1,234 research outputs found

    Enhancing Trajectory-Based Operations for UAVs through Hexagonal Grid Indexing: A Step towards 4D Integration of UTM and ATM

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    Aviation is expected to face a surge in the number of manned aircraft and drones in the coming years, making it necessary to integrate Unmanned Aircraft System Traffic Management (UTM) into Air Traffic Management (ATM) to ensure safe and efficient operations. This research proposes a novel hexagonal grid-based 4D trajectory representation framework for unmanned aerial vehicle (UAV) traffic management that overcomes the limitations of existing square/cubic trajectory representation methods. The proposed model employs a hierarchical indexing structure using hexagonal cells, enabling efficient ground based strategic conflict detection and conflict free 4D trajectory planning. Additionally, the use of Hexagonal Discrete Global Grid Systems provides a more accurate representation of UAV trajectories, improved sampling efficiency and higher angular resolution. The proposed approach can be used for predeparture conflict free 4D trajectory planning, reducing computational complexity and memory requirements while improving the accuracy of strategic trajectory conflict detection. The proposed framework can also be extended for air traffic flow management trajectory planning, Air Traffic Control (ATC) workload measurement, sector capacity estimation, dynamics airspace sectorization using hexagonal sectors and traffic density calculation, contributing to the development of an efficient UTM system, and facilitating the integration of UAVs into the national airspace system with AT

    Pharmacy and formulation support for paediatric clinical trials in England

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    Availability and sourcing of investigational drugs for paediatric clinical trials is known to be a challenge for investigator-led clinical trials. The National Institute of Health Research Clinical Research Network: Children (CRN: Children) provides support for formulations and pharmacy related issues to researchers planning and setting up paediatric clinical trials within England. This paper reviews pharmacy and formulation support provided to a consecutive series of investigator-led clinical studies supported by CRN:Children. Case studies are included to describe some of the unique pharmaceutical challenges encountered. 44 trials were reviewed and a total of 103 products were required to support these clinical trials. UK authorised products were suitable for use for 62 of these 103 products. In the remaining 41 cases, 4 could be sourced as an authorised product within the European Union and the remaining 37 required bespoke manufacture. Bespoke manufacture of an investigational drug or placebo is costly. Typical costs for the initial development and testing of a bespoke investigational drug or placebo were in the range of £30,000–100,000 per product. The estimated cost for 19 out of 45 trials was available; in summary, the costs on a per patient per day of therapy basis ranged from under £1 to almost £600; short studies involving multiple agents are obviously the most expensive. This range is dependent upon the need for bespoke manufacture and also the number of participants within the trial. The arrangements for investigational drug supply can greatly affect the study design, regulatory requirements, trial logistics, as well as the total cost of research. As investigational product related activities are often costly, necessitating months of advance planning, it is imperative that specialist inputs are sought from the very start of the study design and planning process

    Examining Type 1 Diabetes Mathematical Models Using Experimental Data

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    Type 1 diabetes requires treatment with insulin injections and monitoring glucose levels in affected individuals. We explored the utility of two mathematical models in predicting glucose concentration levels in type 1 diabetic mice and determined disease pathways. We adapted two mathematical models, one with [Formula: see text]-cells and the other with no [Formula: see text]-cell component to determine their capability in predicting glucose concentration and determine type 1 diabetes pathways using published glucose concentration data for four groups of experimental mice. The groups of mice were numbered Mice Group 1–4, depending on the diabetes severity of each group, with severity increasing from group 1–4. A Markov Chain Monte Carlo method based on a Bayesian framework was used to fit the model to determine the best model structure. Akaike information criteria (AIC) and Bayesian information criteria (BIC) approaches were used to assess the best model structure for type 1 diabetes. In fitting the model with no [Formula: see text]-cells to glucose level data, we varied insulin absorption rate and insulin clearance rate. However, the model with [Formula: see text]-cells required more parameters to match the data and we fitted the [Formula: see text]-cell glucose tolerance factor, whole body insulin clearance rate, glucose production rate, and glucose clearance rate. Fitting the models to the blood glucose concentration level gave the least difference in AIC of [Formula: see text] , and a difference in BIC of [Formula: see text] for Mice Group 4. The estimated AIC and BIC values were highest for Mice Group 1 than all other mice groups. The models gave substantial differences in AIC and BIC values for Mice Groups 1–3 ranging from [Formula: see text] to [Formula: see text]. Our results suggest that the model without [Formula: see text]-cells provides a more suitable structure for modelling type 1 diabetes and predicting blood glucose concentration for hypoglycaemic episodes

    Cognitive outcomes in patients with essential tremor treated with deep brain stimulation: a systematic review

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    IntroductionEssential tremor (ET) is a common neurological disease. Deep brain stimulation (DBS) to the thalamic ventral intermediate nucleus (VIM) or the adjacent structures, such as caudal zona incerta/ posterior subthalamic area (cZi/PSA), can be effective in treating medication refractory tremor. However, it is not clear whether DBS can cause cognitive changes, in which domain, and to what extent if so.MethodsWe systematically searched PubMed and the Web of Science for available publications reporting on cognitive outcomes in patients with ET who underwent DBS following the PICO (population, intervention, comparators, and outcomes) concept. The PRISMA guideline for systematic reviews was applied.ResultsTwenty relevant articles were finally identified and included for review, thirteen of which were prospective (one also randomized) studies and seven were retrospective. Cognitive outcomes included attention, memory, executive function, language, visuospatial function, and mood-related variables. VIM and cZi/PSA DBS were generally well tolerated, although verbal fluency and language production were affected in some patients. Additionally, left-sided VIM DBS was associated with negative effects on verbal abstraction, word recall, and verbal memory performance in some patients.ConclusionSignificant cognitive decline after VIM or cZi/PSA DBS in ET patients appears to be rare. Future prospective randomized controlled trials are needed to meticulously study the effect of the location, laterality, and stimulation parameters of the active contacts on cognitive outcomes while considering possible medication change post-DBS, timing, standard neuropsychological battery, practice effects, the timing of assessment, and effect size as potential confounders

    A mutation in the major autophagy gene, WIPI2, associated with global developmental abnormalities

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    We describe a large consanguineous pedigree from a remote area of Northern Pakistan, with a complex developmental disorder associated with wide-ranging symptoms, including mental retardation, speech and language impairment and other neurological, psychiatric, skeletal and cardiac abnormalities. We initially carried out a genetic study using the HumanCytoSNP-12 v2.1 Illumina gene chip on nine family members and identified a single region of homozygosity shared amongst four affected individuals on chromosome 7p22 (positions 3059377–5478971). We performed whole-exome sequencing on two affected individuals from two separate branches of the extended pedigree and identified a novel nonsynonymous homozygous mutation in exon 9 of the WIPI2 (WD-repeat protein interacting with phosphoinositide 2) gene at position 5265458 (c.G745A;pV249M). WIPI2 plays a critical role in autophagy, an evolutionary conserved cellular pathway implicated in a growing number of medical conditions. The mutation is situated in a highly conserved and critically important region of WIPI2, responsible for binding PI(3)P and PI(3,5)P2, an essential requirement for autophagy to proceed. The mutation is absent in all public databases, is predicted to be damaging and segregates with the disease phenotype. We performed functional studies in vitro to determine the potential effects of the mutation on downstream pathways leading to autophagosome assembly. Binding of the V231M mutant of WIPI2b to ATG16L1 (as well as ATG5–12) is significantly reduced in GFP pull-down experiments, and fibroblasts derived from the patients show reduced WIPI2 puncta, reduced LC3 lipidation and reduced autophagic flux

    Faecal metabolome and its determinants in inflammatory bowel disease

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    OBJECTIVE: Inflammatory bowel disease (IBD) is a multifactorial immune-mediated inflammatory disease of the intestine, comprising Crohn's disease and ulcerative colitis. By characterising metabolites in faeces, combined with faecal metagenomics, host genetics and clinical characteristics, we aimed to unravel metabolic alterations in IBD.DESIGN: We measured 1684 different faecal metabolites and 8 short-chain and branched-chain fatty acids in stool samples of 424 patients with IBD and 255 non-IBD controls. Regression analyses were used to compare concentrations of metabolites between cases and controls and determine the relationship between metabolites and each participant's lifestyle, clinical characteristics and gut microbiota composition. Moreover, genome-wide association analysis was conducted on faecal metabolite levels.RESULTS: We identified over 300 molecules that were differentially abundant in the faeces of patients with IBD. The ratio between a sphingolipid and L-urobilin could discriminate between IBD and non-IBD samples (AUC=0.85). We found changes in the bile acid pool in patients with dysbiotic microbial communities and a strong association between faecal metabolome and gut microbiota. For example, the abundance of Ruminococcus gnavus was positively associated with tryptamine levels. In addition, we found 158 associations between metabolites and dietary patterns, and polymorphisms near NAT2 strongly associated with coffee metabolism.CONCLUSION: In this large-scale analysis, we identified alterations in the metabolome of patients with IBD that are independent of commonly overlooked confounders such as diet and surgical history. Considering the influence of the microbiome on faecal metabolites, our results pave the way for future interventions targeting intestinal inflammation.</p

    FGF23 expression is a promising immunohistochemical diagnostic marker for undifferentiated pleomorphic sarcoma of bone (UPSb)

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    © 2024 The Authors. Published by MDPI. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.3390/genes15020242Background: Undifferentiated pleomorphic sarcoma of bone (UPSb) is a rare primary bone sarcoma that lacks a specific line of differentiation. Distinguishing between UPSb and other malignant bone sarcomas, including dedifferentiated chondrosarcoma and osteosarcoma, is challenging due to their overlapping features. We have previously identified that UPSb tumours have elevated mRNA levels of Fibroblast Growth Factor 23 (FGF23) transcripts compared to other sarcomas including osteosarcoma. In the present study, we evaluated the specificity and practicality of FGF23 immunoreactivity as a specific diagnostic tool to differentiate UPSb tumours from osteosarcomas and dedifferentiated chondrosarcomas. Methods: A total of 10 UPSb, 10 osteosarcoma, and 10 dedifferentiated chondrosarcoma cases (all high-grade), were retrieved and immunohistochemistry for FGF23 was performed. Results: FGF23 protein was expressed at high levels in 80–90% of undifferentiated pleomorphic sarcoma of the bone cases, whereas it was expressed at significantly lower levels in dedifferentiated chondrosarcoma and osteosarcoma cases. A semiquantitative analysis, considering the intensity of immunoreactivity, confirmed significantly elevated FGF23 expression levels in UPSb tissues compared to those observed in osteosarcoma and dedifferentiated chondrosarcoma tissues. Conclusions: The results we present here suggest that FGF23 immunohistochemistry may be a useful tool to aid in differentiating UPSb from morphologically similar malignant bone sarcomas, especially in situations where sampling is restricted and there is limited clinical information available.Funding for the study was provided by the Bone Cancer Research Trust (BCRT) with grant code BCRT/7020. This research was also funded in part by the Kuwait Medical Genetics Centre (KMGC), Ministry of Health, Kuwait; the Italian Ministry of Health (Ricerca Corrente L4097 and L4135, IRCCS Istituto Ortopedico Galeazzi); and the Rotha Abraham Bequest, New Cross Hospital, Wolverhampton, UK.Published versio
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