The comparable structural,elastic anisotropic and thermophysical properties of advanced U–Si fuel to baseline UO2: a DTF method

The European Physical Journal B - Molecular dynamics and Monte Carlo methods are common measurements to study the diffusion coefficients of the fluid particles under restricted conditions. Here,...     

利用空间位阻和氢溢流协同作用促进5-羟甲基糠醛选择性加氢制备5-甲基糠醛

化学工业生产中，用氢气为还原剂，通过选择性加氢可以制备多种重要化学品。5-羟甲基糠醛是重要的生物质基平台化合物，而5-甲基糠醛是用途广泛的化学品。由5-羟甲基糠醛加氢得到5-甲基糠醛是一条非常理想的路径，但是选择性活化C-OH非常困难。本文设计并制备了Pt@PVP/Nb₂O₅(PVP: 聚乙烯吡咯烷酮)催化剂，该催化体系巧妙地结合了位阻效应、氢溢流和催化剂界面的电子效应，系统研究了该催化剂对5-羟甲基糠醛选择性加氢制备5-甲基糠醛催化性能，在最优条件下，5-甲基糠醛的选择性可达92%。利用密度泛函理论计算研究了5-羟甲基糠醛选择性加氢制备5-甲基糠醛反应路径。     

Connectivity keeping stars or double-stars in 2-connected graphs

In Mader (2010), Mader conjectured that for every positive integer $k$ and every finite tree $T$ with order $m$, every $k$-connected, finite graph $G$ with $\delta \left(G\right)\ge ?\frac{3}{2}k?+m?1$ contains a subtree $T^{\prime }$ isomorphic to $T$ such that $G?V\left(T^{\prime }\right)$ is $k$-connected. In the same paper, Mader proved that the conjecture is true when $T$ is a path. Diwan and Tholiya (2009) verified the conjecture when $k=1$. In this paper, we will prove that Mader’s conjecture is true when $T$ is a star or double-star and $k=2$.     

Manipulating the Stacking of Triplet Chromophores in the Crystal Form for Ultralong Organic Phosphorescence

Provided here is evidence showing that the stacking between triplet chromophores plays a critical role in ultralong organic phosphorescence (UOP) generation within a crystal. By varying the structure of a functional unit, and different on‐off UOP behavior was observed for each structure. Remarkably, 24CPhCz, having the strongest intermolecular interaction between carbazole units exhibited the most impressive UOP with a long lifetime of 1.06 s and a phosphorescence quantum yield of 2.5 %. 34CPhCz showed dual‐emission UOP and thermally activated delayed fluorescence (TADF) with a moderately decreased phosphorescence lifetime of 770 ms, while 35CPhCz only displayed TADF owing to the absence of strong electronic coupling between triplet chromophores. This study provides an explanation for UOP generation in crystal and new guidelines for obtaining UOP materials.     

The siRNAsome: A Cation‐Free and Versatile Nanostructure for siRNA and Drug Co‐delivery

Nanoparticles show great potential for drug delivery. However, suitable nanostructures capable of loading a range of drugs together with the co‐delivery of siRNAs, which avoid the problem of cation‐associated cytotoxicity, are lacking. Herein, we report an small interfering RNA (siRNA)‐based vesicle (siRNAsome), which consists of a hydrophilic siRNA shell, a thermal‐ and intracellular‐reduction‐sensitive hydrophobic median layer, and an empty aqueous interior that meets this need. The siRNAsome can serve as a versatile nanostructure to load drug agents with divergent chemical properties, therapeutic proteins as well as co‐delivering immobilized siRNAs without transfection agents. Importantly, the inherent thermal/reduction‐responsiveness enables controlled drug loading and release. When siRNAsomes are loaded with the hydrophilic drug doxorubicin hydrochloride and anti‐P‐glycoprotein siRNA, synergistic therapeutic activity is achieved in multidrug resistant cancer cells and a tumor model.     

Pharmacokinetics of monoester‐diterpenoid alkaloids in myocardial infarction and normal rats after oral administration of Sini decoction by microdialysis combined with liquid chromatography–tandem mass spectrometry

Monoester‐diterpenoid alkaloids are the main bioactive components of Sini decoction, which is a well‐known traditional Chinese medicine formula for the treatment of myocardial infarction (MI) and heart failure in China. In this work, an ultra‐high‐performance liquid chromatography–mass spectrometry combined with microdialysis method was successfully established and applied for investigating for the first time comparative plasma pharmacokinetics of three monoester‐diterpenoid alkaloids (benzoylmesaconitine, benzoylaconitine and benzoylhypacoitine) in normal and MI rats after oral administration of Sini decoction. The statistical results of pharmacokinetic parameters demonstrated that benzoylmesaconitine, benzoylaconitine and benzoylhypacoitine showed lower peak concentration, longer half‐life, smaller area under the concentration–time curve, slower clearance, time to peak concentration and mean residence time in MI rats than in normal rats (p < 0.05), which indicated that monoester‐diterpenoid alkaloids exhibited lower systemic exposure and slower elimination in the MI rats. The results provided the experimental basis for understanding the metabolic fate and therapeutic effects of Sini decoction.     

Aggregation‐Induced Electrochemiluminescence of Carboranyl Carbazoles in Aqueous Media

The aggregation‐induced electrochemiluminescence (AIECL) of carboranyl carbazoles in aqueous media was investigated for the first time. Quantum yields, morphologies, and particle sizes were observed to determine the electrochemiluminescence (ECL) performance of these aggregated organic dots (ODs). All compounds exhibit much higher ECL stability and intensity than the carborane‐free compound, demonstrating the essential role of the carboranyl motif. Moreover, the results of cyclic voltammetry (CV) suggest that oxidation/reduction reactions take place at the carboranyl motif. The excited states of ODs were proposed to be generated by the mechanism of surface state transitions. More importantly, these compounds show a reductive–oxidative mechanism in contrast to other organic materials that show oxidative–reductive mechanisms. Our experiments and data have established the relation between AIE organic structures and ECL properties that has a strong potential for biological and diagnostic applications.     

Development of three novel benzothiazole-based ratiometric fluorescent chemosensor for detecting of hydrazine in serum and gas phase via ESIPT process and different recognition sites

In this article, we have successfully designed and synthesized three novel ratiometric fluorescent probes BTP-LA, BTP-LB and BTP-LN for detection of hydrazine based on benzothiazole-derived fluorophores and different recognition sites. The probes BTP-LA, BTP-LB and BTP-LN displays a good fluorescence ratio emission signals, high selectivity and large emission shifts (>100 nm) toward hydrazine. The three probes BTP-LA, BTP-LB and BTP-LN can be used not only to detect hydrazine in serum, but also to detect gaseous hydrazine in air. More importantly, compared with probes BTP-LB and BTP-LN, BTP-LA has lower saturation concentration (200 µM) and detection limits (1.22 × 10^?7 M) to hydrazine.