Class separation of mutagenic polycyclic organic material in grilled and smoked foods

Zusammenfassung Es wird über ein Verfahren zur Abtrennung der in gegrillten und geräucherten Lebensmitteln enthaltenen mutagenen polycyclischen organischen Stoffe in einzelne Klassen berichtet. Das Verfahren umfaßt eine erste Extraktion mit Aceton, das Abscheiden von Fett und Proteinen durch Ausfällung bei –55 °C und eine Säure-Base-Extraktion. Die weitere Fraktionierung erfolgte durch Gelfiltration und Silicagel-Chromatographie. Bei vier Proben von gegrillten Würsten waren 80 bis 90% der extrahierten Mutagenität (TA98 + S9) in den basischen Fraktionen enthalten. Die in der Flamme gegrillten Würste hatten eine höhere Mutagenität als die auf Holzkohle gegrillten. Bei den geräucherten Fischen war die Mutagenität gering und verteilte sich gleichmäßig auf die basischen und die neutralen/sauren Fraktionen. Einige Proben zeigten schwache Direktmutagenität in den neutralen/sauren Fraktionen. Die Anwesenheit von Nitrit in den gegrillten Würsten hatte keinen erheblichen Einfluß auf die Mutagenität. Die Gaschromatographie, Selektive Ionregistrierung-Technik, wurde erfolgreich zur Identifizierung mehrerer PAH-Verbindungen eingesetzt, und mit ihr konnten mehrere Nitro-PAH und oxydierte Verbindungen vorläufig identifiziert werden. Der Nachweis der Mutagene in den basischen Fraktionen gestaltete sich jedoch wegen Peak-Schweifbildung und mit-eluierenden Materials kompliziert.Summary A method for class separation of mutagenic polycyclic organic material in grilled and smoked foods is described. The procedure involves an initial extraction with acetone, removal of fat and proteins by precipitation at –55 °C, and an acid-base extraction. Further fractionation was carried out by gel filtration and silica gel chromatography. In four samples of grilled sausages, 80%–90% of the extracted mutagenicity (TA98 + S9) was contained in the basic fractions. Flame-grilled sausages showed higher mutagenicity than charcoal-grilled ones. In a smoked fish sample, the mutagenicity was low and evenly distributed between the basic and the neutral/acidic fractions. A few samples showed a weak direct-acting mutagenicity in the neutral/acidic fractions. The presence of nitrite in grilled sausages did not influence the mutagenicity markedly. Gas chromatography-selected ion monitoring was used to successfully identify a number of polycyclic aromatic hydrocarbons (PAHs) and tentatively identify several nitro-PAHs and oxygenated compounds. However, the identification of mutagens in the basic fractions was complicated by peak tailing and the presence of co-eluting material.

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Abtrennung mutagenen polycyclischen organischen Materials in gegrillten und geräucherten Lebensmitteln

     

Patent evolution in relation to public/private R&D investment and corporate profitability: Evidence from the United States

Summary In this paper we analyze the (historical) co-evolution of technological development and economic progress (by relating public and private R&D investment, patenting, and corporate profitability). We relate to the work ofSchmookler(1966),Griliches(1990),Pakes&Griliches(1980) andPakes(1986) who all have studied the techno-economic interplay by considering patents as in indicator of technological performance. We use United States industry and government data over the period 1953-1998 (45 years). Co-evolution analysis over this period reveals a strong interdependency among the variables. Patent evolution is strongly related to the development of private R&D and corporate profitability; the levels of public and private R&D expenditure in combination with the level of technological output (i.e. patents) have a strong predictive and explanatory power towards corporate profitability (R² value of 94.9%). Causality tests reveal a joint determination between R&D investment and corporate profitability (L=2; p<0.01).     

Engineering of Saccharomyces cerevisiae for the production of (+)-ambrein

The triterpenoid (+)-ambrein is the major component of ambergris, a coprolite of the sperm whale that can only be rarely found on shores. Upon oxidative degradation of (+)-ambrein, several fragrance molecules are formed, amongst them (−)-ambrox, one of the highest valued compounds in the perfume industry. In order to generate a Saccharomyces cerevisiae whole-cell biocatalyst for the production of (+)-ambrein, intracellular supply of the squalene was enhanced by overexpression of two central enzymes in the mevalonate and sterol biosynthesis pathway, namely the N-terminally truncated 3-hydroxy-3-methylglutaryl-CoA reductase 1 (tHMG) and the squalene synthase (ERG9). In addition, another key enzyme in sterol biosynthesis, squalene epoxidase (ERG1) was inhibited by an experimentally defined amount of the inhibitor terbinafine in order to reduce flux of squalene towards ergosterol biosynthesis while retaining sufficient activity to maintain cell viability and growth. Heterologous expression of a promiscuous variant of Bacillus megaterium tetraprenyl-β-curcumene cyclase (BmeTC-D373C), which has been shown to be able to catalyse the conversion of squalene to 3-deoxyachillol and then further to (+)-ambrein resulted in production of these triterpenoids in S. cerevisiae for the first time. Triterpenoid yields are comparable with the best microbial production chassis described in literature so far, the methylotrophic yeast Pichia pastoris. Consequently, we discuss similarities and differences of these two yeast species when applied for whole-cell (+)-ambrein production.     

Phase and morphology evolution of calcium carbonate precipitated by carbonation of hydrated lime

Phase and morphology evolution of CaCO₃ precipitated during carbonation of lime pastes via the reaction Ca(OH)₂ + CO₂ → CaCO₃ + H₂O has been investigated under different conditions (pCO₂ ≈ 10^−3.5 atm at 60 % RH and 93 % RH; pCO₂ = 1 atm at 93 % RH) using XRD, FTIR, TGA, and SEM. Simulations of the pore solution chemistry for different stages and conditions of carbonation were performed using the PHREEQC code to investigate the evolution of the chemistry of the system. Results indicate initial precipitation of amorphous calcium carbonate (ACC) which in turn transforms into scalenohedral calcite under excess Ca²⁺ ions. Because of their polar character, { 21[`3]4 } \left\{ {21\bar{3}4} \right\} scalenohedral faces (type S) interact more strongly with excess Ca<sup>2+</sup> than non-polar { 10[`1]4 } \left\{ {10\bar{1}4} \right\} rhombohedral faces (type F), an effect that ultimately favors the stabilization of { 21[`3]4 } \left\{ {21\bar{3}4} \right\} faces. Following the full consumption of Ca<sup>2+</sup> ions and further dissolution of CO<sub>2</sub> leading to a pH drop of the pore solution, { 21[`3]4 } \left\{ {21\bar{3}4} \right\} scalenohedra are subjected to dissolution. This eventually results in re-precipitation of { 10[`1]4 } \left\{ {10\bar{1}4} \right\} rhombohedra at close-to-neutral pH. This crystallization sequence progresses through the carbonated depth with a strong dependence on the degree of exposure to CO₂, which is controlled by the carbonated pore structure governing the diffusion of CO₂. Both the carbonation process and the scalenohedral-to-rhombohedral transformation are kinetically favored under high RH and high pCO₂. Supersaturation plays a critical role on the nucleation density and size of CaCO₃ crystals. These results have important implications in understanding the behavior of ancient and modern lime mortars for applications in architectural heritage conservation.     

Effect of free water removal from early-age hydrated cement pastes on thermal analysis

In order to follow the progress of cement hydration by analytical techniques, the ongoing hydration reactions must be stopped by complete removal of free water. A comparison between solvent exchange, oven drying and vacuum drying, using thermal analysis, is presented for early-age hydrated cement pastes. Results show that oven drying at 105 °C accelerates hydration, causes dehydration of some hydrated cement phases and favours carbonation. Solvent exchange with ethanol, ether and methanol results in a strong absorption and an incomplete removal of solvents. FT-IR and XRD gave evidence of the formation of carbonate-like phases due to an interaction upon heating, i.e. during thermal analysis, between the strongly absorbed solvents and the cement compounds or hydrates. Vacuum drying reveals reliable results as no interaction products can be formed and the Ca(OH)₂ content, determined by thermal analysis, gives a good approximation of the real amount of Ca(OH)₂.     

Science cited in patents: A geographic "flow" analysis of bibliographic citation patterns in patents

The interplay and cross-fertilization between science and technology, but also the specific role of science for technological development, have received ample attention in both the research and the policy communities. It is in this context that the concepts of absorptive capacity and knowledge spillovers play an important role. We operationalize the science-technology link by quantifying and modeling bibliographic references to the scientific literature as they occur in patents. This approach allows exploring the associative patterns between science creation (as emerging from the scientific literature) and technology development (as emerging from the patent literature). In the current paper, we focus on an analysis of the geographic distribution of the science citation patterns in patents, singling out two fields of (different) technological development, namely biotechnology and information technology. In both fields, the science citation flows from the European, Japanese and US science bases into USPTO and EPO-patents are explored and modeled. Intensive geographic citation flows between the regions are identified, pointing (amongst others) to the strength of both the US and the European science bases as sources for technological activity and creativity around the world.     

Organizing for Continuous Innovation: On the Sustainability of Ambidextrous Organizations

Organizing for innovation does not present itself as a straightforward exercise. The complexities entailed when implementing an innovation strategy can be related directly to the multitude of objectives it comprises. Recently, several scholars have advanced the notions of semi‐ or quasi‐structures and ambidextrous organizations to handle these multiple requirements. These organizational forms imply the simultaneous presence of different activities, exhibiting differences in technology and market maturation. As a consequence, financial returns will reflect this diversified resource allocation pattern. Moreover, as higher levels of complexity are being introduced; ambidextrous organizations will encounter additional, organizational, costs. Compared to organizations that focus on the most profitable part of the portfolio, ambidextrous organizations – ceteris paribus – tend to be inferior in terms of financial returns. Within this contribution we explore under which conditions ambidextrous organizations can outperform focused firms; considered a prerequisite for their sustainability. In order to do so, we develop an analytical framework depicting the differential value dynamics, focused and ambidextrous firms can enact. Our findings reveal the relevancy of adopting extended time frames as well as introducing interface management practices aimed at cross‐fertilization. Finally, the synergetic potential of (underlying) technologies comes to the forefront as necessary in order for ambidextrous organizations to become sustainable.     

Genomic organization, fine-mapping, and expression of the human islet-brain 1 (IB1)/c-Jun-amino-terminal kinase interacting protein-1 (JIP-1) gene

Islet-brain 1 (IB1), a regulator of the pancreatic beta-cell function in the rat, is homologous to JIP-1, a murine inhibitor of c-Jun amino-terminal kinase (JNK). Whether IB1 and JIP-1 are present in humans was not known. We report the sequence of the 2133-bp human IB1 cDNA, the expression, structure, and fine-mapping of the human IB1 gene, and the characterization of an IB1 pseudogene. Human IB1 is 94% identical to rat IB1. The tissue-specific expression of IB1 in human is similar to that observed in rodent. The IB1 gene contains 12 exons and maps to chromosome 11 (11p11.2-p12), a region that is deleted in DEFECT-11 syndrome. Apart from an IB1 pseudogene on chromosome 17 (17q21), no additional IB1-related gene was found in the human genome. Our data indicate that the sequence and expression pattern of IB1 are highly conserved between rodent and human and provide the necessary tools to investigate whether IB1 is involved in human diseases.