scholarly journals Adsorption of RNA on mineral surfaces and mineral precipitates

2017 ◽  
Vol 13 ◽  
pp. 393-404 ◽  
Author(s):  
Elisa Biondi ◽  
Yoshihiro Furukawa ◽  
Jun Kawai ◽  
Steven A Benner
Keyword(s):  
Calcium Carbonate ◽  
Periodic Table ◽  
Alkaline Earth ◽  
Laboratory Experiments ◽  
Mineral Surfaces ◽  
Carbonate Minerals ◽  
Natural Mineral ◽  
Large Molecules ◽  
Polymorphic Forms ◽  
Differential Binding

The prebiotic significance of laboratory experiments that study the interactions between oligomeric RNA and mineral species is difficult to know. Natural exemplars of specific minerals can differ widely depending on their provenance. While laboratory-generated samples of synthetic minerals can have controlled compositions, they are often viewed as "unnatural". Here, we show how trends in the interaction of RNA with natural mineral specimens, synthetic mineral specimens, and co-precipitated pairs of synthetic minerals, can make a persuasive case that the observed interactions reflect the composition of the minerals themselves, rather than their being simply examples of large molecules associating nonspecifically with large surfaces. Using this approach, we have discovered Periodic Table trends in the binding of oligomeric RNA to alkaline earth carbonate minerals and alkaline earth sulfate minerals, where those trends are the same when measured in natural and synthetic minerals. They are also validated by comparison of co-precipitated synthetic minerals. We also show differential binding of RNA to polymorphic forms of calcium carbonate, and the stabilization of bound RNA on aragonite. These have relevance to the prebiotic stabilization of RNA, where such carbonate minerals are expected to have been abundant, as they appear to be today on Mars.

scholarly journals Sorption and Desorption of Vanadate, Arsenate and Chromate by Two Volcanic Soils of Equatorial Africa

Soil Systems ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 22
Author(s):  
Sara Gonzalez-Rodriguez ◽  
Maria Luisa Fernandez-Marcos
Keyword(s):  
Laboratory Experiments ◽  
Sorption Isotherms ◽  
Soil Samples ◽  
Mineral Surfaces ◽  
Volcanic Soils ◽  
Iron Species ◽  
Freundlich Model ◽  
Equatorial Africa ◽  
Relevant Role ◽  
Icp Mass Spectrometry

Sorption of oxyanions by soils and mineral surfaces is of interest due to their role as nutrients or pollutants. Volcanic soils are variable charge soils, rich in active forms of aluminum and iron, and capable of sorbing anions. Sorption and desorption of vanadate, arsenate, and chromate by two African andosols was studied in laboratory experiments. Sorption isotherms were determined by equilibrating at 293 K soil samples with oxyanion solutions of concentrations between 0 and 100 mg L−1 V, As, or Cr, equivalent to 0−2.0 mmol V L−1, 0−1.3 mmol As L−1, and 0−1.9 mmol Cr L−1, in NaNO3; V, As, or Cr were determined by ICP-mass spectrometry in the equilibrium solution. After sorption, the soil samples were equilibrated with 0.02 M NaNO3 to study desorption. The isotherms were adjusted to mathematical models. After desorption with NaNO3, desorption experiments were carried out with a 1 mM phosphate. The sorption of vanadate and arsenate was greater than 90% of the amount added, while the chromate sorption was much lower (19–97%). The sorption by the Silandic Andosol is attributed to non-crystalline Fe and Al, while in the Vitric Andosol, crystalline iron species play a relevant role. The V and Cr sorption isotherms fitted to the Freundlich model, while the As sorption isotherms conformed to the Temkin model. For the highest concentrations of oxyanions in the equilibrating solution, the sorbed concentrations were 37–38 mmol V kg−1, 25 mmol As kg−1, and 7.2–8.8 mmol Cr kg−1. The desorption was low for V and As and high for Cr. The comparison of the sorption and desorption isotherms reveals a pronounced hysteresis for V in both andosols and for Cr in the Silandic Andosol. Phosphate induced almost no V desorption, moderate As desorption, and considerable Cr desorption.

Oxygen Spectroscopy and Polarization-Dependent Imaging Contrast (PIC)-Mapping of Calcium Carbonate Minerals and Biominerals

2014 ◽  
Vol 118 (28) ◽  
pp. 8449-8457 ◽  
Author(s):  
Ross T. DeVol ◽  
Rebecca A. Metzler ◽  
Lee Kabalah-Amitai ◽  
Boaz Pokroy ◽  
Yael Politi ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Carbonate Minerals

scholarly journals The band spectra associated with zinc, cadmium, and mercury

1929 ◽  
Vol 122 (789) ◽  
pp. 201-210 ◽  
Keyword(s):  
Absorption Spectra ◽  
Small Proportion ◽  
Periodic Table ◽  
Alkali Metals ◽  
Alkaline Earth ◽  
Diatomic Molecules ◽  
Alkaline Earth Elements ◽  
Zinc Cadmium ◽  
Band Spectra ◽  
Methods Of Measurement

Tbe band spectra of the alkali metals are now well known, and it has been established that they are due to a small proportion of diatomic molecules, which are normally present in the vapours of these metals. It is as yet uncertain how many other metals, with vapours which, according to the ordinary methods of measurement, appear to be monatomic, give similar spectroscopic proof of association. Throughout a large number of experiments with the saturated vapours of the alkaline earth elements, up to 1200° C., we have found no evidence of band spectra which can be attributed to diatomic molecules of these metals. The elements of Group II b of the Periodic Table are much more interesting in this respect, and it is with experiments on the absorption spectra of these that this communication is concerned.

scholarly journals A Naturally Occurring Mutation in FcγRIIA: A Q to K127 Change Confers Unique IgG Binding Properties to the R131 Allelic Form of the Receptor

Blood ◽  
1998 ◽  
Vol 91 (2) ◽  
pp. 656-662 ◽  
Author(s):  
Cynthia F. Norris ◽  
Luminita Pricop ◽  
Sean S. Millard ◽  
Scott M. Taylor ◽  
Saul Surrey ◽  
...  
Keyword(s):  
Disease Susceptibility ◽  
Screening Methods ◽  
Allelic Form ◽  
Fcγ Receptors ◽  
Binding Properties ◽  
Naturally Occurring ◽  
Igg Binding ◽  
Polymorphic Forms ◽  
Differential Binding ◽  
Therapeutic Monoclonal Antibodies

Abstract FcγRIIa is widely expressed on hematopoietic cells. There are two known allelic polymorphic forms of FcγRIIa, FcγRIIa-R131 and FcγRIIa-H131, which differ in the amino acid at position 131 in the second Ig-like domain. In contrast to FcγRIIa-R131, FcγRIIa-H131binds hIgG2 but not mIgG1, and this differential binding has clinical implications for host defense, autoimmune disease, immunohematologic disease, and response to therapeutic monoclonal antibodies. We identified a novel FcγRIIA genotype in a healthy individual homozygous for FcγRIIA R/R131 in whom a C to A substitution at codon 127 changes glutamine (Q) to lysine (K) in one of the two FcγRIIA genes. This individual's homozygosity for FcγRIIA-R/R131 leads to the prediction that the receptors on her cells would not bind hIgG2. Monocyte and neutrophil phagocytosis of hIgG2-opsonized erythrocytes was significantly higher (P < .05) for cells from this K/Q127, R/R131 individual than for Q/Q127, R/R131 donors. Platelet aggregation stimulated by an mIgG1 anti-CD9 antibody in this individual was significantly different (P < .05) from Q/Q127, H/R131 and Q/Q127, H/H131 donors and similar to Q/Q127, R/R131. Our data show that the K127/R131 receptors have a unique phenotype, binding both hIgG2 and mIgG1. Further functionally significant mutations in human Fcγ receptors and possible novel mechanisms for inherited differences in disease susceptibility should be sought with unbiased screening methods.

Study of One Sort of Romanian Diatomite as Precursor in the Synthesis of Some Metallic Silicates

2008 ◽  
Vol 59 (6) ◽  
Author(s):  
Dan Macarovici ◽  
Viorel Paraschiv ◽  
Elisabeth-Jeanne Popovici
Keyword(s):  
Calcium Carbonate ◽  
Magnesium Oxide ◽  
Alkaline Earth ◽  
Thermal Reaction ◽  
Calcium Silicates ◽  
Magnesium Silicates ◽  
Calcium And Magnesium ◽  
Alkaline Earth Silicates

The behaviour of one sort of Romanian diatomite as precursor in the synthesis of calcium and magnesium silicates was studied. The calcination of this diatomite, 3 h at 10000C in air, does not produce major modifications in structure and composition. In the same conditions, the thermal reaction between diatomite and calcium carbonate leads to a mixture of calcium silicates (CaSiO3, Ca2SiO4, Ca3SiO5) whereas the reaction product with magnesium oxide is orthomagnesium silicate (Mg2SiO4 - forsterite). This sort of Romanian diatomite can play the same role as other silica sources in the synthesis of alkaline-earth silicates.

Influence of Micro Environments and Microorganisms on the Transport Properties of Redox-Sensitive Elements (E.G. Technetium)

1990 ◽  
Vol 212 ◽  
Author(s):  
Hanskarl Brühl ◽  
Asaf Pekdeger ◽  
Andreas Winkler
Keyword(s):  
Transport Properties ◽  
Laboratory Experiments ◽  
Microbial Metabolism ◽  
Mineral Surfaces ◽  
Microbial Activities ◽  
Transport Behaviour

ABSTRACTIn laboratory experiments immobilisation of Tc under oxic conditions was observed. The transport behaviour of redox-sensitive elements is not only controlled by the geochemical “frame conditions” which can be measured within the macro environment. Immobilisation behaviour of Tc strongly depends on micro environments and on microbial metabolism. Micro environments which may develope on the mineral surfaces can detoriate the mobility of Tc, furthermore the fixation of Tc is influenced by microbial activities.

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