Terahertz beam with radial or orthogonal to laser polarization from a single-color femtosecond filament.

At the selected frequencies from 0.3 to 10 THz we measured the two-dimensional (2D) distributions of fluence and polarization of terahertz (THz) emission from a single-color femtosecond filament. At the majority of frequencies studied, the THz beam has a donut-like shape with azimuthal modulations and radial polarization. At the maximal modulation, THz beam takes the form of the two lobes and polarization of the THz field degenerates into orthogonal to the laser pulse polarization direction. Violation of the radially polarized donut beam shape is due to destructive interference of THz waves driven by light pressure directed along the laser beam propagation axis and ponderomotive force parallel to the laser polarization.

Observation of conical emission from DC-biased filament at 10 THz.

The terahertz (THz) radiation emitted by an air-based femtosecond filament biased by a static electric field is known to have on-axis shape and relatively low frequency spectrum in contrast to the unbiased single-color and two-color schemes. Here, we measure the THz emission of a 15-kV/cm-biased filament in air produced by a 740-nm, 1.8-mJ, 90-fs pulse and demonstrate that a flat-top on-axis THz angular distribution of the emission at 0.5-1 THz transforms into a contrast ring-shaped one at 10 THz.

Flat-top THz directional diagram of a DC-biased filament.

In the experiment, the laser pulse (744 nm, 0.5 mJ, 90 fs) focused into the air gap between the plane electrodes biased by a 10 kV/cm field (DC-biased filament) produced terahertz (THz) radiation. At the selected frequencies of ν=0.3, 0.5, 1 THz, a wide flat-top angular distribution was measured by a bolometer rotating in the plane of the electrodes. The simulations based on the unidirectional pulse propagation equation with fine 0.01 THz resolution and 3 PHz frequency domain showed the transition of the THz directional diagram from the flat-top at ν≲1THz to the conical one at ν>8THz due to the destructive interference of THz waves from the ionization front propagating with the superluminal velocity. Refraction on the plasma is not the major factor in ring formation.

[Autoimmune processes after long-term low-level exposure to electromagnetic fields (the results of an experiment). Part 4. Manifestation of oxidative intracellular stress-reaction after long-term non-thermal EMF exposure of rats].

This paper presents the results of the study of the effects of long-term low-level exposure of rats to microwaves. Rats were exposed in far field to 2450 MHz continuous wave fields providing an incident power density at the cages of 500 microW/cm2 for 7 hours daily for a total of 30 days resulting in a whole-body SAR of 0.16 +/- 0.04 W/kg. Three groups ("EMF-exposure", "sham-exposure" and cage-control) were formed, each consisting of 16 rats. Circulating antibodies (IgA, IgG and IgM) directed against 16 chemical substances were evaluated in coded serum from each group of rats by enzyme multiplied analysis (ELISA test). An increased amount of compounds resulting from interaction of amino acids with nitric oxide (NO) or its derivatives (NO2-Tyrosine, NO-Arginine, NO-Cysteine + NO-Bovine Serum Albumin, NJ-Methionine + NO-Asparagine + No-Histidine, NO-BTrypnohan + NJ-Tyrosin), fatty acids with small chains, hydroxylated fatty acids, palmitic/myristic/oleic acid, AZE (product of oxidation of fatty acids) was found in blood serum from EMF-exposed rats. As a rule, antibodies to conjugated antigens were seen for IgM, rarely seen for IgG and were completely absent for IgA. The levels of antibodies were higher on day 7 after the exposure compared to those on day 14 after the exposure.

[Clinical and molecular-genetic characteristics of X-linked spinal-bulbar amyotrophy (Kennedy's disease) in the Sakha Republic (Yakutia)]. / Klinicheskaia i molekuliarno-geneticheskaia kharakteristika Kh-stseplennoi spinal'no-bul'barnoi amiotrofii Kennedi v Respublike Sakha (Iakutiia).

AIM: To perform a clinical-genealogical and molecular genetic analysis of X-linked spinal-bulbar amyotrophy (Kennedy's disease) in the Sakha Republic (Yakutia). MATERIAL AND METHODS: Six patients, aged from 30 to 60 years, from 4 unrelated Yakut families registered in the Republican genetics registry of hereditary and congenital abnormalities of the Sakha Republic were studied. The average age of onset was 45.1±4.4 years. A clinical-genealogical and molecular genetic methods were used. RESULTS AND CONCLUSION: The prevalence of spinal-bulbar amyotrophy Kennedy in the Republic of Sakha (Yakutia) is 1.3 per 100 thousand, among Yakut men is 2.8 per 100 thousand. Clinical manifestations of the disease in the patients included in the study were similar to those described previously in the literature. Patients underwent molecular genetic diagnosis in exon 1 of the androgen receptor (AR) gene. All of them carried the allele with more than 38 CAG repeats. There was an inverse correlation between the age at disease onset and the number of CAG-repeats. A method of DNA diagnosis of Kennedy's disease with visualization on an agarose gel has been introduced in genetic testing.

Tight focusing of electromagnetic fields by large-aperture mirrors.

We derive nonparaxial input conditions for simulations of tightly focused electromagnetic fields by means of unidirectional nonparaxial vectorial propagation equations. The derivation is based on the geometrical optics transfer of the incident electric field from significantly curved reflecting surfaces such as parabolic and conical mirrors to the input plane, with consideration of the finite thickness of the focusing element and large convergence angles, making the propagation vectorial and nonparaxial. We have benchmarked numerical solutions of propagation equations initiated with the nonparaxial input conditions against the solutions of Maxwell equations obtained by vectorial diffraction integrals. Both transverse and longitudinal components of the electric field obtained by these methods are in excellent agreement.

[Adaptation of different modifications of enzyme immunoassay and immune blot assay to assess the candidate vaccine HIVREPOL against HIV/AIDS].

A preclinical trial of the vaccine HIVREPOL provided a complex of methods for assessing the identity and specific activity of vaccines against HIVIAIDS. The identity of "HIVREPOL" has been assessed by indirect enzyme immunoassay (EIA): the vaccine specifically binds the antibodies of the sera from HIV-infected individuals. Immune blot assay was the most informative method for assessing the identity of the candidate vaccine. The sera from HIVREPOL-vaccinated mice recognized the proteins gp41, p24, p55 of cultured HIV1 on "New-Lay-Blot1" strips. The bands corresponding to p24 were revealed in the line blots "Blot-HIV-1/2+O" and "INNO-LIA-HIV-Confirmation". The specific activity of the HIVREPOL vaccine was confirmed from the reactivity of sera of the mice vaccinated with recombinant proteins of the immunosorbents available in EIA test systems for the detection of HIV antibodies. Competitive EIA established the antigen-binding activity of sera from HIVREPOL-vaccinated mice against the native reference HIV-1 antigen.

The secondary structure of bacteriophage DNA in situ. VIII. The reaction of sodium bisulphite with intraphage cytosine as a probe for studying the DNA-protein interaction.

To obtain data on the viral nucleoprotein a study has been made of the reaction of sodium bisulphite with cytosine in the intraphage DNA of the phage Sd. The CHlO4 hydrolysates of the bisulphite-modified phage Sd have demonstrated a decrease of 18% in the cytosine content and the presence of the products with the properties of cytosyl-amino acids (the main amino acid responsible for the DNA-protein interaction involving cytosine is lysine). But when prior to hydrolysis the modified phage was disintegrated under mild conditions in 0.1--1 M NaCl solution or Tris-HCl buffer (pH 7), neither the decrease in the cytosine content nor cytosyl-amino acids have been found. An exception is the heating of the phage at 70 degrees C in a medium containing 0.05 M phosphate buffer (pH 7.9--8.5), when an 18% decrease in the cytosine content and subsequent appearance of cytosyl-amino acids have also been observed. The presence of cytosyl-amino acids which are the nucleotide-protein cross-links is confirmed by the results of viscometry, equilibrium centrifugation in cesium sulphate gradient and determinations of the survival percentage. It is suggested that the reaction between bisulphite and cytosine in the phage Sd stops at the stage of the intermediate product C5-C6-dihydro-C6-sulphopyrimidine whose amino group is shielded by interaction with protein (product VII). This product can exist only under in situ conditions: with disintegration of nucleoprotein (destruction of phage particles or ejection of the DNA) in phosphate-free media the product VII reverts into the initial cytosine. Under the conditions of acid hydrolysis or destruction of phage in the presence of phosphate ions product VII undergoes transamination with cleavage of SO3 and restoration of the C5-C6 double bond producing cytosyl-amino acids. The factors determining the stability of the product VII are discussed.

[Polymorphism of CTG-repeats in the DMPK gene in populations of Yakutia and central Asia].

Allele frequency distribution of CTG-repeat in the 3'-flanking region of DMPK gene was analyzed in populations of Yakutia (three ethnogeographical groups of Yakuts, Evenks, Evens, Yukaghirs, Dolgans) and Central Asia (Kazakhs, Uzbeks, Uighurs). Frequencies of CTG alleles were found to be significantly different in two regions. Allele frequency distribution in populations of Yakutia was similar to Asian populations, whereas Central Asian populations showed similarity to European populations. The features of allele spectrum in Yakut populations were discussed in terms of high prevalence of myotonic dystrophy in Yakuts. Our result supports the hypothesis of founder effect in spread of myotonic dystrophy in Yakuts. The phylogenetic relationships between the investigated populations based on polymorphism of CTG-locus of the DMPK gene have been analyzed as well.

[Comparison CCR5de132 mutation in the CCR5 gene frequencies in Russians, Tuvinians, and in different groups of HIV-infected individuals].

The 32-bp deletion (CCR5del32 mutation) in the CCR5 (chemokine (C-C motif) receptor 5) gene, encoding CCR5 chemokine receptor, is one of the factors determining natural resistance to human immunodeficiency virus (HIV-1) infection. In the present study, the samples of Russians (n = 107), Tuvinians (n = 50), and HIV-infected individuals were examined for the presence of CCR5del32 mutation in the CCR5 gene. The CCR5del32 allele frequency in Russians and Tuvinians constituted 7.84 and 2%, respectively. Among HIV-1 infected individuals, two groups, of macrophage-tropic HIV-1 strain- and T-cell-tropic HIV-1 strain-infected were distinguished. The CCR5del32 allele frequency in the first group (6.45%) was lower than in the second one (8.73%). Statistical treatment of the HIV-1 infected individuals typing data showed that the difference in the CCR5del32 allele frequencies between the groups of sexually (macrophage-tropic) and parenterally (T-cell-tropic) infected individuals observed was within the limit of random deviation.

[Immunomodulating action of energizing drugs during dosed fasting]. / Immunomoduliruiushchee deistvie énergiziruiushchikh preparatov pri dozirovannom golodanii.

Cessation of nutrient entry suppresses glycogen production in hepatocytes. Triggering of the lipid pathway of energy supply limits carbohydrate utilization because of citrate block development. Fasting involves impairment of erythrocyte structure and membranes, increase of hepatocyte membrane permeability, and decrease of functional activity of lymphocyte population. These changes can be due to glucose deficit in capillaries of lymphoid organs. Study of effects of riboxin, mildronate, glucose, benfothiamine, and their combinations on immune response of rats after 5- of 7-day fasting led the authors to a conclusion that an immunomodulating effect can be induced by combinations of riboxin or mildronate with glucose and benfothiamine.

[The immunomodulating action of intermittent fasting under temperature, toxic and food loads]. / Immunomoduliruiushchee deistvie preryvistogo golodaniia pri temperaturnykh, toksicheskikh i alimentarnykh nagruzkakh.

Immune response to intermittent fasting was studied in rats. The immunomodulating effect was registered. To a certain degree, this may be due to fasting-induced reduction in blood levels of antiproteolytic proteins and lipid peroxidation products which have immunosuppressive activity.

[The clinical-genealogic and molecular-genetic characteristics of oculopharyngeal muscular dystrophy in the Republic of Sakha (Yakutia)].

The clinical-genealogic and molecular-genetic investigation of oculopharyngeal muscular dystrophy (OPMD) in the Republic of Sakha (Yakutia) was performed. It was investigated 33 unrelated Yakut families with 38 patients and 2 russian families with 2 patients and 59 their healthy relatives as well. The high clinical polymorphism of disease was found in patients with OPMD. The mutation in exon 1 of the PABPN1 gene resulting in the expansion of GCG-repeats up to 10 is revealed. Using direct sequencing of the PABPN1 gene in 17 families (16 Yakut, 1 Russian), we identified a type of this mutation as an insertion of 4 GCG-repeats. Frequency of OPMD in the Yakut population is 1:11 680 that is 10-20 times higher comparing to european populations. This is a first report on the patients with OPMD from the Republic of Sakha with diagnosis confirmed by molecular-genetic analysis.

[Interaction between sodium bisulfite and bacteriophage SD DNA]. / Issledovanie reaktsii bisul'fita natriia s DNK bakteriofaga SD.

The interaction between sodium bisulfite and the cytosine residues within the intraphage DNA of phage SD was studied to elucidate the structure of viral nucleoprotein. Hydrolysis with perchloric acid of bisulfite-modified phage SD results in 18% decrease of cytosine and appearance of products having the properties of cytosyl amino acids (most probably cytosyl lysine). When the modified phage before hydrolysis was subjected to mild destruction in 0.1--1 M NaCl or Tris-HCl buffer (pH 7.0), neither the decrease of cytosine nor the appearance of cytosyl peptides was observed. However, these results were observed when the phage was heated at 70 degrees C in a medium containing 0.05 M phosphate buffer, pH 7.9--8.5. The presence of cytosyl amino acids in the modified phage, representing nucleotide-protein covalent cross-links explains the results of viscosometry and centrifugation in CS2SO4 density gradient. It is assumed that the bisulfite reaction with cytosine within phage SD is completed at the stage of intermediate product formation, i.e. C5--C6-dihydro-C6-sulfopyrimidine, in which the amino group is screened by interaction with protein (product VII). This product may exist only in situ; when the phage nucleoprotein is destroyed in phsophate-free media, product VII is converted into original cytosine. Under acidic hydrolysis or in the presence of phosphate ions under heating, product VII undergoes transamination accompanied by SO3 split-off and reconstitution of C5--C6 double bond to form cytosylamino acids.

The use of synthetic peptides in the diagnosis of HIV infections.

The antigenic structure of HIV proteins was analyzed semiempirically. Peptides mimicking fragments of the main structural HIV-1 proteins (p17, p24, gp41, and gp120) were selected and synthesized, with account taken of the level of conservation of various HIV genome fragments. The synthesized peptides were then subjected to immunological study with human sera in an enzyme-linked immunosorbent assay (ELISA). Peptides from two regions were found to be particularly immunoreactive with sera from HIV-1 infected persons: the C-terminal end of gp120 and a sequence approximately sixty to eighty amino acids in from the N-terminus of gp41. In fact, more than 96% of HIV-1 positive sera reacted with peptide 495-516 of gp120 (SP-III), peptide 584-602 of gp41 (LS-19), and peptide 601-616 of gp41 (SP-15). Additionally, twelve out of twelve serum samples from Ugandans infected with HIV-1 reacted with both SP-III (from HTLV-III) and SP-29 (gp41, 598-609; from the LAV-ELI isolate), suggesting that these immunodominant sites are useful diagnostically irrespective of the infecting isolates. HIV-2 peptides were also synthesized, and immunoreactivity and cross-reactivity examined. Only two peptides (581-603 of gp32 and 592-605 of gp32) reacted with all of the six HIV-2 positive sera tested. These peptides did not react with HIV-1 positive sera or control sera from healthy blood donors.(ABSTRACT TRUNCATED AT 250 WORDS)