15 research outputs found

    An Agent-Based Approach to Self-Organized Production

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    The chapter describes the modeling of a material handling system with the production of individual units in a scheduled order. The units represent the agents in the model and are transported in the system which is abstracted as a directed graph. Since the hindrances of units on their path to the destination can lead to inefficiencies in the production, the blockages of units are to be reduced. Therefore, the units operate in the system by means of local interactions in the conveying elements and indirect interactions based on a measure of possible hindrances. If most of the units behave cooperatively ("socially"), the blockings in the system are reduced. A simulation based on the model shows the collective behavior of the units in the system. The transport processes in the simulation can be compared with the processes in a real plant, which gives conclusions about the consequencies for the production based on the superordinate planning.Comment: For related work see http://www.soms.ethz.c

    Impact of Dose Reduction Strategies on Image Quality of Coronary CTA in Real-World Clinical Practice: A Subanalysis of PROTECTION VI Registry Data

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    BACKGROUND. Dose reduction strategies for coronary CTA (CCTA) have been underused in clinical practice given concern that the strategies may lower image quality.OBJECTIVE. The purpose of this study was to explore associations between dose reduction strategies and CCTA image quality in real-world clinical practice.METHODS. This subanalysis of the international Prospective Multicenter Registry on Radiation Dose Estimates of Cardiac CT Angiography in Daily Practice in 2017 (PROTECTION VI) study included 3725 patients (2109 men, 1616 women; median age, 59 years) who underwent CCTA for coronary artery evaluation performed at 55 sites in 32 countries. CCTA image sets were reviewed at a core laboratory. A range of patient and scan characteristics, including use of three dose reduction strategies (prospective ECG triggering, low tube potential, and iterative image reconstruction) and image dose, were recorded. A single core laboratory member reviewed all examinations for quantitative image quality measures, including signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), and reviewed 50% of examinations to assign a qualitative CCTA image quality score and a semiquantitative coronary calcification measure. Multivariable logistic regression models were used to identify predictors of image quality. A second core laboratory member repeated quantitative measures for 100 examinations and the qualitative measure for 383 (approximately 20%) examinations to assess interreader agreement.RESULTS. Independent predictors (p < .05) of SNR were female sex (effect size, 2.70), lower body mass index (0.38 per 1-unit decrease), stable sinus rhythm (1.71), and scanner manufacturer (variable effect across manufacturers). These factors were also the only independent predictors of CNR. Independent predictors (p < .05) of CCTA image quality were heart rate (0.17 per 10 beats/min reduction) and coronary calcification (0.15 per coronary calcification grade). None of the three dose-saving strategies or dose-length product was an independent predictor of any image quality measure. Interreader agreement analysis showed intraclass correlation coefficients of 0.874 for SNR and 0.891 for CNR and a kappa value of 0.812 for the qualitative score.CONCLUSION. This large international multicenter study shows that three dose reduction strategies were not associated with decreased CCTA image quality.CLINICAL IMPACT. The dose reduction strategies should be routinely implemented in clinical CCTA.Cardiolog

    Perfil eletroforético das proteínas séricas de serpentes Crotalus durissus terrificus (cascavel) criadas em cativeiro Serum protein electrophoresis profile of the rattlesnake Crotalus durissus terrificus kept in captivity

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    As serpentes peçonhentas dos gêneros Bothrops e Crotalus têm sido mantidas em cativeiro visando à extração de venenos para a produção de imunobiológicos. O conhecimento da fisiologia desses animais e as alterações na concentração de proteínas e suas frações séricas são importantes para a identificação precoce de importantes enfermidades que cursam com estados de hipoproteinemia e hiperproteinemia. O objetivo do trabalho foi determinar a concentração de proteína total e o perfil eletroforético das proteínas séricas de serpentes Crotalus durissus terrificus (cascavel) criadas em cativeiro. Foram colhidas amostras de sangue da veia coccígea ventral de 21 serpentes adultas e sadias, divididas em dois grupos: Grupo 1 de 12 machos com peso médio de 588,89±193,55g, e Grupo 2 de nove fêmeas com peso médio de 708,33±194,04g. A proteína total sérica foi determinada pelo método de refratometria e a eletroforese em gel de agarose. Obtiveram-se valores da proteína total sérica (g/dL) de 4,51±0,50 para machos e de 4,82±0,72 para fêmeas, e para machos e fêmeas de 4,64±0,61. Foram identificadas pela eletroforese quatro frações protéicas (g/dL): albumina, a, b, g-globulinas e calculada a relação albumina:globulina. As serpentes fêmeas apresentaram maiores valores para as variáveis, albumina e para a relação albumina/globulina (AG) diferindo significativamente (P<0,05) do grupo de machos, porém sem significado clínico.<br>The poisonous snakes of the genera Crotalus and Bothrops have been kept in captivity with the purpose of extracting poison for the production of immunobiological. Knowledge of the physiology of these animals and serum proteins concentration changes are important for early identification of major diseases which lead to states of hypoproteinemia and hyperproteinemia. The objective was to determine the concentration of total protein and serum protein electrophoresis profile of Crotalus durissus terrificus (rattlesnake) in captivity. Blood samples were taken from the ventral coccygeal vein of 21 adult and healthy snakes divided into groups: Group 1 with 12 males, weighing in average 588.89±193.55g, and Group 2 with nine females, weighing in average 708.33±194.04g. The total serum concentration of protein was determined by the method of refractometry and agarose gel electrophoresis. The total protein values in the serum for females was 4.82±0.72, for males 4.51±0.50 and males and females 4.64±0.61, identified by four fractions (g/dL): albumin, a, b and g-globulin. Additionally the albumin/globulin ratio was calculated. The female snakes showed higher values for the variables, albumin and the albumin/globulin (AG) differed significantly (P<0.05) from the group of male snakes, but there was no clinical significance

    Perfis clínico e hematológico de camundongos submetidos ao envenenamento escorpiônico experimental por Tityus fasciolatus

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    Estudou-se o quadro clínico do veneno decorrente do envenenamento por Tityus fasciolatus e sua ação refletida nos componentes hematológicos no modelo murino. Para o estudo do perfil hematológico, foram utilizados 54 camundongos Swiss CF1, machos, com 30g, distribuídos em três grupos (G) (n=18) inoculados via subcutânea com: 50µL de PBS (G1); 24µg de veneno de T. fasciolatus (G2) e 8µg de veneno de T. serrulatus (G3). Cada grupo foi subdividido em três subgrupos (n=6) de acordo com o momento da coleta de sangue que foi estipulada em uma, oito e 24h após a inoculação do veneno, e foram realizados o hemograma e a dosagem de proteínas totais e fracionadas. O veneno de T. fasciolatus na dose de 24µg causou piloereção, comportamento nociceptivo, secreção nasal e oral acentuada, dispneia, prurido na face e reflexos exacerbados. No exame hematológico, foram observadas policitemia relativa e leucocitose com linfocitose

    Aspirin and Statin Therapy for Nonobstructive Coronary Artery Disease:Five-year Outcomesfrom the CONFIRM Registry

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    Purpose: In this cohort study, 5-year data from the Coronary CT Angiography Evaluation for Clinical Outcomes: An International Multicenter Registry (ie, CONFIRM) were examined to identify associations of baseline aspirin and statin use with mortality, major adverse cardiovascular events (MACE), and myocardial infarction (MI) in individuals without substantial (.50%) stenosis.Materials and Methods: In this prospective cohort study, all participants in the registry underwent coronary CT angiography and were classified as having no detectable coronary plaque or having nonobstructive coronary artery disease (CAD) (1%-49% stenosis). Participants with obstructive (.50%) stenosis were excluded from analysis. The study commenced in June 2003 and was completed in March 2016. All unadjusted and risk-adjusted analyses utilized the Cox proportional hazard model with hospital sites modeled using shared frailty.Results: A total of 6386 participants with no detectable plaque or with nonobstructive CAD were included (mean age, 56.0 years 6 13.3 [SD], 52% men). The mean follow-up period was 5.66 years 6 1.10. Nonobstructive CAD (n = 2815, 44% of all participants included in the study) was associated with a greater risk of all-cause mortality (10.6% [298 of 2815] vs 4.8% [170 of 3571], P <.001) compared to those without CAD (n = 3571, 56%). Baseline aspirin and statin use was documented for 1415 and 1429 participants, respectively, with nonobstructive CAD, and for 1560 and 1565 participants without detectable plaque, respectively. In individuals with nonobstructive CAD, baseline aspirin use was not associated with a reduction in MACE (10.9% [102 of 936] vs 14.7% [52 of 355], P =.06), all-cause mortality (9.6% [95 of 991] vs 10.9% [46 of 424], P =.468), or MI (4.4% [41 of 936] vs 6.2% [22 of 355], P =.18). On multivariate risk-adjusted analysis, baseline statin use was associated with a lower rate of MACE (hazard ratio, 0.59; 95% CI: 0.40, 0.87; P =.007). Neither therapy improved clinical outcomes for participants with no detectable plaque.Conclusion: In participants with nonobstructive CAD, baseline use of statins, but not of aspirin, was associated with improved clinical outcomes. Neither therapy was associated with benefit in participants without plaque.Cardiolog
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