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1.
Int J Behav Nutr Phys Act ; 19(1): 141, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36451168

RESUMO

BACKGROUND: Whole-of-school programs have demonstrated success in improving student physical activity levels, but few have progressed beyond efficacy testing to implementation at-scale. The purpose of our study was to evaluate the scale-up of the 'Internet-based Professional Learning to help teachers promote Activity in Youth' (iPLAY) intervention in primary schools using the RE-AIM framework. METHODS: We conducted a type 3 hybrid implementation-effectiveness study and collected data between April 2016 and June 2021, in New South Wales (NSW), Australia. RE-AIM was operationalised as: (i) Reach: Number and representativeness of students exposed to iPLAY; (ii) Effectiveness: Impact of iPLAY in a sub-sample of students (n = 5,959); (iii) Adoption: Number and representativeness of schools that received iPLAY; (iv) Implementation: Extent to which the three curricular and three non-curricular components of iPLAY were delivered as intended; (v) Maintenance: Extent to which iPLAY was sustained in schools. We conducted 43 semi-structured interviews with teachers (n = 14), leaders (n = 19), and principals (n = 10) from 18 schools (11 from urban and 7 from rural locations) to determine program maintenance. RESULTS: Reach: iPLAY reached ~ 31,000 students from a variety of socio-economic strata (35% of students were in the bottom quartile, almost half in the middle two quartiles, and 20% in the top quartile). EFFECTIVENESS: We observed small positive intervention effects for enjoyment of PE/sport (0.12 units, 95% CI: 0.05 to 0.20, d = 0.17), perceptions of need support from teachers (0.26 units, 95% CI: 0.16 to 0.53, d = 0.40), physical activity participation (0.28 units, 95% CI: 0.10 to 0.47, d = 0.14), and subjective well-being (0.82 units, 95% CI: 0.32 to 1.32, d = 0.12) at 24-months. Adoption: 115 schools received iPLAY. IMPLEMENTATION: Most schools implemented the curricular (59%) and non-curricular (55%) strategies as intended. Maintenance: Based on our qualitative data, changes in teacher practices and school culture resulting from iPLAY were sustained. CONCLUSIONS: iPLAY had extensive reach and adoption in NSW primary schools. Most of the schools implemented iPLAY as intended and effectiveness data suggest the positive effects observed in our cluster RCT were sustained when the intervention was delivered at-scale. TRIAL REGISTRATION: ACTRN12621001132831.


Assuntos
Internet , Instituições Acadêmicas , Humanos , Adolescente , Estudantes , Coleta de Dados , Prazer
2.
Epidemiol Infect ; 146(7): 920-930, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29636119

RESUMO

Coinfection with human immunodeficiency virus (HIV) and viral hepatitis is associated with high morbidity and mortality in the absence of clinical management, making identification of these cases crucial. We examined characteristics of HIV and viral hepatitis coinfections by using surveillance data from 15 US states and two cities. Each jurisdiction used an automated deterministic matching method to link surveillance data for persons with reported acute and chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infections, to persons reported with HIV infection. Of the 504 398 persons living with diagnosed HIV infection at the end of 2014, 2.0% were coinfected with HBV and 6.7% were coinfected with HCV. Of the 269 884 persons ever reported with HBV, 5.2% were reported with HIV. Of the 1 093 050 persons ever reported with HCV, 4.3% were reported with HIV. A greater proportion of persons coinfected with HIV and HBV were males and blacks/African Americans, compared with those with HIV monoinfection. Persons who inject drugs represented a greater proportion of those coinfected with HIV and HCV, compared with those with HIV monoinfection. Matching HIV and viral hepatitis surveillance data highlights epidemiological characteristics of persons coinfected and can be used to routinely monitor health status and guide state and national public health interventions.


Assuntos
Coinfecção/epidemiologia , Infecções por HIV/epidemiologia , Hepatite Viral Humana/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Coinfecção/virologia , Feminino , Infecções por HIV/virologia , Hepatite Viral Humana/virologia , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Saúde Pública , Estados Unidos/epidemiologia , Adulto Jovem
3.
Occup Med (Lond) ; 64(4): 297-304, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24850818

RESUMO

BACKGROUND: The Australian general practice workforce is ageing. This and a trend towards higher exit intentions and earlier retirement make it increasingly important to identify those work and personal factors affecting intention to leave, which are amenable to change. AIMS: To assess the various work, occupational and individual health factors associated with early retirement intentions among Australian rural general practitioners (GPs) that may be amenable to intervention. METHODS: A cross-sectional study of GPs practising in rural Australia. Odds ratios of early retirement intentions across work, occupational and individual health factors were calculated. RESULTS: There were 92 participants (response rate 56%), and 47% of responders intended to retire before 65. GPs with medium to high burnout levels had higher odds of intending to retire. Increased job satisfaction and work ability scores were associated with decreased retirement intentions, whereas increased physical and mental work ability demands were associated with an increase in retirement intentions. Absenteeism was not related to retirement intentions but presenteeism was. GPs reporting any work-related sleep problems were found to have a 3-fold increase in the odds of early retirement intentions. The odds of early retirement intentions also increased with higher psychological distress, worsening general health and longer working hours. CONCLUSIONS: From a health policy reform perspective, the greatest impact on reducing early retirement intentions among ageing GPs could potentially be made by intervening in areas of working hours, burnout and work-related sleep issues, followed by job satisfaction, psychological distress, health, general workability and mental and physical work ability.


Assuntos
Atitude do Pessoal de Saúde , Esgotamento Profissional , Medicina Geral , Intenção , Satisfação no Emprego , Aposentadoria , Carga de Trabalho , Absenteísmo , Adulto , Austrália , Estudos Transversais , Feminino , Clínicos Gerais/psicologia , Saúde , Nível de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Transtornos do Sono-Vigília , Estresse Psicológico
4.
Eur J Radiol ; 174: 111399, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38428318

RESUMO

OBJECTIVE: To perform a systematic review and meta-analysis of the diagnostic accuracy of deep learning (DL) algorithms in the diagnosis of wrist fractures (WF) on plain wrist radiographs, taking healthcare experts consensus as reference standard. METHODS: Embase, Medline, PubMed, Scopus and Web of Science were searched in the period from 1 Jan 2012 to 9 March 2023. Eligible studies were patients with wrist radiographs for radial and ulnar fractures as the target condition, studies using DL algorithms based on convolutional neural networks (CNN), and healthcare experts consensus as the minimum reference standard. Studies were assessed with a modified QUADAS-2 tool, and we applied a bivariate random-effects model for meta-analysis of diagnostic test accuracy data. RESULTS: Our study was registered at PROSPERO with ID: CRD42023431398. We included 6 unique studies for meta-analysis, with a total of 33,026 radiographs. CNN performance compared to reference standards for the included articles found a summary sensitivity of 92% (95% CI: 80%-97%) and a summary specificity of 93% (95% CI: 76%-98%). The generalized bivariate I-squared statistic indicated considerable heterogeneity between the studies (81.90%). Four studies had one or more domains at high risk of bias and two studies had concerns regarding applicability. CONCLUSION: The diagnostic accuracy of CNNs was comparable to that of healthcare experts in wrist radiographs for investigation of WF. There is a need for studies with a robust reference standard, external data-set validation and investigation of diagnostic performance of healthcare experts aided with CNNs. CLINICAL RELEVANCE STATEMENT: DL matches healthcare experts in diagnosing WFs, which potentially benefits patient diagnosis.

5.
Vet Pathol ; 50(6): 980-8, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23482522

RESUMO

Porcine circovirus type 2 (PCV2) infection is the cause of postweaning multisystemic wasting syndrome (PMWS). It has been speculated whether cell types permissive of replication are found in the primary lymphoid organs and whether infection of these tissues has an important role in the pathogenesis of PMWS. The aim of this study was to determine if primary lymphoid organ cells support viral replication during PCV2 infection. This was done by histopathological examination of thymus and bone marrow from pigs experimentally inoculated with PCV2 (n = 24), mock-infected pigs (n = 12), pigs naturally affected by PMWS (n = 33), and age-matched healthy control animals (n = 29). In situ hybridization (ISH) techniques were used to detect PCV2 nucleic acid irrespective of replicative status (complementary probe, CP) or to detect only the replicative form of the virus (replicative form probe, RFP). PCV2 was not detected in the experimentally PCV2-inoculated pigs or the control animals. Among the PMWS-affected pigs, 19 of 20 (95%) thymuses were positive for PCV2 by CP ISH, and 7 of 19 (37%) of these also supported viral replication. By CP ISH, PCV2 was detected in 16 of 33 (48%) bone marrow samples, and 5 of 16 (31%) of these also supported replication. The 2 ISH probes labeled the same cell types, which were histiocytes in both organs and lymphocytes in thymus. The RFP labeled fewer cells than the CP. Thus, PCV2 nucleic acids and replication were found in bone marrow and thymus of PMWS-affected pigs, but there was no evidence that primary lymphoid organ cells are major supporters of PCV2 replication.


Assuntos
Infecções por Circoviridae/veterinária , Circovirus/isolamento & purificação , Hibridização In Situ/veterinária , Doenças dos Suínos/patologia , Replicação Viral , Síndrome de Emaciação/veterinária , Animais , Medula Óssea/patologia , Medula Óssea/virologia , Estudos de Casos e Controles , Infecções por Circoviridae/patologia , Infecções por Circoviridae/virologia , Circovirus/genética , Circovirus/fisiologia , DNA Viral/genética , DNA Viral/isolamento & purificação , Sus scrofa , Suínos , Doenças dos Suínos/virologia , Timo/patologia , Timo/virologia , Síndrome de Emaciação/patologia , Síndrome de Emaciação/virologia
6.
Med Phys ; 39(3): 1218-26, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22380352

RESUMO

PURPOSE: In this paper, the effect on image quality of significantly reducing the primary electron energy of a radiotherapy accelerator is investigated using a novel waveguide test piece. The waveguide contains a novel variable coupling device (rotovane), allowing for a wide continuously variable energy range of between 1.4 and 9 MeV suitable for both imaging and therapy. METHOD: Imaging at linac accelerating potentials close to 1 MV was investigated experimentally and via Monte Carlo simulations. An imaging beam line was designed, and planar and cone beam computed tomography images were obtained to enable qualitative and quantitative comparisons with kilovoltage and megavoltage imaging systems. The imaging beam had an electron energy of 1.4 MeV, which was incident on a water cooled electron window consisting of stainless steel, a 5 mm carbon electron absorber and 2.5 mm aluminium filtration. Images were acquired with an amorphous silicon detector sensitive to diagnostic x-ray energies. RESULTS: The x-ray beam had an average energy of 220 keV and half value layer of 5.9 mm of copper. Cone beam CT images with the same contrast to noise ratio as a gantry mounted kilovoltage imaging system were obtained with doses as low as 2 cGy. This dose is equivalent to a single 6 MV portal image. While 12 times higher than a 100 kVp CBCT system (Elekta XVI), this dose is 140 times lower than a 6 MV cone beam imaging system and 6 times lower than previously published LowZ imaging beams operating at higher (4-5 MeV) energies. CONCLUSIONS: The novel coupling device provides for a wide range of electron energies that are suitable for kilovoltage quality imaging and therapy. The imaging system provides high contrast images from the therapy portal at low dose, approaching that of gantry mounted kilovoltage x-ray systems. Additionally, the system provides low dose imaging directly from the therapy portal, potentially allowing for target tracking during radiotherapy treatment. There is the scope with such a tuneable system for further energy reduction and subsequent improvement in image quality.


Assuntos
Radioterapia Guiada por Imagem/métodos , Tomografia Computadorizada de Feixe Cônico , Elétrons , Imagens de Fantasmas , Radiometria
7.
Environ Sci Technol ; 46(20): 10948-56, 2012 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-22989332

RESUMO

Occurrence of anthropogenic (129)I in seawater has provided invaluable information about water circulation and exchange rates, but results on (129)I species (iodide and iodate) are limited and only available for surface water. We here present the first extensive results on (129)I and (127)I species in samples of seawater depth profiles, which were collected in August 2006 and April 2007 in the Skagerrak, Kattegat, and Baltic Proper. The results expose ≤10% annual reduction of iodate as (129)I is transported from the English Channel along the Dutch coast and German Bight into the Skagerrak and Kattegat. The results also suggest strong variability between surface and bottom seawater with respect to the predominant iodine species. Distribution of iodide and iodate of both (127)I and (129)I in the Kattegat mainly reflects water mixing process rather than speciation transformation. In water of the Baltic Proper, high (127)I(-)/(127)IO(3)(-) and (129)I(-)/(129)IO(3)(-) values suggest effective reduction of iodate with a maximum rate of 8 × 10(-7) ((127)IO(3)(-)) and 6 × 10(-14) ((129)IO(3)(-)) (g/m(3).day). The reduction process of iodate seems to be related to decomposition of organic matter and photochemically induced reactions.


Assuntos
Radioisótopos do Iodo/análise , Água do Mar/análise , Poluentes Radioativos da Água/análise , Monitoramento de Radiação , Poluição Química da Água/estatística & dados numéricos
8.
Environ Res ; 112: 28-39, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22137101

RESUMO

Seafood is the predominant food source of several organoarsenic compounds. Some seafood species, like crustaceans and seaweed, also contain inorganic arsenic (iAs), a well-known toxicant. It is unclear whether human biotransformation of ingested organoarsenicals from seafood result in formation of arsenicals of health concern. The present controlled dietary study examined the urinary excretion of arsenic compounds (total arsenic (tAs), iAs, AB (arsenobetaine), dimethylarsinate (DMA) and methylarsonate (MA)) following ingestion of a single test meal of seafood (cod, 780 µg tAs, farmed salmon, 290 µg tAs or blue mussel, 690 µg tAs or potato (control, 110 µg tAs)) in 38 volunteers. The amount of ingested tAs excreted via the urine within 0-72 h varied significantly among the groups: Cod, 74% (52-92%), salmon 56% (46-82%), blue mussel 49% (37-78%), control 45% (30-60%). The estimated total urinary excretion of AB was higher than the amount of ingested AB in the blue mussel group (112%) and also ingestion of cod seemed to result in more AB, indicating possible endogenous formation of AB from other organoarsenicals. Excretion of iAs was lower than ingested (13-22% of the ingested iAs was excreted in the different groups). Although the ingested amount of iAs+DMA+MA was low for all seafood groups (1.2-4.5% of tAs ingested), the urinary DMA excretion was high in the blue mussel and salmon groups, counting for 25% and 11% of the excreted tAs respectively. In conclusion our data indicate a possible formation of AB as a result of biotransformation of other organic arsenicals. The considerable amount of DMA excreted is probably not only due to methylation of ingested iAs, but due to biotransformation of organoarsenicals making it an inappropriate biomarker of iAs exposure in populations with a high seafood intake.


Assuntos
Arsenicais/urina , Ácido Cacodílico/urina , Contaminação de Alimentos , Alimentos Marinhos , Poluentes Químicos da Água/farmacocinética , Adulto , Animais , Biotransformação , Monitoramento Ambiental , Feminino , Cadeia Alimentar , Contaminação de Alimentos/análise , Gadiformes/metabolismo , Humanos , Masculino , Mytilus edulis/metabolismo , Noruega , Salmão/metabolismo , Alimentos Marinhos/análise , Adulto Jovem
9.
Clin Oncol (R Coll Radiol) ; 34(10): e421-e429, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35691760

RESUMO

AIMS: To determine the relationship between local relapse following radical radiotherapy for muscle-invasive bladder cancer (MIBC) and radiation dose. MATERIALS AND METHODS: Patients with T2-4N0-3M0 MIBC were recruited to a phase II study assessing the feasibility of intensity-modulated radiotherapy to the bladder and pelvic lymph nodes. Patients were planned to receive 64 Gy/32 fractions to the bladder tumour, 60 Gy/32 fractions to the involved pelvic nodes and 52 Gy/32 fractions to the uninvolved bladder and pelvic nodes. Pre-treatment set-up was informed by cone-beam CT. For patients who experienced local relapse, cystoscopy and imaging (CT/MRI) was used to reconstruct the relapse gross tumour volume (GTVrelapse) on the original planning CT . GTVrelapse D98% and D95% was determined by co-registering the relapse image to the planning CT utilising deformable image registration (DIR) and rigid image registration (RIR). Failure was classified into five types based on spatial and dosimetric criteria as follows: A (central high-dose failure), B (peripheral high-dose failure), C (central elective dose failure), D (peripheral elective dose failure) and E (extraneous dose failure). RESULTS: Between June 2009 and November 2012, 38 patients were recruited. Following treatment, 18/38 (47%) patients experienced local relapse within the bladder. The median time to local relapse was 9.0 months (95% confidence interval 6.3-11.7). Seventeen of 18 patients were evaluable based on the availability of cross-sectional relapse imaging. A significant difference between DIR and RIR methods was seen. With the DIR approach, the median GTVrelapse D98% and D95% was 97% and 98% of prescribed dose, respectively. Eleven of 17 (65%) patients experienced type A failure and 6/17 (35%) patients type B failure. No patients had type C, D or E failure. MIBC failure occurred in 10/17 (59%) relapsed patients; of those, 7/11 (64%) had type A failure and 3/6 (50%) had type B failure. Non-MIBC failure occurred in 7/17 (41%) patients; 4/11 (36%) with type A failure and 3/6 (50%) with type B failure. CONCLUSION: Relapse following radiotherapy occurred within close proximity to the original bladder tumour volume and within the planned high-dose region, suggesting possible biological causes for failure. We advise caution when considering margin reduction for future reduced high-dose radiation volume or partial bladder radiotherapy protocols.


Assuntos
Radioterapia de Intensidade Modulada , Neoplasias da Bexiga Urinária , Estudos Transversais , Humanos , Recidiva Local de Neoplasia/diagnóstico por imagem , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/radioterapia , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/efeitos adversos , Radioterapia de Intensidade Modulada/métodos , Bexiga Urinária/diagnóstico por imagem , Neoplasias da Bexiga Urinária/diagnóstico por imagem , Neoplasias da Bexiga Urinária/radioterapia
10.
Clin Oncol (R Coll Radiol) ; 34(8): 526-533, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35597698

RESUMO

AIMS: Inclusion of the internal mammary chain in the radiotherapy target volume (IMC-RT) improves disease-free and overall survival in higher risk breast cancer patients, but increases radiation doses to heart and lungs. Dosimetric data show that either modified wide-tangential fields (WT) or volumetric modulated arc therapy (VMAT) together with [AQ1]voluntary deep inspiration breath hold (vDIBH) keep mean heart doses below 4 Gy in most patients. However, the impact on departmental resources has not yet been documented. This phase II clinical trial compared the time taken to deliver IMC-RT using either WT and vDIBH or VMAT and vDIBH, together with planning time, dosimetry, set-up reproducibility and toxicity. MATERIALS AND METHODS: Left-sided breast cancer patients requiring IMC-RT were randomised to receive either WT(vDIBH) or VMAT radiotherapy. The primary outcome was treatment time, powered to detect a minimum difference of 75 min (5 min/fraction) between techniques. The population mean displacement, systematic error and random error for cone beam computed tomography chest wall matches in three directions of movement were calculated. Target volume and organ at risk doses were compared between groups. Side-effects, including skin (Radiation Therapy Oncology Group), lung and oesophageal toxicity (Common Terminology Criteria for Adverse Events v 4.03) rates, were compared between the groups over 3 months. Patient-reported outcome measures, including shoulder toxicity at baseline, 6 months and 1 year, were compared. RESULTS: Twenty-one patients were recruited from a single UK centre between February 2017 and January 2018. The mean (standard deviation) total treatment time per fraction for VMAT treatments was 13.2 min (1.7 min) compared with 28.1 min (3.3 min) for WT(vDIBH). There were no statistically significant differences in patient set-up errors in between groups. The average mean heart dose for WT(vDIBH) was 2.6 Gy compared with 3.4 Gy for VMAT(vDIBH) (P = 0.13). The mean ipsilateral lung V17Gy was 32.8% in the WT(vDIBH) group versus 34.4% in the VMAT group (P = 0.2). The humeral head (mean dose 16.8 Gy versus 2.8 Gy), oesophagus (maximum dose 37.3 Gy versus 20.1 Gy) and thyroid (mean dose 22.0 Gy versus 11.2 Gy) all received a statistically significantly higher dose in the VMAT group. There were no statistically significant differences in skin, lung or oesophageal toxicity within 3 months of treatment. Patient-reported outcomes of shoulder toxicity, pain, fatigue, breathlessness and breast symptoms were similar between groups at 1 year. CONCLUSION: VMAT(vDIBH) and WT(vDIBH) are feasible options for locoregional breast radiotherapy including the IMC. VMAT improves nodal coverage and delivers treatment more quickly, resulting in less breath holds for the patient. This is at the cost of increased dose to some non-target tissues. The latter does not appear to translate into increased toxicity in this small study.


Assuntos
Neoplasias da Mama , Radioterapia de Intensidade Modulada , Neoplasias Unilaterais da Mama , Neoplasias da Mama/radioterapia , Feminino , Humanos , Órgãos em Risco/efeitos da radiação , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/efeitos adversos , Radioterapia de Intensidade Modulada/métodos , Reprodutibilidade dos Testes , Neoplasias Unilaterais da Mama/radioterapia
11.
Environ Sci Technol ; 45(3): 903-9, 2011 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-21190361

RESUMO

Radioactive anthropogenic pollution has raised concerns about the present and future environmental status of the semienclosed Baltic Sea. We here study the distribution and inventory of the anthropogenic radioactive (129)I in water depth profiles collected from 16 sites in August 2006 and 19 sites in April 2007 in the Baltic Proper and related Kattegat and Skagerrak basins. The results reveal considerable differences of (129)I concentration in terms of spatial and temporal variability and expose relatively high concentrations in the deep waters. Variability in the concentration of (127)I, stable natural isotope of iodine, seems to follow changes in the seawater salinity, but in oxygen-poor bottom waters sediment diagenetic release may contribute to the concentration of both isotopes in the water body. Inventory estimates show that (129)I in August 2006 (24.2 ± 15.4 kg) is higher than that in April 2007 (14.4 ± 8.3 kg) within the southern and central Baltic Proper whereas almost a constant load occurs in the Kattegat Basin. Calculated model inventory shows correspondence to empirical data and provides a guideline for future environmental assessment on the impact of (129)I load in the studied region.


Assuntos
Isótopos de Iodo/análise , Água do Mar/química , Poluentes Radioativos da Água/análise , Água Doce/química , Sedimentos Geológicos/química , Oceanos e Mares , Monitoramento de Radiação , Salinidade , Estações do Ano
12.
Bioelectromagnetics ; 32(2): 102-12, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21225887

RESUMO

The development and analysis of three waveguides for the exposure of small biological in vitro samples to mobile communication signals at 900 MHz (GSM, Global System for Mobile Communications), 1.8 GHz (GSM), and 2 GHz (UMTS, Universal Mobile Telecommunications System) is presented. The waveguides were based on a fin-line concept and the chamber containing the samples bathed in extracellular solution was placed onto two fins with a slot in between, where the exposure field concentrates. Measures were taken to allow for patch clamp recordings during radiofrequency (RF) exposure. The necessary power for the achievement of the maximum desired specific absorption rate (SAR) of 20 W/kg (average over the mass of the solution) was approximately P(in) = 50 mW, P(in) = 19 mW, and P(in) = 18 mW for the 900 MHz, 1800 MHz, and 2 GHz devices, respectively. At 20 W/kg, a slight RF-induced temperature elevation in the solution of no more than 0.3 °C was detected, while no thermal offsets due to the electromagnetic exposure could be detected at the lower SAR settings (2, 0.2, and 0.02 W/kg). A deviation of 10% from the intended solution volume yielded a calculated SAR deviation of 8% from the desired value. A maximum ±10% variation in the local SAR could occur when the position of the patch clamp electrode was altered within the area where the cells to be investigated were located.


Assuntos
Exposição Ambiental/análise , Células Ciliadas Auditivas Internas/citologia , Células Ciliadas Auditivas Internas/efeitos da radiação , Técnicas de Patch-Clamp/instrumentação , Ondas de Rádio , Absorção , Temperatura
13.
Clin Oncol (R Coll Radiol) ; 33(6): 350-368, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33972024

RESUMO

Technological advancement has facilitated patient-specific radiotherapy in bladder cancer. This has been made possible by developments in image-guided radiotherapy (IGRT). Particularly transformative has been the integration of volumetric imaging into the workflow. The ability to visualise the bladder target using cone beam computed tomography and magnetic resonance imaging initially assisted with determining the magnitude of inter- and intra-fraction target change. It has led to greater confidence in ascertaining true anatomy at each fraction. The increased certainty of dose delivered to the bladder has permitted the safe reduction of planning target volume margins. IGRT has therefore improved target coverage with a reduction in integral dose to the surrounding tissue. Use of IGRT to feed back into plan and dose delivery optimisation according to the anatomy of the day has enabled adaptive radiotherapy bladder solutions. Here we undertake a review of the stepwise developments underpinning IGRT and adaptive radiotherapy strategies for external beam bladder cancer radiotherapy. We present the evidence in accordance with the framework for systematic clinical evaluation of technical innovations in radiation oncology (R-IDEAL).


Assuntos
Radioterapia Guiada por Imagem , Radioterapia de Intensidade Modulada , Neoplasias da Bexiga Urinária , Tomografia Computadorizada de Feixe Cônico , Humanos , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Neoplasias da Bexiga Urinária/diagnóstico por imagem , Neoplasias da Bexiga Urinária/radioterapia
14.
Hernia ; 25(6): 1481-1490, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34392436

RESUMO

PURPOSE: Negative pressure wound therapy on closed incisions (iNPWT) is a wound dressing system developed to promote wound healing and avoid complications after surgical procedures. The effect of iNPWT is well established in various surgical fields, however, the effect on postoperative wound complications after ventral hernia repair remains unknown. The aim of this systematic review and meta-analysis was to investigate the effect of iNPWT on patients undergoing open ventral hernia repair (VHR) compared with conventional wound dressing. MATERIALS AND METHODS: This systematic review and meta-analysis followed the PRISMA guidelines. The databases PubMed, Embase, Cochrane Library, Web of science and Cinahl were searched for original studies comparing iNPWT to conventional wound dressing in patients undergoing VHR. The primary outcome was surgical site occurrence (SSO), secondary outcomes included surgical site infection (SSI) and hernia recurrence. RESULTS: The literature search identified 373 studies of which 10 were included in the meta-analysis including a total of 1087 patients. Eight studies were retrospective cohort studies, one was a cross-sectional pilot study, and one was a randomized controlled trial. The meta-analysis demonstrated that iNPWT was associated with a decreased risk of SSO (OR 0.27 [0.19, 0.38]; P < 0.001) and SSI (OR 0.32 [0.17, 0.55]; P < 0.001). There was no statistically significant association with the risk of hernia recurrence (OR 0.62 [0.27, 1.43]; P = 0.26). CONCLUSION: Based on the findings of this systematic review and meta-analysis iNPWT following VHR was found to significantly reduce the incidence of SSO and SSI, compared with standard wound dressing. INPWT should be considered for patients undergoing VHR.


Assuntos
Hérnia Ventral , Tratamento de Ferimentos com Pressão Negativa , Estudos Transversais , Hérnia Ventral/etiologia , Herniorrafia/efeitos adversos , Humanos , Tratamento de Ferimentos com Pressão Negativa/métodos , Projetos Piloto , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos Retrospectivos , Infecção da Ferida Cirúrgica/etiologia , Infecção da Ferida Cirúrgica/prevenção & controle , Infecção da Ferida Cirúrgica/cirurgia
15.
Clin Oncol (R Coll Radiol) ; 33(7): 461-467, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33766503

RESUMO

AIMS: Adaptive radiotherapy (ART) is an emerging advanced treatment option for bladder cancer patients. Therapeutic radiographers (RTTs) are central to the successful delivery of this treatment. The purpose of this work was to evaluate the image-guided radiotherapy (IGRT) and ART experience of RTTs before participating in the RAIDER trial. A plan of the day (PoD) quality assurance programme was then implemented. Finally, the post-trial experience of RTTs was evaluated, together with the impact of trial quality assurance participation on their routine practice. MATERIALS AND METHODS: A pre-trial questionnaire to assess the experience of the RTT staff group in IGRT and ART in bladder cancer was sent to each centre. Responses were grouped according to experience. The PoD quality assurance programme was implemented, and the RAIDER trial commenced. During stage 1 of the trial, RTTs reported difficulties in delivering PoD and the quality assurance programme was updated accordingly. A follow-up questionnaire was sent assessing experience in IGRT and ART post-trial. Any changes in routine practice were also recorded. RESULTS: The experience of RTTs in IGRT and ART pre-trial varied. For centres deemed to have RTTs with more experience, the initial PoD quality assurance programme was streamlined. For RTTs without ART experience, the full quality assurance programme was implemented, of which 508 RTTs completed. The quality assurance programme was updated (as the trial recruited) and it was mandated that at least one representative RTT (regardless of pre-trial experience) participated in the update in real-time. The purpose of the updated quality assurance programme was to provide further support to RTTs in delivering a complex treatment. Engagement with the updated quality assurance programme was high, with RTTs in 24/33 centres participating in the real-time online workshop. All 33 UK centres reported all RTTs reviewed the updated training offline. Post-trial, the RTTs' experience in IGRT and ART was increased. CONCLUSION: Overall, 508 RTTs undertook the PoD quality assurance programme. There was a high engagement of RTTs in the PoD quality assurance programme and trial. RTTs increased their experience in IGRT and ART and subsequently updated their practice for bladder cancer and other treatment sites.


Assuntos
Radioterapia (Especialidade) , Radioterapia Guiada por Imagem , Ensaios Clínicos como Assunto/normas , Diagnóstico por Imagem , Humanos , Planejamento da Radioterapia Assistida por Computador , Inquéritos e Questionários
16.
Earth Space Sci ; 7(9): e2019EA001066, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33134435

RESUMO

We present a 1:10-M-scale geologic map of the Aphrodite Map Area (AMA) of Venus (0°N-57°S/60-80°E). Geologic mapping employed NASA Magellan synthetic aperture radar and altimetry data. The AMA geologic map, with detailed structural elements and geologic units covering over one eighth of Venus' surface, affords an important and unique perspective to test models of global-scale geologic processes through time. Geologic relations record a history inconsistent with global catastrophic resurfacing. The AMA displays a regional coherence of preserved geologic patterns that record three sequential geologic eras: the ancient era, the Artemis superstructure era, and the youngest fracture zone era. The ancient era and Artemis superstructure, with a footprint covering more than 25% of the surface, are recorded in the Niobe Map Area to the north. The latter two eras likely overlap in time. The fracture zone domain, part of a globally extensive province, marks the most spatially focused tectonomagmatic domain within the AMA. Impact craters are both cut by and overprint fracture zone structures. Twelve percent of AMA impact craters that occur within the fracture zone domain predate or formed during fracture zone development. This observation indicates the relative youth of the fracture zone era and is consistent with the possibility that this domain remains geologically active. The AMA records a rich geologic history of large tract of the surface of Venus and provides an important framework to formulate new working hypotheses of Venus evolution and contribute to planning future studies of the surface of planets.

17.
Clin Oncol (R Coll Radiol) ; 32(2): 93-100, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31400946

RESUMO

AIMS: Node-positive bladder cancer (NPBC) carries a poor prognosis and has traditionally been treated palliatively. However, surgical series suggest that a subset of NPBC patients can achieve long-term control after cystectomy and lymph node dissection. There is little published data regarding the use of radiotherapy to treat NPBC patients. This is in part due to concerns regarding the toxicity of whole-pelvis radiotherapy using conventional techniques. We hypothesised that, using intensity-modulated radiotherapy (IMRT), the pelvic nodes and bladder could be treated within a radical treatment volume with acceptable toxicity profiles. MATERIALS AND METHODS: The Intensity-modulated Pelvic Node and Bladder Radiotherapy (IMPART) trial was a phase II single-centre prospective study designed to assess the feasibility of delivering IMRT to treat the bladder and pelvic nodes in patients with node-positive or high-risk node-negative bladder cancer (NNBC). The primary end point was meeting predetermined dose constraints. Secondary end points included acute and late toxicity, pelvic relapse-free survival and overall survival. RESULTS: In total, 38 patients were recruited and treated between June 2009 and November 2012; 22/38 (58%) had NPBC; 31/38 (81.6%) received neoadjuvant chemotherapy; 18/38 (47%) received concurrent chemotherapy; 37/38 (97%) patients had radiotherapy planned as per protocol. Grade 3 gastrointestinal and genitourinary acute toxicity rates were 5.4 and 20.6%, respectively. At 1 year, the grade 3 late toxicity rate was 5%; 1-, 2- and 5-year pelvic relapse-free survival rates were 55, 37 and 26%, respectively. The median overall survival was 1.9 years (95% confidence interval 1.1-3.8) with 1-, 2- and 5-year overall survival rates of 68, 50 and 34%, respectively. CONCLUSION: Delivering IMRT to the bladder and pelvic nodes in NPBC and high-risk NNBC is feasible, with low toxicity and low pelvic nodal recurrence rates. Long-term control seems to be achievable in a subset of patients. However, relapse patterns suggest that strategies targeting both local recurrence and the development of distant metastases are required to improve patient outcomes.


Assuntos
Linfonodos/efeitos da radiação , Pelve/efeitos da radiação , Radioterapia de Intensidade Modulada/métodos , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Linfonodos/patologia , Masculino , Pessoa de Meia-Idade , Pelve/patologia , Estudos Prospectivos
18.
J Cell Biol ; 107(2): 811-9, 1988 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-3417771

RESUMO

To address the question of insulin-like growth factor (IGF) I localization and synthesis in kidney, we used two complementary experimental approaches: immunohistochemistry of fixed paraffin-embedded rat kidney sections; and measurement of IGF I mRNA in isolated components of the rat nephron, using a highly sensitive and specific solution hybridization assay. Immunostainable IGF I was localized exclusively to principal cells of cortical and medullary collecting ducts. Administration of growth hormone to hypophysectomized rats for 8 d resulted in enhanced immunohistochemical staining of IGF I within collecting ducts, but no detectable IGF I in other portions of the nephron. The abundance of IGF I mRNA was 7-12-fold higher in isolated papillary collecting ducts than in proximal tubules or glomeruli, and was enriched 10-fold compared with whole kidney. Our data demonstrate colocalization of IGF I and IGF I mRNA in the collecting duct, consistent with focal expression of the IGF I gene at this site.


Assuntos
Fator de Crescimento Insulin-Like I/biossíntese , Túbulos Renais Coletores/metabolismo , Túbulos Renais/metabolismo , Somatomedinas/biossíntese , Animais , Autorradiografia , Peso Corporal/efeitos dos fármacos , Feminino , Substâncias de Crescimento/farmacologia , Imuno-Histoquímica , Fator de Crescimento Insulin-Like I/análise , Fator de Crescimento Insulin-Like I/genética , Rim/análise , Rim/efeitos dos fármacos , Rim/crescimento & desenvolvimento , Túbulos Renais Coletores/análise , Masculino , Hibridização de Ácido Nucleico , Tamanho do Órgão/efeitos dos fármacos , Prolactina/farmacologia , RNA Mensageiro/análise , Ratos , Ratos Endogâmicos
19.
Science ; 260(5107): 526-30, 1993 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-17830434

RESUMO

Eastern Aphrodite Terra, a deformed region with high topographic relief on Venus, has been interpreted as analogous to a terrestrial extensional or convergent plate boundary. However, analysis of geological and structural relations indicates that the tectonics of eastern Aphrodite Terra is dominated by blistering of the crust by magma diapirs. The findings imply that, within this region, vertical tectonism dominates over horizontal tectonism and, consequently, that this region is neither a divergent nor a convergent plate boundary.

20.
Phys Med Biol ; 54(12): 3847-64, 2009 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-19491449

RESUMO

A new method is proposed for scatter-correction of cone-beam CT images. A coarse reconstruction is used in initial iteration steps. Modelling of the x-ray tube spectra and detector response are included in the algorithm. Photon diffusion inside the imaging subject is calculated using the Monte Carlo method. Photon scoring at the detector is calculated using forced detection to a fixed set of node points. The scatter profiles are then obtained by linear interpolation. The algorithm is referred to as the coarse reconstruction and fixed detection (CRFD) technique. Scatter predictions are quantitatively validated against a widely used general-purpose Monte Carlo code: BEAMnrc/EGSnrc (NRCC, Canada). Agreement is excellent. The CRFD algorithm was applied to projection data acquired with a Synergy XVI CBCT unit (Elekta Limited, Crawley, UK), using RANDO and Catphan phantoms (The Phantom Laboratory, Salem NY, USA). The algorithm was shown to be effective in removing scatter-induced artefacts from CBCT images, and took as little as 2 min on a desktop PC. Image uniformity was greatly improved as was CT-number accuracy in reconstructions. This latter improvement was less marked where the expected CT-number of a material was very different to the background material in which it was embedded.


Assuntos
Algoritmos , Artefatos , Tomografia Computadorizada de Feixe Cônico/métodos , Intensificação de Imagem Radiográfica/métodos , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Interpretação Estatística de Dados , Método de Monte Carlo , Reprodutibilidade dos Testes , Espalhamento de Radiação , Sensibilidade e Especificidade
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