702 research outputs found
Chylous ascites associated with chylothorax; a rare sequela of penetrating abdominal trauma: a case report
We present the case of a patient with the rare combination of chylous ascites and chylothorax resulting from penetrating abdominal injury. This patient was successfully managed with total parenteral nutrition. This case report is used to highlight the clinical features and management options of this uncommon but challenging clinical problem
Base-induced cyclisations of ortho-substituted nitro-aromatics
In Chapter I some of the chemical, biological and physical properties of purine analogues, particularly benzimidazole N-oxides, are briefly discussed. In Chapter II, the preparations of 4-, 5-, 6-, and 7-amino-1H-benzimidazole 3-oxides are described. The methods employed involve base-induced cyclisation of suitably protected aminonitrophenyl glycine derivatives (esters or nitriles) followed by hydrolysis of the ester or nitrile and decarboxylation. In Chapter III, attempts are made to prepare imidazopyridine N-oxides, an area of N-oxide chemistry little explored. Although few derivatives of this class of compound are synthesised, the preparation of the parent 3H-imidazo[4 ,5-b]pyridine 1-oxide is accomplished. In Chapter IV, the possibility of preparing 1-methylbenzimidazole 3-oxides by the methods used in Chapters II and III is investigated, but unexpected results are obtained e.g. cyclisation of O-nitropheny1-sarcosine esters gives 1-hydroxy-4-methylquinoxaline-2, 3-diones. These reactions have instigated an investigation into the general mechanism for the base-induced cyclisations discussed in this thesis
Systems Engineering Simulator (SES) Simulator Planning Guide
The simulation process, milestones and inputs are unknowns to first-time users of the SES. The Simulator Planning Guide aids in establishing expectations for both NASA and non-NASA facility customers. The potential audience for this guide includes both internal and commercial spaceflight hardware/software developers. It is intended to assist their engineering personnel in simulation planning and execution. Material covered includes a roadmap of the simulation process, roles and responsibilities of facility and user, major milestones, facility capabilities, and inputs required by the facility. Samples of deliverables, facility interfaces, and inputs necessary to define scope, cost, and schedule are included as an appendix to the guide
On Validating Closed-Loop Behaviour from Noisy Frequency-Response Measurements
It is shown how noisy closed-loop frequency-response measurements can be used to obtain pointwise in frequency bounds on the possible difference between the actual closed-loop system and the closed-loop comprising a nominal model of the plant and the stabilising controller. To this end, Vinnicombe's gap metric framework for robustness analysis plays a central role. Indeed, an optimisation problem and corresponding algorithm are proposed for estimating the chordal distance between the frequency responses of the nominal plant model and a plant that is consistent with the closed-loop data and a priori information, when projected onto the Riemann sphere
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The EBR-II Spent Fuel Treatment Program
Argonne National Laboratory has refurbished and equipped an existing hot cell facility for demonstrating a high-temperature electrometallurgical process for treating spent nuclear fuel from the Experimental Breeder Reactor-11. Two waste forms will be produced and qualified for geologic disposal of the fission and activation products. Relatively pure uranium will be separated for storage. Following additional development, transuranium elements will be blended into one of the high-level waste streams. The spent fuel treatment program will help assess the viability of electrometallurgical technology as a spent fuel management option
The SUMOylation pathway suppresses arbovirus replication in <i>Aedes aegypti</i> cells
Mosquitoes are responsible for the transmission of many clinically important arboviruses that cause significant levels of annual mortality and socioeconomic health burden worldwide. Deciphering the mechanisms by which mosquitoes modulate arbovirus infection is crucial to understand how viral-host interactions promote vector transmission and human disease. SUMOylation is a post-translational modification that leads to the covalent attachment of the Small Ubiquitin-like MOdifier (SUMO) protein to host factors, which in turn can modulate their stability, interaction networks, sub-cellular localisation, and biochemical function. While the SUMOylation pathway is known to play a key role in the regulation of host immune defences to virus infection in humans, the importance of this pathway during arbovirus infection in mosquito vectors, such as Aedes aegypti (Ae. aegypti), remains unknown. Here we characterise the sequence, structure, biochemical properties, and tissue-specific expression profiles of component proteins of the Ae. aegypti SUMOylation pathway. We demonstrate significant biochemical differences between Ae. aegypti and Homo sapiens SUMOylation pathways and identify cell-type specific patterns of SUMO expression in Ae. aegypti tissues known to support arbovirus replication. Importantly, depletion of core SUMOylation effector proteins (SUMO, Ubc9 and PIAS) in Ae. aegypti cells led to enhanced levels of arbovirus replication from three different families; Zika (Flaviviridae), Semliki Forest (Togaviridae), and Bunyamwera (Bunyaviridae) viruses. Our findings identify an important role for mosquito SUMOylation in the cellular restriction of arboviruses that may directly influence vector competence and transmission of clinically important arboviruses
Pre-analytical and analytical variables that influence urinary volatile organic compound measurements
There has been rapidly accelerating interest in the utilization of volatile organic compounds (VOCs) as non-invasive methods for rapid point-of-care medical diagnostics. There is widespread variation in analytical methods and protocols, with little understanding of the effects of sample storage on VOC profiles. This study aimed to determine the effects on VOC profiles of different storage times, at room temperature, prior to freezing, of sealed urine samples from healthy individuals. Analysis using Field Asymmetric Ion Motility Spectrometry (FAIMS) determined the alterations in VOC and total ion count profiles as a result of increasing room temperature storage times. Results indicated that increasing exposure time to room temperature prior to freezing had a threefold effect. Firstly, increased urinary VOC profile variability, with a plateau phase between 12 and 48 hours, before further degradation. Secondly, an increase in total ion count with time exposed to room temperature. Finally, a deterioration in VOCs with each sample run during the analysis process. This provides new insight into the effect of storage of urine samples for VOC analysis using FAIMS technology. Results of this study provide a recommendation for a 12-hour maximum duration at room temperature prior to storage
Clinical outcomes at 12 months and risk of inflammatory bowel disease in patients with an intermediate raised fecal calprotectin : a āreal-worldā view
Objectives:
A recent systematic review confirmed the usefulness of fecal calprotectin (FC) in distinguishing organic (inflammatory bowel disease (IBD)) from non-organic gastrointestinal disease (irritable bowel syndrome (IBS)). FC levels 92% to exclude organic gastrointestinal (GI) disease. Levels >250ā
Ī¼g/g correlate with endoscopic IBD disease activity; sensitivity 90%. We aimed to determine clinical outcomes in intermediate raised FC results (50ā250ā
Ī¼g/g).
Setting:
Primary care general practices in Coventry and Warwickshire, and 3 secondary care hospitals.
Participants:
443 FC results in adults (>16ā
years old) were reviewed from July 2012 to October 2013. Clinical data was collected from hospital databases and general practitioners. Long-term clinical data was available in 41 patients (out of 48).
Primary and secondary outcome measures:
The number of new diagnoses of IBD, IBS and other diagnoses for the intermediate group. The number referred and discharged from secondary care.
Results:
A new IBD diagnosis was made in 19% (n=8) of intermediate results (1% of normal and 38% of raised results). 5% (n=2) of intermediate results had known IBD in remission. A new IBS diagnosis was made in 27% (n=11) of intermediate results, while 34% (n=14) remained undiagnosed, although 8 of these were not referred to secondary care.
Conclusions:
FC testing remains useful in aiding diagnosis of organic GI conditions. However, unlike negative and strongly positive FC results, intermediate FC results lead to a mixture of diagnoses. The OR of a new diagnosis of IBD for an intermediate result compared to normal FC result was 26.6, while an intermediate FC result gave an OR of 0.54 for a new IBS diagnosis compared to normal FC. For intermediate FC results, 1 in 3 patients remained in secondary care after 12ā
months with an OR of 3.6 compared to a normal FC result
Minimal Gluten Exposure Alters Urinary Volatile Organic Compounds in Stable Coeliac Disease
Coeliac disease (CD) patients are distinguishable from healthy individuals via urinary volatile organic compounds (VOCs) analysis. We exposed 20 stable CD patients on gluten-free diet (GFDs) to a 14-day, 3 g/day gluten challenge (GCh), and assessed urinary VOC changes. A control cohort of 20 patients continued on GFD. Urine samples from Days 0, 7, 14, 28 and 56 were analysed using Lonestar FAIMS and Markes Gas ChromatographyāTime of FlightāMass Spectrometer (GC-TOF-MS). VOC signatures on D (day) 7ā56 were compared with D0. Statistical analysis was performed using R. In GCh patients, FAIMS revealed significant VOC differences for all time points compared to D0. GC-TOF-MS revealed significant changes at D7 and D14 only. In control samples, FAIMS revealed significant differences at D7 only. GC-TOF-MS detected no significant differences. Chemical analysis via GC-MS-TOF revealed 12 chemicals with significantly altered intensities at D7 vs. D0 for GCh patients. The alterations persisted for six chemicals at D14 and one (N-methyltaurine) remained altered after D14. This low-dose, short-duration challenge was well tolerated. FAIMS and GC-TOF-MS detected VOC signature changes in CD patients when undergoing a minimal GCh. These findings suggest urinary VOCs could have a role in monitoring dietary compliance in CD patients
An assessment of candidate genes to assist prognosis in gastric cancer
Gastric cancer (GC) is the fourth commonest cancer worldwide, with the second highest mortality rate. Its poor mortality is linked to delayed presentation. There is a drive towards non-invasive biomarker screening and monitoring of many different types of cancer, although with limited success so far. We aimed to determine if any genes from a 32-gene panel could be used to determine GC prognosis. We carried out a retrospective study on the expression of 32 genes, selected for their proven or potential links to GC, on historic formalin fixed paraffin-embedded (FFPE) GC specimens from our unit. Gene expression was measured using quantitative nuclease protection assays (qNPA) technology. Following statistical analysis of the results, immunohistochemical staining for eight genes, both discriminating and non-discriminating, was conducted in seven age and sex matched non-metastatic: metastatic GC pairings. The stained samples were reviewed by two blinded consultant histopathologists. Multivariate Cox analysis of the gene expression data revealed metastatic status, age, sex and five genes appeared to influence GC survival. Genes negatively influencing survival included and (relative risks 2.20, 3.73 and 7.53 respectively). Genes conveying survival benefit included and (relative risks 0.10 and 0.24 respectively). Immunohistochemical staining of seven age and sex matched non-metastatic: metastatic pairs revealed no association between gene expression and protein expression. Our study found several genes whose expression may affect GC prognosis. However, immunohistochemical analysis revealed no association between gene expression and protein expression. It remains to be determined whether gene expression or protein expression are reliable means of assessing GC prognosis
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