531 research outputs found
Een proef ter bepaling van de werking van het chloride in stalmest op de zetmeelopbrengst van fabrieksaardappelen
Proef over de effecten van stikstof, kalium en chloride op de zetmeelopbrengst van fabrieksaardappelen
Concordant HIV Infection and Visceral Leishmaniasis in Ethiopia: The Influence of Antiretroviral Treatment and Other Factors on Outcome
Verslag over 1958 t/m 1962 van het bodemvruchtbaarheidsproefperceel Pr 1227 op de proefboerderij "Kooyenburg" te Rolde
Verslag van een bodemvruchtbaarheidsproef met rode klaver en stoppelknollen op het bedrijf van de heer G.J.F. Smit te Beltrum
Induction of annexin-1 at transcriptional and post-transcriptional level in rat brain by methylprednisolone and the 21-aminosteroid U74389F
Brain tissue of rats pretreated with methylprednisolone or with the 21-aminosteroid U74389F, and that of untreated control rats, was assessed for the expression of annexin-1 (Anx-1) and the transcription of its mRNA. For this purpose Anx-1 cDNA was amplified and simultaneously a T7-RNA-polymerase promoter was incorporated into the cDNA using a polymerase chain reaction (PCR). Then digoxigenin-11-UTP was incorporated into the transcribed cRNA with T7-RNA-polymerase. With this probe in situ hybridization was carried out on sections of the brain. The probe was visualized by an immunoassay using an antidigoxigenin antibody conjugate. Anx-1 protein was assessed by means of immunohistochemistry using a polyclonal antibody. The various brain areas of the control animals showed an appreciable amount of Anx-1 at mRNA or protein level; on the other hand, the animals which had been pretreated with either steroid, showed a more intense Anx-1 mRNA signal than the controls in many areas. In the pretreated animals Anx-1 immunostaining was unchanged in cortex, basal ganglia, amygdala and septum, but more intense in hippocampus, hypothalamus and thalamus. In ependyma, choroid plexus, meninges, and vascular walls there was no Anx-1 mRNA transcription detectable. An opposite profile was shown by the Anx-1 immunoreactivity, the protein was present in control animals as well as the steroid-pretreated animals, suggesting that here the protein was either from systemic origin, or has diffused from adjacent structures. The results indicated that Anx-1 mRNA transcription is upregulated by either steroid, and that in the untreated animals there is a resting level of Anx-1 mRNA transcription, presumably reflecting physiological influences on Anx-1 expression
Enabling mechanical separation of enantiomers through controlled batchwise concomitant crystallization : digital design and experimental validation
In the pharmaceutical industry the separation of chiral molecules is important due to the different physiochemical properties that the enantiomers of a chiral drug possess. Therefore, resolution techniques are used to separate such enantiomers from one another. In particular, preferential crystallization is a common technique used to separate conglomerate-forming compounds, due to its high selectivity. However, the efficient separation of enantiomers in a batchwise preferential crystallization process through seeding with the preferred enantiomer alone is still inefficient, since unwanted nucleation of the counter enantiomer is inevitable. Here, we demonstrate a model-based digital design for the separation of enantiomers for a conglomerate-forming compound (asparagine monohydrate), by using mechanical separation by sieving after crystallization, whereby the separation is enabled by a designed bias in the crystal size distributions of each enantiomer. This bias is created by a concomitant crystallization of both enantiomers using optimized seeding and cooling profiles obtained from a population balance model. In this way, a high level of control is achieved over a batchwise preferential crystallization process, since the crystallization of both enantiomers is controlled. We show that, through this separation method, material with impurity levels as low as 6 wt % can be obtained. To our knowledge this is the first demonstration of modeling such a process to separate enantiomers of a conglomerate-forming compound
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