Temperature response of sucrose palmitate solutions: Role of ratio between monoesters and diesters.

HYPOTHESIS: Aqueous solutions of long-chain water-soluble sucrose ester surfactants exhibit non-trivial response to temperature variations, revealing a peak in viscosity around 40-50 °C. While previous investigations have explored the structures within sucrose stearate systems at various constant temperatures, a comprehensive understanding of the entire temperature dependence and the underlying molecular factors, contributing to this phenomenon is currently missing. EXPERIMENTS: Temperature dependent properties and supramolecular structures formed in aqueous solutions of commercial sucrose palmitate were examined using SAXS/WAXS, DSC, optical microscopy, rheological measurements, NMR, and cryo-TEM. FINDINGS: The underlying mechanism governing this unusual behavior is revealed and is shown to relate to the mono- to di-esters ratio in the solutions. Solutions primarily containing sucrose monoesters (monoesters molecules ≳ 98% of all surfactant molecules) exhibit behavior typical of nonionic surfactants, with minimal changes with temperature. In contrast, the coexistence of mono- and di-esters results in the formation of discrete monodisperse diester particles and a network of partially fused diester particles at low temperature. As the temperature approaches the diesters' melting point, wormlike mixed micelles form, causing a viscosity peak. The height of this peak increases significantly with the diester concentration. Further temperature increase leads to fluidization of surfactant tails and formation of branched micelles, while excess diester molecules phase separate into distinct droplets.

Maternal Uterine Artery Adenoviral Vascular Endothelial Growth Factor (Ad.VEGF-A165) Gene Therapy Normalises Fetal Brain Growth and Microglial Activation in Nutrient Restricted Pregnant Guinea Pigs.

Fetal growth restriction (FGR) is associated with uteroplacental insufficiency, and neurodevelopmental and structural brain deficits in the infant. It is currently untreatable. We hypothesised that treating the maternal uterine artery with vascular endothelial growth factor adenoviral gene therapy (Ad.VEGF-A165) normalises offspring brain weight and prevents brain injury in a guinea pig model of FGR. Pregnant guinea pigs were fed a restricted diet before and after conception and received Ad.VEGF-A165 (1 × 1010 viral particles, n = 18) or vehicle (n = 18), delivered to the external surface of the uterine arteries, in mid-pregnancy. Pregnant, ad libitum-fed controls received vehicle only (n = 10). Offspring brain weight and histological indices of brain injury were assessed at term and 5-months postnatally. At term, maternal nutrient restriction reduced fetal brain weight and increased microglial ramification in all brain regions but did not alter indices of cell death, astrogliosis or myelination. Ad.VEGF-A165 increased brain weight and reduced microglial ramification in fetuses of nutrient restricted dams. In adult offspring, maternal nutrient restriction did not alter brain weight or markers of brain injury, whilst Ad.VEGF-A165 increased microglial ramification and astrogliosis in the hippocampus and thalamus, respectively. Ad.VEGF-A165 did not affect cell death or myelination in the fetal or offspring brain. Ad.VEGF-A165 normalises brain growth and markers of brain injury in guinea pig fetuses exposed to maternal nutrient restriction and may be a potential intervention to improve childhood neurodevelopmental outcomes in pregnancies complicated by FGR.

The self-reported density of truck traffic on residential streets and the impact on asthma, hay fever and eczema in young adolescents

BACKGROUND: Conflicting results have been reported, mostly in developed countries, on the relationship between exposure to traffic and allergic diseases. This study aims to examine the impact of truck traffic on asthma, rhinitis and eczema in early adolescence in Skopje, the capital of the Republic of Macedonia, as a developing country with a lower middle rate of high truck traffic exposure and low prevalence rates of allergic diseases. METHODS: Self-reported data was used, obtained through the International Study of Asthma and Allergies in Childhood Phase 3 written questionnaires, from 3026 adolescents aged 13-14 years from Skopje. Truck traffic density on the street of residence on weekdays was correlated to current and ever-diagnosed asthma, rhinitis and eczema by odds ratios (OR, 95% CI) in binary logistic regression, with and without adjustments for potential confounding factors separately and for their joint effect. RESULTS: A positive association of truck traffic density appeared to be limited to current dry night cough (aOR: 1.63; 1.07-2.47; aOR: 2.17; 1.40-3.35; and aOR: 2.33; 1.43-3.79 for truck traffic seldom, frequently through the day, and almost the whole day, respectively) with an exposure-response relationship and to current wheeze only for truck traffic almost the whole day (aOR: 1.87; 1.02-3.42). CONCLUSION: The findings suggest an aggravating effect of truck traffic on current asthma symptoms, but not on asthma, allergic rhinitis and eczema diagnoses. It seems that it probably has an impact as a direct respiratory irritant in early adolescence

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