Spray-dried enteric solid dispersion as a novel oral delivery system for a pentapeptide analog of thymopentin

IRI-426 (Ac-Arg-Pro-Asp-Val-Phe-NH₂) is a biologically active and enzyme-resistant analog of thymopentin (Arg-Lys-Asp-Val-Tyr), a pentapeptide corresponding to an active site of the thymic hormone thymopoietin. Enteric formulation of this enzyme resistant pentapeptide could be valuable for oral administration by providing protection from acid proteolysis in the gastric juice and release and absorption in the duodenum. Using a drug-to-polymer ratio of 1 to 10, an enteric solid dispersion of IRI-426 was prepared with an acid-insoluble, pH-sensitive polymer Eudragit S-100, by the spray-drying technique. The USP rotating paddle method and 190 proof ethyl alcohol, USP were used as received. All solvents used in the analytical procedure were of HPLC grade.     

The kinetics of the in situ polymerization of glycidyl methacrylate in wood using dynamic mechanical measurements

The in situ polymerization of glycidyl methacrylate in wood, in the presence of uranyl nitrate, (UN), and/or 2,2′-azo-bis-isobutyronitrile, (AIBN), has been investigated in the temperature range 55°-72°C. The course of the polymerization reaction was followed by measurement of tan 5 in an automated Rheovibron viscoelastometer. The kinetics, studied by applying the Guggenheim method to the data, showed the polymerization to be first order whether catalyzed by UN or initiated by AIBN. The activation energy (E_α) for AIBN-initiated polymerization was 121 kJ/mol, and was unaffected by varying monomer concentration in acetone. On the other hand, E_α for the UN-catalyzed polymerization was found to be 59.1 and 73.5 kJ/mol respectively for the neat and 50 percent monomer concentration reaction mixture. The enhancement in E_α is attributed to the complexatton of the dioxouranium (VI) ion in the presence of solvent acetone, with consequent reduction in catalytic activity.     

Interactions of hydrated metal ions with nucleotides: the crystal structure of barium adenosine 5'-monophosphate heptahydrate

The crystal and molecular structure of barium adenosine 5'-monophosphate heptahydrate was determined from x-ray diffraction data. Crystals of barium adenosine 5'-monophosphate heptahydrate are monoclinic, space group C2, with a = 32.559(3), b = 6.969(3), c = 9.597(1) A, and beta = 100.31(1) degrees. Intensity data were collected with an automated diffractometer. The structure was solved by the heavy-atom method and refined by least-squares to R = 0.034. This structure provides an example of an outer-sphere metal-nucleotide complex, in which a completely hydrated metal ion interacts with the nucleotide only through water bridges. The barium ion is coordinated to eight water molecules, which form a slightly distorted square antiprism. Seven of the eight water molecules from the barium hydration shell are hydrogen bonded to phosphate groups; three of these water molecules are also hydrogen bonded to other suitable acceptor sites on the base and ribose moieties. The conformation about the glycosidic bond is anti, with chiCN = 69 degrees, and, as in most nucleotide structures, the conformation about the C(4')-C(5') bond is gauche-gauche. However, the ribose displays an unusual conformation (best described as C(4')-exo) not previously observed in crystal structures of nucleosides or nucleotides, other than 3',5'-cyclic nucleotides. It is possible that this unusual conformation is a consequence of the metal-water-nucleotide bridging interactions.     

Digestibility of carbohydrates of raw and cooked bengal gram (cicer arietinum), green gram (phaseolus aureus) and horse gram (dolichos biflorus)

In vitro digestion with pancreatin, preceded by pepsin, increased the rate of liberation of maltose from soaked Bengal gram, Green gram and Horse gram on blending first in water prior to cooking instead of cooking first before blending. However, the faecal bulk and caecal volume were not significantly different when the legumes were fed to rats after cooking as such, or cooking prior to, or after, blending. The results indicate that increasing the rate of digestion of carbohydrates may not be of value in reducing the flatulence caused by these legumes.     

Representing natural language with Prolog

The authors describe the use of Prolog to build a syntactic list structure and a syntactic-semantic structure and to incorporate the semantic structure into a background structure that conveys the meanings of the individual words in the sentence in the context of general work knowledge. This semantic structure is then placed in the context of the sentence being parsed. Rather than rely solely on case grammar to represent the functions of words in a sentence, the authors have extended this technique to include a frame structure (which gives semantic details of the verb and the relations of other words to it) for a sentence's verbs to build the syntactic-semantic structure. Using this frame structure conveys more information than using only the case-grammar approach. The authors then place the syntactic-semantic structure in the context of its background knowledge, using the principles of partitioned networks in which word meanings are placed in a hierarchical structure that represents the background knowledge.<>