When applying a diagnostic technique to complex systems, whose dynamics, constraints, and environment evolve over time, being able to re-evaluate the residuals that are capable of detecting defaults and proposing the most appropriate ones can quickly prove to make sense. For this purpose, the concept of adaptive diagnosis is introduced. In this work, the contributions of information theory are investigated in order to propose a Fault-Tolerant multi-sensor data fusion framework. This work is part of studies proposing an architecture combining a stochastic filter for state estimation with a diagnostic layer with the aim of proposing a safe and accurate state estimation from potentially inconsistent or erroneous sensors measurements. From the design of the residuals, using α-Rényi Divergence (α-RD), to the optimization of the decision threshold, through the establishment of a function that is dedicated to the choice of α at each moment, we detail each step of the proposed automated decision-support framework. We also dwell on: (1) the consequences of the degree of freedom provided by this α parameter and on (2) the application-dictated policy to design the α tuning function playing on the overall performance of the system (detection rate, false alarms, and missed detection rates). Finally, we present a real application case on which this framework has been tested. The problem of multi-sensor localization, integrating sensors whose operating range is variable according to the environment crossed, is a case study to illustrate the contributions of such an approach and show the performance. 相似文献
A formal computation proving a new operator identity from known ones is, in principle, restricted by domains and codomains of linear operators involved, since not any two operators can be added or composed. Algebraically, identities can be modelled by noncommutative polynomials and such a formal computation proves that the polynomial corresponding to the new identity lies in the ideal generated by the polynomials corresponding to the known identities. In order to prove an operator identity, however, just proving membership of the polynomial in the ideal is not enough, since the ring of noncommutative polynomials ignores domains and codomains. We show that it suffices to additionally verify compatibility of this polynomial and of the generators of the ideal with the labelled quiver that encodes which polynomials can be realized as linear operators. Then, for every consistent representation of such a quiver in a linear category, there exists a computation in the category that proves the corresponding instance of the identity. Moreover, by assigning the same label to several edges of the quiver, the algebraic framework developed allows to model different versions of an operator by the same indeterminate in the noncommutative polynomials. 相似文献
Matrix metalloproteinases (MMPs) are a large family of zinc-dependent endoproteases known to exert multiple regulatory roles in tumor progression. A variety of chemical classes have been explored for targeting individual MMP isoforms. In the present study, we further developed our isatin based scaffold BB0223107 capable of binding to and inactivating MMP-2 in a zinc-independent manner (Agamennone et al., 2016). Forty four new compounds were synthesized based on the modified BB0223107. All compounds were tested in enzyme inhibition assays against MMP-2, ?8 and ?13. SAR studies demonstrated that 5-het(aryl)-3-aminoindolin-2-ones (37–39) were active toward MMP-2 and MMP-13. The most potent compounds 33 and 37 displayed an IC50 of 3 µM against MMP-13 and showed a negligible activity toward MMP-8; almost all new compounds were inactive toward MMP-8. Replacement of the isatin ring with a biaryl system (compound 33) did not decrease the potency against MMP-13 but reduced the selectivity. Structure-based computational studies were carried out to rationalize the inhibitory activity data. The analysis of binding geometries confirmed that all fragments occupied the S1′ site in the three enzymes while no ligand was able to bind the catalytic zinc ion. To the best of our knowledge, this is the first example of 3-aminoindolin-2-one-based MMP inhibitors that, based on the computer modeling study, do not coordinate the zinc ion. Thus, the het(aryl)-3-aminoindolin-2-one derivatives emerge as a drug-like and promising chemotype that, along with the hetaryl variations, represents an alternative and thrifty tool for chemical space exploration aimed at MMP inhibitor design. 相似文献
Human motion induced vibration has very low frequency, ranging from 2 Hz to 5 Hz. Traditional vibration isolators are not effective in low-frequency regions due to the trade-off between the low natural frequency and the high load capacity. In this paper, inspired by the human spine, we propose a novel bionic human spine inspired quasi-zero stiffness (QZS) vibration isolator which consists of a cascaded multi-stage negative stiffness structure. The force and stiffness characteristics are investigated first, the dynamic model is established by Newton’s second law, and the isolation performance is analyzed by the harmonic balance method (HBM). Numerical results show that the bionic isolator can obtain better low-frequency isolation performance by increasing the number of negative structure stages, and reducing the damping values and external force values can obtain better low-frequency isolation performance. In comparison with the linear structure and existing traditional QZS isolator, the bionic spine isolator has better vibration isolation performance in low-frequency regions. It paves the way for the design of bionic ultra-low-frequency isolators and shows potential in many engineering applications.
Laportea bulbifera (Sieb. et. Zucc.) Wedd has long been utilized in Traditional Chinese Medicines (TCM) for the treatment of rheumatoid arthritis. However, the study of systematic anti-inflammatory chemical constituents in L. bulbifera has never been reported. Thus, bioassay-guided isolation for its roots part led to 46 compounds, including 38 phenolic derivatives. Their structures were determined on the basis of 1H and 13C NMR and MS spectra. All compounds were isolated from L. bulbifera for the first time except for 13 compounds. Most of the compounds showed good COX-2 inhibitory activity (IC50: 0.13–3.94 μM) and DPPH radical-scavenging activity (IC50: 1.57–9.55 μM). Four compounds (4, 17, 35, and 43) with different skeletons showed preferential COX-2 over COX-1 inhibition with selective indices ranging from 12 to 171. High content active compounds are important for elucidating the basis of the active substance of TCM. Compound 4 (COX-2, IC50 0.24 μM), a high content compound, represented one of the best selective COX-2 inhibitors. Another high content active compound (35) with a different skeleton might have different mechanism. Further study for the inhibition kinetics against COX-2 indicated compounds 4 and 35 were noncompetitive and competitive COX-2 inhibitors, respectively. Moreover, molecular docking and molecular dynamics simulation data further indicated that compound 4 could bind in the cavity of COX-2 and interacted with key residues VAL-538, PHE-142, and GLY-225 of COX-2 through hydrogen bonds. The results indicated that L. bulbifera roots could be applied as antioxidant and anti-inflammatory agents due to their potent selective COX-2 inhibitory and antioxidant activity of phenolic compounds. 相似文献
Traditional Chinese medicine (TCM) is the key to unlock treasures of Chinese civilization. TCM and its compound play a beneficial role in medical activities to cure diseases, especially in major public health events such as novel coronavirus epidemics across the globe. The chemical composition in Chinese medicine formula is complex and diverse, but their effective substances resemble “mystery boxes”. Revealing their active ingredients and their mechanisms of action has become focal point and difficulty of research for herbalists. Although the existing research methods are numerous and constantly updated iteratively, there is remain a lack of prospective reviews. Hence, this paper provides a comprehensive account of existing new approaches and technologies based on previous studies with an in vitro to in vivo perspective. In addition, the bottlenecks of studies on Chinese medicine formula effective substances are also revealed. Especially, we look ahead to new perspectives, technologies and applications for its future development. This work reviews based on new perspectives to open horizons for the future research. Consequently, herbal compounding pharmaceutical substances study should carry on the essence of TCM while pursuing innovations in the field. 相似文献
Koneramines (LROR′, R=Ph or Ts; R′=Me, iPr) and their complexes were found to emerge from the system of pyridine‐2‐carboxaldehyde and N‐phenyl/tosylethylenediamine when a primary or secondary alcohol was used as solvent. Imidazolidinylpyridines (LR, R=Ph or Ts) became major emergents whereas hemi‐aminals (LROH, R=Ph or Ts) are minor emergents of the system when tertiary butanol was used as the solvent; the bulky tertiary butyl group prevented the addition of alcohol to the iminium ion that diverted the equilibrium towards imidazolidinylpyridines. By playing with the components of the reaction mixture, crystals of the metastable intermediates bound to copper(II) and/or zinc(II) were obtained and the structures were determined by X‐ray diffraction analysis. The reported results shed light on how to control the emergents of the multicomponent reaction mixture that forms koneramines. Reactivity studies of the intermediates pave the way for a new type of koneramine complexes that are new dipicolylamines where the two pyridine moieties of the resulting koneramine are not the same. 相似文献