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1.
Oper Dent ; 47(5): 549-561, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36026699

RESUMO

This study aimed to evaluate the effect of desensitizing and conventional mouth rinses on dentin tubule occlusion. Dentin hypersensitivity was simulated by EDTA application for five minutes. The specimens were randomly allocated into the following groups: desensitizing mouth rinses (Colgate Sensitive, Elmex Sensitive Professional, Listerine Advanced Defense Sensitive, Sensodyne Cool Mint); conventional mouth rinses (Colgate Plax, Elmex Caries Protection, Listerine Anticaries, Sensodyne Pronamel); a negative control (C-: distilled water); and Clinpro XT Varnish was the positive control (C+). Subsequently, the specimens were submitted to an erosive or abrasive challenge (performed separately) and to an erosive/abrasive cycling for five days (n=10 for each challenge). After treatment, challenges, and cycling, the specimens were analyzed in an environmental scanning electron microscope to verify the number of open dentin tubules (ODTs), counted by using Image J software (National Institutes of Health, Bethesda, MD, USA). Data were analyzed by the Kruskal-Wallis, Friedman and Dunn tests, with Bonferroni correction (α=0.05). Groups did not differ at baseline (p>0.05). At the post-treatment, erosion and abrasion stages, C+ was the only group that showed a reduction in ODTs compared to C-(p<0.05). In the other groups, numbers did not differ significantly from C- (p>0.05). After cycling, none of the groups exhibited significant reduction in ODTs other than C- (p>0.05); however, C+, Listerine Anticaries, and Colgate Plax had a lower number of ODTs than Listerine Sensitive and Sensodyne Pronamel. No mouth rinse was able to promote significant occlusion of the dentin tubules after treatment and the challenges. C+ was the only product that effectively promoted tubular occlusion, but this effect did not withstand several erosive and abrasive challenges.


Assuntos
Dessensibilizantes Dentinários , Benzoatos , Dentina , Dessensibilizantes Dentinários/farmacologia , Dessensibilizantes Dentinários/uso terapêutico , Diaminas , Ácido Edético , Fluoretos , Microscopia Eletrônica de Varredura , Antissépticos Bucais/farmacologia , Antissépticos Bucais/uso terapêutico , Dodecilsulfato de Sódio , Fluoreto de Sódio , Água
2.
Nat Astron ; 4: 228-233, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32500095

RESUMO

Titan has an active methane-based hydrologic cycle1 that has shaped a complex geologic landscape2, making its surface one of most geologically diverse in the solar system. Despite the different materials, temperatures, and gravity fields between Earth and Titan, many surface features are similar between the two worlds and can be interpreted as products of the same geologic processes3. However, Titan's thick and hazy atmosphere has hindered the identification of geologic features at visible wavelengths and the study of surface composition4. Here we identify and map the major geologic units on Titan's surface using radar and infrared data from the Cassini orbiter spacecraft. Correlations between datasets enabled us to produce a global map even where data sets were incomplete. The spatial and superposition relations between major geologic units reveals the likely temporal evolution of the landscape and gives insight into the interacting processes driving its evolution. We extract the relative dating of the various geological units by observing their spatial superposition in order to get information on the temporal evolution of the landscape. Dunes and lakes are relatively young, while hummocky/mountainous terrains are the oldest on Titan. Our results also show that Titan's surface is dominated by sedimentary/depositional processes with significant latitudinal variation, with dunes at the equator, plains at mid-latitudes and labyrinth terrains and lakes at the poles.

3.
Mar Pollut Bull ; 140: 30-34, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30803647

RESUMO

Polycyclic aromatic hydrocarbons (PAH) have been reported as acetylcholinesterase (AChE) inibitors, although in vitro studies on PAH effects on AChE activity are scarce and have only been performed using electric eel brain extracts. Thus, this study investigated PAH effects on brain AChE activity in a tropical fish species in Southeastern Brazil, mullet (Mugil liza). Mullet specimens were obtained from Guanabara Bay (N = 20), Rio de Janeiro, Brazil. Brain AChE was extracted and exposed to an environmentally relevant concentration of Pyrene, Chrysene, Phenanthrene, and Naphthalene, and PAH metabolites, 2-Naphthol and 1-OH-Pyrene. AChE activity inhibition was observed, although no difference was observed between high- and low- molecular weight PAH. 2-Naphthol was a less potent AChE inhibitor than Naphthalene, albeit non-significantly. Further studies are required, since only one PAH concentration was used herein. Mullet brain extracts seem to be adequate to assess possible neurotoxic PAH effects on fish AChE.


Assuntos
Encéfalo/enzimologia , Inibidores da Colinesterase/toxicidade , Exposição Ambiental/efeitos adversos , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Smegmamorpha/metabolismo , Acetilcolinesterase/metabolismo , Animais , Encéfalo/efeitos dos fármacos , Brasil , Ecotoxicologia/métodos , Proteínas de Peixes/antagonistas & inibidores , Proteínas de Peixes/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Clima Tropical , Poluentes Químicos da Água/metabolismo , Poluentes Químicos da Água/toxicidade
4.
Lasers Med Sci ; 34(3): 449-455, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30215185

RESUMO

To evaluate the effect of Er,Cr:YSGG laser, associated with fluoride application, on the prevention/control of dentin erosion. Dentin slabs were embedded in acrylic resin, flattened, and polished. Half of the specimens were previously eroded (10 min immersion in 1% citric acid solution) and half were kept sound. The specimens (n = 10 each substrate) were randomly allocated into the experimental groups, according to the following treatments: control (no treatment); APF gel (1.23% F, 1 min); Er,Cr:YSGG laser irradiation (P1: 0.25 W, 20 Hz, 2.8 J/cm2, tip S75, beam diameter of 750 µm, 1 mm away from the surface); Er,Cr:YSGG laser irradiation (P2: 0.50 W, 20 Hz, 5.7 J/cm2, tip S75, beam diameter of 750 µm, 1 mm away from the surface); APF gel + Er,Cr:YSGG laser P1 and; APF gel + Er,Cr:YSGG laser P2. Afterwards, the specimens underwent an erosion-remineralization cycling, consisting of a 5-min immersion into 0.3% citric acid, followed by 60-min exposure to artificial saliva. This procedure was repeated 4×/day, for 5 days. Surface loss (SL, in µm) was determined by optical profilometry. Specimens from each group were analyzed by environmental scanning electron microscopy (n = 3). Data were statistically analyzed (α = 0.05). For the eroded specimens, APF gel presented the lowest SL, being different from the control. For the sound specimens, none of the groups differed from the control, except for Er,Cr:YSGG laser P2, which presented the highest SL. When substrates were compared, only the eroded specimens of the control and APF + Er,Cr:YSGG laser P1 Groups showed higher SL. Selective structure removal was observed for the laser-treated groups. None of the Er,Cr:YSGG laser parameters were effective in the prevention/control dentin erosion. The laser was also unable to enhance the protection of fluoride against dentin erosion.


Assuntos
Fluoreto de Fosfato Acidulado/uso terapêutico , Dentina/efeitos dos fármacos , Progressão da Doença , Lasers de Estado Sólido/uso terapêutico , Erosão Dentária/tratamento farmacológico , Erosão Dentária/prevenção & controle , Animais , Bovinos , Dentina/ultraestrutura , Microscopia Eletrônica de Varredura
5.
Environ Monit Assess ; 190(9): 564, 2018 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-30167796

RESUMO

Tropical coastal lagoons are highly productive environments exhibiting high biodiversity. However, the use of these ecosystems by local communities is of concern, since this generally leads to environmental degradation. The Imboassica coastal lagoon, located in Macaé city, in Northern Rio de Janeiro, is an important ecosystem in the state, however, already displaying signs of anthropogenic impacts. Carnivorous fish Hoplias malabaricus specimens were sampled from this impacted site, as well as from a reference area. Fish from Imboassica Lagoon presented lower condition factor, lower cholinesterase activity, and higher percentage of erythrocyte micronuclei when compared to fish from the reference site. Metals in fish from Imboassica Lagoon were always higher than Encantada Lagoon, with some seasonal differences, where some metals were higher in the rainy season compared to the dry season in muscle tissue, with the exception of Cu, Fe, Sr, and Zn; and in the liver, except for Ba, Cd, Cr, Ni, and Sr. Cr and Mn in the edible muscle portion of the fish were higher than the limits established by Brazilian and International legislations as permissible for human consumption, thus leading to concerns regarding public health risks for the local population that use fish as their main protein source.


Assuntos
Ecossistema , Exposição Ambiental/efeitos adversos , Peixes/metabolismo , Metais Pesados/metabolismo , Alimentos Marinhos/análise , Água do Mar , Poluentes Químicos da Água/metabolismo , Animais , Biomarcadores/metabolismo , Brasil , Colinesterases/metabolismo , Exposição Ambiental/análise , Monitoramento Ambiental/métodos , Eritrócitos , Humanos , Fígado/metabolismo , Micronúcleos com Defeito Cromossômico , Músculos/metabolismo , Chuva , Estações do Ano , Clima Tropical
6.
PLoS One ; 11(9): e0163317, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27655611

RESUMO

Acetylcholinesterase (AChE) is an important enzyme in the control of the neuronal action potential and sensitive to organophosphate inhibition. Brain fish AChE is less sensitive to organophosphate inhibition than AChE from terrestrial animals, although this sensitivity is variable among species and has not yet been fully evaluated in fish species. In this setting, inhibition kinetic constants for progressive irreversible inhibition of brain acetylcholinesterase due to methyl-paraoxon exposure were determined in three fish species (Mugil liza, Genidens genidens and Lagocephalus laevigatus) and hen (Gallus domesticus). Enzyme extraction using a detergent was shown to be adequate, and samples presented activity inhibition in high substrate concentrations and suppression of inhibition by methyl-paraoxon in the presence of the substrate, similar to kinetic patterns from purified enzyme preparations. Catfish (G. genidens) AChE presented the highest sensitivity among the evaluated fish species (IC50 = 1031.20 nM ± 63.17) in comparison to M. liza and L. laevigatus (IC50: 2878.83 ± 421.94 and 2842.5 ± 144.63 nM respectively). The lower dissociation constant (Kd = 20.3 ± 2.95 µM) of catfish AChE showed greater enzyme affinity for methyl-paraoxon, explaining this species higher sensitivity to organophosphates. Hen AChE presented higher ki (900.57 ± 65.3 mM-1min-1) and, consequently, greater sensitivity to methyl-paraoxon, explained by a lower Kd (0.6 ± 0.13 µM). Furthermore, hen AChE did not differentiate between the propionylthiocholine and acetylthiocholine substrates, indicating easier access of methyl-paraoxon to the hen enzyme activity site. The results obtained herein indicate a suitable extraction of AChE and, despite different inhibition kinetic constants, demonstrate that fish AChE is less sensitive to methyl-paraoxon, probably due to reduced access to the catalytic center which provides greater enzyme substrate selectivity.

7.
Lett Appl Microbiol ; 63(3): 183-8, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27416521

RESUMO

UNLABELLED: Paranaguá Bay is one of the largest estuarine systems on the Southern Brazilian coast. The only recorded cholera outbreak in this region since the early 20th century occurred in 1999 and resulted in 467 cases and at least three reported deaths in a population of approx. 150 000 people. This short communication reports historical, unpublished data related to that outbreak. Water, zooplankton and bivalve samples were collected and evaluated using direct fluorescence assay to determine whether Vibrio cholerae serogroups O1 and O139 were present in the estuarine system at that time. Most of the water (83%) and zooplankton samples (75%) were positive for V. cholerae O1, while V. cholerae O139 was not detected. Shellfish (Mytella sp.) were also positive for V. cholerae O1. These results indicate that the estuary, including biological vectors such as copepods and bivalves, comprise an important reservoir of V. cholerae O1 and a probable waterborne pathway for the disease, in addition to contamination with untreated sewage. SIGNIFICANCE AND IMPACT OF THE STUDY: Despite most of the cholera cases that occurred in Brazil during the 7th pandemic were located in the northern areas of the country, a significant outbreak in Paranaguá, an estuary in the south coast, resulted in at least three deaths in 1999. We report here the detection of Vibrio cholerae O1 in water, zooplankton and bivalve samples during the outbreak, using direct fluorescence assay as an alternative method for the traditional plate culture employed at the time by the Brazilian Sanitary Agency. Results demonstrate that aquatic natural reservoirs comprise a potential route of transmission of cholera, in addition to untreated sewage and routine monitoring is recommended.


Assuntos
Bivalves/microbiologia , Cólera/epidemiologia , Copépodes/microbiologia , Esgotos/microbiologia , Vibrio cholerae O1/isolamento & purificação , Zooplâncton/microbiologia , Animais , Brasil , Cólera/microbiologia , Estuários , Humanos , Pandemias , Microbiologia da Água
8.
Braz. j. biol ; 76(2): 279-291, Apr.-June 2016. tab, graf
Artigo em Inglês | LILACS | ID: lil-781407

RESUMO

Abstract This study evaluated changes in the community of rotifers and microcrustaceans associated with the construction of a large and dendritic reservoir in Iguaçu River (Brazil), as the last reservoir of a sequence of five cascading systems. Differences were clear between pre-filling and post-filling phases for organisms and some of environmental variables. In the pre-filling phase, the community was more homogeneous along the downstream river gradient, and spatial compartmentalization in the new reservoir was common during the post-filling phase. From 140 identified taxa, 10 species occurred exclusively in the pre-filling phase and 32 in the post-filling phase. After completion of the fifth reservoir filling-up, opportunistic, pioneer and fast-developing species quickly dominated, and downstream of the fourth reservoir the pre-filling decreasing gradient of richness, diversity and evenness disappeared. Richness of rotifers and cladocerans, cladocerans diversity, and evenness of rotifers, cladocerans and copepods were generally higher in the post-filling phase. A non-metric multidimensional analysis based on a presence/absence matrix depicted a homogeneous and dense group of species associated to the pre-filling phase and a second, dispersed group related to the post-filling phase. Spearman correlations pointed out significant positive effects of transparency on rotifer species richness in the post-filling phase, and negative effects on the microcrustacean richness in the pre-filling phase. Dam construction caused disruption of the downstream lotic gradient along the series of dams, leading to the development of distinct species in lentic spatial compartments.


Resumo Esse estudo analisou os efeitos da construção de um reservatório largo e dendrítico no Brasil sobre a comunidade de rotíferos e microcrustáceos, sendo o último reservatório de uma cascata de cinco. Houve claras diferenças entre as fases pré e pós-enchimento para os organismos e para algumas variáveis ambientais. Na fase pré-enchimento, a comunidade foi mais homogênea no gradiente longitudinal no rio a jusante, e na fase pós-enchimento houve compartimentalização espacial no novo reservatório. Dos 140 táxons identificados, dez espécies ocorreram exclusivamente na fase pré-enchimento e 32 na fase pós-enchimento. Após o enchimento, espécies oportunistas, pioneiras e de rápido desenvolvimento foram dominantes, e desapareceu o gradiente de decréscimo a jusante do quarto reservatório para a riqueza, diversidade e equitabilidade durante a fase pré-enchimento. A riqueza de rotíferos e cladóceros, a diversidade de cladóceros, e a equitabilidade de rotíferos, cladóceros e copépodes foram elevadas na fase pós-enchimento. A análise de escalonamento multidimensional não-métrico sobre a matriz de presença e ausência mostrou um grupo homogêneo e denso de espécies e meses de amostragem na fase pré-enchimento, e outro grupo disperso na fase pós-enchimento. Correlações de Spearman apontaram efeitos significativos da transparência sobre a riqueza de rotíferos na fase pós-enchimento, e efeitos negativos sobre a riqueza de microcrustáceos na outra fase. Os efeitos da construção do reservatório causaram rompimento no gradiente lótico contínuo a jusante do quarto reservatório observado na fase pré-enchimento, permitindo o desenvolvimento de espécies em compartimentos espaciais lênticos.


Assuntos
Animais , Rotíferos/fisiologia , Zooplâncton/fisiologia , Rios , Estações do Ano , Brasil , Dinâmica Populacional , Densidade Demográfica , Aquicultura/métodos , Copépodes/fisiologia , Fenômenos Ecológicos e Ambientais , Hidrobiologia
9.
Braz J Biol ; 76(2): 279-91, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26983084

RESUMO

This study evaluated changes in the community of rotifers and microcrustaceans associated with the construction of a large and dendritic reservoir in Iguaçu River (Brazil), as the last reservoir of a sequence of five cascading systems. Differences were clear between pre-filling and post-filling phases for organisms and some of environmental variables. In the pre-filling phase, the community was more homogeneous along the downstream river gradient, and spatial compartmentalization in the new reservoir was common during the post-filling phase. From 140 identified taxa, 10 species occurred exclusively in the pre-filling phase and 32 in the post-filling phase. After completion of the fifth reservoir filling-up, opportunistic, pioneer and fast-developing species quickly dominated, and downstream of the fourth reservoir the pre-filling decreasing gradient of richness, diversity and evenness disappeared. Richness of rotifers and cladocerans, cladocerans diversity, and evenness of rotifers, cladocerans and copepods were generally higher in the post-filling phase. A non-metric multidimensional analysis based on a presence/absence matrix depicted a homogeneous and dense group of species associated to the pre-filling phase and a second, dispersed group related to the post-filling phase. Spearman correlations pointed out significant positive effects of transparency on rotifer species richness in the post-filling phase, and negative effects on the microcrustacean richness in the pre-filling phase. Dam construction caused disruption of the downstream lotic gradient along the series of dams, leading to the development of distinct species in lentic spatial compartments.


Assuntos
Copépodes/fisiologia , Rios , Rotíferos/fisiologia , Zooplâncton/fisiologia , Animais , Aquicultura/métodos , Brasil , Fenômenos Ecológicos e Ambientais , Hidrobiologia , Densidade Demográfica , Dinâmica Populacional , Estações do Ano
10.
Int Endod J ; 49(7): 700-5, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26174577

RESUMO

AIM: To evaluate the amount of apically extruded debris produced by ProTaper Universal (PTU), ProTaper Next (PTN), WaveOne (WO) and Reciproc (R) systems after large apical preparations. METHODOLOGY: Sixty mandibular premolars with a single canal were selected and randomly assigned into 4 groups (n = 15) according to the system used for root canal preparation: PTU, PTN, WO and R groups. Canal preparations were performed up to size 40 in each group. Distilled water was used as an irrigant, and the apically extruded debris from each tooth was collected in pre-weighted glass vials and dried. The average weight of debris was assessed using a microbalance, and the data were analysed statistically using one-way analysis of variance and the post hoc Tukey multiple comparison test (α = 0.05). RESULTS: The PTU system was associated with significantly more debris than the other systems (P < 0.05). No significant differences were found between PTN, WO and R systems (P > 0.05). CONCLUSIONS: All systems were associated with apical debris extrusion when canals were prepared to a large apical size. The PTU system was associated with more debris extrusion.


Assuntos
Preparo de Canal Radicular/instrumentação , Ápice Dentário/cirurgia , Dente Pré-Molar/cirurgia , Humanos , Preparo de Canal Radicular/métodos
11.
Eur J Cancer Care (Engl) ; 25(4): 668-74, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26087364

RESUMO

Oral mucositis is a painful condition that occurs in 80% of patients who undergo haematopoietic stem cell transplantation (HSCT). Our objective was to determine the impact of mucositis on quality of life (QoL) of patients subjected to HSCT treated with low-level laser therapy (LLLT). Patients were evaluated: (1) on the first day of treatment; (2) 5 days after autologous or 8 days after allogeneic transplantation; (3) once bone marrow had integrated; and (4) 30 days after discharge. Clinical evaluation was performed using the World Health Organization criteria; oral health QoL was measured using the Oral Health Impact Profile (OHIP-14); and mucositis symptoms with the Patient-Reported Oral Mucositis Symptom (PROMS) scale. The higher the score, the lower the patient's QoL. The OHIP-14 responses showed that at D + 5/D + 8, all domains had the highest scores, while at times 1 and 4, the scores were lower. In the PROMS scale, all domains scored worst at time 2, and the differences between the scores at the four times were statistically significant. The study has shown that QoL improves over time in patients undergoing LLLT therapy for mucositis prevention.


Assuntos
Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Terapia com Luz de Baixa Intensidade/métodos , Estomatite/radioterapia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Neoplasias Hematológicas/terapia , Hospitalização , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Saúde Bucal , Estudos Prospectivos , Qualidade de Vida , Adulto Jovem
12.
J Biomed Nanotechnol ; 10(12): 3647-57, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26000378

RESUMO

Main-stay in treatment of leishmaniasis relies on chemotherapy but none of the current drugs combines high activity and low toxicity at affordable costs. Dinitroanilines are a new class of drugs with proved in vitro antileishmanial activity. However the development of their pharmaceutical formulations has been compromised by low water solubility and low accumulation in diseased organs. These limitations can be overcome by incorporation in lipid-based nanoformulations such as liposomes and solid lipid nanoparticles. In previous work this strategy was already followed with the incorporation of a dinitroaniline, oryzalin, resulting in the improvement of the biodistribution profile. The present work aims at demonstrating the in vitro and in vivo therapeutic activity of these oryzalin nanoformulations, and establishing a systematic comparison of both systems. After oryzalin incorporation suitable physicochemical properties for parenteral administration were obtained. Nanoformulations revealed reduced cytotoxicity and haemolytic activity when compared with free-oryzalin, while retaining the in vitro intracellular activity. Therapeutic activity, assessed in a murine model of visceral leishmaniasis, was evaluated in terms of number of administrations, dose-response and influence of the lipid excipient. Results demonstrate the superiority of both oryzalin nanoformulations on the reduction of parasitic burden in liver and spleen as compared to the control group (84 to 91%) and similar to Glucantime. A strong reduction in ED50 values (3 to 65 fold) as compared to free-oryzalin was also obtained, depending on the organ and nanoformulation used. Both oryzalin nanoformulations are potential candidates as therapeutic agents against visceral leishmaniasis.


Assuntos
Dinitrobenzenos/administração & dosagem , Leishmania/efeitos dos fármacos , Leishmaniose/tratamento farmacológico , Leishmaniose/patologia , Lipídeos/química , Lipossomos/química , Nanocápsulas/química , Sulfanilamidas/administração & dosagem , Animais , Antiprotozoários/administração & dosagem , Antiprotozoários/química , Difusão , Dinitrobenzenos/química , Leishmania/citologia , Leishmania/fisiologia , Masculino , Teste de Materiais , Camundongos , Camundongos Endogâmicos BALB C , Nanocápsulas/administração & dosagem , Nanocápsulas/ultraestrutura , Sulfanilamidas/química , Resultado do Tratamento
13.
Science ; 331(6023): 1414-7, 2011 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-21415347

RESUMO

Although there is evidence that liquids have flowed on the surface at Titan's equator in the past, to date, liquids have only been confirmed on the surface at polar latitudes, and the vast expanses of dunes that dominate Titan's equatorial regions require a predominantly arid climate. We report the detection by Cassini's Imaging Science Subsystem of a large low-latitude cloud system early in Titan's northern spring and extensive surface changes (spanning more than 500,000 square kilometers) in the wake of this storm. The changes are most consistent with widespread methane rainfall reaching the surface, which suggests that the dry channels observed at Titan's low latitudes are carved by seasonal precipitation.


Assuntos
Metano , Saturno , Atmosfera , Meio Ambiente Extraterreno , Astronave
16.
Science ; 318(5848): 237-40, 2007 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-17932289

RESUMO

The New Horizons (NH) spacecraft observed Io's aurora in eclipse on four occasions during spring 2007. NH Alice ultraviolet spectroscopy and concurrent Hubble Space Telescope ultraviolet imaging in eclipse investigate the relative contribution of volcanoes to Io's atmosphere and its interaction with Jupiter's magnetosphere. Auroral brightness and morphology variations after eclipse ingress and egress reveal changes in the relative contribution of sublimation and volcanic sources to the atmosphere. Brightnesses viewed at different geometries are best explained by a dramatic difference between the dayside and nightside atmospheric density. Far-ultraviolet aurora morphology reveals the influence of plumes on Io's electrodynamic interaction with Jupiter's magnetosphere. Comparisons to detailed simulations of Io's aurora indicate that volcanoes supply 1 to 3% of the dayside atmosphere.

17.
Science ; 318(5848): 240-3, 2007 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-17932290

RESUMO

Jupiter's moon Io is known to host active volcanoes. In February and March 2007, the New Horizons spacecraft obtained a global snapshot of Io's volcanism. A 350-kilometer-high volcanic plume was seen to emanate from the Tvashtar volcano (62 degrees N, 122 degrees W), and its motion was observed. The plume's morphology and dynamics support nonballistic models of large Io plumes and also suggest that most visible plume particles condensed within the plume rather than being ejected from the source. In images taken in Jupiter eclipse, nonthermal visible-wavelength emission was seen from individual volcanoes near Io's sub-Jupiter and anti-Jupiter points. Near-infrared emission from the brightest volcanoes indicates minimum magma temperatures in the 1150- to 1335-kelvin range, consistent with basaltic composition.

18.
Science ; 311(5766): 1401-5, 2006 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-16527965

RESUMO

The Cassini spacecraft completed three close flybys of Saturn's enigmatic moon Enceladus between February and July 2005. On the third and closest flyby, on 14 July 2005, multiple Cassini instruments detected evidence for ongoing endogenic activity in a region centered on Enceladus' south pole. The polar region is the source of a plume of gas and dust, which probably emanates from prominent warm troughs seen on the surface. Cassini's Composite Infrared Spectrometer (CIRS) detected 3 to 7 gigawatts of thermal emission from the south polar troughs at temperatures up to 145 kelvin or higher, making Enceladus only the third known solid planetary body-after Earth and Io-that is sufficiently geologically active for its internal heat to be detected by remote sensing. If the plume is generated by the sublimation of water ice and if the sublimation source is visible to CIRS, then sublimation temperatures of at least 180 kelvin are required.


Assuntos
Saturno , Meio Ambiente Extraterreno , Astronave , Análise Espectral
19.
J Dairy Sci ; 88(9): 3211-9, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16107411

RESUMO

Phenotypic characteristics, antimicrobial susceptibility, and genetic relationships were analyzed in 107 Staphylococcus aureus isolates recovered from cows with subclinical mastitis in Southeastern Brazil. Thirteen different biochemical patterns were detected among isolates. A predominant pattern represented by about 54% of the isolates was distributed among several herds. Isolates of distinct phenotypic profiles were also detected within a herd. Susceptibility to ampicillin, cefotaxime, cephalotin, chloramphenicol, erythromycin, gentamycin, kanamycin, nitrofurantoin, norfloxacin, ofloxacin, oxacillin, penicillin, rifampin, sulfamethoxazole-trimethoprim, tetracycline, trimethoprim, and vancomycin, determined by the disk diffusion method, was observed in 44.9% of isolates. On the other hand, 55.1, 7.4, and 2.8% of the strains were resistant to ampicillin/penicillin, tetracycline, and erythromycin, respectively. Genetic diversity was analyzed by pulsed-field gel electrophoresis using SmaI as the restriction enzyme. All isolates could be typed by pulsed-field gel electrophoresis, which identified 16 types and 24 subtypes. Type A and its subtypes comprised 54.2% of all isolates and were recovered from 6 of the 9 herds analyzed. Other types and subtypes were also found in multiple herds. Although multiple types and subtypes were found within a specific herd, a predominant type was frequently observed.


Assuntos
Farmacorresistência Bacteriana , Mastite Bovina/microbiologia , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/metabolismo , Animais , Brasil , Bovinos , Eletroforese em Gel de Campo Pulsado , Feminino , Fermentação , Variação Genética , Genótipo , Mastite Bovina/tratamento farmacológico , Testes de Sensibilidade Microbiana , Leite/microbiologia , Fenótipo , Staphylococcus aureus/genética
20.
J Control Release ; 103(2): 419-34, 2005 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-15763624

RESUMO

The aim of this study was firstly to refine a rat model of arthritis, the adjuvant arthritis (AA) model, by studying the time course of the disease, introducing new evaluation methods such as haematological and biochemical parameters in order to identify the main stages of the disease. An optimisation of treatment schedule and evaluation criteria was developed. This refinement provided novel non-invasive anti-inflammatory treatment of the AA with SOD by using mixed lipid vesicles specially developed for transdermal delivery, Transfersomes (Tfs), this being the second major aim. The time course of AA includes a first stage: 1 day after the disease induction, the induced paw volume more than doubled and the paw circumference increased by approx. 50%. Two weeks later, another stage occurred where the disease shifted from the local arthritis form towards polyarthritis: an additional increase of volume and circumference of the induced and non-induced paws, occurred. The animals also started to loose weight around day 14 after the disease induction. Radiographic observable lesions increased correspondingly. Treatment of animals, started at day 1 after induction, by epicutaneous application of SOD-Tfs showed that 1 mg SOD/kg body weight is more efficient than 0.66 mg SOD /kg body weight. As a positive control, SOD liposomes intravenously injected were used for comparison and confirmed the biological efficiency of epicutaneously applied SOD in Tfs. SOD solution and empty Tfs epicutaneously applied exerted no effect. In addition, epicutaneous application of SOD-Tfs used prophylactically was able to suppress the induced rat paw oedema. Radiographic images showed less joint lesions in SOD-Tfs treated animals in comparison with control and placebo treated rats. It was shown for the first time that SOD incorporated into Tfs and applied onto a skin area not necessarily close to the inflamed tissue is able to promote non-invasive treatment of induced arthritis.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Artrite Experimental/tratamento farmacológico , Portadores de Fármacos/administração & dosagem , Superóxido Dismutase/uso terapêutico , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/química , Artrite Experimental/sangue , Artrite Experimental/diagnóstico por imagem , Ácido Ascórbico/sangue , Portadores de Fármacos/química , Extremidades/diagnóstico por imagem , Contagem de Leucócitos , Lipossomos , Masculino , Tamanho da Partícula , Radiografia , Ratos , Ratos Wistar , Compostos de Sulfidrila/sangue , Superóxido Dismutase/administração & dosagem , Superóxido Dismutase/química , Resultado do Tratamento
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