticles ◽  
Dunaliella Viridis ◽  
Functional Disorders ◽  
High Degree ◽  
Cerium Iv Ammonium Nitrate ◽  
Cerium Compounds

Recently, nanobiotechnology has been developing intensively; therefore, various properties of nanoparticles, which depend on their origin, concentration, and size, are of interest. It is known that CeO2 nanoparticles cause a positive biological effect. These particles are able to penetrate through biomembranes. At the same time, there are assumptions about a high degree of biological risks when using nanomaterials, and it is obvious that the biosafety of nanomaterials is decisive in the development of new products, including for medicine. The cytotoxicity of samples of cerium salts and cerium dioxide nanoparticles of different sizes was assessed at different concentrations using D. viridis. The cytotoxicity level by morphological and functional disorders of D. viridis was investigated, as determined by the change in cell shape, accumulation of inclusions, loss of flagellum, change in nature and movement, the formation of micro- and macroaggregates by D. viridis cells and exometabolite release. The cytotoxicity coefficient was calculated as a quotient of total detected changes divided by their number. It was shown that cerium salts (cerium (IV) ammonium nitrate and cerium (III) chloride) had pronounced cytotoxicity, which exceeded cytotoxicity values of the control by 7 and 6 times, respectively. Cerium dioxide nanoparticles with a size of 6 nm at a concentration of 0.01 M showed intermediate cytotoxicity, which exceeded control values by 3.5 times, and after the effect of nanoparticles with a size of 2 nm at a concentration of 0.1 M, the cytotoxicity coefficient corresponded to control values. The addition of inactivated blood serum to the incubation mixture resulted in a decreased cytotoxic effect of cerium dioxide. The use of D. viridis as a test system will supplement the arsenal of biotesting tools for nanomaterials and the study of the mechanisms of their effect.

scholarly journals STUDIES ON X-RAY EFFECTS

1922 ◽  
Vol 35 (4) ◽  
pp. 475-485 ◽  
Author(s):  
Waro Nakahara ◽  
James B. Murphy
Keyword(s):  
Small Dose ◽  
Biological Effect ◽  
Lymphoid Organs ◽  
X Rays ◽  
Thin Glass ◽  
X Ray ◽  
Spark Gap ◽  
Mitotic Figures ◽  
High Degree ◽  
Ray Effects

A study has been made of the biological effect of a small dose of soft x-rays given off by a special water-cooled tube with a window of thin glass, operated at ½ inch spark-gap and 11 milliamperes. Mice exposed for 1 minute show 2 days later in the blood an increase in the number of lymphocytes and in the lymphoid organs an increased number of mitotic figures. There occurs also a marked dilatation of the vessels of the suprarenals, particularly between the cortex and medulla. The latter condition did not appear until after 24 hours and was still present 14 days after the treatment. No change was detected in other organs. Mice treated in this way showed a high degree of resistance to cancer transplants. The amount of resistance varied with the time of the inoculation after the treatment. The resistance was not increased before 3 days after and was at its highest point 10 days after the treatment.

Fate of cerium dioxide (CeO2) nanoparticles in municipal wastewater during activated sludge treatment

2012 ◽  
Vol 108 ◽  
pp. 300-304 ◽  
Author(s):  
Francisco Gómez-Rivera ◽  
James A. Field ◽  
Dustin Brown ◽  
Reyes Sierra-Alvarez
Keyword(s):  
Activated Sludge ◽  
Cerium Dioxide ◽  
Municipal Wastewater ◽  
Ceo2 Nanoparticles ◽  
Sludge Treatment

scholarly journals Release of gold (Au), silver (Ag) and cerium dioxide (CeO2) nanoparticles from sewage sludge incineration ash

2021 ◽  
Author(s):  
Jonas Wielinski ◽  
Alexander Gogos ◽  
Andreas Voegelin ◽  
Christoph R. Müller ◽  
Eberhard Morgenroth ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Sewage Sludge ◽  
Cerium Dioxide ◽  
Ceo2 Nanoparticles ◽  
Engineered Nanoparticles ◽  
Sewage Sludge Ash ◽  
Sludge Incineration ◽  
Sludge Ash

Conservative engineered nanoparticles (ENPs) that resist transformation during wastewater treatment and sludge incineration can be released from sewage sludge ash. Transient ENPs that undergo transformation are retained in the sewage sludge ash.

Synthesis and antimicrobial activities of Manganese (Mn) and iron (Fe) co-doped Cerium dioxide (CeO2) Nanoparticles

2021 ◽  
Vol 600 ◽  
pp. 412562
Author(s):  
Muhammad Moazzam Latif ◽  
Anwar-ul- Haq ◽  
Faheem Amin ◽  
Muhammad Ajaz-un-Nabi ◽  
Ikram-ullha Khan ◽  
...  
Keyword(s):  
Cerium Dioxide ◽  
Antimicrobial Activities ◽  
Ceo2 Nanoparticles ◽  
Co Doped

Design of Hydraulic System for Electrohydraulic Servo Valve Test Bed

2013 ◽  
Vol 288 ◽  
pp. 84-87
Author(s):  
Dong Hai Su ◽  
Xiao Dong Tang
Keyword(s):  
Hydraulic System ◽  
High Efficiency ◽  
Performance Testing ◽  
Test System ◽  
Test Bed ◽  
Servo Valve ◽  
System A ◽  
Automated Test System ◽  
Static Performance ◽  
High Degree

According to the needs of the electrohydraulic servo valve dynamic and static performance testing, designed an automated test system for the test of the static characteristics and dynamic characteristics test combinations together. Its advantage includes a stable system, a high degree of automation, simple operation, and high efficiency, full-featured.

Analysis and Research of Hydraulic Roof Bolter in Performance Testing

2015 ◽  
Vol 733 ◽  
pp. 607-610
Author(s):  
Bin Zhou ◽  
Ying Yang ◽  
Kun Ming Yang ◽  
Yuan Bo Dong
Keyword(s):  
Rotational Speed ◽  
Performance Testing ◽  
Test System ◽  
Test Methods ◽  
Operating Principle ◽  
Roof Bolter ◽  
Speed Flow ◽  
High Degree

We propose a test system which is easy to operate, and has high degree of automation, and introduce its detail of operating principle and test methods, and according to the requirements of the hydraulic jumbler performance, mainly test the rotational speed, flow, torque and propulsion and other performances of the hydraulic bolt rig. The measured results were analyzed and studied, and then the measures for improvement were proposed.

Does natural organic matter increase the bioavailability of cerium dioxide nanoparticles to fish?

2015 ◽  
Vol 12 (6) ◽  
pp. 673 ◽  
Author(s):  
Rhys M. Goodhead ◽  
Blair D. Johnston ◽  
Paula A. Cole ◽  
Mohammed Baalousha ◽  
David Hodgson ◽  
...  
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Cerium Dioxide ◽  
Natural Waters ◽  
Biological Effects ◽  
Fulvic Acids ◽  
Consumer Products ◽  
Ceo2 Nanoparticles ◽  
Aggregation Behaviour ◽  
Analytical Approaches

Environmental context Nanoparticles are present in growing volumes of consumer products and are suspected to be released into the environment at detectable levels. We focus on cerium dioxide nanoparticles and investigate their availability to fish from the water column, where we found increasing concentrations of natural organic material increased the ceria measured in the fish gills. This complex interaction between nanoparticle behaviour and uptake from environmentally relevant test systems is significantly understudied. Abstract Natural organic colloids affect the fate and behaviour of nanoparticles in the aquatic environment but how these interactions affect the bioavailability of nanoparticles to organisms is a major knowledge gap in risk-assessment analysis. Here, we investigated interactions of citrate-coated cerium dioxide (CeO2) nanoparticles with fulvic acids, representing natural organic matter, and assessed their bioavailability to fish (common carp, Cyprinus carpio) exposed chronically (32days) via the water. We show a fulvic acid concentration-related enhancement in the uptake of cerium (Ce) into gill tissues, with some evidence for an enhanced Ce uptake also into kidney and brain tissues in the presence of fulvic acids, but with more variable responses. We present evidence for differences in the aggregation behaviour for CeO2 nanoparticles in the different exposure scenarios, with reduced CeO2 particle aggregate size with citrate coating and fulvic acids, as determined from dynamic light scattering. We highlight that multiple analytical approaches are essential for understanding the dynamic nature of the particles and also that interpretations on measured particle sizes and characteristics may differ depending on the technique(s) employed. We conclude that conditions in natural waters are likely to play a fundamental role in affecting bioavailability and thus potential biological effects of CeO2 particles.

Relative Biological Effect of 14-Mev Neutrons with the Broad Bean Root (Vicia faba) as a Test System

1958 ◽  
Vol 9 (5) ◽  
pp. 548 ◽  
Author(s):  
J. F. Spalding ◽  
S. B. Hawkins ◽  
J. A. Sayeg
Keyword(s):  
Vicia Faba ◽  
Biological Effect ◽  
Broad Bean ◽  
Test System ◽  
Bean Root

Preparation and Characterization of Conductive Polyaniline/Cerium Dioxide Composites

2010 ◽  
Vol 663-665 ◽  
pp. 686-689
Author(s):  
Hui Huang ◽  
Zhong Cheng Guo
Keyword(s):  
Fourier Transform ◽  
Cerium Dioxide ◽  
In Situ Polymerization ◽  
Ceo2 Nanoparticles ◽  
Pure Pani ◽  
X Ray Diffraction ◽  
Maximum Conductivity ◽  
Conductive Polyaniline

Conductive polyaniline/cerium dioxide (PANI/CeO2) composites have been synthesized by in-situ polymerization of aniline in the presence of CeO2 nanoparticles. The structure and thermal stability of obtained composites were characterized by Fourier-transform infrared spectra (FTIR), Fourier-transform Raman spectra (FT-Raman), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The results showed that PANI and CeO2 nanoparticles were not simply blended, and a strong interaction existed at the interface of CeO2 and PANI. In the PANI/CeO2 composite, the degree crystallinity of PANI increased and diffraction pattern of CeO2 was amorphous. And that the composites were more thermally stable than that of the pure PANI. Electrical conductivity measurements indicated that the conductivity of PANI/CeO2 composites was much higher than that of the pure PANI and the maximum conductivity obtained was 11.68 S/cm at 17.5 wt% of CeO2.

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