A method of determining the bremsstrahlung flux-weighted average photonuclear cross section.

Based on a developed analytical model, a method is proposed for measuring the photonuclear cross section averaged over bremsstrahlung flux without application of additional target-monitor of photon flux. The method involves the use of a thin isotopic target, that completely overlaps the photon beam (a photonuclear converter), as well as an algorithm for processing the data on the yield of a reaction under study in such a target. The novel technique was validated on the reactions 100Mo(γ,n)99Mo and 58Ni(γ,n)57Ni in the range of photon end-point energy of 40.7-93.9 MeV. The photon flux-weighted average cross sections of the reactions measured experimentally are in good agreement with Monte Carlo simulations and TALYS predictions on their excitation functions.

Development and validation of an analytical model of isotope production by bremsstrahlung radiation.

An analytical method is used to describe isotope production at an electron accelerator. The key characteristics that determine the total target activity and its distribution have been established. The expressions for the reaction yield depend explicitly on the irradiation regime and parameters of the giant dipole resonance. The model predictions for the bremsstrahlung spectrum and yield of the reference reactions are in good agreement with the results of simulation and experiment.

Binding Potency of Heparin Immobilized on Activated Charcoal for DNA Antibodies.

In vitro experiments showed that heparin adsorbed on activated charcoal can bind antibodies raised against native and single-stranded DNA in a diluted sera pool with a high level of these DNA. Thus, heparin used as anticoagulant during hemosorption procedure can demonstrate supplementary therapeutic activity resulting from its interaction with various agents involved in acute and chronic inflammatory reactions such as DNA- and RNA-binding substances, proinflammatory cytokines, complement components, growth factors, etc. Research and development of heparin-containing carbonic adsorbents for the therapy of numerous inflammatory and autoimmune diseases seems to be a promising avenue in hematology.

Nanodiamonds of Laser Synthesis for Biomedical Applications.

In recent decade detonation nanodiamonds (DND), discovered 50 years ago and used in diverse technological processes, have been actively applied in biomedical research as a drug and gene delivery carrier, a contrast agent for bio-imaging and diagnostics and an adsorbent for protein separation and purification. In this work we report about nanodiamonds of high purity produced by laser assisted technique, compare them with DND and consider the prospect and advantages of their use in the said applications.

[Effect of apparatus plasmapheresis on the bowel barrier and motility function in patients with acute necrotizing pancreatitis].

Influence of therapeutic plasmapheresis on bowel barrier function and evacuation was investigated in 83 patients with severe acute necrotizing pancreatitis. Except standard therapy patient obtained therapeutic plasmapheresis using "Haemonetics" PCS 2 system. Complex treatment of patients with acute necrotizing pancreatitis and dynamic ileus using plasmapheresis increases contractive and propulsive function of stomach and duodenum and prolongs period of activity of these organs on 32%. Intestinal barrier function associates with restoration of bowel evacuation. Addition of plasmapheresis to standard therapy of necrotizing pancreatitis can be effective prevention of dynamic ileus.

[Hemocoagulation disorders in patients with acute pancreatitis].

62 patients with acute pancreatitis (AP) were examined in order to determine hemocoagulation disorders. The obtained results showed that the patients developed the consumptive coagulopathy with high levels of D-dimer, activation and exhaustion of antithrombin III (AT III). The development of hemocoagulation disturbances in patients with severe AP was confirmed through decrease of activity of AT III up to 68% and high level of D-dimer>693 ng/ml.

Experiment LEND of the NASA Lunar Reconnaissance Orbiter for high-resolution mapping of neutron emission of the Moon.

The scientific objectives of neutron mapping of the Moon are presented as 3 investigation tasks of NASA's Lunar Reconnaissance Orbiter mission. Two tasks focus on mapping hydrogen content over the entire Moon and on testing the presence of water-ice deposits at the bottom of permanently shadowed craters at the lunar poles. The third task corresponds to the determination of neutron contribution to the total radiation dose at an altitude of 50 km above the Moon. We show that the Lunar Exploration Neutron Detector (LEND) will be capable of carrying out all 3 investigations. The design concept of LEND is presented together with results of numerical simulations of the instrument's sensitivity for hydrogen detection. The sensitivity of LEND is shown to be characterized by a hydrogen detection limit of about 100 ppm for a polar reference area with a radius of 5 km. If the presence of ice deposits in polar "cold traps" is confirmed, a unique record of many millions of years of lunar history would be obtained, by which the history of lunar impacts could be discerned from the layers of water ice and dust. Future applications of a LEND-type instrument for Mars orbital observations are also discussed.

The Dynamic Albedo of Neutrons (DAN) experiment for NASA's 2009 Mars Science Laboratory.

We present a summary of the physical principles and design of the Dynamic Albedo of Neutrons (DAN) instrument onboard NASA's 2009 Mars Science Laboratory (MSL) mission. The DAN instrument will use the method of neutron-neutron activation analysis in a space application to study the abundance and depth distribution of water in the martian subsurface along the path of the MSL rover.

[The closed joint-stock company "Amiko" (X-ray equipment)]. / Zakrytoe aktsionernoe obshchestvo "Amiko" (rentgenotekhnika).

The paper presents data on the closed joint-stock company AMIKO: basic lines of its activities, history, manufactured and designed products.

[The interaction of organophosphorus amino acid analogs with cytochrome P-450 2B4]. / Vzaimodeistvie fosfororganicheskikh analogov aminokislot s tsitokhromom P450 2B4.

Interaction between phosphorus amino acids analogs, 1-aminoalkylphosphonous and 1-aminoalkylthiophosphonic acids, and microsomes from the liver of phenobarbital-induced rabbits was studied. The phosphorus amino acids analogs cause type I and reverse type I spectral changes, respectively. A new reaction in the microsomal monooxygenase system was revealed. In the presence of NADPH, 1-aminoalkylphosphonous acids can be transformed to the corresponding 1-aminoalkylphosphonic acids by the reaction P-H-->P-OH. The reaction was monitored by 1H-NMR spectroscopy. 1-Aminoalkylphosphonous acids also serve as substrates for the NADPH-dependent monooxygenase system. 31P-NMR has shown that the oxidative desulfuration produces 1-aminoalkylphosphonous acids according to the reaction P=S-->P=O. Neither 1-aminoalkylphosphonous nor 1-aminoalkylphosphonic acids are deaminated in the NADPH-dependent monooxygenase system as follows from 1H-NMR spectroscopy.

Reductase and oxygenase activities of semisynthetic flavocytochromes based on cytochrome P450 2B4.

A synthetic flavocytochrome with the reductase and oxygenase activities was obtained by covalent binding of riboflavin to cytochrome P450 2B4. The reactions catalyzed by the newly synthesized flavocytochromes were studied. Formation of carboxycomplex with the reduced form of hemoprotein led to 60-80% inhibition of oxygenase reactions indicating the leading role of reduced heme iron in generating active oxygen species by flavocytochromes.

[Surface of cytochrome P-450 2B4: structure and function]. / Poverkhnost' tsitokhroma P-4502B4: struktura i funktsii.

The review is devoted to the identification and structure of one of the cytochromes P450s-cytochrome P-450 2B4 derived from the rabbit liver endoplasmic reticulum. A critical review is made of the data on this enzyme membrane topology, its active site's structure and localization of its membrane and water-exposed regions. The paper is based on the data available in the literature and the authors' own findings. Various experimental and calculating methods used to identify the topography of cytochrome P450 are covered in the paper.

[Induction of Ca2+-dependent chemiluminescent response of peritoneal macrophages with bacterial lipopolysaccharides]. / Induktsiia Ca2+-zavisimogo khemiliuminestsentnogo otveta peritoneal'nykh makrofagov bakterial'nym lipopolisacharidom.

A lipopolysaccharide preparation obtained from Klebsiella pneumonia was shown to affect primarily the peritoneal macrophages after intraperitoneal administration. Transition of the macrophages to a new metabolic state in response to opsonized zymosan was responsible for a distinct increase in the rate of luminol-dependent chemoluminescence. At the same time, the macrophages produced chemiluminescence was only slightly increased in the presence of Ca2+ ionophore A23187. These dissimilar alterations observed suggest that the primary reaction of macrophages in response to the lipopolysaccharide occurred with the increase in content of intracellular free calcium. Administration of finoptin (calcium influx inhibitor) into suspension of macrophages caused a decrease in the rate of chemiluminescence response.

Analysis of the nucleotide and derived amino acid sequences of the SsoII restriction endonuclease and methyltransferase.

A 2648-bp fragment from the P4 plasmid of Shigella sonnei strain 47 coding for the SsoII restriction endonuclease (ENase) and methyltransferase (MTase) (recognition sequence 5'-CCNGG) was sequenced. Two divergently arranged open reading frames of 905 bp for the SsoII ENase (R.SsoII) and 1137 bp for the MTase (M.SsoII) were identified. The coding regions are separated by 110 bp. The calculated M(r) of R.SsoII (35937) and M.SsoII (42887) are in good agreement with values previously obtained by in vitro transcription-translation experiments, i.e., 35 and 43 kDa for the ENase and MTase, respectively. The M.SsoII amino acid (aa) sequence revealed a considerable similarity to m5C-MTases recognizing the related sequences--M.EcoRII, M.dcm, M.MspI, M.BsuFI, M.HpaII, and M.HhaI. Surprisingly, the greatest degree of homology has been observed between the aa sequences of M.SsoII and M.NlaX, with an unidentified recognition sequence. The multiple alignment of aa sequences helps to identify the blocks of conserved aa in variable regions of MTases. These conserved aa can play a key role in target recognition. Some aspects of evolution of m5C-MTases are discussed.

[The role of heme in formation of the native structure of cytochrome P-450 LM2]. / Rol' gema v formirovanii nativnoi struktury tsitokhroma P-450 LM2.

The role of heme in the formation of cytochrome P-450 native structure was investigated. It was shown that treatment of purified and membrane-bound hemoproteins with H2O2 results in the total destruction of heme. After incubation with hemine the apoprotein thus obtained forms a catalytically active cytochrome P-450. The efficiency of this process depends on the enzyme microenvironment. The membrane-bound apoprotein may be reconstituted by 70-80%, whereas the soluble one--by 50%. It is concluded that the observed differences may be accounted for by a greater stability of the membrane-bound protein structure.

[Structural organization and localization of cytochromes P450 in the membrane]. / Strukturnaia organizatsiia i raspolozhenie tsitokhromov P450 v membrane.

The secondary structure prediction of 19 microsomal cytochrome P-450s from two different families was made based on their amino acid sequences. It was shown that there is a structural similarity between the heme-binding sites of these enzymes and the bacterial P-450cam. An average predicted secondary structure of cytochrome P-450 proteins with 70% accuracy contains about 46% alpha-helices, 12% beta-strands, 9% beta-turns and 33% random coil. In the region of the 35-120 residues in microsomal P-450s two adjacent beta alpha beta-units (the Rossmann domain) were recognized, which may interact with the NADPH-cytochrome P-450 reductase. Using the procedure of identification of hydrophobic and membrane-associated alpha-helical segments of 23 cytochromes, only one N-terminal transmembrane anchor was predicted. Also the heme-binding site perhaps includes surface-bound helix. A model of vertebrate microsomal P-450s is proposed. That is an amphypathic membrane protein located on the cytoplasmic face of the endoplasmic reticulum, their active center lies out/on the bilayer border.

[The effect of microenvironment and formation of intra-molecular links on the tertiary structure of cytochrome P-450 LM2]. / Vliianie mikrookruzheniia i obrazovaniia vnutrimolekuliarnykh shivok na formirovanie tretichnoi struktury tsitokhroma LM2.

The effect of intramolecular cross-links formation in isolated cytochrome P-450 LM2 on its reactivation after incorporation into the liposome lipid bilayer was studied. Treatment with bifunctional reagents results in the inactivation of the solubilized haemoprotein. The degree of the enzyme immobilization determines the degree of inhibition of p-nitroanisol demethylation and aniline hydroxylation. Whereas the complete inhibition of oxidation of type II substrate turnover needs two intramolecular cross-links, that of type I substrates necessitates at least seven cross-links. The incorporation of modified and native enzymes into the membrane lipid bilayer at temperatures above the phase transition point results in the enzyme activation. However, in case of the preimmobilized enzyme the activation does not reach the maximal values. Both stabilized and liposome-incorporated cytochrome P-450 can fully be reactivated via the cross-link disulfide bond reduction. No such effect is observed at temperatures below the phase transition point.

[ESR-spectroscopy of cytochrome P-450 LM2 in the soluble and membrane-bound state]. / EPR-spektroskopiia spin-mechenogo tsitokhroma P-450 LM2 v izolirovannom i membranno-sviazannom sostoianiiakh.

Influence of microenvironment on the structure of spin-labeled cytochrome P-450 LM2 was studied. The distance between the spin-label which is covalently bound to cysteine-152 and heme ferrum in soluble protein is 17 A and 23 A in the membrane-bound one. The spin-label was exposed in water solution in both cases. It was shown that solubilized cytochrome P-450 LM2 in water solution forms the aggregates consisting of 4-6 monomers.