19 research outputs found
Emerging pharmaceutical therapies in cardiopulmonary resuscitation and post-resuscitation syndrome
No full textBiodiversity, abundance, seasonal and diurnal airborne pollen distribution patterns at two different heights in Augsburg, Germany.
No full textAirborne pollen are the most important aeroallergens worldwide. Because of climate change, pollen seasonality and abundance have been altering significantly, raising the fundamental question: when and how much is the pollen exposure increasing? To answer this, we applied a multi-resolution study design, from bi-hourly to yearly scale, investigating the diversity, abundance and temporal occurrence of airborne pollen. The whole spectrum of airborne pollen concentrations was registered during 2015–2017, using a 7-day recording Hirst-type volumetric trap. Monitoring took place at ground-level, where we mostly commute and reside, and at the ‘gold-standard’ rooftop-level (12 m above ground level), at resolutions: A) bi-hourly, B) daily. The biodiversity and the relative abundance of all taxa were assessed, and the first pollen season calendars, along with circadian calendars, for Augsburg, Germany, were developed. More than 40 pollen types were identified, of which 13 were the most abundant (>0.5% relative abundance each, accounting for a total of 91.8%). Biodiversity did not present any striking differences between heights, with pollen from Urticaceae, Betula and Poaceae representing consistently more than half of the regional atmospheric biodiversity. At rooftop-level, pollen abundances often appeared to be higher, particularly for Betula, Picea and Quercus. The main pollen season extended from March to October, with the highest peak occurring April–May. At rooftop-level, the pollen seasons of most taxa were observed earlier and the overall seasons were longer. Within the day, higher pollen concentrations were observed either at midday to early afternoon (Urticaceae, Poaceae, Plantago and mostly taxa at ground-level) or night to early morning, frequently with multi-modal diurnal patterns (Betula, Fraxinus and mostly taxa at rooftop-level). Our findings reveal that generalisation of abundance and temporal distribution patterns between ground-level and ‘gold-standard’ rooftop-level pollen measurements should be intensively reconsidered. While the pollen diversity and abundance may be well represented within this height range, the temporal occurrence is not, with pollen vertical variability being more important than originally anticipated. Hence, we need to reassess when and how much the relevant pollen exposure is increasing
Percutaneous ablation techniques for renal cell carcinoma: current status and future trends
No full textPercutaneous ablation is an increasingly applied technique for the treatment of localized renal tumors, especially for elderly or co-morbid patients, where co-morbidities increase the risk of traditional nephrectomy. Ablative techniques are technically suited for the treatment of tumors generally not exceeding 4 cm, which has been set as general consensus cutoff and is described as the upper threshold of T1a kidney tumors. This threshold cutoff is being challenged, but with still limited evidence. Percutaneous ablation techniques for the treatment of renal cell carcinoma (RCC) include radiofrequency ablation, cryoablation, laser or microwave ablation; the main advantage of all these techniques over surgery is less invasiveness, lower complication rates and better patient tolerability. Currently, international guidelines recommend percutaneous ablation either as intervention for frail patients or as a first line tool, provided that the tumor can be radically ablated. The purpose of this article is to describe the basic concepts of percutaneous ablation in the treatment of RCC. Controversies concerning techniques and products and the need for patient-centered tailored approaches during selection among the different techniques available will be discussed. © 2019, © 2019 The Author(s). Published with license by Taylor & Francis Group, LLC
Clinical predictors of all‐cause mortality in patients presenting to specialist heart failure clinic with raised NT‐proBNP and no heart failure
No full textAims
Clinical outcomes for patients suspected of having heart failure (HF) who do not meet the diagnostic criteria of any type of HF by echocardiography remain unknown. The aim of this study was to investigate the clinical predictors of all‐cause mortality in patients with suspected HF, a raised N‐terminal pro‐b‐type natriuretic peptide (NTproBNP) and who do not meet the diagnostic criteria of any type of HF by echocardiography.
Methods and results
Relevant data were taken from the S heffield HEA rt F ailure (SHEAF) registry (222349P4). The inclusion criteria were presence of symptoms raising suspicion of HF, NTproBNP > 400 pg/mL, and preserved left ventricular function. Exclusion criteria were any type of HF by echocardiography. The outcome was defined as all‐cause mortality. Cox proportional‐hazards regression model was used to investigate the association between the survival time of patients and clinical variables; 1031 patients were identified with NTproBNP > 400 pg/mL but who did not have echocardiographic evidence of HF. All‐cause mortality was 21.5% (222 deaths) over the mean follow‐up (FU) period of 6 ± 2 years. NTproBNP was similar in patients who were alive or dead (P = 0.96). However, age (HR 1, P 627 pg/mL, NYHA class predicted death (II, 19.6%; III, 27.4%; IV, 66.7%; P < 0.01).
Conclusions
Patients with no HF on echocardiography but raised NTproBNP suffer excess mortality particularly in the presence of certain clinical variables. Age, male gender, worsening CKD stage, presence of COPD, and dementia are independently associated with all‐cause mortality in these patients. An NTproBNP > 627 pg/mL coupled with NYHA class could identify patients at greatest risk of death
Soot production in a tubular gas turbine combustor
No full textSoot production in gas turbine combustors is not desirable since it is the major source
of exhaust smoke emission and its thermal radiation to the combustor liner deteriorates the liner
durability. Soot formation involves comparatively slow chemistry and equilibrium can not be
applied to soot modelling in the combustor flow field.
. The exact sooting process in the
combustor is poorly understood given both the complexity and the limited experimental data
available. The work reported in this thesis seeks to first develop in-situ techniques for
retrieving spatially-resolved soot properties, mainly soot particle volume fraction, from within
the combustor and also to apply the measured results to comparisons with predicted soot
concentrations.
Two probing methods have been demonstrated which also incorporate a laser absorption
technique. The sight probe proves to be more reliable in the present measurements. The
evaluation of the physical probing techniques in sooty laboratory flames reveals that the flame
structure will not be substantially distorted by the probe. The disturbance caused by the probe
is localised, a feature which is evident in the reported water flow visualization test. The
necessary inert gas purge can be minimised to reduce the local aerodynamic perturbation. The
measured soot volume fraction distributions are comparable with sooting levels reported in
flame studies in the literature. The peak soot volume fractions are located off-axis,
characteristic of the fuel atornization. The measurementsin the primary zone are restricted by
the multi-phase character of the flow, where soot absorption can not be readily discriminated
from fuel droplet scattering. Measurements are reported over a range of air-fuel ratios, inlet
pressures and temperatures.
Time-averageds calard istributionsa t the nominald ilution sectionh ave beeno btained
in addition to the soot measuremenut sing probe sampling and standard gas analysis.
Correlationso f carbond ioxide with mixture fraction reveala clear relationshipa t overall lean
conditionsc onsistenwt ith widely usedm odelleda ssumptions.T here are less well-correlated
relationshipsb etweent emperaturea ndm ixture fraction, possiblyd ue to the influenceo f scalar
fluctuationsa nda lsoo f the scalard issipationr ate. Sootl oadingi n the presentf low conditions
is characteristicallylo w, basedo n the mixture fraction ands ootv olumef raction data. Thermal
radiation in the visible spectrum shows a distinct narrow band spectra in addition to the soot
continuum, which is believed to arise fromC2radical emission. The mean radiation intensities,
predictedb y usingt he measuredte mperaturea nds ootc oncentrationre sults,a rei n generallo wer
than the measured mean intensities. Temperature fluctuation levels may be particularly
influential in some of these calculations.
Sootm odellingi n the combustohr asb eenu ndertakenb y applyinga n extendedla minar
flamelet concept. The two-equations oot formation model has beenp rimarily developedo n
laminar flames. The comparisono f the computationa nd measuremenstu ggeststh at this soot
model holds promise in the context of prediction in the combustor. In the absenceo f a
satisfactoryt heoreticald escriptiono f the fuel-air burning in the combustor,w heret he liquid
kerosinee mployedis replacedb y gaseoups ropane,t he computeds calarp rofiles are inconsistent
in some importantr espectsw ith the measuredo nes. This exerts a major effect on the soot
predictioni n terms of the quantitatived etail in the computationw, hich is howeverc rucial for
the soot model development. The original flow field modelling needs to be improved for the
purpose of further soot model refinement
Recommended terminology for aerobiological studies: automatic and real-time monitoring methods
No full textUnidad de excelencia María de Maeztu CEX2019-000940-MSince Galán et al. (2017) published important definitions for terms to be used in aerobiological studies, techniques have evolved regarding automatic and real-time monitoring of pollen and fungal spores, with a range of different technologies having been established over the past decade. These developments have been accompanied by the emergence of a new set of specific and common terminologies related not only to the instrumental hardware but also particularly to the machine learning algorithms that are used to classify particles. The aim of this article is to update the recommended aerobiological terminology, including definitions related to automatic and real-time monitoring and to new applications using real-time data, such as numerical forecast models. This is particularly important for the standardisation of procedures, the homogenisation of time series, using data from both manual and automatic methods, as well as simply for ensuring the community has a common language to work with
Characterisation of the octogenarians presenting to the diagnostic heart failure clinic: SHEAF registry
No full textIntroduction Heart failure (HF) incidence is increasing in older adults with high hospitalisation and mortality rates. Treatment is complicated by side effects and comorbidities. We investigated the clinical characteristics of octogenarians presenting to the HF clinic.
Methods Data were collected on octogenarians (80–89 years) referred to the HF clinic in two periods. The data included demographics, HF phenotype, comorbidities, symptoms and treatment. We investigate the temporal changes in clinical characteristics using χ2 test. We aimed to determine the clinical characteristics which were associated with optimisation of HF pharmacological intervention in the clinic, conducting multivariate regression analysis. Statistical significance is determined at p<0.05.
Results Data were collected in April 2012 to January 2014 and in June 2021 to December 2022. In this cross-sectional study of temporal data, 571 octogenarians were referred to the clinic in the latter period, in whom the prevalence of HF was 68.48% (391 patients). HF with preserved ejection fraction (HFpEF) was the most common phenotype and increased significantly compared with the first period (46.3% and 29.2%, p<0.001). Frailty, chronic kidney disease and ischaemic heart disease increased significantly versus the first period (p<0.001). During the second period, and following the consultation, of the patients with HF with reduced ejection fraction (HFrEF), 86.4% and 82.7% were on a beta blocker and on an ACE inhibitor/angiotensin receptor blocker/angiotensin receptor-neprilysin inhibitor, respectively. Clinical characteristics associated with further optimisations of HF pharmacological therapy in the HF clinic were: New York Heart Association (NYHA) functional class III and the presence of HFrEF phenotype
Conclusions With a prevalence of HF at 68% among the octogenarians referred to the HF clinic, HFpEF incidence is rising. The decision to optimise HF pharmacological treatment in octogenarians is driven by NYHA functional class III and the presence of HFrEF phenotype
Author Correction: Biological heterogeneity in idiopathic pulmonary arterial hypertension identified through unsupervised transcriptomic profiling of whole blood (Nature Communications, (2021), 12, 1, (7104), 10.1038/s41467-021-27326-0)
No full text\ua9 2022, The Author(s).The original version of this Article omitted Richard C Trembath from the UK National PAH Cohort Study consortium from Health and Life Sciences, King’s College London. This has been corrected in both the PDF and HTML versions of the Article
Inflammatory markers and plaque morphology: An optical coherence tomography study
No full textBackground: OCT with its unique image resolution is the ideal method to detect culprit lesion characteristics in different clinical presentations. The identification of inflammatory markers related to plaque characteristics may be of clinical importance. Methods: Thirty-two patients with acute coronary syndromes (ACS) and fourteen patients with stable angina pectoris (SAP) were enrolled in this study. Culprit lesion morphology was assessed by optical coherence tomography (OCT) in patients with ACS and SAP. The possible relations between serum levels of high sensitivity-C reactive protein (hs-CRP) and interleukin-18 (IL-18) with plaque characteristics were investigated in those patients. Results: Plaque rupture and thin-cap fibroatheroma (TCFA) were detected more frequently in ACS patients compared with SAP patients, (78.6% vs. 14.3%, p<0.001, 92.9% vs. 14.3%, p<0.001, respectively). Higher levels of serum hs-CRP and IL-18 were found in patients with plaque rupture vs. those with no plaque rupture (median value: 19.2 mg/L vs. 1.6 mg/L, p<0.001 and 219.5 pg/ml vs. 127.5 pg/ml, p=0.001 respectively), and TCFA vs. those without TCFA (median value: 15.2 mg/L vs. 1.6 mg/L, p=0.004 and 209.0 pg/ml vs. 153.2 pg/ml, p=0.03 respectively). Serum hs-CRP was the only independent predictor of plaque rupture (p=0.02, odds ratio 1.1, 95% confidence interval 1.0 to 1.2). A cut-off value of hs-CRP>4.5 mg/L could detect ruptured plaque with a sensitivity of 91.7% and a specificity of 77.8%. Conclusions: OCT detected plaque rupture and TCFA more frequent in ACS patients compared with SAP. Elevated hs-CRP and IL-18 were positively related to plaque instability and rupture. (C) 2010 Elsevier Ireland Ltd. All rights reserved
