206 research outputs found

    Discrete Time Analysis of Multi-Queue Systems with Multiple Departure Streams in Material Handling and Production under Different Service Rules

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    In this work, we present a modelling approach in order to depict service rules holistically. The developed model is called multi-queue system with multiple departure streams (MQSMDS). The MQSMDS is modelled as a discrete time Markov chain. On the basis of a numerical study, the system characteristics are evaluated. The results of this work enable a rapid and low-cost analysis of material handling and production systems as well as a fast and easy identification of suitable service rules

    Investigation of the influence of calibration practices on cytogenetic laboratory performance for dose estimation

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    Purpose: In the frame of the QA program of RENEB, an inter-laboratory comparison (ILC) of calibration sources used in biological dosimetry was achieved to investigate the influence of calibration practices and protocols on the results of the dose estimation performance as a first step to harmonization and standardization of dosimetry and irradiation practices in the European biological dosimetry network. Materials and methods: Delivered doses by irradiation facilities used by RENEB partners were determined with EPR/alanine dosimetry system. Dosimeters were irradiated in the same conditions as blood samples. A short survey was also performed to collect the information needed for the data analysis and evaluate the diversity of practices. Results: For most of partners the deviation of delivered dose from the targeted dose remains below 10%. Deviations larger than 10% were observed for five facilities out of 21. Origins of the largest discrepancies were identified. Correction actions were evaluated as satisfactory. The re-evaluation of some ILC results for the fluorescence in situ hybridization (FISH) and premature chromosome condensation (PCC) assays has been performed leading to an improvement of the overall performances. Conclusions: This work has shown the importance of dosimetry in radiobiology studies and the needs of harmonization, standardization in irradiation and dosimetry practices and educational training for biologists using ionizing radiation.European Community’s Seventh Framework Program [grant agreement No. 295513

    Critical Role of Methylglyoxal and AGE in Mycobacteria-Induced Macrophage Apoptosis and Activation

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    Apoptosis and activation of macrophages play an important role in the host response to mycobacterial infection involving TNF-α as a critical autocrine mediator. The underlying mechanisms are still ill-defined. Here, we demonstrate elevated levels of methylglyoxal (MG), a small and reactive molecule that is usually a physiological product of various metabolic pathways, and advanced glycation end products (AGE) during mycobacterial infection of macrophages, leading to apoptosis and activation of macrophages. Moreover, we demonstrate abundant AGE in pulmonary lesions of tuberculosis (TB) patients. Global gene expression profiling of MG-treated macrophages revealed a diverse spectrum of functions induced by MG, including apoptosis and immune response. Our results not only provide first evidence for the involvement of MG and AGE in TB, but also form a basis for novel intervention strategies against infectious diseases in which MG and AGE play critical roles

    Clinical outcomes and characteristics of critically ill patients with influenza- and COVID-19-induced ARDS: A retrospective, matched cohort study

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    IntroductionSeasonal epidemic influenza and SARS-CoV-2 are the most frequent viruses causing acute respiratory distress syndrome (ARDS). To what extent these two etiologies differ in ICU patients remains uncertain. We, therefore, aimed at comparing the severity and outcomes of influenza and SARS-CoV-2-induced ARDS in mechanically ventilated patients.MethodsThis retrospective, analytic, single-center study was conducted in the medical ICU of Nancy University Hospital in France. Adult patients hospitalized with confirmed influenza (from 2009 to 2019) or SARS-CoV-2-induced ARDS (between March 2020 and May 2021) and those under mechanical ventilation were included. Each patient with influenza was matched with two patients with COVID-19, with the same severity of ARDS. The primary endpoint was death in ICU on day 28. The secondary endpoints were the duration of vasopressors, the use of renal replacement therapy, the duration of mechanical ventilation, and the ICU length of stay.ResultsA total of 42 patients with influenza were matched with 84 patients with COVID-19. They had similar sex distribution, age, Charlson comorbidity index, and ARDS severity. On day 28, 11 (26.2%) patients in the influenza group and nine (10.7%) patients in the COVID-19 group had died (p = 0.0084, HR = 3.31, CI 95% [1.36–8.06]). In the univariate Cox model, being infected with SARS-CoV-2, SOFA and SAPS II scores, initial arterial pH, PaCO2, PaO2/FiO2, serum lactate level, platelet count, and use of renal replacement therapy were significantly associated with mortality. In the multivariate Cox model, the SOFA score at admission (p < 0.01, HR = 1.284, CI 95% [1.081; 1.525]) and the initial pH (p < 0.01, HR = 0.618, CI 95% [0.461; 0.828]) were the only predictors of mortality. The type of virus had no influence on mortality, though patients with COVID-19 underwent longer mechanical ventilation and received more neuromuscular blockers and prone positioning.ConclusionIn mechanically ventilated patients with ARDS, 28-day mortality was higher among patients with influenza as compared to patients with COVID-19 because of a higher initial extra-pulmonary severity. However, the type of virus was not, by itself, correlated with mortality

    A Comparison of Cooling Techniques to Treat Cardiac Arrest Patients with Hypothermia

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    Introduction. We sought to compare the performance of endovascular cooling to conventional surface cooling after cardiac arrest. Methods. Patients in coma following cardiopulmonary resuscitation were cooled with an endovascular cooling catheter or with ice bags and cold-water-circulating cooling blankets to a target temperature of 32.0–34.0°C for 24 hours. Performance of cooling techniques was compared by (1) number of hourly recordings in target temperature range, (2) time elapsed from the written order to initiate cooling and target temperature, and (3) adverse events during the first week. Results. Median time in target temperature range was 19 hours (interquartile range (IQR), 16–20) in the endovascular group versus. 10 hours (IQR, 7–15) in the surface group (P = .001). Median time to target temperature was 4 (IQR, 2.8–6.2) and 4.5 (IQR, 3–6.5) hours, respectively (P = .67). Adverse events were similar. Conclusion. Endovascular cooling maintains target temperatures better than conventional surface cooling

    Managing granulomatous-lymphocytic interstitial lung disease in common variable immunodeficiency disorders : e-GLILDnet International Clinicians Survey

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    Background Granulomatous-lymphocytic interstitial lung disease (GLILD) is a rare, potentially severe pulmonary complication of common variable immunodeficiency disorders (CVID). Informative clinical trials and consensus on management are lacking. Aims The European GLILD network (e-GLILDnet) aims to describe how GLILD is currently managed in clinical practice and to determine the main uncertainties and unmet needs regarding diagnosis, treatment and follow-up. Methods The e-GLILDnet collaborators developed and conducted an online survey facilitated by the European Society for Immunodeficiencies (ESID) and the European Respiratory Society (ERS) between February-April 2020. Results were analyzed using SPSS. Results One hundred and sixty-one responses from adult and pediatric pulmonologists and immunologists from 47 countries were analyzed. Respondents treated a median of 27 (interquartile range, IQR 82-maximum 500) CVID patients, of which a median of 5 (IQR 8-max 200) had GLILD. Most respondents experienced difficulties in establishing the diagnosis of GLILD and only 31 (19%) had access to a standardized protocol. There was little uniformity in diagnostic or therapeutic interventions. Fewer than 40% of respondents saw a definite need for biopsy in all cases or performed bronchoalveolar lavage for diagnostics. Sixty-six percent used glucocorticosteroids for remission-induction and 47% for maintenance therapy; azathioprine, rituximab and mycophenolate mofetil were the most frequently prescribed steroid-sparing agents. Pulmonary function tests were the preferred modality for monitoring patients during follow-up. Conclusions These data demonstrate an urgent need for clinical studies to provide more evidence for an international consensus regarding management of GLILD. These studies will need to address optimal procedures for definite diagnosis and a better understanding of the pathogenesis of GLILD in order to provide individualized treatment options. Non-availability of well-established standardized protocols risks endangering patients

    Development of an online SPE–LC–MS-based assay using endogenous substrate for investigation of soluble epoxide hydrolase (sEH) inhibitors

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    Soluble epoxide hydrolase (sEH) is a promising therapeutic target for the treatment of hypertension, pain, and inflammation-related diseases. In order to enable the development of sEH inhibitors (sEHIs), assays are needed for determination of their potency. Therefore, we developed a new method utilizing an epoxide of arachidonic acid (14(15)-EpETrE) as substrate. Incubation samples were directly injected without purification into an online solid phase extraction (SPE) liquid chromatography electrospray ionization tandem mass spectrometry (LC–ESI–MS–MS) setup allowing a total run time of only 108 s for a full gradient separation. Analytes were extracted from the matrix within 30 s by turbulent flow chromatography. Subsequently, a full gradient separation was carried out on a 50X2.1 mm RP-18 column filled with 1.7 μm core–shell particles. The analytes were detected with high sensitivity by ESI–MS–MS in SRM mode. The substrate 14(15)-EpETrE eluted at a stable retention time of 96 ± 1 s and its sEH hydrolysis product 14,15-DiHETrE at 63 ± 1 s with narrow peak width (full width at half maximum height: 1.5 ± 0.1 s). The analytical performance of the method was excellent, with a limit of detection of 2 fmol on column, a linear range of over three orders of magnitude, and a negligible carry-over of 0.1% for 14,15-DiHETrE. The enzyme assay was carried out in a 96-well plate format, and near perfect sigmoidal dose–response curves were obtained for 12 concentrations of each inhibitor in only 22 min, enabling precise determination of IC50 values. In contrast with other approaches, this method enables quantitative evaluation of potent sEHIs with picomolar potencies because only 33 pmol L−1 sEH were used in the reaction vessel. This was demonstrated by ranking ten compounds by their activity; in the fluorescence method all yielded IC50 ≤ 1 nmol L−1. Comparison of 13 inhibitors with IC50 values >1 nmol L−1 showed a good correlation with the fluorescence method (linear correlation coefficient 0.9, slope 0.95, Spearman’s rho 0.9). For individual compounds, however, up to eightfold differences in potencies between this and the fluorescence method were obtained. Therefore, enzyme assays using natural substrate, as described here, are indispensable for reliable determination of structure–activity relationships for sEH inhibition

    Investigation of the influence of calibration practices on cytogenetic laboratory performance for dose estimation

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    Purpose: In the frame of the QA program of RENEB, an inter-laboratory comparison (ILC) of calibration sources used in biological dosimetry was achieved to investigate the influence of calibration practices and protocols on the results of the dose estimation performance as a first step to harmonization and standardization of dosimetry and irradiation practices in the European biological dosimetry network. Materials and methods: Delivered doses by irradiation facilities used by RENEB partners were determined with EPR/alanine dosimetry system. Dosimeters were irradiated in the same conditions as blood samples. A short survey was also performed to collect the information needed for the data analysis and evaluate the diversity of practices. Results: For most of partners the deviation of delivered dose from the targeted dose remains below 10%. Deviations larger than 10% were observed for five facilities out of 21. Origins of the largest discrepancies were identified. Correction actions were evaluated as satisfactory. The re-evaluation of some ILC results for the fluorescence in situ hybridization (FISH) and premature chromosome condensation (PCC) assays has been performed leading to an improvement of the overall performances. Conclusions: This work has shown the importance of dosimetry in radiobiology studies and the needs of harmonization, standardization in irradiation and dosimetry practices and educational training for biologists using ionizing radiation
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