Rapid finding and quantification of the major antioxidant in water extracts of three marine drug organisms from China by online HPLC-DAD/MS-DPPH

A method based on high-performance liquid chromatography (HPLC) with diode array detector coupled with electrospray ionisation-mass spectrometry and an online detection system for radical scavenging was established and used to rapidly find and quantify antioxidant compounds in the water extracts of Hippocampus japonicus Kaup, Hippocampus kuda Bleeker and Syngnathus acus Linnaeus. The online screening results revealed the presence of one major radical scavenging compound identified as hypoxanthine by comparison of mass data and retention time with the standard. Subsequently, the developed HPLC method was applied to quantify hypoxanthine in different H. japonicus, H. kuda and S. acus samples. The results indicated that the developed HPLC method is simple and reliable for the quantification of hypoxanthine with a detection limit at 0.002 μg mL(-1), and a high recovery from 96.3% to 102.1%. This method provides a powerful tool for rapid identification and quantification of free radical scavenging compounds in complex marine natural products.     

Studies on the thermodynamics of solvent extraction of indium (III) with HDEHMTPCA

The equilibrium molalities In³⁺ in {In₂(SO₄)₃ + Na₂SO₄ + HDEHMTPCA + n-C₈H₁₈ + water} were measured at ionic strength from (0.1 to 2.0) mol · kg⁻¹ containing Na₂SO₄ as supporting electrolyte in aqueous phase and at constant molality extractant at temperatures from (278.15 to 303.15) K in organic phase. The standard extraction constants K⁰ at various temperatures were obtained by methods of extrapolation and polynomial approximation. Thermodynamic quantities for the extraction process were calculated.     

巯基乙酸锑(Ⅲ)配合物合成与晶体结构

以三氧化二锑和巯基乙酸在水溶液中反应合成了配合物HSb(SCH2COO)2,并通过元素分析、红外光谱、X射线粉末衍射进行了表征,利用单晶X射线四圆衍射法测定了晶体结构,结果表明该配合物晶体属于单斜晶系,C2/c空间群,晶胞参数为:a=1.40005(8)nm,b=1.19121(8)nm,c=1.23588(8)nm,β=126.822(1)°,V=1.6499(2)nm^3,Dc=2.439g·cm^-3,Z=8,R1=0.0250。并对X射线粉末衍射数据进行了指标化,其结果与单晶数据吻合。     

Doping silver nanoparticles in AOT lyotropic lamellar phases

The organic lyotropic liquid crystal with long-range structural order is used as template to assemble inorganic/organic hybrid by doping pre-fabricated Ag nanoparticles. The lamellar hybrid with both hydrophilic and hydrophobic particles doped simultaneously is realized for the first time. The change of template structure after doping and the stability origin of dual-doped system are characterized by small angle X-ray scattering and polarized optical microscopy. Results show that the interaction and space matching between surfactant bilayers and doped particles are key factors to obtain stable hybrid.     

High Crystalline Prussian White Nanocubes as a Promising Cathode for Sodium‐ion Batteries

Prussian blue and its analogues (PBAs) have been recognized as one of the most promising cathode materials for room‐temperature sodium‐ion batteries (SIBs). Herein, we report high crystalline and Na‐rich Prussian white Na₂CoFe(CN)₆ nanocubes synthesized by an optimized and facile co‐precipitation method. The influence of crystallinity and sodium content on the electrochemical properties was systematically investigated. The optimized Na₂CoFe(CN)₆ nanocubes exhibited an initial capacity of 151 mA h g^?1, which is close to its theoretical capacity (170 mA h g^?1). Meanwhile, the Na₂CoFe(CN)₆ cathode demonstrated an outstanding long‐term cycle performance, retaining 78 % of its initial capacity after 500 cycles. Furthermore, the Na₂CoFe(CN)₆ Prussian white nanocubes also achieved a superior rate capability (115 mA h g^?1 at 400 mA g^?1, 92 mA h g^?1 at 800 mA g^?1). The enhanced performances could be attributed to the robust crystal structure and rapid transport of Na ions through large channels in the open‐framework. Most noteworthy, the as‐prepared Na₂CoFe(CN)₆ nanocubes are not only low‐cost in raw materials but also contain a rich sodium content (1.87 Na ions per lattice unit cell), which will be favorable for full cell fabrication and large‐scale electric storage applications.     

A novel silane coupling agent with peroxy groups used as an initiator in the graft polymerization of AN or MMA on nano-TiO<Subscript>2</Subscript>

A novel peroxy group-containing silane coupling agent was synthesized and anchored on the surface of titanium dioxide nanoparticles (nano-TiO₂) to form an immobilized-initiator-modified nano-TiO₂ species. In this study, the kinetic parameters of the peroxy group-containing silane were tested and assessed using DSC. The pre-exponential factor (A_d) was 8.973?×?10⁸ and the activation energy (E_a) was 80.736 kJ mol^?1. Moreover, the empirical Arrhenius equation was determined to be ln K_d?=???80.736/RT?+?ln(8.973?×?10⁸). To obtain continuous polymers, acrylonitrile (AN) and methyl methacrylate (MMA) were polymerized using the novel peroxy group-containing silane and FeSO₄ as an initiator system. The number average molecular weights (M_n of PAN?=?3×10⁴ and M_n of PMMA?=?1.4?×?10⁵) and polydispersity indexes (PDI of PAN?=?2.76 and PDI of PMMA?=?1.65) were determined by GPC. It was suggested that the redox initiation system can generate highly reactive species on the surfaces of inorganic nanoparticles. The nano-TiO₂-grafted polymers were successfully obtained.     

Quantitative interrogation of protein co-aggregation using multi-color fluorogenic protein aggregation sensors

Co-aggregation of multiple pathogenic proteins is common in neurodegenerative diseases but deconvolution of such biochemical process is challenging. Herein, we developed a dual-color fluorogenic thermal shift assay to simultaneously report on the aggregation of two different proteins and quantitatively study their thermodynamic stability during co-aggregation. Expansion of spectral coverage was first achieved by developing multi-color fluorogenic protein aggregation sensors. Orthogonal detection was enabled by conjugating sensors of minimal fluorescence crosstalk to two different proteins via sortase-tag technology. Using this assay, we quantified shifts in melting temperatures in a heterozygous model protein system, revealing that the thermodynamic stability of wild-type proteins was significantly compromised by the mutant ones but not vice versa. We also examined how small molecule ligands selectively and differentially interfere with such interplay. Finally, we demonstrated these sensors are suited to visualize how different proteins exert influence on each other upon their co-aggregation in live cells.

A little leak will sink a great ship! We prepared a series of multi-color protein aggregation sensors and developed a dual-color thermal shift assay to simultaneously and quantitatively report on protein co-aggregation of two different proteins.