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Creeping flow through a swarm of spherical particles, where each particle consists of a solid core covered by a liquid shell coated with monomolecular layer of surfactant layer, is studied using the cell model technique. The analytical solution of the problem for four models: Happel's, Kuwabara's, Kvashin's and Cunningham's (usually referred to as Mehta-Morse's) is derived. The drag force acting on each particle in the cell is evaluated for the four models. In limiting cases the drag force reduces to earlier analytical results. Results are discussed and presented in graphical forms. [ABSTRACT FROM AUTHOR]

Turfgrass thatch development is a direct consequence of an imbalance between growth and decomposition of organic residues. This study was conducted to determine the characteristics of thatch and the underlying soil in a three-year-old stand of Southshore creeping bentgrass (Agrostis palustris Huds.) and a six-year-old stand of Meyer zoysiagrass (Zoysia japonica Steud.). Intact thatch + soil cores were randomly collected from the two sites for thatch and soil bulk density and total porosity determinations. Disturbed samples of thatch and soil were processed and analyzed for total microbial biomass carbon (C); basal and specific maintenance respiration rates; total C, nitrogen (N) and hydrogen (H) contents; easily mineralizable, soluble, oxidizable and lignin C fractions, and organic matter quality. While the total microbial biomass C content and basal respiration rates were higher in thatches, the specific maintenance respiration rates were significantly lower in soils. Total, soluble, oxidizable and lignin C, and total N and H contents were significantly greater in thatches than in soils. Although the absolute amounts of soluble and oxidizable C contents were smaller in soil than in the thatch, the soluble and oxidizable C as fractions of total C were significantly lower in thatches than in soils. The bentgrass thatch contained more microbial biomass and lignin C than the zoysiagrass thatch. Both thatches had lower bulk densities and higher total porosities than the underlying soils. Spectrophotometric analyses suggested an accumulation of finer size organic matter in the bentgrass thatch than in the zoysiagrass thatch. An increase in microbial biomass and total C, but a substantial decrease in specific maintenance respiration rates, suggest that thatch development under turf may be acting as a C sink. A decline in microbial biomass and total C contents, but significant increases in specific maintenance respiration rates, suggest that soils under thatch may be serving as sources of CO2 to the troposphere. The effect was more pronounced at the zoysiagrass site than at the bentgrass site. [ABSTRACT FROM AUTHOR]

Background: Worsening renal function (WRF) is common in hospitalized patients being treated for acute heart failure. However, discriminating clinically significant WRF remains challenging. In patients hospitalized with acute heart failure, we evaluated if blood and urine biomarkers of cardiac and kidney dysfunction were associated with adverse outcomes., Methods: We identified 175 of 927 participants in the AKINESIS study (Acute Kidney Neutrophil Gelatinase-Associated Lipocalin Evaluation of Symptomatic Heart Failure Study) who met criteria for stage 1 or 2 Kidney Disease: Improvement Global Outcomes acute kidney injury during the first 3 days of hospitalization. We measured 24 blood and urine biomarkers from specimens collected within 24 hours of meeting acute kidney injury criteria. The primary composite outcome consisted of worsening WRF (higher acute kidney injury stage), need for dialysis, or death at 30 days. Biomarkers' association with the composite outcome was assessed with logistic regression by tertiles and area under the curve (AUC)., Results: Of the 175 participants, 32 (18%) developed the primary composite outcome. Only history of chronic kidney disease was significantly different between those with and without the composite outcome. The highest tertile of plasma Gal-3 (galectin-3) and urine epidermal growth factor were associated with increased odds of the composite outcome compared with the lowest tertile in unadjusted analyses. After adjusting for serum creatinine, systolic blood pressure, and blood urea nitrogen, only the highest tertile of Gal-3 was associated with greater odds of the composite outcome (odds ratio, 4.6 [95% CI, 1.4-16.0). Gal-3 had the highest AUC (0.70 [95% CI, 0.58-0.82]), while epidermal growth factor had a lower AUC (0.63 [95% CI, 0.53-0.74]). Notably, urine biomarkers of kidney tubule injury were not associated with the composite outcome., Conclusions: Tubular injury does not occur in most patients with acute heart failure experiencing WRF, consistent with the functional mechanisms of WRF in this patient population., Registration: URL: https://www.clinicaltrials.gov/study/NCT01291836?term=NCT01291836&rank=1; Unique identifier: NCT01291836.

Solute carriers (SLCs) are membrane transporters that import and export a range of endogenous and exogenous substrates, including ions, nutrients, metabolites, neurotransmitters, and pharmaceuticals. Despite having emerged as attractive therapeutic targets and markers of disease, this group of proteins is still relatively underdrugged by current pharmaceuticals. Drug discovery projects for these transporters are impeded by limited structural, functional, and physiological knowledge, ultimately due to the difficulties in the expression and purification of this class of membrane-embedded proteins. Here, we demonstrate methods to obtain high-purity, milligram quantities of human SLC transporter proteins using codon-optimized gene sequences. In conjunction with a systematic exploration of construct design and high-throughput expression, these protocols ensure the preservation of the structural integrity and biochemical activity of the target proteins. We also highlight critical steps in the eukaryotic cell expression, affinity purification, and size-exclusion chromatography of these proteins. Ultimately, this workflow yields pure, functionally active, and stable protein preparations suitable for high-resolution structure determination, transport studies, small-molecule engagement assays, and high-throughput in vitro screening.

Child growth measurements are critical vital signs to track, with every individual child growth curve potentially revealing a story about a child's health and well-being. Simply put, every baby born requires basic building blocks to grow and thrive: proper nutrition, love and care, and medical health. To ensure that every child who is missing one of these vital aspects is identified, growth is traditionally measured at birth and each well-child visit. While the blue and pink growth curves appear omnipresent in pediatric clinics, it is surprising to realize that their use only became standard of care in 1977 when the National Center for Health Statistics (NCHS) adopted the growth curve as a clinical tool for health. Behind this practice lies a socioeconomically, culturally, and politically complex interplay of individuals and institutions around the world. In this review, we highlight the often forgotten past, current state of practice, and future potential of this powerful clinical tool: the growth reference chart, with a particular focus on clinical genetics practice. The goal of this article is to understand ongoing work in the field of anthropometry (the scientific study of human measurements) and its direct impact on modern pediatric and genetic patient care., (© 2023 Wiley Periodicals LLC.)

Children with autism spectrum disorder (ASD) with rigidities, anxiety or sensory preferences may establish a pattern of holding urine and stool, which places them at high risk of developing bladder bowel dysfunction (BBD). BBD, despite being common, is often unrecognised in children with ASD. With this case report of a 7-year-old girl with ASD presenting with acute retention of urine, we attempt to understand the underlying factors which may contribute to the association between BBD and ASD. Literature review indicates a complex interplay of factors such as brain connectivity changes, maturational delay of bladder function, cognitive rigidities and psychosocial stressors in children with ASD may possibly trigger events which predispose some of them to develop BBD. Simple strategies such as parental education, maintaining a bladder bowel diary and treatment of constipation may result in resolution of symptoms., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Multidrug and toxic compound extrusion (MATE) transport proteins confer multidrug resistance on pathogenic microorganisms and affect pharmacokinetics in mammals. Our understanding of how MATE transporters work, has mostly relied on protein structures and MD simulations. However, the energetics of drug transport has not been studied in detail. Many MATE transporters utilise the electrochemical H + or Na + gradient to drive substrate efflux, but NorM-VC from Vibrio cholerae can utilise both forms of metabolic energy. To dissect the localisation and organisation of H + and Na + translocation pathways in NorM-VC we engineered chimaeric proteins in which the N-lobe of H + -coupled NorM-PS from Pseudomonas stutzeri is fused to the C-lobe of NorM-VC, and vice versa. Our findings in drug binding and transport experiments with chimaeric, mutant and wildtype transporters highlight the versatile nature of energy coupling in NorM-VC, which enables adaptation to fluctuating salinity levels in the natural habitat of V. cholerae.

LmrA is a bacterial ATP-binding cassette (ABC) multidrug exporter that uses metabolic energy to transport ions, cytotoxic drugs, and lipids. Voltage clamping in a Port-a-Patch was used to monitor electrical currents associated with the transport of monovalent cationic HEPES + by single-LmrA transporters and ensembles of transporters. In these experiments, one proton and one chloride ion are effluxed together with each HEPES + ion out of the inner compartment, whereas two sodium ions are transported into this compartment. Consequently, the sodium-motive force (interior negative and low) can drive this electrogenic ion exchange mechanism in cells under physiological conditions. The same mechanism is also relevant for the efflux of monovalent cationic ethidium, a typical multidrug transporter substrate. Studies in the presence of Mg-ATP (adenosine 5'-triphosphate) show that ion-coupled HEPES + transport is associated with ATP-bound LmrA, whereas ion-coupled ethidium transport requires ATP binding and hydrolysis. HEPES + is highly soluble in a water-based environment, whereas ethidium has a strong preference for residence in the water-repelling plasma membrane. We conclude that the mechanism of the ABC transporter LmrA is fundamentally related to that of an ion antiporter that uses extra steps (ATP binding and hydrolysis) to retrieve and transport membrane-soluble substrates from the phospholipid bilayer.

Aim: To describe nutritional practices among preterm extremely low-birthweight (ELBW) infants and their impact on growth and to compare differences in nutritional intervention and comorbidities between those with limited growth velocity (GV < 25th percentile) and those with GV > 25th percentile., Methods: A prospective cohort study was conducted to assess total protein and energy intake for week 1, days 14, 21 and 28 of life. Post-natal growth was calculated by measuring GV using an exponential model. Univariable analysis was applied to identify the potential risk factors associated with poor GV at day 28 and at discharge from hospital., Results: The median GV from birth to day 28 was 9.84 g/kg/day and 11.87 g/kg/day for GV from birth to discharge. Increased protein and energy intake was associated with higher GV at discharge. Hypotension needing inotropes, necrotising enterocolitis (NEC), patent ductus arteriosus and chronic lung disease were significantly associated with reduced GV at discharge. Infants with NEC, hypotension needing inotropes and sepsis took a significantly longer time to achieve full enteral nutrition. A longer time to attain full enteral feeds was associated with slower GV at discharge. Small-for-gestational-age babies increased from 22% at birth to 66.6% at discharge., Conclusions: GV at discharge was positively correlated with increasing protein and energy intake in the first 28 days and adversely affected by the presence of neonatal morbidities. There was strong evidence of extra-uterine growth restriction, with the majority of preterm ELBW infants having lower z scores at discharge compared to at birth., (© 2017 Paediatrics and Child Health Division (The Royal Australasian College of Physicians).)