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Lebedeva O, Kultin D, Kalmykov K, Snytko V, Kuznetsova I, Orekhov A, Zakharov A, Kustov L. Nanorolls Decorated with Nanotubes as a Novel Type of Nanostructures: Fast Anodic Oxidation of Amorphous Fe-Cr-B Alloy in Hydrophobic Ionic Liquid. ACS Appl Mater Interfaces 2021; 13:2025-2032. [PMID: 33397077 DOI: 10.1021/acsami.0c19392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The formation of oxide nanorolls decorated with nanotubes during anodic oxidation of amorphous Fe70Cr15B15 alloy in hydrophobic ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate (IL) was revealed. The unusual architecture was observed for the first time on the surface of amorphous alloy. The generation of the novel type of nanostructure by electrochemical oxidation of the amorphous Fe70Cr15B15 alloy occurs only in hydrophobic ionic liquid and in the presence of the natural oxide film at the surface. Anodization of the oxide-free metal surface of the amorphous Fe70Cr15B15 alloy to be achieved by the treatment of the electrode with benzoic acid was found to result in no formation of both nanorolls and nanotubes. Electrochemical behavior of the amorphous Fe70Cr15B15 alloy in ionic liquid was proved to depend strongly on the state of the electrode surface before oxidation. The influence of the state of the surface of amorphous Fe70Cr15B15 alloy leading to the nanostructure formation was studied by means of preliminary partial etching with benzoic acid of various concentrations.
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Affiliation(s)
- Olga Lebedeva
- Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Dmitry Kultin
- Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Konstantin Kalmykov
- Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Victoria Snytko
- Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Irina Kuznetsova
- Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Andrey Orekhov
- A.V. Shubnikov Institute of Crystallography of Federal Research Center "Crystallography and Photonics" of the Russian Academy of Sciences, 59 Leninsky prospect, Moscow 119333, Russia
| | - Alexandre Zakharov
- Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
- Department of Fundamental Sciences, Moscow N.E. Bauman State Technical University, 2-ya Baumanskaya 5, Moscow 105005, Russia
| | - Leonid Kustov
- Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
- Zelinsky Institute of Organic Chemistry, Leninsky prospect, 47, Moscow 119991, Russia
- National Science and Technology University "MISiS", Leninsky prosp. 4, Moscow 119049, Russia
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Begrambekov L, Gordeev A, Ma Y, Vayakis G, Shigin P, Sadovsky Y, Zakharov A, Walsh M. Development of Quality Tungsten Coating on Ceramics as a Microwave Shield for ITER High-Frequency Magnetic Sensor. Fusion Science and Technology 2020. [DOI: 10.1080/15361055.2019.1589206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- L. Begrambekov
- National Research Nuclear University (MEPhI), 115409, Moscow, Kashirskoe shosse 31, Russia
| | - A. Gordeev
- National Research Nuclear University (MEPhI), 115409, Moscow, Kashirskoe shosse 31, Russia
| | - Y. Ma
- Fircroft Engineering, Lingley House, 120 Birchwood Point, Birchwood Boulevard, Warrington WA3 7QH, United Kingdom
- ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul Lez Durance Cedex, France
| | - G. Vayakis
- ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul Lez Durance Cedex, France
| | - P. Shigin
- ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul Lez Durance Cedex, France
| | - Ya Sadovsky
- National Research Nuclear University (MEPhI), 115409, Moscow, Kashirskoe shosse 31, Russia
| | - A. Zakharov
- National Research Nuclear University (MEPhI), 115409, Moscow, Kashirskoe shosse 31, Russia
| | - M. Walsh
- ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul Lez Durance Cedex, France
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Kate OO, Zakharov A, Khivintseva H, Kalinin V. Efficiency of virtual reality application as an acceleration of motor rehabilitation in patients in the acute period of stroke. J Neurol Sci 2019. [DOI: 10.1016/j.jns.2019.10.1634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Flege JI, Krisponeit JO, Höcker J, Hoppe M, Niu Y, Zakharov A, Schaefer A, Falta J, Krasovskii EE. Nanoscale analysis of the oxidation state and surface termination of praseodymium oxide ultrathin films on ruthenium(0001). Ultramicroscopy 2017; 183:61-66. [PMID: 28526269 DOI: 10.1016/j.ultramic.2017.05.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Revised: 04/18/2017] [Accepted: 05/09/2017] [Indexed: 10/19/2022]
Abstract
The complex structure and morphology of ultrathin praseodymia films deposited on a ruthenium(0001) single crystal substrate by reactive molecular beam epitaxy is analyzed by intensity-voltage low-energy electron microscopy in combination with theoretical calculations within an ab initio scattering theory. A rich coexistence of various nanoscale crystalline surface structures is identified for the as-grown samples, notably comprising two distinct oxygen-terminated hexagonal Pr2O3(0001) surface phases as well as a cubic Pr2O3(111) and a fluorite PrO2(111) surface component. Furthermore, scattering theory reveals a striking similarity between the electron reflectivity spectra of praseodymia and ceria due to very efficient screening of the nuclear charge by the extra 4f electron in the former case.
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Affiliation(s)
- J I Flege
- Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, 28359 Bremen, Germany; MAPEX Center for Materials and Processes, University of Bremen, 28359 Bremen, Germany.
| | - J-O Krisponeit
- Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, 28359 Bremen, Germany; MAPEX Center for Materials and Processes, University of Bremen, 28359 Bremen, Germany
| | - J Höcker
- Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, 28359 Bremen, Germany
| | - M Hoppe
- Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, 28359 Bremen, Germany
| | - Y Niu
- MAX IV Laboratory, Box 118, 221 00 Lund, Sweden
| | - A Zakharov
- MAX IV Laboratory, Box 118, 221 00 Lund, Sweden
| | - A Schaefer
- Division of Synchrotron Radiation Research, Lund University, 221 00 Lund, Sweden
| | - J Falta
- Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, 28359 Bremen, Germany; MAPEX Center for Materials and Processes, University of Bremen, 28359 Bremen, Germany
| | - E E Krasovskii
- Departamento de Física de Materiales, Universidad del Pais Vasco UPV/EHU, 20080 San Sebastián/Donostia, Basque Country, Spain; Donostia International Physics Center (DIPC), 20018 San Sebastián/Donostia, Basque Country, Spain; IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
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Zakharov A, Vitale C, Kilinc E, Koroleva K, Fayuk D, Shelukhina I, Naumenko N, Skorinkin A, Khazipov R, Giniatullin R. Hunting for origins of migraine pain: cluster analysis of spontaneous and capsaicin-induced firing in meningeal trigeminal nerve fibers. Front Cell Neurosci 2015; 9:287. [PMID: 26283923 PMCID: PMC4516892 DOI: 10.3389/fncel.2015.00287] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Accepted: 07/13/2015] [Indexed: 12/19/2022] Open
Abstract
Trigeminal nerves in meninges are implicated in generation of nociceptive firing underlying migraine pain. However, the neurochemical mechanisms of nociceptive firing in meningeal trigeminal nerves are little understood. In this study, using suction electrode recordings from peripheral branches of the trigeminal nerve in isolated rat meninges, we analyzed spontaneous and capsaicin-induced orthodromic spiking activity. In control, biphasic single spikes with variable amplitude and shapes were observed. Application of the transient receptor potential vanilloid 1 (TRPV1) agonist capsaicin to meninges dramatically increased firing whereas the amplitudes and shapes of spikes remained essentially unchanged. This effect was antagonized by the specific TRPV1 antagonist capsazepine. Using the clustering approach, several groups of uniform spikes (clusters) were identified. The clustering approach combined with capsaicin application allowed us to detect and to distinguish “responder” (65%) from “non-responder” clusters (35%). Notably, responders fired spikes at frequencies exceeding 10 Hz, high enough to provide postsynaptic temporal summation of excitation at brainstem and spinal cord level. Almost all spikes were suppressed by tetrodotoxin (TTX) suggesting an involvement of the TTX-sensitive sodium channels in nociceptive signaling at the peripheral branches of trigeminal neurons. Our analysis also identified transient (desensitizing) and long-lasting (slowly desensitizing) responses to the continuous application of capsaicin. Thus, the persistent activation of nociceptors in capsaicin-sensitive nerve fibers shown here may be involved in trigeminal pain signaling and plasticity along with the release of migraine-related neuropeptides from TRPV1 positive neurons. Furthermore, cluster analysis could be widely used to characterize the temporal and neurochemical profiles of other pain transducers likely implicated in migraine.
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Affiliation(s)
- A Zakharov
- Laboratory of Neurobiology, Kazan Federal University Kazan, Russia ; Department of Physiology, Kazan State Medical University Kazan, Russia
| | - C Vitale
- Department of Neurobiology, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland Kuopio, Finland
| | - E Kilinc
- Department of Neurobiology, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland Kuopio, Finland ; Medical Faculty, Department of Physiology, Abant Izzet Baysal University Bolu, Turkey
| | - K Koroleva
- Laboratory of Neurobiology, Kazan Federal University Kazan, Russia ; Department of Neurobiology, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland Kuopio, Finland
| | - D Fayuk
- Department of Neurobiology, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland Kuopio, Finland
| | - I Shelukhina
- Department of Neurobiology, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland Kuopio, Finland ; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS Moscow, Russia
| | - N Naumenko
- Department of Neurobiology, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland Kuopio, Finland
| | - A Skorinkin
- Laboratory of Neurobiology, Kazan Federal University Kazan, Russia ; Department of Neurobiology, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland Kuopio, Finland ; Kazan Institute of Biochemistry and Biophysics Kazan, Russia
| | - R Khazipov
- Laboratory of Neurobiology, Kazan Federal University Kazan, Russia ; INSERM U901/Aix Marseille University Marseille, France
| | - R Giniatullin
- Laboratory of Neurobiology, Kazan Federal University Kazan, Russia ; Department of Neurobiology, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland Kuopio, Finland
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Lebedeva O, Dzhungurova G, Zakharov A, Kultin D, Kustov L, Krasovskii V, Kalmykov K, Dunaev S. Surface state of sacrificial copper electrode by electropolishing in hydrophobic ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide. ACS Appl Mater Interfaces 2013; 5:10551-10558. [PMID: 24111936 DOI: 10.1021/am402213r] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Anodic dissolution of natural surface-oxidized, air-annealed, cathodically reduced, and cathodically deposited copper in hydrophobic ionic liquid 1-buthyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide under galvanostatic conditions by means of gravimetric measurements was studied. The resulting samples were mirror-like oxide-free copper pattern. The mechanism of the electropolishing of oxidized copper surface was considered. The consequent anodic reactions Cu2O - 1e = Cu(+) + CuO, CuO - 2e = Cu(2+) + O, and Cu - 1e = Cu(+) take place. The electropolishing itself occurs over oxygen-free copper surface due to competitive residual water discharge in the pits and copper dissolution on the roughness.
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Affiliation(s)
- Olga Lebedeva
- Department of Chemistry, Lomonosov Moscow State University , 119991 Moscow, Russia
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Zakharov A, Jämsä-Jounela SL. Iterative optimization of the economic efficiency of an industrial process within the validity area of the static plant model and its application to a Pulp Mill. Comput Chem Eng 2011. [DOI: 10.1016/j.compchemeng.2010.10.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Kapetanovic IM, Crowell JA, Krishnaraj R, Zakharov A, Lindeblad M, Lyubimov A. Exposure and toxicity of green tea polyphenols in fasted and non-fasted dogs. Toxicology 2009; 260:28-36. [PMID: 19464566 DOI: 10.1016/j.tox.2009.03.007] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2009] [Revised: 02/26/2009] [Accepted: 03/06/2009] [Indexed: 01/16/2023]
Abstract
Standardized green tea extract was evaluated for exposure and toxicity in Beagle dogs following oral dosing by capsules. The main component (-)-epigallocatechin gallate (EGCG) accounted for 56-72% of the material. A 9-month chronic study (0, 200, 500, and 1000 mg/kg/day) was done in fasted dogs to take advantage of the reported improved catechin bioavailability with fasting. Extensive morbidity, mortality, and pathology of many major organs led to its early termination at 6.5 months and prevented identification of the toxicity mechanisms. A follow-up 13-week study examined the exposure to and toxicity of the extract. In general, toxicities were less severe than in the chronic study during the same interval. Dosing in a fed state resulted in considerably lower and less variable exposure than found under fasted conditions. Toxicity was less frequent and of lesser severity with lower exposure but limited sample size and large variability prevented reaching that definitive conclusion. Differences in mortality and morbidity between the preliminary terminated chronic and follow-up subchronic studies with the same dose of the same drug lot and similar exposure were not fully resolved as there may be other as yet unclear confounding factors.
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Affiliation(s)
- I M Kapetanovic
- Chemopreventive Agent Development Research Group, Division of Cancer Prevention, National Cancer Institute, Bethesda, MD 20892, USA.
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Abstract
Some computational tools for medicinal chemistry freely available on the Internet were compared to examine whether the results of prediction obtained with different methods coincided or not. It was shown that the correlation coefficients varied from 0.65 to 0.90 for log P (seven methods), from 0.01 to 0.73 for aqueous solubility (four methods), and from 0.19 to 0.73 for drug-likeness (three methods). While for log P estimates, reasonable average pairwise correlation was found, for aqueous solubility and drug-likeness it was rather poor. Therefore, using computational tools freely available via the Internet, medicinal chemists should evaluate their accuracy versus experimental data for particular series of compounds. In contrast to prediction of above mentioned properties, which can be done with several Internet tools, wide profiling of biological activity can be obtained only with PASS Inet (http://www.ibmc.msk.ru/PASS). PASS Inet was tested by a dozen medicinal chemists for compounds from different chemical series with various kinds of biological activity, and in the majority of cases the results of prediction coincided with the experiments. New anxiolytics, antiarrhythmics, antileishmanials, and other biologically active agents have been identified on this basis. The advantages and limitations of computer-aided predictions for medicinal chemistry via the Internet are discussed.
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Affiliation(s)
- A Geronikaki
- School of Pharmacy, Department of Pharmaceutical Chemistry, Aristotle University of Thessaloniki, Thessaloniki, Greece.
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Poroikov V, Filimonov D, Lagunin A, Gloriozova T, Zakharov A. PASS: identification of probable targets and mechanisms of toxicity. SAR QSAR Environ Res 2007; 18:101-10. [PMID: 17365962 DOI: 10.1080/10629360601054032] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Toxicity of chemical compound is a complex phenomenon that may be caused by its interaction with different targets in the organism. Two distinct types of toxicity can be broadly specified: the first one is caused by the strong compound's interaction with a single target (e.g. AChE inhibition); while the second one is caused by the moderate compound's interaction with many various targets. Computer program PASS predicts about 2500 kinds of biological activities based on the structural formula of chemical compounds. Prediction is based on the robust analysis of structure-activity relationships for about 60,000 biologically active compounds. Mean accuracy exceeds 90% in leave-one-out cross-validation. In addition to some kinds of adverse effects and specific toxicity (e.g. carcinogenicity, mutagenicity, etc.), PASS predicts approximately 2000 kinds of biological activities at the molecular level, that providing an estimated profile of compound's action in biological space. Such profiles can be used to recognize the most probable targets, interaction with which might be a reason of compound's toxicity. Applications of PASS predictions for analysis of probable targets and mechanisms of toxicity are discussed.
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Affiliation(s)
- V Poroikov
- Institute of Biomedical Chemistry of Russian Academy of Medical Sciences, Pogodinskaya Street 10, Moscow, 119121, Russia.
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Johnston M, Zakharov A, Koh L, Armstrong D. Subarachnoid injection of Microfil reveals connections between cerebrospinal fluid and nasal lymphatics in the non-human primate. Neuropathol Appl Neurobiol 2006; 31:632-40. [PMID: 16281912 DOI: 10.1111/j.1365-2990.2005.00679.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Based on quantitative and qualitative studies in a variety of mammalian species, it would appear that a significant portion of cerebrospinal fluid (CSF) drainage is associated with transport along cranial and spinal nerves with absorption taking place into lymphatic vessels external to the central nervous system. CSF appears to convect primarily through the cribriform plate into lymphatics associated with the submucosa of the olfactory and respiratory epithelium. However, the significance of this pathway for CSF absorption in primates has never been established unequivocally. In past studies, we infused Microfil into the subarachnoid compartment of numerous species to visualize CSF transport pathways. The success of this method encouraged us to use a similar approach in the non-human primate. Yellow Microfil was injected post mortem into the cisterna magna of 6 years old Barbados green monkeys (Cercopithecus aethiops sabeus, n = 6). Macroscopic and microscopic examination revealed that Microfil was (1) distributed throughout the subarachnoid compartment, (2) located in the perineurial spaces associated with the fila olfactoria, (3) present within the olfactory submucosa, and (4) situated within an extensive network of lymphatic vessels in the nasal submucosa, nasal septum and turbinate tissues. We conclude that the Microfil distribution patterns in the monkey were very similar to those observed in many other species suggesting that significant nasal lymphatic uptake of CSF occurs in the non-human primate.
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Affiliation(s)
- M Johnston
- Neuroscience Program, Department of Laboratory Medicine and Pathobiology, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, ON, Canada.
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Mäki-Petäys H, Zakharov A, Viljakainen L, Corander J, Pamilo P. Genetic changes associated to declining populations of Formica ants in fragmented forest landscape. Mol Ecol 2005; 14:733-42. [PMID: 15723665 DOI: 10.1111/j.1365-294x.2005.02444.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We monitored populations of two wood ant species, Formica aquilonia and Formica lugubris, through annual mapping of the colonies in a fragmenting forest landscape from 1966 to 1998. The genetic population structure was studied at the end of the study period by using 12 microsatellite loci. Fragmentation of forest led to a decline and spatial redistribution of populations. Changes in the spatial distribution were particularly pronounced in the highly polygynous (many queens in a single nest) species F. aquilonia, whose local populations declined or became extinct, or relocated themselves and colonized new patches. The genetic relationships of the remaining subpopulations indicated the historical developments, revealing the boundaries of the historical populations (high values of genetic differentiation, F(ST)), recolonization histories (genetic affinities revealed by Bayesian analyses) and population decline (reduced variation). Big genetic differences could be detected over short distances, so differentiation also depended on social factors. Our results showed that a genetic study can be reliably used to dissect the recent historical changes underlying the present population structure, and that species with different social structures can respond differently to habitat changes. Combining our demographic and genetic results suggests that habitat fragmentation forms a clear threat on a local scale with large negative effects on ant population viability.
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Affiliation(s)
- H Mäki-Petäys
- Department of Biology, University of Oulu, P.O.Box 3000, 90014 Oulu, Finland.
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Zakharov A, Carchilan M, Stepurina T, Rotari V, Wilson K, Vaintraub I. A comparative study of the role of the major proteinases of germinated common bean (Phaseolus vulgaris L.) and soybean (Glycine max (L.) Merrill) seeds in the degradation of their storage proteins. J Exp Bot 2004; 55:2241-9. [PMID: 15333645 DOI: 10.1093/jxb/erh247] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Two types of cysteine proteases, low-specificity enzymes from the papain family and Asn-specific from the legumain family are generally considered to be the major endopeptidases responsible for the degradation of seed storage proteins during early seedling growth. The action of the corresponding enzymes (CPPh1 and LLP, respectively) from common bean (Phaseolus vulgaris L.) on phaseolin (the common bean storage protein), and on the homologous soybean (Glycine max (L.) Merrill) storage protein, beta-conglycinin, was studied. Under the action of LLP, proteolysis of phaseolin was limited to cleavage of its interdomain linker. No cleavage of the interdomain linker occurred in beta-conglycinin with LLP. LLP action was restricted to splitting off the disordered N-terminal extensions of alpha and alpha' subunits. No extensive hydrolysis (degradation to short TCA-soluble peptides) of either protein occurred under the action of LLP. CPPh1 cleaved the phaseolin subunits into roughly half-sized fragments at the onset of proteolysis. The cleavage was accompanied by a small (8-10%) decrease of protein. No decrease of protein occurred with further incubation. Thus the two most active proteinases detected in common bean seedlings individually were incapable of the extensive degradation of phaseolin. Extensive hydrolysis of phaseolin was only achieved by the consecutive action of LLP and CPPh1. Similar cleavages occurred during the action of CPPh1 on beta-conglycinin. However, by contrast with phaseolin, CPPh1 by itself accomplished the extensive hydrolysis of beta-conglycinin. The differences in the course of proteolysis of the proteins studied were determined by their structural peculiarities.
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Affiliation(s)
- A Zakharov
- Laboratory of Protein Chemistry, Moldova State University, Mateevici str.60, MD-2009, Kishinev, Republic of Moldov
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Zakharov A, Papaiconomou C, Koh L, Djenic J, Bozanovic-Sosic R, Johnston M. Integrating the roles of extracranial lymphatics and intracranial veins in cerebrospinal fluid absorption in sheep. Microvasc Res 2004; 67:96-104. [PMID: 14709407 DOI: 10.1016/j.mvr.2003.08.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
At relatively low cerebrospinal fluid (CSF) pressures, the majority of CSF drainage in 6- to 8-month-old sheep occurs through the cribriform plate into lymphatic vessels in the nasal submucosa. As CSF pressures are elevated, other absorption sites are recruited and these may include transport through arachnoid projections. To test for the transport of CSF directly into the venous sinus, the concentration of a tracer (131I-human serum albumin [HSA]) administered into the CSF compartment was measured in the confluence of the intracranial venous sinuses (torcular) and in the peripheral blood (inferior vena cava). CSF pressures were adjusted to favor absorption. Enrichment of the CSF tracer in the cranial venous system was most evident when the CSF-venous sinus pressure gradients were high. Peak concentration differences occurred 90 s after the CSF pressures were elevated. When pressure gradients approached 30 cm H(2)O, tracer concentrations in the torcular were approximately twofold higher than those observed in peripheral blood. The greatest concentration differences favoring the torcular were obtained when the CSF-venous sinus pressure gradients were elevated to high levels (20- to 40 cm H(2)O) and when CSF access to the paranasal lymphatics and CSF transport into the spinal subarachnoid compartment were prevented. In conjunction with previous studies, these results are compatible with the view that CSF absorption in the adult animal can occur directly into the cranial venous system. However, contrary to the established view, this pathway may represent a secondary system that is recruited to compliment lymphatic transport when global absorption capacity is stressed or compromised.
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Affiliation(s)
- A Zakharov
- Neuroscience Research, Department of Laboratory Medicine and Pathobiology, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, M4N 3M5, Toronto, Ontario, Canada
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Jourdan M, Zakharov A, Foerster M, Adrian H. Evidence for multiband superconductivity in the heavy Fermion compound UNi2Al3. Phys Rev Lett 2004; 93:097001. [PMID: 15447128 DOI: 10.1103/physrevlett.93.097001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2004] [Indexed: 05/24/2023]
Abstract
Epitaxial thin films of the heavy fermion superconductor UNi2Al3 with Tc(max)=0.98 K were investigated. The transition temperature Tc depends on the current direction which can be related to superconducting gaps opening at different temperatures. Also the influence of the magnetic ordering at TN approximately 5 K on R(T) is strongly anisotropic, indicating different coupling between the magnetic moments and itinerant charge carriers on the multisheeted Fermi surface. The upper critical field Hc2(T) suggests an unconventional spin-singlet superconducting state.
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Affiliation(s)
- M Jourdan
- Institut für Physik, Johannes Gutenberg-Universität, Staudingerweg 7, 55128 Mainz, Germany.
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Zakharov A, Papaiconomou C, Djenic J, Midha R, Johnston M. Lymphatic cerebrospinal fluid absorption pathways in neonatal sheep revealed by subarachnoid injection of Microfil. Neuropathol Appl Neurobiol 2004; 29:563-73. [PMID: 14636163 DOI: 10.1046/j.0305-1846.2003.00508.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
There is mounting evidence that a significant portion of cerebrospinal fluid drainage is associated with transport along cranial and spinal nerves with absorption taking place into lymphatic vessels external to the central nervous system. To characterize these pathways further, yellow Microfil was infused into the cisterna magna of 2-7-day-old lambs post mortem to perfuse either the cranial or spinal subarachnoid compartments. In some animals, blue Microfil was perfused into the carotid arteries simultaneously. Microfil was observed in lymphatic networks in the nasal mucosa, covering the hard and soft palate, conchae, nasal septum, the ethmoid labyrinth and the lateral walls of the nasal cavity. Many of these lymphatics drained into vessels located on the lateroposterior wall of the nasopharynx and from this location drained to the retropharyngeal lymph nodes. Additionally, lymphatics containing Microfil penetrated the lateral wall of the nasal cavity and joined with superficial lymphatic ducts travelling towards the submandibular and preauricular lymph nodes. In two cases, lymphatic vessels were observed anastomosing with deep veins in the retropharyngeal area. Microfil was also distributed within the nerve trunks of cranial and spinal nerves. The contrast agent was located in longitudinal channels within the endoneurial space and lymphatics containing Microfil were observed emerging from the mesoneurium. In summary, Microfil distribution patterns in neonatal lambs illustrated the important role that cranial and spinal nerves play in linking the subarachnoid compartment with extracranial lymphatics.
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Affiliation(s)
- A Zakharov
- Neuroscience Research, Department of Laboratory Medicine and Pathobiology, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
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Papaiconomou C, Zakharov A, Azizi N, Djenic J, Johnston M. Reassessment of the pathways responsible for cerebrospinal fluid absorption in the neonate. Childs Nerv Syst 2004; 20:29-36. [PMID: 14605840 DOI: 10.1007/s00381-003-0840-z] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2003] [Indexed: 10/26/2022]
Abstract
OBJECTIVE In neonatal lambs, the quantitative evidence suggests that a significant volume of cranial CSF drainage is associated with transport along olfactory nerves with absorption primarily into extracranial lymphatics in the paranasal region. Arachnoid granulations appear to be poorly developed at this level of development and their function is unknown. In this report, we tested whether a CSF protein tracer ((131)I-human serum albumin) could transport directly into the superior sagittal sinus of newborn lambs. METHODS AND RESULTS The concentration of the tracer administered into the CSF compartment was measured in the confluence of the intracranial venous sinuses (torcula) and in the peripheral blood (inferior vena cava). Enrichment of the CSF tracer in the cranial venous system was most evident when the CSF-venous sinus pressure gradients approached 20-30 cm H(2)O. CONCLUSION The data suggests that neonatal CSF can be absorbed directly into the cranial venous system. However, contrary to the classical view, this route may represent an auxiliary system that is recruited to compliment lymphatic transport when intracranial pressures are very high.
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Affiliation(s)
- C Papaiconomou
- Neuroscience Research, Department of Laboratory Medicine and Pathobiology, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
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Kim C, Li B, Papaiconomou C, Zakharov A, Johnston M. Functional impact of lymphangiogenesis on fluid transport after lymph node excision. Lymphology 2003; 36:111-9. [PMID: 14552030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
When a lymph node is excised, lymphangiogenesis occurs to maintain flow in the affected area. However, a complex network of small vessels replaces the node and these newly formed vessels might increase resistance to lymph transport. To test this in sheep, the popliteal lymph node from one hind limb was removed surgically. The contralateral node was left intact. After 4 to 6 weeks (a period that allowed regenerated vessels to restore flow), a prenodal lymphatic vessel in each limb was cannulated with a polyethylene catheter to permit saline infusion into the node or lymphatic regeneration site. Infusion pressures were monitored from t-pieces inserted between the infusion pump and the point of entry of the catheters in the prenodal ducts. We observed that the flow rate versus perfusion pressure relationships were significantly different in the 2 experimental preparations (node intact limbs, n = 13; node excised limbs, n = 10). In the limbs undergoing lymphangiogenesis, much higher infusion pressures were required to generate a given flow rate. Additionally, the regenerated lymphatic network provided a significantly increased resistance to flow. The data suggested that lymphangiogenesis restored fluid continuity to some extent in the area occupied originally by the popliteal lymph node. However, the transport properties exhibited by the newly formed lymphatics were insufficient to restore flow parameters to their original state.
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Affiliation(s)
- C Kim
- Department of Laboratory Medicine and Pathobiology, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Ontario, Canada
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Papaiconomou C, Bozanovic-Sosic R, Zakharov A, Johnston M. Does neonatal cerebrospinal fluid absorption occur via arachnoid projections or extracranial lymphatics? Am J Physiol Regul Integr Comp Physiol 2002; 283:R869-76. [PMID: 12228056 DOI: 10.1152/ajpregu.00173.2002] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Arachnoid villi and granulations are thought to represent the primary sites where cerebrospinal fluid (CSF) is absorbed. However, these structures do not appear to exist in the fetus but begin to develop around the time of birth and increase in number with age. With the use of a constant pressure-perfusion system in 2- to 6-day-old lambs, we observed that global CSF transport (0.012 +/- 0.003 ml x min(-1) x cmH(2)O(-1)) and CSF outflow resistance (96.5 +/- 17.8 cmH(2)O x ml(-1) x min) were very similar to comparable measures in adult animals despite the relative paucity of arachnoid villi at this stage of development. In the neonate, the recovery patterns of a radioactive protein CSF tracer in various lymph nodes and tissues indicated that CSF transport occurred through multiple lymphatic pathways. An especially important route was transport through the cribriform plate into extracranial lymphatics located in the nasal submucosa. To investigate the importance of the cribriform route in cranial CSF clearance, the cranial CSF compartment was isolated surgically from its spinal counterpart. When the cribriform plate was sealed extracranially under these conditions, CSF transport was impaired significantly. These data demonstrate an essential function for lymphatics in neonatal CSF transport and imply that arachnoid projections may play a limited role earlier in development.
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Affiliation(s)
- C Papaiconomou
- Neuroscience Research, Department of Laboratory Medicine and Pathobiology, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Toronto, Ontario, M4N 3M5
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Mollanji R, Bozanovic-Sosic R, Zakharov A, Makarian L, Johnston MG. Blocking cerebrospinal fluid absorption through the cribriform plate increases resting intracranial pressure. Am J Physiol Regul Integr Comp Physiol 2002; 282:R1593-9. [PMID: 12010739 DOI: 10.1152/ajpregu.00695.2001] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cerebrospinal fluid (CSF) drains through the cribriform plate (CP) in association with the olfactory nerves. From this location, CSF is absorbed into nasal mucosal lymphatics. Recent data suggest that this pathway plays an important role in global CSF transport in sheep. In this report, we tested the hypothesis that blocking CSF transport through this pathway would elevate resting intracranial pressure (ICP). ICP was measured continuously from the cisterna magna of sheep before and after CP obstruction in the same animal. To block CSF transport through the CP, an external ethmoidectomy was performed. The olfactory and adjacent mucosa were removed, and the bone surface was sealed with tissue glue. To restrict our analysis to the cranial CSF system, CSF transport into the spinal subarachnoid compartment was prevented with a ligature tightened around the thecal sac between C1 and C2. Sham surgical procedures had no significant effects, but in the experimental group CP obstruction elevated ICP significantly. Mean postobstruction steady-state pressures (18.0 +/- 3.8 cmH(2)O) were approximately double the preobstruction values (9.2 +/- 0.9 cmH(2)O). These data support the concept that the olfactory pathway represents a major site for CSF drainage.
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Affiliation(s)
- R Mollanji
- Trauma Research Program, Department of Laboratory Medicine and Pathobiology, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Toronto, Ontario M4N 3M5, Canada
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Makhankov A, Arkhipov I, Federici G, Gorodetsky A, Ibbott C, Komarov V, Kuzmin Y, Lipko A, Markin A, Mazul I, Odintsov V, Tivey R, Zakharov A. Design of a radiative semi-transparent liner for the ITER divertor cassette. Fusion Engineering and Design 2000. [DOI: 10.1016/s0920-3796(00)00380-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Senyuk V, Rotari V, Becker C, Zakharov A, Horstmann C, Müntz K, Vaintraub I. Does an asparaginyl-specific cysteine endopeptidase trigger phaseolin degradation in cotyledons of kidney bean seedlings? Eur J Biochem 1998; 258:546-58. [PMID: 9874222 DOI: 10.1046/j.1432-1327.1998.2580546.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
An asparaginyl-specific cysteine endopeptidase which was named 'legumain-like proteinase' (LLP) and has an apparent molecular mass of 38.1 kDa was isolated from cotyledons of kidney bean (Phaseolus vulgaris L.) seedlings and partially characterized. It is, to our knowledge, the first known proteinase which in vitro extensively degrades native phaseolin, the major storage globulin of this grain legume. Phaseolin that in vitro had been partially degraded by LLP (Pvitro) and phaseolin that was isolated after partial in vivo breakdown 6 days after the start of seed imbibition (Pvivo) showed similar fragment patterns on SDS/polyacrylamide gels. The fragments had identical cleavage sites in Pvitro and Pvivo as determined by partial amino acid sequencing. In both types of partially degraded phaseolin, these cleavage sites have asparagine in the P1 position. Two of the cleavage sites are located in the beta-barrel domain of the C-terminal module and only one cleavage site was found in the beta-barrel domain of the N-terminal module according to the consensus structural model of phaseolin subunits. These results suggest that very likely LLP could in vivo be responsible for the initiation of phaseolin proteolysis. Two different legumain-specific clones named cp6b and p21b were isolated from a cDNA library of germinated bean cotyledons. Cp6b encodes LLP, while p21b encodes a VPE-like enzyme. Southern-blot analysis revealed a single gene copy for Pv-VPE and, presumably, at least two gene copies for LLP in the kidney bean genome. Northern-blot analysis indicated that mRNAs for both clones appear de novo during seed germination. However, the developmental patterns of the transcript levels corresponding to the two clones differed significantly. The temporal pattern of phaseolin degradation and of LLP polypeptide levels agreed well with the suggestion that LLP plays a key role in the mobilization of phaseolin during and after kidney bean germination.
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Affiliation(s)
- V Senyuk
- Laboratory of Protein Chemistry, State University of Moldova, Kishinev, Republic Moldova.
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