Jožef Stefan Institute

About: Jožef Stefan Institute is a facility organization based out in Ljubljana, Slovenia. It is known for research contribution in the topics: Liquid crystal & Dielectric. The organization has 3828 authors who have published 12614 publications receiving 291025 citations.

Activity Based Probes as a tool for Functional Proteomic Analysis of Proteases

Abstract: Traditional proteomics methodology allows global analysis of protein abundance but does not provide information on the regulation of protein activity. Proteases, in particular, are known for their multilayered post-translational activity regulation that can lead to a significant difference between protease abundance levels and their enzyme activity. To address these issues, the field of activity-based proteomics has been established in order to characterize protein activity and monitor the functional regulation of enzymes in complex proteomes. In this review, we present structural features of activity-based probes for proteases and discuss their applications in proteomic profiling of various catalytic classes of proteases.

Blood Pressure Estimation from Photoplethysmogram Using a Spectro-Temporal Deep Neural Network.

Abstract: Blood pressure (BP) is a direct indicator of hypertension, a dangerous and potentially deadly condition. Regular monitoring of BP is thus important, but many people have aversion towards cuff-based devices, and their limitation is that they can only be used at rest. Using just a photoplethysmogram (PPG) to estimate BP is a potential solution investigated in our study. We analyzed the MIMIC III database for high-quality PPG and arterial BP waveforms, resulting in over 700 h of signals after preprocessing, belonging to 510 subjects. We then used the PPG alongside its first and second derivative as inputs into a novel spectro-temporal deep neural network with residual connections. We have shown in a leave-one-subject-out experiment that the network is able to model the dependency between PPG and BP, achieving mean absolute errors of 9.43 for systolic and 6.88 for diastolic BP. Additionally we have shown that personalization of models is important and substantially improves the results, while deriving a good general predictive model is difficult. We have made crucial parts of our study, especially the list of used subjects and our neural network code, publicly available, in an effort to provide a solid baseline and simplify potential comparison between future studies on an explicit MIMIC III subset.

Expert-guided subgroup discovery: methodology and application

Abstract: This paper presents an approach to expert-guided subgroup discovery. The main step of the subgroup discovery process, the induction of subgroup descriptions, is performed by a heuristic beam search algorithm, using a novel parametrized definition of rule quality which is analyzed in detail. The other important steps of the proposed subgroup discovery process are the detection of statistically significant properties of selected subgroups and subgroup visualization: statistically significant properties are used to enrich the descriptions of induced subgroups, while the visualization shows subgroup properties in the form of distributions of the numbers of examples in the subgroups. The approach is illustrated by the results obtained for a medical problem of early detection of patient risk groups.

Inhibition of papain-like cysteine proteases and legumain by caspase-specific inhibitors: when reaction mechanism is more important than specificity

Abstract: We report here that a number of commonly used small peptide caspase inhibitors consisting of a caspase recognition sequence linked to chloromethylketone, fluoromethylketone or aldehyde reactive group efficiently inhibit other cysteine proteases than caspases. The in vitro studies included cathepsins B, H, L, S, K, F, V, X and C, papain and legumain. Z-DEVD-cmk was shown to be the preferred irreversible inhibitor of most of the cathepsins in vitro, followed by Z-DEVD-fmk, Ac-YVAD-cmk, Z-YVAD-fmk and Z-VAD-fmk. Inactivation of legumain by all the inhibitors investigated was moderate, whereas cathepsins H and C were poorly inhibited or not inhibited at all. Inhibition by aldehydes was not very potent. All the three fluoromethylketones efficiently inhibited cathepsins in Jurkat and human embryonic kidney 293 cells at concentrations of 100 microM. Furthermore, they completely inhibited cathepsins B and X activity in tissue extracts at concentrations as low as 1 microM. These results suggest that data based on the use of these inhibitors should be taken with caution and that other proteases may be implicated in the processes previously ascribed solely to caspases.

Alkaline-earth doping in (K,Na)NbO3 based piezoceramics

Abstract: In this contribution the effect of alkaline-earth (AE) dopants Mg2+, Ca2+, Sr2+ and Ba2+ on sinterability and functional response of KNN is studied. Ceramic powders with the general formula (K0.5Na0.5)1−2yAEyNbO3, y = 0.005 were prepared by classical ceramic processing. The values of 94–95% of theoretical density (TD) are obtained for stoichiometric KNN after sintering at 1115 °C for 2 h. Calcium and strontium doping promotes densification while magnesium doping inhibits it. In the case of Ba-doping a secondary phase forms. The dielectric constant and piezo d33 coefficient determined by Berlincourt piezo d33-meter of Ca and Sr-doped KNN ceramics are 500 and 95 pC/N, respectively, while the values for undoped KNN are slightly lower.