Influence of Temperature and Concentration on the Self-Assembly of Nonionic CiEjSurfactants: A Light Scattering Study

Nonionic poly(ethylene oxide) alkyl ether (C$_{i}$iE$_{j}$) surfactants self-assemble into aggregates of various sizes and shapes above their critical micelle concentration (CMC). Knowledge on solution attributes such as CMC as well as aggregate characteristics is crucial to choose the appropriate surfactant for a given application, e.g., as a micellar solvent system. In this work, we used static and dynamic light scattering to measure the CMC, aggregation number (N$_{agg}$), and hydrodynamic radius (R$_{h}$) of four different C$_{i}$E$_{j}$ surfactants (C$_{8}$E$_{5}$, C$_{8}$E$_{6}$, C$_{10}$E$_{6}$, and C$_{10}$E$_{8}$). We examined the influence of temperature, concentration, and molecular structure on the self-assembly in the vicinity of the CMC. A minimum in the CMC vs temperature curve was identified for all surfactants investigated. Further, extending the hydrophilic and hydrophobic chain lengths leads to an increase and decrease of the CMC, respectively. The size of the aggregates strongly depends on temperature. N$_{agg}$ and R$_{h}$ increase with increasing temperature for all surfactants investigated. Additionally, N$_{agg}$ and R$_{h}$ both increase with increasing surfactant concentration. The data obtained in this work further improve the understanding of the influence of temperature and molecular structure on the self-assembly of C$_{i}$iE$_{j}$ surfactants and will further foster their use in micellar solvent systems

The genetic basis of natural variation for iron homeostasis in the maize IBM population

BACKGROUND: Iron (Fe) deficiency symptoms in maize (Zea mays subsp. mays) express as leaf chlorosis, growth retardation, as well as yield reduction and are typically observed when plants grow in calcareous soils at alkaline pH. To improve our understanding of genotypical variability in the tolerance to Fe deficiency-induced chlorosis, the objectives of this study were to (i) determine the natural genetic variation of traits related to Fe homeostasis in the maize intermated B73 × Mo17 (IBM) population, (ii) to identify quantitative trait loci (QTLs) for these traits, and (iii) to analyze expression levels of genes known to be involved in Fe homeostasis as well as of candidate genes obtained from the QTL analysis. RESULTS: In hydroponically-grown maize, a total of 47 and 39 QTLs were detected for the traits recorded under limited and adequate supply of Fe, respectively. CONCLUSIONS: From the QTL results, we were able to identify new putative candidate genes involved in Fe homeostasis under a deficient or adequate Fe nutritional status, like Ferredoxin class gene, putative ferredoxin PETF, metal tolerance protein MTP4, and MTP8. Furthermore, our expression analysis of candidate genes suggested the importance of trans-acting regulation for 2’-deoxymugineic acid synthase 1 (DMAS1), nicotianamine synthase (NAS3, NAS1), formate dehydrogenase 1 (FDH1), methylthioribose-1-phosphate isomerase (IDI2), aspartate/tyrosine/aromatic aminotransferase (IDI4), and methylthioribose kinase (MTK)

Occupational exposure to N-nitrosamines and pesticides and risk of pancreatic cancer

Objectives Animal evidence shows that N-nitrosamines and similar xenobiotic compounds are pancreatic carcinogens. We aimed to determine whether occupational exposure to N-nitrosamines or to pesticides increases risk of pancreatic cancer development. Methods Participants (504 cases, 643 controls) in a population-based case-control study (The Queensland Pancreatic Cancer Study) provided data on demographic, medical and lifestyle factors and lifetime job histories. Specific questions were asked regarding work in rubber and leather industries, metalworking jobs and occupational or direct use of pesticides on animals or crops. An occupational hygienist reviewed this information (blind to case status) to assess likelihood of exposure to N-nitrosamines and pesticides, and estimated level and frequency of such exposures. Results No associations were found for risk of pancreatic cancer and occupational exposure to N-nitrosamines (OR=0.85, 95% CI 0.51 to 1.42) and no associations were seen with level or frequency of exposure. No associations were observed for ever exposure to pesticides in general (OR=0.90, 95% CI 0.61 to 1.33) or to any of the pesticide subgroups. Stratification by history of cigarette smoking did not change these results. Conclusions This comprehensive analysis of a large case-control study does not support an association between occupational exposure to N-nitrosamines or pesticide use and risk of pancreatic cancer

VLBI Probes of Jet Physics in Neutrino-Candidate Blazars

In recent years, evidence has accumulated that some high-energy cosmic neutrinos can be associated with blazars. The strongest evidence for an individual association was found in the case of the blazar TXS 0506+056 in 2017. In July 2019, another track-like neutrino event (IC190730A) was found spatially coincident with the well-known bright flat-spectrum radio quasar PKS 1502+106. PKS 1502+106 was not found to be in a particularly elevated gamma-ray state, but exhibited a remarkably bright radio outburst at the time of the neutrino detection, similar to TXS 0506+056. We have performed a multi-frequency VLBI study from 15 GHz up to 86 GHz on TXS 0506+056, PKS 1502+106 and one additional neutrino-candidate blazar (PKS 0215+015) to study the radio structure of neutrino candidate blazars in response to their neutrino association. We have obtained target of opportunity observations with the VLBA for all three sources within $\sim$1 month from their associated neutrino events and are performing multi-epoch studies of the jet kinematics at 15 GHz as part of the MOJAVE program. Here, we present first results on TXS 0506+056 at 86 GHz and one additional 43 GHz image obtained 27 days after IC170922A, closer in time to the neutrino event than previously published images. We also give an overview about our recent work on PKS 1502+106 and PKS 0215+015.Comment: 8 pages, 1 figure, 1 table, Proceedings of 38th International Cosmic Ray Conference (ICRC2023

HTAD patient pathway: Strategy for diagnostic work-up of patients and families with (suspected) heritable thoracic aortic diseases (HTAD). A statement from the HTAD working group of VASCERN

Loeys-dietz syndrome; Marfan syndrome; Thoracic aortic aneurysmSíndrome de Loeys-dietz; Síndrome de Marfan; Aneurisma aòrtic toràcicSíndrome de loeys-dietz; Síndrome de Marfan; Aneurisma aórtico torácicoHeritable thoracic aortic diseases (HTAD) are rare pathologies associated with thoracic aortic aneurysms and dissection, which can be syndromic or non-syndromic. They may result from genetic defects. Associated genes identified to date are classified into those encoding components of the (a) extracellular matrix (b) TGFβ pathway and (c) smooth muscle contractile mechanism. Timely diagnosis allows for prompt aortic surveillance and prophylactic surgery, hence improving life expectancy and reducing maternal complications as well as providing reassurance to family members when a diagnosis is ruled out. This document is an expert opinion reflecting strategies put forward by medical experts and patient representatives involved in the HTAD Rare Disease Working Group of VASCERN. It aims to provide a patient pathway that improves patient care by diminishing time to diagnosis, facilitating the establishment of a correct diagnosis using molecular genetics when possible, excluding the diagnosis in unaffected persons through appropriate family screening and avoiding overuse of resources. It is being recommended that patients are referred to an expert centre for further evaluation if they meet at least one of the following criteria: (1) thoracic aortic dissection (3.5 or 2.5–3.5 if non-hypertensive or hypertensive and 3), (3) family history of HTAD with/without a pathogenic variant in a gene linked to HTAD, (4) ectopia lentis without other obvious explanation and (5) a systemic score of >5 in adults and >3 in children. Aortic imaging primarily relies on transthoracic echocardiography with magnetic resonance imaging or computed tomography as needed. Genetic testing should be considered in those with a high suspicion of underlying genetic aortopathy. Though panels vary among centers, for patients with thoracic aortic aneurysm or dissection or systemic features these should include genes with a definitive or strong association to HTAD. Genetic cascade screening and serial aortic imaging should be considered for family screening and follow-up. In conclusion, the implementation of these strategies should help standardise the diagnostic work-up and follow-up of patients with suspected HTAD and the screening of their relatives.CHAFEA Specific Grant Agreement for Year 1 HP-ERN-SGA-2016 10 Project n° 769036 (from March 2017 to February 2018) 11 - CHAFEA Specific Grant Agreement for Year 2 HP-ERN-SGA-2017 12 Project n° 811609 (from March 2018 to February 2019) 13 - CHAFEA Specific Grant Agreement for Year 3 to 5 HP-ERN-SGA-2018 14 Project n° 847081 (from March 2019 to February 2022)

Representativeness and repeatability of microenvironmental personal and head exposures to radio-frequency electromagnetic fields

The aims of this study were to: i) investigate the repeatability and representativeness of personal radio frequency-electromagnetic fields (RF-EMFs) exposure measurements, across different microenvironments, ii) perform simultaneous evaluations of personal RF-EMF exposures for the whole body and the head, iii) validate the data obtained with a head-worn personal distributed exposimeter (PDE) against those obtained with an on-body worn personal exposimeter (PEM). Data on personal and head RF-EMF exposures were collected by performing measurements across 15 microenvironments in Melbourne, Australia. A body-worn PEM and a head-worn PDE were used for measuring body and head exposures, respectively. The summary statistics obtained for total RF-EMF exposure showed a high representativeness (r(2) > 0.66 for two paths in the same area) and a high repeatability over time (r(2) > 0.87 for repetitions of the same path). The median head exposure in the 900 MHz downlink band ranged between 0.06 V/m and 0.31 V/m. The results obtained during simultaneous measurements using the two devices showed high correlations (0.42 < r(2) < 0.94). The highest mean total RF-EMF exposure was measured in Melbourne's central business district (0.89 V/m), whereas the lowest mean total exposure was measured in a suburban residential area (0.05 V/m). This study shows that personal RF-EMF microenvironmental measurements in multiple microenvironments have high representativeness and repeatability over time. The personal RF-EMF exposure levels (i.e. body and head exposures) demonstrated moderate to high correlations

Bi-directional modulation of AMPA receptor unitary conductance by synaptic activity

BACKGROUND: Knowledge of how synapses alter their efficiency of communication is central to the understanding of learning and memory. The most extensively studied forms of synaptic plasticity are long-term potentiation (LTP) and its counterpart long-term depression (LTD) of AMPA receptor-mediated synaptic transmission. In the CA1 region of the hippocampus, it has been shown that LTP often involves a rapid increase in the unitary conductance of AMPA receptor channels. However, LTP can also occur in the absence of any alteration in AMPA receptor unitary conductance. In the present study we have used whole-cell dendritic recording, failures analysis and non-stationary fluctuation analysis to investigate the mechanism of depotentiation of LTP. RESULTS: We find that when LTP involves an increase in unitary conductance, subsequent depotentiation invariably involves the return of unitary conductance to pre-LTP values. In contrast, when LTP does not involve a change in unitary conductance then depotentiation also occurs in the absence of any change in unitary conductance, indicating a reduction in the number of activated receptors as the most likely mechanism. CONCLUSIONS: These data show that unitary conductance can be bi-directionally modified by synaptic activity. Furthermore, there are at least two distinct mechanisms to restore synaptic strength from a potentiated state, which depend upon the mechanism of the previous potentiation

Interleukin-12/23 deficiency differentially affects pathology in male and female Alzheimer's disease-like mice

Pathological aggregation of amyloid-β (Aβ) is a main hallmark of Alzheimer's disease (AD). Recent genetic association studies have linked innate immune system actions to AD development, and current evidence suggests profound gender differences in AD pathogenesis. Here, we characterise gender-specific pathologies in the APP23 AD-like mouse model and find that female mice show stronger amyloidosis and astrogliosis compared with male mice. We tested the gender-specific effect of lack of IL12p40, the shared subunit of interleukin (IL)-12 and IL-23, that we previously reported to ameliorate pathology in APPPS1 mice. IL12p40 deficiency gender specifically reduces A plaque burden in male APP23 mice, while in female mice, a significant reduction in soluble Aβ without changes in Aβ plaque burden is seen. Similarly, plasma and brain cytokine levels are altered differently in female versus male APP23 mice lacking IL12p40, while glial properties are unchanged. These data corroborate the therapeutic potential of targeting IL-12/IL-23 signalling in AD, but also highlight the importance of gender considerations when studying the role of the immune system and AD