664 research outputs found
Patient-specific stopping power calibration for proton therapy planning based on single-detector proton radiography.
A simple robust optimizer has been developed that can produce patient-specific calibration curves to convert x-ray computed tomography (CT) numbers to relative stopping powers (HU-RSPs) for proton therapy treatment planning. The difference between a digitally reconstructed radiograph water-equivalent path length (DRRWEPL) map through the x-ray CT dataset and a proton radiograph (set as the ground truth) is minimized by optimizing the HU-RSP calibration curve. The function of the optimizer is validated with synthetic datasets that contain no noise and its robustness is shown against CT noise. Application of the procedure is then demonstrated on a plastic and a real tissue phantom, with proton radiographs produced using a single detector. The mean errors using generic/optimized calibration curves between the DRRWEPL map and the proton radiograph were 1.8/0.4% for a plastic phantom and -2.1/ - 0.2% for a real tissue phantom. It was then demonstrated that these optimized calibration curves offer a better prediction of the water equivalent path length at a therapeutic depth. We believe that these promising results are suggestive that a single proton radiograph could be used to generate a patient-specific calibration curve as part of the current proton treatment planning workflow
A Communications-Oriented Perspective on Traffic Management Systems for Smart Cities: Challenges and Innovative Approaches
The growing size of cities and increasing population mobility have determined a rapid increase in the number of vehicles on the roads, which has resulted in many challenges for road traffic management authorities in relation to traffic congestion, accidents, and air pollution. Over the recent years, researchers from both industry and academia have been focusing their efforts on exploiting the advances in sensing, communication, and dynamic adaptive technologies to make the existing road traffic management systems (TMSs) more efficient to cope with the aforementioned issues in future smart cities. However, these efforts are still insufficient to build a reliable and secure TMS that can handle the foreseeable rise of population and vehicles in smart cities. In this survey, we present an up-to-date review of the different technologies used in the different phases involved in a TMS and discuss the potential use of smart cars and social media to enable fast and more accurate traffic congestion detection and mitigation. We also provide a thorough study of the security threats that may jeopardize the efficiency of the TMS and endanger drivers' lives. Furthermore, the most significant and recent European and worldwide projects dealing with traffic congestion issues are briefly discussed to highlight their contribution to the advancement of smart transportation. Finally, we discuss some open challenges and present our own vision to develop robust TMSs for future smart cities
Treatment strategies for Sjögrenâs syndrome with childhood onset: a systematic review of the literature
OBJECTIVES:
SS with childhood onset is a rare autoimmune disease characterized by heterogeneous presentation. The lack of validated classification criteria makes it challenging to diagnose. Evidence-based guidelines for treatment of juvenile SS are not available due to the rarity of disease and the paucity of research in this patient population. This systematic review aims to summarize and appraise the current literature focused on pharmacological strategies for management of SS with childhood onset.
METHODS:
PubMed and MEDLINE/Scopus databases up to December 2020 were screened for suitable reports highlighting pharmacological treatment of SS with childhood onset using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2009 reporting checklist. Animal studies were excluded.
RESULTS:
A total of 43 studies (34 case reports, 8 mini case series and 1 pilot study) were eligible for analysis. The studies retrieved included girls in 88% (120/137) of cases and had very low confidence levels. HCQ was prescribed for parotid swelling, as well as in association with MTX and NSAIDs in patients with arthritis and arthralgia. Corticosteroids such as long courses of oral prednisone and i.v. methylprednisolone were commonly prescribed for children with severe disease presentations. Rituximab was mainly indicated for mucosa-associated lymphoid tissue lymphoma and renal and nervous system complications. Other conventional DMARDs were prescribed in selected cases with extraglandular manifestations.
CONCLUSION:
Various therapies are used for the management of juvenile SS and are prescribed based on expert clinicianâs opinion. There are currently no good-quality studies that allow clinical recommendations for treatment of SS with childhood onset
Menâs Health Research in New Zealand: A Scoping Review
Background: Globally, there has been a growing awareness of the health challenges faced by men. The current public health agenda in Aotearoa New Zealand (NZ) does not specifically address the needs of men. The aim of this scoping review was to capture the major health issues facing men in NZ and particularly to identify the knowledge gaps in the understanding of menâs health within the NZ context. This was achieved by presenting key data on their health status and systematically mapping research in NZ related to menâs health; international data are also referenced for context as relevant. Method: A search and screening of the literature were conducted using Ovid, Web of Science and Scopus databases from January 1996 to July 2021, with advice from a medical librarian. Search terms included âmenâs/maleâs healthâ and âmenâs/maleâs health NZ.â An environmental scan of international literature was also carried out and information from the Ministry of Health and Statistics NZ was obtained to provide context of the status of research on menâs health in NZ. Main Findings: In keeping with international literature, the major health issues for men in NZ are life-limiting diseases including cancer and cardiovascular disease, the spread of overweight and obesity, issues with masculinity and help-seeking behaviours, unhealthy lifestyles, mental health issues and poor health literacy. The main areas of research related to menâs health from the NZ literature were highlighted. Discussion: Menâs health remains an under-recognised issue in NZ. If we are to address current inequities in health for men, clinicians, researchers and relevant agencies need to pay more attention to menâs health issues and take up the challenge to highlight and promote menâs health status in NZ
Ageing well in older men in Otago and Southland of New Zealand: a focus group study protocol
Background: Men in New Zealand (NZ) do not enjoy the same level of health and wellbeing as women. Men generally experience a higher incidence of, and mortality from, major diseases; most importantly, life expectancies for men in NZ are approximately four years less than for women. Such disparities vary across rural and urban communities, and across ethnic sub-groups. In particular, MÄori men live some seven years less than other NZ men. Despite such inequalities, menâs health is not recognised as a priority by healthcare providers, government, or at the wider societal level. This qualitative study seeks to address this, by contributing to our understanding of factors associated with health and wellbeing for men in the ageing process. Study findings will also inform the development of a national survey of older men. Method: Focus groups will be used to explore the expectations and experiences of health and wellbeing in a cohort of older men (â„45 years) in the Otago and Southland regions. Topics to be explored will include gender role conflict, health service help-seeking, lifestyle behaviours, social engagement, and self-identified health risks. In total, five groups are planned (6-10 men per group) and will be conducted in urban, rural, and urban-rural adjunct areas. Focus groups will be recorded, and transcribed verbatim. Transcriptions will be coded for themes using the abductive thematic analysis approach. Results: This paper presents a protocol of a study in progress, and results are not yet known. Discussion: This is the first qualitative study focussing on ageing well in men in NZ. It will contribute to our understanding of this aspect of menâs health, andâultimatelyâhelp to inform interventions and policies to better support men to age positively
Developing and Implementing a Framework for System Level Measures: lessons from New Zealand
Background: Measuring performance is now the norm in health systems. System Level Measures (SLMs), implemented at New Zealandâs Counties Manukau Health (CMH) are designed to support quality improvement activities undertaken across the health system using only a small set of measures. While the healthcare and performance measurement literature contains information regarding the facilitators and barriers to quality improvement initiatives, there is an absence of studies into whether these factors are germane to the establishment and implementation of a SLM framework.
Methods: A purposive sample of thirteen senior managers and clinicians involved in the construction and implementation of SLMs were invited to participate. Semi-structured telephone interviews were completed and recordings transcribed verbatim. Transcriptions were thematically analysed using a general inductive approach.
Findings: In total, ten interviews took place. Six facilitative themes were identified including: dispersed and focused leadership; communication; data; alignment of the measures with organisational strategic data; alignment of the measures with organisational strategic plans and values; stakeholder engagement; and a dedicated project team. Conversely, five themes were identified that hindered the process. These were: reaching consensus; perfection versus pragmatism; duplication and process burden; achieving buy-in and workload.
Discussion: The factors that facilitate and hinder establishing and implementing a framework of SLMs are common to other quality improvement approaches. However, this study demonstrated that these factors were also germane to SLMs. These findings are of particular relevance as researchers and policy makers elsewhere increasingly aim to adopt measurement arrangements for health systems that address equity, safety, quality, access and cost.
Abbreviations: CMH â Counties Manukau Health; DHB â District Health Board; IHI â Institute for Healthcare Improvement; QI â Quality Improvement; SLM â System Level Measure
Dose ratio proton radiography using the proximal side of the Bragg peak
Purpose: In recent years there has been a movement towards single-detector proton radiography, due to its potential ease of implementation within the clinical environment. One such single-detector technique is the dose ratio method, in which the dose maps from two pristine Bragg peaks are recorded beyond the patient. To date, this has only been investigated on the distal side of the lower energy Bragg peak, due to the sharp fall-off. We investigate the limits and applicability of the dose ratio method on the proximal side of the lower energy Bragg peak, which has the potential to allow a much wider range of water-equivalent thicknesses (WET) to be imaged. Comparisons are made with the use of the distal side of the Bragg peak. Methods: Using the analytical approximation for the Bragg peak we generated theoretical dose ratio curves for a range of energy pairs, and then determined how an uncertainty in the dose ratio would translate to a spread in the WET estimate. By defining this spread as the accuracy one could achieve in the WET estimate, we were able to generate look-up graphs of the range on the proximal side of the Bragg peak that one could reliably use. These were dependent on the energy pair, noise level in the dose ratio image and the required accuracy in the WET. Using these look-up graphs we investigated the applicability of the technique for a range of patient treatment sites. We validated the theoretical approach with experimental measurements using a complementary metal oxide semiconductor active pixel sensor (CMOS APS), by imaging a small sapphire sphere in a high energy proton beam. Results: Provided the noise level in the dose ratio image was 1% or less, a larger spread of WETs could be imaged using the proximal side of the Bragg peak (max 5.31 cm) compared to the distal side (max 2.42 cm). In simulation it was found that, for a pediatric brain, it is possible to use the technique to image a region with a square field equivalent size of 7.6 cm2, for a required accuracy in the WET of 3 mm and a 1% noise level in the dose ratio image. The technique showed limited applicability for other patient sites. The CMOS APS demonstrated a good accuracy, with a root-mean-square-error of 1.6 mm WET. The noise in the measured images was found to be Ï =1.2% (standard deviation) and theoretical predictions with a 1.96Ï noise level showed good agreement with the measured errors. Conclusions: After validating the theoretical approach with measurements, we have shown that the use of the proximal side of the Bragg peak when performing dose ratio imaging is feasible, and allows for a wider dynamic range than when using the distal side. The dynamic range available increases as the demand on the accuracy of the WET decreases. The technique can only be applied to clinical sites with small maximum WETs such as for pediatric brains
Preferential transcription of the mutated allele in NPM1 mutated acute myeloid leukaemia
Nucleophosmin is commonly both over-expressed and mutated in acute myeloid leukemia (AML). NPM1 mutations are always heterozygous. In addition, NPM1 has a number of different splice variants with the major variant encoded by exons 1â9 and 11â12 (NPM1.1). Further variants include NPM1.2 which lacks exons 8 and 10 and NPM1.3 which comprises exons 1â10 (and so lacks the region of sequence mutated in AML). In this study we quantified the expression of these three variants in 108 AML patient samples with and without NPM1 mutations and also assessed the level of expression from the wild-type and mutant alleles in variants NPM1.1 and NPM1.2. The results show that NPM1.1 is the most commonly expressed variant, however transcripts from wild-type and mutated alleles do not occur at equal levels, with a significant bias toward the mutated allele. Considering the involvement of mutant nucleophosmin in the progression and maintenance of AML, a bias towards mutated transcripts could have a significant impact on disease maintenance
3D-imaging of Printed Nanostructured Networks using High-resolution FIB-SEM Nanotomography
Networks of solution-processed nanomaterials are important for multiple
applications in electronics, sensing and energy storage/generation. While it is
known that network morphology plays a dominant role in determining the physical
properties of printed networks, it remains difficult to quantify network
structure. Here, we utilise FIB-SEM nanotomography to characterise the
morphology of nanostructured networks. Nanometer-resolution 3D-images were
obtained from printed networks of graphene nanosheets of various sizes, as well
as networks of WS2 nanosheets, silver nanosheets and silver nanowires.
Important morphological characteristics, including network porosity,
tortuosity, pore dimensions and nanosheet orientation were extracted and linked
to network resistivity. By extending this technique to interrogate the
structure and interfaces within vertical printed heterostacks, we demonstrate
the potential of this technique for device characterisation and optimisation.Comment: 6 figure
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