6,136 research outputs found

    State of the Art on Prediction of Concrete Pumping

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    Large scale constructions needs to estimate a possibility for pumping concrete. In this paper, the state of the art on prediction of concrete pumping including analytical and experimental works is presented. The existing methods to measure the rheological properties of slip layer (or called lubricating layer) are first introduced. Second, based on the rheological properties of slip layer and parent concrete, models to predict concrete pumping (flow rate, pumping pressure, and pumpable distance) are explained. Third, influencing factors on concrete pumping are discussed with the test results of various concrete mixes. Finally, future need for research on concrete pumping is suggested.ope

    Factors Associated with Severe Late Toxicity After Concurrent Chemoradiation for Locally Advanced Head and Neck Cancer: An RTOG Analysis

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    Purpose Concurrent chemoradiotherapy (CCRT) for squamous cell carcinoma of the head and neck (SCCHN) increases both local tumor control and toxicity. This study evaluates clinical factors that are associated with and might predict severe late toxicity after CCRT. Methods Patients were analyzed from a subset of three previously reported RTOG trials of concurrent chemoradiotherapy for locally advanced SCCHN (RTOG 91-11; 97-03; and 99-14). Severe late toxicity was defined in this secondary analysis as chronic Grade 3-4 pharyngeal/laryngeal toxicity (RTOG/EORTC late toxicity scoring system) and/or requirement for a feeding tube ≥2 years after registration and/or potential treatment-related death (e.g. pneumonia) within 3 years. Case-control analysis was performed, with a multivariable logistic regression model that included pre-treatment and treatment potential factors. Results A total of 230 patients were evaluable for this analysis, 99 cases (patients with severe late toxicities) and 131 controls; thus 43% of evaluable patients had a severe late toxicity. On multivariable analysis, significant variables correlated with the development of severe late toxicity were older age (odds ratio 1.05 per year; p = 0.001); advanced T-stage (odds ratio 3.07; p=0.0036); larynx/hypopharynx primary site (odds ratio 4.17; p=0.0041); and neck dissection after chemo-RT (odds ratio 2.39; p=0.018). Conclusions Severe late toxicity following CCRT is common. Older age, advanced T-stage, and larynx/ hypopharynx primary site were strong independent risk American Society of Clinical Oncology. Machtay, M. et al: J. Clin. Oncol. 26 (21), 2008:3582-3589

    Children and older adults exhibit distinct sub-optimal cost-benefit functions when preparing to move their eyes and hands

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    "© 2015 Gonzalez et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited"Numerous activities require an individual to respond quickly to the correct stimulus. The provision of advance information allows response priming but heightened responses can cause errors (responding too early or reacting to the wrong stimulus). Thus, a balance is required between the online cognitive mechanisms (inhibitory and anticipatory) used to prepare and execute a motor response at the appropriate time. We investigated the use of advance information in 71 participants across four different age groups: (i) children, (ii) young adults, (iii) middle-aged adults, and (iv) older adults. We implemented 'cued' and 'non-cued' conditions to assess age-related changes in saccadic and touch responses to targets in three movement conditions: (a) Eyes only; (b) Hands only; (c) Eyes and Hand. Children made less saccade errors compared to young adults, but they also exhibited longer response times in cued versus non-cued conditions. In contrast, older adults showed faster responses in cued conditions but exhibited more errors. The results indicate that young adults (18 -25 years) achieve an optimal balance between anticipation and execution. In contrast, children show benefits (few errors) and costs (slow responses) of good inhibition when preparing a motor response based on advance information; whilst older adults show the benefits and costs associated with a prospective response strategy (i.e., good anticipation)

    Reproducibility of measurements of potential doubling time of tumour cells in the multicentre National Cancer Institute protocol T92-0045

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    We compared the flow cytometric measurement and analysis of the potential doubling time (Tpot) between three centres involved in the National Cancer Institute (NCI) protocol T92-0045. The primary purpose was to understand and minimize the variation within the measurement. A total of 102 specimens were selected at random from patients entered into the trial. Samples were prepared, stained, run and analysed in each centre and a single set of data analysed by all three centres. Analysis of the disc data set revealed that the measurement of labelling index (LI) was robust and reproducible. The estimation of duration of S-phase (Ts) was subject to errors of profile interpretation, particularly DNA ploidy status, and analysis. The LI dominated the variation in Tpot such that the level of final agreement, after removal of outliers and ploidy agreement, reached correlation coefficients of 0.9. The sample data showed poor agreement within each of the components of the measurement. There was some improvement when ploidy was in agreement, but correlation coefficients failed to exceed values of 0.5 for Tpot. The data suggest that observer-associated analysis of Ts and tissue processing and tumour heterogeneity were the major causes of variability in the Tpot measurement. The first two aspects can be standardized and minimized, but heterogeneity will remain a problem with biopsy techniques. © 1999 Cancer Research Campaig

    The Classical Harmonic Vibrations of the Atomic Centers of Mass with Micro Amplitudes and Low Frequencies Monitored by the Entanglement between the Two Two-level Atoms in a Single mode Cavity

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    We study the entanglement dynamics of the two two-level atoms coupling with a single-mode polarized cavity field after incorporating the atomic centers of mass classical harmonic vibrations with micro amplitudes and low frequencies. We propose a quantitative vibrant factor to modify the concurrence of the two atoms states. When the vibrant frequencies are very low, we obtain that: (i) the factor depends on the relative vibrant displacements and the initial phases rather than the absolute amplitudes, and reduces the concurrence to three orders of magnitude; (ii) the concurrence increases with the increase of the initial phases; (iii) the frequency of the harmonic vibration can be obtained by measuring the maximal value of the concurrence during a small time. These results indicate that even the extremely weak classical harmonic vibrations can be monitored by the entanglement of quantum states.Comment: 10 pages, 3 figure

    Fluorescence characterization of clinically-important bacteria

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    Healthcare-associated infections (HCAI/HAI) represent a substantial threat to patient health during hospitalization and incur billions of dollars additional cost for subsequent treatment. One promising method for the detection of bacterial contamination in a clinical setting before an HAI outbreak occurs is to exploit native fluorescence of cellular molecules for a hand-held, rapid-sweep surveillance instrument. Previous studies have shown fluorescence-based detection to be sensitive and effective for food-borne and environmental microorganisms, and even to be able to distinguish between cell types, but this powerful technique has not yet been deployed on the macroscale for the primary surveillance of contamination in healthcare facilities to prevent HAI. Here we report experimental data for the specification and design of such a fluorescence-based detection instrument. We have characterized the complete fluorescence response of eleven clinically-relevant bacteria by generating excitation-emission matrices (EEMs) over broad wavelength ranges. Furthermore, a number of surfaces and items of equipment commonly present on a ward, and potentially responsible for pathogen transfer, have been analyzed for potential issues of background fluorescence masking the signal from contaminant bacteria. These include bedside handrails, nurse call button, blood pressure cuff and ward computer keyboard, as well as disinfectant cleaning products and microfiber cloth. All examined bacterial strains exhibited a distinctive double-peak fluorescence feature associated with tryptophan with no other cellular fluorophore detected. Thus, this fluorescence survey found that an emission peak of 340nm, from an excitation source at 280nm, was the cellular fluorescence signal to target for detection of bacterial contamination. The majority of materials analysed offer a spectral window through which bacterial contamination could indeed be detected. A few instances were found of potential problems of background fluorescence masking that of bacteria, but in the case of the microfiber cleaning cloth, imaging techniques could morphologically distinguish between stray strands and bacterial contamination

    Protein crystals in adenovirus type 5-infected cells: requirements for intranuclear crystallogenesis, structural and functional analysis

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    Intranuclear crystalline inclusions have been observed in the nucleus of epithelial cells infected with Adenovirus serotype 5 (Ad5) at late steps of the virus life cycle. Using immuno-electron microscopy and confocal microscopy of cells infected with various Ad5 recombinants modified in their penton base or fiber domains, we found that these inclusions represented crystals of penton capsomers, the heteromeric capsid protein formed of penton base and fiber subunits. The occurrence of protein crystals within the nucleus of infected cells required the integrity of the fiber knob and part of the shaft domain. In the knob domain, the region overlapping residues 489–492 in the FG loop was found to be essential for crystal formation. In the shaft, a large deletion of repeats 4 to 16 had no detrimental effect on crystal inclusions, whereas deletion of repeats 8 to 21 abolished crystal formation without altering the level of fiber protein expression. This suggested a crucial role of the five penultimate repeats in the crystallisation process. Chimeric pentons made of Ad5 penton base and fiber domains from different serotypes were analyzed with respect to crystal formation. No crystal was found when fiber consisted of shaft (S) from Ad5 and knob (K) from Ad3 (heterotypic S5-K3 fiber), but occurred with homotypic S3K3 fiber. However, less regular crystals were observed with homotypic S35-K35 fiber. TB5, a monoclonal antibody directed against the Ad5 fiber knob was found by immunofluorescence microscopy to react with high efficiency with the intranuclear protein crystals in situ. Data obtained with Ad fiber mutants indicated that the absence of crystalline inclusions correlated with a lower infectivity and/or lower yields of virus progeny, suggesting that the protein crystals might be involved in virion assembly. Thus, we propose that TB5 staining of Ad-infected 293 cells can be used as a prognostic assay for the viability and productivity of fiber-modified Ad5 vectors

    Comparing the performance of FA, DFA and DMA using different synthetic long-range correlated time series

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    Notwithstanding the significant efforts to develop estimators of long-range correlations (LRC) and to compare their performance, no clear consensus exists on what is the best method and under which conditions. In addition, synthetic tests suggest that the performance of LRC estimators varies when using different generators of LRC time series. Here, we compare the performances of four estimators [Fluctuation Analysis (FA), Detrended Fluctuation Analysis (DFA), Backward Detrending Moving Average (BDMA), and centred Detrending Moving Average (CDMA)]. We use three different generators [Fractional Gaussian Noises, and two ways of generating Fractional Brownian Motions]. We find that CDMA has the best performance and DFA is only slightly worse in some situations, while FA performs the worst. In addition, CDMA and DFA are less sensitive to the scaling range than FA. Hence, CDMA and DFA remain "The Methods of Choice" in determining the Hurst index of time series.Comment: 6 pages (including 3 figures) + 3 supplementary figure

    Cooperative coupling of ultracold atoms and surface plasmons

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    Cooperative coupling between optical emitters and light fields is one of the outstanding goals in quantum technology. It is both fundamentally interesting for the extraordinary radiation properties of the participating emitters and has many potential applications in photonics. While this goal has been achieved using high-finesse optical cavities, cavity-free approaches that are broadband and easy to build have attracted much attention recently. Here we demonstrate cooperative coupling of ultracold atoms with surface plasmons propagating on a plane gold surface. While the atoms are moving towards the surface they are excited by an external laser pulse. Excited surface plasmons are detected via leakage radiation into the substrate of the gold layer. A maximum Purcell factor of ηP=4.9\eta_\mathrm{P}=4.9 is reached at an optimum distance of z=250 nmz=250~\mathrm{nm} from the surface. The coupling leads to the observation of a Fano-like resonance in the spectrum.Comment: 9 pages, 4 figure

    Is Microsporidial keratitis an emerging cause of stromal keratitis? – a case series study

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    BACKGROUND: Microsporidial keratitis is a rare cause of stromal keratitis. We present a series of five cases of microsporidial keratitis from a single centre in southern India with microbiologic and histopathologic features. CASE PRESENTATION: Patient charts of five cases of microsporidial stromal keratitis diagnosed between January 2002 and June 2004 were reviewed retrospectively for clinical data, microbiologic and histopathologic data. The presence of microsporidia was confirmed by special stains on corneal scrapings and/or corneal tissues, and electron microscopy. All patients were immunocompetent with a preceding history of trauma in three. Four patients presented with unilateral, small, persisting deep stromal infiltrates, of uncertain etiology, in the cornea, which were not responding to conventional antimicrobial treatment and required penetrating keratoplasty in three. Fifth case was unsuspected and underwent keratoplasty for post-traumatic scar. Three of five cases were diagnosed on corneal scrapings, prior to keratoplasty, while two were diagnosed only on histology. The microsporidia appeared as oval well defined bodies with dense staining at one pole. None of the patients showed recurrence following keratoplasty. CONCLUSION: Microsporidia, though rare, should be suspected in chronic culture-negative stromal keratitis. Organisms could lie dormant without associated inflammation
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