31 research outputs found
Effect of the acrylic acid content on the permeability and water uptake of latex films
Acrylic acid (AA) is a monomer commonly employed in emulsion polymerization
to provide electrostatic colloidal stability and improve specific film
performance. The addition of AA not only modifies the kinetics of the
polymerization, but also it takes part in the interaction between colloidal
particles, which has a strong influence on their packing and consequent latex
film properties. In this contribution a theoretical modeling of the latex film
formation is presented and compared to experimental results: water vapor
permeability and latex film capacitance are studied as a function of AA
content. It has been shown that water uptake is mainly affected by film
morphology which in turn is defined by intercolloidal interaction and drying
rate.Comment: 16 pages, 7 figure
Cardiovascular changes and neonatal outcome in IUGR fetuses born to normotensive and preeclamptic mothers
Cardiovascular changes and neonatal outcome in IUGR fetuses born to normotensive and preeclamptic mothers.
A preliminary investigation on placenta protein profile reveals only modest changes in well controlled gestational diabetes mellitus.
Gestational diabetes mellitus (GDM) is associated with a wide range of tissue-specific changes depending on the quality of glycemic control of the mothers. Here we tested the hypothesis that GDM is associated with alterations in the human term placenta proteome. For this aim, two different approacheswere employed. The placenta homogenates from 20 healthy subjects and those from 20 GDM pregnant women were pooled. The two samples thus obtained were analyzed by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) and the proteins detected were tentatively identified by comparison of their molecular weight with the Human Protein Reference Database, restricting the search to the species expressed in the placenta tissue. However this approach led to misleading results: in fact, an in deep analysis of the spectra and tandem mass spectrometry (MS/MS) measurements of the digestion products from the protein detected, unequivocally proved that the species observed are maternal and fetal globins. Consequently, the two pools were analyzed by 1D sodium dodecyl sulphate polyacrylamide gel electrophoresis; the different bands obtained were digested by trypsin and the digestion products were analyzed by MALDI-MS; the protein identification was carried out by comparison of the peptide mass fingerprint with databases. Only modest quantitative differences were observed between the placenta protein profiles of healthy and GDM subjects, indicating that GDM, if well controlled, induces only minor changes in the placental proteome. One example of differently expressed proteins in the placenta homogenate pool from GDM and the controls was the SRRM1 protein, a member of the serine-arginine protein kinase family; for GDM samples, the MALDI spectrum of its digestion products showed the presence of molecular species attributable to glycation and glyco-oxidation processes
Spontaneous Facial Expressions of Distress in Fetuses
From a large sample of fetuses examined through three-and four-dimensional ultrasonography at different gestational ages, episodes in which distress expressions were recognizable were extracted and analyzed using Baby FACS (Oster, 2009). Coders first identified AU4 (brow knotting) produced by the depressor glabellae (procerus) and the depressor supercilii muscles. This facial action knots the brow due to lowering of glabella. Its presence (except with a strong AU9 in AU9+AU12) has been used as criterion to recognize a distress episode. Then coders described all facial actions that co-occurred with the presence of brow knotting (AU4), distinguishing it from the knitting of the brow due to medial contraction by the isolated action of the corrugator supercilii muscle (AU3; brow knitting). Ultrasonographic examination of the fetal face (from 15 to 24 FPS) was conducted by using a Voluson 730 (Kretztechnik, Zipf, Austria) and an abdominal transducer of 5MHz. The data analyzed to date suggest that distress expressions are exhibited very early in prenatal development, at least from 20 weeks of gestational age, and that their form is very similar, if not identical, to distress expressions observed in full term neonates. This means that a fundamental facial expression important in early mother-infant communication emerges as an organized motor pattern very early in development, well before the possibility of serving as an interactive signal
Spontaneous Facial Expressions of Distress in Fetuses
From a large sample of fetuses examined through three-and four-dimensional ultrasonography at different gestational ages, episodes in which distress expressions were recognizable were extracted and analyzed using Baby FACS (Oster, 2009). Coders first identified AU 4 (brow knotting) produced by the depressor glabellae (procerus) and the depressor supercilii muscles. This facial action knots the brow due to the lowering of glabella. Its presence (except with a strong AU 9 in AU 9+AU 12) has been used as criterion in order to recognize a distress episode. Then coders described all those facial actions that co-occurred with the presence of brow knotting (AU 4), distinguishing it from the knitting of the brow due to medial contraction by the isolated action of the corrugator supercilii muscle (AU 3; brow knitting). Ultrasonographic examination of the fetal face (from 15 to 24 FPS) was conducted by using a Voluson 730 (Expert GE Healthcare) and an abdominal transducer of 5MHz. The data analyzed to date suggests that distress expressions are exhibited very early in prenatal development, at least from 20 weeks of gestational age, and that their form is very similar, if not identical, to those observed in full term neonates. This means that a fundamental family of facial expressions important in early mother-infant communication emerges as an organized and differentiated motor pattern very early in development, well before the possibility of serving as interactive signals