Doped Ceria Catalysts for NOx Storage and Reduction

The new Euro 7 protocol, proposed by the Commission on 26th October 2022, concerning emissions of leanburn engines, presents a need for further optimisation of existing after-treatment technologies. It reveals a 35% reduction to the NOx emission limit for cars and vans, compared to Euro 6 . A well-known technology employed to reduce NOx to clean emissions in light-duty vehicles is the Lean NOx Trap (LNT). LNTs employ catalysts consisting of PGMs supported on ceria (CeO2) or other mixed oxides. Ceria’s redox property makes it an attractive selection, as well as its ability to store NOx at low temp (<300 ̊C), especially when Pt is present. Storage properties of ceria can be further enhanced by doping. Dopants reportedly allow ceria to function better at low temperature (<300 ̊C), and to reduce the PGM loading required to achieve the same conversion efficiencies. The RE metals Sm, Pr and Nd have been employed as dopants on CeO2 for LNT applications to increase surface oxygen content, oxygen vacancies, defect densities, and cause changes to the Pt-ceria interaction. These structural changes can allow for higher NSC during lean operation and enhanced activation during rich purge. Sm, Pr and Nd doped catalysts (10 wt.%) were synthesised on a range of ceria based catalysts with different Pt loadings (0-1 wt.%). Morphological changes observed through dopant addition has been investigated and related to catalytic performance increases.

Coordination Variability after Hip Replacement Surgery: A Case Report

Patients with unilateral hip replacement surgery have an increased risk for additional joint replacement surgeries in the contralateral limb. Reduced coordination variability (Cvar) is associated with orthopedic disorders. Differences in joint Cvar after hip replacement surgery may provide information regarding the progression to a healthier state. The purpose of this study was to examine differences in surgical and contralateral limb knee and hip Cvar before and after surgery. A male participant completed gait analyses prior to total hip arthroplasty, three weeks following surgery (post-op) and ten months after surgery. He walked at a preferred speed while three-dimensional kinematic and kinetic data were recorded. A modified vector coding technique was used to determine the bilateral Cvar throughout stance for thigh-leg and pelvis-thigh flexion/extension and internal/external rotation coordination. Cvar was averaged for the stance phase of gait at each visit. Effect Size (ES) was calculated to determine clinically significant differences in variability both between the surgical and contralateral limbs and for each visit (Tables 1 and 2). In the surgical limb, variability was similar at all visits for pelvis-thigh and thigh-shank flexion/extension and internal/external rotation (ES\u3c0.5). Differences in (Cvar) between the surgical and contralateral limbs diminished with time. While Cvar in the surgical limb did not change, Cvar in the contralateral limb decreased over time. This may indicate a decline in health and an increased risk for orthopedic disorders in the contralateral limb after hip replacement surgery

Gating-by-tilt of mechanosensitive membrane channels

We propose an alternative mechanism for the gating of biological membrane channels in response to membrane tension that involves a change in the slope of the membrane near the channel. Under biological membrane tensions we show that the energy difference between the closed (tilted) and open (untilted) states can far exceed kBT and is comparable to what is available under simple ilational gating. Recent experiments demonstrate that membrane leaflet asymmetries (spontaneous curvature) can strong effect the gating of some channels. Such a phenomenon would be more easy to explain under gating-by-tilt, given its novel intrinsic sensitivity to such asymmetry.Comment: 10 pages, 2 figure

The effect of the bend on technique and performance during maximal effort sprinting

This study investigated changes in performance and technique that occur during maximal effort bend sprinting compared to straight-line sprinting under typical outdoor track conditions. Utilising a repeated measures design, three-dimensional video analysis was conducted on seven male sprinters in both conditions (bend radius: 37.72 m). Mean race velocity decreased from 9.86 m/s to 9.39 m/s for the left step (p = 0.008) and from 9.80 m/s to 9.33 m/s for the right step (p = 0.004) on the bend compared to the straight, a 4.7% decrease for both steps. This was due mainly to a 0.11 Hz (p = 0.022) decrease in step frequency for the left step and a 0.10 m (p = 0.005) reduction in race step length for the right step. The left hip was 4.0° (p = 0.049) more adducted at touchdown on the bend than the straight. Furthermore, the bend elicited significant differences between left and right steps in a number of variables including ground contact time, touchdown distance and hip flexion/extension and abduction/adduction angles. The results indicate that the roles of the left and right steps may be functionally different during bend sprinting. This specificity should be considered when designing training programmes

Multi-parameter models of innovation diffusion on complex networks

A model, applicable to a range of innovation diffusion applications with a strong peer to peer component, is developed and studied, along with methods for its investigation and analysis. A particular application is to individual households deciding whether to install an energy efficiency measure in their home. The model represents these individuals as nodes on a network, each with a variable representing their current state of adoption of the innovation. The motivation to adopt is composed of three terms, representing personal preference, an average of each individual's network neighbours' states and a system average, which is a measure of the current social trend. The adoption state of a node changes if a weighted linear combination of these factors exceeds some threshold. Numerical simulations have been carried out, computing the average uptake after a sufficient number of time-steps over many realisations at a range of model parameter values, on various network topologies, including random (Erdos-Renyi), small world (Watts-Strogatz) and (Newman's) highly clustered, community-based networks. An analytical and probabilistic approach has been developed to account for the observed behaviour, which explains the results of the numerical calculations

The integration of BRCA testing into oncology clinics.

Purpose The PARP inhibitor, Olaparib, is approved for women with BRCA-mutated ovarian cancer. Therefore there is an urgent need to test patients and obtain results in time to influence treatment. Models of BRCA testing, such as the mainstreaming oncogenetic pathway, involving oncology health professionals are being used. The authors report on the establishment of the extended role of the clinical nurse specialist in consenting women for BRCA testing in routine gynaecology-oncology clinics using the mainstreaming model.Methods Nurses undertook generic consent training and specific counselling training for BRCA testing in the form of a series of online videos, written materials and checklists before obtaining approval to consent patients for germline BRCA1 and BRCA2 mutations.Results Between July 2013 and December 2015, 108 women with ovarian cancer were counselled and consented by nurses in the medical oncology clinics at a single centre (The Royal Marsden, UK). This represented 36% of all ovarian cancer patients offered BRCA testing in the oncology clinics at the centre. Feedback from patients and nurses was encouraging with no significant issues raised in the counselling and consenting process.Conclusion The mainstreaming model allows for greater access to BRCA testing for ovarian cancer patients, many of whom may benefit from personalised therapy (PARP inhibitors). This is the first report of oncology nurses in the BRCA testing pathway. Specialist oncology nurses trained in BRCA testing have an important role within a multidisciplinary team counselling and consenting patients to undergo BRCA testing

A Systems Engineering Approach to Modeling and Analysis of Chronic Obstructive Pulmonary Disease (COPD)

Chronic Obstructive Pulmonary Disease (COPD) is a progressive lung disease characterized by airflow limitation. This study develops a systems engineering framework for representing important mechanistic details of COPD in a model of the cardio-respiratory system. In this model, we present the cardio-respiratory system as an integrated biological control system responsible for regulating breathing. Four engineering control system components are considered: sensor, controller, actuator, and the process itself. Knowledge of human anatomy and physiology is used to develop appropriate mechanistic mathematical models for each component. Following a systematic analysis of the computational model, we identify three physiological parameters associated with reproducing clinical manifestations of COPD - changes in the forced expiratory volume (FEV), lung volumes, and pulmonary hypertension. We quantify the changes in these parameters (airway resistance, lung elastance, and pulmonary resistance) as the ones that result in a systemic response that is diagnostic of COPD. A multivariate analysis reveals that the changes in airway resistance have a broad impact on the human cardio-respiratory system, and that the pulmonary circuit is stressed beyond normal under hypoxic environments in most COPD patients.Comment: 25 pages, 15 figure

Activation of native TRPC1/C5/C6 channels by endothelin-1 is mediated by both PIP3 and PIP2 in rabbit coronary artery myocytes

We investigate activation mechanisms of native TRPC1/C5/C6 channels (termed TRPC1 channels) by stimulation of endothelin-1 (ET-1) receptor subtypes in freshly dispersed rabbit coronary artery myocytes using single channel recording and immunoprecipitation techniques. ET-1 evoked non-selective cation channel currents with a unitary conductance of 2.6 pS which were not inhibited by either ET(A) or ET(B) receptor antagonists, respectively BQ-123 and BQ788, when administered separately. However, in the presence of both antagonists, ET-1-evoked channel activity was abolished indicating that both ET(A) and ET(B) receptor stimulation activate this conductance. Stimulation of both ET(A) and ET(B) receptors evoked channel activity which was inhibited by the protein kinase C (PKC) inhibitor chelerythrine and by anti-TRPC1 antibodies indicating that activation of both receptor subtypes causes TRPC1 channel activation by a PKC-dependent mechanism. ET(A) receptor-mediated TRPC1 channel activity was selectively inhibited by phosphoinositol-3-kinase (PI-3-kinase) inhibitors wortmannin (50 nm) and PI-828 and by antibodies raised against phosphoinositol-3,4,5-trisphosphate (PIP(3)), the product of PI-3-kinase-mediated phosphorylation of phosphatidylinositol 4,5-bisphosphate (PIP(2)). Moreover, exogenous application of diC8-PIP(3) stimulated PKC-dependent TRPC1 channel activity. These results indicate that stimulation of ET(A) receptors evokes PKC-dependent TRPC1 channel activity through activation of PI-3-kinase and generation of PIP(3). In contrast, ET(B) receptor-mediated TRPC1 channel activity was inhibited by the PI-phospholipase C (PI-PLC) inhibitor U73122. 1-Oleoyl-2-acetyl-sn-glycerol (OAG), an analogue of diacylglycerol (DAG), which is a product of PI-PLC, also activated PKC-dependent TRPC1 channel activity. OAG-induced TRPC1 channel activity was inhibited by anti-phosphoinositol-4,5-bisphosphate (PIP(2)) antibodies and high concentrations of wortmannin (20 μm) which depleted tissue PIP(2) levels. In addition exogenous application of diC8-PIP(2) activated PKC-dependent TRPC1 channel activity. These data indicate that stimulation of ET(B) receptors evokes PKC-dependent TRPC1 activity through PI-PLC-mediated generation of DAG and requires a permissive role of PIP(2). In conclusion, we provide the first evidence that stimulation of ET(A) and ET(B) receptors activate native PKC-dependent TRPC1 channels through two distinct phospholipids pathways involving a novel action of PIP(3), in addition to PIP(2), in rabbit coronary artery myocytes

Ensemble prediction for nowcasting with a convection-permitting model—I: description of the system and the impact of radar-derived surface precipitation rates

A key strategy to improve the skill of quantitative predictions of precipitation, as well as hazardous weather such as severe thunderstorms and flash floods is to exploit the use of observations of convective activity (e.g. from radar). In this paper, a convection-permitting ensemble prediction system (EPS) aimed at addressing the problems of forecasting localized weather events with relatively short predictability time scale and based on a 1.5 km grid-length version of the Met Office Unified Model is presented. Particular attention is given to the impact of using predicted observations of radar-derived precipitation intensity in the ensemble transform Kalman filter (ETKF) used within the EPS. Our initial results based on the use of a 24-member ensemble of forecasts for two summer case studies show that the convective-scale EPS produces fairly reliable forecasts of temperature, horizontal winds and relative humidity at 1 h lead time, as evident from the inspection of rank histograms. On the other hand, the rank histograms seem also to show that the EPS generates too much spread for forecasts of (i) surface pressure and (ii) surface precipitation intensity. These may indicate that for (i) the value of surface pressure observation error standard deviation used to generate surface pressure rank histograms is too large and for (ii) may be the result of non-Gaussian precipitation observation errors. However, further investigations are needed to better understand these findings. Finally, the inclusion of predicted observations of precipitation from radar in the 24-member EPS considered in this paper does not seem to improve the 1-h lead time forecast skill