This study deals with the enhancement of reliability of vehicle dynamic model for the stability controller design by estimating the effect of uncertainties in both tire forces and vehicle dynamics. ...In this respect, any selected initial kinetic model of vehicle is updated at each instant by adding some complementary terms using a novel prediction approach. The proposed estimation method uses the information fusion between the inertial measurement unit (IMU) and the aided systems including the global navigation satellite system (GNSS) and the calibrated compass system. The bias of acceleration sensors and the drift of gyroscope are compensated using a novel adaptive algorithm by which the estimator weights are tuned automatically. Therefore, the vehicle longitudinal and lateral velocities together with the yaw rate are accurately estimated with a high frequency. The proposed estimation algorithm is mathematically analyzed for the stochastic stability and experimentally evaluated through real-world vehicular tests. Accordingly, a nonlinear controller for vehicle directional stability is designed based on the updated dynamic model within the CarSim software environment as a virtual vehicle experiment platform. The obtained results reveal that, the designed data fusion algorithm remarkably improves the estimation performance in the presence of system and measurement uncertainties. Also, the controller designed by the estimated vehicle dynamic model will be reliable and robust in the presence of uncertainties.
•Novel estimation of reliable kinetic model for vehicle dynamics in the presence of uncertainties.•Stochastic stability analysis of the proposed estimation algorithm.•Automatically tuning the estimator weights by a novel data fusion algorithm for various driving conditions.•Experimental verification of the proposed estimator in several vehicular tests.•Design of vehicle stability controller using the reliable estimated model.
This study focuses on the precise model estimation for a position control problem actuated by a shape memory alloy (SMA) wire. Because the hysteresis characteristic of SMA introduces complexities in ...system modelling and adds degrees of freedom, a model with reduced order is implemented for controller design. This model is online updated by calculating a complementary term from the measured data to compensate for the SMA actuator dynamics and other parametric uncertainties. The position controller, derived from the formulated reduced‐order model, adapts itself to real conditions and is cost‐effective due to the use of only displacement sensor. The saturation of the control input is modelled within the structure of a constrained optimization problem solved by Karush–Kuhn–Tucker theorem. The boundedness of mean and covariance of tracking error and its derivative is demonstrated by stochastic analysis. The experimental results conducted on a platform incorporating a SMA wire show the efficiency of the proposed system in precisely controlling the position by admissible voltage range. The comparative results with a sliding mode controller indicate higher accuracy for the proposed controller to reduce the effect of uncertainties.
This study focuses on the precise model estimation for a position control problem actuated by a shape memory alloy wire made of nickel‐titanium. The position controller, designed from the constructed reduced‐order model, adapts itself to real conditions and is cost‐effective due to the use of only a displacement sensor.
In this review we examine techniques, software, and statistical analyses used in label-free quantitative proteomics studies for area under the curve and spectral counting approaches. Recent advances ...in the field are discussed in an order that reflects a logical workflow design. Examples of studies that follow this design are presented to highlight the requirement for statistical assessment and further experiments to validate results from label-free quantitation. Limitations of label-free approaches are considered, label-free approaches are compared with labelling techniques, and forward-looking applications for label-free quantitative data are presented. We conclude that label-free quantitative proteomics is a reliable, versatile, and cost-effective alternative to labelled quantitation.
Abstract
In this pandemic SARS-CoV-2 crisis, any attempt to contain and eliminate the virus will also stop its spread and consequently decrease the risk of severe illness and death. While ozone ...treatment has been suggested as an effective disinfection process, no precise mechanism of action has been previously reported. This study aimed to further investigate the effect of ozone treatment on SARS-CoV-2. Therefore, virus collected from nasopharyngeal and oropharyngeal swab and sputum samples from symptomatic patients was exposed to ozone for different exposure times. The virus morphology and structure were monitored and analyzed through Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM), Atomic Absorption Spectroscopy (AAS), and ATR-FTIR. The obtained results showed that ozone treatment not only unsettles the virus morphology but also alters the virus proteins’ structure and conformation through amino acid disturbance and Zn ion release from the virus non-structural proteins. These results could provide a clearer pathway for virus elimination and therapeutics preparation.
Stem cells and their derivatives are novel pharmaceutics that have the potential for use as tissue replacement therapies. However, the heterogeneous characteristics of stem cell cultures have ...hindered their biomedical applications. In theory and practice, when cell type-specific or stage-specific cell surface proteins are targeted by unique antibodies, they become highly efficient in detecting and isolating specific cell populations. There is a growing demand to identify reliable and actionable cell surface markers that facilitate purification of particular cell types at specific developmental stages for use in research and clinical applications. The identification of these markers as very important members of plasma membrane proteins, ion channels, transporters, and signaling molecules has directly benefited from proteomics and tools for proteomics-derived data analyses. Here, we review the methodologies that have played a role in the discovery of cell surface markers and introduce cutting edge single cell proteomics as an advanced tool. We also discuss currently available specific cell surface markers for stem cells and their lineages, with emphasis on the nervous system, heart, pancreas, and liver. The remaining gaps that pertain to the discovery of these markers and how single cell proteomics and identification of surface markers associated with the progenitor stages of certain terminally differentiated cells may pave the way for their use in regenerative medicine are also discussed.
Brain-derived neurotrophic factor (BDNF) has a unique role in the neuronal development, differentiation, and survival in the developing and adult nervous system. A common single-nucleotide ...polymorphism in the pro-region of the human BDNF gene, resulting in a valine to methionine substitution (Val66Met), has been associated with the susceptibility, incidence, and clinical features of several neurodegenerative disorders. Much research has been dedicated to evaluating the effects of polymorphism in the past decade, and functional effects of this genetic variation. A better understanding of how this naturally occurring polymorphism associates with or influences physiology, anatomy, and cognition in both healthy and diseased adults in neurodegenerative conditions will help understand neurochemical mechanisms and definable clinical outcomes in humans. Here we review the role and relevance of the BDNF Val66Met polymorphism in neurodegenerative diseases, with particular emphasis on glaucoma, multiple sclerosis (MS), Alzheimer's disease (AD) and Parkinson's disease (PD). Several controversies and unresolved issues, including small effect sizes, possible ethnicity, gender, and age effects of the BDNF Val66Met are also discussed with respect to future research.
Background. As the most common diseases globally, oral and dental diseases are closely related to people’s behavior. The present study is aimed at developing a program to prevent primary teeth decay ...in children using the intervention mapping approach. Methods. This study protocol is aimed at using the intervention mapping approach as the planning framework. The study consists of six steps of intervention mapping, including needs assessment based on the relevant literature review, development of an objectives matrix for changing people’s behaviors and environmental factors, program preparation, program implementation, and program evaluation to develop a family-centered program. Results. The use of the intervention mapping approach helped us identify the outcomes and functional objectives, develop an appropriate intervention program, and evaluate the program. Conclusions. The intervention mapping approach is an appropriate guide to developing a systematic and evidence-based program.
In this paper, an optimal nonlinear attitude controller is designed and implemented as hardware in the loop for a spacecraft simulator under various failures of reaction wheels. The proposed ...controller is developed in the closed form based on predicting the nonlinear continuous responses of spacecraft simulator. The special case of the controller when all uncertainties are ignored leads to feedback linearization. However, the stability of the controller in the presence of parametric uncertainties and unmodeled dynamics of the platform is analyzed, and the effect of the prediction time on the boundedness of system responses is presented. A redundant reaction wheel is located in the platform to compensate for failures of three main reaction wheels. How to distribute torque between healthy wheels under different types of failure including stuck and oscillatory failures is addressed and experimentally implemented. The laboratory results that are consistent with computer simulations show the accuracy and validity of the designed controller. It is seen that the spacecraft attitude converges in a limited time in the presence of system uncertainties and actuator failures.
Retinoid X receptors (RXRs) present a subgroup of the nuclear receptor superfamily with particularly high evolutionary conservation of ligand binding domain. The receptor exists in α, β, and γ ...isotypes that form homo-/heterodimeric complexes with other permissive and non-permissive receptors. While research has identified the biochemical roles of several nuclear receptor family members, the roles of RXRs in various neurological disorders remain relatively under-investigated. RXR acts as ligand-regulated transcription factor, modulating the expression of genes that plays a critical role in mediating several developmental, metabolic, and biochemical processes. Cumulative evidence indicates that abnormal RXR signalling affects neuronal stress and neuroinflammatory networks in several neuropathological conditions. Protective effects of targeting RXRs through pharmacological ligands have been established in various cell and animal models of neuronal injury including Alzheimer disease, Parkinson disease, glaucoma, multiple sclerosis, and stroke. This review summarises the existing knowledge about the roles of RXR, its interacting partners, and ligands in CNS disorders. Future research will determine the importance of structural and functional heterogeneity amongst various RXR isotypes as well as elucidate functional links between RXR homo- or heterodimers and specific physiological conditions to increase drug targeting efficiency in pathological conditions.
Despite growing evidence for the characteristic signs of Alzheimer's disease (AD) in the neurosensory retina, our understanding of retina–brain relationships, especially at advanced disease stages ...and in response to therapy, is lacking. In transgenic models of AD (APPSWE/PS1∆E9; ADtg mice), glatiramer acetate (GA) immunomodulation alleviates disease progression in pre‐ and early‐symptomatic disease stages. Here, we explored the link between retinal and cerebral AD‐related biomarkers, including response to GA immunization, in cohorts of old, late‐stage ADtg mice. This aged model is considered more clinically relevant to the age‐dependent disease. Levels of synaptotoxic amyloid β‐protein (Aβ)1–42, angiopathic Aβ1–40, non‐amyloidogenic Aβ1–38, and Aβ42/Aβ40 ratios tightly correlated between paired retinas derived from oculus sinister (OS) and oculus dexter (OD) eyes, and between left and right posterior brain hemispheres. We identified lateralization of Aβ burden, with one‐side dominance within paired retinal and brain tissues. Importantly, OS and OD retinal Aβ levels correlated with their cerebral counterparts, with stronger contralateral correlations and following GA immunization. Moreover, immunomodulation in old ADtg mice brought about reductions in cerebral vascular and parenchymal Aβ deposits, especially of large, dense‐core plaques, and alleviation of microgliosis and astrocytosis. Immunization further enhanced cerebral recruitment of peripheral myeloid cells and synaptic preservation. Mass spectrometry analysis identified new parallels in retino‐cerebral AD‐related pathology and response to GA immunization, including restoration of homeostatic glutamine synthetase expression. Overall, our results illustrate the viability of immunomodulation‐guided CNS repair in old AD model mice, while shedding light onto similar retino‐cerebral responses to intervention, providing incentives to explore retinal AD biomarkers.
In this study, Doustar et al. revealed that retinal Abeta burden predicts its brain levels in old, late‐stage murine models of Alzheimer's disease and further in response to immunotherapy. Substantial therapeutic effects are detected even at such advanced disease stage; immunomodulation effectively mitigates vascular and parenchymal amyloid‐beta deposition, diminishes neuroinflammation, as well as restores synaptic density and retino‐cerebral glutamine synthetase levels.
PDF
