Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 285
Filtrar
Mais filtros

Eixos temáticos
Tipo de documento
Intervalo de ano de publicação
1.
Nature ; 612(7939): 228-231, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36477127

RESUMO

Gamma-ray bursts (GRBs) are flashes of high-energy radiation arising from energetic cosmic explosions. Bursts of long (greater than two seconds) duration are produced by the core-collapse of massive stars1, and those of short (less than two seconds) duration by the merger of compact objects, such as two neutron stars2. A third class of events with hybrid high-energy properties was identified3, but never conclusively linked to a stellar progenitor. The lack of bright supernovae rules out typical core-collapse explosions4-6, but their distance scales prevent sensitive searches for direct signatures of a progenitor system. Only tentative evidence for a kilonova has been presented7,8. Here we report observations of the exceptionally bright GRB 211211A, which classify it as a hybrid event and constrain its distance scale to only 346 megaparsecs. Our measurements indicate that its lower-energy (from ultraviolet to near-infrared) counterpart is powered by a luminous (approximately 1042 erg per second) kilonova possibly formed in the ejecta of a compact object merger.


Assuntos
Astros Celestes
2.
Nature ; 600(7890): 621-624, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34937892

RESUMO

Magnetars are strongly magnetized, isolated neutron stars1-3 with magnetic fields up to around 1015 gauss, luminosities of approximately 1031-1036 ergs per second and rotation periods of about 0.3-12.0 s. Very energetic giant flares from galactic magnetars (peak luminosities of 1044-1047 ergs per second, lasting approximately 0.1 s) have been detected in hard X-rays and soft γ-rays4, and only one has been detected from outside our galaxy5. During such giant flares, quasi-periodic oscillations (QPOs) with low (less than 150 hertz) and high (greater than 500 hertz) frequencies have been observed6-9, but their statistical significance has been questioned10. High-frequency QPOs have been seen only during the tail phase of the flare9. Here we report the observation of two broad QPOs at approximately 2,132 hertz and 4,250 hertz in the main peak of a giant γ-ray flare11 in the direction of the NGC 253 galaxy12-17, disappearing after 3.5 milliseconds. The flare was detected on 15 April 2020 by the Atmosphere-Space Interactions Monitor instrument18,19 aboard the International Space Station, which was the only instrument that recorded the main burst phase (0.8-3.2 milliseconds) in the full energy range (50 × 103 to 40 × 106 electronvolts) without suffering from saturation effects such as deadtime and pile-up. Along with sudden spectral variations, these extremely high-frequency oscillations in the burst peak are a crucial component that will aid our understanding of magnetar giant flares.


Assuntos
Astros Celestes , Atmosfera
3.
Actas Dermosifiliogr ; 115(6): 572-582, 2024 Jun.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-38395223

RESUMO

Allergic contact dermatitis induced by the use of ophthalmic topical drugs is one of the most common causes of eyelid dermatitis. The introduction of new formulations, both of active ingredients and excipients, and the lack of marketing in some of them, makes patch testing in patients whose source of contact are topical ophthalmic drugs truly challenging. Across this manuscript, most, if not all, topical ophthalmic drugs used in our national health system have been collected, including information on the allergens available, and the concentration and vehicle advised for those that still remain unavailable.


Assuntos
Alérgenos , Dermatite Alérgica de Contato , Soluções Oftálmicas , Dermatite Alérgica de Contato/etiologia , Humanos , Espanha , Alérgenos/efeitos adversos , Soluções Oftálmicas/efeitos adversos , Testes do Emplastro
4.
Postgrad Med J ; 99(1173): 669-678, 2023 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-37389581

RESUMO

Paraneoplastic neurological syndromes (PNSs) comprise a subset of immune-mediated nervous system diseases triggered by an underlying malignancy. Each syndrome usually shows a distinct clinical presentation and outcome according to the associated neural antibodies. PNSs generally have a subacute onset with rapid progression and severe neurological disability. However, some patients may have hyperacute onset or even show chronic progression mimicking neurodegenerative diseases. Updated diagnostic criteria for PNS have been recently established in order to increase diagnostic specificity and to encourage standardisation of research initiatives related to PNS. Treatment for PNS includes oncological therapy and immunomodulation to halt neurological deterioration although current treatment options are seldom effective in reversing disability. Nevertheless, growing knowledge and better understanding of PNS pathogenesis promise better recognition, earlier diagnosis and novel treatment strategies. Considering that PNSs provide a model of effective anticancer immunity, the impact of these studies will extend far beyond the field of neurology.


Assuntos
Encefalite , Neurologia , Humanos , Encefalite/diagnóstico , Encefalite/terapia
5.
Postgrad Med J ; 2023 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-37036000

RESUMO

Paraneoplastic neurological syndromes (PNSs) comprise a subset of immune-mediated nervous system diseases triggered by an underlying malignancy. Each syndrome usually shows a distinct clinical presentation and outcome according to the associated neural antibodies. PNSs generally have a subacute onset with rapid progression and severe neurological disability. However, some patients may have hyperacute onset or even show chronic progression mimicking neurodegenerative diseases. Updated diagnostic criteria for PNS have been recently established in order to increase diagnostic specificity and to encourage standardisation of research initiatives related to PNS. Treatment for PNS includes oncological therapy and immunomodulation to halt neurological deterioration although current treatment options are seldom effective in reversing disability. Nevertheless, growing knowledge and better understanding of PNS pathogenesis promise better recognition, earlier diagnosis and novel treatment strategies. Considering that PNSs provide a model of effective anticancer immunity, the impact of these studies will extend far beyond the field of neurology.

6.
J Dairy Sci ; 104(6): 7122-7134, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33773786

RESUMO

In natural settings, dairy cows separate from the herd to give birth. When kept indoors, seeking isolation before calving may be restricted and may depend on space and resources provided in maternity housing. The effect of group maternity pens on behavior around calving and labor progress is unknown. Therefore, the objective of this study was to determine the effects of stocking density and provision of a blind in group bedded pack maternity pens on lying and social behavior as well as length of labor of preparturient dairy animals. The study was conducted as a complete randomized block design with a 2 × 2 factorial arrangement of treatments including stocking density and presence or absence of a blind, resulting in a total of 4 treatments: (1) high stocking density (7.7-12.9 m2 lying space/cow) with a blind, (2) low stocking density (15.4-25.8 m2) with a blind, (3) high stocking density without a blind, and (4) low stocking density without a blind. A total of 127 primiparous heifers and 247 multiparous cows were housed in mixed-parity groups from approximately 3 wk before and immediately after calving. During the 4 h before calving, lying behavior (lying time and bouts) was collected automatically using accelerometers, and social behavior (agonistic interactions, allogrooming, and attention from other cows), stage II labor duration, and frequency of position change during stage II labor were collected using video. Lying behavior was collected with accelerometers. Regardless of treatment, lying time and bouts increased as calving approached. Cows and heifers performed more lying bouts in low stocking density pens compared with high stocking density pens. Agonistic interactions and allogrooming were not different between treatments. Other cows spent more time paying attention to focal animals regardless of stocking density as calving approached, but time spent paying attention was reduced by the presence of a blind during h -2 before calving. The hazard of calving unassisted was greater for cows and heifers in low stocking density pens with a blind compared with all other treatments. Further, animals in pens with a blind tended to change positions fewer times during stage II labor. These results suggest that providing a blind in group maternity pens may improve the calving environment for cows and heifers and, in combination with low stocking density, may reduce the amount of time spent in labor.


Assuntos
Comportamento Animal , Trabalho de Parto , Animais , Bovinos , Feminino , Abrigo para Animais , Lactação , Paridade , Parto , Gravidez , Comportamento Social
7.
J Helminthol ; 94: e89, 2019 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-31544721

RESUMO

The relationship between epilepsy and the presence of visceral larva migrans caused by Toxocara canis in Mexican children remains uncertain; however, this relationship needs to be elucidated because these parasite larvae can invade the human central nervous system. Accordingly, this study aimed to determine the frequency and specificity of anti-T. canis antibodies in the sera of children with epilepsy to determine the relationship between this parasite and epilepsy. The sera samples of 214 children were examined: 111 children diagnosed with epilepsy and 103 clinically healthy children without neurological disorders. In the sera of each group, the presence and specificity of anti-T. canis and anti-Ascaris lumbricoides antibodies, as well as the cross-reactivity between them, were assessed using enzyme-linked immunosorbent assay and Western blotting analysis. Among the children with epilepsy, 25.2% exhibited seropositivity to T. canis. Cross-reactivity against the A. lumbricoides antigen was present in 46.8% of the children with epilepsy, whereas 11.7% of the children with epilepsy and anti-T. canis antibodies did not exhibit cross-reactivity against this antigen. The Western blotting analysis of the sera from the children with epilepsy demonstrated the presence of T. canis proteins, with molecular weights of 24, 35, 55, 70, 120 and 210 kDa, and A lumbricoides proteins with molecular weights of 70, 80 and 110 kDa. Our results revealed the presence of anti-T. canis antibodies in the children with epilepsy; furthermore, cross-reactivity tests with A. lumbricoides showed the importance of the presence of anti-T. canis antibodies in revealing the relationship between this parasite and epilepsy in children.


Assuntos
Anticorpos Anti-Helmínticos/sangue , Epilepsia/parasitologia , Larva Migrans Visceral/imunologia , Adolescente , Animais , Antígenos de Helmintos/sangue , Antígenos de Helmintos/imunologia , Western Blotting , Estudos de Casos e Controles , Criança , Pré-Escolar , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática , Epilepsia/imunologia , Feminino , Humanos , Lactente , Larva , Larva Migrans Visceral/complicações , Masculino , México , Toxocara canis
10.
Bull Environ Contam Toxicol ; 100(4): 593-599, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29445848

RESUMO

Ammonia levels were evaluated in the urban environment of Madrid City, Spain. A total of 110 samplers were distributed throughout the city. Vehicle traffic density, garbage containers and sewers were identified as local emission sources of ammonia. The average ammonia concentrations were 4.66 ± 2.14 µg/m3 (0.39-11.23 µg/m3 range) in the winter and 5.30 ± 1.81 µg/m3 (2.33-11.08 µg/m3 range) in the summer. Spatial and seasonal variations of ammonia levels were evaluated. Hotspots were located in the south and center of Madrid City in both winter and summer seasons, with lower ammonia concentrations located in the north (winter) and in the west and east (summer). The number of representative points that were needed to establish a reliable air quality monitoring network for ammonia was determined using a combined clustering and kriging approach. The results indicated that 40 samplers were sufficient to provide a reliable estimate for Madrid City.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar , Amônia/análise , Monitoramento Ambiental/métodos , Cidades , Estações do Ano , Espanha
13.
Vox Sang ; 110(2): 193-5, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26509738

RESUMO

Malaria is a vectorborne disease caused by protozoan of the genus Plasmodium, which can also be transmitted by the transfusion of infected red blood cells. One year after return from a travel to Honduras, a Spanish traveller developed vivax malaria. Prior to the onset of symptoms, the donor made a donation that tested non-reactive using an immunological test for malaria. Samples from the donor taken before donation and tested by serological and molecular methods were negative but positive at the time of hospital admission. The possible sources of the donors' infection, imported versus locally acquired, are discussed.


Assuntos
Doadores de Sangue , Malária Vivax/sangue , Adulto , Humanos , Malária Vivax/epidemiologia , Malária Vivax/etiologia , Espanha
14.
Genet Mol Res ; 15(1)2016 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-27051035

RESUMO

The objective of the present study was to investigate single nucleotide polymorphisms (SNPs) located in three candidate genes previously reported to have effects on fertility and milk production traits in a population of 123 Holstein cows. The milk production traits evaluated included lifetime averages of milk yield, protein concentration, and fat concentration. Fertility traits evaluated included lifetime averages of services per conception and days-open. Candidate genes included those encoding diacylglycerol acyltransferase (DGAT1), leptin receptor (LEPR), and calpastatin (CAST). A total of 60 SNPs were selected (20 per gene) at equidistant locations on each candidate gene to identify potential linkage with causative mutations. Four SNPs were identified as being significantly associated with the evaluated fertility traits. Specifically, SNPs rs109663724 and rs137673193 were significantly associated with lifetime average days-open, while rs109663724 and rs135560721 were significantly associated with lifetime average number of services per conception. Five SNP (rs109663724, rs132699547, rs135423283, rs135576599, and rs13675432) were significantly associated with lifetime averages of milk protein concentration and milk fat concentration, with only one SNP (rs109663724) being significantly associated with the average lifetime milk yield. Although multiple SNPs were identified in the current study as being significantly associated with milk production and fertility traits, it is essential that these SNPs are validated in larger populations, under more diverse environments, and that additional SNPs and candidate genes are evaluated prior to their implementation into selection strategies.


Assuntos
Proteínas de Ligação ao Cálcio/genética , Bovinos/genética , Diacilglicerol O-Aciltransferase/genética , Fertilidade/genética , Lactação/genética , Polimorfismo de Nucleotídeo Único , Receptores para Leptina/genética , Animais , Bovinos/fisiologia , Feminino , Característica Quantitativa Herdável
15.
Genet Mol Res ; 15(4)2016 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-27808386

RESUMO

The objective of the present study was to evaluate single nucleotide polymorphisms (SNPs) located in two quantitative trait locus (QTL) regions (BTA 6 and BTA 20) that are associated with bovine respiratory disease (BRD). A population of 323 crossbred steers sired by five purebred sire breeds during 2010-2013 (Angus, Braford, Braunvieh, Charolais, and Simmental) were evaluated for BRD susceptibility during the finishing process at a commercial feedlot. A total of 21 animals representing all sire breeds were affected with BRD at some time during the finishing process over the 4-year period. Although multiple sire breeds were evaluated in the present study, no sire breed effects were detected. A total of 82 SNPs were evaluated (58 on BTA 6 and 24 on BTA 20) in the present study for potential associations with BRD incidence. When evaluating the previously described QTL regions on BTA 6, three SNPs (rs42968895, rs42823614, and rs43448463) were significantly (P < 0.05) associated with BRD incidence. Another three SNPs (rs42477340, rs42512588, and rs42524468) were identified as significantly associated with BRD on the previously described BTA 6 QTL region. For both of these regions, animals inheriting different genotypes differed in BRD incidence during the finishing period. Although multiple SNPs were identified as being significantly associated with BRD incidence in the present study, these SNP associations should be validated in larger and more diverse populations.


Assuntos
Complexo Respiratório Bovino/genética , Doenças dos Bovinos/genética , Animais , Bovinos , Genótipo , Hibridização Genética , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas
16.
Genet Mol Res ; 15(2)2016 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-27420951

RESUMO

Brahman cattle are important in tropical regions due to their ability to tolerate excessive heat and parasites. However, Brahman cattle exhibit lower carcass quality characteristics when compared to Bos taurus breeds. The objective of this study was to evaluate potential associations between single nucleotide polymorphisms (SNPs) in six candidate genes for carcass quality and composition traits in a population of Brahman and Brahman-influenced steers. Steers were evaluated through the American Brahman Breeders Association carcass evaluation project in Gonzales, Texas. Carcass traits measured included hot carcass weight, ribeye area, marbling score, yield grade, quality grade, dressing percent, and Warner-Bratzler shear force score. Six previously described candidate genes were chosen for SNP analysis based on their previous association with growth and carcass traits. Candidate genes utilized in the current study included calpastatin (CAST), calpain (CAPN3), thyroglobulin (TG), growth hormone, insulin growth factor 1, and adiponectin. Six unique SNPs from three candidate genes (TG, CAST, and CAPN3) were significantly associated (P < 0.001) with carcass quality traits (marbling score and quality grade). A genotypic effect was observed for all significant SNPs, with differing levels of performance observed for animals inheriting different genotypes. Although multiple SNPs in the current study were significantly (P < 0.001) associated with growth and carcass traits, they should be validated in larger populations prior to implementation in selection strategies.


Assuntos
Bovinos/genética , Carne/normas , Polimorfismo de Nucleotídeo Único , Característica Quantitativa Herdável , Adiponectina/genética , Animais , Proteínas de Ligação ao Cálcio/genética , Calpaína/genética , Bovinos/crescimento & desenvolvimento , Genótipo , Hormônio do Crescimento/genética , Fator de Crescimento Insulin-Like I/genética , Masculino , Tireoglobulina/genética
17.
Med Intensiva ; 40(7): 395-402, 2016 Oct.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-27068001

RESUMO

OBJECTIVES: To validate Trauma and Injury Severity Score (TRISS) methodology as an auditing tool in the Spanish ICU Trauma Registry (RETRAUCI). DESIGN: A prospective, multicenter registry evaluation was carried out. SETTING: Thirteen Spanish Intensive Care Units (ICUs). PATIENTS: Individuals with traumatic disease and available data admitted to the participating ICUs. INTERVENTIONS: Predicted mortality using TRISS methodology was compared with that observed in the pilot phase of the RETRAUCI from November 2012 to January 2015. Discrimination was evaluated using receiver operating characteristic (ROC) curves and the corresponding areas under the curves (AUCs) (95% CI), with calibration using the Hosmer-Lemeshow (HL) goodness-of-fit test. A value of p<0.05 was considered significant. MAIN VARIABLES OF INTEREST: Predicted and observed mortality. RESULTS: A total of 1405 patients were analyzed. The observed mortality rate was 18% (253 patients), while the predicted mortality rate was 16.9%. The area under the ROC curve was 0.889 (95% CI: 0.867-0.911). Patients with blunt trauma (n=1305) had an area under the ROC curve of 0.887 (95% CI: 0.864-0.910), and those with penetrating trauma (n=100) presented an area under the curve of 0.919 (95% CI: 0.859-0.979). In the global sample, the HL test yielded a value of 25.38 (p=0.001): 27.35 (p<0.0001) in blunt trauma and 5.91 (p=0.658) in penetrating trauma. TRISS methodology underestimated mortality in patients with low predicted mortality and overestimated mortality in patients with high predicted mortality. CONCLUSIONS: TRISS methodology in the evaluation of severe trauma in Spanish ICUs showed good discrimination, with inadequate calibration - particularly in blunt trauma.


Assuntos
Mortalidade Hospitalar , Índices de Gravidade do Trauma , Humanos , Unidades de Terapia Intensiva , Valor Preditivo dos Testes , Estudos Prospectivos , Curva ROC , Sistema de Registros , Espanha
18.
Med Intensiva ; 40(6): 327-47, 2016.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-26440993

RESUMO

OBJECTIVE: To describe the characteristics and management of severe trauma disease in Spanish Intensive Care Units (ICUs). Registry of trauma in the ICU (RETRAUCI). Pilot phase. DESIGN: A prospective, multicenter registry. SETTING: Thirteen Spanish ICUs. PATIENTS: Patients with trauma disease admitted to the ICU. INTERVENTIONS: None. MAIN VARIABLES OF INTEREST: Epidemiology, out-of-hospital attention, registry of injuries, resources utilization, complications and outcome were evaluated. RESULTS: Patients, n=2242. Mean age 47.1±19.02 years. Males 79%. Blunt trauma 93.9%. Injury Severity Score 22.2±12.1, Revised Trauma Score 6.7±1.6. Non-intentional in 84.4% of the cases. The most common causes of trauma were traffic accidents followed by pedestrian and high-energy falls. Up to 12.4% were taking antiplatelet medication or anticoagulants. Almost 28% had a suspected or confirmed toxic influence in trauma. Up to 31.5% required an out-of-hospital artificial airway. The time from trauma to ICU admission was 4.7±5.3hours. At ICU admission, 68.5% were hemodynamically stable. Brain and chest injuries predominated. A large number of complications were documented. Mechanical ventilation was used in 69.5% of the patients (mean 8.2±9.9 days), of which 24.9% finally required a tracheostomy. The median duration of stay in the ICU and in hospital was 5 (range 3-13) and 9 (5-19) days, respectively. The ICU mortality rate was 12.3%, while the in-hospital mortality rate was 16.0%. CONCLUSIONS: The pilot phase of the RETRAUCI offers a first impression of the epidemiology and management of trauma disease in Spanish ICUs.


Assuntos
Mortalidade Hospitalar , Unidades de Terapia Intensiva , Ferimentos e Lesões/epidemiologia , Adulto , Idoso , Feminino , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sistema de Registros , Espanha
19.
Nature ; 459(7246): 540-2, 2009 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-19478778

RESUMO

Since the 1995 discovery of the broad iron K-line emission from the Seyfert galaxy MCG-6-30-15 (ref. 1), broad iron K lines have been found in emission from several other Seyfert galaxies, from accreting stellar-mass black holes and even from accreting neutron stars. The iron K line is prominent in the reflection spectrum created by the hard-X-ray continuum irradiating dense accreting matter. Relativistic distortion of the line makes it sensitive to the strong gravity and spin of the black hole. The accompanying iron L-line emission should be detectable when the iron abundance is high. Here we report the presence of both iron K and iron L emission in the spectrum of the narrow-line Seyfert 1 galaxy 1H 0707-495. The bright iron L emission has enabled us to detect a reverberation lag of about 30 s between the direct X-ray continuum and its reflection from matter falling into the black hole. The observed reverberation timescale is comparable to the light-crossing time of the innermost radii around a supermassive black hole. The combination of spectral and timing data on 1H 0707-495 provides strong evidence that we are witnessing emission from matter within a gravitational radius, or a fraction of a light minute, from the event horizon of a rapidly spinning, massive black hole.


Assuntos
Meio Ambiente Extraterreno/química , Ferro/análise , Ferro/química
20.
J Vet Pharmacol Ther ; 38(3): 265-70, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25269447

RESUMO

The purpose of this study was to compare the pharmacokinetics of meloxicam in mature swine after intravenous (i.v.) and oral (p.o.) administration. Six mature sows (mean bodyweight ± standard deviation = 217.3 ± 65.68 kg) were administered an i.v. or p.o. dose of meloxicam at a target dose of 0.5 mg/kg in a cross-over design. Plasma samples collected up to 48 h postadministration were analyzed by high-pressure liquid chromatography and mass spectrometry (HPLC-MS) followed by noncompartmental pharmacokinetic analysis. Mean peak plasma concentration (CMAX ) after p.o. administration was 1070 ng/mL (645-1749 ng/mL). TMAX was recorded at 2.40 h (0.50-12.00 h) after p.o. administration. Half-life (T½ λz ) for i.v. and p.o. administration was 6.15 h (4.39-7.79 h) and 6.83 h (5.18-9.63 h), respectively. The bioavailability (F) for p.o. administration was 87% (39-351%). The results of this study suggest that meloxicam is well absorbed after oral administration.


Assuntos
Anti-Inflamatórios não Esteroides/farmacocinética , Suínos/metabolismo , Tiazinas/farmacocinética , Tiazóis/farmacocinética , Administração Oral , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/sangue , Cromatografia Líquida de Alta Pressão/veterinária , Estudos Cross-Over , Feminino , Injeções Intravenosas/veterinária , Espectrometria de Massas/veterinária , Meloxicam , Tiazinas/administração & dosagem , Tiazinas/sangue , Tiazóis/administração & dosagem , Tiazóis/sangue
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa