Synthesis of monoglycerides by glycerolysis of rapeseed oil using immobilized lipase

Reaction conditions for the synthesis of monoglycerides (MG) by enzyme-catalyzed glycerolysis of rapeseed oil using Lipozyme® IM have been studied. Silica gel was used to adsorb the glycerol to overcome the problems of low glycerol solubility in the organic phase. An experimental design was used where temperature, time, the ratio of silica gel to glycerol (w/w), the water activity (a) _w , the isooctane concentration, and the ratio of glycerol to triglycerides (mol/mol) were varied. Response surface methodology was used to evaluate initial reaction rate and yield for the different products. The best yield of MG achieved under the studied conditions was 17.4% (mol fatty acid in substance/total mol fatty acid in mixture) (75°C, 20 h, silica gel/glycerol 2:1, a _w =0.17, 48% isooctane, glycerol/triglycerides 6:1). The same conditions yielded 36.8% diglycerides, 13.6% free fatty acids (FFA), and 36.9% triglycerides. This is at the same level as the equilibrium yield. The yield of MG is low compared to the final yield achieved with solid-phase glycerolysis. However, in solid-phase glycerolysis the reaction mixture becomes solid, and therefore the solid-phase process is not suitable for industrial application. The formation of FFA was very fast compared to the synthesis of MG. Equilibrium for FFA was reached within 2 h, and the yield was strongly affected by the a _w . Increasing a _w greatly increased the formation of FFA. In the a _w ratio 0.06–0.3, the yield of FFA increased from 4 to 19% while the yield of MG was nearly unaffected. As FFA is an undesired product, it is important to keep the a _w as low as possible.     

Intracellular Uptake and Toxicity of Ag and CuO Nanoparticles: A Comparison Between Nanoparticles and their Corresponding Metal Ions

An increased understanding of nanoparticle toxicity and its impact on human health is essential to enable a safe use of nanoparticles in our society. The aim of this study is to investigate the role of a Trojan horse type mechanism for the toxicity of Ag‐nano and CuO‐nano particles and their corresponding metal ionic species (using CuCl₂ and AgNO₃), i.e., the importance of the solid particle to mediate cellular uptake and subsequent release of toxic species inside the cell. The human lung cell lines A549 and BEAS‐2B are used and cell death/membrane integrity and DNA damage are investigated by means of trypan blue staining and the comet assay, respectively. Chemical analysis of the cellular dose of copper and silver is performed using atomic absorption spectroscopy. Furthermore, transmission electron microscopy, laser scanning confocal microscopy, and confocal Raman microscopy are employed to study cellular uptake and particle‐cell interactions. The results confirm a high uptake of CuO‐nano and Ag‐nano compared to no, or low, uptake of the soluble salts. CuO‐nano induces both cell death and DNA damage whereas CuCl₂ induces no toxicity. The opposite is observed for silver, where Ag‐nano does not cause any toxicity, whereas AgNO₃ induces a high level of cell death. In conclusion: CuO‐nano toxicity is predominantly mediated by intracellular uptake and subsequent release of copper ions, whereas no toxicity is observed for Ag‐nano due to low release of silver ions within short time periods.     

Collaboration uncovered: Exploring the adequacy of measuring university-industry collaboration through co-authorship and funding

Summary Analysing co-authored publications has become the standard way to measure research collaborations. At the same time bibliometric researchers have advised that co-authorship based indicators should be handled with care as a source of evidence on actual scientific collaboration. The aim of this study is to assess how well university-industry collaborations can be identified and described using co-authorship data. This is done through a comparison of co-authorship data with industrial funding to a medical university. In total 436 companies were identified through the two methods. Our results show that one third of the companies that have provided funding to the university had not co-authored any publications with the university. Further, the funding indicator identified only 16% of the companies that had co-authored publications. Thus, both co-authorship and funding indicators provide incomplete results. We also observe a case of conflicting trends between funding and co-authorship indicators. We conclude that uncritical use of the two indicators may lead to misinterpretation of the development of collaborations and thus provide incorrect data for decision-making.     

Is it better or just the same? Article identification strategies impact bibliometric assessments

Summary This study demonstrates that the choice of search strategy for article identification has an impact on evaluation and policy analysis of research areas. We have assessed the scientific production in two areas at one research institution during a ten-year period. We explore the recall and precision of three article identification strategies: journal classifications, keywords and authors. Our results show that the different search strategies have varying recall (0.38-1.00) and precision (0.50-1.00). In conclusion, uncritical analysis based on rudimentary article identification strategies may lead to misinterpretation of the development of research areas, and thus provide incorrect data for decision-making.     

Psychological treatment of late-life anxiety: An empirical review.

This study provides a meta-analytic review of nonpharmacological interventions for late-life anxiety, focusing on treatment efficacy. Included in the analysis are studies in which a comparison was made either to a control condition or to another treatment. A total of 15 outcome studies, published or reported between January 1975 and January 2002, were identified involving 495 participants (mean age exceeding 55.0 years and a grand mean of 69.5 years) and providing 20 separate treatment interventions. The analysis indicated that psychological interventions were reliably more effective than no treatment on self-rated and clinician-rated measures of anxiety, yielding an effect size of .55. Maintenance of treatment gains (a minimum of 6 months follow-up) was insufficiently reported across studies to allow for a reliable demonstration of an overall estimate of long-term efficacy. It is concluded that psychological interventions produce significant improvements, but the analyses must be qualified by data limitations in the research synthesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relevance of season and nucleotide catabolism on changes in fillet quality during chilled storage of raw Atlantic salmon (Salmo salar L.)

Farmed 5–6 kg Atlantic salmon were pre-rigor filleted, vacuum packed and subsequently analysed after 1, 9 and 13 days of storage at 4 °C. The study was repeated in February, April, August and October. The conversion of hypoxanthine (Hx) showed the highest seasonal variation among the nucleotide metabolites, with an inverse relationship with sea temperature at harvesting (R² = 0.95–0.96). The Hx content was inversely related to fresh odour and flavour (R² = 0.81–0.83), but positively to tenderness (R² = 0.87). Hence, these results suggest that salmon reared in seawater of 11–15 °C (August–October) maintain a superior sensory quality for a longer period post-mortem than salmon reared at 6–8 °C (February–April). The colour intensity increased from days 1 to 9 post-mortem, probably due to rigor contraction. The highest increase in drip loss was observed in October and the lowest in April. It is proposed that seawater temperature significantly influences the storage life of raw salmon, and that Hx is a valuable biomarker for sensory quality.     

Perception of pesticide use by farmers and neighbors in two periurban areas

Public concern about pesticide use is high although varying with social factors. Individual differences in ‘perception’ and attitude to pesticide use might be particularly evident in periurban regions where farmers and other people live together. This was investigated using a questionnaire sent to 600 farmers and 600 non-farmers in two periurban areas of Sweden. ‘Neighbors’¹ were found to have a more negative attitude to pesticides than farmers, who were slightly positive to the use. Neighbors perceived pesticide use in agriculture to be more harmful to the environment than did farmers and also to reduce the quality of products. Both farmers and neighbors thought that farmers are the predominant users of pesticides. However, reported pesticide users within the home setting were just as common among the neighbors as among the farmers. Perceptions of pesticide use were also found to differ between periurban regions within the country. Attitudes and perceptions of pesticide use, as well as of who is the user, differ based on the group of people in a periurban environment and between different regions. Such differences might play a role for tensions and conflicts in the periurban area of a society and also for regulations of pesticide use.