1,449 research outputs found

    Optimized perturbation method for the propagation in the anharmonic oscillator potential

    Full text link
    The application of the optimized expansion for the quantum-mechanical propagation in the anharmonic potential λx4\lambda x^4 is discussed for real and imaginary time. The first order results in the imaginary time formalism provide approximations to the free energy and particle density which agree well with the exact results in the whole range of temperatures.Comment: 13 pages, plain LATEX, 3 compressed and uuencoded Postscript figures, submitted to Phys.Lett.

    Occurrence of Legionella spp. in thermal environments: Virulence factors and biofilm formation in isolates from a spa☆ , ☆☆

    Get PDF
    Abstract The aim of the study was to evaluate the occurrence of Legionella spp. in the water system of a spa in the city of Naples by analyzing water, air and surface samples. On the whole, 312 samples were collected and analyzed in the course of 10 months. Legionella CYE Agar Base and Legionella Latex Test (Oxoid©) were used to identify and serotype presumptive Legionella pneumophila strains. A further identification was carried out by rDNA16S and ITS region amplification followed by a sequence analysis by DNA Sequencing Analysis software (Applied Biosystems). Similarity search was performed using BLAST algorithm against the GenBank database (NCBI GenBank). Specific in-vitro tests aimed to evaluate the production of esoenzymes (hemolysins, collagenases, mucinases, lipases, proteinases, DNAses, elastases) on GC-FC Agar were also carried out. Finally, a crystal violet staining method (absorbance at 570 nm) was used to evaluate the ability of the strains to produce biofilm in a 96-multiwell polyethylene plate. All samples were negative for L. pneumophila. Six different Legionella strains were isolated from water samples and identified as Legionella londiniensis and Legionella spp. A significant (from 1000 to 10,000 CFU/L) and a low to moderate (from 100 to 1000 CFU/L) contamination were detected respectively in the 5% and 4% of samples; 91% of water samples showed a Legionella spp. amount less than 100 CFU/L. Two Legionella londiniensis isolates showed collagenases, caseinases, proteinases and gelatinases activities, being classified as potentially pathogenic bacteria. None of the isolates were classified as strong biofilm producer but they showed a moderate to weak ability to form biofilm on polyethylene. This result is significant because large part of the spa pipelines is plastic-coated. The highest frequency of isolation of Legionella spp. was detected in the unit for Thermal Mud Therapy, which showed a relative risk value equal to 1.69 (CI 95% 0.60–4.70). Although our results proved a moderate contamination in different water samples, the presence of potentially pathogenic environmental strains of Legionella spp. should not be underestimated because most part of costumers attending the spa are old and sick people, and Legionella strains can represent a real risk

    Impact of Isolated Tricuspid Valve Repair on Right Ventricular Remodelling in an Adult Congenital Heart Disease Population

    Get PDF
    BackgroundSurgical repair of isolated congenital tricuspid valve (TV) disease is rare with no well-defined indication and outcomes. Moreover, the role of right ventricle (RV) in this context has not yet been investigated.ObjectivesWe sought to assess the impact of congenital TV repair on cardiac remodelling and clinical–functional status and the importance of the RV function in an adult congenital heart disease (ACHD) population.Methods and resultsFrom January 2005 to December 2015, 304 patients underwent TV surgery in our centre. Of these, 27 (ACHD) patients had isolated TV repair. Patients were evaluated with preoperative and postoperative transthoracic echocardiogram. Survival rate has been investigated with a mean clinical follow-up (FU) of 3.7 ± 2.3 years, whereas the mean echocardiographic FU was 2.9 ± 1.8 years. The clinical and functional status of patients showed a statistically significant improvement after the surgical repair in terms of New York Heart Association class (66.7 vs 7.4%; p < 0.01), clinical signs of heart failure (29.6 vs 7.4%; p < 0.01), and left ventricular function (14.8 vs 7.4%; p < 0.01). The RV and right atrium diameter were significantly reduced after surgery (5.15 ± 1.21 vs 4.32 ± 1.16; p < 0.01) and (44.7 ± 16.7 vs 26.7 ± 9.2; p < 0.01), respectively. The degree of postoperative pulmonary hypertension was also significantly reduced (40.7 vs 7.4%; p < 0.01). The survival rate was 96.3% at 1 year and 93.7% at 5 years. One patient (3.7%) had early failure of the tricuspid repair requiring a reoperation.ConclusionIsolated TV repair for adult congenital disease significantly improved patients’ clinical and functional status and allowed right ventricular remodelling and functional improvement

    Usefulness of a simple sleep-deprived EEG protocol for epilepsy diagnosis in de novo subjects.

    Get PDF
    OBJECTIVE: In case series concerning the role of EEG after sleep deprivation (SD-EEG) in epilepsy, patients' features and protocols vary dramatically from one report to another. In this study, we assessed the usefulness of a simple SD-EEG method in well characterized patients. METHODS: Among the 963 adult subjects submitted to SD-EEG at our Center, in the period 2003-2010, we retrospectively selected for analysis only those: (1) evaluated for suspected epileptic seizures; (2) with a normal/non-specific baseline EEG; (3) still drug-free at the time of SD-EEG; (4) with an MRI analysis; (5) with at least 1year follow-up. SD-EEG consisted in SD from 2:00 AM and laboratory EEG from 8:00 AM to 10:30 AM. We analyzed epileptic interictal abnormalities (IIAs) and their correlations with patients' features. RESULTS: Epilepsy was confirmed in 131 patients. SD-EEG showed IIAs in 41.2% of all patients with epilepsy, and a 91.1% specificity for epilepsy diagnosis; IIAs types observed during SD-EEG are different in generalized versus focal epilepsies; for focal epilepsies, the IIAs yield in SD-EEG is higher than in second routine EEG. CONCLUSIONS: This simple SD-EEG protocol is very useful in de novo patients with suspected seizures. SIGNIFICANCE: This study sheds new light on the role of SD-EEG in specific epilepsy populations

    Analisi di settore: i discount in Europa

    Get PDF
    Indice: Definizione del business - Analisi del macroambiente - Analisi della domanda - Analisi dell'offerta - Prospettive e tendenze competitiv

    Critérios técnico-econômicos para o dimensionamento de sistemas de bombeamento para zonas altas

    Get PDF
    -O trabalho desenvolvido foi motivado por uma realidade muito freqüente para os responsáveis pelos sistemas de abastecimento de água potável nas cidades, que necessitam solucionar o problema de atendimento às zonas de topografia mais acentuada que sofrem ocupações humanas. Nestas situações periodicamente se faz necessária a revisão e/ou o redimensionamento em sistemas de elevação mecânica (bombeamento) e, sendo assim, espera-se que os serviços prestados pelas companhias responsáveis pelo setor apresentem o menor custo possível. A análise econômica proposta, de uma maneira simplista, visto que evidentemente existem diversas variáveis em questão, trata de fazer uma comparação entre: (A) Aumentar a potência do conjunto elevatório então existente, construindo-se um reservatório ou deslocando-se o reservatório existente para um ponto mais alto, a fim de que todos os habitantes sejam abastecidos a partir desse reservatório; (B) Instalar uma bomba, possivelmente menor, na base do reservatório existente, recalcando uma vazão para a zona alta, onde seria construído um novo reservatório, a fim de abastecer os habitantes daquela zona mais alta. Para este fim a metodologia adotada analisou a variação dos resultados segundo dois parâmetros: a relação das alturas entre os pontos de abastecimento e a relação entre populações da zona mais baixa e da zona de maior altitude. Os valores monetários finais, que dependem da situação escolhida e dos parâmetros acima citados, levam em conta o preço do equipamento de recalque (bomba), o preço da tubulação e sua instalação, o preço dos reservatórios de acordo com seu volume e o valor gasto com energia elétrica pelo sistema em um período de 10 anos. A pesquisa teve como objetivo geral fornecer uma ferramenta computacional que possibilite a definição de valores monetários e a determinação da situação técnico-econômica mais favorável, quando do redimensionamento de um sistema de bombeamento para abastecer zonas altas com água potável

    Comparative toxicities of selected rare earth elements: Sea urchin embryogenesis and fertilization damage with redox and cytogenetic effects

    Get PDF
    Background: Broad-rangingadverseeffectsareknownforrareearthelements(REE),yetonlyafew studies testedthetoxicityofseveralREE,promptingstudiesfocusingonmulti-parameterREEtoxicity. Methods: TrichloridesaltsofY,La,Ce,Nd,Sm,EuandGdweretestedin Paracentrotuslividus sea urchin embryos andspermfor:(1)developmentaldefectsineitherREE-exposedlarvaeorintheoffspringof REE-exposedsperm;(2)fertilizationsuccess;(3)mitoticanomaliesinREE-exposedembryosandinthe offspring ofREE-exposedsperm,and(4)reactiveoxygenspecies(ROS)formation,andmalondialdehyde (MDA)andnitricoxide(NO)levels. Results: REEs affected P.lividus larvaewithconcentration-relatedincreaseindevelopmentaldefects, 106 to 104 M, rankingas:Gd(III)4Y(III)4La(III)4Nd(III)≅Eu(III)4Ce(III)≅Sm(III). Nominalcon- centrations ofREEsaltswereconfirmed byinductivelycoupledplasmamassspectrometry(ICP-MS). Significant increasesinMDAlevels,ROSformation,andNOlevelswerefoundinREE-exposedembryos. Sperm exposuretoREEs(105 to 104 M) resultedinconcentration-relateddecreaseinfertilization success alongwithincreaseinoffspringdamage.Decreasedmitoticactivityandincreasedaberration ratesweredetectedinREE-exposedembryosandintheoffspringofREE-exposedsperm. Conclusion: REE-associated toxicityaffectingembryogenesis,fertilization,cytogeneticandredoxend- points showeddifferentactivitiesoftestedREEs.Damagetoearlylifestages,alongwithredoxandcy- togeneticanomaliesshouldbethefocusoffutureREEtoxicitystudies

    Performance Evaluation of Microbial Fuel Cells Fed by Solid Organic Waste: Parametric Comparison between Three Generations

    Get PDF
    Abstract In this paper, the results of three generations of reactors for the direct conversion of the Organic Fraction of Municipal Solid Waste (OFMSW) in electrical energy are presented. The different generations corresponds to the prototype realized in the Energy Lab of the University of Naples "Parthenope" and have been monitored along a period of over three years in terms of polarization and power curves, in order to assess the feasibility of Microbial Fuel Cell as a promising source for future, sustainable energy generation

    Laparoscopic treatment of a yolk sac tumor. Case report and literature review

    Get PDF
    We report the case of a yolk sac tumor of the ovary in a 26 years old woman. The laparoscopic approach and the BEP chemotherapy were fundamental to have a minimally invasive treatment and to preserve fertilit
    • …
    corecore