Surface reconstructions and premelting of the (100) CaF2 surface

In this work, surface reconstructions on the (100) surface of CaF2 are comprehensively investigated. The configurations were explored by employing the Minima Hopping Method (MHM) coupled to a machine-learning interatomic potential, that is based on a charge equilibration scheme steered by a neural network (CENT). The combination of these powerful methods revealed about 80 different morphologies for the (100) surface with very similar surface formation energies differing by not more than 0.3 J m−2. To take into account the effect of temperature on the dynamics of this surface as well as to study the solid–liquid transformation, molecular dynamics simulations were carried out in the canonical (NVT) ensemble. By analyzing the atomic mean-square displacements (MSD) of the surface layer in the temperature range of 300–1200 K, it was found that in the surface region the F sublattice is less stable and more diffusive than the Ca sublattice. Based on these results we demonstrate that not only a bulk system, but also a surface can exhibit a sublattice premelting that leads to superionicity. Both the surface sublattice premelting and surface premelting occur at temperatures considerably lower than the bulk values. The complex behaviour of the (100) surface is contrasted with the simpler behavior of other low index crystallographic surfaces

Compatibility of entomopathogenic fungi Beauveria bassiana and Metarhizium anisopliae with some pesticides

Entomopathogenic fungi may be affected by pesticides used to protect crop plants. The in vitro compatibility of Beauveria bassiana and Metarhizium anisopliae with three fungicides and 16 insecticides was evaluated. The formulations of pesticides were tested in three concentrations (mean concentration (MC), half MC and twice the MC). All tested fungicides, at three concentrations, were incompatible with these two fungi and significantly inhibited fungal development, germination of spores and spore production. Insecticides, except for spinosad, deltametrin, imidachloprid and abamectin, were incompatible with these two fungi at high concentration and caused complete or strong inhibition of fungal development. The compatible insecticide with B. bassiana and M. anisopliae, at three concentrations, found to be spinosad. Abamectin, imidachloprid and deltametrin, however at half MC and MC were compatible with B. bassiana. Deltametrin, abamectin and hexafloron at half MC were compatible with M. anisopliae. We conclude that these pesticides with the defined formulations could be used with the entomopathogenic fungi in integrated pest management programs

A fingerprint based metric for measuring similarities of crystalline structures

Measuring similarities/dissimilarities between atomic structures is important for the exploration of potential energy landscapes. However, the cell vectors together with the coordinates of the atoms, which are generally used to describe periodic systems, are quantities not suitable as fingerprints to distinguish structures. Based on a characterization of the local environment of all atoms in a cell we introduce crystal fingerprints that can be calculated easily and allow to define configurational distances between crystalline structures that satisfy the mathematical properties of a metric. This distance between two configurations is a measure of their similarity/dissimilarity and it allows in particular to distinguish structures. The new method is an useful tool within various energy landscape exploration schemes, such as minima hopping, random search, swarm intelligence algorithms and high-throughput screenings

The frequency of human leukocyte antigen-DRB1 alleles, using sequence-based genotyping in 68 parents-child trios study in Iranian subjects

Background: The human leukocyte antigen-DRB1 (HLA-DRB1) locus is one of the most polymorphic human loci and has a crucial role in the immune system. Assessing the allelic frequencies of HLA-DRB1 locus would be a fundamental factor in defining the origin of populations, relationships with other populations, disease association studies and the constitution of unrelated bone marrow donor registries. In the current study HLA-DRB1 alleles and their frequencies are determined in a family-based study by DNA sequencing-based typing high-resolution (2 field) level of typing. Materials and Methods: Genomic DNA from 3 members of 68 unrelated families (a total of 204 individuals) was extracted. Exon 2 of DRB1 gene was amplified and performed useing AssignTM SBT v4.7 sequence analysis software.Results: We had DRB1*11:04 with frequency of 0.0931, DRB1*03:01 with 0.0882, DRB1*11:01 with 0.0735, DRB1*13:01 with 0.071 and also alleles DRB1*08:03, DRB1*13:42, DRB1*14:04 and DRB1*14:07 with frequency of 0.0024.Conclusion: A total of 34 different alleles were found in the study subjects with DRB1*11:04, DRB1*03:01, DRB1*11:01 being the most frequent alleles respectively.  

HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) versus adult T-cell leukemia/lymphoma (ATLL)

ObjectivesHuman T cell leukemia virus-1 (HTLV-1) infection may lead to one or both diseases including HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) or adult T cell leukemia lymphoma (ATLL). The complete interactions of the virus with host cells in both diseases is yet to be determined. This study aims to construct an interaction network for distinct signaling pathways in these diseases based on finding differentially expressed genes (DEGs) between HAM/TSP and ATLL.ResultsWe identified 57 hub genes with higher criteria scores in the primary protein-protein interaction network (PPIN). The ontology-based enrichment analysis revealed following important terms: positive regulation of transcription from RNA polymerase II promoter, positive regulation of transcription from RNA polymerase II promoter involved in meiotic cell cycle and positive regulation of transcription from RNA polymerase II promoter by histone modification. The upregulated genes TNF, PIK3R1, HGF, NFKBIA, CTNNB1, ESR1, SMAD2, PPARG and downregulated genes VEGFA, TLR2, STAT3, TLR4, TP53, CHUK, SERPINE1, CREB1 and BRCA1 were commonly observed in all the three enriched terms in HAM/TSP vs. ATLL. The constructed interaction network was then visualized inside a mirrored map of signaling pathways for ATLL and HAM/TSP, so that the functions of hub genes were specified in both diseases.Peer reviewe

Ab-initio study of the stability and electronic properties of wurtzite and zinc-blende BeS nanowires

In this work we study the structural stability and electronic properties of the Beryllium sulphide nanowires (NWs) in both zinc blende (ZB) and wurtzite (WZ) phases with triangle and hexagonal cross section, using first principle calculations within plane-wave pseudopotential method. A phenomenological model is used to explain the role of dangling bonds in the stability of the NWs. In contrast to the bulk phase, ZB-NWs with diameter less than 133.3 (angstrom) are found to be less favorable over WZ-NWs, in which the surface dangling bonds (DBs) on the NW facets play an important role to stabilize the NWs. Furthermore, both ZB and WZ NWs are predicted to be semiconductor and the values of the band gaps are dependent on the surface DBs as well as the size and shape of NWs. Finally, we performed atom projected density-of states (PDOSs) analysis by calculating the localized density of states on the surface atoms, as well as on the core and edge atoms.Comment: 9 Pages, 6 Figure

Association between heavy metals and colon cancer: an ecological study based on geographical information systems in North-Eastern Iran

Background: Colorectal cancer has increased in Middle Eastern countries and exposure to environmental pollutants such as heavy metals has been implicated. However, data linking them to this disease are generally lacking. This study aimed to explore the spatial pattern of age-standardized incidence rate (ASR) of colon cancer and its potential association with the exposure level of the amount of heavy metals existing in rice produced in north-eastern Iran. Methods: Cancer data were drawn from the Iranian population-based cancer registry of Golestan Province, northeastern Iran. Samples of 69 rice milling factories were analysed for the concentration levels of cadmium, nickel, cobalt, copper, selenium, lead and zinc. The inverse distance weighting (IDW) algorithm was used to interpolate the concentration of this kind of heavy metals on the surface of the study area. Exploratory regression analysis was conducted to build ordinary least squares (OLS) models including every possible combination of the candidate explanatory variables and chose the most useful ones to show the association between heavy metals and the ASR of colon cancer. Results: The highest concentrations of heavy metals were found in the central part of the province and particularly counties with higher amount of cobalt were shown to be associated with higher ASR of men with colon cancer. In contrast, selenium concentrations were higher in areas with lower ASR of colon cancer in men. A significant regression equation for men with colon cancer was found (F(4,137) = 38.304, P < .000) with an adjusted R2 of 0.77. The predicted ASR of men colon cancer was − 58.36 with the coefficients for cobalt = 120.33; cadmium = 80.60; selenium = − 6.07; nickel = − 3.09; and zinc = − 0.41. The association of copper and lead with colon cancer in men was not significant. We did not find a significant outcome for colon cancer in women. Conclusion: Increased amounts of heavy metals in consumed rice may impact colon cancer incidence, both positively and negatively. While there were indications of an association between high cobalt concentrations and an increased risk for colon cancer, we found that high selenium concentrations might instead decrease the risk. Further investigations are needed to clarify if there are ecological or other reasons for these discrepancies. Regular monitoring of the amount of heavy metals in consumed rice is recommended.This study was supported by Golestan University of Medical Sciences (grant number of 90–10–1-30209)