Nanofabricated atom optics: Atom chips

Abstract

Small tight trapping and guiding potentials can be created for neutral atoms moving microns above surfaces patterned with nanofabricated charged and current-carrying structures. Surfaces holding such structures form atom chips which, for coherent matter wave optics, may form the basis for a variety of novel applications and research tools, similar to integrated circuits in electronics. In this paper we describe the basic principles of atom chip experiments.     

Comparative assessment of genotoxicity of mineral water packed in polyethylene terephthalate (PET) and glass bottles

The potential migration of genotoxic compounds into mineral water stored in polyethylene terephthalate (PET) bottles was evaluated by an integrated chemical/biological approach using short-term toxicity/genotoxicity tests and chemical analysis. Six commercial brands of still and carbonated mineral water bottled in PET and in glass were stored at 40 °C for 10 days in a stove according to the standard EEC total migration test (82/711/EEC), or at room temperature in the dark. After treatment, the samples were analysed using gas-chromatography/mass spectrometry (GC/MS) to detect volatile and non-volatile compounds, the Microtox^® test to evaluate potential toxicity of the samples, and three mutagenicity tests - Tradescantia and Allium cepa micronucleus tests and the Comet assay on human leukocytes - to detect their genotoxic activity.GC/MS analysis did not detect phthalates or acetaldehyde in the water samples. The Microtox^® test found no toxic effects. Mutagenicity tests detected genotoxic properties of some samples in both PET and glass bottles. Statistical analyses showed a positive association between mineral content and mutagenicity (micronuclei in A. cepa and DNA damage in human leukocytes). No clear effect of treatment and PET bottle was found. These results suggest the absence of toxic compounds migrating from PET regardless of time and conditions of storage. In conclusion, bottle material and stove treatment were not associated with the genotoxic properties of the water; the genotoxic effects detected in bottled water may be related to the characteristics of the water (minerals and CO₂ content).     

Melt Mixing of Ethylene/Butyl Acrylate/Glycidyl Methacrylate Terpolymers with LDPE and PET

The chemical modification by melt‐mixing of an EBAGMA terpolymer with LDPE and PET was investigated with the aim to use these EBAGMA/LDPE and EBAGMA/PET blends (in equal weight quantities) as compatibilizer master batches to improve the compatibility of the LDPE/PET system. It is shown that when the EBAGMA terpolymer is melt blended with LDPE, almost 40% of the initial amount of EBAGMA is linked to the LDPE backbone. In contrast, in the case of EBAGMA/PET, FT‐IR spectra indicate the total reactivity between the two components through the reaction of the epoxy group of EBAGMA with the PET terminal groups. SEM analysis shows that both master batches present two well‐interconnected phases.

     

In vitro fertilisation with frozen-thawed bovine sperm sexed by flow cytometry and validated for accuracy by real-time PCR

The methodologies used for cytometric sorting of fresh spermatozoa never allowed a clear resolution of sexual chromosomes of frozen-thawed semen. To devise a novel method for the production of bovine predefined sexed embryos using frozen-thawed semen, sorting efficiency of different protocols was studied using a new quantitative real-time PCR method to verify the purity of sexed semen. To this aim, after Percoll separation, frozen-thawed samples were stained at different temperatures and concentrations of Hoechst 33342 using a short-incubation time. The concentration of Hoechst 33342 of 500 mug/ml at a temperature of 37 degrees C provided good and stable fluorescence signals. Preventing the sperm clustering by adding 0.6% BSA in the 90% Percoll fraction led to X-bearing sperms purity of 91+/-2%. Thereafter, sorted sperms were used for in vitro fertilisation (IVF). Despite the lower cleavage rates reported in the sorted groups when compared with the control groups (40 vs 48%, P<0.01), blastocyst formation in the sorted and control groups was not different (27 vs 24% of the cleaved respectively). The PCR analysis of 30 blastocysts confirmed 26 embryos to be correctly sexed (87%). Transfer of two embryos per recipient into six synchronised heifers resulted in four pregnancies. Two abortions occurred at day 60, while two pregnancies went to term delivering two female calves. In conclusion, high purity and repeatability of sorting was obtained with frozen-thawed bull semen that was subsequently used for IVF giving rise to viable embryos and offspring. In addition, real-time PCR revealed to be an optimal support for these studies, providing a rapid and reliable estimation of flow cytometric efficiency.     

Structure and Morphology Development in Films of mLLDPE/LDPE Blends During Blowing

Summary: In this work the analysis of the structure orientation, morphology, relaxation time and optical properties of blown films of mLLDPE, LDPE and their blends were performed by using WAXD, SALS, AFM, DSC and rheological and haze tests. For mLLDPE film, the crystals do not present “a”‐axis orientation along the machine direction; a distinct spherulite like superstructure is seen. The film surface is very rough. The values of bulk and surface haze are higher than LDPE and blends, whereas the relaxation time is lower. For LDPE film the (110) planes are parallel and at same time twisted with respect to the layer of the film with the “a”‐axis well oriented along the machine direction. No spherulite superstructure is observed and the surface of the film is more regular. High values of relaxation time are observed. The surface haze is the predominant contribution to the total haze. For the blend films no clear and distinct spherulite structures are observed. The orientation degree increases with composition never approaching that of LDPE. The surface is very more regular and smooth than that of the pure polymers. The haze values are below the values of pure materials. It was underlined that bulk and surface morphology and orientation degree of the crystalline planes along the machine direction dictate the optical properties of the films. Moreover both orientation and morphology are defined by the PE molecular and melt rheology characteristics, processing conditions and blend composition.

Total, bulk and surface haze of mLLDPE/LDPE blend films as a function of composition.     

Fruit quality of Italian pomegranate (<Emphasis Type="Italic">Punica granatum</Emphasis> L.) autochthonous varieties

Pomegranate is getting an increasing attention for its health-promoting effects. Collection and characterization of plants of local sources has been performed, and five accessions have been propagated and cultivated in a collection field for extra situ investigations. Accessions differ for pomological traits and chemical composition. Three of them, MG1, MG2, and MG3, belong to typology with low-medium acidity and high sugar content, while the other two, Tordimonte A and B, belong to typology with high acidity. In the juice and in the peels’ extract of Tordimonte A accession a high level of punicalin has been found through chromatographic determinations, while the presence of punicalagin was found in the juice of accession MG1. The accessions MG1, MG2, and MG3 seem particularly suitable for direct commercialization of fruits due to the fruit traits and quality (sweet varieties), while Tordimonte A and B could be valuable for juice processing (sour varieties).     

Effects of hydrocolloids on chemical properties and cooking quality of gluten‐free spaghetti

The effects of different hydrocolloids on chemical composition and cooking quality of spaghetti based on maize and oat flours were investigated. Rheological and texture properties of the gluten‐free dough were also assessed. Amount of 2% of gellan gum, carboxymethylcellulose, pectin, agar, egg protein powder, tapioca starch, guar seed flour and chitosan were separately added to the formulation. The samples enriched with hydrocolloids generally showed a different rheological behaviour compared with the control samples. As regards chemical composition, spaghetti with chitosan showed a value of insoluble dietary fibres (8.0%) higher than the control ones (3.9%). Moreover, results highlighted that most hydrocolloids improved cooking quality and texture properties of spaghetti (adhesiveness, cooking loss, hardness), thus supporting their application in gluten‐free pasta.