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1.
J Appl Clin Med Phys ; : e14396, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38894588

RESUMO

Noncoplanar arc optimization has been shown to reduce OAR doses in SRS/SRT and has the potential to reduce doses to OARs in SBRT. Extracranial targets have additional considerations, including large OARs and, in the case of the liver, volume constraints on the healthy liver. Considering pathlengths through OARs that encompass target volumes may lead to specific dose reductions as in the encompassing healthy liver tissue. These optimizations must also leverage delivery efficiency and trajectory sampling to ensure ease of clinical translation. The purpose of this research is to generate optimized static-couch arcs that separately consider serial and parallel OARs and arc delivery efficiency, with a trajectory sampling metric, towards the aim of reducing dose to OARs and the surrounding healthy liver tissue. Separate BEV cost maps were created for parallel, and serial OARs by means of a fast ray-triangle intersection algorithm. An additional BEV cost map was created for the liver which, by definition, encompasses the liver tumors. The individual costs of these maps were summed and combined with the sampling metric for 100 000 random combinations of arc trajectories. A search algorithm was applied to find an arc trajectory solution that satisfied BEV cost and sampling optimization, while also ensuring an efficient delivery was possible with a low number of arcs. This method of arc selection was evaluated for 16 liver SBRT patients characterized by small and large target volumes. Comparisons were made with a clinical arc template of coplanar arcs. Dosimetric plan quality was evaluated using published guidelines and metrics from RTOG1112. Four of five plan quality metrics for the liver were significantly reduced when planned with optimized noncoplanar arcs. Median (range) reductions of the volumes receiving 10, 18, and 21 Gy were found of 140.4 (295.8) cc (p = 0.001), 28.2 (230.6) cc (p = 0.002) and 18.5 (155.5) cc (p = 0.04). A significant increase in median (range) dose to the right kidney of 0.2 ± 0.9 Gy (p = 0.03) was also found using optimized noncoplanar arcs, which was below the tolerance of 10 Gy for all cases. The average number of arcs chosen was 4 ± 1. Optimizing serial and parallel OARs separately during static couch noncoplanar arc selection significantly reduced the dose to the liver during SBRT using a moderate number of arcs.

2.
Circulation ; 144(19): 1543-1552, 2021 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-34459659

RESUMO

BACKGROUND: Percutaneous closure of the left atrial appendage (LAA) is an alternative to chronic oral anticoagulation to reduce stroke risk in patients with nonvalvular atrial fibrillation. The Amulet IDE trial (Amplatzer Amulet Left Atrial Appendage Occluder IDE Trial) was designed to evaluate the safety and effectiveness of the dual-seal mechanism of the Amulet LAA occluder compared with the Watchman device. METHODS: Patients with nonvalvular atrial fibrillation at increased risk of stroke were randomly assigned (1:1) to undergo percutaneous implantation of a LAA occluder with the Amulet occluder or Watchman device. The primary end points included safety (composite of procedure-related complications, all-cause death, or major bleeding at 12 months), effectiveness (composite of ischemic stroke or systemic embolism at 18 months), and the rate of LAA occlusion at 45 days. Prespecified secondary end points included a composite of all stroke, systemic embolism, or cardiovascular/unexplained death at 18 months, major bleeding at 18 months, and superiority test of the 3 primary end points. RESULTS: A total of 1878 patients were enrolled. The Amulet occluder was noninferior to the Watchman device for the primary safety end point (14.5% versus 14.7%; difference=-0.14 [95% CI, -3.42 to 3.13]; P<0.001 for noninferiority). Major bleeding and all-cause death were similar between groups (10.6% versus 10.0% and 3.9% versus 5.1%, respectively). Procedure-related complications were higher for the Amulet occluder (4.5% versus 2.5%), largely related to more frequent pericardial effusion and device embolization. The Amulet occluder was noninferior to the Watchman device for the primary effectiveness end point (2.8% versus 2.8%; difference=0.00 [95% CI, -1.55 to 1.55]; P<0.001 for noninferiority), and the composite of stroke, systemic embolism, or cardiovascular/unexplained death (5.6% versus 7.7%, difference=-2.12 [95% CI, -4.45 to 0.21]; P<0.001 for noninferiority). The rate of major bleeding was similar between groups (11.6% versus 12.3%; difference=-0.71 [95% CI, -3.72 to 2.31]; P=0.32 for superiority). LAA occlusion was higher for the Amulet occluder than for the Watchman device (98.9% versus 96.8%; difference=2.03 [95% CI, 0.41-3.66]; P<0.001 for noninferiority; P=0.003 for superiority). CONCLUSIONS: The Amulet occluder was noninferior for safety and effectiveness of stroke prevention for nonvalvular atrial fibrillation compared with the Watchman device and superior for LAA occlusion. Procedure-related complications were higher with the Amulet occluder and decreased with operator experience. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02879448.


Assuntos
Dispositivo para Oclusão Septal/normas , Acidente Vascular Cerebral/terapia , Idoso , Feminino , Humanos , Masculino
3.
N Engl J Med ; 377(11): 1022-1032, 2017 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-28902590

RESUMO

BACKGROUND: Whether closure of a patent foramen ovale reduces the risk of recurrence of ischemic stroke in patients who have had a cryptogenic ischemic stroke is unknown. METHODS: In a multicenter, randomized, open-label trial, with blinded adjudication of end-point events, we randomly assigned patients 18 to 60 years of age who had a patent foramen ovale (PFO) and had had a cryptogenic ischemic stroke to undergo closure of the PFO (PFO closure group) or to receive medical therapy alone (aspirin, warfarin, clopidogrel, or aspirin combined with extended-release dipyridamole; medical-therapy group). The primary efficacy end point was a composite of recurrent nonfatal ischemic stroke, fatal ischemic stroke, or early death after randomization. The results of the analysis of the primary outcome from the original trial period have been reported previously; the current analysis of data from the extended follow-up period was considered to be exploratory. RESULTS: We enrolled 980 patients (mean age, 45.9 years) at 69 sites. Patients were followed for a median of 5.9 years. Treatment exposure in the two groups was unequal (3141 patient-years in the PFO closure group vs. 2669 patient-years in the medical-therapy group), owing to a higher dropout rate in the medical-therapy group. In the intention-to-treat population, recurrent ischemic stroke occurred in 18 patients in the PFO closure group and in 28 patients in the medical-therapy group, resulting in rates of 0.58 events per 100 patient-years and 1.07 events per 100 patient-years, respectively (hazard ratio with PFO closure vs. medical therapy, 0.55; 95% confidence interval [CI], 0.31 to 0.999; P=0.046 by the log-rank test). Recurrent ischemic stroke of undetermined cause occurred in 10 patients in the PFO closure group and in 23 patients in the medical-therapy group (hazard ratio, 0.38; 95% CI, 0.18 to 0.79; P=0.007). Venous thromboembolism (which comprised events of pulmonary embolism and deep-vein thrombosis) was more common in the PFO closure group than in the medical-therapy group. CONCLUSIONS: Among adults who had had a cryptogenic ischemic stroke, closure of a PFO was associated with a lower rate of recurrent ischemic strokes than medical therapy alone during extended follow-up. (Funded by St. Jude Medical; RESPECT ClinicalTrials.gov number, NCT00465270 .).


Assuntos
Anticoagulantes/uso terapêutico , Forame Oval Patente/tratamento farmacológico , Forame Oval Patente/terapia , Inibidores da Agregação Plaquetária/uso terapêutico , Prevenção Secundária/métodos , Dispositivo para Oclusão Septal , Acidente Vascular Cerebral/prevenção & controle , Adolescente , Adulto , Anticoagulantes/efeitos adversos , Quimioterapia Combinada , Feminino , Seguimentos , Forame Oval Patente/complicações , Forame Oval Patente/mortalidade , Humanos , Análise de Intenção de Tratamento , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Inibidores da Agregação Plaquetária/efeitos adversos , Recidiva , Dispositivo para Oclusão Septal/efeitos adversos , Método Simples-Cego , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/etiologia , Tromboembolia Venosa/etiologia , Adulto Jovem
4.
J Environ Manage ; 268: 110704, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32510439

RESUMO

Land managers often need to predict watershed-scale erosion rates after disturbance or other land cover changes. This study compared commonly used hillslope erosion models to simulate post-fire sediment yields (SY) at both hillslope and watershed scales within the High Park Fire, Colorado, U.S.A. At hillslope scale, simulated SY from four models- RUSLE, AGWA/KINEROS2, WEPP, and a site-specific regression model-were compared to observed SY at 29 hillslopes. At the watershed scale, RUSLE, AGWA/KINEROS2, and WEPP were applied to simulate spatial patterns of SY for two 14-16 km2 watersheds using different scales (0.5-25 ha) of hillslope discretization. Simulated spatial patterns were compared between models and to densities of channel heads across the watersheds. Three additional erosion algorithms were implemented within a land surface model to evaluate effects of parameter uncertainty. At the hillslope scale, SY was only significantly correlated to observed SY for the empirical model, but at the watershed scale, sediment loads were significantly correlated to observed channel head densities for all models. Watershed sediment load increased with the size of the hillslope sub-units due to the nonlinear effects of hillslope length on simulated erosion. SY's were closest in magnitude to expected watershed-scale SY when models were divided into the smallest hillslopes. These findings demonstrate that current erosion models are fairly consistent at identifying areas with low and high erosion potential, but the wide range of predicted SY and poor fit to observed SY highlight the need for better field observations and model calibration to obtain more accurate simulations.


Assuntos
Incêndios , Sedimentos Geológicos , Colorado , Monitoramento Ambiental , Modelos Teóricos , Solo
5.
Am Heart J ; 211: 45-53, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30831333

RESUMO

The Amulet IDE Trial is an ongoing, prospective, randomized, multi-national trial, designed to evaluate the safety and effectiveness of the AMPLATZER Amulet Left Atrial Appendage Occluder for stroke prevention in comparison to the WATCHMAN Left Atrial Appendage Closure Device in patients with non-valvular atrial fibrillation. METHODS: Non-valvular atrial fibrillation patients at high risk of stroke (CHADS2 score ≥2 or a CHA2DS2-VASc score of ≥3) who are suitable candidates for left atrial appendage occlusion (LAAO) will be fully informed and requested to participate in the trial. A total of 1878 patients at up to 150 sites worldwide will be randomized in a 1:1 ratio between the AMPLATZER Amulet device (investigational) and the Boston Scientific WATCHMAN device (control). Each patient will be followed for 5 years, with follow-up assessments at discharge, 45 days, 3, 6, 9, 12, 18, and 24 months and then annually. The trial has three primary endpoints: A composite of procedure-related complications, or all-cause death, or major bleeding through 12 months (safety); a composite of ischemic stroke or systemic embolism through 18 months (effectiveness); and effective device LAAO, defined as residual jet around the device ≤5 mm at the 45-day visit (mechanism of action). SUMMARY: The Amulet IDE Trial is the first randomized head-to-head LAAO device trial and will provide data for the AMPLATZER Amulet occluder in a population with a high risk of stroke and bleeding.


Assuntos
Fibrilação Atrial/cirurgia , Procedimentos Cirúrgicos Cardíacos/instrumentação , Dispositivo para Oclusão Septal , Anticoagulantes/efeitos adversos , Anticoagulantes/uso terapêutico , Fibrilação Atrial/complicações , Cateterismo Cardíaco , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Causas de Morte , Fibrinolíticos/efeitos adversos , Fibrinolíticos/uso terapêutico , Hemorragia/induzido quimicamente , Hemorragia/prevenção & controle , Humanos , Complicações Pós-Operatórias , Estudos Prospectivos , Desenho de Prótese , Fatores de Risco , Dispositivo para Oclusão Septal/efeitos adversos , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/prevenção & controle
6.
Ann Sci ; 75(3): 201-233, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30027833

RESUMO

As one of his first acts upon becoming Astronomer Royal in 1835, George Airy made moves to set up a new observatory at Greenwich to study the Earth's magnetic field. This paper uses Airy's correspondence to argue that, while members of the reform movement in British science were putting pressure on the Royal Observatory to branch out into geomagnetism and meteorology, Airy established the magnetic observatory on his own initiative, ahead of Alexander von Humboldt's request for British participation in the worldwide magnetic charting project that later became known as the 'Magnetic Crusade'. That the Greenwich magnetic observatory did not become operational until 1839 was due to a series of incidental factors that provide a case study in the technical and political obstacles to be overcome in building a new government observatory. Airy attached less importance to meteorology than he did to geomagnetism. In 1840, he set up a full programme of meteorological observations at Greenwich - and thus turned his magnetic observatory into the 'Magnetic and Meteorological department' - only as the price of foiling an attempt by Edward Sabine and others in the London scientific elite to found a rival magnetic and meteorological observatory. Studying the origins of Airy's Magnetic and Meteorological department highlights how important the context of other institutions and trends in science is to understanding the development of Britain's national observatory.


Assuntos
Astronomia/história , Magnetismo/história , Meteorologia/história , História do Século XIX , Reino Unido
7.
J Environ Manage ; 198(Pt 2): 66-77, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28501609

RESUMO

A small but growing number of watershed investment programs in the western United States focus on wildfire risk reduction to municipal water supplies. This paper used return on investment (ROI) analysis to quantify how the amounts and placement of fuel treatment interventions would reduce sediment loading to the Strontia Springs Reservoir in the Upper South Platte River watershed southwest of Denver, Colorado following an extreme fire event. We simulated various extents of fuel mitigation activities under two placement strategies: (a) a strategic treatment prioritization map and (b) accessibility. Potential fire behavior was modeled under each extent and scenario to determine the impact on fire severity, and this was used to estimate expected change in post-fire erosion due to treatments. We found a positive ROI after large storm events when fire mitigation treatments were placed in priority areas with diminishing marginal returns after treating >50-80% of the forested area. While our ROI results should not be used prescriptively they do show that, conditional on severe fire occurrence and precipitation, investments in the Upper South Platte could feasibly lead to positive financial returns based on the reduced costs of dredging sediment from the reservoir. While our analysis showed positive ROI focusing only on post-fire erosion mitigation, it is important to consider multiple benefits in future ROI calculations and increase monitoring and evaluation of these benefits of wildfire fuel reduction investments for different site conditions and climates.


Assuntos
Conservação dos Recursos Naturais/economia , Incêndios , Investimentos em Saúde , Colorado , Desastres , Florestas , Estados Unidos
8.
N Engl J Med ; 368(12): 1092-100, 2013 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-23514286

RESUMO

BACKGROUND: Whether closure of a patent foramen ovale is effective in the prevention of recurrent ischemic stroke in patients who have had a cryptogenic stroke is unknown. We conducted a trial to evaluate whether closure is superior to medical therapy alone in preventing recurrent ischemic stroke or early death in patients 18 to 60 years of age. METHODS: In this prospective, multicenter, randomized, event-driven trial, we randomly assigned patients, in a 1:1 ratio, to medical therapy alone or closure of the patent foramen ovale. The primary results of the trial were analyzed when the target of 25 primary end-point events had been observed and adjudicated. RESULTS: We enrolled 980 patients (mean age, 45.9 years) at 69 sites. The medical-therapy group received one or more antiplatelet medications (74.8%) or warfarin (25.2%). Treatment exposure between the two groups was unequal (1375 patient-years in the closure group vs. 1184 patient-years in the medical-therapy group, P=0.009) owing to a higher dropout rate in the medical-therapy group. In the intention-to-treat cohort, 9 patients in the closure group and 16 in the medical-therapy group had a recurrence of stroke (hazard ratio with closure, 0.49; 95% confidence interval [CI], 0.22 to 1.11; P=0.08). The between-group difference in the rate of recurrent stroke was significant in the prespecified per-protocol cohort (6 events in the closure group vs. 14 events in the medical-therapy group; hazard ratio, 0.37; 95% CI, 0.14 to 0.96; P=0.03) and in the as-treated cohort (5 events vs. 16 events; hazard ratio, 0.27; 95% CI, 0.10 to 0.75; P=0.007). Serious adverse events occurred in 23.0% of the patients in the closure group and in 21.6% in the medical-therapy group (P=0.65). Procedure-related or device-related serious adverse events occurred in 21 of 499 patients in the closure group (4.2%), but the rate of atrial fibrillation or device thrombus was not increased. CONCLUSIONS: In the primary intention-to-treat analysis, there was no significant benefit associated with closure of a patent foramen ovale in adults who had had a cryptogenic ischemic stroke. However, closure was superior to medical therapy alone in the prespecified per-protocol and as-treated analyses, with a low rate of associated risks. (Funded by St. Jude Medical; RESPECT ClinicalTrials.gov number, NCT00465270.).


Assuntos
Fibrinolíticos/uso terapêutico , Forame Oval Patente/terapia , Prevenção Secundária , Dispositivo para Oclusão Septal , Acidente Vascular Cerebral/prevenção & controle , Adulto , Cateterismo Cardíaco/efeitos adversos , Embolia/etiologia , Embolia/prevenção & controle , Feminino , Fibrinolíticos/efeitos adversos , Seguimentos , Forame Oval Patente/complicações , Forame Oval Patente/tratamento farmacológico , Forame Oval Patente/mortalidade , Humanos , Análise de Intenção de Tratamento , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Prospectivos , Risco , Dispositivo para Oclusão Septal/efeitos adversos , Método Simples-Cego , Acidente Vascular Cerebral/etiologia , Resultado do Tratamento
9.
Br J Hist Sci ; 48(3): 409-33, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26256312

RESUMO

Built in 1769 as a private observatory for King George III, Kew Observatory was taken over in 1842 by the British Association for the Advancement of Science (BAAS). It was then quickly transformed into what some claimed to be a 'physical observatory' of the sort proposed by John Herschel - an observatory that gathered data in a wide range of physical sciences, including geomagnetism and meteorology, rather than just astronomy. Yet this article argues that the institution which emerged in the 1840s was different in many ways from that envisaged by Herschel. It uses a chronological framework to show how, at every stage, the geophysicist and Royal Artillery officer Edward Sabine manipulated the project towards his own agenda: an independent observatory through which he could control the geomagnetic and meteorological research, including the ongoing 'Magnetic Crusade'. The political machinations surrounding Kew Observatory, within the Royal Society and the BAAS, may help to illuminate the complex politics of science in early Victorian Britain, particularly the role of 'scientific servicemen' such as Sabine. Both the diversity of activities at Kew and the complexity of the observatory's origins make its study important in the context of the growing field of the 'observatory sciences'.


Assuntos
Astronomia/história , Meteorologia/história , Política , Ciência/história , Sociedades Científicas/história , História do Século XIX , Magnetismo/história , Reino Unido
10.
Ann Sci ; : 1-4, 2018 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-30238825
11.
Heart Rhythm O2 ; 3(5): 493-500, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36340489

RESUMO

Background: Left atrial appendage (LAA) occlusion is an alternative therapy to oral anticoagulants to reduce stroke risk in patients with nonvalvular atrial fibrillation (NVAF). The Amulet IDE trial compared the Amplatzer™ Amulet™ occluder (Abbott) with the Watchman™ 2.5 device (Boston Scientific) for LAA occlusion in patients with NVAF. Objective: The purpose of this study was to describe outcomes of the Amulet IDE trial roll-in cohort. Methods: At US sites up to 3 patients per implanter could be implanted with the Amulet occluder in the roll-in phase. The primary Endpoints in the Amulet IDE trial included safety (composite of procedure-related complications, all-cause death, or major bleeding at 12 months), effectiveness (composite of ischemic stroke or systemic embolism at 18 months), and rate of LAA occlusion at 45 days. Results: A total of 201 roll-in patients were enrolled. Device success occurred in 99% of patients, and device closure (residual jet ≤5 mm) was observed in 98.9% of patients at 45 days. The safety endpoint rate was numerically higher (worse) in the roll-in cohort compared to the randomized Amulet occluder cohort (18.4% vs 14.5%). Six patients (3.1%) experienced an ischemic stroke and 0 patients with a systemic embolism within 18 months, which was similar to the primary effectiveness endpoint rate in the randomized Amulet occluder cohort (2.8%). Conclusions: Despite lack of experience of the operators with the Amulet occluder in the roll-in phase, device implant success was high, a high rate of device closure was achieved, and low stroke rates were observed in patients with NVAF.

12.
BMJ Open ; 12(6): e059689, 2022 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-35715176

RESUMO

INTRODUCTION: Patient engagement in healthcare research is a necessity to ensure that research objectives align with priorities, outcomes and needs of the population under study, and to facilitate ease of implementation and adoption of findings. In clinical trials, there is an increasing focus on patient engagement during the planning and conduct of clinical trials due to the potential for ethical and methodological benefits. As patient engagement in clinical trials increases, there is a need to evaluate the approaches of these activities to contribute evidence on what is most appropriate and successful. The purpose of this study is to evaluate patient engagement processes and the activities of patient partners during and after a paediatric mental healthcare trial. METHODS AND ANALYSIS: Using a mixed-methods study design, we will evaluate patient partners' engagement activities across set time-points during the trial and after trial completion. In this study, the term 'patient partner' is inclusive of two groups of people with lived experience: (1) caregivers (parents, formal/informal caregivers and family), and (2) youth (aged 15-24 years). Engagement will be evaluated using the participant and project questionnaires of the Public and Patient Engagement Evaluation Tool (PPEET), followed sequentially by semi-structured interviews. Quantitative data from the PPEET questionnaire will be analysed and reported using descriptive statistics. Data from open-ended questions from the PPEET questionnaires and semi-structured interviews will be analysed using thematic analysis. ETHICS AND DISSEMINATION: Approval from Athabasca University Research Ethics Board will be obtained for this project. Findings will be disseminated at both academic and public venues whether in-person or online, and using platforms that are caregiver and youth friendly. TRIAL REGISTRATION NUMBER: NCT04902391.


Assuntos
Serviços de Saúde Mental , Pais , Adolescente , Cuidadores , Humanos , Participação do Paciente , Projetos de Pesquisa , Adulto Jovem
13.
J Am Acad Child Adolesc Psychiatry ; 61(7): 946-948, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35772868

RESUMO

Over the past decade, visits to American and Canadian emergency departments (EDs) for child and youth mental health care have increased substantially.1,2 Acute mental health crises can occur as a result of a variety of concerns, including those that are life threatening (eg, suicide attempts), pose safety concerns (eg, suicidal intentions, aggressive behaviors, alcohol and other drug use), and are physically distressing to the child or youth (eg, panic attacks). ED health care providers play a vital role in assessing the safety and well-being of the child or youth and referring them to services for ongoing care.3,4 During the ED visit, assessment and care should pinpoint risks, inform treatment, and consider family needs and preferences as part of a patient-centered approach. Yet, this approach to care is not widely adopted in EDs. Most EDs do not require the use of pediatric-specific mental health tools to guide assessments or have patient-centered procedures in place to guide the care of patients with mental health emergencies.5-7 Our team believes these limitations have led to the provision of acute mental health care that can lack sufficient quality and efficiency. This study protocol describes a trial designed to evaluate if a novel mental health care bundle that was co-designed with parents and youth results in greater improvements in the well-being of children and youth 30 days after seeking ED care for mental health and/or substance misuse concerns compared with existing care protocols. We hypothesize that the bundle will positively impact child and youth well-being, while also providing cost-effective health care system benefits.


Assuntos
Serviços de Saúde Mental , Transtornos Relacionados ao Uso de Substâncias , Adolescente , Canadá , Criança , Serviço Hospitalar de Emergência , Humanos , Saúde Mental , Estudos Multicêntricos como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto , Transtornos Relacionados ao Uso de Substâncias/psicologia
14.
Hist Sci ; 59(1): 73-92, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-30474405

RESUMO

Traditionally, historians have taken it for granted that Britain's National Physical Laboratory (NPL) was created as the result of demands from a "professional" body of university-based physicists for a state-funded scientific institution. Yet paying detailed attention to the history of the NPL's originating institution, Kew Observatory, shows that the story is not so clear-cut. Starting in the 1850s, Kew Observatory was partly a center for testing meteorological instruments and other scientific equipment in return for fees. Long after the 1850s, the observatory was run by self-funded devotees of science. Paid university physicists only assumed a dominant role on its governing committee in the last two decades of the nineteenth century, by which time instrument-testing was already the observatory's main role. This paper argues that the rise of the university physicists - together with the desire of some of these physicists for a national institution that tested electrical standards - can only partially explain the origins of the NPL, and that Kew was in some ways a national physical laboratory before there were many physics teaching posts in British universities. This paper is a case study that illustrates a need to reassess the importance of university physicists in shaping British science at the end of the nineteenth century.

15.
J Med Econ ; 21(7): 656-665, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29564942

RESUMO

OBJECTIVE: Compared to medical therapy alone, percutaneous closure of patent foramen ovale (PFO) further reduces risk of recurrent ischemic strokes in carefully selected young to middle-aged patients with a recent cryptogenic ischemic stroke. The objective of this study was to evaluate the cost-effectiveness of this therapy in the context of the United Kingdom (UK) healthcare system. METHODS: A Markov cohort model consisting of four health states (Stable after index stroke, Post-Minor Recurrent Stroke, Post-Moderate Recurrent Stroke, and Death) was developed to simulate the economic outcomes of device-based PFO closure compared to medical therapy. Recurrent stroke event rates were extracted from a randomized clinical trial (RESPECT) with a median of 5.9-year follow-up. Health utilities and costs were obtained from published sources. One-way and probabilistic sensitivity analyses (PSA) were performed to assess robustness. The model was discounted at 3.5% and reported in 2016 Pounds Sterling. RESULTS: Compared with medical therapy alone and using a willingness-to-pay (WTP) threshold of £20,000, PFO closure reached cost-effectiveness at 4.2 years. Cost-effectiveness ratios (ICERs) at 4, 10, and 20 years were £20,951, £6,887, and £2,158, respectively. PFO closure was cost-effective for 89% of PSA iterations at year 10. Sensitivity analyses showed that the model was robust. CONCLUSIONS: Considering the UK healthcare system perspective, percutaneous PFO closure in cryptogenic ischemic stroke patients is a cost-effective stroke prevention strategy compared to medical therapy alone. Its cost-effectiveness was driven by substantial reduction in recurrent strokes and patients' improved health-related quality-of-life.


Assuntos
Forame Oval Patente/cirurgia , Prevenção Secundária/economia , Prevenção Secundária/métodos , Acidente Vascular Cerebral/economia , Acidente Vascular Cerebral/prevenção & controle , Adolescente , Adulto , Análise Custo-Benefício , Feminino , Fibrinolíticos/administração & dosagem , Forame Oval Patente/complicações , Recursos em Saúde/economia , Recursos em Saúde/estatística & dados numéricos , Humanos , Masculino , Cadeias de Markov , Pessoa de Meia-Idade , Modelos Econométricos , Qualidade de Vida , Recidiva , Índice de Gravidade de Doença , Acidente Vascular Cerebral/etiologia , Reino Unido , Adulto Jovem
16.
Nurse Educ Today ; 36: 172-7, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26454714

RESUMO

BACKGROUND: There is evidence that nursing students experience stress and anxiety and a reduction in self-efficacy when undertaking clinical placements. Previous reports have identified that a structured three-day program within the Bachelor of Nursing (BN) clinical practicum reduces the students self-report of anxiety and increases self-efficacy. However, it is unreported whether these improved outcomes are sustained for the duration of the clinical placement. OBJECTIVE: The aim of this study was to evaluate the duration of the effect of a three-day structured learning program within the clinical placement on final year Bachelor of Nursing student's report of anxiety and self-efficacy pre- and post-program participation in this intervention and following completion of the clinical practicum. DESIGN: A repeated measures design. SETTING: University-based Clinical School of Nursing, acute care clinical practicum. PARTICIPANTS: Final year Bachelor of Nursing students. METHODS: The intervention comprised the three-day program on starting the clinical practicum. A questionnaire included the anxiety subscale of The Hospital Anxiety & Depression Scale (The HAD) and the General Self-Efficacy Scale (GSES-12). The questionnaire was completed on day one (time one), upon completion of the three-day program (time two) and upon completion of placement on day 18 (time three). RESULTS: The questionnaire response rate varied over time. There was a statistically significant effect in reducing anxiety over time: F(1.73,74.46)=25.20, p<0.001 and increasing self-efficacy over time F(1.32,41.04)=7.72, p<0.004. CONCLUSIONS: This is the first report that we are aware of that has measured final year Bachelor of Nursing student's report of both anxiety and self-efficacy over repeated measures of time. Students continue to benefit from a structured learning program and the benefit of the intervention is sustained for the clinical placement duration.


Assuntos
Bacharelado em Enfermagem/organização & administração , Aprendizagem , Humanos , Autoeficácia , Inquéritos e Questionários
17.
Circulation ; 109(1): 108-13, 2004 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-14662713

RESUMO

BACKGROUND: The precise role of arterial barotrauma-mediated apoptosis in causing restenosis is unclear. The purpose of this study was to determine if a link exists between angioplasty-mediated medial smooth muscle cell apoptosis and subsequent neointimal hyperplasia. METHODS AND RESULTS: Bilateral iliac artery angioplasty was performed in 25 male New Zealand White rabbits. Simultaneous with balloon injury, each artery was treated locally with either the caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp(Ome)-fluoromethylketone (ZVAD-fmk) or control. In the acute cohort that was survived to 4 hours (n=10, 7 high dose and 3 low dose), an apoptotic index was calculated using the terminal deoxynucleotidyl TUNEL method. In the intermediate cohort that was survived to 2 weeks (n=5), luminal reendothelialization was measured via CD-31 staining. In the chronic cohort that was survived to 4 weeks (n=10), neointimal area was measured. In the acute cohort, there was a 40% reduction in the apoptotic index with high-dose ZVAD-fmk (P=0.008) and a 33% reduction with low-dose ZVAD-fmk (P=0.08). At 2 weeks, there was no significant difference in the degree of luminal reendothelialization. However, at 4 weeks, there was a 33% (0.33+/-0.23 versus 0.22+/-0.20 mm2) (P<0.005) reduction in neointimal area in ZVAD-fmk-treated arteries. CONCLUSIONS: The local delivery of ZVAD-fmk during balloon injury inhibits smooth muscle cell apoptosis. This corresponds to a significant reduction in neointimal proliferation seen at 4 weeks without a significant change in the degree of reendothelialization at 2 weeks.


Assuntos
Angioplastia Coronária com Balão/efeitos adversos , Apoptose/fisiologia , Caspases/fisiologia , Reestenose Coronária/patologia , Músculo Liso Vascular/patologia , Clorometilcetonas de Aminoácidos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Inibidores de Caspase , Reestenose Coronária/enzimologia , Reestenose Coronária/prevenção & controle , Hiperplasia , Masculino , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/lesões , Coelhos , Túnica Íntima/patologia
18.
Proc (Bayl Univ Med Cent) ; 28(3): 365-6, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26130891

RESUMO

We present a patient with an isolated right-sided superior vena cava draining into the left atrium with a persistent left-sided superior vena cava emptying into the right atrium. During an agitated saline injection into the patient's right upper extremity intravenous line, the patient suffered an acute transient ischemic attack. To our knowledge, this is the only reported case of this rare anomaly incidentally uncovered during an echocardiogram with saline contrast study.

19.
J Invasive Cardiol ; 15(2): 60-2, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12556615

RESUMO

The low molecular weight heparin enoxaparin is often administered to patients on long-term anticoagulation regimens who temporarily discontinue warfarin prior to undergoing invasive procedures. The clinical outcome of all enoxaparin-treated patients who underwent cardiac catheterization or coronary artery interventional procedures (n = 119) was evaluated. A total of 5 patients (4.2%) requiring anticoagulation (3 with chronic atrial fibrillation and 2 with ventricular thrombi) developed severe late enoxaparin-associated hemorrhagic or vascular complications at the femoral arterial puncture site between 3 and 11 days post-procedure. Complications included development of femoral arterial pseudoaneurysm (n = 3), hypotension (systolic blood pressure < 90 mmHg) (n = 2), acute decrease in hemoglobin levels to < 8.5 mg/dl (n = 4) and cardiac arrest (n = 1). In patients receiving standard dose enoxaparin after percutaneous invasive cardiac procedures, there is the potential for delayed and severe access site hemorrhagic and vascular complications.


Assuntos
Anticoagulantes/uso terapêutico , Cateterismo Cardíaco , Heparina de Baixo Peso Molecular/uso terapêutico , Complicações Pós-Operatórias/tratamento farmacológico , Complicações Pós-Operatórias/etiologia , Idoso , Idoso de 80 Anos ou mais , Angioplastia Coronária com Balão , Doença das Coronárias/complicações , Doença das Coronárias/terapia , Feminino , Doenças das Valvas Cardíacas/complicações , Doenças das Valvas Cardíacas/terapia , Humanos , Injeções Subcutâneas , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
20.
J Invasive Cardiol ; 15(2): 68-70, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12556618

RESUMO

Whether arterial closure devices can be used safely in a coagulopathic population undergoing cardiac catheterization and at high risk for groin complications, such as liver transplant candidates, is unknown. In this prospective, non-randomized consecutive series of 80 liver transplant candidates undergoing coronary angiography, manual compression and arterial closure devices were compared. Ilio-femoral angiography was performed to determine suitability for use of the closure device. Bleeding and vascular complications were recorded along with time to ambulation. Arterial closure devices were used in 31 patients (39%), whereas manual compression was used in 49 patients (50 procedures) (61%). There were no significant differences between the two groups with respect to age, sex, cardiac risk factors, peripheral vascular disease, baseline platelet count or baseline INR. There were 10 total vascular complications out of 50 procedures (20%) in the manual compression group compared to 2 vascular complications out of 31 procedures in the arterial closure device group (6%; p = 0.12). The time to ambulation was significantly less in the group receiving arterial closure devices versus manual compression (4.2 1.8 hours versus 6.6 3.7 hours, respectively; p = 0.0003). In coagulopathic patients at higher risk for groin complications, arterial closure devices can be safely used and decrease time to ambulation compared to manual compression.


Assuntos
Angiografia Coronária , Coração Auxiliar , Transplante de Fígado/instrumentação , Cateterismo Cardíaco/instrumentação , Estudos de Coortes , Segurança de Equipamentos , Feminino , Coração Auxiliar/efeitos adversos , Humanos , Illinois , Falência Hepática/complicações , Falência Hepática/epidemiologia , Falência Hepática/cirurgia , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/diagnóstico por imagem , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Estudos Prospectivos , Resultado do Tratamento
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