A tree-decomposed transfer matrix for computing exact Potts model partition functions for arbitrary graphs, with applications to planar graph colourings

Combining tree decomposition and transfer matrix techniques provides a very general algorithm for computing exact partition functions of statistical models defined on arbitrary graphs. The algorithm is particularly efficient in the case of planar graphs. We illustrate it by computing the Potts model partition functions and chromatic polynomials (the number of proper vertex colourings using Q colours) for large samples of random planar graphs with up to N=100 vertices. In the latter case, our algorithm yields a sub-exponential average running time of ~ exp(1.516 sqrt(N)), a substantial improvement over the exponential running time ~ exp(0.245 N) provided by the hitherto best known algorithm. We study the statistics of chromatic roots of random planar graphs in some detail, comparing the findings with results for finite pieces of a regular lattice.Comment: 5 pages, 3 figures. Version 2 has been substantially expanded. Version 3 shows that the worst-case running time is sub-exponential in the number of vertice

Ultrasound delivery of Surface Enhanced InfraRed Absorption active gold-nanoprobes into fibroblast cells: a biological study via Synchrotron-based InfraRed microanalysis at single cell level

Ultrasound (US) induced transient membrane permeabilisation has emerged as a hugely promising tool for the delivery of exogenous vectors through the cytoplasmic membrane, paving the way to the design of novel anticancer strategies by targeting functional nanomaterials to specific biological sites. An essential step towards this end is the detailed recognition of suitably marked nanoparticles in sonoporated cells and the investigation of the potential related biological effects. By taking advantage of Synchrotron Radiation fourier transform infrared micro-spectroscopy (SR-microftiR) in providing highly sensitive analysis at the single cell level, we studied the internalisation of a nanoprobe within fibroblasts (NIH-3T3) promoted by low-intensity US. To this aim we employed 20 nm gold nanoparticles conjugated with the IR marker 4-aminothiophenol. The significant Surface Enhanced Infrared Absorption provided by the nanoprobes, with an absorbance increase up to two orders of magnitude, allowed us to efficiently recognise their inclusion within cells. Notably, the selective and stable SR- microftiR detection from single cells that have internalised the nanoprobe exhibited clear changes in both shape and intensity of the spectral profile, highlighting the occurrence of biological effects. Flow cytometry, immunofluorescence and murine cytokinesis-block micronucleus assays confirmed the presence of slight but significant cytotoxic and genotoxic events associated with the US-nanoprobe combined treatments. our results can provide novel hints towards US and nanomedicine combined strategies for cell spectral imaging as well as drug delivery-based therapies

Chromosome numbers for the Italian flora: 9

In this contribution, new chromosome data obtained on material collected in Italy are presented. It includes counts from six populations of three taxa within the genus Pulmonaria, two of which are endemic to Italy (P. vallarsae subsp. apennina and P. vallarsae subsp. vallarsae); the other is the widespread European P. officinalis. In addition, two counts from Potentilla detommasii and Stachys thirkei, two eastern Mediterranean species, are also reported

Fixture-abutment connection surface and micro-gap measurements by 3D micro-tomographic technique analysis

X-ray micro-tomography (micro-CT) is a miniaturized form of conventional computed axial tomography (CAT) able to investigate small radio-opaque objects at a-few-microns high resolution, in a non-destructive, non-invasive, and tri-dimensional way. Compared to traditional optical and electron microscopy techniques, which provide two-dimensional images, this innovative investigation technology enables a sample tri-dimensional analysis without cutting, coating or exposing the object to any particular chemical treatment. X-ray micro-tomography matches ideal 3D microscopy features: the possibility of investigating an object in natural conditions and without any preparation or alteration; non-invasive, non-destructive, and sufficiently magnified 3D reconstruction; reliable measurement of numeric data of the internal structure (morphology, structure and ultra-structure). Hence, this technique has multi-fold applications in a wide range of fields, not only in medical and odontostomatologic areas, but also in biomedical engineering, materials science, biology, electronics, geology, archaeology, oil industry, and semi-conductors industry. This study shows possible applications of micro-CT in dental implantology to analyze 3D micro-features of dental implant to abutment interface. Indeed, implant-abutment misfit is known to increase mechanical stress on connection structures and surrounding bone tissue. This condition may cause not only screw preload loss or screw fracture, but also biological issues in peri-implant tissues

Square-planar vs. Trigonal bipyramidal geometry in Pt(II) complexes containing triazole-based glucose ligands as potential anticancer agents

This article describes the synthesis, characterization, and biological activity of novel square-planar cationic platinum(II) complexes containing glucoconjugated triazole ligands and a comparison with the results obtained from the corresponding five-coordinate complexes bearing the same triazole ligands. Stability in solution, reactivity with DNA and small molecules of the new compounds were evaluated by NMR, fluorescence, and UV–vis absorption spectroscopy, together with their cytotoxic action against pairs of immortalized and tumorigenic cell lines. The results show that the square-planar species exhibit greater stability than the corresponding five-coordinate ones. Furthermore, although the square-planar complexes are less cytotoxic than the latter ones, they exhibit a certain selectivity. These results simultaneously demonstrate that overall stability is a fundamental prerequisite for preserving the performance of the agents and that coordinative saturation constitutes a point in favor of their biological action

Contributi per una flora vascolare di Toscana. IV (181-246)

New localities and/or confirmations concerning 66 specific and subspecific plant taxa of Tuscan vascular flora, belonging to 55 genera and 33 families are presented: Acanthus (Acanthaceae), Chenopodium (Amaranthaceae), Oenanthe, Pteroselinum (Apiaceae), Melomphis (Asparagaceae), Anthemis , Artemisia, Carduus (Asteraceae), Myosotis (Boraginaceae), Alyssum, Lepidium, Malcolmia (Brassicaceae), Phyteuma (Campanulaceae), Centranthus, Lonicera, Valerianella (Caprifoliaceae), Cerastium, Sagina, Silene (Caryophyllaceae), Helianthemum (Cistaceae), Carex, Cyperus, Rhynchospora, Schoenoplectus (Cyperaceae), Chamaesyce (Euphorbiaceae), Astragalus, Vicia (Fabaceae), Hypericum (Hypericaceae), Freesia, Iris, Romulea (Iridaceae), Stachys (Lamiaceae), Gagea (Liliaceae), Montia (Montiaceae), Ludwigia (Onagraceae), Anacamptis, Barlia, Corallorhiza (Orchidaceae), Orobanche, Rhinanthus (Orobanchaceae), Oxalis (Oxalidaceae), Linaria, Veronica (Plantaginaceae), Holcus, Phleum, Rostraria (Poaceae), Rumex (Polygonaceae), Lysimachia (Primulaceae), Ranunculus (Ranunculaceae), Alchemilla, Rosa (Rosaceae), Ruppia (Ruppiaceae), Solanum (Solanaceae), Urtica (Urticaceae), Asphodeline (Xanthorrhoeaceae). In the end, the conservation status of the units and eventual protection of the cited biotopes are discussed

Contributi per una flora vascolare di Toscana. II (86-142)

New localities and/or confirmations concerning 57 specific and subspecific plant taxa of Tuscan vascular flora, belonging to 48 genera and 32 families: Alisma (Alismataceae), Amaranthus (Amaranthaceae), Spirodela (Araceae), Paradisea (Asparagaceae), Asplenium (Aspleniaceae), Artemisia, Eclipta, Senecio, Silybum (Asteraceae), Cardamine, Diplotaxis (Brassicaceae), Petrorhagia , Silene, Spergula, (Caryophyllaceae), Sedum (Crassulaceae), Cyperus, Fimbristylis, Isolepis (Cyperaceae), Lathyrus, Ornithopus, Trifolium, Vicia (Fabaceae), Fumaria (Fumariaceae), Erodium (Geraniaceae), Hydrocharis (Hydrocharitaceae), Crocus (Iridaceae), Isoëtes (Isoëtaceae), Juncus (Juncaceae), Clinopodium, Mentha (Lamiaceae), Linun (Linaceae), Lythrum, Peplis (Lythraceae), Menyanthes (Menyanthaceae), Montia (Montiaceae), Spiranthes (Orchidaceae), Oxalis (Oxalidaceae), Callitriche, Kickxia, Veronica (Plantaginaceae), Lolium, Vulpia (Poaceae), Polypodium (Polypodiaceae), Lysimachia (Primulaceae), Cheilanthes (Pteridaceae), Ranunculus (Ranunculaceae), Aphanes (Rosaceae), Thymelaea (Thymelaeaceae). In the end, the conservation status of the units and eventual protection of the cited biotopes are discussed

Contributi per una flora vascolare di Toscana. III (143-180)

New localities and/or confirmations concerning 38 specific and subspecific plant taxa of Tuscan vascular flora, belonging to 29 genera and 23 families: Orlaya (Apiaceae), Ornithogalum (Asparagaceae), Tolpis (Asteraceae), Symphytum (Boraginaceae), Hornungia, Lepidium (Brassicaceae), Centranthus (Caprifoliaceae), Silene, Stellaria (Caryophyllaceae), Carex (Cyperaceae), Dryopteris (Dryopteridaceae), Monotropa (Ericaceae), Astragalus (Fabaceae), Hypericum (Hypericaceae), Crocus (Iridaceae), Isoëtes (Isoëtaceae), Clinopodium (Lamiaceae), Orobanche (Orobanchaceae), Osmunda (Osmundaceae), Linaria (Plantaginaceae), Arrhenatherum, Crypsis, Hyparrhenia, Rostraria, Vulpia (Poaceae), Groenlandia (Potamogetonaceae), Cheilanthes (Pteridaceae), Valantia (Rubiaceae), Viola (Violaceae). In the end, the conservation status of the units and eventual protection of the cited biotopes are discussed

Contributi per una flora vascolare di Toscana. VI (320-356)

New localities and/or confirmations concerning 37 specific and subspecific plant taxa of Tuscan vascular flora, belonging to 35 genera and 25 families are presented: Amaranthus, Atriplex (Amaranthaceae), Leucojum (Amaryllidaceae), Centaurea, Cota, Echinops, Hieracium, Senecio (Asteraceae), Alyssum, Matthiola (Brassicaceae), Euonymus (Celastraceae), Bulliarda, Sedum (Crassulaceae), Carex, Schoenoplectus (Cyperaceae), Euphorbia (Euphorbiaceae), Erodium (Geraniaceae), Gladiolus (Iridaceae), Lavandula (Lamiaceae), Lythrum (Lyhraceae), Montia (Montiaceae), Epipactis (Orchidaceae), Orobanche (Orobanchaceae), Osmunda (Osmundaceae), Glaucium (Papaveraceae), Gratiola, Plantago (Plantaginaceae), Glyceria, Paspalum (Poaceae), Polygala (Polygalaceae), Soldanella (Primulaceae), Anogramma (Pteridaceae), Staphysagria (Ranunculaceae), Malus (Rosaceae), Urtica (Urticaceae). In the end, the conservation status of the units and eventual protection of the cited biotopes are discussed