Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 181
Filtrar
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.
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.

5.
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
6.
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.

7.
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
8.
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.

9.
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.

10.
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
11.
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
12.
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
13.
FEBS Lett ; 414(2): 319-22, 1997 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-9315710

RESUMO

Ballistic transfection, based on cell and tissue bombardment by the tungsten and gold microparticles covered with the gene DNA, was used for the delivery of a bacterial beta-galactosidase and a full-length cDNA copy of the human dystrophin genes into mouse skeletal muscles. CMV-lacZ, SV40-lacZ, LTR-lacZneo and full-length cDNA dystrophin (pDMD-1, approximately 16 kb) in eukaryotic expression vector pJ OMEGA driven by mouse leukaemia virus promotor (pMLVDy) were used throughout the studies. Musculus glutaeus superficialis of C57BL/6J and quadriceps femoris of mdx male mice were opened surgically under anesthesia and bombarded by means of the gene-gun technique originally developed by us. Different mixtures of gold and tungsten particles at ratios of 4:1, 1:1, 1:4 were applied. X-gal assay revealed marked beta-gal activity, both in total muscles and whole muscle fibers on histological sections, up to three months after transfection. The most intensive staining was observed after SV40-lacZ delivery. No staining was detected with LTR-lacZneo DNA as well as in untreated muscles. The higher tungsten particle concentration in the bombardment mixture correlated with more intense X-gal staining. At the gold/tungsten ratio of 1:4 the microparticles penetrated the musculus glutaeus superficialis and transfected the underlying musculus glutaeus medius as well. Immuno-cytochemical assay for human dystrophin revealed dystrophin positive myofibers (DPM) in the bombarded area up to two months after transfection. The proportion of DMP varied from 2.5% on day 17 up two 5% on day 60 after bombardment compared to only 0.5% in the control mdx mice. These results suggest the applicability of particle bombardment for gene delivery into muscle fibers.


Assuntos
Distrofina/biossíntese , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/metabolismo , beta-Galactosidase/biossíntese , Animais , Biolística/métodos , DNA Complementar , Distrofina/genética , Vetores Genéticos , Humanos , Vírus da Leucemia Murina , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos mdx , Regiões Promotoras Genéticas , Transfecção/métodos , beta-Galactosidase/genética
14.
Bioorg Khim ; 21(1): 3-8, 1995 Jan.
Artigo em Russo | MEDLINE | ID: mdl-7710421

RESUMO

Studies of the origin of bioactive metabolites of marine actinomycetes are reviewed. Structures and properties of new metabolites from indigenous marine bacteria from Actinomycetales order, such as a benzanthraquinone antibiotic from a strain of the Chainia purpurogena, istamycins, aplasmomycins, altemicidin, new phenazine esters. C13-butanolide, marinone and debromomarinone, palmyromycin, urauchimicins and some others compounds are presented. Prospects of marine biotechnology and microbiology (with considerable emphasis on the development of the basis biology of marine microorganisms in cultures collection) are discussed.


Assuntos
Actinomycetales/química , Antibacterianos/isolamento & purificação , Biologia Marinha
15.
Bioorg Khim ; 18(10-11): 1424-40, 1992.
Artigo em Russo | MEDLINE | ID: mdl-1299219

RESUMO

Recent studies on bioactive metabolites from marine macro- and microorganisms are reviewed with 83 refs. Structures of new sulphated and glycosylated secondary metabolites, which have been reported to have antifungal, immunomodulatory, and cytotoxic properties, are given. Some peculiarities of biosynthesis of natural compounds in marine organisms are revealed. It was shown that some natural products, isolated earlier from sponges, are produced by microbial symbionts. Different physiological activities associated with 8000 marine microbial (mainly symbiotic) strains are discussed as well as some prospects of marine biochemistry and biotechnology development.


Assuntos
Bioquímica , Biotecnologia , Biologia Marinha , Animais , Fenômenos Bioquímicos , Invertebrados/química , Preparações Farmacêuticas/isolamento & purificação , Farmacologia , Microbiologia da Água
16.
Bioorg Khim ; 26(4): 315-20, 2000 Apr.
Artigo em Russo | MEDLINE | ID: mdl-10857024

RESUMO

A competitive ELISA using the intact toxin as a coating antigen for detecting palytoxin was developed. This immunoassay allows palytoxin (PTX) to be determined in the range of 6-250 ng/ml. In sensitivity, this determination is comparable with RIA but is three times inferior to ELISA using monoclonal antibodies. Inhibition experiments using some toxins of marine invertebrates proved the serological specificity of the palytoxin binding to antibodies. Both the indirect and competitive ELISA were used to find PTX-producing bacteria among 420 isolates of sea bacteria. It was found that gram-negative bacteria Aeromonas sp. and Vibrio sp. associated with toxic samples of the soft coral Palythoa sp. produced compounds antigenically related to PTX.


Assuntos
Acrilamidas/metabolismo , Cnidários , Venenos de Cnidários/metabolismo , Acrilamidas/química , Acrilamidas/toxicidade , Animais , Cnidários/metabolismo , Venenos de Cnidários/química , Venenos de Cnidários/toxicidade , Ensaio de Imunoadsorção Enzimática , Dose Letal Mediana , Camundongos , Estrutura Molecular
17.
Vestn Ross Akad Med Nauk ; (2): 39-44, 1993.
Artigo em Russo | MEDLINE | ID: mdl-7688619

RESUMO

Oral and dermal administrations of vaccinia virus into rabbits, guinea pigs, and monkeys demonstrated a milder (without homeostasis disturbance) course of the vaccinal process with oral immunization, intensive immunity forming in minimal sensitization of the body was compared with dermal one. The results of revaccination in adults with oral smallpox vaccine and primary immunization in Ethiopia showed that oral immunization with vaccinia virus was safe, effective and lowly reactogenic. The comparative study of the preparation in remote revaccination (5 or more years later) proved its advantage over dermal vaccine. It consists in ecological safety (vaccinia virus excretion into the environment during 1 and 11 days, respectively, by 10-fold concentration reduction), reactogenicity (5 and 33% of common reactions, respectively) in the same immunogenicity.


Assuntos
Imunização/métodos , Vacina Antivariólica/administração & dosagem , Vacinas Sintéticas/administração & dosagem , Vaccinia virus/imunologia , Vacinas Virais/administração & dosagem , Administração Cutânea , Administração Oral , Animais , Avaliação de Medicamentos , Avaliação Pré-Clínica de Medicamentos , Etiópia , Haplorrinos , Humanos , Imunização Secundária , Coelhos , Segurança , Vacina Antivariólica/efeitos adversos , Vacina Antivariólica/imunologia , Comprimidos , Vacinas Sintéticas/efeitos adversos , Vacinas Sintéticas/imunologia , Vacinas Virais/efeitos adversos , Vacinas Virais/imunologia
18.
Usp Fiziol Nauk ; 33(4): 94-103, 2002.
Artigo em Russo | MEDLINE | ID: mdl-12449810

RESUMO

Are cited data about identification regulators of materials non-mediators of the nature executing direct and return (ortho- and retrograde) interplay of motoneurons and myocytes of a skeletal musculation. Neuro- and myotrophogenes are submitted by polypeptide materials dispossessed by specific specificity. The definite functional properties and endocellular processes in muscle cages and motoneurons are adjusted by miscellaneous kinds conforming neuro- and myotrophogenes.


Assuntos
Neurônios Motores/fisiologia , Músculo Esquelético/fisiologia , Transmissão Sináptica/fisiologia , Animais , Contração Muscular/fisiologia , Fibras Musculares Esqueléticas/fisiologia , Músculo Esquelético/citologia , Músculo Esquelético/inervação
19.
Vopr Virusol ; 46(1): 4-8, 2001.
Artigo em Russo | MEDLINE | ID: mdl-11233287

RESUMO

The problem of transgenic plants application to production of antigens, antibodies, enzymes, and hormones is discussed. Transgenic plants are a highly effective system for production of bioactive molecules. Prospects for using transgenic plants expressing viral and bacterial antigens for mucosal immunization are discussed.


Assuntos
Plantas Geneticamente Modificadas/metabolismo , Vacinas , Anticorpos , Antígenos/biossíntese , Enzimas/biossíntese , Hormônios/biossíntese
20.
Vopr Virusol ; 39(2): 82-4, 1994.
Artigo em Russo | MEDLINE | ID: mdl-8017061

RESUMO

The protective role of virus-neutralizing antibody was demonstrated in Ebola virus-infected animals (Papio hamadryas) used in experiments on the development of passive humoral immunity by using specific immunoglobulin. Two immunizations of the monkeys with purified concentrated Ebola virus antigen with complete Freund adjuvant was shown to confirm intensive immunity to subsequent challenge protecting 80% of the immunized animals. It is concluded that effective preparations may be developed for specific prophylaxis of Ebola fever.


Assuntos
Ebolavirus , Febres Hemorrágicas Virais/prevenção & controle , Doenças dos Macacos/prevenção & controle , Animais , Anticorpos Antivirais/sangue , Especificidade de Anticorpos , Antígenos Virais/imunologia , Antígenos Virais/isolamento & purificação , Ebolavirus/imunologia , Feminino , Febres Hemorrágicas Virais/imunologia , Imunização/métodos , Imunoglobulinas/imunologia , Imunoglobulinas/isolamento & purificação , Masculino , Doenças dos Macacos/imunologia , Papio , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA