In recent years, owing to unsatisfactory clinical imaging clarity and depths in the living body for early diagnosis and prognosis, novel imaging modalities with high bioimaging performance have been ...actively explored. The remarkable headway made in the second near-infrared region (NIR-II, 1000-1700 nm) has promoted the development of biomedical imaging significantly. NIR-II fluorescence imaging possesses a number of merits which prevail over the traditional and NIR-I (400-900 nm) imaging modalities in fundamental research, such as reduced photon scattering, as well as auto-fluorescence and improved penetration depth. Functional probes for instant and precise feedback of
information are at the core of this modality for superb imaging. Herein, we review the recently developed fluorophores including carbon nanotubes, organic small molecules, quantum dots, conjugated polymers and rare-earth-doped materials to present superior and multifunctionality of biomedical imaging in the NIR-II regions (1000-1700 nm).
This paper addresses the problem of global finite-time adaptive stabilization for a class of high-order uncertain nonlinear systems. A new finite-time stability result is established to provide a ...less conservative estimation of convergent time in uncertain situation, and a state feedback stabilizer with an adaptive mechanism is constructed by applying continuous domination to adaptive fashion of the systems to be considered. The main novelty of this paper is the skillful development of an analytic strategy and the delicate selection of Lyapunov functions in searching for the adaptive fast finite-time stabilizer. A benchmark example is given to demonstrate the effectiveness of the proposed strategy.
This paper is concerned with the improvement of finite-time stability theorem and its application in stabilizing a class of high-order nonlinear systems globally. The novel control strategy unifies ...the construction of Lyapunov functions, which are used to deal with high-order and low-order nonlinear growth rates separately in the existing results. Convergent time is shortened greatly without requiring large control effort, but it suffers long period from traditional finite-time stabilization scheme when initial state is far away from the origin. Finally, two simulation examples including a practical one are presented to illustrate the efficiency of the proposed strategy.
Abstract The circulating renin-angiotensin system (RAS) is a classic endocrine system that regulates cardiovascular homeostasis during physiologic and pathologic states. Accumulated evidence has ...shown the presence of components of RAS in various tissues, which are upregulated in certain pathological conditions. Locally produced angiotensin (Ang)II may play an important role in tissue repair/remodeling in autocrine and/or paracrine manners. Following acute myocardial infarction (MI), cardiac repair occurs in the infarcted myocardium and structural remodeling is developed in noninfarcted myocardium, which are accompanied by activated cardiac RAS. In this review, the current understanding of independent activation of cardiac RAS and its regulation in the pathogenesis of myocardial repair/remodeling after MI is discussed.
Summary
This article designs an adaptive event‐triggered controller to solve the problem of global finite‐time stabilization for a class of uncertain nonlinear systems. By using the symbol function ...technique, the event‐triggered error is completely compensated, the adaptive technique and the back‐stepping method are simultaneously applied to the controller design, and the new way of designing controller is completed on the basis of fast finite‐time stability theory. Subsequently, taking Lyapunov stability theorem into account, the system stability is proved, and the system is demonstrated by contradiction to be non‐zeno. Finally, giving a simulation example to display the feasibility of this method.
Since the first example of using a thiourea‐amine organocatalyst was reported in 2003, research on thiourea‐based amines and phosphines in asymmetric catalysis has shown the excellent performance of ...chiral thiourea‐amine/phosphine organocatalysts in a variety of highly enantioselective reactions. In this Minireview, the iconic catalysts and transformations are highlighted and discussed.
Thiourea‐amine/phosphine organocatalysts: Since the demonstration of the first example of using thiourea‐amine organocatalysts in 2003, research on thiourea‐based amines and phosphines in asymmetric catalysis has shown that they could successfully catalyze a variety of highly enantioselective reactions. In this Minireview, the iconic catalysts and transformations are summarized and discussed.
Active power decoupling methods are developed to deal with the inherent ripple power at twice the grid frequency in single-phase systems generally by adding active switches and energy storage units. ...They have obtained a wide range of applications, such as photovoltaic (PV) systems, light-emitting diodes (LEDs) drivers, fuel cell (FC) power systems, and electric vehicle (EV) battery chargers, etc. This paper provides a comprehensive review of active power decoupling circuit topologies. They are categorized into two groups in terms of the structure characteristics: independent and dependent decoupling circuit topologies. The former operates independently with the original converter, and the latter, however, shares the power semiconductor devices with the original converter partially and even completely. The development laws for the active power decoupling topologies are revealed from the view of "duality principle," "switches sharing," and "differential connection." In addition, the exceptions and special cases are also briefly introduced. This paper is targeted to help researchers, engineers, and designers to construct some new decoupling circuit topologies and properly select existing ones according to the specific application.
Summary
This paper is concerned with global stabilization via output feedback for a class of stochastic nonlinear systems with time‐varying continuous output function. Under linear growth conditions, ...a new double‐domination method is proposed for the first time to construct an output‐feedback stabilizing controller. Different from the related results, the design of the observer is performed without using the information on the output function and nonlinearities. This paper also provides a viewpoint at the feedback stabilization to eliminate the continuous measurement error originating from inaccurate detection of system state. A simulation example is presented to demonstrate the effectiveness of control strategy.
Brain organoids have been used to recapitulate the processes of brain development and related diseases. However, the lack of vasculatures, which regulate neurogenesis and brain disorders, limits the ...utility of brain organoids. In this study, we induced vessel and brain organoids respectively, and then fused two types of organoids together to obtain vascularized brain organoids. The fused brain organoids were engrafted with robust vascular network-like structures, and exhibited increased number of neural progenitors, in line with the possibility that vessels regulate neural development. Fusion organoids also contained functional blood-brain-barrier (BBB)-like structures, as well as microglial cells, a specific population of immune cells in the brain. The incorporated microglia responded actively to immune stimuli to the fused brain organoids and showed ability of engulfing synapses. Thus, the fusion organoids established in this study allow modeling interactions between the neuronal and non-neuronal components
, in particular the vasculature and microglia niche.
In vivo second near‐infrared (NIR‐II, 1.0–1.7 µm) bioimaging , a rapidly expanding imaging tool for preclinical diagnosis and prognosis, is of great importance to afford precise dynamic actions in ...vivo with high spatiotemporal resolution, deeper penetration, and decreasing light absorption and scattering. In the course of preclinical practices, organic and inorganic emitters with NIR‐II signals are indispensable keys to open the invisible biological window. In this review, NIR‐II emitters, including but not limited to organic emitters like organic small molecules and copolymers, and inorganic emitters such as lanthanide‐based nanocrystals, quantum dots like Ag2S dots, and carbon nanotubes, are described, especially regarding their unique optical features and noteworthy functions for animal bioimaging. Along with these existing advances, the challenges and potential spaces for further progress are discussed to offer an approximate direction for future researches.
In vivo second near‐infrared bioimaging is of great importance to provide precise information with high temporal and spatial resolution and deeper penetration depth. In this mini review, NIR‐II contrast agents including organic and inorganic materials are described with respective features and unique optical functions for animal bioimaging. Later, the challenges and potential spaces for further progress are also discussed.
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