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1.
Nature ; 561(7721): E2, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29930351

RESUMO

Change history: In this Letter, the Acknowledgements section should have included the following sentence: "The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.". This omission has been corrected online.

2.
Nature ; 556(7702): 469-472, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29695849

RESUMO

Massive galaxy clusters have been found that date to times as early as three billion years after the Big Bang, containing stars that formed at even earlier epochs1-3. The high-redshift progenitors of these galaxy clusters-termed 'protoclusters'-can be identified in cosmological simulations that have the highest overdensities (greater-than-average densities) of dark matter4-6. Protoclusters are expected to contain extremely massive galaxies that can be observed as luminous starbursts 7 . However, recent detections of possible protoclusters hosting such starbursts8-11 do not support the kind of rapid cluster-core formation expected from simulations 12 : the structures observed contain only a handful of starbursting galaxies spread throughout a broad region, with poor evidence for eventual collapse into a protocluster. Here we report observations of carbon monoxide and ionized carbon emission from the source SPT2349-56. We find that this source consists of at least 14 gas-rich galaxies, all lying at redshifts of 4.31. We demonstrate that each of these galaxies is forming stars between 50 and 1,000 times more quickly than our own Milky Way, and that all are located within a projected region that is only around 130 kiloparsecs in diameter. This galaxy surface density is more than ten times the average blank-field value (integrated over all redshifts), and more than 1,000 times the average field volume density. The velocity dispersion (approximately 410 kilometres per second) of these galaxies and the enormous gas and star-formation densities suggest that this system represents the core of a cluster of galaxies that was already at an advanced stage of formation when the Universe was only 1.4 billion years old. A comparison with other known protoclusters at high redshifts shows that SPT2349-56 could be building one of the most massive structures in the Universe today.

3.
Nature ; 553(7686): 51-54, 2018 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-29211721

RESUMO

According to the current understanding of cosmic structure formation, the precursors of the most massive structures in the Universe began to form shortly after the Big Bang, in regions corresponding to the largest fluctuations in the cosmic density field. Observing these structures during their period of active growth and assembly-the first few hundred million years of the Universe-is challenging because it requires surveys that are sensitive enough to detect the distant galaxies that act as signposts for these structures and wide enough to capture the rarest objects. As a result, very few such objects have been detected so far. Here we report observations of a far-infrared-luminous object at redshift 6.900 (less than 800 million years after the Big Bang) that was discovered in a wide-field survey. High-resolution imaging shows it to be a pair of extremely massive star-forming galaxies. The larger is forming stars at a rate of 2,900 solar masses per year, contains 270 billion solar masses of gas and 2.5 billion solar masses of dust, and is more massive than any other known object at a redshift of more than 6. Its rapid star formation is probably triggered by its companion galaxy at a projected separation of 8 kiloparsecs. This merging companion hosts 35 billion solar masses of stars and has a star-formation rate of 540 solar masses per year, but has an order of magnitude less gas and dust than its neighbour and physical conditions akin to those observed in lower-metallicity galaxies in the nearby Universe. These objects suggest the presence of a dark-matter halo with a mass of more than 100 billion solar masses, making it among the rarest dark-matter haloes that should exist in the Universe at this epoch.

4.
Phys Rev Lett ; 131(22): 228302, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38101339

RESUMO

We study motility-induced phase separation (MIPS) in living active matter, in which cells interact through chemical signaling, or quorum sensing. In contrast to previous theories of MIPS, our multiscale continuum model accounts explicitly for genetic regulation of signal production and motility. Through analysis and simulations, we derive a new criterion for the onset of MIPS that depends on features of the genetic network. Furthermore, we identify and characterize a new type of oscillatory instability that occurs when gene regulation inside cells promotes motility in higher signal concentrations.


Assuntos
Redes Reguladoras de Genes , Percepção de Quorum , Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica
5.
Phys Rev Lett ; 126(12): 125101, 2021 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-33834792

RESUMO

Multipoint in situ observations of the solar wind are used to identify the magnetic topology and current density of turbulent structures. We find that at least 35% of all structures are both actively evolving and carrying the strongest currents, actively dissipating, and heating the plasma. These structures are comprised of ∼1/5 3D plasmoids, ∼3/5 flux ropes, and ∼1/5 3D X points consistent with magnetic reconnection. Actively evolving and passively advecting structures are both close to log-normally distributed. This provides direct evidence for the significant role of strong turbulence, evolving via magnetic shearing and reconnection, in mediating dissipation and solar wind heating.

6.
Osteoporos Int ; 31(10): 1837-1851, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32500301

RESUMO

Decision aids (DAs) are evidence-based tools that support shared decision-making (SDM) implementation in practice; this study aimed to identify existing osteoporosis DAs and assess their quality and efficacy; and to gain feedback from a patient advisory group on findings and implications for further research. We searched multiple bibliographic databases to identify research studies from 2000 to 2019 and undertook an environmental scan (search conducted February 2019, repeated in March 2020). A pair of reviewers, working independently selected studies for inclusion, extracted data, evaluated each trial's risk of bias, and conducted DA quality assessment using the International Patient Decision Aid Standards (IPDAS). Public contributors (patients and caregivers with experience of osteoporosis and fragility fractures) participated in discussion groups to review a sample of DAs, express preferences for a new DA, and discuss plans for development of a new DA. We identified 6 studies, with high or unclear risk of bias. Across included studies, use of an osteoporosis DA was reported to result in reduced decisional conflict compared with baseline, increased SDM, and increased accuracy of patients' perceived fracture risk compared with controls. Eleven DAs were identified, of which none met the full set of IPDAS criteria for certification for minimization of bias. Public contributors expressed preferences for encounter DAs that are individualized to patients' own needs and risk. Using a systematic review and environmental scan, we identified 11 decision aids to inform patient decisions about osteoporosis treatment and 6 studies evaluating their effectiveness. Use of decision aids increased accuracy of risk perception and shared decision-making but the decision aids themselves fail to comprehensively meet international quality standards and patient needs, underpinning the need for new DA development.


Assuntos
Técnicas de Apoio para a Decisão , Osteoporose , Tomada de Decisões , Humanos , Osteoporose/diagnóstico , Osteoporose/tratamento farmacológico , Participação do Paciente
7.
BJOG ; 127(13): 1696-1703, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32683738

RESUMO

OBJECTIVE: To estimate the incidence of cystic fibrosis in pregnancy and to explore obstetric and neonatal outcomes. DESIGN: A population-based descriptive study using the methodology of the UK Obstetric Surveillance System (UKOSS). SETTING: All consultant-led maternity units in the UK. POPULATION: All pregnant women with a diagnosis of cystic fibrosis who booked for antenatal care in a UK obstetric unit between March 2015 and February 2017. METHODS: Prospective case collection identified using UKOSS monthly notification. MAIN OUTCOME MEASURES: Incidence, maternal morbidity, maternal mortality, gestation at delivery, neonatal mortality, neonatal morbidity. RESULTS: We report 71 pregnancies over a 2-year period. There was one early miscarriage, four terminations and three sets of twins, resulting in the live birth of 69 infants. There were no maternal deaths. One infant died following spontaneous preterm birth at 29 weeks' gestation. The mean gestation at delivery was 36.2 completed weeks. The mean birthweight centile for gestational age was the 61st centile. We report a positive correlation between both maternal lung function (FEV1 ) and mean gestation at delivery, and between FEV1 and mean birthweight centile for gestational age. CONCLUSIONS: Pregnancy outcomes are generally good in women with cystic fibrosis. Successful pregnancy is possible even in those women with FEV1 <60% predicted, although such women have higher chance of preterm delivery and a smaller baby. TWEETABLE ABSTRACT: Pregnant women with cystic fibrosis who have poorer lung function at the beginning of pregnancy have a higher risk of having a premature or smaller baby.


Assuntos
Fibrose Cística/epidemiologia , Complicações na Gravidez/epidemiologia , Resultado da Gravidez , Adulto , Feminino , Humanos , Incidência , Lactente , Morte do Lactente , Recém-Nascido , Morte Materna , Gravidez , Estudos Prospectivos , Reino Unido/epidemiologia , Adulto Jovem
8.
Colorectal Dis ; 22(12): 1842-1849, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32865317

RESUMO

AIM: Enhanced recovery after surgery (ERAS) protocols aim to optimize recovery through a series of evidence-based recommendations. A key component of ERAS is the provision of patient education. Whilst the recommendation for this is strong, the evidence to inform its format, timing and delivery is unclear. The aim of this review was to describe previous educational interventions used to improve recovery after colorectal surgery and to explore opportunities for future research. METHODS: A systematic scoping review was performed. MEDLINE and Embase databases were searched between 1 January 1990 and 12 February 2020. Studies which described or assessed the effectiveness of a patient education or information resource to improve recovery after colorectal surgery were eligible. Outcomes of interest included the format, timing and delivery of interventions, as well as key features of intervention and study design. A narrative synthesis of data was produced through a process of charting and summarizing key results. RESULTS: A total of 1298 papers were inspected, and 11 were eligible for inclusion. Five papers were reports of randomized controlled trials, and others reported a mix of non-randomized and qualitative studies. The design of educational interventions included audio-visual resources (n = 3), smartphone device applications (n = 3) and approaches to facilitate person-to-person counselling (n = 5). Most of the counselling interventions reported positive outcomes (mainly in length of hospital stay), whereas the other types reported mixed results. Patients and the public were seldom involved as collaborators in the design of interventions. CONCLUSIONS: Patient education is generally advantageous, but there is insufficient evidence to optimize its design and delivery in the setting of colorectal surgery.


Assuntos
Cirurgia Colorretal , Procedimentos Cirúrgicos do Sistema Digestório , Recuperação Pós-Cirúrgica Melhorada , Humanos , Tempo de Internação , Educação de Pacientes como Assunto
9.
Colorectal Dis ; 22(4): 459-464, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31701620

RESUMO

INTRODUCTION: Gastrointestinal recovery describes the restoration of normal bowel function in patients with bowel disease. This may be prolonged in two common clinical settings: postoperative ileus and small bowel obstruction. Improving gastrointestinal recovery is a research priority but researchers are limited by variation in outcome reporting across clinical studies. This protocol describes the development of core outcome sets for gastrointestinal recovery in the contexts of postoperative ileus and small bowel obstruction. METHOD: An international Steering Group consisting of patient and clinician representatives has been established. As overlap between clinical contexts is anticipated, both outcome sets will be co-developed and may be combined to form a common output with disease-specific domains. The development process will comprise three phases, including definition of outcomes relevant to postoperative ileus and small bowel obstruction from systematic literature reviews and nominal-group stakeholder discussions; online-facilitated Delphi surveys via international networks; and a consensus meeting to ratify the final output. A nested study will explore if the development of overlapping outcome sets can be rationalized. DISSEMINATION AND IMPLEMENTATION: The final output will be registered with the Core Outcome Measures in Effectiveness Trials initiative. A multi-faceted, quality improvement campaign for the reporting of gastrointestinal recovery in clinical studies will be launched, targeting international professional and patient groups, charitable organizations and editorial committees. Success will be explored via an updated systematic review of outcomes 5 years after registration of the core outcome set.


Assuntos
Íleus , Obstrução Intestinal , Técnica Delphi , Humanos , Íleus/etiologia , Obstrução Intestinal/etiologia , Avaliação de Resultados em Cuidados de Saúde , Projetos de Pesquisa
10.
Br J Surg ; 106(11): 1464-1471, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31393612

RESUMO

BACKGROUND: Research waste is a major challenge for evidence-based medicine. It implicates misused resources and increased risks for research participants. The aim of this study was to quantify constituent components of waste in surgical RCTs and explore targets for improvement. METHODS: ClinicalTrials.gov was searched for RCTs registered between January 2011 and December 2012 using the keyword 'surgery'. The primary outcome was research waste, defined as non-publication, inadequate reporting or presence of an avoidable design limitation. Serial systematic searches of PubMed and Scopus databases were performed to determine publication status. Adequacy of reporting was assessed using the CONSORT checklist. Avoidable design limitations were evaluated according to the presence of bias and/or the absence of a cited systematic review of the literature. RESULTS: Of 5617 registered RCTs, 304 met all eligibility criteria. Overall, 259 of 304 (85·2 per cent) demonstrated at least one feature of waste. Of these, 221 (72·7 per cent) were published in a peer-reviewed journal and 219 were accessible for full-text review. Only 73 of 131 (55·7 per cent) RCTs with a pharmacological intervention and 24 of 88 (27 per cent) with a non-pharmacological intervention were reported adequately, and 159 of 219 (72·6 per cent) demonstrated an avoidable design limitation. Multicentre (odds ratio 0·31, 95 per cent c.i. 0·11 to 0·88) and externally funded (OR 0·35, 0·15 to 0·82) RCTs were less associated with research waste. CONCLUSION: This study identified a considerable burden of research waste in surgical RCTs. Future initiatives should target improvements in single-centre, poorly supported RCTs.


ANTECEDENTES: El despilfarro en investigación es uno de los mayores retos para la medicina basada en la evidencia. Conlleva mala utilización de los recursos y aumento de los riesgos para los participantes en las investigaciones. El objetivo de este trabajo fue cuantificar los componentes que conforman este despilfarro en los ensayos aleatorizados y controlados (randomised controlled trials, RCTs) del ámbito quirúrgico y explorar los aspectos clave de mejora. MÉTODOS: Se realizó una búsqueda de los RCTs registrados en la base de datos ClinicalTrials.gov entre enero de 2011 y diciembre de 2012, utilizando la palabra clave cirugía. La variable primaria fue el despilfarro en investigación, definido como la no publicación, el informe inadecuado o la presencia de debilidades del diseño evitables. Para determinar el estado de las publicaciones, se realizaron búsquedas sistemáticas en las bases de datos PubMed y Scopus. La adecuación del informe se evaluó usando la lista de verificación CONSORT. Las debilidades del diseño evitables se evaluaron de acuerdo con la presencia de sesgo y/o la ausencia de citación en revisiones sistemáticas publicadas en la literatura. RESULTADOS: De los 5.617 RCTs registrados, 304 cumplieron con los criterios de elegibilidad. De ellos, 259/304 (85%) cumplieron al menos una de las características de despilfarro. De estos, 221 (73%) se publicaron en una revista con peer review y 219 eran accesibles a texto completo. Únicamente 73/131 (56%) RCTs con una intervención farmacológica y 24/88 (27%) con una intervención no farmacológica presentaban un informe adecuado, y 159/219 (73%) se demostró una debilidad del diseño evitable. Los RCTs multicéntricos (OR: 0,31; i.c. del 95%: 0,11 a 0,88) y con financiación externa (OR: 0,35; i.c. del 95%: 0,15 a 0,82) se asociaron con menos despilfarro de investigación. CONCLUSIÓN: Este estudio constató una carga considerable de despilfarro en investigación en los RCTs quirúrgicos. Se deberían promover iniciativas de mejora, especialmente dirigidas a los RCTs realizados en un solo centro y con menos financiación.


Assuntos
Ensaios Clínicos Controlados Aleatórios como Assunto/normas , Estudos Transversais , Humanos , Publicações/estatística & dados numéricos , Ensaios Clínicos Controlados Aleatórios como Assunto/estatística & dados numéricos , Projetos de Pesquisa/normas , Projetos de Pesquisa/estatística & dados numéricos , Procedimentos Cirúrgicos Operatórios/estatística & dados numéricos
11.
Br J Surg ; : 1611-1616, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31577372

RESUMO

BACKGROUND: Patients are increasingly taking an active role in the design and delivery of surgical research. Public communication of results should also be encouraged, but this is often limited to non-expert commentary. This study assessed the role of plain English abstracts disseminated via social media in engaging patients and clinicians in the communication of surgical research. METHODS: A three-arm randomized controlled trial with crossover of two intervention arms was performed. Manuscripts accepted for publication in BJS were allocated to one of three arms and disseminated via Twitter: plain English abstracts, visual abstracts and standard tweets. The primary outcome was online engagement (a composite of tweets, replies and likes) by members of the public within 14 days. The secondary outcome was online engagement by healthcare professionals. RESULTS: Forty-one manuscripts were randomized to plain English abstracts (14), visual abstracts (14) and standard tweets (13). The number of public engagements was low, with a mean of 1·8 (range 0-8), 2·5 (0-11), and 1·2 (0-4) for plain English abstracts, visual abstracts and standard tweets respectively. The mean number of engagements by healthcare professionals was 29·4 (6-66), 45·3 (6-161) and 28·8 (10-52) respectively. Overall, visual abstracts attracted a significantly greater number of engagements than plain English ones (P < 0·001). CONCLUSION: Online, public engagement with surgical research was low. Overall engagement (predominantly from healthcare professionals) was enhanced by the use of visual abstracts.


ANTECEDENTES: Los pacientes están tomando cada vez más un papel activo en el diseño y en la difusión de la investigación quirúrgica. También se debe fomentar la comunicación pública de los resultados, pero a menudo ésta se limita a comentarios de personas no expertas. Este estudio evaluó el papel de los resúmenes redactados en un inglés sencillo difundidos a través de las redes sociales para involucrar a pacientes y médicos en la comunicación de la investigación quirúrgica. MÉTODOS: Se realizó un ensayo aleatorizado y controlado de tres brazos con un diseño cruzado de los dos brazos de intervención. Los manuscritos aceptados para publicación en BJS se asignaron a tres brazos y se difundieron vía twitter: resúmenes redactados en un inglés sencillo, resúmenes visuales, y tweets estándar. El criterio de valoración principal fue la interacción online (variable compuesta de tweets, respuestas y me gusta) por parte del público durante los primeros 14 días. El criterio de valoración secundario fue la interacción online de los profesionales de la salud. RESULTADOS: Un total de 41 manuscritos se asignaron al azar a resúmenes redactados en un inglés sencillo (n = 14), resúmenes visuales (n = 14) y tweets estándar (n = 13). El número de interacciones por parte del público fue bajo, con una media de 1,8 (rango 0-8), 2,5 (rango 0-11) y 1,2 (rango 0-4) para resúmenes en inglés sencillo, resúmenes visuales y tweets estándar, respectivamente. El número medio de interacciones por profesionales de la salud fue de 29,4 (rango 6-66), 45,3 (6-161) y 28,8 (10-52). En general, los resúmenes visuales atrajeron un número significativamente mayor de interacciones que los de inglés sencillo (P = 0,001). CONCLUSIÓN: La interacción online del público con la investigación quirúrgica fue baja. La participación general (predominantemente de profesionales de la salud) mejoró mediante el uso de resúmenes visuales. Los próximos trabajos podrían considerar si el público desea interaccionar y de qué modo con resúmenes redactados en un inglés sencillo.

12.
AIDS Behav ; 23(1): 222-251, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30073636

RESUMO

This systematic literature review identified factors associated with sexual risks related to sexually transmitted infections (STI), HIV and other blood-borne viruses (BBV) among women using heroin and other drugs. The search strategy included five databases (PubMed, EMBASE, PsycNET, Web of Science, Scopus), and PsycEXTRA for grey literature. Out of the 12,135 publications screened, 30 peer-reviewed articles were included. Most publications were cross-sectional (n = 25), quantitative (n = 23) and included 11,305 women. Factors identified were: (1) socio-demographics; (2) gender roles and violence against women; (3) substance use; (4) transactional sex; (5) partner characteristics, partner's drug use, and context of sex; (6) preferences, negotiation and availability of condoms; (7) HIV status and STIs; (8) number of sexual partners; (9) love and trust; (10) reproductive health and motherhood; and (11) risk awareness and perception of control. Overall, this review highlights important implications for future research and practice, and provides evidence for developing STI/BBV preventive strategies.


Assuntos
Infecções por HIV/epidemiologia , Dependência de Heroína/epidemiologia , Infecções Sexualmente Transmissíveis/epidemiologia , Violência/estatística & dados numéricos , Viroses/epidemiologia , Patógenos Transmitidos pelo Sangue , Preservativos , Estudos Transversais , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Negociação , Saúde Reprodutiva , Fatores de Risco , Assunção de Riscos , Trabalho Sexual/estatística & dados numéricos , Comportamento Sexual , Parceiros Sexuais , Transtornos Relacionados ao Uso de Substâncias/epidemiologia
13.
Nature ; 498(7454): 338-41, 2013 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-23698363

RESUMO

Stellar archaeology shows that massive elliptical galaxies formed rapidly about ten billion years ago with star-formation rates of above several hundred solar masses per year. Their progenitors are probably the submillimetre bright galaxies at redshifts z greater than 2. Although the mean molecular gas mass (5 × 10(10) solar masses) of the submillimetre bright galaxies can explain the formation of typical elliptical galaxies, it is inadequate to form elliptical galaxies that already have stellar masses above 2 × 10(11) solar masses at z ≈ 2. Here we report multi-wavelength high-resolution observations of a rare merger of two massive submillimetre bright galaxies at z = 2.3. The system is seen to be forming stars at a rate of 2,000 solar masses per year. The star-formation efficiency is an order of magnitude greater than that of normal galaxies, so the gas reservoir will be exhausted and star formation will be quenched in only around 200 million years. At a projected separation of 19 kiloparsecs, the two massive starbursts are about to merge and form a passive elliptical galaxy with a stellar mass of about 4 × 10(11) solar masses. We conclude that gas-rich major galaxy mergers with intense star formation can form the most massive elliptical galaxies by z ≈ 1.5.

14.
Nature ; 495(7441): 344-7, 2013 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-23485967

RESUMO

In the past decade, our understanding of galaxy evolution has been revolutionized by the discovery that luminous, dusty starburst galaxies were 1,000 times more abundant in the early Universe than at present. It has, however, been difficult to measure the complete redshift distribution of these objects, especially at the highest redshifts (z > 4). Here we report a redshift survey at a wavelength of three millimetres, targeting carbon monoxide line emission from the star-forming molecular gas in the direction of extraordinarily bright millimetre-wave-selected sources. High-resolution imaging demonstrates that these sources are strongly gravitationally lensed by foreground galaxies. We detect spectral lines in 23 out of 26 sources and multiple lines in 12 of those 23 sources, from which we obtain robust, unambiguous redshifts. At least 10 of the sources are found to lie at z > 4, indicating that the fraction of dusty starburst galaxies at high redshifts is greater than previously thought. Models of lens geometries in the sample indicate that the background objects are ultra-luminous infrared galaxies, powered by extreme bursts of star formation.

15.
Nature ; 496(7445): 329-33, 2013 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-23598341

RESUMO

Massive present-day early-type (elliptical and lenticular) galaxies probably gained the bulk of their stellar mass and heavy elements through intense, dust-enshrouded starbursts--that is, increased rates of star formation--in the most massive dark-matter haloes at early epochs. However, it remains unknown how soon after the Big Bang massive starburst progenitors exist. The measured redshift (z) distribution of dusty, massive starbursts has long been suspected to be biased low in z owing to selection effects, as confirmed by recent findings of systems with redshifts as high as ~5 (refs 2-4). Here we report the identification of a massive starburst galaxy at z = 6.34 through a submillimetre colour-selection technique. We unambiguously determined the redshift from a suite of molecular and atomic fine-structure cooling lines. These measurements reveal a hundred billion solar masses of highly excited, chemically evolved interstellar medium in this galaxy, which constitutes at least 40 per cent of the baryonic mass. A 'maximum starburst' converts the gas into stars at a rate more than 2,000 times that of the Milky Way, a rate among the highest observed at any epoch. Despite the overall downturn in cosmic star formation towards the highest redshifts, it seems that environments mature enough to form the most massive, intense starbursts existed at least as early as 880 million years after the Big Bang.

16.
Clin Radiol ; 74(7): 496-502, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31126587

RESUMO

One of the most challenging areas of radiological imaging in children is the diagnosis of physical abuse. There is a dearth of paediatric radiologists willing to act as expert witnesses, particularly in the family courts. There are a number of reasons why radiologists may not be interested or willing to put themselves forward to work as expert witnesses in this field. A group of imaging experts recently formed the "British Society of Paediatric Radiology (BSPR) Working Group on Imaging in Suspected Physical Abuse (SPA)". The group comprises radiologists and neuroradiologists with current or previous experience of providing expert witness reports to the court in cases of SPA. The group met in January 2019 to explore pragmatic solutions to the chronic inefficiencies in both medical and legal practices and the challenges that arise from working in a legal arena with different structures, goals, and assessment criteria. Key issues concerned organisational inefficiencies, variable support from National Health Service Trusts and the Royal College of Radiologists to conduct this work, and the risk/benefit of involvement. This work is important for the patient, parents, and society in general, and highly rewarding for clinical practitioners who are involved, but there are several issues with current practices that discourage active participation. With several members of the group either retired or close to retirement, the shortage of experts is becoming a pressing issue within the UK, which requires an engaged multidisciplinary group to come up with creative solutions. Here, the group provide a consensus opinion highlighting the current barriers and potential facilitators to increasing the number of radiologists willing to provide opinions to the court.


Assuntos
Maus-Tratos Infantis/legislação & jurisprudência , Prova Pericial/legislação & jurisprudência , Mão de Obra em Saúde , Pediatria/legislação & jurisprudência , Radiologistas/legislação & jurisprudência , Criança , Humanos , Sociedades Médicas , Reino Unido
17.
J Math Biol ; 78(7): 2059-2092, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30826846

RESUMO

Calcium signalling is one of the most important mechanisms of information propagation in the body. In embryogenesis the interplay between calcium signalling and mechanical forces is critical to the healthy development of an embryo but poorly understood. Several types of embryonic cells exhibit calcium-induced contractions and many experiments indicate that calcium signals and contractions are coupled via a two-way mechanochemical feedback mechanism. We present a new analysis of experimental data that supports the existence of this coupling during apical constriction. We then propose a simple mechanochemical model, building on early models that couple calcium dynamics to the cell mechanics and we replace the hypothetical bistable calcium release with modern, experimentally validated calcium dynamics. We assume that the cell is a linear, viscoelastic material and we model the calcium-induced contraction stress with a Hill function, i.e. saturating at high calcium levels. We also express, for the first time, the "stretch-activation" calcium flux in the early mechanochemical models as a bottom-up contribution from stretch-sensitive calcium channels on the cell membrane. We reduce the model to three ordinary differential equations and analyse its bifurcation structure semi-analytically as two bifurcation parameters vary-the [Formula: see text] concentration, and the "strength" of stretch activation, [Formula: see text]. The calcium system ([Formula: see text], no mechanics) exhibits relaxation oscillations for a certain range of [Formula: see text] values. As [Formula: see text] is increased the range of [Formula: see text] values decreases and oscillations eventually vanish at a sufficiently high value of [Formula: see text]. This result agrees with experimental evidence in embryonic cells which also links the loss of calcium oscillations to embryo abnormalities. Furthermore, as [Formula: see text] is increased the oscillation amplitude decreases but the frequency increases. Finally, we also identify the parameter range for oscillations as the mechanical responsiveness factor of the cytosol increases. This work addresses a very important and not well studied question regarding the coupling between chemical and mechanical signalling in embryogenesis.


Assuntos
Algoritmos , Sinalização do Cálcio , Cálcio/metabolismo , Embrião de Mamíferos/metabolismo , Desenvolvimento Embrionário , Células Epiteliais/metabolismo , Mecanotransdução Celular , Simulação por Computador , Embrião de Mamíferos/citologia , Células Epiteliais/citologia , Humanos , Modelos Biológicos
18.
Br J Surg ; 105(7): 797-810, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29469195

RESUMO

BACKGROUND: Postoperative ileus (POI) is characterized by delayed gastrointestinal recovery following surgery. Current knowledge of pathophysiology, clinical interventions and methodological challenges was reviewed to inform modern practice and future research. METHODS: A systematic search of MEDLINE and Embase databases was performed using search terms related to ileus and colorectal surgery. All RCTs involving an intervention to prevent or reduce POI published between 1990 and 2016 were identified. Grey literature, non-full-text manuscripts, and reanalyses of previous RCTs were excluded. Eligible articles were assessed using the Cochrane tool for assessing risk of bias. RESULTS: Of 5614 studies screened, 86 eligible articles describing 88 RCTs were identified. Current knowledge of pathophysiology acknowledges neurogenic, inflammatory and pharmacological mechanisms, but much of the evidence arises from animal studies. The most common interventions tested were chewing gum (11 trials) and early enteral feeding (11), which are safe but of unclear benefit for actively reducing POI. Others, including thoracic epidural analgesia (8), systemic lidocaine (8) and peripheral µ antagonists (5), show benefit but require further investigation for safety and cost-effectiveness. CONCLUSION: POI is a common condition with no established definition, aetiology or treatment. According to current literature, minimally invasive surgery, protocol-driven recovery (including early feeding and opioid avoidance strategies) and measures to avoid major inflammatory events (such as anastomotic leak) offer the best chances of reducing POI.


Assuntos
Colo/cirurgia , Íleus/prevenção & controle , Complicações Pós-Operatórias/prevenção & controle , Reto/cirurgia , Goma de Mascar , Colectomia/efeitos adversos , Nutrição Enteral , Humanos , Íleus/fisiopatologia , Complicações Pós-Operatórias/fisiopatologia
19.
Colorectal Dis ; 20(1): O17-O25, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29178625

RESUMO

AIM: The management of postoperative ileus following colorectal surgery remains controversial. It is the commonest complication after elective colorectal resection and is associated with an increased incidence of postoperative adverse events. The prevention and management of postoperative ileus remains unstandardized. This study aims to describe an international profile of gastrointestinal recovery after colorectal surgery and will assess the role of non-steroidal anti-inflammatory drugs, when used as postoperative analgesia, in expediting the return of gastrointestinal function. METHODS: A multicentre, student- and trainee-led, prospective cohort study will be conducted across both Europe and Australasia. Adult patients undergoing elective colorectal resection during 2-week data collection periods between January and April 2018 will be included. A site-specific questionnaire will capture compliance to Enhanced Recovery after Surgery components at participating centres. The primary outcome is time to gastrointestinal recovery, measured using a composite outcome of bowel function and oral tolerance. The impact of non-steroidal anti-inflammatory drugs on gastrointestinal recovery will be evaluated along with safety data with respect to anastomotic leak, acute kidney injury and complications within 30 days of surgery. DISCUSSION: This protocol describes the methodology of an international, observational assessment of gastrointestinal recovery after colorectal surgery. It discusses key challenges and describes how the results will impact on future investigation. The study will be conducted across a large student- and trainee-led collaborative network, with prospective quality assurance and data validation strategies.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Cirurgia Colorretal/efeitos adversos , Íleus/terapia , Complicações Pós-Operatórias/terapia , Recuperação de Função Fisiológica/efeitos dos fármacos , Adulto , Anti-Inflamatórios não Esteroides/efeitos adversos , Australásia , Estudos de Coortes , Colo/patologia , Colo/cirurgia , Procedimentos Cirúrgicos Eletivos/efeitos adversos , Europa (Continente) , Feminino , Humanos , Masculino , Complicações Pós-Operatórias/etiologia , Estudos Prospectivos , Reto/patologia , Reto/cirurgia
20.
J Public Health (Oxf) ; 40(4): 676-683, 2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-29145590

RESUMO

Background: Rising use of foodbanks highlights food insecurity in the UK. Adverse life events (e.g. unemployment, benefit delays or sanctions) and financial strains are thought to be the drivers of foodbank use. This research aimed to explore who uses foodbanks, and factors associated with increased food insecurity. Methods: We surveyed those seeking help from front line crisis providers from foodbanks (N = 270) and a comparison group from Advice Centres (ACs) (N = 245) in relation to demographics, adverse life events, financial strain and household food security. Results: About 55.9% of foodbank users were women and the majority were in receipt of benefits (64.8%). Benefit delays (31.9%), changes (11.1%) and low income (19.6%) were the most common reasons given for referral. Compared to AC users, there were more foodbank users who were single men without children, unemployed, currently homeless, experiencing more financial strain and adverse life events (P = 0.001). Food insecurity was high in both populations, and more severe if they also reported financial strain and adverse life events. Conclusions: Benefit-related problems appear to be a key reason for foodbank referral. By comparison with other disadvantaged groups, foodbank users experienced more financial strain, adverse life events, both increased the severity of food insecurity.


Assuntos
Financiamento Pessoal , Assistência Alimentar , Abastecimento de Alimentos/estatística & dados numéricos , Adulto , Escolaridade , Feminino , Assistência Alimentar/estatística & dados numéricos , Abastecimento de Alimentos/economia , Humanos , Masculino , Estado Civil , Pobreza/economia , Pobreza/estatística & dados numéricos , Reino Unido
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