•A new approach for determining the settling velocity of microplastic particles.•Microplastic-fine sediment interaction through five settling velocity regions.•3D-numerical Modelling of microplastic ...transport in the tidal Weser river.•Higher probability of small microplastic to pass the estuary and reach the open sea.•Higher microplastic concentration in the estuarine turbidity zone.
Microplastic (MP) pollution is an important challenge for human life which has consequently affected the natural system of other organisms. Mismanagement and also careless handling of plastics in daily life has led to an accelerating contamination of air, water and soil compartments with MP. Under estuarine conditions, interactions with suspended particulate matter (SPM) like fine sediment in the water column play an important role on the fate of MP. Further studies to better understand the corresponding transport and accumulation mechanisms are required. This paper aims at providing a new modeling approach improving the MP settling velocity formulation based on higher suspended fine sediment concentrations, as i.e. existent in estuarine turbidity zones (ETZ). The capability of the suggested approach is examined through the modeling of released MP transport in water and their interactions with fine sediment (cohesive sediment/fluid mud). The model results suggest higher concentrations of MP in ETZ, both in the water column as well as the bed sediment, which is also supported by measurements. The key process in the modeling approach is the integration of small MP particles into estuarine fine sediment aggregates. This is realized by means of a threshold sediment concentration, above which the effective MP settling velocity increasingly approaches that of the sediment aggregates. The model results are in good agreement with measured MP mass concentrations. Moreover, the model results also show that lighter small MP particles can easier escape the ETZ towards the open sea.
Stroke is costly, although little is known about the long-term costs of survivors of stroke. In previous cost-of-illness studies, lifetime costs have been modeled based on estimates to 5 years after ...stroke. Building on previous work from the North East Melbourne Stroke Incidence Study (NEMESIS), we aimed to describe resource use at 10 years and recalculate the lifetime societal costs of ischemic and hemorrhagic (intracerebral hemorrhage) stroke.
Ten-year patient-level resource use data were obtained and updated prices and population demographic statistics for 2010 were applied to our cost-of-illness models. We incorporated incidence data from a larger study region of NEMESIS than that used in the previous model and new 10-year survival and recurrent stroke rates. One-way sensitivity and probabilistic multivariable uncertainty analyses were undertaken.
For ischemic stroke, the overall average annual direct costs at 10 years (US dollars USD 5207) were comparable to those for survivors between 3 and 5 years (USD5438). However, the contribution of some costs varied (eg, medications contributed 13% at 5 years and 20% at 10 years). For intracerebral hemorrhage, annual direct costs were considerably (24%) greater at 10 years than estimated using 3 to 5 year data. Greater average lifetime costs per case were found using the updated models (ischemic stroke: previous model USD51806 and current USD68 769; intracerebral hemorrhage: previous model USD43 786 and current USD54 956 per case). Following sensitivity and multivariable uncertainty analyses, the findings were robust.
Costs to 10 years after stroke have not previously been reported. Our findings demonstrate the importance of estimating resource use over longer periods for forecasting lifetime estimates.
Certification is a critical component of quality assurance in medicine. From the certification of individual persons, through units and up to whole hospitals, certification stimulates testing and ...optimization of treatment processes, thereby improving the quality of care. Minimum case numbers needed to acquire a certificate are an important and objective attribute of quality. Advantages of certification include an improved treatment of patients, structured training of new employees and enhanced cost efficiency.
1 Institut für Neurophysiologie,
Universität zu Köln, 50931 Köln; and
2 Institut für Neurobiologie und Biophysik,
Institut für Biologie III, Albert-Ludwigs Universtität
Freiburg, 79104 Freiburg, ...Germany
Embryonic stem cells
differentiate into cardiac myocytes, repeating in vitro the structural
and molecular changes associated with cardiac development. Currently,
it is not clear whether the electrophysiological properties of the
multicellular cardiac structure follow cardiac maturation as well. In
long-term recordings of extracellular field potentials with
microelectrode arrays consisting of 60 substrate-integrated electrodes,
we examined the electrophysiological properties during the ongoing
differentiation process. The beating frequency of the growing
preparations increased from 1 to 5 Hz concomitant to a decrease of the
action potential duration and action potential rise time. A
developmental increase of the conduction velocity could be attributed
to an increased expression of connexin43 gap junction channels. Whereas
isoprenalin elicited a positive chronotropic response from the first
day of spontaneous beating onward, a concentration-dependent negative
chronotropic effect of carbachol only developed after ~4 days. The in
vitro development of the three-dimensional cardiac preparation thus
closely follows the development described for the mouse embryonic
heart, making it an ideal model to monitor the differentiation of
electrical activity in embryonic cardiomyocytes.
cardiac development; microelectrode array; excitation spread; connexin43; mouse embryonic stem cells
Purpose of Review
Posterior reversible encephalopathy syndrome, or PRES, is a constellation of severe, acute hypertension and specific brain imaging findings. This may be caused by failure of the ...cerebral autoregulatory system to manage acute or severe changes in blood pressure. The incidence in children is unknown but estimated to be more common in children with predisposing factors including renal disease, autoimmune disease, malignancy, solid organ transplantation, stem cell transplantation, hypertension, sepsis, and exposure to certain medications.
Recent Findings
Management of PRES includes addressing hypertension, removing offending agents when possible, and anti-epileptic medications.
Summary
Most children with PRES recover completely, but recurrence is possible. Lack of resolution of imaging findings likely portends a worse prognosis.
Pulmonary hypertension (PH) is an important contributor to morbidity and mortality in patients with left-sided heart disease, including valvular heart disease. In this context, elevated left atrial ...pressure primarily leads to the development of post-capillary PH. Despite the fact that repair of left-sided valvular heart disease by surgical or interventional approaches will improve PH, recent studies have highlighted that PH (pre- or post-interventional) remains an important predictor of long-term outcome. Here, we review the current knowledge on PH in valvular heart disease taking into account new hemodynamic PH definitions, and the distinction between post- and pre-capillary components of PH. A specific focus is on the precise characterization of hemodynamics and cardiopulmonary interaction, and on potential strategies for the management of residual PH after mitral or aortic valve interventions. In addition, we highlight the clinical significance of tricuspid regurgitation, which may occur as a primary condition or as a consequence of PH and right heart dilatation (functional). In this context, proper patient selection for potential tricuspid valve interventions is crucial. Finally, the article highlights gaps in evidence, and points toward future perspectives.
Physician well-being is an important contributor to both job satisfaction and patient outcomes. Rates of burnout among physicians vary by specialty, ranging from 35 to 70%. Among pediatric residents, ...longitudinal data demonstrates consistent rates of burnout around 50-60%, although little is known about burnout among pediatric subspecialty fellows. Specifically, the degree of burnout among pediatric nephrologists remains unknown, as does the impact faculty burnout may have on trainee burnout. We sought to evaluate prevalence and predictors of burnout among US pediatric nephrology fellows and faculty, and assess for interactions between groups. In this multi-center pilot survey of all United States pediatric nephrology training programs from February to April 2020, burnout was assessed through abbreviated Maslach Burnout Inventory and predictors were explored through survey items devoted to demographic, personal characteristics, and job and career satisfaction questions. A total of 30/34 available fellows and 86/102 faculty from 11 institutions completed the survey (overall response rate 85%). The prevalence of burnout was 13% among fellows and 16% among faculty. Demographic (age, gender, year of training, faculty rank, marital status) and program factors (fellowship size, faculty size, current block/rotation, vacation or weekend off timing) were not significantly associated with burnout. Faculty and fellows with burnout reported significantly lower quality of life (5.3 vs. 7.9,
< 0.05), higher perceived stress (2.4 vs. 1.4,
< 0.05) and lower satisfaction with career choice (66 vs. 22%) and work life balance (28 vs. 0%), compared to those without burnout (
< 0.05 for all). Other important factors positively associated with burnout included lower institutional support for wellness programs and lower satisfaction with both colleague and faculty support. Larger studies are needed to explore if burnout is truly less prevalent among pediatric nephrology fellows and faculty compared to pediatric residents and graduate physicians. A larger sample size is also necessary to determine whether any interactions exist between the faculty and trainee roles in the developments of burnout. Future studies should also explore how to promote well-being through addressing key factors such as overall learning/working environment, stress reduction, and building personal resilience.
Objective To evaluate and characterize the degree of blood pressure (BP) control in children on chronic dialysis and to identify significant predictors of hypertension and BP control in these ...patients. Study design Linear and logistic regression models were used to examine trends in BP and BP control in a cross-sectional sample of patients on chronic dialysis aged 1-21 years enrolled in the North American Pediatric Renal Trials and Collaborative Studies registry from 1992-2008. Results At 6 months after dialysis initiation, 67.9% of patients had uncontrolled or untreated hypertension, and 57.8% were prescribed antihypertensive medications. More recent year of dialysis initiation was associated with a higher use of antihypertensive medication and lower systolic BP and diastolic BP z scores ( P < .001) measured over time from 6 months to 3 years post dialysis initiation. Other factors associated with higher BP included black race, glomerular disease, younger age, hemodialysis (systolic BP only), and antihypertensive use. There were significant differences in BP control by dialysis modality and disease etiology, with patients on hemodialysis or those with glomerular diseases having the highest percentage of uncontrolled hypertension. Conclusions Despite widespread antihypertensive use, many pediatric patients on dialysis are at risk for untreated or uncontrolled hypertension. Additional efforts are needed to improve management of hypertension in these children.
PDF
