156 research outputs found
Revealing latent trajectories of (intended) train travel during and after COVID-19
This study investigates whether the decline in public transit ridership is a temporary phenomenon or indicative of a structural shift in travel patterns and attitudes. We estimate a latent class trajectory model using data from a comprehensive and large-scale survey administered by the Dutch national train operator conducted at eight different points in time after the onset of the pandemic. Six latent trajectories in train use and stated future intentions to use the train are revealed, showing different ‘recovery’ pathways. Whereas low-educated frequent commuters travel almost as much as before, highly educated frequent commuters and mixed-purpose travellers still travel much less, even in the last wave when all restrictions are lifted. The results indicate that travellers belonging to these classes have structurally changed their behaviour. The shift to working from home is more pronounced than the shift to private car use
Characterization of Arabidopsis enhanced disease susceptibility mutants that are affected in systemically induced resistance
In Arabidopsis, the rhizobacterial strain Pseudomonas fluorescens WCS417r triggers jasmonate (JA)- and
ethylene (ET)-dependent induced systemic resistance (ISR) that is effective against different pathogens.
Arabidopsis genotypes unable to express rhizobacteria-mediated ISR against the bacterial pathogen
Pseudomonas syringae pv. tomato DC3000 (Pst DC3000) exhibit enhanced disease susceptibility towards
this pathogen. To identify novel components controlling induced resistance, we tested 11 Arabidopsis
mutants with enhanced disease susceptibility (eds) to pathogenic P. syringae bacteria for WCS417rmediated
ISR and pathogen-induced systemic acquired resistance (SAR). Mutants eds4-1, eds8-1 and
eds10-1 failed to develop WCS417r-mediated ISR, while mutants eds5-1 and eds12-1 failed to express
pathogen-induced SAR. Whereas eds5-1 is known to be blocked in salicylic acid (SA) biosynthesis,
analysis of eds12-1 revealed that its impaired SAR response is caused by reduced sensitivity to this
molecule. Analysis of the ISR-impaired eds mutants revealed that they are non-responsive to induction
of resistance by methyl jasmonate (MeJA) (eds4-1, eds8-1 and eds10-1), or the ET precursor 1-
aminocyclopropane-1-carboxylate (ACC) (eds4-1 and eds10-1). Moreover, eds4-1 and eds8-1 showed
reduced expression of the plant defensin gene PDF1.2 after MeJA and ACC treatment, which was
associated with reduced sensitivity to either ET (eds4-1) or MeJA (eds8-1). Although blocked in
WCS417r-, MeJA- and ACC-induced ISR, eds10-1 behaved normally for several other responses to MeJA
or ACC. The results indicate that EDS12 is required for SAR and acts downstream of SA, whereas EDS4,
EDS8 and EDS10 are required for ISR acting either in JA signalling (EDS8), ET signalling (EDS4), or
downstream JA and ET signalling (EDS10) in the ISR pathway
Understanding implementation of comprehensive geriatric care programs: a multiple perspective approach is preferred
Background: The Prevention and Reactivation Care Program (PReCaP) provides a novel approach targeting hospital-related functional decline among elderly patients. Despite the high expectations, the PReCaP was not effective in preventing functional decline (ADL and iADL) among older patients. Although elderly PReCaP patients demonstrated slightly better cognitive functioning (Mini Mental State Examination; 0.4 [95% confidence interval (CI) 0.2–0.6]), lower depression (Geriatric Depression Scale 15; –0.9 [95% –1.1 to –0.6]), and higher perceived health (Short-form 20; 5.6 [95% CI 2.8–8.4]) 1 year after admission than control patients, the clinical relevance was limited. Therefore, this study aims to identify factors impacting on the effectiveness of the implementation of the PReCaPand geriatric care ‘as usual’. Methods: We conducted semi-structured interviews with 34 professionals working with elderly patients in three hospitals, selected for their comparable patient case mix and different levels of geriatric care. Five non-participatory observations were undertaken during multidisciplinary meetings. Patient files (n = 42), hospital protocols, and care plans were screened for elements of geriatric care. Clinical process data were analysed for PReCaP components. Results: The establishment of a geriatric unit and employment of geriatricians demonstrates commitment to geriatric care in hospital A. Although admission processes are comparable, early identification of frail elderly patients only takes place in hosptial A. Furthermore, nursing care in the hospital A geriatric unit excels with regard to maximizing patient independency, an important predictor for hospital-related functional decline. Transfer nurses play a key role in arranging post-discharge geriatric follow-up care. Geriatric consultations are performed by g
The Prevention and Reactivation Care Program: intervention fidelity matters.
The Prevention and Reactivation Care Program (PReCaP) entails an innovative multidisciplinary, integrated and goal oriented approach aimed at reducing hospital related functional decline among elderly patients. Despite calls for process evaluation as an essential component of clinical trials in the geriatric care field, studies assessing fidelity lag behind the number of effect studies. The threefold purpose of this study was (1) to systematically assess intervention fidelity of the hospital phase of the PReCaP in the first year of the intervention delivery; (2) to improve our understanding of the moderating factors and modifications affecting intervention fidelity; and (3) to explore the feasibility of the PReCaP fidelity assessment in view of the modifications. Based on the PReCaP description we developed a fidelity instrument incorporating nineteen (n=19) intervention components. A combination of data collection methods was utilized, i.e. data collection from patient records and individual Goal Attainment Scaling care plans, in-depth interviews with stakeholders, and non-participant observations. Descriptive analysis was performed to obtain levels of fidelity of each of the nineteen PReCaP components. Moderating factors were identified by using the Conceptual Framework for Implementation Fidelity. Ten of the nineteen intervention components were always or often delivered to the group of twenty elderly patients. Moderating factors, suc
Cardiac Shear Wave Elastography Using a Clinical Ultrasound System
The propagation velocity of shear waves relates to tissue stiffness. We prove that a regular clinical cardiac ultrasound system can determine shear wave velocity with a conventional unmodified tissue Doppler imaging (TDI) application. The investigation was performed on five tissue phantoms with different stiffness using a research platform capable of inducing and tracking shear waves and a clinical cardiac system (Philips iE33, achieving frame rates of 400-700 Hz in TDI by tuning the normal system settings). We also tested the technique in vivo on a normal individual and on typical pathologies modifying the consistency of the left ventricular wall. The research platform scanner was used as reference. Shear wave velocities measured with TDI on the clinical cardiac system were very close to those measured by the research platform scanner. The mean difference between the clinical and research systems was 0.18 ± 0.22 m/s, and the limits of agreement, from -0.27 to +0.63 m/s. In vivo, the velocity of the wave induced by aortic valve closure in the interventricular septum increased in patients with expected increased wall stiffness
Parasternal Versus Apical View in Cardiac Natural Mechanical Wave Speed Measurements
Shear wave speed measurements can potentially be used to noninvasively measure myocardial stiffness to assess the myocardial function. Several studies
showed the feasibility of tracking natural mechanical waves
induced by aortic valve closure in the interventricular septum, but different echocardiographic views have been used.
This article systematically studied the wave propagation
speeds measured in a parasternal long-axis and in an apical
four-chamber view in ten healthy volunteers. The apical and
parasternal views are predominantly sensitive to longitudinal or transversal tissue motion, respectively, and could,
therefore, theoretically measure the speed of different wave
modes. We found higher propagation speeds in apical than
in the parasternal view (median of 5.1 m/s versus 3.8 m/s,
p < 0.01, n = 9). The results in the different views were not
correlated (r = 0.26, p = 0.49) and an unexpectedly large
variability among healthy volunteers was found in apical
view compared with the parasternal view (3.5–8.7 versus
3.2–4.3 m/s, respectively). Complementary finite element
simulations of Lamb waves in an elastic plate showed that
different propagation speeds can be measured for different
particle motion components when different wave modes are
induced simultaneously. The in vivo results cannot be fully
explained with the theory of Lamb wave modes. Nonetheless, the results suggest that the parasternal long-axis view
is a more suitable candidate for clinical diagnosis due to the
lower variability in wave speeds
Sortase A-mediated site-specific labeling of camelid single-domain antibody-fragments: a versatile strategy for multiple molecular imaging modalities
Imaging- and therapeutic targets in neoplastic and musculoskeletal inflammatory diseas
Native blood speckle vs ultrasound contrast agent for particle image velocimetry with ultrafast ultrasound - In vitro experiments
Ultrafast contrast enhanced ultrasound, combined with echo particle image velocimetry (ePIV), can provide accurate, multidimensional hemodynamic flow field measurement. However, the use of ultrasound contrast agent (UCA) still prevents this method from becoming a truly versatile and non-invasive diagnostic tool. In this study, we investigate the use of native blood instead of UCA backscatter for ePIV measurements and compare their accuracy in vitro. Additionally, the effect of measurement depth is experimentally assessed. Blood mimicking fluid (BMF) was pumped through a 10 mm diameter tube producing parabolic flow profiles, adding UCA in the case of contrast imaging. Plane wave imaging at 5000 framesper-second was performed with a Verasonics Vantage system and a linear array. The tube was imaged at three different depths: 25, 50 and 100 mm. Singular value decomposition (SVD) was assessed for clutter suppression against mean background subtraction. PIVlab was used as a PIV implementation. With SVD, BMF provided almost equal ePIV accuracy as UCA, except at 100 mm depth where UCA provided better accuracy. Use of clutter suppression greatly improved ePIV results, but minimal differences in ePIV accuracy were noted between mean and SVD filtered groups (BMF or UCA). Accuracy decreased with increasing depth, likely due to reduced elevation resolution, resulting in out-of-plane smoothing of velocity gradients
Reproducibility of Natural Shear Wave Elastography Measurements
For the quantification of myocardial function, myocardial stiffness can potentially be measured non-invasively
MYOCARDIAL STRETCH POST-ATRIAL CONTRACTION IN HEALTHY VOLUNTEERS AND HYPERTROPHIC CARDIOMYOPATHY PATIENTS
In cardiac high-frame-rate color tissue Doppler imaging (TDI), a wave-like pattern travels over the
interventricular septum (IVS) after atrial contraction. The propagation velocity of this myocardial stretch postatrial contraction (MSPa) was proposed as a measure of left ventricular stiffness. The aim of our study was to
investigate the MSPa in patients with hypertrophic cardiomyopathy (HCM) compared with healthy volunteers.
Forty-two healthy volunteers and 33 HCM patients underwent high-frame-rate (>500 Hz) TDI apical echocardiography. MSPa was visible in TDI, M-mode and speckle tracking. When assuming a wave propagating with constant velocity, MSPa in healthy volunteers (1.6 § 0.3 m/s) did not differ from that in HCM patients (1.8 §
0.8 m/s, p = 0.14). Yet, in 42% of patients with HCM, the MSPa had a non-constant velocity over the wall: in the
basal IVS, the velocity was lower (1.4 § 0.5 m/s), and in the mid-IVS, much higher (6.1 § 3.4 m/s, p < 0.0001),
and this effect was related to the septal thickness. The reason is hypothesized to be the reaching of
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