1,915 research outputs found

    Onset of unsteady horizontal convection in rectangle tank at Pr=1Pr=1

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    The horizontal convection within a rectangle tank is numerically simulated. The flow is found to be unsteady at high Rayleigh numbers. There is a Hopf bifurcation of RaRa from steady solutions to periodic solutions, and the critical Rayleigh number RacRa_c is obtained as Rac=5.5377Ă—108Ra_c=5.5377\times 10^8 for the middle plume forcing at Pr=1Pr=1, which is much larger than the formerly obtained value. Besides, the unstable perturbations are always generated from the central jet, which implies that the onset of instability is due to velocity shear (shear instability) other than thermally dynamics (thermal instability). Finally, Paparella and Young's [J. Fluid Mech. 466 (2002) 205] first hypotheses about the destabilization of the flow is numerically proved, i.e. the middle plume forcing can lead to a destabilization of the flow.Comment: 4pages, 6 figures, extension of Chin. Phys. Lett. 2008, 25(6), in pres

    Phenological characteristics of different winegrape cultivars in Central Italy

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    Statistical models based on temperature accumulation are used to estimate grapevine phenology (e.g. bud break, flowering) through summation of daily heat requirements calibrated from a base temperature and a given date. This study was designed to define the grapevine agro-phenological behaviour through analysis of potential trends of some principal phenological phenomena, such as flowering, harvest, and berry sugar levels at harvest. The data utilized were recorded over a 13-year period (2000-2012) for different grape varieties in the Umbria wine region in central Italy. Moreover, to determine the more important relationships between meteorological variables and recorded data, partial least-squares regressions were carried out. The trend analysis for berry sugar accumulation shows increasing degrees during the study period that were linked more to the 'Grechetto' cultivar than to the 'Chardonnay' and 'Merlot' cultivars, and then to 'Cabernet'. The statistical model that was focused on the study of the relationships between mean annual berry sugar levels and meteorological variables showed that mean maximum temperatures in April and July are the most important predictive variables for berry sugar accumulation, through their positive influence on berry sugar degree

    International Consensus Statement on Allergy and Rhinology: Rhinosinusitis

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    BACKGROUND: The body of knowledge regarding rhinosinusitis (RS) continues to expand, with rapid growth in number of publications yet substantial variability in the quality of those presentations. In an effort to both consolidate and critically appraise this information, rhinologic experts from around the world have produced the International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR:RS). This executive summary consolidates the findings of the ICAR:RS document. METHODS: ICAR:RS presents over 140 topics in the forms of evidence-based reviews with recommendations (EBRRs) and evidence-based reviews (EBR). The structured recommendations of the EBRR sections are summarized in this executive summary. RESULTS: This summary compiles the EBRRs regarding medical and surgical management of acute RS (ARS) and chronic RS with and without nasal polyps (CRSwNP and CRSsNP). CONCLUSION: This ICAR:RS Executive Summary provides a compilation of the evidence-based recommendations for medical and surgical treatment of the most common forms of RS

    Searching for antimicrobial photosensitizers among a panel of BODIPYs

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    In recent years, antimicrobial Photodynamic Therapy (aPDT) gained increasing attention for its potential to inhibit the growth and spread of microorganisms, both as free-living cells and/or embedded in biofilm communities. In this scenario, compounds belonging to the family of boron-dipyrromethenes (BODIPYs) represent a very promising class of photosensitizers for applications in antimicrobial field. In this study, twelve non-ionic and three cationic BODIPYs were assayed for the inactivation of Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans. As expected, S. aureus showed to be very sensitive to BODIPYs and mild conditions were sufficient to reach good rates of photoinactivation with both neutral and monocationic ones. Surprisingly, one neutral compound (named B9 in this study) resulted the best BODIPY to photoinactivate P. aeruginosa PAO1. The photoinactivation of C. albicans was reached with both neutral and mono-cationic BODIPYs. Furthermore, biofilms of the three model microorganisms were challenged with BODIPYs in light-based antimicrobial technique. S. aureus biofilms were successfully inhibited with milder conditions than those applied to P. aeruginosa and C. albicans. Notably, it was possible to eradicate 24-h-old biofilms of both S. aureus and P. aeruginosa. In conclusion, this study supports the potential of neutral BODIPYs as pan-antimicrobial PSs. Graphical abstract: [Figure not available: see fulltext.]

    Photo-Inactivation of Staphylococcus aureus by Diaryl-Porphyrins

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    Photodynamic Antimicrobial Chemotherapy (PACT) has received great attention in recent years since it is an effective and promising modality for the treatment of human oral and skin infections with the advantage of bypassing pathogens' resistance to antimicrobials. Moreover, PACT applications demonstrated a certain activity in the inhibition and eradication of biofilms, overcoming the well-known tolerance of sessile communities to antimicrobial agents. In this study, 13 diaryl-porphyrins (mono-, di-cationic, and non-ionic) P1-P13 were investigated for their potential as photosensitizer anti-Staphylococcus aureus. The efficacy of the diaryl-porphyrins was evaluated through photo-inactivation tests. Crystal-violet staining combined with viable count techniques were aimed at assaying their anti-biofilm activity. Among the tested compounds, the neutral photosensitizer P4 was better than the cationic ones, irrespective of their corresponding binding rates. In particular, P4 was active in inhibiting the biofilm formation and in impairing the viability of the adherent and planktonic populations of a 24 h old biofilm. The inhibitory activity was also efficient against a methicillin resistant S. aureus strain. In conclusion, the diaryl-porphyrin family represents a reservoir of promising compounds for photodynamic applications against the pathogen S. aureus and in preventing the formation of biofilms that cause many infections to become chronic

    hic Rhodus, hic salta: Tito Orlandi és Julianne Nyhan beszélgetése

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    Contrast-enhanced ultrasound features of hepatocellular carcinoma in dogs

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    BACKGROUND: This study aimed to describe the contrast-enhanced ultrasound (CEUS) features of canine hepatocellular carcinoma (HCC) in relation to cellular differentiation and lesion size. METHODS: Sixty dogs with a cytological diagnosis of HCC and that underwent a CEUS examination were retrospectively selected. The wash-in and wash-out patterns of contrast enhancement, along with the time to wash-in and the time to wash-out, of each lesion were recorded. A dimensional cut-off value of 3\u2009cm was adopted for classification. RESULTS: Cellular differentiation had a significant influence on both wash-in (chi-squared=16.99; P<0.001) and wash-out (chi-squared=10.9; P=0.004) patterns of contrast enhancement. Lesion size had a lower, but still significant, influence on both wash-in (chi-squared=12.7; P=0.005) and wash-out (chi-squared=7.42; P=0.024) patterns. A homogeneous hyperenhancement in the arterial phase followed by homogeneous wash-out were suggestive of a well-differentiated HCC. The cellular differentiation of lesions with inhomogeneous hyperenhancement or hypoenhancement/no enhancement as well as an inhomogeneous wash-out or no wash-out could not be inferred. CONCLUSIONS: No significant difference in the time to wash-in and the time to wash-out in relation to cellular differentiation or lesion size was evident. CEUS has the potential to improve efficiency in the diagnosis of HCCs in dogs

    Use of phase change materials in retail display cabinets to reduce the effect of defrosts

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    Phase change materials (PCMs) have the potential to reduce temperature fluctuations in retail display cabinets. There are several areas where reducing temperature fluctuations may be beneficial, e.g. minimising effects of defrosts and to damp the day/night variation in refrigeration duty. PCMs were placed below the shelves in a closed door multi-deck cabinet with the aim of reducing temperature fluctuations during defrosts. The cabinet was tested in a test room conforming to the EN23953 test standard (climate class 3). The cabinet was tested with and without the PCMs. No measurable effect for the PCMs was found. A finite difference model was used to explain the results and suggest improvements. Predictions showed the problem was due to the limited heat transfer coefficient, surface area and low thermal conductivity of the PCM

    Trifarotene: a current review and perspectives in dermatology

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    Retinoids have numerous applications in inflammatory, dyskeratotic, and oncohematology diseases. Retinoids have now reached the fourth generation, progressively reducing toxicity whilst increasing their efficacy. Trifarotene is a new fourth-generation retinoid with a selective action on RAR-γ. In this review, we reported the trials—both concluded and in progress—including the use of trifarotene in dermatological diseases. Studies were identified by searching electronic databases (MEDLINE, EMBASE, PubMed, Cochrane, Trials.gov) from 2012 to today and reference lists of respective articles. Only articles published in English language were included. Randomized trials evaluating trifarotene tolerability, safety, and efficacy in congenital ichthyosis and acne have demonstrated great results and mild side effects, leading to the approval by the FDA of trifarotene for the treatment of lamellar ichthyosis in 2014, and of acne vulgaris in October 2019. No high-quality randomized clinical trials have evaluated the treatment of primary cutaneous lymphomas with trifarotene. Finally, we are hypothesizing future perspectives in the treatment of non-melanoma skin cancers, fungal infections, photoaging, and hand-foot skin reactions with trifarotene
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