Comparison of toxic effects of iron-molybdenum polyoxometalates and mixture of their components

Introduction. The physicochemical properties and the impact on living organisms of nanoparticles and components that make up nanoparticles may differ radically, however, insufficient attention is paid to a comparative study of the toxicity of nanoparticles and constituents of nanoparticles. Material and methods. Biochemical and hematological parameters in the blood of 50 male Wistar rats were determined after a single, seven-fold and thirty-fold intramuscular injection of an aqueous solution of iron-molybdenum nanocluster polyoxometalates (POM) and a mixture of the POM components at a dose of 1.5 mg/kg. A solution of a POM components’ mixture was obtained by the destruction of POM with an increase in pH, followed by neutralization, since POM are unstable in an alkaline medium. Results. The introduction of POM did not cause deviations from the norm in the activity of AST, ALT, total alkaline phosphatase and its bone isoenzyme, α-amylase, protein content, urea and creatinine, which indicates the absence of cytolytic syndrome, including in the liver and myocardium, no damage to the acinar part of pancreas, changes in bone tissue, preservation of the protein-synthetic function of the liver and the filtering ability of the kidneys. The introduction of a solution of POM components (molybdenum, iron) was accompanied by an increase in the activity of AST, alkaline phosphatase, the AST / ALT ratio after 7 injections and an increase in the last two parameters after 30 injections. The impact of POM is characterized by an increase in the content of hemoglobin and erythrocytes in the blood and less pronounced leukopenia, in contrast to the mixture of POM components. Conclusion. A less pronounced deviation from the norm of biochemical parameters and a lower degree of leukopenia make it possible to assess the effect of POM nanoparticles as less toxic than the action of POM components not organized into nanoparticles.

Activity Coefficients for Liquid Organic Reactions: Towards a Better Understanding of True Kinetics with the Synthesis of Jasmin Aldehyde as Showcase

The aldol condensation of benzaldehyde and heptanal is taken as an example of reversible liquid phase organic reactions to show that inclusion of activity coefficients reveal distinct differences in conversion and product distribution when different solvents methanol, ethanol, n-propanol, or n-butanol are used. The purpose of this work is to show a pronounced solvent effect for a given set of identical kinetic parameters, i.e., the same liquid phase kinetics can result in different conversion and yield values, depending on the choice of solvent. It was shown that subsequent parameter estimation without inclusion of the activity coefficients resulted in a pronounced deviation from the ‘true’ kinetics, up to a factor of 30. It is proposed that the usage of average activity coefficients gives already a significant improvement, resulting in acceptable parameter estimates.

Enantiopure and racemic alanine as bridging ligands in Ca and Mn chain polymers

Under accelerated and controlled evaporation, chain polymers crystallize from aqueous solutions of CaIIand MnIIhalides with enantiopure L-alanine or racemic DL-alanine. In all ten solids thus obtained zwitterionic amino acid ligands bridge neighbouring cations. The exclusively O-donor-based coordination sphere around the metal cations is completed by aqua ligands; the halides remain uncoordinated and act as counter-anions for the cationic strands. Despite the differences in ionic radii and electronic structure between the main group and the transition metal cation, their derivatives with L-alanine share a common structure type. In contrast, the solids derived from DL-alanine differ and adopt structures depending on the metal cation and the halide. Homochiral chains of either chirality or heterochiral chains with different arrangements of crystallographic inversion centres along the polymer strands are encountered. On average, the six-coordinated CaIIcations, devoid of any ligand field effect, show more pronounced deviation from idealized octahedral geometry than thed-block cation MnII.

Magnetization Measurements of 5µm Ba0.6K0.4BiO3 Crystals: Approach to Intrinsic Behavior with Decreasing Size

Magnetization measurements on cubic Ba0.6K0.4BiO3 crystals, approximately 5µm in radius, have been obtained using a recently-developed electrodynamic force balance technique. The onset of flux entry in an external filed H is marked by a pronounced deviation from a linear magnetization at a critical field H*c1 together with a noticeable reorientation of the crystal near H = 0, a reorientation caused by a field-induced torque on the remanent moment. The dependence of H*c1 on temperature is linear over the temperature range 7K≤T≤30K with a slope approximately a factor of three higher than published values. These higher values of H*c1 imply either intrinsically cleaner material with a reduced Ginzburg-Landau parameter K or higher surface critical fields. These results suggest that the intrinsic properties of high-Tc superconductors may be more accurately reflected in small crystals which are more likely to be of higher quality than larger crystals.

Assessment of Different Mathematical Models for Calculating and Expressing the Results of Coagulation Test Procedures

SummaryCoagulation activity, expressed as percentage of normal and as clotting time ratio, was estimated in 220 specimens from patients on long-term anticoagulant treatment by 3 different coagulation test procedures, i.e. Thrombotest, Simplastin-A and Normotest. The estimates were calculated from the same determinations.The distribution of percentage values showed a fairly pronounced deviation from normality. After logarithmic transformation, the distribution was normalized, the regression lines between Thrombotest and other tests became parallel, and that between PIVKA-insensitive systems was shifted to a 45° line. Logarithmic transformation also stabilized the residual variance. These features make percentage values accessible for treatment according to the standard methods of bioassay statistics.Attempts to normalize the distribution of ratio values by various transformations were unsuccessful. Formal analysis of data revealed a variation in the proportionality of ratio values with the level of estimated coagulation defect. This may restrict the usefulness of the ratio approach. Logarithmic transformation partly reduced the discrepancy.

Polymer/Solvent Interaction Parameters

Solutions in which one of the components is a high polymer and the other component is a small-molecule solvent behave in a markedly different manner than do solutions of low molecular weight components. For example, the latter obey Raoult's law if the heat of mixing is negligible; however, many polymer solutions show pronounced deviation from ideality even at concentrations of one percent or less (Figures 1–7). These deviations are due to enthalpy and entropy effects which arise from large differences in size between solvent and solute molecules. Ability to predict the solubility characteristics of polymer/solvent systems, and to calculate values of the colligative properties of such systems, is important in engineering studies of polymer processes. This paper presents a compilation of data which can be used in conjunction with the Flory-Huggins theory of polymer solutions to predict properties of polymer solutions. A method is given for predicting polymer/solvent interaction parameters (μ) for systems for which experimental data are not available. Also included is a comparison between the proposed method and two other semiempirical methods for predicting μ.

Presumed Trade and Aberrant Pottery

The pottery in the following sections is not considered to belong to the Alto Focus complex, but to occur with it at different points in the Davis site occupation by trade or other means. If the writer appears to vacillate over what is and what is not trade pottery here, it is due in part to the problem of separating what could have been produced at the site (as extreme variations of resident styles) from what probably was not (because of some distinctive attribute which would mark it as foreign). In certain cases of pronounced deviation, a foreign origin is obvious enough, particularly when the source areas are well known. But where the whole tradition is similar as in the clay-tempered pottery of the lower Mississippi Valley region, and a great range of decorative techniques was employed for long periods of time, the problem is not easy.

TOXINS AND ANTITOXINS--SNAKE VENOMS AND ANTIVENINS

A specific antivenin against crotalus venom can be prepared bv the immunization of goats. A specific antivenin against water moccasin venom can be produced by the immunization of goats with this venom, modified by hydrochloric acid. Immunization with the unmodified venom is very difficult. The toxicity of crotalus venom is diminished more than fifty percent. by passage through a Chamberland filter. There is a simple relation between the toxicity and the body weight for guinea-pigs weighing from 250 to 500 grams. Smaller guinea-pigs (125 grams) are comparatively less resistant. The toxicity is smaller by subcutaneous than by intraperitoneal injection (guinea-pigs), or by intravenous injection (rabbits). White rats are very resistant. The toxicity of cobra venom is not measurably diminished by filtration through a Chamberland filter. The relation between the amount of venom and the corresponding time of death is very regular, and can be expressed by a curve of asymptotic nature. Lecithin does not increase the toxicity. The tracings representing toxin-antitoxin neutralization for the three venoms (crotalus, cobra and moccasin) show deviation from the straight line. This deviation is most pronounced for the toxic quota of the venoms. The tracing representing crotalus venomantivenin neutralization, determined on guinea-pigs, can, within errors of experiment, be expressed by the equation: Free toxin · Free antitoxin = K · toxin-antitoxin. The corresponding tracing determined on rabbits is somewhat different, but both tracings are much more markedly curved than that for cobra venom-antivenin. The neutralization tracing of water moccasin venom shows the peculiarity, that small amounts of antivenin decrease the toxicity to a minimum, but the toxicity is again increased by further addition of antitoxin. The tracing representing neutralization of the haemolysins of the three venoms are different from the tracings of neutralization of the toxins, and approach very closely to a straight line. Still, in all instances, the determinations with great concentrations of antilysin show pronounced deviation, perhaps due to some dissociation of the toxin-antitoxin combination.