823 research outputs found
Clayey materials from the Sierra de la Demanda Range (Spain): their potential as raw materials for the building ceramics industry
This work describes the possible use of thick Early Cretaceous clay deposits, which
occur in the southern sector of the Sierra de la Demanda range, as raw materials in the manufacture
of ceramic articles. The global mineralogical composition is characterized by high proportions of
phyllosilicates and quartz with variable quantities of feldspars, carbonates and hematite. The clay
mineralogy differentiates two types of raw materials: illitic clay and kaolinitic-illitic clay. A
granulometric distribution in the 2Ăż60 mm fraction, good behaviour during the drying stage and
acceptable results in firing tests confirmed that most samples can be utilized as raw material in the
building ceramics industry. The range of suitable firing temperatures for these materials is
950Ăż1000Ă«C, a temperature which needs to be raised for samples with a high percentage of kaolinite
and quartz. Moreover, other materials with abundant calcite (20Ăż30%) are suitable for use as
modifiers of some properties or colour
Finding and counting vertex-colored subtrees
The problems studied in this article originate from the Graph Motif problem
introduced by Lacroix et al. in the context of biological networks. The problem
is to decide if a vertex-colored graph has a connected subgraph whose colors
equal a given multiset of colors . It is a graph pattern-matching problem
variant, where the structure of the occurrence of the pattern is not of
interest but the only requirement is the connectedness. Using an algebraic
framework recently introduced by Koutis et al., we obtain new FPT algorithms
for Graph Motif and variants, with improved running times. We also obtain
results on the counting versions of this problem, proving that the counting
problem is FPT if M is a set, but becomes W[1]-hard if M is a multiset with two
colors. Finally, we present an experimental evaluation of this approach on real
datasets, showing that its performance compares favorably with existing
software.Comment: Conference version in International Symposium on Mathematical
Foundations of Computer Science (MFCS), Brno : Czech Republic (2010) Journal
Version in Algorithmic
Dexamethasone blocks the migration of the human neuroblastoma cell line SK-N-SH
Glucocorticoids (Gc) influence the differentiation of neural crestderived cells such as those composing sympathoadrenal tumors like pheochromocytomas, as well as neuroblastomas and gangliomas. In order to obtain further information on the effects of Gc on cells evolving from the neural crest, we have used the human neuroblastoma cell line SK-N-SH to analyze: 1) the presence and the binding characteristics of Gc receptors in these cells, 2) the effect of dexamethasone (Dex) on the migration of SK-N-SH cells, and 3) the effect of Dex on the organization of the cytoskeleton of SK-N-SH cells. We show that: 1) receptors that bind [ 3 H]-Dex with high affinity and high capacity (Kd of 9.6 nM, Bmax of 47 fmol/mg cytosolic protein, corresponding to 28,303 sites/cell) are present in cytosolic preparations of SK-N-SH cells, and 2) treatment with Dex (in the range of 10 nM to 1 µM) has an inhibitory effect (from 100% to 74 and 43%, respectively) on the chemotaxis of SK-N-SH cells elicited by fetal bovine serum. This inhibition is completely reversed by the Gc receptor antagonist RU486 (1 µM), and 3) as demonstrated by fluorescent phalloidin-actin detection, the effect of Dex (100 nM) on SK-NSH cell migration is accompanied by modifications of the cytoskeleton organization that appear with stress fibers. These modifications did not take place in the presence of 1 µM RU486. The present data demonstrate for the first time that Dex affects the migration of neuroblastoma cells as well as their cytoskeleton organization by interacting with specific receptors. These findings provide new insights on the mechanism(s) of action of Gc on cells originating in the neural crest
Endolysosomal targeting of a clinical chlorin photosensitiser for light-triggered delivery of nano-sized medicines
A major problem with many promising nano-sized biotherapeutics including macromolecules is that owing to their size they are subject to cellular uptake via endocytosis, and become entrapped and then degraded within endolysosomes, which can significantly impair their therapeutic efficacy. Photochemical internalisation (PCI) is a technique for inducing cytosolic release of the entrapped agents that harnesses sub-lethal photodynamic therapy (PDT) using a photosensitiser that localises in endolysosomal membranes. Using light to trigger reactive oxygen species-mediated rupture of the photosensitised endolysosomal membranes, the spatio-temporal selectivity of PCI then enables cytosolic release of the agents at the selected time after administration so that they can reach their intracellular targets. However, conventional photosensitisers used clinically for PDT are ineffective for photochemical internalisation owing to their sub-optimal intracellular localisation. In this work we demonstrate that such a photosensitiser, chlorin e6, can be repurposed for PCI by conjugating the chlorin to a cell penetrating peptide, using bioorthogonal ligation chemistry. The peptide conjugation enables targeting of endosomal membranes so that light-triggered cytosolic release of an entrapped nano-sized cytotoxin can be achieved with consequent improvement in cytotoxicity. The photoproperties of the chlorin moiety are also conserved, with comparable singlet oxygen quantum yields found to the free chlorin
Comparison of protein carbonyl (Pco), paraoxonase-1 (pon1) and c-reactive protein (crp) as diagnostic and prognostic markers of septic inflammation in dogs
Reliable diagnostic and prognostic markers of sepsis are lacking, but essential in veterinary medicine. We aimed to assess the accuracy of C-Reactive Protein (CRP), protein carbonyls (PCO) and paraoxonase-1 (PON1) in differentiating dogs with sepsis from those with sterile inflammation and healthy ones, and predict the outcome in septic dogs. These analytes were retrospectively evaluated at admission in 92 dogs classified into healthy, septic and polytraumatized. Groups were compared using the Kruskal–Wallis test, followed by a Mann–Whitney U test to assess differences between survivors and non-survivors. Correlation between analytes was assessed using the Spearman’s test, and their discriminating power was assessed through a Receiver Operating Characteristic (ROC) curve. PON1 and CRP were, respectively, significantly lower and higher in dogs with sepsis compared with polytraumatized and clinically healthy dogs (p < 0.001 for both the analytes), and also in dogs with trauma compared with healthy dogs (p = 0.011 and p = 0.017, respectively). PCO were significantly increased in septic (p < 0.001) and polytraumatized (p < 0.005) as compared with healthy dogs. PON1 and CRP were, respectively, significantly lower and higher in dogs that died compared with survivors (p < 0.001 for both analytes). Ultimately, evaluation of CRP and PON1 at admission seems a reliable support to diagnose sepsis and predict outcomes
Concomitant infections with canine parvovirus type 2 and intracellular tick-borne pathogens in two puppy dogs
In this report the concomitant infection with canine parvovirus type 2 (CPV-2), Hepatozoon canis and Ehrlichia canis in two puppy dogs from Southern Italy is described. Dogs were referred to a veterinary university hospital for the acute onset of lethargy and gastrointestinal signs. A complete clinical and clinicopathological evaluation was carried out and the multiple infection was confirmed by microscopic detection of inclusion bodies in peripheral blood smear, rapid immunoenzymatic tests, indirect fluorescent antibody tests, and molecular assays. Sequence analysis revealed that the CPV-2 identified belonged to the 2c variant and had amino acid residues in the predicted VP2 protein typical of "Asian-like" strains widespread in Asia and occasionally reported in Romania, Nigeria and Italy, particularly in the region of Sicily. Numerous monocytes were infected by both H. canis gamonts and E. canis morulae, suggesting that this co-infection is not accidental and that E. canis preferably infects those cells parasitized by H. canis. The clinical presentation of these animals was severe but supportive cares associated with early etiological therapy allowed a good prognosis. Movement of puppies from geographic areas where vector-borne pathogens are endemic must be carefully evaluated and core vaccinations and ectoparasite prevention treatments must be rigorously adopted
Deposits, composition and technological behavior of fluxes for ceramic tiles
The ceramic tile industry is a big consumer of feldspathic rocks and further raw materials able to act as flux during firing. This demand is currently fed with the recourse to a wide range of sources of igneous, sedimentary, metamorphic and metasomatic origin. The main geological features of flux deposits actually exploited by the ceramic industry are reviewed. The chemical and mineralogical composition is described to have a general picture of raw fluxes as well as average data and compositional perimeter for deposits of different origin. Overall beneficiation routes are drawn to trace the compositional path from deposit to commercial flux. The technological behavior in tile-making is shortly overviewed and new experimental data are provided on flux fusibility (by hot-stage microscopy). A chart is proposed to discriminate fluxes according to different fusibility
Approximating Clustering of Fingerprint Vectors with Missing Values
The problem of clustering fingerprint vectors is an interesting problem in
Computational Biology that has been proposed in (Figureroa et al. 2004). In
this paper we show some improvements in closing the gaps between the known
lower bounds and upper bounds on the approximability of some variants of the
biological problem. Namely we are able to prove that the problem is APX-hard
even when each fingerprint contains only two unknown position. Moreover we have
studied some variants of the orginal problem, and we give two 2-approximation
algorithm for the IECMV and OECMV problems when the number of unknown entries
for each vector is at most a constant.Comment: 13 pages, 4 figure
Novel sequence variants of viral hexon and fibre genes in two dogs with canine adenovirus type 1-associated disease
There is little information on sequence variation of canine adenovirus type 1 (CAdV-1), the aetiological agent of infectious canine hepatitis (ICH). This study reports hexon and fibre gene sequence variants of CAdV-1 in a dog with systemic ICH and a dog with the ocular form of the disease (\ue2\u80\u98blue eye\ue2\u80\u99) in Northern Italy in 2013. One of the sequence variants matched a CAdV-1 fox sequence previously detected in Italy
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