Latest ArticlesThe similarity of local structure-connection pattern and volumetrically compressive strain between host and guest phases can be used to stabilize heteroid metastable matter and tune the local structure and properties. Here a series of metastable ABO3 (A = Mn; B = Mn0.5Mo0.5, Mn1/3Ta2/3, and Mn0.5Ta0.5) were trapped in LiTaO3 to form solid-solutions, where the difference of solid solubility limit reveals the barrier of size effect on chemical pressure. All samples show antiferromagnetic characters, in which the (LiTaO3)1--[Mn(Mn0.5Mo0.5)O3] series exhibit more complex magnetic and dielectric behaviors with the increasing of metastable guest phase, stemming from the complex interactive mechanism between Mn2+ and Mo6+. The cell parameter variation of (LiTaO3)1--[Mn(Mn0.5Ta0.5)O3] shows a more regularly changing tendency, on account of the smallest size barrier. These findings show that chemical pressure can effectively stimulate the physical pressure to intercept and modulate a metastable phase at atomic-scale by compressibility effect between like structures at ambient pressure.
Developing efficient dual–phase emission emitters upon organoboron luminophores remains a formidable challenge due to the ubiquitous self–absorption and deleterious π-π interactions from aromatic structure. Here, a new family of benzothiazole–enolate–based organoboron luminophores (HN1–4) with effective dual–phase emission was constructed. HN4 showed almost the highest quantum yield (QY) among this type of compound so far. The three-ring–fused rigid skeleton and moderate intramolecular charge transfer (ICT) effect ensured that HN4 could give rise to extremely strong emission in any solution (QY up to 99%). X-ray crystallographic analysis showed that the twisted core structure constructed by the boronic coordination of two penta-fluorobenzene of HN4 was responsible for intense emission in the solid state (QY up to 68%). Besides, HN4 exhibited a unique response to mechanical force accompanied by a reversible change of the QY. We believe that this strategy provides beneficial inspiration and methodology to design materials with high emissive quantum yield that can be used in a variety of luminescent events.
The macrocyclic family comprising pillar[n]arenes and cucurbit[n]urils have received much attention recently. However, studies on the construction of supramolecular complexes formed directly with derivatized pillar[n]arenes and cucurbit[n]urils are scant. Given the interest in such systems, herein we have synthesized a new type of naphthalene-derivatized pillar[n]arene NTP5 and selected Q[10] as the host molecule. The 4-[2-(1-naphthalenyl)ethenyl]pyridine of NTP5 is encapsulated by Q[10] and formed a host-guest complex in water-acetic acid (1:1) solution accompanied by enhanced fluorescence, which changed the morphology of NTP5 from a sphere to a porous form. In addition, the fluorescence of Q[10]-NTP5 can be quenched by the addition of the highly toxic pesticide paraquat (PQ), and the mechanism was shown to be the formation of a new charge transfer ternary system of Q[10]-NTP5-PQ. This work provides new ideas for the contribution of supramolecular assemblies based on derivatized pillar[n]arenes and their combination with cucurbit[n]urils and reveals their potential applications.
We demonstrate a synaptic transistor that uses a thermally crosslinked three-dimensional network to accommodate ionic liquid to form an ion gel layer. The synaptic transistor successfully emulated important synaptic plasticity, such as paired-pulse facilitation, spike-number dependent plasticity, spike-voltage dependent plasticity, and spike-rate dependent plasticity; these responses imply successful use of the ion gel. Moreover, the device realized "OR" and "AND" logic operations, and high-pass filtering behavior. Energy consumption of the device can be reduced to sub-femtojoule level, which is below that of biological synapses. Compared with traditional physical cross-linking using block copolymers, this method provides a facile strategy to prepare ion gels with tunable properties by altering the polymers and crosslinkers, and to enormously reduce the price by replacing expensive block copolymers or eliminating additional synthesis processes. This report provides a versatile strategy for design of synaptic transistors and their applications in neuromorphic electronics.
Efficient determination of tumor exosomes using portable devices is crucial for the establishment of facile and convenient early cancer diagnostic methods. However, it is still challenging to effectively amplify the detection signal to achieve tumor exosomes detection with high sensitivity by portable devices. To address this issue, we developed a portable multi-amplified temperature sensing strategy for highly sensitive detecting tumor exosomes based on multifunctional manganese dioxide/IR780 nanosheets (MnO2/IR780 NSs) nanozyme with high oxidase-like activity and enhanced photothermal performance. Inspiringly, MnO2/IR780 NSs were synthesized via a facile one-step method with mild experimental conditions, which not only exhibited a stronger photothermal effect than that of MnO2 but also showed excellent oxidase-like activity that can catalyze the oxidation of 3, 3′, 5, 5′-tetramethylbenzidine (TMB) to generate TMB oxide (oxTMB) with a robust photothermal property, thus conjoining with MnO2/IR780 NSs to further enhance the temperature signal. The present assay enables highly sensitive determination of tumor exosomes with the detection limit down to 5.1 × 103 particles/mL, which was comparable or superior to those of the most previously reported sensors. Furthermore, detection of tumor exosomes spiked in biological samples was successfully realized. More importantly, our method showed the recommendable portability, robust applicability, and easy manipulation. By taking advantages of these features, this high-performance photothermal sensor offered a promising alternative means for nondestructive early cancer diagnosis and treatment efficacy evaluation.
Liposomes have been widely exploited as a drug delivery system in treating tumors because of their advantage to enhance anti-tumor efficacy and reduce side effects. In this study, the tumor-targeted 2-dodecyl-6-methoxycyclohexa-2, 5-diene-1, 4-dione (DMDD, i.e., Averrhoa carambola extractive) liposomes (HA/TN-DLP) were conducted and assessed. HA/TN-DLP showed controllable drug loading (up to 83%) with high stability. In vitro and in vivo studies showed good cell uptake behavior and high inhibition rate of breast cancer compared to free DMDD. HA/TN-DLP might be the suitable for DMDD due to its better advantages in delivery, penetrability, and targeting-tumor capability. For in vivo mouse model tests, HA/TN-DLP effectively inhibited tumor growth compared to free DMDD. Further analyses indicated that HA/TN-DLP inhibited the glycerophospholipid metabolism pathway by reducing the biosynthesis of phosphatidylcholine and 1-acyl-sn-glycero-3-phosphocholine through regulating the expressions of CEPT1 and LYPLA1, and inhibited tumor cell growth by regulating the PI3K/Akt and NF-κB signaling pathways. In conclusion, the obviously enhanced antitumor effect further demonstrated that HA/TN-DLP may be a promising tumor-targeting agent.
Multiple contiguous quaternary carbon stereocenters (CQS) are highly challenging, yet important structural motifs in organic synthesis. Here, we describe a visible light induced catalytic [2 + 2] cycloaddition approach that constructed up to four CQS in a pentacyclic fused ring system diastereoselectively, from the readily accessible dienamides with pendent heteroaryls. Variously substituted dienamides have been cyclized with heteroaryls to provide a range of novel CQS-containing scaffolds (26 examples, up to 96% yield and > 20:1 dr ratio). Mechanistic studies revealed that it may proceed through an uncommon β-C radical initiated 7-endo cyclization from the biradical intermediate.
Visible-light-mediated para-C–H difluoroalkylation of anilides via combination of steric effects and Lewis acid activation strategies has been developed. The addition of (C6H5O)2P(O)OH and Ag2CO3 properly tune the redox potential of ruthenium catalyst and leads to mild reaction conditions. The protocol exhibits broad functional group tolerance and allows the late-stage functionalization of complex bioactive molecules.
Lipid droplet (LD) fluorescent imaging plays an important role in the detection of lipid-related diseases. Due to their poor photostability and low hydrophobicity of currently available LD imaging fluorophores, LD imaging is limited by its short imaging period and low imaging contrast. Herein, we reasonably designed a highly lipophilic compound Cou-Flu with excellent photostability and excimer-monomer transition property. It exhibited weak excimer emission in cytoplasm, but strong monomer emission in LDs, enabling high contrast LD imaging and LD movement tracing in cells. Zebrafish imaging study demonstrated that Cou-Flu was also suitable for in vivo LD detection with excellent sensitivity. We anticipate that Cou-Flu could be widely applied to understand LD-related intracellular activities and even LD-related diseases in the future.
Sepsis is the leading cause of death in intensive care unit (ICU), which is caused by deregulated immune responses to pathogens infection. Clinically, sepsis treatment is limited to antibiotics and supportive care, while there still lacks of specific molecular therapy. As a type of immune dysfunction disease, macrophages have been recognized as the key immune cells precipitating in the whole process of sepsis, which is activated into M1-like to trigger various inflammatory responses at early stage whereas polarized into M2-like to cause immunosuppression in later stage. Therefore, great attention has been paid on the design of nanomedicines to regulate the functions of macrophages for etiological treatment of sepsis, by virtue of the unique advantages of nano-drug delivery systems, such as enhanced drug bioavailability, targetability, reduced side-effects. This critical review aims to summarize the recent progress of macrophages-regulating nanoparticles for sepsis therapy. First, the essential roles of macrophages in the development and progression of sepsis have been introduced, including the positive roles of macrophages to combat infections and dysfunction of macrophages to cause body damages. We then focus our main attention to discuss the nanomedicines with different therapeutic mechanisms corresponding to each stage of sepsis, such as infection blockage, inflammation inhibition, immune functions recovery, as well as multifunctional nanomedicines. Finally, a few limitations of current nanomedicines are highlighted, and future perspective are speculated for potential clinical translation, which might pave the way for the development of macrophages-centered nanomedicines for more effective sepsis therapy.