300 research outputs found

    Effect of high pressure homogenization (HPH) on the rheological properties of tomato juice: Creep and recovery behaviours

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    AbstractHigh pressure homogenization (HPH) is a non-thermal technology that has been proposed as a partial or total substitute for the thermal processing of food. Although its effect on microbial inactivation has been widely studied, the rheological changes occurring in fruit products need better describing. The present work evaluated the effect of HPH (up to 150MPa) on the creep and recovery properties of tomato juice. The mechanical Burger's model explained juice creep compliance well, and its parameters (Newtonian dashpots and Hookean springs) were evaluated as a function of the homogenization pressure. HPH processing increased both tomato juice elastic and viscous behaviours, which could be attributed to the disruption of suspended particles during processing. Moreover, each Burger's model constituent could be related to the product internal structure. The results obtained highlighted the possible applications of the HPH process as a valuable tool to promote physical changes in food products

    Effect of high pressure homogenization (HPH) on the rheological properties of tomato juice: Time-dependent and steady-state shear

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    AbstractHigh pressure homogenization (HPH) is a non-thermal technology that has been widely studied as a partial or total substitute for the thermal processing of food. Although microbial inactivation has been widely studied, there are only a few works in the literature reporting the physicochemical changes caused in fruit products due to HPH, especially those regarding the rheological properties. The present work evaluated the effect of HPH (up to 150MPa) on the time-dependent and steady-state shear rheological properties of tomato juice. HPH reduced the mean particle diameter and particle size distribution (PSD), and increased its consistency and thixotropy. The rheological results were in accordance with the PSD observed. The rheological properties of the juice were evaluated by the Herschel–Bulkley and Falguera–Ibarz models (steady-state shear) and Figoni–Shoemaker and Weltman models (time-dependent). The parameters of these equations were modelled as a function of the homogenization pressure. The models obtained described the experimental values well, and contributed to future studies on product and process development

    Transplacental induction of membranous nephropathy in a neonate

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    We report a case of renal failure in a newborn infant due to membranous glomerulonephritis. The patient was anuric in the first 3 weeks of life, after which renal function recovered. The serum of the mother contained IgG antibodies which reacted with tubular brush borders and glomeruli of adult and fetal human kidneys. Reactivity with renal epithelium from human kidneys was detected. We suggest that a transplacental, passive Heymann nephritis-like mechanism was the pathogenesis of the neonate's symptoms, although the antigen(s) involved was shown not to be gp 330 or any of the renal antigens known to be involved in experimental nephropathies

    The Self Model and the Conception of Biological Identity in Immunology

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    The self/non-self model, first proposed by F.M. Burnet, has dominated immunology for sixty years now. According to this model, any foreign element will trigger an immune reaction in an organism, whereas endogenous elements will not, in normal circumstances, induce an immune reaction. In this paper we show that the self/non-self model is no longer an appropriate explanation of experimental data in immunology, and that this inadequacy may be rooted in an excessively strong metaphysical conception of biological identity. We suggest that another hypothesis, one based on the notion of continuity, gives a better account of immune phenomena. Finally, we underscore the mapping between this metaphysical deflation from self to continuity in immunology and the philosophical debate between substantialism and empiricism about identity

    Sustainable change: long-term efforts toward developing a learning organization

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    Globalization and intensified competition require organizations to change and adapt to dynamic environments in order to stay competitive. This article describes a longitudinal action research study supporting the strategic change of a trading company. The strategic change was accompanied by planned changes in organizational structures and processes, management systems, emerging changes in leadership, and organization members’ attitudes and behaviors, and it was supported by management development activities. Longitudinal data over a 4-year period including participant observation and interviews reveal that a systemic approach, a learning and becoming perspective toward change, trust, an appropriate role perception, and the specific use of management instruments contribute to sustained change that resulted in performance improvements and a move toward a learning organization. We conclude with implications for strategic change and suggestions for further research in this area

    Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events

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    The B0B^0-Bˉ0\bar B^0 oscillation frequency has been measured with a sample of 23 million \B\bar B pairs collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we select events in which both B mesons decay semileptonically and use the charge of the leptons to identify the flavor of each B meson. A simultaneous fit to the decay time difference distributions for opposite- and same-sign dilepton events gives Δmd=0.493±0.012(stat)±0.009(syst)\Delta m_d = 0.493 \pm 0.012{(stat)}\pm 0.009{(syst)} ps1^{-1}.Comment: 7 pages, 1 figure, submitted to Physical Review Letter

    Multicentre comparison of a diagnostic assay: Aquaporin-4 antibodies in neuromyelitis optica

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    Objective Antibodies to cell surface central nervous system proteins help to diagnose conditions which often respond to immunotherapies. The assessment of antibody assays needs to reflect their clinical utility. We report the results of a multicentre study of aquaporin (AQP) 4 antibody (AQP4-Ab) assays in neuromyelitis optica spectrum disorders (NMOSD). Methods Coded samples from patients with neuromyelitis optica (NMO) or NMOSD (101) and controls (92) were tested at 15 European diagnostic centres using 21 assays including live (n=3) or fixed cell-based assays (n=10), flow cytometry (n=4), immunohistochemistry (n=3) and ELISA (n=1). Results Results of tests on 92 controls identified 12assays as highly specific (0-1 false-positive results). 32 samples from 50 (64%) NMO sera and 34 from 51 (67%) NMOSD sera were positive on at least two of the 12 highly specific assays, leaving 35 patients with seronegative NMO/spectrum disorder (SD). On the basis of a combination of clinical phenotype and the highly specific assays, 66 AQP4-Ab seropositive samples were used to establish the sensitivities (51.5-100%) of all 21 assays. The specificities (85.8-100%) were based on 92 control samples and 35 seronegative NMO/SD patient samples. Conclusions The cell-based assays were most sensitive and specific overall, but immunohistochemistry or flow cytometry could be equally accurate in specialist centres. Since patients with AQP4-Ab negative NMO/SD require different management, the use of both appropriate control samples and defined seronegative NMOSD samples is essential to evaluate these assays in a clinically meaningful way. The process described here can be applied to the evaluation of other antibody assays in the newly evolving field of autoimmune neurology

    Impact of nationwide enhanced implementation of best practices in pancreatic cancer care (PACAP-1): A multicenter stepped-wedge cluster randomized controlled trial

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    Background: Pancreatic cancer has a very poor prognosis. Best practices for the use of chemotherapy, enzyme replacement therapy, and biliary drainage have been identified but their implementation in daily clinical practice is often suboptimal. We hypothesized that a nationwide program to enhance implementation of these best practices in pancreatic cancer care would improve survival and quality of life. Methods/design: PACAP-1 is a nationwide multicenter stepped-wedge cluster randomized controlled superiority trial. In a per-center stepwise and randomized manner, best practices in pancreatic cancer care regarding the use of (neo)adjuvant and palliative chemotherapy, pancreatic enzyme replacement therapy, and metal biliary stents are implemented in all 17 Dutch pancreatic centers and their regional referral networks during a 6-week initiation period. Per pancreatic center, one multidisciplinary team functions as reference for the other centers in the network. Key best practices were identified from the literature, 3 years of data from existing nationwide registries within the Dutch Pancreatic Cancer Project (PACAP), and national expert meetings. The best practices follow the Dutch guideline on pancreatic cancer and the current state of the literature, and can be executed within daily clinical practice. The implementation process includes monitoring, return visits, and provider feedback in combination with education and reminders. Patient outcomes and compliance are monitored within the PACAP registries. Primary outcome is 1-year overall survival (for all disease stages). Secondary outcomes include quality of life, 3- and 5-year overall survival, and guideline compliance. An improvement of 10% in 1-year overall survival is considered clinically relevant. A 25-month study duration was chosen, which provides 80% statistical power for a mortality reduction of 10.0% in the 17 pancreatic cancer centers, with a required sample size of 2142 patients, corresponding to a 6.6% mortality reduction and 4769 patients nationwide. Discussion: The PACAP-1 trial is designed to evaluate whether a nationwide program for enhanced implementation of best practices in pancreatic cancer care can improve 1-year overall survival and quality of life. Trial registration: ClinicalTrials.gov, NCT03513705. Trial opened for accrual on 22th May 2018
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