When a wetting liquid is displaced by air in a capillary tube, a wetting film develops between the tube wall and the air that is responsible for the snap-off mechanism of the gas phase. By dissolving a dye in the wetting phase it is possible to relate a measure of the absorbance in the capillary to the thickness of liquid films. These data could be used to compare with cutting edge numerical simulations of the dynamics of snap-off for which experimental and numerical data are lacking. Drainage experiments in constricted capillary tubes were performed where a dyed wetting liquid is displaced by air for varying flow rates. We developed an optical method to measure liquid film thicknesses that range from 3 to 1000μm. The optical measures are validated by comparison with both theory and direct numerical simulations. In a constricted capillary tube we observed, both experimentally and numerically, a phenomenon of snap-off coalescence events in the vicinity of the constriction that bring new insights into our understanding and modeling of two-phase flows. In addition, the good agreement between experiments and numerical simulations gives confidence to use the numerical method for more complex geometries in the future.
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http://dx.doi.org/10.1016/j.jcis.2017.07.092 | DOI Listing |
Am J Obstet Gynecol
January 2025
Hasselt University, Faculty of Medicine and Life Sciences, Agoralaan, 3590 Diepenbeek, Belgium; Department of Obstetrics and Gynaecology, ZOL Genk, campus St. Jan, Schiepse Bos 6, 3600 Genk, Belgium.
Objective: To investigate the association between functional parameters of the microcirculation and the systemic cardiovascular system in a population of pregnant women at risk for gestational hypertension disorders.
Study Design: For this observational study, women at high cardiovascular risk according to maternal anthropometrics, obstetric and medical history, were recruited at random gestational age depending on time of referral to the outpatient clinic for high risk prenatal care at Ziekenhuis Oost Limburg, Genk Belgium. After birth, data of maternal and neonatal outcome were obtained from the hospital records: only women with normal pregnancy (n = 142) and with preeclampsia (n = 34) were included in this analysis.
Br J Pharmacol
January 2025
Department of Pharmacology, University of Oxford, Oxford, UK.
Background And Purpose: TMEM16A chloride channels constitute a depolarising mechanism in arterial smooth muscle cells (SMCs) and contractile cerebral pericytes. TMEM16A pharmacology is incompletely defined. We elucidated the mode of action and selectivity of a recently identified positive allosteric modulator of TMEM16A (PAM_16A) and of a range of TMEM16A inhibitors.
View Article and Find Full Text PDFToxics
December 2024
Shanxi Key Laboratory of Coal-Based Emerging Pollutant Identification and Risk Control, Research Center of Environment and Health, College of Environment and Resource, Shanxi University, Taiyuan 030006, China.
As one of the most common air pollutants, fine particulate matter (PM) increases the risk of diseases in various systems, including the urinary system. In the present study, we exposed male and female C57BL/6J mice to PM for 8 weeks. Examination of renal function indices, including creatinine (CRE), blood urea nitrogen (BUN), uric acid (UA), and urinary microalbumin, indicated that the kidneys of female mice, not male mice, underwent early renal injury, exhibiting glomerular hyperfiltration.
View Article and Find Full Text PDFJ Vis Exp
December 2024
Department of Ophthalmology, Boston University Chobanian & Avedisian School of Medicine;
Ischemia-reperfusion injuries are known to cause a range of retinal pathologies, including diabetic retinopathy, glaucoma, retinal vascular occlusions, and other vaso-occlusive conditions. This manuscript presents a method for inducing ischemia-reperfusion injury in a mouse model. The method utilized anterior chamber cannulation attached to a saline reservoir, generating hydrostatic pressure to raise the intraocular pressure to 90-100 mmHg.
View Article and Find Full Text PDFBiophys J
December 2024
Department of Pharmacology, Larner College of Medicine, Vermont Center for Cardiovascular and Brain Health, University of Vermont, Burlington, Vermont. Electronic address:
Amyloid beta (Aβ) peptide accumulation on blood vessels in the brain is a hallmark of neurodegeneration. While Aβ peptides constrict cerebral arteries and arterioles, their impact on capillaries is less understood. Aβ was recently shown to constrict brain capillaries through pericyte contraction, but whether-and if so how-Aβ affects endothelial cells (ECs) remains unknown.
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