4,914 research outputs found
A new record of the Red swamp crayfish, Procambarus clarkii (Girard, 1852) (Crustacea Cambaridae), in Sicily, Italy
May antitransglutaminase levels predict severity of duodenal lesions in adults with celiac disease?
Background and Objective: Pediatric guidelines on celiac disease (CD) state that children with anti‐transglutaminase antibodies (TGAs) >×10 upper limit of normal (ULN) may avoid endos-copy and biopsy. We aimed to evaluate whether these criteria may be suitable for villous atrophy diagnosis in CD adults. Materials and Methods: We retrospectively enrolled patients with CD aged >18 years. TGAs were expressed as xULN. Duodenal lesions were classified as atrophic or non-atrophic according to Marsh‐Oberhuber. Fisher’s exact and t‐test were used for variables compari-son. Receiver operating characteristics (ROC) curve analysis was performed with estimation of area under the curve (AUC), sensitivity, specificity, and positive and negative predictive value (PPV/NPV). Results: One hundred and twenty‐one patients were recruited. Sixty patients (49.6%) had TGA >×10 ULN, and 93 (76.8%) had villous atrophy. The cut‐off of >×10 ULN had sensitivity = 53.7%, specificity = 64.3%, PPV = 83.3%, and NPV = 29.5% to predict atrophy. Therefore, considering pediatric criteria, in 50 (41.3%) patients, biopsy could have been avoided. Patient subgroup with atrophy had higher TGA levels despite being not significant (37.2 ± 15.3 vs. 8.0 ± 1.3 ULN, p = 0.06). In adults, a slightly better diagnostic performance was obtained using a cut‐off of TGA >×6.2 ULN (sensitivity = 57.1%, specificity = 65.6%, and AUC = 0.62). Conclusions: Despite our confirmation that villous atrophy is linked to high TGA levels, CD and atrophy diagnosis based only on serology is not reliable in adults
The perplexity of targeting genetic alterations in hepatocellular carcinoma
Genetic heterogeneity is a well-recognized feature of hepatocellular carcinoma (HCC). The coexistence of multiple genetic alterations in the same HCC nodule contributes to explain why gene-targeted therapy has largely failed. Targeting of early genetic alterations could theoretically be a more effective therapeutic strategy preventing HCC. However, the failure of most targeted therapies has raised much perplexity regarding the role of genetic alterations in driving cancer as the main paradigm. Here, we discuss the methodological and conceptual limitations of targeting genetic alterations and their products that may explain the limited success of the novel mechanism-based drugs in the treatment of HCC. In light of these limitations and despite the era of the so-called “precision medicine,” prevention and early diagnosis of conditions predisposing to HCC remain the gold standard approach to prevent the development of this type of cancer. Finally, a paradigm shift to a more systemic approach to cancer is required to find optimal therapeutic solutions to treat this disease
Astronomía: una experiencia
Desde el año 2001 se desarrolla en la EEM N° 31 Libertador General Don José de San Martín de La Plata el Taller de Astronomía y Ciencias del Espacio. En dicho año fue seleccionado como proyecto innovador en el llamado que realizó el Ministerio de Educación de la Nación en el marco del PRODYMES II. El objetivo del proyecto es la difusión de la astronomía dentro del establecimiento, acercando al alumno a la ciencia por medio de diferentes actividades: observación del cielo, manejo del telescopio, obtención de fotografías, asistencia a encuentros semanales, el boletín astronómico y participación en las exposiciones realizadas en el colegio. Posteriormente se incluyeron nuevas actividades, relacionadas con la actividad espacial inscribiendo al establecimiento en proyectos de la NASA y en programas de la ESA (agencia espacial europea). La experiencia recogida durante estos años muestra que los alumnos se comprometen con las distintas actividades del taller, para muchos de ellos se abre un mundo desconocido comienzan a observar el cielo y comparten con sus compañeros los conocimientos adquiridos.Departamento de Ciencias Exactas y Naturale
Influence of Polyphenol Levels on the Perception of Aroma in Vitis vinifera cv. Malbec wine
The aim of this study was to explore the effect of two ranges of polyphenols naturally present in Malbec wine,high concentrations (4.5-7.2 g/L) and low (1.4-3.2 g/L), on the perception of aroma. Samples with a maximumethanol level of 13.5% were taken from the fermentation tanks before the clarification and filtration process. AQuantitative Descriptive Analysis of wines was assessed by ten trained assessors, and HS-SPME-GC-MS andphysicochemical analyses were performed. The intensities of fruity (P < 0.01), citrus (P < 0.01), strawberry (P< 0.05), cooked fruit (P < 0.01) and floral (P < 0.01) aromas decreased when the level of polyphenols increased.Neither volatile compounds nor physicochemical analyses were significant in the two groups of wines
Trace metal distributions in Posidonia oceanica and sediments from Taranto Gulf (Ionian Sea, Southern Italy)
Distribution of metals (Hg, Pb, Sn, Cu, Cd and Zn) was determined in sediments and in different tissues of Posidonia oceanica collected from San Pietro Island, Taranto Gulf (Ionian Sea, Southern Italy). In seagrass, results, compared with metal concentrations in sediments, showed that the highest concentrations of Hg, Pb, Sn and Cu were found in the roots, while in the green leaves were found the highest levels of Cd and Zn. Instead the lowest metal concentrations were found in the basal part of the leaf. Levels of metals in the leaves were similar to those found by other authors in uncontaminated areas of the Mediterranean Sea. Mercury levels in roots were correlated to levels in sediments. This could demonstrate the plant memorizes sediments contamination . This study reinforces the usefulness and the relevance of Posidonia oceanica as an indicator of spatial metal contamination and an interesting tool for environmental quality evaluation
Heavy metals monitoring in mussels Mytilus galloprovincialis from the Apulian coasts (Southern Italy)
Concentrations of six heavy metals (Cd, Cr, Cu, Hg, Pb and Zn) and one semi-metal (As) were determined in tissues of mussels Mytilus galloprovincialis collected along the Apulian coasts (Mediterranean sea). This project, performed in 2009, was targeted toward the assessment of levels and spatial distribution of metals in the environment in order to evaluate the coastal water quality using mussels as bioindicators and health risk for mussel consumers.The concentrations (mg/kg d.w.) of these metals ranged from 6.35 to 76.17 for arsenic (As), 0.38 to 2.54 for cadmium (Cd), 0.96 to 9.46 for chromium (Cr), 5.26 to 19.22 for copper (Cu), 0.10 to 0.81 for mercury (Hg), 25.00 to 110.51 for zinc (Zn) and from 0.37 to 3.25 for lead (Pb). These levels were lower than the permissible limits set by European Commission and FAO with the exception for Cr in three sampling stations. Evaluation of the risk associated to molluscs consumption for human health suggested that there is no evident risk for a moderate Mytilus g. consumer, however heavy metals concentrations must be monitored periodically and carefully with respect to the consumers health
Possibile origine e consistenza di un popolamento di Quercus trojana Webb subsp. trojana (Fagaceae) nel Bosco della Ficuzza (Palermo, Sicilia
Possible origin and demographic asset of a population of Quercus trojana Webb subsp. trojana
(Fagaceae) in the wood of Ficuzza (Palermo, Sicily). The first record of Macedonian oak in Sicily is
reported. The finding consists of 73 adult and 4 young individuals. A morphometric analysis of all
of them, along with an assessment of their phytosanitary status was carried out. They all grow
between 700 and 850 m a.s.l. on a 2,30 ha area, characterized by a land mosaic of shrubland and forest
patches. Notwithstanding two years of researches, no ultimate proof has been found on their
alien status. On this purpose, several alternative hypothesis are formulated and their strengths and
weaknesses are discussed. Considering that the environmental conditions of Ficuzza fit very well the
ecological requirements of Quercus trojana, even the native status of local population cannot be
totally rejected. On the other hand, many data support its recent introduction. In fact, according to
interviews to old forest workers, archive documents and aerial photos, most part of the trees of this
area have been planted just few years after the end of the Second World War, and dendrochronological
analyses have pointed out that the biggest Macedonian oaks of Sicily are no more than 50-60
years old. Whatever the origin of local Macedonian oak population is, the presence of natural renovation
testifies, at least, its full naturalisation within the Sicilian territory
Variational Field Theoretic Approach to Relativistic Scattering
Nonperturbative polaron variational methods are applied, within the so-called
particle or worldline representation of relativistic field theory, to study
scattering in the context of the scalar Wick - Cutkosky model. Important
features of the variational calculation are that it is a controlled
approximation scheme valid for arbitrary coupling strengths, the Green
functions have all the cuts and poles expected for the exact result at any
order in perturbation theory and that the variational parameters are
simultaneously sensitive to the infrared as well as the ultraviolet behaviour
of the theory. We generalize the previously used quadratic trial action by
allowing more freedom for off-shell propagation without a change in the
on-shell variational equations and evaluate the scattering amplitude at first
order in the variational scheme. Particular attention is paid to the
-channel scattering near threshold because here non-perturbative effects can
be large. We check the unitarity of a our numerical calculation and find it
greatly improved compared to perturbation theory and to the zeroth order
variational results.Comment: 26 pages, Latex, 5 postscript figures embedded with epsf, submitted
to Nucl. Phys.
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