Absorption Test (absorption + test)

Distribution by Scientific Domains

Selected Abstracts

Use of the d -Xylose Absorption Test to Measure Abomasal Emptying Rate in Healthy Lactating Holstein-Friesian Cows and in Cows with Left Displaced Abomasum or Abomasal Volvulus

Thomas Wittek
We determined the abomasal emptying rates of Holstein-Friesian cows at different stages of lactation, with left displaced abomasum (LDA), or immediately after surgical correction of LDA or abomasal volvulus (AV). d -xylose (0.5 g/kg body weight [BW], 50% solution) was injected into the abomasum in healthy cows (group 1, 4,7 days in milk [DIM], n = 7; group 2, 90,120 DIM, n = 7; group 3, >300 DIM, n = 7) and in cows with LDA (n = 10; group 4). d -xylose was injected into the abomasum during right flank laparotomy in cows with LDA (n = 22; group 5) and cows with AV (n = 15; group 6). The time to maximal serum d -xylose concentration was used as an index of emptying rate. The abomasal emptying rates for cows in groups 1, 2, and 3 were similar, whereas emptying was slower in cows with LDA and in cows after surgical correction of LDA or AV. The abomasal emptying rate of cows with LDA was slowed to a greater extent immediately after surgery, when compared to the rate obtained before surgery. There was no difference in abomasal emptying rate immediately after surgical correction between cows with LDA or AV. The results indicate that the increased incidence of LDA in the first month of lactation is not associated with an intrinsic decrease in abomasal emptying rate in healthy cows. Our findings also demonstrate that surgical correction further slows the emptying rate in cows with LDA. [source]

Assessing the effect of diclazuril on the intestinal absorptive capacity of broilers infected with experimental coccidiosis, using d -xylose absorption test

No abstract is available for this article. [source]

Gastric emptying: the validity of the paracetamol absorption test adjusted for individual pharmacokinetics

A. W. Medhus
An algorithm for the paracetamol absorption test for gastric emptying, adjusting for individual pharmacokinetics, was recently developed. The aim of the present study was to validate the use of this algorithm. Furthermore, the algorithm was applied to elucidate whether a gastric tube interferes with the rate of gastric emptying. A caloric liquid meal with paracetamol was administered orally to nine healthy volunteers on two separate days. On one occasion, the subjects were intubated with a nasogastric tube and the meal was aspirated from the stomach 45 min after meal intake. The percentage of the meal retained in the stomach at the time of aspiration was determined by analyses of paracetamol in the aspirate and compared with calculations by the algorithm. On the other examination day, the same meal was ingested without tube and aspiration. The median percentage of the meal retained in the stomach at aspiration was 47% (range 33,70%) calculated by the algorithm and 48% (range 23,61%) based on the aspiration data. The correlation between the emptying parameters was r=0.97 (P < 0.001). The median of gastric emptying parameters was similar when the number of samples included in the calculation by the algorithm was reduced, but the range tended to increase. The gastric tube moderately inhibited gastric emptying during the period 20,40 min after meal intake (P < 0.05), but for the period from meal intake until start of aspiration, no inhibition was found. The present study demonstrates that the novel algorithm for the paracetamol absorption test provides valid estimates for gastric emptying. [source]

1H NMR spectroscopic method for diagnosis of malabsorption syndrome: a pilot study

Lakshmi Bala
Abstract Despite its well-documented limitations, colorimetry has been commonly used for the d -xylose test in the diagnosis of malabsorption syndrome (MAS). With a possibility of overcoming its limitations, the use of 1H NMR spectroscopy for D -xylose test is explored herein. Urine samples from 35 adults with suspected MAS were obtained before and after oral ingestion of D -xylose. The diagnosis of MAS was based on fecal fat (72,h excretion using Van de Kamer's technique, normal <,7,g/24,h and/or Sudan III stain of spot stool specimen, normal,10 droplets/high power field) and/or endoscopic duodenal biopsy. Urinary excretion of D -xylose over 5,h after consumption of 5,g D -xylose, using both colorimetry and NMR was compared (normal,1,g/5,g/5,h). In vitro experiments on the standard specimens of D -xylose were also performed independently using both methods. Colorimetry showed a lower value for the quantity of D -xylose excreted in urine than NMR [median 0.73 (0.17,1.89,g) vs 1.37 (0.17,3.23,g), respectively; p<0.0001, Wilcoxon's signed ranks test]. Colorimetry and NMR correctly diagnosed 11/12 and 10/12 (p=N.S.) patients with MAS and 14/23 and 20/23 (p<0.05) without MAS, respectively. Sensitivity and specificity of colorimetry and NMR were 91.6 and 60.7% vs 83.3 and 86.9%, respectively. In in vitro experiments, the values obtained for standard xylose using NMR showed a maximum error of 7%, whereas the colorimetric method showed 20%. The NMR method is simple and may be more accurate for the D -xylose absorption test. Colorimetry was found to be inferior as compared with NMR due to its low specificity. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Identification of the motilin cells in duodenal epithelium of premature infants

Toshiya Nishikubo
AbstractBackground:,The aim of the present study was to examine the presence of motilin in the duodenal epithelial cells of premature infants of <32 weeks gestation. Methods:,Specimens from 10 deceased infants (gestational age: 26.4 ± 2.7 weeks and birthweight: 808 ± 303 g) were examined as subjects. All infants died of severe cardiopulmonary disorder or intraventricular hemorrhage (grade IV). The average survival period was 3.1 ± 1.9 days. Autopsies were performed and formalin-fixed duodenums were immunostained with rabbit antiserum to motilin by the labeled streptavidin,biotin (LSAB) method. An adult duodenum obtained by pancreatoduodenectomy was also examined for the presence of motilin as a positive control specimen. An absorption test using motilin peptide was performed to prove the specificity of the binding with rabbit antiserum to motilin. Results:,Motilin-containing cells were detected in the adult specimen, and the binding by rabbit antiserum to motilin was completely inhibited by excess amounts of motilin peptide, indicating that this binding was specific to motilin. All 10 infants had presence of motilin antigen in the epithelial cells of their duodenums. Conclusion:,This preliminary study indicates that the immunohistological analysis is specific to detect motilin-containing cells, and certifies the presence of motilin in duodenal epithelial cells of premature infants of <32 weeks gestation, including one at only 22 weeks gestation. [source]

Ein Trocknungskoeffizient für Baustoffe

BAUPHYSIK, Issue 3 2009
Gregor A. Scheffler Dr.-Ing.
Berechnungsverfahren; Feuchte Wärme; Versuche Abstract Ein wesentliches Element der hygrothermischen Charakterisierung von Baustoffen ist der Trocknungsversuch. Im Gegensatz zu anderen Feuchtetransportexperimenten wie dem Diffusionsversuch oder dem Wasseraufnahmeexperiment ist es bislang nicht möglich, aus der Trocknung einen einfachen Kennwert abzuleiten. In vielen Fällen, beispielsweise in der Interaktion von Forschung und Industrie, aber auch beim praktischen Vergleich bzw. der Auswahl geeigneter Baustoffe wäre ein solcher Kennwert jedoch wünschenswert. Im vorliegenden Artikel wird zunächst die Bedeutung des Trocknungsversuches für die hygrische Charakterisierung von Baustoffen herausgestellt, aus der sich das Bestreben ableitet, das Trocknungsverhalten zu standardisieren und einen Einzahlen-Materialkennwert zu definieren. Nach einer die verschiedenen Einflussfaktoren der Trocknung differenzierenden Einleitung werden bestehende Ansätze für die Standardisierung des Trocknungsverlaufes bzw. die Ableitung eines Trocknungskoeffizienten vorgestellt. Die einhergehenden Probleme werden diskutiert und weitere Möglichkeiten evaluiert. Ein einfacher Trocknungskoeffizient, der sich aus dem Trocknungsverlauf ableiten lässt, wird definiert. Die Korrelation dieses Koeffizienten mit dem Wasseraufnahmekoeffizienten und dem Dampfdiffusionswiderstand wird analysiert. Sein zusätzlicher Informationsgehalt wird in diesem Zusammenhang kritisch hinterfragt. Im Ergebnis steht die Definition des Trocknungskoeffizienten als ein neuer, unabhängiger Materialkennwert, der die Feuchtetransporteigenschaften im Übergang zwischen hygroskopischem und gesättigtem Transport beschreibt. Mit diesem Kennwert ist es möglich, Baustoffe einfach und schnell hinsichtlich ihres Trocknungsverhaltens zu unterscheiden und zu beurteilen, was insbesondere bei feuchtesensitiven Materialien von Bedeutung ist. A drying coefficient for building materials. The drying experiment is an important element of the hygrothermal characterisation of building materials. Contrary to other moisture transport experiments as the vapour diffusion and the water absorption test, it is until now not possible to derive a simple coefficient for the drying. However, in many cases such a coefficient would be highly appreciated, e.g. in interaction of industry and research or for the distinction and selection of suitable building materials throughout design and practise. This article first highlights the importance of drying experiments for hygrothermal characterisation of building materials on which the attempt is based to standardize the drying experiment as well as to derive a single number material coefficient. The drying itself is briefly reviewed and existing approaches are discussed. On this basis, possible definitions are evaluated. Finally, a drying coefficient is defined which can be determined based on measured drying data. The correlation of this coefficient with the water absorption and the vapour diffusion coefficient is analyzed and its additional information content is critically challenged. As result, a drying coefficient has been derived and defined as a new and independent material parameter. It contains information about the moisture transport properties throughout the wide range of moisture contents from hygroscopic up to saturation. With this new and valuable coefficient, it is now possible to distinguish and select building materials quickly and easily by means of their drying behaviour. This is particularly important for moisture sensitive materials. [source]

The influence of impact object characteristics on impact force and force absorption by mouthguard material

Tomotaka Takeda
Abstract,,, Most impact force and impact energy absorption tests for mouthguards have used a steel ball in a drop-ball or the pendulum device. However, in reality most sports-related trauma is caused by objects other than the steel ball, e.g. various sized balls, hockey puck, or bat or stick. Also, the elasticity, the velocity and the mass of the object could change the degree and the extent of injuries. In this study, we attempted to measure the impact force from actual sports equipment in order to clarify the exact mechanism of dental-related sports injuries and the protective effects of mouthguards. The present study was conducted using the pendulum impact device and load cell. Impact objects were removable. Seven mobile impact objects were selected for testing: a steel ball, baseball, softball, field hockey ball, ice hockey puck, cricket ball, and wooden baseball bat. The mouthguard material used in this study was a 3-mm-thick Drufosoft (Dreve-Dentamid GmbH, Unna, Germany), and test samples were made of the one-layer type. The peak transmitted forces without mouthguard ranged from the smallest (ice hockey stick, 46.9 kgf) to the biggest (steel ball, 481.6 kgf). The peak transmitted forces were smaller when the mouthguard was attached than without it for all impact materials but the effect was significantly influenced by the object type. The steel ball showed the biggest (62.1%) absorption ability while the wooden bat showed the second biggest (38.3%). The other balls or the puck showed from 0.6 to 6.0% absorbency. These results show that it is important to test the effectiveness of mouthguards on specific types of sports equipment. In future, we may select different materials and mouthguard designs suitable for specific sports. [source]

Synthesis, characterization and properties of organoclay-modified polyurethane/epoxy interpenetrating polymer network nanocomposites

Qingming Jia
Abstract organoclay-modified polyurethane/epoxy interpenetrating network nanocomposites (oM-PU/EP nanocomposites) were prepared by adding organophilic montmorillonite (oMMT) to interpenetrating polymer networks (IPNs) of polyurethane and epoxy resin (PU/EP) which had been prepared by a sequential polymerization technique. Wide-angle X-ray diffraction (WAXD) and transmission electronic microscopy (TEM) analysis showed that the interpenetrating process of PU and EP improved the exfoliation and dispersion degree of oMMT. The effects of the NCO/OH ratio (isocyanate index), the weight ratio of PU/EP and oMMT content on the phase structure and the mechanical properties of the oM-PU/EP nanocomposites were studied by tensile testing and scanning electronic microscopy (SEM). Water absorption tests showed that the PU/EP interpenetrating networks and oMMT had synergistic effects on improvement in the water resistance of the oM-PU/EP nanocomposites. Differential scanning calorimetry (DSC) analysis showed that PU was compatible with EP and that the glass transition temperature (Tg) of the oM-PU/EP nanocomposites increased with the oMMT content up to 3 wt%, and then decreased with further increasing oMMT content. The thermal stability of these nanocomposites with various oMMT contents was studied by thermogravimetric analysis (TGA), and the mechanism of thermal stability improvement was discussed according to the experimental results. Copyright © 2005 Society of Chemical Industry [source]