Raman spectroscopic and theoretical study of liquid and solid water within the spectral region 1600-2300cm-1.

Raman spectra of liquid water and ice were measured at different temperatures. The intensity of the band assigned to bending vibrations of water molecules was observed to decrease at the liquid-to-solid transition, while the Raman line near 2200cm-1 showed an anomalously high intensity in the solid phase. A tetrahedral model was used for computer analysis of the observed spectral changes. Quantum-chemical calculations of the structure, normal vibrations and Raman spectra in the harmonic approximation, as well as frequencies and intensities of some vibrations using 1D and 2D potential energy surfaces, were carried out using B3LYP with the cc-pVTZ basis set. The influence of the number of hydrogen bonds on the frequency and Raman activity of the bending vibrations was analyzed. The possibility of hydrogen bond weakening upon excitation of the combined bending-rocking vibration due to the large amplitude of this vibration is considered.

MP4 Study of the Anharmonic Coupling of the Shared Proton Stretching Vibration of the Protonated Water Dimer in Equilibrium and Transition States.

The structure and harmonic and anharmonic IR spectra of the protonated water dimer (PWD) were calculated in C1, C2, and Cs symmetry at the MP4/acc-pVTZ level of theory. We found that structure and IR spectra are practically identical in C2 and C1 symmetry, demonstrating that an equilibrium C1 configuration of the PWD is not realized. Anharmonic coupling of the shared proton stretching vibration with all other modes in the PWD in C2 and Cs symmetry was the focus of this investigation. For this purpose, 28 two-dimensional potential energy surfaces (2D PES) were built at the MP4/acc-pVTZ level of theory and the corresponding vibrational Schrödinger equations were solved using the DVR method. Differences in the coupling of the investigated mode with other modes in the C2 and Cs configurations, along with some factors that determine the red- or blue-shift of the stretching vibration frequency, were analyzed. We obtained a rather reasonable value of the stretching frequency of the bridging proton (1058.4 cm-1) unperturbed by Fermi resonance. The Fermi resonance between the fundamental vibration ν7 and the combined vibration ν2 + ν6 of the same symmetry was analyzed through anharmonic second-order perturbation theory calculations, as well as by 3D PES constructed using Q2, Q6, and Q7 as normal coordinates. A significant (up to 50%) transfer of intensity from the fundamental vibration to the combined one was found. We have estimated the frequency of the bridging proton stretching vibration in the Cs configuration of the PWD based on calculations of the intrinsic anharmonicity and anharmonic double modes interactions at the MP4/acc-pVTZ level of theory (1261 cm-1).

Histamine H3R receptor activation in the dorsal striatum triggers stereotypies in a mouse model of tic disorders.

Tic disorders affect ~5% of the population and are frequently comorbid with obsessive-compulsive disorder, autism, and attention deficit disorder. Histamine dysregulation has been identified as a rare genetic cause of tic disorders; mice with a knockout of the histidine decarboxylase (Hdc) gene represent a promising pathophysiologically grounded model. How alterations in the histamine system lead to tics and other neuropsychiatric pathology, however, remains unclear. We found elevated expression of the histamine H3 receptor in the striatum of Hdc knockout mice. The H3 receptor has significant basal activity even in the absence of ligand and thus may modulate striatal function in this knockout model. We probed H3R function using specific agonists. The H3 agonists R-aminomethylhistamine (RAMH) and immepip produced behavioral stereotypies in KO mice, but not in controls. H3 agonist treatment elevated intra-striatal dopamine in KO mice, but not in controls. This was associated with elevations in phosphorylation of rpS6, a sensitive marker of neural activity, in the dorsal striatum. We used a novel chemogenetic strategy to demonstrate that this dorsal striatal activity is necessary and sufficient for the development of stereotypy: when RAMH-activated cells in the dorsal striatum were chemogenetically activated (in the absence of RAMH), stereotypy was recapitulated in KO animals, and when they were silenced the ability of RAMH to produce stereotypy was blocked. These results identify the H3 receptor in the dorsal striatum as a contributor to repetitive behavioral pathology.

Temperature dependence of the intensity of the vibration-rotational absorption band ν2 of H2O trapped in an argon matrix.

Using two sets of effective rotational constants for the ground (000) and the excited bending (010) vibrational states the calculation of frequencies and intensities of vibration-rotational transitions for J″=0-2; and J'=0-3; was carried out in frame of the model of a rigid asymmetric top for temperatures from 0 to 40K. The calculation of the intensities of vibration-rotational absorption bands of H2O in an Ar matrix was carried out both for thermodynamic equilibrium and for the case of non-equilibrium population of para- and ortho-states. For the analysis of possible interaction of vibration-rotational and translational motions of a water molecule in an Ar matrix by 3D Schrödinger equation solving using discrete variable representation (DVR) method, calculations of translational frequencies of Н2О in a cage formed after one argon atom deleting were carried out. The results of theoretical calculations were compared to experimental data taken from literature.

Theoretical study of the C-H/O-H stretching vibrations in malonaldehyde.

IR and Raman spectra of the malonaldehyde molecule and its deuterated analogues were calculated in the B3LYP/cc-pVQZ approximation. Anharmonicity effects were taken into account both in the context of a standard model of the second order perturbation theory and by constructing the potential energy surfaces (PES) with a limited number of dimensions using the Cartesian coordinates of the hydroxyl hydrogen atom and the stretching coordinates of С-Н, C-D, O-H, and O-D bonds. It was shown that in each of the two equivalent forms of the molecule, besides the global minimum, an additional local minimum at the PES is formed with the energy more than 3,000 cm(-1) higher than the energy in the global minimum. Calculations carried out by constructing the 2D and 3D PESs indicate a high anharmonicity level and multiple manifestations of the stretching О-Н vibrations, despite the fact that the model used does not take into account the splitting of the ground-state and excited vibrational energy levels. In particular, the vibration with the frequency 3,258 cm(-1) may be associated with proton transfer to the region of a local minimum of energy. Comparing the results obtained with the experimental data presented in the literature allowed us to propose a new variant of bands assignments in IR and Raman spectra of the molecule in the spectral region 2,500-3,500 cm(-1).

Pyridine N-oxide/trichloroacetic acid complex in acetonitrile: FTIR spectra, anharmonic calculations and computations of 1-3D potential surfaces of O-H vibrations.

FTIR spectra of pyridine N-oxide and trichloroacetic acid H-bonded complex in acetonitrile were studied at 20 and 50°C. The calculations of equilibrium configurations of the complex and their IR spectra in harmonic- and anharmonic approximations were carried out at the level of B3LYP/cc-pVTZ/PCM. However both approximations turned out to be incompetent determining the frequency of the O-Н stretching vibration. In order to reveal the causes of essential discrepancies between calculated and experimental data one-, two- and three-dimensional potential energy surfaces (PES) of the O-H…O bridge proton motion in the frame of fixed other atoms in the complex were calculated. The frequencies of O-H…O stretching and bending vibrations were calculated by numerical solution of the Schrödinger equation. It is shown that only the approach of proton motion on the 3D PES allows obtaining a good agreement between the calculated and the experimental values of the frequencies of the О-Н stretching vibrations.

[Current methods for preparing samples on working with hematology analyzers].

The paper raises a problem of preparing samples in hematology. It considers whether the preanalytical stage is of importance in hematological studies. The use of disposal vacuum blood collection systems is shown to solve the problem in the standardization of a blood sampling procedure. The benefits of the use of close tube hematology analyzers are also considered.

[Principles and potentialities of the standardization of morphocytochemical diagnosis of acute leukemias].

Under the present conditions, the competitive capacity of a health care facility is provided by the high level and timeliness of diagnosis of disease. The diagnosis of the types of acute leukemia (AL) may be accomplished immunologically, by using a 33-marker panel and without consideration of the morphocytochemical parameters of blast cells. But such an approach complicates and prolongs the examination of patients with AL. Moreover, morphocytochemical data more exactly define the stages of blast cell differentiation than does the immunological phenotype. Their preparation methods are simple and cost-effective. Only M0, M6, and M7 forms of leukemia require compulsory blast cell phenotyping, particularly in the differential diagnosis of acute myeloid leukemia and acute lymphoblastic leukemia. Search for new markers of leukemia cells, including lesions at the chromosomal or molecular levels, is under way. Some of them are only of theoretical value while other markers have been already used by hematologists to diagnose leukemia. Standardization in this essence is the self-assessment of a facility and reference comparison, which are based on the principles of its orientation to the patient, the adjusted system for controlling the quality of health care that is up to the world standards rather than the compliance with the state-regulated standard. The present paper discusses the ways of establishing the uniform rates and requirements for the morphocytochemical diagnosis of acute leukemias.

[Microvzor-2: a system for automated dry blood smear analysis]. / Mikrovzor-2: kompleks avtomaticheskogo analiza krovi po sukhomu mazku.

Upgraded system Microvzor-2 for investigation of blood morphology in space flight is composed of soft- and hardware for dry smear image analysis. Ground-based testing showed that it could be utilized to investigate a broad spectrum of blood parameters in space flight, including erythrocytes, hemoglobin content in erythrocytes, volumetric erythrocyte distribution, diagnostics of anisocytosis, and poikilocytosis, leukocytes and leukocyte count. Analyzed are smears prepared from a fixed volume of finger blood. The process consists of smear scanning, input of the vision field images in the spacecraft computer and ensuing automated identification and counting. Information is stored in a dedicated database. Results of analysis are displayed as forms and cell galleries.

[PCR-detection of markers for epidemiologically-significant strains of Vibrio cholerae 0139, isolated in Siberia]. / PtsR-detektsiia markerov épidemicheskoi znachimosti shtammov Vibrio cholerae 0139, izolirovannykh v Sibiri.

Fourteen V. cholerae 0139 strains were isolated in 1996-1999 in Siberia from the Ob river (Novosibirsk) and bogs and lakes (Irkutsk). The strains were tested in PCR for the key virulence determinants (ctx AB, tcp, acf). The genomes lacked these elements, and therefore the strains were acknowledged avirulent. The results correlate completely with the data of phenotypical analysis, characterizing the pathogenic characteristics of isolated strains.

[Eltor cholera in Latin America]. / Kholera El'tor v Latinskoi Amerike.

Cholera epidemics in South and Central America in the period 1991-1999 are characterized. The mechanisms of existence of Vibrio eltor in environmental objects have been substantiated. The causes and conditions of endemic foci formation which determine the infection spread not only within the countries of the subcontinent, but also far beyond its borders are shown. The effectiveness of cholera control interventions is evaluated.

[Comparative study of various methods for determining Vibrio cholerae toxigenicity]. / Sravnitel'noe izuchenie razlichnykh metodov opredeleniia toksigennosti Vibrio cholerae.

Testing of 138 Vibrio cholerae strains for gene determinants responsible for the production of cholera enterotoxin by the polymerase chain reaction (PCR) and gene probing using molecular CT-probe showed good correlation of the results of different methods and correlation of these data with studies of V. cholerae strain virulence in vivo and in hemolytic activity test. The advantages of PCR in rapid assessment of the toxigenicity and epidemic significance of V. cholerae strains are demonstrated.

[Quantitative morphology of periferal erythrocytes and bone marrow erythrokaryocytes in acute leukemia and hemopoietic depressions]. / Kolichestvennaia morfologiia éritritsitov perifericheskoi krovi i éritrokariotsitov kostnogo mozga pri ostrykh leikozakh i depressiiakh krovetvoreniia.

Morphology of peripheral blood erythrocytes was studied in patients with acute leukemia and aplastic anemia by a Russian cytoanalyzer Mekos-C. Twenty-eight patients with acute myeloblastic leukemia, 15 with acute lymphoblastic leukemia, and 11 with aplastic anemia were examined. Erythrocytes (n = 500) were examined in fixed non-stained blood smears. Hemoglobin content and morphometric parameters of each cell were studied and automatic classification of cells was carried out. The data of computer morphodensitometry are compatible with the data of cytochemical studies of the bone marrow erythroid cells (PAS reaction after McManus). The results indicate circulation of erythrocyte subpopulations differing by shape and other signs (hemoglobin content, section area, shape factor) in the blood of patients with acute leukemia and aplastic anemia. The share of pathological erythrocytes in the peripheral blood reflects failure of erythropoiesis.

Dopaminergic involvement in the process of reinforcement from diethyl ether vapor in rats.

1. Male and female Wistar rats were placed in boxes for 30 min daily and allowed to nose-poke in two holes on opposite walls, which opened into evaporation chambers through valves. One chamber contained diethyl ether vapor another-air, the contents being alternated randomly. 2. Rats inhaled the contents of evaporation chambers while nose-poking differed by the level of intake of diethyl ether vapor. Rats with the intake time of more than 3 sec formed about 15% of population. Their preference for diethyl ether was above 0.55. 3. There was significant negative correlation between the time of vapor inhalation and the time of immobility in forced swimming test in females but not in males. 4. Withdrawal of diethyl ether vapor decreased the inhalation time. On the first day after ether deprivation inhalation time rose above average level. Relationship between concentration of ether vapor and the time of its inhalation was inverted U-shaped function. Substitution of acetone vapor elevated the time of the vapor inhalation. 5. D-amphetamine in dose 0.05 mg/kg elevated the time of inhalation of and preference for ether vapor in some rats. In doses 0.05-1.0 mg/kg amphetamine selectively suppressed the time of vapor inhalation. 6. Haloperidol in doses 0.05 and 0.1 mg/kg elevated the time of vapor inhalation on the first day in females and suppressed it in doses 0.05-0.3 mg/kg dose-dependently on the second day. Atypical neuroleptic cis-carbidine elevated the time of vapor inhalation in doses 2.5 and 5.0 mg/kg and suppressed it at 10 mg/kg. 7. Diethyl ether vapor can be established as reinforcer in rats. Female rats are more liable to reinforcement from ether vapor than males and show more pronounced response to haloperidol. This may be related to its more active behavior in the forced swimming situation. 8. The results point to potential involvement of dopamine system in the process of reinforcement from ether vapor.

[Blood viscosity, deformability and morphological types of erythrocytes in vibration disease]. / Viazkost' krovi, deformiruemost' i morfologicheskie tipy éritrotsitov pri vibratsionnoi bolezni.

The study evaluating pathogenesis of microcirculatory disorders in subjects with vibration disease covered 63 patients. The patients demonstrated trends to low blood (and, especially, serum) viscosity, to decreased RBC deformability evaluated by filtration and viscosimetry methods, higher number of degenerative and reversibly changed RBC (echinocytes and stomatocytes). The authors discuss the role of these rheological disorders in pathogenesis of angiodystonic syndrome in vibration disease.