172 research outputs found
SPECTROModule: A modular in-situ spectroscopy platform for exobiology and space sciences
The evolution of the solar system and the origin of life remain some of the most intriguing questions for humankind. Addressing these questions experimentally is challenging due to the difficulty of mimicking environmental conditions representative for Early Earth and/or space conditions in general in ground-based laboratories. Performing experiments directly in space offers the great chance to overcome some of these obstacles and to possibly find answers to these questions. Exposure platforms in Low Earth Orbit (LEO) with the possibility for long-duration solar exposure are ideal for investigating the effects of solar and cosmic radiation on various biological and non-biological samples. Up to now, the Exobiology and space science research community has successfully made use of the International Space Station (ISS) via the EXPOSE facility to expose samples to the space environment with subsequent analyses after return to Earth. The emerging small and nanosatellite market represents another opportunity for astrobiology research as proven by the robotic O/OREOS mission, where samples were monitored in-situ, i.e. in Earth orbit. In this framework, the European Space Agency is developing a novel Exobiology facility outside the ISS. The new platform, which can host up to four different experiments, will combine the advantages of the ISS (long-term exposure, sample return capability) with near-real-time in-situ monitoring of the chemical/biological evolution in space. In particular, ultravioletâvisible (UVâVis) and infrared (IR) spectroscopy were considered as key non-invasive methods to analyse the samples in situ. Changes in the absorption spectra of the samples developing over time will reveal the chemical consequences of exposure to solar radiation. Simultaneously, spectroscopy provides information on the growth rate or metabolic activities of biological cultures. The first quartet of experiments to be performed on-board consists of IceCold, OREOcube and Exocube (dual payload consisting of ExocubeChem and ExocubeBio). To prepare for the development of the Exobiology facility, ground units of the UVâVis and IR spectrometers were studied, manufactured and tested as precursors of the flight units. The activity led to a modular in-situ spectroscopy platform able to perform different measurements (e.g. absorbance, optical density, fluorescence measurements) at the same time on different samples. We describe here the main features of the ground model platform, the verification steps, results and approach followed in the customization of commercialâoff-the-shelf (COTS) modules to make them suitable for the space environment. The environmental tests included random and shock vibration, thermal vacuum cycles in the range â20 °C to +40 °C and irradiation of the components with a total dose of 1800 rad (18 Gy). The results of the test campaign consolidated the selection of the optical devices for the Exobiology Facility. The spectroscopic performance of the optical layout was tested and benchmarked in comparison with state-of-the-art laboratory equipment and calibration standards showing good correlation. This includes spectra of samples sets relevant for the flight experiments and a performance comparison between the SPECTROModule ground model and state-of-the-art laboratory spectrometers. Considering the large number of samples and different types of optical measurements planned on-board the ISS, the main outcome was the implementation of an LED-photodiode layout for the optical density and fluorescence measurements of IceCold (42 samples) and ExocubeBio (111 samples); while the UVâVis spectrometer will be mainly focused on the change of the absorption spectra of the 48 samples of OREOcube.The ExocubeChem samples (in total 48) will be analysed by infrared spectroscopy. The ground platform supports the establishment of analogue research capabilities able to address the long-term objectives beyond the current application
Defining decision thresholds for judgments on health benefits and harms using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Evidence to Decision (EtD) frameworks : A protocol for a randomised methodological study (GRADE-THRESHOLD)
Introduction The Grading of Recommendations Assessment, Development and Evaluation (GRADE) and similar Evidence to Decision (EtD) frameworks require its users to judge how substantial the effects of interventions are on desirable and undesirable people-important health outcomes. However, decision thresholds (DTs) that could help understand the magnitude of intervention effects and serve as reference for interpretation of findings are not yet available. The objective of this study is an approach to derive and use DTs for EtD judgments about the magnitude of health benefits and harms. We hypothesise that approximate DTs could have the ability to discriminate between the existing four categories of EtD judgments (Trivial, Small, Moderate, Large), support panels of decision-makers in their work, and promote consistency and transparency in judgments. Methods and analysis We will conduct a methodological randomised controlled trial to collect the data that allow deriving the DTs. We will invite clinicians, epidemiologists, decision scientists, health research methodologists, experts in Health Technology Assessment (HTA), members of guideline development groups and the public to participate in the trial. Then, we will investigate the validity of our DTs by measuring the agreement between judgments that were made in the past by guideline panels and the judgments that our DTs approach would suggest if applied on the same guideline data. Ethics and dissemination The Hamilton Integrated Research Ethics Board reviewed this study as a quality improvement study and determined that it requires no further consent. Survey participants will be required to read a consent statement in order to participate in this study at the beginning of the trial. This statement reads: You are being invited to participate in a research project which aims to identify indicative DTs that could assist users of the GRADE EtD frameworks in making judgments. Your input will be used in determining these indicative thresholds. By completing this survey, you provide consent that the anonymised data collected will be used for the research study and to be summarised in aggregate in publication and electronic tools. PROTOCOL registration number NCT05237635
The GRADE Working Group clarifies the construct of certainty of evidence
The authors would like to thank colleagues at the Swedish Agency for Health Technology Assessment and Assessment of Social Services (SBU) who, through participating in a series of seminars, contributed with valuable input on the initial draft of the presented approaches. The authors also thank all GRADE Working Group members who have contributed to the paper during group discussions at Grade Working Group meetings. The Health Services Research Unit, University of Aberdeen, receives core funding from the Chief Scientist Office of the Scottish Government Health Directorates. The Parker Institute, Bispebjerg and Frederiksberg Hospital is supported by a core grant from the Oak Foundation (OCAY-13-309). SVK is funded by a NRS Scottish Senior Clinical Fellowship (SCAF/15/02), the Medical Research Council (MC_UU_12017/13 & MC_UU_12017/15) and Chief Scientistâs Office (SPHSU13 & SPHSU15).Peer reviewedPublisher PD
Improving the quality of toxicology and environmental health systematic reviews:What journal editors can do
Systematic reviews are fast increasing in prevalence in the toxicology and environmental health literature. However, how well these complex research projects are being conducted and reported is unclear. Since editors have an essential role in ensuring the scientific quality of manuscripts being published in their journals, a workshop was convened where editors, systematic review practitioners, and research quality control experts could discuss what editors can do to ensure the systematic reviews they publish are of sufficient scientific quality. Interventions were explored along four themes: setting standards; reviewing protocols; optimizing editorial workflows; and measuring the effectiveness of editorial interventions. In total, 58 editorial interventions were proposed. Of these, 26 were shortlisted for being potentially effective, and 5 were prioritized as short-term actions that editors could relatively easily take to improve the quality of published systematic reviews. Recent progress in improving systematic reviews is summarized, and outstanding challenges to further progress are highlighted
World Allergy Organization (WAO) Diagnosis and Rationale for Action against CowÊŒs Milk Allergy (DRACMA) Guidelines
The global impact of the DRACMA guidelines cowâs milk allergy clinical practice
Background: The 2010 Diagnosis and Rationale for Action against Cowâs Milk Allergy (DRACMA) guidelines are the only Grading of Recommendations Assessment, Development and Evaluation (GRADE) guidelines for cowâs milk allergy (CMA). They indicate oral food challenge (OFC) as the reference test for diagnosis, and suggest the choice of specific alternative formula in different clinical conditions. Their recommendations are flexible, both in diagnosis and in treatment.
Objectives & methods: Using the Scopus citation records, we evaluated the influence of the DRACMA guidelines on milk allergy literature. We also reviewed their impact on successive food allergy and CMA guidelines at national and international level. We describe some economic consequences of their application.
Results: DRACMA are the most cited CMA guidelines, and the second cited guidelines on food allergy. Many subsequent guidelines took stock of DRACMAâs metanalyses adapting recommendations to the local context. Some of these chose not to consider OFC as an absolute requirement for the diagnosis of CMA. Studies on their implementation show that in this case, the treatment costs may increase and there is a risk of overdiagnosis. Interestingly, we observed a reduction in the cost of alternative formulas following the publication of the DRACMA guidelines.
Conclusions: DRACMA reconciled international differences in the diagnosis and management of CMA. They promoted a cultural debate, improved clinicianâs knowledge of CMA, improved the quality of diagnosis and care, reduced inappropriate practices, fostered the efficient use of resources, empowered patients, and influenced some public policies. The accruing evidence on diagnosis and treatment of CMA necessitates their update in the near futur
American Society of Hematology 2019 guidelines for management of venous thromboembolism : prevention of venous thromboembolism in surgical hospitalized patients
Background: Venous thromboembolism (VTE) is a common source of perioperative morbidity and mortality. Objective: These evidence-based guidelines from the American Society of Hematology (ASH) intend to support decision making about preventing VTE in patients undergoing surgery. Methods: ASH formed a multidisciplinary guideline panel balanced to minimize bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline-development process, including performing systematic reviews. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations, which were subject to public comment. Results: The panel agreed on 30 recommendations, including for major surgery in general (n = 8), orthopedic surgery (n = 7), major general surgery (n = 3), major neurosurgical procedures (n = 2), urological surgery (n = 4), cardiac surgery and major vascular surgery (n = 2), major trauma (n = 2), and major gynecological surgery (n = 2). Conclusions: For patients undergoing major surgery in general, the panel made conditional recommendations for mechanical prophylaxis over no prophylaxis, for pneumatic compression prophylaxis over graduated compression stockings, and against inferior vena cava filters. In patients undergoing total hip or total knee arthroplasty, conditional recommendations included using either aspirin or anticoagulants, as well as for a direct oral anticoagulant over low-molecular-weight heparin (LMWH). For major general surgery, the panel suggested pharmacological prophylaxis over no prophylaxis, using LMWH or unfractionated heparin. For major neurosurgery, transurethral resection of the prostate, or radical prostatectomy, the panel suggested against pharmacological prophylaxis. For major trauma surgery or major gynecological surgery, the panel suggested pharmacological prophylaxis over no prophylaxis.Peer reviewe
Childhood asthma prevalence and risk factors in three Eastern European countries - the Belarus, Ukraine, Poland Asthma Study (BUPAS): an international prevalence study
individual participant data meta-analysis of randomised trials study protocol
Introduction Parenteral anticoagulants may improve outcomes in patients with
cancer by reducing risk of venous thromboembolic disease and through a direct
antitumour effect. Study-level systematic reviews indicate a reduction in
venous thromboembolism and provide moderate confidence that a small survival
benefit exists. It remains unclear if any patient subgroups experience
potential benefits. Methods and analysis First, we will perform a
comprehensive systematic search of MEDLINE, EMBASE and The Cochrane Library,
hand search scientific conference abstracts and check clinical trials
registries for randomised control trials of participants with solid cancers
who are administered parenteral anticoagulants. We anticipate identifying at
least 15 trials, exceeding 9000 participants. Second, we will perform an
individual participant data meta-analysis to explore the magnitude of survival
benefit and address whether subgroups of patients are more likely to benefit
from parenteral anticoagulants. All analyses will follow the intention-to-
treat principle. For our primary outcome, mortality, we will use multivariable
hierarchical models with patient-level variables as fixed effects and a
categorical trial variable as a random effect. We will adjust analysis for
important prognostic characteristics. To investigate whether intervention
effects vary by predefined subgroups of patients, we will test interaction
terms in the statistical model. Furthermore, we will develop a risk-prediction
model for venous thromboembolism, with a focus on control patients of
randomised trials. Ethics and dissemination Aside from maintaining participant
anonymity, there are no major ethical concerns. This will be the first
individual participant data meta-analysis addressing heparin use among
patients with cancer and will directly influence recommendations in clinical
practice guidelines. Major cancer guideline development organisations will use
eventual results to inform their guideline recommendations. Several knowledge
users will disseminate results through presentations at clinical rounds as
well as national and international conferences. We will prepare an evidence
brief and facilitate dialogue to engage policymakers and stakeholders in
acting on findings. Trial registration number PROSPERO CRD4201300352
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