287 research outputs found

    Convex optimization problem prototyping for image reconstruction in computed tomography with the Chambolle-Pock algorithm

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    The primal-dual optimization algorithm developed in Chambolle and Pock (CP), 2011 is applied to various convex optimization problems of interest in computed tomography (CT) image reconstruction. This algorithm allows for rapid prototyping of optimization problems for the purpose of designing iterative image reconstruction algorithms for CT. The primal-dual algorithm is briefly summarized in the article, and its potential for prototyping is demonstrated by explicitly deriving CP algorithm instances for many optimization problems relevant to CT. An example application modeling breast CT with low-intensity X-ray illumination is presented.Comment: Resubmitted to Physics in Medicine and Biology. Text has been modified according to referee comments, and typos in the equations have been correcte

    The electronic absorption spectrum of crystallinechromyl chloride at 1.7[deg]K

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    The spectrum of chromyl chloride, CrO2Cl2 , in the region 6000 A-3800 A hasbeen obtained for the crystalline substance at temperatures down to 1.7[deg]K. Three absorption systems have been observed, together with the start of a fourth system at [lambda] < 3800 A. One of the systems has been analyzed in some detail and shown to be in agreement with conclusions drawn from the spectrum of the vapor.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33234/1/0000624.pd

    The impact of passive alveolar molding vs. nasoalveolar molding on cleft width and other parameters of maxillary growth in unilateral cleft lip palate

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    Objective Passive alveolar molding (PAM) and nasoalveolar molding (NAM) are established presurgical infant orthodontic (PSIO) therapies for cleft lip palate (CLP) patients. PAM guides maxillary growth with a modified Hotz appliance, while NAM also uses extraoral taping and includes nasal stents. The effects of these techniques on alveolar arch growth have rarely been compared. Material and methods We retrospectively compared 3D-scanned maxillary models obtained before and after PSIO from infants with unilateral, non-syndromic CLP treated with PAM ( n  = 16) versus NAM ( n  = 13). Nine anatomical points were set digitally by four raters and transversal/sagittal distances and rotations of the maxilla were measured. Results Both appliances reduced the anterior cleft, but NAM percentage wise more. NAM decreased the anterior and medial transversal width compared to PAM, which led to no change. With both appliances, the posterior width increased. The alveolar arch length of the great and small segments and the sagittal length of the maxilla increased with PAM but only partially with NAM. However, NAM induced a significant greater medial rotation of the larger and smaller segment compared to PAM with respect to the lateral angle. Conclusions NAM and PAM presented some significant differences regarding maxillary growth. While NAM reduced the anterior cleft and effectively rotated the segments medially, PAM allowed more transversal and sagittal growth. Clinical relevance The results of this study should be taken into consideration when to decide whether to use PAM or NAM, since they show a different outcome within the first few months. Further studies are necessary regarding long-term differences.Open Access funding enabled and organized by Projekt DEAL.Friedrich-Alexander-Universität Erlangen-Nürnberg (1041

    The methodological quality is insufficient in clinical practice guidelines in the context of COVID-19: systematic review

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    OBJECTIVES: The number of published clinical practice guidelines related to COVID-19 has rapidly increased. This study explored if basic methodological standards of guideline development have been met in the published clinical practice guidelines related to COVID-19. STUDY DESIGN AND SETTING: Rapid systematic review from February 1 until April 27, 2020 using MEDLINE [PubMed], CINAHL [Ebsco], Trip and manual search, including all types of healthcare workers providing any kind of healthcare to any patient population in any setting. RESULTS: There were 1342 titles screened and 188 guidelines included. The highest average AGREE II domain score was 89% for scope and purpose, the lowest for rigor of development (25%). Only eight guidelines (4%) were based on a systematic literature search and a structured consensus process by representative experts (classified as the highest methodological quality). The majority (156; 83%) was solely built on an informal expert consensus. A process for regular updates was described in 27 guidelines (14%). Patients were included in the development of only one guideline. CONCLUSION: Despite clear scope, most publications fell short of basic methodological standards of guideline development. Clinicians should use guidelines that include up-to-date information, were informed by stakeholder involvement, and employed rigorous methodologies

    A comprehensive study on the relationship between image quality and imaging dose in low-dose cone beam CT

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    While compressed sensing (CS) based reconstructions have been developed for low-dose CBCT, a clear understanding on the relationship between the image quality and imaging dose at low dose levels is needed. In this paper, we qualitatively investigate this subject in a comprehensive manner with extensive experimental and simulation studies. The basic idea is to plot image quality and imaging dose together as functions of number of projections and mAs per projection over the whole clinically relevant range. A clear understanding on the tradeoff between image quality and dose can be achieved and optimal low-dose CBCT scan protocols can be developed for various imaging tasks in IGRT. Main findings of this work include: 1) Under the CS framework, image quality has little degradation over a large dose range, and the degradation becomes evident when the dose < 100 total mAs. A dose < 40 total mAs leads to a dramatic image degradation. Optimal low-dose CBCT scan protocols likely fall in the dose range of 40-100 total mAs, depending on the specific IGRT applications. 2) Among different scan protocols at a constant low-dose level, the super sparse-view reconstruction with projection number less than 50 is the most challenging case, even with strong regularization. Better image quality can be acquired with other low mAs protocols. 3) The optimal scan protocol is the combination of a medium number of projections and a medium level of mAs/view. This is more evident when the dose is around 72.8 total mAs or below and when the ROI is a low-contrast or high-resolution object. Based on our results, the optimal number of projections is around 90 to 120. 4) The clinically acceptable lowest dose level is task dependent. In our study, 72.8mAs is a safe dose level for visualizing low-contrast objects, while 12.2 total mAs is sufficient for detecting high-contrast objects of diameter greater than 3 mm.Comment: 19 pages, 12 figures, submitted to Physics in Medicine and Biolog

    2019 EULAR recommendations for the generic core competences of health professionals in rheumatology

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    Background/objectives. To maintain and optimize the quality of care provided by healthprofessionals in rheumatology (HPRs), adequate educational offerings are needed. This task force (TF) aimed to develop evidence-based recommendations for the generic core competences of healthprofessionals in rheumatology, with specific reference to nurses, physical therapists (PTs) andoccupational therapists (OTs) to serve as a basis for their postgraduate education.Methods. The EULAR standardised operating procedures for the development of recommendationswere followed. A TF including rheumatologists, nurses, PTs, OTs, patient-representatives, aneducationalist, methodologists and researchers from 12 countries met twice. In the first TF meeting,13 research questions were defined to support a systematic literature review (SLR). In the secondmeeting, the SLR evidence was discussed and recommendations formulated. Subsequently, level ofevidence and strength of recommendation were assigned and level of agreement (LoA) determined(0-10 rating scale).Results. Three overarching principles were identified and 10 recommendations were developed forthe generic core competences of HPRs. The SLR included 79 full-text papers, 20 of which addressedthe competences, knowledge, skills, attitudes and/or educational needs of HPRs from multipleprofessions. The average LoA for each recommendation ranged from 9.42 to 9.79. Consensus wasreached both on an education and research agenda.Conclusion. Evidence and expert opinion informed a set of recommendations providing guidance onthe generic core competences of HPRs. Implementation of these recommendations in thepostgraduate education of HPRs at the international and national level is advised, consideringvariation in health care systems and professional roles.Keywords: competences; educational needs; recommendations; health professionals; rheumatolog

    Suitability for e-health of non-pharmacological interventions in connective tissue diseases: scoping review with a descriptive analysis

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    OBJECTIVE: Non-pharmacological interventions support patients with connective tissue diseases to better cope with and self-manage their diseases. This study aimed to map existing evidence on non-pharmacological interventions in patients with systemic lupus erythematosus (SLE), systemic sclerosis (SSc) and mixed connective tissue diseases regarding content, feasibility and potential suitability in an e-health setting. METHODS: A literature search was performed in eight different databases in July 2020. The intervention\u27s content was extracted using the \u27Better reporting of interventions: template for intervention description and replication (TIDieR) checklist and guide\u27. A Sankey diagram and descriptive statistics were used to analyse the data and illustrate the relationships between the interventions. RESULTS: Of 8198 identified records, 119 papers were eligible. One hundred and four of them (87.4%) were conducted between 2000 and 2020, mainly in the USA (SLE n=24 (21.2%), SSc n=16 (14.2%)), Brazil (SLE n=8 (7.1%), SSc n=5 (4.4%)) and Italy (SLE n=0 (0%), SSc n=12 (10.6%)). Fifty-two studies (SLE n=24 (21.2%), SSc n=28 (24.8%)) used multicomponent interventions. The single interventions were physical exercises (SLE n=16 (14.2%), SSc n=17 (15.0%)), coaching/counselling (SLE n=11 (18.0%), SSc n=0 (0%)) and education (SLE n=2 (1.8%), SSc n=3 (2.7%)). Primary outcomes focused on physical function (SLE n=1 (0.9%), SSc n=15 (13.3%)), mouth opening in SSc (n=4 (5.9%)) and physical capacity (SLE n=2 (1.8%), SSc n=1 (0.9%)). No interventions for mixed connective tissue disease were found. CONCLUSION: There was a great variety in the intervention\u27s content due to differences in body structure, activity limitations and participation restrictions in SLE and SSc. These results highlight the need for personalised, multicomponent, non-pharmacological interventions, which could be delivered as e-health interventions

    EULAR recommendations for the non-pharmacological management of systemic lupus erythematosus and systemic sclerosis

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    Objective To develop evidence-based recommendations for the non-pharmacological management of systemic lupus erythematosus (SLE) and systemic sclerosis (SSc). Methods A task force comprising 7 rheumatologists, 15 other healthcare professionals and 3 patients was established. Following a systematic literature review performed to inform the recommendations, statements were formulated, discussed during online meetings and graded based on risk of bias assessment, level of evidence (LoE) and strength of recommendation (SoR; scale A–D, A comprising consistent LoE 1 studies, D comprising LoE 4 or inconsistent studies), following the European Alliance of Associations for Rheumatology standard operating procedure. Level of agreement (LoA; scale 0–10, 0 denoting complete disagreement, 10 denoting complete agreement) was determined for each statement through online voting. Results Four overarching principles and 12 recommendations were developed. These concerned common and disease-specific aspects of non-pharmacological management. SoR ranged from A to D. The mean LoA with the overarching principles and recommendations ranged from 8.4 to 9.7. Briefly, non-pharmacological management of SLE and SSc should be tailored, person-centred and participatory. It is not intended to preclude but rather complement pharmacotherapy. Patients should be offered education and support for physical exercise, smoking cessation and avoidance of cold exposure. Photoprotection and psychosocial interventions are important for SLE patients, while mouth and hand exercises are important in SSc. Conclusions The recommendations will guide healthcare professionals and patients towards a holistic and personalised management of SLE and SSc. Research and educational agendas were developed to address needs towards a higher evidence level, enhancement of clinician–patient communication and improved outcomes

    EULAR recommendations for the non-pharmacological management of systemic lupus erythematosus and systemic sclerosis

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    Objective To develop evidence-based recommendations for the non-pharmacological management of systemic lupus erythematosus (SLE) and systemic sclerosis (SSc). Methods A task force comprising 7 rheumatologists, 15 other healthcare professionals and 3 patients was established. Following a systematic literature review performed to inform the recommendations, statements were formulated, discussed during online meetings and graded based on risk of bias assessment, level of evidence (LoE) and strength of recommendation (SoR; scale AD , A comprising consistent LoE 1 studies, D comprising LoE 4 or inconsistent studies), following the European Alliance of Associations for Rheumatology standard operating procedure. Level of agreement (LoA; scale 0-10, 0 denoting complete disagreement, 10 denoting complete agreement) was determined for each statement through online voting. Results Four overarching principles and 12 recommendations were developed. These concerned common and disease-specific aspects of non-pharmacological management. SoR ranged from A to D. The mean LoA with the overarching principles and recommendations ranged from 8.4 to 9.7. Briefly, non-pharmacological management of SLE and SSc should be tailored, person-centred and participatory. It is not intended to preclude but rather complement pharmacotherapy. Patients should be offered education and support for physical exercise, smoking cessation and avoidance of cold exposure. Photoprotection and psychosocial interventions are important for SLE patients, while mouth and hand exercises are important in SSc. Conclusions The recommendations will guide healthcare professionals and patients towards a holistic and personalised management of SLE and SSc. Research and educational agendas were developed to address needs towards a higher evidence level, enhancement of clinician-patient communication and improved outcomes
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