Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 62
Filtrar
1.
Nature ; 589(7841): 211-213, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33442039

RESUMO

Soft γ-ray repeaters exhibit bursting emission in hard X-rays and soft γ-rays. During the active phase, they emit random short (milliseconds to several seconds long), hard-X-ray bursts, with peak luminosities1 of 1036 to 1043 erg per second. Occasionally, a giant flare with an energy of around 1044 to 1046 erg is emitted2. These phenomena are thought to arise from neutron stars with extremely high magnetic fields (1014 to 1015 gauss), called magnetars1,3,4. A portion of the second-long initial pulse of a giant flare in some respects mimics short γ-ray bursts5,6, which have recently been identified as resulting from the merger of two neutron stars accompanied by gravitational-wave emission7. Two γ-ray bursts, GRB 051103 and GRB 070201, have been associated with giant flares2,8-11. Here we report observations of the γ-ray burst GRB 200415A, which we localized to a 20-square-arcmin region of the starburst galaxy NGC 253, located about 3.5 million parsecs away. The burst had a sharp, millisecond-scale hard spectrum in the initial pulse, which was followed by steady fading and softening over 0.2 seconds. The energy released (roughly 1.3 × 1046 erg) is similar to that of the superflare5,12,13 from the Galactic soft γ-ray repeater SGR 1806-20 (roughly 2.3 × 1046 erg). We argue that GRB 200415A is a giant flare from a magnetar in NGC 253.

2.
QJM ; 114(3): 167-173, 2021 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-33484260

RESUMO

Idiopathic pulmonary fibrosis (IPF) is a progressive fatal disease affecting over 100 000 people in Europe with an increasing incidence. Available treatments offer only slowing of disease progression and are poorly tolerated by patients leading to cessation of therapy. Lung transplant remains the only cure. Therefore, alternative treatments are urgently required. The pathology of IPF is complex and poorly understood and thus creates a major obstacle to the discovery of novel treatments. Additionally, preclinical assessment of new treatments currently relies upon animal models where disparities with human lung biology often hamper drug development. At a cellular level, IPF is characterized by persistent and abnormal deposition of extracellular matrix by fibroblasts and alveolar epithelial cell injury which is seen as a key event in initiation of disease progression. In-depth investigation of the role of alveolar epithelial cells in health and disease has been impeded due to difficulties in primary cell isolation and culture ex vivo. Novel strategies employing patient-derived induced pluripotent stem cells engineered to produce type 2 alveolar epithelial cells (iAEC2) cultured as three-dimensional organoids have the potential to overcome these hurdles and inform new effective precision treatments for IPF leading to improved survival and quality of life for patients worldwide.


Assuntos
Organoides , Animais , Europa (Continente) , Fibroblastos , Humanos , Fibrose Pulmonar Idiopática , Pulmão , Qualidade de Vida
4.
Eur Arch Otorhinolaryngol ; 277(5): 1515-1523, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32062743

RESUMO

PURPOSE: The aim of this paper is to determine whether health-related quality of life (HRQOL) at diagnosis of head and neck cancer (HNC) is associated with overall survival following treatment with curative intent after adjusting for other factors. METHODS: Data were collected from 5511 participants of the Head and Neck 5000 study (HN5000). HRQOL was measured using the EORTC QLQ-C30. Questionnaire and covariate data were available from 2171 participants diagnosed as follows: oral cavity (655), oropharynx HPV+ (723) and HPV- (277), and larynx (516). On average, participants were followed up 3.2 years (SD 1.2) after diagnosis. Data were adjusted for age, gender, co-morbidity, intended treatment, education level, income from benefits, smoking status and alcohol consumption. RESULTS: There was a clinically meaningful difference between Global HRQOL scores at diagnosis and survival in an unadjusted and adjusted model: [HR = 0.86, CI 0.82-0.89, p < 0.001 (unadjusted) and HR = 0.90, CI 0.86-0.94, p < 0.001 (adjusted)]. In analyses stratified by tumour site and HPV status, this association was similarly noted before adjustment and persisted after. There were some tumour sub-site variations: improved survival for people with laryngeal cancer reporting higher levels of physical role or social functioning and people with oral cancer reporting higher levels of role or social functioning. CONCLUSION: As survival is the main priority for most people diagnosed with cancer, pre-treatment HRQOL is an additional factor to be included in risk stratification and case-mix adjustments. There is merit in incorporating HRQOL into routine clinical care as this is a useful facet in patient-clinician decision making, prognostication and recovery.


Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Cognição , Neoplasias de Cabeça e Pescoço/diagnóstico , Neoplasias de Cabeça e Pescoço/terapia , Humanos , Prognóstico , Qualidade de Vida
5.
Oral Oncol ; 101: 104504, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31835074

RESUMO

BACKGROUND: Head and neck cancer (HNC) is an important cause of morbidity and mortality globally. Radical treatment methods may result in facial disfigurement and/or functional difficulties with subsequent adverse impacts on health-related quality of life (HRQoL). Guidelines suggest that HRQoL should be measured repeatedly throughout treatment to enable refined treatment protocols and tailored follow-up support but questionnaires are often long and burdensome. We compared condition-specific and generic metrics to assess HRQoL for people with this condition. METHODS: We used data from the prospective Head and Neck 5000 clinical cohort study - 5511 participants with a new diagnosis of HNC between 2011 and 2014. HRQoL data were collected at baseline from 2065 people who completed both the condition-specific EORTC-QLQ-C30 and the shorter, generic EQ-5D-5L questionnaires. RESULTS: There was strong evidence of association between comparable scales on each questionnaire at baseline: higher levels of functioning and lower levels of reported symptoms assessed with EQ-5D-5L were associated with lower EORTC-QLQ-C30 symptom scores. A moderate relationship (0.61) was found between overall QoL in the EQ-5D-5L index and self-perceived health (EQ VAS). CONCLUSIONS: HRQoL data collected from the generic EQ-5D-5L and cancer-specific EORTC-QLQ-C30 questionnaires are comparable at baseline for people diagnosed with HNC. This would allow a reduced burden of data collection but the EQ-5D-5L may not be sensitive to some condition-specific symptoms. Clinicians and researchers must clarify their aims and outcomes of interest before choosing their HRQoL measures. Further work is required to examine the ability to detect change in these measures over time.


Assuntos
Neoplasias de Cabeça e Pescoço/epidemiologia , Qualidade de Vida , Idoso , Feminino , Neoplasias de Cabeça e Pescoço/diagnóstico , Neoplasias de Cabeça e Pescoço/terapia , Inquéritos Epidemiológicos , Humanos , Masculino , Pessoa de Meia-Idade , Morbidade , Mortalidade , Estadiamento de Neoplasias , Autorrelato , Inquéritos e Questionários
6.
Int J Clin Pharm ; 41(6): 1592-1598, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31650506

RESUMO

Background To improve antimicrobial use, incorporation of a pharmacist in antimicrobial stewardship initiatives in the emergency department has been recommended. Recognizing the potential value, a pharmacist-led antimicrobial stewardship (AMS) service which included review and follow up of microbiology results for patients discharged from the pediatric emergency department (PED) with suspected infections was implemented at our local institution. Objective The objective of this study was to evaluate the impact of pharmacists delivering this service compared to usual care. Setting Pediatric emergency department at the IWK Health Centre in Halifax, Canada. Method This study was completed as a retrospective chart review of pediatric patients discharged from the PED 6 months before and after implementation of the pharmacist-led AMS service. Data was extracted from electronic medical records. Data were reported descriptively and compared using a two-sided chi-square test and ordinal logistic regression. Main outcome measures The primary outcome measure was rate of return visits to the PED within 96 h of initial presentation. Results This study included 1070 patient encounters pre-implementation and 1040 patient encounters post-implementation. The rate of return visits to the PED within 96 h was 12.0% (129/1070) pre-implementation vs. 10.0% (100/1049) post-implementation (p = 0.07). The rate of return visits or hospitalization at 30 days was 22.1% (237/1070) pre-implementation compared to 19.9% (207/1040) in the post-implementation phase (p = 0.21). Inappropriate antimicrobial therapy was identified more often in the pre-implementation phase (7.0%, 68/975) vs. the post-implementation phase (5.0%, 46/952), p = 0.047. Time to notification within the first day after discharge occurred more frequently in the post-implementation phase (53.3%, 80/150) as compared to the pre-implementation phase (40.3%, 52/129, p = 0.0298). Conclusion Although this pharmacist-led AMS service did not significantly affect the rate of return visits or hospitalization, it may have led to more judicious use of antimicrobial agents and faster time to notification.


Assuntos
Gestão de Antimicrobianos , Serviço Hospitalar de Emergência/organização & administração , Farmacêuticos/organização & administração , Serviço de Farmácia Hospitalar/organização & administração , Anti-Infecciosos/administração & dosagem , Criança , Pré-Escolar , Registros Eletrônicos de Saúde , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Prescrição Inadequada/estatística & dados numéricos , Lactente , Masculino , Nova Escócia , Readmissão do Paciente/estatística & dados numéricos , Papel Profissional , Estudos Retrospectivos
7.
Vet J ; 227: 15-22, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29031325

RESUMO

Animal shelters struggle to function at their 'right size' in terms of physical, staffing and outcome capacity, especially with seasonal fluctuations in cat intake. To address this, a Capacity for Care (C4C) management model was devised to balance health and welfare requirements of all animals while maintaining or improving goals for positive outcomes, such as adoption or transfer. In this observational study of three shelters, applying the C4C management system gave each organization an optimal average daily shelter cat population target (to be achieved through proactive length of stay management) and helped each shelter to increase the size of their feline housing units. Pre- and post-C4C implementation data were evaluated to determine impact on average monthly isolation ward populations and cat outcomes such as adoptions and shelter deaths (euthanasia/died). Improved outcomes including increased adoption probability, decreased shelter death probability and fewer cats requiring infectious disease isolation were seen after C4C institution. Results suggest that implementation of this management model could help other shelters achieve similar results.


Assuntos
Bem-Estar do Animal , Gatos , Abrigo para Animais , Bem-Estar do Animal/organização & administração , Animais , Abrigo para Animais/organização & administração , Abrigo para Animais/normas , Modelos Organizacionais , Animais de Estimação
8.
Vet J ; 210: 68-76, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26965085

RESUMO

Veterinary services are increasingly used in animal shelters, and shelter medicine is an emerging veterinary specialty. However, little is known about working relationships between animal shelters and veterinarians. The aims of this survey were to characterize working relationships that shelter personnel have and want with veterinarians, identify opinions that shelter managers have regarding the veterinarians they work with, and determine areas for relationship growth between veterinarians and shelter managers. An electronic survey was distributed to 1373 managers of North American animal shelters; 536 (39.0%) responded. Almost all shelters had some veterinary relationship, and most had regular relationships with veterinarians. The proportion of shelters that used local clinics (73.9%) was significantly higher than the proportion that retained on-site paid veterinarians (48.5%). The proportion of respondents who did not have but wanted a paid on-site veterinarian (42%) was significantly higher than the proportion of respondents who did not use local clinics but wanted to (7.9%). These data suggest shelter managers valued veterinary relationships, and wished to expand on-site veterinary services. Almost all shelters in this study provided some veterinary care, and all respondents identified at least one common infectious disease, which, for most, had a substantial negative impact on shelter successes. Respondents indicated that the most important roles and greatest expertise of veterinarians were related to surgery, diagnosis and treatment of individual animals. Education of both veterinarians and shelter managers may help ensure that shelters benefit from the full range of services veterinarians can provide, including expertise in disease prevention and animal behavior.


Assuntos
Bem-Estar do Animal , Pesquisas sobre Atenção à Saúde , Abrigo para Animais , Medicina Veterinária , Técnicos em Manejo de Animais , Animais , Atenção à Saúde
10.
Phys Rev Lett ; 110(24): 241101, 2013 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-25165903

RESUMO

Jet reheating via nuclear collisions has recently been proposed as the main mechanism for gamma-ray burst (GRB) emission. In addition to producing the observed gamma rays, collisional heating must generate 10-100 GeV neutrinos, implying a close relation between the neutrino and gamma-ray luminosities. We exploit this theoretical relation to make predictions for possible GRB detections by IceCube + DeepCore. To estimate the expected neutrino signal, we use the largest sample of bursts observed by the Burst and Transient Source Experiment in 1991-2000. GRB neutrinos could have been detected if IceCube + DeepCore operated at that time. Detection of 10-100 GeV neutrinos would have significant implications, shedding light on the composition of GRB jets and their Lorentz factors. This could be an important target in designing future upgrades of the IceCube + DeepCore observatory.

11.
Nature ; 461(7268): 1258-60, 2009 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-19865166

RESUMO

Gamma-ray bursts (GRBs) are produced by rare types of massive stellar explosion. Their rapidly fading afterglows are often bright enough at optical wavelengths that they are detectable at cosmological distances. Hitherto, the highest known redshift for a GRB was z = 6.7 (ref. 1), for GRB 080913, and for a galaxy was z = 6.96 (ref. 2). Here we report observations of GRB 090423 and the near-infrared spectroscopic measurement of its redshift, z = 8.1(-0.3)(+0.1). This burst happened when the Universe was only about 4 per cent of its current age. Its properties are similar to those of GRBs observed at low/intermediate redshifts, suggesting that the mechanisms and progenitors that gave rise to this burst about 600,000,000 years after the Big Bang are not markedly different from those producing GRBs about 10,000,000,000 years later.

12.
Vet Pathol ; 45(1): 51-3, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18192575

RESUMO

An outbreak of acute, fatal, hemorrhagic pneumonia was observed in more than 1,000 mixed breed dogs in a single animal shelter. The Department of Anatomic Pathology at the University of California at Davis School of Veterinary Medicine performed necropsies on dogs that were found moribund in acute respiratory distress or found dead with evidence of nasal bleeding. All dogs had hemothorax and an acute, fibrinosuppurative pneumonia. Large numbers of gram-positive cocci were observed within the lungs of all dogs and within septic thromboemboli of remote organs in about 50% of cases. Bacterial cultures from the dogs and their environment revealed widespread beta-hemolytic Streptococus equi subspecies zooepidemicus (Lancefield Group C). Extensive diagnostic testing failed to reveal the consistent presence of copathogens in individual cases. The clinical, epidemiologic, molecular biologic, and pathologic data indicate that a single clone of S. zooepidemicus was the cause of an acutely fatal respiratory infection in these dogs.


Assuntos
Surtos de Doenças/veterinária , Doenças do Cão/epidemiologia , Doenças do Cão/microbiologia , Pneumonia Bacteriana/veterinária , Infecções Estreptocócicas/veterinária , Streptococcus equi/isolamento & purificação , Animais , Doenças do Cão/patologia , Cães , Hemorragia , Abrigo para Animais , Pneumonia Bacteriana/microbiologia , Pneumonia Bacteriana/patologia , Prevalência , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/mortalidade , Infecções Estreptocócicas/patologia
13.
Vet Pathol ; 44(2): 218-21, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17317801

RESUMO

Three independent, fatal outbreaks of Streptococcus canis infection occurred in a 2-year period in shelter cats. The outbreaks occurred in Northern California (Yolo County), Southern California (Kern County), and North Carolina (Guilford County). An estimation of the affected population is >150 cats among 3 affected shelters, with a mortality rate of up to 30%. Among 20 cats submitted for necropsy there were 2 distinct pathologic presentations. The first (shelters 1 and 2) was skin ulceration and chronic respiratory infection that progressed, in some cats, to necrotizing sinusitis and meningitis. The second (shelter 3) was rapid progression from necrotizing fasciitis with skin ulceration to toxic shock-like syndrome, sepsis, and death. S canis was the sole pathogen identified in most cases. Whether hypervirulent S canis strains exist is unknown; there is little understanding of how these bacteria cause invasive disease in cats.


Assuntos
Doenças do Gato/epidemiologia , Doenças do Gato/microbiologia , Surtos de Doenças/veterinária , Infecções Estreptocócicas/veterinária , Streptococcus/crescimento & desenvolvimento , Animais , California/epidemiologia , Gatos , North Carolina/epidemiologia , Infecções Estreptocócicas/epidemiologia , Infecções Estreptocócicas/patologia
14.
Nature ; 444(7122): 1050-2, 2006 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-17183317

RESUMO

Gamma-ray bursts (GRBs) are short, intense flashes of soft gamma-rays coming from the distant Universe. Long-duration GRBs (those lasting more than approximately 2 s) are believed to originate from the deaths of massive stars, mainly on the basis of a handful of solid associations between GRBs and supernovae. GRB 060614, one of the closest GRBs discovered, consisted of a 5-s hard spike followed by softer, brighter emission that lasted for approximately 100 s (refs 8, 9). Here we report deep optical observations of GRB 060614 showing no emerging supernova with absolute visual magnitude brighter than M(V) = -13.7. Any supernova associated with GRB 060614 was therefore at least 100 times fainter, at optical wavelengths, than the other supernovae associated with GRBs. This demonstrates that some long-lasting GRBs can either be associated with a very faint supernova or produced by different phenomena.

15.
Nature ; 440(7081): 164, 2006 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-16525462

RESUMO

Long gamma-ray bursts (GRBs) are bright flashes of high-energy photons that can last for tens of minutes; they are generally associated with galaxies that have a high rate of star formation and probably arise from the collapsing cores of massive stars, which produce highly relativistic jets (collapsar model). Here we describe gamma- and X-ray observations of the most distant GRB ever observed (GRB 050904): its redshift (z) of 6.29 means that this explosion happened 12.8 billion years ago, corresponding to a time when the Universe was just 890 million years old, close to the reionization era. This means that not only did stars form in this short period of time after the Big Bang, but also that enough time had elapsed for them to evolve and collapse into black holes.

16.
Nature ; 440(7081): 184-6, 2006 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-16525466

RESUMO

The prompt gamma-ray emission from gamma-ray bursts (GRBs) should be detectable out to distances of z > 10 (ref. 1), and should therefore provide an excellent probe of the evolution of cosmic star formation, reionization of the intergalactic medium, and the metal enrichment history of the Universe. Hitherto, the highest measured redshift for a GRB has been z = 4.50 (ref. 5). Here we report the optical spectrum of the afterglow of GRB 050904 obtained 3.4 days after the burst; the spectrum shows a clear continuum at the long-wavelength end of the spectrum with a sharp cut-off at around 9,000 A due to Lyman alpha absorption at z approximately 6.3 (with a damping wing). A system of absorption lines of heavy elements at z = 6.295 +/- 0.002 was also detected, yielding the precise measurement of the redshift. The Si ii fine-structure lines suggest a dense, metal-enriched environment around the progenitor of the GRB.

17.
Nature ; 437(7060): 845-50, 2005 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-16208362

RESUMO

The final chapter in the long-standing mystery of the gamma-ray bursts (GRBs) centres on the origin of the short-hard class of bursts, which are suspected on theoretical grounds to result from the coalescence of neutron-star or black-hole binary systems. Numerous searches for the afterglows of short-hard bursts have been made, galvanized by the revolution in our understanding of long-duration GRBs that followed the discovery in 1997 of their broadband (X-ray, optical and radio) afterglow emission. Here we present the discovery of the X-ray afterglow of a short-hard burst, GRB 050709, whose accurate position allows us to associate it unambiguously with a star-forming galaxy at redshift z = 0.160, and whose optical lightcurve definitively excludes a supernova association. Together with results from three other recent short-hard bursts, this suggests that short-hard bursts release much less energy than the long-duration GRBs. Models requiring young stellar populations, such as magnetars and collapsars, are ruled out, while coalescing degenerate binaries remain the most promising progenitor candidates.

18.
Nature ; 437(7060): 851-4, 2005 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-16208363

RESUMO

Gamma-ray bursts (GRBs) come in two classes: long (> 2 s), soft-spectrum bursts and short, hard events. Most progress has been made on understanding the long GRBs, which are typically observed at high redshift (z approximately 1) and found in subluminous star-forming host galaxies. They are likely to be produced in core-collapse explosions of massive stars. In contrast, no short GRB had been accurately (< 10'') and rapidly (minutes) located. Here we report the detection of the X-ray afterglow from--and the localization of--the short burst GRB 050509B. Its position on the sky is near a luminous, non-star-forming elliptical galaxy at a redshift of 0.225, which is the location one would expect if the origin of this GRB is through the merger of neutron-star or black-hole binaries. The X-ray afterglow was weak and faded below the detection limit within a few hours; no optical afterglow was detected to stringent limits, explaining the past difficulty in localizing short GRBs.

19.
Nature ; 437(7060): 855-8, 2005 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-16208364

RESUMO

Gamma-ray bursts (GRBs) fall into two classes: short-hard and long-soft bursts. The latter are now known to have X-ray and optical afterglows, to occur at cosmological distances in star-forming galaxies, and to be associated with the explosion of massive stars. In contrast, the distance scale, the energy scale and the progenitors of the short bursts have remained a mystery. Here we report the discovery of a short-hard burst whose accurate localization has led to follow-up observations that have identified the X-ray afterglow and (for the first time) the optical afterglow of a short-hard burst; this in turn led to the identification of the host galaxy of the burst as a late-type galaxy at z = 0.16 (ref. 10). These results show that at least some short-hard bursts occur at cosmological distances in the outskirts of galaxies, and are likely to be caused by the merging of compact binaries.

20.
Nature ; 435(7039): 181-4, 2005 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-15889085

RESUMO

The explosion that results in a cosmic gamma-ray burst (GRB) is thought to produce emission from two physical processes: the central engine gives rise to the high-energy emission of the burst through internal shocking, and the subsequent interaction of the flow with the external environment produces long-wavelength afterglows. Although observations of afterglows continue to refine our understanding of GRB progenitors and relativistic shocks, gamma-ray observations alone have not yielded a clear picture of the origin of the prompt emission nor details of the central engine. Only one concurrent visible-light transient has been found and it was associated with emission from an external shock. Here we report the discovery of infrared emission contemporaneous with a GRB, beginning 7.2 minutes after the onset of GRB 041219a (ref. 8). We acquired 21 images during the active phase of the burst, yielding early multi-colour observations. Our analysis of the initial infrared pulse suggests an origin consistent with internal shocks.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...