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- Hernaiz, M., et al.
(författare)
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The contact angle of nanofluids as thermophysical property
- 2019
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier BV. - 0021-9797. ; 547, s. 393-406
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Tidskriftsartikel (refereegranskat)abstract
- Droplet volume and temperature affect contact angle significantly. Phase change heat transfer processes of nanofluids – suspensions containing nanometre-sized particles – can only be modelled properly by understanding these effects. The approach proposed here considers the limiting contact angle of a droplet asymptotically approaching zero-volume as a thermophysical property to characterise nanofluids positioned on a certain substrate under a certain atmosphere. Graphene oxide, alumina, and gold nanoparticles are suspended in deionised water. Within the framework of a round robin test carried out by nine independent European institutes the contact angle of these suspensions on a stainless steel solid substrate is measured with high accuracy. No dependence of nanofluids contact angle of sessile droplets on the measurement device is found. However, the measurements reveal clear differences of the contact angle of nanofluids compared to the pure base fluid. Physically founded correlations of the contact angle in dependency of droplet temperature and volume are obtained from the data. Extrapolating these functions to zero droplet volume delivers the searched limiting contact angle depending only on the temperature. It is for the first time, that this specific parameter, is understood as a characteristic material property of nanofluid droplets placed on a certain substrate under a certain atmosphere. Together with the surface tension it provides the foundation of proper modelling phase change heat transfer processes of nanofluids.
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| 5. |
- Anand, Kanwlajeet J. S., et al.
(författare)
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Assessment of continuous pain in newborns admitted to NICUs in 18 European countries
- 2017
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Ingår i: Acta Paediatrica. - : John Wiley & Sons. - 0803-5253 .- 1651-2227. ; 106:8, s. 1248-1259
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Tidskriftsartikel (refereegranskat)abstract
- Aim: Continuous pain occurs routinely, even after invasive procedures, or inflammation and surgery, but clinical practices associated with assessments of continuous pain remain unknown.Methods: A prospective cohort study in 243 Neonatal Intensive Care Units (NICUs) from 18 European countries recorded frequency of pain assessments, use of mechanical ventilation, sedation, analgesia, or neuromuscular blockade for each neonate upto 28 days after NICU admission.Results: Only 2113/6648 (31·8%) of neonates received assessments of continuous pain, occurring variably among tracheal ventilation (TrV, 46·0%), noninvasive ventilation (NiV, 35·0%), and no ventilation (NoV, 20·1%) groups (p<0·001). Daily assessments for continuous pain occurred in only 10·4% of all neonates (TrV: 14·0%, NiV: 10·7%, NoV: 7·6%; p<0·001). More frequent assessments of continuous pain occurred in NICUs with pain guidelines, nursing champions, and surgical admissions prompted (all p<0·01), and for newborns <32 weeks gestational age, those requiring ventilation, or opioids, sedatives-hypnotics, general anesthetics (O-SH-GA) (all p<0·001), or surgery (p=0·028). Use of O-SH-GA drugs increased the odds for pain assessment in the TrV (OR:1·60, p<0·001) and NiV groups (OR:1·40, p<0·001).Conclusion: Assessments of continuous pain occurred in less than one-third of NICU admissions, and daily in only 10% of neonates. NICU clinical practices should consider including routine assessments of continuous pain in newborns.
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| 6. |
- Carbajal, Ricardo, et al.
(författare)
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Pain Assessment in Ventilated and Non-Ventilated Neonates in NICUS across Europe : Results from the EUROPAIN Study
- 2016
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Konferensbidrag (refereegranskat)abstract
- Aim of Investigation: Pain from invasive or noninvasive procedures, mechanical ventilation, or painful medical and surgical conditions is commonplace in neonatal intensive care units (NICUs). While prevention and treatment of neonatal pain seem essential, an adequate analgesic approach cannot be implemented without relevant and timely pain assessments. Data on neonatal pain assessment practices are scarce, with undefined best practices or clinical benefits. We aimed to describe pain assessment practices in 243 NICUs from 18 European countries and to examine the NICU and patient characteristics influencing pain assessments at the bedside.Methods: Demographic data, modes of respiration, use of sedation, analgesia, or neuromuscular blockers, frequency and types of pain assessments were recorded for all newborns during the first 28 days of NICU admission. Multivariable models tested the associations between the performance of pain assessments and center and neonatal factors.Results: Among 6648 neonates enrolled, highest level of ventilation during the study period classified patients into tracheal ventilation (TV, n=2138 [32%]), non-invasive ventilation (NIV, n=1493 [23%]), and spontaneous ventilation groups (SV, n=3017 [45%]). Pain assessments were performed in 1250 (58%), 672 (45%), and 916 (30%) of these groups respectively (p<0.001). Using data from 78,742 patient-days, we found that 2,838 (43%) neonates received 4.3 (5.2) pain assessments per neonate and per day (median (IQR): 2.4 (1-5)), whereas 3810 (57%) neonates did not receive any pain assessments. Pain assessments occurred on every day of the NICU stay in 461/2138 (22%) TV patients, 236/1493 (16%) NIV patients, and 393/3016 (13%) SV patients (p<0.001).Many different pain assessment methods were used; the EDIN scale was used most frequently (42.3% among those who had at least one pain assessment). We analysed 33,625 patient-days in the TV group to test for associations between pain assessment and the use of opioids, sedatives-hypnotics, or general anaesthetics (O-SH-GA). The rates of pain assessments on patient-days with and without O-SH-GA use were, respectively, 57% vs. 43% while receiving mechanical ventilation, and 60% vs. 34% while not receiving mechanical ventilation (both p<0.001). Multivariable analyses showed that NICU-based guidelines, nursing leadership, and increased surgical admissions promoted the use of routine pain assessments (p<0.001). More pain assessments were performed in newborns below 32-weeks gestational age, those with decreased severity of illness, those already intubated at admission, those requiring mechanical or non-invasive ventilation, or surgery, or use of O-SH-GA.Conclusion: Even though pain is considered the 5th vital sign, only 43% of NICU neonates received bedside pain assessments. Clinical practice variability and low rates of pain assessments in NICUS may reflect weaknesses in the current paradigm used for neonatal pain assessments, their subjectivity, lack of inter-rater reliability, and other long-standing concerns. Results suggest that training to improve the rate of pain assessment in NICUs will enhance pain management in NICUs.Trial Registration: ClinicalTrials.gov #NCT01694745
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| 7. |
- Isles, Peter D. F., et al.
(författare)
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Modeling the drivers of interannual variability in cyanobacterial bloom severity using self-organizing maps and high-frequency data
- 2017
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Ingår i: Inland Waters. - : TAYLOR & FRANCIS LTD. - 2044-2041 .- 2044-205X. ; 7:3, s. 333-347
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Tidskriftsartikel (refereegranskat)abstract
- It is well established that cyanobacteria populations in shallow lakes exhibit dramatic fluctuations on both interannual and intraannual timescales; however, despite extensive research, disentangling the drivers of interannual variability in bloom severity has proved challenging. Critical thresholds of abiotic drivers such as wind, irradiance, air temperature, and tributary inputs may control the development and collapse of blooms, but these thresholds are difficult to identify in large and complex datasets. In this study, we compared high-frequency estimates of oxygen metabolism in a shallow bay of Lake Champlain to concurrent measurements of physical and chemical parameters over 3 years with very different bloom dynamics. We clustered the data using supervised and unsupervised self-organizing maps to identify the environmental drivers associated with key stages of bloom development. We then used threshold analysis to identify subtle yet important thresholds of thermal stratification that drive transitions between bloom growth and decline. We found that extended periods with near-surface temperature differentials above 0.20 degrees C were associated with the initial development of bloom conditions, and subsequent frequency and timing of wind mixing events had a strong influence on interannual variability in bloom severity. The methods developed here can be widely applied to other high frequency lake monitoring datasets to identify critical thresholds controlling bloom development.
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| 8. |
- Reischauer, Sven, et al.
(författare)
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Cloche is a bHLH-PAS transcription factor that drives haemato-vascular specification
- 2016
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 535:7611, s. 294-298
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Tidskriftsartikel (refereegranskat)abstract
- Vascular and haematopoietic cells organize into specialized tissues during early embryogenesis to supply essential nutrients to all organs and thus play critical roles in development and disease. At the top of the haemato-vascular specification cascade lies cloche, a gene that when mutated in zebrafish leads to the striking phenotype of loss of most endothelial and haematopoietic cells(1-4) and a significant increase in cardiomyocyte numbers(5). Although this mutant has been analysed extensively to investigate mesoderm diversification and differentiation(1-7) and continues to be broadly used as a unique avascular model, the isolation of the cloche gene has been challenging due to its telomeric location. Here we used a deletion allele of cloche to identify several new cloche candidate genes within this genomic region, and systematically genome-edited each candidate. Through this comprehensive interrogation, we succeeded in isolating the cloche gene and discovered that it encodes a PAS-domain-containing bHLH transcription factor, and that it is expressed in a highly specific spatiotemporal pattern starting during late gastrulation. Gain-of-function experiments show that it can potently induce endothelial gene expression. Epistasis experiments reveal that it functions upstream of etv2 and tal1, the earliest expressed endothelial and haematopoietic transcription factor genes identified to date. A mammalian cloche orthologue can also rescue blood vessel formation in zebrafish cloche mutants, indicating a highly conserved role in vertebrate vasculogenesis and haematopoiesis. The identification of this master regulator of endothelial and haematopoietic fate enhances our understanding of early mesoderm diversification and may lead to improved protocols for the generation of endothelial and haematopoietic cells in vivo and in vitro.
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