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1.
Phys Rev Lett ; 126(15): 152002, 2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33929235

RESUMO

We present the first measurement of the fluctuations in the number of muons in extensive air showers produced by ultrahigh energy cosmic rays. We find that the measured fluctuations are in good agreement with predictions from air shower simulations. This observation provides new insights into the origin of the previously reported deficit of muons in air shower simulations and constrains models of hadronic interactions at ultrahigh energies. Our measurement is compatible with the muon deficit originating from small deviations in the predictions from hadronic interaction models of particle production that accumulate as the showers develop.

2.
Phys Rev Lett ; 125(12): 121106, 2020 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-33016715

RESUMO

We report a measurement of the energy spectrum of cosmic rays above 2.5×10^{18} eV based on 215 030 events. New results are presented: at about 1.3×10^{19} eV, the spectral index changes from 2.51±0.03(stat)±0.05(syst) to 3.05±0.05(stat)±0.10(syst), evolving to 5.1±0.3(stat)±0.1(syst) beyond 5×10^{19} eV, while no significant dependence of spectral features on the declination is seen in the accessible range. These features of the spectrum can be reproduced in models with energy-dependent mass composition. The energy density in cosmic rays above 5×10^{18} eV is [5.66±0.03(stat)±1.40(syst)]×10^{53} erg Mpc^{-3}.

3.
Allergy ; 72(2): 232-243, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27170552

RESUMO

BACKGROUND: Human rhinoviruses (HRVs) are one of the main causes of virus-induced asthma exacerbations. Infiltration of B lymphocytes into the subepithelial tissue of the lungs has been demonstrated during rhinovirus infection in allergic individuals. However, the mechanisms through which HRVs modulate the immune responses of monocytes and lymphocytes are not yet well described. OBJECTIVE: To study the dynamics of virus uptake by monocytes and lymphocytes, and the ability of HRVs to induce the activation of in vitro-cultured human peripheral blood mononuclear cells. METHODS: Flow cytometry was used for the enumeration and characterization of lymphocytes. Proliferation was estimated using 3 H-thymidine or CFSE labeling and ICAM-1 blocking. We used bead-based multiplex assays and quantitative PCR for cytokine quantification. HRV accumulation and replication inside the B lymphocytes was detected by a combination of in situ hybridization (ISH), immunofluorescence, and PCR for positive-strand and negative-strand viral RNA. Cell images were acquired with imaging flow cytometry. RESULTS: By means of imaging flow cytometry, we demonstrate a strong and quick binding of HRV types 16 and 1B to monocytes, and slower interaction of these HRVs with CD4+ T cells, CD8+ T cells, and CD19+ B cells. Importantly, we show that HRVs induce the proliferation of B cells, while the addition of anti-ICAM-1 antibody partially reduces this proliferation for HRV16. We prove with ISH that HRVs can enter B cells, form their viral replication centers, and the newly formed virions are able to infect HeLa cells. In addition, we demonstrate that similar to epithelial cells, HRVs induce the production of pro-inflammatory cytokines in PBMCs. CONCLUSION: Our results demonstrate for the first time that HRVs enter and form viral replication centers in B lymphocytes and induce the proliferation of B cells. Newly formed virions have the capacity to infect other cells (HeLa). These findings indicate that the regulation of human rhinovirus-induced B-cell responses could be a novel approach to develop therapeutics to treat the virus-induced exacerbation of asthma.


Assuntos
Linfócitos B/imunologia , Linfócitos B/virologia , Ativação Linfocitária/imunologia , Infecções por Picornaviridae/imunologia , Infecções por Picornaviridae/virologia , Rhinovirus/fisiologia , Subpopulações de Linfócitos B/imunologia , Subpopulações de Linfócitos B/metabolismo , Linfócitos B/metabolismo , Citocinas/metabolismo , Feminino , Humanos , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Leucócitos Mononucleares/virologia , Masculino , Monócitos/imunologia , Monócitos/metabolismo , Monócitos/virologia , Infecções por Picornaviridae/metabolismo , Rhinovirus/classificação , Sorogrupo , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Subpopulações de Linfócitos T/virologia , Ligação Viral , Internalização do Vírus , Replicação Viral
4.
Phys Rev Lett ; 116(24): 241101, 2016 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-27367377

RESUMO

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8±0.7(stat)±6.7(syst) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principles calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.

5.
Phys Rev Lett ; 117(19): 192001, 2016 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-27858429

RESUMO

Ultrahigh energy cosmic ray air showers probe particle physics at energies beyond the reach of accelerators. Here we introduce a new method to test hadronic interaction models without relying on the absolute energy calibration, and apply it to events with primary energy 6-16 EeV (E_{CM}=110-170 TeV), whose longitudinal development and lateral distribution were simultaneously measured by the Pierre Auger Observatory. The average hadronic shower is 1.33±0.16 (1.61±0.21) times larger than predicted using the leading LHC-tuned models EPOS-LHC (QGSJetII-04), with a corresponding excess of muons.

6.
Allergy ; 69(5): 658-67, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24684577

RESUMO

BACKGROUND: The relationships between tonsillar immune responses, and viral infection and allergy are incompletely known. OBJECTIVE: To study intratonsillar/nasopharyngeal virus detections and in vivo expressions of T-cell- and innate immune response-specific cytokines, transcription factors, and type I/II/III interferons in human tonsils. METHODS: Palatine tonsil samples were obtained from 143 elective tonsillectomy patients. Adenovirus, bocavirus-1, coronavirus, enteroviruses, influenza virus, metapneumovirus, parainfluenza virus, rhinovirus, and respiratory syncytial virus were detected using PCR. The mRNA expression levels of IFN-α, IFN-ß, IFN-γ, IL-10, IL-13, IL-17, IL-28, IL-29, IL-37, TGF-ß, FOXP3, GATA3, RORC2, and Tbet were directly analyzed by quantitative RT-PCR. RESULTS: Fifty percentage of subjects reported allergy, 59% had ≥1 nasopharyngeal viruses, and 24% had ≥1 intratonsillar viruses. Tonsillar virus detection showed a strong negative association with age; especially rhinovirus or parainfluenza virus detection showed positive association with IFN-γ and Tbet expressions. IL-37 expression was positively associated with atopic dermatitis, whereas IFN-α, IL-13, IL-28, and Tbet expressions were negatively associated with allergic diseases. Network analyses demonstrated strongly polarized clusters of immune regulatory (IL-10, IL-17, TGF-ß, FOXP3, GATA3, RORC2, Tbet) and antiviral (IFN-α, IFN-ß, IL-28, IL-29) genes. These two clusters became more distinctive in the presence of viral infection or allergy. A negative correlation between antiviral cytokines and IL-10, IL-17, IL-37, FOXP3, and RORC2 was observed only in the presence of viruses, and interestingly, IL-13 strongly correlated with antiviral cytokines. CONCLUSIONS: Tonsillar cytokine expression is closely related to existing viral infections, age, and allergic illnesses and shows distinct clusters between antiviral and immune regulatory genes.


Assuntos
Tonsila Palatina/imunologia , Tonsila Palatina/virologia , Viroses/imunologia , Adolescente , Adulto , Criança , Análise por Conglomerados , Citocinas/genética , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Redes Reguladoras de Genes , Humanos , Masculino , Tonsila Palatina/metabolismo , Fatores de Transcrição/genética , Transcriptoma , Viroses/genética , Adulto Jovem
7.
Biochem Res Int ; 2024: 8827402, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38665151

RESUMO

Vitamin B12 (cobalamin) is a water-soluble molecule required for the proper functioning of metabolism, blood and DNA synthesis, and neurological development. Vitamin B12 exists in several forms: methylcobalamin (MeCbl), adenosylcobalamin (AdoCbl), hydroxycobalamin (OHCbl), and cyanocobalamin (CNCbl). This study aimed to evaluate the effect of cigarette smoke on the chemical structure of methylcobalamin and hydroxycobalamin forms of vitamin B12. MeCbl and OHCbl were markedly affected by exposure to cigarette smoke. The resemblance of the Rt between MeCbl and OHCbl and CNCbl indicates that exposure to cigarette smoke extracts chemically alters MeCbl and OHCbl to CNCbl, warranting in vivo research investigations.

8.
Eur Phys J C Part Fields ; 75(6): 269, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26120280

RESUMO

Energy-dependent patterns in the arrival directions of cosmic rays are searched for using data of the Pierre Auger Observatory. We investigate local regions around the highest-energy cosmic rays with [Formula: see text] eV by analyzing cosmic rays with energies above [Formula: see text] eV arriving within an angular separation of approximately 15[Formula: see text]. We characterize the energy distributions inside these regions by two independent methods, one searching for angular dependence of energy-energy correlations and one searching for collimation of energy along the local system of principal axes of the energy distribution. No significant patterns are found with this analysis. The comparison of these measurements with astrophysical scenarios can therefore be used to obtain constraints on related model parameters such as strength of cosmic-ray deflection and density of point sources.

9.
Thromb Haemost ; 65(5): 535-40, 1991 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-1871715

RESUMO

An assay for a direct photometric determination of F XIII in untreated and undiluted plasma was developed. In a one-step procedure F XIII is activated by thrombin and Ca2+ and cross-links glycine-ethylester to a specific glutamine containing peptide substrate. The released ammonia is incorporated into alpha-ketoglutarate by glutamate dehydrogenase, and the NADH consumption of this reaction is measured photometrically at 340 nm. NADH-consumption is directly proportional to the F XIII activity. Fibrin polymerization and the corresponding turbidity is avoided by the use of a fibrin aggregation inhibitor. The procedure is rapid and simple and enables to measure within the range of 0 to 150% F XIII. It can be performed with automated analyzers as well as with common photometric equipment. The normal range of F XIII activity in 167 healthy donors was determined to be 70 to 140%.


Assuntos
Fator XIII/análise , Sequência de Aminoácidos , Calibragem , Humanos , Cinética , Dados de Sequência Molecular , Fotometria , Reprodutibilidade dos Testes
10.
Thromb Res ; 49(6): 581-9, 1988 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-2455361

RESUMO

Oxidative inactivation of alpha-1-proteinase inhibitor (A1-P1) and plasminogen activator inhibitor-1 (PAI-1), both members of the serine protease inhibitor (serpin) superfamily, using mild oxidation conditions has been already demonstrated. The oxidation mechanism has been shown to involve conversion of methionine to methionine sulfoxide in the reactive center of the inhibitors. In this study evidence is presented that alpha-2-antiplasmin (A2-PI) and antithrombin III (AT III) can also be inactivated by means of oxidation. For total inactivation of 50 pM A1-PI about 10 nM chloramine T (CT) and for the same molar concentration of A2-PI and AT III about 250 nM CT were found necessary. C1-inhibitor (C1-INH) showed some resistance to oxidation that could be overcome only by increasing CT to an amount (greater than 2000 nM) already beginning to inactivate the corresponding C1-esterase. As target enzymes for A2-PI, AT III, and A1-PI plasmin, thrombin and elastase, respectively, were used. Their activity was not impaired by the oxidation conditions applied. As there is no methionine in the reactive center of AT III an additional mechanism for oxidative inactivation of serpins has to be taken into consideration. Oxidation seems to be a general mechanism for altering the balances between serine proteases and their inhibitors in favour of the protease.


Assuntos
Antitrombina III/antagonistas & inibidores , Proteínas Inativadoras do Complemento 1/metabolismo , Fibrinolisina/antagonistas & inibidores , alfa 2-Antiplasmina/metabolismo , Proteínas Sanguíneas/metabolismo , Humanos , Oxirredução , alfa 1-Antitripsina
11.
Arq. Inst. Biol. ; 79(4)2012.
Artigo em Inglês | VETINDEX | ID: vti-698674

RESUMO

In the semiarid of the state of Paraíba, the anti-rabies vaccination is not common, most of the local inhabitants who deal with the animals do not know the incidence of the disease in the region. In this study, samples of foxes (Pseudalopex vetulus), insectivorous bats (Molossus molossus), raccoons (Procyon cancrivorous) and domestic animals brains were submitted to the diagnosis of rabies, by using the direct fluorescent antibody technique (d-FAT) and mouse inoculation test (MIT). Of the 581 examined materials, 50 (8.60 %) were positive for d-FAT and 47 (8.09 %) for MIT. From the positive samples for rabies, RNAs were extracted and transformed to cDNA, at the Laboratory of Rabies/Faculdade de Medicina Veterinária e Zootecnia/USP, SP. The phylogenetic characterization of the N gene was performed at the Universidade de São Paulo, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Medicina Veterinária Preventiva e Saúde Animal, Universidade Nihon, Faculdade de Ciências Bioresource, Fujisawa, Kanagawa, Japão. Based on the results of genotyping and phylogenetic analyzes, it is concluded that the epidemiology of rabies is complex in the semiarid of Paraíba, with different viral variants being maintained in domestic dogs, foxes, insectivorous bats and vampire bats. All the isolates examined belong to the genotype I of the genus Lyssavirus and it is possible to state that in the region, foxes are important sylvatic reservoirs of the rabies virus.


No semiárido do Estado da Paraíba, a vacinação antirrábica não é comum, a maioria dos habitantes locais que lidam com os animais não conhece a incidência da doença na região. Neste estudo, amostras do cérebro de raposas (Pseudalopex vetulus), de morcegos insetívoros (Molossus molossus), de guaxinins (Procyon cancrivorous) e de animais domésticos foram submetidas ao diagnóstico da raiva, pela técnica de imunofluorescência direta (IFD) e inoculação intracerebral em camundongos (ICC). Dos 581 materiais examinados, 50 (8,60%) foram positivos para IFD e 47 (8,09%) para o ICC. Das amostras positivas para raiva, os RNAs foram extraídos e transformados em DNA, no Laboratório de Raiva/Faculdade de Medicina Veterinária e Zootecnia/USP, SP. A caracterização filogenética do gene N foi realizada no Centro de Investigação Veterinária, Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Ciências Bioresource, Nihon University, Fujisawa, Kanagawa, Japão. Com base nos resultados das análises filogenéticas e genotipagem, conclui-se que a epidemiologia da raiva é complexa no semiárido da Paraíba, com diferentes variantes virais sendo mantidas em cães domésticos, raposas, morcegos insetívoros e morcegos hematófagos. Todos os isolados analisados pertencem ao genótipo I do gênero Lyssavirus, e é possível afirmar que, na região, as raposas são importantes reservatórios silvestres do vírus da raiva.

12.
Arq. Inst. Biol ; 79(4)out.-dez. 2012.
Artigo em Inglês | LILACS-Express | VETINDEX | ID: biblio-1462198

RESUMO

In the semiarid of the state of Paraíba, the anti-rabies vaccination is not common, most of the local inhabitants who deal with the animals do not know the incidence of the disease in the region. In this study, samples of foxes (Pseudalopex vetulus), insectivorous bats (Molossus molossus), raccoons (Procyon cancrivorous) and domestic animals brains were submitted to the diagnosis of rabies, by using the direct fluorescent antibody technique (d-FAT) and mouse inoculation test (MIT). Of the 581 examined materials, 50 (8.60 %) were positive for d-FAT and 47 (8.09 %) for MIT. From the positive samples for rabies, RNAs were extracted and transformed to cDNA, at the Laboratory of Rabies/Faculdade de Medicina Veterinária e Zootecnia/USP, SP. The phylogenetic characterization of the N gene was performed at the Universidade de São Paulo, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Medicina Veterinária Preventiva e Saúde Animal, Universidade Nihon, Faculdade de Ciências Bioresource, Fujisawa, Kanagawa, Japão. Based on the results of genotyping and phylogenetic analyzes, it is concluded that the epidemiology of rabies is complex in the semiarid of Paraíba, with different viral variants being maintained in domestic dogs, foxes, insectivorous bats and vampire bats. All the isolates examined belong to the genotype I of the genus Lyssavirus and it is possible to state that in the region, foxes are important sylvatic reservoirs of the rabies virus.


No semiárido do Estado da Paraíba, a vacinação antirrábica não é comum, a maioria dos habitantes locais que lidam com os animais não conhece a incidência da doença na região. Neste estudo, amostras do cérebro de raposas (Pseudalopex vetulus), de morcegos insetívoros (Molossus molossus), de guaxinins (Procyon cancrivorous) e de animais domésticos foram submetidas ao diagnóstico da raiva, pela técnica de imunofluorescência direta (IFD) e inoculação intracerebral em camundongos (ICC). Dos 581 materiais examinados, 50 (8,60%) foram positivos para IFD e 47 (8,09%) para o ICC. Das amostras positivas para raiva, os RNAs foram extraídos e transformados em DNA, no Laboratório de Raiva/Faculdade de Medicina Veterinária e Zootecnia/USP, SP. A caracterização filogenética do gene N foi realizada no Centro de Investigação Veterinária, Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Ciências Bioresource, Nihon University, Fujisawa, Kanagawa, Japão. Com base nos resultados das análises filogenéticas e genotipagem, conclui-se que a epidemiologia da raiva é complexa no semiárido da Paraíba, com diferentes variantes virais sendo mantidas em cães domésticos, raposas, morcegos insetívoros e morcegos hematófagos. Todos os isolados analisados pertencem ao genótipo I do gênero Lyssavirus, e é possível afirmar que, na região, as raposas são importantes reservatórios silvestres do vírus da raiva.

13.
Arq. Inst. Biol. ; 78(2)2011.
Artigo em Português | VETINDEX | ID: vti-759525

RESUMO

ABSTRACT Rotavirus is the main cause of diarrhea in young animals of several species. They are classified as a genus within the virus family Reoviridae. Rotaviruses have a segmented genome made up of a double-stranded RNA. It is divided into 11 segments and surrounded by a triple protein capsid. In this study, Rotavirus was detected by polyacrylamide gel electrophoresis (PAGE) in feces samples of 80-day-old goats during a diarrhea outbreak in a milk-producing herd. The samples electrophoretic pattern, called cap01/2007, was characterized as Group A rotavirus. A 20% fecal suspension in buffer TRIS 0.1M pH 7.3 was filtered and treated with crystalline trypsin in a 5 mg/mL concentration for viral isolation. Caprine sample Cap01/2007 was inoculated in MA-104 cells (Rhesuss kidneys) with a 48-hour growth. Two treatments (T1 and T2) were tested. In T1, maintenance medium without trypsin was added (Dulbecco-MEM) after adsorption (buffer at 37º C for 1h) the inoculum was maintained. In treatment T2, the previous procedure without the inoculum was performed. Cytopathic effect was observed in the first passage for both treatments (T1 and T2) with 48h inoculation, and viral isolation was then confirmed by PAGE. Migration design remained unchanged after 3 successive passages. This is the first report of isolation of caprine rotavirus in Brazil.


RESUMO Rotavírus é a principal causa de diarreia em animais jovens de várias espécies. Os rotavirus estão classificados na família Reoviridae e contêm um genoma formado por 11 segmentos de RNA de cadeia dupla, envolvidos em três camadas proteicas. Neste estudo, foi detectado rotavírus pela eletroforese em gel de poliacrilamida (PAGE) em amostras de fezes de caprinos, com 80 dias de idade, durante surto de diarreia em um rebanho leiteiro. O perfil eletroforético das amostras, denominadas cap01/2007 e cap02/2007, foi caracterizado no PAGE como sendo de rotavírus do grupo A. Para o isolamento viral, suspensão fecal a 20% em tampão tris 0,1M pH 7,3 foi filtrada e tratada com tripsina cristalina na concentração de 5mg/mL. A amostra caprina cap01/2007 foi inoculada em cultura de células MA104 (Rim de Macaco Rhesus). Foram testados dois tratamentos (T1 e T2): após adsorção (estufa 37º C por uma hora) adicionou-se meio de manutenção (Dulbecco-MEM) sem tripsina, mantendo o inóculo (T1). No tratamento 2 (T2), foi realizado o mesmo pro cedimento anterior, porém o inóculo foi dispensado. O efeito citopático foi observado na primeira passagem para ambos os tratamentos (T1 e T2) com 48 horas de inoculação e o isolamento viral foi confirmado no PAGE. O perfil de migração manteve-se inalterado após três passagens sucessivas. Este é o primeiro relato de isolamento de rotavírus em caprinos no Brasil.

14.
Arq. Inst. Biol. ; 77(4)2010.
Artigo em Português | VETINDEX | ID: vti-761559

RESUMO

ABSTRACT An epidemiological survey of all cases of bovine rabies that occurred in Mato Grosso, Brazil, during the years 1996 to 2006 was conducted by way of the analysis of the epidemic curve, by calculating the sum, average, standard deviation, maximum and minimum values of the occurrence of rabies in three ecosystems; statistical analysis between the actual cattle in the three biomes of the state and the number of cases of rabies cattle; and the seasonal distribution and disease situation in the state in relation to the national scene. The data were organized by taking into account the month and year of occurrence of rabies and the geographic region of the origin of the material. The different cities involved were classified according to their location in regions of Cerrado, the Pantanal and the Amazon. It was found that the variation in the number of positive cases of the disease has been increasing in recent years, with the largest number of cases occurring in the Cerrado biome, which showed a trend of annual increase. Beginning in the year 2004 the Cerrado ecosystem passed from the situation of enzootic to epizootic, making it evident that the main bovine rabies problem in the state of Mato Grosso is situated in the Cerrado biome.


RESUMO Um levantamento epidemiológico de todos os casos de raiva bovina ocorridos no Estado de Mato Grosso durante os anos de 1996 a 2006 foi realizado pela análise da curva epidêmica, por meio do cálculo do somatório, média, desvio padrão, valores máximos e mínimos da ocorrência de casos de raiva nos três ecossistemas; análise estatística entre o efetivo bovino nos três biomas do estado e o número de casos de raiva bovina; a distribuição sazonal e a situação da doença no estado em relação ao panorama nacional. Para organização dos dados, levou-se em consideração o mês e o ano de ocorrência da raiva e a região geográfica de origem do material. Os diferentes municípios envolvidos foram classificados conforme sua localização nas regiões de Cerrado, Pantanal e Amazônia. Constatou-se que a variação no número de casos positivos da enfermidade tem sido crescente nos últimos anos, sendo que o maior número de casos deu-se no bioma Cerrado, que apresentou uma tendência de aumento anual. A partir do ano de 2004, o ecossistema Cerrado passou da situação de enzootia para epizootia, ficando pois, evidente que o principal problema de raiva em bovinos no Estado de Mato Grosso está situado no bioma Cerrado.

15.
Arq. Inst. Biol. ; 77(1)2010.
Artigo em Português | VETINDEX | ID: vti-759763

RESUMO

ABSTRACT A total of 53 rabies virus (RV) isolates originating from cattle in the state of Mato Grosso, Brazil, were genetically characterized. Partial nucleoprotein gene sequences of these isolates were phylogenetically and geographically analyzed. Cattle isolates, which clustered with the vampire bat related RV group, were further subdivided into 7 subgroups. These subgroups were distributed widely in lowland regions, with some subgroups separated from each other by small mountains and hydrographical features. These results indicate that cattle rabies is derived from several regionally-defined variants, which suggests that its geographical distribution is related to that of the vampire bat population.


RESUMO Foram caracterizados, geneticamente e geograficamente, o sequenciamento parcial da nucleoproteína (gene N) de 53 isolados do vírus da raiva (VR) originários do Estado de Mato Grosso, Brasil. Os isolados de bovinos, que se encontravam no grupo do VR relacionado a morcegos hematófagos, foram posteriormente subdivididos em sete subgrupos genéticos. Estes subgrupos foram distribuídos em regiões de terras planas, com alguns subgrupos separados por formações de pequenas montanhas e hidrografia. Estes resultados indicam que a raiva em bovinos é derivada de diversas variantes regionalmente definidas, o que sugere que sua distribuição geográfica está relacionada as populações de morcegos hematófagos.

16.
Egyptian Journal of Chemistry. 2007; 50 (3): 303-312
em Inglês | IMEMR | ID: emr-82368

RESUMO

A new method for anodic stripping voltammetric determination of silver [I] using unmodified carbon paste electrode is described. In this method, the silver sample containing 10% phthalic acid solution is pre-concentrated on the electrode at -400 mV for 30 s. The deposited metal is then oxidized by anodic stripping voltammetric sweep. Chemical and electrical parameters affecting the voltammetric measurements are optimized. The peak current is proportional to the Ag [I] concentration over the range 0.5-50 ng/ml [r = 0.997], and the detection limit is 0.2-ng/ml. The relative standard deviation is 2% for 50 ng/ml [four replicates]. Satisfactory results are obtained on applying the proposed method to the determination of Ag [I] in digested samples of topical creams containing 1% silver sulphadiazine. No interference due to many cations is observed. In contrast, 10-fold excess of Cu ions has been shown serious interference, but on adding either 0.2 mM 4-[pyridyl-2-azo] resorcinol [PAR] or thiocyanate, the overlapped peaks can be separated into two well-defined peaks and consequently both cations, Ag and Cu can be determined simultaneously


Assuntos
Eletrodos , Anti-Infecciosos Locais
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