728 research outputs found

    Mathematical model investigation of long-term transport of ocean-dumped sewage sludge related to remote sensing

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    An existing, three-dimensional, Eulerian-Lagrangian finite-difference model was modified and used to examine the transport processes of dumped sewage sludge in the New York Bight. Both in situ and laboratory data were utilized in an attempt to approximate model inputs such as mean current speed, horizontal diffusion coefficients, particle size distributions, and specific gravities. The results presented are a quantitative description of the fate of a negatively buoyant sewage sludge plume resulting from continuous and instantaneous barge releases. Concentrations of the sludge near the surface were compared qualitatively with those remotely sensed. Laboratory study was performed to investigate the behavior of sewage sludge dumping in various ambient density conditions

    Nanoparticle characterization: What to measure?

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    What to measure? is a key question in nanoscience, and it is not straightforward to address as different physicochemical properties define a nanoparticle sample. Most prominent among these properties are size, shape, surface charge, and porosity. Today researchers have an unprecedented variety of measurement techniques at their disposal to assign precise numerical values to those parameters. However, methods based on different physical principles probe different aspects, not only of the particles themselves, but also of their preparation history and their environment at the time of measurement. Understanding these connections can be of great value for interpreting characterization results and ultimately controlling the nanoparticle structure–function relationship. Here, the current techniques that enable the precise measurement of these fundamental nanoparticle properties are presented and their practical advantages and disadvantages are discussed. Some recommendations of how the physicochemical parameters of nanoparticles should be investigated and how to fully characterize these properties in different environments according to the intended nanoparticle use are proposed. The intention is to improve comparability of nanoparticle properties and performance to ensure the successful transfer of scientific knowledge to industrial real‐world applications

    Installation of fuel cell-based cogeneration systems in the commercial and retail sector: Assessment in the framework of the {COMSOS} project

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    This work studies the technical and economic feasibility of the introduction of a SOFC-based cogeneration system to supply non-residential buildings with electricity and heat. The techno-economic evaluation is performed for the hotel and hospital sectors, by introducing real hourly load profiles (electrical and thermal) for the buildings. The analysis considers different countries in terms of energy intensity (and load profiles), cost of energy and regulations/incentives. Results are achieved by comparing the SOFC scenario with a benchmark one where electricity is supplied by the grid and heat by a natural gas fed boiler and evaluating the relative payback time between the two solutions. The analysis showed that, despite the current high investment cost of the SOFC system, in countries such as Germany, Italy and UK (where electricity prices are among the highest in Europe), the option is yet advisable if supported by effective subsidies (already existing for cogeneration systems), and it could offer a competitive alternative to traditional systems, especially in the hospital sector, where the relative payback time is achieved in the 10th year for UK, and in the 14th year for Germany and Italy. A cost reduction scenario has also been analyzed: results show that the SOFC is the best option in most of the locations, both economically and in terms of environmental impact (pollutants emissions reduction)

    Remote ischaemic preconditioning in coronary artery bypass surgery: a meta-analysis

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    Aim Randomised trials exploring remote ischaemic preconditioning (RIPC) in patients undergoing coronary artery bypass graft (CABG) surgery have yielded conflicting data regarding potential cardiovascular and renal protection, and are individually flawed by small sample size. Methods Three investigators independently searched the MEDLINE, EMBASE and Cochrane databases to identify randomised trials testing RIPC in patients undergoing CABG. Results Nine studies with 704 patients were included. Standardised mean difference of troponin I and T release showed a significant decrease ( 120.36 (95% CI 120.62 to 120.09)). This difference held true after excluding the trials with cross-clamp fibrillation, the study with off-pump CABG and studies using a flurane as anaesthetic agent ( 120.41 (95% CI 120.69 to 120.12), 120.38 (95% CI 120.70 to 120.07) and 120.37 (95% CI 120.63 to 120.12), respectively). A similar trend was also obtained for patients with multivessel disease ( 120.41 (95% CI 120.73 to 120.08)). The trials evaluating postoperative creatinine reported a non-significant reduction (0.02 (95% CI 120.09 to 0.13)). Moreover, the length of in-hospital stay was not influenced by the kind of treatment (weighted mean difference 0.27 (95% CI 120.24 to 0.79)). Conclusion RIPC reduced the release of troponin in patients undergoing CABG. Larger randomised trials are needed to clarify the presence of a causal relationship between RIPC-induced troponin release and clinical adverse events

    Transverse Dynamics and Energy Tuning of Fast Electrons Generated in Sub-Relativistic Intensity Laser Pulse Interaction with Plasmas

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    The regimes of quasi-mono-energetic electron beam generation were experimentally studied in the sub-relativistic intensity laser plasma interaction. The observed electron acceleration regime is unfolded with two-dimensional-particle-in-cell simulations of laser-wakefield generation in the self-modulation regime.Comment: 10 pages, 5 figure

    Epidemiology and social impact of early onset dementia in the province of Modena, Northern Italy

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    Aims of the study. Early onset dementia (EOD), defined as onset of dementia <65 years, has a much higher social impact compared to the more common late onset dementia. EOD epidemiologic data in Italy are extremely scarce, and international estimates of prevalence are considerably variable, ranging between 15.1 and 153/100.000 in the age 45-65. We present data from an ongoing study aimed at establishing EOD epidemiology in a Northern Italy community (Modena province, around 700.000 inhabitants). Materials. We retrospectively recruited all patients residing in Modena province referred to the Modena Baggiovara Hospital Neurologic Clinic CDCD (Centro disturbi cognitivi e demenze), by family practitioners and geriatricians of the province. Eligible patients were those affected by EOD from 2012 to January 2019. EOD was diagnosed in patients <65 years presenting with cognitive/behavioral symptoms, following a comprehensive neurological examination by a cognitive neurologist, as well as brain MRI, FDG PET scanning and CSF analyses when appropriate. Methods. We collected clinical data such as age at onset, disease severity at time of diagnosis, time delay from onset to diagnosis, and epidemiologic data including residence and occupational status. Results. We identified 223 patients with an EOD diagnosis from 2012 to January 2019. Of these, 103 are males (46,2%). 97 patients have AD (21 lvPPA, 13 PCA, 2 frontal variant), 47 have FTD (33 bvFTD, 14 svPPA), 6 have leucoencephalopathy. Mean onset age was 58,6 years (SD 5,1). Median time from symptoms onset to diagnosis was 3.1 years (SD 29,83). Mean MMSE score at diagnosis was 22,63/30 (SD 5,2). 24 patients were working at time of diagnosis (10,76%) and had to quit working due to the cognitive impairment. Two patients (0,89%) had young children (<18) at time of diagnosis. Discussion. We provide the first epidemiological data on EOD in Italy. These are consistent with the estimates calculated by transposing European data to the population of Modena province (estimated prevalence=200 patients, detected prevalence=223 patients)1. Our data show a higher percentage of atypical AD phenotypes and FTD in the EOD group compared to late onset disease2. Also, CAA and leucoencephalopaties were over-represented compared to LOD. From a social perspective, EOD has significant impacts on patients and their families: patients are generally forced to leave work, and their children are expected to need psychological support, currently not routinely available. Conclusions. Our population study provides the first data regarding EOD epidemiology and social impact in Italy

    Hypertrophic Adenoid Is A Major Infection Site Of Human Bocavirus 1.

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    Human bocavirus 1 (HBoV1) is associated with respiratory infections worldwide, mainly in children. Similar to other parvoviruses, it is believed that HBoV1 can persist for long periods of time in humans, probably through maintaining concatemers of the virus single-stranded DNA genome in the nuclei of infected cells. Recently, HBoV-1 was detected in high rates in adenoid and palatine tonsils samples from patients with chronic adenotonsillar diseases, but nothing is known about the virus replication levels in those tissues. A 3-year prospective hospital-based study was conducted to detect and quantify HBoV1 DNA and mRNAs in samples of the adenoids (AD), palatine tonsils (PT), nasopharyngeal secretions (NPS), and peripheral blood (PB) from patients undergoing tonsillectomy for tonsillar hypertrophy or recurrent tonsillitis. HBoV1 was detected in 25.3% of the AD samples, while the rates of detection in the PT, NPS, and PB samples were 7.2%, 10.5%, and 1.7%, respectively. The viral loads were higher in AD samples, and 27.3% of the patients with HBoV had mRNA detectable in this tissue. High viral loads and detectable mRNA in the AD were associated with HBoV1 detection in the other sample sites. The adenoids are an important site of HBoV1 replication and persistence in children with tonsillar hypertrophy. The adenoids contain high HBoV1 loads and are frequently positive for HBoV mRNA, and this is associated with the detection of HBoV1 in secretions.523030-

    Search for correlation between GRB's detected by BeppoSAX and gravitational wave detectors EXPLORER and NAUTILUS

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    Data obtained during five months of 2001 with the gravitational wave (GW) detectors EXPLORER and NAUTILUS were studied in correlation with the gamma ray burst data (GRB) obtained with the BeppoSAX satellite. During this period BeppoSAX was the only GRB satellite in operation, while EXPLORER and NAUTILUS were the only GW detectors in operation. No correlation between the GW data and the GRB bursts was found. The analysis, performed over 47 GRB's, excludes the presence of signals of amplitude h >=1.2 * 10^{-18}, with 95 % probability, if we allow a time delay between GW bursts and GRB within +-400 s, and h >= 6.5 * 10^{-19}, if the time delay is within +- 5 s. The result is also provided in form of scaled likelihood for unbiased interpretation and easier use for further analysis.Comment: 14 pages, 7 figures. Latex file, compiled with cernik.cls (provided in the package

    SIOP Ependymoma I: Final results, long term follow-up and molecular analysis of the trial cohort: A BIOMECA Consortium Study

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    BACKGROUND: SIOP Ependymoma I was a non-randomised trial assessing event free and overall survival (EFS/OS) of non-metastatic intracranial ependymoma in children aged 3 to 21 years treated with a staged management strategy. A further aim was to assess the response rate (RR) of subtotally resected (STR) ependymoma to vincristine, etoposide and cyclophosphamide (VEC). We report final results with 12-year follow-up and post hoc analyses of recently described biomarkers. METHODS: 74 participants were eligible. Children with gross total resection (GTR) received radiotherapy, whilst those with STR received VEC before radiotherapy. DNA methylation, 1q, hTERT, ReLA, Tenascin-C, H3K27me3 and pAKT status were evaluated. RESULTS: Five- and ten-year EFS was 49.5% and 46.7%, OS was 69.3% and 60.5%. GTR was achieved in 33/74 (44.6%) and associated with improved EFS (p=0.003, HR=2.6, 95% confidence interval (CI) 1.4-5.1). Grade 3 tumours were associated with worse OS (p=0.005, HR=2.8, 95%CI 1.3-5.8). 1q gain and hTERT expression were associated with poorer EFS (p=0.003, HR=2.70, 95%CI 1.49-6.10 and p=0.014, HR=5.8, 95%CI 1.2-28) and H3K27me3 loss with worse OS (p=0.003, HR=4.6, 95%CI 1.5-13.2). Methylation profiles showed expected patterns. 12 participants with STR did not receive chemotherapy; a protocol violation. However, best chemotherapy RR was 65.5% (19/29, 95%CI 45.7-82.1), exceeding the prespecified 45%. CONCLUSIONS: Participants with totally resected ependymoma had the best outcomes. RR of STR to VEC exceeded the pre-specified efficacy criterion. However, cases of inaccurate stratification highlighted the need for rapid central review. 1q gain, H3K27me3 loss and hTERT expression were all associated with poorer survival outcomes

    Quadratic interaction functional for general systems of conservation laws

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    For the Glimm scheme approximation u_\e to the solution of the system of conservation laws in one space dimension \begin{equation*} u_t + f(u)_x = 0, \qquad u(0,x) = u_0(x) \in \R^n, \end{equation*} with initial data u0u_0 with small total variation, we prove a quadratic (w.r.t. \TV(u_0)) interaction estimate, which has been used in the literature for stability and convergence results. No assumptions on the structure of the flux ff are made (apart smoothness), and this estimate is the natural extension of the Glimm type interaction estimate for genuinely nonlinear systems. More precisely we obtain the following results: \begin{itemize} \item a new analysis of the interaction estimates of simple waves; \item a Lagrangian representation of the derivative of the solution, i.e. a map x(t,w)\mathtt x(t,w) which follows the trajectory of each wave ww from its creation to its cancellation; \item the introduction of the characteristic interval and partition for couples of waves, representing the common history of the two waves; \item a new functional Q\mathfrak Q controlling the variation in speed of the waves w.r.t. time. \end{itemize} This last functional is the natural extension of the Glimm functional for genuinely nonlinear systems. The main result is that the distribution Dttx(t,w)D_{tt} \mathtt x(t,w) is a measure with total mass \leq \const \TV(u_0)^2
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