SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The characterisation of three phenobarbital modifications by thermic examination procedures (DSC, DTA) is being described. Modification I was obtained by thermic treatment of the brands (modification II) from Hungary and the GDR. The spray product prepared, consisting of very fine hollow spheres, was identified as modification III. Besides the particle size distribution the form of the particle was determined by scanning electron microscopy (REM). The best results regarding saturation solubility and speed of dissolution were found for the spray product.
Four products of phenobarbital (I, II1, II2, III) are manufactured into tablets with the dry binders Avicel PH 101 or Heweten 40 using different pressures by direct tabletting. The physical properties of the resulting tablets are different according to the modification of phenobarbital, the binders used and the pressure during tabletting. The dissolution behaviour of the drug may be changed by the different technological and physical parameters.
The preparation of 4 modifications and 2 spray dried products of tolbutamid is described. The characterization is performed by thermoanalytical methods (thermomicroscopy, DSC). Scanning electron microscopy and investigations of solubility complete the results.
The modifications and spray dried products of tolbutamide published in a former article, are investigated furthermore by X-Ray diffraction. The indication of the reflexes in X-Ray diffraction patterns of 2 modifications is performed. Transformations of modification are provable in consequence of thermal stress.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
To test the hypothesis that the H-2 polymorphism is adaptive, the degree of polymorphism of loci linked to the H-2 complex on chromosome 17 of the house mouse was compared to the degree of polymorphism of loci located on other chromosomes. Published theoretical analyses show that polymorphisms subject to natural selection usually reduce the polymorphism of linked neutral loci. The first test of the hypothesis was based on data obtained from a survey of the polymorphism of 12 isozyme-encoding loci in wild house mice from Europe, North Africa and South America. Results of this test showed that, on the average, H-2 linked loci were as polymorphic as loci located on other chromosomes. In fact, the data suggested that H-2 linked loci might be more polymorphic than other loci. To test this hypothesis more rigorously, data for the 12 isozyme-encoding loci were augmented with data from published surveys of the polymorphisms of 59 loci in house mice from Europe and North America. Results of these tests showed that polymorphic loci linked to the H-2 complex tended to be more, rather than less, polymorphic than loci located on other chromosomes. The cluster of highly polymorphic loci seems to be related to linkage of these loci to the highly polymorphic H-2 complex, but the way in which the influence is exerted could not be readily explained.