269 research outputs found

    REGULATORY ROLE OF OX22HIGH T-CELLS IN MERCURY-INDUCED AUTOIMMUNITY IN THE BROWN NORWAY RAT

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    The monoclonal antibody OX22 defines a functional split within CD4+ T cells in the rat, with OX22high cells mainly producing interleukin 2 (IL-2) and interferon γ and responsible for delayed-type hypersensitivity responses, and OX22low cells mainly producing IL-4 and -5 and responsible for providing B cell help. There are reciprocal interactions between OX22high and OX22low cells, and it has been suggested that the OX22low subset has a role in the prevention of autoimmunity. We have used OX22 in vivo to define the role of these subsets in mercuric chloride-induced autoimmunity in the Brown Norway rat. In this model, there is polyclonal B cell activation and animals develop widespread tissue injury. Treatment of thymectomized animals with OX22 led to a profound reduction in the number of OX22high T cells in the peripheral blood. OX22-treated animals consistently developed more severe tissue injury than controls given an irrelevant antibody of the same isotype. Control animals pretreated with broad spectrum antimicrobial drugs showed milder tissue injury, but this protective effect of antimicrobials was lost in OX22-treated animals. Transfer of naive T cells to OX22-treated animals provided protection, but if T cells were depleted in vitro of OX22high cells before transfer, this effect was lost. These data provide evidence for a protective immunoregulatory role for OX22high T cells in mercuric chloride-induced autoimmunity.link_to_subscribed_fulltex

    Investigations on the thermo-physical properties of nanofluid-based carbon nanofibers under modified testing conditions

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    Rod shaped carbon nanofibers with 1wt%, 3wt% and 5wt% of iron catalyst loadings are developed by Chemical Vapour Deposition (CVD) and the morphology of the carbon nanofibers are characterized. Nanofluids are prepared by dispersing 0.5wt% of carbon nanofiber in the mixture of Sodium Dodecyl Sulfate (SDS) and deionized water to measure the thermal conductivity at varying temperature conditions. The results show that the thermal conductivity of nanofluid-based carbon nanofiber decreases with the increment in catalyst loading. The morphology examination indicates an increment in the diameter of carbon nanofiber during catalyst loading. Further surface area study for the nanofibers, based on nitrogen absorption analysis, confirms the possible mechanisms that scale down the thermal transport in nanofluid

    Three steps to data quality

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    The quality of data in general practice clinical information systems varies enormously. This variability jeopardizes the proposed national strategy for an integrated care records service and the capacity of primary care organisations to respond coherently to the demands of clinical governance and the proposed quality-based general practice contract. This is apparent in the difficulty in automating the audit process and in comparing aggregated data from different practices. In an attempt to provide data of adequate quality to support such operational needs, increasing emphasis is being placed on the standardisation of data recording

    A Comparative Study on Laminar Flow of Multiple Orifice Gases through a Tubular Welding Electrode

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    For an attempt to design a recently developed environmentally friendly manual welding process, that is aimed at reducing/eliminating the use of cellulose in its flux coating, a tubular coated welding electrode with a gas passes through the orifice of the tube is necessary. The objective of this study is to investigate and understand the flow characteristics of such intended orifice gasses that are to flow through the electrode tube. An attempt was made to simulate the flow of three different gasses such, argon, helium and carbon dioxide by using a commercial finite element tool with volumetric flow, mean velocity and pressure head as input parameters. A specially made mild steel coated electrode tube with an inner diameter of 1.8 mm was considered for the study. An axisymmetric mode was generated based on the tubular welding electrode dimension with inlet,pipe wall,center line and outlet as boundary regions.The model was simulated with optimum mesh grid size on axial and radial distance of the axisymmetric model. From the result obtained the fluid flow characteristic such as laminar,transition and turbulent were found at selected volume flow rate ranges. The characteristic of fluid flow regions and the relationship of entrance length, pressure variation and maximum velocity at fully developed region were obtained. The simulated results were compared and validated with analytical solutions for the accuracy

    Unstable Temperature Distribution in Friction Stir Welding

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    In the friction stir welding process, a nonuniform and high generated temperature is undesirable. Unstable temperature and distribution affect thermal and residual stresses along the welding line, thus necessitating mitigation. This paper presents a simple method to prevent significant temperature difference along the welding line and also to help nullifying some defect types associated with this welding, such as end-hole, initial unwelded line, and deformed areas. In the experimental investigation, a heat and force thermocouple and dynamometer were utilized while couple-field thermomechanical models were used to evaluate temperature and its distribution, plastic strain, and material displacement. The suggested method generated uniform temperature distributions. Measurement results are discussed, showing a good correlation with prediction

    Prevalence of Campylobacter spp. in diarrhoea samples from patients in New South Wales, Australia

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    Campylobacteriosis is a leading cause of bacterial foodborne disease in many industrialized countries including Australia. New South Wales (NSW) is the most populous state in Australia yet the lack of any Campylobacter species surveillance programs has led to a knowledge gap in the importance of these pathogens as causes of diarrhoea. The data collected in this study demonstrated a need for such programs. In this study, 400 human clinical fecal samples were collected from two NSW locations, Western Sydney and Wagga Wagga, and tested for the presence of Campylobacter spp. Patients were clustered by location, age and gender to assess Campylobacter spp. prevalence within these groups between the two regions. The frequency of Campylobacter spp. was higher in males compared to females in the age groups 0–4 and 5–14 years; 6.4% and 1.0%, and 8.2% and none, respectively (P < 0.05). A second peak was noted in elderly adults compared with those in younger age groups. Based on the findings of the quantitative PCR analysis it was estimated that the age-adjusted prevalence of Campylobacter spp. associated diarrhoea was 159 cases per 100,000 persons. [Int Microbiol 2016; 19(1):33-37]Keywords: Campylobacter species · campylobacteriosis · foodborne diseases · prevalence of pathogens · New South Wales, Australi

    Peritoneal perfusion with oxygenated perfluorocarbon augments systemic oxygenation.

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    BACKGROUND: Despite maximal ventilatory support, many patients die from hypoxia in the setting of potentially reversible pulmonary failure. There remains a pressing need for additional pulmonary supportive care measures, especially techniques that do not require systemic anticoagulation. The objective of our experiments was to determine whether systemic oxygenation could be increased in a large animal, with induced hypoxia, by perfusing the abdominal cavity with oxygenated perfluorocarbons. METHODS: Fifteen pigs with a mean (+/- SD) weight of 45 +/- 5 kg were intubated and rendered hypoxic by ventilating them with a blend of nitrogen and oxygen to achieve subatmospheric concentrations of inspired oxygen ranging from 18 to 10%, resulting in baseline mean Pao(2) range of 65.9 +/- 9.7 to 26.6 +/- 2.8 mm Hg, respectively. Peritoneal perfusion was performed in eight animals with oxygenated perfluorocarbon and in seven control animals with oxygenated saline solution. RESULTS: The average increase in Pao(2) with oxygenated perfluorocarbon perfusion, compared to oxygenated saline solution perfusion, ranged from 8.1 to 18.2 mm Hg. A common treatment effect was estimated across all fraction of inspired oxygen (Fio(2)) values, representing the average mean difference in oxygen uptake between oxygenated perfluorocarbon and saline solution, irrespective of the level of Fio(2). This average was 12.8 mm Hg (95% confidence interval, 7.4 to 18.2; p \u3c 0.001). The most clinically relevant results occurred at an Fio(2) of 14%, resulting in a baseline mean Pao(2) of 39.4 +/- 5.0 mm Hg with oxygenated saline solution perfusion, and a mean Pao(2) of 55.3 +/- 7.6 mm Hg with oxygenated perfluorocarbon perfusion. This corresponded to an increase in arterial oxygen saturation from 73 to 89%. CONCLUSION: These results of our principle experiments demonstrate that the peritoneal cavity can be used for gas exchange and, in our model, yielded clinically relevant increases in systemic arterial oxygen levels. This technique may have the potential for the supportive care of patients dying from hypoxia in the setting of reversible lung injury

    Prediction and measurement of weld dilution in robotic CO2 arc welding

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    Weld dilution is an important feature of weld bead geometry that determines the mechanical and chemical properties of a welded joint. For robotic CO2 arc welding, several welding process parameters are reported to be controlling the dilution. This paper investigates the relationship between four of these process parameters and dilution by depositing ‘bead on plate’ robotic CO2 arc welds over mild steel plates. Two level four factor full factorial design method was used for conducting the experimental runs and linear regression models were developed accordingly. The adequacy of the models were tested by applying students ‘t’ test and the predicted values from the models were plotted against the observed values through scatter diagram. Results showed that the proposed two level full factorial empirical models could predict the weld dilution with reasonable accuracy and ensure uniform weld quality. It can be concluded that robotic CO2 arc welding is a very simple and effective tool for quantifying the main and interactive effects of welding parameters on dilution. Future works should focus in analyzing the influence of variable pure gasses as well as the gas mixture on dilution percentage in robotic arc welding

    Unstable Temperature Distribution in Friction Stir Welding

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    In the friction stir welding process, a nonuniform and high generated temperature is undesirable. Unstable temperature and distribution affect thermal and residual stresses along the welding line, thus necessitating mitigation. This paper presents a simple method to prevent significant temperature difference along the welding line and also to help nullifying some defect types associated with this welding, such as end-hole, initial unwelded line, and deformed areas. In the experimental investigation, a heat and force thermocouple and dynamometer were utilized while couple-field thermomechanical models were used to evaluate temperature and its distribution, plastic strain, and material displacement. The suggested method generated uniform temperature distributions. Measurement results are discussed, showing a good correlation with predictions

    Caring for the patient, caring for the record: an ethnographic study of 'back office' work in upholding quality of care in general practice

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    © 2015 Swinglehurst and Greenhalgh; licensee BioMed Central. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Additional file 1: Box 1. Field notes on summarising (Clover Surgery). Box 2. Extract of document prepared for GPs by summarisers at Clover Surgery. Box 3. Fieldnotes on coding incoming post, Clover (original notes edited for brevity).This work was funded by a research grant from the UK Medical Research Council (Healthcare Electronic Records in Organisations 07/133) and a National Institute of Health Research doctoral fellowship award for DS (RDA/03/07/076). The funders were not involved in the selection or analysis of data nor did they make any contribution to the content of the final manuscript
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