Amplification of elliptically polarized sub-femtosecond pulses in neon-like X-ray laser modulated by an IR field.

Amplification of attosecond pulses produced via high harmonic generation is a formidable problem since none of the amplifiers can support the corresponding PHz bandwidth. Producing the well defined polarization state common for a set of harmonics required for formation of the circularly/elliptically polarized attosecond pulses (which are on demand for dynamical imaging and coherent control of the spin flip processes) is another big challenge. In this work we show how both problems can be tackled simultaneously on the basis of the same platform, namely, the plasma-based X-ray amplifier whose resonant transition frequency is modulated by an infrared field.

Acoustically induced transparency for synchrotron hard x-ray photons.

The induced transparency of opaque medium for resonant electromagnetic radiation is a powerful tool for manipulating the field-matter interaction. Various techniques to make different physical systems transparent for radiation from microwaves to x-rays were implemented. Most of them are based on the modification of the quantum-optical properties of the medium under the action of an external coherent electromagnetic field. Recently, an observation of acoustically induced transparency (AIT) of the 57Fe absorber for resonant 14.4-keV photons from the radioactive 57Co source was reported. About 150-fold suppression of the resonant absorption of photons due to collective acoustic oscillations of the nuclei was demonstrated. In this paper, we extend the AIT phenomenon to a novel phase-locked regime, when the transmitted photons are synchronized with the absorber vibration. We show that the advantages of synchrotron Mössbauer sources such as the deterministic periodic emission of radiation and controlled spectral-temporal characteristics of the emitted photons along with high-intensity photon flux in a tightly focused beam, make it possible to efficiently implement this regime, paving the way for the development of the acoustically controlled interface between hard x-ray photons and nuclear ensembles.

Attosecond Pulse Amplification in a Plasma-Based X-Ray Laser Dressed by an Infrared Laser Field.

High-harmonic generation (HHG) of laser radiation has led to attosecond pulse formation which offers unprecedented temporal resolution in observing and controlling electron and nuclear dynamics. But the energy of attosecond pulses remains quite small, especially for photon energies exceeding 100 eV, which limits their practical applications. We propose a method for amplification of attosecond pulses in the active medium of a plasma-based x-ray laser dressed by a replica of the laser field used for HHG. The experimental implementation is suggested in hydrogenlike C5+ x-ray laser at 3.4 nm wavelength in the "water window" range.

[GENOTYPING OF THE BURKHOLDERIA MALLEI STRAINS BASED ON DIFFERENT REGION ANALYSIS].

Development of the genotyping methods of glanders agent is urgent due to its high pathogenicity, lack of effective preventive measures and threat of the use of Burkholderia mallei as a biological weapon. In this work we proposed a scheme for the typing of the B. mallei strains based on different region analysis (DFR). The choice of variable loci differentially presented in various strains of glanders agents was performed by analyzing annotated whole-genome sequences of the B. mallei strains. Primers and fluorescence probes were designed for 9 selected loci. The amplification conditions for different regions were optimized in two variants: with electrophoretic detection and hybridization-fluorescence detection in the strip format. The possibility of applying the DFR analysis to genetic characterization of strains was assessed in 14 B. mallei strains. The genetic profiles of the studied B. mallei strains revealed that the developed DFR-typing scheme was characterized by high discrimination power (Hunter-Gaston index value was 0.92), reproducibility, rapidity, easy interpretation, and applicability for epidemiological surveillance of glanders.

[ON DEVELOPMENT OF TOOLS OF IMMUNE DIAGNOSTIC OF INFECTIOUS DISEASES: PROBLEMS OF DIAGNOSTIC IN VIVO AND IN VITRO].

The article considers a number of problematic issues concerning development of effective means of immune diagnostic of infectious diseases of bacterial and mycotic etiology related to approaches of choosing appropriate diagnostic targets.

[IDENTIFICATION OF CAUSATIVE AGENTS OF GLANDERS AND MELIOIDOSIS BASED ON PRINCIPLES OF POLYPHASE TAXONOMIC APPROACH].

AIM: Determine an optimal set of the most effective methods of identification and intraspecies typing ofcausative agents ofglanders and melioidosis. Materials andmethods. Bacteriologic, immunochemical, molecular-genetic methods were used. RESULTS: A possibility to identify collection strains of pathogenic and closely related Burkholderia in semiautomatic systems is studied. Means of detection of informative variable genome segments ofthe specified microorganisms were developed, methods of their genetic typing were selected. Effectiveness of application of precipitating mAbs for differentiation of Burkholderia was established. Data on diagnostic possibilities of immunoglobulins fluorescing based on monoclonal antibodies of various etiotropic directionality for detection and identification of B. mallei and B. pseudomallei are generalized. Experimental series of amplification test-systems for identification of glanders and melioidosis causative agents in real-time PCR format are created. CONCLUSION: A number of methods for identification and typing of glanders and melioidosis causative agents is proposed.

[The comparative evalution of informativeness of immunologic and molecular genetic methods and means during stages of specific indication of melioidosis agent].

The reference-center of monitoring of agents of glanders and melioidosis carried out testing of reagents kits for diagnostic of agent of melioidosis and other close-related species of Burkholderiae in vitro. At the stage of specific identification of pathogenic Burkholderiae the diagnostic possibilities of commercial and experimental kits of reagents for express- and rapid analysis were evaluated. The criteria of evaluation of diagnostic value of kits of reagents were sensitivity, specificity and time of implementation of studies. The analysis with application of mono- and multi-locus amplification systems, including real-time polymerase chain reaction permitted during 5-6 hours to implement identification and differentiation of Burkholderia pseufomallei, B. thailandensis and B. cepacia.

[The optimization of algorithm of laboratory diagnostic of Western Nile fever in territory of Russia].

The article deals with results of study of antigenic chiasms between viruses of Western Nile fever and tick-borne encephalitis using binding immunoassay applied to blood serum from patients residing in various regions of Russia. It is established that to get accurate laboratory diagnostic it is reasonable to apply the proposed algorithm of analysis in which alongside with binding immunoassay such differential criterion as positivity rate is to be implemented to speed up and simplify laboratory diagnostic of infections brought on by viruses of Western Nile fever and tick-borne encephalitis.

Formation of a single attosecond pulse via interaction of resonant radiation with a strongly perturbed atomic transition.

We propose a technique to form a single few-cycle attosecond pulse from vacuum ultraviolet or extreme ultraviolet radiation via resonant interaction with hydrogenlike atoms, irradiated by a high-intensity far-off-resonant laser field. The laser field strongly perturbs excited atomic energy levels via the Stark effect and ionizes atoms from the excited states. We show that an isolated attosecond pulse can be formed using either a short incident femtosecond pulse of the resonant radiation or a steep front edge of the laser field. We propose an experimental realization of a single subfemtosecond pulse formation at 121.6 nm in atomic hydrogen and a single sub-100 as pulse formation at 13.5 nm in Li(2+) plasma.

[Epidemiologic situation of West Nile fever in Russia in 2010].

Problem of tropical arbovirus infection--West Nile fever (WNF)--spread in Russian Federation is discussed. Biology of WNF is discussed, WNF sources and reservoir are characterized. WNF outbreaks in Russia during the past 2 decades are presented in detail. Outbreaks of different years, possible causes and epidemiology are discussed. Features of WNF clinical course during various outbreaks and WNF diagnostic problems are presented.

[Molecular genetic analysis of Pseudomonas aeruginosa strains isolated from environment and patients in health care facilities].

AIM: Analysis of genetic heterogeneity of Pseudomonas aeruginosa strains isolated in and out of hospitals. MATERIALS AND METHODS: To study the genetic diversity of 36 strains of P. aeruginosa plasmid analysis, random amplified polymorphic DNA (RAPD) technique as well as polymerase chain reaction for detection of virulence genes algD, lasB, toxA, plcH, plcN, exoS, nan1, and nan2. RESULTS: Epidemically important strains were found in different ecological niches. It was shown that these virulence factors could play important roles in pathogenesis of infection. CONCLUSION: RAPD technique was effective for analysis of P. aeruginosa isolates. Number of studied typing bands differed between related isolates for each random primer.

[Pathogenicity of West Nile virus: molecular markers].

The review describes the phenotypic properties, structure, and expression pattern of West Nile virus genome (Flaviviridae, Flavivirus, Japanese encephalitis antigenic complex), as well as the clinical picture and pathogenesis of its etiologically related disease West Nile fever. It also analyzes the available data on the impact of genetic mutations in the genome on the biological properties of the virus.

[Phenotypic and genotypic identification of bacteria from the Burkholderia cepacia complex].

AIM: Evaluation of the diagnostic value of pheno- and genotypic characteristics of B. cepacia strains collection. MATERIALS AND METHODS: Phenotypic and genetic methods of identification and differentiation of 25 strains of the B. cepacia complex. RESULTS: Polyphasic taxonomic approach utilizing multiple diagnostic tests was used for accurate identification of Burkholderia species. Algorithm for identification of microorganisms from the B. cepacia complex was developed. CONCLUSION: Combined use of phenotypic and molecular genetic tests, such as recA gene PCR, is recommended for differentiation of the B. cepacia complex genomovars.

[Comparative assessment of DNA extraction methods for identification of glanders and melioidosis etiological agents by PCR].

Pathogenic Burkholderia are considered as a cause of dangerous infections and potential agents of bioterrorism. Comparative assessment of different methods of extraction and purification of DNA for PCR analysis of pure cultures and samples contaminated by etiological agents of glanders and melioidosis was performed. Samples of soil and food artificially contaminated by pathogenic Burkholderia as well as organs of infected animals were tested. DNA was extracted by methods of boiling, nucleosorption with presence of guanidine thiocyanate, guanidine thiocyanatephenol extraction, guanidine thiocyanate-phenol extraction with additional purification of DNA by nucleosorption. Amplification was performed by "Flash" technique and detector of fluorescence was used for analysis of PCR products. Utilization of the recommended methods of preparation depending on the nature of sample let to detect by the "Flash" technique the etiological agents of glanders and melioidosis in concentration =10(3) microbial cells per ml. Choice of DNA extraction and purification methods is determined by type of a sample and presence in it of admixtures inhibiting PCR.

[Identification of the agents of coccidioidomycosis using polymerase chain reaction].

Two pairs of primers for diagnosis of coccidioidomycosis using the method of PCR were constructed. One pair was used for identification of the two species of Coccidioides (C. immitis and C. posadasil) on the basis of MBP-1 gene. The other pair was chosen on the basis of SOWgp82 gene, which encodes an immunodominant, spherule outer wall glycoprotein for detecting only C. posadasii. The used primers allowed the agents of coccidioidomycosis to be detected using PCR with high sensitivity and specificity. The effective method of isolation of fungus DNA from soil contaminated with arthroconidia of Coccidioides spp. was developed. It includes guanidinthiocyanate-phenol-chloroform deproteinization followed by DNA purification using nuclear sorption.

[The use of multilocus sequence typing (MLST) and randomly amplified polymorphic DNA (RAPD) for the differentiation between strains of Burkholderia mallei].

Burkholderia mallei is highly pathogenic microorganism for both humans and animals. In this work, the possibility of the use of the genotyping method for differentiation between strains of B. mallei was studied. A collection of 14 isolates of B. mallei was characterized using randomly amplified polymorphic DNA (RAPD) and multilocus sequence typing (MLST). RAPD was the best method used for detecting strain differences of B. mallei. It was suggested that this method would be an increasingly useful molecular epidemiological tool.

[The use of polymerase chain reaction for detection of the agents of glanders and melioidosis using experimental infection].

Glanders and melioidosis are severe infectious diseases of people and animals. The causative agents of these infections refer to the potential agents of bioterrorism of group B. In this work the possibility of use of flagellin-based primers for the identification of B. mallei and B. pseudomallei and for diagnosis of experimental glanders and melioidosis was studied. The obtained results permit to make a conclusion that PCR using the developed primers may be recommended for the incorporation in the scheme of laboratory diagnosis of glanders and melioidosis both for the identification of clean cultures and in experimental clinical material.

[Molecular-genetic approaches to diagnosis and intraspecific typing of causative agents of glanders and melioidosis].

Pathogenic Burkholderia--Burkholderia mallei and Burkholderia pseudomallei--are causative agents of glanders and melioidosis, severe infectious diseases of man and animals. They are regarded as potential agents of bioterrorism. The existing bacteriological and immunological methods of identification of B. mallei and B. pseudomallei are not efficient enough for the rapid diagnosis and typing of strains. Described in the paper are molecular methods of detection of the agents by PCR, hybridization and strain typing made on the basis of bacterial total cell protein profiles, RAPD, ribotyping as well as of plasmid and DNA microrestriction analyses.

[Use of PCR for identification of Burkholderia mallei]. / Ispol'zovanie PTsR dlia identifikatsii Burkholderia mallei.

Stimuli of glanders belong to the potential agents of biological terror. The possibility to use various primers in the identification of B. mallei was investigated and the significance of polymerase chain reaction (PCR) was defined within the scheme of laboratory glanders diagnosis in the offered paper. The constructed amplifying test-systems can be used to detect the glanders both in the environmental objects contaminated with B. mallei and in experimental clinical material.

[Identification of the causative agents of glanders and melioidosis by polymerase chain reaction]. / Identifikatsiia vozbuditelei sapa i melioidoza s pomoshch'iu polimeraznoi tsepnoi reaktsii.

Burkholderia mallei and B. pseudomallei are causative agents of glanders and melioidosis, respectively, i.e. severe and fatal infection diseases of man and animal. The computer-based analysis of the 23S rRNA gene sites was used for selecting the primers. Two pairs of primers were chosen for the identification of B. mallei and Bpseudomallei. DNAs from 48 B. pseudomallei and 15 strains of B. mallei, unlike from other geterological bacteria, were positively amplified. Therefore, the method of polymerase chain reaction can be used in laboratory diagnosis of glanders and melioidosis.