Sulfosuccinate and Sulfocarballylate Surfactants As Charge Control Additives in Nonpolar Solvents

A series of eight sodium sulfonic acid surfactants with differently branched tails (four double-chain sulfosuccinates and four triple-chain sulfocarballylates) were studied as charging agents for sterically stabilized poly­(methyl methacrylate) (PMMA) latexes in dodecane. Tail branching was found to have no significant effect on the electrophoretic mobility of the latexes, but the number of tails was found to influence the electrophoretic mobility. Triple-chain, sulfocarballylate surfactants were found to be more effective. Several possible origins of this observation were explored by comparing sodium dioctylsulfosuccinate (AOT1) and sodium trioctylsulfocarballylate (TC1) using identical approaches: the inverse micelle size, the propensity for ion dissociation, the electrical conductivity, the electrokinetic or ζ potential, and contrast-variation small-angle neutron scattering. The most likely origin of the increased ability of TC1 to charge PMMA latexes is a larger number of inverse micelles. These experiments demonstrate a small molecular variation that can be made to influence the ability of surfactants to charge particles in nonpolar solvents, and modifying molecular structure is a promising approach to developing more effective charging agents

A Comprehensive Three-Dimensional Model of the Cochlea

The human cochlea is a remarkable device, able to discern extremely small amplitude sound pressure waves, and discriminate between very close frequencies. Simulation of the cochlea is computationally challenging due to its complex geometry, intricate construction and small physical size. We have developed, and are continuing to refine, a detailed three-dimensional computational model based on an accurate cochlear geometry obtained from physical measurements. In the model, the immersed boundary method is used to calculate the fluid-structure interactions produced in response to incoming sound waves. The model includes a detailed and realistic description of the various elastic structures present. In this paper, we describe the computational model and its performance on the latest generation of shared memory servers from Hewlett Packard. Using compiler generated threads and OpenMP directives, we have achieved a high degree of parallelism in the executable, which has made possible several large scale numerical simulation experiments that study the interesting features of the cochlear system. We show several results from these simulations, reproducing some of the basic known characteristics of cochlear mechanics.Comment: 22 pages, 5 figure

Endotoxin and House Dust Mite Allergen Levels on Synthetic and Buckwheat Pillows

Pillows are known to contain significant levels of indoor allergens and endotoxin, that are of importance to house dust mite sensitized asthmatics. Buckwheat pillows are commonly used in Korea. We studied the levels of the house dust mite allergen, Der f 1, and endotoxin on new synthetic and buckwheat pillows and their accumulation over three months. Endotoxin levels were significantly higher on new buckwheat pillows compared to synthetic pillows; geometric mean levels (95% CI) were 60,950 EU/g (30,270-122,700) and 4,887 EU/g (2,570-9,311) respectively (p<0.001). No Der f 1 was detected on the new pillows. After three months Der f 1 levels were similar on buckwheat and synthetic pillows, geometric mean levels (95% CI) were 1.16 µg/g (0.02-8.13) and 1.08 µg/g (0.19-1.68) respectively. These results indicate that buckwheat pillows are a source of very high endotoxin levels that may be of relevance to asthma severity of atopic asthmatics

Rumination Moderates the Association Between Resting High-Frequency Heart Rate Variability and Perceived Ethnic Discrimination

Williams, D. P., Pandya, K. D., Hill, L. K., Kemp, A. H., Way, B. M., Thayer, J., & Koenig, J. (2017). Rumination Moderates the Association between Resting High-Frequency Heart Rate Variability and Perceived Ethnic Discrimination. Journal of Psychophysiology, 1–10. http://doi.org/10.1027/0269-8803/a00020

Associations of depression-anxiety and dyslipidaemia with subclinical carotid arterial disease: Findings from the Whitehall II Study

Aims There is mixed evidence for an association between depression and/or anxiety and carotid intima-media thickness, and limited information on the related role of dyslipidaemia. Here we report associations between depression and/or anxiety and intima-media thickness in the Whitehall II cohort, considering the moderating effects of sex and dyslipidaemia. Methods A total of 2822 men and 1112 women (61 ± 6 years) were studied during phase 7 (2002–2004) of the Whitehall II study. Intima-media thickness and lipid levels were assessed, and questionnaires (general health questionnaire and the Centre for Epidemiologic Studies depression scale) were completed. Linear regression was used to explore relationships between depression and/or anxiety and intima-media thickness and the moderating effects of sex and dyslipidaemia. Results A total of 1461 participants were categorised with depression and/or anxiety. The association between depression and/or anxiety and intima-media thickness differed between men and women so analyses were undertaken separately by sex. In men, intima-media thickness was significantly associated with dyslipidaemia (P = 0.002) but not depression and/or anxiety (P = 0.29). In women, both dyslipidaemia and depression and/or anxiety were independently associated with intima-media thickness (P = 0.028 and P = 0.031). The greatest intima-media thickness was in women with both depression and/or anxiety and dyslipidaemia. These results were replicated when the general health questionnaire score was substituted for depression and/or anxiety and non-high-density lipoprotein cholesterol for dyslipidaemia. Conclusions Depression and/or anxiety is associated with increased intima-media thickness in women but not in men. Dyslipidaemia is associated with intima-media thickness in both men and women. Women with both depression and/or anxiety and dyslipidaemia are potentially at the greatest risk of cardiovascular disease

Extracellular vesicles could be a putative posttranscriptional regulatory mechanism that shapes intracellular RNA levels in Plasmodium falciparum

© 2023 The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/Plasmodium falciparum secretes extracellular vesicles (PfEVs) that contain parasite-derived RNA. However, the significance of the secreted RNA remains unexplored. Here, we compare secreted and intracellular RNA from asexual cultures of six P. falciparum lines. We find that secretion of RNA via extracellular vesicles is not only periodic throughout the asexual intraerythrocytic developmental cycle but is also highly conserved across P. falciparum isolates. We further demonstrate that the phases of RNA secreted via extracellular vesicles are discernibly shifted compared to those of the intracellular RNA within the secreting whole parasite. Finally, transcripts of genes with no known function during the asexual intraerythrocytic developmental cycle are enriched in PfEVs compared to the whole parasite. We conclude that the secretion of extracellular vesicles could be a putative posttranscriptional RNA regulation mechanism that is part of or synergise the classic RNA decay processes to maintain intracellular RNA levels in P. falciparum.Peer reviewe

Complete Genome Sequences of Two Temperate Bacillus subtilis Phages Isolated at Tumamoc Hill Desert Laboratory

Bacteriophages are important in structuring bacterial communities, including desert soils dominated by Bacillus species. Here, we describe two genetically similar temperate phages isolated on a Bacillus subtilis strain from soil in Tucson, Arizona. Their double-stranded DNA (dsDNA) genomes contain 98 and 102 genes, with a set of 4 genes being found in only one phage

Insulin resistance and carotid intima-media thickness mediate the association between resting-state heart rate variability and executive function: A path modelling study

Background: Research has linked high-frequency heart rate variability (HF-HRV) to cognitive function. The present study adopts a modern path modelling approach to understand potential causal pathways that may underpin this relationship. Methods: Here we examine the association between resting-state HF-HRV and executive function in a large sample of civil servants from Brazil (N = 8114) recruited for the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). HF-HRV was calculated from 10-min resting-state electrocardiograms. Executive function was assessed using the trail-making test (version B). Results and conclusions: Insulin resistance (a marker of type 2 diabetes mellitus) and carotid intima-media thickness (subclinical atherosclerosis) mediated the relationship between HRV and executive function in seriatim. A limitation of the present study is its cross-sectional design; therefore, conclusions must be confirmed in longitudinal study. Nevertheless, findings support that possibility that HRV provides a 'spark' that initiates a cascade of adverse downstream effects that subsequently leads to cognitive impairment.Fil: Kemp, Andrew H.. University of Sydney; Australia. Universidade de Sao Paulo; BrasilFil: Rodríguez López, Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones y Estudios sobre Cultura y Sociedad. Universidad Nacional de Córdoba. Centro de Investigaciones y Estudios sobre Cultura y Sociedad; Argentina. University of Sydney; Australia. Universidad Autónoma de Madrid; EspañaFil: Passos, Valeria M. A.. Universidade Federal de Minas Gerais; BrasilFil: Bittencourt, Marcio S.. Universidade de Sao Paulo; BrasilFil: Dantas, Eduardo M.. University of Vale do São Francisco; BrasilFil: Mill, José G.. Universidade Federal do Espírito Santo; BrasilFil: Ribeiro, Antonio L. P.. Universidade Federal de Minas Gerais; BrasilFil: Thayer, Julian F.. Ohio State University; Estados UnidosFil: Bensenor, Isabela M.. Universidade de Sao Paulo; BrasilFil: Lotufo, Paulo A.. Universidade de Sao Paulo; Brasi