Virus-Like Microfossils in the 1.64 Ga Siliceous Rocks From Hogland Island, Russia

Several varieties of virus-like microfossils, morphologically similar to modern giant viruses of the Mimiviridae family, have been identified in microquartzites in the 1.64 Ga volcanogenic-sedimentary strata in Hogland Island in the Gulf of Finland, Russia. Microquartzites contain graphite enriched in a light carbon isotope 12С, as is typical for the rocks forming with participation of living matter. Abundant remains of silificated and ferruginizated microfossils of planktonic microorganisms and virus-like structures were found in fragments of silificated biofilms. However, virus-like microfossils exceed modern giant viruses in linear dimensions by a factor of a thousand or more (Belyaev, 2018; 2019; Belyaev, Yukhalin, 2021) and contain structures similar to eukaryotic nuclei. In addition, data were obtained that can be interpreted as a fact of parasitic relationships of virus-like formations with microfossils of amoeba-like microorganisms. Inside, and in the immediate surroundings of some virus-like structures, small oval zonal formations occur, which, possibly, represent silificated viral particles, the most ancient obligate super parasites similar to "satellite" virophages in mimiviruses (La Scola, et al., 2008). Apatite grains found in the mineralized cytoplasm and nuclei of virus-like microfossils, most likely, crystallized from phosphoric acid residues of decayed nucleotides. This allowed for the first time to roughly estimate the size of the genomes of the most ancient virus-like structures, which exceeded the genomes of modern giant viruses and unicellular organisms by a factor of thousands (Belyaev, Yukhalin, 2021). The genome masses of eukaryotic microfossils and virus-like structures were also estimated following the principle of genomic-nuclear proportionality, according to which the molecular weights of genomes are directly proportional to the size of the nuclei. In this case, the size of genomes of virus-like structures estimated both form the enclosed apatite grains and the size of nuclei, averaged tens of thousands of picograms and, thus, could contain tens of thousands billions of base pairs. It is assumed that microfossils of virus-like structures from the group of unclear systematic position Dinoviridae Incertae sedis were representatives of the extinct family of unicellular facultative parasites or were the ancestors of giant viruses of the Mimiviridae family.

Effect of Mg Treatment on the Nucleation and Ostwald Growth of Inclusions in Fe-O-Al-Mg Melt

This study aimed to investigate the effect of Mg treatment on the nucleation and ostwald growth of inclusions. Deoxidized experiments with Al (0.05%Al) and Al-Mg (0.05%Al + 0.03%Mg) were carried out at 1873 K, and the composition, number, and size of inclusions were studied as a function of holding time. Homogeneous nucleation theory and ostwald ripening were utilized to calculate the nucleation rate, the critical size of nuclei, and coarsening rate of inclusions. The results show that small inclusions were more easily found in the steels with Al-Mg complex deoxidation, and the number of inclusions with Al-Mg complex deoxidation is larger at an early stage of deoxidation. The critical size of nuclei increases in the order of MgAl2O4 (0.3–0.4 nm) < Al2O3 (0.4–0.6 nm), and the nucleation rate increases in the order of Al2O3 (1100 cm−3 s−1) < MgAl2O4 (1200 cm−3s−1), which is consistent with the experimental results. Moreover, the coarsening rate of MgAl2O4 inclusions was smaller than Al2O3 inclusions in both the value of kd(cal.) from ostwald growth and the value of kd(obs.) from inclusion size. The effect of Mg addition on coarsening of inclusion was analyzed and their mechanism was discussed based on ostwald ripening theory and Factsage calculation.

Temperature dependent pairing gap in nuclei

Based on theoretical models and experimental evidences of a soft phase transition, with significant, but not abrupt changes in pairing gap of nuclei, a modified pairing gap function was suggested and examined for some of nuclei in our previous publications. Now, we propose a new method to extract the parameters, which exist in the modified pairing gap function. This method is based on phenomenological models, which consider the small size of nuclei and the effect of thermal fluctuations, at the vicinity of the critical temperature. The obtained pairing gap function by this method is easily applicable in the microscopic model calculations within an entire temperature range, from zero to temperatures above the critical point.

Size-Controlled Synthesis of CoFe2O4Nanoparticles Potential Contrast Agent for MRI and Investigation on Their Size-Dependent Magnetic Properties

Cobalt ferrite nanoparticles (CoFe2O4NPs) were synthesized by coprecipitation followed by treatments with diluted nitric acid and sodium citrate. Transmission electron microscope (TEM) and photon correlation spectroscopy (PCS) characterization showed that the size distributions of these nanoparticles were monodisperse and that no aggregation occurred. This colloid showed a long-term stability. Through adjustment of the concentrations of reactants and reaction temperature, the size of the NPs can be tuned from 6 to 80 nm. The size-control mechanism is explained by a nucleation-growth model, where the local concentration of monomers is assumed to decide the size of nuclei, and reaction temperatures influence the growth of nuclei. Magnetization and relaxivityr1,2measurements showed that the NPs revealed size-dependent magnetization and relaxivity properties, which are explained via a “dead magnetic layer” theory where reductions of saturation magnetization (Ms) andr1,2are assumed to be caused by the demagnetization of surface spins.

Changes in Lymantria dispar protocerebral neurosecretory neurons after exposure to cadmium

Gypsy moth 4th instar caterpillars were fed for 3 days with an artificial diet supplemented with increasing cadmium (Cd) concentrations (0, 10, 30, 100 and 250 ?g?g of dry food weight). Changes in the morphometric characteristics of A1? dorso-medial and L2 dorso-lateral neurosecretory neurons (nsn) were analyzed. In the A1? nsn, Cd supplements led to an enhanced nuclear size, except in the group treated with 250 ?g Cd?g in the form of dry food. The size of L2 type nsn was increased in the groups provided with 30 and 100 ?g Cd?g, while no differences in the size of nuclei was detected in L2 neurons among the experimental groups.

Same-day breast core biopsy result: Effect on ER/PR and HER-2 scores

e11585 Background: The peloris rapid tissue processor promises same-day biopsy results. It uses a unique ActivFlo system achieving fast processing by rapid even heating and reagent exchange. The effect on ER/PR, Her2 scores and morphology of tumour cells are assessed Methods: 80 breast core biopsies were so far included in this study. For each case, one of three core biopsies was processed by the Peloris and the other two by the Leica histology processor for next day reporting. Each core biopsy was fixed in formalin for at least 3 - 6 hours before being processed by both systems.Immunohistochemistry for ER, PR and Her2 was carried out as well as FISH for borderline Her2 cases scoring 2+. Microscopical features were compared by the same histopathologist and tumour grade and type were recorded Results: On comparing cases processed by Peloris and Leica, 47 out of 68 biopsies (69%) scored exactly the same for ER and PR. 16 biopsies (23.5%) had minor scoring differences but did not affect the overall hormone receptor status. In total, 63 out of 68 biopsies (94%) scored similar receptor status. 4 cases (6%) had differing ER/PR status. 56 cases had Her2 tested, 51 (91%) had similar scores and 5 (9%) had different scores. 14 borderline cases had FISH tests and no different results were seen between Peloris and Leica processed tissue. Morphologically there were differences in size of nuclei and nuclear chromatin appearances. We have started the second part of the study in which biopsies for the Peloris are loaded immediately on receipt giving about 30 minutes of formalin fixation. Of the 9 biopsies so far processed, there have been no noticeable differences between the fixed tissue on the Leica processor and the fresh tissue on Peloris with regards to ER, PR and Her2. Conclusions: In conclusion, immunohistochemistry for ER/PR and Her2 is similar in 93% and 91% cases respectively. Results for FISH test were similar in all 14 cases. However, morphological differences were noted and the effect on tumour grade was discussed. Further evaluation and comparison of tissue using both processors on morphological architecture need to be carried out and any differences reported. No significant financial relationships to disclose.

A Combinatorial Chemistry Study of YAG Nucleation

ABSTRACTA combinatorial method to screen large numbers of dopants that affect the nucleation of yttrium-aluminum garnet was developed. The method involves heat-treatment of electron-transparent sol-derived thin films on TEM grids, and counting the number and size of nuclei by TEM. Advantages and limitations of the technique are discussed. Preliminary results are presented.