The pH-Dependent Controlled Release of Encapsulated Vitamin B1 from Liposomal Nanocarrier

In this work, we firstly presented a simple encapsulation method to prepare thiamine hydrochloride (vitamin B₁)-loaded asolectin-based liposomes with average hydrodynamic diameter of ca. 225 and 245 nm under physiological and acidic conditions, respectively. In addition to the optimization of the sonication and magnetic stirring times used for size regulation, the effect of the concentrations of both asolectin carrier and initial vitamin B₁ on the entrapment efficiency (EE %) was also investigated. Thermoanalytical measurements clearly demonstrated that after the successful encapsulation, only weak interactions were discovered between the carriers and the drug molecules. Moreover, the dissolution profiles under physiological (pH = 7.40) and gastric conditions (pH = 1.50) were also registered and the release profiles of our liposomal B₁ system were compared with the dissolution profile of the pure drug solution and a manufactured tablet containing thiamin hydrochloride as active ingredient. The release curves were evaluated by nonlinear fitting of six different kinetic models. The best goodness of fit, where the correlation coefficients in the case of all three systems were larger than 0.98, was reached by application of the well-known second-order kinetic model. Based on the evaluation, it was estimated that our liposomal nanocarrier system shows 4.5-fold and 1.5-fold larger drug retention compared to the unpackaged vitamin B₁ under physiological conditions and in artificial gastric juice, respectively.     

Zur Cyanethylierung von Hydrochinazolinonen

Cyanoethylation of Hydroquinazolinones By the reaction of acrylonitrile with octahydroquinazolinone-spirocyclohexane ( 1 ), cyanoethyl-octahydroquinazolinone-spirocyclohexane ( 2 ) is formed. Compound 2 and hydrogen-peroxide yield 5a-cyanoethyl-5-oxo-perhydro-oxaziridino[3,2-j]-quinazolin-2-spirocyclohexane ( 5 ). 2-Phenyl-octahydroquinazolinone ( 7 ) and acrylonitrile form 3,5a-biscyanoethyl-2-phenyl-octahydroquinazolinone-(4) ( 8 ). Compound 8 and hydrogenperoxide yield 3-phenyl-4,5a-biscyanoethyl-4-oxoperhydro-oxaziridino[3,2-j]-quinazoline ( 9 ). Compound 9 rearranges with ferrous sulphate to 3,4a-bis-cyanoethyl-4-oxo-8a-hydroxy-2-phenyl-octahydro-quinazoline ( 10 ).     

Cyansäureester. 35. Über Bildung und Folgereaktionen von N-Cyanatophthalimid. Neue spezifisch aktivierte und blockierte Isatosäurederivate

Cyanic Acid Esters. 35. On Formation and Consecutive Reactions of N-Cyanato Phthalimide. New Specifically Activated and Blocked Isatoic Acid Derivatives Depending on the reaction conditions N-hydroxy-phthalimide affords on treatment with cyanogen bromide via N-cyanato phthalimide 2 the iminocarbonate 3 and isatoic acid derivatives 7 and 16 . Both the latter react with nucleophiles as isatoic acid derivatives activated on the carboxylic group and protected on the carbamic group or vice versa, furnishing N,N-bis alkoxycarbonyl anthranilic acid amides 9 , N-alkoxycarbonyl anthranilic acid amides 12 , o-alkoxycarbonyl phenyl ureas 17 and the benzotriazepin-2,5-dione 14 . The structures of the new compounds are proved by ¹H-n.m.r. and ¹³C-n.m.r. measurements as well as independent synthesis.     

Die Nitril-Carboxamid-Umlagerung

The Nitrile Carboxamide Rearrangement By reaction of cyclohexanone-2-carboxamide ( 4 ) with cyan amide 1-cyano-cyclohex-1-en-2-yl-urea ( 6 ) is formed via nitrile carboxamide rearrangement. Whilst compound 6 with 1,2-diaminobenzene hydrochloride forms 11-amino-1 H-2,3,4,5-tetrahydrodibenzo[b,e][1,4]diazepin hydrochloride ( 8 and 8a ), compound 6 and 1,2-diaminobenzene form hexahydro-benzimidazo[1,2-c]-quinazolin-6-one ( 12 ). Compound 8 with sodium hydroxide yields 11-amino-1 H-2,3,4,11a-tetrahydrodibenzo[b,e]-[1,4]diazepin ( 9 ). Compound 6 reacts with cyclohexylamine to form N-(1-cyanocyclohex-1-en-2-yl)-N′-cyclohexyl urea ( 10 ). Compound 10 with 1,4- or 1,2-diaminobenzene hydrochloride yields compound 7 and 8 . In alkaline solution 10 cyclises to 4-amino-3-cyclohexyl-2,3,5,6,7,8-hexahydroquinazolin-2-one ( 11 ). Compound 4 and malonitrile form either 3-amino-4-cyano-1,2,5,6,7,8-hexahydro-isoquinol-1-one ( 13 ) or 1-amino-4-cyano-2,3,5,6,7,8-hexahydro-isoquinol-3-one ( 14 ). Compound 13 and alkaline formaldehyde react to cyanooctahydroisoquinoline-[2,3-c] [1,3,5]oxdiazin-6-one ( 17 ). 2-Cyanoethyl-cyclohexan-one-2-carboxamide ( 22 ), prepared by Michael-reaction from 4 and acrylonitrile, forms via nitrile carboxamide rearrangement 10-cyano-1,2,3,4,5,6,7,10-octahydroquinolin-2-one ( 24 ) and 2-(1′-cyano-cyclohexyl-2′-one)-propionic acid ( 25 ). Nucleophilic attack of the NH₂-group at the cyanogroup of compound 22 forms 5-(spirocyclohexan-2′-one)-hexahydropyridin-2,6-dione ( 27 ).     

Preparation of Uniform Colloidal Strontium Ferrite Particles

A procedure is described that yields uniform ferrite particles containing strontium. The process consists of crystallizing the solids from a ferrous hydroxide gel in the presence of SrCl₂ and a mild oxidizing agent (KNO₃) at 90°C. The amount of Sr²⁺ in the particles can be varied with the concentration of the SrCl₂ in the original system, but its content decreases with extensive washings. Calcination of the powder partially inhibits the leaching of Sr²⁺. Magnetic properties of such materials are also given.     

Understanding the impact of business cases on IT investment decisions: An analysis of municipal e-government projects

This study synthesizes the extant literature to derive an integrative developmental framework for IT business cases that can be applied to diagnose the feasibility of technological investments. We then construct a theoretical model that postulates the impact of IT business case elements on the initial cost estimates of technological investments. Subsequently, our theoretical model is subjected to empirical validation through content analysis of IT business cases developed for municipal e-government projects. Findings indicate that the richness of the richness of business cases translates to more initial costs being identified in technological investments, thereby conserving resources for the organization through informed investment decisions.     

Machines Outperform Laypersons in Recognizing Emotions Elicited by Autobiographical Recollection

Over the last decade, an increasing number of studies have focused on automated recognition of human emotions by machines. However, performances of machine emotion recognition studies are difficult to interpret because benchmarks have not been established. To provide such a benchmark, we compared machine with human emotion recognition. We gathered facial expressions, speech, and physiological signals from 17 individuals expressing 5 different emotional states. Support vector machines achieved an 82% recognition accuracy based on physiological and facial features. In experiments with 75 humans on the same data, a maximum recognition accuracy of 62.8% was obtained. As machines outperformed humans, automated emotion recognition might be ready to be tested in more practical applications.     

Tune in to your emotions: a robust personalized affective music player

The emotional power of music is exploited in a personalized affective music player (AMP) that selects music for mood enhancement. A biosignal approach is used to measure listeners’ personal emotional reactions to their own music as input for affective user models. Regression and kernel density estimation are applied to model the physiological changes the music elicits. Using these models, personalized music selections based on an affective goal state can be made. The AMP was validated in real-world trials over the course of several weeks. Results show that our models can cope with noisy situations and handle large inter-individual differences in the music domain. The AMP augments music listening where its techniques enable automated affect guidance. Our approach provides valuable insights for affective computing and user modeling, for which the AMP is a suitable carrier application.     

Synthese von Δ16-17(Trialkylstannyl)steroiden aus 17-Ketosteroiden. II

Syntheses of Δ¹⁶-17(Trialkylstannyl)steroids from 17-Ketosteroids. II . The oxidation of the hydrazones of 17-ketosteroids by iodine yields Δ¹⁶-17-iodosteroids ( 2 , 4 ). Starting with 2 or 8 (the 3-tetrahydropyranylether of 4 ) and lithium(tribu-tyl)stannate, Δ¹⁶-17(tributylstannyl)steroids ( 5 , 9 ) are synthesized. The reaction is catalyzed by electronrich complexes of nickel and palladium. In the course of side reactions Δ¹⁶-olefines ( 6 , 10 ) and the „dimers”︁ 7 and 11 , the products of a cross coupling of the Δ¹⁶-17-iodosteroids, and the Δ¹⁶-17-tributylstannylsteroids are obtained. The mechanisms of these side reactions and the influence of the solvent (THF, HMPA) are discussed. The tributylstannylsteroids are to be used as intermediates for the syntheses of steroid hormones from the 17-ketosteroids.