32 research outputs found
Changes in maternal body composition and metabolism of dairy goats during pregnancy.
Abstract: The objective of this study was to evaluate the mobilization of nutrients in goats of different gestation types and pregnancy stages. Forty-four Saanen and Oberhasli goats were studied. The goats of each breed and gestation type (single or twin) were slaughtered at different gestational ages (80, 110, and 140 days of pregnancy), forming a completely randomized design in a 2 × 3 × 2 factorial arrangement (two breeds, three gestational ages, and two types of pregnancy). The slaughter procedure involved separating the empty body, mammary glands, uterus with membranes and fetal fluid, and fetus(es). For the females slaughtered at 140 days of pregnancy, blood was collected to analyze metabolites and hormones every 15 days during gestation. The dry matter (DM) intake was lower in goats with twin pregnancies. The relative daily retention rate of the nutrients in the body was positive at 100 days of pregnancy but became negative at 140 days (-0.18±0.25 g DM kg-1 of maternal body d-1) and did not differ with breed or number of fetuses. Fetal growth in twin pregnancies was 66% higher than in single pregnancies. The highest levels of ß-hydroxybutyrate and non-esterified fatty acids were observed beginning at 100 days of gestation. Serum total protein and albumin levels decreased after 125 days of gestation. Serum urea levels were reduced after 80 days of gestation. Plasma 17ß-estradiol levels increased with the advance of pregnancy, and IGF-1 was highest between 60 and 80 days of gestation. The maternal metabolism throughout pregnancy does not vary with the type of pregnancy, and pregnant goats need greater nutritional intake during the final third of the gestational period regardless of the breed or type of pregnancy
Increased Number of Cerebellar Granule Cells and Astrocytes in the Internal Granule Layer in Sheep Following Prenatal Intra-amniotic Injection of Lipopolysaccharide
Chorioamnionitis is an important problem in perinatology today, leading to brain injury and neurological handicaps. However, there are almost no data available regarding chorioamnionitis and a specific damage of the cerebellum. Therefore, this study aimed at determining if chorioamnionitis causes cerebellar morphological alterations. Chorioamnionitis was induced in sheep by the intra-amniotic injection of lipopolysaccharide (LPS) at a gestational age (GA) of 110Â days. At a GA of 140Â days, we assessed the mean total and layer-specific volume and the mean total granule cell (GCs) and Purkinje cell (PC) number in the cerebelli of LPS-exposed and control animals using high-precision design-based stereology. Astrogliosis was assessed in the gray and white matter (WM) using a glial fibrillary acidic protein staining combined with gray value image analysis. The present study showed an unchanged volume of the total cerebellum as well as the molecular layer, outer and inner granular cell layers (OGL and IGL, respectively), and WM. Interestingly, compared with controls, the LPS-exposed brains showed a statistically significant increase (+20.4%) in the mean total number of GCs, whereas the number of PCs did not show any difference between the two groups. In addition, LPS-exposed animals showed signs of astrogliosis specifically affecting the IGL. Intra-amniotic injection of LPS causes morphological changes in the cerebellum of fetal sheep still detectable at full-term birth. In this study, changes were restricted to the inner granule layer. These cerebellar changes might correspond to some of the motor or non-motor deficits seen in neonates from compromised pregnancies
1-Hexanol Based Catalyst Inks for Catalyst Layer Preparation for a DMFC
Abstract
The catalyst ink preparation for a catalyst layer production by screen printing for a direct methanol fuel cell (DMFC) is evaluated. Among a large variety of solvents 1-hexanol was chosen for the preparation due to its properties fitting the requirements for the ink preparation. 1-hexanol based catalyst inks lead to thicker catalyst layers compared to isopropyl-/propylalcohol based catalyst inks, currently used in-house. Despite showing different layer properties, MEAs based on 1-hexanol or isopropyl-/propylalcohol based catalyst layers show comparable electrochemical performances. When using 1-hexanol based catalyst inks the dispersion procedure shows great influence on the outcoming catalyst layer. Long dispersion periods and a medium power output of ultrasonication of the catalyst dispersion are beneficial and lead to good coating qualities of the catalyst layer and therefore to high electrochemical performances.</jats:p