AFM of metallic nano-particles and nano-structures in heavily irradiated NaCl

AFM investigations are reported for heavily, electron irradiated NaCl crystals in ultra high vacuum (UHV) in the non-contact mode with an UHV AFM/STM Omicron system. To avoid chemical reactions between the radiolytic Na and oxygen and water, the irradiated samples were cleaved and prepared for the experiments in UHV. At the surface of freshly cleaved samples, we have observed sodium nano-precipitates with shapes, which depend on the irradiation dose and the volume fraction of the radiolytic Na. It appears that the nano-structures consist of (i) isolated nano-particles, (ii) more or less random aggregates of these particles, (iii) fractally shaped networks and (iv) ‘‘fabrics’’ consisting of bundles of Quasi-1D arrays forming polymeric networks of nano-particles. Almost independent of the concentration of the metallic Na in the samples the size of the individual nano-particles is in the range 1–3 nm. Our new AFM results are fully in line with our CESR and previous Raman scattering results.

Effect of the medium on the acid-base properties of α-aminophosphoryl compounds

Structural thermodynamic analysis of the acidity of α-aminophosphoryl compounds in water-isopropanol systems was carried out by means of evaluation of the Gibbs energies of transfer of species involved in protolytic equilibria. Protonated (deprotonated) forms of structurally diverse aminophosphoryl compounds similarly interact by the mechanism of specific and universal solvation with each of the water-isopropanol solvents (100, 50, and 25 vol % of water) in the reaction series used. For this reason, there are significant linear correlations between acidity parameters for various media, which makes possible successful predictions of the acid-base properties of structurally diverse compounds of the class studied in water-isopropanol media with various water contents. © 2005 Pleiades Publishing, Inc

Radiolysis of NaCl at high and low temperatures: development of size distribution of bubbles and colloids

New experimental results are presented on low temperature irradiation (18 °C) of rock-salt samples which had been exposed to initial doses up to 320 GRad at 100 °C. Differential scanning calorimetry (DSC) shows that the latent heat of melting (LHM) of sodium colloids decreases during subsequent low-temperature irradiation, whereas the stored energy (SE) increases slowly, indicating that the process of radiolysis continues. The decrease of the LHM is due to dissolution of large colloids, because the intensities of the melting peaks decrease during the second stage irradiation at low temperature. The model is formulated to describe the nucleation kinetics and the evolution of the size distribution of chlorine precipitates and sodium colloids in NaCl under high dose irradiation. It is shown that the mechanism of dissolution of large Na colloids during low temperature irradiation can be related to melting of sodium colloids.

Targeting Protein-Protein Interactions for Parasite Control

Finding new drug targets for pathogenic infections would be of great utility for humanity, as there is a large need to develop new drugs to fight infections due to the developing resistance and side effects of current treatments. Current drug targets for pathogen infections involve only a single protein. However, proteins rarely act in isolation, and the majority of biological processes occur via interactions with other proteins, so protein-protein interactions (PPIs) offer a realm of unexplored potential drug targets and are thought to be the next-generation of drug targets. Parasitic worms were chosen for this study because they have deleterious effects on human health, livestock, and plants, costing society billions of dollars annually and many sequenced genomes are available. In this study, we present a computational approach that utilizes whole genomes of 6 parasitic and 1 free-living worm species and 2 hosts. The species were placed in orthologous groups, then binned in species-specific ortholgous groups. Proteins that are essential and conserved among species that span a phyla are of greatest value, as they provide foundations for developing broad-control strategies. Two PPI databases were used to find PPIs within the species specific bins. PPIs with unique helminth proteins and helminth proteins with unique features relative to the host, such as indels, were prioritized as drug targets. The PPIs were scored based on RNAi phenotype and homology to the PDB (Protein DataBank). EST data for the various life stages, GO annotation, and druggability were also taken into consideration. Several PPIs emerged from this study as potential drug targets. A few interactions were supported by co-localization of expression in M. incognita (plant parasite) and B. malayi (H. sapiens parasite), which have extremely different modes of parasitism. As more genomes of pathogens are sequenced and PPI databases expanded, this methodology will become increasingly applicable

Effects of Elevated Temperature and Carbon Dioxide on the Growth and Survival of Larvae and Juveniles of Three Species of Northwest Atlantic Bivalves

Rising CO2 concentrations and water temperatures this century are likely to have transformative effects on many coastal marine organisms. Here, we compared the responses of two life history stages (larval, juvenile) of three species of calcifying bivalves (Mercenaria mercenaria, Crassostrea virginica, and Argopecten irradians) to temperatures (24 and 28°C) and CO2 concentrations (∼250, 390, and 750 ppm) representative of past, present, and future summer conditions in temperate estuaries. Results demonstrated that increases in temperature and CO2 each significantly depressed survival, development, growth, and lipid synthesis of M. mercenaria and A. irradians larvae and that the effects were additive. Juvenile M. mercenaria and A. irradians were negatively impacted by higher temperatures while C. virginica juveniles were not. C. virginica and A. irradians juveniles were negatively affected by higher CO2 concentrations, while M. mercenaria was not. Larvae were substantially more vulnerable to elevated CO2 than juvenile stages. These findings suggest that current and future increases in temperature and CO2 are likely to have negative consequences for coastal bivalve populations

SURGICAL TACTICS FOR LARGE AND GIANT ESOPHAGEAL HIATAL HERNIA

The  OBJECTIVE  is to improve  the  results of surgical  treatment of patients with large  and  giant  EHH. MATERIAL AND METHODS.  We  present our  experience of surgical  treatment of 25  patients with large  and  giant  EHH, who  underwent laparoscopic  interventions according to  the  original  technique, which  consisted in the  method of plasty  of esophageal hiatus:   the   mesh  implant   was   installed   and   fixed  in  the   posterior  mediastinum  above  the   diaphragm.  RESULTS. Intraoperative  bleeding  was   noted   in  2  (8  %)  patients,  which  did  not  require   conversion.  In  the  near   postoperative period,   no  complications  were  noted.   In  the  long-term   periods from  1  to  5  years, there   was  no  recurrence of  EHH and  complications associated  with the  use   of mesh implant.  CONCLUSION.  Videoendosurgical  interventions  are  the operations  of  choice  in  the  treatment  of  patients  with  large  and  giant  EHH.  The  most  effective  method  of  plasty for  large  and  giant  EHH  is  the  combined plasty  of  the  esophageal hiatus   by  a  mesh implant  in  combination  with  a posterior  cruroraphy,  with  the  installation   and   fixation  of  the  mesh implant  in  the  posterior mediastinum above  the cruses of diaphragm