Latest ArticlesConia-ene reactions, as a type of ene reactions, have not become a remarkable focus until the beginning of 21st century, when Lewis acids served as powerful catalysts and found an increasingly broad utilization in this field. Consequently, the catalytic Conia-ene reactions have gained great significance in synthetic chemistry due to their high efficiency and atom economy on the construction of valuable cyclic molecules. During the past two decades, the rapid development of transition-metal catalysis and organocatalysis has imposed a profound impact on the exploration of asymmetric Conia-ene reactions. As a result, several strategies have been developed and applied successfully. Organized on the basis of the catalytic system, this review comprehensively presents a summary of recent progress achieved in this emerging domain, aimed at highlighting the reactions' features, practicalities, and the mechanistic rationale is presented where possible.
There is an increasing demand of using the low-cost and sustainable cobalt to replace its noble congeners (rhodium and iridium) as reflected by the recent upsurge of cobalt catalysis in the diverse organic transformations. Since all the redox reactivity of cobalt catalysis highly relies on the capability of the interconversion between their oxidation states (most frequently +1, +2 and +3), electrochemistry perfectly meets such a requirement owing to its outstanding performance in the redox manipulation. In this review, we highlight the recent advances in the merger of cobalt catalysis and electrochemistry in organic synthesis.
Lithium-ion batteries (LIBs) have evolved into the mainstream power source of energy storage equipment by reason of their advantages such as high energy density, high power, long cycle life and less pollution. With the expansion of their applications in deep-sea exploration, aerospace and military equipment, special working conditions have placed higher demands on the low-temperature performance of LIBs. However, at low temperatures, the severe polarization and inferior electrochemical activity of electrode materials cause the acute capacity fading upon cycling, which greatly hindered the further development of LIBs. In this review, we summarize the recent important progress of LIBs in low-temperature operations and introduce the key methods and the related action mechanisms for enhancing the capacity of the various cathode and anode materials. It aims to promote the development of high-performance electrode materials and broaden the application range of LIBs.
The intrinsic liquid interface of Na-K alloy allays concerns about dendrite growth on metal anodes that are thermodynamically within the room temperature (20–22 ℃). Nevertheless, it hinders the formation of a stable electrode structure due to the inferior wettability induced by considerable liquid tension. In addition, the dominant ionic carrier in the Na-K alloy is subject to multiple factors, which is not conducive to customized battery design. This review, based on recently reported frontier achievements on Na-K liquid anodes, summarizes practical strategies for promoting the wettability by high-temperature induction, capillary effect, vacuum infiltration, and solid interface protection. Furthermore, four selection mechanisms of the dominant ionic carrier are presented: (1) ion property dominated, (2) cathode dominated, (3) separator dominated, and (4) solid electrolyte interface dominated. Notably, initial electrolytes in energy storage systems have been unable to play a decisive role in ionic selection. Utilizing a superior wettability strategy and simultaneously identifying the dominant ionic carrier can facilitate the tailored application of dendrite-free Na-K liquid anodes.
As natural blood components, erythrocytes were good candidates for being used as drug delivery systems to improve the pharmacokinetics, biocompatibility and many other aspects of different drugs. The advantages brought by erythrocytes making erythrocyte-derived drug delivery systems, also known as erythrocyte carriers, suitable for various anti-cancer agents, especially newly invented agents like nanoparticles, which were characterized by their undesired systematic toxicity, anaphylactic reactions and poor biocompatibility. Current researches on erythrocyte carriers in cancer therapy showed inspiring results in four major aspects: cancer enzyme therapy, delivering chemotherapeutic agents, combining with nanoparticles, and several other anti-cancer agents for gene or immune therapy. This novel delivering system was now undergoing the translation process from laboratory to clinical practice. Erythrocyte carriers for cancer enzyme therapy have entered the stage of clinical trial and have showed promising outcomes, and others were still at pre-clinical stage. In summary, erythrocyte-derived drug delivery system might play an indispensable role in the management of cancer in the future.
Flexible rechargeable Zn-air batteries are considered as one of the most promising battery systems to drive flexible and wearable electronic devices owing to their high safety, high gravimetric energy density, low self-discharge and low cost. One of the key challenges is to develop air electrodes with high performance and high mechanical flexibility. This minireview discusses the recent progress in the design and fabrication of flexible air electrodes. It focuses on the latest innovations in bifunctional oxygen reduction reaction and oxygen evolution reaction electrocatalysts, mainly including carbon-based materials (e.g., heteroatom-doped carbon, metal-nitrogen moieties doped carbon), metal oxides (e.g., spinel oxides, perovskite oxides) and their composites. It aims to provide an insight into the structure-property relationship of bifunctional catalysts. We also discuss the challenges and future perspectives.
As a new treatment technique, photothermal therapy (PTT) has aroused worldwide attention in cancer treatment, mainly due to its excellent absorption ability, easy regulation, and biodegradability. Photothermal conversion materials with enhanced permeability and retention effect can be targeted easily to tumor tissue. They can accumulate efficiently to tumor tissues and allow normal tissues and organs not to be affected by temperature, thus significantly helping to reduce the systemic toxicity and improve the antitumor effect. However, PTT alone often suffers from therapeutic resistance and reduced therapeutic efficacy, due to photothermal nanomaterial-mediated fundamental cellular defense mechanism of heat shock response, which could be inhibited by small interfering RNA (siRNA). Nevertheless, photothermal conversion materials as an excellent siRNA delivery carrier may considerably enhance the delivery efficiency of siRNA. Therefore, photothermal and RNA interfering (RNAi) synergistic therapy has recently aroused extensive attention in tumor treatment. In this review, we mainly summarize the recent advances of photothermal and RNAi synergistic therapy, including some synergistic therapeutic nanoplatforms of inorganic and organic photothermal materials and other combined therapies such as combining with small molecular antitumor agents or PDT/imaging. The combination of various treatment techniques may considerably improve the synergistic therapeutic effect of PTT and RNAi in the treatment of cancers.
A new kind of emissive small-molecular organic cage has been developed via the combination of coupling and condensation reactions, which shows outstanding solubility, structural stability and potential spatial isomeric chirality. Interestingly, through the introduction of proper donor and acceptor units, this emissive organic cage is the first among organic cages to exhibit red aggregation-induced delayed fluorescence with photoluminescence emission at 603 nm. The finding not only expands the types of emissive small-molecular organic cages, but also represents an important step for further development of red delayed fluorescence materials with good solubility and aggregation-induced emission feature.
In continuation of our efforts toward the discovery of potent HIV-1 NNRTIs with diverse structures, a series of novel S-DACO analogues of 6-(2-cyclohexyl-1-alkyl)-2-(2-oxo-2-phenyl-ethylsulfanyl)pyrimidin-4(3H)-ones were designed, synthesized and evaluated for their antiviral activities in MT-4 cells. Most of these new compounds showed moderate to good activities against wild type HIV-1 with IC50 values ranging from 7.55 μmol/L to 0.018 μmol/L. Among them, compound 5c was identified as the most promising inhibitor against HIV-1 replication with an IC50 = 0.018 μmol/L, CC50 = 194 μmol/L, and SI = 12791, which was much more potent than the reference drugs NVP and DLV and comparable to AZT and EFV. In addition, 5c also exhibited improved activity against double mutant HIV-1 strain RES056 compared to that of the reference drugs NVP/DLV and DB02. The preliminary structure-activity relationship (SAR) and molecular modeling studies were also discussed, which provides some useful indications for guiding the further rational design of new S-DACO analogues.
Nanoparticle surface property is crucial for circulation stability, cellullar uptake and other biological characteristics. Zwitterionic pillar[n]arenes (ZPns) were used to coat gold nanoparticles (GNPs) via host-guest interaction. The resulting GNPs demonstrated higher stability in blood serum compared to polyethylene glycol (PEG)-coated GNPs. ZPn-coated GNPs were responsive to UV-irradiation, competitive displacement and acidic pH. UV-irradiation or competitive displacement could lead to the removal of ZPn coating to expose GNPs, which enhanced cell uptake efficiency by 5.9- and 7.4-fold, respectively.