Autolysis and the endogenous proteinases characterised in beardless barb (Anematichthys apogon) muscle

Beardless barb is a common fish species used in fermentation of fish paste Ka-pi-plaa. Autolytic profile of beardless barb muscle showed the maximum autolysis was at 50 °C, at both acidic and alkaline pH values. With augmentation concentration of NaCl, autolytic activity slightly decreased. Endogenous proteinases isolated from fish muscle in crude extract forms were also characterised. The acidic proteinases had optimum activity at pH 3.0 and 50°C, and they showed higher proteolytic activity than the alkaline proteinases which were optimally active at pH 9.0 and 50 °C. Proteinases in peak at pH 3.0 were inhibited by pepstatin A, but those in peak at pH 9.0 were highly inhibited by PMSF, TLCK and soybean trypsin inhibitor, suggesting that both aspartic and serine proteinases were existed in beardless barb muscle. The proteinases were stable in pH range of 2.0-5.0 but unstable at the temperatures higher than 40 °C. NaCl suppressed the proteolytic activity, ATP activated the proteinase activity, while CaCl₂, MgCl₂ and CoCl₂ exhibited no influence on the activity. The results implied that cathepsin D is the predominant proteinase responsible for autolysis in beardless barb. The findings were useful to improve the processing and qualities of Ka-pi-plaa product using beardless barb as raw material.     

Bitterstoffe beim Erhitzen von Saccharose, Maltose und Prolin 2. Mitteilung

Summary In addition to the mono- and dipyrrolidinohexosereductones described recently (Z Lebensm Unters Forsch (1984) 178:356) two further bittertasting compounds were isolated from heated mixtures of proline and sucrose (molar ratio 3: 1, 190 °C, 30 min) and also synthesized, namely 2,3-bis-(1-pyrrolidinyl)2-cyclopenten-l-one and 2,3-bis(1-pyrrolidinyl)-5methyliden-2-cyclopenten-l-one. The recognition thresholds (mmol/1) are 0.15–0.25 and 0.06–0.12 respectively. Both compounds have a burning bitter taste character. From a maltose-proline reaction mixture 2--glucosyl-5-hydroxy-5-methyl-4-piperidinyl-2-cyclopenten-1-one was isolated. When the dihydroxypyranone VI was heated with proline, 2,5-dihydroxy-5-methyl-4-prohnyl-2-cyclopenten-1-one and the cyclopent(b)azepinones XI and XII were among the compounds formed. These compounds also have a bitter taste character.Zusammenfassung Zusätzlich zu den kürzlich beschriebenen Mono- and Dipyrrolidinohexosereduktionen (Z Lebensm Unters Forsch (1984) 178:356) wurden zwei weitere bittere Verbindungen aus erhitzten Mischungen von Prolin and Saccharose (Molverhältnis 3:1, 190 °C, 30 min) isoliert and synthetisiert. Es handelt sich um 2,3-Bis-(1-Pyrrolidinyl)-2-cyclopenten-1-on und 2,3-Bis-(1-Pyrrolidinyl)-5-methyliden-2-cyclopenten-1-on. Die Erkennungsschwellenwerte (mmol/1) sind 0,15-0,25 and 0,06-0,12. Beide Verbindungen haben einen brennend-bitteren Geschmack. Aus einem Maltose-Prolin-Umsetzungsgemisch gelang die Isolierung des 2--Glucosyl-5-hydroxy-5-methyl-4-piperidinyl-2-cyclopenten-1-ons. Bei der Reaktion des Dihydropyranons VI mit Prolin wurden u. a. das 2,5-Dihydroxy-5-methyl-4-prolinyl2-cyclopenten-1-on sowie die Cyclopent(b)azepinone XI and XII gebildet. Diese Verbindungen sind ebenfalls mehr oder weniger stark bitter.     

A grammar approach for combining product configuration modelling with behavioural aspects and simulations

The effective modelling of configurable products must handle the complex problem of representation of the configurable products, learning new configurable products and analysis of their behaviour. However, currently in advanced CAD systems, there exists no systematic and effective method for designing configurations and integrating behavioural aspects and simulations. This paper proposes and develops a grammar-based design approach to support both the computer-aided design for configuration and computing in CAD systems. Two interrelated questions are taken into account: (1) What are the hypothesis, properties and features for product configuration? (2) How can the product based on configuration features be represented and how can the configuration representation method integrate the numerical computing in design? This approach, under the guide of the proposed formal modelling, is implemented in computers. A design case study illustrates the proposed approach.     

Synthese von Heterocyclen durch C?C-Knüpfung. IV. Heterocyclensynthesen durch intramolekulare Dien-Reaktion

Synthesis of Heterocyclic Compounds by C C-bond Closure. IV. Synthesis of Heterocyclic Compounds by Intramolecular Dienreaction N-2-Cyclohexenyl-N-isopropylcinnamamide 8 cyclizes at 230°C to give the decahydronaphthindolone 9 . N-Alkyl-N-allylcinnamamides 10 analogously form 1 H-hexahydrobenzisoindolones 11 . N-Alkyl-N-allylsorbamides 14 cyclize at 150°C to 1 H-hexahydroisoindolones 15 . 15b yields the cyclic enamide 16 by alkali catalyzed shift of the double bond. Tricyclic lactames 19 and 20 are formed by thermal isomerization of N-cycloalkenylsorbamides 18a and 18b , respectively.     

Dynamic Behavior of Composites under Preloading

Polymers with characteristic damping properties are obtained by compounding them with additives. The mechanical behavior under vibration conditions of these compounds is characterized by dynamic moduli which depend on the static preload. The test results of a PU-compound are presented in this paper. The obtained results enable one to calculate the complex moduli of a special dynamic constitutive equation, which then enables one to calcualte stress and strain of dynamic deformations of structures under static preload. The paper presents a method to calculate such loading conditions on a system, too. A finite element analysis is used to determine the frequency response which characterizes the damping behavior of the structure.     

Determination of the distribution of air and water in porous media by electrical impedance tomography and magneto-electrical imaging

Monitoring the distribution of water content is essential for understanding hydrological processes in the lithosphere and the pedosphere. The movement of water in unsaturated rock formations and in the vadose zone is influenced by different processes (mainly infiltration, evaporation, percolation and capillary flow) which may be rate determining depending on the actual conditions. The interdependence of these processes also strongly influences the transport and distribution of solutes in the pore space. In order to gain a better understanding of the movement and distribution of water in unsaturated media, systematic investigations with non-invasive or minimal invasive methods appear to be most suitable. Studies on the distribution of electrical conductivity can improve risk analysis concerning waste disposals in general and nuclear waste repositories in particular. Induced polarization and magnetic flux density determined with two highly sensitive accessories yield additional information and may allow for better discrimination of coupled flow processes. Electrical impedance tomography (EIT) with 20 current injection and 48 voltage electrodes was used here to monitor the evaporation of tap water from a container filled with sand under laboratory conditions at 20 °C. The results are compared with data obtained by determining spectral induced polarization (SIP) of sand during desaturation in a multi-step outflow equipment. Infiltration processes and evaporation from sand saturated with 0.01 M CaCl₂ were determined by magneto-electrical resistivity imaging technique (MERIT). The results were obtained from a long-term experiment under controlled conditions.     

Interactions of colloidal particles with complex ions and polymers

The lecture represented a review of the work done in the author’s laboratory dealing with the behavior of a variety of submicronic particles in the presence of simple and complex ions, surface active agents, polyelectrolytes and polymers. Experimentally, the stability of colloidal sols, which can be readily followed by optical methods, was investigated as a function of the composition of the electrolyte environments. This approach offers a number of advantages when the evaluation of solid-solute interactions is attempted. By selecting various colloidal sols one can study the interactions of counterions with particles of different surface properties, such as the charge density, type and concentration of stabilizing ions, degree of solvation, surface ionization, etc. One of five papers presented at the Symposium, “Basic Aspects of Detergency,” AOCS-ISF World Congress, Chicago, September 1970. This lecture summary was prepared during the author’s stay at the Swedish Institute for Surface Chemistry, Stockholm.     

Stickstoffbindung in Soda- und Hochofenschlacken

Stand der Erkenntnisse über die Entstickung von Roheisen durch Soda und die Stickstoffbindung in Schlacke. Analytisch-chemischer Versuchsplan. Untersuchung von Betriebsschlacken und entsprechenden synthetischen Schmelzen sowie Aufstellung einer Stickstoffbilanz der Sodabehandlung von Thomasroheisen. Deutung der Entstickung bei der Sodabehandlung. Hinweise auf die Stickstoffbewegung im Hochofen.     

Thermofraktographie zur Schnellanalyse von Kunststoffen. 4. Mitt.: Identifizierung der Basiskomponenten von Epoxidharzen

Thermofractography is suitable for the rapid identification of the basic components of epoxy resins. 2–3 mg of the polymer sample are being heated in the temperature gradient of 200 to 450°C. The thus forming decomposition products are being transferred as a starting line onto the separating thin layer by means of a carrier gas. After development the thermofractogram (TFG) shows in the temperature range of 200 to approx. 350°C the free oligomeres. The resulting phenols and their subsequent products appear on the TFG from 350°C. A cycloaliphatic type does not give phenolic fragments. The degradation mechanisms of epoxy resins are being discussed in regard to the TFG results and are being confirmed by establishing TGA curves. For the rapid evaluation of the thermofractograms of epoxy resins a questioning scheme is given as an evaluation key.     

Construction and analysis of ground models and their refinements as a foundation for validating computer-based systems

We explain why for the verified software challenge proposed in Hoare (J ACM 50(1): 63–69, 2003), Hoare and Misra (Verified software: theories, tools, experiments. Vision of a Grand Challenge project. In: [Meyer05]) to gain practical impact, one needs to include rigorous definitions and analysis, prior to code development and comprising both experimental validation and mathematical verification, of ground models, i.e., blueprints that describe the required application-content of programs. This implies the need to link via successive refinements the relevant properties of such high-level models in a traceable and checkable way to code a compiler can verify. We outline the Abstract State Machines (ASM) method, a discipline for reliable system development which allows one to bridge the gap between informal requirements and executable code by combining application-centric experimentally validatable system modelling with mathematically verifiable stepwise detailing of abstract models to compile-time-verifiable code.