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2.
Nature ; 622(7982): 255-260, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37648866

RESUMO

Neptune-sized planets exhibit a wide range of compositions and densities, depending on factors related to their formation and evolution history, such as the distance from their host stars and atmospheric escape processes. They can vary from relatively low-density planets with thick hydrogen-helium atmospheres1,2 to higher-density planets with a substantial amount of water or a rocky interior with a thinner atmosphere, such as HD 95338 b (ref. 3), TOI-849 b (ref. 4) and TOI-2196 b (ref. 5). The discovery of exoplanets in the hot-Neptune desert6, a region close to the host stars with a deficit of Neptune-sized planets, provides insights into the formation and evolution of planetary systems, including the existence of this region itself. Here we show observations of the transiting planet TOI-1853 b, which has a radius of 3.46 ± 0.08 Earth radii and orbits a dwarf star every 1.24 days. This planet has a mass of 73.2 ± 2.7 Earth masses, almost twice that of any other Neptune-sized planet known so far, and a density of 9.7 ± 0.8 grams per cubic centimetre. These values place TOI-1853 b in the middle of the Neptunian desert and imply that heavy elements dominate its mass. The properties of TOI-1853 b present a puzzle for conventional theories of planetary formation and evolution, and could be the result of several proto-planet collisions or the final state of an initially high-eccentricity planet that migrated closer to its parent star.

3.
Science ; 374(6572): 1271-1275, 2021 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-34855492

RESUMO

Ultrashort-period (USP) exoplanets have orbital periods shorter than 1 day. Precise masses and radii of USP exoplanets could provide constraints on their unknown formation and evolution processes. We report the detection and characterization of the USP planet GJ 367b using high-precision photometry and radial velocity observations. GJ 367b orbits a bright (V-band magnitude of 10.2), nearby, and red (M-type) dwarf star every 7.7 hours. GJ 367b has a radius of 0.718 ± 0.054 Earth-radii and a mass of 0.546 ± 0.078 Earth-masses, making it a sub-Earth planet. The corresponding bulk density is 8.106 ± 2.165 grams per cubic centimeter­close to that of iron. An interior structure model predicts that the planet has an iron core radius fraction of 86 ± 5%, similar to that of Mercury's interior.

4.
Radiother Oncol ; 161: 166-176, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34146616

RESUMO

BACKGROUND: Radiotherapy reduces in-breast recurrence risk in early breast cancer (EBC) in older women. This benefit may be small and should be balanced against treatment effect and holistic patient assessment. This study described treatment patterns according to fitness and impact on health-related quality-of-life (HRQoL). METHODS: A multicentre, observational study of EBC patients aged ≥ 70 years, undergoing breast-conserving surgery (BCS) or mastectomy, was undertaken. Associations between radiotherapy use, surgery, clinico-pathological parameters, fitness based on geriatric parameters and treatment centre were determined. HRQoL was measured using the European Organisation for the Research and Treatment of Cancer (EORTC) questionnaires. RESULTS: In 2013-2018 2811 women in 56 UK study centres underwent surgery with a median follow-up of 52 months. On multivariable analysis, age and tumour risk predicted radiotherapy use. Among healthier patients (based on geriatric assessments) with high-risk tumours, 534/613 (87.1%) having BCS and 185/341 (54.2%) having mastectomy received radiotherapy. In less fit individuals with low-risk tumours undergoing BCS, 149/207 (72.0%) received radiotherapy. Radiotherapy effects on HRQoL domains, including breast symptoms and fatigue were seen, resolving by 18 months. CONCLUSION: Radiotherapy use in EBC patients ≥ 70 years is affected by age and recurrence risk, whereas geriatric parameters have limited impact regardless of type of surgery. There was geographical variation in treatment, with some fit older women with high-risk tumours not receiving radiotherapy, and some older, low-risk, EBC patients receiving radiotherapy after BCS despite evidence of limited benefit. The impact on HRQoL is transient.


Assuntos
Neoplasias da Mama , Idoso , Neoplasias da Mama/radioterapia , Neoplasias da Mama/cirurgia , Estudos de Coortes , Feminino , Humanos , Mastectomia , Mastectomia Segmentar , Qualidade de Vida , Radioterapia Adjuvante
5.
Br J Cancer ; 125(2): 209-219, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33972747

RESUMO

BACKGROUND: Chemotherapy improves outcomes for high risk early breast cancer (EBC) patients but is infrequently offered to older individuals. This study determined if there are fit older patients with high-risk disease who may benefit from chemotherapy. METHODS: A multicentre, prospective, observational study was performed to determine chemotherapy (±trastuzumab) usage and survival and quality-of-life outcomes in EBC patients aged ≥70 years. Propensity score-matching adjusted for variation in baseline age, fitness and tumour stage. RESULTS: Three thousands four hundred sixteen women were recruited from 56 UK centres between 2013 and 2018. Two thousands eight hundred eleven (82%) had surgery. 1520/2811 (54%) had high-risk EBC and 2059/2811 (73%) were fit. Chemotherapy was given to 306/1100 (27.8%) fit patients with high-risk EBC. Unmatched comparison of chemotherapy versus no chemotherapy demonstrated reduced metastatic recurrence risk in high-risk patients(hazard ratio [HR] 0.36 [95% CI 0.19-0.68]) and in 541 age, stage and fitness-matched patients(adjusted HR 0.43 [95% CI 0.20-0.92]) but no benefit to overall survival (OS) or breast cancer-specific survival (BCSS) in either group. Chemotherapy improved survival in women with oestrogen receptor (ER)-negative cancer (OS: HR 0.20 [95% CI 0.08-0.49];BCSS: HR 0.12 [95% CI 0.03-0.44]).Transient negative quality-of-life impacts were observed. CONCLUSIONS: Chemotherapy was associated with reduced risk of metastatic recurrence, but survival benefits were only seen in patients with ER-negative cancer. Quality-of-life impacts were significant but transient. TRIAL REGISTRATION: ISRCTN 46099296.


Assuntos
Antraciclinas/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Hidrocarbonetos Aromáticos com Pontes/uso terapêutico , Qualidade de Vida/psicologia , Taxoides/uso terapêutico , Trastuzumab/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Antraciclinas/efeitos adversos , Neoplasias da Mama/psicologia , Hidrocarbonetos Aromáticos com Pontes/efeitos adversos , Tratamento Farmacológico , Feminino , Humanos , Satisfação do Paciente/estatística & dados numéricos , Pontuação de Propensão , Estudos Prospectivos , Análise de Sobrevida , Taxoides/efeitos adversos , Trastuzumab/efeitos adversos , Resultado do Tratamento
6.
Eur J Cancer ; 144: 269-280, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33373871

RESUMO

INTRODUCTION: Older patients with early breast cancer (EBC) derive modest survival benefit from chemotherapy but have increased toxicity risk. Data on the impact of chemotherapy for EBC on quality of life in older patients are limited, but this is a key determinant of treatment acceptance. We aimed to investigate its effect on quality of life in older patients enrolled in the Bridging the Age Gap study. MATERIALS AND METHODS: A prospective, multicentre, observational study of EBC patients ≥70 years old was conducted in 2013-2018 at 56 UK hospitals. Demographics, patient, tumour characteristics, treatments and adverse events were recorded. Quality of life was assessed using the European Organisation for Research and Treatment of Cancer Quality-of-Life Questionnaires (EORTC-QLQ) C30, BR23 and ELD 15 plus the Euroqol-5D (eq-5d) over 24 months and analysed at each time point using baseline adjusted linear regression analysis and propensity score-matching. RESULTS: Three thousand and four hundred sixteen patients were enrolled in the study; 1520 patients undergoing surgery and who had high-risk EBC were included in this analysis. 376/1520 (24.7%) received chemotherapy. At 6 months, chemotherapy had a significant negative impact in several EORTC-QLQ-C30 domains, including global health score, physical, role, social functioning, cognition, fatigue, nausea/vomiting, dyspnoea, appetite loss, diarrhoea and constipation. Similar trends were documented on other scales (EORTC-QLQ-BR23, EORTC-QLQ-ELD15 and EQ-5D-5L). Its impact was no longer significant at 18-24 months in unmatched and matched cohorts. CONCLUSIONS: The negative impact of chemotherapy on quality-of-life is clinically and statistically significant at 6 months but resolves by 18 months, which is crucial to inform decision-making for older patients contemplating chemotherapy. TRIAL REGISTRATION NUMBER ISRCTN: 46099296.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/psicologia , Carcinoma Ductal de Mama/psicologia , Carcinoma Lobular/psicologia , Qualidade de Vida , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/tratamento farmacológico , Carcinoma Ductal de Mama/patologia , Carcinoma Lobular/tratamento farmacológico , Carcinoma Lobular/patologia , Feminino , Seguimentos , Humanos , Prognóstico , Estudos Prospectivos , Inquéritos e Questionários
7.
Nature ; 585(7825): 363-367, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32939071

RESUMO

Astronomers have discovered thousands of planets outside the Solar System1, most of which orbit stars that will eventually evolve into red giants and then into white dwarfs. During the red giant phase, any close-orbiting planets will be engulfed by the star2, but more distant planets can survive this phase and remain in orbit around the white dwarf3,4. Some white dwarfs show evidence for rocky material floating in their atmospheres5, in warm debris disks6-9 or orbiting very closely10-12, which has been interpreted as the debris of rocky planets that were scattered inwards and tidally disrupted13. Recently, the discovery of a gaseous debris disk with a composition similar to that of ice giant planets14 demonstrated that massive planets might also find their way into tight orbits around white dwarfs, but it is unclear whether these planets can survive the journey. So far, no intact planets have been detected in close orbits around white dwarfs. Here we report the observation of a giant planet candidate transiting the white dwarf WD 1856+534 (TIC 267574918) every 1.4 days. We observed and modelled the periodic dimming of the white dwarf caused by the planet candidate passing in front of the star in its orbit. The planet candidate is roughly the same size as Jupiter and is no more than 14 times as massive (with 95 per cent confidence). Other cases of white dwarfs with close brown dwarf or stellar companions are explained as the consequence of common-envelope evolution, wherein the original orbit is enveloped during the red giant phase and shrinks owing to friction. In this case, however, the long orbital period (compared with other white dwarfs with close brown dwarf or stellar companions) and low mass of the planet candidate make common-envelope evolution less likely. Instead, our findings for the WD 1856+534 system indicate that giant planets can be scattered into tight orbits without being tidally disrupted, motivating the search for smaller transiting planets around white dwarfs.

8.
Nature ; 583(7814): 39-42, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32612222

RESUMO

The interiors of giant planets remain poorly understood. Even for the planets in the Solar System, difficulties in observation lead to large uncertainties in the properties of planetary cores. Exoplanets that have undergone rare evolutionary processes provide a route to understanding planetary interiors. Planets found in and near the typically barren hot-Neptune 'desert'1,2 (a region in mass-radius space that contains few planets) have proved to be particularly valuable in this regard. These planets include HD149026b3, which is thought to have an unusually massive core, and recent discoveries such as LTT9779b4 and NGTS-4b5, on which photoevaporation has removed a substantial part of their outer atmospheres. Here we report observations of the planet TOI-849b, which has a radius smaller than Neptune's but an anomalously large mass of [Formula: see text] Earth masses and a density of [Formula: see text] grams per cubic centimetre, similar to Earth's. Interior-structure models suggest that any gaseous envelope of pure hydrogen and helium consists of no more than [Formula: see text] per cent of the total planetary mass. The planet could have been a gas giant before undergoing extreme mass loss via thermal self-disruption or giant planet collisions, or it could have avoided substantial gas accretion, perhaps through gap opening or late formation6. Although photoevaporation rates cannot account for the mass loss required to reduce a Jupiter-like gas giant, they can remove a small (a few Earth masses) hydrogen and helium envelope on timescales of several billion years, implying that any remaining atmosphere on TOI-849b is likely to be enriched by water or other volatiles from the planetary interior. We conclude that TOI-849b is the remnant core of a giant planet.

9.
Astrophys J Lett ; 868(2)2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31360431

RESUMO

We report the detection of a transiting planet around π Men (HD 39091), using data from the Transiting Exoplanet Survey Satellite (TESS). The solar-type host star is unusually bright (V = 5.7) and was already known to host a Jovian planet on a highly eccentric, 5.7-year orbit. The newly discovered planet has a size of 2.04 ± 0.05 R ⊕ and an orbital period of 6.27 days. Radial-velocity data from the HARPS and AAT/UCLES archives also displays a 6.27-day periodicity, confirming the existence of the planet and leading to a mass determination of 4.82±0.85 M ⊕. The star's proximity and brightness will facilitate further investigations, such as atmospheric spectroscopy, asteroseismology, the Rossiter-McLaughlin effect, astrometry, and direct imaging.

10.
Nature ; 546(7659): 514-518, 2017 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-28582774

RESUMO

The amount of ultraviolet irradiation and ablation experienced by a planet depends strongly on the temperature of its host star. Of the thousands of extrasolar planets now known, only six have been found that transit hot, A-type stars (with temperatures of 7,300-10,000 kelvin), and no planets are known to transit the even hotter B-type stars. For example, WASP-33 is an A-type star with a temperature of about 7,430 kelvin, which hosts the hottest known transiting planet, WASP-33b (ref. 1); the planet is itself as hot as a red dwarf star of type M (ref. 2). WASP-33b displays a large heat differential between its dayside and nightside, and is highly inflated-traits that have been linked to high insolation. However, even at the temperature of its dayside, its atmosphere probably resembles the molecule-dominated atmospheres of other planets and, given the level of ultraviolet irradiation it experiences, its atmosphere is unlikely to be substantially ablated over the lifetime of its star. Here we report observations of the bright star HD 195689 (also known as KELT-9), which reveal a close-in (orbital period of about 1.48 days) transiting giant planet, KELT-9b. At approximately 10,170 kelvin, the host star is at the dividing line between stars of type A and B, and we measure the dayside temperature of KELT-9b to be about 4,600 kelvin. This is as hot as stars of stellar type K4 (ref. 5). The molecules in K stars are entirely dissociated, and so the primary sources of opacity in the dayside atmosphere of KELT-9b are probably atomic metals. Furthermore, KELT-9b receives 700 times more extreme-ultraviolet radiation (that is, with wavelengths shorter than 91.2 nanometres) than WASP-33b, leading to a predicted range of mass-loss rates that could leave the planet largely stripped of its envelope during the main-sequence lifetime of the host star.

11.
J Am Osteopath Assoc ; 115(5): 324-30, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25938527

RESUMO

Dissemination is an important part of translational research. When the results of high-quality studies reach a wide audience of peers, they provide an evidence base that can guide practice and improve patient care and safety. From proposal to publication, the authors provide the novice researcher with advice on ethics, tips on selecting a journal, a summary of manuscript requirements, and a brief outline of the submission process and outcomes. By demystifying these processes and outlining some of the basic requirements, the authors hope to encourage novice researchers to engage in quality research and prepare them for disseminating their results.


Assuntos
Pesquisa Biomédica/tendências , Guias como Assunto , Medicina Osteopática/métodos , Editoração/organização & administração , Pesquisadores/organização & administração , Humanos
12.
Cochrane Database Syst Rev ; 5: CD004272, 2014 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-35658165

RESUMO

BACKGROUND: Several studies have evaluated the clinical effectiveness of endocrine therapy alone in women aged 70 years or over with operable breast cancer and who are fit for surgery. OBJECTIVES: To systematically review the evidence for the clinical effectiveness of surgery (with or without adjuvant endocrine therapy) in comparison to primary endocrine therapy in the treatment of operable breast cancer in women aged 70 years and over, both in terms of local progression and mortality. SEARCH METHODS: We conducted an updated search of the Cochrane Breast Cancer Group's Specialised Register (27th March 2013) and new searches of the Cochrane Central Register of Controlled Trials (CENTRAL, 2013, Issue 3), MEDLINE, EMBASE, the World Health Organization's International Clinical Trials Registry Platform (apps.who.int/trialsearch/) and www. CLINICALTRIALS: gov, using the search terms 'early breast cancer', 'endocrine therapy', 'psychosocial' or 'surgery'. SELECTION CRITERIA: Randomised trials comparing surgery, with or without adjuvant endocrine therapy, to primary endocrine therapy in the management of women aged 70 years or over with early breast cancer and who were fit for surgery. DATA COLLECTION AND ANALYSIS: We assessed studies for eligibility and quality, and two review authors independently extracted data from published trials. We derived hazard ratios for time-to-event outcomes, where possible, and used a fixed-effect model for meta-analysis. We extracted toxicity and quality-of-life data, where present. Where outcome data were not available, we contacted trialists and requested unpublished data. MAIN RESULTS: We identified seven eligible trials, of which six had published time-to-event data and one was published only in abstract form with no usable data. The quality of the allocation concealment was adequate in three studies and unclear in the remainder. In each case the endocrine therapy used was tamoxifen. Data, based on an estimated 1081 deaths in 1571 women, did not show a statistically significant difference in favour of either surgery or primary endocrine therapy in respect of overall survival. However, there was a statistically significant difference in terms of progression-free survival, which favoured surgery with (474 participants) or without endocrine therapy (164 participants). The hazard ratios (HRs) for overall survival were: HR 0.98 (95% confidence interval (CI) 0.81 to 1.20, P = 0.85; 3 trials, 495 participants) for surgery alone versus primary endocrine therapy; HR 0.86 (95% CI 0.73 to 1.00, P = 0.06; 3 trials, 1076 participants) for surgery plus endocrine therapy versus primary endocrine therapy. The HRs for progression-free survival were: HR 0.55 (95% CI 0.39 to 0.77, P = 0.0006) for surgery alone versus primary endocrine therapy; HR 0.65 (95% CI 0.53 to 0.81, P = 0.0001) for surgery plus endocrine therapy versus primary endocrine therapy (each comparison based on only one trial). Tamoxifen-related adverse effects included hot flushes, skin rash, vaginal discharge, indigestion, breast pain, sleepiness, headache, vertigo, itching, hair loss, cystitis, acute thrombophlebitis, nausea, and indigestion. Surgery-related adverse effects included paraesthesia on the ipsilateral arm and lateral thoracic wall in those who had axillary clearance. One study suggested that those undergoing surgery suffered more psychosocial morbidity at three months post-surgery, although this difference had disappeared by two years. AUTHORS' CONCLUSIONS: Primary endocrine therapy should only be offered to women with oestrogen receptor (ER)-positive tumours who are unfit for surgery, at increased risk of serious surgical or anaesthetic complications if subjected to surgery, or who refuse surgery. In a cohort of women with significant co-morbid disease and ER-positive tumours it is possible that primary endocrine therapy may be a superior option to surgery. Trials are needed to evaluate the clinical effectiveness of aromatase inhibitors as primary therapy for an infirm older population with ER-positive tumours.

13.
Health Expect ; 14(2): 133-46, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21029281

RESUMO

BACKGROUND: There is interest in interventions that provide support for patients facing challenging decisions, such as the choice between mastectomy and breast conservation surgery for breast cancer. However, it is difficult to implement these interventions. One potential source of resistance is the attitudes of clinicians. OBJECTIVE: To examine specialist breast clinicians' opinions about the provision of decision support interventions (DesIs) for patients. METHODS: As part of the development of a web-based DesI (BresDex), semi-structured interviews were conducted with specialist clinicians [breast surgeons, breast care nurses (BCNs) and oncologists] from four breast units in a UK region, and speciality national opinion leaders. Interviews were recorded, transcribed and analysed using the Framework approach. RESULTS: A majority of the 24 clinicians interviewed did not have a working knowledge of DesIs and were ambivalent or sceptical. Many expressed conflicting opinions: they noted the potential benefits, but at the same time expressed reservations about information overlap, overload and about content that they considered inappropriate. Many wanted access to DesIs to be always under clinical supervision. In particular, they were uncertain as regards how DeSIs could be tailored to individual patients' needs and also accommodate clinical practice variation. BCNs were particularly concerned that DesIs might induce patient anxiety and replace their role. CONCLUSIONS: The concept of providing interventions to support patients in decision-making tasks generated concern, defensiveness and scepticism. These attitudes will be a significant barrier. Implementation efforts will need to recognize and address these issues if these interventions are to become embedded in clinical practice.


Assuntos
Atitude do Pessoal de Saúde , Neoplasias da Mama/cirurgia , Sistemas de Apoio a Decisões Clínicas , Mastectomia/psicologia , Educação de Pacientes como Assunto/métodos , Médicos/psicologia , Neoplasias da Mama/psicologia , Feminino , Humanos , Internet , Entrevistas como Assunto , Masculino , Mastectomia/métodos , Relações Médico-Paciente , Reino Unido
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