Search results for "metals"
showing 10 items of 2013 documents
A flexible robotic cell for in-process inspection of multi-pass welds
2020
Welds are currently only inspected after all the passes are complete and after allowing sufficient time for any hydrogen cracking to develop, typically over several days. Any defects introduced between passes are therefore unreported until fully buried, greatly complicating rework and also delaying early corrections to the weld process parameters. In-process inspection can provide early intervention but involves many challenges, including operation at high temperatures with significant gradients affecting acoustic velocities and, hence, beam directions. Reflections from the incomplete parts of the weld would also be flagged as lack-of-fusion defects, requiring the region of interest (ROI) t…
Determination of Sorption Properties of Heavy Metals in Various Biosorbents
2018
Abstract Various techniques of determination of properties of physicochemical processes of heavy metal sorption in biosorbents were analysed. The methods of preparing and storing samples, conditions of experiment performance, as well as the methods of data interpretation were discussed. Two procedures of study were analysed: (1) in the static system of biosorbent-solution contact and (2) in the system of dynamic flow of solution. Copper cation sorption was studied. The effect of consecutive stages of the study on the quality of final results was shown. A high degree of uncertainty of the sorption capacity assessment was reported, which was dependent on the manner of conducting the study. Th…
The application of electroanalytical methods to determine affinity series of metal cations for functional biosorbent groups
2018
Abstract The affinity of the selected heavy metal cations: Mn 2 + , Ni 2 + , Cu 2 + , Zn 2 + , Cd 2 + , Pb 2 + and Na + , K + , Mg 2 + , Ca 2 + was determined for the functional groups located on the surface of leached barley middlings, so called Brewer's spent grain (BSG) – a by-product of the brewing industry. A simple method for determining the affinity series, with the use of a conductivity meter and a pH-meter, was described. It was demonstrated that the affinity of cations for the functional groups located on the surface of the BSG increases in the series: Na + + 2 + 2 + ≈ Zn 2 + 2 + ≈ Ca 2 + 2 + 2 + 2 + , and the series was determined by comparing concentrations expressed in gram e…
Mineral Profile of Children’s Fast Food Menu Samples
2017
Abstract Children’s fast food menus, including hamburgers served with french fries, dessert, and a soft drink, were analyzed to obtain the mineral profile of trace elements. The developed analytical methodology involved sample digestion under pressure inside a microwave oven with a mixture of HNO3 and H2O2 and inductively coupled plasma-optical emission spectrometry. The method was validated by carrying out the analysis of certified reference materials (NIST 1570a spinach leaves, NCS ZC73016 chicken, and NIST 1568a rice flour) and using recovery experiments. Repeatability was verified by analyzing replicate samples. Twenty-six elements were studied, 12 of which—aluminum, barium, calcium, co…
General Aspects of Metal Ions as Signaling Agents in Health and Disease
2020
This review focuses on the current knowledge on the involvement of metal ions in signaling processes within the cell, in both physiological and pathological conditions. The first section is devoted to the recent discoveries on magnesium and calcium-dependent signal transduction—the most recognized signaling agents among metals. The following sections then describe signaling pathways where zinc, copper, and iron play a key role. There are many systems in which changes in intra- and extra-cellular zinc and copper concentrations have been linked to important downstream events, especially in nervous signal transduction. Iron signaling is mostly related with its homeostasis. However, it is also …
All-atom simulations to studying metallodrugs/target interactions.
2021
Abstract Metallodrugs are extensively used to treat and diagnose distinct disease types. The unique physical–chemical properties of metal ions offer tantalizing opportunities to tailor effective scaffolds for selectively targeting specific biomolecules. Modern experimental techniques have collected a large body of structural data concerning the interactions of metallodrugs with their biomolecular targets, although being unable to exhaustively assess the molecular basis of their mechanism of action. In this scenario, the complementary use of accurate computational methods allows uncovering the minutiae of metallodrugs/targets interactions and their underlying mechanism of action at an atomic…
Response to metals treatment of Fra1, a member of the AP-1 transcription factor family, in P. lividus sea urchin embryos
2018
Abstract Lithium (Li), Nickel (Ni), and Zinc (Zn) are metals normally present in the seawater, although they can have adverse effects on the marine ecosystem at high concentrations by interfering with many biological processes. These metals are toxic for sea urchin embryos, affecting their morphology and developmental pathways. In particular, they perturb differently the correct organization of the embryonic axes (animal-vegetal, dorso-ventral): Li is a vegetalizing agent and Ni disrupts the dorso-ventral axis, while Zn has an animalizing effect. To deeply address the response of Paracentrotus lividus embryos to these metals, we studied the expression profiling of Pl-Fra transcription facto…
Binding and neurotoxicity mitigation of toxic tau oligomers by synthetic heparin like oligosaccharides.
2018
Well-defined heparin like oligosaccharides up to decasaccharides were synthesized. It was discovered for the first time that heparin oligosaccharides, as short as tetrasaccharides, can bind with the most toxic tau species, i.e., tau oligomers with nM KD. The binding significantly reduced the cellular uptake of toxic tau oligomers and protected the cells from tau oligomer induced cytotoxicity.
Molecular Alterations in Spermatozoa of a Family Case Living in the Land of Fires. A First Look at Possible Transgenerational Effects of Pollutants.
2020
In our previous work, we reported alterations in protamines/histones ratio, in DNA binding of these proteins and their involvement in DNA oxidative damage in 84% of the young men living in the Land of Fires. In the present work, we extended our findings, evaluating any alterations in spermatozoa of a family case, a father and son, living in this area, to also give a first look at the possibility of transgenerational inherited effects of environmental contaminants on the molecular alterations of sperm nuclear basic proteins (SNBP), DNA and semen parameters. In the father and son, we found a diverse excess of copper and chromium in the semen, different alterations in SNBP content and low DNA …
Conf-VLKA: A structure-based revisitation of the Virtual Lock-and-key Approach
2016
In a previous work, we developed the in house Virtual Lock-and-Key Approach (VLKA) in order to evaluate target assignment starting from molecular descriptors calculated on known inhibitors used as an information source. This protocol was able to predict the correct biological target for the whole dataset with a good degree of reliability (80%), and proved experimentally, which was useful for the target fishing of unknown compounds. In this paper, we tried to remodel the previous in house developed VLKA in a more sophisticated one in order to evaluate the influence of 3D conformation of ligands on the accuracy of the prediction. We applied the same previous algorithm of scoring and ranking b…