Many studies over the past two decades have shown that people can use brain signals to convey their intent to a computer using brain-computer interfaces (BCIs). BCI systems extract specific features ...of brain activity and translate them into control signals that drive an output. Recently, a category of BCIs that are built on the rhythmic activity recorded over the sensorimotor cortex, i.e., the sensorimotor rhythm (SMR), has attracted considerable attention among the BCIs that use noninvasive neural recordings, e.g., electroencephalography (EEG), and have demonstrated the capability of multidimensional prosthesis control. This paper reviews the current state and future perspectives of SMR-based BCI and its clinical applications, in particular focusing on the EEG SMR. The characteristic features of SMR from the human brain are described and their underlying neural sources are discussed. The functional components of SMR-based BCI, together with its current clinical applications, are reviewed. Finally, limitations of SMR-BCIs and future outlooks are also discussed.
For the problem of power allocation between a distributed multistatic radar network and a smart jammer, the application of non-cooperative game theory is employed to address the issue in this paper. ...Consequently, three scenarios of power allocation games are examined. The first two game scenarios, characterized by information asymmetry, are categorized under the Stackelberg game framework, while the final scenario, with information symmetry, is classified as a non-cooperative game. Through the power allocation analyses of the three game scenarios, it is observed that both the radar system and the jammer possess a first-mover advantage. Additionally, the existence and uniqueness of the Nash equilibrium in the games are demonstrated. Based on the best response strategies within the games, three corresponding power allocation game algorithms are proposed. Ultimately, the convergence and performance comparison of the three power allocation game algorithms are validated through simulation experiments.
Most prostate cancers are androgen-sensitive malignancies whose growths depend on the transcriptional activity of the androgen receptor (AR). In the 1940s, Charles Huggins demonstrated that the ...surgical removal of testes in men can result in a dramatic improvement in symptoms and can induce prostate cancer regression. Since then, androgen deprivation therapies have been the standard first-line treatment for advanced prostate cancer, including: surgical castration, medical castration, antiandrogens, and androgen biosynthesis inhibitors. These therapies relieve symptoms, reduce tumor burden, and prolong patient survival, while having relatively modest side effects. Unfortunately, hormone deprivation therapy rarely cures the cancer itself. Prostate cancer almost always recurs, resulting in deadly castration-resistant prostate cancer. The underlying escape mechanisms include androgen receptor gene/enhancer amplification, androgen receptor mutations, androgen receptor variants, coactivator overexpression, intratumoral de novo androgen synthesis, etc. Whereas, the majority of the castration-resistant prostate cancers continuously rely on the androgen axis, a subset of recurrent cancers have completely lost androgen receptor expression, undergone divergent clonal evolution or de-differentiation, and become truly androgen receptor-independent small-cell prostate cancers. There is an urgent need for the development of novel targeted and immune therapies for this subtype of prostate cancer, when more deadly small-cell prostate cancers are induced by thorough androgen deprivation and androgen receptor ablation.
In this paper, the asymptotic stability and synchronization of fractional order Hopfield neural networks (FOHNNs) with time‐varying delay are investigated. First, we propose an extended fractional ...Halanay inequality, which plays an essential role in the proof of the main results. Using the Banach fixed point theorem, the existence and uniqueness of the equilibrium point of the system is proved. Through the extended Halanay inequality and a useful fractional derivative inequality, the sufficient conditions of the asymptotic stability and synchronization are given for FOHNNs. Finally, two numerical examples are presented to illustrate the effectiveness of the theoretical results.
Herein, the catalytic promiscuity of TcCGT1, a new C‐glycosyltransferase (CGT) from the medicinal plant Trollius chinensis is explored. TcCGT1 could efficiently and regio‐specifically catalyze the ...8‐C‐glycosylation of 36 flavones and other flavonoids and could also catalyze the O‐glycosylation of diverse phenolics. The crystal structure of TcCGT1 in complex with uridine diphosphate was determined at 1.85 Å resolution. Molecular docking revealed a new model for the catalytic mechanism of TcCGT1, which is initiated by the spontaneous deprotonation of the substrate. The spacious binding pocket explains the substrate promiscuity, and the binding pose of the substrate determines C‐ or O‐glycosylation activity. Site‐directed mutagenesis at two residues (I94E and G284K) switched C‐ to O‐glycosylation. TcCGT1 is the first plant CGT with a crystal structure and the first flavone 8‐C‐glycosyltransferase described. This provides a basis for designing efficient glycosylation biocatalysts.
A promiscuous C‐glycosyltransferase, TcCGT1, is highlighted. TcCGT1 represents the first flavone 8‐C‐glycosyltransferase that exhibits robust substrate promiscuity towards different types of flavonoids. The crystal structure of TcCGT1, the first crystal structure of a plant CGT, is shown. This work provides a basis for protein engineering to design efficient glycosylation biocatalysts for drug discovery.
Brain activity and connectivity are distributed in the three-dimensional space and evolve in time. It is important to image brain dynamics with high spatial and temporal resolution. ...Electroencephalography (EEG) and magnetoencephalography (MEG) are noninvasive measurements associated with complex neural activations and interactions that encode brain functions. Electrophysiological source imaging estimates the underlying brain electrical sources from EEG and MEG measurements. It offers increasingly improved spatial resolution and intrinsically high temporal resolution for imaging large-scale brain activity and connectivity on a wide range of timescales. Integration of electrophysiological source imaging and functional magnetic resonance imaging could further enhance spatiotemporal resolution and specificity to an extent that is not attainable with either technique alone. We review methodological developments in electrophysiological source imaging over the past three decades and envision its future advancement into a powerful functional neuroimaging technology for basic and clinical neuroscience applications.
Summary
Purpose: The current gold standard for the localization of the cortical regions responsible for the initiation and propagation of the ictal activity is through the use of invasive ...electrocorticography (ECoG). This method is utilized to guide surgical intervention in cases of medically intractable epilepsy by identifying the location and extent of the epileptogenic focus. Recent studies have proposed mechanisms in which the activity of epileptogenic cortical networks, rather than discrete focal sources, contributes to the generation of the ictal state. If true, selective modulation of key network components could be employed for the prevention and termination of the ictal state.
Methods: Here, we have applied graph theory methods as a means to identify critical network nodes in cortical networks during both ictal and interictal states. ECoG recordings were obtained from a cohort of 25 patients undergoing presurgical monitoring for the treatment of intractable epilepsy at the Mayo Clinic (Rochester, MN, U.S.A.).
Key Findings: One graph measure, the betweenness centrality, was found to correlate with the location of the resected cortical regions in patients who were seizure‐free following surgical intervention. Furthermore, these network interactions were also observed during random nonictal periods as well as during interictal spike activity. These network characteristics were found to be frequency dependent, with high frequency gamma band activity most closely correlated with improved postsurgical outcome as has been reported in previous literature.
Significance: These findings could lead to improved understanding of epileptogenesis. In addition, this theoretically allows for more targeted therapeutic interventions through the selected modulation or disruption of these epileptogenic networks.
This paper considers the systematic design of robust stabilizing state feedback controllers for fractional order nonlinear systems with time‐varying delay being possibly unbounded. By using the ...fractional Halanay inequality and the Caputo fractional derivative of a quadratic function, stabilizability conditions expressed in terms of bilinear matrix inequalities are derived. The controllers can then be obtained by computing the gain matrices. In order to derive the gain matrices, two algorithms are proposed by using the existing computationally linear matrix inequality techniques. Two numerical examples with simulation results are provided to demonstrate the effectiveness of the obtained results.
A copper‐catalyzed regio‐reversed asymmetric 3+2 cycloaddition of iminoesters with nitroolefins is disclosed for the first time. This method enables the facile synthesis of polysubstituted chiral ...pyrrolidines bearing at least one chiral quaternary center in high yields with excellent regio‐, diastereo‐, and enantioselectivity. The application of chiral P,S ligands and the unique effect of α‐aryl groups on the iminoesters are key to the success of this method. The practicality and versatility of the reaction are also demonstrated.
A copper‐catalyzed regio‐reversed asymmetric 3+2 cycloaddition of iminoesters with nitroolefins is reported. This method enables the facile synthesis of polysubstituted chiral pyrrolidines bearing at least one chiral quaternary center in high yields with excellent regio‐, diastereo‐, and enantioselectivity. The application of chiral P,S ligands and the unique effect of α‐aryl groups on the iminoesters are key to the success of this method.
PDF
