4,204 research outputs found
Water confined in nanopores: spontaneous formation of microcavities
Molecular Dynamics simulations of water confined in nanometer sized,
hydrophobic channels show that water forms localized cavities for pore diameter
~ 2.0 nm. The cavities present non-spherical shape and lay preferentially
adjacent to the confining wall inducing a peculiar form to the liquid exposed
surface. The regime of localized cavitation appears to be correlated with the
formation of a vapor layer, as predicted by the Lum-Chandler-Weeks theory,
implying partial filling of the pore
Interventi normativi per l’emergenza: perché serve una legge nazionale
Molti dei problemi che si pongono all’indomani di una calamità sono i medesimi e la risposta del legislatore (prima) e della gestione commissariale (poi) non sempre riesce a essere adeguata. Dall'analisi svolta sulle ordinanze emanate nel caso del sisma in Emilia del 2012 è possibile tracciare quali siano gli ambiti rilevanti per l'intervento normativo. Si analizzano inoltre alcuni esempi di effetti economici con-seguenti a un terremoto che colpiscono le famiglie anche nella vita quotidiana, come per i mutui, le polizze assicurative o i contratti per servizi relativi a beni perduti a seguito del sisma. Gli Autori propongono l’adozione di una legge generale che individui preventivamente una serie di misure che il Governo possa direttamente attivare in modo immediato all’indomani di disastri naturali, con l'obiettivo di mettere in atto risposte pronte ed efficaci che riducano gli effetti negativi dell'incertezza nel-le decisioni delle famigli
The invisible businessman: Nuclear physics, patenting practices,and trading activities in the 1930s
In the 1930s the production of patents for the protection of intellectual rights became central to the research activities of Enrico Fermi and his group, consistently with a research policy emerging within the Italian Fascist Regime. Behind their work was an international network consisting of businessmen, industrialists, and multinationals who helped them patent their method for the production of artificial radioactive elements and to promote its industrial exploitation. The lack of research funding combined with a more aggressive foreign policy of the regime made it impossible for the group to continue these activities in Rome, and in 1938 the promulgation
of racial laws forced them to migrate abroad
Early impairment of endothelial structure and function in young normal-weight women with polycystic ovary syndrome
The aim of this study was to evaluate the presence of early vascular damage in young normal-weight women with polycystic ovary syndrome (PCOS).Thirty young normal-weight women with PCOS, who had no additional metabolic or cardiovascular diseases, and 30 healthy women (controls) matched for age and body mass index were studied. A complete hormonal assay was performed in each subject. Serum insulin and glucose levels were measured at baseline and after the oral glucose tolerance test. Plasma endothelin-1 levels and serum lipid profile were also assessed. The endothelial function was studied by flow-mediated dilation on the brachial artery, and arterial structure was evaluated by intima-media thickness measurement using Doppler ultrasound of both common carotid arteries.A significant (P < 0.05) difference in flow-mediated dilation (14.3 +/- 1.9% vs. 18.1 +/- 2.0% for PCOS patients and controls, respectively) and in intima-media thickness (0.53 +/- 0.09 mm vs. 0.39 +/- 0.08 mm for PCOS patients and controls, respectively) was found between PCOS and control subjects. Serum endothelin-1 levels were also significantly (P < 0.05) higher in PCOS patients compared with controls (1.1 +/- 0.4 pmol/liter vs. 0.5 +/- 0.2 pmol/liter for PCOS patients and controls, respectively).In conclusion, our data show that young, normal-weight, nondyslipidemic, nonhypertensive women with PCOS have an early impairment of endothelial structure and function
Influence of intrapulpal pressure simulation on the bond strength of adhesive systems to dentin
The purpose of this study was to evaluate the influence of intrapulpal pressure simulation on the bonding effectiveness of etch & rinse and self-etch adhesives to dentin. Eighty sound human molars were distributed into eight groups, according to the permeability level of each sample, measured by an apparatus to assess hydraulic conductance (Lp). Thus, a similar mean permeability was achieved in each group. Three etch & rinse adhesives (Prime & Bond NT - PB, Single Bond -SB, and Excite - EX) and one self-etch system (Clearfil SE Bond - SE) were employed, varying the presence or absence of an intrapulpal pressure (IPP) simulation of 15 cmH2O. After adhesive and restorative procedures were carried out, the samples were stored in distilled water for 24 hours at 37°C, and taken for tensile bond strength (TBS) testing. Fracture analysis was performed using a light microscope at 40 X magnification. The data, obtained in MPa, were then submitted to the Kruskal-Wallis test ( a = 0.05). The results revealed that the TBS of SB and EX was significantly reduced under IPP simulation, differing from the TBS of PB and SE. Moreover, SE obtained the highest bond strength values in the presence of IPP. It could be concluded that IPP simulation can influence the bond strength of certain adhesive systems to dentin and should be considered when in vitro studies are conducted
Levels of heavy metals in liver and kidney of dogs from urban environment
Lead, cadmium and mercury were detected in liver and kidney tissue of dogs from an urban habitat. Samples were digested in a microwave system and analyzed by atomic absorption spectroscopy. Results of the current study showed that at least one of the three heavy metals was detected in tissues of all examined dogs. These findings make us suppose that humans are exposed to the same heavy metals similar to those of dogs that are exposed since they share the same environment. Mercury concentrations detected in kidney of household dogs were higher than stray dogs, therefore the involvement of pet food in exposure to mercury can be supposed
Tamarix arborea var. arborea and Tamarix parviflora: Two species valued for their adaptability to stress conditions
The choice of stress resistant and highly adaptable species is a fundamental step for landscaping and ornamental purposes in arid and coastal environments such as those in the Mediterranean basin. The genus Tamarix L. includes about 90 species with a high endurance of adversity. We investigated the water relations and photosynthetic response of Tamarix arborea (Sieb. ex Ehrenb.) Bge. var. arborea and T. parviflora DC. growing in an urban environment. Both species showed no evidence of drought or salt stress in summer, and appeared to follow two strategies with T. arborea var. arborea investing in high carbon gain at the beginning of the summer, and then reducing photosynthetic activity at the end of the season, and T. parviflora showing lower but constant levels of photosynthetic activity throughout the vegetative season. For landscaping and ornamental purposes, we suggest T. arborea var. arborea when a fast-growing, high-cover species is necessary, and T. parviflora when less-invasive species are required
LEVELS OF HEAVY METALS IN ITALIAN MARKETED CANNED TUNA
Fish products are essential and irreplaceable components of human diet; nevertheless, they could result in a risk to the health of consumers due to the potential content of some xenobiotics such as heavy metals and persistent organic contaminants (Debeka et al., 2004; Storelli et al., 2005). Constant control network and surveys are valuable tools in order to prevent such risk and to ensure product quality and consumers??? safety. The aim of the current study was to measure the levels of some heavy metals (Hg, Pb, Cd) in samples of marked canned tuna in olive oil.
The results showed that levels of Cd and Hg were always within the law limits and, in many samples, below the detection limit. Pb was found in concentrations exceeding the law limits in 9.8% of the analyzed samples. In conclusion, the results of the current study, quite reassuring in terms of food safety, highlighted the need to constantly monitor the levels of some chemical contaminants in fish products such as heavy metals that might endanger the health of the consumers
Heavy Metals in Canned Tuna from Italian Markets
Fish is a good source of nutrients for humans but can pose a risk to human health because of the possible presence of some xenobiotics such as heavy metals and persistent organic contaminants. Constant monitoring is needed to minimize health risks and ensure product quality and consumer safety. The aim of the present study was to use atomic absorption spectrometry to
determine the concentrations of some heavy metals (Hg, Pb, and Cd) in tuna packaged in different kinds of packages (cans or
glass) in various countries (Italy and elsewhere). Concentrations of Cd and Hg were within the limits set by European
Commission Regulation (EC) No 1881/2006 and in many samples were below the detection limit. Pb concentrations exceeded
European limits in 9.8% of the analyzed samples. These results are reassuring in terms of food safety but highlighted the need to
constantly monitor the concentrations of heavy metals in fish products that could endanger consumer health
High density of tryptase-positive mast cells in human colorectal cancer: a poor prognostic factor related to protease-activated receptor 2 expression
Tryptase(+) mast cells (MCs), abundant in the invasive front of tumours, contribute to tissue remodelling. Indeed, protease-activated receptor-
2 (PAR-2) activation by MC-tryptase is considered an oncogenic event in colorectal cancer (CRC). Recently, we have suggested NHERF1 as a
potential new marker in CRC. In this study, we aimed to determine the distribution of tryptase(+) MCs and PAR-2 and to examine the relationship
between PAR-2 and NHERF1, investigating their reputed usefulness as tumour markers. We studied a cohort of 115 CRC specimens
including primary cancer (C) and adjacent normal mucosa (NM) by immunohistochemical double staining, analyzing the protein expression of
MC-tryptase, PAR-2 and cytoplasmic NHERF1. MC density was higher in NM than in C. Tumours with high TNM stage and poor grade showed
the highest MC density. A higher PAR-2 immunoreactivity characterized tumours most infiltrated by MCs compared with samples with low MC
density. Furthermore, PAR-2 overexpression was associated with advanced TNM stage, poor grade and lymphovascular invasion (LVI). A positive
correlation existed between tryptase(+) MC density and PAR-2 expression. Cytoplasmic NHERF1 was higher in C than in NM and overexpressing
tumours resulted associated with nodal and distant metastases, poor grade and LVI. PAR-2 correlated with cytoplasmic NHERF1 and
the PAR-2(+)/cytoplasmic NHERF1(+) expression immunophenotype identified tumours associated with unfavourable prognosis and aggressive
clinical parameters. Our data indicate that the high density of tryptase(+) MCs at invasive margins of tumours was associated with advanced
stages of CRC and was strongly correlated with PAR-2 expression
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