Enzymatic Formation and Physico-Chemical Behaviour of Uncommon Monoglycerides

Results on the enzymatic monoacylation of glycerol by aid of phenylboronic acid in organic solvents are presented. The comparison of two alternative methods indicates that the ?2-step-method”? (synthesis in one batch unit without isolation of intermediates) is in total more favourable than the ?3-step-method”? (synthesis in two batch units including isolation of intermediates), although yields are somewhat lower. Probably this disadvantage originates from an enzyme inhibition caused by residual free phenylboronic acid in the reaction system. Several varying uncommon fatty acids like (S)-17-hydroxyoctadecanoic acid, 12-hydroxyoctadecanoic acid and 2-hydroxyhexadecanoic acid have been used as oleo-components. As far as no steric hindrance is caused by these substrates, product formation is about 80% (basis ?2-step-method”?). Investigations at the Langmuir film balance showed different film states with specific transition phases for the 1(3)-(17-hydroxy)-octadecanoyl and the 1(3)-(12-hydroxy)-octadecanoyl glycerol. The monoglyceride of the 2-hydroxyhexadecanoic acid proved to be a good emulsifier. Its qualities in this respect were confirmed by the data of the surface and interfacial tension versus n-hexadecane and also by the outcome of the emulsification tests. The enzymatic acylation of a diol like 1,3-propanediol led to the 1-(17-hydroxy)-octadecanoyl-3-propanol (yield: 50%). The film behaviour of this ester was similar to that of the corresponding monoglyceride.     

Toughness optimization of glass‐fiber reinforced PA 6/PA 66‐based composites: Effect of matrix composition and colorants

Mixing of polyamide 6 (PA 6) and polyamide 66 (PA 66) is integrated in the trend of development of new and improved materials by combination of different polymers and some reinforcing materials to polymer composites. The specific polymer composite PA 6/PA 66 reinforced with short glass‐fibers combines the good coloring of PA 6, and the small moisture absorption of PA 66. Technical applications of PA 6/PA 66 composites are mainly used in the automotive industry. Specific requirements of this industry lead to the necessity to optimize the material resistance against crack propagation of the PA 6/PA 66 composites, using mechanical and fracture mechanical methods. So, the present investigations focus on fracture mechanics toughness optimization of the PA 6/PA 66 composites, including unstable and stable crack growth. The aim of this toughness optimization is to find out the optimal mixing ratio of PA 6/PA 66. Applications of PA 6/PA 66 in the automotive industry and specific client wishes are the main reasons for black‐coloring of the PA materials. The influence of several black‐colorants (carbon black, nigrosine, spinel, iron oxide) on mechanical and fracture mechanical properties of the PA composites is also investigated using fracture mechanical methods. As experimental fracture mechanical method, preferentially, the instrumented Charpy impact test (ICIT) and the new cut method to determine the stable crack growth of glass‐fiber reinforced materials was used. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Evaluation and simulation of the peel behavior of polyethylene/polybutene‐1 peel systems

The peel characteristics of sealed low‐density polyethylene/isotactic polybutene‐1 (PE‐LD/iPB‐1) films, with different contents of iPB‐1 up to 20 m.‐% (mass percentage), were evaluated and simulated in dependence on the iPB‐1 content, and in dependence on the peel rate. Sealing involves close contact and localized melting of two films for a few seconds. The required force, to separate the local adhered films, is the peel force, which is influenced, among others, by the content of iPB‐1. The peel force decreases exponentially with increasing iPB‐1 content. Transmission electron microscopy studies reveal a favorable dispersion of the iPB‐1 particles within the seal area, for iPB‐1 concentrations ≥6 m.‐%. Here, the iPB‐1 particles form continuous belt‐like structures, which lead to a stable and reproducible peel process. The investigation of the peel rate‐dependency on the peel characteristics is of important interest for practical applications. The peel force increases with increasing peel rate by an exponential law. A numerical simulation of the present material system proves to be useful to comprehend the peel process, and to understand the peel behavior in further detail. Peel tests of different peel samples were simulated, using a two‐dimensional finite element model, including cohesive zone elements. The established finite element model of the peel process was used to simulate the influence of the modulus of elasticity on the peel behavior. The peel force is independent of the modulus of elasticity, however, the peel initiation value increases with increasing modulus of elasticity. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Efficient Biocatalytic Synthesis of (R)‐Pantolactone

Screening for stereoselective cyanohydrin synthesis in 96‐well plates was employed in the development of an efficient, pH‐stable hydroxynitrile lyase for the conversion of sterically hindered aliphatic aldehydes. Site‐saturation mutagenesis (SSM) resulted in a powerful catalyst for the stereoselective conversion of hydroxypivalaldehyde and pivalaldehyde to their corresponding (R)‐cyanohydrins (ee >97%) which are used as chiral building blocks (e.g., for pantothenic acid production). Furthermore, redesigning the PaHNL5 gene and improving its expression by Pichia pastoris with the help of a new P_AOX1 promoter variant and the helper protein PDI (protein disulfide isomerase) led to elevated amounts of today’s most efficient biocatalyst for vitamin B₅ synthesis.     

Furan and Methylfurans in Foods: An Update on Occurrence,Mitigation, and Risk Assessment

The acceptance of many foods is related to traditional cooking practices, which create taste and texture and are important to digestibility, preservation, and the reduction of foodborne illnesses. A wide range of compounds are formed during the cooking of foods, a number of these have been shown to lead to adverse effects in classical toxicological models and are known as food processing contaminants (FPC). It is essential that the presence and effects of such compounds alone and in combination within the diet are understood such that proportionate risk management measures can be developed, while taking a holistic view across the whole value chain. Furan and alkylfurans (principally 2‐ and 3‐methylfuran) are highly volatile FPC, which are formed in a wide range of foods at low amounts. The focus of research to‐date has been on those foods, which have been identified to be most consequential in terms of being sources of exposure, namely jarred and canned foods for infants and young children (meals and drinks) and coffee (roast and ground, soluble). This report presents (i) new industry data on the occurrence of furan and methylfurans in selected food categories following previous coffee studies, (ii) the most salient parameters that impact furan formation, and (iii) aspects of importance for the risk assessment.     

Das Duftmarkieren des Baummarders(Martes martes) unter Gehegebedingungen

Zusammenfassung Das Markierverhalten von drei Baummarderpaaren unterschiedlichen Alters wurde von Januar bis Dezember 1991 erfaßt (Tab. 1). Es wurden folgende Verhaltensweisen differenziert: stoffwechselbedingte Kot- und Urinabgabe, Kotmarkieren, Urinmarkieren, Abdominalreiben, Körperreiben und Hinterlaufscharren (Abb. 1). Hinterlaufscharren und vermutlich auch Körperreiben sind im agonistischen Kontext angesiedelt.Abdominalreiben ist das mit großem Abstand häufigste Markierverhalten (Tab. 2). Abdominalreiben und Urinmarkieren korrelieren in hohem Maße (Tab. 3, 4). Bei beiden Verhaltensweisen trat im jahreszeitlichen Verlauf bei den drei- und fünfjährigen Tieren, insbesondere den Rüden, ein deutliches Häufigkeitsmaximum zwischen März und Mai auf. Die einjährigen Tiere markierten dagegen häufiger im Herbst und Winter (Abb. 2, Tab. 5). Die jahreszeitlichen Unterschiede der Markierhäufigkeit stehen vermutlich im Zusammenhang mit dem Territorialverhalten. Das abweichende Verhalten der einjährigen Tiere wird als eine altersbedingte Anpassung diskutiert.Zum Abdominalreiben wurden immer wieder dieselben Stellen aufgesucht. Diese Markierstellen wurden von beiden Partnern genutzt (Tab. 6). Möglicherweise dienen gemeinsam genutzte Markierstellen im Freiland zum Informationsaustausch.Abdominalreiben tritt gelegentlich mit Artgenossenbezug auf (Tab. 7). Die Tiere markieren auf dem Körper des Partners, mit Blickkontakt zum Partner, oder es wird an einer Stelle markiert, die soeben vom Partner markiert wurde (Übermarkieren). Partnermarkieren konnte bisher bei keinem anderen einheimischen solitären Marderartigen beobachtet werden.

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Scent marking in pine martens (Martes martes) in captivity

Summary The scent marking behaviour of three pairs of pine martens of different ages was recorded from January to December 1991 (Table 1). The following behaviour patterns were differentiated: Defecation and urination, fecal-marking, urine-marking, abdominal rubbing, body rubbing and scratching with the hind-legs (Fig. 1). Scratching with the hind-legs and possibly body rubbing are associated with the agonistic context.Abdominal rubbing is by far the most frequent marking behaviour (Table 2). Abdominal rubbing and urine marking correlate to a high degree (Tables 3, 4). Both behaviour patterns can frequently be seen in the three year old and the five year old animals, especially the males, from March to May, in the one year old animals in autumn and winter (Fig. 2, Table 5). The seasonal changes in marking frequency are considered as connected to the territorial behaviour. The different behaviour of the yearlings is discussed as an age-specific adaptation.Abdominal rubbing always took place at the same sites. These marking sites were used by both partners (Table 6). In natural environments these common marking sites may be used for an exchange of information.Sometimes abdominal rubbing happens in relation to a conspecific (Table 7). The animals mark on the body of the partner (allomarking), in visual contact with the partner, or they mark at a site, which was just marked by the partner (overmarking). Up to now, allomarking was not observed by any other solitary species of native mustelids.

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Le marquage olfactif de la Martre des pins (Martes martes) dans des conditions d'enclos

Résumé Le comportement de marquage de trois couples de Martre des pins d'âge varié a été relevé de janvier à décembre 1991 (Tabl. 1). Les comportements suivants furent identifiés: défécation et miction en tant que conditionnés par le métabolisme, marquage fécal, marquage urinaire, grattage abdominal, grattage corporel et trépignement des postérieurs (Fig. 1). Le trépignement des postérieurs de même que sans doute le grattage corporel se manifestent dans un contexte antagonique.Le grattement abdominal est de loin le comportement de marquage le plus fréquent (Tabl. 2). Le grattement abdominal et le marquage urinaire se trouvent être en corrélation très marquée (Tabl. 3, 4). Les deux modes de marquage présentèrent un pic saisonnier entre mars et mai chez les sujets de 3 et 5 ans, en particulier chez les mâles. Les sujets d'un an, par contre, marquèrent plus fréquemment en automne et en hiver (Fig. 2, Tabl. 5). Les différences saisonnières de fréquence de marquage sont vraisemblablement à mettre en lien avec le comportement territorial. Le comportement singulier des sujets d'un an est présenté comme une adaptation liée à l'âge.En ce qui concerne le grattage abdominal, ce sont toujours les mêmes lieux qui sont visités par les animaux (Tabl. 7). Ces endroits de marquage sont utilisés par chaque partenaire (Tabl. 6). Sans doute ces lieux communs de marquage servent-ils à un échange d'information sur le terrain.Le grattage abdominal se rapporte parfois aux relations d'individu à individu (Tabl. 7): soit les animaux marquent le corps de leur partenaire tout en gardant avec lui un contact visuel, soit le marquage s'effectue à un endroit lequel est aussitôt re-marqué par le partenaire ("sur-marquage"). Le marquage du partenaire n'a pu, jusqu'à présent, être observé sur aucun autre mustélidé indigène à tempérament solitaire.

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Eingesetzt wurde ein Druckkostenzuschuß der Landesjägerschaft Niedersachsen, für dessen Gewährung verbindlich gedankt wird. — Die Schriftleitung

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Eingesetzt wurde ein Druckkostenzuschuß der Landesjägerschaft Niedersachsen, für dessen Gewährung verbindlich gedankt wird. — Die Schriftleitung     

A simple intrinsic measure for rapid crack propagation in bimodal polyethylene pipe grades validated by elastic–plastic fracture mechanics analysis of data from instrumented Charpy impact test

Conventional test procedures, such as the S4 test to analyze the resistance against rapid crack propagation (RCP) of plastic pipe materials are characterized by usage of a lot of material, are far from saving of time and they are‐in need of special experimental set‐ups. Therefore, in the last decade, small‐scale accelerated reliable tests (SMART) are developed ‐ worldwide to overcome the disadvantage of such conventional tests. In this article, fracture mechanics based analysis of instrumented Charpy impact test data for a set of bimodal high‐density polyethylene pipe grades are compared with data of the conventional Charpy impact test. From this comparison the Charpy impact strength at ?30°C comes forth as a robust reproducible measure of the resistance to RCP and it is therefore proposed as a SMART method to rank materials with respect to RCP resistance. POLYM. ENG. SCI., 57:13–21, 2017. © 2016 Society of Plastics Engineers     

Assessing creativity with divergent thinking tasks: Exploring the reliability and validity of new subjective scoring methods.

Divergent thinking is central to the study of individual differences in creativity, but the traditional scoring systems (assigning points for infrequent responses and summing the points) face well-known problems. After critically reviewing past scoring methods, this article describes a new approach to assessing divergent thinking and appraises its reliability and validity. In our new Top 2 scoring method, participants complete a divergent thinking task and then circle the 2 responses that they think are their most creative responses. Raters then evaluate the responses on a 5-point scale. Regarding reliability, a generalizability analysis showed that subjective ratings of unusual-uses tasks and instances tasks yield dependable scores with only 2 or 3 raters. Regarding validity, a latent-variable study (n=226) predicted divergent thinking from the Big Five factors and their higher-order traits (Plasticity and Stability). Over half of the variance in divergent thinking could be explained by dimensions of personality. The article presents instructions for measuring divergent thinking with the new method. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Screening method for ecotoxicological hazard assessment of 42 pharmaceuticals considering human metabolism and excretory routes

We assessed the ecotoxicological hazard potential of 42 pharmaceuticals from 22 therapeutic groups, including metabolites formed in humans. We treated each parent drug and its metabolites as a mixture of similarly acting compounds. If physicochemical or effect literature data were missing, we estimated these with quantitative structure-activity relationships (QSAR). Additionally, we estimated micropollutant removal efficiency of urine source separation using pharmaceutical information. On average, 50% of a parent drug was metabolized, and 70% was excreted with urine, albeit with large variations among drugs. Metabolism reduced the toxic potential of all but eight drugs. The subsequently modeled risk quotient was mostly below the threshold of one. However, ibuprofen and its metabolites in a mixture could pose an ecotoxicologal risk; and possibly also acetylsalicylic acid, bezafibrate, carbamazepine, diclofenac, fenofibrate, and paracetamol. Lipophilicity and sale quantities of parent drugs alone were insufficient to estimate their ecotoxicological risk. Urine separation could decrease the ecotoxicological risk of some, but not all drugs. The estimated risk quotients were equal in urine and feces, again with large variations among compounds. Because of scientific limitations of the model and inconsistent literature data the results are somewhat uncertain. However, this new approach allows first tier screening of single drugs, thus supporting decision-making.     

Characteristic Oxidation Products of Choline Plasmalogens are Detectable in Cattle and Roe Deer Spermatozoa by MALDI-TOF Mass Spectrometry

Plasmalogens (1-O-alk-1′-enyl-2-acyl-sn-glycero-3-phosphocholines and -phosphoethanolamines) are important constituents of spermatozoa membranes and possess significant antioxidative properties. This particularly holds as plasmalogens from spermatozoa also possess a very high content of highly unsaturated fatty acyl residues (especially 22:6). The organic spermatozoa extracts of two different ruminants (cattle and roe deer) were analyzed for their contents of characteristic choline plasmalogen oxidation products by matrix-assisted laser desorption and ionization time-of-flight (MALDI-TOF) mass spectrometry. It will be shown that 1-hydroxy-2-docosahexaenoyl-sn-glycero-3-phosphocholine (LPC 22:6) and formyl-LPC 22:6 are reliable measures of lipid oxidation of spermatozoa and allow, accordingly, conclusions about the storage conditions. All data on spermatozoa were also confirmed by the investigation of the oxidation behavior of selected reference compounds. It will be shown that, equally if plasmalogens or diacyl PC species are used, oxidation takes place primarily at the double bond next to the glycerol backbone. These data were additionally confirmed by recording the corresponding post source decay (PSD) fragment ion spectra.