Latest ArticlesHerein, two antimony sulfates, named RbSb(SO4)2 (1) and CsSb(SO4)2 (2), have been successfully synthesized with the introduction of Sb3+ cation with stereochemically active lone pairs (SCALP) into sulfates by the conventional hydrothermal method. Both two compounds endow short ultraviolet (UV) absorption edges (281 nm and 278 nm, respectively) and large birefringence (0.171@546 nm and 0.174@546 nm, respectively), which means that they are promising short-wave UV optical materials. Interestingly, though both of the two compounds exhibit similar 1D chained structures, and possess the same functional moieties including SbO4 seesaws and SO4 tetrahedral groups, they exhibit significantly opposite macroscopic symmetries, i.e., compound 1 crystallizes in a centrosymmetric (CS) manner (P21/n) and compound 2 in a noncentrosymmetric (NCS) manner (P212121), due to the size of cations [r(Rb+) = 1.56 Å, r(Cs+) = 1.67 Å] affects the orientation of SCALP of the adjacent Sb3+.
A H4SiW12O40-catalyzed three-component tandem reaction of 2-acylbenzoic acids, primary amines and phosphine oxides to form 3,3-disubstituted isoindolinones was developed. By employing H4SiW12O40 as the catalyst and dimethyl carbonate (DMC) as the solvent, a diverse range of 2-acylbenzoic acid derivatives and primary amines worked well to give the C3-phosphinoyl-functionalized 3,3-disubstituted isoindolinones with the yield range of 61%-87%. Advantages of this transformation include green catalyst and solvent, available starting materials, broad substrate scope, high efficiency and operational simplicity with water as the sole by-product. The strategy achieved an efficient and green molecular fragment assembly to access isoindolinones, which would provide opportunities for the synthesis of potential biologically active molecules in a green manner.
Alcohol consumption is one of the leading causes of death worldwide. Adolescence is a critical period of structural and functional maturation of the brain. Adolescent alcohol use can alter epigenetic modifications. However, little is known on the long-term effects of alcohol consumption during adolescence on RNA epigenetic modifications in brain. Herein, we systematically explored the long-term effects of alcohol exposure during adolescence on small RNA modifications in adult rat brain tissues by comprehensive liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) analysis. We totally detected 26 modifications in small RNA of brain tissues. Notably, we observed most of these modifications were decreased in brain tissues. These results suggest that alcohol exposure during adolescence may impose a long-lasting impact on RNA modifications in brain tissues. This is the first report that alcohol use during adolescence can alter RNA modifications in adult brain. Collectively, this study suggests a long-term adverse effects of alcohol consumption on brain from RNA epigenetics angle by comprehensive mass spectrometry analysis.
DNA circuits are powerful tools in various applications such as logical computation, molecular diagnosis and synthetic biology. Leakage is a major problem in constructing complex DNA circuits. It directly affects the output signal and harms the circuit's performance significantly. In the traditional DNA circuits, the gate complex is a duplex structure. There are insufficient energy barriers to prevent spontaneous detachment of strands, resulting in a leak prone. Herein, we have developed triplex-structure based DNA circuit with ultra-low leakage and high signal-to-noise ratio (SNR). The triplex structure improves the stability in the absence of input. At the same time, the driving force of the strand displacement cascades reduces the influence of the triplex structure on the desired reaction. The SNR of the DNA circuit was increased to 695, while the desired reaction rate remained 90% of the conventional translator circuit. The triplex-structure mediated leakage prevention strategy was further tested at different temperatures and in DNA translator and seesaw circuits. We also constructed modular basic logic gates with a high efficiency and low leakage. On this basis, we further constructed triplex-structure based tertiary DNA logic circuits, and the SNR reached 295, which, to the best of our knowledge, was among the highest of the field. We believe that our scheme provides a novel, valid, and general tool for reducing leakages, and we anticipate that it will be widely adopted in DNA nanotechnology.
The recent advances in accelerated polymerization of N-carboxyanhydrides (NCAs) offer an effective strategy to simplify the preparation of polypeptide materials. However, the fine-tuning of polymerization kinetics, which is critical to differentiate the main polymerization and the side reactions, remains largely unexplored. Herein we report the modulation of polymerization rate of NCA in a water/oil biphasic system. By altering the aqueous pH, the initial location of the initiators, and the pKa of initiating amines, we observed the change in polymerization time from several minutes to a few hours. Due to the high interfacial activity and low pKa value, controlled polymerization was observed from multi-amine initiators even if they were initially located in the aqueous phase. This work not only improves our understanding on the biphasic polymerization mechanism, but also facilitates preparation of versatile polypeptide materials.
A sustainable and practical process is presented for the direct synthesis of sodium tanshinone IIA sulfonate (STS). Our approach was inspired by the well-established and industrially applied batch synthetic route for STS production. We constructed a telescoped two-step continuous flow platform. This involved a continuous tanshinone IIA sulfonation and in-line salt formation. For the setup, we constructed a 3D circular cyclone-type microreactor using femtosecond laser micromachining. Compared to the 68% yield for 2 h in batch, the two-step continuous flow had an STS yield of 90%, achieved for a total residence time of < 3.0 min under optimal conditions. The proposed continuous flow method vastly simplified the operation and improved procedural safety, while significantly reducing the required acid content and wastewater production.
Pillar[n]arenes are a novel class of macrocyclic hosts reported by Ogoshi and co-workers in 2008. Because of their rigid pillar structures, interesting host–guest properties and ease of modifications, pillar[n]arenes have been developed rapidly in the field of functional materials and biomedicine. The modifications of pillar[n]arenes at different positions can give them varied characteristics. Functional groups can be introduced into one position of pillar[n]arenes without changing host–guest properties of pillar[n]arenes. A series of pillar[n]arene dimers, trimers, tetramers and metallacycles can be constructed by mono-functionalized pillar[n]arenes. In this review, two synthetic methods of mono-functionalized pillar[n]arenes are summarized and structures containing mono-functionalized pillar[n]arenes are described. Furthermore, the applications of mono-functionalized pillar[n]arenes in different fields (e.g., supramolecular polymers, sensors, molecular machines, catalysis, biological applications and light-harvesting systems) are also introduced. Hopefully, this article will be useful for researchers studying pillar[n]arenes, especially the mono-functionalized pillar[n]arenes.
Methicillin-resistant Staphylococcus aureus (MRSA), the most common pathogen in hospital and community environments, can cause serious and even fatal infections. The antibiotics currently used for clinical treatment of MRSA have developed resistance, and there is an urgent need to develop new antimicrobials to treat infections caused by MRSA strains. Quinoline analogues play an important role in the development of antimicrobials. Herein, we discussed the current development of antibacterial activities of quinoline analogues, mainly for anti-MRSA activity, and their structure–activity relationships (SARs) from the perspective of using the quinoline nucleus to search for novel potential anti-MRSA candidates. Additionally, the mechanisms of some representative quinoline analogues against MRSA were clarified. Altogether, this review could provide further insights for the rational development of quinoline-based antibacterial drugs, especially against MRSA.
Fast Fe(Ⅲ)/Fe(Ⅱ) circulation in heterogeneous peroxymonosulfate (PMS) activation remains as a bottleneck issue that restricts the development of PMS based advanced oxidation processes. Herein, we proposed a facile ammonia reduction strategy and synthesized a novel FeVO3-x catalysts to activate PMS for the degradation of a typical pharmaceutical, carbamazepine (CBZ). Rapid CBZ removal could be achieved within 10 min, which outperforms most of the other iron or vanadium-based catalysts. Electron paramagnetic resonance analysis and chemical probe experiments revealed SO4•−, •OH, O2•− and high valent iron (Fe(Ⅳ)) were all generated in this system, but SO4•− and Fe(Ⅳ) primarily contributed to the degradation of CBZ. Besides, X-ray photoelectron spectroscopy and X-ray adsorption spectroscopy indicated that both the generated low-valent V provides and oxygen vacancy acted as superior electron donors and accelerated internal electron transfer via the unsaturated V−O−Fe bond. Finally, the proposed system also exhibited satisfactory performance in practical applications. This work provides a promising platform in heterogeneous PMS activation.
The development of core-shell nanoclusters with controllable composition is of utmost importance as the material properties depend on their constituent elements. However, precisely tuning their compositions at the atomic scale is not easily achieved because of the difficulty of using limited macroscopic synthetic methods for atomic-level modulation. In this work, we report an interesting example of precisely regulating the core composition of an inorganic core-shell-type cobalt polyoxoniobate [Co26Nb36O140]32− by controlling reaction conditions, in which the inner Co-core composition could be tune while retaining the outer Nb-shell composition of resulting product, leading to a series of isostructural species with a general formula of {Co26-nNb36+nO140} (n = 0–2). These rare species not only can display good powder and single-crystal proton conductivities, but also might provide helpful and atomic-level insights into the syntheses, structures and composition modifications of inorganic amorphous core-shell heterometal oxide nanoparticles.