890 research outputs found
Characterization of fine metal particles using hyperspectral imaging in automatic WEEE recycling systems
Waste from electric and electronic equipment (WEEE) represents the fastest growing waste stream in EU. The large amount and the high variability of electric and electronic products introduced every year in the market make the WEEE recycling process a complex task, especially considering that mechanical processes currently used by recycling companies are not flexible enough. In this context, hyperspectral imaging systems (HSI) can represent an enabling technology able to improve the recycling rates and the quality of the output products. This study shows the preliminary results achieved using a HSI technology in a WEEE recycling pilot plant, for the characterization of fine metal particles derived from WEEE shredding
High-throughput microfluidic platform for adherent single cells non-viral gene delivery
The widespread use of gene therapy as a therapeutic tool relies on the development of DNA-carrying vehicles devoid of any safety concerns. In contrast to viral vectors, non-viral gene carriers show promise in this perspective, although their low transfection efficiency leads to the necessity to carry out further optimizations. In order to overcome the limitations of traditional macroscale approaches, which mainly consist of time-consuming and simplified models, a microfluidic strategy has been developed to carry out transfection studies on single cells in a high-throughput and deterministic fashion. A single cell trapping mechanism has been implemented, based on the dynamic variation of fluidic resistances. For this purpose, we designed a round-shaped culture chamber integrated with a bottom trapping junction, which modulates the hydraulic resistance. Several layouts of the chamber were designed and computationally validated for optimization of the single cell trapping efficacy. The optimized chamber layout was integrated in a polydimethylsiloxane (PDMS) microfluidic platform presenting two main functionalities: (i) 288 chambers for trapping single cells, and (ii) a serial dilution generator with chaotic mixing properties, able to deliver to the chambers both soluble factors and non-diffusive particles (i.e., polymer/DNA complexes, polyplexes) under spatio-temporally controlled chemical patterns. The devices were experimentally validated and allowed the trapping of individual human glioblastoma–astrocytoma epithelial-like cells (U87-MG) with a trapping efficacy of about 40%. The cells were cultured within the device and underwent preliminary transfection experiments using 25 kDa linear polyethylenimine (lPEI)-based polyplexes, confirming the potentiality of the proposed platform for the future high-throughput screening of gene delivery vectors and for the optimization of transfection protocols
Microfluidic Platform for Adherent Single Cell High-Throughput Screening
This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.Traditionally, in vitro investigations on biology and physiology of cells rely on averaging the
responses eliciting from heterogeneous cell populations, thus being unsuitable for assessing individual cell
behaviors in response to external stimulations. In the last years, great interest has thus been focused on single
cell analysis and screening, which represents a promising tool aiming at pursuing the direct and deterministic
control over cause-effect relationships guiding cell behavior. In this regard, a high-throughput microfluidic
platform for trapping and culturing adherent single cells was presented. A single cell trapping mechanism
was implemented based on dynamic variation of fluidic resistances. A round-shaped culture chamber
(Φ=250μm, h=25μm) was conceived presenting two connections with a main fluidic path: (i) an upper wide
opening, and (ii) a bottom trapping junction which modulates the hydraulic resistance. Several layouts of the
chamber were designed and computationally validated for the optimization of the single cell trapping
efficacy. The optimized chamber layouts were integrated in a polydimethylsiloxane (PDMS) microfluidic
platform presenting two main functionalities: (i) 288 chambers for trapping single cells, and (ii) a chaoticmixer
based serial dilution generator for delivering both soluble factors and non-diffusive molecules under
spatio-temporally controlled chemical patterns. The devices were experimentally validated and allowed for
trapping individual U87-MG (human glioblastoma-astrocytoma epithelial-like) cells and culturing them up to
3 days
Mapping Asbestos-Cement Roofing with Hyperspectral Remote Sensing over a Large Mountain Region of the Italian Western Alps
The World Health Organization estimates that 100 thousand people in the world die every year from asbestos-related cancers and more than 300 thousand European citizens are expected to die from asbestos-related mesothelioma by 2030. Both the European and the Italian legislations have banned the manufacture, importation, processing and distribution in commerce of asbestos-containing products and have recommended action plans for the safe removal of asbestos from public and private buildings. This paper describes the quantitative mapping of asbestos-cement covers over a large mountainous region of Italian Western Alps using the Multispectral Infrared and Visible Imaging Spectrometer sensor. A very large data set made up of 61 airborne transect strips covering 3263 km2 were processed to support the identification of buildings with asbestos-cement roofing, promoted by the Valle d’Aosta Autonomous Region with the support of the Regional Environmental Protection Agency. Results showed an overall mapping accuracy of 80%, in terms of asbestos-cement surface detected. The influence of topography on the classification’s accuracy suggested that even in high relief landscapes, the spatial resolution of data is the major source of errors and the smaller asbestos-cement covers were not detected or misclassified
In vitro and in vivo evaluation of a new active heat moisture exchanger.
INTRODUCTION: In order to improve the efficiency of heat moisture exchangers (HMEs), new hybrid humidifiers (active HMEs) that add water and heat to HMEs have been developed. In this study we evaluated the efficiency, both in vitro and in vivo, of a new active HME (the Performer; StarMed, Mirandola, Italy) as compared with that of existing HMEs (Hygroster and Hygrobac; Mallinckrodt, Mirandola, Italy).
METHODS: We tested the efficiency by measuring the temperature and absolute humidity (AH) in vitro using a test lung ventilated at three levels of minute ventilation (5, 10 and 15 l/min) and at two tidal volumes (0.5 and 1 l), and in vivo in 42 patients with acute lung injury (arterial oxygen tension/fractional inspired oxygen ratio 283 +/- 72 mmHg). We also evaluated the efficiency in vivo after 12 hours.
RESULTS: In vitro, passive Performer and Hygrobac had higher airway temperature and AH (29.2 +/- 0.7 degrees C and 29.2 +/- 0.5 degrees C, [P < 0.05]; AH: 28.9 +/- 1.6 mgH2O/l and 28.1 +/- 0.8 mgH2O/l, [P < 0.05]) than did Hygroster (airway temperature: 28.1 +/- 0.3 degrees C [P < 0.05]; AH: 27 +/- 1.2 mgH2O/l [P < 0.05]). Both devices suffered a loss of efficiency at the highest minute ventilation and tidal volume, and at the lowest minute ventilation. Active Performer had higher airway temperature and AH (31.9 +/- 0.3 degrees C and 34.3 +/- 0.6 mgH2O/l; [P < 0.05]) than did Hygrobac and Hygroster, and was not influenced by minute ventilation or tidal volume. In vivo, the efficiency of passive Performer was similar to that of Hygrobac but better than Hygroster, whereas Active Performer was better than both. The active Performer exhibited good efficiency when used for up to 12 hours in vivo.
CONCLUSION: This study showed that active Performer may provide adequate conditioning of inspired gases, both as a passive and as an active device
Comparative chondrogenesis of human cells in a 3D integrated experimental/computational mechanobiology model
We present an integrated experimental–computational
mechanobiology model of chondrogenesis. The
response of human articular chondrocytes to culture medium
perfusion, versus perfusion associated with cyclic pressurisation,
versus non-perfused culture, was compared in a pellet
culture model, and multiphysic computation was used
to quantify oxygen transport and flow dynamics in the various
culture conditions. At 2 weeks of culture, the measured
cell metabolic activity and the matrix content in
collagen type II and aggrecan were greatest in the perfused+
pressurised pellets. The main effects of perfusion
alone, relative to static controls, were to suppress collagen
type I and GAG contents, which were greatest in
the non-perfused pellets. All pellets showed a peripheral
layer of proliferating cells, which was thickest in the perfused
pellets, and most pellets showed internal gradients
in cell density and matrix composition. In perfused pellets,
the computed lowest oxygen concentration was 0.075mM
(7.5% tension), the maximal oxygen flux was
477.5 nmol/m2/s and the maximal fluid shear stress, acting
on the pellet surface, was 1.8mPa (0.018 dyn/cm2). In the
non-perfused pellets, the lowest oxygen concentration was
0.003mM (0.3% tension) and the maximal oxygen flux was
102.4nmol/m2/s.Alocal correlationwas observed, between
the gradients in pellet properties obtained from histology,
and the oxygen fields calculated with multiphysic simulation.
Our results showup-regulation of hyalinematrix protein
production by human chondrocytes in response to perfusion
associated with cyclic pressurisation. These results could be
favourably exploited in tissue engineering applications
Generation of localized modes in an electrical lattice using subharmonic driving
We show experimentally and numerically that an intrinsic localized mode (ILM) can be stably produced (and experimentally observed) via subharmonic, spatially homogenous driving in the context of a nonlinear electrical lattice. The precise nonlinear spatial response of the system has been seen to depend on the relative location in frequency between the driver frequency, , and the bottom of the linear dispersion curve, . If lies just below , then a single ILM can be generated in a 32-node lattice, whereas when lies within the dispersion band, a spatially extended waveform resembling a train of ILMs results. To our knowledge, and despite its apparently broad relevance, such an experimental observation of subharmonically driven ILMs has not been previously reported
Expression of Distal-less, dachshund, and optomotor blind in Neanthes arenaceodentata (Annelida, Nereididae) does not support homology of appendage-forming mechanisms across the Bilateria
The similarity in the genetic regulation of
arthropod and vertebrate appendage formation has been
interpreted as the product of a plesiomorphic gene
network that was primitively involved in bilaterian
appendage development and co-opted to build appendages
(in modern phyla) that are not historically related
as structures. Data from lophotrochozoans are needed to
clarify the pervasiveness of plesiomorphic appendage forming
mechanisms. We assayed the expression of three
arthropod and vertebrate limb gene orthologs, Distal-less
(Dll), dachshund (dac), and optomotor blind (omb), in
direct-developing juveniles of the polychaete Neanthes
arenaceodentata. Parapodial Dll expression marks premorphogenetic
notopodia and neuropodia, becoming restricted
to the bases of notopodial cirri and to ventral
portions of neuropodia. In outgrowing cephalic appendages,
Dll activity is primarily restricted to proximal
domains. Dll expression is also prominent in the brain. dac
expression occurs in the brain, nerve cord ganglia, a pair
of pharyngeal ganglia, presumed interneurons linking a
pair of segmental nerves, and in newly differentiating
mesoderm. Domains of omb expression include the brain,
nerve cord ganglia, one pair of anterior cirri, presumed
precursors of dorsal musculature, and the same pharyngeal
ganglia and presumed interneurons that express dac.
Contrary to their roles in outgrowing arthropod and
vertebrate appendages, Dll, dac, and omb lack comparable
expression in Neanthes appendages, implying independent
evolution of annelid appendage development. We infer
that parapodia and arthropodia are not structurally or
mechanistically homologous (but their primordia might
be), that Dll’s ancestral bilaterian function was in sensory
and central nervous system differentiation, and that
locomotory appendages possibly evolved from sensory
outgrowths
SANIT\uc0 E CONTROLLO MERCANTILE ALLE BOCCHE DI CATTARO: IL LAZZARETTO DI CASTELNUOVO, 1700-1797
The Republic of Venice always had a focus on health policy. In the Adriatic Sea it joined
and crossed the policy of maritime and merchant control that traditionally the Serenissima claimed
to exercise on the so-called "Gulf of Venice". Maritime health inspections and checks were intended
not only for safeguarding public health, but also for recognizing, controlling and possibly
channelling trade flows. An interesting case-study in this regard is the Bay of Kotor, where the
needs of health and those of traffic control noticeably correlated. In order to carry out health and
commercial surveillance, a new Lazaretto was activated in the early 18th century at Castelnuovo,
recently reconquered by the Serenissima and very well placed for the controlling of the Mouths
Adducts of functionalized Graphene layers with Ag nanoparticles for Antimicrobial applications
Health and environmental impacts of multi-drug resistance (MDR) pathogens are becoming more and
more relevant nowadays, thus increasing the need of developing new, safe and effective
antimicrobials.
This research was focused on the synthesis, the characterization and the evaluation of the
antimicrobial and cytotoxic activity of hybrid nanomaterials made up through a simple and
sustainable functionalization of three carbon substrates, namely Graphite, Carbon black and Carbon
nanotubes, with a pyrrole moiety (SP) and silver nanoparticles (Ag-NP) [1, 2]. The adducts were
analyzed by means of thermogravimetric analyses (TGA), transmission electron microscopy
(HRTEM) and X-ray diffraction analyses (WAXD), which confirmed the successful functionalization
of raw materials. UV-vis spectroscopy and dynamic/electrophoretic light scattering (DLS/ELS)
provided information regarding carbon suspensions stability, particles sizes and surface charge.
Results from microbiological tests revealed an outstanding enhancement of the antimicrobial activity
promoted by the functionalization with Ag nanoparticles, maintaining unaltered the cytotoxic levels
exerted by not-functionalized materials. In the light of these results, a possible bactericidal
mechanism based on the synergy between mechanical and oxidative stresses at the bacterial
membrane level is proposed
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