81 research outputs found
Experimental Parameter Study and Inherent Scattering of Safety Characteristics of Dusts
Safety characteristics are widely used in industrial processes to avoid explosive atmospheres (primary explosion protection) or to mitigate the consequences of an explosion (constructive explosion protection). Several laboratory parameters influence the determined values when performing the test series such as the beginning pressure and the pre-ignition pressure rise, the ignition source, the ignition energy, the burning duration and volume or the concentration of the combustible substance.
In the different standards for the determination of safety characteristics of dusts there is no statement about the scattering or the deviation when parameters are chosen or occur on the borders of their allowed range. Thus, two laboratories might determine values that are hardly comparable for the same given substance.
This article summarizes some of the influential factors that cause a deviation and shows the inherent scattering of dust tests when all other parameters are kept constant. It also provides some advice how to minimize the deviation and the scattering with little effort
Spatially and temporally resolved electron density measurements in streamers in dielectric liquids
Morphological correlates to cognitive dysfunction in schizophrenia as studied with Bayesian regression
BACKGROUND: Relationships between cognitive deficits and brain morphological changes observed in schizophrenia are alternately explained by less gray matter in the brain cerebral cortex, by alterations in neural circuitry involving the basal ganglia, and by alteration in cerebellar structures and related neural circuitry. This work explored a model encompassing all of these possibilities to identify the strongest morphological relationships to cognitive skill in schizophrenia. METHODS: Seventy-one patients with schizophrenia and sixty-five healthy control subjects were characterized by neuropsychological tests covering six functional domains. Measures of sixteen brain morphological structures were taken using semi-automatic and fully manual tracing of MRI images, with the full set of measures completed on thirty of the patients and twenty controls. Group differences were calculated. A Bayesian decision-theoretic method identified those morphological features, which best explained neuropsychological test scores in the context of a multivariate response linear model with interactions. RESULTS: Patients performed significantly worse on all neuropsychological tests except some regarding executive function. The most prominent morphological observations were enlarged ventricles, reduced posterior superior vermis gray matter volumes, and increased putamen gray matter volumes in the patients. The Bayesian method associated putamen volumes with verbal learning, vigilance, and (to a lesser extent) executive function, while caudate volumes were associated with working memory. Vermis regions were associated with vigilance, executive function, and, less strongly, visuo-motor speed. Ventricular volume was strongly associated with visuo-motor speed, vocabulary, and executive function. Those neuropsychological tests, which were strongly associated to ventricular volume, showed only weak association to diagnosis, possibly because ventricular volume was regarded a proxy for diagnosis. Diagnosis was strongly associated with the other neuropsychological tests, implying that the morphological associations for these tasks reflected morphological effects and not merely group volumetric differences. Interaction effects were rarely associated, indicating that volumetric relationships to neuropsychological performance were similar for both patients and controls. CONCLUSION: The association of subcortical and cerebellar structures to verbal learning, vigilance, and working memory supports the importance of neural connectivity to these functions. The finding that a morphological indicator of diagnosis (ventricular volume) provided more explanatory power than diagnosis itself for visuo-motor speed, vocabulary, and executive function suggests that volumetric abnormalities in the disease are more important for cognition than non-morphological features
Identification of Novel Functional Inhibitors of Acid Sphingomyelinase
We describe a hitherto unknown feature for 27 small drug-like molecules, namely functional inhibition of acid sphingomyelinase (ASM). These entities named FIASMAs (Functional Inhibitors of Acid SphingoMyelinAse), therefore, can be potentially used to treat diseases associated with enhanced activity of ASM, such as Alzheimer's disease, major depression, radiation- and chemotherapy-induced apoptosis and endotoxic shock syndrome. Residual activity of ASM measured in the presence of 10 µM drug concentration shows a bimodal distribution; thus the tested drugs can be classified into two groups with lower and higher inhibitory activity. All FIASMAs share distinct physicochemical properties in showing lipophilic and weakly basic properties. Hierarchical clustering of Tanimoto coefficients revealed that FIASMAs occur among drugs of various chemical scaffolds. Moreover, FIASMAs more frequently violate Lipinski's Rule-of-Five than compounds without effect on ASM. Inhibition of ASM appears to be associated with good permeability across the blood-brain barrier. In the present investigation, we developed a novel structure-property-activity relationship by using a random forest-based binary classification learner. Virtual screening revealed that only six out of 768 (0.78%) compounds of natural products functionally inhibit ASM, whereas this inhibitory activity occurs in 135 out of 2028 (6.66%) drugs licensed for medical use in humans
Defining high bleeding risk in patients undergoing percutaneous coronary intervention: a consensus document from the Academic Research Consortium for High Bleeding Risk
Identification and management of patients at high bleeding risk undergoing percutaneous coronary intervention are of major importance,
but a lack of standardization in defining this population limits trial design, data interpretation, and clinical decision-making. The Academic
Research Consortium for High Bleeding Risk (ARC-HBR) is a collaboration among leading research organizations, regulatory authorities,
and physician-scientists from the United States, Asia, and Europe focusing on percutaneous coronary intervention–related bleeding. Two meetings of the 31-member consortium were held in Washington, DC, in April 2018 and in Paris, France, in October 2018. These meetings were organized by the Cardiovascular European Research Center on behalf of the ARC-HBR group and included representatives of
the US Food and Drug Administration and the Japanese Pharmaceuticals and Medical Devices Agency, as well as observers from the
pharmaceutical and medical device industries. A consensus definition of patients at high bleeding risk was developed that was based on
review of the available evidence. The definition is intended to provide consistency in defining this population for clinical trials and to complement clinical decision-making and regulatory review. The proposed ARC-HBR consensus document represents the first pragmatic
approach to a consistent definition of high bleeding risk in clinical trials evaluating the safety and effectiveness of devices and drug regimens for patients undergoing percutaneous coronary intervention
Defining High Bleeding Risk in Patients Undergoing Percutaneous Coronary Intervention A Consensus Document From the Academic Research Consortium for High Bleeding Risk
Identification and management of patients at high bleeding
risk undergoing percutaneous coronary intervention are of major
importance, but a lack of standardization in defining this population
limits trial design, data interpretation, and clinical decision-making.
The Academic Research Consortium for High Bleeding Risk (ARC-HBR)
is a collaboration among leading research organizations, regulatory
authorities, and physician-scientists from the United States, Asia, and
Europe focusing on percutaneous coronary intervention–related bleeding.
Two meetings of the 31-member consortium were held in Washington,
DC, in April 2018 and in Paris, France, in October 2018. These meetings
were organized by the Cardiovascular European Research Center on
behalf of the ARC-HBR group and included representatives of the US
Food and Drug Administration and the Japanese Pharmaceuticals and
Medical Devices Agency, as well as observers from the pharmaceutical
and medical device industries. A consensus definition of patients at high
bleeding risk was developed that was based on review of the available
evidence. The definition is intended to provide consistency in defining this
population for clinical trials and to complement clinical decision-making
and regulatory review. The proposed ARC-HBR consensus document
represents the first pragmatic approach to a consistent definition of
high bleeding risk in clinical trials evaluating the safety and effectiveness
of devices and drug regimens for patients undergoing percutaneous
coronary intervention
C4 nephritic factor in patients with immune-complex-mediated membranoproliferative glomerulonephritis and C3-glomerulopathy
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