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1.
Phys Rev Lett ; 131(17): 171001, 2023 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-37955508

RESUMEN

Pulsar Timing Array experiments probe the presence of possible scalar or pseudoscalar ultralight dark matter particles through decade-long timing of an ensemble of galactic millisecond radio pulsars. With the second data release of the European Pulsar Timing Array, we focus on the most robust scenario, in which dark matter interacts only gravitationally with ordinary baryonic matter. Our results show that ultralight particles with masses 10^{-24.0} eV≲m≲10^{-23.3} eV cannot constitute 100% of the measured local dark matter density, but can have at most local density ρ≲0.3 GeV/cm^{3}.

2.
Nature ; 530(7591): 453-6, 2016 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-26911781

RESUMEN

In recent years, millisecond-duration radio signals originating in distant galaxies appear to have been discovered in the so-called fast radio bursts. These signals are dispersed according to a precise physical law and this dispersion is a key observable quantity, which, in tandem with a redshift measurement, can be used for fundamental physical investigations. Every fast radio burst has a dispersion measurement, but none before now have had a redshift measurement, because of the difficulty in pinpointing their celestial coordinates. Here we report the discovery of a fast radio burst and the identification of a fading radio transient lasting ~6 days after the event, which we use to identify the host galaxy; we measure the galaxy's redshift to be z = 0.492 ± 0.008. The dispersion measure and redshift, in combination, provide a direct measurement of the cosmic density of ionized baryons in the intergalactic medium of ΩIGM = 4.9 ± 1.3 per cent, in agreement with the expectation from the Wilkinson Microwave Anisotropy Probe, and including all of the so-called 'missing baryons'. The ~6-day radio transient is largely consistent with the radio afterglow of a short γ-ray burst, and its existence and timescale do not support progenitor models such as giant pulses from pulsars, and supernovae. This contrasts with the interpretation of another recently discovered fast radio burst, suggesting that there are at least two classes of bursts.

3.
Nature ; 501(7467): 391-4, 2013 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-23945588

RESUMEN

Earth's nearest candidate supermassive black hole lies at the centre of the Milky Way. Its electromagnetic emission is thought to be powered by radiatively inefficient accretion of gas from its environment, which is a standard mode of energy supply for most galactic nuclei. X-ray measurements have already resolved a tenuous hot gas component from which the black hole can be fed. The magnetization of the gas, however, which is a crucial parameter determining the structure of the accretion flow, remains unknown. Strong magnetic fields can influence the dynamics of accretion, remove angular momentum from the infalling gas, expel matter through relativistic jets and lead to synchrotron emission such as that previously observed. Here we report multi-frequency radio measurements of a newly discovered pulsar close to the Galactic Centre and show that the pulsar's unusually large Faraday rotation (the rotation of the plane of polarization of the emission in the presence of an external magnetic field) indicates that there is a dynamically important magnetic field near the black hole. If this field is accreted down to the event horizon it provides enough magnetic flux to explain the observed emission--from radio to X-ray wavelengths--from the black hole.

6.
Air Med J ; 38(3): 150-153, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31122577

RESUMEN

OBJECTIVE: The aim of this study was to quantify the effect of helicopter hot loading on the time to percutaneous intervention (time-to-PCI) in patients with ST-segment elevation myocardial infarction (STEMI) undergoing interhospital transfer. METHODS: We performed a retrospective cohort study using data from 2009 to 2014, looking at all patients who had an STEMI, were transferred from a single non-PCI hospital by helicopter emergency medical services, and who received PCI intervention at the PCI-capable hospital. Differences in loading method, flight details, and patient demographics were analyzed to measure the effectiveness of the intervention. RESULTS: During the 5-year study period, 134 STEMI patients were transferred. Sixty-four were hot loaded (47.7%), and 70 were cold loaded. Patients who were hot loaded had a median reduction in interhospital transfer and time-to-PCI of 22.3 minutes from 91.0 minutes (interquartile range, 65-117 minutes) by cold load to 69.5 minutes (interquartile range, 47.5-91.5 minutes) by hot load. There was no increase in reported safety-related events during the hot load process. The median length of hospital stay was equivalent for both groups at 3 days. CONCLUSIONS: This protocol of helicopter hot loading STEMI patients presenting to a non-PCI hospital significantly reduced the median time of interhospital transfer and time-to-PCI without an increase in reported safety events.


Asunto(s)
Ambulancias Aéreas , Transferencia de Pacientes/métodos , Infarto del Miocardio con Elevación del ST/terapia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Transferencia de Pacientes/estadística & datos numéricos , Estudios Retrospectivos , Factores de Tiempo
7.
Philos Trans A Math Phys Eng Sci ; 376(2120)2018 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-29661980

RESUMEN

Pulsars are highly magnetized and rapidly rotating neutron stars. As they spin, the lighthouse-like beam of radio emission from their magnetic poles sweeps across the Earth with a regularity approaching that of the most precise clocks known. This precision combined with the extreme environments in which they are found, often in compact orbits with other neutron stars and white dwarfs, makes them excellent tools for studying gravity. Present and near-future pulsar surveys, especially those using the new generation of telescopes, will find more extreme binary systems and pulsars that are more precise 'clocks'. These telescopes will also greatly improve the precision to which we can measure the arrival times of the pulses. The Square Kilometre Array will revolutionize pulsar searches and timing precision. The increased number of sources will reveal rare sources, including possibly a pulsar-black hole binary, which can provide the most stringent tests of strong-field gravity. The improved timing precision will reveal new phenomena and also allow us to make a detection of gravitational waves in the nanohertz frequency regime. It is here where we expect to see the signature of the binary black holes that are formed as galaxies merge throughout cosmological history.This article is part of a discussion meeting issue 'The promises of gravitational-wave astronomy'.

8.
11.
Ir Med J ; 111(10): 839, 2018 12 06.
Artículo en Inglés | MEDLINE | ID: mdl-30560635

RESUMEN

Introduction Drain usage is commonplace in head and neck surgery. There is an increasing body of literature disputing their routine placement in certain procedures. The aim of this study is to explore modern-day practice in terms of drain usage and the use of haemostatic agents. Methods A simple questionnaire was devised and sent to 35 ENT Surgeons across 10 units nationally. Results There was an overall response rate of 77.1% (n=27). There was considerable heterogeneity amongst surgeons in terms of indication for insertion, how the decision is made to remove the drain and if any alternative/adjunctive haemostatic agents are being used. Discussion The management of drains is poorly defined and guidelines are lacking. With increased pressure on resources, the risk of infection and discomfort to the patient, further reflection is required to evaluate if careful patient selection rather than habitual drain insertion in every case is more appropriate.


Asunto(s)
Drenaje/estadística & datos numéricos , Cabeza/cirugía , Cuello/cirugía , Utilización de Procedimientos y Técnicas/estadística & datos numéricos , Cirujanos/estadística & datos numéricos , Biopsia , Branquioma/cirugía , Hemostáticos , Irlanda/epidemiología , Ganglios Linfáticos/cirugía , Disección del Cuello , Paratiroidectomía , Glándulas Salivales/cirugía , Encuestas y Cuestionarios , Quiste Tirogloso/cirugía , Tiroidectomía
12.
Ir Med J ; 109(6): 427, 2016 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-27814444

RESUMEN

Epistaxis represents the most common ENT emergency and its management has been a focus of audit recently, with consideration given to the associated economic burden. The aim of our study is to evaluate the management of epistaxis in terms of treatments used, duration of stay, recurrence and cost. A retrospective review of hospital inpatient enquiry (HIPE) data from a single secondary referral centre was undertaken during a four year period. Four hundrefd and thirty-four patients were identified. The majority (n= 262, 60.3%) were male and the average age was 64.2 years. The vast majority (n=362, 83.4%) were managed non-operatively. Only 15 patients (3.4%) were managed surgically. The average length of stay was 2.5 days and did not vary greatly between the treatment groups. The recurrence rate was 8.2% (n=36). Approximate costs of packing vs EUA and cautery suggest that packing alone is more economical but more data is needed to fully compare the options.


Asunto(s)
Epistaxis/terapia , Cauterización/economía , Embolización Terapéutica/economía , Embolización Terapéutica/métodos , Epistaxis/economía , Femenino , Humanos , Tiempo de Internación/estadística & datos numéricos , Masculino , Recurrencia , Estudios Retrospectivos , Factores de Tiempo
13.
Ir Med J ; 108(5): 147-9, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-26062242

RESUMEN

Infants born to women with hepatitis B virus (HBV) are at risk of vertical transmission. This risk is significantly reduced with correct post-natal treatment After initial perinatal management and neonatal treatment, these infants receive subsequent follow up HBV immunisations at two, four and six months. These infants then require post vaccination serological testing. This review was conducted to determine the number of infants born to mothers with HBV in the National Maternity Hospital who had appropriate post vaccination serological testing. There were seventy-eight HBV infections identified antenatally in the years 2010 and 2011 resulting in seventy live born infants at our institution. Thirteen (18.6%) infants had evidence of post vaccination serological testing. This is below international rates of follow up. There is an urgent need for a centralised national programme to ensure adequate follow up and management of all infants born to women with HBV in Ireland.


Asunto(s)
Anticuerpos contra la Hepatitis B/sangre , Antígenos de Superficie de la Hepatitis B/sangre , Vacunas contra Hepatitis B/administración & dosificación , Hepatitis B , Transmisión Vertical de Enfermedad Infecciosa , Complicaciones Infecciosas del Embarazo , Femenino , Estudios de Seguimiento , Hepatitis B/sangre , Hepatitis B/epidemiología , Hepatitis B/terapia , Hepatitis B/transmisión , Maternidades/estadística & datos numéricos , Humanos , Recién Nacido , Irlanda/epidemiología , Monitorización Inmunológica/métodos , Atención Perinatal/métodos , Embarazo , Complicaciones Infecciosas del Embarazo/sangre , Complicaciones Infecciosas del Embarazo/epidemiología , Complicaciones Infecciosas del Embarazo/terapia , Pruebas Serológicas/métodos , Vacunación/métodos
14.
Radiography (Lond) ; 28(2): 348-352, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-34916128

RESUMEN

INTRODUCTION: Breast cancer is one of the most prevalent cancers in women, however Irish Traveller women have lower breast screening rates than that of the general population. This work aims to address the gap in knowledge of Irish Traveller womens' perceptions of breast screening and the perceived barriers and enablers to attendance. METHODS: This phenomenological qualitative study involves interviews with Irish Traveller women and Health Care Professionals and discusses the incentives and barriers to attending breast screening mammography in Ireland. The work investigated attitudes and decision making amongst the Irish Traveller women across breast screening and breast health. The research investigated the participants knowledge, experience and opinions about the topic of Irish Traveller womens' attendance at BreastCheck and breast health RESULTS: Influences that create barriers to breast screening for Irish Traveller women include inequality and family/community support, fear, literacy and education, embarrassment and the health care professional, stress and appointment suitability. Findings also demonstrate inadequate data and information is available in Ireland regarding Irish Traveller women attending breast screening. CONCLUSION: Irish Traveller women face several influences when it comes to attending breast screening. The existing Irish national breast screening programme provides a health promotion service however, it is impossible to assess poor attendance at screening without the presence of an ethnic identifier. It would be very beneficial for screening promotion to record the ethnicity of attendees for statistical progress. This would benefit Irish Traveller women by recording the progress of attendance in the breast screening programme and creating a need for awareness and education within the annual reports. IMPLICATIONS FOR PRACTICE: Creating awareness and educating Irish Traveller women about the breast screening programme may remove barriers and lead to improved attendance rates.


Asunto(s)
Neoplasias de la Mama , Neoplasias de la Mama/diagnóstico por imagen , Detección Precoz del Cáncer , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , Mamografía , Tamizaje Masivo
15.
J Laryngol Otol ; 136(12): 1275-1277, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35485749

RESUMEN

OBJECTIVE: Idiopathic subglottic stenosis describes subglottic stenosis where no inflammatory, traumatic, iatrogenic or other causative aetiology can be identified. The present study aimed to outline our institution's experience of patients diagnosed with idiopathic subglottic stenosis and describe a very rarely reported familial association. METHODS: A retrospective review was conducted of prospectively maintained medical records from 2011 to 2020. Patient clinical, radiological and intra-operative data were reviewed to assess for defined endpoints. RESULTS: Ten patients with idiopathic subglottic stenosis were identified in this series. One familial pairing was identified, with two sisters presenting with the condition. Successful treatment with carbon dioxide laser and dilatation was achieved in most cases. CONCLUSION: Idiopathic subglottic stenosis represents a rare, clinically challenging pathology. Management with endoscopic laser and balloon dilatation is an effective treatment. This paper highlights a very rare familial association, and describes our experience in treating idiopathic subglottic stenosis.


Asunto(s)
Laringoestenosis , Láseres de Gas , Humanos , Constricción Patológica , Laringoestenosis/genética , Laringoestenosis/terapia , Dilatación/efectos adversos , Endoscopía/efectos adversos , Láseres de Gas/uso terapéutico , Estudios Retrospectivos
16.
Science ; 367(6477): 577-580, 2020 01 31.
Artículo en Inglés | MEDLINE | ID: mdl-32001656

RESUMEN

Radio pulsars in short-period eccentric binary orbits can be used to study both gravitational dynamics and binary evolution. The binary system containing PSR J1141-6545 includes a massive white dwarf (WD) companion that formed before the gravitationally bound young radio pulsar. We observed a temporal evolution of the orbital inclination of this pulsar that we infer is caused by a combination of a Newtonian quadrupole moment and Lense-Thirring (LT) precession of the orbit resulting from rapid rotation of the WD. LT precession, an effect of relativistic frame dragging, is a prediction of general relativity. This detection is consistent with an evolutionary scenario in which the WD accreted matter from the pulsar progenitor, spinning up the WD to a period of <200 seconds.

17.
Euro Surveill ; 14(44)2009 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-19941779

RESUMEN

From 28 April 2009 to 3 October 2009, 205 cases of confirmed pandemic H1N1 influenza were hospitalised in Ireland. Detailed case-based epidemiological information was gathered on all hospitalised cases. Age-specific hospitalisation rates were highest in the age group of 15 to 19 year-olds and lowest in those aged 65 years and over. Nineteen hospitalised cases (9%) were admitted to intensive care units (ICU) where the median length of stay was 24 days. Four hospitalised cases (2%) died. Fifty-one percent of hospitalised cases and 42% of ICU cases were not in a recognised risk group. Asthma was the most common risk factor among cases; however, people with haemoglobinopathies and immunosuppression were the most over-represented groups.


Asunto(s)
Hospitalización , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Gripe Humana/epidemiología , Vigilancia de la Población , Adolescente , Adulto , Anciano , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Gripe Humana/diagnóstico , Unidades de Cuidados Intensivos , Irlanda/epidemiología , Tiempo de Internación , Masculino , Persona de Mediana Edad , Adulto Joven
18.
J Laryngol Otol ; 131(6): 480-486, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28367769

RESUMEN

BACKGROUND: The incidence of thyroid cancer is increasing. There is conflicting evidence as to why. However, studies suggest that it is not an apparent increase resulting from enhanced diagnostic practices, but a true increase with more affected patients. This study aimed to assess racial variation in thyroid cancer. METHOD: A narrative systematic review of the literature was conducted. RESULTS: Eight retrospective cohort studies were identified, comprising 611 777 adult patients. Variations exist between racial groups, which are also dependent on gender; white patients have a slightly higher male population when compared to their counterparts. Black and white patients have a higher proportion of follicular cancer. Hispanics were younger at the age of diagnosis. Outcomes are greatly affected by socioeconomic status. CONCLUSION: This study identified many gaps in the way that these types of data are presented. A more concise manner of reporting, with individual-level risk factors, is recommended.


Asunto(s)
Población Negra/estadística & datos numéricos , Disparidades en el Estado de Salud , Hispánicos o Latinos/estadística & datos numéricos , Neoplasias de la Tiroides/etnología , Población Blanca/estadística & datos numéricos , Adulto , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Factores Sexuales , Factores Socioeconómicos , Neoplasias de la Tiroides/epidemiología
19.
Ir J Med Sci ; 186(1): 247-254, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26822733

RESUMEN

BACKGROUND: The Royal Victoria Eye and Ear Hospital provides a specialised ear, nose and throat (ENT) Emergency department (ED) service open to patients from the entire country, operating from 9 am to 5 pm on weekdays. Recently, this has been under threat of closure. AIMS: We analyse and determine the role of this ED in the current context and compare results to a previous study from June 1990. METHODS: A prospective study over a 1-month period (March 2014) was conducted. A questionnaire was used, adapted from the study in 1990. RESULTS: Comparative figures from June 1990 are in parentheses. During the study period, there were 945 (1167) consultations from 887 (779) patients. 57 % (45 %) were new patients and 43 % (55 %) were return patients. Repeat attendances were necessary in 54 (325) patients during this month. 56 % (35 %) were referred by their General Practitioner (GP), 38 % (52 %) self-referred, 2 % (8 %) by other hospitals and 4 % (5 %) from other sources. Diagnoses included otitis externa in 24 % (21 %), cerumen in 20 % (15 %), epistaxis in 6 % (9 %), Eustachian tube dysfunction in 12 %, foreign body removal in 4 % (5 %) and four new cases of head and neck cancer. Attendance numbers vary during the year but demand has risen over time. CONCLUSIONS: A dedicated ED provides an important role for ENT in Ireland and offers valuable experience for trainees. The loss of such a department may lead to an overwhelming burden on services in other hospitals.


Asunto(s)
Servicio de Urgencia en Hospital/estadística & datos numéricos , Hospitales , Enfermedades Otorrinolaringológicas/epidemiología , Adolescente , Adulto , Niño , Preescolar , Enfermedades del Oído/terapia , Femenino , Médicos Generales , Humanos , Lactante , Recién Nacido , Irlanda , Masculino , Persona de Mediana Edad , Nariz/patología , Enfermedades Otorrinolaringológicas/terapia , Faringe/patología , Estudios Prospectivos , Derivación y Consulta , Adulto Joven
20.
Aliment Pharmacol Ther ; 44(10): 1005-1017, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27630001

RESUMEN

BACKGROUND: The risk of mother-to-child transmission of hepatitis B virus (HBV) has been quoted as 70-90% among women positive for hepatitis B surface antigen (HBsAg) and e antigen (HBeAg), and 5-30% among HBsAg-positive HBeAg-negative women. These risks are derived from Asia; little is known about sub-Saharan Africa. AIM: To determine the risk of mother-to-child transmission in sub-Saharan Africa, according to maternal HBeAg and type of prophylaxis. METHODS: We searched Medline, Global Health, Embase, African Journals Online and African Index Medicus. We included observational or interventional studies that enrolled infants of HBV-infected women, and that tested for HBsAg or HBV DNA between 3 and 12 months of age. RESULTS: Fifteen articles from 11 African countries were included. Among HBeAg-positive women, the pooled risk was 38.3% (95% CI: 7.0-74.4%) without prophylaxis, which was significantly lower than the lower bound of 70-90% risk in the literature (P = 0.007). Among HBeAg-negative women, the pooled risk was 4.8% (95% CI: 0.1-13.3%) without prophylaxis, which lays within the lower range of the 5-30% risk in Asia. By extrapolating the pooled transmission risks to the number of births to infectious mothers, an estimated 1% of newborns (n = 367 250) are annually infected with HBV at birth in sub-Saharan Africa. CONCLUSIONS: Compared to Asia, the risk of mother-to-child transmission is low in sub-Saharan Africa. However, the annual number of infants perinatally infected with HBV is twice the number of incident paediatric HIV infections in sub-Saharan Africa (n = 190 000). This highlights the importance of preventing mother-to-child transmission of HBV in sub-Saharan Africa, which has been long neglected.


Asunto(s)
Hepatitis B/transmisión , Transmisión Vertical de Enfermedad Infecciosa , Complicaciones Infecciosas del Embarazo , África del Sur del Sahara , Femenino , Hepatitis B/sangre , Hepatitis B/virología , Humanos , Madres , Embarazo , Riesgo
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