One Stone Several Birds: Self-Localizing Submicrocages with Dual Loading Points for Multifunctional Drug Delivery.

As the core index, how to improve bioavailability of loaded cargoes has been a hot topic of drug carriers. In our study, aminated ß-cyclodextrin (ß-CD) as cross-linking points was first integrated into three-dimensional poly(acrylamide-co-acrylonitrile) network to build up a unique submicrocage (466.2± 47.6 nm), featuring upper critical solution temperature (UCST; ∼40 °C), high volume expansion coefficient and excellent biocompatibility. Hereinto hydrophobic ß-elemene was locally loaded in ß-CD with high loading efficiency (8.72%) and encapsulation efficiency (78.60%) through hydrophobic desolvation and host-guest interaction. Above UCST, the release of the loaded ß-elemene was accelerated to 72.87% in 24 hours, together with the enhanced sensitization effect of synergized radiotherapy. Given spontaneous long-lasting delivery, targeted embolization, and post-treatment removal of such UCST-type submicrocage, it is anticipated to provide a novel, facile, efficient and versatile strategy of comprehensive anticancer treatments for high drug bioavailability. This article is protected by copyright. All rights reserved.

Integrated PtxCoy-Hierarchical Carbon Matrix Electrocatalyst for Efficient Hydrogen Evolution Reaction.

Pt-based catalysts are regarded as state-of-the-art electrocatalysts for producing clean hydrogen energy; however, their wide application is restricted by their low abundance, high cost, and poor stability. Herein, we report an integrated PtxCoy-hierarchical carbon matrix electrocatalyst (Pt/Co@NCNTs, Pt3Co@NCNTs, PtCo@NCNTs, and PtCo3@NCNTs) that is developed using a thermally driven Co migration strategy forming alloy nanoparticles to achieve efficient hydrogen evolution reaction (HER). Benefiting from its electronic regulation effect and unique hierarchical hollow structure, the Pt3Co@NCNTs catalyst loaded with 11.5 wt % Pt exhibits superior catalytic performance and durability for HER compared with commercial 20 wt % Pt/C. Under both alkaline and acidic conditions, Pt3Co@NCNTs exhibits excellent HER activity with overpotentials of 21 and 45 mV at 10 mA cm-2, respectively. Density functional theory (DFT) results further verify that the interaction between Pt and Co in Pt3Co@NCNTs can modulate electronic rearrangement, optimize the d-band center, and accelerate water dissociation and *H desorption, thereby enhancing HER activity.

Cu-In Dual Sites with Sulfur Defects Toward Superior Ethanol Electrosynthesis from CO2 Electrolysis.

The electrosynthesis of multi-carbon chemicals from excess CO2 is an area of great interest for research and commercial applications. However, improving both the yield of CO2 -to-ethanol conversion and the stability of the catalyst at the same time is proving to be a challenging issue. Here we propose to stabilize active Cu(I) and In dual sites with sulfur defects through an electro-driven intercalation strategy, which leads to the delocalization of electron density that enhances orbital hybridizations between the Cu-C and In-H bonds. Hence, the energy barrier for the rate-limiting *CHO formation step is reduced toward the key *OCHCHO* formation during ethanol production, which is also facilitated by the combined Cu site enabling C-C coupling and In site with a higher oxygen affinity based on both thermodynamic and kinetic calculations. Accordingly, such dual-site catalyst achieves a high partial current density toward ethanol of 409 ± 15 mA/cm2 for over 120 hours. Furthermore, a scaled-up flow cell is assembled with an industrial-relevant current of 5.7 A for over 36 hours, in which the carbon loss is less than 2.5% and single-pass carbon efficiency is around 19%. This article is protected by copyright. All rights reserved.

Asymmetric Synthesis of Remotely Chiral Naphthols and Naphthylamines via Naphthoquinone Methides.

Quinone methides are well-established intermediates in asymmetric synthesis. In contrast, their extended analogues with the carbonyl and methide units distributed across two different rings have not been exploited in asymmetric synthesis. Herein, we achieved the first asymmetric process involving such intermediates. Specifically, the use of suitable chiral phosphoric acids enabled in situ generation of 2-naphthoquinone 8-methides and the corresponding aza counterparts for mild one-pot asymmetric nucleophilic addition. These processes provided rapid access to a wide range of previously less accessible remotely chiral naphthols and naphthylamines with both high efficiency and excellent enantioselectivity. Control experiment and DFT calculations provided important insights into the reaction mechanism, which likely involves two phosphoric acid molecules in the enantiodetermining transition states. This work serves as a proof of concept for the exploitation of new types of extended quinone methides as versatile intermediates for asymmetric synthesis, thus providing a new platform for the efficient construction of remote benzylic stereogenic centers of aromatic compounds.

A Highly-Lithiophilic Mn3O4/ZnO-Modified Carbon Nanotube Film for Dendrite-Free Lithium Metal Anodes.

Lithium metal anode is deemed as a potential candidate for high energy density batteries, which has attracted increasing attention. Unfortunately, Li metal anode suffers from issues such as dendrite grown and volume expansion during cycling, which hinders its commercialization. Herein, we designed a porous and flexible self-supporting film comprising of single-walled carbon nanotube (SWCNT) modified with a highly-lithiophilic heterostructure (Mn3O4/ZnO@SWCNT) as the host material for Li metal anodes. The p-n-type heterojunction constructed by Mn3O4 and ZnO generates a built-in electric field that facilitates electron transfer and Li+ migration. Additionally, the lithiophilic Mn3O4/ZnO particles serve as the pre-implanted nucleation sites, dramatically reducing the lithium nucleation barrier due to their strong binding energy with lithium atoms. Moreover, the interwoven SWCNT conductive network effectively lowers the local current density and alleviates the tremendous volume expansion during cycling. Thanks to the aforementioned synergy, the symmetric cell composed of Mn3O4/ZnO@SWCNT-Li can stably maintain a low potential for more than 2500 h at 1 mA cm-2 and 1 mAh cm-2. Furthermore, the Li-S full battery composed of Mn3O4/ZnO@SWCNT-Li also shows excellent cycle stability. These results demonstrate that Mn3O4/ZnO@SWCNT has great potential as a dendrite-free Li metal host material.

Phase wavefront perturbation calculation model for spectroscopic refractive index matching of hybrid materials.

A low-cost flexible spectroscopic refractive index matching (SRIM) material with bandpass filtering properties without incidence angle and polarization dependence by randomly dispersing inorganic C a F 2 particles in organic polydimethylsiloxane (PDMS) materials was proposed in our previous study. Since the micron size of the dispersed particles is much larger than the visible wavelength, the calculation based on the commonly used finite-difference time-domain (FDTD) method to simulate light propagation through the SRIM material is too bulky; however, on the other hand, the light tracing method based on Monte Carlo theory in our previous study cannot adequately explain the process. Therefore, a novel approximate calculation model, to the best of our knowledge, based on phase wavefront perturbation is proposed that can well explain the propagation of light through this SRIM sample material and can also be used to approximate the soft scattering of light through composite materials with small refractive index differences, such as translucent ceramics. The model simplifies the complex superposition of wavefront phase disturbances and the calculation of scattered light propagation in space. The scattered and nonscattered light ratios; the light intensity distribution after transmission through the spectroscopic material; and the influence of absorption attenuation of the PDMS organic material on the spectroscopic performance are also considered. The simulation results based on the model are in great agreement with the experimental results. This work is important to further improve the performance of SRIM materials.

[Effects of Nitrogen and Phosphorus Addition on Soil Nutrient Content and Stoichiometry in Desert Grassland].

In order to discuss the response of soil nutrient content, stoichiometric ratio, and dynamic nutrient balance to the addition of multiple restrictive nutrients, the correlation between available nutrients and total nutrients in soil, as well as the indication of soil total and available stoichiometric characteristics, were studied in a desert grassland subjected to 4 years of nutrient addition treatments. The Ningxia desert grassland was used as the research object to carry out nitrogen (N) and phosphorus (P) addition experiments. The experiment included four treatments:control (CK), N addition[10 g·(m2·a)-1], P addition[10 g·(m2·a)-1], and NP co-addition (10 g·(m2·a)-1 N+10 g·(m2·a)-1 P). The results showed that:① in the fourth year of nutrient addition, soil total nitrogen (TN) content was significantly increased. The N:P ratio was significantly increased by N addition, and soil organic carbon (SOC) content was significantly increased by P addition and NP co-addition. In the third and fourth years of nutrient addition, the soil available N:P ratio (AN:AP) was significantly increased by N addition; N addition and NP co-addition significantly increased the content of ammonium nitrogen (NH4+-N) and nitrate nitrogen (NO3--N) but significantly reduced the soil available C:N ratio. P addition and NP co-addition significantly increased total phosphorus (TP) and soil available phosphorus (AP), whereas it significantly reduced the soil total and available C:P and N:P ratios. ② The interaction between N addition and P addition had a combined effect on NH4+-N, AP, available C:N, and AN:AP ratio of desert grassland. ③ The soil C:N ratio was relatively stable in desert grassland, soil N:P ratio was mainly limited by soil TP content, and the soil available C:P and AN:AP ratios were mainly limited by soil AP content. ④ There were cumulative effects of N and P additions on soil N, SOC, and inorganic nitrogen. N limitation in desert grassland was alleviated by N addition, whereas it was aggravated by P addition and NP co-addition. The variation coefficients of soil available stoichiometric characteristics were higher than that of soil total stoichiometric characteristics. Soil available stoichiometry was more sensitive to N and P addition than soil total stoichiometry in desert grassland, which could better reflect the effects of N and P addition on soil ecological stoichiometry and as a rapid indicator of soil nutrient status in desert grassland.

Boosting oxygen evolution reaction activity and durability of phosphate doped Ni(OH)2/FeOOH hierarchical microtubes by morphology engineering and reconstruction strategy.

Developing electrocatalysts with remarkable activity and durability is significant for efficient oxygen evolution reaction (OER). Herein, we designed phosphate doped Ni(OH)2/FeOOH hierarchical microtubes (denoted as POx-Ni(OH)2/FeOOH HMTs), obtained by phosphate doped NiFe Prussian blue analogue hierarchical microtubes (denoted as P-NF-PBA HMTs) completely reconstructing in OER process. POx-Ni(OH)2/FeOOH HMTs possess an extremely low overpotential of 237 mV at 30 mA cm-2 in alkaline electrolyte with the Tafel slope of 35 mV dec-1, and the catalysts can maintain excellent durability for 100 h at 30 mA cm-2. The remarkable electrochemical catalytic activity comes from the advantages of the hierarchical hollow structure, the modulation of electronic structure caused by phosphate doping, and the synergistic effect of Ni(OH)2 and FeOOH species produced by catalyst complete reconstruction in the OER process. This work may provide an effective strategy to develop highly efficient and durable electrocatalysts towards OER.

Lithiophilic hollow Co3[Co(CN)6]2 embedded carbon nanotube film for dendrite-free lithium metal anodes.

Lithium metal is considered to be an ideal anode material due to its ultra-high theoretical capacity and extremely low electric potential. Unfortunately, the infinite volume expansion and unregulated formation of lithium dendrites in the plating/stripping process restrict its practical utilization. Herein, we designed a hollow Co3[Co(CN)6]2 (CoCoPBA) embedded high-conductivity carbon film as a three-dimensional (3D) lithiophilic current collector (h-CoCoPBAs@SWCNT). The interwoven carbon nanotubes with hollow nanoparticles can effectively promote electron transfer and reduce local current density, adapting to the huge volume expansion in long-term electrochemical cycling. At the same time, lithiophilic hollow CoCoPBA nanoparticles provide abundant active sites due to their large surface area, efficiently reducing nucleation overpotential and making lithium deposition easier and more uniform, both confirmed by theoretical calculation and experiment. Accordingly, compared with bare Cu electrodes, h-CoCoPBAs@SWCNT electrodes have a flat and uniform Li deposition morphology, which is beneficial to enhance the cycle life of lithium metal anodes. And the symmetrical cell assembled by h-CoCoPBAs@SWCNT shows stable cycling performance of more than 500 h at 2 mA cm-2 with 1 mAh cm-2. Besides, the assembled lithium-sulfur full cell also has higher cycle stability and rate performance.

Mild Intermolecular Synthesis of a Cyclopropane-Containing Tricyclic Skeleton: Unusual Reactivity of Isobenzopyryliums.

Cyclopropanes embedded in a polycyclic bridged architecture are a versatile structural motif, but such complex frameworks often impose substantial synthetic challenges. Herein we introduce a new approach for the expedient access to such spring-loaded strained systems via an exceptionally mild intermolecular convergent process between the readily available isobenzopyryliums and vinyl boronic acids. Different from the typical conventional approaches, our protocol does not involve the highly active carbenoid intermediates or strong conditions in order to overcome the disfavored kinetic and thermodynamic problems. Instead, the key cyclopropane ring was formed between the well-positioned nucleophile and electrophile in the adduct from the regioselective [4+2] cycloaddition. Thus, this unusual process also represents a new reactivity of the versatile isobenzopyryliums. The choice of a Brønsted acid catalyst with proper acidity is crucial to the high efficiency and selectivity for this multiple bond-forming process. The strained products are precursors to other useful synthetic building blocks.

In(OTf)3-Catalyzed Synthesis of 2,3-Dihydro-1H-benzo[e]indoles and 2,3-Dihydrobenzofurans via [3 + 2] Annulation.

An In(OTf)3-catalyzed intermolecular [3 + 2] annulation for the synthesis of 2,3-dihydro-1H-benzo[e]indoles and 2,3-dihydrobenzofurans from readily available substrates has been achieved. This approach takes advantage of oxetane and para-quinone methide as important functional units in the key intermediate. ß-Naphthylamines and phenols have been demonstrated as excellent reaction partners.