| 1. |
- Aad, G, et al.
(author)
-
- 2015
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swepub:Mat__t
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| 2. |
- Schael, S, et al.
(author)
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Precision electroweak measurements on the Z resonance
- 2006
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In: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
-
Research review (peer-reviewed)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
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| 3. |
- Schael, S., et al.
(author)
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Electroweak measurements in electron positron collisions at W-boson-pair energies at LEP
- 2013
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In: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 532:4, s. 119-244
-
Research review (peer-reviewed)abstract
- Electroweak measurements performed with data taken at the electron positron collider LEP at CERN from 1995 to 2000 are reported. The combined data set considered in this report corresponds to a total luminosity of about 3 fb(-1) collected by the four LEP experiments ALEPH, DELPHI, 13 and OPAL, at centre-of-mass energies ranging from 130 GeV to 209 GeV. Combining the published results of the four LEP experiments, the measurements include total and differential cross-sections in photon-pair, fermion-pair and four-fermion production, the latter resulting from both double-resonant WW and ZZ production as well as singly resonant production. Total and differential cross-sections are measured precisely, providing a stringent test of the Standard Model at centre-of-mass energies never explored before in electron positron collisions. Final-state interaction effects in four-fermion production, such as those arising from colour reconnection and Bose Einstein correlations between the two W decay systems arising in WW production, are searched for and upper limits on the strength of possible effects are obtained. The data are used to determine fundamental properties of the W boson and the electroweak theory. Among others, the mass and width of the W boson, m(w) and Gamma(w), the branching fraction of W decays to hadrons, B(W -> had), and the trilinear gauge-boson self-couplings g(1)(Z), K-gamma and lambda(gamma), are determined to be: m(w) = 80.376 +/- 0.033 GeV Gamma(w) = 2.195 +/- 0.083 GeV B(W -> had) = 67.41 +/- 0.27% g(1)(Z) = 0.984(-0.020)(+0.018) K-gamma - 0.982 +/- 0.042 lambda(gamma) = 0.022 +/- 0.019. (C) 2013 Elsevier B.V. All rights reserved.
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| 4. |
- Chernikova, Dina, 1982, et al.
(author)
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Experimental and numerical investigations of radiation characteristics of Russian portable/compact pulsed neutron generators: ING-031 ING-07, ING-06 and ING-10-20-120
- 2014
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In: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 746, s. 74-86
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Journal article (peer-reviewed)abstract
- The present paper discusses results of full-scale experimental and numerical investigations of influence of construction materials of portable pulsed neutron generators ING-031, ING-07, ING-06 and ING-10-20-120 (VNIIA, Russia) to their radiation characteristics formed during and after an operation (shutdown period). In particular, it is shown that an original monoenergetic isotropic angular distribution of neutrons emitted by TiT target changes into the significantly anisotropic angular distribution with a broad energy spectrum stretching to the thermal region. Along with the low energetic neutron part, a significant amount of photons appears during the operation of generators. In the pulse mode of operation of neutron generator, a presence of the construction materials leads to the "tailing" of the original neutron pulse and the appearance of an accompanying photon pulse at similar to 3 ns after the instant neutron pulse. In addition to that, reactions of neutron capture and inelastic scattering lead to the creation of radioactive nuclides, such as Co-58, Cu-62, Cu-64 and F-18, which form the so-called activation radiation. Thus, the selection of a portable neutron generator for a particular type of application has to be clone considering radiation characteristics of the generator itself. This paper will be of interest to users of neutron generators, providing them with valuable information about limitations of a specific generator and with recommendations for improving the design and performance of the generator as a whole. (c) 2014 Elsevier B.V. All rights reserved.
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| 5. |
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| 6. |
- Aurino, Pier Paolo, 1985, et al.
(author)
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Reversible metal-insulator transition of Ar-irradiated LaAlO3/SrTiO3 interfaces
- 2015
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In: Physical Review B - Condensed Matter and Materials Physics. - 2469-9950 .- 2469-9969. ; 92:15
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Journal article (peer-reviewed)abstract
- The conducting state of a quasi-two-dimensional electron gas (q2DEG), formed at the heterointerface between the two wide-bandgap insulators LaAlO3 (LAO) and SrTiO3, can be made completely insulating by low-energy, 150-eV, Ar+ irradiation. The metallic behavior of the interface can be recovered by high-temperature oxygen annealing. The electrical transport properties of the recovered q2DEG are exactly the same as before the irradiation. Microstructural investigations confirm that the transition is not due to physical etching or crystal lattice distortion of the LAO film below its critical thickness. They also reveal a correlation between electrical state, LAO film surface amorphization, and argon ion implantation. The experimental results are in agreement with density functional theory calculations of Ar implantation and migration in the LAO film. This suggests that the metal-insulator transition may be caused by charge trapping in the defect amorphous layer created during the ion irradiation.
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| 7. |
- Satanin, L., et al.
(author)
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Introduction of spring-assisted cranioplasty for scaphocephaly in Russia: first cases evaluated using detailed craniometry and principal component analysis
- 2019
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In: Journal of Plastic Surgery and Hand Surgery. - : Medical Journals Sweden AB. - 2000-656X .- 2000-6764. ; 53:3, s. 173-179
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Journal article (peer-reviewed)abstract
- Spring-assisted cranioplasty (SAC) was recently introduced in Moscow. This study provides a detailed analysis of the results of the first 14 SAC cases in Russia. The patients underwent a computed tomography scan before surgery and prior to spring removal 3 months later. Fourteen cases (10 males and 4 females) were operated on, with a mean surgery time of 56 +/- 14 min. All operations were uneventful, with a mean hospital stay of 4.2 days. Detailed craniometry of the 10 male patients and their matched controls revealed that SAC induced changes in the shape of the entire skull. The cranial index of the male patients increased from 68.2 to 72.3, whereas it remained stable at similar to 80 for the controls. The anterior and middle skull heights were significantly larger in cases as compared with controls but shifted toward normal levels following SAC. Additionally, SAC increased parietal bone curvature, and principal component analysis showed that post-SAC morphological changes in patients were comparable to normal growth changes in the skull morphology of the controls. However, several months after the operation, patients continued to display a clearly distinct cranial morphology as compared with that of controls. These results indicated that SAC is a safe technique that showed good surgical results immediately after introduction.
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| 8. |
- Varfolomeyev, S, et al.
(author)
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Postgenomic chemistry (IUPAC Technical Report)
- 2005
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In: Pure and Applied Chemistry. - : Walter de Gruyter GmbH. - 0033-4545 .- 1365-3075. ; 77:9, s. 1641-1654
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Journal article (peer-reviewed)abstract
- Numerous areas of chemistry can benefit from the ongoing genomic revolution. Here, we discuss and highlight trends in chemistry in the postgenomic era. The areas of interest include combinatorial approaches in organic chemistry; design and analysis of proteins containing unnatural amino acids; trace element-containing proteins; design and characterization of new enzyme types; applications of postgenomic chemistry in drug design; identification of lipid networks and global characterization of lipid molecular species; development of recombinant and self-proliferating polymers; and applications in food chemistry and bioanalytical chemistry based on new nanoanalytical systems and novel recognition elements.
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| 9. |
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| 10. |
- Alpeeva, IS, et al.
(author)
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Bi-enzyme alcohol biosensors based on genetically engineered alcohol oxidase and different peroxidases
- 2005
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In: Microchimica Acta. - : Springer Science and Business Media LLC. - 1436-5073 .- 0026-3672. ; 152:1-2, s. 21-27
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Journal article (peer-reviewed)abstract
- We report on the development of a bi-layer bi-enzyme biosensor architecture using different peroxidases and alcohol oxidase from Hansenula polymorpha C-105 as biological recognition elements. The sensor architecture comprises a first layer containing either horseradish peroxidase or royal palm tree peroxidase crosslinked with an Osmium complex-modified redox hydrogel. On top, a second layer was formed by electrochemically induced precipitation of a cathodic electrodeposition paint simultaneously entrapping alcohol oxidase isolated from a genetically modified strain of Hansenula polymorpha C-105. The sensor architecture was optimized with respect to effective electron transfer and stability of the enzyme. The main characteristics of the biosensors are an apparent maximal current I-max(app) of 572-940 nA, an apparent Michaelis constant K-M(app) of 9.5 mM, a sensitivity of 60-98 nA mM(-1) and an improved operational stability represented by a deactivation constant of 1.5-2.0 x 10(-4) min(-1).
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| 11. |
- Alpeeva, I, et al.
(author)
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Cyclometalated Ruthenium(II) Complexes As Efficient Redox Mediators in Peroxidase Catalysis
- 2003
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In: Journal of Biological Inorganic Chemistry. - : Springer Science and Business Media LLC. - 1432-1327 .- 0949-8257. ; 8:6, s. 683-688
-
Journal article (peer-reviewed)abstract
- Cyclometalated ruthenium(II) complexes, [Ru II(C~N)(N~N) 2]PF 6 [HC~N=2-phenylpyridine (Hphpy) or 2-(4'-tolyl)pyridine; N~N=2,2'-bipyridine, 1,10-phenanthroline, or 4,4'-dimethyl-2,2'-bipyridine], are rapidly oxidized by H 2O 2 catalyzed by plant peroxidases to the corresponding Ru III species. The commercial isoenzyme C of horseradish peroxidase (HRP-C) and two recently purified peroxidases from sweet potato (SPP) and royal palm tree (RPTP) have been used. The most favorable conditions for the oxidation have been evaluated by varying the pH, buffer, and H 2O 2 concentrations and the apparent second-order rate constants ( k app) have been measured. All the complexes studied are oxidized by HRP-C at similar rates and the rate constants k app are identical to those known for the best substrates of HRP-C (10 6–10 7 M -1 s -1). Both cationic (HRP-C) and anionic (SPP and RPTP) peroxidases show similar catalytic efficiency in the oxidation of the Ru II complexes. The mediating capacity of the complexes has been evaluated using the SPP-catalyzed co-oxidation of [Ru II(phpy)(bpy) 2]PF 6 and catechol as a poor peroxidase substrate as an example. The rate of enzyme-catalyzed oxidation of catechol increases more than 10,000-fold in the presence of the ruthenium complex. A simple routine for calculating the rate constant k c for the oxidation of catechol by the Ru III complex generated enzymatically from [Ru II(phpy)(bpy) 2] + is proposed. It is based on the accepted mechanism of peroxidase catalysis and involves spectrophotometric measurements of the limiting Ru II concentration at different concentrations of catechol. The calculated k c value of 0.75 M -1 s -1 shows that the cyclometalated Ru II complexes are efficient mediators in peroxidase catalysis.
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| 12. |
- Boikov, Y. A., et al.
(author)
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Elastically strained and relaxed La0.67Ca0.33MnO3 films grown on lanthanum aluminate substrates with different orientations
- 2016
-
In: Physics of the Solid State. - : Pleiades Publishing Ltd. - 1063-7834 .- 1090-6460. ; 58:12, s. 2560-2566
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Journal article (peer-reviewed)abstract
- Structure of 40-nm thick La0.67Ca0.33MnO3 (LCMO) films grown by laser evaporation on (001) and (110) LaAlO3 (LAO) substrates has been investigated using the methods of medium-energy ion scattering and X-ray diffraction. The grown manganite layers are under lateral biaxial compressive mechanical stresses. When (110)LAO wafers are used as the substrates, stresses relax to a great extent; the relaxation is accompanied by the formation of defects in a (3-4)-nm thick manganite-film interlayer adjacent to the LCMO-(110)LAO interface. When studying the structure of the grown layers, their electro- and magnetotransport parameters have been measured. The electroresistance of the LCMO films grown on the substrates of both types reached a maximum at temperature T (M) of about 250 K. At temperatures close to T (M) magnetoresistance of the LCMO/(110)LAO films exceeds that of the LCMO/(001)LAO films by 20-30%; however, the situation is inverse at low temperatures (T < 150 K). At T < T (M) , the magnetotransport in the grown manganite films significantly depends on the spin ordering in ferromagnetic domains, which increase with a decrease in temperature.
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| 13. |
- Boikov, Yu A., et al.
(author)
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Structure and magneto-transport parameters of partially relaxed and coherently grown La0.67Ba0.33MnO3 films
- 2013
-
In: Physics of the Solid State. - 1063-7834 .- 1090-6460. ; 55:10, s. 2043-2050
-
Journal article (peer-reviewed)abstract
- X-ray diffraction (XRD) and medium-energy ion scattering (MEIS) have been used to reveal distortions in the crystal lattice of La0.67Ba0.33MnO3 (LBMO) films formed in relaxation of mechanical stresses. The LBMO films 25 nm thick have been prepared by laser deposition. The XRD and MEIS data obtained suggest that biaxially and mechanically elastically stressed LBMO layers grow coherently on LSATO substrates, whose crystal lattice parameter differs only weakly from the corresponding LBMO parameter, whereas in the bulk of manganite films grown on LaAlO3 substrates, stresses relax partially. Stresses do not relax in the LBMO interface about 4 nm thick adjoining LaAlO3. The electro- and magneto-transport parameters of partially relaxed LBMO films have been compared with those obtained for coherently grown manganite films with approximately the same tetragonal distortion of the lattice cell (a (aSyen)/a (aEuro-) = 1.024-1.030; a (aEuro-) and a (aSyen) are the unit cell parameters in the substrate plane and normal to it, respectively). At temperatures substantially lower than the Curie temperature, the electrical resistivity rho of LBMO films fits the relation rho = rho(0) + rho(1) T (2) + rho(2)(H)T (4.5); the coefficients rho(0) and rho(1) do not depend on temperature T and magnetic field, and rho(2) does not depend on temperature but almost linearly decreases with increasing magnetic field strength H. The coefficient rho(2) for partially relaxed LBMO films is substantially larger than that for coherently grown manganite layers.
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| 14. |
- Castillo Leon, Jaime, et al.
(author)
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Purification and substrate specificity of peroxidase from sweet potato tubers
- 2002
-
In: Plant Science. - 0168-9452. ; 163:5, s. 1011-1019
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Journal article (peer-reviewed)abstract
- Previously the screening of tropical plants demonstrated a high peroxidase activity in sweet potato (Ipomoea batatas) tubers. The major peroxidase pool is localized in peel. Using peel of sweet potato as a source, the sweet potato peroxidase (SPP) has been isolated and purified to homogeneity. The enzyme purification included homogenization, extraction of colored compounds and consecutive chromatographies on Phenyl-Sepharose and DEAE-Toyopearl. The purified SPP had specific activity of 4900 U mg(-1) protein, RZ (ratio of absorbances at 403 and 280 nm, respectively) 3.4, molecular mass of 37 kDa and isoelectric point of 3.5. The spectrum of peroxidase from sweet potato is typical for plant peroxidases with a Soret maximum at 401 nm and the maxima in the visible region at 497 and 638 nm, respectively. The substrate specificity of SPP is distinct from the specificity of other plant peroxidases, ferulic acid being the best substrate for SPP.
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| 15. |
- Dyakonova, V. E., et al.
(author)
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Complex avoidance behavior and its neurochemical regulation in the land snail Cepea numerals
- 1995
-
In: General Pharamacology. - 0306-3623. ; 26, s. 773-777
-
Journal article (peer-reviewed)abstract
- .1. In hot plate experiments, the pulmonate land snail Cepaea nemoralis displays a biphasic passive/active avoidance behaviour composed of retraction and subsequent searching mediated by antagonistic muscular systems. The switch, between the behaviours, is under neuronal control.2.2. Leu- and met-enkephalin, as well as FMRFamide-antiserum, attenuated the retraction response and potentiated the searching behaviour. Opposite effects were achieved by injection of antisera to the enkephalins.3.3. Both retraction and searching behaviours were potentiated by 5-HT. Methysergide antagonized the effects of the enkephalins on the searching behaviour.4.4. We conclude that endogenous opioids act antagonistic to FMRFamide in the neuronally controlled switch between passive and active avoidance behaviour.
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| 16. |
- Dyakonova, V, et al.
(author)
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Effects of naloxone on c-jun/AP-1 in MET-enkephalin- and FMRFamide-immunoreactive neurons of a gastropod snail
- 1999
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In: Acta Biologica Hungarica. - 0236-5383. ; 50:1-3, s. 43-54
-
Journal article (peer-reviewed)abstract
- 1. Opioid- and FMRFamide (FMRFa)-ergic systems are believed to play antagonistic behavioral roles in both higher and lower animals. In our previous experiments on a snail, behavioral choice has been demonstrated to be dependent on a balance between FMRFa and enkephalins [7]. Here, we examined if the disturbance of the balance causes changes in the activity of both systems. Opiate receptor blocker naloxone was applied and its effect on c-jun expression of met-enkephalin (MEnk)- and FMRFa-ergic neurons was examined immunocytochemically in terrestrial gastropod snail Cepaea nemoralis. 2. In control, untreated snails, central neurons with c-jun/AP-1-like-immunoreactivity were found to occur. These included MEnk-, FMRFa- and 5HT-immunoreactive (-ir) neurons, as was revealed by double-labelling. 3. After treatment with naloxone for 4 h, the following changes were observed: (i) increase in the number of MEnk-ir neurons; increase in the number of neurons showing c-jun/AP-1 and MEnk double-labeling; (ii) disappearance of c-jun/AP-1-immunoreactivity from some FMRFa-ir neurons. 4. It is suggested that immediate early genes are involved in the mechanisms responsible for the reciprocal regulation of the opioid and antiopioid neuropeptide systems.
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| 17. |
- Elofsson, Rolf, et al.
(author)
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Is nitric oxide (NO) produced by invertebrate neurons?
- 1993
-
In: NeuroReport. - 1473-558X. ; 4, s. 279-282
-
Journal article (peer-reviewed)abstract
- NADPH-DIAPHORASE (NADPHd) is known to be identical to nitric oxide (NO) synthase in the mammalian nervous system, and is therefore used as a marker of NO-producing neurones. Using the histochemical reaction for NADPHd, we searched for such neurones in a selection of invertebrates. Special emphasis was given to molluscs. No selective neuronal staining was found in representatives of coelenterates, turbellarians, nematodes and urochordates. In all annelids, arthropods and molluscs examined, with the exception of a chiton, specific neurones were selectively stained. The reaction was particularly strong in pulmonate molluscs where scattered positive neurones were found in various ganglia and clustered symmetrically in the paired buccal ganglia. Biochemical assay of NO synthase in osphradia of the gastropod mollusc Lymnaea stagnalis revealed a formation of citrullin that was inhibited by the specific NO synthase N[omega]-nitro-L-arginine (NO2Arg). Both histochemical and biochemical methods indicate that NO can be used as a signal molecule by specific neurones in advanced invertebrates.
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| 18. |
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| 19. |
- Kalaboukhov, Alexei, 1975, et al.
(author)
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Electrical and structural properties of ABO3/SrTiO3 interfaces
- 2012
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In: Materials Research Society Symposium Proceedings. - Warrendale, Pa. : Springer Science and Business Media LLC. - 0272-9172. - 9781605114316 ; 1454, s. 167-172, s. 167-172
-
Conference paper (peer-reviewed)abstract
- Electrical transport and microstructure of interfaces between nm-thick films of various perovskite oxides grown by pulsed laser deposition (PLD) on TiO2 terminated SrTiO3 (STO) substrates are compared. LaAlO3/STO and KTaO3/STO interfaces become quasi-2DEG after a critical film thickness of 4 unit cell layers. The conductivity survives long anneals in oxygen atmosphere. LaMnO3/STO interfaces remain insulating for all film thicknesses and NdGaO3/STO interfaces are conducting but the conductivity is eliminated after oxygen annealing. Medium-energy ion spectroscopy and scanning transmission electron microscopy detect cationic intermixing within several atomic layers from the interface in all studied interfaces. Our results indicate that the electrical reconstruction in the polar oxide interfaces is a complex combination of different mechanisms, and oxygen vacancies play an important role.
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| 20. |
- Kalaboukhov, Alexei, 1975, et al.
(author)
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Improved cationic stoichiometry and insulating behavior at the interface of LaAlO3/SrTiO3 formed at high oxygen pressure during pulsed-laser deposition
- 2011
-
In: Europhysics Letters. - : IOP Publishing. - 0295-5075 .- 1286-4854. ; 93:3
-
Journal article (peer-reviewed)abstract
- Medium-energy ion spectroscopy, MEIS, and scanning transmission electron microscopy, STEM, were used to correlate the atomic structure of LaAlO3/SrTiO3 interfaces with their electrical properties. Interfaces were prepared at high (5x10(-2) mbar) and low (10(-4) mbar) oxygen pressure by pulsed-laser deposition. The high-oxygen-pressure heterostructures were insulating for all thicknesses while the low-oxygen-pressure ones became metallic for thicknesses above 4 unit cells. MEIS data show enhancement of the Sr surface peak and suppression of the La one in interfaces prepared at low oxygen pressure, which is interpreted as a La-Sr intermixing. The effect was considerably smaller in high-oxygen-pressure samples. Analysis of high-angle annular-dark-field STEM images of the LAO films also indicates intermixing between La and Sr in low-oxygen-pressure samples, supporting MEIS data. Our results reveal the important role of oxygen pressure on the formation of the interface electron gas. Copyright (C) EPLA, 2011
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| 21. |
- Kalaboukhov, Alexei, 1975, et al.
(author)
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Inhomogeneous Microstructure and Electrical Transport Properties at the LaAlO3/SrTiO3 Interface
- 2012
-
In: Japanese Journal of Applied Physics. - 1347-4065 .- 0021-4922. ; 51:11(spec.issue), s. article no. 11PG10 -
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Journal article (peer-reviewed)abstract
- Medium-energy ion spectroscopy (MEIS), scanning transmission electron microscopy (STEM) and X-ray photoemission spectroscopy (XPS) were used to investigate the composition and microstructure of LaAlO3/SrTiO3 (LAO/STO) interfaces grown by pulsed laser deposition of LAO on TiO2-terminated STO substrates under different oxidizing conditions. MEIS and XPS indicated Sr/La and Al/Ti intermixing within several atomic layers at all studied interfaces. XPS and STEM revealed that La diffuses deeper than Al. Analysis of the MEIS data suggests inhomogeneous lateral distribution of the diffused elements. This is further supported by the observation of a large positive magneto-resistance at low temperatures. We discuss the role of lateral inhomogeneities on the formation of the electron gas at the LAO/STO interface.
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| 22. |
- Moroz, Leonid, et al.
(author)
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Serotonin- and FMRFamide-immunoreactive nerve elements in the chiton, Lepidopleurus asellus (Mollusca, Polyplacophora)
- 1994
-
In: Cell and Tissue Research. - 1432-0878. ; 275:2, s. 277-282
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Journal article (peer-reviewed)abstract
- The distribution of serotonin-like and FMRFamide-like immunoreactive (5HT-ir and FMRFa-ir, respectively) neurons in the nervous system of the chiton Lepidopleurus asellus (Mollusca, Polyplacophora) was studied using an immunocytochemical technique. The neurons were distributed in characteristic patterns in the central nervous system, the 5HT-ir neurons predominating in the ventral (pedal) cords and FMRFa-ir neurons in the lateral cords. In the body wall including the foot, a tight network of 5HT-ir and FMRFa-ir nerve fibers is found, the former being mostly attributed to the musculature whereas the latter seems to be associated with the blood sinuses. Intraepithelial neurons of both types are abundant in the fore-and hindgut. The presence and general distribution in the central and peripheral nervous system of the 5HT-ir and FMRFa-ir elements seems thus to be similar in simple and advanced molluscs. The relationship between these neurons and their targets in the body also appears to be well conserved in molluscs.
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| 23. |
- Nezlin, Leonid, et al.
(author)
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Immunolabeled neuroactive substances in the osphradium of the pond snail, Lymnea stagnalis.
- 1994
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In: Cell and Tissue Research. - 1432-0878. ; 275, s. 269-275
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Journal article (peer-reviewed)abstract
- The osphradium of molluscs is assumed to be a sensory organ. The present investigation in Lymnaea stagnalis has established two ultrastructurally different types of dendrites in the sensory epithelium. Cells immunoreactive to leucine-enkephalin and FMRFamide send processes to the sensory epithelium. These neurons of the osphradial ganglion are thus considered to be part of the sensory system, as are methionine-enkephalin-immunoreactive cells in the mantle wall in the vicinity of the osphradium. The complexity of the osphradial ganglion is further demonstrated by serotonin-immunoreactive neurons innervating the muscular coat around the osphradial canal and methionine-enkephalin-immunoreactive cells sending projections to the central nervous system.
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| 24. |
- Nezlin, Leonid P, et al.
(author)
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Transmitter-specific subsets of sensory elements in the prosobranch osphradium.
- 1994
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In: Biological Bulletin. - : University of Chicago Press. - 0006-3185 .- 1939-8697. ; 187, s. 174-184
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Journal article (peer-reviewed)abstract
- The osphradium is a putative chemosensory organ of aquatic molluscs. Previously, we identified two distinct types of primary sensory neurons in the osphradial ganglion of freshwater pulmonates, one immunoreactive to leucine-enkephalin (LEnk-ir) and another to FMRFamide (FMRFa-ir). In addition, NADPH diaphorase (NADPHd)-positive elements apparently producing nitric oxide (NO) were demonstrated in the organ. In the present study, prosobranch molluscs, which have retained the osphradial sensory neurons within the epithelium, were studied. Both types of peptidergic neurons, as well as NADPHd-positive cells, were found within the epithelium or in a basiepithelial position in the relatively simple osphradium of the mesogastropod Littorina littorea and in the complex, bipectinate osphradium of the neogastropod Buccinum undatum. Similar evidence was also obtained for another mesogastropod, Ampullarius sp. Transmitter-specific sensory cell types like those discovered in the osphradium are also present as single neuroepithelial cells in other organs of the mantle complex in prosobranchs and in the pelecypod Anodonta cygnea. We suggest that evolutionarily conservative, transmitter-specific types of epithelial and neuroepithelial sensory cells predated the osphradium, which developed as the site of their concentration, while retaining characteristic subsets of sensory neurons.
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| 25. |
- Sakharov, Dmitri A, et al.
(author)
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Patterns of enkephalin immunolabeling in the pulmonate snail Cepea nemoralis and related molluscs.
- 1993
-
In: Brain Research. - 1872-6240. ; 620, s. 114-121
-
Journal article (peer-reviewed)abstract
- In the land pulmonate snailCepaea nemoralis, immunocytochemical localization of methionine- and leucine-enkephalin-like substances was demonstrated in specific populations of brain neurons. Methionine-enkephalin reactivity is also present in the peripheral nervous system as (i) abundant axonal projections of central neurons to the sole of the foot, and (ii) sparse local neurons of the head and mantle wall. Similar peripheral methionine-enkephalinergic elements were found immunocytochemically in all pulmonates (Helins aspersa, Lymnaea stagnalis) and prosobranchs (Littorina littorea, Acmaea testudinalis) examined and seem therefore conserved among gastropods. Their distribution was different from those of nervous elements labeled by antisera against serotonin and FMRFamide. The chitonLepidopleurus asellus considered to be a more primitive mollusc, had both types of enkephalin-immunoreactive elements in the central nervous system whereas peripheral methionine-enkephalin- immunoreactive elements were lacking. It is suggested on the morphological evidence that enkephalinergic (especially methionine-enkephalinergic) neurons are part of a sensory system mediating analgetic effects in molluscs.
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| 26. |
- Serenkov, I.T., et al.
(author)
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Structural distortions induced during stress relaxation affecting electrical transport of nanometer-thick La0.67(Ba,Ca)0.33MnO3 films
- 2010
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In: Physica B: Condensed Matter. - : Elsevier BV. - 0921-4526. ; 404:23-24, s. 5234-5236
-
Journal article (peer-reviewed)abstract
- X-ray diffraction (XRD) and medium-energy ion scattering (MEIS) were used to clarify distortions induced during mechanical stress relaxation in nanometer-thick epitaxial La0.67Ba0.33MnO3 (LBMO) and La0.67Ca0.33MnO3 (LCMO) films fabricated by pulsed laser deposition. It follows from measured XRD and MEIS spectra that LBMO films grown on mismatched LaAlO3 were partly relaxed in the main part of the film, leaving about 4 nm heavily strained portion close to the interface. The critical thickness of LCMO films grown on LaAlO3 substrates was several times larger than that of LBMO due to a better match in lattice parameters. Electro- and magneto-transport parameters of nanometer-thick manganite films grown on mismatched substrates differed markedly from those of LBMO and LCMO layers nucleated and grown on well-matched ones because of non-stoichiometry, biaxial mechanical stresses, and phase separation. The resistivity ρ of manganite films grown coherently at a substrate with small mismatch obeyed the relation ρ=ρ1+ρ2(H)T4.5 at temperatures well below the Curie point. Parameter ρ1 was temperature T and magnetic field H independent while ρ2 was temperature independent but decreased linearly with increasing H.
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| 27. |
- Sparr, Emma, et al.
(author)
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Islet amyloid polypeptide-induced membrane leakage involves uptake of lipids by forming amyloid fibers
- 2004
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In: FEBS Letters. - : Wiley. - 1873-3468 .- 0014-5793. ; 577:1-2, s. 117-120
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Journal article (peer-reviewed)abstract
- Fibril formation of islet amyloid polypeptide (IAPP) is associated with cell death of the insulin-producing pancreatic beta-cells in patients with Type 2 Diabetes Mellitus. A likely cause for the cytotoxicity of human TAPP is that it destroys the barrier properties of the cell membrane. Here, we show by fluorescence confocal microscopy on lipid vesicles that the process of hIAPP amyloid formation is accompanied by a loss of barrier function, whereby lipids are extracted from the membrane and taken up in the forming amyloid deposits. No membrane interaction was observed when preformed fibrils were used. It is proposed that lipid uptake from the cell membrane is responsible for amyloid-induced membrane damage and that this represents a general mechanism underlying the cytotoxicity of amyloid forming proteins. (C) 2004 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.
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