Erratum: Lattice Dynamics of EuO: Evidence for Giant Spin-Phonon Coupling [Phys. Rev. Lett. 116, 185501 (2016)].

This corrects the article DOI: 10.1103/PhysRevLett.116.185501.

Lattice Dynamics of EuO: Evidence for Giant Spin-Phonon Coupling.

Comprehensive studies of lattice dynamics in the ferromagnetic semiconductor EuO have been performed by a combination of inelastic x-ray scattering, nuclear inelastic scattering, and ab initio calculations. A remarkably large broadening of the transverse acoustic phonons was discovered at temperatures above and below the Curie temperature T_{C}=69 K. This result indicates a surprisingly strong momentum-dependent spin-phonon coupling induced by the spin dynamics in EuO.

Anomalous Lattice Dynamics of EuSi_{2} Nanoislands: Role of Interfaces Unveiled.

We report a systematic lattice dynamics study of EuSi_{2} films and nanoislands by in situ nuclear inelastic scattering on ^{151}Eu and ab initio theory. The Eu-partial phonon density of states of the nanoislands exhibits anomalous excess of phonon states at low and high energies, not present in the bulk and at the EuSi_{2}(001) surface. We demonstrate that atomic vibrations along the island-substrate interface give rise to phonon states both at low and high energies, while atomic vibrations across the island-island interface result in localized high-energy phonon modes.

Expression analysis of genes involved in apoptosis, proliferation and endoplasmic reticulum stress in ionomycin/PMA treated Jurkat cells.

PURPOSE: Activation of T cells by direct stimulation with phorbol 12-myristate 13-acetate (PMA) and ionomycin (Io) results in numerous downstream signals that activate pathways enabling T cells to proliferate and produce cytokines. Inducible T cell activation is regulated predominantly at the transcriptional level. Therefore, we were interested to analyze the transcriptional activity of the 19 genes involved in the regulation of several important cellular processes. METHODS: Quantitative real-time (RT) PCR analysis was performed using mRNA-specific primers and SybrGreen for relative mRNA expression levels of all the examined genes. RESULTS: Our results showed c-kit expression in Jurkat cells, further confirmed by sequencing of c-kit mRNAspecific PCR product. The expected increased expression of interleukin (IL)-2 mRNA, together with moderate Ki-67 upregulation, indicate the proliferation of PMA/Io treated Jurkat cells. Significant upregulation of nuclear factor (NF)-κB, JNK and the prosurvival Bcl-2 was followed by activation of only one protein kinase RNA-like endoplasmic reticulum kinase (PERK) out of 3 main endoplasmic reticulum (ER) stress subpathways (ATF6 and spliced XBP were downregulated). NF-κB and JNK activation, as well as ERK downregulation were reactive oxygen species (ROS)-independent, shown by the lack of activation of antioxidative enzymes (SOD, NOS, GSTP1, gGCS and GR). C-kit was downregulated in the absence of exogenous SCF (c-kit ligand). CONCLUSION: Based on these data it is concluded that the PMA/Io treatment of Jurkat cells induced increased expression of IL-2, followed by upregulation of prosurvival genes belonging to the Bcl-2 family. Neither c-kit nor the antioxidative system were activated, excluding their role in Jurkat T-cell activation in the absence of exogenous c-kit ligand SCF.

Molecular diversity and evolutionary history of rabies virus strains circulating in the Balkans.

Molecular studies of European classical rabies viruses (RABV) have revealed a number of geographically clustered lineages. To study the diversity of Balkan RABV, partial nucleoprotein (N) gene sequences were analysed from a unique panel of isolates (n = 210), collected from various hosts between 1972 and 2006. All of the Balkan isolates grouped within the European/Middle East Lineage, with the majority most closely related to East European strains. A number of RABV from Bosnia & Herzegovina and Montenegro, collected between 1986 and 2006, grouped with the West European strains, believed to be responsible for the rabies epizootic that spread throughout Europe in the latter half of the 20th Century. In contrast, no Serbian RABV belonged to this sublineage. However, a distinct group of Serbian fox RABV provided further evidence for the southwards wildlife-mediated movement of rabies from Hungary, Romania and Serbia into Bulgaria. To determine the optimal region for evolutionary analysis, partial, full and concatenated N-gene and glycoprotein (G) gene sequences were compared. Whilst both the divergence times and evolutionary rates were similar irrespective of genomic region, the 95 % highest probability density (HPD) limits were significantly reduced for full N-gene and concatenated NG-gene sequences compared with partial gene sequences. Bayesian coalescent analysis estimated the date of the most common recent ancestor of the Balkan RABV to be 1885 (95 % HPD, 1852-1913), and skyline plots suggested an expansion of the local viral population in 1980-1990, which coincides with the observed emergence of fox rabies in the region.

Expression analysis of genes involved in epigenetic regulation and apoptosis in human malignant haematopoietic cell lines treated with 5-azacytidine.

PURPOSE: The aim of this study was to investigate the modulation of the expression status of 10 different genes involved in epigenetic regulation and apoptosis by the DNA methyltransferase (DNMT) inhibitor 5-azacytidine (5-Aza), as markers of response to treatment, in two different human malignant haematopoietic cell lines. METHODS: In our analysis we used the SybrGreen technology and gene-specific primers for the qRT-PCR analysis of 10 genes, in cDNA of PC-MDS and K562 cell lines, treated by 1 micromole of 5-Aza for 24h. RESULTS: DNMT1 and DNMT3A showed statistically significant decrease of expression in 5-Aza-treated PC-MDS cells, whereas DNMT3B showed significantly decreased expression in 5-Aza-treated K562 cells. The members of the Bcl- 2 family of apoptosis-regulating genes Bcl-2 and Bax showed statistically significant differences in expression, in comparison with non-treated PC-MDS cells. Our most interesting result was the significant upregulation (re-expression) of p15, in 5-Aza-treated PC-MDS cells. CONCLUSION: The re-expression of p15 in PC-MDS cell line evaluated by qRT-PCR makes this novel cell line a suitable model for the studies of pharmacologic demethylation as a plausible mechanism resulting in hematologic response in myelodysplastic syndrome (MDS).

Noncollinear magnetization structure at the thickness-driven spin-reorientation transition in epitaxial Fe films on W(110).

An in-plane spin-reorientation transition occurring during the growth of epitaxial Fe films on W(110) was studied in situ by using the nuclear resonant scattering of synchrotron radiation. The spin-reorientation transition originates at the Fe/W(110) interface and proceeds via a noncollinear spin structure resembling a planar domain wall that propagates towards the surface with increasing film thickness.

Quantitative real time-polymerase chain reaction method in Bcr-Abl translocation diagnostics.

PURPOSE: The quantitative real-time polymerase chain reaction (qRT-PCR) is used in the detection of molecular events involved in leukemogenesis, such as the Bcr-Abl gene translocation, the most important factor in the pathogenesis of chronic myeloid leukaemia (CML). The main aim of our study was to test the reproducibility, specificity and sensitivity of the qRT-PCR in the detection of Bcr-Abl gene translocation. METHODS: In complementary (c)DNA, isolated from K562 Bcr-Abl positive cell line, we performed qRT-PCR analysis with Bcr-Abl specific primers. For qRT-PCR analysis, we used serial dilutions of the newly synthesized cDNA in order to establish the detection threshold of this method. RESULTS: Using the specific primers for the Bcr-Abl translocation, we obtained the specific translocation product in cDNA sample of K562 human erythroid leukemia cell line. qRT- PCR showed significant sensitivity with the detection threshold for the Bcr-Abl fluorescent signal, which enabled the precise detection that was accurate within a 10-fold dilution range, and a dynamic range of 5 orders of magnitude. CONCLUSION: The results of our study showed that the application of the qRT-PCR is the optimal method for the detection of Bcr-Abl gene translocation, characterized by high reproducibility, specificity and sensitivity.

Vibrational properties of alpha- and sigma-phase Fe-Cr alloy.

Experimental and theoretical studies, of the Fe-partial phonon density of states (PDOS) for Fe52.5Cr47.5 alloy having alpha and sigma phases were carried out. The former using the nuclear resonant inelastic x-ray scattering method, and the latter with the direct one. Characteristic features of PDOS, which distinguish one phase from the other, were revealed and successfully reproduced by the theory. Data pertinent to the dynamics such as the Lamb-Mössbauer factor, f, the kinetic energy per atom, E(k), and the mean force constant, D, were directly derived, while vibrational specific heat at constant volume, C(V), and vibrational entropy, S were calculated using the Fe partial PDOS. Based on the values of f and C(V), we determined Debye temperatures, Theta(D). An excellent agreement for some quantities derived from experiment and first-principles theory, like C(V) and quite good ones for others like D and S were obtained.

Stabilization of antiferromagnetic order in FeO nanolayers.

We have studied the evolution of the magnetic state of a nanometer thick antiferromagnetic (AFM) FeO layer during its formation using nuclear resonant scattering of synchrotron radiation. In contact to ferromagnetic Fe, the FeO layer does not show magnetic order at room temperature (RT). Once embedded between two Fe layers, magnetic coupling to the adjacent ferromagnets leads to a drastic increase of the Néel temperature far above RT, while the blocking temperature remains below 30 K. The presented results evidence the role that the ferromagnetic surrounding plays in modifying the magnetic state of ultrathin AFM layers.

Molecular epidemiology of lyssaviruses in Eurasia.

The Lyssavirus genus, a member of the Rhabdoviridae family, consists of seven established related viruses (genotypes 1-7). Rabies cases in Eurasia are principally attributed to three of these genotypes, namely genotype 1 (RABV, classical rabies) and to a lesser extent genotypes 5 and 6 (European bat lyssaviruses type-1 and -2). In addition, four newly identified divergent lyssaviruses have been isolated from insectivorous bats. The molecular diversity of classical rabies viruses (genotype 1, RABV) has been studied at the global level and reference has been made to the existence of a number of European strains in a range of mammalian species. It is accepted that these viruses cluster within a 'Cosmopolitan Lineage' having ancestral roots in Europe in the 17th century before its widespread dispersal to Asia, Africa and the Americas as a result of European exploration and colonization.

Vibrational properties of nanograins and interfaces in nanocrystalline materials.

The vibrational dynamics of nanocrystalline Fe(90)Zr(7)B(3) was studied at various phases of crystallization. The density of phonon states (DOS) of the nanograins was separated from that of the interfaces for a wide range of grain sizes and interface thicknesses. The DOS of the nanograins does not vary with their size and down to 2 nm grains still closely resembles that of the bulk. The anomalous enhancement of the phonon states at low and high energies originates from the DOS of the interfaces and scales linearly to their atomic fraction.

Phonons in iron: from the bulk to an epitaxial monolayer.

The confinement of materials in low-dimensional structures has significant impact on propagating excitations like phonons. Using the isotope-specific 57Fe nuclear resonant vibrational spectroscopy we were able to determine elastic and thermodynamic properties of ultrathin Fe films on W(110). With decreasing thickness one observes a significant increase of the mean atomic displacement that goes along with an enhancement of vibrational modes at low energies as compared to the bulk. The analysis reveals that these deviations result from atomic vibrations of the single atomic layers at the two boundaries of the film, while the atoms inside the films vibrate almost bulklike.

Phonons at the Fe(110) surface.

The in-plane density of phonon states of clean Fe(110) surface was measured separately for the first, second, and further atomic monolayers using nuclear inelastic scattering of synchrotron radiation. The results show that atoms of the first layer vibrate with frequencies significantly lower and amplitudes much larger than those in the bulk, and that vibrational spectra along two perpendicular in-surface directions are different. The vibrations of the second layer are already very close to those of the bulk. The good agreement of the experimental results and the first-principles calculations allows for detailed understanding of the observed phenomena.

Molecular epidemiology of rabies viruses in Europe.

Several different strains of classical rabies virus co-circulate in Europe. In order to investigate the roles of the host species and topography on the molecular epidemiology of these viruses, a 400 bp region of the nucleoprotein gene was sequenced and compared with more than 500 European virus isolates. Viruses from 21 European countries were represented including some unique panels of archived isolates from the former Republic of Yugoslavia, Estonia, the Czech Republic, Poland and Austria. Phylogenetic analysis of 198 unique sequences demonstrated numerous groups of viruses clustered at both geographical and host-species levels.

[10 years' of production and use of human rabies immunoglobulin in Yugoslavia]. / Deset godina proizvodnje i primene humanog imunoglobulina protiv besnila u Jugoslaviji.

Application of the rabies immunoglobuline is a compulsory part of the prophylaxis of rabies in all severe, transdermal lesions caused by rabies infected animals. Sylvatic rabies has spread in the past few years throughout the whole Yugoslavia, and human cases of rabies have also been reported in other East European countries. In order to achieve the highest level of rabies prophylaxis, apart from postinfective rabies vaccination, it is necessary to provide passive immunization using specific antibodies against rabies. After successful immunization of the young, healthy volunteers in 1990, National Blood Transfusion Institute, in cooperation with the Pasteur Institute from Novi Sad, prepared the first quantities of immunized plasma by plasmapheresis procedure and human rabies immunoglobuline. Without national production, sufficient quantities of human rabies immunoglobuline could not be provided, since the price on the world market is rather high (over $1000 per patient).

Typing of field rabies virus strains in FR Yugoslavia by limited sequence analysis and monoclonal antibodies.

A total of 32 rabies virus isolates (15 of fox, 14 of cat and 3 of dog origin) from the territory of FR Yugoslavia were collected from December 1996 till February 1998 and analyzed by limited sequencing of N gene and by indirect immunofluorescence and a panel of 20 antinucleocapsid monoclonal antibodies (MAbs). All examined strains were characterized as sylvatic fox strains. Two main genetic variants were detected, 15 isolates belonging to Group I, 14 belonging to Group II, while the remaining 3 could not be classified into any group. This classification was confirmed by MAbs. The obtained results indicate at least two independent cycles of rabies transmission, probably resulting from multiple modes of transmission to the territories now belonging to FR Yugoslavia.

Antisense antiviral agents: about the optimal approach.

The vast majority of recent efforts to synthesize effective antisense preparations for antiviral therapy have been made by using oligonucleotides, agents able to inhibit only a relatively small portion of the viral genome. That is the main reason why this approach is far from optimal. The optimal approach, however, is the accomplishment of the total inhibition of the viral genome. Here, a general protocol for preparation of the antisense antiviral agents with optimal properties for in vivo application is proposed, irrespective of the viral genome nucleotide sequence.

Adequate selection of anticancer agents: a task which can be fulfilled by changing selection criteria.

An analysis of anticancer agents' selection based on the effect on tumor cell colony formation inhibition after exposure to the agent under investigation is performed. The real significance of such a method, as well as the probable negative clinical consequences of its use for screening of agents for cancer therapy are pointed out. Also, principles of overcoming the inadequacy of tumor cell clones' expansion inhibition tests and their equivalents are proposed.

Immunogenicity of BHK-rabies vaccine in human volunteers.

The production of rabies vaccine on baby hamster kidney (BHK-21) cells for human use is discussed. Long term experience in application of this vaccine in animals, without any noticeable complications and findings of inactivation of contaminated DNA from the cell substrate by beta-propiolactone have justified its recommendation for human use. Preliminary results of applying this simple, adjuvant vaccine in volunteers, confirmed its good tolerability and immunogenicity.