During the last few years, the preparation of novel fluorescent probes for the selective detection of chemical species inside mitochondria has attracted considerable attention because of their wide ...applications in chemistry, biology, and medical science. This feature article focuses on the recent advances in the design principles and recognition mechanisms of these kinds of fluorescent probes. In addition, their applications for the detection of reactive oxygen species (ROS), nitric oxide, reactive sulfur species (RSS), thioredoxin (Trx), metal ions, anions, etc. in the mitochondrion is discussed as well.
Diabetic nephropathy (DN) is the major microvascular complication of diabetes mellitus and the most important cause of end‐stage renal disease worldwide. Metformin is the preferred oral hypoglycaemic ...drug for type 2 diabetes mellitus (T2DM). Recent studies have shown that besides lowering blood glucose, metformin also has protective effects on renal function, but its mechanism is not clear. In this study, we established a diabetic rat model by high‐fat feeding combined with intraperitoneal injection of streptozotocin. Their changes of renal function, oxidative stress, histopathology and structure, and autophagy were observed after 8 weeks of metformin treatment at different dose. Sirt1 inhibitor EX527 and metformin were used to observe whether the protective effect of metformin on DN kidney was achieved through the Sirt1/FoxO1 autophagic signalling pathway. The results showed that metformin could protect renal function by up‐regulating autophagy level, alleviating oxidative stress level of renal tissue and pathological and structural changes of glomeruli, and inhibiting the expression of extracellular matrix. Sirt1 inhibitor could block the protective effect of metformin on kidney of diabetic rats, suggesting that metformin could alleviate kidney injury in diabetic rats by inducing Sirt1/FoxO1 autophagy signal axis. So metformin could alleviate renal injury in diabetic rats, which may be achieved by regulating Sirt1/FoxO1 autophagic signalling pathway and inducing renal autophagy.
A look at the use of nanowire electrodes in electrochemical energy storage devices is presented. Topics discussed include interfaces of nanowire electrodes.
De novo organogenesis, which gives rise to adventitious roots and shoots, is a type of plant regeneration for survival after wounding. In Arabidopsis (Arabidopsis thaliana), two main cell fate ...transition steps are required to establish the root primordium during de novo root organogenesis from leaf explants. The first step from regeneration-competent cells to root founder cells involves activation of WUSCHEL-RELATED HOMEOBOX11 (WOX11) and WOX12 (WOX11/12) expression by auxin. However, the molecular mechanism controlling the second step of fate transition from root founder cells to root primordium is poorly understood. In this study, we show that the expression levels of WOX11/12 decrease while those of WOX5 and 7 (WOX5/7) increase during the transition from root founder cells to the root primordium. WOX11/12 function genetically upstream of WOX5/7, and the WOX11/12 proteins directly bind to the promoters of WOX5/7 to activate their transcription. Mutations in WOX5/7 result in defective primordium formation. Overall, our data indicate that the expression switch from WOX11/12 to WOX5/7 is critical for initiation of the root primordium during de novo root organogenesis.
The most intriguing properties of non-Hermitian systems are found near the exceptional points (EPs) at which the Hamiltonian matrix becomes defective. Because of the complex topological structure of ...the energy Riemann surfaces close to an EP and the breakdown of the adiabatic theorem due to non-Hermiticity, the state evolution in non-Hermitian systems is much more complex than that in Hermitian systems. For example, recent experimental work Doppler et al., Nature (London) 537, 76 (2016) demonstrated that dynamically encircling an EP can lead to chiral behaviors; i.e., encircling an EP in different directions results in different output states. Here, we propose a coupled ferromagnetic waveguide system that carries two EPs and design an experimental setup in which the trajectory of state evolution can be controlled in situ using a tunable external field, allowing us to dynamically encircle zero, one, or even two EPs experimentally. The tunability allows us to control the trajectory of encircling in the parameter space, including the size of the encircling loop and the starting/end point. We discovered that whether or not the dynamics is chiral actually depends on the starting point of the loop. In particular, dynamically encircling an EP with a starting point in the parity-time-broken phase results in nonchiral behaviors such that the output state is the same no matter which direction the encircling takes. The proposed system is a useful platform to explore the topology of energy surfaces and the dynamics of state evolution in non-Hermitian systems and will likely find applications in mode switching controlled with external parameters.
In modern agriculture, seeking eco-friendly ways to promote plant growth and enhance crop productivity is of priority. Biostimulants are a group of substances from natural origin that contribute to ...boosting plant yield and nutrient uptake, while reducing the dependency on chemical fertilizers. Developing biostimulants from by-products paves the path to waste recycling and reduction, generating benefits for growers, food industry, registration and distribution companies, as well as consumers. The criteria to select designated by-products for valorizing as biostimulant are: absence of pesticide residue, low cost of collection and storage, sufficient supply and synergy with other valorization paths. Over the years, projects on national and international levels such as NOSHAN, SUNNIVA, and Bio2Bio have been initiated (i) to explore valorization of by-products for food and agriculture industries; (ii) to investigate mode of action of biostimulants from organic waste streams. Several classes of waste-derived biostimulants or raw organic material with biostimulant components were shown to be effective in agriculture and horticulture, including vermicompost, composted urban waste, sewage sludge, protein hydrolysate, and chitin/chitosan derivatives. As the global market for biostimulants continues to rise, it is expected that more research and development will expand the list of biostimulants from by-products. Global nutrient imbalance also requires biostimulant to be developed for targeted market. Here, we review examples of biostimulants derived from agricultural by-products and discuss why agricultural biomass is a particularly valuable source for the development of new agrochemical products.
Two efficient blue thermally activated delayed fluorescence compounds, B‐oCz and B‐oTC, composed of ortho‐donor (D)–acceptor (A) arrangement were designed and synthesized. The significant ...intramolecular D–A interactions induce a combined charge transfer pathway and thus achieve small ΔEST and high efficiencies. The concentration quenching can be effectively inhibited in films of these compounds. The blue non‐doped organic light emitting diodes (OLEDs) based on B‐oTC prepared from solution processes shows record‐high external quantum efficiency (EQE) of 19.1 %.
Blue note: Highly efficient blue thermally activated delayed fluorescent (TADF) materials have been developed by using a new design strategy. Solution‐processed, non‐doped blue organic light‐emitting diodes based on these emitters realized record‐high external quantum efficiency of 19.1 %.
This article addresses the decentralized tracking control problem for a class of strong interconnected nonlinear systems with actuator faults. The considered interconnections are allowed to be ...dominated by some bounding functions, which are linear growth in the status of all subsystems. First, an adaptive high-gain technique is introduced to deal with the unknown strong interconnections. Then, a group of fault-tolerant controllers is designed to adaptively compensate for the effects of the actuator failures, in which the controller gain parameters are adjusted online only according to local available information. Furthermore, with the aid of an algebraic graph theory result, it is proved that all signals of the closed-loop system are globally uniformly bounded, and the tracking errors of all subsystems converge to zero asymptotically. The effectiveness of the proposed control algorithm is demonstrated by a numerical simulation.
Muscles and joints make highly coordinated motion, which can be partly mimicked to drive robots or facilitate activities. However, most cases primarily employ actuators enabling simple deformations. ...Therefore, a mature artificial motor system requires many actuators assembled with jointed structures to accomplish complex motions, posing limitations and challenges to the fabrication, integration, and applicability of the system. Here, a holistic artificial muscle with integrated light‐addressable nodes, using one‐step laser printing from a bilayer structure of poly(methyl methacrylate) and graphene oxide compounded with gold nanorods (AuNRs), is reported. Utilizing the synergistic effect of the AuNRs with high plasmonic property and wavelength‐selectivity as well as graphene with good flexibility and thermal conductivity, the artificial muscle can implement full‐function motility without further integration, which is reconfigurable through wavelength‐sensitive light activation. A biomimetic robot and artificial hand are demonstrated, showcasing functionalized control, which is desirable for various applications, from soft robotics to human assists.
A holistic artificial muscle with integrated light‐addressable nodes, using one‐step laser printing from a bilayer structure of poly(methyl methacrylate) and graphene oxide compounded with gold nanorods, is reported. The artificial muscle can implement full‐function motility without further integration, which is reconfigurable through wavelength‐sensitive light activation. A biomimetic robot and artificial hand is demonstrated, showcasing functionalized control, which is desirable for various applications.
Abstract
Dynamically encircling an exceptional point (EP) in parity-time (
PT
) symmetric waveguide systems exhibits interesting chiral dynamics that can be applied to asymmetric mode switching for ...symmetric and anti-symmetric modes. The counterpart symmetry-broken modes (i.e., each eigenmode is localized in one waveguide only), which are more useful for applications such as on-chip optical signal processing, exhibit only non-chiral dynamics and therefore cannot be used for asymmetric mode switching. Here, we solve this problem by resorting to anti-parity-time (anti-
PT
) symmetric systems and utilizing their unique topological structure, which is very different from that of
PT
-symmetric systems. We find that the dynamical encircling of an EP in anti-
PT
-symmetric systems with the starting point in the
PT
-broken phase results in chiral dynamics. As a result, symmetry-broken modes can be used for asymmetric mode switching, which is a phenomenon and application unique to anti-
PT
-symmetric systems. We perform experiments to demonstrate the new wave-manipulation scheme, which may pave the way towards designing on-chip optical systems with novel functionalities.
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