Identification of Sex Pheromone Components of Nettle Caterpillar, Setothosea asigna

Gas chromatographic–electroantennographic detection (GC-EAD) analyses of female nettle caterpillar, Setothosea asigna, pheromone gland extracts revealed seven antennally active compounds. Based on their retention indices on three fused silica columns (DB-5, DB-23, and DB-210), these compounds were hypothesized and, through comparative GC, GC-EAD and GC-mass spectrometry with authentic standards, confirmed to be Δ10-undecenal, dodecanal, (E)-9-dodecenal (E9–12:Ald), (Z)-9-dodecenal, (E)-9-dodecen-1-ol, (E)-9,11-dodecadienal (E9,11–12:Ald), and (E)-9,11-dodecadienol. E9–12:Ald and E9,11–12:Ald were most abundant in female S. asigna pheromone extracts. In field trapping experiments in Palembang, Indonesia, synthetic E9–12: Ald and E9,11–12:Ald at a 1:1 ratio, but not singly, attracted S. asigna males. Attractiveness of these two aldehydes could not be enhanced further through the addition of their corresponding alcohols and/or other aldehydic candidate pheromone components. Use of E9–12:Ald and E9,11–12:Ald for pheromone-based monitoring of S. asigna populations will require lure formulations that minimize pheromone degradation by ultraviolet radiation and atmospheric oxidation.     

Vom Schwangerschaftsabbruch zur Embryonenselektion?

Ethik in der Medizin -     

A method for determination of length distributions of multiwalled carbon nanotubes before and after melt processing

A relatively simple method to determine the length distribution of carbon nanotubes (CNTs) before and after melt processing was developed. This involves the selection of a suitable solvent for dispersing pristine CNTs as well as to dissolve the matrix of melt mixed composites and the choice of an appropriate nanotube concentration. The length of suitably individualized CNTs was visualized using transmission electron microscopy and length distributions were measured using image analysis. Examples are shown for Baytubes® C150HP and Nanocyl™ NC7000 and their melt mixed composites with polycarbonate where the same procedure was applied to both, measuring the initial length distribution and the distribution after recovering from the composites. These results indicated a significant shortening after melt processing up to 30% of the initial length.     

Reprint of: Improved cytotoxicity testing of magnesium materials

Metallic magnesium (Mg) and its alloys are highly suitable for medical applications as biocompatible and biodegradable implant materials. Magnesium has mechanical properties similar to bone, stimulates bone regeneration, is an essential non-toxic element for the human body and degrades completely within the body environment. In consequence, magnesium is a promising candidate as implant material for orthopaedic applications. Protocols using the guideline of current ISO standards should be carefully evaluated when applying them for the characterization of the cytotoxic potential of degradable magnesium materials. For as-cast material we recommend using 10 times more extraction medium than recommended by the ISO standards to obtain reasonable results for reliable cytotoxicity rankings of degradable materials in vitro. In addition primary isolated human osteoblasts or mesenchymal stem cells should be used to test magnesium materials.     

Improved cytotoxicity testing of magnesium materials

Metallic magnesium (Mg) and its alloys are highly suitable for medical applications as biocompatible and biodegradable implant materials. Magnesium has mechanical properties similar to bone, stimulates bone regeneration, is an essential non-toxic element for the human body and degrades completely within the body environment. In consequence, magnesium is a promising candidate as implant material for orthopaedic applications. Protocols using the guideline of current ISO standards should be carefully evaluated when applying them for the characterization of the cytotoxic potential of degradable magnesium materials. For as-cast material we recommend using 10 times more extraction medium than recommended by the ISO standards to obtain reasonable results for reliable cytotoxicity rankings of degradable materials in vitro. In addition primary isolated human osteoblasts or mesenchymal stem cells should be used to test magnesium materials.     

Modeling Usage: Techniques and Tools

This review of four usage-modeling techniques clarifies key elements of each technique and their strengths and weaknesses from the perspective of usage-centered development. It also points to tools where appropriate. Finally, the authors argue for applying a template-supported use scenario integrating the three approaches.     

Irreführende Leitbilder Zum Mythos der Individualisierung durch pharmakogenetische Behandlungskonzepte. Eine kritische Anmerkung

Zusammenfassung Die prospektive Analyse der ethischen Implikationen medizinisch-technischer Innovationen läuft immer auch Gefahr, sich in den Wunschbildern von Marketingexperten zu verfangen. Vor diesem Hintergrund könnte es durchaus nützlich sein, die Erkenntnisse der Wissenschafts- und Technikforschung zur Genese und Entwicklung neuer Techniken auszuschöpfen. Dies erscheint gerade auch für die ins Phantastische weisende Zukunft der Individualisierung medikamentöser Therapie, wie man ihr häufig in der Beschreibung pharmakogenetischer Behandlungskonzepte begegnet, angebracht. Techniken, die sich noch im Entwicklungsstadium befinden und deren breite Anwendung noch einige Jahre auf sich warten lassen wird, sollten sehr sorgfältig auf ihren Realitätsgehalt und das zu erwartende Leistungspotenzial hin analysiert werden. Dazu gehört v. a. auch eine kritische Auseinandersetzung mit den Leitbildern, Visionen und Nutzenversprechen, mit denen technische Innovationen oft sehr absichtsvoll ausgestattet werden. Wird dabei die Distanz zur Rhetorik der Protagonisten der neuen Techniken nicht gewahrt, gerät die ethische Reflexion unvermittelt in die Rolle, profane Marketingstrategien wortgewandt und ideenreich zu veredeln.     

Optical isomers of 3,13-dimethylheptadecane: Sex pheromone components of the western false hemlock looper,Nepytia freemani (Lepidoptera: Geometridae)

(3S, 13R)-3, 13-Dimethylheptadecane [(3S, 13R)-3, 13-dime-17Hy] is the major pheromone component of the western false hemlock looper (WFHL),Nepytia freemani. In comparative gas chromotographic-electroantennographic detection (GC-EAD) analyses of stereoselectively synthesized isomers, 1 pg of (3S, 13R)-dime-17Hy elicited significantly stronger electrophysiological responses by male WFHL antennae than did 1 pg of separately injected (3R, 13R)-, (3R, 13S)- or (3S, 13S)-3, 13-dime-17Hy. In field experiments with individually tested stereoisomers. (3S, 13R)-3, 13-dime-17Hy was the only stereoisomer to attract males, but the four-stereoisomer blend was 3.6 times more attractive. Quaternary and all binary combinations of (3S, 13R)-3, 13-dime-17Hy with the other stereoisomers were equally attractive, suggesting that synergisytic behavioral activity in WFHL resided with either one of (3R, 13R)-, (3R, 13S)-, or (3S, 13S)-3, 13-dime-17Hy. Because optical isomers of (di)methylhydrocarbons do not separate on currently available columns, it remains unknown whether female WFHL also produce a four-stereoisomer pheromone blend. Substitutionality of pheromone stereoisomers without loss of behavioural activity has not previously been reported, but favorably compares with the concept of pheromone redundancy that was first suggested for the multiple pheromone component blend of the cabbage looper moth,Trichoplusia ni.     

Biologisches Verfahren zum unspezifischen Nachweis g?rungshemmender Substanzen in Wein

Zusammenfassung Zum Nachweis von gärungshemmenden Steffen im Wein wurde eine neue biologische Methode entwickelt, die auf dem Prinzip er Keimzahlbestimmung durch stufenweise Verdünnung beruht. Für den Test wird die zu untersuchende Probe steril in eine Reihe von Reagensgläserm gefüllt und mit dem gleichen Volumen eines Nährmediums versetzt, das außer den Nährstoffen zusätzlich Brenztraubensäure zum Binden von schwefliger Säure enthält Diesem Testgemisch wird eine sehr verdünnte Suspension einer alkoholresistenten Hefe zugesetzt. Die Verdünnung wird so gewählt, daß in der höchsten Verdünnungsstufe nur noch einzelne Zellen je Einsaatvolumen vorhanden sind. Nach der Einsaat wird das Testgemisch 4–6 Tage bei 27° C gehalten. In allen Röhrchen, denen Hefezellen zugesetzt werden, wird eine deutliche Trübung und Gasbildung sichtbar werden. Enthält die Probe jedoch Hemmstoffe, so verringert sich die Anzahl der Röhrchen, in denen e in Hefewachstum erkennbar ist. Mit dieser Keimzahlmethode werden Hemmstoffe unspezifisch nachgewiesen; für folgende Substanzen wurde die Nachweisgrenze in Wein bestimmt: Kaliumsorbat 60 mg/l, Natriumazid 1 mg/l, Natriumfluorid 10 mg/l, p-Chlorbenzoesäure 3 mg/l, Actidion < 0,05 mg/l, Monobromessigsäure 2 mg/l. Da die Methode nicht spezifisch ist, können such Fungicide nachgewiesen werden, wenn sie in ausreichender Konzentration vorliegen. — Infolge der Verdünnung wird die Keimzahlmethode durch den Alkoholgehalt des Weines niche beeinträchtigt. Bei der Untersuchung einer Reihe von Weinen wurden natürlich vorkommende Hemmstoffe nicht gefunden.

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Biological method for unspecific detection of preservatives in wine

Summary Employing the method of the determination of the most probable number of single cell organisms by step-wise serial dilution, a new method for the detection of preservatives in wine has been developed. The sample to be investigated is distributed into a series of test tubes, to which the equal volume of a nutrient solution is added. This reduces the alcohol content of the sample sufficiently. The added solution contains sugar, yeast extract and pyruvie acid, which is needed to bind free SO₂ which might be present in the wine sample. To this mixture very dilute suspensions of cells of a yeast strain resistant to alcohol are added. The dilution of this suspension is such that the highest dilution used for inoculation contains no or only a single yeast cell. The same volume of this inoculum (1 ml) is used for each test tube with the mixture of wine sample and nutrient solution. After inoculation the tubes are kept for 4–6 days at 27° C. All tubes that have received an inoculum containing at least one viable yeast cell will show growth by becoming turbid. The most probable number of cells is calculated from these results. If however, the wine sample contains preservatives, the number of tubes showing yeast growth and thus the most probable number of cells will be reduced. This reduction in the most probable number can be used for the unspecific detection of preservatives. The detection limits of the following compounds were found to be potassium sorbate 60 mg/l, sodium azide 1 mg/l, sodium fluoride. 10 mg/l, p-chlorobenzoic acid 3 mg/l, actidione < 0.05 mg/l, monobromoacetic acid 2 mg/l. The proposed method is somewhat more sensitive than the usual fermentation test. Fungicides and detergents can also be detected, when they are present in inhibiting amounts. The disadvantage of the method is the need to sterilize the sample, but this can be done by simple means. In an investigation of white and red wines no natural inhibitors were found which interfer with the method for the unspecific detection of preservatives.

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Diese Arbeit wurde durch Gewährung einer Sachbeihilfe des Forschungsringes des Deutschen Weinbaues unterstützt.