2,897 research outputs found
Treponema denticola in Disseminating Endodontic Infections
Treponema denticola is a consensus periodontal pathogen that has recently been associated with endodontic pathology. In this study, the effect of mono-infection of the dental pulp with T. denticola and with polymicrobial “red-complex” organisms (RC) (Porphyromonas gingivalis, Tannerella forsythia, and T. denticola) in inducing disseminating infections in wild-type (WT) and severe-combined-immunodeficiency (SCID) mice was analyzed. After 21 days, a high incidence (5/10) of orofacial abscesses was observed in SCID mice mono-infected with T. denticola, whereas abscesses were rare in SCID mice infected with the red-complex organisms or in wildtype mice. Splenomegaly was present in all groups, but only mono-infected SCID mice had weight loss. T. denticola DNA was detected in the spleen, heart, and brain of mono-infected SCID mice and in the spleen from mono-infected wild-type mice, which also had more periapical bone resorption. The results indicate that T. denticola has high pathogenicity, including dissemination to distant organs, further substantiating its potential importance in oral and linked systemic conditions
Multibaseline phase unwrapping for InSAR topography estimation
Multibaseline Synthetic Aperture Radar (SAR) Interferometry (INSAR) can be successfully exploited for automatic phase unwrapping and high quality Digital Elevation Model (DEM) reconstruction. The information coming from several
interferograms with different baselines increases the elevation ambiguity interval and allows automatic phase unwrapping. The height of each pixel in the image is
considered as a random variable: a Maximum-Likelihood (ML) estimation of the height is carried out by exploiting the probability density function of the interferometric phase, that depends on the local coherence value. After phase unwrapping is possible to combine all the information available, getting a combined DEM that is more reliable than each single DEM. Results obtained using ERS-1/2 SAR data gathered over Vesuvius and Etna are presented. In both cases an accuracy better than 8 meters was obtained
Observation of electro-activated localized structures in broad area VCSELs
We demonstrate experimentally the electro-activation of a localized optical
structure in a coherently driven broad-area vertical-cavity surface-emitting
laser (VCSEL) operated below threshold. Control is achieved by
electro-optically steering a writing beam through a pre-programmable switch
based on a photorefractive funnel waveguide.Comment: 5 Figure
An efficient and versatile synthesis of new Trojan-horse cephalosporins
A useful synthesis of new dual-action cephalosporins is reported. These molecules could represent a fascinating tool for treatment of bacterial infectious diseases, since they display a possible inhibitor activity towards beta-lactamase-expressing bacteria. The major advantage of this 3-step synthetic approach lies in its versatility, which allows the systematic preparation of a wide pool of new molecules
HyFlex EDM rotary Ni-Ti prototypes: the effect of an innovative machining technology on Ni-Ti wear
Aim. HyFlex EDM files were recently introduced pre- senting an innovative electro discharge machining (EDM) process of fabrication. The aim of this study was to evalua- te the surface and microstructural alterations of new and in vitro used HyFlex EDM Ni-Ti rotary prototypes.
Methods. The surface and microstructural characteristi- cs of 15 new HyFlex EDM instruments were analyzed by ESEM equipped with energy dispersive x-ray spectropho- tometry (EDS) and optical metallographic imaging. Instru- ments were subjected to instrumentation tests on severely curved root canals (ranging between 50° and 70°) of ex- tracted multi-rooted teeth. Once that canal patency was verified with a #10 K-file, the working length was determi- ned by subtracting 1mm. HyFlex EDM files were used with a 16:1 reduction handpiece X-Smart (Dentsply Maillefer, Baillagues, Switzerland) following the manufacture’s direc- tion, at 500 rpm and 2.5Ncm, with slightly apical pressure and pecking motion. The operative sequence was: 25/12 at 2/3 of the WL, 10/05 and 25/08 at WL. Irrigation was per- formed at every change of instrument, with a total amount of3mlof5%NaOCland3mlof10%EDTA(Ogna,Mug- giò, Italy). Each instrument was used in 10 curved canals, washed in an ultrasonic bath containing detergent for 10 min and then autoclaved at 134°C. Surface and microstruc- tural characterizations were repeated on used instruments at same points and with same angulations to compare the pre- and postoperative micrographs, in order to verify the appearance of fractures, unwinding, microcracks, blade di- sruption and tip deformation.
Results. Surface and microstructural characteriza- tion of new instruments revealed the typical features of a NiTi ED-Machined alloy with an irregular and “craters-like” surface. High magnification microgra- phs disclosed a non-uniform structure were pits, po- res and voids caused the peculiar aspect of a “rough- spark-machined” surface. No fractures were registered during instrumentation of curved canals. Surface and microstructural characterization of used files revealed no wear and no degradation of the 25.12 and 25.08 files. The tip segment was confirmed as the most me- chanically stressed portion of 10.05 prototypes. All the instruments, after several uses, well-preserved the “craters-like” irregular surface without cutting edge al- terations. The metallographic inspection on the cross section of brand new HyFlex EDM files showed an homogeneous martensitic phase. The microstructure appeared uniform from the surface to the bulk, and no microcracks or defect were identified, even at high optical magnification (1000X).
Conclusion. Unaltered spark-machined surface and low microstructural degradation are the main features of recently introduced HyFlex EDM. Caution would be re- commended regarding reuse of small HyFlex EDM files. Instruments exhibited a safe in vitro use in presence of severely curved canals
Cardiorespiratory and gastrointestinal parasites of dogs in north-west Italy
The present study was conducted to evaluate the prevalence of gastrointestinal and cardio-respiratory
parasites in dogs in Liguria (northwest Italy) which is a region that has scarcely been studied. A
total of 450 dogs (260 males and 190 females) were enrolled in the study from 2009 and 2013. All
dogs lived in a rural or semi-rural environment in the provinces of Imperia (n = 352) or Savona (n =
98), Liguria. Coprological examinations showed that 197 dogs (43.8 %, CI 38.7-48.9 %) were infected
by parasites. Specifi cally, 3.3 % of the dogs presented only cardio-respiratory species, 32.4 %
only intestinal species, and 8.0 % presented a mixed infection.
The most frequent intestinal parasites were Toxocara canis (20 %), Trichuris vulpis (17.8 %), Ancylostomatidae
(12 %), Coccidia (2.7 %), Aonchotheca putorii (1.8 %) and Toxascaris leonina (1.8 %).
The cardio-respiratory species found were Eucoleus aerophilus (9.6 %), Eucoleus boehmi (1.6 %),
Angiostrongylus vasorum (0.7 %), and Crenosoma vulpis (0.2 %). A total of 116 dogs (25.8 %) were
parasitized by a single species, multiple infections were observed in 81 dogs (18.0 %) up to a six-order
infection.
This preliminary study highlighted that the prevalence of intestinal parasites in investigated area is
high. Cardio respiratory parasites were detected in an area that has not been investigated before.
The creation of a more extensive sampling programme of the area, on a provincial basis in order to
build a more detailed map of prevalences for different species of dog parasites throughout Liguria, a
more extensive sampling programme of the area needs to be created - ideally for each province
A few remarks on integral representation for zonal spherical functions on the symmetric space
The integral representation on the orthogonal groups for zonal spherical
functions on the symmetric space is used to obtain a
generating function for such functions. For the case N=3 the three-dimensional
integral representation reduces to a one-dimensional one.Comment: Latex file, 10 pages, amssymb.sty require
On the class distribution labelling step sensitivity of co-training
Co-training can learn from datasets having a small number of labelled examples and a large number of unlabelled ones. It is an iterative algorithm where examples labelled in previous iterations are used to improve the classification of examples from the unlabelled set.
However, as the number of initial labelled examples is often small we do not have reliable estimates regarding the underlying population which generated the data. In this work we make the claim that the proportion in which examples are labelled is a key parameter to co-training.
Furthermore, we have done a series of experiments to investigate how the proportion in which we label examples in each step influences cotraining performance. Results show that co-training should be used with care in challenging domains.IFIP International Conference on Artificial Intelligence in Theory and Practice - Knowledge Acquisition and Data MiningRed de Universidades con Carreras en Informática (RedUNCI
Spectroscopic and morphological data assessing the apatite forming ability of calcium hydroxide-releasing materials for pulp capping
A pulp capping material must perform as a barrier and protect the dental pulpal complex by inducing the formation of a new dentin bridge or dentin-like tissue. Being a favorable condition for the healing process, the apatite forming ability of TheraCal (light-curable Portland-dimethacrylate cement) and Dycal (calcium hydroxide-based) pulp capping materials was studied in two simulated body fluids, i.e. Dulbecco's Phosphate Buffered Saline (DPBS) and Hank's Balanced Salt Solution (HBSS). The cements were analyzed before and after soaking in these media for different times (1\u201328 days) by ESEM-EDX, micro-Raman and IR spectroscopy. This data article refers to \u201cAn in vitro study on dentin demineralization and remineralization: collagen rearrangements and influence on the enucleated phase\u201d (Di Foggia et al., 2019)
Energy Loss, Electron Screening, and the Astrophysical 3He(d,p)4He cross section
We reanalyze the low-energy 3He(d,p)4He cross section measurements of
Engstler et al. using recently measured energy loss data for proton and
deuteron beams in a helium gas. Although the new 3He(d,p)4He S-factors are
significantly lower than those reported by Engstler et al. they clearly show
the presence of electron screening effects. From the new S-factors we find an
electron screening energy in agreement with the adiabatic limit.Comment: 8 Page RevTeX document, two postscript figures, now in a
self-extracting uufile type archiv
- …