•Reaction mechanism, influencing factor, and natural shortcoming of conventional PDT.•Strategies for construction of the optimized UCNP-PS systems for efficient UC-PDT.•Representative examples of ...UC-PDT combining with some traditional anti-cancer methods.•Guidance for design and synthesis of the future new UCNP-PS for synergistic UC-PDT.
Photodynamic therapy (PDT) has become widely accepted and utilized for tumor therapy. Considering the natural shortcomings (e.g., lack of an ideal photosensitizer and limited light penetration depth), lanthanide doped upconversion nanoparticles (Ln-doped UCNP), which can be excited with near-infrared light (NIR) for UV/visible/NIR upconversion luminescence (UCL) emissions, show great potential for augmenting biological treatment with PDT for solid tumors and for visual bioimaging of disease lesions. This review summarizes the basic concepts and important influence factors on PDT, the optimized construction of UCNP-based photosensitizer (UCNP-PS) systems, and some representative examples of UCNP-based PDT (UC-PDT) applications in combination with other traditional therapy methods, such as chemotherapy, radiotherapy, photothermal therapy (PTT) and gene therapy. This review will provide guidance for the design and fabrication of future new UCNP-based nanocomposites for synergistic UC-PDT therapy.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
As a metal‐free nitrogen reduction reaction (NRR) photocatalyst, g‐C3N4 is available from a scalable synthesis at low cost. Importantly, it can be readily functionalized to enhance photocatalytic ...activities. However, the use of g‐C3N4‐based photocatalysts for the NRR has been questioned because of the elusive mechanism and the involvement of N defects. This work reports the synthesis of a g‐C3N4 photocatalyst modified with cyano groups and intercalated K+ (mCNN), possessing extended visible‐light harvesting capacity and superior photocatalytic NRR activity (NH3 yield: 3.42 mmol g−1 h−1). Experimental and theoretical studies suggest that the ‐C≡N in mCNN can be regenerated through a pathway analogous to Mars van Krevelen process with the aid of the intercalated K+. The results confirm that the regeneration of the cyano group not only enhances photocatalytic activity and sustains the catalytic cycle, but also stabilizes the photocatalyst.
Active site: A superior g‐C3N4 photocatalyst for the nitrogen reduction reaction (NRR) is reported. The catalyst features ‐C≡N groups and intercalated K+, and is used as model to investigate the mechanistic pathway of the photocatalytic NRR involving ‐C≡N‐type active sites.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The development of efficient and cheap bifunctional oxygen electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) to be applied in rechargeable metal-air ...batteries and unitized generative fuel cells (URFCs) operated with alkaline electrolytes is highly crucial and challenging. Here we report high-performance bifunctional electrocatalysts of transition metal nanoparticles encapsulated in nitrogen-doped carbon nanotubes (M/N-CNTs, M = Fe, Co, and Ni). The optimized Co/N-CNT hybrid shows the highest efficient bifunctional catalytic activity and excellent stability towards both the ORR and OER. The oxygen electrode activity parameter Delta E (the criteria for judging the overall catalytic activity of bifunctional electrocatalysts) value for Co/N-CNTs is 0.78 V, which surpasses those of Pt/C and RuO2 catalysts and most of the non-precious metal based bifunctional electrocatalysts reported in the previous literature studies. Furthermore, excellent long-term catalytic durability holds great promise in fields of renewable energy applications.
Several decades of research have identified the specific tumor microenvironment (TME) to develop promising nanotheranostics, such as pH‐sensitive imaging, acidity‐sensitive starving therapy, and ...hydrogen peroxide‐activated chemotherapy, etc. Herein, a novel TME‐mediated nanoplatform employing antiferromagnetic pyrite nanocubes is presented, exploiting the intratumoral, overproduced peroxide for self‐enhanced magnetic resonance imaging (MRI) and photothermal therapy (PTT)/chemodynamic therapy (CDT). Through the activation of excessive peroxide in the tumor microenvironment, pyrite can lead to in situ surface oxidation and generate hydroxyl radicals to kill tumor cells (i.e., CDT). The increase of the valence state of surface Fe significantly promotes the performance of MRI accompanied by CDT. Furthermore, the localized heat by photothermal treatment can accelerate the intratumoral Fenton process, enabling a synergetic PTT/CDT. To our best knowledge, this is the first study to use the TME‐response valence‐variable strategy based on pyrite for developing a synergetic nanotheranostic, which will open up a new dimension for the design of other TME‐based anticancer strategies.
An innovative tumor microenvironment‐mediated nanoplatform for self‐enhanced magnetic resonance imaging and chemodynamic therapy/photothermal therapy is developed.
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This letter presents a fast blind recognition method for Bose, Chaudhuri, and Hocquenghem (BCH) code from noisy intercepted bit-streams. This approach employs the fact that the t-error-correcting BCH ...code has 2t continuous roots, and the roots correspond with the zero spectral. Specifically, the Galois field Fourier transform is simplified (S-GFFT) by using the property of conjugate roots. Then, the distribution characteristics of continuous zero spectra are analyzed. If the continuous zero spectra satisfy the threshold condition which is derived by the probability of zero spectrum component, the corresponding estimated length is the code length, and the relevant positions correspond to the continuous roots of the generated polynomial. Finally, the generator polynomial can be reconstructed based on algebras theory. Compared to the existing solutions, the computational amount of S-GFFT at most accounts for 60% of GFFT, and the proposed scheme manages to recognize the code parameters without traversing the whole candidate datasets.
It is highly crucial and challenging to develop bifunctional oxygen electrocatalysts for oxygen reduction reactions (ORRs) and oxygen evolution reactions (OERs) in rechargeable metal-air batteries ...and unitized regenerative fuel cells (URFCs). Herein, a facile and cost-effective strategy is developed to prepare mesoporous Fe–N-doped graphene-like carbon architectures with uniform Fe3C nanoparticles encapsulated in graphitic layers (Fe3C@NG) via a one-step solid-state thermal reaction. The optimized Fe3C@NG800-0.2 catalyst shows comparable ORR activity with the state-of-the-art Pt/C catalyst and OER activity with the benchmarking RuO2 catalyst. The oxygen electrode activity parameter ΔE (the criteria for judging the overall catalytic activity of bifunctional electrocatalysts) value for Fe3C@NG800-0.2 is 0.780 V, which surpasses those of Pt/C and RuO2 catalysts as well as those of most nonprecious metal catalysts. Significantly, excellent long-term catalytic durability holds great promise in fields of rechargeable metal-air batteries and URFCs.
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Local hypoxia in tumors is an undesirable consequence of photodynamic therapy (PDT), which will lead to greatly reduced effectiveness of this therapy. Bioreductive pro‐drugs that can be activated at ...low‐oxygen conditions will be highly cytotoxic under hypoxia in tumors. Based on this principle, double silica‐shelled upconversion nanoparticles (UCNPs) nanostructure capable of co‐delivering photosensitizer (PS) molecules and a bioreductive pro‐drug (tirapazamine, TPZ) were designed (TPZ‐UC/PS), with which a synergetic tumor therapeutic effect has been achieved first by UC‐based (UC‐) PDT under normal oxygen environment, immediately followed by the induced cytotoxicity of activated TPZ when oxygen is depleted by UC‐PDT. Treatment with TPZ‐UC/PS plus NIR laser resulted in a remarkably suppressed tumor growth as compared to UC‐PDT alone, implying that the delivered TPZ has a profound effect on treatment outcomes for the much‐enhanced cytotoxicity of TPZ under PDT‐induced hypoxia.
Synergetic therapy: Strong hypoxia created by upconversion photodynamic therapy (UC‐PDT) activates bioreductive pro‐drugs co‐delivered to form cytotoxic species, thereby potentiating the synergetic anticancer efficacy of UC‐PDT. This process was accomplished by using upconversion‐based nanoparticles designed to simultaneously deliver photosensitizer molecules and bioreductive pro‐drugs in silica layers.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
It is an important issue that exposed active nitrogen atoms (e.g., edge or amino N atoms) in graphitic carbon nitride (g‐C3N4) could participate in ammonia (NH3) synthesis during the photocatalytic ...nitrogen reduction reaction (NRR). Herein, the experimental results in this work demonstrate that the exposed active N atoms in g‐C3N4 nanosheets can indeed be hydrogenated and contribute to NH3 synthesis during the visible‐light photocatalytic NRR. However, these exposed N atoms can be firmly stabilized through forming BNC coordination by means of B‐doping in g‐C3N4 nanosheets (BCN) with a B‐doping content of 13.8 wt%. Moreover, the formed BNC coordination in g‐C3N4 not only effectively enhances the visible‐light harvesting and suppresses the recombination of photogenerated carriers in g‐C3N4, but also acts as the catalytic active site for N2 adsorption, activation, and hydrogenation. Consequently, the as‐synthesized BCN exhibits high visible‐light‐driven photocatalytic NRR activity, affording an NH3 yield rate of 313.9 µmol g−1 h−1, nearly 10 times of that for pristine g‐C3N4. This work would be helpful for designing and developing high‐efficiency metal‐free NRR catalysts for visible‐light‐driven photocatalytic NH3 synthesis.
The BNC coordination formed by boron doping in g‐C3N4 nanosheets is the catalytic active site for the high‐efficiency photocatalytic nitrogen reduction reaction. It also effectively immobilizes the exposed active N atoms of g‐C3N4, inhibits the recombination of photogenerated charges, and improves the visible‐light harvesting efficiency.
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This paper investigates the switching control problem for aero-engines. An event-triggered switching control strategy is presented based on the proposed switched equilibrium manifold expansion (EME) ...model of the aero-engine in order to enhance the speed regulation performance. First, a switching law is given using an optimization index for the candidate EME models, which utilize different mappings based on the off-line data of the aero-engine so that the switched EME model has higher accuracy than general EME models. Then, controllers for the subsystems of the switched EME model are designed using the exact feedback linearization technique. Asymptotic stability of the closed-loop switched system is ensured for arbitrary switching with the given condition. This enables us to pursue other performances via design of switching law with stability guaranteed. An event-triggered switching law is constructed for the controllers to get a better performance. Finally, a case study for a two-spool turbofan engine is performed to verify the effectiveness and superiority of the proposed control strategy.
Aqueous Zn-ion batteries (ZIBs) are emerging candidates for safe and eco-friendly large-scale energy storage, but the critical challenge is to develop stable and robust cathode materials for ...reversible and fast Zn2+ intercalation. In the present work, the drawbacks of pure hydrated vanadium oxides (VOH), including low ion mobility and cycling instability, are mitigated by modifying the local atomic environment and increasing the amount of tetravalent vanadium cations. These effects are achieved by introducing trivalent Al-ions during a one-step hydrothermal synthesis. The expanded lattice spacing and improved conductivity of the synthesized Al–VOH enable rapid Zn2+ diffusion and electron transfer, leading to a high capacity of 380 mAh·g−1 at 50 mA g−1, as well as the excellent long-term cycling stability (capacity maintained over 3000 cycles). Further investigations of the reaction kinetics and mechanism reveal the effects of introducing Al-ions, and the role of Zn2+ trapped upon initial charging plays in promoting the subsequent electrochemical process and preventing the structural degradation.
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•Al-ions were introduced into hydrated vanadium oxide through hydrothermal reaction.•The lattice spacing of the product is expanded.•Improved ion diffusion rate and conductivity result in a higher capacity.•Al-ions and trapped Zn-ions assist in stabilizing the structure.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
