269 research outputs found
Ultrastructural aspects of two different mast cell populations in human healthy gingival tissue
The results of our recent microscopy studies clearly have demonstrated the constant presence of numerous metachromatic cells in healthy human gingival connective tissue. Despite the great number of studies on mast cell population in many human organs (lung, skin, uterus, and bowel), at the present time few are the studies regarding the morphostructural aspects of mast cells in the human gingiva. The aim of this study was to assess by transmission electron microscopy the presence of mast cells in the healthy human gingiva and to characterize the ultrastructural aspects of mast cells populations. 30 specimens of human gingival tissue were collected from 30 patients with informed consent. The samples were prepared for T.E.M. examination. In all the ultrathin sections observed we detected numerous and ubiquitarious mast cells. These exhibited several morphological types of cytoplasmic granules with characteristic subgranular architectural variety in shape and density. This allowed us to divide mast cells into two groups: cells with granules consisted of compact coiled scrolls, fine granular material and lattice - grating configuration, and cells containing granules with discrete scrolls formed by more concentric lamellae and particulate structure. The two ultrastructural aspects observed correspond to McTC and McT of the international literature. Therefore in the human gingival connective tissue, like in other organs, two types of mast cells are clearly present. Surprisingly, the human gingival tissue shows, like the lung, McT as the prevailing subpopulation, in contrast to the skin, uterus and gastrointestinal submucosa where McTC prevail. Dans le cadre dâune Ă©tude sur la population cellulaire du tissu conjonctif gingival humain nous avons constatĂ©, en microscopie optique, la prĂ©sence constante de nombreuses cellules metachromatiques. Pour dĂ©finir la nature de telles cellules et pour en dĂ©terminer les aspects ultra-structuraux, nous avons Ă©tudiĂ© au microscope Ă©lectronique Ă transmission 30 biopsies du tissu gingival humain, cliniquement sain. Dans tous les Ă©chantillons examinĂ©s nous avons observĂ© de nombreux mastocytes dont le contenu granulaire nous est apparu caractĂ©risĂ© par un aspect « Ă particules » et « en rouleaux » ou bien, dans dâautres Ă©lĂ©ments cellulaires, par un aspect «en grillage». Les deux aspects ultrastructuraux dĂ©crits nous permettent de distinguer les mastocytes gingivaux en deux sous-populations, diffĂ©rentes comme lâont confirmĂ© plusieurs auteurs, selon la localisation anatomique, selon la structure intĂ©rieure et le contenu enzymatique des granules, et, enfin, selon la rĂ©action Ă des substances sĂ©crĂ©tagogues
Escherichia coli specific secretory IgA and cytokines in human milk from mothers of different ethnic groups resident in northern Italy.
Breast milk supplies many bioactive components. Neonates protection from pathogenic bacteria is mainly attributable to secretory IgA antibodies present in human milk in an amount depending on previous antigenic exposure. To bring new details into the field of immunological memory in secretory immunity, we evaluated the production of s-IgA specific for E. coli (E. coli s-IgA), and of proinflammatory (IL-6 and IL-8) or anti-inflammatory (IL-10) cytokines in the milk of mothers of different ethnic groups exposed in the past to poor conditions, but nowadays living in Italy in adequate conditions. Mothers from Italy, Africa, Asia and Eastern European Countries were included in the study. Anti- E. coli s-IgA, IL-6, IL-8 and IL-10 were determined by ELISA. Breast milk of all the foreign mothers presented higher levels of E. coli s-IgA than Italians, and for Asian and African mothers were significative (p=0.031 and p=0.015, respectively). Milk from women of Eastern European Countries revealed the highest IL-8 levels (p=0.026), while milk from Asian women presented the greatest concentration of IL-6 (p=0.04); however, the Africans reported the lowest concentrations of IL-10 (p=0.045). Since all the mothers had been living in Italy for some time, we believe that the presence of high levels of E. coli s-IgA, supported by high levels of pro-inflammatory cytokine, is part of a persisting immunological secretory memory
An Algebraic Approach to Linear-Optical Schemes for Deterministic Quantum Computing
Linear-Optical Passive (LOP) devices and photon counters are sufficient to
implement universal quantum computation with single photons, and particular
schemes have already been proposed. In this paper we discuss the link between
the algebraic structure of LOP transformations and quantum computing. We first
show how to decompose the Fock space of N optical modes in finite-dimensional
subspaces that are suitable for encoding strings of qubits and invariant under
LOP transformations (these subspaces are related to the spaces of irreducible
unitary representations of U(N)). Next we show how to design in algorithmic
fashion
LOP circuits which implement any quantum circuit deterministically. We also
present some simple examples, such as the circuits implementing a CNOT gate and
a Bell-State Generator/Analyzer.Comment: new version with minor modification
Considérations sur des tests de biocompatibilité «in vivo» et «in vitro» de quelques ciments endodontiques
The major goal endodontic therapy has been achieved by condensing filling materials into the root canal. Itâs not uncommon to find excess material into the periapical tissue. It therefore becomes obligatory to use fillings materials that have acceptable biocompatibility.The purpose of this investigation was to obtain a «toxicity profile» of some endodontics materials and to compare our observations to results present in literature.The gutta-percha and five endodontic filling cements were tested «in vivo» and «in vitro».The in vivo biocompatibility involved the placement of the test material in 10 mm. Teflon tubes with an outer diameter of 1.3 mm which were implanted subcutaneously into rats. The implants were left in situ for periods of 30 and 90 days. The «hemolysis test» is designed for «in vitro» evaluations.The istological examination showed different intensity and extent cellular responses. In some cases severe infiltration of inflammatory cell and areas with necrotis were seen.At conclusion, the endodontics material evaluated showed slight, moderate and severe reactions; therefore a different pattern in tissue response.Dans le domaine odontologique, ainsi que dans les autres branches de la mĂ©decine, lâexigence dâamĂ©liorer constamment la biocompatibilitĂ© des matĂ©riaux utilisĂ©s comme thĂ©rapeutique, surtout quand ces matĂ©riaux sont destinĂ©s à «cohabiter» longtemps avec lâorganisme, est de plus en plus ressentie.Dans le cadre dâun vaste programme de recherche, les auteurs se sont proposĂ© dâĂ©valuer la biocompatibilitĂ© rĂ©elle de quelques matĂ©riaux endodontiques choisis parmi les plus courants en Italie: câest dans ce but quâont Ă©tĂ© effectuĂ©s des tests «in vitro» (test de lâĂ©molyse dâhĂ©maties de lapin) et «in vivo» (selon la technique de Safavi et al. qui prĂ©voit lâimplantation du matĂ©riel Ă tester dans le tissu sous-cutanĂ© du rat).Les rĂ©sultats des tests ont dĂ©montrĂ© la variabilitĂ© du grade de biocompatibilitĂ© des matĂ©riaux soumis Ă lâexpĂ©rimentation. Certains matĂ©riaux nâont provoquĂ© en effet quâune lĂ©gĂšre rĂ©action des tissus, dâautres ont dĂ©terminĂ© la formation dâimportants infiltrats de cellules inflammatoires, de macrophages, de cellules gĂ©antes de corps Ă©tranger et de colliquation nĂ©crotique tissulaire
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
GEMS (Gamma Energy Marine Spectrometer) is a prototype of an autonomous radioactivity sensor for underwater measurements, developed in the framework for a development of a submarine telescope for neutrino detection (KM3NeT Design Study Project). The spectrometer is highly sensitive to gamma rays produced by 40K decays but it can detect other natural (e.g., 238U,232Th) and anthropogenic radio-nuclides (e.g., 137Cs). GEMS was firstly tested and calibrated in the laboratory using known sources and it was successfully deployed for a long-term (6 months) monitoring at a depth of 3200 m in the Ionian Sea (Capo Passero, offshore Eastern Sicily). The instrument recorded data for the whole deployment period within the expected specifications. This monitoring provided, for the first time, a continuous time-series of radioactivity in deep-sea.In press4.5. Studi sul degassamento naturale e sui gas petroliferiJCR Journalope
Les perles dâĂ©mail: aspects ultrastructuraux et hypothĂšses de morphogenĂšse
Five enamel pearls were examined by Scanning Electron Microscope. Some external pearls presented a bare enamel surface, others were covered by a thin layer of cementum.The enamel pearls showed irregular dystrofic enamel surface or a thin layer without structure, rows of irregular Tomeâs processes pits, enamel caps and focal holes. Some enamel pearls revealed little areas of enamel surface resorption like-resorbing lacunae with, in some cases, areas of tissue repair.La perle dâĂ©mail est une masse circulaire de matĂ©riel calcifiĂ© qui apparait le plus souvent dans la bifurcation des molaires et est attachĂ©e Ă la surface externe de la dent. Elle peut aussi ĂȘtre interne mais nous en savons trĂšs peu Ă ce sujet Ă cause du manque de publications. Cinq perles externes ont Ă©tĂ© observĂ©es au microscope Ă©lectronique Ă balayage.Tandis que certaines perles externes prĂ©sentent une surface Ă nu, dâautres sont recouvertes dâune fine couche de cĂ©ment qui les protĂšge. La surface de la perle dâĂ©mail prĂ©sente des zones irrĂ©guliĂšres dâhypominĂ©ralisation ou une fine couche sans structure, des rangĂ©es de petits trous irrĂ©guliers des processus de Tome et des trous focaux et des cratĂšres
SAS multipass interferometry for monitoring seabed deformation using a high-frequency imaging sonar
Abstract-. This paper presents the results of a two years project led and funded by Eni from 2008 to 2010 with the aim of supporting
the development and experimentation of innovative technology for environmental monitoring. The problem addressed is the precise estimate of possible altimetric variations of the seabed through long-term monitoring. The selected methodology consists in the application of repeat-track interferometry to high-resolution, high-frequency sonar data collected from an AUV during repeated surveys of a seafloor area of interest. The paper describes the experimental measurements conducted at sea, the SAS and interferometry methodologies developed, and the results obtained on artificial objects sitting on the seabed. The quality of the achieved focusing is analyzed. The achieved repeat-pass SAS interferograms are shown and analyzed. The coherence along time of the particular
kind of seabed (silty sand) characterizing the experimental area is presented and the utility of artificial reflectors for long-term SAS interferometry is discussed.Published673-6832.5. Laboratorio per lo sviluppo di sistemi di rilevamento sottomariniN/A or not JCRreserve
GEMS: Underwater spectrometer for long-term radioactivity measurements
GEMS (Gamma Energy Marine Spectrometer) is a prototype of an autonomous radioactivity sensor for underwater measurements, developed in the framework for a development of a submarine telescope for neutrino detection (KM3NeT Design Study Project). The spectrometer is highly sensitive to gamma rays produced by 40K decays but it can detect other natural (e.g., 238U,232Th) and anthropogenic radio-nuclides (e.g., 137Cs). GEMS was firstly tested and calibrated in the laboratory using known sources and it was successfully deployed for a long-term (6 months) monitoring at a depth of 3200 m in the Ionian Sea (Capo Passero, offshore Eastern Sicily). The instrument recorded data for the whole deployment period within the expected specifications. This monitoring provided, for the first time, a continuous time-series of radioactivity in deep-sea
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