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1.
Phys Rev Lett ; 116(24): 241105, 2016 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-27367381

RESUMO

Cosmic-ray electrons and positrons are a unique probe of the propagation of cosmic rays as well as of the nature and distribution of particle sources in our Galaxy. Recent measurements of these particles are challenging our basic understanding of the mechanisms of production, acceleration, and propagation of cosmic rays. Particularly striking are the differences between the low energy results collected by the space-borne PAMELA and AMS-02 experiments and older measurements pointing to sign-charge dependence of the solar modulation of cosmic-ray spectra. The PAMELA experiment has been measuring the time variation of the positron and electron intensity at Earth from July 2006 to December 2015 covering the period for the minimum of solar cycle 23 (2006-2009) until the middle of the maximum of solar cycle 24, through the polarity reversal of the heliospheric magnetic field which took place between 2013 and 2014. The positron to electron ratio measured in this time period clearly shows a sign-charge dependence of the solar modulation introduced by particle drifts. These results provide the first clear and continuous observation of how drift effects on solar modulation have unfolded with time from solar minimum to solar maximum and their dependence on the particle rigidity and the cyclic polarity of the solar magnetic field.

2.
Phys Rev Lett ; 115(11): 111101, 2015 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-26406816

RESUMO

In this work we present results of a direct search for strange quark matter (SQM) in cosmic rays with the PAMELA space spectrometer. If this state of matter exists it may be present in cosmic rays as particles, called strangelets, having a high density and an anomalously high mass-to-charge (A/Z) ratio. A direct search in space is complementary to those from ground-based spectrometers. Furthermore, it has the advantage of being potentially capable of directly identifying these particles, without any assumption on their interaction model with Earth's atmosphere and the long-term stability in terrestrial and lunar rocks. In the rigidity range from 1.0 to ∼1.0×10^{3} GV, no such particles were found in the data collected by PAMELA between 2006 and 2009. An upper limit on the strangelet flux in cosmic rays was therefore set for particles with charge 1≤Z≤8 and mass 4≤A≤1.2×10^{5}. This limit as a function of mass and as a function of magnetic rigidity allows us to constrain models of SQM production and propagation in the Galaxy.

3.
Arch Microbiol ; 197(4): 613-20, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25702316

RESUMO

Two gram-negative, aerobic, brown-pigmented, motile rod-shaped bacteria KMM 9512 and KMM 9513(T) were isolated from a sediment sample collected from the Sea of Japan seashore, Russia. On the basis of the 16S rRNA gene sequence analysis, novel strains KMM 9512 and KMM 9513(T) positioned within the genus Rheinheimera (class Gammaproteobacteria) as a separate subline adjacent to Rheinheimera baltica DSM 14885(T) sharing highest gene sequence similarities of 98.6-97.6 % to their closest phylogenetic relatives, Rheinheimera muenzenbergensis LMG 27269(T), R. baltica DSM 14885(T), Rheinheimera aquimaris JCM 14331(T), Rheinheimera nanhaiensis KACC 14030(T), and Rheinheimera pacifica KMM 1406(T). Strains KMM 9512 and KMM 9513(T) belong to the same separate genospecies on the basis of the 16S rRNA gene sequence similarity (99.8 %) and their DNA relatedness to each other (89 %) and to closely related Rheinheimera species (25-53 %). The major isoprenoid quinone was Q-8, polar lipids consisted of phosphatidylserine, phosphatidylglycerol, phosphatidylethanolamine, unknown aminolipids, unknown aminophospholipids, unknown phospholipids, and unknown lipids, and major fatty acid were C16:0, C16:1 ω7c, C17:1 ω8c, C12:0 3-OH followed by C17:0 and C18:1 ω7c in both strains. Strains KMM 9512 and KMM 9513(T) revealed a remarkable antagonistic activity toward a number of gram-positive and gram-negative microorganisms. On the basis of phylogenetic analysis, DNA-DNA hybridization results, and phenotypic differences, strains KMM 9512 and KMM 9513(T) are proposed to be classified as a novel species of the genus Rheinheimera, Rheinheimera japonica sp. nov. The type strain of this species is KMM 9513(T) = NRIC 0918(T).


Assuntos
Antibacterianos/metabolismo , Chromatiaceae/metabolismo , Sedimentos Geológicos/microbiologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Antibacterianos/farmacologia , Sequência de Bases , Chromatiaceae/classificação , Chromatiaceae/genética , Chromatiaceae/isolamento & purificação , DNA Bacteriano/genética , Ácidos Graxos/análise , Japão , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Oceanos e Mares , Fosfolipídeos/análise , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
4.
Antibiot Khimioter ; 59(9-10): 13-6, 2014.
Artigo em Russo | MEDLINE | ID: mdl-25975110

RESUMO

Tubosan, a new Russian immunostimulator is a derivative of sulfopyrimidine. It stimulated the humoral antiviral immunity in mice, provoked increasing the number of the antibody forming cells in the spleen of mice, immunized by sheep's erythrocytes, and increased the titers of the virus-neutralizing antibodies after immunization by inactivated and live vaccines VEE. The Tubosan ability to lower the reactogenicity of the live VEE vaccine provided new perspectives for using such immunomodulators in medical practice.


Assuntos
Anticorpos Neutralizantes/biossíntese , Anticorpos Antivirais/biossíntese , Encefalomielite Equina Venezuelana/prevenção & controle , Imunidade Humoral/efeitos dos fármacos , Fatores Imunológicos/administração & dosagem , Pirimidinas/administração & dosagem , Adjuvantes Imunológicos/administração & dosagem , Animais , Encefalomielite Equina Venezuelana/imunologia , Encefalomielite Equina Venezuelana/virologia , Eritrócitos/química , Eritrócitos/imunologia , Cobaias , Imunização , Camundongos , Camundongos Endogâmicos BALB C , Federação Russa , Ovinos , Baço/citologia , Baço/imunologia
5.
Phys Rev Lett ; 111(8): 081102, 2013 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-24010424

RESUMO

Precision measurements of the positron component in the cosmic radiation provide important information about the propagation of cosmic rays and the nature of particle sources in our Galaxy. The satellite-borne experiment PAMELA has been used to make a new measurement of the cosmic-ray positron flux and fraction that extends previously published measurements up to 300 GeV in kinetic energy. The combined measurements of the cosmic-ray positron energy spectrum and fraction provide a unique tool to constrain interpretation models. During the recent solar minimum activity period from July 2006 to December 2009, approximately 24,500 positrons were observed. The results cannot be easily reconciled with purely secondary production, and additional sources of either astrophysical or exotic origin may be required.

9.
Artigo em Russo | MEDLINE | ID: mdl-23297643

RESUMO

AIM: Evaluate safety of prophylaxis of viral hemorrhagic fevers by specific heterologous immunoglobulins. MATERIALS AND METHODS: Clinical-laboratory examination of 24 individuals after intramuscular administration of heterologous Ebola immunoglobulin was carried out. Anaphylactogenicity of the immunoglobulins was studied by WD 42-28-8-89 in guinea pigs compared with commercial preparations. RESULTS: Immediate type reactions were not observed. In individuals with normal anamnesis the number of local reactions was 31%, general in the form of lung serum disease - 13%. In individuals with unfavorable anamnesis against the background of desensitization therapy there were almost no reactions; without it local reactions were present in 50%, mild severity serum lung disease - in 17%, medium - in 33%. Immunoglobulins against especially dangerous viral agents by anaphylactogenic properties did not differ from commercial heterologous preparations. CONCLUSION: Application of specific immunoglobulins from horse blood sera (the main means of protection from dangerous and especially dangerous exotic viral infections) with compliance by desensitization principles is relatively safe. Safe level of sensitization properties is characterized by anaphylaxis index up to 3.7 for guinea pigs.


Assuntos
Anticorpos Antivirais/administração & dosagem , Vacinas contra Ebola/administração & dosagem , Doença pelo Vírus Ebola/prevenção & controle , Imunoglobulinas/administração & dosagem , Adulto , Anafilaxia , Animais , Anticorpos Antivirais/sangue , Vacinas contra Ebola/sangue , Ebolavirus/imunologia , Feminino , Cobaias , Doença pelo Vírus Ebola/imunologia , Doença pelo Vírus Ebola/virologia , Cavalos , Humanos , Imunização , Imunoglobulinas/sangue , Injeções Intramusculares , Pulmão , Masculino
10.
Phys Rev Lett ; 106(20): 201101, 2011 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-21668214

RESUMO

Precision measurements of the electron component in the cosmic radiation provide important information about the origin and propagation of cosmic rays in the Galaxy. Here we present new results regarding negatively charged electrons between 1 and 625 GeV performed by the satellite-borne experiment PAMELA. This is the first time that cosmic-ray e⁻ have been identified above 50 GeV. The electron spectrum can be described with a single power-law energy dependence with spectral index -3.18 ± 0.05 above the energy region influenced by the solar wind (> 30 GeV). No significant spectral features are observed and the data can be interpreted in terms of conventional diffusive propagation models. However, the data are also consistent with models including new cosmic-ray sources that could explain the rise in the positron fraction.

11.
Science ; 332(6025): 69-72, 2011 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-21385721

RESUMO

Protons and helium nuclei are the most abundant components of the cosmic radiation. Precise measurements of their fluxes are needed to understand the acceleration and subsequent propagation of cosmic rays in our Galaxy. We report precision measurements of the proton and helium spectra in the rigidity range 1 gigavolt to 1.2 teravolts performed by the satellite-borne experiment PAMELA (payload for antimatter matter exploration and light-nuclei astrophysics). We find that the spectral shapes of these two species are different and cannot be described well by a single power law. These data challenge the current paradigm of cosmic-ray acceleration in supernova remnants followed by diffusive propagation in the Galaxy. More complex processes of acceleration and propagation of cosmic rays are required to explain the spectral structures observed in our data.

12.
Phys Rev Lett ; 105(12): 121101, 2010 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-20867623

RESUMO

The satellite-borne experiment PAMELA has been used to make a new measurement of the cosmic-ray antiproton flux and the antiproton-to-proton flux ratio which extends previously published measurements down to 60 MeV and up to 180 GeV in kinetic energy. During 850 days of data acquisition approximately 1500 antiprotons were observed. The measurements are consistent with purely secondary production of antiprotons in the Galaxy. More precise secondary production models are required for a complete interpretation of the results.

13.
Sud Med Ekspert ; 52(2): 29-31, 2009.
Artigo em Russo | MEDLINE | ID: mdl-19507737

RESUMO

Previous studies have shown that signs of drowning in fresh water are of low diagnostic value. Regardless of the mechanism of drowning death, a certain amount of water enters the blood and somehow changes its composition. The objective of this study was to determine water fractions in the blood of drowned subjects. It included 30 cases of drowning deaths. The control group comprised 30 cases of hanging and 7 bodies found in water after the death on land. The water content in the blood was measured in accordance with the universally accepted diagnostic procedure from the difference of freezing temperatures of free and bound water. It was shown that arterial blood and its constituent components as well as whole venous blood and concentrated red cells mass of drowned subjects contained significantly more water than the blood of those who died on land. The rise was in the first place attributable to the selective increase of the free water fraction. Changes of water content in the blood were virtually identical in the drowned subjects who died from asphyxia and from aspiration of water. The data obtained in this study may be used as additional diagnostic signs of drowning death.


Assuntos
Afogamento/sangue , Patologia Legal/métodos , Mudanças Depois da Morte , Água/análise , Eritrócitos/química , Humanos , Plasma/química
14.
Nature ; 458(7238): 607-9, 2009 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-19340076

RESUMO

Antiparticles account for a small fraction of cosmic rays and are known to be produced in interactions between cosmic-ray nuclei and atoms in the interstellar medium, which is referred to as a 'secondary source'. Positrons might also originate in objects such as pulsars and microquasars or through dark matter annihilation, which would be 'primary sources'. Previous statistically limited measurements of the ratio of positron and electron fluxes have been interpreted as evidence for a primary source for the positrons, as has an increase in the total electron+positron flux at energies between 300 and 600 GeV (ref. 8). Here we report a measurement of the positron fraction in the energy range 1.5-100 GeV. We find that the positron fraction increases sharply over much of that range, in a way that appears to be completely inconsistent with secondary sources. We therefore conclude that a primary source, be it an astrophysical object or dark matter annihilation, is necessary.

15.
Phys Rev Lett ; 102(5): 051101, 2009 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-19257498

RESUMO

A new measurement of the cosmic-ray antiproton-to-proton flux ratio between 1 and 100 GeV is presented. The results were obtained with the PAMELA experiment, which was launched into low-Earth orbit on-board the Resurs-DK1 satellite on June 15th 2006. During 500 days of data collection a total of about 1000 antiprotons have been identified, including 100 above an energy of 20 GeV. The high-energy results are a tenfold improvement in statistics with respect to all previously published data. The data follow the trend expected from secondary production calculations and significantly constrain contributions from exotic sources, e.g., dark matter particle annihilations.

16.
Mikrobiologiia ; 76(4): 502-6, 2007.
Artigo em Russo | MEDLINE | ID: mdl-17974207

RESUMO

A comparative study of the adhesion of epiphytic bacteria and marine free-living, saprophytic, and pathogenic bacteria on seagrass leaves and abiotic surfaces was performed to prove the occurrence of true epiphytes of Zostera marina and to elucidate the bacterium-plant symbiotrophic relationships. It was shown that in the course of adhesion to the seagrass leaves of two taxonomically different bacteria, Cytophaga sp. KMM 3552 and Pseudoalteromonas citrea KMM 461, isolated from the seagrass surface, the number of viable cells increased 3-7-fold after 60 h of incubation, reaching 1.0-2.0 x 10(5) cells/cm2; however, in the case of adhesion of these bacteria to abiotic surfaces, such as glass or metal, virtually no viable cells were observed after 60 h of incubation. Such selectivity of cell adhesion was not observed in the case of three other bacterial species studied, viz., Vibrio alginolyticus KMM 3551, Bacillus subtilis KMM 430, and Pseudomonas aeruginosa KMM 433. The amount of viable cells of V. alginolyticus KMM 3551 adsorbed on glass and metal surfaces increased twofold after 40 h of incubation. The cells of saprophytic B. subtilis KMM 430 and pathogenic P. aeruginosa KMM 433 adsorbed on three studied substrata remained viable for 36 h and died by the 60th hour of incubation.


Assuntos
Alteromonas/fisiologia , Aderência Bacteriana , Bacteroidetes/fisiologia , Folhas de Planta/microbiologia , Zosteraceae/microbiologia , Bacillus subtilis/fisiologia , Vidro , Pseudomonas aeruginosa/fisiologia , Aço Inoxidável , Propriedades de Superfície , Vibrio alginolyticus/fisiologia
17.
Mikrobiol Z ; 68(4): 10-20, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17100323

RESUMO

Two orange-pigmented Gram-positive, aerobic bacteria were isolated from enrichment culture during degradation of brown alga Fucus evanescens thalluses. In this work, atomic force microscopy (AFM) has been used to study the cell morphology. The non-contact mode imaging revealed unusual irregular coccoid shape of cells, possessing a single flagellum. Bacteria produced carotenoid pigments, were chemo-organotrophic, alkaliphilic and halo-tolerant growing well on nutrient media containing up to 15% NaCl. Growth temperature ranged from 5 to 45 degrees C. The DNA base compositions were 48 mol% G + C and the level of DNA similarity of two strains was conspecific (98%). A comparative phylogenetic analysis of 16S rRNA gene sequences revealed that the strain KMM 3738 tightly clustered with recently described Planococcus maritimus (99.9% 16S rRNA gene sequence similarity). DNA-DNA hybridisation experiments revealed that DNA from the KMM 3738 showed 12-15% and 16-35% of genetic relatedness with the DNA of type strains of the genera Planomicrobium and Planococcus, respectively, and 87% with DNA from Planococcus maritimus, indicating that new isolates belong to the later species.


Assuntos
Fucus/microbiologia , Bactérias Gram-Positivas/isolamento & purificação , Técnicas de Tipagem Bacteriana , DNA Bacteriano/análise , Bactérias Gram-Positivas/genética , Bactérias Gram-Positivas/ultraestrutura , Microscopia Eletrônica de Transmissão , Filogenia , RNA Bacteriano/análise , RNA Ribossômico 16S/análise
18.
Mar Biotechnol (NY) ; 7(3): 173-8, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15906116

RESUMO

An alkaline phosphatase with unusually high specific activity has been found to be produced by the marine bacterium Cobetia marina (strain KMM MC-296) isolated from coelomic liquid of the mussel Crenomytilus grayanus. The properties of enzyme, such as a very high specific activity (15000 DE U/1 mg of protein), no activation with divalent cations, resistance to high concentrations of inorganic phosphorus, as well as substrate specificity toward 5' nucleotides suggest that the enzyme falls in an intermediate position between unspecific alkaline phosphatases (EC 3.1.3.1) and 5' nucleotidases (EC 3.1.3.5).


Assuntos
5'-Nucleotidase/isolamento & purificação , Fosfatase Alcalina/isolamento & purificação , Halomonadaceae/enzimologia , Mytilidae/microbiologia , Animais , Concentração de Íons de Hidrogênio , Ponto Isoelétrico , Peso Molecular , Oceano Pacífico , Especificidade por Substrato
19.
Mikrobiologiia ; 74(6): 766-71, 2005.
Artigo em Russo | MEDLINE | ID: mdl-16400986

RESUMO

A comparative study of the lipid composition of 26 strains (including type strains) of marine Gammaproteobacteria belonging to the genera Shewanella, Alteromonas, Pseudoalteromonas, Marinobacterium, Microbulbifer, and Marinobacter was carried out. The bacteria exhibited genus-specific profiles of ubiquinones, phospholipids, and fatty acids, which can serve as reliable chemotaxonomic markers for tentative identification of new isolates. The studied species of the genus Shewanella were distinguished by the presence of two types of isoprenoid quinones, namely, ubiquinones Q-7 and Q-8 and menaquinones MK-7 and MMK-7; five phospholipids typical of this genus, namely, phosphatidylethanolamine (PE), phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), lyso-PE, and acyl-PG; and the fatty acids 15:0, 16:0, 16:1 (n-7), 17:1 (n-8), i-13:0, and i-15:0. The high level of branched fatty acids (38-45%) and the presence of eicosapentaenoic acid (4%) may serve as criteria for the identification of this genus. Unlike Shewanella spp., bacteria of the other genera contained a single type of isoprenoid quinone: Q-8 (Alteromonas, Pseudoalteromonas, Marinobacterium, and Microbulbifer) or Q-9 (Marinobacter). The phospholipid compositions of these bacteria were restricted to three components: two major phospholipids (PE and PG) and a minor phospholipid, bisphosphatidic acid (Alteromonas and Pseudoalteromonas) or DPG (Marinobacterium, Microbulbifer, and Marinobacter). The bacteria exhibited genus-specific profiles of fatty acids.


Assuntos
Lipídeos/análise , Biologia Marinha , Shewanella/química , Shewanella/classificação , Microbiologia da Água , Ácido Eicosapentaenoico/análise , Extremo Oriente , Ácidos Graxos/análise , Oceanos e Mares , Fosfolipídeos/análise , Especificidade da Espécie
20.
Biochemistry (Mosc) ; 69(3): 262-9, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15061691

RESUMO

The marine bacterium Pseudoalteromonas citrea KMM 3297 is an associate of the holothurian Apostichopus japonicus. When grown in a medium containing glucose, the strain produces two intracellular alginolytic enzymes, AlI and AlII. Fucoidan from the brown alga Fucus evanescens induces synthesis of one more alginolytic enzyme, AlIII. These enzymes were separated using anion-exchange chromatography. The alginate lyase AlI completely retains its activity at 35 degrees C, AlII and AlIII being stable at 45 degrees C. The alginate lyases exhibit maximal activities in the range of pH 7-8. The molecular weights of AlI, AlII, and AlIII determined by gel filtration are 25, 79, and 61 kD, respectively. All the investigated enzymes are endo-type alginate lyases. They catalyze degradation of polyguluronate (poly-G) and polymannuronate (poly-M) yielding oligosaccharides of the polymerization degree of 5 > or = n > or = 3 with the unsaturated bond between the C4 and C5 atoms of the non-reducing terminus. A mixture of these three enzymes exhibits synergism while acting on the polymeric substrate. The Km values of the alginate lyase AlI for poly-G and poly-M are 24 and 34 micro g/ml, respectively. Alginate lyase AlIII exhibits less affinity to poly-M (Km = 130.0 microg/ml) than to poly-G (Km = 40.0 microg/ml). NaCl (0.2 M), MgCl2 and MgSO4 (0.01 M) activate all three enzymes more than twofold. The presence of several alginolytic enzymes of different specificity provides efficient destruction of alginic acids of brown algae by the strain P. citrea KMM 3297.


Assuntos
Alginatos/química , Ácido Glucurônico/química , Bactérias Gram-Negativas/enzimologia , Ácidos Hexurônicos/química , Liases/química , Polissacarídeos Bacterianos/química , Polissacarídeos/química , Animais , Cromatografia por Troca Iônica , Temperatura Alta , Concentração de Íons de Hidrogênio , Cinética , Liases/isolamento & purificação , Metais/química , Peso Molecular , Feófitas/química , Pepinos-do-Mar/microbiologia , Especificidade por Substrato
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