Pheromone emission by individual females of carnation tortrix,Cacoecimorpha pronubana

The emission of five pheromone components by individualCacoecimorpha pronubana females was measured during 15-min sampling intervals. Pheromone was only released during female calling. Blend ratios emitted by individual females were constant over three calling periods, despite variations in release rates. Release ratios of the Δ11-componentsZ11-14∶Ac,E11-14∶Ac, andZ11-14∶OH were similar for all females tested, but release ratios of Z9-14∶Ac to the Δ 11-components showed significant interindividual variation.     

Integration of an SCR in an active clamp

This paper presents the integration of an SCR into a HV power clamp. For low currents the structure operates in “active clamp” mode and clamps the voltage to a value above the maximum operating voltage. After snapback the structure clamps the voltage to a low value as an SCR.     

Micromotor-Assisted Keratinocytes Migration in a Floating Paper Chip

In vitro epidermis models are important to evaluate and study disease progression and possible dermal drug delivery. An in vitro epidermis model using floating paper chips as a scaffold for proliferation and differentiation of primary human keratinocytes is reported. The formation of the four main layers of the epidermis (i.e., basal, spinosum, granulose, and cornified layers) is confirmed. The development of a cornified layer and the tight junction formation are evaluated as well as the alterations of organelles during the differentiation process. Further, this in vitro model is used to assess keratinocyte migration. Finally, magnetic micromotors are assembled, and their ability to aid cell migration on paper chips is confirmed when a static magnetic field is present. Taken together, this attempt to combine bottom-up synthetic biology with dermatology offers interesting opportunities for studying skin disease pathologies and evaluate possible treatments.     

Fluidized bed chemical vapor deposition of silicon on carbon nanotubes for Li-ion batteries

Silicon was deposited on balls of entangled multi-walled carbon nanotubes (CNT) with a mean diameter of several hundreds of microns, by Fluidized Bed Chemical Vapor Deposition from silane (SiH4). The weight total percentage of deposited silicon was between 30 and 70%, to test their efficacy in Li-ion battery anodes. TEM and SEM imaging revealed that silicon deposits were of the form of nanoparticles uniformly dispersed on the whole CNT surface. The diameter of these nanoparticles increases with the deposited silicon percentage from 18 to 36 nm whereas their density remains constant at 5 10(22) nanoparticles/g of CNT. This indicates a low affinity of chemical species born from silane pyrolysis with the CNT surface for nucleation. The increase of the silicon nanoparticles diameter leads to the decrease of the specific surface area and the porous volume of the balls, probably due to the filling of the pores of the CNT network by silicon. A slight increase of the mean diameter of the balls was observed for the two highest silicon percentages, certainly due to the ability of the CNT network to be deformed under the mechanical stress induced by the silicon nanoparticles growth.     

Development of a candidate reference method for the simultaneous quantitation of the boar taint compounds androstenone, 3α-androstenol, 3β-androstenol, skatole, and indole in pig fat by means of stable isotope dilution analysis-headspace solid-phase microextraction-gas chromatography/mass spectrometry

The steroidal pig pheromones androstenone (5α-androst-16-en-3-one), 3α-androstenol (5α-androst-16-en-3α-ol), and 3β-androstenol (5α-androst-16-en-3β-ol) as well as the heterocyclic aromatic amines skatole and indole, originating from microbial degradation of tryptophan in the intestine of pigs, are frequently recognized as the major compounds responsible for boar taint. A new procedure, applying stable isotope dilution analysis (SIDA) and headspace solid-phase microextraction-gas chromatography/mass spectrometry (HS-SPME-GC/MS) for the simultaneous quantitation of these boar taint compounds in pig fat was developed and validated. The deuterated compounds androstenone-d(3), 3β-androstenol-d(3), skatole-d(3), and indole-d(6) were synthesized and successfully employed as internal standards for SIDA. The new procedure is characterized by a fast, simple, and economic sample preparation: methanolic extraction of the melted fat followed by a freezing and an evaporation step allows for extraction and enrichment of all five analytes. Additional time-consuming cleanup steps were not necessary, as HS-SPME sampling overcomes fat-associated injector and column contamination. The method has been validated by determining intra- and interday precision and accuracy as well as the limit of detection (LOD) and limit of quantitation (LOQ). Additionally, a cross-validation for androstenone, skatole, and indole was carried out comparing the results of 25 back fat samples obtained simultaneously by the new SIDA-HS-SPME-GC/MS procedure with those obtained in separate GC/MS and high-performance liquid chromatography fluorescence detection (HPLC-FD) measurements. The cross-validation revealed comparable results and confirms the feasibility of the new SIDA-HS-SPME-GC/MS procedure.     

Cimaterol and clenbuterol residue analysis by HPLC-HPTLC in liver

Summary A method has been developed for the analysis of cimaterol and clenbuterol residues in liver, with detection limits of 0.25 g/kg and 0.5 g/kg, respectively. The recovery varied from 55% to 60%. After extraction, a clean-up procedure with Baker-spe C-18 columns was performed. The two chemical compounds of interest were eluted with methanol. Cimaterol and clenbuterol were quantitatively determined by high-performance liquid chromatography (HPLC) using an RP-Select B (5 m) column and a post-column reaction procedure. The positive results were confirmed by high-performance thinlayer chromatography (HPTLC) as this technique reaches the same level of sensitivity as the HPLC method.

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Rückstandsbestimmung von Cimaterol und Clenbuterol in Leber mittels HPLC-HPTLC

Zusammenfassung Es wurde eine Methode zur Rückstandsbestimmung von Cimaterol und Clenbuterol in Leber entwickelt mit den Nachweisgrenzen von 0,25 g/kg für Cimaterol und 0,5 g/kg für Clenbuterol. Die Ausbeute lag zwischen 55–60%. Nach der Extraktion wurde die Reinigung auf Baker-spe C-18 Kolonnen vorgenommen und die beiden uns interessierenden Produkte durch Methanol eluiert. Cimaterol und Clenbuterol wurden quantitativ durch HPLC auf einer RP-Select B-(5 m) Kolonne und mittels einer Nach-Kolonnen-Reaktion bestimmt. HPTLC diente zur Bestätigung positiver Resultate, da hiermit die gleiche Nachweisgrenze wie für HPLC erreicht wird.

     

Biological behaviour of buccal cells exposed to blue light

Blue light is used in dental practise to cure resin-based materials, but the path of the light often includes oral tissues such as gingival tissues. While adverse effects of blue light exposure on cells – such as retina cells – are well known, few studies have investigated the impact of blue light exposure on oral cells. The aim of the present in vitro study was to assess the biological effects of blue light emitted by two dental curing devices (a plasma-arc and a light-emitting diode curing unit) on human gingival fibroblasts. Light intensities and light-induced temperature rise were respectively measured with a radiometer and a thermocouple. Cellular response to blue light exposure was assessed by the observation of cell morphology (scanning electron microscopy) and the estimation of cell mitochondrial activity (MTT assay). Light intensities measured at the clinical distance were 488 ± 42 mW/cm² for the plasma-arc unit and ranged from 61 ± 5 to 140 ± 16 mW/cm² for the light-emitting diodes unit, according to the curing program used. The highest temperature rise was 0.5 and 3.5 °C for exposure to the plasma-arc light and to the light-emitting diodes light, respectively. Results showed no differences between exposed- and non-exposed cells in regards to cell morphology. However, cells exposed to blue light presented an increased mitochondrial activity compared to control cells (non-exposed), and mostly those exposed to plasma-arc light.     

Tongue pressure recordings during speech using complete denture

This paper describes an original experimental procedure to measure mechanical interactions between tongue and teeth during speech production. Using edentulous people as subjects, pressure transducers are inserted in their complete denture duplicate. Physiology is respected during sound and pressure recording as with standard complete denture. Original calibration device is also described in order to know what kind of information can be extracted from the data. The measurements are realized in different experimental conditions in order to remove the auditory and the orosensory feedbacks. Then the first results of the pilot study are presented.     

Biomaterial surface properties modulate in vitro rat calvaria osteoblasts response: Roughness and or chemistry?

The aim of this study was a better understanding of the regulation mechanisms of in vitro osteoblast activity on biomaterials. Rat osteoblast behaviour on different surfaces was studied. Surfaces with different roughness (and a similar surface chemistry) or with different surface chemistry (and a similar roughness) were compared. Cellular morphology was observed by scanning electron microscopy and cell adhesion was quantified using an image analysis system. Osteoblast proliferation was quantified by a MTT test and total protein content and alkaline phosphatase (ALP) activity were evaluated by spectrophotometry. Data were compared by statistical analysis.

Results showed that NiTi surface roughness did not influence osteoblasts morphology, adhesion, total protein content and ALP activity whereas it modulated cell proliferation. Roughness was shown to stimulate cell proliferation. For smooth surfaces exhibiting two different chemical compositions, adhesion rate was found to be higher on Thermanox® than on NiTi whereas proliferation was shown to be smaller. ALP activity was also modulated by surface chemistry. Thus, cell adhesion and ALP activity were found to be more governed by surface chemistry than by roughness whereas cell proliferation was shown to be modulated by roughness (this effect increasing during cell culture) and by chemistry (this effect remaining stable in time) together. Total protein content and cell morphology were found to be independent of both parameters (roughness and chemistry). Effects of surface chemistry were discussed in terms of wettability and electron acceptor/donor properties of the surfaces of interest. Immunofluorescence images of adhesion proteins could not demonstrate differences between the three surfaces.     

Assessment of an in-situ technique to estimate the degradation of lipids in the rumen

In-situ disappearance of alfalfa hay, soybean, soybean meal and maize grain lipids and fatty acids were measured using two dairy cows. Bags were removed after 1, 2, 4 and 8 h incubation. Bacterial colonisation was estimated by labelling bacteria by a ¹⁵N infusion into the rumen. Results were then subtracted from calculations. Bacterial dry matter, lipids and fatty acids were highest for alfalfa hay and lowest for soybean. Disappearance of lipids and fatty acids was significantly higher for maize than for the other feeds. Stearic and octadecenoic acids appeared in hay and soybean as products of hydrogenation but no distinction could be made between fatty acids leaving the bags and fatty acids appearing or disappearing due to hydrogenation. Complete linolenic acid hydrogenation seems to be limited by the rate of hydrogenation of stearic acid into octadecenoic acids. Nylon bags seem to be a valuable tool to estimate hydrogenation or protection against hydrogenation in high linolenic content feeds.