347 research outputs found

    Microplastics in deep water : a combined GC-MS e FT-IR approach

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    Microplastics are water-insoluble, solid polymer particles that are 645\u202fmm in size. A lower size boundary has not been defined, but particles below 1\u202f\u3bcm are usually referred to as nanoplastics rather than microplastics. The ubiquity of microplastics of all sizes in surface water, groundwater and wastewater has raised the question if pollution of drinking water occurs and to date, few studies indeed described the presence of this new contaminant in tap and bottled water. Toxicity it is not yet known, they might cause local inflammations in the gut, but a transport into organs might occur. As a final problem in this field, microplastics in the environment are difficult to sample, to identify and standardized methods do not exist. For this reason, we have been involved in a research project finalized to the definition of a protocol strategy for sampling and analysis of microplastics in drinking waters, coming from deep water wells, in the networks of three large cities in the Northern part of Italy. The project is on going and presently two groups of deep water samples have been collected in the city of Milano and Brescia, before and after the treatment stages used for the urban network. Great attention has been paid to sampling and extraction steps as microplastic contamination, in this kind of samples, is expected to be very low and contamination during sampling might occur through air or materials. Analytical methods have been defined for the detection of main microplastic contamination, like PE/PP, PS, PA, PVC e PET residues > 1 \ub5m. Samples have been analysed first by a non-destructive approach using a Spotlight 200i microscope equipped with a \ub5ATR probe and coupled to an FT-IR spectrophotometer, followed by a mass spectrometric characterization of the polymers by a solid phase microextration (SPME) GC-MS of thermal decomposition products (TED) of microplastic residues. Results will be presented and critically discussed

    Transducer Arrays over A²B Networks in Industrial and Automotive Applications: Clock Propagation Measurements

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    Advanced automotive applications like Active Noise Cancellation (ANC) and Individual Listening Zones (ILZ) require a high number of transducers (i.e., microphones, accelerometers, and loudspeakers) usually arranged as arrays. Transducer arrays are widely employed in several applications besides automotive field, such as teleconferencing systems, industrial and civil monitoring of noise and vibrations. Automotive Audio Bus ( A2B ) is an audio transport protocol that solves the latest requirements of automotive and industrial fields. A2B allows transporting up to 32 channels in a multi-node daisy chain network and guarantees synchronization and low deterministic latency. This paper aims to develop a clock propagation model of an A2B network composed by transducer arrays. This model will be useful to evaluate the impact of the bus on the array performance. Firstly, a theoretical description of the A2B protocol and jitter analysis is provided. It follows a description of the jitter measures carried out on the clocks distributed along the A2B network. Lastly, latency introduced by nodes of the network is investigated

    First evidence of protein modulation by polystyrene microplastics in a freshwater biological model

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    Microplastics (MPs)are now one of the major environmental problems due to the large amount released in aquatic and terrestrial ecosystems, as well as their diffuse sources and potential impacts on organisms and human health. Still the molecular and cellular targets of microplastics\u2019 toxicity have not yet been identified and their mechanism of actions in aquatic organisms are largely unknown. In order to partially fill this gap, we used a mass spectrometry based functional proteomics to evaluate the modulation of protein profiling in zebra mussel (Dreissena polymorpha), one of the most useful freshwater biological model. Mussels were exposed for 6 days in static conditions to two different microplastic mixtures, composed by two types of virgin polystyrene microbeads (size = 1 and 10 \u3bcm)each one. The mixture at the lowest concentration contained 5 7 105 MP/L of 1 \u3bcm and 5 7 105 MP/L of 10 \u3bcm, while the higher one was arranged with 2 7 106 MP/L of 1 \u3bcm and 2 7 106 MP/L of 10 \u3bcm. Proteomics\u2019 analyses of gills showed the complete lack of proteins\u2019 modulation after the exposure to the low-concentrated mixture, while even 78 proteins were differentially modulated after the exposure to the high-concentrated one, suggesting the presence of an effect-threshold. The modulated proteins belong to 5 different classes mainly involved in the structure and function of ribosomes, energy metabolism, cellular trafficking, RNA-binding and cytoskeleton, all related to the response against the oxidative stress

    Human Adipose-Derived Stem Cell-Conditioned Medium Promotes Vascularization of Nanostructured Scaffold Transplanted into Nude Mice

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    Several studies have been conducted on the interaction between three-dimensional scaffolds and mesenchymal stem cells for the regeneration of damaged tissues. Considering that stem cells do not survive for sufficient time to directly sustain tissue regeneration, it is essential to develop cell-free systems to be applied in regenerative medicine. In this work, by in vivo experiments, we established that a collagen-nanostructured scaffold, loaded with a culture medium conditioned with mesenchymal stem cells derived from adipose tissue (hASC-CM), exerts a synergic positive effect on angiogenesis, fundamental in tissue regeneration. To this aim, we engrafted athymic BALB-C nude mice with four different combinations: scaffold alone; scaffold with hASCs; scaffold with hASC crude protein extract; scaffold with hASC-CM. After their removal, we verified the presence of blood vessels by optical microscopy and confirmed the vascularization evaluating, by real-time PCR, several vascular growth factors: CD31, CD34, CD105, ANGPT1, ANGPT2, and CDH5. Our results showed that blood vessels were absent in the scaffold grafted alone, while all the other systems appeared vascularized, a finding supported by the over-expression of CD31 and CDH5 mRNA. In conclusion, our data sustain the capability of hASC-CM to be used as a therapeutic cell-free approach for damaged tissue regeneration

    Transducer Arrays Over A²B Networks in Industrial and Automotive Applications: Clock Propagation Measurements

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    Advanced automotive applications like Active Noise Cancellation (ANC) and Individual Listening Zones (ILZ) require a high number of transducers (i.e., microphones, accelerometers, and loudspeakers) usually arranged as arrays. Transducer arrays are widely employed in several applications besides automotive field, such as teleconferencing systems, industrial and civil monitoring of noise and vibrations. Automotive Audio Bus ( A2B\text{A}^{2}\text{B} ) is an audio transport protocol that solves the latest requirements of automotive and industrial fields. A2B\text{A}^{2}\text{B} allows transporting up to 32 channels in a multi-node daisy chain network and guarantees synchronization and low deterministic latency. This paper aims to develop a clock propagation model of an A2B\text{A}^{2}\text{B} network composed by transducer arrays. This model will be useful to evaluate the impact of the bus on the array performance. Firstly, a theoretical description of the A2B\text{A}^{2}\text{B} protocol and jitter analysis is provided. It follows a description of the jitter measures carried out on the clocks distributed along the A2B\text{A}^{2}\text{B} network. Lastly, latency introduced by nodes of the network is investigated

    Effect of fluxinin meglumin, recombinant bovine somatotropin and/or human chorionic gonadotropin in reducing embryo mortality in nelore cows (Bos taurus indicus).

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    Pharmacologic strategies have been employed to reduce the embryonic mortality in cattle (2, 4)

    Follicular dynamics and pregnancy rates in Bos taurus x Bos indicus embryo transfer recipients treated to increase plasma progesterone concentrations

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    Abstract The aim of this study was to evaluate the effects of GnRH, LH, hCG or exogenous progesterone administration on plasma progesterone concentrations and pregnancy rates following embryo transfer in Bos taurus x Bos indicus cross-bred heifers. In Experiment 1, animals with body condition scores 3.5 (1 to 5 scale) were synchronized with two injections of a prostaglandin F2 analog 13 days apart. Heifers detected in estrus (day 0; n = 37) were randomly assigned on day 7 to receive one of five treatments: Control (2 ml saline im; n = 6), GnRH (10 g Buserelin im; n = 8), hCG (1500 IU Chorulon im; n = 8), LH (25 mg pLH im; n = 7) or a CIDR-B device for 13 days (n = 8). Ovarian ultrasonography was performed daily from day 6 until the subsequent estrus. Heifers in the GnRH, hCG and LH groups were evaluated every 12 h between days 7 and 9 to confirm ovulation of the first-wave dominant follicle. Blood samples were collected daily for determination of P4 levels. Estrus detection was performed daily with the aid of androgenized cows. Ovulation rate for the first wave dominant follicle was 100% for heifers treated with GnRH, hCG and LH. Between days 13 and 17, the mean diameter of original CLs, diameter of accessory CLs and P4 concentrations were greater in heifers treated with hCG than in heifers in all other groups (P < 0.05). Duration of the luteal phase (number of days with a P4 concentration 1.0 ng/ml) was similar in hCG (14.3 ± 0.6), LH (13.4 ± 0.6), GnRH (13.4 ± 0.4), CIDR-B (14.5 ± 0.2) and Control (12.8 ± 0.5) groups. In Experiment 2, animals were kept on a grazing regimen at commercial farms in Brazil and were synchronized with one injection of a prostaglandin F2 analog. The same hormonal treatments as in Experiment 1 were given on day 7 after estrus at the time of transfer of frozen/thawed embryos to Bos taurus x Bos indicus recipients (n = 485). Pregnancy rates were higher in GnRH-(53.5%; 53/99) and hCG-(51.0%; 49/96) treated heifers (P < 0.05) than in control heifers (28.6%; 28/98), but were similar to heifers treated with CIDR devices (41.1%; 39/95) and LH (45.4%; 44/97). It was concluded that the improvement in conception rates in hCG treated Bos taurus x Bos indicus cross-bred heifers receiving frozen/thawed embryos were due to both P4-dependent and P4-independent mechanisms
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