scholarly journals In vitro safety evaluation of rare earth-lean alloys for permanent magnets manufacturing

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Carlos Rumbo ◽  
Cristina Cancho Espina ◽  
Jürgen Gassmann ◽  
Olivier Tosoni ◽  
Rocío Barros García ◽  
...  
Keyword(s):  
Rare Earth ◽  
Permanent Magnets ◽  
Vibrio Fischeri ◽  
Model Organisms ◽  
In Vitro Assays ◽  
Lower Percentage ◽  
Magnetic Characteristics ◽  
Toxicological Evaluation ◽  
The Impact

AbstractDue to their exceptional physico-chemical and magnetic characteristics, rare earth (RE) permanent magnets are applied in multiple critical technologies. However, several environmental and economic difficulties arising from obtaining RE elements have prompted the search of alternatives with acceptable magnetic properties but containing a lower percentage of these elements in their composition. The aim of this work was to perform a preliminary toxicological evaluation of three forms of newly developed RE-lean alloys (one NdFeTi and two NdFeSi alloys) applying different in vitro assays, using as a benchmark a commercial NdFeB alloy. Thus, the effects of the direct exposure to powder suspensions and to their derived leachates were analysed in two model organisms (the A549 human cell line and the yeast Saccharomyces cerevisiae) applying both viability and oxidative stress assays. Moreover, the impact of the alloy leachates on the bioluminescence of Vibrio fischeri was also investigated. The obtained data showed that only the direct interaction of the alloys particulates with the applied organisms resulted in harmful effects, having all the alloys a comparable toxicological potential to that presented by the reference material in the conditions tested. Altogether, this study provides new insights about the safety of NdFeTi and NdFeSi alloys.

Toxicological evaluation of MnAl based permanent magnets using different in vitro models

Chemosphere ◽  
2021 ◽  
Vol 263 ◽  
pp. 128343
Author(s):  
Carlos Rumbo ◽  
Cristina Cancho Espina ◽  
Vladimir V. Popov ◽  
Konstantin Skokov ◽  
Juan Antonio Tamayo-Ramos
Keyword(s):  
Permanent Magnets ◽  
In Vitro Models ◽  
Toxicological Evaluation

scholarly journals UV-visible photodegradation of naproxen in water – Structural elucidation of photoproducts and potential toxicity

2020 ◽  
Vol 26 (6) ◽  
pp. 400-408
Author(s):  
Noemi Cazzaniga ◽  
Zsuzsanna Varga ◽  
Edith Nicol ◽  
Stéphane Bouchonnet
Keyword(s):  
Mass Spectrometry ◽  
High Performance ◽  
Vibrio Fischeri ◽  
Software Tool ◽  
In Vitro Assays ◽  
Naphthaleneacetic Acid ◽  
Ion Cyclotron Resonance ◽  
Potential Toxicity ◽  
Uv Visible

The UV-visible photodegradation of Naproxen (6-methoxy-α-methyl-2-naphthaleneacetic acid, CAS: 22204-53-1), one of the most used and detected non-steroidal anti-inflammatory drugs (NSAIDs) in the world, and its ecotoxicological consequences were investigated in an aqueous medium. The photo-transformation products were analyzed and the structures of photoproducts were elucidated using gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) and high-performance liquid chromatography coupled with ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (LC-FTICR-MS). Seven photoproducts were detected and characterized, photo-transformation mechanisms have been postulated to rationalize their formation under irradiation. In silico Q.S.A.R. (Quantitative Structure-Activity Relationship) toxicity predictions were performed with the Toxicity Estimation Software Tool (T.E.S.T.) and in vitro assays were carried out on Vibrio fischeri bacteria. Some of the obtained photoproducts exhibit higher potential toxicity than Naproxen itself but the whole toxicity of the irradiated solution is not of major concern.

Misch-Metal and/or Aluminum Substitutions in ND-FE-B Permanent Magnets

1987 ◽  
Vol 96 ◽  
Author(s):  
B. M. Ma ◽  
C. J. Willzian
Keyword(s):  
Rare Earth ◽  
Permanent Magnets ◽  
Alloy System ◽  
Magnetic Characteristics ◽  
Al Doping ◽  
Sintered Magnet ◽  
Al Content ◽  
Misch Metal ◽  
Heavy Rare Earth Elements ◽  
Energy Products

ABSTRACTThe effects of misch-metal–and/or Al substitutions in the Nd-Fe-B alloy system have been investigated. Selected compositions were processed into magnets using the conventional powder metallurgy technique. As expected, misch-metal substitutions act to degrade the intrinsic magnetic characteristics and thus degrade the properties of the sintered magnet. It was observed that at a level of 25% of the total rare earth being comprised of misch-metal, energy products of the order of 25 MGOe were still able to be achieved. Processing of such material is difficult because higher sintering temperatures are required to fully densify the magnet, and the grain growth that occurs at these temperatures dramatically reduces the coercivity. The effects of misch-metal substitutions are quantified in this discussion.Al was found to be beneficial for improving the coercivity in both the Nd-Fe-B and misch-metal-Fe-B alloy systems. Unfortunately Al substitutions reduce both the remanence and the Curie temperature. If the Al content is kept to 1 wt.% or less, magnets exhibiting reasonable properties can be made. Al doping as opposed to doping with expensive heavy rare earth elements such as Th or Dy is a less costly method of improving Hei, in the Nd-Fe-B magnets.

Soaps and Detergents: Alternatives to Animal Eye Irritation Tests

1996 ◽  
Vol 15 (1) ◽  
pp. 1-44 ◽  
Author(s):  
Mildred S. Christian ◽  
Robert M. Diener
Keyword(s):  
False Negative ◽  
Screening Tools ◽  
Current Status ◽  
In Vitro Assays ◽  
Computer Search ◽  
Eye Irritation ◽  
Vitro Assay ◽  
Predictive Values ◽  
The Impact

An extensive computer search was conducted, and a comprehensive overview of the current status of alternatives to animal eye irritation tests was obtained. A search of Medline and Toxline databases (1988 to present) was supplemented with references from sources regarding in vitro eye irritation. Particular attention was paid to soap and detergent products and related ingredients. Eighty-five references are included in the review; the in vitro assays are categorized, and their predictive values for assessing acute ocular irritation are evaluated and compared with the Draize rabbit eye irritation assay and with each other. The present review shows that the increased activity of scientists from academia, industry, and regulatory agencies has resulted in substantial progress in developing alternative in vitro procedures and that a number of large, interlaboratory evaluations and international workshops have assisted in the selection process. However, none of these methodologies has obtained acceptance for regulatory classification purposes. Conclusions drawn from this review include that (a) no single in vitro assay is considered capable of replacing the Draize eye irritation test; (b) the chorioallantoic membrane vascular assay (CAMVA) or the hen egg test-chorio-allantoic membrane test (HET-CAM), the chicken or bovine enucleated eye test, the neutral red and plasminogen activation assays for cytotoxicity, and the silicon microphysiometer appear to have the greatest potential as screening tools for eye irritation; and (c) choosing a specific assay or series of assays will depend on the type of agent tested and the impact of false-negative or false-positive results. New assays will continue to be developed and should be included in future evaluations, when sufficient data are available.

Efficient near Net-Shape Production of High Energy Rare Earth Magnets by Laser Beam Melting

2017 ◽  
Vol 871 ◽  
pp. 137-144 ◽  
Author(s):  
Nikolaus Urban ◽  
Alexander Meyer ◽  
Sven Kreitlein ◽  
Felix Leicht ◽  
Jörg Franke
Keyword(s):  
Rare Earth ◽  
Laser Beam ◽  
Permanent Magnets ◽  
High Energy ◽  
Parameter Study ◽  
Efficient Production ◽  
Rare Earth Magnet ◽  
Laser Beam Melting ◽  
Near Net Shape ◽  
The Impact

In this publication we report on our progress in investigating the energy efficient production of rare earth permanent magnets by Laser Beam Melting in the powder bed (LBM). This innovative additive manufacturing process offers the potential to produce magnets of complex geometries without an energy intensive oven sintering step. Another advantage that increases the efficiency of this possible new process route is the high degree of material utilization due to a near net shape production of the magnets. Hence only little material is wasted during a post processing machining step. The main challenge in processing rare earth magnet alloys by means of LBM is the brittle mechanical behavior of the material and the change in microstructure due to the complete remelting of the magnet powder. We therefor expanded the parameter study presented in previous work in order to further increase relative density and magnetic properties of the specimens. In this context process stability and reproducibility could also be increased. This was achieved by investigating the impact of different exposure patterns and varying laser spot sizes. Simultaneously to the experiments the energy consumption of the LBM process was measured and compared with conventional rare earth magnet production routes.

scholarly journals ­ Functional Characterization of 5’ UTR Cis-Acting Sequence Elements That Modulate Translational Efficiency in P. Falciparum and Humans

2021 ◽  
Author(s):  
Valentina E. Garcia ◽  
Rebekah Dial ◽  
Joseph L DeRisi
Keyword(s):  
Translational Regulation ◽  
Base Composition ◽  
Functional Characterization ◽  
Gc Content ◽  
Untranslated Regions ◽  
Model Organisms ◽  
Translational Efficiency ◽  
Regulatory Sequences ◽  
The Impact

Abstract BackgroundThe eukaryotic parasite Plasmodium falciparum causes millions of malarial infections annually while drug resistance to common antimalarials is further confounding eradication efforts. Translation is an attractive therapeutic target that will benefit from a deeper mechanistic understanding. As the rate limiting step of translation, initiation is a primary driver of translational efficiency. It is a complex process regulated by both cis and trans acting factors, providing numerous potential targets. Relative to model organisms and humans, P. falciparum mRNAs feature unusual 5’ untranslated regions suggesting cis-acting sequence complexity in this parasite may act to tune levels of protein synthesis through their effects on translational efficiency. MethodsHere, we deployed in vitro translation to compare the role of cis-acting regulatory sequences in P. falciparum and humans. Using parasite mRNAs with high or low translational efficiency, the presence, position, and termination status of upstream “AUG”s, in addition to the base composition of the 5’ untranslated regions, were characterized. ResultsThe density of upstream “AUG”s differed significantly among the most and least efficiently translated genes in P. falciparum, as did the average “GC” content of the 5’ untranslated regions. Using exemplars from highly translated and poorly translated mRNAs, multiple putative upstream elements were interrogated for impact on translational efficiency. Upstream “AUG”s were found to repress translation to varying degrees, depending on their position and context, while combinations of upstream “AUG”s had nonadditive effects. The base composition of the 5’ untranslated regions also impacted translation, but to a lesser degree. Surprisingly, the effects of cis-acting sequences were remarkably conserved between P. falciparum and humans. ConclusionWhile translational regulation is inherently complex, this work contributes toward a more comprehensive understanding of parasite and human translational regulation by examining the impact of discrete cis-acting features, acting alone or in context.

scholarly journals Nutritional Potential and Toxicological Evaluation of Tetraselmis sp. CTP4 Microalgal Biomass Produced in Industrial Photobioreactors

Molecules ◽  
2019 ◽  
Vol 24 (17) ◽  
pp. 3192 ◽  
Author(s):  
Hugo Pereira ◽  
Joana Silva ◽  
Tamára Santos ◽  
Katkam N. Gangadhar ◽  
Ana Raposo ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Essential Amino Acids ◽  
Nutritional Composition ◽  
In Vitro Assays ◽  
Toxicological Evaluation ◽  
Microalgal Biomass ◽  
Industrial Setting ◽  
Industrial Strains ◽  
Food And Feed

Commercial production of microalgal biomass for food and feed is a recent worldwide trend. Although it is common to publish nutritional data for microalgae grown at the lab-scale, data about industrial strains cultivated in an industrial setting are scarce in the literature. Thus, here we present the nutritional composition and a microbiological and toxicological evaluation of Tetraselmis sp. CTP4 biomass, cultivated in 100-m3 photobioreactors at an industrial production facility (AlgaFarm). This microalga contained high amounts of protein (31.2 g/100 g), dietary fibres (24.6 g/100 g), digestible carbohydrates (18.1 g/100 g) and ashes (15.2 g/100 g), but low lipid content (7.04 g/100 g). The biomass displayed a balanced amount of essential amino acids, n-3 polyunsaturated fatty acids, and starch-like polysaccharides. Significant levels of chlorophyll (3.5 g/100 g), carotenoids (0.61 g/100 g), and vitamins (e.g., 79.2 mg ascorbic acid /100 g) were also found in the biomass. Conversely, pathogenic bacteria, heavy metals, cyanotoxins, mycotoxins, polycyclic aromatic hydrocarbons, and pesticides were absent. The biomass showed moderate antioxidant activity in several in vitro assays. Taken together, as the biomass produced has a balanced biochemical composition of macronutrients and (pro-)vitamins, lacking any toxic contaminants, these results suggest that this strain can be used for nutritional applications.

scholarly journals Intratumoral injection reduces toxicity and antibody-mediated neutralization of immunocytokine in a mouse melanoma model

2020 ◽  
Vol 8 (2) ◽  
pp. e001262
Author(s):  
Claire C Baniel ◽  
Elizabeth G Sumiec ◽  
Jacqueline A Hank ◽  
Amber M Bates ◽  
Amy K Erbe ◽  
...  
Keyword(s):  
Tumor Regression ◽  
Interleukin 2 ◽  
Intratumoral Injection ◽  
In Vitro Assays ◽  
Human Antibody ◽  
Severe Toxicity ◽  
Tumor Bearing ◽  
The Impact

BackgroundSome patients with cancer treated with anticancer monoclonal antibodies (mAbs) develop antidrug antibodies (ADAs) that recognize and bind the therapeutic antibody. This response may neutralize the therapeutic mAb, interfere with mAb effector function or cause toxicities. We investigated the potential influence of ADA to modify the tumor-binding capability of a tumor-reactive ‘immunocytokine’ (IC), namely, a fusion protein (hu14.18-IL2) consisting of a humanized, tumor-reactive, anti-GD2 mAb genetically linked to interleukin 2. We characterize the role of treatment delivery of IC (intravenous vs intratumoral) on the impact of ADA on therapeutic outcome following IC treatments in an established antimelanoma (MEL) regimen involving radiotherapy (RT) +IC.MethodsC57BL/6 mice were injected with human IgG or the hu14.18-IL2 IC to develop a mouse anti-human antibody (MAHA) response (MAHA+). In vitro assays were performed to assess ADA binding to IC using sera from MAHA+ and MAHA− mice. In vivo experiments assessed the levels of IC bound to tumor in MAHA+ and MAHA− mice, and the influence of IC route of delivery on its ability to bind to B78 (GD2+) MEL tumors.ResultsMAHA is inducible in C57BL/6 mice. In vitro assays show that MAHA is capable of inhibiting the binding of IC to GD2 antigen on B78 cells, resulting in impaired ADCC mediated by IC. When B78-bearing mice are injected intravenously with IC, less IC binds to B78-MEL tumors in MAHA+ mice than in MAHA− mice. In contrast, when IC is injected intratumorally in tumor-bearing mice, the presence of MAHA does not detectibly impact IC binding to the tumor. Combination therapy with RT+IT-IC showed improved tumor regression compared with RT alone in MAHA+ mice. If given intratumorally, IC could be safely readministered in tumor-bearing MAHA+ mice, while intravenous injections of IC in MAHA+ mice caused severe toxicity. Histamine levels were elevated in MAHA+ mice compared with MAHA− mice after reintroduction of IC.ConclusionsIntratumoral injection may be a means of overcoming ADA neutralization of therapeutic activity of tumor-reactive mAbs or ICs and may reduce systemic toxicity, which could have significant translational relevance.

Abstracts

2008 ◽  
Vol 27 (6) ◽  
pp. 405-405
Author(s):  
David J. Dix
Keyword(s):  
Risk Assessment ◽  
High Throughput ◽  
Environmental Protection Agency ◽  
High Throughput Screening ◽  
Human Health Risk ◽  
Environmental Chemicals ◽  
In Vitro Assays ◽  
The Impact ◽  
Toxicity Pathways

The U.S. Environmental Protection Agency (EPA), National Toxicology Program (NTP), and National Institutes of Health (NIH) Chemical Genomics Center (NCGC) have complementary research programs designed to improve chemical toxicity evaluations by developing high throughput screening (HTS) methods that evaluate the impact of environmental chemicals on key toxicity pathways. These federal partners are coordinating an extension of the EPA’s ToxCast program, the NTP’s HTS initiative, and the NCGC’s Molecular Libraries Initiative into a collaborative research program focused on identifying toxicity pathways and developing in vitro assays to characterize the ability of chemicals to perturb those pathways. The goal is to develop new paradigm for high throughput toxicity testing that collects mechanistic and quantitative data from in vitro assays measuring chemical modulation of biological processes involved in the progression to toxicity. As toxicity pathways are identified, the in vitro assays can be optimized for comparison to in vivo animal studies, and for predicting effects in humans. Subsequent computational modeling of toxicity pathway responses and appropriate chemical dosimetry will need to be developed to make these predictions relevant for human health risk assessment. This work was reviewed by EPA and approved for publication but does not necessarily reflect official Agency policy. Index Terms: Toxicogenomics, High Throughput Screening/Testing, EPA ToxCast, Chemical Risk Assessment

scholarly journals Effects of Processing on Polyphenolic and Volatile Composition and Fruit Quality of Clery Strawberries

Antioxidants ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 632
Author(s):  
Stefania Garzoli ◽  
Francesco Cairone ◽  
Simone Carradori ◽  
Andrei Mocan ◽  
Luigi Menghini ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Central Italy ◽  
In Vitro Assays ◽  
Bioactive Metabolites ◽  
Total Phenolic ◽  
Color Analysis ◽  
Food Ingredient ◽  
Red Color ◽  
The Impact

Strawberries belonging to cultivar Clery (Fragaria x ananassa (Duchesne ex Weston)), cultivated in central Italy were subjected to a multi-methodological experimental study. Fresh and defrosted strawberries were exposed to different processing methods, such as homogenization, thermal and microwave treatments. The homogenate samples were submitted to CIEL*a*b* color analysis and Head-Space GC/MS analysis to determine the impact of these procedures on phytochemical composition. Furthermore, the corresponding strawberry hydroalcoholic extracts were further analyzed by HPLC-DAD for secondary metabolites quantification and by means of spectrophotometric in vitro assays to evaluate their total phenolic and total flavonoid contents and antioxidant activity. These chemical investigations confirmed the richness in bioactive metabolites supporting the extraordinary healthy potential of this fruit as a food ingredient, as well as functional food, highlighting the strong influence of the processing steps which could negatively impact on the polyphenol composition. Despite a more brilliant red color and aroma preservation, non-pasteurized samples were characterized by a lower content of polyphenols and antioxidant activity with respect to pasteurized samples, as also suggested by the PCA analysis of the collected data.

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